Provider: National Science Library - National Research Council Canada / Bibliothèque scientifique nationale - Conseil national de recherches Canada Content: text/plain; charset="UTF-8" TY - JOUR TI - Development of low cost fuselage frames by resin transfer molding DO - 10.4271/2013-01-2325 AU - Salek, Hasan AU - Trudeau, Paul T2 - SAE Technical Paper SN - 0148-7191 SP - 2013-01-2325 KW - Airframes KW - Fuselages KW - Molding KW - Resins AB - This paper presents work on the development of a low cost fuselage C-frame for aircraft primary structure using a Light Resin Transfer Molding (RTM) process. Compared to labor intensive hand layup prepreg technologies, Light RTM offers some substantial advantages by reducing infrastructure requirements such as hydraulic presses or autoclaves. Compared to Prepreg, Light RTM tooling creates two finished surfaces, which is an advantage during installation due to improved dimensional accuracy. The focus of this work was to develop means of achieving high fiber volume fraction structural frames using low cost tooling and a low volume manufacturing strategy. In this case a three piece Light RTM mold was developed using an internal mandrel. To achieve the strength requirements, a combination of crimped and non-crimped fabrics were selected for the reinforcing preform. This made it possible to reduce the number of flat patterns by more than 8 times, saving layup time compared to the prepreg counterpart. The processing parameters were optimized to reduce cycle time. Permeability, in-situ resin cure monitoring and coefficient of thermal expansion tests were used in the numerical simulations. Process induced deformation and resin flow simulations were completed to provide input for the tool design. In addition to all the process improvements, risk mitigation testing was completed to validate the design allowables. This work was a collaborative effort by an integrated product development team consisting of design, stress and materials and processing functions. DA - 2013/07/19 PY - 2013 PB - SAE International LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 30c6bc4e-baae-4b3f-867e-7e9dfd692f69 ER - TY - JOUR TI - The near wake of a freely flying European starling DO - 10.1063/1.4807064 AU - Kirchhefer, Adam J. AU - Kopp, Gregory A. AU - Gurka, Roi T2 - Physics of Fluids SN - 1070-6631 SN - 1089-7666 VL - 25 IS - 5 SP - 051902 AB - The wake of a freely flying European starling (Sturnus vulgaris) has been measured using high speed, time-resolved, particle image velocimetry, simultaneously with high speed cameras which imaged the bird. These have been used to generate vector maps that can be associated with the bird's location and wing configuration in the wind tunnel. Time series of measurements have been expressed as composite wake plots which depict segments of the wing beat cycle for various spanwise locations in the wake. Measurements indicate that downwash is not produced during the upstroke, suggesting that the upstroke does not generate lift. As well, the wake velocities imply the presence of streamwise vortical structures, in addition to tip vortices. These two characteristics indicate similarities between the wake of a bird and the wake of a bat, which may be general features of the wakes of flapping wings. DA - 2013/05 PY - 2013 PB - AIP LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8f6933e6-f7e7-4f8c-ac8a-a8f9822e8a66 ER - TY - JOUR TI - Wind-tunnel investigations of an inclined stay cable with a helical fillet AU - Larose, Guy L. AU - D'auteuil, Annick AU - Bosch, Harold R. AU - Jakobson, Jasna B. AU - Macdonald, John H. G. T2 - European and African Conferences on Wind Engineering T3 - 6th European and African Conferences on Wind Engineering (EACWE), July 7-11, 2013, Cambridge, UK AB - An experimental study of the effect of adding a helical fillet to the surface of a stay cable in relation to its response to wind-induced excitation was carried out on a 1:1 scale free-to-respond sectional model at the National Research Council Canada. The experiments revealed that a stay cable with a helical fillet inclined at 60◦ to the flow can experience wind induced vibrations with large amplitudes in smooth or turbulent flow for a low level of structural damping. The oscillations observed appeared to be self-limited in amplitude and could be mitigated with an increase of structural damping. The experiments revealed also that the aerodynamic forces at the source of the vibrations were highly sensitive to a rotation of the cable model about its axis. Measurements of the external diameter of the smooth cable model have shown a maximum eccentricity equivalent to 1% of the mean diameter which appeared to be sufficient to influence the aerodynamics of the cable model, even with the helical fillet in place. DA - 2013/07/11 PY - 2013 PB - Internal Association of Wind Engineering (IAWE) LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : eebeca48-1dc8-4fc1-b475-aecc294e2af9 ER - TY - JOUR TI - Using a systems dynamics model to assess skill level impact AU - Urbanic, R. J. AU - Bacioiu, G. M. T2 - 2013 Industrial and Systems Engineering Research Conference T3 - 2013 Industrial and Systems Engineering Research Conference, May 18-22, 2013, Puerto Rico SP - 4110 EP - 4119 KW - cognition and reasoning; performance evaluation; human subjects; skills AB - Research activities have been performed to identify areas of complexity related to the product, process or operational tasks. The developed framework decouples the manufacturing complexity aspects using a systematic approach to decompose the problem into key impact factors. The result of this model provides insight into the system sensitivities when considering human characteristics. However, the model is a static model. Skill levels improve with experience and repetition. The actors within a system may have different levels of skills and knowledge, and how and where these resources are utilized within a system will impact inventory and throughput. As well, people have different learning characteristics. Both these static and dynamic elements impact the system performance. This research presents a systems dynamics model that contains production rules and rules to evaluate the impact of human skill level variations based on the complexity of a task / set of tasks. The impact of positioning a set of personnel with different skill levels on different positions in an assembly line is explored. DA - 2013/05/22 PY - 2013 PB - Institute of Industrial and Systems Engineers LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : eaf88311-7edb-4f1b-a6da-18c4789666ea ER - TY - CHAP TI - Use of QDOT photoluminescence for codification and authentication purposes DO - 10.1201/b15490-14 AU - Chang, Shoude T2 - Luminescence SN - 978-981-4241-95-3 SN - 978-981-4267-72-4 SP - 343 EP - 366 DA - 2013/12/21 PY - 2013 PB - Pan Stanford Publishing / CRCnetBASE LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e1d1dbf3-4917-41fd-b65d-478551e3a3e1 ER - TY - JOUR TI - Transcriptome profiling identifies candidate genes associated with the accumulation of distinct sulfur γ-glutamyl dipeptides in Phaseolus vulgaris and Vigna mungo seeds DO - 10.3389/fpls.2013.00060 AU - Liao, Dengqun AU - Cram, Dustin AU - Sharpe, Andrew G. AU - Marsolais, Frédéric T2 - Frontiers in Plant Science SN - 1664-462X VL - 4 SP - 60 KW - sulfur metabolism; gamma-glutamyl dipeptides; S-methylcysteine; Vigna mungo; Phaseolus vulgaris; developing seed; 454 transcriptome sequencing AB - Common bean (Phaseolus vulgaris) and black gram (Vigna mungo) accumulate γ-Glutamyl-S-methylcysteine and γ-Glutamyl-methionine in seed, respectively. Transcripts were profiled by 454 pyrosequencing data at a similar developmental stage coinciding with the beginning of the accumulation of these metabolites. Expressed sequence tags were assembled into Unigenes, which were assigned to specific genes in the early release chromosomal assembly of the P. vulgaris genome. Genes involved in multiple sulfur metabolic processes were expressed in both species. Expression of Sultr3 members was predominant in P. vulgaris, whereas expression of Sultr5 members predominated in V. mungo. Expression of the cytosolic SERAT1;1 and -1;2 was approximately fourfold higher in P. vulgaris while expression of the plastidic SERAT2;1 was twofold higher in V. mungo. Among BSAS family members, BSAS4;1, encoding a cytosolic cysteine desulfhydrase, and BSAS1;1, encoding a cytosolic O-acetylserine sulphydrylase were most highly expressed in both species. This was followed by BSAS3;1 encoding a plastidic β-cyanoalanine synthase which was more highly expressed by 10-fold in P. vulgaris. The data identify BSAS3;1 as a candidate enzyme for the biosynthesis of S-methylcysteine through the use of methanethiol as substrate instead of cyanide. Expression of GLC1 would provide a complete sequence leading to the biosynthesis of γ-Glutamyl-S-methylcysteine in plastids. The detection of S-methylhomoglutathione in P. vulgaris suggested that homoglutathione synthetase may accept, to some extent, γ-Glutamyl-S-methylcysteine as substrate, which might lead to the formation of S-methylated phytochelatins. In conclusion, 454 sequencing was effective at revealing differences in the expression of sulfur metabolic genes, providing information on candidate genes for the biosynthesis of distinct sulfur amino acid γ-Glutamyl dipeptides between P. vulgaris and V. mungo. DA - 2013/03/25 PY - 2013 PB - Frontiers Media LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ac776722-b7eb-4793-85f6-4807d1e27b09 ER - TY - JOUR TI - Thermal control of continuous resistance welding of fiberglass laminates for automated manufacturing DO - 10.1115/DETC2013-13343 AU - Mantegh, Iraj AU - Zammar, Imad AU - Ahmadi, Mojtaba AU - Yousefpour, Ali T2 - 18th Design for Manufacturing and the Life Cycle Conference / 2013 ASME/IEEE International Conference on Mechatronic and Embedded Systems and Applications T3 - ASME 2013 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, Aug. 4-7, 2013, Portland, Oregon, USA SN - 978-0-7918-5591-1 VL - 4 SP - DETC2013-13343 KW - welding; laminates; manufacturing; glass reinforced plastics AB - Resistance welding is an alternative process to mechanical fastening and adhesive bonding in joining thermoplastic composites. The resistance welding procedure involves the Joule heating of a heating element located between two adjoining thermoplastics. The application of heat causes the material in the interface between two surfaces to melt. The current stops then and the interfacing surfaces bound under a compaction pressure, while cooling. This results in a fusion bond between the two components. A fuzzy logic controller is designed and implemented in real-time using the temperature estimate as the feedback signal. The result is a controller capable of maintaining the weld temperature within 10% of the reference temperature. DA - 2013/08/04 PY - 2013 PB - ASME LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f6668403-3520-475c-bce1-b037d31c523c ER - TY - JOUR TI - Therapeutic potential of amniotic fluid-derived cells for treating the injured nervous system DO - 10.1139/bcb-2013-0019 AU - Rennie, Kerry AU - Haukenfrers, Julie AU - Ribecco-Lutkiewicz, Maria AU - Ly, Dao AU - Jezierski, Anna AU - Smith, Brandon AU - Zurakowski, Bogdan AU - Martina, Marzia AU - Gruslin, Andrée AU - Bani-Yaghoub, Mahmud T2 - Biochemistry and Cell Biology SN - 0829-8211 SN - 1208-6002 VL - 91 IS - 5 SP - 271 EP - 286 KW - amniotic fluid; brain injury; cell-based therapy; gap junctions; micro-RNAs; stem cells KW - liquide amniotique; lésion cérébrale; thérapie cellulaire; jonctions communicantes; micro ARN; cellules souches AB - There is a need for improved therapy for acquired brain injury, which has proven resistant to treatment by numerous drugs in clinical trials and continues to represent one of the leading causes of disability worldwide. Research into cell-based therapies for the treatment of brain injury is growing rapidly, but the ideal cell source has yet to be determined. Subpopulations of cells found in amniotic fluid, which is readily obtained during routine amniocentesis, can be easily expanded in culture, have multipotent differentiation capacity, are non-tumourigenic, and avoid the ethical complications associated with embryonic stem cells, making them a promising cell source for therapeutic purposes. Beneficial effects of amniotic fluid cell transplantation have been reported in various models of nervous system injury. However, evidence that amniotic fluid cells can differentiate into mature, functional neurons in vivo and incorporate into the existing circuitry to replace lost or damaged neurons is lacking. The mechanisms by which amniotic fluid cells improve outcomes after experimental nervous system injury remain unclear. However, studies reporting the expression and release of neurotrophic, angiogenic, and immunomodulatory factors by amniotic fluid cells suggest they may provide neuroprotection and (or) stimulate endogenous repair and remodelling processes in the injured nervous system. In this paper, we address recent research related to the neuronal differentiation of amniotic fluid-derived cells, the therapeutic efficacy of these cells in animal models of nervous system injury, and the possible mechanisms mediating the positive outcomes achieved by amniotic fluid cell transplantation. AB - Il est nécessaire d’améliorer la thérapie des lésions cérébrales acquises, celles-ci s’étant montrées résistantes au traitement par différents médicaments lors d’essais cliniques, et continuant d’être parmi les principales causes de handicap a` travers le monde. La recherche de thérapies cellulaires pour traiter les lésions cérébrales croît rapidement, mais la source idéale de cellules n’a pas encore été déterminée. Des sous-populations de cellules trouvées dans le liquide amniotique, qui est rapidement obtenu lors d’une amniocentèse de routine, peuvent être facilement propagées en culture, possèdent une capacité de différenciation multipotente, sont non tumorogènes et évitent les complications éthiques associées a` l’utilisation de cellules souches embryonnaires, faisant d’elles une source prometteuse de cellules a` des fins thérapeutiques. Les effets bénéfiques de la transplantation de cellules du liquide amniotique ont été rapportés dans différents modèles de lésions du système nerveux. Toutefois, la preuve que les cellules du liquide amniotique peuvent se différencier en neurones fonctionnels matures in vivo et s’incorporer dans les circuits existants pour remplacer les neurones perdus ou endommagés reste a` faire. Les mécanismes par lesquels les cellules du liquide amniotique améliorent les résultats a` la suite d’un dommage expérimental au système nerveux demeurent flous. Toutefois, des études rapportant l’expression et la libération de facteurs neurotrophiques, angiogéniques et immunomodulateurs par les cellules du liquide amniotique suggèrent qu’elles peuvent conférer une neuro-protection et/ou stimuler des processus endogènes de réparation et de remodelage du système nerveux lésé. Dans cet article, nous nous intéressons a` la recherche récente relative a` la différenciation neuronale des cellules dérivées du liquide amniotique ainsi qu’aux mécanismes possibles qui mènent a` l’issue positive résultant de la transplantation de cellules du liquide amniotique DA - 2013/05/16 PY - 2013 PB - NRC Research Press LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : cfc1c748-f9dc-4ad8-b652-fddaf7b040e7 ER - TY - JOUR TI - Theoretical analysis of high order harmonic generation from bulk crystals DO - 10.1364/FIO.2013.FW6C.4 AU - Vampa, Giulio AU - Mcdonald, Chris R. AU - Orlando, Gianfranco AU - Klug, Dennis D. AU - Corkum, Paul B. AU - Brabec, Thomas T2 - Frontiers in Optics 2013 T3 - Frontiers in Optics 2013, Oct. 6-10, 2013, Orlando, Florida SN - 978-1-55752-988-6 SP - FW6C.4 AB - We investigate High order Harmonic Generation in crystals exposed to intense mid-IR light and find that the interband polarization build-up dominates. In the Keldysh limit, we derive an intuitive picture of HHG in solids. DA - 2013/10/10 PY - 2013 PB - Optical Society of America LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 62616966-1408-4601-95c2-655ec2fc46ab ER - TY - JOUR TI - The Space Geodesy Project and radio frequency interference characterization and mitigation DO - 10.1109/IGARSS.2013.6721146 AU - Hilliard, Lawrence M. AU - Beaudoin, C. AU - Corey, B. E. AU - Tourain, C. L. AU - Petrachenko, B. AU - Dickey, John T2 - 2013 IEEE International Geoscience and Remote Sensing Symposium (IGARSS) T3 - IGARSS 2013 : IEEE International Geoscience and Remote Sensing Symposium, July 21-27, 2013, Melbourne, Australia SN - 978-1-4799-1114-1 SP - 278 EP - 281 KW - broadband antennas; radio frequency; navigation; broadband communication; adaptation models AB - The Space Geodesy Project (SGP) development by NASA is an effort to co-locate the four international geodetic techniques Satellite Laser Ranging (SLR) and Lunar Laser Ranging (LLR), Very Long Baseline Interferometry (VLBI), Global Navigation Satellite System (GNSS), and Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS) into one tightly referenced campus and coordinated reference frame analysis. The SGP requirement locates these stations within a small area to maintain line-of-sight and frequent automated survey known as the vector tie system. This causes a direct conflict with the new broadband VLBI technique. Broadband means 2-14 GHz, and RFI susceptibility at -80 dBW or higher due to sensitive RF components in the front end of the radio receiver. DA - 2013/07/26 PY - 2013 PB - IEEE LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : bdabf143-6396-452d-88f8-62cb1bbd562e ER - TY - CHAP TI - The significance of astrocytic glutathione system in neuroprotection : a potential role for circumin AU - Sandhu, Jagdeep K. AU - Sodja, Caroline AU - Byrd, Angele AU - Cadieux, Christian AU - Lanthier, Patricia AU - Walker, P. Roy AU - Sikorska, Marianna T2 - Glutathione : biochemistry, mechanisms of action and biotechnological implications SN - 978-1-62417-460-5 SP - 95 EP - 110 AB - Decreased brain content of thiol antioxidant glutathione (GSH) is regarded as an indicator of excessive oxidative stress, which, in turn, is recognized as a contributing factor to the development and progression of several age-related neurodegenerative diseases. Brain GSH is mainly produced by astroglia and their metabolic coupling with neurons allows the latter cells to maintain a sufficient antioxidant defense under physiological conditions. Neurons, however, are very sensitive to GSH depletion; hence any impairment in astrocyte-neuron GSH metabolic interactions, as it may occur in brain pathologies, would render neurons more susceptible to oxidative injuries. This also implies that agents capable of elevating brain GSH level could prove useful as neuroprotectants. In this chapter, we review data that supports these suppositions, generated using human NT2/N neurons and NT2/A astrocytes obtained by differentiation of NT2/D1 cells. Indeed, the results showed that astrocytes rendered neurons more resistant to toxic injuries and supported neuronal survival even in the presence of low GSH levels. They could not, however, support the neurons under chronic GSH depletion. We also tested curcumin, a naturally occurring polyphenol with anti-inflammatory and antioxidant properties, for its ability to alter the GSH levels in NT2/N and NT2/A cells. Since curcumin is insoluble in aqueous media it is difficult to establish convincingly its efficacy. Here we have applied a solubilizing method developed in our laboratory (US patent No. 6,045,826 and 7,645,816; Ubisol technology licensed to Zymes LLC) to produce a water-soluble nano-micellar complex between PSS (polyoxyethanyl -sitosteryl sebacate) and curcumin (WS-Cur) which can be readily tested under any experimental conditions. The data showed that a 24 h treatment with WS-Cur increased GSH levels in both cell types and that this treatment was neuroprotective. Our results add to the growing body of evidence indicating that agents capable of modulating GSH, such as WS-Cur, might prove highly beneficial in the management of oxidative stress-induced neurodegeneration. Furthermore, strategies aimed at modulating and restoring astrocyte function, for example, by increasing GSH, might present new opportunities for repairing and restoring brain function. DA - 2013/02/28 PY - 2013 PB - Nova Science Publishers LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : adb3fde7-070b-4a08-9e9a-362a204d6453 ER - TY - JOUR TI - The role of the Kramers-Henneberger atom in the higher-order Kerr effect DO - 10.1109/CLEOE-IQEC.2013.6801163 AU - Patchkovskii, S. AU - Richter, M. AU - Morales, F. AU - Smirnova, O. AU - Ivanov, M. T2 - 2013 Conference on Lasers and Electro-Optics Europe and International Quantum Electronics Conference (CLEO®/Europe-IQEC 2013) T3 - CLEO®/Europe-IQEC 2013, May 12th to 16th, 2013, Munich, Germany SN - 978-1-4799-0594-2 SN - 978-1-4799-0593-5 KW - Atomic beams; Atom lasers; Laser modes; Laser excitation; Atomic clocks; Numerical models AB - We present a generalized model for the intensity dependent response of atoms in strong IR laser fields, describing deviations in the nonlinear response at the frequency of the driving field from the standard model (linear Kerr effect + plasma defocusing) based on the formation of the stable KH states. According to our numerical simulations, shaping the driving laser pulse allows one to reveal a prominent resonance structure in the Kerr response of an individual atom, which can only be explained by population transfer into excited KH states. DA - 2013/05/16 PY - 2013 PB - IEEE LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e2c634d6-b405-4f63-8d2b-ef6ba71ddf96 ER - TY - JOUR TI - The productivity and impact of astronomical telescopes - a bibliometric study for 2007 - 2011 AU - Crabtree, Dennis R. T2 - 14th International Society of Scientometrics and Informetrics Conference T3 - 14th International Society of Scientometrics and Informetrics Conference, July 15th to 19th, 2013, Vienna, Austria SN - 2175-1935 SN - 9783200031357 VL - II SP - 2092 EP - 2094 AB - Since the telescope was invented in the early 17th century, astronomers have relied on increasingly complex and expensive instruments to further their studies of the Universe. The next generation of telescopes, with apertures of approximately 30-m, will cost more than $1B to construct. The main product of modern observatories are the publications in refereed journals based on data obtained using their telescope(s). DA - 2013/07/19 PY - 2013 PB - AIT Austrian Institute of Technology LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : dfec5188-728d-4568-bab6-9826de3f184d ER - TY - JOUR TI - The observation of highly ordered domains in membranes with cholesterol DO - 10.1371/journal.pone.0066162 AU - Armstrong, Clare L. AU - Marquardt, Drew AU - Dies, Hannah AU - Kučerka, Norbert AU - Yamani, Zahra AU - Harroun, Thad A. AU - Katsaras, John AU - Shi, An-Chang AU - Rheinstädter, Maikel C. T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 6 AB - Rafts, or functional domains, are transient nano- or mesoscopic structures in the exoplasmic leaflet of the plasma membrane, and are thought to be essential for many cellular processes. Using neutron diffraction and computer modelling, we present evidence for the existence of highly ordered lipid domains in the cholesterol-rich (32.5 mol%) liquid-ordered () phase of dipalmitoylphosphatidylcholine membranes. The liquid ordered phase in one-component lipid membranes has previously been thought to be a homogeneous phase. The presence of highly ordered lipid domains embedded in a disordered lipid matrix implies non-uniform distribution of cholesterol between the two phases. The experimental results are in excellent agreement with recent computer simulations of DPPC/cholesterol complexes [Meinhardt, Vink and Schmid (2013). Proc Natl Acad Sci USA 110(12): 4476–4481], which reported the existence of nanometer size domains in a liquid disordered lipid environment. DA - 2013/06/18 PY - 2013 PB - PLOS one LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e41ac6b2-5073-4e20-a67b-e67a9464b411 ER - TY - JOUR TI - The JCMT Gould Belt Survey : SCUBA-2 observations of radiative feedback in NGC 1333 DO - 10.1093/mnrasl/sls015 AU - Hatchell, J. AU - Wilson, T. AU - Drabek, E. AU - Curtis, E. AU - Richer, J. AU - Nutter, D. AU - Di Francesco, J. AU - Ward-Thompson, D. T2 - Monthly Notices of the Royal Astronomical Society: Letters SN - 1745-3925 SN - 1745-3933 VL - 429 IS - 1 SP - L10 EP - L14 KW - stars: formation; dust; extinction; submillimetre: ISM; stars: protostars AB - We present observations of NGC 1333 from SCUBA-2 on the James Clerk Maxwell Telescope (JCMT), observed as a JCMT Gould Belt Survey pilot project during the shared risk campaign when the first of four arrays was installed at each of 450 and 850 μm. Temperature maps are derived from 450 and 850 μm ratios under the assumption of constant dust opacity spectral index β = 1.8. Temperatures indicate that the dust in the northern (IRAS 6/8) region of NGC 1333 is hot, 20–40 K, due to heating by the B star SVS3, other young stars in the IR/optically visible cluster and embedded protostars. Other luminous protostars are also identified by temperature rises at the 17 arcsec resolution of the ratio maps (0.02 pc assuming a distance of 250 pc for Perseus). The extensive heating raises the possibility that the radiative feedback may lead to increased masses for the next generation of stars. DA - 2013/02/11 PY - 2013 PB - The authors on behalf of the JCMT GBS Consortium (Oxford) LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 20ef263d-6b06-4e58-bff9-df04444e7a41 ER - TY - JOUR TI - The graphene phonon dispersion with C¹² and C¹³ isotopes DO - 10.1063/1.4848322 AU - Whiteway, Eric AU - Bernard, Simon AU - Yu, Victor AU - Austing, D. Guy AU - Hilke, Michael T2 - AIP Conference Proceedings T3 - The Physics of Semiconductors : Proceedings of the 31st International Conference on the Physics of Semiconductors (ICPS) 2012, July 29th-August 3rd, 2012, Zurich, Switzerland VL - 1566 IS - 1 SP - 135 EP - 136 AB - Using very uniform large scale chemical vapor deposition grown graphene transferred onto silicon, we were able to identify 15 distinct Raman lines associated with graphene monolayers. This was possible thanks to a combination of different carbon isotopes and different Raman laser energies and extensive averaging without increasing the laser power. This allowed us to obtain a detailed experimental phonon dispersion relation for many points in the Brillouin zone. We further identified a D+D' peak corresponding to a double phonon process involving both an inter- and intra-valley phonon. In order to both eliminate substrate effects and to probe large areas, we undertook to study Raman scattering for large scale chemical vapor deposition (CVD) grown graphene using two different isotopes (C12 and C13) so that we can effectively exclude and subtract the substrate contributions, since a heavier mass downshifts only the vibrational properties, while keeping all other properties the same. DA - 2013/12/31 PY - 2013 PB - AIP LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ec8afa05-5892-42fa-b2c4-0d41967616a6 ER - TY - JOUR TI - Abstract A248: integrated therapeutic antibody development at the National Research Council of Canada DO - 10.1158/1535-7163.TARG-13-A248 AU - Jaramillo, M. L. AU - Marcil, A. AU - Durocher, Y. AU - Gilbert, R. AU - Mullick, A. AU - Kelly, J. AU - O'connor-mccourt, M. AU - Massie, B. T2 - Molecular Cancer Therapeutics SN - 1535-7163 SN - 1538-8514 VL - 12 IS - 11 Supplement SP - A248 EP - A248 AB - Advances in genomics and antibody engineering have enabled the development of an innovative class of targeted therapies, namely therapeutic antibodies, for the treatment of diseases with significant unmet medical needs such as cancer. Therapeutic antibodies represent one of the largest and fastest growing classes of medications. The NRC has built a chain of cutting edge technology platforms needed to discover, engineer and produce therapeutic monoclonal antibodies with the goal of partnering with industrial and academic centers to advance research and development of this important class of therapeutics. Target Identification- To establish and validate the technology platforms, tumor targets for candidate therapeutic antibody production were identified using a combination of proteomics, transcriptomics and bioinformatic approaches. Out of these lists, approximately 40 tumor targets were selected (known therapeutic antibody targets were excluded), and over 3,000 antibodies of mouse and camelid origin were then generated against these targets. Antibody generation- Once identified, the recombinant target protein of interest was produced using the NRC's high efficiency cell expression platforms in CHO or HEK293 cells and purified protein was used for immunization or panning. For targets which were difficult to express or purify, the capabilities for direct immunization with plasmid DNA constructs were utilized. Clone selection was carried out by ELISA and typically 50 antibodies/target were identified for further characterization. Antibody characterization and validation- The affinities of the antibodies were determined by SPR biosensor analysis. Reverse phase protein arrays and Western blot analysis on protein mixes and cell line extracts allowed the characterization of the specificity of the antibodies. SPR-based epitope binning was carried out in order to characterize the diversity of the antibody collections and to enable the selection of representative antibodies from each epitope bin for further analysis. Select antibodies were assessed in appropriate cell-based assays for prioritization based on function. Therapeutic antibody Optimization, Bioprocessing and Biomanufacturing- Therapeutic antibodies selected for development can be further optimized using antibody engineering technologies to humanize them and/or modify their glycosylation patterns to improve their effector function, pharmacokinetics, solubility and stability as well as reduce their immunogenicity. The NRC platform for large scale protein production has the capacity to manufacture up to 500 g of commercial grade antibody using serum free, low endotoxin media in a cGMP certified CHO cell line which is ready for transfer to CMOs or other industrial partners. DA - 2013/11/01 PY - 2013 PB - American Association for Cancer Research LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 48620866-e604-46da-927c-8af3a64ad827 ER - TY - CHAP TI - The fundamentals and fun of biocatalysis DO - 10.1533/9781908818355.1.17 AU - Lau, Peter C. K. AU - Grosse, Stephan T2 - Marine Enzymes for Biocatalysis SN - 9781907568800 SP - 17 EP - 69 DA - 2013/09/30 PY - 2013 PB - Woodhead Publishing LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : db469082-79bf-4498-81f2-2db308fafec9 ER - TY - JOUR TI - Final A&T stages of the Gemini Planet Finder DO - 10.12839/AO4ELT3.16014 AU - Hartung, Markus AU - Macintosh, Bruce AU - Poyneer, Lisa AU - Savransky, Dmitry AU - Gavel, Don AU - Palmer, Dave AU - Thomas, Sandrine AU - Dillon, Daren AU - Chilcote, Jeffrey AU - Ingraham, Patrick AU - Sadakuni, Naru AU - Wallace, Kent AU - Perin, Marshall D. AU - Marois, Christian AU - Maire, Jerome AU - Rantakyro, Frederik AU - Hibon, Pascale AU - Saddlemyer, Les AU - Goodsell, Stephen T2 - Adaptive Optics for Extremely Large Telescopes (Third AO4ELT Conference) T3 - Third AO4ELT Conference - Adaptive Optics for Extremely Large Telescopes, May 26-31, 2013, Florence Italy SN - 978-88-908876-0-4 AB - The Gemini Planet Imager (GPI) is currently in its final Acceptance & Testing stages. GPI is an XAO system based on a tweeter & woofer architecture (43 & 9 actuators respectively across the pupil), with the tweeter being a Boston Michromachines 64² MEMS device. The XAO AO system is tightly integrated with a Lyot apodizing coronagraph. Acceptance testing started in February 2013 at the University of California, Santa Cruz. A conclusive acceptance review was held in July 2013 and the instrument was found ready for shipment to the Gemini South telescope on Cerro Pachon, Chile. Commissioning at the telescope will take place by the end of 2013, matching the summer window of the southern hemisphere. According to current estimates the 3 year planet finding campaign (890 allocated hours) might discover, image, and spectroscopically analyze 20 to 40 new exo-planets. Final acceptance testing of the integrated instrument can always bring up surprises when using cold chamber and flexure rig installations. The latest developments are reported. Also, we will give an overview of GPI's lab performance, the interplay between subsystems such as the calibration unit (CAL) with the AO bench. We report on-going optimizations on the AO controller loop to filter vibrations and last but not least achieved contrast performance applying speckle nulling. Furthermore, we will give an outlook of possible but challenging future upgrades as the implementation of a predictive controller or exchanging the conventional 48x48 SH WFS with a pyramid. With the ELT era arising, GPI will proof as a versatile and path-finding testbed for AO technologies on the next generation of ground-based telescopes. DA - 2013/05/31 PY - 2013 PB - Centre pour la Communication Scientifique Directe LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b31cf478-8761-4711-8d1b-c2d31169a74f ER - TY - JOUR TI - Evaluation of astrometry errors due to the optical surface distortions in adaptive optics systems and science instruments DO - 10.12839/AO4ELT3.13285 AU - Ellerbroek, Brent AU - Herriot, Glen AU - Suzuki, Ryuji AU - Schoeck, Matthias T2 - Third AO4ELT Conference - Adaptive Optics for Extremely Large Telescopes T3 - Third AO4ELT Conference - Adaptive Optics for Extremely Large Telescopes, May 26-31, 2013, Florence, Italy SN - 978-88-908876-0-4 AB - The objectives for high precision astrometry on ELTs will be challenging, with requirements in the range from 10 to 50 micro-arc-seconds for some instruments and science cases. Reducing and correctly calibrating the systematic and quasi-static errors introduced by optical surface distortions will be an important part of meeting these goals. In a recently submitted paper, we described an analytical Fourier domain model for evaluating these effects as the sum of three terms: (i) under-sampling errors, due to measuring the effects of static surface distortions using a finite number of discrete reference sources; (ii) unknown beam wander across the static surface distortions due to line-of-sight jitter or boresighting errors, and (iii) quasi-static errors due to slowly varying surface distortions. In this paper, we apply these methods to evaluating this term in the astrometry error budgets for the TMT Infrared Imaging Spectrograph (IRIS) and the facility AO system, NFIRAOS. The inputs to this exercise include the original top-down allocations for this error term, the original optical surface specifications for IRIS and NFIRAOS as derived earlier on the basis of wavefront error requirements, our assessment of the feasible density and positioning accuracy for an array of calibration sources, and the expected beam wander due to tip/tilt jitter and bore-sighting errors between NFIRAOS and IRIS. The astrometry error computed for these initial parameters was considerably larger than the top-down allocation due to the contributions from the NFIRAOS double-pane entrance window, which is close to the system's input focal plane. The error can be reduced to fall within the allocation by defining tighter, but still feasible, specifications for these elements. We also evaluated the astrometry errors due to quasi-static drift of the figures of the NFIRAOS deformable mirrors, and determined that they are acceptable for RMS wavefront distortions of up to about 30 nm RMS. DA - 2013/05/26 PY - 2013 PB - Arcetri Astrophysical Observatory LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 61220a3d-cde1-4e7e-888d-ad4b73a2c74b ER - TY - JOUR TI - CLEO®/Europe - IQEC 2013 looking inside the recollision process DO - 10.1109/CLEOE-IQEC.2013.6801131 AU - Shafir, Dror AU - Soifer, Hadas AU - Bruner, Barry D. AU - Dagan, Michal AU - Mairesse, Yann AU - Vozzi, Caterina AU - Stagira, Salvatore AU - Patchkovskii, Serguei AU - Ivanov, Misha Yu. AU - Smirnova, Olga AU - Dudovich, Nirit T2 - 2013 Conference on Lasers and Electro-Optics Europe and International Quantum Electronics Conference T3 - CLEO®/Europe-IQEC 2013, May 12-16, 2013, Munich, Germany SN - 978-1-4799-0594-2 SN - 978-1-4799-0593-5 SP - 1 EP - 1 KW - Ionization; Tunneling; Harmonic analysis; Radiative recombination AB - Probing the ionization times and the recollision times by adding a weak perturbation in simple atomic systems was discussed. The results deviated from the simple classical model were found to be in agreement with the quantum path analysis. The multiple channel ionization and the differences between two ionization channels were probed in aligned CO2 molecules. DA - 2013/05/16 PY - 2013 PB - IEEE LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c7561950-a022-4247-a2dc-1baf1aca34a4 ER - TY - CHAP TI - A new perspective on the development of cholesterol-lowering products DO - 10.5772/54729 AU - V.G., Sandhya AU - Wang, Yanwen T2 - Using Old Solutions to New Problems: Natural Drug Discovery in the 21st Century SN - 978-953-51-1158-0 SP - 181 EP - 213 AB - Cardiovascular disease (CVD) is the principal cause of death worldwide, representing nearly 30% of the annual global mortality and 10% of global health burden. The current status of CVD is now on international scale; which can be considered as the commonest chronic illness in both developed and developing countries, causing the most deaths and the greatest impact on morbidity. In 2006, CVD was the leading cause of death for Canadians, representing 30% of all deaths. A total number of 1.3 million Canadians are diagnosed having heart disease accounting for 5% among those above 12 years and 23% at 75 years and older. The increased rate of obesity and diabetes combined with further aging of the population will likely lead to an increase in the number of people with CVD in the future. This will compromise the health of Canadians, put a strain on the health care system, and have a significant economic impact on Canada. Similarly, over the past five decades the prevalence of CVD has steadily increased in economically developing countries. These countries will account for 76% of an estimated 25 million death due to CVD in 2020. On an international basis, by 2020 CVD will reach nearly epidemic proportions and become the cause of more deaths, disability and economic loss than any others group of diseases. The number of fatalities by CVD projected to increase to over 20 million a year by 2020 and over 24 million a year by 2030. Apparently, understanding the aetiology of CVD and accordingly develop preventive and therapeutic approaches to address this health threat continues to be critically important in the next decades although significant achievements have been made in the past decades. DA - 2013/06/19 PY - 2013 PB - INTECH LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 462e391f-24b0-486a-9d22-1cd665ca8efd ER - TY - JOUR TI - UV or PAA for wastewater disinfection: a comparison of the impact on virulence genes DO - 10.2175/193864713813503738 AU - Biswal, Basanta kumar AU - Gehr, Ronald AU - Khairallah, Ramzi AU - Bibi, Kareem AU - Mazza, Alberto AU - Masson, Luke AU - Frigon, Dominic T2 - Proceedings of the Water Environment Federation SN - 1938-6478 VL - 2013 IS - 2 SP - 136 EP - 154 AB - Ultraviolet (UV) and peracetic acid (PAA) disinfection have been used in municipal wastewater treatment plants (WWTPs) for their biocidal effect on microorganisms. The current study used PCR-Bioplex and DNA microarray genotyping techniques to investigate the impact of UV and PAA on the change in frequency of virulence genes in E. coli isolates and on the prevalence of uropathogenic E. coli (UPEC) isolates in wastewater effluents. Effluents from four WWTPs (activated sludge [AS], biofiltration [BF] and physicochemical [PC1 and PC2]) located in Québec, Canada, were sampled before disinfection and exposed to UV or PAA doses in the lab to reach a target count of approximately 200 CFU/100 mL. To achieve this, the required UV fluences ranged between 7 – 30 mJ/cm2, depending on the plant, while the PAA dose varied between 0.9 – 2.0 mg/L. E. coli isolates totaling 1,766 were extracted from the samples pre- and post- disinfection, then screened by PCR/Bioplex to detect those likely to be UPECs, using three virulence genes (hlyA, papC and cnf1). The UPEC pathotypes of the positively screened isolates were confirmed by microarrays. The proportion of UPEC isolates decreased in all samples after disinfection, with that due to UV varying between 22% – 80%, and the reduction due to PAA ranging between 11% – 100%. The average reductions by UV (55%) and PAA (52%) were statistically significant (P<0.05). Gene frequency analysis revealed that the decline in the population of UPEC pathotypes by UV or PAA was not linked to specific virulence factors as most virulence genes were lost, suggesting that entire pathogenicity islands (PAIs), carrying clusters of virulence genes, were lost through disinfection. Thus, this study showed that both UV and PAA disinfection appear to significantly reduce the proportions of UPECs in the surviving E. coli populations in wastewater effluents. DA - 2013/01/01 PY - 2013 PB - Water Environment Federation LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c407e5b4-2238-414c-93e4-c18814915b7d ER - TY - JOUR TI - Optimal routing strategies for autonomous underwater vehicles in time-varying environment DO - 10.1016/j.robot.2013.08.010 AU - Eichhorn, Mike T2 - Robotics and Autonomous Systems SN - 0921-8890 VL - 67 SP - 33 EP - 43 KW - path planning; geometrical graph; graph methods; time-varying environment; AUV; AUV “SLOCUM Glider”; autonomous systems AB - This paper presents a mission system and the therein implemented algorithms for path planning in a time-varying environment based on graph methods. The basic task of the introduced path planning algorithms is to find a time-optimal path from a defined start position to a goal position with consideration of the time-varying ocean current for an autonomous underwater vehicle (AUV). Building on this, additional practice-oriented considerations in planning are discussed in this paper. Such points are the discussion of possible methods to accelerate the algorithms and the determination of the optimal departure time. The solutions and algorithms presented in this paper are focused on path planning requirements for the AUV “SLOCUM Glider”. These algorithms are equally applicable to other AUVs or aerial mobile autonomous systems. DA - 2013/08/29 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e39b6a40-995b-41b1-9bc8-aa350c57b67b ER - TY - JOUR TI - PO-0875: Patient specific scatter distributions in CBCT imaging calculated by Monte Carlo simulations DO - 10.1016/S0167-8140(15)33181-9 AU - Thing, R.S. AU - Bernchou, U. AU - Mainegra-Hing, E. AU - Brink, C. T2 - Radiotherapy and Oncology SN - 0167-8140 VL - 106 SP - S336 AB - This paper proposes a hybrid software-hardware high-resolution projection system for 3D imaging based on fringe projection. The proposed solution combines the advantages of a digital projection with those of an analogue one. It is programmable and allows a high projection rate by avoiding mechanical displacements in the projection system. Moreover, it does not suffer from the limitations of digital systems such as the presence of inter-pixel gaps and limited resolution. The proposed projection system is relatively inexpensive to build since it is composed of a simple arrangement off-the-shelf components. The system is a combination of a low-resolution digital device such as a DMD, LCoS or LCD, some optical components and software to generate the fringe patterns. A prototype of a 3D scanner based on the proposed projection system is used to asses the fitness of the proposed technology. DA - 2013/03 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3d63db1c-ea86-413b-9c5a-a4afc5c8571c ER - TY - JOUR TI - Global framework for the assessment, development and demonstration of structural health and load monitoring systems AU - Rocha, Bruno AU - Yanishevsky, M. AU - Beltempo, Christopher Andre AU - Rutledge, Robert AU - Bellinger, Nicholas C. AU - Martinez, Marcias J. T2 - CASI Conference Proceedings T3 - CASI 2013 AB - Properly deployed Structural Health Monitoring (SHM) has the potential to benefit the design, operation and maintenance of aircraft. For current aircraft, SHM could help extend operational lives while reducing operational (and maintenance) costs and increasing availability and operational safety. In addition, the implementation of SHM during the design stage of new aircraft could result in weight reduction through optimized design and the incorporation of active safety measures. However, a significant level of development, testing and demonstration is still required for SHM systems to attain the required maturity for deployment on ground and flight tests, and operational aircraft. With this intent, the National Research Council of Canada (NRC) has created a global framework, complete with a set of structural platforms facilitating an accurate assessment, development and demonstration of SHM systems. These platforms, with increasing levels of structural complexity, can accommodate SHM systems at different Technology Readiness Levels (TRL). The first level of structural complexity presents a simple 2 m long aluminium beam, with solid, rectangular cross section, the behaviour of which is well characterized through analytical and numerical methods. The second platform presents a slightly increased structural complexity, consisting of a typical representative 2 m long aircraft wing skin with riveted z-stringers, containing two different aluminium alloys. The third level of complexity presents a hybrid material aircraft wing box representative structure, with internal aluminium structures and carbon fibre reinforced epoxy composite skins. The final platforms consist of a full scale CF188 aircraft wing and a Bell 407 helicopter tail boom, representative of the current aerospace structures to trial sensors and measurement systems. In all of these platforms, representative load conditions applied during full scale tests or observed during flight operations can be applied through the use of several hydraulic actuators and actuation configurations. These load conditions range from static and quasi-static bending, torsion and coupled load conditions, to low frequency cyclic loading (either constant amplitude or operational spectra) and higher frequency vibration associated with buffet and flutter. Beyond the assessment, development and demonstration of load monitoring techniques and sensor systems, these platforms also offer the opportunity for the development and assessment of SHM techniques and systems capabilities to detect and monitor damage growth. In order to assess the TRL of the different SHM systems, replaceable components are introduced, either in a pristine condition, or with existing or artificially introduced representative damage, which can be grown during the application of the testing loads. Furthermore, these test platforms are being prepared to introduce representative flight operation environmental conditions, such as temperature and humidity. DA - 2013/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4d111787-38b6-4474-9e9b-6997ff130bb4 ER - TY - JOUR TI - Optical image sensors and their application in radon detection DO - 10.1117/12.2033635 AU - Griffin, Ryan H. AU - Tarr, N. Garry AU - Cheben, Pavel AU - Schmid, Jens AU - Boudoux, Caroline AU - Chen, Lawrence R. AU - Delâge, André AU - Janz, Siegfried AU - Kashyap, Raman AU - Lockwood, David J. AU - Loock, Hans-peter AU - Mi, Zetian T2 - Photonics North 2013 T2 - SPIE Proceedings; no. 8915 T3 - Photonics North 2013, Monday 3 June 2013, Ottawa, Canada SP - 89151C AB - This paper reports on the development and testing of a direct reading radon detector assembled from consumer electronics at very low cost. An electrostatic concentrator constructed by metalizing a plastic funnel is used to focus charged radon progeny onto the exposed surface of an optical image sensor from a webcam. Alpha particles emitted by the collected progeny strike the image sensor, generating sufficient charge to completely saturate one or more pixels The high voltage required by the concentrator is generated using a simple Cockcroft-Walton charge pump. A personal computer is used to analyze the webcam data. Alpha particles were counted at a rate of 5.2 counts/ hour at a radon concentration of 159 Bq/ m3. DA - 2013/10/11 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8efe5fec-86c7-4327-a908-c689b4c47b8a ER - TY - JOUR TI - Transferring markup tags in statistical machine translation: a two-stream approach AU - Joanis, Eric AU - Stewart, Darlene AU - Larkin, Samuel AU - Kuhn, Roland T2 - Proceedings of the 2nd Workshop on Post-editing Technology and Practice (WPTP-2) T3 - MT Summit XIV Workshop on Post-editing Technology and Practice, September 2, 2013, Nice, France SP - 73 EP - 81 AB - Translation agencies are introducing sta- tistical machine translation (SMT) into the work flow of human translators. Typ- ically, SMT produces a first-draft transla- tion, which is then post-edited by a per- son. SMT has met much resistance from translators, partly because of professional conservatism, but partly because the SMT community has often neglected some practical aspects of translation. Our paper discusses one of these: transferring formatting tags such as bold or italic from the source to the target document with a low error rate, thus freeing the post-editor from having to reformat SMT-generated text. In our “two-stream” approach, tags are stripped from the input to the decoder, then reinserted into the resulting target-language text. Tag trans- fer has been tackled by other SMT teams, but only a few have published descrip- tions of their work. This paper contrib- utes to understanding tag transfer by ex- plaining our approach in detail. DA - 2013/09 PY - 2013 UR - http://www.mt-archive.info/10/MTS-2013-W2-TOC.htm LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a7b782a4-ee8d-4e93-bc8a-ea188154fc35 ER - TY - JOUR TI - Translating the genomics revolution: the need for an international gene therapy consortium for monogenic diseases DO - 10.1038/mt.2013.4 AU - Tremblay, Jacques p AU - Xiao, Xiao AU - Aartsma-rus, Annemieke AU - Barbas, Carlos AU - Blau, Helen m AU - Bogdanove, Adam j AU - Boycott, Kym AU - Braun, Serge AU - Breakefield, Xandra o AU - Bueren, Juan a AU - Buschmann, Michael AU - Byrne, Barry j AU - Calos, Michele AU - Cathomen, Toni AU - Chamberlain, Jeffrey AU - Chuah, Marinee AU - Cornetta, Kenneth AU - Davies, Kay e AU - Dickson, J george AU - Duchateau, Philippe AU - Flotte, Terence r AU - Gaudet, Daniel AU - Gersbach, Charles a AU - Gilbert, Rénald AU - Glorioso, Joseph AU - Herzog, Roland w AU - High, Katherine a AU - Huang, Wenlin AU - Huard, Johnny AU - Joung, J keith AU - Liu, Depei AU - Liu, Dexi AU - Lochmüller, Hanns AU - Lustig, Lawrence AU - Martens, Jeffrey AU - Massie, Bernard AU - Mavilio, Fulvio AU - Mendell, Jerry r AU - Nathwani, Amit AU - Ponder, Katherine AU - Porteus, Matthew AU - Puymirat, Jack AU - Samulski, Jude AU - Takeda, Shin’ichi AU - Thrasher, Adrian AU - Vandendriessche, Thierry AU - Wei, Yuquan AU - Wilson, James m AU - Wilton, Steve d AU - Wolfe, John h AU - Gao, Guangping T2 - Molecular Therapy SN - 1525-0016 SN - 1525-0024 VL - 21 IS - 2 SP - 266 EP - 268 DA - 2013/02 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0b766c26-91ab-4a3d-96b7-4563d30a7a1c ER - TY - JOUR TI - T4 report: a roadmap for hazard monitoring and risk assessment of marine biotoxins on the basis of chemical and biological test systems DO - 10.14573/altex.2013.4.487 AU - Daneshian, Mardas AU - Botana, Luis M. AU - Bottein, Marie-Yasmine Dechraoui AU - Buckland, Gemma AU - Campàs, Mònica AU - Dennison, Ngaire AU - Dickey, Robert W. AU - Diogène, Jorge AU - Fessard, Valérie AU - Hartung, Thomas AU - Humpage, Andrew AU - Leist, Marcel AU - Molgó, Jordi AU - Quilliam, Michael A. AU - Rovida, Costanza AU - Suarez-Isla, Benjamin A. AU - Tubaro, Aurelia AU - Wagner, Kristina AU - Zoller, Otmar AU - Dietrich, Daniel T2 - Altex SN - 1868-596X SN - 1868-8551 VL - 40 IS - 4 SP - 487 EP - 545 KW - marine biotoxins; risk assessment; consumer protection; regulatory toxicology AB - Aquatic food accounts for over 40% of global animal food products, and the potential contamination with toxins of algal origin - marine biotoxins - poses a health threat for consumers. The gold standards to assess toxins in aquatic food have traditionally been in vivo methods, i.e., the mouse as well as the rat bioassay. Besides ethical concerns, there is also a need for more reliable test methods because of low inter-species comparability, high intra-species variability, the high number of false positive and negative results as well as questionable extrapolation of quantitative risk to humans. For this reason, a transatlantic group of experts in the field of marine biotoxins was convened from academia and regulatory safety authorities to discuss future approaches to marine biotoxin testing. In this report they provide a background on the toxin classes, on their chemical characterization, the epidemiology, on risk assessment and management, as well as on their assumed mode of action. Most importantly, physiological functional assays such as in vitro bioassays and also analytical techniques, e.g., liquid chromatography coupled mass spectrometry (LC-MS), as substitutes for the rodent bioassay are reviewed. This forms the basis for recommendations on methodologies for hazard monitoring and risk assessment, establishment of causality of intoxications in human cases, a roadmap for research and development of human-relevant functional assays, as well as new approaches for a consumer directed safety concept. DA - 2013 PY - 2013 PB - ALTEX Edition LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1608241a-2844-478d-977c-e8f955c4d740 ER - TY - JOUR TI - The distance to NGC 1316 (Fornax A): yet another curious case DO - 10.1051/0004-6361/201220756 AU - Cantiello, M. AU - Grado, A. AU - Blakeslee, J. P. AU - Raimondo, G. AU - Di Rico, G. AU - Limatola, L. AU - Brocato, E. AU - Della Valle, M. AU - Gilmozzi, R. T2 - Astronomy & Astrophysics SN - 0004-6361 SN - 1432-0746 VL - 552 SP - A106 SP - 1 EP - 22 KW - Elliptical galaxies KW - Lenticular galaxies KW - Galaxy distances KW - Redshifts KW - Cluster galaxies KW - Galaxy NGC 1316 KW - Galaxy photometry KW - Stellar content KW - Peculiar galaxies AB - AIMS: The distance of NGC 1316, the brightest galaxy in the Fornax cluster, provides an interesting test for the cosmological distance scale. First, because Fornax is the second largest cluster of galaxies within ≲25 Mpc after Virgo and, in contrast to Virgo, has a small line-of-sight depth; and second, because NGC 1316 is the single galaxy with the largest number of detected Type Ia supernovae (SNe Ia), giving the opportunity to test the consistency of SNe Ia distances both internally and against other distance indicators. METHODS: We measure surface brightness fluctuations (SBF) in NGC 1316 from ground- and space-based imaging data. The sample provides a homogeneous set of measurements over a wide wavelength interval. The SBF magnitudes, coupled with empirical and theoretical absolute SBF calibrations, are used to estimate the distance to the galaxy. We also present the first B-band SBF measurements of NGC 1316 and use them together with the optical and near-IR SBF data to analyze the properties of field stars in the galaxy. RESULTS: We obtain mag, or d = 20.8 ± 0.5(stat.) ± 1.5(sys.) Mpc. When placed in a consistent Cepheid distance scale, our result agrees with the distances from other indicators. On the other hand, our distance is ~17% larger than the most recent estimate based on SNe Ia. Possible explanations for this disagreement are the uncertain level of internal extinction, and/or calibration issues. Concerning the stellar population analysis, we confirm the results from other spectro-photometric indicators: the field stars in NGC 1316 are dominated by a component with roughly solar metallicity and intermediate age. A non-negligible mismatch exists between B-band SBF models and data. We confirm that such behavior can be accounted for by an enhanced percentage of hot horizontal branch stars. CONCLUSIONS: Our study of the SBF distance to NGC 1316, and the comparison with distances from other indicators, raises some concern about the homogeneity between the calibrations of different indicators. If not properly placed in the same reference scale, significant differences can occur, with dramatic impact on the cosmological distance ladder. Our results on the stellar populations properties show that SBF data over a broad wavelength interval are an efficient means of studying the properties of unresolved systems in peculiar cases like NGC 1316. DA - 2013/04/10 PY - 2013 PB - EDP Sciences LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f2dd2715-987e-466a-b807-4117686d0201 ER - TY - JOUR TI - The alleviation of wake vortex encounter loads, a study of flight research data AU - Brown, Anthony P. T2 - Transactions of Japanese Society for Medical and Biological Engineering T3 - 35th Annual International Conference of IEEE Engineering in Medicine and Biology Society in conjunction with 52nd Annual Conference of Japanese Society for Medical and Bological Engineering, July 3-7 2013, Osaka, Japan SN - 18814379 VL - 51 IS - SUPPL AB - Wake vortex encounters, occurring in air transport operations, involve substantial loads, which can result in aggravated flight-path upsets. In order to explore flight control system design for alleviation, the alleviatory effects of conventional flight control surface deflections, upon wake vortex encounter loads has been examined. For this, data was gathered during NRC T33 wake turbulence flight research, of Heavy and Super Category jet transports engaged in enroute operations. Comparative data consists of stick-fixed wake vortex encounters and manually-applied alleviatory control inputs to conventional flight control surfaces. For the alleviatory control-input case, the inputs are experience-based, fully-learned, in other words categorised as instinctive. As such, they were of a high frequency-band, for manual control inputs. Thus, they represent a close-to-limit ability to alleviate wake vortex encounter loads, for the T33 with manual control inputs. The reduction in loads between the two cases, stick-fixed and stick-alleviatory was of the order of 50-60%. Given the greater bandwidth of digital flight control systems, it is reasonable to speculate that a wake vortex loads alleviation of significantly greater than 50% could be possible with a digital flight control system, based upon the appropriate flight control laws. DA - 2013 PY - 2013 PB - Japan Soc. of Med. Electronics and Biol. Engineering LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1eaf2123-2a8a-4ca6-a1d8-8ec9421ba939 ER - TY - JOUR TI - Texture based segmentation method to detect atherosclerotic plaque from optical tomography images AU - Prakash, Ammu AU - Hewko, Mark AU - Sowa, Michael AU - Sherif, Sherif T2 - Advanced microscopy techniques III T2 - Optics InfoBase Conference Papers T3 - European Conference on Biomedical Optics, May 12-16 2013, Munich, Germany SN - 2162-2701 SN - 9780819496461 KW - Atherosclerosis KW - Image processing KW - Image texture KW - Optical coherence tomography KW - Plaque AB - Optical coherence tomography (OCT) imaging has been widely employed in assessing cardiovascular disease. Atherosclerosis is one of the major cause cardio vascular diseases. However visual detection of atherosclerotic plaque from OCT images is often limited and further complicated by high frame rates. We developed a texture based segmentation method to automatically detect plaque and non plaque regions from OCT images. To verify our results we compared them to photographs of the vascular tissue with atherosclerotic plaque that we used to generate the OCT images. Our results show a close match with photographs of vascular tissue with atherosclerotic plaque. Our texture based segmentation method for plaque detection could be potentially used in clinical cardiovascular OCT imaging for plaque detection. DA - 2013 PY - 2013 PB - OSA Publishing LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ac1d6ca3-0cbe-47f8-b03e-47eb7c77157f ER - TY - JOUR TI - Structure of the benzene dimer - governed by dynamics DO - 10.1002/anie.201300653 AU - Schnell, Melanie AU - Erlekam, Undine AU - Bunker, P. R. AU - von Helden, Gert AU - Grabow, Jens-Uwe AU - Meijer, Gerard AU - van der Avoird, Ad T2 - Angewandte Chemie International Edition SN - 1433-7851 VL - 52 IS - 19 SP - 5180 EP - 5183 KW - Ab initio calculations KW - Internal rotation KW - Noncovalent interactions KW - Rotational spectroscopy KW - Tunneling AB - The benzene dimer, an important prototype for studying noncovalent interactions, exhibits characteristic splitting patterns in its rotational spectrum, which for a long time were not understood. A new theoretical model reveals their origin: a concerted internal motion involving sixfold hindered rotation tunneling of the molecule forming the stem of the T-shaped structure and tilt tunneling of the cap. DA - 2013/05/03 PY - 2013 PB - Wiley LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d7b02dd1-353d-47ee-8695-aa331333a80a ER - TY - CHAP TI - Single-domain antibodies and their utility DO - 10.1002/0471142735.im0217s103 AU - Baral, Toya Nath AU - MacKenzie, Roger AU - Ghahroudi, Mehdi Arbabi T2 - Current Protocols in Immunology SN - 9780471142737 IS - SUPPL 103 SP - 2.17 SP - 1 EP - 57 KW - Single-domain antibody KW - Heavy-chain antibodies KW - VHH KW - Antibody fragment KW - Dimeric VHH KW - Pentabodies KW - Multivalency AB - Engineered monoclonal antibody fragments have gained market attention due to their versatility and tailor-made potential and are now considered to be an important part of future immunobiotherapeutics. Single-domain antibodies (sdAbs), also known as nanobodies, are derived from VHHs [variable domains (V) of heavy-chain-only antibodies (HCAb)] of camelid heavy-chain antibodies. These nature-made sdAbs are well suited for various applications due to their favorable characteristics such as small size, ease of genetic manipulation, high affinity and solubility, overall stability, resistance to harsh conditions (e.g., low pH, high temperature), and low immunogenicity. Most importantly, sdAbs have the feature of penetrating into cavities and recognizing hidden epitopes normally inaccessible to conventional antibodies, mainly due to their protruding CDR3/H3 loops. In this unit, we will present and discuss comprehensive and step-by-step protocols routinely practiced in our laboratory for isolating sdAbs from immunized llamas (or other members of the Camelidae family) against target antigens using phage-display technology. Expression, purification, and characterization of the isolated sdAbs will then be described, followed by presentation of several examples of applications of sdAbs previously characterized in our laboratory and elsewhere. DA - 2013/11/18 PY - 2013 PB - Wiley LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e552ed0a-502f-47b3-a6f6-9daf5bd955d3 ER - TY - JOUR TI - Simulation studies of the Cl⁻ + CH₃I SN2 nucleophilic substitution reaction: Comparison with ion imaging experiments DO - 10.1063/1.4795495 AU - Zhang, Jiaxu AU - Lourderaj, Upakarasamy AU - Sun, Rui AU - Mikosch, Jochen AU - Wester, Roland AU - Hase, William L. T2 - The Journal of Chemical Physics SN - 0021-9606 VL - 138 IS - 11 SP - 114309 KW - Reaction mechanisms KW - Collusion induced chemical reactions KW - Density functional theory KW - Ion molecule reactions KW - Energy transfer AB - In the previous work of Mikosch Science 319, 183 (2008)10.1126/science. 1150238, ion imaging experiments were used to study the Cl⁻ CH₃I → ClCH₃ I⁻ reaction at collision energies Erel of 0.39, 0.76, 1.07, and 1.9 eV. For the work reported here MP2(fc)ECPd direct dynamics simulations were performed to obtain an atomistic understanding of the experiments. There is good agreement with the experimental product energy and scattering angle distributions for the highest three Erel, and at these energies 80 or more of the reaction is direct, primarily occurring by a rebound mechanism with backward scattering. At 0.76 eV there is a small indirect component, with isotropic scattering, involving formation of the pre- and post-reaction complexes. All of the reaction is direct at 1.07 eV. Increasing Erel to 1.9 eV opens up a new indirect pathway, the roundabout mechanism. The product energy is primarily partitioned into relative translation for the direct reactions, but to CH₃Cl internal energy for the indirect reactions. The roundabout mechanism transfers substantial energy to CH₃3Cl rotation. At E rel 0.39 eV both the experimental product energy partitioning and scattering are statistical, suggesting the reaction is primarily indirect with formation of the pre- and post-reaction complexes. However, neither MP2 nor BhandHECPd simulations agree with experiment and, instead, give reaction dominated by direct processes as found for the higher collision energies. Decreasing the simulation Erel to 0.20 eV results in product energy partitioning and scattering which agree with the 0.39 eV experiment. The sharp transition from a dominant direct to indirect reaction as Erel is lowered from 0.39 to 0.20 eV is striking. The lack of agreement between the simulations and experiment for Erel 0.39 eV may result from a distribution of collision energies in the experiment andor a shortcoming in both the MP2 and BhandH simulations. Increasing the reactant rotational temperature from 75 to 300 K for the 1.9 eV collisions, results in more rotational energy in the CH₃Cl product and a larger fraction of roundabout trajectories. Even though a ClCH₃-I⁻ post-reaction complex is not formed and the mechanistic dynamics are not statistical, the roundabout mechanism gives product energy partitioning in approximate agreement with phase space theory. DA - 2013/03/21 PY - 2013 PB - AIP Publishing LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1da4aab7-2090-4660-8836-ecdc0acc7a6b ER - TY - JOUR TI - Simplified non-linear FE model to predict staged capacity deterioration of RC columns subjected to combined ultimate or seismic and reinforcement corrosion loads AU - Mohammed, Amina AU - Almansour, Husham T2 - Annual Conference of the Canadian Society for Civil Engineering 2013: Know-How - Savoir-Faire T3 - Annual Conference of the Canadian Society for Civil Engineering 2013: Know-How - Savoir-Faire, May 29-June 1 2013, Montreal, QC, Canada SN - 978-1-63439-897-8 VL - 5 IS - January SP - 4339 EP - 4348 AB - The quasi-static and the low frequency cyclic loading-to-failure tests have shown that the stiffness degradation and strength of RC columns are reduced in a staged pattern. Although several studies have demonstrated this strength and stiffness degradation using complicated high-level 2D and 3D modeling approaches, a simplified numerical approach is required. Simplified non-linear finite element model developed by the authors is used in this paper to capture the staged damage and collapse of RC columns subjected to extreme loads. The model performs inelastic sectional and element analysis phases considering the instantaneous and successive changes of the sectional and element properties throughout the progress of the loading steps and the critical stages of corrosion-induced damages. The model considers all possible state of strain distributions on a concrete beam-column, and the nonlinear instantaneous sectional properties and the internal forces are calculated ensuring the equilibrium of all the internal and external forces in the section level. It is found that the proposed simplified nonlinear finite element model is numerically stable in all cases of strain distributions, both in static and dynamic analysis. The model shows that the load displacement curve of the columns subjected to quasi-static loading or the envelop of the load-displacement hysteretic relationship can be found using quasi-static analysis. The model can predict the nonlinear behavior of non-corroded and corroded specimens with high accuracy. Further research is required to accurately define the critical stages of damages incorporating field and experimental data of damaged RC columns and higher level non-linear finite element techniques. DA - 2013 PY - 2013 PB - Canadian Society for Civil Engineering LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 71c2b9bb-9b96-4f52-81af-15ed78ac47bd ER - TY - JOUR TI - Short/Small crack model development for aircraft structural life assessment AU - Liao, Min AU - Renaud, Guillaume AU - Bombardier, Yan T2 - 13th International Conference on Fracture 2013, ICF 2013 T3 - 13th International Conference on Fracture, June 16-21 2013, Beijing, China SN - 978-62993-369-6 VL - 1 SP - 96 EP - 105 AB - This paper presents the testing and modeling results from an NRC project on short/small1 crack model development for aircraft structures. Fatigue tests were conducted for 7075-T73 hand forging aluminium material using precracked compact tension (C(T)) and naturally cracked single edge-notch tension (SENT) coupons, under various stress ratios. The adjusted compliance ratio (ACR) method was used for the C(T) coupon tests aiming to quantify remote closure due to plasticity and forging-induced residual stresses. For the SENT coupons, three-dimensional StressCheck finite element (FE) models were developed to accurately calculate the stress intensity factors of surface and corner cracks. Both C(T) and SENT test data were combined to develop short-long fatigue crack growth rate models. These models were then used in crack growth life analyses for coupon and component cases, taken from transport aircraft under spectrum loadings. It was shown that the newly developed models resulted in more accurate fatigue life estimations. DA - 2013 PY - 2013 PB - Chinese Society of Theoretical and Applied Mechanics LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ee91e536-0ca9-44ac-9d46-ceb6c9e3b0a1 ER - TY - JOUR TI - Shaping polarization of attosecond pulses via laser control of electron and hole dynamics DO - 10.1109/CLEOE-IQEC.2013.6801152 AU - Morales, F. AU - Barth, I. AU - Serbinenko, V. AU - Patchkovskii, S. AU - Smirnova, O. T2 - 2013 Conference on Lasers & Electro-Optics Europe & International Quantum Electronics Conference CLEO EUROPE/IQEC T3 - 2013 Conference on Lasers & Electro-Optics Europe & International Quantum Electronics Conference CLEO EUROPE/IQEC, May 12-16 2013, Munich, Germany SN - 978-1-4799-0593-5 SP - 6801152 SP - 1 EP - 1 AB - We present [1] a way to control and shape the polarization of attosecond pulses generated by HHG by using the combination of the fundamental radiation and its second harmonic, both linearly polarized, in perpendicular geometry. By extending the multi-electron analysis done in the C02 molecule in previous works [2] to treat the two-color laser fields, we explore the rich possibilities that this control mechanism offers. DA - 2013/05 PY - 2013 PB - IEEE LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9c86e2aa-7c47-4d4d-986a-07ddc19bd639 ER - TY - JOUR TI - Shaping polarization of attosecond pulses via laser control of electron and hole dynamics AU - Morales, F. AU - Barth, I. AU - Serbinenko, V. AU - Patchkovskii, S. AU - Smirnova, O. T2 - 2013 Conference on Lasers & Electro-Optics, International Quantum Electronics Conference T2 - Optics InfoBase Conference Papers T3 - 2013 Conference on Lasers & Electro-Optics Europe & International Quantum Electronics Conference CLEO EUROPE/IQEC, May 12-16 2013, Munich, Germany SN - 2162-2701 SN - 978-1-4799-0594-2 SP - CG_5_6 DA - 2013/05 PY - 2013 PB - OSA Publishing LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b5ec8d54-b42b-416d-a390-bf56701606e5 ER - TY - JOUR TI - Serum biomarkers of papillary thyroid cancer DO - 10.1186/1916-0216-42-16 AU - Makki, Fawaz M. AU - Taylor, S. Mark AU - Shahnavaz, Ali AU - Leslie, Andrew AU - Gallant, Jeffrey AU - Douglas, Susan AU - Teh, Evelyn AU - Trites, Jonathan AU - Bullock, Martin AU - Inglis, Karen AU - Pinto, Devanand M. AU - Hart, Robert D. T2 - Journal of Otolaryngology - Head and Neck Surgery SN - 1916-0216 VL - 42 IS - 1 SP - 16 KW - Thyroid KW - Cancer KW - Papillary KW - Serum biomarkers AB - OBJECTIVE: To identify serum biomarkers of papillary thyroid cancer. METHODS: Prospective analysis was performed of banked tumor and serum specimens from 99 patients with thyroid masses. Enzyme-linked immunosorbent assay (ELISA) was employed to measure levels of five serum proteins previously demonstrated to be up-regulated in papillary thyroid cancer (PTC): angiopoietin-1 (Ang-1), cytokeratin 19 (CK-19), tissue inhibitor of metalloproteinase-1 (TIMP-1), chitinase 3 like-1 (YKL-40), and galectin-3 (GAL-3). Serum levels were compared between patients with PTC and those with benign tumors. RESULTS: A total of 99 patients were enrolled in the study (27 men, 72 women), with a median age of 54 years. Forty-three patients had PTC and 58 cases were benign tumors. There were no statistically significant differences when comparing all five different biomarkers between PTC and other benign thyroid tumors. The p-values were 0.94, 0.48, 0.72, 0.48, and 0.90 for YKL-40, Gal-3, CK19, TIMP-1, and Ang-1, respectively. CONCLUSIONS: Serum levels of four of the five proteins were elevated in patients with thyroid masses relative to normal values. However, the difference between benign and PTC was not significant. Two of the markers (Gal-3 & TIMP-1) displayed a greater potential difference, which may warrant further investigation. This study suggests that other serum markers should be sought. This is the first study to investigate potential serum biomarkers based on over-expressed proteins in thyroid cancer versus benign pathology. DA - 2013/02/17 PY - 2013 PB - BioMed Central Ltd LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 7534034e-7042-4743-bbe8-4b254a8f22a1 ER - TY - JOUR TI - Sensespotting: never let your parallel data tie you to an old domain AU - Carpuat, Marine AU - Daume III, Hal AU - Henry, Katie AU - Irvine, Ann AU - Jagarlamudi, Jagadeesh AU - Rudinger, Rachel T2 - ACL 2013 - 51st Annual Meeting of the Association for Computational Linguistics, Proceedings of the Conference T3 - 51st Annual Meeting of the Association for Computational Linguistics, August 4-9 2013, Sofia, Bulgaria SN - 9781937284503 VL - 1 SP - 1435 EP - 1445 AB - Words often gain new senses in new domains. Being able to automatically identify, from a corpus of monolingual text, which word tokens are being used in a previously unseen sense has applications to machine translation and other tasks sensitive to lexical semantics. We define a task, SenseSpotting, in which we build systems to spot tokens that have new senses in new domain text. Instead of difficult and expensive annotation, we build a goldstandard by leveraging cheaply available parallel corpora, targeting our approach to the problem of domain adaptation for machine translation. Our system is able to achieve F-measures of as much as 80%, when applied to word types it has never seen before. Our approach is based on a large set of novel features that capture varied aspects of how words change when used in new domains. DA - 2013 PY - 2013 PB - Association for Computational Linguistics LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 559b8e7b-80bf-4aec-a2a0-33ddb4572af4 ER - TY - JOUR TI - Revising ASHRAE climatic data for design and standards - Part 1: Overview and data AU - Thevenard, Didier AU - Cornick, Steve T2 - ASHRAE Transactions T3 - ASHRAE Annual Conference, June 22-26 2013, Denver, CO, USA SN - 9781936504541 VL - 119 IS - 2 SP - 181 EP - 193 AB - ASHRAE Research Project RP-1613 prepared an update of the climatic design conditions for the "Climatic Design Information" chapter of ASHRAE Handbook--Fundamentals and for ANSI/ASHRAE Standard 169, Weather Data for Building Design Standards. This update resulted in an increase of the number of stations to 6443 (a 16% increase compared to 2009) and the inclusion of precipitation data used in particular to determine climate zones in energy standard ANSI/ ASHRAE/IES Standard 90.1. A more recent period of record (1986-2010 for most stations) was used to incorporate changes in the climate. Compared to the previous edition, climatic design temperatures are generally slightly higher, cooling degree are slightly higher, and heating degree-days are lower, which is indicative of a general warming of the climate. In addition, RP-1613 prepared an update of the Weather Data Viewer, a stand-alone product used by engineers to access the full single- and joint-frequency distributions of all the climatic design parameters listed in ASHRAE Handbook--Fundamentals, as well as additional parameters, such as temperature bin data and wind roses. Part two of the paper, "Revising ASHRAE Climatic Data for Design and Standards--Part II: Clear-Sky Solar Radiation Model," provides a detailed description of the changes made to the clear-sky solar radiation model. DA - 2013 PY - 2013 PB - ASHRAE LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 45db8087-1bf8-47de-a991-de3792b6c0b4 ER - TY - JOUR TI - Review of Canadian flight deck and cabin smoke and fire incidents: 2001-2010 DO - 10.4271/2013-01-2307 AU - Lebbin, Paul T2 - SAE International Journal of Aerospace SN - 1946-3901 VL - 6 IS - 1 SP - 286 EP - 298 AB - This paper presents a review of the flight deck and cabin fire and smoke incidents reported to the Canadian airworthiness authorities over a ten year span. The fire and smoke related diversions are categorized to identify areas where efforts could be increased to improve safety. The costs of diversions are estimated to identify areas where operators could reduce costs by seeking technologies to reduce the number of diversions without any impact on safety. Only twenty-eight investigation reports into fire and smoke incidents onboard aircraft have been published over the past three decades. These reports are not sufficient to identify areas where operators can reduce their operating costs. The Canadian airworthiness authorities received over 1,000 smoke and fire incidents from the years 2001 to 2010, of which, over 680 reported fire and smoke in the flight deck and cabin compartments for various makes and models of aircraft. Some of these flight deck and cabin incidents were related to in-flight entertainment or galley systems that were remedied while in-flight and did not require a diversion in most cases. The remaining incidents were found to be related to ingestion of oil, de-icing fluids and equipment and electrical failures that, in many cases, prompted the pilots to declare an emergency and divert. This paper categorizes the flight deck and cabin related fire and smoke incidents to suggest specific areas for airframers and operators to focus their efforts in reducing flight diversions that will not only reduce costs, but improve safety. DA - 2013/07/20 PY - 2013 PB - SAE International LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6267f94d-fec4-4029-ae50-0495b2b55f0a ER - TY - JOUR TI - Residual stresses in welded stiffened steel plates—an experimental comparative study DO - 10.1520/MPC20130007 AU - Kenno, Sara Y. AU - Das, Sreekanta AU - Rogge, Ronald B. AU - Gharghouri, Michael A. T2 - Materials Performance and Characterization SN - 2165-3992 VL - 2 IS - 1 SP - 231 EP - 243 KW - Diffraction KW - Residual stresses KW - Stiffened steel plate KW - Welding-induced residual stresses AB - This paper examines the residual stress distributions at selected depths in three stiffened 350WT steel plates representing typical stiffened steel plates used in modern ship construction. Residual stresses can develop from the welding process, and the magnitude of these stresses can be high enough to cause an early onset of yielding. Therefore, fatigue or other failures can also occur when welding-induced residual stresses are combined with service-load-induced stresses. In this study, the welding-induced residual stresses of these stiffened steel plate specimens were quantified at the near surface using the X-Ray diffraction method and at various depths using the neutron diffraction method. Transverse and longitudinal stress components for all three specimens were collected and analyzed. The residual stress profiles determined from both methods were found to be similar. However, some disagreement was found within the heat-affected zone of the weld bead. This paper discusses the residual stress distributions found in the three specimens and compares the two methods of measurement. DA - 2013/02/06 PY - 2013 PB - ASTM International LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4d2acfb7-11fe-41cf-b6a4-4cba2da9a112 ER - TY - JOUR TI - Relating centromeric topography in fixed human chromosomes to a-satellite DNA and CENP-B distribution DO - 10.1159/000348744 AU - Khan, W. A. AU - Chisholm, R. AU - Tadayyon, S. AU - Subasinghe, A. AU - Norton, P. AU - Samarabandu, J. AU - Johnston, L. J. AU - Knoll, J. H. AU - Rogan, P. K. T2 - Cytogenetic and Genome Research SN - 1424-859X SN - 1424-8581 VL - 139 IS - 4 SP - 234 EP - 242 KW - Satellite DNA KW - Atomic force microscopy KW - CENP-B KW - Centromere topography KW - Human metaphase chromosomes KW - Immuno-FISH AB - Despite extensive analyses on the centromere and its associated proteins, detailed studies of centromeric DNA structure have provided limited information about its topography in condensed chromatin. We have developed a method with correlative fluorescence light microscopy and atomic force microscopy that investigates the physical and structural organization of -satellite DNA sequences in the context of its associated protein, CENP-B, on human metaphase chromosome topography. Comparison of centromeric DNA and protein distribution patterns in fixed homologous chromosomes indicates that CENP-B and -satellite DNA are distributed distinctly from one another and relative to observed centromeric ridge topography. Our approach facilitates correlated studies of multiple chromatin components comprising higher-order structures of human metaphase chromosomes. DA - 2013/05 PY - 2013 PB - Karger LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4e3b0687-e1b9-4502-b46f-4477bb138896 ER - TY - JOUR TI - Re-inventing multimode interference couplers using subwavelength gratings DO - 10.1109/CLEOE-IQEC.2013.6801454 AU - Ortega-Monux, A. AU - Halir, R. AU - Maese-Novo, A. AU - Alonso-Ramos, C. AU - Zavargo-Peche, L. AU - Perez-Galacho, D. AU - Molina-Fernandez, I. AU - Wanguemert-Perez, J. G. AU - Cheben, P. AU - Schmid, J. H. AU - Lapointe, J. AU - Xu, D. AU - Janz, S. T2 - 2013 Conference on Lasers & Electro-Optics Europe & International Quantum Electronics Conference CLEO EUROPE/IQEC T3 - 2013 Conference on Lasers & Electro-Optics Europe & International Quantum Electronics Conference CLEO EUROPE/IQEC, May 12-16 2013, Munich, Germany SN - 978-1-4799-0593-5 SP - 1 EP - 1 KW - Bragg gratings KW - Talbot effect KW - Integrated optoelectronics KW - Light interference KW - Optical couplers KW - Refractive index AB - Multimode-Interference (MMI) devices are fundamental building blocks in photonic integrated circuits, where they are used for power splitting and combining, optical switches and modulators, Mach-Zehnder interferometers and 90o hybrids for coherent optical receivers. MMIs are based on the self-image principle, by which the guided modes of the multimode region interfere to form replicas of the input field with specific amplitude and phase relations. These relations are known to depend on i) the core/cladding refractive indexes (n₁/n₂), ii) the core width (W) and length (L) of the multimode region and iii) the number, width and position of the access ports. In this work, we show that by using sub-wavelength structures within an MMI, the self-imaging properties can be significantly altered, leading to ultra-short or ultra-broadband devices. DA - 2013/05 PY - 2013 PB - IEEE LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 21bcf016-0a8b-46f4-9250-8f72e7bc3981 ER - TY - JOUR TI - Re-inventing multimode interference couplers using subwavelength gratings AU - Ortega-Monux, A. AU - Halir, R. AU - Maese-Novo, A. AU - Alonso-Ramos, C. AU - Zavargo-Peche, L. AU - Perez-Galacho, D. AU - Molina-Fernandez, I. AU - Wanguemert-Perez, J. G. AU - Cheben, P. AU - Schmid, J. H. AU - Lapointe, J. AU - Xu, D. AU - Janz, S. T2 - Optics InfoBase Conference Papers T3 - The European Conference on Lasers and Electro-Optics, CLEO_Europe, May 12-16 2013, Munich, Germany SN - 978-1-4799-0594-2 DA - 2013 PY - 2013 PB - The Optical Society LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 38a3fb06-f3c2-47b7-b7dc-750b60c2e91e ER - TY - JOUR TI - Reflections on journal bearings performance with surface texturing AU - Dadouche, Azzedine AU - Conlon, Martin J. T2 - 5th World Tribology Congress, WTC 2013 T3 - 5th World Tribology Congress, September 8-13 2013, Torino, Italy SN - 9781634393522 VL - 1 SP - 280 EP - 283 DA - 2013 PY - 2013 PB - Politecnico di Torino LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2dda476e-b48a-4490-8e8c-456791a87e7f ER - TY - JOUR TI - Rectification of piezoelectric dynamometer force signals during low frequency vibration assisted drilling DO - 10.1115/IMECE2013-65307 AU - Sadek, A. AU - Meshreki, M. AU - Attia, M. H. T2 - ASME 2013 International Mechanical Engineering Congress and Exposition Volume 2B: Advanced Manufacturing T3 - ASME 2013 International Mechanical Engineering Congress and Exposition, November 15-21 2013, San Diego, California, USA SN - 978-0-7918-5619-2 SP - V02BT02A049 SP - 1 EP - 6 KW - Drilling KW - Vibration KW - Signals KW - Dynamometers AB - In vibration assisted drilling (VAD), a controlled harmonic motion is superimposed over the principal drilling feed motion in order to create an intermittent cutting state, which reduces cutting forces and temperatures, facilitates chip removal, and increases the possibility for dry machining. However, accurate force measurements during VAD operations has been a challenge especially in systems, where the force transducer is part of the vibrating mass mounted on the shaker head, due to the dynamic force errors. Conventional signal filtering and compensation techniques were found to be not applicable for attenuating undesirable VAD dynamic force components, which exist in the measured force signals at the same frequency of superimposed modulation. This research work presents a corrective dynamic model that rectifies the erroneous VAD tangential and axial force signals measured by a commercial piezoelectric dynamometer mounted on electro-magnetic shakers for the low frequency/high amplitude (LF/HA) regime. An experimental modal analysis in tangential and axial directions was conducted in order to define the transfer function of a multiple degrees of freedom VAD system mounted on a vibrating base (shaker). The rectified force is then obtained by plugging the relative motion between the dynamometer base and face measured during cutting into the system transfer function. The predicted rectified force components showed very high conformance with known impact and sinusoidal excitation forces used for validation. Moreover, the developed corrective model was capable of predicting some features in the VAD force signals that were not fully captured in the measured force signals during cutting. DA - 2013/11/15 PY - 2013 PB - ASME LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 00da48ce-2291-41ab-b223-849730155639 ER - TY - JOUR TI - Production of ceramic coatings on AA6061 aluminum alloy using plasma electrolytic oxidation AU - Dehnavi, Vahid AU - Luan, Ben Li AU - Liu, Xing Yang AU - Shoesmith, David W. AU - Rohani, Sohrab T2 - Materials Science and Technology Conference and Exhibition 2013, MS and T 2013 T3 - Materials Science and Technology Conference and Exhibition, October 27-31 2013, Montreal QC, Canada SN - 9781629933092 VL - 3 SP - 2247 EP - 2254 KW - Aluminum alloy 6061 KW - Ceramic coatings KW - Plasma electrolytic oxidation AB - Plasma electrolytic oxidation (PEO) is a relatively novel surface finishing technique that converts the surface of light metals and alloys into oxide layers. For Al alloys, the coatings produced by PEO mainly consist of oxides with high hardness and therefore are more suitable for tribological applications than the substrate material. The PEO coatings can also effectively protect the base metal against corrosion. In this study ceramic coatings were deposited on 6061 Al alloy substrates using an alkaline electrolyte. The morphology, microstructure, compositions, and growth behavior of the coatings were analyzed using SEM, energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). The results suggest that the coating growth behavior is a function of the PEO process stages. This information can be used to better understand the PEO coating growth behavior and to improve the quality of the coatings for required applications. DA - 2013 PY - 2013 PB - Association for Iron & Steel Technology LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9c32096b-7c89-48b8-a005-600efbfda850 ER - TY - JOUR TI - Preparation for scaling studies of ice-crystal icing at the NRC Research Altitude Test Facility DO - 10.2514/6.2013-2675 AU - Struk, Peter M. AU - Bencic, Timothy AU - Tsao, Jen-Ching AU - Fuleki, Dan AU - Knezevici, Daniel C. T2 - 5th AIAA Atmospheric and Space Environments Conference T3 - 5th AIAA Atmospheric and Space Environments Conference, June 24-27 2013, San Diego, CA, USA SP - 1 EP - 21 AB - This paper describes preparation for ice-crystal icing scaling work utilizing the Cascade rig at the National Research Council (NRC) of Canada’s Research Altitude Test Facility (RATFac). Tests supporting this work and continuing the collaboration between NASA and NRC on ice-crystal icing took place between March 26 and April 11, 2012. The focus was on several aspects but emphasized characterization of the RATFac cloud including watercontent and test-section uniformity as well as particle-size measurements. Water content measurements utilized the Science Engineering Associates (SEA) Multi-Element probe while cloud uniformity measurements used light scattering from particles passing through a laser sheet. Finally, particle size-spectra measurements used two developmental shadowgraph systems. Details of these measurements as well as selected results are presented. An analysis algorithm is presented that interprets mixed-phase measurements from the SEA probe using calibrations from individual water and ice clouds. The analysis is applied to one mixedphase data set generated with a glaciated cloud combined with supplemental water. The test section temperature was below freezing to prevent the natural melting of the ice crystals. The analysis algorithm relies on the measurement of test-section humidity to account for cloud evaporation. Results of the cloud-uniformity measurements using scattered light suggest that the measured intensity is a good first-order measurement of concentration, independent of the water phase. Steeper intensity gradients across the test section are observed with increasing ice-water content. For particle-size measurements, both shadowgraphy methods provide high-quality images of the particles. These images will be processed to establish particle-size distributions and morphology characteristics. The results from this work will help guide future ice-crystal icing research including scaling studies. DA - 2013/06/24 PY - 2013 PB - American Institute of Aeronautics and Astronautics CY - Reston, Virginia LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 27ab6e4f-cc5f-42c5-b996-b82fa3c8d004 ER - TY - JOUR TI - Power spectra and auto correlation analysis of hyperfine-induced long period oscillations in the tunneling current of coupled quantum dots DO - 10.1063/1.4848373 AU - Harack, B. AU - Leary, A. AU - Coish, W. A. AU - Hilke, M. AU - Yu, G. AU - Payette, C. AU - Gupta, J. A. AU - Austing, D. G. T2 - The Physics of Semiconductors: Proceedings of the 31st International Conference on the Physics of Semiconductors (ICPS) T2 - AIP Conference Proceedings; no. 1566 T3 - 31st International Conference on the Physics of Semiconductors (ICPS), July 29-Aug 3 2012, Zurich, Switzerland SN - 0094-243X SN - 9780735411944 SP - 237 EP - 238 KW - Quantum dots KW - Tunneling KW - Magnetic fields KW - Spectrum analysis KW - Magnetic hysteresis AB - We outline power spectra and auto correlation analysis performed on temporal oscillations in the tunneling current of coupled vertical quantum dots. The current is monitored for ∼2325 s blocks as the magnetic field is stepped through a high bias feature displaying hysteresis and switching: hallmarks of the hyperfine interaction. Quasi-periodic oscillations of ∼2 pA amplitude and of ∼100 s period are observed in the current inside the hysteretic feature. Compared to the baseline current outside the hysteretic feature the power spectral density is enhanced by up to three orders of magnitude and the auto correlation displays clear long lived oscillations about zero. DA - 2013 PY - 2013 PB - American Institute of Physics Inc. LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2ef53086-afc4-4779-8b1c-493c33985f85 ER - TY - JOUR TI - Plant Acyl-CoA:Lysophosphatidylcholine Acyltransferases (LPCATs) have different specificities in their forward and reverse reactions DO - 10.1074/jbc.M113.521815 AU - Lager, Ida AU - Lindberg Yilmaz, Jenny AU - Zhou, Xue-Rong AU - Jasieniecka, Katarzyna AU - Kazachkov, Michael AU - Wang, Peng AU - Zou, Jitao AU - Weselake, Randall AU - Smith, Mark A. AU - Bayon, Shen AU - Dyer, John M. AU - Shockey, Jay M. AU - Heinz, Ernst AU - Green, Allan AU - Banas, Antoni AU - Stymne, Sten T2 - Journal of Biological Chemistry SN - 0021-9258 SN - 1083-351X VL - 288 IS - 52 SP - 36902 EP - 36914 AB - Acyl-CoA:lysophosphatidylcholine acyltransferase (LPCAT) enzymes have central roles in acyl editing of phosphatidylcholine (PC). Plant LPCAT genes were expressed in yeast and characterized biochemically in microsomal preparations of the cells. Specificities for different acyl-CoAs were similar for seven LPCATs from five different species, including species accumulating hydroxylated acyl groups in their seed oil, with a preference for C18-unsaturated acyl-CoA and low activity with palmitoyl-CoA and ricinoleoyl (12-hydroxyoctadec-9-enoyl)-CoA. We showed that Arabidopsis LPCAT1 and LPCAT2 enzymes catalyzed the acylation and de-acylation of both sn positions of PC, with a preference for the sn-2 position. When acyl specificities of the Arabidopsis LPCATs were measured in the reverse reaction, sn-2-bound oleoyl, linoleoyl, and linolenoyl groups from PC were transferred to acyl-CoA to a similar extent. However, a ricinoleoyl group at the sn-2-position of PC was removed 4–6-fold faster than an oleoyl group in the reverse reaction, despite poor utilization in the forward reaction. The data presented, taken together with earlier published reports on in vivo lipid metabolism, support the hypothesis that plant LPCAT enzymes play an important role in regulating the acyl-CoA composition in plant cells by transferring polyunsaturated and hydroxy fatty acids produced on PC directly to the acyl-CoA pool for further metabolism or catabolism. DA - 2013/11/04 PY - 2013 PB - American Society for Biochemistry and Molecular Biology LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4673c77e-e816-4d49-adc9-511e33e07af1 ER - TY - JOUR TI - PLA melt crystallization and stereocomplex formation enhancement by means of nucleation and plasticization AU - Saeidlou, Sajjad AU - Huneault, Michel A. AU - Li, Hongbo AU - Park, Chul B. T2 - Annual Technical Conference - ANTEC, Conference Proceedings T3 - 71st Annual Technical Conference of the Society of Plastics Engineers, April 22-24 2013,Cincinnati, OH, USA SN - 9781632665300 VL - 3 SP - 2217 EP - 2219 AB - Effect of the two crystallization enhancement strategies, i.e. nucleation and plasticization, which are commonly used to promote polylactide (PLA) homocrystallization was investigated on the stereocomplex formation between poly(L-lactic acid) (PLLA) and poly(D-lactic acid) (PDLA). The goal was to enhance the kinetics and yield of stereocomplex formation from the melt for future applications in PLA melt processing. Blends with 5% PDLA with nucleating agent and/or plasticizer were prepared via melt-blending and characterized by differential scanning calorimetry (DSC) technique. Results suggest that combination of nucleation and plasticization is very effective in simultaneous enhancement of stereocomplex formation and homocrystallization. DA - 2013 PY - 2013 PB - Society of Plastics Engineers LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2b90c42e-22c3-43f6-8cd4-7116da663651 ER - TY - JOUR TI - Photouncaging of ceramides promotes reorganization of liquid-ordered domains in supported lipid bilayers DO - 10.1021/la3039158 AU - Carter Ramirez, Daniel M. AU - Pitre, Spencer P. AU - Kim, Young Ah AU - Bittman, Robert AU - Johnston, Linda J. T2 - Langmuir SN - 0743-7463 SN - 1520-5827 VL - 29 IS - 10 SP - 3380 EP - 3387 AB - 6-Bromo-7-hydroxycoumarin (Bhc)-caged ceramide (Cer) analogs were incorporated into supported lipid bilayers containing a mixture of coexisting liquid-ordered (L₀) and liquid-disordered (Ld) phases. The release of N-palmitoyl and N-butanoyl-d-erythro-sphingosine (C16- and C4-Cer) by the photolysis of caged Cers using long-wavelength UV light was studied using a combination of atomic force microscopy and fluorescence microscopy. This approach demonstrated the ability to generate Cer with spatial and temporal control, providing an alternative method to the enzymatic generation of Cer. The generation of C16-Cer from Bhc-C16-Cer disrupted the L₀ domains, with the incorporation of small fluid-phase regions and the disappearance of some smaller domains. Cer-rich gel-phase domains were not observed, in contrast to results reported by either direct Cer incorporation or enzymatic Cer generation. The photorelease of C4-Cer from Bhc-C4-Cer resulted in qualitatively similar changes in bilayer morphology, with the disappearance of some L₀ domains and no evidence of Cer-rich gel domains but with a smaller height difference between the ordered and disordered phases. DA - 2013/02/12 PY - 2013 PB - ACS Publications LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : efe4c16f-42cb-483f-9423-b9dd955d6a32 ER - TY - JOUR TI - Pentavalent single-domain antibodies reduce Campylobacter jejuni motility and colonization in chickens DO - 10.1371/journal.pone.0083928 AU - Riazi, Ali AU - Strong, Philippa C. R. AU - Coleman, Russell AU - Chen, Wangxue AU - Hirama, Tomoko AU - van Faassen, Henk AU - Henry, Matthew AU - Logan, Susan M. AU - Szymanski, Christine M. AU - MacKenzie, Roger AU - Ghahroudi, Mehdi Arbabi AU - Mantis, Nicholas J. T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 12 SP - e83928 SP - 1 EP - 12 AB - Campylobacter jejuni is the leading cause of bacterial foodborne illness in the world, with symptoms ranging from acute diarrhea to severe neurological disorders. Contaminated poultry meat is a major source of C. jejuni infection, and therefore, strategies to reduce this organism in poultry, are expected to reduce the incidence of Campylobacter-associated diseases. We have investigated whether oral administration of C. jejuni-specific single-domain antibodies would reduce bacterial colonization levels in chickens. Llama single-domain antibodies specific for C. jejuni were isolated from a phage display library generated from the heavy chain IgG variable domain repertoire of a llama immunized with C. jejuni flagella. Two flagella-specific single-domain antibodies were pentamerized to yield high avidity antibodies capable of multivalent binding to the target antigen. When administered orally to C. jejuni-infected two-day old chicks, the pentabodies significantly reduced C. jejuni colonization in the ceca. In vitro, the motility of the bacteria was also reduced in the presence of the flagella-specific pentabodies, suggesting the mechanism of action is through either direct interference with flagellar motility or antibody-mediated aggregation. Fluorescent microscopy and Western blot analyses revealed specific binding of the anti-flagella pentabodies to the C. jejuni flagellin. DA - 2013/12/31 PY - 2013 PB - PLOS LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c9f638d2-25f9-438f-b2d9-52b5cfa4d3a6 ER - TY - JOUR TI - Particle size effects on ice crystal accretion - part II DO - 10.2514/6.2013-2676 AU - Knezevici, Daniel C. AU - Fuleki, Dan AU - Currie, Thomas C. AU - Galeote, Brian AU - Chalmers, Jennifer AU - Macleod, James D. T2 - 5th AIAA Atmospheric and Space Environments Conference T3 - 5th AIAA Atmospheric and Space Environments Conference, June 24-27 2013, San Diego, CA, USA AB - This paper describes ongoing research intended to simulate ice accretion in an inter-compressor duct bleed slot resulting from the ingestion of altitude ice crystals. The authors have previously shown that ice crystal particle size plays an important role in the ice crystal accretion phenomenon. It was also shown that ice crystal particle size affects the degree of natural melt that occurs for a given aerodynamic condition. The data presented herein decouples the effects of ice particle melt and particle size distribution to generate accretions with the same ratio of freestream liquid-to-total water fraction. The effects of wet bulb temperature and ice particle size on the natural melting of ice crystals are discussed. An ice preservation procedure is followed to allow tracings of the accretion to be taken along the test article. Ice crystal particle size distribution is characterized using a shadowgraphy imaging technique. Finally, the reduction in accretion rate relative to the theoretical maximum rate of surface accretion by ice crystal particles is discussed. The test article simulates a forward facing, inclined endwall bleed slot in a gas turbine compressor as a simplified two-dimensional representation. The geometry, having a surface inclined 20° to the incoming flow, proved to be susceptible to mixed phase ice crystal accretion. Particle size and particularly the large particle tail of the distribution had a significant impact on the magnitude of accretion under mixed phase test conditions for wet bulb temperatures above and below 0°C. The leading edge growth rates were found to be 1/4 to 1/9 of the theoretical growth rate suggesting that erosion, splashing, particle bounce and other loss mechanism rates are significant. The ice tracings were used to estimate an accretion mass for a hypothetical large bypass ratio gas turbine. It was found that approximately 4kg of ice could be generated should the inter-compressor duct be exposed to the conditions tested for 5 minutes. DA - 2013/06/24 PY - 2013 PB - American Institute of Aeronautics and Astronautics CY - Reston, Virginia, USA LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ae7abae9-df63-40d8-a9e5-4e94f3cbbe10 ER - TY - JOUR TI - Oxygen transport parameters in Nafion(R) 117 under controlled relative humidity DO - 10.1149/05801.1097ecst AU - Novitski, D. AU - Xie, Z. AU - Holdcroft, S. T2 - ECS Transactions SN - 1938-6737 SN - 1938-5862 VL - 58 IS - 1 SP - 1097 EP - 1103 AB - Solid state electrochemical techniques have provided insight into the effect of relative humidity on oxygen mass transport properties in Nafion® 117. Specifically, subsequent potential step coulometric measurements taken over a period of time have shown that the act of measurement affects the catalyst-membrane interface. It is postulated that the formation of product water at the interface leads to interactions with the Nafion® 117 surface and results in local domain changes. This effect has been shown to be reversible provided there is adequate rest time between measurements to allow for water diffusion from the interface. DA - 2013/08/31 PY - 2013 PB - Electrochemical Society Inc. LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 92257e0d-ec93-469b-b126-2461b68e1b2f ER - TY - JOUR TI - Optimization of the cutting conditions for high speed drilling of woven composites DO - 10.1115/DETC2013-12992 AU - Meshreki, Mouhab AU - Hamza, Karim AU - Nassef, Ashraf O. AU - Attia, Helmi T2 - Volume 3A: 39th Design Automation Conference T3 - ASME 2013 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, August 4-7 2013, Portland, Oregon, USA SN - 978-0-7918-5588-1 SP - V03AT03A003 SP - 1 EP - 11 KW - Drilling KW - Optimization KW - Cutting KW - Woven composites AB - The present work proposes a new algorithm for the optimization of cutting parameters in the high speed drilling of woven composites. The cutting parameters under consideration are the feed rate and the spindle speed. Three performance parameters are to be minimized. These are the exit delamination, the surface roughness and the thrust force. These performance parameters are observed experimentally. One of the challenges that face the experimental testing of these parameters is the high cost of the drilling tools and specimen materials. Therefore, the minimization of the number of experimental tests is a necessary requirement. The algorithm presented hybridizes Kriging as a meta-modeling technique with evolutionary multi-objective optimization to optimize the cutting parameters while intelligently selecting the new set of cutting parameters in each iteration. After starting with a factorial design of the search space, and after testing the performance criteria at these points, the algorithm fits a multi-dimensional surface using Kriging. This step is followed by an evolutionary search on the fitted model. The search spreads a population of search points in the direction of better performance criteria as well as in the direction of un-sampled space. The previous two steps are conducted iteratively for a pre-defined number of iterations. In the final iteration, the population of search points is clustered to yield a small number of new points at which the new experiments will be conducted. The whole process is iterated until the maximum number of allowable experiments is achieved. The algorithm is tested using an existing set of previously published experimental data that are dense enough to predict the actual response surface of the performance criteria. Results showed that the algorithm smartly moved into the direction of higher performance criteria with a low number of experimental trials. DA - 2013/08/04 PY - 2013 PB - ASME LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 670c8724-3d14-42a3-90e1-8a4789b4d49d ER - TY - JOUR TI - Optimization of breakwater reconstruction at Mont Louis, Québec AU - Knox, Paul AU - Cornett, Andrew AU - Drouin, Alain T2 - Proceedings, Annual Conference - Canadian Society for Civil Engineering T3 - Annual Conference of the Canadian Society for Civil Engineering 2013: Know-How - Savoir-Faire, May 29-June 1 2013, Monteal, QC, Canada SN - 978-1-63439-897-8 VL - 1 IS - January SP - 139 EP - 150 AB - The Port of Mont Louis is located on the south shore of the Gulf of St. Lawrence, roughly 120 km west of Gaspé, Québec. A 450 m long breakwater was constructed on the east side of the bay in 1955 to form a sheltered harbour basin and to serve as a commercial wharf. Since this time, the structure has been exposed to numerous severe storms that have caused considerable damage, and today this important infrastructure asset is in urgent need of repair. In December 2006 the National Research Council of Canada (NRC) was commissioned by Public Works and Government Services Canada (PWGSC) to conduct numerical and physical model studies to guide the design of repair works for the wharf and surrounding breakwater. The proposed repair works were rather complex and nonconventional, as they involved constructing a new rubble-mound breakwater on top of the badly damaged structure. They also involved integrating a dynamically re-shaping (berm-style) armour layer design in some areas together with more conventional statically stable designs in others. Desktop and numerical modeling was performed to help define the nearshore wave conditions used as inputs for the physical modeling. A three-dimensional physical model was subsequently constructed and used to investigate the performance of the proposed repairs under a range of site-specific design conditions, including extreme water levels and harsh wave conditions. This paper summarizes the numerical and physical modelling studies and their important role in optimizing and verifying the breakwater reconstruction proposed for Mont Louis. The physical modelling allowed the proposed designs to be optimized to improve their hydraulic performance (stability), enhance their constructability, and reduce costs where possible. DA - 2013 PY - 2013 PB - Canadian Society for Civil Engineering LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ccf69208-6364-4066-93ab-ea2b7cbd4d98 ER - TY - JOUR TI - On-line monitoring and parameter estimation of a Microbial Fuel Cell operated with intermittent connection of the external resistor DO - 10.3182/20131216-3-IN-2044.00064 AU - Coronado, Javier AU - Tartakovsky, Boris AU - Perrier, Michel T2 - IFAC Proceedings Volumes T3 - 12th IFAC Symposium on Computer Applications in Biotechnology, December 16-18 2013, Mumbai, India SN - 1474-6670 VL - 46 IS - 31 SP - 233 EP - 237 KW - Microbial Fuel Cell KW - Real-time monitoring KW - Parameter estimation KW - Internal resistance AB - This study describes on-line monitoring and parameter estimation during Microbial Fuel Cell operation with a pulse-width modulated connection of the external resistor (R-PWM mode) at low and high frequencies. Analysis of the output voltage profiles acquired during R-PWM tests showed the presence of slow and fast dynamic components, which can be described by an equivalent circuit model suitable for process monitoring and control applications. To demonstrate the proposed monitoring and parameter estimation procedure, the MFC was operated at several influent concentrations of acetate (carbon source) and an on-line parameter estimation procedure was used for estimating internal resistance and internal capacitance. Furthermore, these parameters were re-estimated at the end of each test yielding similar results. The proposed on-line procedure can be used for real-time process optimization. DA - 2013 PY - 2013 PB - IFAC Secretariat LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 730da531-8c5e-4847-8479-10cb377cb96d ER - TY - JOUR TI - On the rheocasting of high integrity hollow shape components for automotive applications using 357 aluminum alloy DO - 10.4028/www.scientific.net/SSP.192-193.539 AU - Samuel, Ehab AU - Zheng, Chang Qing AU - Côté, Pascal T2 - Solid State Phenomena T3 - 12th International Conference on Semi-Solid Processing of Alloys and Composites, October 8-11 2012, Cape Town, South Africa SN - 1662-9779 VL - 192-193 SP - 539 EP - 544 KW - 357 aluminum alloy KW - Hollow shape KW - Rheocasting KW - SEED KW - Semi-solid AB - Recent studies regarding semi-solid casting as a viable alternative to conventional liquid metal casting have been met with considerable interest. The dual nature of semi-solid materials results in a marked decrease in internal defects otherwise associated with conventional casting methods. In recent years, the National Research Council Canada - Aluminum Technology Centre (NRC-ATC) has dedicated itself to better understanding the behaviour of semi-solid aluminum alloys, notably 357, using the SEED (Swirled Enthalpy Equilibration Device) rheocasting method. SEED is a novel process which relies on the mechanical agitation and cooling of molten aluminum to produce a semi-solid billet. This billet is then injected into a die to yield the desired cast shape. The current work focuses on the rheocasting of a 357 aluminum alloy support bracket, consisting of four rings. Material flow around a ring is known to result in a welding of the two metal fronts. Traces of porosity and oxides can sometimes be found at the weld, unless preventative measures are taken. These include the use of overflows attached to the ring via a web as well as a careful control of the casting parameters. At NRC-ATC, several parts were rheocast and then subjected to both destructive and non-destructive testing, in an effort to better understand the material flow behaviour around these rings. The results obtained are presented herein. DA - 2013 PY - 2013 PB - Trans Tech Publications Ltd. LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f3294238-cfa5-4de9-bfd1-55aa8fd972bb ER - TY - JOUR TI - Numerical simulation of flow, temperature and composition variation in the snout and sink roll region of continuous galvanizing baths AU - Ajersch, F. AU - Ilinca, F. AU - Goodwin, F. E. T2 - Materials Science and Technology Conference and Exhibition 2013, MS & T 2013 T3 - Materials Science and Technology Conference and Exhibition 2013, October 27-31 2013, Montreal, QC, Canada SN - 9781629933092 VL - 2 SP - 1145 EP - 1152 KW - Continuous galvanizing KW - Dross minimization KW - Numerical simulation KW - Snout pumping AB - The snout and sink roll regions of a continuous galvanizing operation are of critical importance in achieving automotive quality coated steel products. Entrainment of dross particles into the deposited coating originating in the regions of the snout and at the pinch between the strip and the sink roll contribute to the difficulty of maintaining a defect free surface. Previous numerical models have described the flow,temperature and compositional variations in these regions in a conventional operation. In order to optimize the coating quality new numerical simulations were carried out by introducing a pumping system which can direct flow to these specific areas. The effect of circulating bath composition liquid zinc using an industrially tested pumping system directed to the inside surface of the strip within the snout and into the pinch area were analysed. Velocity, temperature and compositional gradients were calculated and compared to the standard configuration not using pumps. The results indicated that the quality of the coated steel can be improved using this system. DA - 2013 PY - 2013 PB - Association for Iron & Steel Technology LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 7b901217-265a-41cc-acd5-326f13711243 ER - TY - JOUR TI - Novel K-band prime focus reflector-coupled focal plane array AU - Locke, Lisa S. AU - Bornemann, Jens AU - Claude, Stéphane T2 - European Microwave Conference T3 - 43rd European Microwave Conference, October 7-10 2013, Nuremberg, Germany SN - 9782874870316 SP - 211 EP - 214 KW - Antipodal Vivaldi antenna KW - Focal plane array KW - K-band KW - Mutual coupling KW - Prime focus reflector KW - Wideband AB - A wideband focal plane array (FPA) covering the full K-band (18 - 26.5 GHz) is proposed for use in passive imaging and microwave astronomy. Focal plane arrays are revolutionizing microwave and millimeter-wave imaging by replacing conventional single-pixel feed horns with arrays of planar elements, decreasing the survey time dramatically. The extent and element spacing of a rectangular array is determined by comparing classic and encircled power techniques. A prime focus reflector-feed configuration is considered with f/D=0.45. Far-field performances of arrays of simple Gaussian feeds and also imported Vivaldi feeds, which include mutual coupling between elements, are evaluated by PO/PTD techniques. DA - 2013/10 PY - 2013 PB - IEEE LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a284c1d7-7ad3-40af-a9a9-a180bcbc58e6 ER - TY - JOUR TI - Neutral assessment of the National Research Council Canada evaluation function AU - Fraser, Melissa A. AU - Tremblay, Ghislaine H. AU - Bourgeois, Isabelle AU - Lahey, Robert T2 - Canadian Journal of Program Evaluation SN - 0834-1516 VL - 28 IS - 2 SP - 85 EP - 96 AB - Federal government departments and agencies are required to conduct a neutral assessment of their evaluation function once every five years under the Treasury Board Secretariat’s Policy on Evaluation (2009). This article describes the National Research Council’s experience conducting the first neutral assessment of its evaluation function. Based on learning from this first assessment, best practices that NRC intends on replicating, as well as lessons learned for future assessments, are discussed. This article may be of interest to both federal and non-federal organizations seeking to conduct a neutral assessment in an effort to improve their evaluation services and products. AB - Les ministères et les agences du gouvernement fédéral doivent effectuer un examen neutre de leur fonction d’évaluation une fois à tous les cinq ans selon la politique du Secrétariat du Conseil du Trésor sur l’évaluation (2009). Cet article décrit l’expérience du Conseil national de recherches du Canada dans le cadre de la réalisation du premier examen neutre de sa fonction d’évaluation. À partir des apprentissages découlant du premier examen, les bonnes pratiques ainsi que les leçons apprises que le CNRC entend répliquer dans des exercices futures sont discutées. Cet article pourrait s’avérer d’intérêt pour les organisations fédé-rales et non-fédérales cherchant à mener un examen neutre dans le but d’améliorer leurs services et produits d’évaluation. DA - 2013 PY - 2013 PB - Canadian Evaluation Society LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : cc06df75-9593-4223-8935-526c22867a8f ER - TY - JOUR TI - Near-infrared photoluminescence of orange color standards – then and now DO - 10.1080/09500340.2013.818171 AU - Zwinkels, Joanne C. AU - Noël, Mario AU - Hillman, Sean T2 - Journal of Modern Optics SN - 0950-0340 SN - 1362-3044 VL - 60 IS - 14 SP - 1115 EP - 1123 KW - Ceramic color standard KW - Colorimetry KW - NIR KW - Photoluminescence KW - Spectrophotometry AB - The presence of near-infrared (NIR) photoluminescence has been recently reported in some of the second series of Ceramic Color Standards (CCSII) that are widely used in the calibration and performance evaluation of color measuring instruments. The impact of this photoluminescence effect can cause significant colorimetric errors particularly for broadband measurements using a detector with high spectral responsivity in the NIR region. The magnitude of this effect has been demonstrated for specific color standards and specific instrument systems but has not been unambiguously quantified to allow general predictions or absolute comparisons of different instrument designs or different ceramic tiles. Here we present absolute NIR photoluminescence measurements on three different formulations of the CCSII orange ceramic color standard using the National Research Council of Canada (NRC) Reference Spectrofluorimeter whose spectral range has been recently extended to 1000 nm. The validation for this extended spectral range is shown by comparison of an independent method of instrument calibration using a different combination of physical standards. It is convincingly shown that the two different leaded formulations of this ceramic orange standard issued in 2000 and 2011 have no significant photoluminescence and thus can be used for calibration with any type of spectrophotometer design whereas the unleaded formulation issued in 2011 has significant NIR photoluminescence and should not be used for instrument calibration and validation over an extended range into the NIR for certain spectrophotometers with relatively high throughput in the NIR region, such as a spectrophotometer with polychromatic illumination mode using a xenon source or with monochromatic illumination mode using a Si detector. It is shown that for colorimetric applications, the impact of this NIR fluorescence is only significant for the latter spectrophotometer design with broadband detection with a Si or spectrally flat detector and is negligible with a narrowband PMT detector. These calculated colorimetric results are also consistent with previously estimated colorimetric errors for this type of orange CCSII ceramic tile used to transfer calibration between these two types of detector systems. DA - 2013/08/08 PY - 2013 PB - Taylor & Francis Group LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1b46ba2d-899b-4952-af18-697fd8b5e123 ER - TY - CHAP TI - Multiscale molecular modeling of degradation phenomena in catalyst layers of polymer electrolyte fuel cells DO - 10.1201/b15259-12 AU - Malek, Kourosh AU - Mashio, Tetsuya T2 - Polymer Electrolyte Fuel Cells SN - 978-981-4310-82-6 SN - 978-981-4364-40-9 SP - 511 EP - 547 DA - 2013/07/09 PY - 2013 PB - Pan Stanford Publishing Pte. Ltd. LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2b8035d9-e02a-4d2e-bcd5-2be4b7178c02 ER - TY - JOUR TI - Multi-leg structures in ice - examining global loading uncertainties AU - Barker, A. AU - Sayed, M. T2 - 22nd International Conference on Port and Ocean Engineering under Arctic Conditions (POAC 2013) T3 - 22nd International Conference on Port and Ocean Engineering under Arctic Conditions, June 9-13, Espoo, Finland VL - 1 SP - 512 EP - 524 AB - The ISO 19906 Arctic Offshore Standard (2010) represents a great advancement for standards as they pertain to Arctic engineering. However, uncertainties remain for a number of topic areas, including global loading on multi-leg structures in ice. These uncertainties include the effects of sheltering, the width of damaged ice and the effect of jamming. Additional uncertainties pertain to the effects of ridge loading and various ice properties. This paper numerically examines some of these uncertainties, through a parametric study approach. The results present the ice forces on a representative structure, as well as broken ice zone widths. The results show that peak loads are associated with ice drift at an angle, as observed in other laboratory and numerical simulations. In addition, loads increase with decreasing clearance between the legs. The results have applications not only for multi-leg oil and gas structures in ice-covered water, but could be further examined in the context of bridge piers and offshore fields of wind turbine towers. DA - 2013 PY - 2013 PB - Lulea University of Technology LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e987d29a-ee8d-4e7e-871d-feccee175158 ER - TY - JOUR TI - mPUMA: a computational approach to microbiota analysis by de novo assembly of operational taxonomic units based on protein-coding barcode sequences DO - 10.1186/2049-2618-1-23 AU - Links, Matthew G AU - Chaban, Bonnie AU - Hemmingsen, Sean M. AU - Muirhead, Kevin AU - Hill, Janet E. T2 - Microbiome SN - 2049-2618 VL - 1 IS - 1 SP - 23 SP - 1 EP - 7 KW - Operational taxonomic unit KW - Automated sequence analysis pipeline KW - 60 kDa chaperonin KW - Cpn 60 KW - Microbial profiling KW - Microbiota KW - Microbiota analysis AB - BACKGROUND: Formation of operational taxonomic units (OTU) is a common approach to data aggregation in microbial ecology studies based on amplification and sequencing of individual gene targets. The de novo assembly of OTU sequences has been recently demonstrated as an alternative to widely used clustering methods, providing robust information from experimental data alone, without any reliance on an external reference database. RESULTS: Here we introduce mPUMA (microbial Profiling Using Metagenomic Assembly, http://mpuma.sourceforge.net), a software package for identification and analysis of protein-coding barcode sequence data. It was developed originally for Cpn 60 universal target sequences (also known as Gro EL or Hsp 60). Using an unattended process that is independent of external reference sequences, mPUMA forms OTUs by DNA sequence assembly and is capable of tracking OTU abundance. mPUMA processes microbial profiles both in terms of the direct DNA sequence as well as in the translated amino acid sequence for protein coding barcodes. By forming OTUs and calculating abundance through an assembly approach, mPUMA is capable of generating inputs for several popular microbiota analysis tools. Using SFF data from sequencing of a synthetic community of Cpn 60 sequences derived from the human vaginal microbiome, we demonstrate that mPUMA can faithfully reconstruct all expected OTU sequences and produce compositional profiles consistent with actual community structure. CONCLUSIONS: mPUMA enables analysis of microbial communities while empowering the discovery of novel organisms through OTU assembly. DA - 2013/08/15 PY - 2013 PB - BioMed Central LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 955b5ec2-0dcb-40d9-bd9c-f420ff33cf75 ER - TY - JOUR TI - Modelling coastal processes at Shippagan Gully inlet, New Brunswick, Canada AU - Cornett, A. AU - Provan, M. AU - Nistor, I AU - Drouin, A. T2 - Annual Conference of the Canadian Society for Civil Engineering 2013: Know-How - Savoir-Faire T3 - Annual Conference of the Canadian Society for Civil Engineering 2013: Know-How - Savoir-Faire, May 29-June 1 2013, Montreal, QC, Canada SN - 9781634398978 VL - 1 IS - January SP - 128 EP - 138 AB - This paper describes the development, calibration and application of a numerical model of the hydrodynamic and sedimentary processes at a dynamic tidal inlet known as Shippagan Gully, located on the Gulf of St-Lawrence near Le Goulet, New Brunswick. The new model has been developed to provide guidance concerning the response of the inlet mouth to various potential interventions aimed at increasing navigation safety. The new model is based on coupling the most recent CMS-Flow and CMSWave models developed by the US Army Corps of Engineers. The coupled model is capable of simulating the depth-averaged currents generated within Shippagan Gully and along the neighbouring coastline due to the effects of tides, winds and waves; the transport of non-cohesive sediments; and the resulting changes in seabed morphology. The development of the model and the steps taken to calibrate and validate it against field measurements are described. The application of the model to predict the coastal processes and the response of the inlet mouth to several storms is described and discussed. The influences of storm direction and storm surge on coastal processes is presented and discussed. The research described herein will contribute to an improved understanding of the hydrodynamics and sedimentary processes at strongly ebb-dominated tidal inlets in general and Shippagan Gully in particular. DA - 2013 PY - 2013 PB - Canadian Society for Civil Engineering LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e516569e-e2dd-4ee4-a6e7-13fc84e4c4db ER - TY - JOUR TI - Mixed gas sorption of CO2/CH4 mixtures in PIM-1 and PTMSP membranes: experiments and modeling AU - Vopicka, O. AU - De Angelis, M. G. AU - Sarti, G. C. AU - Guiver, M. D. T2 - Separations Division 2013 T3 - Separations Division 2013 - Core Programming Area at the 2013 AIChE Annual Meeting: Global Challenges for Engineering a Sustainable Future, November 3-8 2013, San Francisco, CA, USA SN - 9781634390545 SP - 647 EP - 648 AB - Sorption of pure methane, carbon dioxide and their binary mixtures in two glassy polymers, poly(1-trimethylsilyl-1-propyne) (PTMSP), and the first polymer of intrinsic microporosity (PIM-1), has been studied experimentally and theoretically, at 35.0 ºC. Measurements were obtained on a newly designed pressure decay sorption apparatus for mixtures of gases, having the basic construction according to Sanders et al. [1], but with a more versatile procedure than that used in [1], which allowed to measure sorption isotherms at constant partial pressure of one component of the gas mixture. Indeed this novel method allows one to measure sorption isotherms i) at constant composition of the gaseous phase, ii) at constant fugacity of one component or iii) at constant equilibrium pressure. The first protocol, in particular, allows to mimic better the real constraints faced when dealing with a membrane separation process, where one has a gas stream of fixed composition, in which only the total pressure can be varied, by compression. The pressure decay apparatus is coupled to a gas chromatograph Varian CP-4900 Micro-GC equipped with a capillary column and with a thermal conductivity detector for analysis of the gas phase composition. In the case of PTMSP, the mixture n-C4/CH4 was initially considered, to provide a direct comparison with literature data [2] and validation of the method. Indeed, the sorption of n-C4/CH4mixtures showed a reasonable agreement with the existing mixed gas sorption data [2]. On the other hand, the CO2/CH4mixed sorption data in PTMSP are completely new, and were measured in the range from 0 to 33 atm of total equilibrium pressure, and from 5 to 90 mol.% of carbon dioxide in the gaseous phase. Furthermore, the same characterization of CO2/CH4 mixed sorption was performed in PIM-1: the pressure range inspected was the same as in PTMSP, while the composition of CO2 ranged from 10 to 50 mol.%. PTMSP membrane was cast from a solution of toluene, immersed in methanol and then dried under vacuum before characterization; its density was 0.77±0.01 g/cm3. The PIM-1 membrane was prepared from a filtered ca. 2.0 wt.% chloroform solution of PIM-1 and heated in vacuum at 70 °C, then submerged in methanol and dried under vacuum at 70 °C. The density of pure PIM-1 was (1.143±0.008) g/cm3at 25°C. For both PTMSP and PIM-1, the mixed gas solubility differs significantly from the pure gas value, and, in particular, the solubility of both components is depressed by the presence of the second one, as it often happens in glassy polymers.[3] The solubility selectivity ranges between 2 and 6 for PTMSP and between 5 and 10 for PIM-1. The methane solubility, however, is more significantly depressed by CO2 than that of CO2 is decreased by CH4, therefore the real solubility selectivity (CO2/CH4) for PTMSP and PIM-1 is higher than the ideal solubility selectivity. Such effect becomes more significant with increasing the mole fraction of CO2 in the gaseous phase and with pressure, and is more significant for PIM-1 than for PTMSP. Indeed, the real solubility selectivity becomes 3 times higher than the ideal one in PTMSP for a fraction of 70 mol.% of CO2 in the gas phase, while for PIM-1 such point is reached with a lower concentration of CO2(50 mol.%). Both results indicate the presence of a competition for available polymer matrix sites, which is not surprising due to the nature of physical sorption in glassy matrices, and possibly also of different interactions between polymer and penetrants. To investigate that behavior, the Non-Equilibrium Lattice Fluid model (NELF) was used [3], while the widely used Dual Mode Sorption (DMS) model was also considered as a reference tool. The NELF model, as well as the DMS, does not require additional parameters for the prediction of the mixed gas behavior, and is fully predictive provided a few pure gas sorption data in the polymer matrix. Indeed, binary interaction parameters are the same as in the pure gas case, and the swelling induced by the mixture is estimated from pure gas swelling. Remarkably, in the DMS model, only competition (depression) effects are accounted for, because the mixed gas additional term (positive) appears only in the denominator of the expression for solubility. The NELF model provided quantitative predictions of the mixed gas sorption of CO2 and CH4under pure- and mixed-gas conditions in PTMSP and in PIM-1. The solubility selectivity is also predicted, although with less accuracy, by the NELF model. The DMS model works fairly well in the case of PTMSP, but provides poorer predictions than the NELF model of the mixed gas solubility in PIM-1. Sorption of mixtures of CO2 and CH4 in PTMSP and in PIM-1 was predictable with the NELF model with an accuracy that is comparable to the experimental one, which could reduce the need for the laborious measurements of mixed gas sorption in polymers. Better insights and interpretation of the mixed gas sorption mechanism can also be obtained by using the NELF model. DA - 2013/11 PY - 2013 PB - American Institute of Chemical Engineers LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4d4c4331-c55f-4f9e-8816-60caccb2a8cc ER - TY - JOUR TI - Microstructure and hardness properties of a diffusion brazed powder metallurgy beta gamma alloy using a TiNi eutectic braze foil AU - Sawatzky, Trevor AU - Seo, Dongyi AU - Hong, Jae-Keun AU - Saari, Henry T2 - Materials Science & Technology Conference and Exhibition 2013 (MS&T'13) T3 - Materials Science and Technology Conference and Exhibition, October 27-31 2013, Montreal, QC, Canada SN - 9781629933092 VL - 1 SP - 104 EP - 115 KW - Diffusion brazing KW - Microhardness KW - Microstructure KW - Titanium aluminide AB - A TiNi eutectic braze alloy in foil form is utilized to diffusion braze a powder metallurgy beta gamma alloy with a nominal composition of TiAl-4Nb-3Mn (at%). The parent material is consolidated by a two-step hot isostatic pressing process, followed by a step-cooled solution heat treatment to produce a fully lamellar microstructure with fine lamellae and limited beta phase growth at the colony boundaries. Diffusion brazing experiments are conducted under vacuum at various isothermal holding temperatures and times ranging from 1030C for 30 minutes to 1150C for 70 minutes. The typical microstructures and mechanical properties of the joints are characterized by SEM, EDS, and microhardness measurements. The interfacial morphology of the brazed joints changes primarily with isothermal holding temperature. Microhardness levels reduced with diffusion brazing at 1150 C for 70 minutes due to reduced volume fraction of nickel rich phases and increased volume fraction of the gamma phase at the centerline of the joint. DA - 2013/10 PY - 2013 PB - Association for Iron & Steel Technology LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c7b1f830-72a6-4d34-a0c8-558e2729c36e ER - TY - JOUR TI - Microfluidic lab on-a-chip devices for high throughput rare cell sorting AU - Fatanat-Didar, T. AU - Li, K. AU - Veres, T. AU - Tabrizian, M. T2 - European Cells and Materials T3 - 4th International Symposium on Surfaces and Interfaces for Biomaterials, September 24-28 2013, Rome, Italy SN - 1473-2262 VL - 26 IS - SUPPL 6 DA - 2013 PY - 2013 PB - AO Foundation LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9cb1033f-92ad-45f5-99aa-e41f37ba3d54 ER - TY - JOUR TI - Microbial competition in polar soils: a review of an understudied but potentially important control on productivity DO - 10.3390/biology2020533 AU - Bell, Terrence AU - Callender, Katrina AU - Whyte, Lyle AU - Greer, Charles T2 - Biology SN - 2079-7737 VL - 2 IS - 2 SP - 533 EP - 554 KW - Competition KW - Arctic KW - Antarctic KW - Bacteria KW - Fungi KW - Biogeochemistry KW - Biodegradation KW - Soil KW - Microbial communities AB - Intermicrobial competition is known to occur in many natural environments, and can result from direct conflict between organisms, or from differential rates of growth, colonization, and/or nutrient acquisition. It has been difficult to extensively examine intermicrobial competition in situ, but these interactions may play an important role in the regulation of the many biogeochemical processes that are tied to microbial communities in polar soils. A greater understanding of how competition influences productivity will improve projections of gas and nutrient flux as the poles warm, may provide biotechnological opportunities for increasing the degradation of contaminants in polar soil, and will help to predict changes in communities of higher organisms, such as plants. DA - 2013/03/27 PY - 2013 PB - MDPI LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 664fc12d-8973-46b4-a36c-38312d3df9b0 ER - TY - JOUR TI - Metabolomic analysis of cold acclimation of Arctic Mesorhizobium sp. strain N₃₃ DO - 10.1371/journal.pone.0084801 AU - Ghobakhlou, Abdollah AU - Laberge, Serge AU - Antoun, Hani AU - Wishart, David S. AU - Xia, Jianguo AU - Krishnamurthy, Ramanarayan AU - Mandal, Rupasri T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 12 SP - e84801 SP - 1 EP - 15 KW - Fatty acids KW - Metabolites KW - Cell metabolism KW - Gas chromotography KW - Glycolipids KW - Phospholipids KW - Lipids KW - Neutral lipids AB - Arctic Mesorhizobium sp. N₃₃ isolated from nodules of Oxytropis arctobia in Canada’s eastern Arctic has a growth temperature range from 0°C to 30°C and is a well-known cold-adapted rhizobia. The key molecular mechanisms underlying cold adaptation in Arctic rhizobia remains totally unknown. Since the concentration and contents of metabolites are closely related to stress adaptation, we applied GC-MS and NMR to identify and quantify fatty acids and water soluble compounds possibly related to low temperature acclimation in strain N33. Bacterial cells were grown at three different growing temperatures (4°C, 10°C and 21°C). Cells from 21°C were also cold-exposed to 4°C for different times (2, 4, 8, 60 and 240 minutes). We identified that poly-unsaturated linoleic acids 18∶2 (9, 12) & 18∶2 (6, 9) were more abundant in cells growing at 4 or 10°C, than in cells cultivated at 21°C. The mono-unsaturated phospho/neutral fatty acids myristoleic acid 14∶1(11) were the most significantly overexpressed (45-fold) after 1hour of exposure to 4°C. As reported in the literature, these fatty acids play important roles in cold adaptability by supplying cell membrane fluidity, and by providing energy to cells. Analysis of water-soluble compounds revealed that isobutyrate, sarcosine, threonine and valine were more accumulated during exposure to 4°C. These metabolites might play a role in conferring cold acclimation to strain N₃₃ at 4°C, probably by acting as cryoprotectants. Isobutyrate was highly upregulated (19.4-fold) during growth at 4°C, thus suggesting that this compound is a precursor for the cold-regulated fatty acids modification to low temperature adaptation. DA - 2013/12/30 PY - 2013 PB - PLOS LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 49795730-847e-4362-8355-82639b942be8 ER - TY - JOUR TI - Measurement of energy and timing resolution of very highly pixellated LYSO crystal blocks with multiplexed SiPM readout for use in a small animal PET/MR insert DO - 10.1109/NSSMIC.2013.6829134 AU - Thompson, Christopher J. AU - Goertzen, Andrew L. AU - Kozlowski, Poitr AU - Retière, Fabrice AU - Stortz, Greg AU - Sossi, Vesna AU - Zhang, Xuezhu T2 - 2013 IEEE Nuclear Science Symposium and Medical Imaging Conference (2013 NSS/MIC) T3 - 2013 IEEE Nuclear Science Symposium and Medical Imaging Conference, October 27-November 2 2013, Seoul, Korea (South) SN - 1082-3654 SN - 978-1-4799-0534-8 SN - 978-1-4799-0533-1 SN - 978-1-4799-3423-2 SP - 1 EP - 5 KW - PET KW - Silicon photo-multiplier KW - Small Animal PET insert for MRI scanner AB - Arrays of silicon photo-multipliers (SiPMs) are good candidates for the readout of detectors in PET MR inserts due to their high packing density, efficiency, low bias voltage and insensitivity to magnetic fields. In this study we report the readout performance of SensL SiPM arrays in terms of their ability to resolve all elements of pixellated lutetium oxy-orthosilicate (LYSO) crystals, and their energy and timing resolution. A SensL SB4-300-35-CER SiPM array consisting of sixteen 3 × 3 mm elements were used as light sensor. An LYSO crystal block consisting of 10×10 1.2 mm × 1.2 mm × 6.0 mm crystals on the bottom layer and 9×9 1.2 mm × 1.2 mm × 4.0 mm crystals on the top layer (which is offset by ½ the crystal width) was mounted on the SensL array, and covers over 95% of its area. A DPC encoding multiplexor with HDMI cable readout made by the Triumf Instrumentation group with a footprint suitable for allowing 16 modules to form a ring inside a Brooker 7T MR rodent imager was used as a readout. The HDMI cable supplies power, and provides readout of four channels and the device temperature. The average energy resolution for all 100 crystals in the lower layer was 11.3±1.8% and 10.8±1.2% for the 81 crystals in the upper layer. The average timing resolution for all 100 crystals in the lower layer was 2.52±0.23 nsec. and 2.55±0.23 nsec. for the 81 crystals in the upper layer. DA - 2013/10 PY - 2013 PB - IEEE LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 840c9a46-52ce-4e86-8692-c229398595ad ER - TY - JOUR TI - Marine renewable energy and the plight of dreamers and schemers AU - Winsor, Fraser AU - Healy, Mark AU - Polagye, Brian T2 - Journal of Ocean Technology SN - 1718-3200 VL - 8 IS - 1 SP - 39 EP - 48 AB - The article focuses on the efforts of start up investors and companies to enhance their investments in the marine renewable energy (MRE) industry. It states that the framework of the government in the industry should be flexible to help MRE companies lessen financial and technical risks. According to the author, it is also essential that startups have sufficient engineering and science resources to address financial risks. DA - 2013/01 PY - 2013 PB - Fisheries and Marine Institute of Memorial University of Newfoundland LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 53ac91c5-77a3-4367-8004-8115e69da621 ER - TY - CHAP TI - Magnetism and spintronics in graphene AU - Dharma-Wardana, M. W. C. T2 - Spintronics in Nanoscale Devices SN - 9789814411691 SN - 9789814411707 SP - 181 EP - 198 DA - 2013/07/13 PY - 2013 PB - Pan Stanford Publishing LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 63df77d4-809f-4603-9d96-d000d14cfa9f ER - TY - JOUR TI - Lipopolysaccharide structure of Helicobacter pylori serogroup O:3 DO - 10.1016/j.carres.2013.03.008 AU - Altman, Eleonora AU - Chandan, Vandana AU - Li, Jianjun AU - Vinogradov, Evgeny T2 - Carbohydrate Research SN - 0008-6215 VL - 378 SP - 139 EP - 143 KW - Helicobacter pylori KW - LPS KW - Structure KW - NMR KW - MS AB - In this study, we describe a re-investigation of the lipopolysaccharide structure of Helicobacter pylori serogroup O:3. Application of NMR and MS approaches to the analysis of oligosaccharides obtained through degradation of LPS from H. pylori serogroup O:3 by various methods confirmed that its general architecture was identical to that of LPS from H. pylori strains 26695 and SS1 and followed a sequential linear assembly of the α-1,6-glucan, dd-heptan, and O-chain components. Additionally, MALDI-MS analysis demonstrated that a significant proportion of H. pylori serogroup O:3 LPS was terminated with α-1,6-glucan and was not further substituted by dd-heptan and the O-chain polysaccharide. DA - 2013/03/16 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1d9d8173-a6e0-4886-a6c5-88d24cb99837 ER - TY - JOUR TI - Internal conversion vs. intersystem crossing – what drives the dynamics of cyclic α,β-enones? DO - 10.1051/epjconf/20134105029 AU - Schalk, O. AU - Lang, P. AU - Schuurman, M. S. AU - Wu, G. AU - Bradler, M. AU - Riedle, E. AU - Stolow, A. AU - Chergui, M. T2 - EPJ Web of Conferences T3 - 18th International Conference on Ultrafast Phenomena, July 8-13 2012,Lausanne, Switzerland SN - 2100-014X VL - 41 SP - 05029 SP - 1 EP - 3 AB - The origin of ultrafast intersystem crossing and its competitiveness with singlet pathways was studied in cyclic α,β-enones by transient absorption, time-resolved photoelectron spectroscopy and ab initio calculations. DA - 2013/03/13 PY - 2013 PB - EDP Sciences LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3582b214-bde9-4385-ab1f-49aa67c93453 ER - TY - JOUR TI - Insertion profiles of 4 headless compression screws DO - 10.1016/j.jhsa.2013.04.027 AU - Hart, Adam AU - Harvey, Edward J. AU - Lefebvre, Louis-Philippe AU - Barthelat, Francois AU - Rabiei, Reza AU - Martineau, Paul A. T2 - The Journal of Hand Surgery SN - 0363-5023 VL - 38 IS - 9 SP - 1728 EP - 1734 KW - Headless compression screw KW - Insertion depth KW - Insertion torque KW - Interfragmentary compression KW - Scaphoid fracture AB - PURPOSE: In practice, the surgeon must rely on screw position (insertion depth) and tactile feedback from the screwdriver (insertion torque) to gauge compression. In this study, we identified the relationship between interfragmentary compression and these 2 factors. METHODS: The Acutrak Standard, Acutrak Mini, Synthes 3.0, and Herbert-Whipple implants were tested using a polyurethane foam scaphoid model. A specialized testing jig simultaneously measured compression force, insertion torque, and insertion depth at half-screw-turn intervals until failure occurred. RESULTS: The peak compression occurs at an insertion depth of −3.1 mm, −2.8 mm, 0.9 mm, and 1.5 mm for the Acutrak Mini, Acutrak Standard, Herbert-Whipple, and Synthes screws respectively (insertion depth is positive when the screw is proud above the bone and negative when buried). The compression and insertion torque at a depth of −2 mm were found to be 113 ± 18 N and 0.348 ± 0.052 Nm for the Acutrak Standard, 104 ± 15 N and 0.175 ± 0.008 Nm for the Acutrak Mini, 78 ± 9 N and 0.245 ± 0.006 Nm for the Herbert-Whipple, and 67 ± 2N, 0.233 ± 0.010 Nm for the Synthes headless compression screws. CONCLUSIONS: All 4 screws generated a sizable amount of compression (> 60 N) over a wide range of insertion depths. The compression at the commonly recommended insertion depth of −2 mm was not significantly different between screws; thus, implant selection should not be based on compression profile alone. Conically shaped screws (Acutrak) generated their peak compression when they were fully buried in the foam whereas the shanked screws (Synthes and Herbert-Whipple) reached peak compression before they were fully inserted. Because insertion torque correlated poorly with compression, surgeons should avoid using tactile judgment of torque as a proxy for compression. CLINICAL RELEVANCE: Knowledge of the insertion profile may improve our understanding of the implants, provide a better basis for comparing screws, and enable the surgeon to optimize compression. DA - 2013/06/25 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 68a6a5be-a5a5-454a-b39f-56c5a711debd ER - TY - JOUR TI - Infrared spectra of the NeC₂D₄ and ArC₂D₄ complexes DO - 10.1016/j.jms.2013.05.013 AU - Rezaei, M. AU - Michaelian, K. H. AU - Mckellar, A. R. W. AU - Moazzen-Ahmadi, N. T2 - Journal of Molecular Spectroscopy SN - 0022-2852 VL - 289 SP - 21 EP - 25 KW - Ethylene KW - Argon KW - Neon KW - Infrared spectrum KW - Dimer KW - van der Waals KW - Supersonic jet AB - Spectra of Ne─C₂D₄ and Ar─C₂D₄ are studied in the ν11 fundamental band region of C₂D₄ (≈2200 cm⁻¹) using a tuneable quantum cascade laser to probe a pulsed supersonic slit jet expansion. The spectra are those of perpendicular bands of near-prolate asymmetric rotors, but with a doubling of transitions due to tunneling. These tunneling splittings are due to hindered internal rotation of C₂D₄ around its C─C axis, and are more prominent for Ne─C₂D₄ than for Ar─C₂D₄. The analysis yields the first direct measurement of the A rotational constants for these complexes, and shows that the vibrational shifts are very small (<0.3 cm⁻¹). Attempts to observe the spectrum of He─C₂D₄ were not successful. DA - 2013/06/07 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4c4013d8-bc29-4e8b-bc55-fddbbcfd7964 ER - TY - JOUR TI - Impact sound insulation of hybrid wood-concrete masonry assemblies AU - Zeitler, Berndt AU - Schoenwald, Stefan AU - Sabourin, Ivan T2 - 42nd International Congress and Exposition on Noise Control Engineering 2013, INTER-NOISE 2013: Noise Control for Quality of Life T3 - 42nd International Congress and Exposition on Noise Control Engineering 2013: Noise Control for Quality of Life, September 15-18 2013, Innsbruck, Austria SN - 9781632662675 VL - 2 SP - 1586 EP - 1595 AB - As part of a research project to develop design solutions for concrete-masonry buildings for the Canadian market, a study was conducted on the impact and airborne flanking sound insulation performance of hybrid assemblies with concrete masonry walls and wood joist floors. The effect of junction coupling is investigated in an ISO 15712 flanking prediction context. In the paper, predicted flanking path data will be compared to measured data. Recommendations will be made on how appropriate the application of ISO 15712 is on this type of hybrid assembly. DA - 2013 PY - 2013 PB - OAL-Osterreichischer Arbeitsring fur Larmbekampfung LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 532b250e-516b-4b50-9376-af7bc5df7a83 ER - TY - JOUR TI - Impact induced detonation of cased explosive AU - Downes, D. AU - Nejad Ensan, M. AU - Bouamoul, A. T2 - Proceedings - 27th International Symposium on Ballistics, BALLISTICS 2013 T3 - 27th International Symposium on Ballistics 2013, April 22-26 2013, Freiburg, Germany SN - 9781605951065 VL - 1 SP - 916 EP - 927 AB - Fragments of aluminium impacting on Composition B explosives encased in rolled homogenous armour (RHA) steel were investigated using the explicit nonlinear finite element method. The investigation focused on shock to detonation simulations of Composition B, with the objective of determining the critical velocity which would generate a shock wave strong enough to cause detonation of the explosive and the resulting pressure profile of the detonation wave. Detonation scenarios at low, intermediate, high impact velocity were investigated. It was observed that a) at intermediate velocities detonation was due to the development of localized hot spots caused by the compression of the explosive from the initial shockwave; b) at high impact velocity, initiation of the explosive was caused by the initial incident wave behind the top casing/explosive interface. c) At low impact velocity, initiation of the explosive may be caused by the increased pressure of reflecting waves against the surfaces of the explosive casing. This case served to show the importance of capturing all confining surfaces correctly as any surface enhance detonation. Advanced features of the simulation includes Arbitrary-Lagrangian-Eulerian (ALE) approach, the Elastic Plastic Hydrodynamic constitutive material model and the Ignition and Growth of Reaction in High Explosive eq uation of state (IGRHE-EOS) to account for the probability that the explosive may not detonate when impacted. DA - 2013 PY - 2013 PB - DEStech Publications Inc. LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8006513e-6403-41e5-8b39-8e2e4fd50277 ER - TY - JOUR TI - Hybrid polymer-cellulose nanocrystal suspensions as smart materials AU - Boluk, Y. T2 - TAPPI International Conference on Nanotechnology 2013 T3 - TAPPI International Conference on Nanotechnology 2013, June 24-27 2013, Stockholm, Sweden SN - 9781510815681 SP - 303 EP - 320 DA - 2013 PY - 2013 PB - TAPPI Press LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 7ceacbbb-4f56-4d36-87ad-5086908e9540 ER - TY - JOUR TI - Hyperfine-induced hysteretic funnel structure in spin blockaded tunneling current of coupled vertical quantum dots at low magnetic field DO - 10.1063/1.4848357 AU - Leary, A. AU - Wicha, A. AU - Harack, B. AU - Coish, W. A. AU - Hilke, M. AU - Yu, G. AU - Payette, C. AU - Gupta, J. A. AU - Austing, D. G. T2 - The Physics of Semiconductors: Proceedings of the 31st International Conference on the Physics of Semiconductors T3 - 31st International Conference on the Physics of Semiconductors 2012, 29 July–3 August 2012, Zurich, Switzerland SN - 9780735411944 SP - 205 EP - 206 KW - Magnetic fields KW - Polarization KW - Quantum dot devices KW - Leakage currents KW - High voltage KW - Direct current transmission AB - We outline the properties of the hyperfine-induced funnel structure observed in the two-electron spin blockade region of a weakly coupled vertical double quantum dot device. Hysteretic steps in the leakage current occur due to dynamic nuclear polarization when either the bias voltage or the magnetic field is swept up and down. When the bias voltage is swept, an intriguing ∼3 mT wide cusp near 0 T appears in the down-sweep position, and when the magnetic field is swept, the current at 0 T can be switched from "low" to "high" as the bias is increased. DA - 2013 PY - 2013 PB - AIP Publishing LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 35e18247-e4ee-4a50-a6de-2d8a39f16807 ER - TY - JOUR TI - How to reveal subsurface defects in Kevlar® composite materials after an impact loading using infrared vision and optical NDT techniques? DO - 10.1016/j.engfracmech.2013.02.030 AU - Bendada, A. AU - Sfarra, S. AU - Genest, M. AU - Paoletti, D. AU - Rott, S. AU - Talmy, E. AU - Ibarra-Castanedo, C. AU - Maldague, X. T2 - Engineering Fracture Mechanics SN - 0013-7944 VL - 108 SP - 195 EP - 208 KW - Composites KW - Debonding KW - Infrared vision KW - Optical testing KW - Defects AB - An integrated system between infrared vision and optical non-destructive testing techniques can be considered a viable, robust and reliable approach for both aerospace manufacturing and in-service inspections. In this paper, infrared vision is applied in different spectral bands on two impacted panels made of aramid–phenolic composite by applying two different methods, respectively: (1) near and short-wave infrared reflectography and transmittography, and (2) mid-wave active infrared thermography. Furthermore, optical methods, namely digital speckle photography and holographic interferometry, are used as well to highlight the damages due to the impacts on the samples. Some techniques provide more straightforward detection capabilities than others for different defect types. DA - 2013/03/07 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9d2cc8d4-4ae7-4168-9a69-9364ffa03ebb ER - TY - JOUR TI - High harmonic cutoff energy scaling and laser intensity measurement with a 1.8 μm laser source DO - 10.1080/09500340.2013.765067 AU - Shiner, A. D. AU - Trallero-Herrero, C. AU - Kajumba, N. AU - Schmidt, B. E. AU - Bertrand, J. B. AU - Kim, Kyung Taec AU - Bandulet, H.-C. AU - Comtois, D. AU - Kieffer, J.-C. AU - Rayner, D. M. AU - Corkum, P. B. AU - Légaré, F. AU - Villeneuve, D. M. T2 - Journal of Modern Optics SN - 0950-0340 SN - 1362-3044 VL - 60 IS - 17 SP - 1458 EP - 1465 KW - High harmonic generation KW - Phase matching AB - High harmonic generation in gas targets leads to the production of attosecond pulses. The process of high harmonic generation requires that the gas be ionized by an intense femtosecond laser field. The highest photon energy produced is related to the laser intensity times the wavelength squared. This cutoff is reached only if good phase matching is achieved. Using a laser with a wavelength of 1800 nm, we estimate the laser intensity in the gas jet by recording the ion yield, and simultaneously record the high harmonic spectrum. We show that the cutoff energy matches the measured intensity, confirming that good phase matching is achieved to 100 eV. We also use the ion collector to characterize the spatial size of the gas jet and to measure the confocal parameter of the laser beam, parameters that are useful for numerical modelling. DA - 2013/02/12 PY - 2013 PB - Taylor & Francis LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b8aa3aa5-6df7-4317-82c1-b18e93fb94b2 ER - TY - JOUR TI - Herschel-HIFI observations of high-JCO and isotopologues in star-forming regions: from low to high mass DO - 10.1051/0004-6361/201220472 AU - San José-García, I. AU - Mottram, J. C. AU - Kristensen, L. E. AU - van Dishoeck, E. F. AU - Yıldız, U. A. AU - van der Tak, F. F. S. AU - Herpin, F. AU - Visser, R. AU - McCoey, C. AU - Wyrowski, F. AU - Braine, J. AU - Johnstone, D. T2 - Astronomy & Astrophysics SN - 0004-6361 SN - 1432-0746 VL - 553 SP - A125 SP - 1 EP - 29 KW - Astrochemistry KW - Star formation KW - Protostar KW - ISM molecules KW - ISM kinematics KW - ISM dynamics AB - CONTEXT. Our understanding of the star formation process has traditionally been confined to certain mass or luminosity boundaries because most studies focus only on low-, intermediate-, or high-mass star-forming regions. Therefore, the processes that regulate the formation of these different objects have not been effectively linked. As part of the “Water In Star-forming regions with Herschel” (WISH) key programme, water and other important molecules, such as CO and OH, have been observed in 51 embedded young stellar objects (YSOs). The studied sample covers a range of luminosities from <1 to >10⁵L⊙. AIMS. We analyse the CO line emission towards a large sample of embedded protostars in terms of both line intensities and profiles. This analysis covers a wide luminosity range in order to achieve better understanding of star formation without imposing luminosity boundaries. In particular, this paper aims to constrain the dynamics of the environment in which YSOs form. METHODS. Herschel-HIFI spectra of the ¹²CO J = 10–9, ¹³CO J = 10–9 and C18O J = 5–4, J = 9–8 and J = 10–9 lines were analysed for a sample of 51 embedded protostars. In addition, JCMT spectra of ¹²CO J = 3–2 and C¹⁸O J = 3–2 extend this analysis to cooler gas components. We focussed on characterising the shape and intensity of the CO emission line profiles by fitting the lines with one or two Gaussian profiles. We compared the values and results of these fits across the entire luminosity range covered by WISH observations. The effects of different physical parameters as a function of luminosity and the dynamics of the envelope-outflow system were investigated. RESULTS. All observed CO and isotopologue spectra show a strong linear correlation between the logarithms of the line and bolometric luminosities across six orders of magnitude on both axes. This suggests that the high-J CO lines primarily trace the amount of dense gas associated with YSOs and that this relation can be extended to larger (extragalactic) scales. The majority of the detected ¹²CO line profiles can be decomposed into a broad and a narrow Gaussian component, while the C¹⁸O spectra are mainly fitted with a single Gaussian. For low- and intermediate-mass protostars, the width of the C¹⁸O J = 9–8 line is roughly twice that of the C¹⁸O J = 3–2 line, suggesting increased turbulence/infall in the warmer inner envelope. For high-mass protostars, the line widths are comparable for lower- and higher-J lines. A broadening of the line profile is also observed from pre-stellar cores to embedded protostars, which is due mostly to non-thermal motions (turbulence/infall). The widths of the broad ¹²CO J = 3–2 and J = 10–9 velocity components correlate with those of the narrow C¹⁸O J = 9–8 profiles, suggesting that the entrained outflowing gas and envelope motions are related but independent of the mass of the protostar. These results indicate that physical processes in protostellar envelopes have similar characteristics across the studied luminosity range. DA - 2013/05/23 PY - 2013 PB - EDP Sciences LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : cbb2752b-2e8b-4547-931c-871d8b971c19 ER - TY - JOUR TI - Herschel observations of the W3 GMC: clues to the formation of clusters of high-mass stars DO - 10.1088/0004-637X/766/2/85 AU - Rivera-Ingraham, A. AU - Martin, P. G. AU - Polychroni, D. AU - Motte, F. AU - Schneider, N. AU - Bontemps, S. AU - Hennemann, M. AU - Men'shchikov, A. AU - Nguyen Luong, Q. AU - André, Ph. AU - Arzoumanian, D. AU - Bernard, J.-Ph. AU - Di Francesco, J. AU - Elia, D. AU - Fallscheer, C. AU - Hill, T. AU - Li, J. Z. AU - Minier, V. AU - Pezzuto, S. AU - Roy, A. AU - Rygl, K. L. J. AU - Sadavoy, S. I. AU - Spinoglio, L. AU - White, G. J. AU - Wilson, C. D. T2 - The Astrophysical Journal SN - 0004-637X SN - 1538-4357 VL - 766 IS - 2 SP - 85 SP - 1 EP - 14 KW - Dust KW - Extinction KW - Infrared stars KW - Westerhout 3 KW - Individual stars KW - Early-type stars KW - Star formation AB - The W3 GMC is a prime target for the study of the early stages of high-mass star formation. We have used Herschel data from the HOBYS key program to produce and analyze column density and temperature maps. Two preliminary catalogs were produced by extracting sources from the column density map and from Herschel maps convolved to 500 μm resolution. Herschel reveals that among the compact sources (FWHM < 0.45 pc), W3 East, W3 West, and W3 (OH) are the most massive and luminous and have the highest column density. Considering the unique properties of W3 East and W3 West, the only clumps with ongoing high-mass star formation, we suggest a "convergent constructive feedback" scenario to account for the formation of a cluster with decreasing age and increasing system/source mass toward the innermost regions. This process, which relies on feedback by high-mass stars to ensure the availability of material during cluster formation, could also lead to the creation of an environment suitable for the formation of Trapezium-like systems. In common with other scenarios proposed in other HOBYS studies, our results indicate that an active/dynamic process aiding in the accumulation, compression, and confinement of material is a critical feature of the high-mass star/cluster formation, distinguishing it from classical low-mass star formation. The environmental conditions and availability of triggers determine the form in which this process occurs, implying that high-mass star/cluster formation could arise from a range of scenarios: from large-scale convergence of turbulent flows to convergent constructive feedback or mergers of filaments. DA - 2013/03/13 PY - 2013 PB - IOP Publishing LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b32f4759-ccf7-4ab3-98ce-925de81a099e ER - TY - JOUR TI - Genomics, microbiomes, single cell analysis and next-generation sequencing DO - 10.1016/j.mimet.2013.11.007 AU - Köhler, Gerwald A. AU - Lau, Peter C. K. T2 - Journal of Microbiological Methods SN - 0167-7012 VL - 95 IS - 3 SP - 400 EP - 400 DA - 2013/12/03 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ace929f4-fada-4c63-b3e3-f73edca27bd5 ER - TY - JOUR TI - Femtosecond laser desorption of thin polymer films from a dielectric surface DO - 10.1364/CLEO_SI.2013.CM3H.3 AU - Mercadier, Laurent AU - Peng, Jiahui AU - Sultan, Yasir AU - Rayner, David M. AU - Corkum, Paul B. T2 - CLEO: 2013 T3 - CLEO: Science and Innovations, June 9-14 2013, San Jose, CA, USA SN - 978-1-55752-972-5 SP - CM3H.3 AB - We desorb polymer films from fused silica with a femtosecond laser and characterize the results by atomic force microscopy. Our study as a function of beam geometry and energy reveals two ways of achieving spatially controlled nanodesorption. DA - 2013 PY - 2013 PB - OSA CY - Washington, D.C. LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a89d1796-0255-4ec6-8f5f-cc384f9eea2f ER - TY - JOUR TI - Experimental study of structures subjected to hydrodynamic and debris impact forces AU - Al-Faesly, T. Q. AU - Nistor, I. AU - Palermo, D. AU - Cornett, A. T2 - Proceedings, Annual Conference - Canadian Society for Civil Engineering T3 - Annual Conference of the Canadian Society for Civil Engineering 2013: Know-How - Savoir-Faire, May 29-June 1 2013, Montreal, QC, Canada VL - 1 IS - January SP - 118 EP - 127 AB - An accurate estimation of tsunami-induced forces on nearshore structures is an important step towards the design of tsunami-resilient buildings. The University of Ottawa, in collaboration with the Canadian Hydraulics Centre (CHC) of the National Research Council, located in Ottawa, has established a comprehensive experimental and numerical modeling program focusing on tsunami-structure interaction with the ultimate goal of improving tsunami mitigation methods and strategies. As part of this experimental program, the authors conducted laboratory tests on the impact of extreme hydrodynamic forces and floating debris on two structural models with different cross sections (square and circular). These structures were subjected to supercritical hydraulic bores that are similar to ones generated by broken tsunami waves advancing inland. The structural models were instrumented with sensors capable of recording time histories of the hydraulic bore depth, as well as the lateral displacement, acceleration, pressures, forces, and moments imposed on the two structural models. The bore depth and bore velocity were recorded and analyzed, and the bore-structure interaction was also investigated. The time histories of the impact force resulting from wooden debris hitting the structural models were also recorded and analyzed. The authors further investigated existing formulas provided by the most recent tsunami-resistant engineering design guideline (FEMA P-646, 2012) and the Coastal Construction Manual (FEMA P-55, 2011) to compare the experimentally-recorded hydrodynamic and debris impact forces with current prescriptions. DA - 2013 PY - 2013 PB - Canadian Society for Civil Engineering LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 800addbc-7c44-4487-a80f-a6b348b1ffac ER - TY - JOUR TI - Experimental studies of mixed-phase sticking efficiency for ice crystal accretion in jet engines AU - Currie, Thomas C. AU - Fuleki, Dan AU - Mahallati, Ali T2 - Transactions of Japanese Society for Medical and Biological Engineering T3 - 35th Annual International Conference of IEEE Engineering in Medicine and Biology Society, EMBC 2013 in conjunction with 52nd Annual Conference of Japanese Society for Medical and Biological Engineering, JSMBE, July 3-7 2013, Osaka, Japan SN - 1881-4379 VL - 51 IS - SUPPL AB - Aircraft jet engines operating at high altitudes in ice crystal clouds can experience operational problems and/or damage resulting from accretion of ingested ice crystals within the compressor. It is believed the ice crystals partially melt, allowing them to stick to internal components. A method for modelling such mixed-phase accretion is required to de-risk new engine designs, modify existing designs with such icing issues and define critical operating points for scrutiny in proposed ice crystal certification tests. This paper presents preliminary results for a modelling approach which treats the accretion process as strictly a sticking phenomenon, ignoring heat transfer, phase change, runback and other location-dependent effects commonly used in the analysis of supercooled water icing. Ice-on-ice growth is described by a sticking efficiency, defined as the fraction of the mixed-phase impinging mass flux which remains on the surface (i.e. sticks). Experimental results are presented for 3 test articles tested in a small mixed-phase icing tunnel located in an altitude chamber (Research Altitude Test Facility or RATFac) at the National Research Council of Canada. These results show that the sticking efficiency is highly correlated with the ratio of liquid water content (LWC) to total water content (TWC) in the freestream, reaching a maximum value of 0.4-0.5 at melt (LWC/TWC) ratios in the approximate range 10-20%, as measured with a multi-element probe. It is shown that sticking efficiencies are largely independent of TWC, Mach number (M) and particle size at normal incidence (i.e. at the stagnation point) at these melt ratios, at least in the limited ranges of these variables investigated, but are strongly dependent on these parameters at oblique impingement angles. It is also shown that accretions can grow to a very large size at an almost constant rate at high levels of TWC. The experimental results are used to develop an erosion-based semi-empirical accretion model which at least partially explains this super-growth phenomenon and predicts most of the experimental results with acceptable fidelity. The model predicts that the almost unlimited growth observed in the experiments is possible at lower Mach numbers (e.g. 0.25) for TWC levels exceeding ~10g/m3, when the sticking efficiency remains finite at all particle impingement angles. The model also predicts that such growth is unlikely for higher Mach numbers (e.g. 0.4), at least for the 45μ (MVD) particles to which the model is applied. Smaller particles will likely extend the Mach number range over which the sticking efficiency remains finite. DA - 2013 PY - 2013 PB - Japan Soc. of Med. Electronics and Biol. Engineering LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 50d089c6-5029-4d78-b250-1564ce8220ec ER - TY - JOUR TI - Experimental characterization and multi-objective optimization of the orbital drilling process of CFRP DO - 10.1115/IMECE2013-65311 AU - Sadek, A. AU - Nassef, A. O. AU - Meshreki, M. AU - Attia, M. H. T2 - Volume 2B: Advanced Manufacturing T3 - ASME 2013 International Mechanical Engineering Congress and Exposition, November 15-21 2013, San Diego, CA, USA SN - 978-0-7918-5619-2 SP - V02BT02A078 SP - 1 EP - 8 KW - Drilling KW - Carbon reinforced plastics KW - Pareto optimization KW - Experimental characterization AB - Defects associated with drilling of Carbon Fiber-Reinforced Polymers (CFRPs) are of major economic and safety concerns for aerospace manufacturers. One of the most critical defects associated with drilling of CFRP laminates is delamination of layers which can be avoided by keeping the drilling forces below some threshold levels. Orbital Drilling (OD) is an emerging drilling process that exhibits lower cutting forces and temperatures, easier chip removal, higher produced surface quality, longer tool life, and a high possibility for dry machining. The OD process is featured by cyclic engagement and disengagement between the tool and the workpiece whereby a considerable part of the work done by the tool is directed towards the tangential direction while the work done in the axial direction is reduced. This reduces the risk of delamination at the exit. The objective of this research work is to investigate the effect of the OD process key parameters with respect to the produced hole attributes (surface roughness, delamination, and hole accuracy), as well as the cutting forces and temperatures. All the OD tests were performed under dry conditions using a four-flute 6.35 mm end-mill. The cutting forces were recorded using a 3-component dynamometer Kistler 9255B and cutting temperatures were measured using a FLIR ThermoVision A20M Infrared camera at the holes exit. A full factorial design of the experiment was used whereby the feeds varied from 60 to 360 mm/min and the speeds from 6,000 to 16,000 rpm. The test material used was a quasi-isotropic laminate comprising woven graphite epoxy prepreg. Analysis of the results showed 45% reduction in the axial force component in orbital drilling (OD), compared to conventional drilling. None of the holes produced by the entire set of experiments has experienced any entry or exit delamination. ANOVA was used to identify the significance of the controllable variables on the experimental outputs. To overcome the challenge of optimizing the competing parameters of the hole quality attributes while maximizing the productivity, an algorithm was applied by hybridizing Kriging as a meta-modeling technique with evolutionary multi-objective optimization to optimize the cutting parameters. DA - 2013/11/15 PY - 2013 PB - ASME LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9ebedb3b-c59b-48d3-befd-c0ba685e6f95 ER - TY - JOUR TI - Evaluation of innovative high performance lubricants for compaction of complex powder metallurgy parts AU - Paris, V. AU - Thomas, Y. AU - St-Laurent, S. T2 - Proceedings Euro PM2013 : International Powder Metallurgy Congress & Exhibition T3 - International Powder Metallurgy Congress and Exhibition, September 15-18 2013, Gothenburg, Sweden SN - 9781899072408 VL - 2 SP - 145 EP - 150 AB - A clear trend in the PM community for the past years is the development of increasingly more complex parts. Multi-level, tall and high green density parts are favoured in order to obtain the best mechanical performances while keeping the manufacturing costs as low as possible. To some extent, such advances are dependent on the metal powder feedstock. High performance lubricants added to the metal powder mix should, amongst others, promote a superior die-fill and an easier ejection from the die. This article evaluates the behaviour of lubricant PR-2, a high performance lubricant developed by Rio Tinto Metal Powders. A water-atomised steel powder mix containing 2.0% copper, 0.55% graphite and variable amounts of the high performance lubricant was tested on an industrial press. The press was run in fully automatic mode during extended periods of time and the part-to-part weight variation was measured. The powder was also characterised for its die-filling behaviour. The lubricant is compared to other commonly used PM lubricants such as Acrawax C and Kenolube. DA - 2013 PY - 2013 PB - European Powder Metallurgy Association LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 47b77e18-4b7e-4001-af0d-3ca82c97a6bf ER - TY - JOUR TI - Evaluation of global ice load impacts based on real-time monitoring of ship motions AU - Nyseth, Håvard AU - Frederking, Robert AU - Sand, Bjørnar T2 - Proceedings of the International Conference on Port and Ocean Engineering under Arctic Conditions T3 - 22nd International Conference on Port and Ocean Engineering under Arctic Conditions, June 9-13 2013, Espoo, Finland SN - 0376-6756 SN - 2077-7841 SP - 1 EP - 10 AB - As part of the ColdTech program, the Norwegian Coastguard vessel KV Svalbard has been equipped with an inertial measurement device (MRU) to record global ship motions in six degrees of freedom during ramming of heavy ice features. The objective of the measurement campaign was to look further into the possibility of using recorded whole-ship motions to evaluate the response of the ship and the global loads acting on the hull for different types of ship-ice interactions. The system has been tested during two expeditions around the Svalbard islands and the Fram Strait in 2011 and 2012. This paper should be considered as an introduction to the measurement campaign, and discusses the authors’ views on the applicability and limitations of such a monitoring system. Although similar measurements have been carried out in earlier projects, the actual usability of the system and the potential for further development to obtain a better understanding of the ice loads and the ship response during ramming have not previously been discussed in detail. The post-processing of the recorded data and further evaluation of the global ice loads derived from the measured ship motions are discussed in brief and exemplified using the recordings from a controlled impact with a distinct ice feature. Detailed discussions and validity of results will however be presented in a separate paper. Assumptions made and uncertainties connected to the proposed procedure are also discussed. DA - 2013 PY - 2013 PB - Lulea University of Technology LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 22a41743-d843-4f00-acc2-2c67c33ce94e ER - TY - JOUR TI - Evacuation in ice: ice loads on a lifeboat during field trials DO - 10.1115/OMAE2013-10689 AU - Ré, António J. Simões AU - Veitch, Brian T2 - Volume 6: Polar and Arctic Sciences and Technology; Offshore Geotechnics; Petroleum Technology Symposium T3 - ASME 2013 32nd International Conference on Ocean, Offshore and Arctic Engineering, June 9-14 2013, Nantes, France SN - 978-0-7918-5540-9 VL - 6 SP - V006T07A015 KW - Stress KW - Ice KW - Lifeboats AB - Full-scale field trials of a conventional lifeboat in pack ice have yielded insights into the design and operation of evacuation craft in ice. The multi-year trials program used an instrumented lifeboat to investigate design considerations such as powering and propulsion, hull form, maneuvering, ice loads and ergonomics. Operational issues that have been examined include ice management for emergency evacuation, coxswain competence and training. This paper focuses on local ice loads measured on the hull during aggressive operations in pack ice. Field measurements are presented and the implications for design and safe operations are discussed. DA - 2013/06/09 PY - 2013 PB - ASME LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4f8abcd3-3cd5-4a6c-acc7-40b0c8e3b590 ER - TY - JOUR TI - Erratum: The possible contribution of gravity measurements to the difference between the NIST and NRC watt balance results DO - 10.1088/0026-1394/50/5/557 AU - Newell, D. B. AU - Liard, J. O. AU - Inglis, A. D. AU - Eckl, M. C. AU - Winester, D. AU - Silliker, R. J. AU - Gagnon, C. G. L. T2 - Metrologia SN - 0026-1394 SN - 1681-7575 VL - 50 IS - 5 SP - 557 EP - 558 DA - 2013/10/01 PY - 2013 PB - IOP Publishing LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 421c4747-0636-40df-9291-b568135c2522 ER - TY - JOUR TI - ERRATUM: “Studies of variability in proto-planetary nebulae. II.light and velocity curve analyses of IRAS 22272+5435 AND 22223+4327” (2013, ApJ, 766, 116) DO - 10.1088/0004-637X/777/1/80 AU - Hrivnak, Bruce J. AU - Lu, Wenxian AU - Sperauskas, Julius AU - Van Winckel, Hans AU - Bohlender, David AU - Začs, Laimons T2 - The Astrophysical Journal SN - 0004-637X SN - 1538-4357 VL - 777 IS - 1 SP - 80 EP - 80 DA - 2013/11/01 PY - 2013 PB - IOP Publishing LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e005078a-d143-433e-86e4-3a69ce758feb ER - TY - JOUR TI - Erratum: “Structure and dynamics of the globular cluster Palomar 13” (2011, ApJ, 743, 167) DO - 10.1088/0004-637X/778/1/85 AU - Bradford, J. D. AU - Geha, M. AU - Muñoz, R. R. AU - Santana, F. A. AU - Simon, J. D. AU - Côté, P. AU - Stetson, P. B. AU - Kirby, E. AU - Djorgovski, S. G. T2 - The Astrophysical Journal SN - 0004-637X SN - 1538-4357 VL - 778 IS - 1 SP - 85 EP - 85 DA - 2013/11/20 PY - 2013 PB - IOP Publishing LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 35eea46d-cf37-4bd9-8c72-cefd60b66901 ER - TY - JOUR TI - Erratum to “On the effect of the peening trajectory in shot peen forming” [Finite Elem. Anal. Des. 69 (2013) 48–61] DO - 10.1016/j.finel.2013.07.006 AU - Gariépy, A. AU - Larose, S. AU - Perron, C. AU - Bocher, P. AU - Lévesque, M. T2 - Finite Elements in Analysis and Design SN - 0168-874X VL - 74 SP - 111 EP - 111 DA - 2013/08/13 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9a47ae5d-9369-475b-bd30-439ff74d0192 ER - TY - JOUR TI - Erratum to “Hybrid fire testing for assessing performance of structures in fire – methodology” [Fire Saf. J. 58 (May 2013) 170–179] DO - 10.1016/j.firesaf.2013.10.001 AU - Mostafaei, Hossein T2 - Fire Safety Journal SN - 0379-7112 VL - 61 SP - 355 EP - 355 DA - 2013/10 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : cf836647-8ffa-4ce8-a1ea-efa925137e21 ER - TY - JOUR TI - Corrigendum to “Effects of synthesis condition on formation of desired crystal structures of doped-TiO₂/carbon composite supports for ORR electrocatalysts” [Electrochim. Acta 77 (2012) 225–231] DO - 10.1016/j.electacta.2013.05.076 AU - Bing, Yonghong AU - Neburchilov, Vladimir AU - Song, Chaojie AU - Baker, Ryan AU - Guest, Alan AU - Ghosh, Dave AU - Ye, Siyu AU - Campbell, Stephen AU - Zhang, Jiujun T2 - Electrochimica Acta SN - 0013-4686 VL - 103 SP - 277 EP - 277 DA - 2013/06/11 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c9b7236d-eba7-45b5-89ec-309fda36a9ef ER - TY - JOUR TI - Cluster-formation in the Rosette molecular cloud at the junctions of filaments (Corrigendum) DO - 10.1051/0004-6361/201118566e AU - Schneider, N. AU - Csengeri, T. AU - Hennemann, M. AU - Motte, F. AU - Didelon, P. AU - Federrath, C. AU - Bontemps, S. AU - Di Francesco, J. AU - Arzoumanian, D. AU - Minier, V. AU - André, Ph. AU - Hill, T. AU - Zavagno, A. AU - Nguyen-Luong, Q. AU - Attard, M. AU - Bernard, J.-Ph. AU - Elia, D. AU - Fallscheer, C. AU - Griffin, M. AU - Kirk, J. AU - Klessen, R. AU - Könyves, V. AU - Martin, P. AU - Men’shchikov, A. AU - Palmeirim, P. AU - Peretto, N. AU - Pestalozzi, M. AU - Russeil, D. AU - Sadavoy, S. AU - Sousbie, T. AU - Testi, L. AU - Tremblin, P. AU - Ward-Thompson, D. AU - White, G. T2 - Astronomy & Astrophysics SN - 0004-6361 SN - 1432-0746 VL - 551 SP - C1 KW - Errata KW - Addenda KW - Evolution KW - HII regions KW - ISM clouds KW - ISM structure DA - 2013/02/11 PY - 2013 PB - EDP Sciences LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a8ede489-9663-4c21-9fe4-ba782f593b2a ER - TY - JOUR TI - Corrigendum to “Carbon-Nb₀.₀₇Ti₀.₉₃O₂ composite supported Pt-Pd electrocatalysts for PEM fuel cell oxygen reduction reaction” [Electrochim. Acta 75 (2012) 220–228] DO - 10.1016/j.electacta.2013.05.075 AU - Ignaszak, Anna AU - Song, Chaojie AU - Zhu, Weimin AU - Wang, Yan-Jie AU - Zhang, Jiujun AU - Bauer, Alex AU - Baker, Ryan AU - Neburchilov, Vladimir AU - Ye, Siyu AU - Campbell, Stephen T2 - Electrochimica Acta SN - 0013-4686 VL - 103 SP - 276 EP - 276 DA - 2013/06/11 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 01d70ff7-64ec-46d5-b476-de41183e4104 ER - TY - JOUR TI - Effect of runner and gate configuration on the performance of D-LFT composite parts AU - Bravo, V. L. AU - McLeod, M. R. AU - Porretta, C. T2 - Society of Plastics Engineers - 13th Annual Automotive Composites Conference and Exhibition, ACCE 2013 T3 - 13th Annual Automotive Composites Conference and Exhibition, September 11-13, 2013, Novi, MI, USA SN - 9781510808409 VL - 1 SP - 227 EP - 240 AB - Direct long fibre thermoplastics (D-LFT) composites based on polypropylene and glass fibre (PP/GF) are widely used for the manufacturing of semi-structural and structural automotive applications that include front-end carriers, running boards and door carriers, among other parts. The D-LFT process has a number of advantages when compared to the two step pre-compounded LFT pellet process, of which the most relevant are the cost reduction associated to the elimination of an intermediate step of producing pellets, the flexibility of modifying material formulations in-house at convenience and the reduction of heat and shear history of the material. Among the various configurations commercially available for D-LFT systems, two processes were considered for the present project. In the first process reinforcing fibres are fed and mixed with a molten polymer in a twin screw compounder and then extruded into a rectangular cross-section profile. This extrudate (sometimes referred to as a "log") is automatically cut to a specific length and transferred by a robot arm to a vertical compression moulding press where the polymer/fibre compound is moulded to the desired shape. The moulding can be done by means of direct compression of the log or by its placement into a mould shot-pot device that actuates after the mould is completely closed. A second approach involves the use of an injection moulding compounding unit, comprised of a twin screw compounder and a shot-pot (incorporated this time into the compounding-injection unit) that discharges material through a long nozzle into the sprue of the mould in similar fashion as the conventional injection moulding process. This paper deals with the hypothesis that the differences in the geometry of the flow channels for these two approaches affect the length, dispersion and distribution of fibres in the polymer matrix. It has been well documented in literature that fibre length affects the mechanical properties of the composite material while dispersion and distribution affect the uniformity of these properties ['"]. A systematic analysis of composite material produced with the two processing methods described above was carried out. A Coperion-Dieffenbacher D-LFT system, using a shot-pot mould, and a Coperion-Husky, using the compounding-injection moulding process, were employed to mould identical parts under similar compounding conditions. Samples were taken from the parts for a comparison of the respective fibre lengths and distribution patterns of the two moulding technologies using the micro computed tomography (CT) scanning technique. A characterization of fibre length distribution was performed on the samples using image analysis software after pyrolysis. Resulting mechanical properties were compared to provide a comprehensive picture of the two processing technologies. DA - 2013 PY - 2013 PB - Society of Plastics Engineers LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 089eb4b9-ff54-4b8c-8e41-f02efa037a55 ER - TY - JOUR TI - Effect of lubricant particle size distribution on the processing and properties of P/M ferrous parts AU - Thomas, Yannig AU - Bernier, Fabrice AU - St Laurent, Sylvain AU - Paris, Vincent T2 - International Powder Metallurgy Congress and Exhibition, Euro PM 2013 T3 - International Powder Metallurgy Congress and Exhibition, September 15-18 2013, Gothenburg, Sweden SN - 9781899072408 AB - The role of lubricants during compaction is crucial and nowadays even more important, due to the increased number of PM parts with higher densities and/or challenging ejection conditions. The development of new lubricants for single compaction requires however an excellent understanding of the lubrication mechanisms and the behaviour of these new compounds. In this paper, the effect of the lubricant particle size distribution on the compaction and ejection behaviour, but also on the static and dynamic properties of ferrous powder metallurgy parts is studied. Indeed, as parts reach higher densities, the influence of the size and shape of pores become dominant on the mechanical performance and particularly fatigue resistance of the parts. Water atomized powder mixes containing different particles sizes of ethylene-bis-stearamide (EBS) lubricant were compacted both on a laboratory press and on an industrial mechanical press at higher speed rates. In addition to compressibility curves and static sintered mechanical properties, complete ejection curves and fatigue tests results are presented. DA - 2013 PY - 2013 PB - European Powder Metallurgy Association LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : dd4c1ddf-3048-4b04-b2ed-21d55d4c9557 ER - TY - JOUR TI - Does a prestellar core always become protostellar? Tracing the evolution of cores from the prestellar to protostellar phase DO - 10.1093/mnras/stt006 AU - Anathpindika, S. AU - Di Francesco, James T2 - Monthly Notices of the Royal Astronomical Society SN - 0035-8711 SN - 1365-2966 VL - 430 IS - 3 SP - 1854 EP - 1866 KW - Hydrodynamics KW - Star formation AB - Recently, a subset of starless cores whose thermal Jeans mass is apparently overwhelmed by the mass of the core has been identified, e.g. the core L183. In the literature, massive cores such as this one are often referred to as ‘super-Jeans cores’. As starless cores are perhaps on the cusp of forming stars, a study of their dynamics will improve our understanding of the transition from the prestellar to the protostellar phase. In this work, we use non-magnetic polytropes belonging originally to the family of the Isothermal sphere. For the purpose, perturbations were applied to individual polytropes, first by replacing the isothermal gas with a gas that was cold near the centre of the polytrope and relatively warm in the outer regions, and secondly, through a slight compression of the polytrope by raising the external confining pressure. Using this latter configuration, we identify thermodynamic conditions under which a core is likely to remain starless. In fact, we also argue that the attribute ‘super-Jeans’ is subjective and that these cores do not formally violate the Jeans stability criterion. On the basis of our test results, we suggest that gas temperature in a star-forming cloud is crucial towards the formation and evolution of a core. Simulations in this work were performed using the particle-based smoothed particle hydrodynamics algorithm. However, to establish numerical convergence of the results we suggest similar tests with a grid scheme, such as the adaptive mesh refinement. DA - 2013/02/13 PY - 2013 PB - Oxford University Press LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e24c87ae-085f-40ad-8192-306519fc1b2c ER - TY - JOUR TI - Disruptive innovations with nanocrystalline cellulose (NCC) and flexible packaging industry AU - Boluk, Yaman T2 - PLACE Flexible Packaging Symposium 2013: New Technologies T3 - TAPPI PLACE Flexible Packaging Symposium 2013, April 8 2013, Orlando, FL, USA SN - 9781510815711 SP - 47 EP - 62 DA - 2013 PY - 2013 PB - TAPPI Press LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 84a9cc4d-4603-48ce-b834-e2ac87f95f97 ER - TY - JOUR TI - Development of a simple and reliable PDMS interconnect for high throughput microfluidic applications DO - 10.1007/s00542-013-2037-z AU - Mu, C. J. AU - Zhang, Z. Y. AU - Lin, M. AU - Cao, X. C. T2 - Microsystem Technologies SN - 0946-7076 SN - 1432-1858 VL - 21 IS - 1 SP - 147 EP - 154 KW - Flow rate ratio KW - PDMS microfluidic channel KW - PDMS surface KW - Thick glass substrate KW - Disposable PDMS KW - Sheath flow KW - Bonding strength AB - Microfluidic interconnects act as bridges to connect microscopic channels with macroscopic environments, enabling the microfluidic device to perform its designed functions. In this study, we report a new method to prepare a reliable PDMS interconnect that is able to handle high throughput applications and can be easily incorporated into PDMS microfluidic devices. Using a regular glass plate as an assisting component, we prepare a reliable PDMS interconnect that establishes a strong connection between PDMS surface and an externally inserted stainless steel tubing coupler by using oxygen plasma and epoxy adhesives. In characterizing the resulting PDMS interconnect, we demonstrate that this new PDMS interconnect shows outstanding performances, withstanding flow pressures up to 1.8 MPa in leak-proof tests and pull-out forces up to 100 N, both of which are much higher than previously reported values for PDMS interconnects. In addition, we show that this new epoxy-assisted interconnect is free of contamination and clogging, which results in a highly reproducible fabrication process to prepare a reliable PDMS interconnects. Taken together, we believe that the outstanding performances of the new PDMS interconnect make it a promising candidate for both high throughput and multi-inlet/outlet PDMS microfluidic system applications. DA - 2013/12/17 PY - 2013 PB - Springer International Publishing LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 26acd6de-900e-49de-8914-43fd80bbfcc6 ER - TY - JOUR TI - Development of a sensor for total temperature and humidity measurements under mixed-phase and glaciated icing conditions AU - Fuleki, Dan M. AU - Mahallati, Ali AU - Knezevici, Daniel C. AU - Currie, Thomas C. AU - Macleod, James D. T2 - Transactions of Japanese Society for Medical and Biological Engineering T3 - 35th Annual International Conference of IEEE Engineering in Medicine and Biology Society, in conjunction with 52nd Annual Conference of Japanese Society for Medical and Bological Engineering, July 3-7 2013, Osaka, Japan SN - 1881-4379 VL - 51 IS - SUPP AB - This paper presents a critical development to a prototype sensor that is capable of measuring total air temperature and humidity in a mixed-phase environment, consisting of liquid water droplets and ice crystals. The sensor has fast and stable measurement response under particularly challenging mixed-phase conditions. Total temperature and humidity levels measured with the probe are in good agreement with the results of analytical energy and moisture balances. DA - 2013 PY - 2013 PB - Japan Soc. of Med. Electronics and Biol. Engineering LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a6ace8b2-520b-4a03-a0bf-d26d31bf6443 ER - TY - JOUR TI - Developing performance estimates for high precision astrometry with TMT AU - Schock, Matthias AU - Do, Tuan AU - Ellerbroek, Brent AU - Herriot, Glen AU - Meyer, Leo AU - Suzuki, Ryuji AU - Wang, Lianqi AU - Yelda, Sylvana T2 - Third AO4ELT Conference Adaptive Optics for Extremely Large Telescopes Proceedings T3 - 3rd Conference on Adaptive Optics for Extremely Large Telescopes, May 26-31 2013, Florence, Italy SN - 978-88-908876-0-4 AB - Adaptive optics on Extremely Large Telescopes will open up many new science cases or expand existing science into regimes unattainable with the current generation of telescopes. One example of this is high-precision astrometry, which has requirements in the range from 10 to 50 micro-arcsec for some instruments and science cases. Achieving these requirements imposes stringent constraints on the design of the entire observatory, but also on the calibration procedures, observing sequences and the data analysis techniques. This paper summarizes our efforts to develop a top down astrometry error budget for TMT. It is predominantly developed for the first-light AO system, NFIRAOS, and the IRIS instrument, but many terms are applicable to other configurations as well. Astrometry error sources are divided into 5 categories: reference source and catalog errors, atmospheric refraction correction errors, other residual atmospheric effects, opto mechanical errors and focal plane measurement errors. Results are developed in parametric form whenever possible. However, almost every error term in the error budget depends on the details of the astrometry observations, such as whether absolute or differential astrometry is the goal, whether one observes a sparse or crowded field, what the time scales of interest are, etc. Thus, it is not possible to develop a single error budget that applies to all science cases and separate budgets are developed and detailed for key astrometric observations. Our error budget is consistent with the requirements for differential astrometry of tens of micro-arcsec for certain science cases. While no show stoppers have been found, the work has resulted in several modifications to the NFIRAOS optical surface specifications and reference source design that will help improve the achievable astrometry precision even further. DA - 2013 PY - 2013 PB - INAF - Osservatorio Astrofisico di Arcetri Largo Enrico Fermi LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : fc237c64-bbde-4cbf-81a9-f9102af64b3f ER - TY - JOUR TI - Determination of strontium isotope amount ratios in biological tissues using MC-ICPMS DO - 10.1039/c3ay00028a AU - Irrgeher, Johanna AU - Prohaska, Thomas AU - Sturgeon, Ralph E. AU - Mester, Zoltán AU - Yang, Lu T2 - Analytical Methods SN - 1759-9660 SN - 1759-9679 VL - 5 IS - 7 SP - 1687 EP - 1694 AB - A protocol is described for the accurate and precise determination of Sr isotope amount ratios in the TORT-3 candidate lobster hepatopancreas certified reference material (CRM) from the National Research Council Canada. Parameters affecting the separation of Sr and Rb based on a double pass of the dissolved sample matrix through a column packed with Eichrom Sr Spec resin were investigated in detail. Matrix elements were removed and the Rb concentration was reduced to below 0.002% (expressed as the ⁸⁵Rb/⁸⁸Sr intensity ratio) in the purified solutions of TORT-3. Fractionation on the column was eliminated as quantitative recovery (98 ± 4% mean and 1 SD, n = 18) of strontium was obtained. A modified method of standard-sample bracketing with internal normalization for mass bias correction was employed using natural Zr added to both the sample and a solution of NIST SRM 987 used as the bracketing standard. Each iSr/⁸⁶Sr ratio (⁸⁸Sr/⁸⁶Sr, ⁸⁷Sr/⁸⁶Sr and ⁸⁴Sr/⁸⁶Sr) was used to separately calibrate an individual ⁹¹Zr/⁹⁰Zr ratio, which was then used to correct corresponding ⁸⁸Sr/⁸⁶Sr, ⁸⁷Sr/⁸⁶Sr and ⁸⁴Sr/⁸⁶Sr ratios in the sample. The interference from residual ⁸⁴Rb on ⁸⁴Sr was corrected for by simultaneous measurement of ⁸⁵Rb and the use of the IUPAC ⁸⁴Rb/⁸⁵Rb ratio of 0.385706, which was itself mass bias corrected assuming the same mass bias for ⁸⁴Sr/⁸⁶Sr and ⁸⁴Rb/⁸⁵Rb. SRM 987 standard solutions used for method validation returned ratios in good agreement with their certified values, confirming the accuracy of the approach. Absolute isotope amount ratios of 0.056526 ± 0.000048, 0.70937 ± 0.00010 and 8.3824 ± 0.0012 (U, k = 2) for ⁸⁴Sr/⁸⁶Sr, ⁸⁷Sr/⁸⁶Sr, ⁸⁸Sr/⁸⁶Sr, respectively, were obtained in TORT-3. The main contributors to the measurement uncertainties of the TORT-3 Sr isotope ratios are the certified values in SRM 987. Values of −0.442 ± 0.071‰, −1.363 ± 0.036‰ and 0.454 ± 0.030‰ (mean and 1 SD, n = 18) characterize δ⁸⁴/⁸⁶Sr, δ⁸⁷/⁸⁶Sr and δ⁸⁸/⁸⁶Sr in TORT-3, respectively. DA - 2013/02/08 PY - 2013 PB - Royal Society of Chemistry LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2637f116-e05a-4e96-9583-ed7c7c45769b ER - TY - JOUR TI - Detecting and locating fatigue cracks in a complex wing-box structure using the acoustic emission technique: A verification study AU - Gagar, Daniel AU - Martinez, Marcias AU - Yanishevsky, Marko AU - Rocha, Bruno AU - McFeat, Jim AU - Foote, Peter AU - Irving, Phil T2 - Structural Health Monitoring 2013: A Roadmap to Intelligent Structures - Proceedings of the 9th International Workshop on Structural Health Monitoring T3 - 9th International Workshop on Structural Health Monitoring: A Roadmap to Intelligent Structures, September 10-12 2013, Palo Alto, California, USA SN - 9781605951157 VL - 1 SP - 65 EP - 72 AB - Acoustic Emission (AE) is recognized for its potential as a Structural Health Monitoring (SHM) technique, offering several advantages, such as passive sensing and wide area monitoring, making it particularly attractive for aerospace applications. Realistic structures, like aircraft wings for example, consist of structural elements of complex geometry, manufactured with different materials. Individually these elements may influence the performance of the SHM technique in detecting and locating structural damage. In this research, the capabilities of the AE technique to identify and locate damage in complex structures were assessed. These assessments were performed without disclosure of the damage location to the AE equipment operator. Four piezoelectric AE sensors were mounted on spars of the aircraft wing representative structure prior to conducting a series of constant amplitude loading fatigue tests. One of the spars contained a fatigue crack seeded at a location unknown to the damage monitoring analyst. The sensors monitored AE generated from the spars and event location estimates were obtained using time of flight analysis with a wave velocity value determined experimentally. The AE monitoring successful detected and located the hidden fatigue crack; this was independently verified by three nondestructive testing (NDT) methods. DA - 2013 PY - 2013 PB - DEStech Publications LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : eba85109-6463-4927-9161-18202e74e653 ER - TY - JOUR TI - Coulomb explosion imaging of NO2 dissociation DO - 10.1364/LS.2013.LTu4H.2 AU - Ding, Xiaoyan AU - Lee, Kevin AU - Staudte, Andre AU - Villeneuve, David M. AU - Corkum, Paul B. T2 - Frontiers in Optics 2013 T3 - Laser Science 2013, October 6-10 2013, Orlando, Florida, USA SN - 978-1-55752-987-9 SP - LTu4H.2 AB - We use an intense few-cycle pulse to probe the structural dynamics of pre-dissociating NO2. We show that enhanced ionization gives us preferential access to just-dissociating molecules over not-yet-dissociated - or already-dissociated - molecules. DA - 2013 PY - 2013 PB - OSA CY - Washington, D.C. LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a7536c1c-3099-417b-b038-39b1d6a8da57 ER - TY - JOUR TI - Corrosion resistance properties of superhydrophobic copper surfaces fabricated by one-step electrochemical modification process DO - 10.1016/j.apsusc.2013.06.034 AU - Huang, Ying AU - Sarkar, D. K. AU - Gallant, Danick AU - Chen, X-Grant T2 - Applied Surface Science SN - 0169-4332 VL - 282 SP - 689 EP - 694 KW - Corrosion KW - Stability KW - Superhydrophobic KW - Copper KW - One-step process KW - SEM KW - XRD KW - IRRAS AB - Superhydrophobic copper surfaces have been prepared by a one-step electrochemical modification process in an ethanolic stearic acid solution. In this work, the corrosion properties of hydrophobic copper surface and superhydrophobic copper surfaces were analyzed by means of electrochemical analyses and compared with that of as-received bare copper substrate. The decrease of corrosion current density (icorr) as well as the increase of polarization resistance (Rp) obtained from potentiodynamic polarization curves revealed that the superhydrophobic film on the copper surfaces improved the corrosion resistance performance of the copper substrate. DA - 2013/06/15 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 33b8064e-8005-48db-b63f-decbf9c200a9 ER - TY - JOUR TI - Corrigendum to “Nb-doped TiO₂/carbon composite supports synthesized by ultrasonic spray pyrolysis for proton exchange membrane (PEM) fuel cell catalysts” [J. Power Sources 220 (2012) 1–9] DO - 10.1016/j.jpowsour.2013.01.153 AU - Senevirathne, Keerthi AU - Neburchilov, Vladimir AU - Alzate, Vanesa AU - Baker, Ryan AU - Neagu, Roberto AU - Zhang, Jiujun AU - Campbell, Stephen AU - Chhina, Harmeet AU - Ye, Siyu T2 - Journal of Power Sources SN - 03787753 VL - 232 DA - 2013/02/09 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 21ec5d76-5bff-4fdf-af67-6ed2ce2c50d1 ER - TY - JOUR TI - Corrigendum to “Bacterial community evidence for anaerobic degradation of petroleum hydrocarbons in cold climate groundwater” [Cold Reg. Sci. Technol., Volume 86 (2013) pp. 55–68] DO - 10.1016/j.coldregions.2013.01.007 AU - Yeung, C. William AU - Van Stempvoort, Dale R. AU - Spoelstra, John AU - Bickerton, Greg AU - Voralek, John AU - Greer, Charles W. T2 - Cold Regions Science and Technology SN - 0165-232X VL - 89 SP - 48 EP - 48 DA - 2013/02/10 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 88f8a87a-b4b7-40bb-92f6-17b539a15e1c ER - TY - JOUR TI - Control of the systematic shifts of the strontium ion optical frequency standard at the 10 mHz level DO - 10.1109/EFTF-IFC.2013.6702065 AU - Dube, Pierre AU - Madej, Alan A. AU - Tibbo, Maria AU - Bernard, John E. T2 - 2013 Joint European Frequency and Time Forum & International Frequency Control Symposium (EFTF/IFC) T3 - 2013 Joint European Frequency and Time Forum & International Frequency Control Symposium (EFTF/IFC), July 21-25 2013, Prague, Czech Republic SN - 978-1-4799-0342-9 SP - 521 EP - 524 KW - Blackbody radiation KW - Frequency standards KW - Measurment uncertainty KW - Microwave measurement KW - Strontium KW - Trapped ions AB - An overview of the key methods used to reduce the uncertainty of the systematic shifts of the strontium ion optical frequency standard is presented. An uncertainty of 10 mHz at a clock frequency of 445 THz is obtained, limited by the uncertainty of the blackbody radiation shift. The uncertainty estimates of other shifts such as micromotion and electric quadrupole shifts are on the order of 1 mHz or less. The effectiveness of the methods used to reduce or cancel the shifts is illustrated with experiments comparing two ion traps. One has strong micromotion levels while the other, the reference trap, provides good control over the shifts. Despite nominal shifts of 70 Hz in the trap with large micromotion levels, the agreement with the reference trap is at the sub-Hz level. DA - 2013/07 PY - 2013 PB - IEEE LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8c57d872-ca7d-4fc9-b410-14927f5cf574 ER - TY - JOUR TI - Compositional and morphological changes of ordered PtxFey/C oxygen electroreduction catalysts DO - 10.1002/cctc.201200614 AU - Chen, Liang AU - Chan, Mickey C. Y. AU - Nan, Feihong AU - Bock, Christina AU - Botton, Gianluigi A. AU - Mercier, Patrick H. J. AU - Macdougall, Barry R. T2 - ChemCatChem SN - 1867-3880 VL - 5 IS - 6 SP - 1449 EP - 1460 KW - Iron KW - Platinum KW - Carbon KW - Supported catalysts KW - Reduction AB - Changes in the O₂ reduction activity (ORR) and structure of carbon-supported catalysts upon electrochemical stress testing are investigated. Focus is placed on two alloy catalysts of nominal Pt₃Fe/C and Pt₃Fe2/C compositions. Energy dispersive X-ray spectroscopy (EDXS) spot and line analyses reveal a dependence of the Fe composition on the particle size, particularly for the two as-prepared catalysts. The catalyst particles are shown to have a Pt-enriched shell and a PtxFey alloy core. Larger (>≈10 nm) particles are shown to have a higher Fe content that approaches the nominal composition, which suggests that the smaller (<≈6 nm) Pt catalyst particles are more difficult to alloy. High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), XRD, and SEM with EDXS show that Fe is lost gradually from the catalyst particles as a result of extensive potential (E)-cycling. Changes upon E-cycling are observed most clearly for the small (<3 nm) particles, in which Fe is almost entirely depleted. However, the catalytic ORR activities remain constant over an extensive cycling period for the PtxFey/C catalysts and the mass ORR activities decrease proportionally with Pt surface area (Apt). The histograms before and after cycling are compared to observed changes in Apt and are discussed in comparison to E-holding experiments. It is concluded that the dissolution of Pt is a strong contributor for the observed decrease in Apt and mass ORR activity for the PtxFey/C catalysts. The continuous transition between Pt oxide formation and its reduction to Pt metal is suggested to play a major role in the degradation of the PtxFey/C catalysts studied in this work. DA - 2013/03/01 PY - 2013 PB - Wiley LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0d178a01-981f-452f-b758-65d696a8887b ER - TY - JOUR TI - Comparison of T₂ and T₂ *-weighted MR molecular imaging of a mouse model of glioma DO - 10.1186/1471-2342-13-20 AU - Blasiak, Barbara AU - Barnes, Samuel AU - Foniok, Tadeusz AU - Rushforth, David AU - Matyas, John AU - Ponjevic, Dragana AU - Weglarz, Wladyslaw P. AU - Tyson, Randy AU - Iqbal, Umar AU - Abulrob, Abedelnasser AU - Sutherland, Garnette R. AU - Obenaus, Andre AU - Tomanek, Boguslaw T2 - BMC Medical Imaging SN - 1471-2342 VL - 13 IS - 1 SP - 20 SP - 1 EP - 8 KW - Contrast-to-noise ratio KW - MRI KW - Molecular MRI KW - Contrast agents KW - Glioma AB - BACKGROUND Standard MRI has been used for high-grade gliomas detection, albeit with limited success as it does not provide sufficient specificity and sensitivity to detect complex tumor structure. Therefore targeted contrast agents based on iron oxide, that shorten mostly T2 relaxation time, have been recently applied. However pulse sequences for molecular imaging in animal models of gliomas have not been yet fully studied. The aim of this study was therefore to compare contrast-to-noise ratio (CNR) and explain its origin using spin-echo (SE), gradient echo (GE), GE with flow compensation (GEFC) as well as susceptibility weighted imaging (SWI) in T2 and T2* contrast-enhanced molecular MRI of glioma. METHODS A mouse model was used. U87MGdEGFRvIII cells (U87MG), derived from a human tumor, were injected intracerebrally. A 9.4 T MRI system was used and MR imaging was performed on the 10 day after the inoculation of the tumor. The CNR was measured prior, 20 min, 2 hrs and 24 hrs post intravenous tail administration of glioma targeted paramagnetic nanoparticles (NPs) using SE, SWI, GE and GEFC pulse sequences. RESULTS The results showed significant differences in CNR among all pulse sequences prior injection. GEFC provided higher CNR post contrast agent injection when compared to GE and SE. Post injection CNR was the highest with SWI and significantly different from any other pulse sequence. CONCLUSIONS Molecular MR imaging using targeted contrast agents can enhance the detection of glioma cells at 9.4 T if the optimal pulse sequence is used. Hence, the use of flow compensated pulse sequences, beside SWI, should to be considered in the molecular imaging studies. DA - 2013/07/18 PY - 2013 PB - BioMed Central LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1df43221-7f4b-4f0e-aa6b-f087d5baf0b2 ER - TY - JOUR TI - Classical analysis of Coulomb effects in strong-field ionization of H₂⁺ by intense circularly polarized laser fields DO - 10.1103/PhysRevA.88.033411 AU - Doblhoff-Dier, Katharina AU - Dimitriou, Konstantinos I. AU - Staudte, André AU - Gräfe, Stefanie T2 - Physical Review A SN - 1050-2947 SN - 1094-1622 VL - 88 IS - 3 SP - 1 EP - 8 AB - We analyze the distortion of the molecular frame photoelectron angular distributions of H₂⁺ ionized by a strong, circularly polarized infrared laser field using classical trajectory Monte Carlo simulations. We find that the nonisotropic field of the molecular ion rotates the final electron momenta. The degree of distortion from the strong-field approximation's predictions is thereby sensitive to the field strength and the internuclear distance but, counterintuitively, does not necessarily decrease for high field strengths. Furthermore, the distortion also depends crucially on the initial momentum of the classical electron after tunneling, while the exact shape of the ionization rate seems to be less important. A trajectory analysis within our simple model allows us to interpret recent experimental results. DA - 2013/09/10 PY - 2013 PB - American Physical Society LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5bc1d097-91ab-4942-a161-98e52a911b43 ER - TY - JOUR TI - Chemicals from agricultural biomass: chemoenzymatic approach for production of vinylphenols and polyvinylphenols from phenolic acids DO - 10.1515/gps-2012-0082 AU - Leisch, Hannes AU - Grosse, Stephan AU - Morley, Krista AU - Abokitse, Kofi AU - Perrin, Florence AU - Denault, Johanne AU - Lau, Peter C. K. T2 - Green Processing and Synthesis SN - 2191-9550 SN - 2191-9542 VL - 2 IS - 1 SP - 7 EP - 17 KW - Biorefinery KW - Biotransformation KW - Chemoenzymatic synthesis KW - Green polymers KW - Phenolic acids AB - A two-step chemoenzymatic process for the preparation of polyvinylphenols from phenolic acids (PAs), being abundant aromatic constituents found in agricultural biomass, was developed. In the first step, conversion of 4-hydroxycinnamic acid derivatives to the corresponding vinylphenols, mediated by a recombinant phenolic acid decarboxylase, was evaluated using a variety of bioprocessing technologies that include biphasic whole cell and cell free extract biotransformations, a combination of biocatalyst with adsorbent resins for in situ product recovery, and fixed bed reactors using immobilized whole cells. The best yield (90%) with a high space time yield of 4.83 g/l/h was the result of a combination of crude enzyme extracts of the recombinant Escherichia coli (E. coli) with water immiscible organic solvents such as toluene. In the second step, cationic and radical polymerizations were tested to produce polyvinylguaiacol (PVG) from vinyl phenols. Characterization of PVG by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and nanoindentation test are reported here for the first time. The feasibility of the chemoenzymatic process for the production of aromatic polymers from biomass was demonstrated by the production of polymers from a mixture of ferulic acid (FA) and p-coumaric acid (pCA), obtained from alkaline hydrolysis of corn bran. Interestingly, nanoindentation tests showed that both PVG and “mixed” PVG polymers showed significantly higher performances than a commercial polystyrene polymer. DA - 2013/01/28 PY - 2013 PB - de Gruyter LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 75018e17-4d4c-4ee8-8fbb-a18b671a3c81 ER - TY - JOUR TI - Characteristics of H13 tool steel coatings by pulsed Nd:YAG laser cladding AU - Wang, Shaodong AU - Chen, Jianyin AU - Xue, Lijue T2 - TMS2013 Annual Meeting Supplemental Proceedings T3 - 142nd Annual Meeting and Exhibition: Linking Science and Technology for Global Solutions, March 3-7 2013, San Antonio, TX, USA SN - 9781118605813 SP - 201 EP - 208 KW - Laser cladding KW - Coating KW - Pulsed Nd:YAG laser KW - H13 tool steel AB - AISI H13 hot-work tool steel has a wide application for mold/die of die casting, hot forging, hot extrusion, hot stamping and plastic injection molding, due to its high toughness, high hot hardness and high thermal fatigue resistance. Laser cladding, a material additive technology, can be used to apply various functional coatings and to repair/reconfigure tool/die. H13 tool steel was successfully laser-clad on carbon steel substrates at room temperature. The microstructure of as-clad coating showed a refined dendritic structure due to fast cooling and rapid solidification. X-ray diffraction (XRD) phase identification revealed that the coating consisted of a majority of martensite phase plus certain amount of retained austenite phase (∼ 20 vol%). Tensile residual stresses were measured in the as-clad H13 coating. The average value of Vickers hardness in the as-clad coating is about 575 Hv0.05. Wear resistance evaluation using pin-on-disc sliding wear testing showed that the wear resistance of as-clad H13 steel coating was similar to or slightly better than that of hardened wrought H13 steel (HRC 54) plate under the wear test condition used in this study, but the wear mechanisms are significantly different. DA - 2013/02/25 PY - 2013 PB - Wiley LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e57a5d32-60c5-466f-9b75-abf5e2c33b38 ER - TY - JOUR TI - Changes in order parameters associated with ceramide-mediated membrane reorganization measured using pTIRFM DO - 10.1021/la403585v AU - Carter Ramirez, Daniel M. AU - Jakubek, Zygmunt J. AU - Lu, Zhengfang AU - Ogilvie, William W. AU - Johnston, Linda J. T2 - Langmuir SN - 0743-7463 SN - 1520-5827 VL - 29 IS - 51 SP - 15907 EP - 15918 AB - The enzymatic generation of ceramide has significant effects on the biophysical properties of lipid bilayers and can lead to the extensive reorganization of cell membranes. We have synthesized and characterized a headgroup-labeled fluorescent lipid probe (NBD-ceramide, NBD-Cer) and demonstrated that it can be used for polarized total internal reflection fluorescence microscopy experiments to probe changes in membrane order that result from ceramide incorporation. NBD-Cer measures significantly higher order parameters for the liquid-ordered (Lₒ) domains (〈P₂〉 = 0.40 ± 0.03) than for the liquid-disordered phase (Ld, fluid, 〈P₂〉 = 0.22 ± 0.02) of phase-separated bilayers prepared from egg sphingomyelin, dioleolyphosphatidylcholine, and cholesterol mixtures. The probe also responds to changes in packing induced by the direct incorporation of ceramide or the variation in the ionic strength of the aqueous medium. Order parameter maps obtained after enzyme treatment of bilayers with coexisting Lₒ and Ld phases show two distinct types of behavior. In regions of high enzyme activity, the initial Lₒ/Ld domains are replaced by large, dark features that have high membrane order corroborating previous hypotheses that these are ceramide-enriched regions of the membrane. In areas of low enzyme activity, the size and shape of the Lo domains are conserved, but there is an increase in the order parameter for the initial Ld phase (〈P₂〉 = 0.30 ± 0.01). This is attributed to the incorporation of ceramide in the Lo domains with the concomitant expulsion of cholesterol into the surrounding fluid phase, increasing its order parameter. DA - 2013/12/05 PY - 2013 PB - American Chemical Society LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : dced12ac-6d2a-41b8-b690-d52b31cb330c ER - TY - JOUR TI - Challenges and opportunities for bacterial vaccine development in the 21st Century DO - 10.2174/13892010113146660230 AU - Duvvuri, Venkata R. AU - Barreto, Luis AU - Wu, Jianhong AU - Tsang, Raymond S. W. T2 - Current Pharmaceutical Biotechnology SN - 1389-2010 VL - 14 IS - 8 SP - 758 EP - 767 KW - Bacterial diseases KW - Genomics KW - Immunomics KW - Mathematical biology KW - Proteomics KW - Vaccinology AB - With the convergence of modern technology in genomics, proteomics, carbohydrate, protein and lipid biochemistry as well as decades of experience in vaccine development and delivery of immunization programs, the Global Vaccine Action Plan has declared 2011 to 2020 as 'The Decade of Vaccines'. This review focuses on bacterial vaccines and summarises the current state of vaccinology in bacteriology and looks forward to the potential of how the newer technologies can impact our knowledge of bacterial diseases and their control through vaccine development. The major breakthroughs in the last couple of decades include low cost high throughput genomics, proteomics, cellular immunology and the delicate network of immune-cytokines, bioinformatics, immune-informatics, and disease modelling. Together, these newer developments can provide a real impact on our understanding of infectious diseases and their control by vaccination. DA - 2013/10 PY - 2013 PB - Bentham Science Publishers LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 28a31833-5724-4b2b-bc44-e623f99c3431 ER - TY - JOUR TI - Can VIP be an alternative solution for energy retrofit for enhancing the thermal performance of wood-frame walls? AU - Saber, Hamed H. AU - Maref, Wahid AU - Gnanamurugan, Ganapathy AU - Nicholls, Mike T2 - Thermal Performance of the Exterior Envelopes of Whole Buildings - 12th International Conference T3 - 12th International Conference on Thermal Performance of the Exterior Envelopes of Whole Buildings, December 1-5, 2013, Clearwater Beach, FL, USA KW - Vacuum Insulation Panel (VIP) KW - Thermal resistance KW - Thermal performance KW - Retrofit KW - Wood-frame wall systems KW - Energy savings. AB - Field monitoring of the dynamic heat transmission characteristics of residential 2 × 6 wood-frame wall systems that had been retrofitted using vacuum insulation panels (VIPs) with glass fiber cores and extruded polystyrene foam (XPS) panels were undertaken in 2011-2012 at the Field Exposure of Walls Facility (FEWF) of the NRC Construction. The main objective of this research was to evaluate the steady-state and transient thermal performance of three wall assemblies (4 ft × 6 ft), two of which incorporated VIPs within an XPS tongue and groove (T&G) configuration and VIPs within an XPS clip-on (C-O) configuration, and a third assembly incorporating only XPS. The three wall assemblies were installed in the FEWF for one year cycle of exposure to outdoor natural weather conditions. The NRC's hygrothermal model, hygIRC-C, was validated against the measured data. Results showed that the model predictions were in good agreement with the experimental data. Given that the VIP could be punctured during the installation process (e.g., inadvertent use of fasteners in wall assembly) or may fail during normal operating conditions or due to imperfection during the manufacturing process, the numerical model was used to conduct parametric analyses in order to predict the thermal resistance (R-value) in cases where one or more VIPs failed. In the final phase of this study, the model was used to predict the yearly cumulative heat losses from the respective wall systems. It is important to point out that the aging effect and the effect of the thermal bridging due to the envelope (i.e., skin) of the VIPs are not accounted for in this study. However, sensitivity analysis of the thickness and thermal conductivity of the VIP envelope was conducted in this paper to investigate the effect of these parameters on the effective R-values of VIP. Results showed that the yearly cumulative heating loads for the XPS retrofit wall specimen was 69.9% and 78.8%, respectively, greater than that obtained for the T&G VIP retrofit wall specimen and the C-O VIP retrofit wall specimen. Furthermore, the results showed that the effect of the furred-airspace assembly in the C-O VIP retrofit wall specimen when the emissivity of all surfaces that bounded the airspace was assumed to be 0.9 resulted in a reduction in the yearly heating load by 5% compared to the T&G VIP retrofit wall specimen without furred-airspace. DA - 2013 PY - 2013 PB - American Society of Heating, Refrigeration, and Air-Conditioning Engineers (ASHRAE) LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3ed46ec6-234b-45dc-8844-2e6cb75e9d1f ER - TY - JOUR TI - A data-driven method for predicting structural degradation using a piezoceramic array AU - Mulligan, Kyle R. AU - Yang, Chunsheng AU - Quaegebeur, Nicolas AU - Masson, Patrice T2 - International Journal of Prognostics and Health Management SN - 2153-2648 VL - 4 IS - 2 SP - 037 SP - 1 EP - 14 KW - SHM KW - PZT KW - data-driven KW - damage prognosis KW - drop-weight impacting KW - composite. KW - data mining KW - machine learning AB - There is a growing use of carbon fiber reinforced polymers (CFRPs) in modern airframes with still a limited understanding of the in-service behavioral characteristics of these structures. Structural Health Monitoring (SHM) technologies that use surface-bonded piezoceramic (PZT) transducers to generate and measure guided waves within these structures have demonstrated promising damage detection and localization results and potential for data gathering in data-driven damage prognosis. This paper investigates the development of a data-driven SHM based damage prognosis system for estimating remaining useful life (RUL) of CFRP coupons following damage initiation. A robust and realistic laboratory data gathering methodology is introduced as a building block for evaluating the feasibility of data-driven damage prognosis for in-service aerospace structures. Data are gathered using a PZT-based SHM system. Using the gathered raw guided wave signals, a number of time and frequency domain features are first extracted which are derived from existing damage imaging and detection algorithms. Then, using various combinations of the feature sets as inputs to generic data mining algorithms, the paper presents estimates of the predicted RUL against actual damage diameter progression. DA - 2013/11/26 PY - 2013 PB - Prognostics and Health Management Society LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 69861b47-9061-445a-a088-418c645c3219 ER - TY - JOUR TI - Bacterial growth at −15 °C; molecular insights from the permafrost bacterium Planococcus halocryophilus Or1 DO - 10.1038/ismej.2013.8 AU - Mykytczuk, Nadia C. S. AU - Foote, Simon J. AU - Omelon, Chris R. AU - Southam, Gordon AU - Greer, Charles W. AU - Whyte, Lyle G. T2 - The ISME Journal SN - 1751-7362 SN - 1751-7370 VL - 7 IS - 6 SP - 1211 EP - 1226 KW - Cryophile KW - Permafrost KW - Cold-active KW - Cold/osmotic adaptation KW - Subzero environments AB - Planococcus halocryophilus strain Or1, isolated from high Arctic permafrost, grows and divides at −15 °C, the lowest temperature demonstrated to date, and is metabolically active at −25 °C in frozen permafrost microcosms. To understand how P. halocryophilus Or1 remains active under the subzero and osmotically dynamic conditions that characterize its native permafrost habitat, we investigated the genome, cell physiology and transcriptomes of growth at −15 °C and 18% NaCl compared with optimal (25 °C) temperatures. Subzero growth coincides with unusual cell envelope features of encrustations surrounding cells, while the cytoplasmic membrane is significantly remodeled favouring a higher ratio of saturated to branched fatty acids. Analyses of the 3.4 Mbp genome revealed that a suite of cold and osmotic-specific adaptive mechanisms are present as well as an amino acid distribution favouring increased flexibility of proteins. Genomic redundancy within 17% of the genome could enable P. halocryophilus Or1 to exploit isozyme exchange to maintain growth under stress, including multiple copies of osmolyte uptake genes (Opu and Pro genes). Isozyme exchange was observed between the transcriptome data sets, with selective upregulation of multi-copy genes involved in cell division, fatty acid synthesis, solute binding, oxidative stress response and transcriptional regulation. The combination of protein flexibility, resource efficiency, genomic plasticity and synergistic adaptation likely compensate against osmotic and cold stresses. These results suggest that non-spore forming P. halocryophilus Or1 is specifically suited for active growth in its Arctic permafrost habitat (ambient temp. ~−16 °C), indicating that such cryoenvironments harbor a more active microbial ecosystem than previously thought. DA - 2013/02/07 PY - 2013 PB - Nature Publishing Group LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8150cd5d-af5b-42e1-96a0-0f4201d04b58 ER - TY - JOUR TI - Attosecond science and technology AU - Corkum, P. B. T2 - The European Conference on Lasers and Electro-Optics T3 - The European Conference on Lasers and Electro-Optics 2013, May 12-16 2013, Munich Germany SN - 2162-2701 SN - 9781479905942 SP - CG_2_1 DA - 2013 PY - 2013 PB - The Optical Society LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 48441f50-e9a1-4bc3-a779-9c121bf76148 ER - TY - CHAP TI - Astronomical Photometry DO - 10.1007/978-94-007-5618-2_1 AU - Stetson, Peter B. T2 - Planets, Stars and Stellar Systems SN - 978-94-007-5617-5 SN - 978-94-007-5618-2 SP - 1 EP - 34 AB - Astronomers use the term “photometry” to refer to the precise measurement of the apparent brightness of astronomical objects in particular specified ranges of electromagnetic wavelength in and near the optically visible band. Historically, this task has been most commonly carried out with the human eye, photographic plates, photomultiplier tubes, and – most recently as of this writing – charge-coupled devices. At wavelengths significantly shorter or longer than the optical region, different detector technologies must be used, and some other term than “photometry” is often used to name the process. DA - 2013 PY - 2013 PB - Springer International Publishing LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1623aa37-837c-43c7-a6a8-a8f5ef15f2b3 ER - TY - JOUR TI - Application of picosecond laser for polishing of AISI H13 tool steel sample prepared by micro milling AU - Khalid Hafiz, Abdullah M. AU - Bordatchev, Evgueni V. AU - Tutunea-Fatan, Remus O. T2 - 41st North American Manufacturing Research Conference 2013 T2 - Transactions of the North American Manufacturing Research Institution of SME; no. Volume 41 T3 - 41st North American Manufacturing Research Conference 2013, June 10-14 2013, Madison, WI, USA SN - 1047-3025 SN - 9781627486972 SP - 239 EP - 248 AB - This paper explores the applicability of picosecond laser (ps) in laser micro polishing (LμP) of AISI H13 tool steel. The melting regime associated with this process was determined experimentally through the variation of the focal offset in order to attain a desired fluence level. To ensure the consistency and certainty of initial surface geometry, the surface was prepared through a micro milling operation with a step-over of 50 μm and scallop height of 2 μm. The LμP experiments were performed at 5 different fluence levels of the melting regime obtained through setting of the focal point at 5 different distances. The polishing performance was evaluated based on the distribution of line profiling average surface roughness (Ra) at various spatial wavelength intervals. Additional statistical metrics such as material ratio function and power spectral density function were also determined in order to establish the process parameters associated with best achievable surface finish. Finally, as a demonstration of the applicability of ps LμP process, a flat micro milled area was polished using optimum process parameters. This operation yielded in 68% surface quality improvement as quantified through the reduction of the areal topography surface roughness (Sa) from 0.53 urn to 0.17 μm. DA - 2013/10 PY - 2013 PB - Society of Manufacturing Engineers LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9001f7ff-199e-4d54-809c-297cb357fef9 ER - TY - JOUR TI - Assessment of fibre optic sensor architectures for structural health monitoring AU - Rocha, B. AU - Barazanchy, D. AU - Sevenois, R. AU - Guo, H. AU - Xiao, G. AU - Mrad, N. T2 - Structural Health Monitoring 2013: A Roadmap to Intelligent Structures T3 - 9th International Workshop on Structural Health Monitoring: A Roadmap to Intelligent Structures, September 10-12, 2013, Stanford University, CA, USA SN - 9781605951157 VL - 1 SP - 470 EP - 477 AB - Fibre Optic Sensors (FOS) present several advantages over their conventional electrical counterparts for Structural Health Monitoring (SHM) of aerospace structures. These sensors are dimensionally small and can be readily embedded into composite structures, or bonded to their surface with minimal effect on weight or aerodynamic characteristics. They also do not generate, and are immune, to Electro-Magnetic Interference (EMI), thus they do not affect neighboring electrical systems or avionics. Fiber Optic Sensors have been widely used for load monitoring in discrete or distributed architectures. Additionally, Fibre Bragg Grating (FBG) sensors, a family of FOS, have been explored for the detecti on of material acoustic waves and damage. Three sensing system configurations, coupled with the use of FBGs, have been studied and reported in the literature for the detection of material acoustic waves; namely, (1) the use of tunable lasers as light source and photodiodes as the light sensors; (2) Broad Band light Sources (BBS) and Arrayed Waveguide Gratings (AWG); and (3) BBS with cascaded, or pairs of phase-shifted FBGs. The first two configurations also offer the ability to perform load monitoring, through strain measurement, in addition to material acoustic wave and damage detection. In an effort to advance the field of Structural Health Monitoring and its implementation in aircraft applications, these three sensing system architectures were evaluated for their capability and ease for the detection of material acoustic waves and damage. Tests were performed using a realistic and aircraft representative skin composite panel, a quasi-isotropic Carbon Fibre Reinforced Polymer (CFRP) skin panel. In the performed evaluati on, material acoustic waves generated by a piezoceramic transducer were accurately and reliably detected using the first (1) and last (3) techni ques. The first architecture was implemented effortlessly and the last presented, inherently, less complexity. The use of the AWG, in the second (2) architecture, presented comparativel y additional challenges to the detection of the generated acoustic waves due to the requirement for a high power light source. As a result of this evaluati on, the first (1) technique was subsequently selected and assessed in damage detection trials with promising results. Due to the demonstrated success of these trials, the experimental composite skin panel, along with the demonstrated damage detecti on technique, are being integrated into the SHM infrastructure being developed at the National Research Council Canada (NRC). This infrastructure consists of structural platforms that range in complexity from a simple 2 m long aluminium beam to full scale aircraft structures - a CF188 wing and a Bell 206 helicopter tail boom. Additionally, such infrastructure offers full scale evaluations and testing of damage detection techniques and technologies and SHM capabilities employing realistic loads and spectra optionally in varying environment conditions. DA - 2013/09/26 PY - 2013 PB - DEStech Publications LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e7892fd2-c211-4311-8c18-7ede913f3d82 ER - TY - JOUR TI - Assessment of acoustic performance of composite structures with viscoelastic treatments AU - Ghinet, Sebastian AU - Osman, Haisam AU - Grewal, Anant T2 - 42nd International Congress and Exposition on Noise Control Engineering 2013 (INTER-NOISE 2013): Noise Control for Quality of Life T3 - 42nd International Congress and Exposition on Noise Control Engineering 2013: Noise Control for Quality of Life, September 15-18 2013, Innsbruck, Austria SN - 9781632662675 VL - 3 SP - 1916 EP - 1923 KW - Composite structures KW - Noise KW - Porous materials KW - Vibration KW - Viscoelastic materials AB - The main objective of the work is to assess the acoustic performance of viscoelastic treatments versus the case when the treatment is incorporated as an equivalent added mass layer in various configurations of isotropic or composite structures under diffuse field excitation. The Discrete Laminate Method (DLM) was used in a Transfer Matrix Method (TMM) framework to compute the sound transmission loss of the structure with added noise control treatment. The numerical approach was compared with numerical results from literature and experimental data and was shown to accurately predict the sound transmission loss of composite structures with incorporated noise control treatments. Moreover, parametric studies of various configurations were considered in order to highlight promising behavioral trends for optimal noise control treatments design. DA - 2013/08 PY - 2013 PB - Institute of Noise Control Engineering LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 27ccdcb6-759d-4845-9423-e71ae924c7e8 ER - TY - JOUR TI - Artificial neural networks for predicting 3D protein shapes from amino acid sequences DO - 10.1109/IJCNN.2013.6706956 AU - Viktor, Herna L. AU - Paquet, Eric AU - Zhao, Jing T2 - The 2013 International Joint Conference on Neural Networks (IJCNN) T3 - 2013 International Joint Conference on Neural Networks IJCNN 2013, August 4-9 2013, Dallas, TX, USA SN - 978-1-4673-6129-3 SN - 978-1-4673-6128-6 SP - 1 EP - 8 KW - Bioinformatics KW - Computer graphics KW - Neural nets KW - Proteins AB - Research has shown that the functionalities of proteins are largely influenced by their three dimensional (3D) shapes. This observation is especially relevant in drug design, where the knowledge of the 3D structure of a protein enables pharmacologists to select the best binding proteins when aiming to moderate functions. However, a relatively small number of 3D shapes are known. In contrast, amino acid sequences may be acquired through very efficient automated, high throughput experimental methods and the amino acid sequences of a vast number of proteins have therefore been identified. It follows that it is important to address this knowledge gap. To this end, this paper introduces an approach to predict the 3D shapes of proteins, utilizing feed-forward artificial neural networks. Our novel solution allows one to learn the representations of the 3D shape associated with a protein by starting directly from its amino acid sequence descriptors. Once a neural network is trained, our search engine enables one to retrieve the closest known 3D shape associated with an unknown, so-called query protein. We evaluate the performance of our approach against the Protein Data Bank (PDB), by considering proteins from a diverse set of families. Our results indicate that our system is able to accurately find the most similar protein structures for a wide variety of protein 3D shapes and diverse protein family sizes. DA - 2013/07/30 PY - 2013 PB - IEEE LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 209f97f4-36fd-4f59-b8cf-127d0877f67d ER - TY - JOUR TI - Application of hybrid micro-cogeneration system—Thermal and power energy solutions for Canadian residences DO - 10.1016/j.enbuild.2013.02.004 AU - Entchev, E. AU - Yang, L. AU - Szadkowski, F. AU - Armstrong, M. AU - Swinton, M. T2 - Energy and Buildings SN - 0378-7788 VL - 60 SP - 345 EP - 354 KW - Hybrid micro-cogeneration system KW - Micro CHP KW - Internal combustion engine KW - High efficiency furnace KW - Load profiles KW - Control strategies AB - This paper presents results from a field trial with a hybrid micro-cogeneration system applied to satisfy both thermal and power needs of a typical Canadian detached house. The hybrid system consists of an internal combustion engine integrated with a high efficiency furnace. It was installed, integrated with the rest of the mechanical systems and demonstrated at the Canadian Center for Housing Technology (CCHT). Cost analysis was performed to examine the economics of such systems in relation to different price structures imposed by the electric utilities. The study revealed that the hybrid micro-cogeneration system performed reliably and generated both heat and power with high efficiency during the heating season and was able to satisfy the heating demand under very cold weather conditions. The power generated by the system was first directed to the house satisfying 50% of the electric load with the other 50% being exported to the grid. The project demonstrated that micro-cogeneration systems when sized to meet the base electric load and design thermal load of the residence are a valuable alternative to the central power generation plants and are able to reliably satisfy the house thermal/power demand even under extreme cold conditions. DA - 2013/02/11 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3b3f9d21-3ce2-4746-a755-209b3051d56f ER - TY - JOUR TI - Analysis of residual strain profiles in distorted aluminum engine blocks by neutron diffraction DO - 10.4271/2013-01-0171 AU - Lombardi, Anthony AU - Ravindran, Comondore (Ravi) AU - Sediako, Dimitry AU - Mackay, Robert T2 - SAE Technical Papers T3 - SAE 2013 World Congress and Exhibition, April 16-18 2013, Montreal QC, Canada SP - 2013-01-0171 SP - 1 EP - 6 KW - Analysis methodologies KW - Aluminum alloys KW - Aluminum engines AB - In recent years, light weight components have been an area of significant importance in automotive design. This has led to the replacement of steel and cast iron with aluminum alloys for many automotive components. For instance, Al-Si alloys have successfully replaced nodular and gray cast iron in the production of large automotive components such as engine blocks. However, excessive residual strain along the cylinder bores of these engine blocks may result in cylinder distortion during engine operation. Therefore, in this study, neutron diffraction was used to evaluate residual strain along the aluminum cylinder bridge and the gray cast iron liners of distorted and undistorted engine blocks. The strains were measured in the hoop, radial, and axial orientations. The results suggest that the residual strain along the aluminum cylinder bridge of the distorted engine block was tensile for all three measured components. Conversely, the undistorted engine block had compressive strains in the axial and radial orientations, while the hoop direction had tensile strain of lower magnitude. The gray iron liners, meanwhile, had compressive residual strain for both engine blocks. The variation in strain, specifically in the aluminum cylinder bridge, suggests that permanent dimensional distortion in the cylinders was triggered by tensile residual stress when exposed to service conditions. DA - 2013/04/08 PY - 2013 PB - SAE International LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d5ca4b61-4069-4ddf-a393-8801d29a5bea ER - TY - JOUR TI - Analysis of residual strain profiles in distorted aluminum engine blocks by neutron diffraction DO - 10.4271/2013-01-0171 AU - Lombardi, Anthony AU - Ravindran, Comondore (Ravi) AU - Sediako, Dimitry AU - Mackay, Robert T2 - SAE International Journal of Materials and Manufacturing T3 - SAE 2013 World Congress and Exhibition, April 16-18 2013, Montreal QC, Canada SN - 1946-3987 VL - 6 IS - 2 SP - 135 EP - 140 KW - Analysis methodologies KW - Aluminum alloys KW - Aluminum engines AB - In recent years, light weight components have been an area of significant importance in automotive design. This has led to the replacement of steel and cast iron with aluminum alloys for many automotive components. For instance, Al-Si alloys have successfully replaced nodular and gray cast iron in the production of large automotive components such as engine blocks. However, excessive residual strain along the cylinder bores of these engine blocks may result in cylinder distortion during engine operation. Therefore, in this study, neutron diffraction was used to evaluate residual strain along the aluminum cylinder bridge and the gray cast iron liners of distorted and undistorted engine blocks. The strains were measured in the hoop, radial, and axial orientations. The results suggest that the residual strain along the aluminum cylinder bridge of the distorted engine block was tensile for all three measured components. Conversely, the undistorted engine block had compressive strains in the axial and radial orientations, while the hoop direction had tensile strain of lower magnitude. The gray iron liners, meanwhile, had compressive residual strain for both engine blocks. The variation in strain, specifically in the aluminum cylinder bridge, suggests that permanent dimensional distortion in the cylinders was triggered by tensile residual stress when exposed to service conditions. DA - 2013/04/08 PY - 2013 PB - SAE International LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 22aaac7c-e06a-40df-982d-a6cda632b173 ER - TY - JOUR TI - An isometry-invariant spectral approach for protein-protein docking DO - 10.1109/BIBE.2013.6701547 AU - De Youngster, Dela AU - Paquet, Eric AU - Viktor, Herna AU - Petriu, Emil T2 - 13th IEEE International Conference on BioInformatics and BioEngineering T3 - 2013 IEEE 13th International Conference on Bioinformatics and Bioengineering (BIBE), November 10-13 2013, Chania, Greece SN - 978-1-4799-3163-7 SP - 1 EP - 6 KW - molecular biophysics KW - deformation KW - molecular configurations KW - proteins KW - spectral analysis AB - The protein docking problem refers to the task of predicting the appropriate matching of one protein molecule (the receptor) to another (the ligand), when attempting to bind them to form a stable complex. Research shows that matching the three-dimensional geometric structures of proteins plays a key role in determining a so-called docking pair. However, the active sites which are responsible for the binding do not always present a rigid-body shape matching problem. Rather, they may undergo deformations when docking occurs, which complicates the process. To address this issue, we present an isometry-invariant and topologically robust partial shape descriptor method for finding complementary protein sites. Our method employs Heat Kernel Signature shape descriptors which are based on the diffusion of heat on surfaces. Our experimental results against the Protein-Protein Benchmark 4.0 demonstrate the viability of our approach. DA - 2013/11 PY - 2013 PB - IEEE LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 675e4b14-deea-47b8-ab28-d88fd28fbbf4 ER - TY - JOUR TI - An accessible, large-print, listening and talking e-book to support families reading together DO - 10.1145/2493190.2494658 AU - Attarwala, Abbas AU - Munteanu, Cosmin AU - Baecker, Ronald T2 - Proceedings of the 15th International Conference on Human-computer interaction with mobile devices and services - MobileHCI 2013 T3 - 15th International Conference on Human-Computer Interaction with Mobile Devices and Services, August 27-30 2013, Munich, Germany SN - 9781450322737 SP - 440 EP - 443 KW - Collaborative reading KW - Aging KW - Visual impairment KW - Assistive technology AB - Reading is an activity that is not only informative or pleasurable, but can have significant social benefits. Especially in a family setting, it is part of the interaction between children and their parents, it helps create a bond between children and their grandparents, and even bring adults and their older parents closer. However, with families increasingly living or spending time in different locations or managing busy schedules that afford very little time together, the social opportunities enabled by reading are often lost. Furthermore, reading can be a challenge for older adults or for those with impaired eyesight. To address these problems, we are proposing ALLT -- an Accessible, Large-Print, Listening and Talking e-book. ALLT is a tablet-based e-reading application that enhances the capabilities of e-book readers through customizable and intelligent accessibility features. It provides support for asynchronous "reading together" by synchronizing the audio recording of one user with the text that is later read by another user. This addresses the needs of a variety of users, from visually impaired adults reading together with a loved one, to children being able to replay an interactive story previously read together with their grandparents. In this demo paper we present ALLT's features and detail how they support asynchronously reading together. DA - 2013/08/29 PY - 2013 PB - ACM Press CY - New York, New York, USA LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 56e2b818-f139-48a9-b8f1-203b534b1448 ER - TY - JOUR TI - Aflatoxin, fumonisin and Shiga toxin-producing Escherichia coli infections in calves and the effectiveness of Celmanax®/Dairyman’s Choice™ applications to eliminate morbidity and mortality losses DO - 10.3390/toxins5101872 AU - Baines, Danica AU - Sumarah, Mark AU - Kuldau, Gretchen AU - Juba, Jean AU - Mazza, Alberto AU - Masson, Luke T2 - Toxins SN - 2072-6651 VL - 5 IS - 10 SP - 1872 EP - 1895 KW - Shiga toxin-producing Escherichia coli KW - Mycotoxin KW - Prebiotic KW - Probiotic KW - Virulence AB - Mycotoxin mixtures are associated with Shiga toxin-producing Escherichia coli (STEC) infections in mature cattle. STEC are considered commensal bacteria in mature cattle suggesting that mycotoxins provide a mechanism that converts this bacterium to an opportunistic pathogen. In this study, we assessed the mycotoxin content of hemorrhaged mucosa in dairy calves during natural disease outbreaks, compared the virulence genes of the STECs, evaluated the effect of the mucosal mycotoxins on STEC toxin expression and evaluated a Celmanax®/Dairyman’s Choice™ application to alleviate disease. As for human infections, the OI-122 encoded nleB gene was common to STEC genotypes eliciting serious disease. Low levels of aflatoxin (1–3 ppb) and fumonisin (50–350 ppb) were detected in the hemorrhaged mucosa. Growth of the STECs with the mycotoxins altered the secreted protein concentration with a corresponding increase in cytotoxicity. Changes in intracellular calcium indicated that the mycotoxins increased enterotoxin and pore-forming toxin activity. A prebiotic/probiotic application eliminated the morbidity and mortality losses associated with the STEC infections. Our study demonstrates: the same STEC disease complex exists for immature and mature cattle; the significance of the OI-122 pathogenicity island to virulence; the significance of mycotoxins to STEC toxin activity; and, finally, provides further evidence that prebiotic/probiotic applications alleviate STEC shedding and mycotoxin/STEC interactions that lead to disease. DA - 2013/10/23 PY - 2013 PB - MDPI LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1f8722f2-d589-4b0c-ba60-b479af2730ac ER - TY - JOUR TI - Acute physiological stress down-regulates mRNA expressions of growth-related genes in Coho salmon DO - 10.1371/journal.pone.0071421 AU - Nakano, Toshiki AU - Afonso, Luis O. B. AU - Beckman, Brian R. AU - Iwama, George K. AU - Devlin, Robert H. AU - Fuentes, Juan T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 8 SP - e71421 SP - 1 EP - 7 KW - Fish physiology KW - Salmon KW - Gene expression KW - Hydrocortisone KW - Marine fish KW - Pituitary gland KW - Growth hormone KW - Blood plasma AB - Growth and development in fish are regulated to a major extent by growth-related factors, such as liver-derived insulin-like growth factor (IGF) -1 in response to pituitary-secreted growth hormone (GH) binding to the GH receptor (GHR). Here, we report on the changes in the expressions of gh, ghr, and igf1 genes and the circulating levels of GH and IGF-1 proteins in juvenile coho salmon (Oncorhynchus kisutch) in response to handling as an acute physiological stressor. Plasma GH levels were not significantly different between stressed fish and prestressed control. Plasma IGF-1 concentrations in stressed fish 1.5 h post-stress were the same as in control fish, but levels in stressed fish decreased significantly 16 h post-stress. Real-time quantitative PCR (qPCR) analysis showed that ghr mRNA levels in pituitary, liver, and muscle decreased gradually in response to the stressor. After exposure to stress, hepatic igf1 expression transiently increased, whereas levels decreased 16 h post-stress. On the other hand, the pituitary gh mRNA level did not change in response to the stressor. These observations indicate that expression of gh, ghr, and igf1 responded differently to stress. Our results show that acute physiological stress can mainly down-regulate the expressions of growth-related genes in coho salmon in vivo. This study also suggests that a relationship between the neuroendocrine stress response and growth-related factors exists in fish. DA - 2013/08/19 PY - 2013 PB - PLOS LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c01f1aaf-d29d-48ff-b8d5-42aad7b01964 ER - TY - JOUR TI - A ΔclpB mutant of Francisella tularensis subspecies holarctica Strain, FSC200, is a more effective live vaccine than F. tularensis LVS in a mouse respiratory challenge model of tularemia DO - 10.1371/journal.pone.0078671 AU - Golovliov, Igor AU - Twine, Susan M. AU - Shen, Hua AU - Sjostedt, Anders AU - Conlan, Wayne AU - Kaufmann, Gunnar F. T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 11 SP - e78671 SP - 1 EP - 8 KW - Francisella tularensis KW - Vaccines KW - Mouse models KW - Respiratory infections KW - Cytokines KW - Chaperone proteins KW - Chemokines KW - Vaccination and immunization AB - Francisella tularensis subsp. tularensis is a highly virulent pathogen for humans especially if inhaled. Consequently, it is considered to be a potential biothreat agent. An experimental vaccine, F. tularensis live vaccine strain, derived from the less virulent subsp. holarctica, was developed more than 50 years ago, but remains unlicensed. Previously, we developed a novel live vaccine strain, by deleting the chaperonin clpB gene from F. tularensis subsp. tularensis strain, SCHU S4. SCHU S4ΔclpB was less virulent for mice than LVS and a more effective vaccine against respiratory challenge with wild type SCHU S4. In the current study, we were interested to determine whether a similar mutant on the less virulent subsp. holarctica background would also outperform LVS in terms of safety and efficacy. To this end, clpB was deleted from clinical holarctica strain, FSC200. FSC200ΔclpB had a significantly higher intranasal LD50 than LVS for BALB/c mice, but replicated to higher numbers at foci of infection after dermal inoculation. Moreover, FSC200ΔclpB killed SCID mice more rapidly than LVS. However, dermal vaccination of BALB/c mice with the former versus the latter induced greater protection against respiratory challenge with SCHU S4. This increased efficacy was associated with enhanced production of pulmonary IL-17 after SCHU S4 challenge. DA - 2013/11/13 PY - 2013 PB - PLOS LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 52f0ccc3-4ef6-42c7-8358-9d349a24a032 ER - TY - BOOK TI - A physicist's view of matter and mind DO - 10.1142/8594 AU - Dharma-Wardana, Chandre SN - 978-981-4425-41-4 SN - 978-981-4425-42-1 SN - 978-981-4425-43-8 AB - This is a highly interdisciplinary book straddling physics and complex systems such as living organisms. The presentation is from the perspective of physics, in a manner accessible to those interested in scientific knowledge integrated within its socio-cultural and philosophical backgrounds. Two key areas of human understanding, namely physics and conscious complex systems, are presented in simple language. An optional technical presentation is also given in parallel where it is needed. DA - 2013/05 PY - 2013 PB - World Scientific Publishing LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : eb9361db-098a-4051-9772-d35b98850740 ER - TY - JOUR TI - 2013 OIC Manufacturing Problem Contest DO - 10.1364/OIC.2013.WC.1 AU - Li, Li AU - Dobrowolski, George T2 - Optical Interference Coatings T2 - Optics InfoBase Conference Papers; no. 2013 T3 - Optical Interference Coatings, June 16-21, 2013, Whistler, B.C. Canada SN - 2162-2701 SN - 978-1-55752-970-1 SP - WC.1 AB - A transmission filter from 400nm to 1100nm is selected for the contest to display current thin film manufacturing capabilities. Filters submitted by participants will be evaluated and the results will be presented at the conference. DA - 2013/06 PY - 2013 PB - OSA Publishing LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 7971e638-c81b-48da-8ba8-5aea843e20d8 ER - TY - JOUR TI - Herschel view of the Taurus B211/3 filament and striations: evidence of filamentary growth? DO - 10.1051/0004-6361/201220500 AU - Palmeirim, P. AU - André, Ph. AU - Kirk, J. AU - Ward-Thompson, D. AU - Arzoumanian, D. AU - Könyves, V. AU - Didelon, P. AU - Schneider, N. AU - Benedettini, M. AU - Bontemps, S. AU - Di Francesco, J. AU - Elia, D. AU - Griffin, M. AU - Hennemann, M. AU - Hill, T. AU - Martin, P. G. AU - Men’shchikov, A. AU - Molinari, S. AU - Motte, F. AU - Nguyen Luong, Q. AU - Nutter, D. AU - Peretto, N. AU - Pezzuto, S. AU - Roy, A. AU - Rygl, K. L. J. AU - Spinoglio, L. AU - White, G. L. T2 - Astronomy & Astrophysics SN - 0004-6361 SN - 1432-0746 VL - 550 SP - A38 SP - 1 EP - 9 KW - Star formation KW - ISM individual objects KW - B211–ISM clouds KW - ISM structure AB - We present first results from the Herschel Gould Belt survey for the B211/L1495 region in the Taurus molecular cloud. Thanks to their high sensitivity and dynamic range, the Herschel images reveal the structure of the dense, star-forming filament B211 with unprecedented detail, along with the presence of striations perpendicular to the filament and generally oriented along the magnetic field direction as traced by optical polarization vectors. Based on the column density and dust temperature maps derived from the Herschel data, we find that the radial density profile of the B211 filament approaches power-law behavior, ρ ∝ r⁻².⁰± ⁰.⁴, at large radii and that the temperature profile exhibits a marked drop at small radii. The observed density and temperature profiles of the B211 filament are in good agreement with a theoretical model of a cylindrical filament undergoing gravitational contraction with a polytropic equation of state: P ∝ ργ and T ∝ ργ⁻¹, with γ = 0.97 ± 0.01 < 1 (i.e., not strictly isothermal). The morphology of the column density map, where some of the perpendicular striations are apparently connected to the B211 filament, further suggests that the material may be accreting along the striations onto the main filament. The typical velocities expected for the infalling material in this picture are ~0.5–1 km s⁻¹, which are consistent with the existing kinematical constraints from previous CO observations. DA - 2013/01/23 PY - 2013 PB - EDP Sciences LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : aafdccc7-bf4b-4710-86dd-1b2c6d148d93 ER - TY - JOUR TI - On some aspects of the wheel/rail interaction DO - 10.1016/j.wear.2013.12.013 AU - Magel, Eric E. AU - Liu, Yan T2 - Wear T3 - The 9th International Conference on Contact Mechanics and Wear of Rail / Wheel Systems, CM2012, 27-30 August 2012, Chengdu, China SN - 0043-1648 VL - 314 IS - 1-2 SP - 132 EP - 139 KW - Wheel–rail interaction; Rolling contact fatigue; Surface roughness; Pummeling; Conformality AB - Problems in tribology and contact mechanics are becoming increasingly amenable to solution through models and simulation. But in application to the wheel/rail contact, there remain a number of very important features for which either gross simplifications or a lack of understanding or ability severely limits the success of those efforts. Examples include models of friction and material response (including damage functions). This paper examines a rather eclectic mix of wheel/rail factors with the goal of encouraging researchers to begin tackling and eradicating some of the bigger problem areas that remain in wheel–rail interaction modeling and to consider more rigorous implementation of real world conditions in simulations. DA - 2013/12/27 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : bdfde29d-c3b0-4d60-9266-38e753bf0af8 ER - TY - JOUR TI - Current knowledge on biotin nutrition in fish and research perspectives DO - 10.1111/raq.12053 AU - Yossa, Rodrigue AU - Sarker, Pallab K. AU - Mock, Donald M. AU - Lall, Santosh P. AU - Vandenberg, Grant W. T2 - Reviews in Aquaculture SN - 1753-5123 VL - 7 IS - 1 SP - 59 EP - 73 KW - Aquatic animals KW - Biotin KW - Fish KW - Nutrition KW - Vitamin AB - Biotin, a water-soluble vitamin, is essential for normal growth, development and health of all animals. In terrestrial animal nutrition, biotin has recently spurred scientific interest because of the increasing body of knowledge on biotin involvement in gene expression, cell cycle and reproduction in mammals, and recent advances in molecular biology techniques allowing a more effective estimation of biotin effects in metabolism and physiology. In contrast, this information is scarce in aquatic animal nutrition, as studies have essentially focused on the estimation of minimum biotin requirement for maximum growth and tissue storage as well as for the formulation of least-cost diet. This scarcity of information is also due to the lack of well-established indicators of biotin status in aquatic organisms. The present review is a comparative analysis of current knowledge on biotin physiology and nutritional biochemistry in terrestrial and aquatic animal nutrition. Also, general information on biotin sources, bioavailability, deficiency and requirement in mammals and fish is provided in order to plan further studies. In the future, biotin nutrition studies in aquaculture should also include haematological parameters, histopathology of the gills, liver and kidney, gonad development, gamete quality and quantity, fecundity, larvae survival and gene expression. Dietary biotin requirement levels should be estimated at every life history stage of farmed fish. The potential contribution of intestinal microflora to biotin supply in different fish species should be investigated. All this information will allow a better understanding of the essentiality of biotin in fish growth, development, reproduction and health. DA - 2013/12/26 PY - 2013 PB - Wiley LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : dba01ec4-9fec-430d-9dae-a57ac383b845 ER - TY - JOUR TI - Attosecond science DO - 10.1007/978-3-642-37623-8_1 AU - Corkum, P. B. T2 - Attosecond Physics: Attosecond Measurements and Control of Physical Systems T2 - Springer Series in Optical Sciences; 177 SN - 0342-4111 SN - 978-3-642-37622-1 SN - 978-3-642-37623-8 SP - 3 EP - 7 AB - Attosecond technology builds on, and contributes to, important historic directions in science. For this reason, the science has the depth to yield important discoveries for a long time. Unfortunately the title "attosecond" science biases us to think mostly about dynamics but many of the most important applications of "attosecond technology" may not be related to dynamics at all. This broad set of applications point to the future impact of the technology. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 7159c965-b146-408c-a633-2f93db1d27e5 ER - TY - JOUR TI - Attosecond science and technology DO - 10.1109/CLEOE-IQEC.2013.6801134 AU - Corkum, P.B. T2 - 2013 Conference on Lasers and Electro-Optics Europe and International Quantum Electronics Conference, CLEO/Europe-IQEC 2013 T3 - 2013 Conference on Lasers and Electro-Optics Europe and International Quantum Electronics Conference, CLEO/Europe-IQEC 2013, 12 May 2013 through 16 May 2013, Munich SP - 6801134 KW - Light KW - Light transmission KW - Quantum electronics KW - Wave packets KW - Attosecond pulse KW - Attosecond pulse generation KW - Attosecond science KW - Broad bandwidths KW - Electron wave packet KW - Intense light pulse KW - Light pulse KW - Soft X-ray KW - Electron optics AB - An intense light pulse can extract an electron wave packet from an atom near a field crest. This wave packet responds to the field, gaining and losing momentum as the field oscillates. During the process portions of the wave packet are inevitably driven back to the ion, and recombining with substantial momentum and thereby transferring the wave packet characteristics into a broad bandwidth burst of radiation that can extend continuously from the ultraviolet to the soft X-rays. Many characteristics of attosecond pulse are imposed by the time-dependent-field of a light pulse. By controlling the time-dependent-field, we control attosecond pulse generation. © 2013 IEEE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b91c5dba-4b4d-4f00-88cf-6a77308051fe ER - TY - JOUR TI - Femtosecond laser desorption of thin polymer films from a dielectric surface DO - 10.1051/matecconf/20130802004 AU - Mercadier, L. AU - Peng, J. AU - Sultan, Y. AU - Davis, T. AU - Rayner, D.M. AU - Corkum, P.B. T2 - MATEC Web of Conferences T3 - Workshop on Progress in Ultrafast Laser Modifications of Materials, 2013, 14 April 2013 through 19 April 2013, Cargese SN - 2261-236X VL - 8 SP - 2004 KW - Atomic force microscopy KW - Polymer films KW - Semiconducting films KW - Ultrashort pulses KW - Beam geometry KW - Dielectric surface KW - Thin polymer films KW - Two ways KW - Ultrafast lasers AB - We desorb polymer films from fused silica with a femtosecond laser and characterize the results by atomic force microscopy. Our study as a function of beam geometry and energy reveals two ways of achieving spatially controlled nanodesorption. © Owned by the authors, published by EDP Sciences, 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 431c2f5d-db1a-43b8-9047-d755957db1c2 ER - TY - JOUR TI - Studying the electronic structure of molecules with high harmonic spectroscopy DO - 10.1007/978-3-642-37623-8_10 AU - Villeneuve, D. M. AU - Bertrand, J. B. AU - Corkum, P. B. AU - Dudovich, N. AU - Itatani, J. AU - Kieffer, J. C. AU - Légaré, F. AU - Levesque, J. AU - Mairesse, Y. AU - Niikura, H. AU - Schmidt, B. E. AU - Shiner, A. D. AU - Wörner, H. J. T2 - Attosecond physics : attosecond measurements and control of physical systems T2 - Springer Series in Optical Sciences SN - 0342-4111 SN - 9783642376221 VL - 177 SP - 159 EP - 190 AB - High harmonic spectroscopy is a tool to study the valence electronic structure of atoms and molecules. It uses the techniques of high harmonic generation, in which a femtosecond laser ionizes the gas sample and XUV radiation is emitted in the forward direction. The XUV intensity, phase and polarization contain information about the orbital from which an electron was removed by the laser. High harmonic spectroscopy reveals details of electron-electron interactions, motion of electronic wave packets, and can follow a chemical reaction. © Springer-Verlag Berlin Heidelberg 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 71da2598-4bda-4844-a45c-4a04847fe6aa ER - TY - JOUR TI - Carrier envelope phase effects in strong field ionization of xenon with few-cycle 1.8 μm laser pulses DO - 10.1051/epjconf/20134102011 AU - Schmidt, B.E. AU - Möller, M. AU - Sayler, A.M. AU - Shiner, A.D. AU - Vampa, G. AU - Légaré, F. AU - Villeneuve, D.M. AU - Paulus, G.G. AU - Corkum, P.B. T2 - EPJ Web of Conferences T3 - 18th International Conference on Ultrafast Phenomena, UP 2012, 8 July 2012 through 13 July 2012, Lausanne SN - 2101-6275 SN - 9782759809561 VL - 41 SP - 2011 AB - Interferometrically CEP controlled few-cycle IR pulses revealed a strong influence on both, directly ionized and rescattered electrons in xenon for pulse durations from 2 to 5 cycles. © Owned by the authors, published by EDP Sciences, 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 91d47713-cfe3-40e7-b907-901bc1d8a7d6 ER - TY - JOUR TI - Attosecond spatial control of ionizing electron wave packets DO - 10.1109/CLEOE-IQEC.2013.6801133 AU - Zhang, L. AU - Xie, X. AU - Roither, S. AU - Kartashov, D. AU - Schoffler, M. AU - Shafir, D. AU - Corkum, P.B. AU - Baltuska, A. AU - Staudte, A. AU - Kitzler, M. T2 - 2013 Conference on Lasers and Electro-Optics Europe and International Quantum Electronics Conference, CLEO/Europe-IQEC 2013 T3 - 2013 Conference on Lasers and Electro-Optics Europe and International Quantum Electronics Conference, CLEO/Europe-IQEC 2013, 12 May 2013 through 16 May 2013, Munich SP - 6801133 KW - Quantum electronics KW - Wave packets KW - Attosecond science KW - Attosecond time scale KW - Electron wave packet KW - Electronic wave packets KW - Free electron KW - Laser fields KW - Polarization planes KW - Spatial control KW - Electron optics AB - Angstrom and attosecond control of free electron wave packets is one of the pinnacles of attosecond science. Orthogonally polarized two-color (OTC) laser fields allow to control the motion of field-ionizing electronic wave packets both in time and space[1]. In OTC pulses time and space are connected and thus an attosecond time scale is established in the polarization plane for both the emitted and the re-colliding wave packets[2,3]. © 2013 IEEE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f001345c-d337-4272-be4c-4aa092823406 ER - TY - JOUR TI - Robotic operation of the DAO 1.2-m telescope and McKellar spectrograph AU - Monin, D. AU - Saddlemyer, L. AU - Bohlender, D. T2 - Revista Mexicana de Astronomia y Astrofisica: Serie de Conferencias T3 - 3rd Workshop on Robotic Autonomous Observatories, Oct. 7-11, 2013, Torremolinos, Malaga, Spain SN - 1405-2059 VL - 45 SP - 69 EP - 70 KW - Instrumentation: spectrographs; Telescopes AB - The DAO 1.2-m telescope has been successfully used to obtain astronomical spectra in unattended robotic mode for a decade and approximately 2/3 of the nights scheduled on the telescope are now used in this fashion. The availability of such robotic operation has boosted the telescope's subscription rate by approximately 50% since telescope users no longer have to travel to the DAO in order to conduct their observing programs. An overview of the robotic system and some details of its operation are presented. DA - 2013/10/11 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 18eff6f3-f5c1-48fe-aec8-bf32f3fe3e3c ER - TY - JOUR TI - Characteristics of electron beam welded CA6NM AU - Sarafan, Sheida AU - Wanjara, Priti AU - Champliaud, Henri AU - Mathieu, Louis AU - Lanteigne, Jacques T2 - Proceedings of Materials Science and Technology T3 - Materials Science and Technology 2013: Advances in Hydroelectric Turbine Manufacturing and Repair, October 27-31, 2013, Montreal Canada SP - 720 EP - 732 AB - In this study, the viability of thick-gauge section assembly for hydroelectric turbine manufacture was considered by electron beam welding CA6NM martensitic stainless steel, a widely utilized hydro-turbine cast material. Particularly, bead-on-plate trials on 60 mm-thick CA6NM plates were carried out using a 42 kW high vacuum electron beam welding system. The influence of the heat input, beam position, beam oscillation (XSF-YSF), and in-situ pre-heating conditions on the characteristics of the weldments, such as the bead geometry, weld integrity, fusion zone and HAZ microstructures and hardness were evaluated. A relationship between the welding parameters and the resulting depth of penetration was established. A methodology for in-situ heating of the thick-gauge section prior to welding was developed and evaluated for reducing welding defects in CA6NM. DA - 2013 PY - 2013 UR - http://www.programmaster.org/PM/PM.nsf/ApprovedAbstracts/404D3E791ABD35B585257AFD000F3965?OpenDocument LA - eng N1 - A CD-only volume C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 78e61e80-823d-4448-8233-0e63f39e6bf6 ER - TY - JOUR TI - Fiber Laser Deposition of INCONEL 718 Using Powders AU - Zhang, Yinan AU - Cao, Xinjin AU - Wanjara, Priti AU - Medraj, Mamoun T2 - Proceedings of Materials Science and Technology T3 - Materials Science and Technology 2013: Symposium on Advanced Materials, Processes and Applications for Additive Manufacturing, October 27-31, 2013, Montreal Canada SP - 37 EP - 49 AB - Additive manufacturing is an emerging manufacturing and remanufacturing (repair) technique for value-added materials such as Inconel 718, particularly using a laser beam as the heating source. In this research work additive manufacturing of Inconel 718 using a continuous wave fiber laser and filler wire feed was studied. To simulate industrial conditions, the deposits were built on parent metal substrates that were extracted from an after-service Inconel 718 aerospace component. The evolution of the macrostructure, defects, microstructure and hardness of the deposits was evaluated in the as-deposited and post-clad heat treated conditions. The hardness of the laser deposits can be fully recovered to the level of the after-serviced parent metal after solution heat treatment and aging. The high integrity deposits had no visible pores but only some minor weld metal liquation cracking, which indicates the great potential of the laser deposition process to manufacture and repair superalloy components for aerospace applications. DA - 2013 PY - 2013 UR - http://www.programmaster.org/PM/PM.nsf/ApprovedAbstracts/0088ED4B38A0CE4C85257B290080720B?OpenDocument LA - eng N1 - A CD-only volume C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8a3e4a87-f4fd-4c10-b28d-d4de6efaa12a ER - TY - JOUR TI - Investigation of friction stir welding for industrial repair of commercially pure aluminum components AU - Larose, Simon AU - Wanjara, Priti AU - Monsarrat, Bruno AU - Comeau, Gail T2 - Proceedings of Materials Science and Technology 2013 T3 - Materials Science and Technology 2013: Symposium on Joining of Advanced and Specialty Materials (JASM XV), October 27-31 2013, Montreal Canada AB - Development of advanced repair technologies has gained increased interest recently stemming from the economic benefits of extending the service life of components. Instead of replacing the component, the failed regions can be refurbished by removing the damaged areas and repairing these with material addition and a suitable welding technology. Variations in material chemistry and dimensional mismatch at the interface between the original component and the added material constitute significant challenges for qualifying the repair process.Friction stir welding (FSW) was deliberated in this work to be the most promising solution for repairing flat commercially pure aluminum components. However, transfer of the FSW process from a laboratory scale to an industrial manufacturing environment has challenges specific to the nature of the application, which have been studied in this work alongside process development and optimization. DA - 2013 PY - 2013 UR - http://www.programmaster.org/PM/PM.nsf/ApprovedAbstracts/E461F19F80DA278085257B4200632441?OpenDocument LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : fb3ce2ec-72a7-47a0-8a76-adad30b8c09b ER - TY - JOUR TI - Effect of post-weld heat treatment on the mechanical properties of AA6061 friction stir welded joints AU - Wanjara, P. AU - Larose, S. AU - Gholipour, J. AU - Brochu, M. T2 - Proceedings of Materials Science and Technology 2013 T3 - Materials Science and Technology 2013: Symposium on Light Metals for Transportation, October 27-31, 2013, Montreal Canada SP - 1344 EP - 1351 AB - Aluminum alloys are increasingly used as part of light-weighting strategies for manufacturing components in the transportation sector. Widespread application has, however, been limited by the low weldability of high strength aluminum alloys, such as crack sensitive grades of the 2XXX, 6XXX and 7XXX series. As a solid-state joining process, friction stir welding (FSW) presents a tremendous potential for assembling 6xxx series aluminum structures due to the low energy involved, which allows lower welding-induced distortions and improved mechanical performance of the joint. In this work, FSW of 3.18 mm thick AA6061-T6 sheets was investigated to examine the influence of weld pitch on the microstructure and mechanical performance of butt joints. The mechanical properties of the welds were found to be lower than those of the AA6061 in the T6 temper. A post-weld heat treatment was effective for bringing the mechanical properties close to the base metal values. DA - 2013 PY - 2013 UR - http://www.programmaster.org/PM/PM.nsf/ApprovedAbstracts/3D45D573D2323A0D85257B420057916F?OpenDocument LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3f56faa2-ae98-455d-a3d6-40b23cc9d5e0 ER - TY - JOUR TI - Monitoring wear and corrosion with integrated ultrasonic transducers AU - Kruger, S.E. AU - Wu, K.-T. AU - Blouin, A. T2 - Journal of the Canadian Institute of Mining Metallurgy and Petroleum T3 - 23rd World Mining Congress, 11-15 August 2013, Montreal, Quebec, Canada VL - 5 IS - 3 KW - wear; corrosion; ultrasonic; permanent transducer; integrated ultrasonic trans AB - Real-time wear and corrosion measurement provides crucial information in determining an optimal schedule for corrective maintenance and is a powerful tool to maximize equipment availability and reliability. This paper presents integrated ultrasonic transducers (IUTs) that—when incorporated into structures to accurately measure the remaining thickness—can determine wear or corrosion losses. Transducers have a small footprint, perform comparable to other commercial ultrasonic transducers, and can withstand temperatures up to 400ºC. Results show that thickness changes of a few micrometres can be detected. Applications of this technology to mining equipment and its potential benefits are discussed. AB - Les mesures en temps réel de l’usure et de la corrosion fournissent de l’information cruciale pour établir un échéancier optimal de maintenance corrective; c’est aussi un puissant outil pour maximiser la disponibilité et la fiabilité des équipements. Cet article présente des transducteurs ultrasoniques intégrés (IUT) qui, lorsqu’incorporés dans des structures pour mesurer avec précision l’épaisseur restante, peuvent déterminer les pertes par usure ou corrosion. Ces transducteurs ont une petite empreinte, ils ont une performance comparable aux autres transducteurs ultrasoniques sur le marché et ils peuvent résister à des températures atteignant 400 °C. Les résultats montrent qu’il est possible de détecter des changements d’épaisseur de quelques micromètres. Les applications de cette technologie aux équipements miniers et ses avantages potentiels sont discutés. DA - 2013/08 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 44f857d4-ff76-4d9b-9795-9f9e1146b448 ER - TY - JOUR TI - Anti-obesity efficacy and mechanism of a Chinese herbal formulation DO - 10.1016/j.jcjd.2013.03.268 AU - Perry, Benjamin AU - Zhang, Junzeng AU - Saleh, Tarek AU - Wang, Yanwen T2 - Canadian Journal of Diabetes SN - 1499-2671 VL - 37 SP - Supplement 2 SP - S268 KW - traditional Chinese medicine; anti-obesity efficacy; Liuwei Dihuang AB - Overweight and obesity have been increasing rapidly over the last couple of decades. It is estimated that by the year 2015, approximately 2.3 billion adults will be classified as overweight (body mass index, BMI (in kg/m2) > 27), at least 700 million of whom will be considered as obese (BMI > 30 kg/m2). As a result, obesity has been referred to by many as a 21st century epidemic. For the treatment and management of overweight and obesity, traditional Chinese medicine (TCM) and the use of herbal formulations has become an increasingly attractive form of alternative/complementary medicine. This trend is also occurring in the face of a weight-loss product market largely typified by mediocre long-term efficacy and safety concerns, and an increasing global desire to seek out and develop both safe and efficacious products from natural sources. An in vivo study using obese-prone rats treated by twice-daily oral gavage with total daily dosages of 500, 1500 or 3500 mg/kg BW of Liuwei Dihuang (LWDH) showed the body weight-lowering efficacy of this herbal formulation. Subsequent in vivo investigations using collected tissues and in vitro studies using relevant cells lines and a 95% ethanol extract of the herbal formulation explored two potential body weight-lowering mechanisms of action, including appetite suppression and enhanced fatty acid oxidation. The results demonstrate the potential of LWDH as a natural agent for the prevention/ management of body weight and highlight its potential. DA - 2013/04 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a829147c-2911-4c8f-934d-3e18e54a6074 ER - TY - JOUR TI - CFHTLenS: the Canada–France–Hawaii Telescope Lensing Survey – imaging data and catalogue products DO - 10.1093/mnras/stt928 AU - Erben, T. AU - Hildebrandt, H. AU - Miller, L. AU - van Waerbeke, L. AU - Heymans, C. AU - Hoekstra, H. AU - Kitching, T.D. AU - Mellier, Y. AU - Benjamin, J. AU - Blake, C. AU - Bonnett, C. AU - Cordes, O. AU - Coupon, J. AU - Fu, L. AU - Gavazzi, R. AU - Gillis, B. AU - Grocutt, E. AU - Gwyn, S.D.J. AU - Holhjem, K. AU - Hudson, M.J. AU - Kilbinger, M. AU - Kuijken, K. AU - Milkeraitis, M. AU - Rowe, B.T.P. AU - Schrabback, T. AU - Semboloni, E. AU - Simon, P. AU - Smit, M. AU - Toader, O. AU - Varaei, S. AU - van Uitert, E. AU - Velander, M. T2 - Monthly Notices of the Royal Astronomical Society SN - 0035-8711 VL - 433 IS - 3 SP - 2545 EP - 2563 KW - CFHTLenS; Canada–France–Hawaii Telescope; data analysis AB - We present data products from the Canada–France–Hawaii Telescope Lensing Survey (CFHTLenS). CFHTLenS is based on the Wide component of the Canada–France–Hawaii Telescope Legacy Survey (CFHTLS). It encompasses 154 deg2 of deep, optical, high-quality, sub-arcsecond imaging data in the five optical filters u*g′r′i′z′. The scientific aims of the CFHTLenS team are weak gravitational lensing studies supported by photometric redshift estimates for the galaxies. This paper presents our data processing of the complete CFHTLenS data set. We were able to obtain a data set with very good image quality and high-quality astrometric and photometric calibration. Our external astrometric accuracy is between 60 and 70 mas with respect to Sloan Digital Sky Survey (SDSS) data, and the internal alignment in all filters is around 30 mas. Our average photometric calibration shows a dispersion of the order of 0.01–0.03 mag for g′r′i′z′ and about 0.04 mag for u* with respect to SDSS sources down to iSDSS ≤ 21. We demonstrate in accompanying papers that our data meet necessary requirements to fully exploit the survey for weak gravitational lensing analyses in connection with photometric redshift studies. In the spirit of the CFHTLS, all our data products are released to the astronomical community via the Canadian Astronomy Data Centre at http://www.cadc-ccda.hia-iha.nrc-cnrc.gc.ca/community/CFHTLens/query.html. We give a description and how-to manuals of the public products which include image pixel data, source catalogues with photometric redshift estimates and all relevant quantities to perform weak lensing studies. DA - 2013/06/18 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 903880af-a4df-4cf9-8823-2fc944f62e5a ER - TY - JOUR TI - A suggested classification for two groups of Campylobacter myoviruses DO - 10.1007/s00705-013-1788-2 AU - Javed, Muhammad Afzal AU - Ackermann, Hans-Wolfgang AU - Azeredo, Joana AU - Carvalho, Carla M. AU - Connerton, Ian AU - Evoy, Stephane AU - Hammerl, Jens André AU - Hertwig, Stefan AU - Lavigne, Rob AU - Singh, Amit AU - Szymanski, Christine M. AU - Timms, Andrew AU - Kropinski, Andrew M. T2 - Archives of Virology SN - 0304-8608 VL - 159 IS - 1 SP - 181 EP - 190 KW - Myoviridae KW - virus protein KW - bacteriophage KW - Campylobacter KW - genetics KW - genome size KW - isolation and purification KW - molecular genetics KW - phylogeny KW - ultrastructure KW - virology KW - virus genome KW - Genome, Viral KW - Molecular Sequence Data KW - Viral Proteins AB - Most Campylobacter bacteriophages isolated to date have long contractile tails and belong to the family Myoviridae. Based on their morphology, genome size and endonuclease restriction profile, Campylobacter phages were originally divided into three groups. The recent genome sequencing of seven virulent campylophages reveal further details of the relationships between these phages at the genome organization level. This article details the morphological and genomic features among the campylophages, investigates their taxonomic position, and proposes the creation of two new genera, the "Cp220likevirus and "Cp8unalikevirus" within a proposed subfamily, the "Eucampyvirinae" DA - 2013/07/24 PY - 2013 PB - Springer International Publishing LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : aa0f1948-423a-43d0-a327-0a0254ba35b7 ER - TY - JOUR TI - Molecular modeling of hydronium ion and water distribution in water-filled Pt nanochannels with corrugated walls DO - 10.1007/s12678-013-0174-x AU - Nouri-Khorasani, Amin AU - Malek, Kourosh AU - Eikerling, Michael T2 - Electrocatalysis SN - 1868-2529 VL - 5 IS - 2 SP - 167 EP - 176 KW - Polymer electrolyte fuel cells KW - Molecular modeling KW - Electrostatic effects KW - Local reaction conditions KW - Catalyst layer effectiveness AB - Classical molecular dynamics was employed to study the impact of nanoconfinement and surface nanostructure on electrostatic phenomena and transport properties in catalyst layer pores of polymer electrolyte fuel cells. The porous structure of an ionomer-free ultrathin catalyst layer was represented by a water-filled nanochannel with corrugated and negatively charged Pt walls. The equilibrium hydronium ion distribution in the channel was used to assess local reaction conditions. We rationalized the effects of nanostructuring and metal surface charge on the electrostatic effectiveness factor of the channel. Furthermore, we investigated the water dynamics in the nanochannel, calculating the self-diffusion coefficients of surface and bulk-like water. DA - 2013/12/11 PY - 2013 PB - Springer International Publishing LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9505ccc5-f711-4b5e-ba34-918f8fe1f002 ER - TY - JOUR TI - Efficient algorithm for crack detection in sewer images from closed-circuit television inspections DO - 10.1061/(ASCE)IS.1943-555X.0000161 AU - Halfawy, Mahmoud R. AU - Hengmeechai, Jantira T2 - Journal of Infrastructure Systems SN - 1076-0342 VL - 20 IS - 2 SP - 4013014 KW - Computer vision KW - Cracks KW - Defects KW - Feature extraction KW - Hough transforms KW - Image understanding KW - Mathematical morphology KW - Sewers KW - Automated defect detection KW - Background noise KW - Morphological operations KW - Pre-processing step KW - Rectangular shapes KW - Sewer inspection KW - Television inspection KW - Vertical edges KW - Crack detection KW - algorithm KW - computer vision KW - television KW - Alberta KW - Calgary KW - Regina KW - Saskatchewan AB - This paper presents a new algorithm for automated crack detection in sewer inspection closed-circuit television (CCTV) images. Cracks often have a long and thin rectangular shape with a darker appearance relative to other components in the image therefore, they typically manifest as edges. The proposed algorithm exploits previous information on the visual characteristics of crack features in typical CCTVimages to efficiently identify actual cracks and filter out background noise. The algorithm consists of three main steps. The first preprocessing step prepares the CCTV image for crack detection by identifying a set of candidate crack fragments using the Sobel method to detect horizontal and vertical edges separately. The Hough transform is then used to identify and remove the edges associated with information labels typically found in CCTV images. The second step applies a set of morphological operations to enhance candidate crack segments by filling the gaps between closely adjacent and aligned edges. The enhancement step results in merging crack fragments that potentially represent segments of the same crack curve. In the third step, two filters are defined based on previous knowledge of the visual characteristics of cracks, and then applied to remove noise edges and extract a set of real crack segments.We tested the proposed algorithm on a set of CCTV videos obtained from the cities of Regina and Calgary in Canada. The experimental results demonstrated the efficiency of the proposed algorithm, and showed its robustness in detecting various patterns of sewer cracks. DA - 2013/12/30 PY - 2013 PB - American Society of Civil Engineers LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 792e7f23-0ddd-4f59-8114-74ac884effa4 ER - TY - JOUR TI - Blood-brain barrier transport of amyloid beta peptides in efflux pump knock-out animals evaluated by in vivo optical imaging DO - 10.1186/2045-8118-10-13 AU - Zhang, Wandong AU - Xiong, Huaqi AU - Callaghan, Debbie AU - Liu, Hong AU - Jones, Aimee AU - Pei, Ke AU - Fatehi, Dorthy AU - Brunette, Eric AU - Stanimirovic, Danica T2 - Fluids and barriers of the CNS VL - 10 IS - 13 KW - Alzheimer’s disease; Aβ peptides; Blood-brain barrier; Mdr-1a/b P-glycoprotein; Abcb1a/b; Abcg2; Optical imaging AB - Aβ transport (flux) across the blood-brain barrier (BBB) is thought to contribute to the pathogenesis of Alzheimer’s disease as well as to elimination of toxic amyloid from the brain by immunotherapy. Several BBB transporters have been implicated in Aβ exchange between brain parenchyma and the circulation, including efflux transporters P-glycoprotein/ABCB1 and BCRP/ABCG2. Here we describe an application of in vivo optical imaging methods to study Aβ transport across the BBB in wild-type or animals deficient in specific efflux transporters. DA - 2013/02/25 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : dd0cc51f-e0c0-4229-a391-d9e21230380f ER - TY - JOUR TI - Altitude scaling of ice crystal accretion DO - 10.2514/6.2013-2677 AU - Currie, T.C. AU - Fuleki, D. AU - Knezevici, D.C. AU - MacLeod, J.D. T2 - 5th AIAA Atmospheric and Space Environments Conference T3 - 5th AIAA Atmospheric and Space Environments Conference, 24 June 2013 through 27 June 2013, San Diego, CA KW - Ice crystal clouds KW - Ice particles KW - Liquid water content KW - National Research Council of Canada KW - Semi-empirical modeling KW - Total water content KW - Volumetric diameters KW - Wet bulb temperature KW - Experiments KW - Sea level KW - Testing KW - Wind tunnels KW - Ice AB - This paper describes experiments performed in an altitude chamber at the National Research Council of Canada (NRC) as the first step towards developing altitude scaling laws and procedures that will possibly allow aero-engines to be certified for operation in ice crystal clouds at high altitude by testing in sea level facilities. The principal objective was to test the hypothesis that accretion within a compressor due to ice crystal ingestion occurs when the local ratio of freestream liquid water content (LWC) to total water content (TWC) lies within a critical range at an accretion-susceptible location. If this hypothesis is correct, the local LWC/TWC ratio is the key parameter that must be matched in tests at low and high pressures to match accretions. Experiments were conducted in a small wind tunnel with an axisymmetric test article, consisting of a hemispherical nose attached to a conical afterbody, at a fixed TWC over a range of LWC/TWC ratios at (absolute) pressures of 34.5 kPa and 69 kPa to test the hypothesis. The LWC/TWC ratio was varied by changing the wet bulb temperature. Accretion steady-state volumes and growth rates measured at the two pressures were compared at conditions which were analytically predicted to produce matched LWC/TWC ratios. Good agreement was achieved in all cases. Accretion growth was greatest for LWC/TWC ratios in the range 10-25%. Additional tests demonstrated that wet bulb temperature, which was identified as an important variable in earlier studies, had little influence on accretion growth beyond its effect on LWC/TWC (i.e. ice particle melting). Tests were also conducted to determine whether accretion growth scales linearly with TWC at constant LWC/TWC. Those tests confirmed that not only does the accretion growth rate in the early growth phase scale in direct proportion to TWC, but so does the final size of the accretion. A simple semi-empirical model for predicting this behavior is described. While most of the tests were conducted with an ice particle median volumetric diameter of 45μ, some of the scaling tests were repeated with larger particles, which produced smaller accretions. © 2013 by Her Majesty the Queen in Right of Canada. Published by the American Institute of Aeronautics and Astronautics. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e5f505f9-21a9-4af6-b530-83363abad861 ER - TY - JOUR TI - Particle size effects on ice crystal accretion - Part II DO - 10.2514/6.2013-2676 AU - Knezevici, D.C. AU - Fuleki, D. AU - Currie, T.C. AU - Galeote, B. AU - Chalmers, J. AU - MacLeod, J. T2 - 5th AIAA Atmospheric and Space Environments Conference T3 - 5th AIAA Atmospheric and Space Environments Conference, 24 June 2013 through 27 June 2013, San Diego, CA KW - Accretion rate KW - Gas turbine compressors KW - Incoming flows KW - Large particles KW - Loss mechanisms KW - Particle size effect KW - Water fraction KW - Wet bulb temperature KW - Compressors KW - Ducts KW - Gas turbines KW - Imaging techniques KW - Particle size KW - Particle size analysis KW - Ice AB - This paper describes ongoing research intended to simulate ice accretion in an inter-compressor duct bleed slot resulting from the ingestion of altitude ice crystals. The authors have previously shown that ice crystal particle size plays an important role in the ice crystal accretion phenomenon. It was also shown that ice crystal particle size affects the degree of natural melt that occurs for a given aerodynamic condition. The data presented herein decouples the effects of ice particle melt and particle size distribution to generate accretions with the same ratio of freestream liquid-to-total water fraction. The effects of wet bulb temperature and ice particle size on the natural melting of ice crystals are discussed. An ice preservation procedure is followed to allow tracings of the accretion to be taken along the test article. Ice crystal particle size distribution is characterized using a shadowgraphy imaging technique. Finally, the reduction in accretion rate relative to the theoretical maximum rate of surface accretion by ice crystal particles is discussed. The test article simulates a forward facing, inclined endwall bleed slot in a gas turbine compressor as a simplified two-dimensional representation. The geometry, having a surface inclined 20° to the incoming flow, proved to be susceptible to mixed phase ice crystal accretion. Particle size and particularly the large particle tail of the distribution had a significant impact on the magnitude of accretion under mixed phase test conditions for wet bulb temperatures above and below 0°C. The leading edge growth rates were found to be 1/4 to 1/9 of the theoretical growth rate suggesting that erosion, splashing, particle bounce and other loss mechanism rates are significant. The ice tracings were used to estimate an accretion mass for a hypothetical large bypass ratio gas turbine. It was found that approximately 4kg of ice could be generated should the inter-compressor duct be exposed to the conditions tested for 5 minutes. © 2013 by Her Majesty the Queen in Right of Canada. Published by the American Institute of Aeronautics and Astronautics. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f1296fb6-b1bc-44c9-8737-0d2c563e6d5e ER - TY - JOUR TI - Micromilled optical elements for edge-lit illumination panels DO - 10.1117/1.JMM.12.2.023002 AU - Ronny, Rahima Afrose AU - Knopf, George K. AU - Bordatchev, Evgueni AU - Nikumb, Suwas T2 - Journal of Micro/Nanolithography, MEMS, and MOEMS SN - 1932-5150 VL - 12 IS - 2 KW - optical light guide panels; edge lighting; micro-optics; micromilling AB - Edge-lit light guide panels (LGPs) with micropatterned surfaces represent a new technology for developing small- and medium-sized illumination sources for application such as automotive, residential lighting, and advertising displays. The shape, density, and spatial distribution of the micro-optical structures (MOSs) imprinted on the transparent LGP must be selected to achieve high brightness and uniform luminance over the active surface. We examine how round-tip cylindrical MOSs fabricated by precision micromilling can be used to create patterned surfaces on low-cost transparent polymethyl-methacrylate substrates for high-intensity illumination applications. The impact of varying the number, pitch, spatial distribution, and depth of the optical microstructures on lighting performance is initially investigated using LightTools™ simulation software. To illustrate the microfabrication process, several 100×100×6 mm3 LGP prototypes are constructed and tested. The prototypes include an “optimized” array of MOSs that exhibit near-uniform illumination (approximately 89%) across its active light-emitting surface. Although the average illumination was 7.3% less than the value predicted from numerical simulation, it demonstrates how LGPs can be created using micromilling operations. Customized MOS arrays with a bright rectangular pattern near the center of the panel and a sequence of MOSs that illuminate a predefined logo are also presented. DA - 2013/04/25 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 45d5bbec-fba0-4145-938a-4a36a1155c86 ER - TY - JOUR TI - Development of an inverse method for material characterization AU - Saboori, M. AU - Champliaud, H. AU - Gholipour, J. AU - Gakwaya, A. AU - Savoie, J. AU - Wanjara, P. T2 - Proceedings of Advances in Hydroelectric Turbine Manufacturing and Repair T3 - Materials Science and Technology 2013, October 27-31, 2013, Montreal, QC, Canada KW - inverse method; finite-element simulation; material properties AB - Conventional engineering analysis involves the determination of material properties under uniaxial loading conditions. The true stress-true strain curves generated through this way have been used in finite element modeling (FEM) of various forming processes. However, this method is only valid up to the onset of necking; after this point the stress state is not uniaxial and the errors between FEM results and experimental data are significant. In this paper a new work hardening equation for predicting material behavior after the instability was used for stainless steel 321 (SS 321) and Inconel 718 IN 718). A finite element model based on an inverse method was devised with the aim of determining the properties of isotropic materials after instability. To facilitate the process of material characterization, an algorithm was developed using LS-DYNA and Matlab software. Verification of this methodology was carried out by comparing the experimental load-displacement data (obtained by tensile testing) with the simulation results. DA - 2013 PY - 2013 LA - eng N1 - A CD-only volume C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 07e725dc-7c5e-4299-b85a-9cc38574a708 ER - TY - BOOK TI - Quebec Safety Code, Chapter VIII – Building, and National Fire Code of Canada 2010 (amended) AU - National Research Council of Canada and Régie du bâtiment du Québec T2 - National Fire Code of Canada KW - Codes and guides AB - This document, published by NRC in collaboration with the Régie du bâtiment du Québec, includes the amendments to Chapter VIII, Building, of the Quebec Safety Code, as well as an amended National Fire Code of Canada 2010 (NFC). Its contents include more stringent Quebec-specific provisions to improve fire safety in sleeping rooms and care occupancies, as well as provisions regarding the inspection and maintenance of building façades, multi-storey garages and water-cooling towers. The amended NFC clearly indicates the changes adopted by Quebec, which apply to the construction and renovation of buildings in that province. As in the case of the NFC, an objective-based approach was used to prepare Chapter VII, Building. The majority of the Code provisions are linked to objectives that describe the overall goals that the provisions are intended to achieve and to functional statements that describe conditions that help satisfy the objectives. This new information allows for flexibility by helping users evaluate alternative solutions to acceptable solutions described in the Code. DA - 2013/03/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 32e342a8-998e-4a43-8abb-7d49dbc392d8 ER - TY - JOUR TI - Simulations of magnetic field gradients due to micro-magnets on a triple quantum dot circuit DO - 10.1063/1.4848532 AU - Poulin-Lamarre, G. AU - Bureau-Oxton, C. AU - Kam, A. AU - Zawadzki, P. AU - Studenikin, S. AU - Aers, G. AU - Pioro-Ladrière, M. AU - Sachrajda, A.S. T2 - THE PHYSICS OF SEMICONDUCTORS: Proceedings of the 31st International Conference on the Physics of Semiconductors (ICPS) 2012 T2 - AIP Conference Proceedings; no. 1566 T3 - 31st International Conference on the Physics of Semiconductors, ICPS 2012, 29 July 2012 through 3 August 2012, Zurich SN - 0094-243X SN - 1551-7616 SN - 9780735411944 SP - 556 EP - 557 KW - Magnetic fields KW - Magnets KW - Different geometry KW - EDSR KW - Field gradient KW - Heisenberg KW - Local magnetic field KW - Magnetic field gradient KW - Micro-magnets KW - Triple quantum KW - Semiconductor quantum dots AB - To quantify the effects of local magnetic fields on triple quantum dots, the Heisenberg Hamiltonian has been diagonalized for three electrons coupled via the exchange interaction. In particular, we have investigated different geometries of micro-magnets located on top of the triple dot in order to optimize the field gradient characteristics. In this paper, we focus on two geometries which are candidates for an addressable EDSR triple quantum dot device. © 2013 AIP Publishing LLC. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 548e2b7c-54dd-487e-afd8-463ad6aca7e9 ER - TY - JOUR TI - Enhanced charge detection: Amplification factor, phase reversal and measurement time dependence DO - 10.1063/1.4848529 AU - Thorgrimson, J. AU - Studenikin, S.A. AU - Aers, G.C. AU - Kam, A. AU - Zawadzki, P. AU - Wasilewski, Z.R. AU - Bogan, A. AU - Sachrajda, A.S. T2 - THE PHYSICS OF SEMICONDUCTORS: Proceedings of the 31st International Conference on the Physics of Semiconductors (ICPS) 2012 T2 - AIP Conference Proceedings; no. 1566 T3 - 31st International Conference on the Physics of Semiconductors, ICPS 2012, 29 July 2012 through 3 August 2012, Zurich SN - 0094-243X SN - 1551-7616 SN - 9780735411944 SP - 550 EP - 551 KW - Amplification factors KW - Charge detection KW - Fringe contrasts KW - Measurement time KW - Phase reversal KW - Spin-qubits KW - Semiconductor quantum dots AB - Studenikin et al.[1] recently demonstrated a significant enhancement of the fringe contrast of coherent Landau-Zener-Stückelberg (LZS) oscillations between singlet S and triplet T+ two-spin states using a modified charge detection technique called enhanced charge detection (ECD). In this paper we explain the amplitude phase reversal and confirm the magnitude of the effect is consistent with our calibrations. We also show that the enhancement cannot be explained by a T1 effect. © 2013 AIP Publishing LLC. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8dc43bc5-d05d-4cf7-a4bc-4527c530fb1c ER - TY - JOUR TI - Coordinate metrology and the proposed E57.02 static pose determination standard AU - MacKinnon, David AU - Beraldin, Jean-Angelo AU - Hong, Tsai AU - Marvel, Jeremy T2 - Journal of the CMSC VL - 8 IS - 1 KW - pose estimation; ASTM; E57; non-contact 3D imaging system; standard AB - We present the Proposed Standard ASTM E57.02 "Standard Test Method for Evaluating Static Pose Measurement Systems" (Work Item ASTM WK31638) and explain why it should be considered important by coordinate metrologists. The stated purpose of the standard is to provide metrics and procedures to evaluate how well a non-contact 3D imaging system is able to determine an object's pose relative to the 3D imaging system. Pose estimation is particularly important for 3D imaging systems that can be moved during the process of generating a digital surface model of a surface, such as arm-mounted 3D imaging systems. The quality of the digital surface model generated by merging multiple depth maps depends on how well the 3D imaging system, or systems, was able to determine their pose during acquisition. We provide a summary of the document to date, the proposed test methods, and the current status of the proposed standard. DA - 2013/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : abdb64b8-874f-4287-bfda-56b35ece5c2a ER - TY - JOUR TI - Proposed E57.02 range measurement performance standard for medium-range 3D imaging systems AU - MacKinnon, David Kenneth AU - Cournoyer, Luc AU - Saidi, Kamel AU - Cheok, Geraldine AU - Bridges, Robert AU - Ingimarson, Darin T2 - Journal of the CMSC VL - 8 IS - 2 AB - In this article, we present the proposed standard ASTM E57.02 “Test Method to Evaluate the Range Measurement Performance of 3D Imaging Systems in the Medium Range” (Work Item ASTM WK12373). The stated purpose of the standard is to provide metrics and procedures to evaluate the range measurement performance of medium-range (2 m to 150 m working distance) noncontact three-dimensional (3D) imaging systems. We provide a summary of the document to date, the proposed test methods, and the current status of the proposed standard. As an example, we also present some preliminary results of experiments performed at the National Research Council Canada (NRCC). DA - 2013/10 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : beb7d886-99bb-4479-9720-5a09506a90fc ER - TY - JOUR TI - On the quality of residential ventilation systems in Canada AU - MacDonald, Iain AU - Magee, R. AU - Fugler, D. T3 - AIVC Workshop on Securing the Quality of Ventilation Systems in Residential Buildings: Status and Perspectives, March 18-19th 2013, Brussels, Belgium AB - The residential ventilation market in Canada is defined by the country’s geography and its relationship with the USA. Codes and standards have been developed in Canada to unify the approach across the country and coordinate with the USA market, however due to regional variations (partially a result of the political structure) the “model” building code developed at the national level is implemented at the provincial/territorial level and can subsequently be modified at the municipal level. This can lead to regional variations in code requirements, e.g. the predominant use of exhaust-only systems in Ontario. The long heating season and cold winters have driven construction standards in Canada to produce air-tight buildings as a matter of course. The current energy code (2012) states that the worst case air change rate at 50 Pa for new build is 3.2 and if the air barrier system has been constructed to a higher standard (prescriptively defined) 2.5 air changes per hour, or the tested value can be used. Given these levels of air tightness were being achieved in the 1980’s it became apparent that deliberate mechanical ventilation was required. This need had been introduced into the building code 1980 but was refined and expanded through 1995 (the code is updated on a five year cycle). In 1991 the mechanical ventilation standard (CSA F-326-M91) was published covering design, installation and commissioning. The rate of new construction in Canada is such that almost 25% of single family homes have been constructed since 1990. Combining this with the code requirements for mechanical ventilation systems it can be concluded that the residential ventilation industry is well developed and mature. Future refinements will be made as our understanding of health and ventilation is further developed and as energy constraints become more pertinent. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d0c2da0e-bea5-48cf-a069-094caddefaaa ER - TY - JOUR TI - Integrated rapid 3D mapping and laser additive repair of gas turbine engine components AU - Xue, Lijue AU - Donovan, Matt AU - Li, Yangsheng AU - Chen, Jianyin AU - Wang, Shaodong AU - Campbell, Glen T2 - 2013 ICALEO Conference Proceedings T3 - 32nd International Congress on Applications of Lasers and Electro-Optics (ICALEO), 2013, Miami FL, USA SP - 318 EP - 325 AB - National Research Council Canada (NRC) has developed precision laser additive repair of worn gas turbine components. The repair system uses integrated 3D mapping and laser additive deposition. The integrated inspection and repair system is capable of inspecting and repairing a worn gas turbine injector in less than one hour. This innovative system dramatically improves repair time and cost of high value gas turbine components. In this paper, a case study will be presented as a joint effort by NRC and UTC Aerospace Systems to evaluate the feasibility of repair of worn fuel injectors from a land based gas turbine engine. The project evaluated the use of laser cladding of cobolt alloy L-605 for repair of worn engine components on a Rolls Royce 501K engine. Test results reveals that laser clad L-605 on wrought L-605 substrate demonstrates comparable or even substantially improved fatigue life as compared to the baseline L-605 specimens at elevated temperature. Laser clad L-605 also shows comparable wear resistance. The paper will demonstrate the improved repair of the fuel injectors via laser cladding repair and the metallurgical evaluation of the repair. The paper documents the improvement of the repair from several weeks and fabrication of several placement componenets to a matter of only a few hours to inspect and repair using the NRC laser additive manufacturing system. DA - 2013 PY - 2013 LA - eng N1 - On CD-ROM C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1ecdfa54-b18e-40c1-b9a6-224570922c33 ER - TY - JOUR TI - 5-axis in-line measurement system for laser materials processing DO - 10.1115/IMECE2013-62932 AU - Li, Yangsheng AU - Xue, Lijue AU - Wang, Shaodong T2 - ASME 2013 International Mechanical Engineering Congress and Exposition, Volume 2A: Advanced Manufacturing T3 - ASME 2013 International Mechanical Engineering Congress and Exposition, November 15-21, 2013, San Diego CA, USA SN - 978-0-7918-5618-5 AB - The dimensional and positional information is very important for laser materials processing of components, especially for laser cladding-based additive manufacturing. Therefore, inspection of the component based on its original CAD model is essential to ensure the component meeting the geometrical requirements. In general, the processed component has to be dismounted from the laser fabrication system before it can be inspected, which is time-consuming and may introduce alignment error from datum. In this paper, a 5-axis in-line measurement system is introduced, in which a non-contact laser measuring method along with CAD/CAM software is integrated to a laser materials processing system. An algorithm has been developed to automatically generate NC programs for measurement and comparison for outside features of components. Therefore, the inspection can be performed just after the component has been fabricated on the same system. Comparing to a 3-axis measuring system we reported before, the developed 5-axis inline measurement system provides much more flexibility, accessibility and accuracy for performing measurement on site. The developed in-line measuring capability can extend the functionality of conventional laser materials processing system and significantly shorten inspection time. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8c531152-b49a-46f1-8da9-fb26544a320d ER - TY - CHAP TI - Methods and role of embryo rescue technique in alien gene transfer DO - 10.1007/978-1-4614-8585-8_4 AU - Lulsdorf, Monika M. AU - Ferrie, Alison AU - Slater, Susan M. H. AU - Yuan, Hai Ying T2 - Alien Gene Transfer in Crop Plants, Volume 1 SN - 978-1-4614-8584-1 SN - 978-1-4614-8585-8 SP - 77 EP - 103 KW - Embryo rescue; Protocols; Oil crops; Cereals; Legumes; Horticulture crops AB - Embryo abortion occurs frequently in wide crosses, and thus embryo rescue is required for survival of the next generation. Rescues are performed by either directly transferring the excised embryo to an artificial medium or indirectly through flower (ovary), immature seed (fertilized ovule), or pod (silique) culture. Various techniques used for oil crops, cereals, legumes, and horticultural crops are presented. Altering medium components were the major routes for developing protocols for each species with adaptations to the base medium, sucrose concentration, or vitamin and growth regulator content. Monocot culture tended to be more direct than dicot culture, where many protocols required a multi-step approach from pod to ovule culture to embryo rescue, shoot regeneration, and root induction. Each step required a specific medium and growth conditions. Hybrid embryos as young as 2 days after pollination have been recovered. However, many species such as soybean and chickpea still need procedures for rescue of very young embryos. In other species hurdles such as poor rooting have been overcome by using grafting techniques. Embryo rescue remains a useful component in any breeding program where wide or interspecific crosses are preformed, where rapid cycling through generations is used, and where germplasm preservation is required. DA - 2013/10/17 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a6d24503-6e97-40b0-ae03-ade774321840 ER - TY - JOUR TI - A generic model of transcriptional regulatory networks : application to plants under abiotic stress DO - 10.1109/GENSIPS.2013.6735922 AU - Tchagang, Alain B. AU - Phan, Sieu AU - Famili, Fazel AU - Pan, Youlian AU - Cutler, Adrian J. AU - Zou, Jitao T3 - 2013 IEEE International Workshop on Genomic Signal Processing and Statistics (GENSIPS), Nov. 17 to 19, 2013, Houston, Texas SN - 978-1-4799-3462-1 SN - 978-1-4799-3461-4 SP - 28 EP - 31 KW - Abiotic-stress response; Adverse environment; Arabidopsis thaliana; Computational approach; Experimental methods; Mathematical method; Stress-responsive gene; Transcriptional regulatory networks AB - Understanding the relationships between transcription factors (TFs) and genes in plants under abiotic stress responses, tolerance and adaptation to adverse environments is very important in developing resilient crop varieties. While experimental methods to characterize stress responsive TFs and their targets are highly accurate, identification and characterization of the role of a given gene in a given stress response event are often laborious and time consuming. Computational approaches, on the other hand, offer a platform to identify new knowledge by integrating high throughput omics data and mathematical methods/models. In this research, we have developed a generic linear model of transcriptional regulatory networks (TRNs) and a companion algorithm to identify and to characterize stress responsive genes and their roles in a given stress response event. The proposed methodology was applied to plants, by using Arabidopsis thaliana as an example, under abiotic stress. Well known interactions were inferred as well as putative novel ones that may play important roles in plants under abiotic stress conditions as confirmed by statistical and literature evidences. DA - 2013/11/19 PY - 2013 PB - IEEE LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a5216d6e-c708-4ee7-95d5-d33eed3d6fa1 ER - TY - JOUR TI - Conductivity control of as-grown branched indium tin oxide nanowire networks DO - 10.1088/0957-4484/25/3/035701 AU - LaForge, J. M. AU - Cocker, T. L. AU - Beaudry, A. L. AU - Cui, K. AU - Tucker, R. T. AU - Taschuk, M. T. AU - Hegmann, F. A. AU - Brett, M. J. T2 - Nanotechnology SN - 0957-4484 VL - 25 IS - 3 SP - 35701 SP - 1 EP - 9 KW - branched nanowires KW - nanowires KW - indium tin oxide KW - Hz time-domain spectroscopy KW - conductivity AB - Branched indium tin oxide (ITO) nanowire networks are promising candidates for transparent conductive oxide applications, such as optoelectronic electrodes, due to their high porosity. However, these branched networks also present new challenges in assessing conductivity. Conventional four-point probe techniques cannot separate the effect of porosity on the long-range conductivity from the intrinsic material conductivity. Here we compare the average nanoscale conductivity within the film measured by terahertz time-domain spectroscopy (THz-TDS) to the film conductivity measured by four-point probe in a branched ITO nanowire network. Both techniques report conductivity increases with deposition flux rate from 0.5 to 3.0 nm s-1, achieving a maximum of ∼10 (Ω cm)-1. Modeling the THz-TDS conductivity data using the Drude-Smith model allows us to distinguish between conductivity increases resulting from morphological changes and those resulting from the intrinsic properties of the ITO. In particular, the intrinsic material conductivity within the nanowires can be extracted, and is found to reach a maximum of ∼3000 (Ω cm)-1, comparable to bulk ITO. To determine the mechanism responsible for increasing conductivity with flux rate, we characterize dopant concentration and morphological changes (i.e., to branching behavior, nanowire diameter and nucleation layers). We propose that changes in the electron density, primarily due to changes in O-vacancy concentration at different flux rates, are responsible for the observed conductivity increase. This understanding will assist balancing structural and conductivity requirements in applications of transparent conductive oxide networks. DA - 2013/12/17 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e63703ed-cbc4-4c5f-859c-de745ccef0f3 ER - TY - JOUR TI - Spatially resolved LMC star formation history - I. Outside in evolution of the outer LMC disc DO - 10.1093/mnras/stt2220 AU - Meschin, I. AU - Gallart, C. AU - Aparicio, A. AU - Hidalgo, S. L. AU - Monelli, M. AU - Stetson, P. B. AU - Carrera, R. T2 - Monthly Notices of the Royal Astronomical Society SN - 0035-8711 VL - 438 IS - 2 SP - stt2220 SP - 1067 EP - 1080 KW - Hertzsprung–Russell and colour–magnitude diagram KW - galaxies: evolution KW - Magellanic Clouds KW - galaxies: stellar content KW - galaxies: structure AB - We study the evolution of three fields in the outer Large Magellanic Cloud (LMC) disc (Rgc = 3.5-6.2 kpc). Their star formation history indicates a stellar population gradient such that younger stellar populations are more centrally concentrated. We identify two main starforming epochs, separated by a period of lower activity between ≃7 and ≃4Gyr ago. Their relative importance varies from a similar amount of stars formed in the two epochs in the innermost field to only 40 per cent of the stars formed in the more recent epoch in the outermost field. The young star-forming epoch continues to the present time in the innermost field, but lasted only till ≃ 0.8 and 1.3Gyr ago at Rgc = 5°.5 and 7°.1, respectively. This gradient is correlated with the measured HI column density and implies an outside-in quenching of the star formation, possibly related to a variation of the size of the HI disc. This could either result from gas depletion due to star formation or ram-pressure stripping, or from to the compression of the gas disc as ram pressure from the MilkyWay halo acted on the LMCinterstellarmedium. The latter two situations may have occurred when the LMC first approached the Milky Way. DA - 2013/12/27 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 57b5f579-4f83-4770-b552-2b317ac47ae8 ER - TY - JOUR TI - The Dominion astrophysical observatory magnetic field survey (DMFS) DO - 10.1017/S1743921314002300 AU - Bohlender, David A. AU - Monin, Dmitry T2 - Magnetic Fields throughout Stellar Evolution T2 - Proceedings of the International Astronomical Union; 9 SN - 1743-9213 SN - 1743-9221 SN - 9781107044982 SP - 288 EP - 289 KW - magnetic fields KW - instrumentation: polarimeteres KW - stars: magnetic fields AB - In this paper we present a few results from the first three years of an ongoing survey of globally-ordered magnetic fields in relatively faint (down to V ≈ 9) upper main sequence peculiar stars that we are conducting on the Dominion Astrophysical Observatory (DAO) Plaskett telescope. The DMFS uses the inexpensive DAO polarimeter module, dimaPol, mounted at the Cassegrain focus of the 1.8 m telescope to detect new magnetic stars and determine rotation periods and longitudinal magnetic field curves using medium-resolution (R ≈ 10,000) circular spectropolarimetry of both the Hβ line and metal lines in an approximately 280 Å wide wavelength region centered on Hβ. By concentrating on the mid-B to A-type peculiar stars, the DMFS provides an extension to the 'Magnetism in Massive Stars' (MIMES) Large Program which concentrated on similar field detections in more massive stars. DA - 2013 PY - 2013 PB - Cambridge University Press PB - International Astronomical Union PB - Union Astronomique Internationale LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0eb42ac1-b899-4432-8bb6-24616dd131f4 ER - TY - JOUR TI - A nuclear forensic method for determining the age of radioactive cobalt sources DO - 10.1039/c3ay41443d AU - Charbonneau, Luc AU - Benoit, Jean-Michel AU - Jovanovic, Slobodan AU - St-Amant, Nadereh AU - Kiser, Stephen AU - Cooke, Michael W. AU - Mercier, Jean-François AU - Nielsen, Kathy AU - Kelly, David AU - Samuleev, Pavel AU - Galea, Raphael AU - Moore, Kimberly AU - Saull, Patrick R. B. AU - Chamberlain, David B. AU - Steeb, Jennifer L. AU - Graczyk, Donald G. AU - Tsai, Yifen AU - Sullivan, Vivian S. AU - Dimayuga, Ike C. AU - Shi, Youqing AU - Rao, Raghu AU - Larivière, Dominic T2 - Analytical Methods SN - 1759-9660 VL - 6 IS - 4 SP - 983 EP - 992 KW - Analytical procedure KW - Chromatographic separations KW - Decontamination factors KW - Mass spectrometric detection KW - Nuclear forensics KW - Radioactive cobalt KW - Solid-phase extraction KW - Cobalt KW - Liquid chromatography KW - Nickel KW - Optimization KW - Radioactivity KW - Resins KW - Radiation decontamination AB - An analytical procedure for determining the relative amounts of ⁶⁰Co and its ⁶⁰Ni daughter in a radioactive cobalt source by means of chromatographic separation and radiometric and mass spectrometric detection was developed, optimized and assessed through two round robin exercises for nuclear forensic investigations. Solid phase extraction (EXC) using Ni resin (Eichrom) and ion exchange (IEC) using Dowex-1X8 (Acros Organics) chromatographic approaches were considered for separating Co and Ni. Decontamination factors of 25 and 2.8 × 10⁶ were measured for EXC and IEC, respectively. Based on those results, only the IEC option was pursued. The effects of particle size, mass of resin, and degree of cross-linkage for decontamination performance were assessed, and the loading/eluting conditions were optimized. Canadian (CNSC, RPB, UL, RMC, AECL) and American (ANL) laboratories participated in two round robin exercises designed by the National Research Council of Canada to determine the suitability and limitations of the proposed methods. Age determination for freshly irradiated sources (<1 a) and for sources with high Ni content was challenging for the laboratories. Nevertheless, age estimates were obtained with sufficient accuracy for nuclear forensic purposes. DA - 2013/10/25 PY - 2013 PB - Royal Society of Chemistry LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 629600d6-50e6-45b8-bf47-52a4e6695964 ER - TY - JOUR TI - A mutant Brassica napus (canola) population for the identification of new genetic diversity via TILLING and next generation sequencing DO - 10.1371/journal.pone.0084303 AU - Gilchrist, Erin J. AU - Sidebottom, Christine H. D. AU - Koh, Chu Shin AU - MacInnes, Tanya AU - Sharpe, Andrew G. AU - Haughn, George W. T2 - PLoS One SN - 1932-6203 VL - 8 IS - 12 SP - e84303 KW - endonuclease KW - mesylic acid ethyl ester KW - plant DNA AB - We have generated a Brassica napus (canola) population of 3,158 EMS-mutagenised lines and used TILLING to demonstrate that the population has a high enough mutation density that it will be useful for identification of mutations in genes of interest in this important crop species. TILLING is a reverse genetics technique that has been successfully used in many plant and animal species. Classical TILLING involves the generation of a mutagenised population, followed by screening of DNA samples using a mismatch-specific endonuclease that cleaves only those PCR products that carry a mutation. Polyacrylamide gel detection is then used to visualise the mutations in any gene of interest. We have used this TILLING technique to identify 432 unique mutations in 26 different genes in B. napus (canola cv. DH12075). This reflects a mutation density ranging from 1/56 kb to 1/308 kb (depending on the locus) with an average of 1/109 kb. We have also successfully verified the utility of next generation sequencing technology as a powerful approach for the identification of rare mutations in a population of plants, even in polyploid species such as B. napus. Most of the mutants we have identified are publically available. DA - 2013/12/20 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9e471459-ef5d-47cd-9368-40c6acbf232c ER - TY - JOUR TI - An activated form of UFO alters leaf development and produces ectopic floral and inflorescence meristems DO - 10.1371/journal.pone.0083807 AU - Risseeuw, Eddy AU - Venglat, Prakash AU - Xiang, Daoquan AU - Komendant, Kristina AU - Daskalchuk, Tim AU - Babic, Vivijan AU - Crosby, William AU - Datla, Raju T2 - PLoS One SN - 1932-6203 VL - 8 IS - 12 SP - e83807 AB - Plants are unique in their ability to continuously produce new meristems and organ primordia. In Arabidopsis, the transcription factor LEAFY (LFY) functions as a master regulator of a gene network that is important for floral meristem and organ specification. UNUSUAL FLORAL ORGANS (UFO) is a co-activator of LEAFY and is required for proper activation of APETALA3 in the floral meristem during the specification of stamens and petals. The ufo mutants display defects in other parts of the flower and the inflorescence, suggestive of additional roles. Here we show that the normal determinacy of the developing Arabidopsis leaves is affected by the expression of a gain-of-function UFO fusion protein with the VP16 transcriptional activator domain. In these lines, the rosette and cauline leaf primordia exhibit reiterated serration, and upon flowering produce ectopic meristems that develop into flowers, bract leaves and inflorescences. These striking phenotypes reveal that developing leaves maintain the competency to initiate flower and inflorescence programs. Furthermore, the gain-of-function phenotypes are dependent on LFY and the SEPALLATA (SEP) MADS-box transcription factors, indicative of their functional interactions with UFO. The findings of this study also suggest that UFO promotes the establishment of the lateral meristems and primordia in the peripheral zone of the apical and floral meristems by enhancing the activity of LFY. These novel phenotypes along with the mutant phenotypes of UFO orthologs in other plant species suggest a broader function for UFO in plants. DA - 2013/12/23 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 95a0ea9b-df14-4ddb-bda1-68c78ce18a98 ER - TY - JOUR TI - Generation of stable engineered chromosomes in soybean DO - 10.5511/plantbiotechnology.13.0704b AU - Zhang, Yunfang AU - Itaya, Asuka AU - Fu, Ping AU - Zheng, Suqin AU - Hulm, Jacquie AU - Blahut-Beatty, Laureen AU - Marillia, Elizabeth-France AU - Lindenbaum, Michael AU - Fabijanski, Steven AU - Simmonds, Daina T2 - Plant biotechnology SN - 1342-4580 VL - 30 IS - 5 SP - 455 EP - 464 KW - Engineered chromosomes KW - artificial chromosomes KW - traits KW - stacking KW - soybean KW - field trial AB - A system for engineering plant chromosomes has been developed to facilitate the introduction of novel genes into the plant genome. The system is based on the establishment of a unique genetic locus within the ribosomal DNA (rDNA) region of the host chromosome to provide a permissive environment for expression of the introduced genes of interest (GOI). The genetic locus can exist within an independent, fully functional "minichromosome" (MC) or as a segment of a modified host chromosome (termed Engineered Trait Locus or ETL). The site-specific integration of transgenes to the rDNA locus isolates them from other endogenous genes, an advantage over conventional transformation in which foreign genes are inserted randomly into the host genome. Furthermore, MCs or ETLs can confer stability and high expression of the transgenes, as demonstrated in mammalian systems. To evaluate this system in plants, several MC and ETL lines have been generated in soybean, an important crop used worldwide for protein and oil consumption. The characterization of a soybean line containing an MC demonstrates that 1) the MC is stable over multiple generations as well as in field conditions, 2) maintaining the MC has no adverse phenotypic consequences, and 3) the MC can provide high-level expression of the introduced GOI. DA - 2013/11 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3299de6e-395b-45e5-aaf7-a48c15088c56 ER - TY - JOUR TI - Guest editorial: 3D imaging, processing and modelling DO - 10.1007/s11263-012-0604-x AU - Godin, Guy AU - Goesele, Michael AU - Matsushita, Yasuyuki AU - Sagawa, Ryusuke AU - Yang, Ruigang T2 - International Journal of Computer Vision SN - 0920-5691 VL - 102 IS - 1-Mar SP - 1 EP - 2 DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : da302550-62a2-410c-97d4-ae91f46ea0f5 ER - TY - JOUR TI - Survey of variable stability helicopter applications in handling qualities research AU - Fletcher, J. AU - Alexander, Marc AU - Hoefinger, Marc T2 - 69th American Helicopter Society International Annual Forum 2013 : Vertical Flight Technical Society, Phoenix, Arizona, USA, 21-23 May 2013. T2 - Annual forum proceedings T3 - 69th American Helicopter Society International Annual Forum 2013, May 21-23, 2013 SN - 1552-2938 SN - 9781627486514 VL - 1 KW - Active control technologies KW - Aerospace products KW - Client requirement KW - Concept demonstration KW - Operational challenges KW - Regulatory standards KW - Technology development KW - Variable stability systems KW - Bells KW - Helicopter rotors KW - Research aircraft KW - Rotors KW - Surveys KW - Helicopters AB - Applications of Variable Stability Systems (VSS) rotorcraft are motivated by client requirements. Areas may include vehicle and technology development, concept demonstration, regulatory standards investigations, and training programs. A survey of civilian Canadian and European full-authority VSS rotorcraft (NRC Bell 205A Airborne Simulator, NRC Bell 412 Advanced Systems Research Aircraft, and DLR EC 135 Active Control Technology/Flying Helicopter Simulator) presents an overview of facilities, applications, operational challenges, and lessons learned. The breadth of scientific capability highlights the potential of these modern facilities to support development of next generation aeronautical and aerospace products. Copyright © 2013 by the American Helicopter Society International, Inc. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e89605a3-a03f-4a57-9ea2-088a3ee28f00 ER - TY - JOUR TI - Substrate integrated waveguide couplers for tapered slot antennas in adaptive receiver applications AU - Locke, Lisa AU - Kordiboroujeni, Zamzam AU - Bornemann, Jens AU - Claude, Stéphane T2 - 2013 7th European Conference on Antennas and Propagation (EuCAP) T3 - 2013 7th European Conference on Antennas and Propagation, EuCAP 2013, 8 April 2013 through 12 April 2013, Gothenburg SN - 978-88-907018-1-8 SN - 978-1-4673-2187-7 SP - 6546824 SP - 2865 EP - 2869 KW - Adaptive receivers KW - Coupler design KW - Design procedure KW - E-field KW - Plane wave KW - Tapered slot antennas KW - Antenna radiation KW - Design KW - Directional couplers KW - Microwave circuits KW - Slot antennas KW - Waveguide couplers KW - Substrate integrated waveguides AB - The design of substrate integrated waveguide couplers for adaptive receiver applications employing tapered slot antennas is presented. Two different 20 dB couplers are designed on low-permittivity substrate, and their performances are verified by commercially available field solvers. For an incident plane wave, the systems of antenna and couplers are demonstrated to provide the desired operation between 18 GHz and 28 GHz in terms of both received E-field levels and propagation through the components. Antenna radiation patterns are provided. Two different SIW coupler designs are compared with measurements and are found in good agreement, thus validating the design procedure. © 2013 EurAAP. DA - 2013 PY - 2013 UR - http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=6546824 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 00342d2e-1ad0-4fdd-b6a9-5851c746e2b2 ER - TY - JOUR TI - Near-field cavity optomechanical probing of nanomechanics AU - Hryciw, Aaron C. AU - Khanaliloo, Behzad AU - Wu, Marcelo AU - Healey, Chris J. AU - Barclay, Paul T2 - CLEO: QELS_Fundamental Science, CLEO:QELS FS 2013 T3 - CLEO: QELS_Fundamental Science, CLEO:QELS FS 2013, June 9-14, 2013, San Jose, CA, USA SN - 978-1-55752-972-5 SP - QTh3B.6 AB - An optical fiber taper placed in the near field of a "split-beam" photonic crystal nanobeam cavity with a physical gap at the cavity center breaks the system's vertical dielectric symmetry, enabling selective optomechanical coupling to multiple cantilever resonances using a single optical nanocavity mode. © 2013 Optical Society of America. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 033fb283-e78f-4412-8b50-300c6a7a83df ER - TY - JOUR TI - Optomechanical torsional sensing in photonic crystal split-beam nanocavities AU - Wu, Marcelo AU - Hryciw, Aaron C. AU - Freeman, Mark R. AU - Davis, John P. AU - Barclay, Paul E. T2 - CLEO: Science and Innovations, CLEO_SI 2013 T3 - CLEO: Science and Innovations, CLEO_SI 2013, June 9-14, 2013, San Jose, CA, USA SN - 978-1-55752-972-5 SP - CW3F.3 KW - Nano-cavities KW - Optomechanical KW - Torsional motion KW - Photonic crystals AB - Photonic crystal split-beam nanocavities are proposed and fabricated for optomechanical detection of torsional motion. Large optomechanical transduction around 20 GHz/nm allows for predicted torsional sensitivities down to 10-20 Nm=pHz. © 2013 Optical Society of America. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f8de648c-b39e-4a14-953a-7f0cf8610fd7 ER - TY - JOUR TI - Characterization of detector modulation-transfer function with noise, edge, and holographic methods DO - 10.1016/j.ultramic.2013.02.021 AU - McLeod, Robert A. AU - Malac, Marek T2 - Ultramicroscopy SN - 0304-3991 VL - 129 SP - 42 EP - 52 KW - Slow-scan CCD detector; CCD camera; Electron detection; Scintillator; Modulation transfer function (MTF); Point spread function (PSF); Noise transfer function (NTF); Noise power spectrum (NPS); Incomplete read-out; Detector quantum efficiency (DQE); Detector noise; Electron holography; Transmission electron microscopy (TEM); Gain reference; Reference images AB - We developed a new method for characterization of detector performance used in the transmission electron microscope (TEM) based on the measured contrast of holographic fringes. The new method changes spatial frequency of the measured holographic fringes, generated by an electrostatic biprism and Schottky or cold field-emission gun, to sample the modulation-transfer function (MTF) of the detector. The MTF of a Gatan Ultrascan™ 1000 charged-coupled detector (CCD) is evaluated using the new method and the results are compared to the established noise and slanted-edge method results. Requirements for accuracy of the edge and noise MTF methods are discussed. We consider issues surrounding incomplete read-out and how it affects the gain reference normalization of the detector. We evaluate how the MTF affects optimization of experimental parameters in the TEM. © 2013 Elsevier B.V. DA - 2013/03/14 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 26dfbc02-49e2-471e-ae97-fdaeb51c9882 ER - TY - JOUR TI - Characterization of biopharmaceuticals by NMR spectroscopy DO - 10.1016/j.trac.2013.03.009 AU - Wishart, David S. T2 - TrAC - Trends in Analytical Chemistry SN - 0165-9936 VL - 48 SP - 96 EP - 111 KW - Biopharmaceuticals; Biosimilar; Characterization; Formulation; Nuclear magnetic resonance (NMR); Oligonucleotide; Peptide; Polysaccharide; Protein; Quality control AB - Recent improvements in nuclear magnetic resonance (NMR) - automation, sensitivity, resolution, pulse-sequence design and spectral processing - are giving novel insights into a wide range of biotech drugs. Real-world applications and emerging trends in biopharmaceutical NMR are being used to help in discovery, design, and characterization of these drugs and to improve assessment of their efficacy, quality and similarity. © 2013 Elsevier Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ac6f3f47-5e19-4da1-87d0-dc81b744d01c ER - TY - JOUR TI - Spray coated high-conductivity PEDOT:PSS transparent electrodes for stretchable and mechanically-robust organic solar cells DO - 10.1016/j.solmat.2012.09.005 AU - Tait, Jeffrey G. AU - Worfolk, Brian J. AU - Maloney, Samuel A. AU - Hauger, Tate C. AU - Elias, Anastasia L. AU - Buriak, Jillian M. AU - Harris, Kenneth D. T2 - Solar Energy Materials and Solar Cells SN - 0927-0248 VL - 110 SP - 98 EP - 106 KW - ITO-free KW - PEDOT:PSS KW - Polymer Solar Cells KW - Spray coating KW - Stretchable electronics KW - Bending tests KW - Conversion efficiency KW - Electrodes KW - Ethylene glycol KW - Flexible electronics KW - Organic solvents KW - Solar cells KW - Conducting polymers AB - High conductivity poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) was spray cast to form highly flexible transparent electrodes for forward- and inverted-mode organic solar cells (OSCs). A multiple solvent ink containing ethylene glycol was developed, and a post-deposition annealing step contributed to a high conductivity of 1070±50 S cm-¹. Sheet resistance and transmission at a wavelength of 550 nm were controlled within 24-259 Ω □-¹ and 71-95%, respectively, which are amongst the best-reported combined characteristics. Forward-mode OSCs with spray coated PEDOT:PSS anodes yielded a power conversion efficiency of 3.2%. Mechanical bending and stretching tests demonstrated that the flexibility of these PEDOT:PSS layers were far superior to that of ITO: elastic moduli were reduced by more than an order of magnitude, and the resistance increased far more slowly under both uniaxial stretching and bending to progressively smaller radii of curvature. With these experiments, the minimum radii of curvature and maximum uniaxial strains at which acceptable performance is maintained were investigated. Collectively, our results illustrate a promising future for the scalable printing of low-cost PEDOT:PSS-based flexible transparent electrodes. © 2012 Crown All rights reserved. DA - 2013/01/03 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4631d676-6b12-48ca-895d-da30b7fcb669 ER - TY - JOUR TI - Tuning iron pyrite thin film microstructure by sulfurization of columnar iron precursors DO - 10.1016/j.solmat.2013.06.028 AU - LaForge, Joshua M. AU - Gyenes, Balazs AU - Xu, Sijia AU - Haynes, Landon K. AU - Titova, Lyubov V. AU - Hegmann, Frank A. AU - Brett, Michael J. T2 - Solar Energy Materials and Solar Cells SN - 0927-0248 VL - 117 SP - 306 EP - 314 KW - Carrier recombination KW - Fabrication routes KW - Glancing Angle Deposition KW - Granular microstructure KW - Optical characterization KW - Photovoltaic devices KW - Photovoltaic power KW - Sulfurization KW - Cracks KW - Deposition KW - Electrooptical materials KW - Failure (mechanical) KW - Grain boundaries KW - Microstructure KW - Photovoltaic cells KW - Pyrites KW - Semiconductor materials KW - Thin films KW - Void fraction KW - Iron AB - Iron pyrite is a promising material for photovoltaic power production due to low material extraction and processing costs and high optical absorption. Reliable production of photovoltaic grade iron pyrite thin films has, however, been challenging. One potential fabrication route is the direct conversion of iron-to-iron pyrite by sulfur annealing (sulfurization). Bulk iron thin films are used typically but they can suffer from cracking or delamination. Herein we report the sulfurization of porous, columnar Fe films deposited with Glancing Angle Deposition (GLAD), which allows us to control the inter-column spacing (void-fraction) of the precursor film. We show that the morphology and microstructure of the iron pyrite films are strongly affected by the void-fraction. By precisely tuning the void-fraction of the precursor film at 82 oblique angle incidence deposition we can produce iron pyrite films with increased crystallite sizes >100 nm with a uniform, crack-free, facetted granular microstructure. Large crystallites may reduce carrier recombination at grain boundaries, which is attractive for photovoltaic devices. Further increasing the void-fraction produces a columnar iron pyrite structure. We also report composition, electrical and optical characterization including a 27 ps lifetime of photocarriers measured with ultrafast optical-pump/THz-probe. Structured, porous precursors offer an alternate route to control microstructure and film stress during fabrication of iron pyrite thin films. © 2013 Elsevier B.V. DA - 2013/10/13 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3fa9f2aa-9581-467f-a7a8-5e6c00785e00 ER - TY - JOUR TI - Selective room temperature nanostructured thin film alcohol sensor as a virtual sensor array DO - 10.1016/j.snb.2012.09.041 AU - Beckers, N. A. AU - Taschuk, M. T. AU - Brett, M. J. T2 - Sensors and Actuators, B: Chemical SN - 0925-4005 VL - 176 SP - 1096 EP - 1102 KW - Detection limits KW - Frequency dependent KW - Frequency-dependent capacitance KW - Glancing Angle Deposition KW - Inter-digitated electrodes KW - Nanostructured thin film KW - Saturation range KW - Virtual sensor KW - Algorithms KW - Chemical sensors KW - Deposition KW - Ethanol KW - Irradiation KW - Methanol KW - Propanol KW - Thin films KW - Vapor deposition AB - Nanostructured SiO2 thin films fabricated via glancing angle deposition on interdigitated electrodes were used as room temperature alcohol sensors. Both frequency dependent capacitance and impedance were used to analyze sensor response to methanol, ethanol, 1-propanol, 2-propanol, and 1-butanol. Sensor responsivity was examined across the entire percent vapour saturation range for the same set of alcohols and the detection limit for ethanol, as an example, was derived. The response and recovery times for ethanol were determined from a pulse test and the responsivity curves, giving values of 66 s and 76 s, respectively. Sensor lifetime was examined for the same set of alcohols with and without irradiation from a UV-LED. We observed that sensor aging for the detection of ethanol and 1-butanol was greatly reduced under irradiation from the UV-LED whereas the UV-LED had little effect on aging for methanol, 1-propanol and 2-propanol. Using the frequency dependent responsivity curves of our sensors, we developed an algorithm that enables a single sensor to distinguish between methanol, ethanol and 2-propanol in a blind protocol test. In five out of seven trials, the algorithm successfully identified both the alcohol and concentration thereby demonstrating room temperature single sensor selectivity. © 2012 Elsevier B.V. All rights reserved. DA - 2013/10/12 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4822f679-5a05-4495-bfc3-64f5540c3797 ER - TY - JOUR TI - Quantitative magneto-mechanical detection and control of the Barkhausen effect DO - 10.1126/science.1231390 AU - Burgess, J. A. J. AU - Fraser, A. E. AU - Fani Sani, F. AU - Vick, D. AU - Hauer, B. D. AU - Davis, J. P. AU - Freeman, M. R. T2 - Science SN - 0036-8075 VL - 339 IS - 6123 SP - 1051 EP - 1054 KW - ferromagnetic material KW - magnetic nanoparticle KW - magnetic method KW - mechanical theory KW - quantitative analysis KW - quantum mechanics KW - torsion KW - Barkhausen effect KW - energy transfer KW - film KW - ion therapy KW - magnetism KW - magnetometry AB - Quantitative characterization of intrinsic and artificial defects in ferromagnetic structures is critical to future magnetic storage based on vortices or domain walls moving through nanostructured devices. Using torsional magnetometry, we observe finite size modifications to the Barkhausen effect in the limiting case of a single vortex core interacting with individual pointlike pinning sites in a magnetic thin film. The Barkhausen effect in this limit becomes a quantitative two-dimensional nanoscale probe of local energetics in the film. Tailoring the pinning potential using single-point focused ion beam implantation demonstrates control of the effect and points the way to integrated magneto-mechanical devices incorporating quantum pinning effects. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3805292c-cd81-4f77-bed3-f35492c8b712 ER - TY - JOUR TI - Merging recent and historic spectra of ε Aurigae: Properties of the system's components, and discovery of a mass transfer stream DO - 10.1086/671781 AU - Griffin, R. Elizabeth AU - Stencel, Robert E. T2 - Publications of the Astronomical Society of the Pacific SN - 0004-6280 VL - 125 IS - 929 SP - 775 EP - 792 AB - This study of new CCD spectra of ε Aur recorded in the blue and near-UV during the 2010 eclipse has been reinforced and extended by the inclusion of some 130 digitized historic spectra from MountWilson (dating back to the 1930s) and from the DAO (dating from 1971). The precise repetition of disk-related spectral-line changes during three successive eclipses indicates that the structure of the disk does not alter appreciably on a time-scale of a least a century.We deduce that the disk has an extensive but optically thin outer layer, and a flat structure that is tilted near to edge-on. We discover that it is receiving from the supergiant a very confined stream of material that is enriched in rare-earth elements. The stream has an approach velocity very similar to the projected rotational velocity of the F star; it has an extremely small velocity dispersion, and is only visible between specific egress phases. We surmise that the F star is a horizontal-branch star though its own photosphere appears, on average, to have a solar composition.We also uncover variable broad emission in the system and find a possible correlation with the F-star's Cepheid-like ~67-day pulsations that cause its photometric variations. © 2013. The Astronomical Society of the Pacific. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5b2551e8-3dd6-4421-9984-f71501e120a3 ER - TY - JOUR TI - Kuiper belt occultation predictions DO - 10.1086/672001 AU - Fraser, Wesley C. AU - Gwyn, Stephen AU - Trujillo, Chad AU - Stephens, Andrew W. AU - Kavelaars, J. J. AU - Brown, Michael E. AU - Bianco, Federica B. AU - Boyle, Richard P. AU - Brucker, Melissa J. AU - Hetherington, Nathan AU - Joner, Michael AU - Keel, William C. AU - Langill, Phil P. AU - Lister, Tim AU - McMillan, Russet J. AU - Young, Leslie T2 - Publications of the Astronomical Society of the Pacific SN - 0004-6280 VL - 125 IS - 930 SP - 1000 EP - 1014 AB - Here we present observations of seven large Kuiper Belt objects. From these observations, weextract a point source catalog with ~0:01″ precision, and astrometry of our target Kuiper Belt objects with0.04-0.08″ precision within that catalog. We have developed a new technique to predict the future occurrenceof stellar occultations by Kuiper Belt objects. The technique makes use of a maximum likelihood approach whichdetermines the best-fit adjustment to cataloged orbital elements of an object. Using simulations of a theoreticalobject, we discuss the merits and weaknesses of this technique compared to the commonly adopted ephemeris offsetapproach. We demonstrate that both methods suffer from separate weaknesses, and thus together provide a fairassessment of the true uncertainty in a particular prediction. We present occultation predictions made by both methodsfor the seven tracked objects, with dates as late as 2015. Finally, we discuss observations of three separate closepassages of Quaoar to field stars, which reveal the accuracy of the element adjustment approach, and which alsodemonstrate the necessity of considering the uncertainty in stellar position when assessing potential occultations. © 2013. The Astronomical Society of the Pacific. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 18e07d33-0c94-4501-9951-d4c1d46da28d ER - TY - JOUR TI - GASKAP-the galactic ASKAP survey DO - 10.1017/pasa.2012.003 AU - Dickey, John M. AU - McClure-Griffiths, Naomi AU - Gibson, Steven J. AU - Gómez, José F. AU - Imai, Hiroshi AU - Jones, Paul AU - Stanimirović, Snežana AU - Van Loon, Jacco Th. AU - Walsh, Andrew AU - Alberdi, A. AU - Anglada, G. AU - Uscanga, L. AU - Arce, H. AU - Bailey, M. AU - Begum, A. AU - Wakker, B. AU - Bekhti, N. Ben AU - Kalberla, P. AU - Winkel, B. AU - Bekki, K. AU - For, B.-Q. AU - Staveley-Smith, L. AU - Westmeier, T. AU - Burton, M. AU - Cunningham, M. AU - Dawson, J. AU - Ellingsen, S. AU - Diamond, P. AU - Green, J. A. AU - Hill, A. S. AU - Koribalski, B. AU - McConnell, D. AU - Rathborne, J. AU - Voronkov, M. AU - Douglas, K. A. AU - English, J. AU - Ford, H. Alyson AU - Lockman, F. J. AU - Foster, T. AU - Gomez, Y. AU - Green, A. AU - Bland-Hawthorn, J. AU - Gulyaev, S. AU - Hoare, M. AU - Joncas, G. AU - Kang, J.-H. AU - Kerton, C. R. AU - Koo, B.-C. AU - Leahy, D. AU - Lo, N. AU - Migenes, V. AU - Nakashima, J. AU - Zhang, Y. AU - Nidever, D. AU - Peek, J. E. G. AU - Tafoya, D. AU - Tian, W. AU - Wu, D. T2 - Publications of the Astronomical Society of Australia SN - 1323-3580 VL - 30 IS - 1 SP - e003 AB - A survey of the Milky Way disk and the Magellanic System at the wavelengths of the 21-cm atomic hydrogen (H i) line and three 18-cm lines of the OH molecule will be carried out with the Australian Square Kilometre Array Pathfinder telescope. The survey will study the distribution of H i emission and absorption with unprecedented angular and velocity resolution, as well as molecular line thermal emission, absorption, and maser lines. The area to be covered includes the Galactic plane (|b| < 10°) at all declinations south of δ = +40°, spanning longitudes 167° through 360°to 79 at b = 0°, plus the entire area of the Magellanic Stream and Clouds, a total of 13 020 deg2. The brightness temperature sensitivity will be very good, typically σT≃ 1 K at resolution 30 arcsec and 1 km s -1. The survey has a wide spectrum of scientific goals, from studies of galaxy evolution to star formation, with particular contributions to understanding stellar wind kinematics, the thermal phases of the interstellar medium, the interaction between gas in the disk and halo, and the dynamical and thermal states of gas at various positions along the Magellanic Stream. © 2013 Astronomical Society of Australia. DA - 2013/01/24 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0b274f85-7ba1-447f-9392-913b11f8cc54 ER - TY - JOUR TI - Science with the Murchison Widefield Array DO - 10.1017/pas.2013.009 AU - Bowman, Judd D. AU - Cairns, Iver AU - Kaplan, David L. AU - Murphy, Tara AU - Oberoi, Divya AU - Staveley-Smith, Lister AU - Arcus, Wayne AU - Barnes, David G. AU - Bernardi, Gianni AU - Briggs, Frank H. AU - Brown, Shea AU - Bunton, John D. AU - Burgasser, Adam J. AU - Cappallo, Roger J. AU - Chatterjee, Shami AU - Corey, Brian E. AU - Coster, Anthea AU - Deshpande, Avinash AU - deSouza, Ludi AU - Emrich, David AU - Erickson, Philip AU - Goeke, Robert F. AU - Gaensler, B. M. AU - Greenhill, Lincoln J. AU - Harvey-Smith, Lisa AU - Hazelton, Bryna J. AU - Herne, David AU - Hewitt, Jacqueline N. AU - Johnston-Hollitt, Melanie AU - Kasper, Justin C. AU - Kincaid, Barton B. AU - Koenig, Ronald AU - Kratzenberg, Eric AU - Lonsdale, Colin J. AU - Lynch, Mervyn J. AU - Matthews, Lynn D. AU - McWhirter, S. Russell AU - Mitchell, Daniel A. AU - Morales, Miguel F. AU - Morgan, Edward H. AU - Ord, Stephen M. AU - Pathikulangara, Joseph AU - Prabu, Thiagaraj AU - Remillard, Ronald A. AU - Robishaw, Timothy AU - Rogers, Alan E. E. AU - Roshi, Anish A. AU - Salah, Joseph E. AU - Sault, Robert J. AU - Shankar, N. Udaya AU - Srivani, K. S. AU - Stevens, Jamie B. AU - Subrahmanyan, Ravi AU - Tingay, Steven J. AU - Wayth, Randall B. AU - Waterson, Mark AU - Webster, Rachel L. AU - Whitney, Alan R. AU - Williams, Andrew J. AU - Williams, Christopher L. AU - Wyithe, J. Stuart B. T2 - Publications of the Astronomical Society of Australia SN - 1323-3580 VL - 30 IS - 1 SP - e031 AB - Significant new opportunities for astrophysics and cosmology have been identified at low radio frequencies. The Murchison Widefield Array is the first telescope in the southern hemisphere designed specifically to explore the low-frequency astronomical sky between 80 and 300 MHz with arcminute angular resolution and high survey efficiency. The telescope will enable new advances along four key science themes, including searching for redshifted 21-cm emission from the EoR in the early Universe; Galactic and extragalactic all-sky southern hemisphere surveys; time-domain astrophysics; and solar, heliospheric, and ionospheric science and space weather. The Murchison Widefield Array is located in Western Australia at the site of the planned Square Kilometre Array (SKA) low-band telescope and is the only low-frequency SKA precursor facility. In this paper, we review the performance properties of the Murchison Widefield Array and describe its primary scientific objectives. © 2013 Astronomical Society of Australia. DA - 2013/04/16 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 90e7f962-93e5-4fab-a482-1b5fea004c1b ER - TY - JOUR TI - Activationless charge transport across 4.5 to 22 nm in molecular electronic junctions DO - 10.1073/pnas.1221643110 AU - Yan, Haijun AU - Bergren, Adam Johan AU - McCreery, Richard AU - Della Rocca, Maria Luisa AU - Martin, Pascal AU - Lafarge, Philippe AU - Lacroix, Jean Christophe T2 - Proceedings of the National Academy of Sciences of the United States of America SN - 0027-8424 VL - 110 IS - 14 SP - 5326 EP - 5330 KW - charge transport KW - electric field KW - electricity KW - high temperature KW - ionization KW - semiconductor KW - Carbon KW - Electronics KW - Hot Temperature KW - Ion Exchange KW - Nanotechnology KW - Quantum Theory KW - Semiconductors AB - In this work, we bridge the gap between short-range tunneling in molecular junctions and activated hopping in bulk organic films, and greatly extend the distance range of charge transport in molecular electronic devices. Three distinct transport mechanisms were observed for 4.5-22-nm-thick oligo(thiophene) layers between carbon contacts, with tunneling operative when d< 8 nm, activated hoppingwhen d> 16nmfor high temperatures and lowbias, and a third mechanism consistent with field-induced ionization of highest occupiedmolecular orbitals or interface states to generate charge carriers when d = 8-22 nm. Transport in the 8-22-nm range is weakly temperature dependent, with a field-dependent activation barrier that becomes negligible at moderate bias. We thus report here a unique, activationless transport mechanism, operative over 8-22-nm distanceswithout involving hopping,which severely limits carriermobility and device lifetime in organic semiconductors. Charge transport in molecular electronic junctions can thus be effective for transport distances significantly greater than the 1-5 nm associated with quantum-mechanical tunneling. DA - 2013/03/18 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d671032b-d2e8-4b82-9133-0b155596f291 ER - TY - JOUR TI - Photonic crystal split-beam nanocavities for torsional optomechanics DO - 10.1117/12.2004456 AU - Wu, Marcelo AU - Hryciw, Aaron C. AU - Khanaliloo, Behzad AU - Healey, Chris AU - Freeman, Mark R. AU - Davis, John P. AU - Barclay, Paul E. T2 - Laser Resonators, Microresonators, and Beam Control XV T2 - Proceedings of SPIE; 8600 T3 - Laser Resonators, Microresonators, and Beam Control XV, February 3-7, 2013, San Francisco, CA, USA SN - 0277-786X SN - 9780819493699 SP - 86001U KW - Environmental stimuli KW - Integrated device KW - Magnetometry KW - Mechanical resonators KW - Nanomechanical resonators KW - Opto-mechanics KW - Photonic crystal nanocavity KW - Silicon photonics KW - Embedded systems KW - Laser resonators KW - Magnetometers KW - Nanomagnetics KW - Nanophotonics KW - Nanotechnology KW - Optical fibers KW - Optical resonators KW - Photonics KW - Resonators KW - Photonic crystals DA - 2013/02/02 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a6c1d716-e0b8-4976-97b8-c94d1a9c460a ER - TY - JOUR TI - ESPRESSO APSU: simplify the life of pupil slicing DO - 10.1117/12.2024843 AU - Conconi, P. AU - Riva, M. AU - Pepe, F. AU - Zerbi, F.M. AU - Cabral, A. AU - Cristiani, S. AU - Megevand, D. AU - Landoni, M. AU - Spanó, P. T2 - Novel Optical Systems Design and Optimization XVI T2 - Proceedings of SPIE; 8842 T3 - 16th Conference of Novel Optical Systems Design and Optimization, August 26-28, 2013, San Diego, CA, USA SN - 0277-786X SN - 9780819496928 SP - 88420P KW - Anamorphic KW - Cylindrical optics KW - Echelle spectrograph KW - Exo-planets KW - Optical components KW - Slit width KW - Very large telescope KW - Optimization KW - Systems analysis DA - 2013/08/25 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f3c79529-4538-42a8-81ad-898e00b702d5 ER - TY - JOUR TI - Meta-modeling optimization of the cutting process during turning titanium metal matrix composites (Ti-MMCs) DO - 10.1016/j.procir.2013.06.153 AU - Aramesh, M. AU - Shi, B. AU - Nassef, A. O. AU - Attia, H. AU - Balazinski, M. AU - Kishawy, H. A. T2 - Procedia CIRP T3 - 14th CIRP Conference on Modeling of Machining Operations, CIRP CMMO 2013, June 13-14, 2013, Turin SN - 2212-8271 VL - 8 SP - 576 EP - 581 KW - Experimental conditions KW - Mechanical and physical properties KW - Meta-modeling technique KW - MMCs KW - Multi-dimensional space KW - Strength pareto evolutionary algorithm KW - Titanium metal matrix composites KW - Tool wear KW - Algorithms KW - Machining centers KW - Multiobjective optimization KW - Surface roughness KW - Wear of materials AB - The Outstanding characteristics of titanium metal matrix composites (Ti-MMCs) have brought them up as promising materials in different industries, such as aerospace and biomedical. They exhibit high mechanical and physical properties, in addition to their low weight, high stiffness and high wear resistance. The presence of the ceramic reinforcements in a metallic matrix further contributes to these preferable properties. However, the high abrasive nature of the ceramic particles limits greatly the machinability of this class of material, as they induce significant tool wear and poor surface finish. In this study an attempt is made to find the optimum cutting conditions in terms of minimizing the tool wear and surface roughness during machining Ti-MMCs. Meta-modeling optimization in performed to achieve the goal. In this study the three independent parameters under consideration are the cutting speed, feed rate and the depth of cut. The response parameters are the surface roughness and the tool wear rate. The independent parameters are divided into a set of levels at which the experiments are conducted. At each experimental condition the two response parameters are measured. Kriging meta-modeling technique is used to fit a model to the response parameters in the multi-dimensional space. These models are used, in turn, within a multi-objective optimization algorithm to find the optimum cutting condition space. The above-mentioned algorithm is based on an evolutionary multi-objective search technique known as SPEA (Strength Pareto Evolutionary Algorithm). Copyright © 2013 Elsevier B.V. DA - 2013/07/03 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 637fcc57-aeb9-48df-8be0-359f4542d345 ER - TY - JOUR TI - Nanopore analysis of wild-type and mutant prion protein (PrPC): single molecule discrimination and PrPC kinetics DO - 10.1371/journal.pone.0054982 AU - Jetha, Nahid N. AU - Semenchenko, Valentyna AU - Wishart, David S. AU - Cashman, Neil R. AU - Marziali, Andre T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 2 SP - e54982 KW - alpha hemolysin KW - asparagine KW - aspartic acid KW - prion protein KW - amino acid sequence KW - amino terminal sequence KW - complex formation KW - Creutzfeldt Jakob disease KW - fatal familial insomnia KW - molecular dynamics KW - nanoanalysis KW - point mutation KW - predictive value KW - protein conformation KW - protein stability KW - wild type KW - kinetics KW - nanopores KW - prion diseases KW - prions KW - protein conformation AB - Prion diseases are fatal neurodegenerative diseases associated with the conversion of cellular prion protein (PrPC) in the central nervous system into the infectious isoform (PrPSc). The mechanics of conversion are almost entirely unknown, with understanding stymied by the lack of an atomic-level structure for PrPSc. A number of pathogenic PrPC mutants exist that are characterized by an increased propensity for conversion into PrPSc and that differ from wild-type by only a single amino-acid point mutation in their primary structure. These mutations are known to perturb the stability and conformational dynamics of the protein. Understanding of how this occurs may provide insight into the mechanism of PrPC conversion. In this work we sought to explore wild-type and pathogenic mutant prion protein structure and dynamics by analysis of the current fluctuations through an organic α-hemolysin nanometer-scale pore (nanopore) in which a single prion protein has been captured electrophoretically. In doing this, we find that wild-type and D178N mutant PrPC, (a PrPC mutant associated with both Fatal Familial Insomnia and Creutzfeldt-Jakob disease), exhibit easily distinguishable current signatures and kinetics inside the pore and we further demonstrate, with the use of Hidden Markov Model signal processing, accurate discrimination between these two proteins at the single molecule level based on the kinetics of a single PrPC capture event. Moreover, we present a four-state model to describe wild-type PrPC kinetics in the pore as a first step in our investigation on characterizing the differences in kinetics and conformational dynamics between wild-type and D178N mutant PrPC. These results demonstrate the potential of nanopore analysis for highly sensitive, real-time protein and small molecule detection based on single molecule kinetics inside a nanopore, and show the utility of this technique as an assay to probe differences in stability between wild-type and mutant prion proteins at the single molecule level. © 2013 Jetha et al. DA - 2013/02/05 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6cd9e418-2d95-4fd1-a7d8-4c39fcc907b8 ER - TY - JOUR TI - The human urine metabolome DO - 10.1371/journal.pone.0073076 AU - Bouatra, Souhaila AU - Aziat, Farid AU - Mandal, Rupasri AU - Guo, An Chi AU - Wilson, Michael R. AU - Knox, Craig AU - Bjorndahl, Trent C. AU - Krishnamurthy, Ramanarayan AU - Saleem, Fozia AU - Liu, Philip AU - Dame, Zerihun T. AU - Poelzer, Jenna AU - Huynh, Jessica AU - Yallou, FaizathS. AU - Psychogios, Nick AU - Dong, Edison AU - Bogumil, Ralf AU - Roehring, Cornelia AU - Wishart, David S. T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 9 SP - e73076 KW - direct flow injection mass spectrometry KW - high performance liquid chromatography KW - mass fragmentography KW - mass spectrometry KW - metabolite KW - metabolome KW - nuclear magnetic resonance spectroscopy KW - urinalysis KW - urine level AB - Urine has long been a "favored" biofluid among metabolomics researchers. It is sterile, easy-to-obtain in large volumes, largely free from interfering proteins or lipids and chemically complex. However, this chemical complexity has also made urine a particularly difficult substrate to fully understand. As a biological waste material, urine typically contains metabolic breakdown products from a wide range of foods, drinks, drugs, environmental contaminants, endogenous waste metabolites and bacterial by-products. Many of these compounds are poorly characterized and poorly understood. In an effort to improve our understanding of this biofluid we have undertaken a comprehensive, quantitative, metabolome-wide characterization of human urine. This involved both computer-aided literature mining and comprehensive, quantitative experimental assessment/validation. The experimental portion employed NMR spectroscopy, gas chromatography mass spectrometry (GC-MS), direct flow injection mass spectrometry (DFI/LC-MS/MS), inductively coupled plasma mass spectrometry (ICP-MS) and high performance liquid chromatography (HPLC) experiments performed on multiple human urine samples. This multi-platform metabolomic analysis allowed us to identify 445 and quantify 378 unique urine metabolites or metabolite species. The different analytical platforms were able to identify (quantify) a total of: 209 (209) by NMR, 179 (85) by GC-MS, 127 (127) by DFI/LC-MS/MS, 40 (40) by ICP-MS and 10 (10) by HPLC. Our use of multiple metabolomics platforms and technologies allowed us to identify several previously unknown urine metabolites and to substantially enhance the level of metabolome coverage. It also allowed us to critically assess the relative strengths and weaknesses of different platforms or technologies. The literature review led to the identification and annotation of another 2206 urinary compounds and was used to help guide the subsequent experimental studies. An online database containing the complete set of 2651 confirmed human urine metabolite species, their structures (3079 in total), concentrations, related literature references and links to their known disease associations are freely available at http://www.urinemetabolome.ca. © 2013 Bouatra et al. DA - 2013/09/04 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 031df9f2-9358-45d9-93f6-9c22017b07fc ER - TY - JOUR TI - Two-dimensional incommensurate and three-dimensional commensurate magnetic order and fluctuations in La2-xBaxCuO4 DO - 10.1103/PhysRevB.88.014412 AU - Wagman, J. J. AU - Van Gastel, G. AU - Ross, K. A. AU - Yamani, Z. AU - Zhao, Y. AU - Qiu, Y. AU - Copley, J. R. D. AU - Kallin, A. B. AU - Mazurek, E. AU - Carlo, J. P. AU - Dabkowska, H. A. AU - Gaulin, B. D. T2 - Physical Review B - Condensed Matter and Materials Physics SN - 1098-0121 VL - 88 IS - 1 SP - 14412 AB - We present neutron-scattering measurements on single crystals of lightly doped La2-xBaxCuO4, with 0≤x≤0.035. These reveal the evolution of the magnetism in this prototypical doped Mott insulator from a three-dimensional (3D) commensurate (C) antiferromagnetic ground state, which orders at a relatively high TN, to a two-dimensional (2D) incommensurate (IC) ground state with finite-ranged static correlations, which appear below a relatively low effective TN. At low temperatures, the 2D IC magnetism coexists with the 3D C magnetism for doping concentrations as low as ∼0.0125. We find no signal of a 3D C magnetic ground state by x∼0.025, consistent with the upper limit of x∼0.02 observed in the sister family of doped Mott insulators, La2-xSrxCuO 4. The 2D IC ground states observed for 0.0125≤x≤0.035 are diagonal, and are rotated by 45 degrees within the orthorhombic basal plane compared with those previously reported for samples with superconducting ground states: La2-xBaxCuO4, with 0.05≤x≤0.095. We construct a phase diagram based solely on magnetic order-parameter measurements, which displays much of the complexity of standard high-temperature superconductivity phase diagrams discussed in the literature. Analysis of high-energy resolution inelastic neutron scattering at moderately low temperatures shows a progressive depletion of the very low-energy dynamic magnetic susceptibility as x increases from 0.0125 to 0.035. This low-energy, dynamic susceptibility falls off with increasing temperature on a scale much higher than the effective 2D IC TN appropriate to these materials. Appreciable dynamic 2D IC magnetic fluctuations inhabit much of the "pseudogap" regime of the phase diagram. ©2013 American Physical Society. DA - 2013/07/12 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c8fd9868-934f-4739-a37b-97483477f5a6 ER - TY - JOUR TI - Single-molecule assays for investigating protein misfolding and aggregation DO - 10.1039/c3cp44564j AU - Hoffmann, Armin AU - Neupane, Krishna AU - Woodside, Michael T. T2 - Physical Chemistry Chemical Physics SN - 1463-9076 VL - 15 IS - 21 SP - 7934 EP - 7948 KW - atomic force microscopy KW - metabolism KW - protein folding KW - protein multimerization KW - spectrofluorometry KW - Amyloid KW - Microscopy, Atomic Force KW - Protein Folding KW - Protein Multimerization KW - Proteins KW - Spectrometry, Fluorescence AB - Protein misfolding and aggregation are relevant to many fields. Recently, their investigation has experienced a revival as a central topic in the research of numerous human diseases, including Parkinson's and Alzheimer's. Much has been learned from ensemble biochemical approaches, but the inherently heterogeneous nature of the underlying processes has obscured many important details. Single-molecule techniques offer unique capabilities to study heterogeneous systems, while providing high temporal and structural resolution to characterize them. In this Perspective, we give an overview of the single-molecule assays that have been applied to protein misfolding and aggregation, which are mainly based on fluorescence and force spectroscopy. We describe some of the technical challenges involved in studying aggregation at the single-molecule level and discuss what has been learned about aggregation mechanisms from the different approaches. © 2013 the Owner Societies. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : dfa77858-e409-4951-a11a-fbdc74e68e5d ER - TY - JOUR TI - Performance of conventional and dispersion-corrected density-functional theory methods for hydrogen bonding interaction energies DO - 10.1039/c3cp51559a AU - DiLabio, Gino A. AU - Johnson, Erin R. AU - Otero-de-la-Roza, Alberto T2 - Physical Chemistry Chemical Physics SN - 1463-9076 VL - 15 IS - 31 SP - 12821 EP - 12828 AB - The approximate CCSD(T)/CBS binding energies for the set of 23 hydrogen-bonded dimers (HB23) of the S66 set reported by Řezá č et al. (J. Chem. Theory Comput. 2011, 7, 2427-2438) were expected to be under-estimated based on the known under-binding tendency of the counterpoise correction combined with small basis sets. In this work, we present binding energies for the HB23 set of dimers obtained using a composite approach recently described by Mackie and DiLabio (J. Chem. Phys. 2011, 135, 134318) that averages the counterpoise- and non-counterpoise-corrected energies, while utilizing standard approaches to obtain CCSD(T)/CBS-type energies. The binding energies for the HB23 set are revised upward by an average of 0.12 kcal mol-¹ and as much as 0.35 kcal mol-¹. We use these improved benchmark-level binding energies to evaluate the ability of pure, hybrid, long-range-corrected, and dispersion-corrected density-functional theory (DFT) methods to accurately predict the binding energies of hydrogen-bonded dimers. We find that, in general, the inclusion of dispersion into the DFT approach is required in order to obtain reasonable results for the HB23 set. We find that the dispersion-corrected DFT methods we tested produce results of variable quality, as measured by mean absolute deviation relative to the revised reference values we computed: B97D, 0.57 kcal mol-¹; B3LYP-D3, 0.44 kcal mol-¹; ωB97XD, 0.25 kcal mol-¹; LC-ωPBE-D3, 0.24 kcal mol-¹; M06-2X, 0.21 kcal mol-¹; B3LYP-DCP, 0.23 kcal mol-¹; B971-XDM, 0.18 kcal mol-¹. © the Owner Societies 2013. DA - 2013/06/27 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5507c92b-7bd6-46c7-9fa1-3f110156acaa ER - TY - JOUR TI - ALD TiO2 coated silicon nanowires for lithium ion battery anodes with enhanced cycling stability and coulombic efficiency DO - 10.1039/c3cp52485j AU - Memarzadeh Lotfabad, Elmira AU - Kalisvaart, Pater AU - Cui, Kai AU - Kohandehghan, Alireza AU - Kupsta, Martin AU - Olsen, Brian AU - Mitlin, David T2 - Physical Chemistry Chemical Physics SN - 1463-9076 VL - 15 IS - 32 SP - 13646 EP - 13657 AB - We demonstrate that silicon nanowire (SiNW) Li-ion battery anodes that are conformally coated with TiO2 using atomic layer deposition (ALD) show a remarkable performance improvement. The coulombic efficiency is increased to ∼99%, among the highest ever reported for SiNWs, as compared to 95% for the baseline uncoated samples. The capacity retention after 100 cycles for the nanocomposite is twice as high as that of the baseline at 0.1 C (60% vs. 30%), and more than three times higher at 5 C (34% vs. 10%). We also demonstrate that the microstructure of the coatings is critically important for achieving this effect. Titanium dioxide coatings with an as-deposited anatase structure are nowhere near as effective as amorphous ones, the latter proving much more resistant to delamination from the SiNW core. We use TEM to demonstrate that upon lithiation the amorphous coating develops a highly dispersed nanostructure comprised of crystalline LiTiO2 and a secondary amorphous phase. Electron energy loss spectroscopy (EELS) combined with bulk and surface analytical techniques are employed to highlight the passivating effect of TiO2, which results in significantly fewer cycling-induced electrolyte decomposition products as compared to the bare nanowires. © 2013 The Owner Societies. DA - 2013/06/18 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : fedb3036-8c5f-41b8-8afa-f84103f32af7 ER - TY - JOUR TI - Thermodynamically destabilized hydride formation in "bulk" Mg-AlTi multilayers for hydrogen storage DO - 10.1039/c3cp52706a AU - Kalisvaart, Peter AU - Shalchi-Amirkhiz, Babak AU - Zahiri, Ramin AU - Zahiri, Benjamin AU - Tan, XueHai AU - Danaie, Mohsen AU - Botton, Gianluigi AU - Mitlin, David T2 - Physical Chemistry Chemical Physics SN - 1463-9076 VL - 15 IS - 39 SP - 16432 EP - 16436 AB - Thermodynamic destabilization of MgH2 formation through interfacial interactions in free-standing Mg-AlTi multilayers of overall "bulk" (0.5 μm) dimensions with a hydrogen capacity of up to 5.5 wt% is demonstrated. The interfacial energies of Mg-AlTi and Mg-Ti (examined as a baseline) are calculated to be 0.81 and 0.44 J m-2. The enhanced interfacial energy of AlTi opens the possibility of creating ultrathin alloy interlayers that provide further thermodynamic improvements in metal hydrides. © 2013 The Owner Societies. DA - 2013/07/29 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d1b40736-ea99-4185-bec0-cdb16809a1dd ER - TY - JOUR TI - Quantum mechanical treatment of binding energy between DNA nucleobases and carbon nanotube: A DFT analysis DO - 10.1016/j.physe.2013.05.024 AU - Chehel Amirani, Morteza AU - Tang, Tian AU - Cuervo, Javier T2 - Physica E: Low-Dimensional Systems and Nanostructures SN - 1386-9477 VL - 54 SP - 65 EP - 71 KW - Basis set superposition errors KW - DFT KW - Geometry optimization KW - Initial configuration KW - Nucleobases KW - Optimized configuration KW - Quantum-mechanical treatments KW - Single-point energy KW - Binding energy KW - Density functional theory KW - DNA KW - Electronic properties KW - Optimization KW - Quantum chemistry KW - Quantum theory KW - Carbon nanotubes AB - The interactions between DNA and carbon nanotubes (CNTs) have been widely studied in recent years. The binding process of DNA with CNT as well as the electronic properties of DNA/CNT hybrids constitutes an interesting yet complicated problem. The binding energy (BE) of the hybridization is one of the most extensively studied parameters for the problem. In this work, density functional theory (DFT) was used to perform geometry optimization of neutral nucleobases including adenine, cytosine, guanine and thymine absorbed on a zigzag (7,0) single-walled CNT and to evaluate the basis set superposition error corrected BE of the optimized configuration. All DFT calculations were performed using the M05-2X functional. The 6-31G(d) basis set was used for the optimization step and single point energy calculations were done using the 6-31G(d,p) basis set. For each nucleobase, we examined the influence of the initial configuration (IC) on the BE value. In particular, we considered 24 different ICs for each nucleobase, and each IC was subjected to an independent optimization and BE calculation. Our results showed that different ICs result in very different BE values and can even change the order of the BE corresponding to different nucleobases. The difference in the BE for a particular nucleobase caused by changes in its IC can be comparable to the difference in the BE between different nucleobases at the same initial position relative to the CNT. This provides an explanation for the discrepancies that exist in the literature on the nucleobase/CNT BE, and suggests that the potential energy surface between the nucleobases and the CNT can have many local minima and care should be exercised in the calculation and interpretation of the BE. © 2013 Elsevier B.V. DA - 2013/06/14 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f1d32ee2-bdca-4bd4-ba1e-574ca1ebb11e ER - TY - CHAP TI - Bioactive rosette nanotubes for bone tissue engineering and drug delivery DO - 10.1002/9781118592403.ch12 AU - Beingessner, Rachel L. AU - Alsbaiee, Alaaeddun AU - Singh, Baljit AU - Webster, Thomas J. AU - Fenniri, Hicham T2 - Peptide Materials: From Nanostructures to Applications SN - 9781119953739 SP - 313 EP - 357 KW - rosette nanotubes; guanine-cytosine motif; self-assembly; bioactive peptides; bone tissue engineering; titanium implant materials; osteoblast; hydrogels; drug delivery AB - This chapter describes novel bio-inspired nanotubular architectures called rosette nanotubes (RNTs), which are self-assembled in water from a guanine-cytosine (the G{n-ary logical and}C motif) hybrid molecule. In the first part of the chapter, the design, synthesis and chemical functionalization of RNTs with amino acid residues, peptides and other organic and inorganic moieties are highlighted. Their stability and physical properties are next examined, followed by in vivo and in vitro toxicity and biocompatibility studies. Finally, RNT applications in bone tissue engineering and in drug delivery are described. In the case of the former, this includes RNTs as 2D coatings on Ti implant materials, as well as their incorporation within currently used pHEMA hydrogels for enhanced bone cell adhesion and growth. © 2013 John Wiley & Sons, Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6e065df3-8a08-467c-ba9b-280271be5cc3 ER - TY - JOUR TI - Optical design of split-beam photonic crystal nanocavities DO - 10.1364/OL.38.001612 AU - Hryciw, Aaron C. AU - Barclay, Paul E. T2 - Optics Letters SN - 0146-9592 VL - 38 IS - 10 SP - 1612 EP - 1614 KW - Elliptical holes KW - High quality factors KW - Mechanical excitations KW - Optical band structure KW - Optical resonance KW - Photonic crystal nanobeam KW - Photonic crystal nanocavities KW - Quality factors KW - Optical design KW - Quantum optics KW - Photonic crystals AB - We design high-quality-factor photonic crystal nanobeam cavities formed by two mechanically isolated cantilevers. These "split-beam" cavities have a physical gap at the center, allowing mechanical excitations of one or both of the cavity halves. They are designed by analyzing the optical band structures and mode profiles of waveguides perforated by elliptical holes and rectangular gaps and are predicted to support optical resonances with quality factors exceeding 10⁶ at wavelengths of ∼1.6 μm. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3d76cbd1-e305-4e3c-8aae-5b47d83d1091 ER - TY - JOUR TI - Photothermal nonlinearity and optical bistability in a graphene-silicon waveguide resonator DO - 10.1364/OL.38.005036 AU - Horvath, Cameron AU - Bachman, Daniel AU - Indoe, Rob AU - Van, Vien T2 - Optics Letters SN - 0146-9592 VL - 38 IS - 23 SP - 5036 EP - 5039 KW - Fabry-Perot resonators KW - Graphene layers KW - Nonlinear index KW - Nonlinear resonance KW - Silicon waveguide KW - Temperature increase KW - Thermal nonlinearities KW - Waveguide resonators KW - Resonators KW - Silicon KW - Waveguides KW - Graphene AB - We report observation of optical bistability and enhanced thermal nonlinearity in a graphene-silicon waveguide resonator. Photo-induced Joule heating in the graphene layer gives rise to a temperature increase in the silicon waveguide core and a corresponding thermo-optic shift in the resonance of the Fabry-Perot resonator. Measurement of the nonlinear resonance spectra showed a 9-fold increase in the effective thermal nonlinear index due to the graphene layer compared with a bare silicon waveguide. © 2013 Optical Society of America. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8eaa2caa-b147-475a-bc38-ed84d6f08657 ER - TY - JOUR TI - Glancing angle deposited nanostructured film Fabry-Perot etalons for optical detection of ultrasound DO - 10.1364/OE.21.006391 AU - Hajireza, Parsin AU - Krause, Kathleen AU - Brett, Michael AU - Zemp, Roger T2 - Optics Express SN - 1094-4087 VL - 21 IS - 5 SP - 6391 EP - 6400 KW - High refractive index KW - Nanostructured thin film KW - Optical detection of ultrasound KW - Photo-acoustic imaging KW - Photoacoustic signals KW - Titanium dioxides (TiO2) KW - Transparent semiconductor KW - Ultrasound transducers KW - Acoustic impedance KW - Deposits KW - Fabrication KW - Reflection KW - Refractive index KW - Sensors KW - Ultrasonic propagation KW - Ultrasonic scattering KW - Ultrasonic testing KW - Ultrasonic transducers KW - Ultrasonics KW - Vapors KW - Fabry-Perot interferometers AB - In this paper a new class of optical Fabry-Perot-based ultrasound detectors using low acoustic impedance glancing angle deposited (GLAD) films is demonstrated. GLAD is a single-step physical vapor-deposition (PVD) technique used to fabricate porous nanostructured thin films. Using titanium dioxide (TiO2), a transparent semiconductor with a high refractive index (n = 2.4), the GLAD technique can be employed to fabricate samples with tailored nano-porosity, refractive index periodicities, and high Q-factor reflectance spectra. The average acoustic impedance of the porous films is lower than bulk materials which will improve acoustic coupling, especially for high acoustic frequencies. For this work, two filters with high reflection in the C-band range and high transparency in the visible range (∼80%) using GLAD films were fabricated. A 23 μm Parylene C layer was sandwiched between these two GLAD films in order to form a GLAD Fabry Perot Interferometer (GLAD-FPI). A high speed tunable continuous wavelength C-band laser was focused at the FPI and the reflection was measured using a high speed photodiode. The ultrasound pressure modulated the optical thickness of the FPI and hence its reflectivity. The fabricated sensor was tested using a 10 MHz unfocused transducer. The ultrasound transducer was calibrated using a hydrophone. The minimum detectable acoustic pressure was measured as 80 ± 20 Pa and the -3dB bandwidth was measured to be 18 MHz. This ultra-sensitive sensor can be an alternative to piezoelectric ultrasound transducers for any techniques in which ultrasound waves need to be detected including ultrasonic and photoacoustic imaging modalities. We demonstrate our GLAD-FPI for photoacoustic signal detection in optical-resolution photoacoustic microscopy (OR-PAM). To the best of our knowledge, this is the first time that a FPI fabricated using the GLAD method has been used for ultrasensitive ultrasound detection. © 2013 Optical Society of America. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0509825e-c87e-4005-86ea-9e86a764f8f1 ER - TY - JOUR TI - Design and fabrication of a planar PDMS transmission grating microspectrometer DO - 10.1364/OE.21.011889 AU - Azmayesh-Fard, Seyed M. AU - Lam, Lawrence AU - Melnyk, Aaron AU - DeCorby, Ray G. T2 - Optics Express SN - 1094-4087 VL - 21 IS - 10 SP - 11889 EP - 11900 KW - Analytical predictions KW - Dispersive behaviors KW - Fluidic components KW - High refractive index KW - Microfluidic channel KW - Monolithic integration KW - Transmission gratings KW - Visible-wavelength range KW - Monolithic integrated circuits KW - Refractive index KW - Microchannels KW - baysilon KW - dimeticone KW - article KW - chemistry KW - electronics KW - equipment KW - equipment design KW - equipment failure KW - microfluidic analysis KW - optical instrumentation KW - refractometry KW - spectroscopy KW - Dimethylpolysiloxanes KW - Equipment Design KW - Equipment Failure Analysis KW - Lenses KW - Microfluidic Analytical Techniques KW - Miniaturization KW - Refractometry KW - Spectrum Analysis AB - We describe the monolithic integration of microfluidic channels, optical waveguides, a collimating lens and a curved focusing transmission grating in a single PDMS-based microsystem. All optical and fluidic components of the device were simultaneously formed in a single layer of high refractive index (n∼1.43) PDMS by soft lithography. Outer layers of lower-index (n∼1.41) PDMS were subsequently added to provide optical and fluidic confinement. Here, we focus on the design and characterization of the microspectrometer part, which employs a novel self-focusing strategy based on cylindrical facets, and exhibits resolution <10 nm in the visible wavelength range. The dispersive behavior of the grating was analyzed both experimentally and using numerical simulations, and the results are in good agreement with simplified analytical predictions. © 2013 Optical Society of America. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3908e4e8-45c9-413f-99f8-40e1ae958838 ER - TY - JOUR TI - Production of 70-nm Cr dots by laser-induced forward transfer DO - 10.1364/OE.21.018525 AU - Sametoglu, Vahit AU - Sauer, Vincent T. K. AU - Tsui, Ying Y. T2 - Optics Express SN - 1094-4087 VL - 21 IS - 15 SP - 18525 EP - 18531 KW - Ablation thresholds KW - Continuous films KW - Incident laser KW - Laser-induced forward transfer KW - Production of KW - Spot sizes KW - Sub-100 nm KW - Ultra-thin KW - Film thickness KW - Mass transfer KW - Ultrathin films AB - The effect of donor film thickness and laser beam fluence on the size of laser-induced forward transfer (LIFT) spots is studied to achieve sub-100 nm features. A 130 fs, 800 nm laser is focused on ultrathin Cr films, and the transfer and ablation thresholds of these films at various thicknesses are determined. The minimum transfer spot size decreases with decreasing donor film thickness and incident laser fluence. Minimum LIFT spots of 70-450 nm diameter are obtained from films of 20-80 nm thickness, respectively. The 70 nm diameter transfer spots obtained from sputtered continuous films are the smallest to date. © 2013 Optical Society of America. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8da14c93-7607-4c27-8867-27ad3bca659a ER - TY - JOUR TI - Numerical hydrodynamic evaluation of propeller (with hub taper) and podded drive in azimuthing conditions DO - 10.1016/j.oceaneng.2013.10.009 AU - Shamsi, Reza AU - Ghassemi, Hassan AU - Molyneux, David AU - Liu, Pengfei T2 - Ocean Engineering SN - 0029-8018 VL - 76 SP - 121 EP - 135 KW - RANS method; Hub taper; Podded drive; Azimuthing condition; Hydrodynamic forces AB - This paper aims to predict the hydrodynamic forces on a propeller with different hub taper angles and a podded drive unit in azimuthing conditions. In order to evaluate the propulsive performance of the podded drive system, a Reynolds-Averaged Navier Stokes (RANS) solver is employed. The method has been first verified by a single propeller with different hub taper angles. The performance curves of the propellers, obtained by numerical methods, have been compared to and validated with experimental results. In the next step, the method has been extended to the podded drive unit for both puller and pusher configurations. The yaw angles of the podded drives are set to vary from -30° to +30° with 5° increments. The propulsive characteristics, including the torque and thrust of the propeller, the axial force, and the side force of the unit are presented as functions of the advance velocity ratio and yaw angle. Computational results are compared to the available experimental data. Finally, it is shown there is good agreement between the experimental measurements and the results of the present numerical method. © 2013 Elsevier Ltd. All rights reserved. DA - 2013/11/13 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5b106a80-4ae3-4d24-a55b-63086f7abc93 ER - TY - JOUR TI - Electron irradiation damage and color centers of MgO nanocube DO - 10.1016/j.nimb.2013.08.042 AU - Zhang, Huai-Ruo AU - Egerton, Ray AU - Malac, Marek T2 - Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms SN - 0168-583X VL - 316 SP - 137 EP - 143 KW - Broad-band lasers KW - Coulomb attraction KW - Electron irradiation damage KW - Energy-loss spectroscopy KW - High energy electron beams KW - MgO KW - Positively charged KW - Color centers KW - Electron energy loss spectroscopy KW - Electrons KW - Transmission electron microscopy KW - Vacancies KW - Magnesia KW - EELS KW - TEM AB - Magnesium oxide (MgO) has been of interest for several decades as a promising tunable broadband laser due to its vacancy defects (color centers). In this work we introduced color centers into MgO nanocube by electron irradiation in a transmission electron microscope (TEM). Square nano-holes were formed from the electron-exit face using 100 and 300 keV electrons, and a broad O-vacancy (color-center) absorption peak around 4.1-6.6 eV was observed by valence-electron energy-loss spectroscopy (VEELS). We investigated the mechanism of MgO damage by high-energy electron beams. The hole formation is believed to involve a mixed removal of diatomic MgO molecules as well as Mg and O species in stoichiometric proportion. Observations using high-resolution transmission electron microscopy (HRTEM) and VEELS suggest that bulk O-vacancies are generated near the electron-exit face, due to the forward momentum transferred from fast-electron collisions and the Coulomb attraction of negative O-ions by the positively charged MgO surface. © 2013 Elsevier B.V. All rights reserved. DA - 2013/09/25 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b5a22712-0573-4d6c-853f-b3e2a1a71de8 ER - TY - JOUR TI - Astrophysics: tracking our neighbours' past DO - 10.1038/504226a AU - McConnachie, Alan T2 - Nature SN - 0028-0836 VL - 504 IS - 7479 SP - 226 EP - 227 AB - The collective motions of dwarf galaxies in planes around the Andromeda galaxy and the Milky Way have presented a challenge to theory. Interactions between galaxy groups in the distant past may have left their imprint on these dwarfs. DA - 2013/12/12 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : cf414d90-6c13-4d33-b129-50a279128971 ER - TY - JOUR TI - Effect of using stencil masks made by focused ion beam milling on permalloy (Ni81Fe19) nanostructures DO - 10.1088/0957-4484/24/11/115301 AU - Bates, J. R. AU - Miyahara, Y. AU - Burgess, J. A. J. AU - Iglesias-Freire, Ó. AU - Grütter, P. T2 - Nanotechnology SN - 0957-4484 VL - 24 IS - 11 SP - 115301 KW - Chemical compositions KW - Electron beam evaporation KW - Energy dispersive X ray spectroscopy KW - Focused ion beam milling KW - Kelvin probe force microscopy KW - Permalloy nanostructures KW - Silicon nitride membrane KW - Unintended consequences KW - Electron beams KW - Electron energy loss spectroscopy KW - Ion implantation KW - Magnetic force microscopy KW - Nanostructures KW - Nickel alloys KW - Silicon nitride KW - Transmission electron microscopy KW - X ray spectroscopy KW - Focused ion beams AB - Focused ion beam (FIB) milling is a common fabrication technique to make nanostencil masks which has the unintended consequence of gallium ion implantation surrounding milled features in silicon nitride membranes. We observe major changes in film structure, chemical composition, and magnetic behaviour of permalloy nanostructures deposited by electron beam evaporation using silicon nitride stencil masks made by a FIB as compared to stencil masks made by regular lithography techniques. We characterize the stenciled structures and both types of masks using transmission electron microscopy, electron energy loss spectroscopy, energy dispersive x-ray spectroscopy, magnetic force microscopy and kelvin probe force microscopy. All these techniques demonstrate distinct differences at a length scale of a 1-100 nm for the structures made using stencil mask fabricated using a FIB. The origin of these differences seems to be related to the presence of implanted ions, a detailed understanding of the mechanism however remains to be developed. © 2013 IOP Publishing Ltd. DA - 2013/02/28 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : bb4563cf-20ae-4c25-a510-74b225a72e28 ER - TY - JOUR TI - SML resist processing for high-aspect-ratio and high-sensitivity electron beam lithography DO - 10.1186/1556-276X-8-139 AU - Mohammad, Mohammad Ali AU - Dew, Steven K. AU - Stepanova, Maria T2 - Nanoscale Research Letters SN - 1931-7573 VL - 8 IS - 1 SP - 1 EP - 7 KW - SML resist; Electron beam lithography; High-aspect-ratio nanolithography; Nanolithography; Nanofabrication; Lift-off; Preventing pattern collapse; Resists (85.40.Hp); Electron beam lithography (85.40.Hp); Nanolithography (81.16.Nd) AB - A detailed process characterization of SML electron beam resist for high-aspect-ratio nanopatterning at high sensitivity is presented. SML contrast curves were generated for methyl isobutyl ketone (MIBK), MIBK/isopropyl alcohol (IPA) (1:3), IPA/water (7:3), n-amyl acetate, xylene, and xylene/methanol (3:1) developers. Using IPA/water developer, the sensitivity of SML was improved considerably and found to be comparable to benchmark polymethylmethacrylate (PMMA) resist without affecting the aspect ratio performance. Employing 30-keV exposures and ultrasonic IPA/water development, an aspect ratio of 9:1 in 50-nm half-pitch dense grating patterns was achieved representing a greater than two times improvement over PMMA. Through demonstration of 25-nm lift-off features, the pattern transfer performance of SML is also addressed. © 2013 Mohammad et al. DA - 2013/03/27 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2c700612-896e-4071-8248-e0882468ce7a ER - TY - JOUR TI - Doping and quantum confinement effects in single Si nanocrystals observed by scanning tunneling spectroscopy DO - 10.1021/nl400570p AU - Wolf, O. AU - Dasog, M. AU - Yang, Z. AU - Balberg, I. AU - Veinot, J. G. C. AU - Millo, O. T2 - Nano Letters SN - 1530-6984 VL - 13 IS - 6 SP - 2516 EP - 2521 KW - Band gap variation KW - Capping ligands KW - Electronic levels KW - Quantum confinement effects KW - scanning-tunneling-spectroscopy KW - Silicon nanocrystals KW - surface-doping KW - Tunneling spectra KW - Charge transfer KW - Energy gap KW - Ligands KW - Nanocrystals KW - Photoluminescence KW - Quantum confinement KW - Scanning KW - Scanning tunneling microscopy KW - Spectroscopy KW - Silicon AB - We have applied scanning tunneling spectroscopy in studies of the electronic level structure of surface-functionalized colloidal Si nanocrystals (Si-NCs) as a function of their size for various capping ligands. The energy gaps extracted from the tunneling spectra increase with decreasing NC size, manifesting the effect of quantum confinement. This is consistent with the blueshift revealed by photoluminescence (PL) from dodecene functionalized Si-NCs. The tunneling spectra measured on NCs functionalized with NH 4Br or allylamine show band-edge shifts toward higher energies, akin to p-type doping. This behavior can be accounted for by the combined contributions of the ligands' dipole moments and charge transfer between a Si-NC and its surface groups. Concomitantly, size-independent PL spectra, which cannot be associated with NC band gap variations, were observed for the latter Si-NCs. © 2013 American Chemical Society. DA - 2013/05/10 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d6c0940d-0c97-437c-a62a-4f624ba4e8f9 ER - TY - JOUR TI - Galaxy pairs in the local group DO - 10.1093/mnrasl/slt011 AU - Fattahi, Azadeh AU - Navarro, Julio F. AU - Starkenburg, Else AU - Barber, Christopher R. AU - McConnachie, Alan W. T2 - Monthly Notices of the Royal Astronomical Society: Letters SN - 1745-3925 VL - 431 IS - 1 SP - L73 EP - L77 AB - Current models of galaxy formation predict that galaxy pairs of comparable magnitudes should become increasingly rare with decreasing luminosity. This seems at odds with the relatively high frequency of pairings among dwarf galaxies in the Local Group. We use literature data to show that ~30 per cent of all the satellites of the Milky Way and Andromeda galaxies brighter than Mv = -8 are found in likely physical pairs of comparable luminosity. Besides the previously recognized pairings of theMagellanic Clouds and of NGC 147/NGC 185, other candidate pairs include the Ursa Minor and Draco dwarf spheroidals, as well as the And I/And III satellites of M31. These pairs are much closer than expected by chance if the radial and angular distributions of satellites were uncorrelated; in addition, they have very similar line-of-sight velocities and luminosities that differ by less than three magnitudes. In contrast, the same criteria pair fewer than 4 per cent of satellites in N-body/semi-analytic models that match the radial distribution and luminosity function of Local Group satellites. If confirmed in studies of larger samples, the high frequency of dwarf galaxy pairings may provide interesting clues to the formation of faint galaxies in the current cosmological paradigm. © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. DA - 2013/02/24 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 58ec8bbf-366e-4258-8df2-51adbfff0515 ER - TY - JOUR TI - Young accreted globular clusters in the outer halo of m31 DO - 10.1093/mnras/sts336 AU - Mackey, A. D. AU - Huxor, A. P. AU - Ferguson, A. M. N. AU - Irwin, M. J. AU - Veljanoski, J. AU - McConnachie, A. W. AU - Ibata, R. A. AU - Lewis, G. F. AU - Tanvir, N. R. T2 - Monthly Notices of the Royal Astronomical Society SN - 0035-8711 VL - 429 IS - 1 SP - 281 EP - 293 AB - We report on observations of two newly discovered globular clusters in the outskirts of M31 made using the Gemini Multi-Object Spectrograph (GMOS) instrument on Gemini North. These objects, PAndAS-7 (PA-7) and PAndAS-8 (PA-8), lie at a galactocentric radius of 87 kpc and are projected, with separation 19 kpc, on to a field halo substructure known as the South-West Cloud. We measure radial velocities for the two clusters which confirm that they are almost certainly physically associated with this feature. Colour-magnitude diagrams reveal strikingly short, exclusively red horizontal branches in both PA-7 and PA-8; both also have photometric [Fe/H]=-1.35±0.15. At this metallicity, the morphology of the horizontal branch is maximally sensitive to age, and we use the distinctive configurations seen in PA-7 and PA-8 to demonstrate that both objects are very likely to be at least 2 Gyr younger than the oldest Milky Way globular clusters. Our observations provide strong evidence for young globular clusters being accreted into the remote outer regions of M31 in a manner entirely consistent with the established picture for the Milky Way, and add credence to the idea that similar processes play a central role in determining the composition of globular cluster systems in large spiral galaxies in general. ©2012 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. DA - 2013/11/28 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4c32742c-0737-4749-a671-36bb72eba52d ER - TY - JOUR TI - The SUMO project I. A survey of multiple populations in globular clusters DO - 10.1093/mnras/stt273 AU - Monelli, M. AU - Milone, A. P. AU - Stetson, P. B. AU - Marino, A. F. AU - Cassisi, S. AU - Molina, A. P. AU - Salaris, M. AU - Aparicio, A. AU - Asplund, M. AU - Grundahl, F. AU - Piotto, G. AU - Weiss, A. AU - Carrera, R. AU - Cebrián, M. AU - Murabito, S. AU - Pietrinferni, A. AU - Sbordone, L. T2 - Monthly Notices of the Royal Astronomical Society SN - 0035-8711 VL - 431 IS - 3 SP - 2126 EP - 2149 AB - We present a general overview and the first results of the SUMO project (a SUrvey of Multiple pOpulations in Globular Clusters). The objective of this survey is the study of multiple stellar populations in the largest sample of globular clusters homogeneously analysed to date. To this aim we obtained high signal-to-noise (S/N > 50) photometry for main sequence stars with mass down to 0.5 M⊙ in a large sample of clusters using both archival and proprietary U, B, V and I data from ground-based telescopes. In this paper, we focus on the occurrence of multiple stellar populations in 23 clusters. We define a new photometric index, CU, B, I = (U - B) - (B - I), which turns out to be very effective for identifying multiple sequences along the red giant branch (RGB). We found that in the V-CU, B, I diagram all clusters presented in this paper show broadened or multimodal RGBs, with the presence of two or more components. We found a direct connection with the chemical properties of different sequences, which display different abundances of light elements (O, Na, C, N and Al). The CU, B, I index is also a powerful tool for identifying distinct sequences of stars along the horizontal branch and, for the first time in the case of NGC 104 (47 Tuc), along the asymptotic giant branch. Our results demonstrate that (i) the presence of more than two stellar populations is a common feature amongst globular clusters, as already highlighted in previous work; (ii) multiple sequences with different chemical contents can be easily identified by using standard Johnson photometry obtained with ground-based facilities; (iii) in the study of globular clustermultiple stellar populations the CU, B, I index is an alternative to spectroscopy, and has the advantage of larger statistics. © 2013 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. DA - 2013/03/21 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 205e2b76-3fd3-4511-bf60-e90c0061fe14 ER - TY - JOUR TI - Dynamics in the satellite system of Triangulum: is And XXII a dwarf satellite of M33? DO - 10.1093/mnras/sts392 AU - Chapman, S. C. AU - Widrow, L. AU - Collins, M. L. M. AU - Dubinski, J. AU - Ibata, R. A. AU - Rich, M. AU - Ferguson, A. M. N. AU - Irwin, M. J. AU - Lewis, G. F. AU - Martin, N. AU - McConnachie, A. AU - Peñarrubia, J. AU - Tanvir, N. T2 - Monthly Notices of the Royal Astronomical Society SN - 0035-8711 VL - 430 IS - 1 SP - 37 EP - 49 AB - We present results from a spectroscopic survey of the dwarf spheroidal galaxy And XXII and the two extended clusters EC1 and EC2. These three objects are candidate satellites of the Triangulum galaxy, M33, which itself is likely a satellite of M31. We use the DEep Imaging Multi-Object Spectrograph (DEIMOS) mounted on the Keck II telescope to derive radial velocities for candidate member stars of these objects and thereby identify the stars that are most likely actual members. 11 probable stellar members are found for And XXII. We obtain an upper limit of σv < 6.0 km s-¹ for the velocity dispersion of And XXII, [Fe/H] ~ -1.6 for its metallicity and 255 pc for the Plummer radius of its projected density profile. We construct a colour-magnitude diagram for And XXII and identify both the red giant branch and the horizontal branch. The position of the latter is used to derive a heliocentric distance to And XXII of 853 ± 26 kpc. The combination of the radial velocity, distance and angular position of And XXII indicate that it is a strong candidate as the first known satellite of M33 and one of the very few examples of a galactic satellite of a satellite. N-body simulations imply that this conclusion is unchanged even if M31 and M33 had a strong encounter in the past few Gyr. We test the hypothesis that the extended clusters highlight tidally stripped galaxies by searching for an excess cloud of halo-like stars in their vicinity. We find such a cloud for the case of EC1 but not for EC2. The three objects imply a dynamical mass for M33 that is consistent with previous estimates. © 2013 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 05de9707-b165-49db-bb51-c27ab22d1f93 ER - TY - JOUR TI - Distant galaxy clusters in the XMM large scale structure survey DO - 10.1093/mnras/sts540 AU - Willis, J. P. AU - Clerc, N. AU - Bremer, M. N. AU - Pierre, M. AU - Adami, C. AU - Ilbert, O. AU - Maughan, B. AU - Maurogordato, S. AU - Pacaud, F. AU - Valtchanov, I. AU - Chiappetti, L. AU - Thanjavur, K. AU - Gwyn, S. AU - Stanway, E. R. AU - Winkworth, C. T2 - Monthly Notices of the Royal Astronomical Society SN - 0035-8711 VL - 430 IS - 1 SP - 134 EP - 156 AB - Distant galaxy clusters provide important tests of the growth of large-scale structure in addition to highlighting the process of galaxy evolution in a consistently defined environment at large look-back time. We present a sample of 22 distant (z > 0.8) galaxy clusters and cluster candidates selected from the 9 deg² footprint of the overlapping X-ray Multi Mirror (XMM) Large Scale Structure (LSS), CFHTLS-Wide and Spitzer-SWIRE surveys. Clusters are selected as extended X-ray sources with an accompanying overdensity of galaxies displaying optical to mid-infrared photometry consistent with z > 0.8. Nine clusters have confirmed spectroscopic redshifts in the interval 0.8 < z < 1.2, four of which are presented here for the first time. A further 11 candidate clusters have between 8 and 10 band photometric redshifts in the interval 0.8 < z < 2.2, while the remaining two candidates do not have information in sufficient wavebands to generate a reliable photometric redshift. All of the candidate clusters reported in this paper are presented for the first time. Those confirmed and candidate clusters with available near-infrared photometry display evidence for a red sequence galaxy population, determined either individually or via a stacking analysis, whose colour is consistent with the expectation of an old, coeval stellar population observed at the cluster redshift. We further note that the sample displays a large range of red fraction values indicating that the clusters may be at different stages of red sequence assembly. We compare the observed X-ray emission to the flux expected from a suite of model clusters and find that the sample displays an effective mass limit M200 ∼ 1 × 10¹⁴ ⊙ with all clusters displaying masses consistent with M200 < 5 × 10¹⁴ M⊙. This XMM distant cluster study represents a complete sample of X-ray-selected z > 0.8 clusters. We discuss the importance of this sample to investigate the abundance of high-redshift clusters and to provide a relatively unbiased view of distant cluster galaxy populations. © 2013 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. DA - 2013/01/28 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9d42320f-624e-4884-a085-a43a42f6eb8c ER - TY - JOUR TI - Speckle observations with PISCO in Merate (Italy) - XII. Astrometric measurements of visual binaries in 2011 DO - 10.1093/mnras/stt1140 AU - Scardia, M. AU - Prieur, J.-L. AU - Pansecchi, L. AU - Argyle, R. W. AU - Spanò, P. AU - Riva, M. AU - Landoni, M. T2 - Monthly Notices of the Royal Astronomical Society SN - 0035-8711 VL - 434 IS - 4 SP - 2803 EP - 2813 AB - We present relative astrometric measurements of visual binaries, made in 2011 with the Pupil Interferometry Speckle camera and COronagraph (PISCO) at the 102-cm Zeiss telescope of the Brera Astronomical Observatory in Merate (Italy). Our observing list contains orbital couples as well as binaries whose motion is still uncertain. We obtained new measurements of 469 objects, with angular separations in the range 0.14-8.1 arcsec, and an average accuracy of 0.02 arcsec. The mean error on the position angles is 0°.7. Most of the position angles were determined without the usual 180° ambiguity with the application of triple-correlation techniques and/or by inspection of the long integration files. Thanks to a newlow-magnification option included in PISCO, we have been able to observe fainter stars than previously. The limiting magnitude of our instrumentation on the Zeiss telescope is now close to mV = 10-12, which permits the observation of some red dwarfs. Finally, we present new revised orbits for ADS8739, 9182 Aa, Ab, 9626 Ba, Bb, 12880 and 14412, partly derived from those observations. The corresponding estimated values for the masses of those systems are compatible with the spectral types. © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. DA - 2013/08/07 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : dd15353a-edaf-4e75-a198-c4ae3f8c3538 ER - TY - JOUR TI - V2494 cyg: A unique FU ori type object in the cygnus OB7 complex DO - 10.1093/mnras/stt626 AU - Magakian, Tigran Yu. AU - Nikogossian, Elena H. AU - Movsessian, Tigran AU - Moiseev, Alexei AU - Aspin, Colin AU - Davis, Chris J. AU - Pyo, Tae-Soo AU - Khanzadyan, Tigran AU - Froebrich, Dirk AU - Smith, Michael D. AU - Moriarty-Schieven, Gerald H. AU - Beck, Tracy L. T2 - Monthly Notices of the Royal Astronomical Society SN - 0035-8711 VL - 432 IS - 4 SP - 2685 EP - 2695 AB - A photometric and spectral study of the variable star V2494 Cyg in the L 1003 dark cloud is presented. The brightness of the star, formerly known as HH 381 IRS, increased by 2.5 mag in R (probably in the 1980s) and since then has remained nearly constant. Since the brightness increase, V2494 Cyg has illuminated a bipolar cometary nebula. The stellar spectrum has several features typical of the FU Ori (FUor) type, plus it exhibits very strong Ha and forbidden emissionlines with high-velocity components. These emission lines originate in the Herbig-Haro (HH) jet near the star. The kinematic age of the jet is consistent with it forming at the time of the outburst leading to the luminosity increase. V2494 Cyg also produces a rather extended outflow; it is the first known FUor with both an observed outburst and a parsec-sized HH flow. The nebula, illuminated by V2494 Cyg, possesses similar morphological and spectral characteristics to Hubble's variable nebula (R Monocerotis/NGC 2261). © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : df076029-5bdf-4fe1-8384-7fbcd096a31b ER - TY - JOUR TI - The VAST survey - III. The multiplicity of A-type stars within 75 pc DO - 10.1093/mnras/stt1932 AU - De Rosa, R. J. AU - Patience, J. AU - Wilson, P. A. AU - Schneider, A. AU - Wiktorowicz, S. J. AU - Vigan, A. AU - Marois, C. AU - Song, I. AU - Macintosh, B. AU - Graham, J. R. AU - Doyon, R. AU - Bessell, M. S. AU - Thomas, S. AU - Lai, O. T2 - Monthly Notices of the Royal Astronomical Society SN - 0035-8711 VL - 437 IS - 2 SP - stt1932 SP - 1216 EP - 1240 DA - 2013/11/26 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0b063bec-c63e-4ed5-8327-f6d6485c9d3e ER - TY - JOUR TI - Newly discovered globular clusters in NGC 147 and NGC 185 from PAndAS DO - 10.1093/mnras/stt1557 AU - Veljanoski, J. AU - Ferguson, A. M. N. AU - Huxor, A. P. AU - Mackey, A. D. AU - Fishlock, C. K. AU - Irwin, M. J. AU - Tanvir, N. AU - Chapman, S. C. AU - Ibata, R. A. AU - Lewis, G. F. AU - McConnachie, A. T2 - Monthly Notices of the Royal Astronomical Society SN - 0035-8711 VL - 435 IS - 4 SP - 3654 EP - 3666 KW - galaxies: globular clusters: general; galaxies: individual: NGC 147; galaxies: individual: NGC 185 AB - Using data from the Pan-Andromeda Archaeological Survey (PAndAS), we have discovered four new globular clusters (GCs) associated with the M31 dwarf elliptical (dE) satellites NGC 147 and NGC 185. Three of these are associated with NGC 147 and one with NGC 185. All lie beyond the main optical boundaries of the galaxies and are the most remote clusters yet known in these systems. Radial velocities derived from low-resolution spectra are used to argue that the GCs are bound to the dwarfs and are not part of the M31 halo population. Combining PAndAS with United Kingdom Infrared Telescope (UKIRT)/WFCAM (Wide- Field Camera) data, we present the first homogeneous optical and near-IR photometry for the entireGCsystems of these dEs. Colour-colour plots and published colour-metallicity relations are employed to constrain GC ages and metallicities. It is demonstrated that the clusters are in general metal poor ([Fe/H] < -1.25 dex), while the ages are more difficult to constrain. The mean (V - η0 colours of the two GC systems are very similar to those of the GC systems of dEs in the Virgo and Fornax clusters, as well as the extended halo GC population in M31. The new clusters bring the GC-specific frequency (SN) to ~9 in NGC 147 and ~5 in NGC 185, consistent with values found for dEs of similar luminosity residing in a range of environments. DA - 2013/09/13 PY - 2013 PB - Oxford University Press LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f130027b-445f-44ca-85e3-1bd5d13b34c5 ER - TY - JOUR TI - The James Clerk Maxwell Telescope Nearby Galaxies Legacy Survey - IX. ¹²CO J = 3→2 observations of NGC 2976 and NGC 3351 DO - 10.1093/mnras/stt1625 AU - Tan, Boon-Kok AU - Leech, J. AU - Rigopoulou, D. AU - Warren, B. E. AU - Wilson, C. D. AU - Attewell, D. AU - Azimlu, M. AU - Bendo, G. J. AU - Butner, H. M. AU - Brinks, E. AU - Chanial, P. AU - Clements, D. L. AU - Heesen, V. AU - Israel, F. AU - Knapen, J. H. AU - Matthews, H. E. AU - Mortier, A. M. J. AU - Mühle, S. AU - Sánchez-Gallego, J. R. AU - Tilanus, R. P. J. AU - Usero, A. AU - van der Werf, P. AU - Zhu, M. T2 - Monthly Notices of the Royal Astronomical Society SN - 0035-8711 VL - 436 IS - 1 SP - 921 EP - 933 AB - We present ¹²CO J = 3→2 maps of NGC 2976 and NGC 3351 obtained with the James Clerk Maxwell Telescope (JCMT), both early targets of the JCMT Nearby Galaxy Legacy Survey (NGLS). We combine the present observations with ¹²CO J = 1→0 data and find that the computed ¹²CO J = 3→2 to ¹²CO J = 1→0 line ratio (R31) agrees with values measured in other NGLS field galaxies. We compute the MH2 value and find that it is robust against the value of R31 used. Using HI data from The HI Nearby Galaxy Survey, we find a tight correlation between the surface density of H2 and star formation rate density for NGC 3351 when ¹²CO J = 3→2 data are used. Finally, we compare the ¹²CO J = 3→2 intensity with the polycyclic aromatic hydrocarbon (PAH) 8 μm surface brightness and find a good correlation in the high surface brightness regions. We extend this study to include all 25 Spitzer Infrared Nearby Galaxies Survey galaxies within the NGLS sample and find a tight correlation at large spatial scales. We suggest that both PAH 8 μm and ¹²CO J = 3→2 are likely to originate in regions of active star formation. © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. DA - 2013/10/03 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : baaf4887-d6a6-4c7a-a076-d802a69064a8 ER - TY - JOUR TI - The orbital ellipticity of satellite galaxies and the mass of the Milky Way DO - 10.1093/mnras/stt1959 AU - Barber, Christopher AU - Starkenburg, Else AU - Navarro, Julio F. AU - McConnachie, Alan W. AU - Fattahi, Azadeh T2 - Monthly Notices of the Royal Astronomical Society SN - 0035-8711 VL - 437 IS - 1 SP - stt1959 SP - 959 EP - 967 AB - We use simulations of MilkyWay-sized dark matter haloes from the Aquarius Project to investigate the orbits of substructure haloes likely, according to a semi-analytic galaxy formation model, to host luminous satellites. These tend to populate the most massive subhaloes and are on more radial orbits than the majority of subhaloes found within the halo virial radius. One reason for this (mild) kinematic bias is that many low-mass subhaloes have apocentres that exceed the virial radius of the host; they are thus excluded from subhalo samples identified within the virial boundary, reducing the number of subhaloes on radial orbits. Two other factors contributing to the difference in orbital shape between dark and luminous subhaloes are their dynamical evolution after infall, which affects more markedly low-mass (dark) subhaloes, and a weak dependence of ellipticity on the redshift of first infall. The ellipticity distribution of luminous satellites exhibits little halo-to-halo scatter, and it may therefore be compared fruitfully with that of Milky Way satellites. Since the latter depends sensitively on the total mass of the Milky Way we can use the predicted distribution of satellite ellipticities to place constraints on this important parameter. Using the latest estimates of position and velocity of dwarfs compiled from the literature, we find that the most likely Milky Way mass lies in the range 6 × 1011M⊙ 16 years in the oxic tailings body. Data shows an association between the Mg-Al hydrotalcite and both As and Ni and point to this Mg-Al hydrotalcite exerting a mineralogical control on the solubility of these contaminants. © 2013 American Chemical Society. DA - 2013/06/06 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : acb721d1-a471-4502-a89d-16d26d64d8cc ER - TY - JOUR TI - Five helicopter accidents with evidence of material and/or design deficiencies DO - 10.1016/j.engfailanal.2012.12.002 AU - Wanhill, R. J. H. AU - Symonds, N. AU - Merati, A. AU - Pasang, T. AU - Lynch, S. P. T2 - Engineering Failure Analysis SN - 1350-6307 VL - 35 SP - 133 EP - 146 KW - Agusta westland KW - Design deficiencies KW - Flight operation KW - Material defect KW - Mission planning KW - Sikorsky KW - Systems failure KW - Failure analysis KW - Forensic engineering KW - Fractography KW - Fracture mechanics KW - Helicopter services KW - Helicopters KW - Accidents AB - Most helicopter accidents are due to problems concerning flight operations, ground duties (mission planning and preparation), training and instructions. These are key issues within the current (European) strategies for greatly reducing the number of accidents in the next few years. However, when accidents occur the subsequent investigations should include or at least consider forensic engineering, even if only to eliminate possible causes like material defects, component and systems failures, and design deficiencies. To illustrate this, the present paper discusses five helicopter accidents with evidence of material and/or design deficiencies. The accidents concerned a Sikorsky S-61N (1974), an Aérospatiale Alouette III (1990), a Westland Lynx SH14D (1998), and two AgustaWestland EH101s (2004, 2006). © 2012 Elsevier Ltd. DA - 2013/01/03 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 10420836-f74e-4df2-9b61-692ee63d2490 ER - TY - JOUR TI - Mesoporous nitrogen-rich carbons derived from protein for ultra-high capacity battery anodes and supercapacitors DO - 10.1039/c2ee23599d AU - Li, Zhi AU - Xu, Zhanwei AU - Tan, Xuehai AU - Wang, Huanlei AU - Holt, Chris M. B. AU - Stephenson, Tyler AU - Olsen, Brian C. AU - Mitlin, David T2 - Energy and Environmental Science SN - 1754-5692 VL - 6 IS - 3 SP - 871 EP - 878 KW - Carbon-based electrodes KW - Electrochemical energy storage KW - Energy applications KW - Graphitized carbons KW - High specific surface area KW - Lithium storage capacity KW - Nitrogen content KW - Specific capacitance KW - Capacitors KW - Graphitization KW - Mesoporous materials KW - Proteins KW - Biosynthesis KW - Electrochemistry KW - Foam AB - In this work we demonstrate that biomass-derived proteins serve as an ideal precursor for synthesizing carbon materials for energy applications. The unique composition and structure of the carbons resulted in very promising electrochemical energy storage performance. We obtained a reversible lithium storage capacity of 1780 mA h g-1, which is among the highest ever reported for any carbon-based electrode. Tested as a supercapacitor, the carbons exhibited a capacitance of 390 F g-1, with an excellent cycle life (7% loss after 10000 cycles). Such exquisite properties may be attributed to a unique combination of a high specific surface area, partial graphitization and very high bulk nitrogen content. It is a major challenge to derive carbons possessing all three attributes. By templating the structure of mesoporous cellular foam with egg white-derived proteins, we were able to obtain hierarchically mesoporous (pores centered at ∼4 nm and at 20-30 nm) partially graphitized carbons with a surface area of 805.7 m2 g -1 and a bulk N-content of 10.1 wt%. When the best performing sample was heated in Ar to eliminate most of the nitrogen, the Li storage capacity and the specific capacitance dropped to 716 mA h g-1 and 80 F g -1, respectively. © 2013 The Royal Society of Chemistry. DA - 2013/01/03 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ef197068-2664-4c0a-9b9e-8d07edde7464 ER - TY - JOUR TI - Disruption of biomolecule function by nanoparticles: how do gold nanoparticles affect Phase I biotransformation of persistent organic pollutants? DO - 10.1016/j.chemosphere.2013.05.004 AU - Lu, Zhe AU - Ma, Guibin AU - Veinot, Johnathan G. C. AU - Wong, Charles S. T2 - Chemosphere SN - 0045-6535 VL - 93 IS - 1 SP - 123 EP - 132 KW - Nanoparticles; Cytochrome P-450; Chiral organic pollutants; Ionic strength; Disruption AB - The potential influence of nanoparticles on cytochrome P-450 (CYP) isozyme mediated Phase I biotransformation of persistent organic pollutants (POPs) in vitro was investigated using citrate-capped gold nanoparticles (AuNPs) and 2,2',3,5',6-pentachlorobiphenyl (PCB 95) as the probe nanoparticle and compound, respectively. AuNPs affected the biotransformation activity of rat CYP2B1 and changed the atropisomeric composition of PCB 95, depending on the incubation time and the AuNP concentration. Electrostatic repulsion between citrate-coated AuNPs and rat CYP2B1 may influence the active conformation of the isozyme and consequently affect its activity and stereoselectivity. In addition, the effects of AuNPs on rat CYP2B1 activity also appeared to be through interference with the CYP catalytic cycle's electron transfer chain. Incubations with AuNPs had a decline in buffer conductance and an absorbance band red shift of AuNPs, from electrostatic interactions of K+ with negatively-charged AuNP aggregates. These ionic strength changes affected the formation rate of nicotinamide adenine dinucleotide phosphate, which provides electrons for the oxidative reaction cycle, and the biotransformation activity and stereoselectivity of CYP. This study suggests that charged nanoparticles may be able to alter the functions of biomolecules directly, by electrostatic interaction, or indirectly, by changes to the surrounding ionic strength. These factors should be taken into account for further understanding and prediction of the environmental behavior and fate of POPs and nanoparticles. © 2013 Elsevier Ltd. DA - 2013/06/10 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3e895c33-7c52-438e-9c32-35a4cd9a1aa1 ER - TY - JOUR TI - Nanocrystalline anatase TiO2: a new anode material for rechargeable sodium ion batteries DO - 10.1039/c3cc45254a AU - Xu, Yang AU - Memarzadeh Lotfabad, Elmira AU - Wang, Huanlei AU - Farbod, Behdokht AU - Xu, Zhanwei AU - Kohandehghan, Alireza AU - Mitlin, David T2 - Chemical Communications SN - 1359-7345 VL - 49 IS - 79 SP - 8973 EP - 8975 KW - anatase nanocrystal KW - carbon KW - nanocrystal KW - sodium ion KW - titanium dioxide KW - unclassified drug KW - adsorption KW - desorption KW - electric battery KW - electrode KW - sodium ion battery KW - storage AB - Anatase TiO2 nanocrystals were successfully employed as anodes for rechargeable Na-ion batteries for the first time. The mesoporous electrodes exhibited a highly stable reversible charge storage capacity of ∼150 mA h g-¹ over 100 cycles, and were able to withstand high rate cycling, fully recovering this capacity after being cycled at rates as high as 2 A g-¹. DA - 2013/08/15 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : bf5baabe-9030-4191-951a-3880a42deb4c ER - TY - JOUR TI - Comparison of the morphology of alkali-silica gel formed in limestones in concrete affected by the so-called alkali-carbonate reaction (ACR) and alkali-silica reaction (ASR) DO - 10.1016/j.cemconres.2013.01.013 AU - Grattan-Bellew, P. E. AU - Chan, Gordon T2 - Cement and Concrete Research SN - 0008-8846 VL - 47 SP - 51 EP - 54 KW - Aggregate particles KW - Alkali carbonate reaction KW - Alkali-silica reaction KW - Dolomitic limestone KW - Highway structures KW - Limestone particles KW - Scanning Electron Microscope KW - SEM-EDX KW - Calcite KW - Carbonation KW - Concretes KW - Morphology KW - Scanning electron microscopy KW - Silica gel KW - Stringers KW - Aggregates AB - The morphology of alkali-silica gel formed in dolomitic limestone affected by the so-called alkali-carbonate reaction (ACR) is compared to that formed in a siliceous limestone affected by alkali-silica reaction (ASR). The particle of dolomitic limestone was extracted from the experimental sidewalk in Kingston, Ontario, Canada that was badly cracked due to ACR. The siliceous limestone particle was extracted from a core taken from a highway structure in Quebec, affected by ASR. Both cores exhibited marked reaction rims around limestone particles. The aggregate particles were polished and given a light gold coating in preparation for examination in a scanning electron microscope. The gel in the ACR aggregate formed stringers between the calcite crystals in the matrix of the rock, whereas gel in ASR concrete formed a thick layer on top of the calcite crystals, that are of the same size as in the ACR aggregate. © 2013 Elsevier Ltd. DA - 2013/03/05 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 772f9ec6-7e1f-4b4d-9ae7-a44984a7f594 ER - TY - JOUR TI - Microbubble-enhanced cell membrane permeability in high gravity field DO - 10.1007/s12195-013-0279-6 AU - He, Chuan AU - Gu, Quanrong AU - Zeng, Hongbo AU - Zhang, Hao AU - Huang, Min AU - Yang, Xiaoyan AU - Xing, James AU - Chen, Jie T2 - Cellular and Molecular Bioengineering SN - 1865-5025 VL - 6 IS - 3 SP - 266 EP - 278 KW - Cell membrane permeability; Microbubbles; DLVO force; Hydrodynamic force; High gravity field; Cavitation; THP-1 monocytes; MCF-7 cells AB - Cell permeability controls the transportation of extracellular materials through cell membranes, which plays a critical role in drug and gene delivery. This work reports an innovative method to enhance the cell permeability through cell-bubble interactions in a high gravity field. In the presence of microbubbles, the cell membrane permeability of mammalian cells was significantly increased in the high gravity field, and up to 80% THP-1 and 70% MCF-7 cells were permeabilized by using FITC-Dextran with average molecular weight of 40 and 70 kDa as fluorescent markers which were found to locate in both cytoplasm and cell nucleus by using a confocal microscope. Micro-scale pores were detected on the cell membrane by a scanning electron microscope after the cellmicrobubble interactions in the high gravity field. The delivery efficiency of FITC-Dextran could be further enhanced in gravity field of higher strength and in solutions with higher volume fraction of microbubbles, though the cell viability would also fall under extreme conditions. A simplified model was proposed to compare the contributions of surface forces (i.e., Derjaguin-Landau-Verwey-Overbeek (DLVO) interaction force and membrane undulation force) with hydrodynamic force associated with cell-bubble interactions in the high gravity field. The hydrodynamic force was found to dominate the cell-bubble interaction while the DLVO force and membrane undulation force only play an important role at small separation (≤10 nm) and low relative velocity of approach (i.e., low gravity field strength). The enhanced cell membrane permeability and formation of micro-scale pores are mainly due to the microbubble-cell interactions through collision and/ or cavitation effects from the bursting of microbubbles. Our results have important implications in many bioengineering processes which are dependent on cell membrane permeability. © 2013 Biomedical Engineering Society. DA - 2013/09/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9a97f3fa-eaf8-46e2-82a2-be22e5c1f25d ER - TY - JOUR TI - Koopmans' multiconfigurational self-consistent field (MCSCF) Fukui functions and MCSCF perturbation theory DO - 10.1139/cjc-2012-0526 AU - Gusarov, Serguey AU - Dmitriev, Yuri Yu AU - Stoyanov, Stanislav R. AU - Kovalenko, Andriy T2 - Canadian Journal of Chemistry SN - 0008-4042 VL - 91 IS - 9 SP - 886 EP - 893 KW - Computational challenges KW - Density functional theory methods KW - Extended Koopmans' approximation KW - Fukui functions KW - Multiconfigurational self-consistent fields KW - Perturbation theory KW - Priority tasks KW - Transition state KW - Chemical reactivity KW - Electronic structure KW - Green's function AB - Prediction of chemical reactivity has become one of the highest priority tasks of computational chemistry since the development of the methods of modeling electronic structure. Despite the general simplicity of the physical concept of reactivity and the rapid development of modern density functional theory (DFT) methods, this task remains state-of-the-art for systems with wavefunctions that have a multiconfigurational character. In such cases, for the accurate description of reactivity one needs to use multiconfigurational approaches that are much heavier computationally then ordinary single-determinant DFT methods. Moreover, the complexity of the calculation of reactivity is increased by the necessity to calculate ionic and transition states. These computational challenges can be addressed by employing the concepts of Koopmans' theorem and its extension to a multiconfigurational case. We present a simplified methodology for the calculation of Fukui functions, based on Koopmans' approximation for multiconfigurational Green's functions developed in our previous works. Also, an extension of this methodology based on perturbation theory has been developed to improve accuracy. © 2013 Published by NRC Research Press. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9b1ecb83-72a8-42f9-acc4-6c5230bd0447 ER - TY - JOUR TI - Density functional theory investigation of the effect of axial coordination and annelation on the absorption spectroscopy of nickel(II) and vanadyl porphyrins relevant to bitumen and crude oils DO - 10.1139/cjc-2012-0532 AU - Stoyanov, Stanislav R. AU - Yin, Cindy-Xing AU - Gray, Murray R. AU - Stryker, Jeffrey M. AU - Gusarov, Serguey AU - Kovalenko, Andriy T2 - Canadian Journal of Chemistry SN - 0008-4042 VL - 91 IS - 9 SP - 872 EP - 878 KW - Annelation KW - Axial coordination KW - Bitumen KW - Metalloporphyrins KW - Soret bands KW - Time dependent density functional theory KW - Asphaltenes KW - Bituminous materials KW - Continuum mechanics KW - Crude oil KW - Density functional theory KW - Heavy oil production KW - Nickel KW - Ultraviolet spectroscopy KW - Porphyrins AB - The vanadium and nickel components in heavy oils and bitumen are important impurities in catalytic processing and form aggregates with other asphaltene components. Metalloporphyrins are commonly analyzed using the characteristic Soret band in the UV-vis absorption spectrum. However, the Soret band of metalloporphyrins in petroleum is broadened and weaker than expected based on the concentration of Ni and V in heavy oils and the extinction coefficients of isolated porphyrins. We hypothesize that the low intensity and broadening of the Soret band could be due to axial coordination of the metal center or fusion (annelation) of aromatic rings on the porphyrin π-system. This hypothesis is examined using the density functional theory for geometry optimization and time-dependent density functional theory (TD-DFT) for calculation of excited states of nickel(II) and vanadyl porphyrins with axially coordinated ligands and annelated polyaromatic hydrocarbons. Predictions of the excited electronic states performed using the tandem of TD-DFT and conductor-like polarizable continuum model of solvation support this hypothesis and provide insight into the extent of Soret band broadening and intensity decrease due to coordination and annelation. These computational results, validated with respect to visible absorption spectra, are important for understanding asphaltene aggregation and spectroscopic characterization and suggest methods for removal of transition metals from heavy oil. © 2013 Published by NRC Research Press. DA - 2013/04/18 PY - 2013 C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 89d2c489-ee0e-44e4-aab0-808d2583952e ER - TY - JOUR TI - Magnetic gold nanoparticles as a vehicle for fluorescein isothiocyanate and DNA delivery into plant cells DO - 10.1139/cjb-2012-0281 AU - Hao, Yuzhi AU - Yang, Xiaoyan AU - Shi, Yongzhong AU - Song, Steven AU - Xing, James AU - Marowitch, Janet AU - Chen, Jianmin AU - Chen, Jie T2 - Botany SN - 1916-2804 VL - 91 IS - 7 SP - 457 EP - 466 KW - canola KW - DNA KW - gene expression KW - gold KW - image analysis KW - nanotechnology KW - plasmid AB - Magnetic gold nanoparticles (mGNPs) with uniform size and morphology synthesized by our sonication treatment method were covalently bound with fluorescein isothiocyanate (FITC) molecules. Driven by an external magnetic field, FITC-labelled nanoparticles were delivered into plant cells with and without cell walls, evident from sectional transmission electron microscopy images. Confocal images further indicate that the green fluorescence in canola protoplasts and walled cells indeed came from the FITC molecules, instead of the chloroplasts' autofluorescence. FITC-labelled nanoparticles had a delivery efficiency of 95% based on confocal images. In further study, plasmids were covalently bound with mGNPs, and delivered into canola cells with and without cell walls. After culturing for 48 h followed by staining with 5-bromo-4-chloro-3-indolyl-β-D-glucuronic acid (X-Gluc), blue colour appeared in the protoplasts, while the walled canola cells showed a green colour that can be interpreted as the combination of blue and yellow from the suspension cells themselves. The presence of the blue colour indicates the expression of the GUS gene; therefore, the plasmids were successfully delivered into the canola cells. Furthermore, on examination, mGNPs were considered to be noncytotoxic by fluorescein diacetate staining. DA - 2013/04/09 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9c65c522-3a81-493b-859b-a3941fd1b27b ER - TY - JOUR TI - Understanding the effect of secondary structure on molecular interactions of poly-l-lysine with different substrates by SFA DO - 10.1021/bm400837t AU - Binazadeh, Mojtaba AU - Faghihnejad, Ali AU - Unsworth, Larry D. AU - Zeng, Hongbo T2 - Biomacromolecules SN - 1525-7797 VL - 14 IS - 10 SP - 3498 EP - 3508 KW - Biomaterial surfaces KW - Derjaguin-Landau-Verwey-Overbeek theories KW - Engineered materials KW - Interaction mechanisms KW - Nonspecific adsorption KW - Secondary structure of proteins KW - Secondary structures KW - Surface forces apparatus KW - Atomic force microscopy KW - Hydrogen bonds KW - Mica KW - Molecular interactions KW - Polyethylene glycols KW - Polyethylene oxides KW - Quartz KW - Gold KW - macrogol KW - alpha helix KW - atomic force microscopy KW - beta sheet KW - circular dichroism KW - concentration (parameters) KW - protein interaction AB - Nonspecific adsorption of proteins on biomaterial surfaces challenges the widespread application of engineered materials, and understanding the impact of secondary structure of proteins and peptides on their adsorption process is of both fundamental and practical importance in bioengineering. In this work, poly-l-lysine (PLL)-based α-helices and β-sheets were chosen as a model system to investigate the effect of secondary structure on peptide interactions with substrates of various surface chemistries. Circular dichroism (CD) was used to confirm the presence of both α-helix and β-sheet structured PLL in aqueous solutions and upon adsorption to quartz, where these secondary structures seemed to be preserved. Atomic force microscopy (AFM) imaging showed different surface patterns for adsorbed α-helix and β-sheet PLL. Interactions between PLL of different secondary structures and various substrates (i.e., PLL, Au, mica, and poly(ethylene glycol) (PEG)) were directly measured using a surface forces apparatus (SFA). It was found that β-sheet PLL films showed higher adsorbed layer thicknesses in general. Adhesion energies of β-sheet versus Au and β-sheet versus β-sheet were considerably higher than that of α-helix versus Au and α-helix versus α-helix systems, respectively. Au and β-sheet PLL interactions seemed to be more dependent on the salt concentration than that of α-helix, while the presence of a grafted PEG layer greatly diminished any attraction with either PLL structure. The molecular interaction mechanism of peptide in different secondary structures is discussed in terms of Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, Alexander-de Gennes (AdG) steric model and hydrogen bonding, which provides important insight into the fundamental understanding of the interaction mechanism between proteins and biomaterials. © 2013 American Chemical Society. DA - 2013/09/16 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e01860f3-9cda-4897-9bc9-125102996819 ER - TY - JOUR TI - Extended photometry for the DEEP2 Galaxy Redshift Survey: a testbed for photometric redshift experiments DO - 10.1088/0067-0049/204/2/21 AU - Matthews, Daniel J. AU - Newman, Jeffrey A. AU - Coil, Alison L. AU - Cooper, Michael C. AU - Gwyn, Stephen D. J. T2 - The Astrophysical Journal, Supplement Series SN - 0067-0049 VL - 204 IS - 2 SP - 21 AB - This paper describes a new catalog that supplements the existing DEEP2 Galaxy Redshift Survey photometric and spectroscopic catalogs with ugriz photometry from two other surveys: the Canada-France-Hawaii Legacy Survey (CFHTLS) and the Sloan Digital Sky Survey (SDSS). Each catalog is cross-matched by position on the sky in order to assign ugriz photometry to objects in the DEEP2 catalogs. We have recalibrated the CFHTLS photometry where it overlaps DEEP2 in order to provide a more uniform data set. We have also used this improved photometry to predict DEEP2 BRI photometry in regions where only poorer measurements were available previously. In addition, we have included improved astrometry tied to SDSS rather than USNO-A2.0 for all DEEP2 objects. In total this catalog contains ∼27, 000 objects with full ugriz photometry as well as robust spectroscopic redshift measurements, 64% of which have r > 23. By combining the secure and accurate redshifts of the DEEP2 Galaxy Redshift Survey with ugriz photometry, we have created a catalog that can be used as an excellent testbed for future photo-z studies, including tests of algorithms for surveys such as LSST and DES. © 2013. The American Astronomical Society. All rights reserved. DA - 2013/01/30 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9d185c2f-4530-4d32-aea8-27a5a22b24f6 ER - TY - JOUR TI - Kinematics of outer halo globular clusters in M31 DO - 10.1088/2041-8205/768/2/L33 AU - Veljanoski, J. AU - Ferguson, A. M. N. AU - MacKey, A. D. AU - Huxor, A. P. AU - Irwin, M. J. AU - Côté, P. AU - Tanvir, N. R. AU - Bernard, E. J. AU - Chapman, S. C. AU - Ibata, R. A. AU - Fardal, M. AU - Lewis, G. F. AU - Martin, N. F. AU - McConnachie, A. AU - Peñarrubia, J. T2 - The Astrophysical Journal Letters SN - 2041-8205 VL - 768 IS - 2 SP - L33 AB - We present the first kinematic analysis of the far outer halo globular cluster (GC) population in the Local Group galaxy M31. Our sample contains 53 objects with projected radii of ∼20-130 kpc, 44 of which have no previous spectroscopic information. GCs with projected radii ≳ 30 kpc are found to exhibit net rotation around the minor axis of M31, in the same sense as the inner GCs, albeit with a smaller amplitude of 79 ± 19 km s-¹. The rotation-corrected velocity dispersion of the full halo GC sample is 106 ± 12 km s-¹, which we observe to decrease with increasing projected radius. We find compelling evidence for kinematic coherence among GCs that project on top of halo substructure, including a clear signature of infall for GCs lying along the northwest stream. Using the tracer mass estimator, we estimate the dynamical mass of M31 within 200 kpc to be M M31 = (1.2-1.5) ± 0.2 × 10¹#&178; M . This value is highly dependent on the chosen model and assumptions within. © 2013. The American Astronomical Society. All rights reserved.. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 7c32c9ab-c025-43ee-b92b-17e19279eee1 ER - TY - JOUR TI - Limits on Quaoar's atmosphere DO - 10.1088/2041-8205/774/2/L18 AU - Fraser, Wesley C. AU - Trujillo, Chad AU - Stephens, Andrew W. AU - Gimeno, German AU - Brown, Michael E. AU - Gwyn, Stephen AU - Kavelaars, J. J. T2 - The Astrophysical Journal Letters SN - 2041-8205 VL - 774 IS - 2 SP - L18 AB - Here we present high cadence photometry taken by the Acquisition Camera on Gemini South, of a close passage by the 540 km radius Kuiper belt object, (50000) Quaoar, of a r′ = 20.2 background star. Observations before and after the event show that the apparent impact parameter of the event was 0.″019 ± 0.″004, corresponding to a close approach of 580 ± 120 km to the center of Quaoar. No signatures of occultation by either Quaoar's limb or its potential atmosphere are detectable in the relative photometry of Quaoar and the target star, which were unresolved during closest approach. From this photometry we are able to put constraints on any potential atmosphere Quaoar might have. Using a Markov chain Monte Carlo and likelihood approach, we place pressure upper limits on sublimation supported, isothermal atmospheres of pure N2, CO, and CH4. For N2 and CO, the upper limit surface pressures are 1 and 0.7 μbar, respectively. The surface temperature required for such low sublimation pressures is 33 K, much lower than Quaoar's mean temperature of 44 K measured by others. We conclude that Quaoar cannot have an isothermal N2 or CO atmosphere. We cannot eliminate the possibility of a CH4 atmosphere, but place upper surface pressure and mean temperature limits of 138 nbar and 44 K, respectively. © 2013. The American Astronomical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b6fdc92b-97b9-4db4-b598-9ce800306916 ER - TY - JOUR TI - PAndAS in the mist: the stellar and gaseous mass within the halos of M31 and M33 DO - 10.1088/0004-637X/763/1/4 AU - Lewis, Geraint F. AU - Braun, Robert AU - McConnachie, Alan W. AU - Irwin, Michael J. AU - Ibata, Rodrigo A. AU - Chapman, Scott C. AU - Ferguson, Annette M. N. AU - Martin, Nicolas F. AU - Fardal, Mark AU - Dubinski, John AU - Widrow, Larry AU - MacKey, A. Dougal AU - Babul, Arif AU - Tanvir, Nial R. AU - Rich, Michael T2 - The Astrophysical Journal SN - 0004-637X VL - 763 IS - 1 SP - 4 AB - Large-scale surveys of the prominent members of the Local Group have provided compelling evidence for the hierarchical formation of massive galaxies, revealing a wealth of substructure that is thought to be the debris from ancient and ongoing accretion events. In this paper, we compare two extant surveys of the M31-M33 subgroup of galaxies: the Pan-Andromeda Archaeological Survey of the stellar structure, and a combination of observations of the H I gaseous content, detected at 21 cm. Our key finding is a marked lack of spatial correlation between these two components on all scales, with only a few potential overlaps between stars and gas. The paucity of spatial correlation significantly restricts the analysis of kinematic correlations, although there does appear to be H I kinematically associated with the Giant Stellar Stream where it passes the disk of M31. These results demonstrate that different processes must significantly influence the dynamical evolution of the stellar and H I components of substructures, such as ram pressure driving gas away from a purely gravitational path. Detailed modeling of the offset between the stellar and gaseous substructures will provide a determination of the properties of the gaseous halos of M31 and M33. © 2013. The American Astronomical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 05ad7b41-94ea-4118-898a-d6bb68445d95 ER - TY - JOUR TI - Thermal plasma in the giant lobes of the radio galaxy Centaurus A DO - 10.1088/0004-637X/764/2/162 AU - O'Sullivan, S. P. AU - Feain, I. J. AU - McClure-Griffiths, N. M. AU - Ekers, R. D. AU - Carretti, E. AU - Robishaw, T. AU - Mao, S. A. AU - Gaensler, B. M. AU - Bland-Hawthorn, J. AU - Stawarz, Ł. T2 - The Astrophysical Journal SN - 0004-637X VL - 764 IS - 2 SP - 162 AB - We present a Faraday rotation measure (RM) study of the diffuse, polarized, radio emission from the giant lobes of the nearest radio galaxy, Centaurus A. After removal of the smooth Galactic foreground RM component, using an ensemble of background source RMs located outside the giant lobes, we are left with a residual RM signal associated with the giant lobes. We find that the most likely origin of this residual RM is from thermal material mixed throughout the relativistic lobe plasma. The alternative possibility of a thin-skin/boundary layer of magnetoionic material swept up by the expansion of the lobes is highly unlikely since it requires, at least, an order of magnitude enhancement of the swept-up gas over the expected intragroup density on these scales. Strong depolarization observed from 2.3 to 0.96 GHz also supports the presence of a significant amount of thermal gas within the lobes; although depolarization solely due to RM fluctuations in a foreground Faraday screen on scales smaller than the beam cannot be ruled out. Considering the internal Faraday rotation scenario, we find a thermal gas number density of ∼10-4 cm -3, implying a total gas mass of ∼1010 M ⊙ within the lobes. The thermal pressure associated with this gas (with temperature kT ∼ 0.5 keV, obtained from recent X-ray results) is approximately equal to the non-thermal pressure, indicating that over the volume of the lobes, there is approximate equipartition between the thermal gas, radio-emitting electrons, and magnetic field (and potentially any relativistic protons present). © 2013. The American Astronomical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b60bf45f-027a-4db9-a101-e05bf2bf48ff ER - TY - JOUR TI - X-ray groups of galaxies in the AEGIS deep and wide fields DO - 10.1088/0004-637X/765/2/117 AU - Erfanianfar, G. AU - Finoguenov, A. AU - Tanaka, M. AU - Lerchster, M. AU - Nandra, K. AU - Laird, E. AU - Connelly, J. L. AU - Bielby, R. AU - Mirkazemi, M. AU - Faber, S. M. AU - Kocevski, D. AU - Cooper, M. AU - Newman, J. A. AU - Jeltema, T. AU - Coil, A. L. AU - Brimioulle, F. AU - Davis, M. AU - McCracken, H. J. AU - Willmer, C. AU - Gerke, B. AU - Cappelluti, N. AU - Gwyn, S. T2 - The Astrophysical Journal SN - 0004-637X VL - 765 IS - 2 SP - 117 AB - We present the results of a search for extended X-ray sources and their corresponding galaxy groups from 800 ks Chandra coverage of the All-wavelength Extended Groth Strip International Survey (AEGIS). This yields one of the largest X-ray-selected galaxy group catalogs from a blind survey to date. The red-sequence technique and spectroscopic redshifts allow us to identify 100% of reliable sources, leading to a catalog of 52 galaxy groups. These groups span the redshift range z ∼ 0.066-1.544 and virial mass range M200 ∼ 1.34 × 10¹³-1.33 × 10¹⁴4. For the 49 extended sources that lie within DEEP2 and DEEP3 Galaxy Redshift Survey coverage, we identify spectroscopic counterparts and determine velocity dispersions. We select member galaxies by applying different cuts along the line of sight or in projected spatial coordinates. A constant cut along the line of sight can cause a large scatter in scaling relations in low-mass or high-mass systems depending on the size of the cut. A velocity-dispersion-based virial radius can cause a larger overestimation of velocity dispersion in comparison to an X-ray-based virial radius for low-mass systems. There is no significant difference between these two radial cuts for more massive systems. Independent of radial cut, an overestimation of velocity dispersion can be created in the case of the existence of significant substructure and compactness in X-ray emission, which mostly occur in low-mass systems. We also present a comparison between X-ray galaxy groups and optical galaxy groups detected using the Voronoi-Delaunay method for DEEP2 data in this field. © 2013. The American Astronomical Society. All rights reserved. DA - 2013/02/26 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 953cb7ce-64dc-4097-88c5-ae8b7c33d53f ER - TY - JOUR TI - Search for high proper motion objects in the CFHTLS deep fields DO - 10.1088/0004-637X/766/1/46 AU - Hu, Juei-Hwa AU - Richer, Harvey AU - Gwyn, Stephen D. J. AU - Ip, Wing-Huen T2 - The Astrophysical Journal SN - 0004-637X VL - 766 IS - 1 SP - 46 AB - We present the results of a search for high proper motion white dwarfs in the deep survey of the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS). The CFHTLS Deep Survey covers 4 deg2 in five filters (u*, g′, r′, i′, and z′). For the first and the fourth fields, we use data for a 5 year baseline from 2004 to 2009. For the second and the third fields, we have a 4 year baseline from 2004 to 2008. Proper motion selection is used to distinguish cool high-velocity white dwarfs from distant objects with similar blue colors such as compact faint galaxies and quasars. We discovered 44 white dwarf candidates brighter than g′ = 24 on the basis of their spectral energy distribution and reduced proper motions. We found one white dwarf candidate with effective temperature less than 4000 K. From its estimated tangential velocity of 31 km s-1 and a distance of 124 pc, it appears to be located in the thin or thick disk of the Galaxy. We also find five candidates having Teff between 4000 K and 5000 K. One candidate in D2 with effective temperature of 5000 K and tangential velocity of 190 km s-1 indicates that it could be in the thick disk or in the halo. The other four candidates are likely located in the thin disk because of their estimated distances and tangential velocity. © 2013. The American Astronomical Society. All rights reserved. DA - 2013/03/06 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 118fe227-7978-4ee1-8e45-57d8a60cb753 ER - TY - JOUR TI - The three-dimensional structure of the m31 satellite system; Strong evidence for an inhomogeneous distribution of satellites DO - 10.1088/0004-637X/766/2/120 AU - Conn, A. R. AU - Lewis, G. F. AU - Ibata, R. A. AU - Parker, Q. A. AU - Zucker, D. B. AU - McConnachie, A. W. AU - Martin, N. F. AU - Valls-Gabaud, D. AU - Tanvir, N. AU - Irwin, M. J. AU - Ferguson, A. M. N. AU - Chapman, S. C. T2 - The Astrophysical Journal SN - 0004-637X VL - 766 IS - 2 SP - 120 DA - 2013/03/15 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : de93f29d-b4d5-44e6-a8c4-c7fb2405d7f8 ER - TY - JOUR TI - The photometric and kinematic structure of face-on disk galaxies. III. Kinematic inclinations from Hα velocity fields DO - 10.1088/0004-637X/768/1/41 AU - Andersen, David R. AU - Bershady, Matthew A. T2 - The Astrophysical Journal SN - 0004-637X VL - 768 IS - 1 SP - 41 AB - Using the integral field unit DensePak on the WIYN 3.5 m telescope we have obtained Hα velocity fields of 39 nearly face-on disks at echelle resolutions. High-quality, uniform kinematic data and a new modeling technique enabled us to derive accurate and precise kinematic inclinations with mean i kin = 23° for 90% of these galaxies. Modeling the kinematic data as single, inclined disks in circular rotation improves upon the traditional tilted-ring method. We measure kinematic inclinations with a precision in sin i of 25% at 20° and 6% at 30°. Kinematic inclinations are consistent with photometric and inverse Tully-Fisher inclinations when the sample is culled of galaxies with kinematic asymmetries, for which we give two specific prescriptions. Kinematic inclinations can therefore be used in statistical "face-on" Tully-Fisher studies. A weighted combination of multiple, independent inclination measurements yield the most precise and accurate inclination. Combining inverse Tully-Fisher inclinations with kinematic inclinations yields joint probability inclinations with a precision in sin i of 10% at 15° and 5% at 30°. This level of precision makes accurate mass decompositions of galaxies possible even at low inclination. We find scaling relations between rotation speed and disk-scale length identical to results from more inclined samples. We also observe the trend of more steeply rising rotation curves with increased rotation speed and light concentration. This trend appears to be uncorrelated with disk surface brightness. © 2013. The American Astronomical Society. All rights reserved.. DA - 2013/05/12 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e487d588-6667-4c2a-b51b-81b15c00f23f ER - TY - JOUR TI - Comprehensive hormone profiling of the developing seeds of four grain legumes DO - 10.1007/s00299-013-1505-3 AU - Slater, Susan M. H. AU - Yuan, Hai ying AU - Lulsdorf, Monika M. AU - Vandenberg, Albert AU - Zaharia, L. Irina AU - Han, Xiumei AU - Abrams, Suzanne R. T2 - Plant Cell Reports SN - 0721-7714 SN - 1432-203X VL - 32 IS - 12 SP - 1939 EP - 1952 KW - Abscisic acid KW - Auxin KW - Chickpea KW - Cytokinin KW - seed development KW - Faba bean KW - Field pea KW - Gibberellin KW - lentil AB - Improvement of in vitro tissue and cell culture protocols in grain legumes such as embryo rescue, interspecific hybridization, and androgenesis requires an understanding of the types, activity, and balance of hormones within developing seeds. Towards this goal, the concentration of auxin, cytokinin, gibberellin, and abscisic acid (ABA) and their precursors and derivatives were measured in the developing seeds of field pea (Pisum sativum L.), chickpea (Cicer arietinum L.), lentil (Lens culinaris Medik.), and faba bean (Vicia faba L.) from 4 days after anthesis until 8 days after reaching maximum fresh weight. The importance of developmental context (developmental time and space) is demonstrated in both the differences and similarities between species for hormone profiles, especially with regard to cytokinin and ABA biosynthesis during the embryo formation. Auxin and its conjugates are significant during the pattern formation stage of all legumes; however, IAA-Asparagine appears important in the Vicieae species and its concentrations are greater than IAA from the globular stage of embryo development on in multi-seed fruits. Finally, the significance of non-polar gibberellins during lentil seed development is highlighted. DA - 2013/09/24 PY - 2013 PB - Springer LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 098f320f-1bb0-4e4c-adbc-bdb551e718eb ER - TY - JOUR TI - Endogenous hormone profiles during early seed development of C. arietinum and C. anatolicum DO - 10.1007/s10725-013-9819-2 AU - Lulsdorf, Monika M. AU - Yuan, Hai Ying AU - Slater, Susan M. H. AU - Vandenberg, Albert AU - Han, Xiumei AU - Zaharia, L. Irina AU - Abrams, Suzanne R. T2 - Plant Growth Regulation SN - 0167-6903 SN - 1573-5087 VL - 71 IS - 2 SP - 191 EP - 198 KW - Abscisic acid KW - C. anatolicum KW - Chickpea KW - Gibberellin KW - Indole-3-acetic acid KW - Zeatin AB - Cicer anatolicum, a perennial species, has ascochyta blight resistance superior to that found in the cultivated chickpea. However, hybridization barriers during early stages of embryo development curtail access to this trait. Since hormones play an essential role in early embryo development, we have determined the hormone profiles of 4-, 8-, and 12-day old seeds from a Canadian chickpea (Cicer arietinum L.) cv. CDC Xena, from Indian cvs. Swetha and Bharati, and from a perennial accession of C. anatolicum (PI 383626). Indole-3-acetic acid content peaked on day 4 in CDC Xena, on day 8 in both Indian cultivars but only on day 12 in C. anatolicum. The cytokinins, isopentenyladenosine (iPA) and trans zeatin riboside (tZR) were predominant in CDC Xena and Swetha seeds on day 4, whereas cis zeatin riboside was the major component in Bharati. In C. anatolicum, iPA maxed out on day 4 and tZR on day 12. The bioactive gibberellin GA1 spiked on day 4 in CDC Xena and Bharati, on day 8 in Swetha but only on day 12 in C. anatolicum. Eight-day old seeds had the highest abscisic acid content in the cultivars but spiked on day 12 in the perennial species. The hormone profiles of the perennial species showed delayed spikes in all four hormone groups indicating that there is a mismatch in the hormone requirements of the different embryos. Improving synchronization of early seed hormone profiles of cultivated and perennial chickpea should improve interspecific hybrid production. DA - 2013/04/30 PY - 2013 PB - Springer LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3d6df9bf-4d51-4979-b1f9-794183539f28 ER - TY - JOUR TI - Flicker effects on brain activity AU - Veitch, Jennifer A. T2 - Lighting Design + Application (The magazine of the Illuminating Engineering Society of North America) VL - 43 IS - 12 SP - 56 EP - 59 AB - In the “bad old days” (25 and more years ago), most commercial and institutional interior lighting consisted of fluorescent lamps run on magnetic ballasts. This light source had an inherent flicker rate of 120 Hz in North America, where the mains AC supply operates at 60 Hz. DA - 2013/12/01 PY - 2013 PB - IES LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 26be6a31-8d48-4db3-8258-ab664946ba83 ER - TY - JOUR TI - Are green buildings better buildings? New research AU - Newsham, Guy R. AU - Birt, Benjamen J. AU - Arsenault, Chantal AU - Thompson, Alexandra J. L. AU - Veitch, Jennifer A. AU - Mancini, Sandra AU - Galasiu, Anca D. AU - Gover, Bradford N. AU - Macdonald, Iain A. AU - Burns, Gregory J. T2 - Canadian Journal of Green Building and Design IS - GBD-Q0413 SP - 20 EP - 22 KW - green buildings; indoor environment quality; post-occupancy evaluation AB - Detailed post-occupancy evaluation research in office buildings suggest that, on average, green buildings do deliver better indoor environment quality and energy efficiency than otherwise similar conventional buildings DA - 2013/12/01 PY - 2013 PB - MarketZone Productions LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 768b1acc-274e-4bbe-8b22-2cfdcdd66f7d ER - TY - JOUR TI - Preferred chromaticity of color-tunable LED lighting DO - 10.1080/15502724.2013.855614 AU - Dikel, Erhan E. AU - Burns, Gregory J. AU - Veitch, Jennifer A. AU - Mancini, Sandra AU - Newsham, Guy R. T2 - LEUKOS SN - 1550-2724 SN - 1550-2716 VL - 10 IS - 2 SP - 101 EP - 115 KW - Light-emitting diode; LED; ofice lighting; spectral tuning; colour tuning; personal preference; individual lighting control; colour quality metrics AB - Previous research has demonstrated that individual personal control over light level benefits individuals and organizations. As a first step toward testing whether light source spectrum choices—which are possible with light emitting diode (LED) systems—offer similar benefits, we examined preferences for various spectra in a scale model of an office. Participants judged the model’s brightness, colorfulness, and pleasantness when lit with five preset spectra with measured correlated color temperatures (CCTs) of 2855, 3728, 4751, 5769, and 6507 K created with five LED channels and one fluorescent spectrum (3750 K measured), all at approximately 500 lx. Then they chose their preferred light spectrum using the five LED channels, once as a free choice and once with an illuminance limit. Judgments of the fluorescent spectrum and the LED spectrum with the closest (matched) CCT did not differ. The preset judgments followed a quadratic pattern, with the lowest and highest CCT conditions having lower ratings than the three middle conditions. The free and illuminance-constrained lighting choices did not differ, with individuals’ selections ranging from 2850 to 14,000 K and generally lying slightly below the blackbody curve. DA - 2013/12/03 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 01cd7b54-3007-4487-9e17-5c6856db8000 ER - TY - JOUR TI - Distributional semantics beyond words : supervised learning of analogy and paraphrase AU - Turney, Peter D. T2 - Transactions of the Association for Computational Linguistics (TACL) VL - 1 SP - 353 EP - 366 AB - There have been several efforts to extend distributional semantics beyond individual words, to measure the similarity of word pairs, phrases, and sentences (briefly, tuples; ordered sets of words, contiguous or noncontiguous). One way to extend beyond words is to compare two tuples using a function that combines pairwise similarities between the component words in the tuples. A strength of this approach is that it works with both relational similarity (analogy) and compositional similarity (paraphrase). However, past work required hand-coding the combination function for different tasks. The main contribution of this paper is that combination functions are generated by supervised learning. We achieve state-of-the-art results in measuring relational similarity between word pairs (SAT analogies and SemEval 2012 Task 2) and measuring compositional similarity between nounmodifier phrases and unigrams (multiplechoice paraphrase questions). DA - 2013/10/01 PY - 2013 PB - ACL LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2a8518e2-c383-4291-ae25-03fadbf71fca ER - TY - JOUR TI - Adaptation of reordering models for statistical machine translation AU - Chen, Boxing AU - Foster, George AU - Kuhn, Roland T2 - Proceedings of the 2013 North America Chapter of the Association for Computational Linguistics : Human Language Technologies T3 - 2013 North American Chapter of the Association for Computational Linguistics: Human Language Technologies, June 9 - 15, 2013, Atlanta, GA SP - 938 EP - 946 AB - Previous research on domain adaptation (DA) for statistical machine translation (SMT) has mainly focused on the translation model (TM) and the language model (LM). To the best of our knowledge, there is no previous work on reordering model (RM) adaptation for phrasebased SMT. In this paper, we demonstrate that mixture model adaptation of a lexicalized RM can significantly improve SMT performance, even when the system already contains a domain-adapted TM and LM. We find that, surprisingly, different training corpora can vary widely in their reordering characteristics for particular phrase pairs. Furthermore, particular training corpora may be highly suitable for training the TM or the LM, but unsuitable for training the RM, or vice versa, so mixture weights for these models should be estimated separately. An additional contribution of the paper is to propose two improvements to mixture model adaptation: smoothing the in-domain sample, and weighting instances by document frequency. Applied to mixture RMs in our experiments, these techniques (especially smoothing) yield significant performance improvements. DA - 2013/07/01 PY - 2013 PB - ACL LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e8bb11c8-a4ab-42c6-ab3b-ad7f3c9f1591 ER - TY - JOUR TI - Improved reordering for phrase-based translation using sparse features AU - Cherry, Colin T2 - Proceedings of the NAACL T3 - NAACL, June 9-14, 2013, Atlanta, Georgia SP - 22 EP - 32 AB - There have been many recent investigations into methods to tune SMT systems using large numbers of sparse features. However, there have not been nearly so many examples of helpful sparse features, especially for phrasebased systems. We use sparse features to address reordering, which is often considered a weak point of phrase-based translation. Using a hierarchical reordering model as our baseline, we show that simple features coupling phrase orientation to frequent words or wordclusters can improve translation quality, with boosts of up to 1.2 BLEU points in Chinese-English and 1.8 in Arabic-English. We compare this solution to a more traditional maximum entropy approach, where a probability model with similar features is trained on wordaligned bitext. We show that sparse decoder features outperform maximum entropy handily, indicating that there are major advantages to optimizing reordering features directly for BLEU with the decoder in the loop. DA - 2013/07/01 PY - 2013 PB - ACL UR - http://aclweb.org/anthology/N/N13/N13-1003.pdf LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : bc772d89-6cbc-4c0e-9a8d-06fe29caf286 ER - TY - JOUR TI - We'll take it from here : letting the users take charge of the evaluation and why that turned out well DO - 10.1145/2468356.2468778 AU - Munteanu, Cosmin AU - Fournier, Hélàne AU - Lapointe, Jean-François AU - Emond, Bruno AU - Kondratova, Irina T2 - CHI '13 Extended Abstracts on Human Factors in Computing Systems T3 - ACM SIGCHI Conference on Human Factors in Computing Systems CHI2013 changing perspectives, April 27–May 2, 2013, Paris, France SN - 9781450319522 SP - 2383 EP - 2384 KW - User studies; evaluation methodology; mixed-reality interaction; immersive gaming AB - The operational challenges faced by law enforcement and public safety personnel are constantly evolving, while the training and certification process has stayed the same. New technologies such as virtual reality, mixed reality, or game-based simulators are being researched as promising enhancements to traditional training methods. However, their widespread adoption, particularly by smaller units, faces barriers such as cost – due in no small part to the difficulties of developing and especially evaluating such large-scale interactive systems. In this case study, we present MINT – a lowcost mixed-reality Multimodal Interactive Training system, aimed at supporting the training of small- and medium-sized law enforcement and infantry units. We discuss the challenges and approaches taken in the participatory design of the training system, its agilebased development and implementation, and its qualitative evaluation with users and subject-matter experts. DA - 2013/04/01 PY - 2013 PB - ACM Press LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4ebebddc-f888-4eb0-b980-fc2d2f721231 ER - TY - JOUR TI - Feature space selection and combination for native language identification AU - Goutte, Cyril AU - Léger, Serge AU - Carpuat, Marine T2 - Proceedings of the 8th Workshop on Innovative Use of NLP for Building Educational Applications (BEA8) T3 - 8th Workshop on Innovative Use of NLP for Building Educational Applications (BEA8), June 13, 2013, Atlanta, GA SP - 96 EP - 100 AB - We decribe the submissions made by the National Research Council Canada to the Native Language Identification (NLI) shared task. Our submissions rely on a Support Vector Machine classifier, various feature spaces using a variety of lexical, spelling, and syntactic features, and on a simple model combination strategy relying on a majority vote between classifiers. Somewhat surprisingly, a classifier relying on purely lexical features performed very well and proved difficult to outperform significantly using various combinations of feature spaces. However, the combination of multiple predictors allowed to exploit their different strengths and provided a significant boost in performance. DA - 2013/08/01 PY - 2013 PB - Association for Computer Linguistics LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 68cbd15c-c2f6-45b1-8017-ded569f2e8e5 ER - TY - JOUR TI - A kinematic study of the Andromeda dwarf spheroidal system DO - 10.1088/0004-637X/768/2/172 AU - Collins, Michelle L. M. AU - Chapman, Scott C. AU - Rich, R. Michael AU - Ibata, Rodrigo A. AU - Martin, Nicolas F. AU - Irwin, Michael J. AU - Bate, Nicholas F. AU - Lewis, Geraint F. AU - Peñarrubia, Jorge AU - Arimoto, Nobuo AU - Casey, Caitlin M. AU - Ferguson, Annette M. N. AU - Koch, Andreas AU - McConnachie, Alan W. AU - Tanvir, Nial T2 - The Astrophysical Journal SN - 0004-637X VL - 768 IS - 2 SP - 172 DA - 2013/04/26 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2594fa1c-77ad-495a-b445-b85a22a2b91f ER - TY - JOUR TI - Stellar populations in compact galaxy groups: A multi-wavelength study of HCGs 16, 22, and 42, their star clusters, and dwarf galaxies DO - 10.1088/0004-637X/770/2/114 AU - Konstantopoulos, I. S. AU - Maybhate, A. AU - Charlton, J. C. AU - Fedotov, K. AU - Durrell, P. R. AU - Mulchaey, J. S. AU - English, J. AU - Desjardins, T. D. AU - Gallagher, S. C. AU - Walker, L. M. AU - Johnson, K. E. AU - Tzanavaris, P. AU - Gronwall, C. T2 - The Astrophysical Journal SN - 0004-637X VL - 770 IS - 2 SP - 114 AB - We present a multi-wavelength analysis of three compact galaxy groups, Hickson compact groups (HCGs) 16, 22, and 42, which describe a sequence in terms of gas richness, from space- (Swift, Hubble Space Telescope (HST), and Spitzer) and ground-based (Las Campanas Observatory and Cerro Tololo Inter-American Observatory) imaging and spectroscopy. We study various signs of past interactions including a faint, dusty tidal feature about HCG 16A, which we tentatively age-date at <1 Gyr. This represents the possible detection of a tidal feature at the end of its phase of optical observability. Our HST images also resolve what were thought to be double nuclei in HCG 16C and D into multiple, distinct sources, likely to be star clusters. Beyond our phenomenological treatment, we focus primarily on contrasting the stellar populations across these three groups. The star clusters show a remarkable intermediate-age population in HCG 22, and identify the time at which star formation was quenched in HCG 42. We also search for dwarf galaxies at accordant redshifts. The inclusion of 33 members and 27 "associates" (possible members) radically changes group dynamical masses, which in turn may affect previous evolutionary classifications. The extended membership paints a picture of relative isolation in HCGs 16 and 22, but shows HCG 42 to be part of a larger structure, following a dichotomy expected from recent studies. We conclude that (1) star cluster populations provide an excellent metric of evolutionary state, as they can age-date the past epochs of star formation; and (2) the extended dwarf galaxy population must be considered in assessing the dynamical state of a compact group. DA - 2013/06/03 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c56b0e56-aeec-494a-a18b-2b6ed66d6dbb ER - TY - JOUR TI - Anchors for the cosmic distance scale: the Cepheids U Sagittarii, CF Cassiopeiae, and CEab Cassiopeiae DO - 10.1051/0004-6361/201322670 AU - Majaess, D. AU - Carraro, G. AU - Moni Bidin, C. AU - Bonatto, C. AU - Berdnikov, L. AU - Balam, D. AU - Moyano, M. AU - Gallo, L. AU - Turner, D. AU - Lane, D. AU - Gieren, W. AU - Borissova, J. AU - Kovtyukh, V. AU - Beletsky, Y. T2 - Astronomy and Astrophysics SN - 0004-6361 VL - 560 SP - A22 KW - Distance scale KW - Hertzsprung-Russell and C-M diagrams KW - Multiband analysis KW - Star clusters KW - Stars: variables: Cepheids KW - Visual binaries AB - New and existing X-ray, UBVJHKsW(1 - 4), and spectroscopic observations were analyzed to constrain fundamental parameters for M 25, NGC 7790, and dust along their sight-lines. The star clusters are of particular importance because they host the classical Cepheids U Sgr, CF Cas, and the visual binary Cepheids CEa and CEb Cas. Precise results from the multiband analysis, in tandem with a comprehensive determination of the Cepheids' period evolution (dP/dt) from ~140 years of observations, helped to resolve concerns raised regarding the clusters and their key Cepheid constituents. Specifically, the distances derived for members of M 25 and NGC 7790 are 630 ± 25 pc and 3.40 ± 0.15 kpc, respectively. DA - 2013/11/29 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : fffdf83f-efeb-4343-9f37-814c11e373f9 ER - TY - JOUR TI - Investigation of the bubble formation in liquid cross-flow using a novel nozzle design DO - 10.1115/FEDSM2013-16498 AU - Jobehdar, Mona Hassanzadeh AU - Gadallah, Aly H. AU - Siddiqui, Kamran AU - Chishty, Wajid A. T2 - ASME 2013 Fluids Engineering Division Summer Meeting T2 - FED T3 - ASME 2013 Fluids Engineering Division Summer Meeting, FEDSM 2013, July 7-11, 2013, Incline Village, Nevada, USA SN - 0888-8116 SN - 9780791855560 VL - 1C AB - Injection of bubbly gas flow into a liquid stream has wide application in chemical and biochemical industries. In these applications, generation of smaller bubble at higher frequency is desirable to achieve better reaction efficiency. We report on an experimental study conducted to investigate the bubble formation in liquid cross-flow using a novel nozzle design developed by Gadallah and Siddiqui [1]. This design is based on the creation of two side holes in the standard nozzle near the main nozzle hole. The experiments were performed in an acrylic square flow channel and high speed imaging was used to capture bubble dynamics. An image processing algorithm was used to quantify the size and frequency of detached bubbles and to track each individual bubble at different gas flow rates and liquid velocities. The results show that the new design of nozzle generates more bubbles of smaller size compared to the standard nozzle with no side hole at low liquid flow rates. It was observed that while the liquid velocity has crucial affect on the bubble size and detachment frequency from a standard nozzle, these parameters are weakly dependent on the liquid flow rate in the novel nozzle. The results show that at low liquid flow rates or in the stagnant liquid, the novel nozzle generates bubbles that are more than 20% smaller in size and more than two times faster compared to the standard nozzle. Copyright © 2013 by ASME and Her Majesty the Queen in Right of Canada. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d93849ef-d5ed-4fd0-99e4-183998860631 ER - TY - JOUR TI - Nanoscale optomechanical sensors: split-beam photonic crystal nanocavities DO - 10.1109/NUSOD.2013.6633101 AU - Hryciw, Aaron AU - Wu, Marcelo AU - Khanaliloo, Behzad AU - Healey, Christopher AU - Barclay, Paul E. T2 - 13th International Conference on Numerical Simulation of Optoelectronic Devices, NUSOD 2013 T2 - Proceedings of the ... International Conference on Numerical Simulation of Optoelectronic Devices T3 - 13th International Conference on Numerical Simulation of Optoelectronic Devices, NUSOD 2013, August 19-22, 2013, Vancouver, BC, Canada SN - 2158-3234 SN - 9781467363105 SP - 6633101 SP - 15 EP - 16 KW - Mechanical displacements KW - Nanomechanical resonances KW - Nanoscale cantilevers KW - Opto-mechanical sensors KW - Photonic crystal nanocavities KW - Photonic crystal nanocavity KW - Resonance frequencies KW - Silicon cantilever KW - Computer simulation KW - Nanocantilevers KW - Nanotechnology KW - Numerical models KW - Optimization KW - Photonic crystals KW - Sensors KW - Optoelectronic devices AB - Optomechanical nanocavities allow nanomechanical resonances to be measured optically with high sensitivity. We have created a new type of photonic crystal nanocavity optomechanical sensor optimized for detecting sources of torque and other forces which can deflect nanoscale cantilevers. This nanocavity consists of two precisely engineered photonic Bragg mirrors patterned in silicon cantilevers and separated by a 50-100 nm wide gap. Simulations of the optical and mechanical modes predict that mechanical displacements of the sub-picogram cantilevers will shift the optical nanocavity resonance frequency at a rate exceeding 20 GHz / nm, and that the nanocavity optical mode may have a quality factor Qo > 10⁶in optimized devices. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 145c9d76-9c9e-4a53-a6b3-d14251fd539a ER - TY - JOUR TI - Integrated process of laser-assisted machining and laser surface heat treatment DO - 10.1115/1.4025832 AU - Shi, B. AU - Attia, H. T2 - Journal of Manufacturing Science and Engineering, Transactions of the ASME SN - 1087-1357 VL - 135 IS - 6 SP - 61021 KW - Empirical model KW - Hardenability KW - Hardened depth KW - Laser surface heat treatments KW - Laser-assisted machining KW - Micro-structure evolutions KW - Numerical investigations KW - Process parameters KW - Finite element method KW - Microstructure KW - Laser beam welding AB - A process is proposed for integrating the laser-assisted machining (LAM) and laser surface heat treatment (LSHT) in a single operation. Experimental and numerical investigations were carried out. LSHT tests were performed to investigate the effect of the process parameters on the microstructure evolution and hardenability. A methodology and an empirical model for prediction of hardened depth were proposed. A two-dimensional finite element (2D-FE) model was developed to predict the phase transformation during the LAM and LSHT processes. The optimization of the LAM process was also investigated using the developed finite element model. Copyright © 2013 by ASME. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a1c0c6d6-b3a1-4e6d-a6f1-cb3119b33fcb ER - TY - JOUR TI - Wave-in-deck loads for an intricate pile-supported pier and variation with deck clearance DO - 10.1115/OMAE2013-11409 AU - Cornett, A. AU - Anglin, D. AU - Elliott, T. T2 - Proceedings of the International Conference on Offshore Mechanics and Arctic Engineering - OMAE T3 - ASME 2013 32nd International Conference on Ocean, Offshore and Arctic Engineering, OMAE 2013, 9 June 2013 through 14 June 2013, Nantes SN - 9780791855317 VL - 1 SP - V001T01A072 AB - Many deck structures are located at elevations low enough to be impacted by large waves. However, due to the highly complex and impulsive nature of the interactions between wave crests and intricate deck structures, establishing reliable estimates of extreme pressures and forces for use in design remains challenging. In this paper, results from an extensive set of three-dimensional scale model tests conducted to support the design of a large pile-supported pier (or jetty) are presented and discussed. Relationships between maximum wave-in-deck loads and the deck clearance (air gap) are presented and discussed. Results from numerical simulations of the wave-structure interaction process obtained using the three-dimensional CFD software FLOW-3D® are also presented and discussed. Finally, some initial comparisons between the numerical and physical modelling are also included. This paper provides new insights concerning the character and magnitude of the hydrodynamic pressures and loads exerted on intricate pile-supported deck structures due to impact by non-linear shallow-water waves, and the relationships between the hydrodynamic forcing and the deck clearance or air gap. Copyright © 2013 by ASME. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 128f144d-cd22-4356-9e24-90b95428cc5b ER - TY - JOUR TI - Comparative xylose metabolism among the ascomycetes C. albicans, S. stipitis and S. cerevisiae DO - 10.1371/journal.pone.0080733 AU - Harcus, D. AU - Dignard, D. AU - Lépine, G. AU - Askew, C. AU - Raymond, M. AU - Whiteway, M. AU - Wu, C. T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 11 SP - e80733 AB - The ascomycetes Candida albicans, Saccharomyces cerevisiae and Scheffersomyces stipitis metabolize the pentose sugar xylose very differently. S. cerevisiae fails to grow on xylose, while C. albicans can grow, and S. stipitis can both grow and ferment xylose to ethanol. However, all three species contain highly similar genes that encode potential xylose reductases and xylitol dehydrogenases required to convert xylose to xylulose, and xylulose supports the growth of all three fungi. We have created C. albicans strains deleted for the xylose reductase gene GRE3, the xylitol dehydrogenase gene XYL2, as well as the gre3 xyl2 double mutant. As expected, all the mutant strains cannot grow on xylose, while the single gre3 mutant can grow on xylitol. The gre3 and xyl2 mutants are efficiently complemented by the XYL1 and XYL2 from S. stipitis. Intriguingly, the S. cerevisiae GRE3 gene can complement the Cagre3 mutant, while the ScSOR1 gene can complement the Caxyl2 mutant, showing that S. cerevisiae contains the enzymatic capacity for converting xylose to xylulose. In addition, the gre3 xyl2 double mutant of C. albicans is effectively rescued by the xylose isomerase (XI) gene of either Piromyces or Orpinomyces, suggesting that the XI provides an alternative to the missing oxido-reductase functions in the mutant required for the xylose-xylulose conversion. Overall this work suggests that C. albicans strains engineered to lack essential steps for xylose metabolism can provide a platform for the analysis of xylose metabolism enzymes from a variety of species, and confirms that S. cerevisiae has the genetic potential to convert xylose to xylulose, although non-engineered strains cannot proliferate on xylose as the sole carbon source. © 2013 Boyles et al. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 70e392a4-3579-458a-a7a2-1396f69be659 ER - TY - JOUR TI - Carbon nanosheet frameworks derived from peat moss as high performance sodium ion battery anodes DO - 10.1021/nn404640c AU - Ding, J. AU - Wang, H. AU - Li, Z. AU - Kohandehghan, A. AU - Cui, K. AU - Xu, Z. AU - Zahiri, B. AU - Tan, X. AU - Lotfabad, E.M. AU - Olsen, B.C. AU - Mitlin, D. T2 - ACS Nano SN - 1936-0851 VL - 7 IS - 12 SP - 11004 EP - 11015 KW - Carbonaceous materials KW - High-rate capacities KW - High-rate performance KW - Interconnected network KW - Lithium-ion battery KW - Optimized structures KW - pore KW - Sodium ion batteries KW - Anodes KW - Carbon KW - Carbonization KW - Graphene KW - Graphite KW - Lithium compounds KW - Metal ions KW - Nanosheets KW - Plants (botany) KW - Peat AB - We demonstrate that peat moss, a wild plant that covers 3% of the earth's surface, serves as an ideal precursor to create sodium ion battery (NIB) anodes with some of the most attractive electrochemical properties ever reported for carbonaceous materials. By inheriting the unique cellular structure of peat moss leaves, the resultant materials are composed of three-dimensional macroporous interconnected networks of carbon nanosheets (as thin as 60 nm). The peat moss tissue is highly cross-linked, being rich in lignin and hemicellulose, suppressing the nucleation of equilibrium graphite even at 1100 C. Rather, the carbons form highly ordered pseudographitic arrays with substantially larger intergraphene spacing (0.388 nm) than graphite (c/2 = 0.3354 nm). XRD analysis demonstrates that this allows for significant Na intercalation to occur even below 0.2 V vs Na/Na+. By also incorporating a mild (300 C) air activation step, we introduce hierarchical micro- and mesoporosity that tremendously improves the high rate performance through facile electrolyte access and further reduced Na ion diffusion distances. The optimized structures (carbonization at 1100 C + activation) result in a stable cycling capacity of 298 mAh g-1 (after 10 cycles, 50 mA g-1), with ∼150 mAh g-1 of charge accumulating between 0.1 and 0.001 V with negligible voltage hysteresis in that region, nearly 100% cycling Coulombic efficiency, and superb cycling retention and high rate capacity (255 mAh g -1 at the 210th cycle, stable capacity of 203 mAh g-1 at 500 mA g-1). © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5f9e4100-fab8-4ed7-be8a-4f61950d41f1 ER - TY - JOUR TI - Characterization of phase transformations and stresses during the welding of a ferritic mild steel DO - 10.1007/s11661-013-2157-1 AU - Dye, D. AU - Stone, H.J. AU - Watson, M. AU - Rogge, R.B. T2 - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science SN - 1073-5623 SP - 1 EP - 8 AB - The transient stresses and phase evolution have been characterized in the quasi-steady state produced around a gas tungsten arc welding torch in a plain carbon (ASTM 1018) steel using in situ neutron diffraction. A novel method has been developed to isolate the deviatoric or plane stress state in the presence of isotropic contributions to the lattice parameter, such as thermal expansion and solute content. The stress state was found to evolve in the anticipated manner, with compressive stresses ahead of the weld and tensile stresses behind the weld, in the weld and heat-affected zone, and compression in the far field behind the weld. In particular, the region of compression in the heat-affected zone adjacent to and just behind the welding torch expected from weld models was observed. The evolution of phase fraction around the weld was also determined using the technique and the stresses obtained from the ferrite phase. © 2013 The Minerals, Metals & Materials Society and ASM International. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 99143edb-52df-4c35-83e2-fe7507639dd3 ER - TY - JOUR TI - Multiple roles of the transcription factor AtMYBR1/AtMYB44 in ABA signaling, stress responses, and leaf senescence DO - 10.1186/1471-2229-13-192 AU - Jaradat, Masrur R. AU - Feurtado, J. Allan AU - Huang, Daiquing AU - Lu, Yongquan AU - Cutler, Adrian J. T2 - BMC Plant Biology SN - 1471-2229 VL - 13 SP - 192 SP - e192-1 EP - e192-19 KW - Arabidopsis thaliana KW - ABA KW - Drought stress KW - transcription factor KW - PYL8 KW - Senescence AB - Background: The transcription factor AtMYBR1 (MYB44) is a member of the MYB family of transcription factors and is expressed throughout the plant life cycle and especially in senescing and wounded leaves. It has previously been shown to be involved in responses to abiotic stress and is regulated by phosphorylation.Results: When MYBR1 was over-expressed under the control of the constitutive 35S promoter in Arabidopsis thaliana (OxMYBR1), leaf senescence was delayed. In contrast loss-of-function mybr1 plants showed more rapid chlorophyll loss and senescence. The MYBR1 promoter strongly drove β-GLUCURONIDASE reporter gene expression in tissues immediately after wounding and many wounding/pathogenesis genes were downregulated in OxMYBR1. OxMYBR1 plants were more susceptible to injury under water stress than wildtype, which was correlated with suppression of many ABA inducible stress genes in OxMYBR1. Conversely, mybr1 plants were more tolerant of water stress and exhibited reduced rates of water loss from leaves. MYBR1 physically interacted with ABA receptor PYR1-LIKE8 (PYL8) suggesting a direct involvement of MYBR1 in early ABA signaling. MYBR1 appears to exhibit partially redundant functions with AtMYBR2 (MYB77) and double mybr1 X mybr2 mutants exhibited stronger senescence and stress related phenotypes than single mybr1 and mybr2 mutants.Conclusions: MYBR1 is a negative regulator of ABA, stress, wounding responses and blocks senescence. It appears to have a homeostatic function to maintain growth processes in the event of physical damage or stress. DA - 2013/11/28 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 259ff518-4322-466e-9584-f86ae16e0ff7 ER - TY - JOUR TI - Bidirectional lipid droplet velocities are controlled by differential binding strengths of HCV core DII protein DO - 10.1371/journal.pone.0078065 AU - Lyn, R.K. AU - Hope, G. AU - Sherratt, A.R. AU - McLauchlan, J. AU - Pezacki, J.P. T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 11 SP - e78065 AB - Host cell lipid droplets (LD) are essential in the hepatitis C virus (HCV) life cycle and are targeted by the viral capsid core protein. Core-coated LDs accumulate in the perinuclear region and facilitate viral particle assembly, but it is unclear how mobility of these LDs is directed by core. Herein we used two-photon fluorescence, differential interference contrast imaging, and coherent anti-Stokes Raman scattering microscopies, to reveal novel core-mediated changes to LD dynamics. Expression of core protein's lipid binding domain II (DII-core) induced slower LD speeds, but did not affect directionality of movement on microtubules. Modulating the LD binding strength of DII-core further impacted LD mobility, revealing the temporal effects of LD-bound DII-core. These results for DII-core coated LDs support a model for core-mediated LD localization that involves core slowing down the rate of movement of LDs until localization at the perinuclear region is accomplished where LD movement ceases. The guided localization of LDs by HCV core protein not only is essential to the viral life cycle but also poses an interesting target for the development of antiviral strategies against HCV. Copyright: © 2013 Lyn et al. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f52de84e-01cb-4719-a07a-1abbbd82336c ER - TY - JOUR TI - Flow-field and conjugate heat transfer of an internally air-cooled nozzle guide vane and shrouds DO - 10.1115/GT2013-94274 AU - Jiang, L. T2 - Proceedings of the ASME Turbo Expo T3 - ASME Turbo Expo 2013: Turbine Technical Conference and Exposition, GT 2013, June 3-7, 2013, San Antonio, Tx, USA SN - 9780791855157 VL - 3 KW - Conjugate heat transfer KW - Critical component KW - Field observations KW - High-fidelity CFD model KW - Nozzle guide vanes KW - Operating condition KW - Steady-state analysis KW - Working environment KW - Computer simulation KW - Cooling systems KW - Exhibitions KW - Rocket nozzles KW - Gas turbines AB - In order to assess the life of gas turbine critical components, it is essential to adequately specify their aero-thermodynamic working environments. Steady-state analyses of the flow field and conjugate heat transfer of an internally air-cooled nozzle guide vane (NGV) and shrouds of a gas turbine engine at the baseline operating conditions are numerically investigated. A high-fidelity CFD model is generated and the simulations are carried out with properly defined boundary conditions. The features of the complicated flow and temperature fields are revealed. In general, the Mach number is lower and the temperature is higher on the NGV pressure side than those on the suction side. There are two high temperature spots on the pressure side, and the temperature across the NGV middle section is relatively low. These findings are closely related to the locations of the holes and outlets of the cooling flow passage, and consistent with the field observation of damaged NGVs. The obtained results provide essential information for the structural, material and life analyses of the NGV/shrouds assembly, and improvement of the cooling flow arrangement. Copyright © 2013 by Her Majesty The Queen in Right of Canada. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a1860078-72c1-4e61-83c5-4d00f23ecb9c ER - TY - JOUR TI - Correlation between intake and ingestive behavior of pasture-grazed heifers DO - 10.5433/1679-0359.2013v34n6p2963 AU - Santana, H.A. AU - Silva, R.R. AU - Carvalho, G.G.P. AU - Silva, F.F. AU - Trindade Jr., G. AU - Pinheiro, A.A. AU - Rodrigues, E.S.O. AU - Filho, G.A. AU - Santana, E.O.C. AU - Mendes, F.B.L. T2 - Semina:Ciencias Agrarias SN - 1676-546X VL - 34 IS - 6 SP - 2963 EP - 2976 AB - The objective of this study was to evaluate the correlation between intake and ingestive behavior of crossbred heifers in grazing tropical. The experiment was conducted on the Princesa do Mateiro Farm, in the city of Ribeirão do Largo, Bahia. A total of 20 heifers with genetic makeup 5/8 dairy Guzerá and 3/8 Holstein, average age of 18 months and body weight of 187 ± 13.1 kg have been used. The experiment lasted 224 days and involved animals raised in a rotational grazing system with Brachiaria brizantha cv. Marandú. Grazing time was not correlated with any of the variables associated with intake. Rumination time showed positive correlations with the intake of forage dry matter (DMIF) and neutral detergent fiber (NDFI). Variables associated with the time spent on feeding at the trough, overall feeding and total chewing were not correlated with intake (P>0.05). There have been positive correlations between the number of grazing periods (NGP) and rumination periods (NRP) and total DM intake (TDMI), organic matter (OMI), forage (DMIF), neutral detergent fiber (NDFI), total carbohydrates (TCHI) and ether extract (EEI). Crude protein intake (CPI) was positively correlated with NGP and NRP. The mouthful rate was positively correlated with TDMI, OMI, DMIF, NDFI, TCHI, EEI and CPI. Average time per swallow was negatively correlated with TDMI, OMI, NDFI, TCHI and EEI. Positive correlations have been observed between the number of mouthfuls per day and TDMI, OMI, DMIF, NDFI, TCHI, EEI. The number of chews per bolus showed negative correlations with DMIS and CPI. The time per cake ruminated has correlated negatively with the intake of crude protein. The number of chews per bolus showed positive correlations with the intakes of dry matter and neutral detergent fiber. The number of boli per day showed positive correlations with DMIF and TCHI. The time spent on chewing showed no significant correlation with intake. In conflict with the national and international literature, the grazing time was not correlated with intake by grass-fed crossbred heifers. The number of activities, the time spent on them and the mouthful rate where shown to be highly associated with the intake variables and can therefore arrange equations to predict intake through the analysis of feeding behavior. The number of mouthfuls performed each day contributes to the intake by pasture-grazed heifers. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5d696339-fa79-451b-85b9-7f8847eb93da ER - TY - JOUR TI - Plant Acyl-CoA:lysophosphatidylcholine acyltransferases (LPCATs) have different specificities in their forward and reverse reactions DO - 10.1074/jbc.M113.521815 AU - Lager, I. AU - Yilmaz, J.L. AU - Zhou, X.-R. AU - Jasieniecka, K. AU - Kazachkov, M. AU - Wang, P. AU - Zou, J. AU - Weselake, R. AU - Smith, M.A. AU - Bayon, S. AU - Dyer, J.M. AU - Shockey, J.M. AU - Heinz, E. AU - Green, A. AU - Banas, A. AU - Stymne, S. T2 - Journal of Biological Chemistry SN - 0021-9258 VL - 288 IS - 52 SP - 36902 EP - 36914 KW - Acyl-CoA KW - Acyltransferase KW - Acyltransferases KW - High selectivity KW - Phosphatidylcholine KW - Reverse reactions KW - Ricinoleic acid KW - Biochemistry KW - Biology AB - Background: Acyl-CoA:lysophosphatidylcholine acyltransferase (LPCAT) enzymes have central roles in acyl editing of phosphatidylcholine. Results: Plant LPCATs were expressed in yeast and biochemically characterized. Conclusion: LPCATs can edit acyl composition of phosphatidylcholine through their combined forward and reverse reactions. Significance: Plant LPCATs play a role in editing both sn-positions of PC and remove ricinoleic acid with high selectivity from this lipid. © 2013 by The American Society for Biochemistry and Molecular Biology, Inc. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ceed2806-4954-4113-aa11-fe44332e2116 ER - TY - JOUR TI - The relationship between energy separation and base drag in turbine blade wakes DO - 10.1115/GT2013-94936 AU - Gostelow, J.P. AU - Carscallen, W.E AU - Kurosaka, M. AU - Mahallati, A. T2 - Proceedings of the ASME Turbo Expo T3 - ASME Turbo Expo 2013: Turbine Technical Conference and Exposition, GT 2013, 3 June 2013 through 7 June 2013, San Antonio, Tx SN - 9780791855225 VL - 6:00 AM KW - Aggressive designs KW - Annular cascades KW - Energy re distributions KW - Energy separations KW - Peak of energies KW - Planar cascades KW - Temperature probes KW - Total temperatures KW - Exhibitions KW - Gas turbines KW - Nozzle design KW - Nozzles KW - Separation KW - Subsonic aerodynamics KW - Vortex shedding KW - Wakes AB - During annular cascade testing of a highly-loaded turbine stage of aggressive design, the nozzle blading experienced a redistribution of the downstream total temperature field. In this ostensibly adiabatic arrangement, the central regions of the vane wakes exhibited a significant decrease in total temperature and their edges showed an unexpected increase. To resolve these anomalous results and obtain detailed information over the Mach number range, the mid-span section of the nozzle was tested in a large scale transonic planar cascade. At high subsonic speeds, vortex shedding created energy redistribution in the wake. This was measured using an 80 kHz bandwidth temperature probe, making it possible to investigate wake total temperature fluctuations in addition to fluctuations in total pressure, and hence entropy. 'Hot spots' of increased total temperature were found to be located at the edge of the wake and 'cold spots' of decreased total temperature were located close to the wake center line. The results from the turbine cascade were consistent with the phenomenon of energy separation behind bluff bodies. High base pressure losses were observed and were also related to the vortex shedding. The blade had a thick trailing edge and the high base pressure loss condition coincided with the peak of energy separation in the wake. The analysis indicates that in the subsonic speed range the phenomena of energy separation and of base pressure deficit are inextricably linked to, and are caused by, vortex shedding. A strategy for minimizing the related adverse impacts on performance is outlined. Copyright © 2013 by ASME. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 26564ba5-3727-4b97-95cc-ae6b49c59879 ER - TY - JOUR TI - Photoluminescence efficiency of self-assembled germanium dots DO - 10.1117/12.2036814 AU - Lockwood, D.J. AU - Rowell, N.L. AU - Barbagiovanni, E.G. AU - Goncharova, L.V. AU - Simpson, P.J. AU - Berbezier, I. AU - Amiard, G. AU - Favre, L. AU - Ronda, A. AU - Faustini, M. AU - Grosso, D. T2 - SPIE - International Society for Optical Engineering. Proceedings T3 - Photonics North 2013 Conference, 3 June 2013 through 5 June 2013, Ottawa, ON SN - 0277-786X SN - 9780819497918 VL - 8915 SP - 891516 KW - Absolute intensity KW - Dots KW - Effective-mass KW - Nanoparticle sizes KW - Near-infrared bands KW - Photoluminescence efficiency KW - Theory KW - Tight binding KW - Atomic force microscopy KW - Binding energy KW - Efficiency KW - Energy gap KW - Infrared devices KW - Photoluminescence KW - Photonics KW - Silica KW - Size distribution KW - Transmission electron microscopy KW - Germanium AB - Under the proviso that the existing tight-binding (TB) and effective mass (EM) theoretical models provide a good description of the Ge dot energy gap versus dot diameter, this work investigates the effect of nanoparticle size and the size distribution on the near infrared PL spectrum obtained from self-assembled Ge dots grown on a thin layer of TiO2 or SiO2 on Si. For the as-grown samples, the dot PL emission occupies a wide near-infrared band between 0.8 and 1 eV. The PL efficiency versus dot size for four samples was obtained in three steps. Firstly, the PL spectrum was converted to an intensity plot versus dot diameter rather than energy by taking the PL emission from each dot to occur at the dot bandgap calculated using the TB or EM model. Secondly, a numerical form for the physical size distribution of that sample was obtained by performing a least-squares fit of a Gaussian to the dot size distribution measured by atomic force microscopy or transmission electron microscopy. Finally, the PL efficiency versus dot size was calculated using the fitted Gaussian dot size distribution to normalize the PL intensity distribution obtained in the first step. Although the absolute intensities of the PL from the samples vary, the calculated curves are all well-fitted by straight lines on a log-log plot with essentially the same slope for all samples, which indicates that under weak confinement there is a universal power-law increase in PL efficiency with decreasing dot size. © 2013 SPIE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f2b53661-2cb8-4938-a4ad-6065dae20c1e ER - TY - JOUR TI - Solvent exchange in sulphoaluminate phases. Part I: Ettringite DO - 10.1680/adcr.12.00042 AU - Khoshnazar, R. AU - Beaudoin, J. AU - Raki, L. AU - Alizadeh, R. T2 - Advances in Cement Research SN - 0951-7197 VL - 25 IS - 6 SP - 314 EP - 321 AB - The change in the microstructure of ettringite and concomitant changes in volume due to the application of organic solvent exchange methods were investigated. Ettringite samples conditioned to 11% relative humidity were treated with methanol, ethanol and iso-propanol, and were examined using different analytical techniques (x-ray diffraction, Fourier transform infrared spectroscopy, thermal gravimetric analysis, scanning electron microscopy and nitrogen BET surface area measurement) to explore the limitations of using these organic solvents in the study of ettringite microstructure. The results suggest that methanol interacts with ettringite and therefore is not recommended for characterisation of this sulphoaluminate phase. Ethanol and iso-propanol did not significantly change the crystalline structure of ettringite, but did result in a higher surface area of the treated sample compared with the surface area of the untreated one. The length-change of ettringite in these alcohols was also determined and the results are presented. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 07a2a74c-89df-421e-89f5-5f48c2ac7908 ER - TY - JOUR TI - G2C2 - II. Integrated colour-metallicity relations for Galactic globular clusters in SDSS passbands DO - 10.1093/mnras/stt2012 AU - Vanderbeke, J. AU - West, M.J. AU - De Propris, R. AU - Peng, E.W. AU - Blakeslee, J.P. AU - Jordán, A. AU - Ĉoté, P. AU - Gregg, M. AU - Ferrarese, L. AU - Takamiya, M. AU - Baes, M. T2 - Monthly Notices of the Royal Astronomical Society SN - 0035-8711 VL - 437 IS - 2 SP - stt2012 SP - 1734 EP - 1749 AB - We use our integrated Sloan Digital Sky Survey (SDSS) photometry for 96 globular clusters in g and z, as well as r and i photometry for a subset of 56 clusters, to derive the integrated colour- metallicity relation (CMR) for Galactic globular clusters.We compare this relation to previous work, including extragalactic clusters, and examine the influence of age, present-day mass function variations, structural parameters and the morphology of the horizontal branch on the relation. Moreover, we scrutinize the scatter introduced by foreground extinction (including differential reddening) and show that the scatter in the CMR can be significantly reduced combining two reddening laws from the literature. In all CMRs, we find some low-reddening young GCs that are offset to the CMR. Most of these outliers are associated with the Sagittarius system. Simulations show that this is due to less age than to a different enrichment history. Finally, we introduce CMRs based on the infrared calcium triplet, which are clearly non-linear when compared to (g′ - i′) and (g′ - z′) colours. © 2013 The Authors. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ae8fed91-0b68-4af5-91bf-4527f410ee04 ER - TY - JOUR TI - Energy-selective optical excitation and detection in InAs/InP quantum dot ensembles using a one-dimensional optical microcavity DO - 10.1063/1.4852116 AU - Gamouras, A. AU - Britton, M. AU - Khairy, M.M. AU - Mathew, R. AU - Dalacu, D. AU - Poole, P. AU - Poitras, D. AU - Williams, R.L. AU - Hall, K.C. T2 - Applied Physics Letters SN - 0003-6951 VL - 103 IS - 25 SP - 253109 KW - Exciton transition energy KW - InAs/InP quantum dots KW - Microcavity modes KW - Narrow-line width KW - Optical microcavities KW - Quantum dot ensemble KW - Quantum state KW - Single quantum dot KW - Microcavities KW - Photoexcitation KW - Quantum computers KW - Quantum theory KW - Semiconductor quantum dots KW - Tantalum oxides KW - Quantum optics AB - We demonstrate the selective optical excitation and detection of subsets of quantum dots (QDs) within an InAs/InP ensemble using a SiO2/Ta 2O5-based optical microcavity. The low variance of the exciton transition energy and dipole moment tied to the narrow linewidth of the microcavity mode is expected to facilitate effective qubit encoding and manipulation in a quantum dot ensemble with ease of quantum state readout relative to qubits encoded in single quantum dots. © 2013 AIP Publishing LLC. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ed321c23-c78b-4d24-8a48-600de0c1d2d8 ER - TY - JOUR TI - Distance and age of the pulsar wind nebula 3C 58 DO - 10.1051/0004-6361/201219839 AU - Kothes, R. T2 - Astronomy and Astrophysics SN - 0004-6361 VL - 560 SP - A18 KW - Absorption measurements KW - Canadian galactic plane surveys KW - Direct measurement KW - Distance determination KW - ISM: individual objects KW - ISM: supernova remnants KW - Pulsar wind nebula KW - Pulsars: individuals KW - Geometrical optics KW - Stars KW - Galaxies AB - Context. A growing number of researchers present evidence that the pulsar wind nebula 3C 58 is much older than predicted by its proposed connection to the historical supernova of A.D. 1181. There is also a great diversity of arguments. The strongest of these arguments rely heavily on the assumed distance of 3.2 kpc determined with H i absorption measurements. Aims. This publication aims at determining a more accurate distance for 3C 58 and at re-evaluating the arguments for an older age. Methods. I have re-visited the distance determination of 3C 58 based on new H i data from the Canadian Galactic Plane Survey and our recent improvements in the knowledge of the rotation curve of the outer Milky Way Galaxy. I also used newly determined distances to objects in the neighbourhood, which are based on direct measurements by trigonometric parallax. Results. I have derived a new more reliable distance estimate of 2 kpc for 3C 58. This makes the connection between the pulsar wind nebula and the historical event from A.D. 1181 once again much more viable. © 2013 ESO. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f6ded7fc-8fe6-488b-8b86-807a9a3c6294 ER - TY - JOUR TI - Neutrino and axion bounds from the globular cluster M5 (NGC 5904) DO - 10.1103/PhysRevLett.111.231301 AU - Viaux, N. AU - Catelan, M. AU - Stetson, P.B. AU - Raffelt, G.G. AU - Redondo, J. AU - Valcarce, A.A.R. AU - Weiss, A. T2 - Physical Review Letters SN - 0031-9007 VL - 111 IS - 23 SP - 231301 KW - Bohr magnetons KW - Confidence limit KW - Globular clusters KW - High-precision KW - Stellar evolutions KW - Systematic uncertainties KW - Elementary particles KW - Uncertainty analysis AB - The red-giant branch (RGB) in globular clusters is extended to larger brightness if the degenerate helium core loses too much energy in "dark channels." Based on a large set of archival observations, we provide high-precision photometry for the Galactic globular cluster M5 (NGC 5904), allowing for a detailed comparison between the observed tip of the RGB with predictions based on contemporary stellar evolution theory. In particular, we derive 95% confidence limits of gae<4.3×10-13 on the axion-electron coupling and μν<4.5×10 -12μB (Bohr magneton μB=e/2me) on a neutrino dipole moment, based on a detailed analysis of statistical and systematic uncertainties. The cluster distance is the single largest source of uncertainty and can be improved in the future. © 2013 American Physical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2bbb9d9c-a77c-430d-85af-890dde2ae4f6 ER - TY - JOUR TI - Endoscopic third ventriculostomy on a microneurosurgery simulator DO - 10.1177/0037549713491519 AU - Jiang, Di AU - Hovdebo, Jordan AU - Cabral, Anne AU - Mora, Vincent AU - Delorme, Sébastien T2 - Simulation SN - 0037-5497 VL - 89 IS - 12 SP - 1442 EP - 1449 KW - Haptic feedbacks KW - Neuro-endoscopy KW - Quantitative metrics KW - Single screen KW - Ventriculostomy KW - Virtual endoscopy KW - Computer simulation KW - Floors KW - Neurosurgery KW - Personnel training KW - Photography KW - Simulators KW - Virtual reality KW - Endoscopy AB - Endoscopic third ventriculostomy is a procedure used to treat hydrocephalus by making a perforation in the floor of the third ventricle of the brain under endoscopic guidance. We report on our initial experience in developing an endoscopic third ventriculostomy simulator for neurosurgery residents, including the definition of the simulation content and integration on NeuroTouch, a simulator for microneurosurgery training. The simulator includes exercises in which the trainee is asked to choose the location of the burr hole and the orientation of the trajectory to the foramen of Monro, or is required to find the third ventricle with a neuro-endoscope and perforate its floor. The simulator provides feedback on trainee performance either graphically or using quantitative metrics. The simulator allows easily switching from endoscopic third ventriculostomy mode to microscopic craniotomy mode using a retractable stereoscope based on a single screen and mirrors, detachable plastic heads, and quick-connect tool handles to give more realistic haptic feedback. © 2013 National Research Council Canada, Crown copyright. DA - 2013/12/04 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 68d4ff2e-633c-4594-a369-b1ccdb4411ce ER - TY - JOUR TI - High output power, fibre-coupled distributed feedback lasers operating near 2.05 μm wavelength range DO - 10.1049/el.2013.2503 AU - Bagheri, M. AU - Frez, C. AU - Kelly, B. AU - Gupta, J.A. AU - Forouhar, S. T2 - Electronics Letters SN - 0013-5194 VL - 49 IS - 24 SP - 1552 EP - 1553 KW - Distributed feedback semiconductor laser KW - High output power KW - Linear polarisation KW - Operating currents KW - Side mode suppression ratios KW - Single mode operation KW - Tunabilities KW - Wavelength ranges KW - Polarization-maintaining fiber KW - Distributed feedback lasers AB - Single-mode operation of fibre-pigtailed distributed feedback semiconductor lasers in the 2.05 μm range has been demonstrated. The lasers are packaged inside standard butterfly modules with output powers in excess of 10 mW at the end of polarisation maintaining optical fibre. The fibre-pigtailed lasers show excellent sidemode suppression ratios ( > 50 dB) and have a mode-hop free tunability larger than 1 nm. The output of the optical fibre has linear polarisation with better than 20 dB extinction over the operating current and temperatures. © The Institution of Engineering and Technology 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2c204ddf-8cd1-47b2-805c-fb2e1b9604bb ER - TY - JOUR TI - Solvent exchange in sulfoaluminate phases. Part II: Monosulfate DO - 10.1680/adcr.12.00055 AU - Khoshnazar, R. AU - Beaudoin, J. AU - Raki, L. AU - Alizadeh, R. T2 - Advances in Cement Research SN - 0951-7197 VL - 25 IS - 6 SP - 322 EP - 331 AB - The influence of organic solvent exchange techniques on the microstructure and the dimensional stability of monosulfate (3CaO.Al2O 3.CaSO4.12H2O) was critically investigated. Monosulfate samples were treated with methanol, ethanol and isopropanol, and examined by different analytical techniques including X-ray diffraction, Fourier transform infrared spectroscopy, thermal gravimetric analysis and scanning electrom microscopy. Nitrogen surface area measurements (Brunauer-Emmett-Teller (BET) method) and length-change of the monosulfate samples in the solvents were also recorded. Evidence was obtained that indicates monosulfate was readily dehydrated from 12 water molecules to ten water molecules once it was treated by the investigated alcohols. The alcohol molecules, however, likely intercalated into the monosulfate structure, limiting an expected decrease in the interlayer distance of the monosulfate structure. Methanol had the greatest damaging effect on the monosulfate microstructure. Ethanol, however, resulted in higher long-term expansion owing to its intermediate molecular size and reactivity with monosulfate compared to methanol and isopropanol. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ef2f90f1-b3ca-42fd-ba83-afbc851e526d ER - TY - JOUR TI - A novel approach to control thermal degradation of PET/organoclay nanocomposites and improve clay exfoliation DO - 10.1016/j.polymer.2012.12.066 AU - Ghanbari, A. AU - Heuzey, M.C. AU - Carreau, P.J. AU - Ton-That, M.T. T2 - Polymer (United Kingdom) SN - 0032-3861 VL - 54 IS - 4 SP - 1361 EP - 1369 KW - Barrier properties KW - Chain extenders KW - Characterization techniques KW - Clay delamination KW - Clay dispersion KW - Clay exfoliation KW - Cloisite KW - Gas barrier KW - Nano-platelets KW - Organoclays KW - Organomodified clay KW - Oxygen permeability KW - PET films KW - Polymer nanocomposite KW - Recoupling KW - Viscoelastic properties KW - Young modulus KW - Delamination KW - Molecular weight KW - Nanocomposites KW - Polyethylene terephthalates KW - Silicates KW - Nanocomposite films AB - Thermal degradation of polyethylene terephthalate (PET) is accelerated in the presence of commercial organoclays, and this remains a challenge for the industry. While a high level of clay delamination is required in polymer nanocomposites, thermal degradation increases furthermore for highly exfoliated morphologies due to an increased exposure of the polymer matrix to silicate nanoplatelets. In this work, two different types of organomodified clay were melt blended with PET in the presence of a multifunctional epoxy-based chain extender, Joncryl® ADR-4368F (Joncryl), to compensate for molecular weight reduction during processing. The chain extender was added via a master-batch approach in order to promote clay delamination before molecular weight increase. The morphological, rheological, mechanical, thermal, and gas barrier characteristics of the nanocomposites were studied using several characterization techniques. A remarkable improvement in viscoelastic properties was observed for samples containing the chain extender due to recoupling of degraded chains. A better clay dispersion, enhanced barrier properties and increased Young modulus were also obtained for nanocomposites containing the chain extender. Compared to neat PET films, the oxygen permeability of nanocomposite films containing 4 wt% Cloisite® 30B and 1 wt% Joncryl decreased by 46%, whereas the corresponding permeability decrease for the Nanomer® I.28E nanocomposite was 40%. A 66% improvement in Young modulus was obtained for nanocomposite films containing 4 wt% Nanomer® I.28E and 1 wt% Joncryl. The improvement of the tensile modulus for the corresponding Cloisite® 30B nanocomposite was slightly less. © 2012 Elsevier Ltd. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : fc8a6cde-ca75-4558-8091-d11540c592a8 ER - TY - JOUR TI - Water and methanol maser survey of protostars in the orion molecular cloud complex DO - 10.1088/0067-0049/209/2/25 AU - Kang, M. AU - Lee, J.-E. AU - Choi, M. AU - Choi, Y. AU - Kim, K.-T. AU - Di Francesco, J. AU - Park, Y.-S. T2 - Astrophysical Journal, Supplement Series SN - 0067-0049 VL - 209 IS - 2 SP - 25 AB - The results of a maser survey toward 99 protostars in the Orion molecular cloud complex are presented. The target sources are low-mass protostars identified from infrared observations. Single-dish observations were carried out in the water maser line at 22 GHz and the methanol class I maser lines at 44, 95, and 133 GHz. Most of the detected sources were mapped to determine the source positions. Five water maser sources were detected, and they are excited by HH 1-2 VLA 3, HH 1-2 VLA 1, L1641N MM1/3, NGC 2071 IRS 1/3, and an object in the OMC 3 region. The water masers showed significant variability in intensity and velocity with time scales of 1 month or shorter. Four methanol emission sources were detected, and those in the OMC 2 FIR 3/4 and L1641N MM1/3 regions are probably masers. The methanol emission from the other two sources in the NGC 2071 IRS 1-3 and V380 Ori NE regions are probably thermal. For the water masers, the number of detections per protostar in the survey region is about 2%, which suggests that the water masers of low-mass protostars are rarely detectable. The methanol class I maser of low-mass protostars is an even rarer phenomenon, with a detection rate much smaller than 1%. © 2013. The American Astronomical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 94f78206-6d5e-4d1d-9f49-a099b5e7a86c ER - TY - JOUR TI - Comparison of solid oxide fuel cell stack performance using detailed and simplified models DO - 10.1115/FuelCell2013-18137 AU - Nishida, R.T. AU - Beale, S.B. AU - Pharoah, J.G. T2 - ASME 2013 11th Int. Conf. on Fuel Cell Science, Eng. and Technology Collocated with the ASME 2013 Heat Transfer Summer Conf. and the ASME 2013 7th Int. Conf. on Energy Sustainability, FUELCELL 2013 T3 - ASME 2013 11th International Conference on Fuel Cell Science, Engineering and Technology, FUELCELL 2013 Collocated with the ASME 2013 Heat Transfer Summer Conference and the ASME 2013 7th International Conference on Energy Sustainability, 14 July 2013 through 19 July 2013, Minneapolis, MN SN - 9780791855522 SP - V001T02A004 AB - Two computational fluid dynamics models have been developed to predict the performance of a solid oxide fuel cell stack, a detailed and a simplified model. In the detailed model, the three dimensional momentum, heat, and species transport equations are coupled with electrochemistry. In the simplified model, the diffusion terms in the transport equations are selectively replaced by rate terms within the core region of the stack. This allows much coarser meshes to be employed at a fraction of the computational cost. Following the mathematical description of the problem, results for a single cell and multi-cell stack are presented. Comparisons of local current density, temperature, and cell voltage indicate that good agreement is obtained between the detailed and simplified models, confirming the validity of the latter as a practical option in stack design. Copyright © 2013 by ASME. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 305098c5-7f5c-4094-b2ce-d52e6277bdb5 ER - TY - JOUR TI - Pillars and globules at the edges of H ii regions: Confronting Herschel observations and numerical simulations DO - 10.1051/0004-6361/201322233 AU - Tremblin, P. AU - Minier, V. AU - Schneider, N. AU - Audit, E. AU - Hill, T. AU - Didelon, P. AU - Peretto, N. AU - Arzoumanian, D. AU - Motte, F. AU - Zavagno, A. AU - Bontemps, S. AU - Anderson, L.D. AU - André, P. AU - Bernard, J.P. AU - Csengeri, T. AU - Di Francesco, J. AU - Elia, D. AU - Hennemann, M. AU - Könyves, V. AU - Marston, A.P. AU - Nguyen Luong, Q. AU - Rivera-Ingraham, A. AU - Roussel, H. AU - Sousbie, T. AU - Spinoglio, L. AU - White, G.J. AU - Williams, J. T2 - Astronomy and Astrophysics SN - 0004-6361 VL - 560 SP - A19 KW - H II regions KW - ISM: individual objects KW - Ism: individual objects: rosettes KW - ISM: Kinematics and dynamics KW - ISM: structure KW - Methods:observational KW - Computer simulation KW - Gases KW - Infrared imaging KW - Ionization of gases KW - Numerical models KW - Shells (structures) KW - Stars KW - Velocity KW - Clouds AB - Context. Herschel far-infrared imaging observations have revealed the density structure of the interface between H ii regions and molecular clouds in great detail. In particular, pillars and globules are present in many high-mass star-forming regions, such as the Eagle nebula (M 16) and the Rosette molecular cloud, and understanding their origin will help characterize triggered star formation. Aims. The formation mechanisms of these structures are still being debated. The initial morphology of the molecular cloud and its turbulent state are key parameters since they generate deformations and curvatures of the shell during the expansion of the H ii region. Recent numerical simulations have shown how pillars can arise from the collapse of the shell in on itself and how globules can be formed from the interplay of the turbulent molecular cloud and the ionization from massive stars. The goal here is to test this scenario through recent observations of two massive star-forming regions, M 16 and the Rosette molecular cloud. Methods. First, the column density structure of the interface between molecular clouds and associated H ii regions was characterized using column density maps obtained from far-infrared imaging of the Herschel HOBYS key programme. Then, the DisPerSe algorithm was used on these maps to detect the compressed layers around the ionized gas and pillars in different evolutionary states. Column density profiles were constructed. Finally, their velocity structure was investigated using CO data, and all observational signatures were tested against some distinct diagnostics established from simulations. Results. The column density profiles have revealed the importance of compression at the edge of the ionized gas. The velocity properties of the structures, i.e. pillars and globules, are very close to what we predict from the numerical simulations. We have identified a good candidate of a nascent pillar in the Rosette molecular cloud that presents the velocity pattern of the shell collapsing on itself, induced by a high local curvature. Globules have a bulk velocity dispersion that indicates the importance of the initial turbulence in their formation, as proposed from numerical simulations. Altogether, this study re-enforces the picture of pillar formation by shell collapse and globule formation by the ionization of highly turbulent clouds. © ESO, 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 65c1520c-4490-40d7-b557-6d5f49aff4c2 ER - TY - JOUR TI - Ultra-fast dynamic imaging of matter DO - 10.1080/09500340.2013.851524 AU - Staudte, A. T2 - Journal of Modern Optics SN - 0950-0340 VL - 60 IS - 17 SP - 1377 EP - 1378 DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c4104e9f-6b76-45f4-aeab-87f874400e9d ER - TY - JOUR TI - Stress intensity factor solution for cracks in panels with arbitrarily located stringers DO - 10.2514/1.C032159 AU - Bombardier, Y. AU - Liao, M. AU - Renaud, G. T2 - Journal of Aircraft SN - 0021-8669 VL - 50 IS - 6 SP - 1787 EP - 1805 AB - This paper presents a stress intensity factor solution for cracks located in panels reinforced with arbitrarily located stringers. The new solution was developed by modifying the constitutive equations of a solution for symmetrically and periodically spaced stringers with riveted rigid fasteners. The new solution supports arbitrary stringer locations with respect to the crack location, includes the capability to model compliant fasteners, improves the accuracy of the equivalent stringer compliance by considering Poisson's effect, and allows the fasteners to be arbitrarily located within each stringer. For the tested cases, the difference between the stress intensity factors calculated using the new closed-form solution and the linear static finite-element analysis results were within 4%. Through two examples for the CC-130 aircraft, it was shown that the closed-form solution developed for a center crack in an infinite sheet could also be used to model an edge crack growing in a relatively large panel. © 2012 AIAA. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5f898a7f-9eb4-45e2-b484-b33427dd241d ER - TY - JOUR TI - Simultaneous determination of Co, Fe, Ni and Pb in carbon nanotubes by means of solid sampling high-resolution continuum source graphite furnace atomic absorption spectrometry DO - 10.1039/c3ja30377b AU - Resano, Martin AU - Bolea-Fernández, Eduardo AU - Mozas, Engracia AU - Flórez, Maria R. AU - Grinberg, Patricia AU - Sturgeon, Ralph E. T2 - Journal of Analytical Atomic Spectrometry SN - 0267-9477 VL - 28 IS - 5 SP - 657 EP - 665 KW - Calibration curves KW - Candidate reference materials KW - Chemical modifiers KW - Cost-effective analysis KW - Graphite furnace atomic absorption spectrometry KW - Limits of detection KW - Simultaneous determinations KW - Straight-forward method KW - Carbon nanotubes KW - Lead KW - Nickel KW - Iron compounds AB - This work explores the possibilities of solid sampling high-resolution continuum source graphite furnace atomic absorption spectrometry for the direct analysis of carbon nanotubes. In particular, the simultaneous determination of Co, Fe, Ni and Pb is intended, as these elements are typically found in these samples as impurities. The results demonstrate that it is possible to find spectral (monitoring of the region between 283.168 and 283.481 nm), furnace (2500 °C for atomization; use of 100 ng Pd as a chemical modifier) and detector (use of side pixels to expand the linear range) conditions that permit the development of a fast and straightforward method for the simultaneous determination of the target elements at the levels at which they are typically found (mg g-1 for Co, Fe and Ni; μg g-1 for Pb) in carbon nanotubes. Limits of detection of 23 pg (Pb), 6 ng (Fe), 65 ng (Ni) and 86 ng (Co) were obtained, which are suitable for this type of sample. In this way, it was feasible to carry out the analysis of the samples investigated (one candidate reference material and three commercially available samples) and achieve accurate results when constructing the calibration curve with aqueous standards. Precision values for 5 solid sample replicates varied between 7 and 15% RSD in most cases. Overall, the proposed method shows important benefits for the cost-effective analysis of such complex samples in routine labs. This journal is © The Royal Society of Chemistry. DA - 2013/02/06 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e182be58-d14b-4997-a7c2-34d6d1cd78c4 ER - TY - JOUR TI - Electrochemical behaviours of titanium nitride (TIN) and chromium nitride (CRN) based pvd coating systems DO - 10.1115/GT2013-94024 AU - Cai, F. AU - Huang, X. AU - Yang, Q. T2 - Proceedings of the ASME Turbo Expo T3 - ASME Turbo Expo 2013: Turbine Technical Conference and Exposition, GT 2013, 3 June 2013 through 7 June 2013, San Antonio, Tx SN - 9780791855195 VL - 5:00 AM KW - Coating microstructures KW - Coating-substrate systems KW - Diffusion layer thickness KW - Effective diffusion coefficients KW - EIS KW - Electrochemical behaviour KW - NaCl aqueous solution KW - PVD coatings KW - Corrosion KW - Corrosion resistance KW - Defects KW - Diffusion KW - Diffusion coatings KW - Electrochemical impedance spectroscopy KW - Exhibitions KW - Gas turbines KW - Hard coatings KW - Pitting KW - Potentiodynamic polarization KW - Titanium nitride KW - Electrochemical corrosion AB - Hard coatings applied to steel components prevent corrosion attacks while at the same time mitigate erosion attack. However, the presence of process related through-coating defects such as pin holes, voids and growth defects, provides accesses for corrosive media to metal substrates, initializing pitting corrosion and eventually resulting in coating failure. This research studies the corrosion behavior of PVD TiN and CrN (CrSiCN) coated steels in 3.5 wt. % NaCl aqueous solution using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The results revealed that in a coating-substrate system, effective diffusion coefficient and diffusion layer thickness control the corrosion resistance; both factors are found to be related to coating microstructure. A denser and thicker coating structure are shown to have lower effective diffusion coefficients and greater effective diffusion layer thicknesses and consequently provided a high resistance to electrochemical corrosion. Copyright © 2013 by ASME. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 09dc585a-56a1-46ca-bfe0-2dfe571b7da1 ER - TY - JOUR TI - Genomics of seed development: Challenges and opportunities for genetic improvement of seed traits in crop plants DO - 10.1016/j.bcab.2013.11.009 AU - Venglat, P. AU - Xiang, D. AU - Wang, E. AU - Datla, R. T2 - Biocatalysis and Agricultural Biotechnology SN - 1878-8181 AB - Seed development represents an important phase in the life cycle of flowering plants including the majority of the crop plants. During this phase, developmental and metabolic programs are coordinated to produce the seed that contains the germline information and storage reserves. Although seed developmental patterns vary significantly between the monocots and dicots, they share several conserved developmental programs. The embryo is the major component of the seed in dicots whereas the endosperm is predominant in monocot seeds. The formation of the dormant seed that protects the embryo and provides nutrition during germination is a key characteristic adaptive feature in the evolution of the angiosperms and a determining factor of yield in crop plants. From a crop perspective, the metabolites and especially the storage products deposited in the seed defines the value of the seed. Despite progress in fundamental understanding of seed development, the global genetic and metabolic programs involved in the making of the seed and their implications to genetic improvement of the seed is yet to be fully exploited in crop plants. So, the major goal of several recent studies is to develop comprehensive systems-level insights into molecular and biochemical programs associated with gene expression, protein and metabolite profiles during seed development in model and crop plants. These integrated systems approaches and studies are producing foundational and comprehensive datasets. In this review, we will present an overview of advances in the developmental, genetic and genomic studies of seed biology and their implications to improve seed characteristics in crop plants. Crown Copyright © 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e4fd06bb-59dd-4ff8-bd59-d910702d9842 ER - TY - JOUR TI - High-level expression of sugar inducible gene2 (HSI2) is a negative regulator of drought stress tolerance in Arabidopsis DO - 10.1186/1471-2229-13-170 AU - Sharma, N. AU - Bender, Y. AU - Boyle, K. AU - Fobert, P.R. T2 - BMC Plant Biology SN - 1471-2229 VL - 13 IS - 1 SP - 170 AB - Background: HIGH-LEVEL EXPRESSION OF SUGAR INDUCIBLE GENE2 (HSI2), also known as VAL1, is a B3 domain transcriptional repressor that acts redundantly with its closest relative, HSI2-LIKE1 (HSL1), to suppress the seed maturation program following germination. Mutant hsi2 hsl1 seedlings are arrested early in development and differentially express a number of abiotic stress-related genes. To test the potential requirement for HSI2 during abiotic stress, hsi2 single mutants and plants overexpressing HSI2 were subjected to simulated drought stress by withholding watering, and characterized through physiological, metabolic and gene expression studies.Results: The hsi2 mutants demonstrated reduced wilting and maintained higher relative water content than wild-type after withholding watering, while the overexpressing lines displayed the opposite phenotype. The hsi2 mutant displayed lower constitutive and ABA-induced stomatal conductance than wild-type and accumulated lower levels of ABA metabolites and several osmolytes and osmoprotectants following water withdrawal. Microarray comparisons between wild-type and the hsi2 mutant revealed that steady-state levels of numerous stress-induced genes were up-regulated in the mutant in the absence of stress but down-regulated at visible wilting. Plants with altered levels of HSI2 responded to exogenous application of ABA and a long-lived ABA analog, but the hsi2 mutant did not show altered expression of several ABA-responsive or ABA signalling genes 4 hr after application.Conclusions: These results implicate HSI2 as a negative regulator of drought stress response in Arabidopsis, acting, at least in part, by regulating transpirational water loss. Metabolic and global transcript profiling comparisons of the hsi2 mutant and wild-type plants do not support a model whereby the greater drought tolerance observed in the hsi2 mutant is conferred by the accumulation of known osmolytes and osmoprotectants. Instead, data are consistent with mutants experiencing a relatively milder dehydration stress following water withdrawal. © 2013 Crown copyright; licensee BioMed Central Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4150d6a3-a62c-4b5d-b057-5d92d58d1be1 ER - TY - JOUR TI - Dynamic positioning simulation of a simplified FPSO in waves DO - 10.1115/OMAE2013-10067 AU - Zhan, D. AU - Very, S. AU - Bass, D. AU - Millan, J. T2 - Proceedings of the International Conference on Offshore Mechanics and Arctic Engineering - OMAE T3 - ASME 2013 32nd International Conference on Ocean, Offshore and Arctic Engineering, OMAE 2013, 9 June 2013 through 14 June 2013, Nantes SN - 9780791855393 VL - 5 SP - V005T06A004 AB - This paper presents a numerical station-keeping simulation in waves (regular and irregular waves) for a simplified FPSO with two DP systems. The main difference of the simulation with these two DP systems was that the first DP system (called MOT DP in this paper) was included in a seakeeping simulation code (MOTSIM) while another DP system (called IOT DP, developed by NRC/IOT) was an external system and installed on another computer (which was the same as the one used to control the vessel in physical model experiments). In order to exchange command messages between the simulation code (MOTSIM) and the IOT DP system, a communication code executed in the same time step was developed by using Windows™ socket functions. By using these two DP systems a station-keeping simulation for a 1:40 scale model FPSO with six azimuthing thrusters was conducted in regular and irregular waves and wind. The seakeeping RAO results in regular waves were compared between these two DP systems, and also with physical model experiments with external IOT DP system and analysis using a commercial linear, 3-dimensional panel code, HydroStar. In irregular waves a mean station keeping force Fx, Fy in horizontal plane was calculated and its total mean force was compared with results from the physical model experiments. Finally, a discussion between these two DP systems was provided. Copyright © 2013 by ASME. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 292da5c8-30e8-4737-9546-ecd3b4ba6f49 ER - TY - JOUR TI - Pre-symptomatic activation of antioxidant responses and alterations in glucose and pyruvate metabolism in niemann-pick type C1-deficient murine brain DO - 10.1371/journal.pone.0082685 AU - Kennedy, B.E. AU - LeBlanc, V.G. AU - Mailman, T.M. AU - Fice, D. AU - Burton, I. AU - Karakach, T.K. AU - Karten, B. T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 12 SP - e82685 AB - Niemann-Pick Type C (NPC) disease is an autosomal recessive neurodegenerative disorder caused in most cases by mutations in the NPC1 gene. NPC1-deficiency is characterized by late endosomal accumulation of cholesterol, impaired cholesterol homeostasis, and a broad range of other cellular abnormalities. Although neuronal abnormalities and glial activation are observed in nearly all areas of the brain, the most severe consequence of NPC1-deficiency is a near complete loss of Purkinje neurons in the cerebellum. The link between cholesterol trafficking and NPC pathogenesis is not yet clear; however, increased oxidative stress in symptomatic NPC disease, increases in mitochondrial cholesterol, and alterations in autophagy/mitophagy suggest that mitochondria play a role in NPC disease pathology. Alterations in mitochondrial function affect energy and neurotransmitter metabolism, and are particularly harmful to the central nervous system. To investigate early metabolic alterations that could affect NPC disease progression, we performed metabolomics analyses of different brain regions from age-matched wildtype and Npc1 -/- mice at pre-symptomatic, early symptomatic and late stage disease by 1H-NMR spectroscopy. Metabolic profiling revealed markedly increased lactate and decreased acetate/acetyl-CoA levels in Npc1-/- cerebellum and cerebral cortex at all ages. Protein and gene expression analyses indicated a presymptomatic deficiency in the oxidative decarboxylation of pyruvate to acetyl-CoA, and an upregulation of glycolytic gene expression at the early symptomatic stage. We also observed a pre-symptomatic increase in several indicators of oxidative stress and antioxidant response systems in Npc1 -/- cerebellum. Our findings suggest that energy metabolism and oxidative stress may present additional therapeutic targets in NPC disease, especially if intervention can be started at an early stage of the disease. © 2013 Kennedy et al. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 12d10c44-bc17-46c7-b388-af001fd7628c ER - TY - JOUR TI - Calculations of narrow-band transimissities and the Planck mean absorption coefficients of real gases using line-by-line and statistical narrow-band models DO - 10.1007/s11708-013-0292-4 AU - Chu, H. AU - Gu, M. AU - Zhou, H. AU - Liu, F. T2 - Frontiers in Energy SN - 2095-1701 SP - 1 EP - 8 AB - Narrow-band transmissivities in the spectral range of 150 to 9300 cm-1 and at a uniform resolution of 25 cm-1 were calculated using the statistical narrow-band (SNB) model with the band parameters of Soufiani and Taine, the more recent parameters of André and Vaillon, and the line-by-line (LBL) method along with the HITEMP-2010 spectroscopic database. Calculations of narrow-band transmissivity were conducted for gas columns of different lengths and containing different isothermal and non-isothermal CO2-H2O-N2 mixtures at 1 atm. Narrow-band transmissivities calculated by the SNB model are in large relative error at many bands. The more recent SNB model parameters of André and Vaillon are more accurate than the earlier parameters of Soufiani and Taine. The Planck mean absorption coefficients of CO2, H2O, CO, and CH4 in the temperature range of 300 to 2500 K were calculated using the LBL method and different versions of the high resolution transmission (HITRAN) and high-temperature spectroscopic absorption parameters (HITEMP) spectroscopic databases. The SNB model was also used to calculate the Planck mean absorption coefficients of these four radiating gases. The LBL results of the Planck mean absorption coefficient were compared with the classical results of Tien and those from the SNB model. © 2013 Higher Education Press and Springer-Verlag Berlin Heidelberg. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 99775fd3-ffbf-4de1-848c-5c8c6f07dbbd ER - TY - JOUR TI - Framework for evaluation of the relative contribution of the process on porosity-cutting force dependence in micromilling of titanium foams DO - 10.1177/0954405413491243 AU - Fakhri, M.A. AU - Bordatchev, E.V. AU - Tutunea-Fatan, O.R. T2 - Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture SN - 0954-4054 VL - 227 IS - 11 SP - 1635 EP - 1650 KW - Cutting forces KW - Micro milling KW - Porous titanium KW - Process parameters KW - Random data analysis KW - Micromachining KW - Milling (machining) KW - Porosity KW - Porous materials KW - Power spectral density KW - Titanium KW - Cutting AB - Porous titanium, characterized by interconnected and large open-cell structures, constitutes one of the most promising bone substitutes that are currently available for surgical orthopedic and dental implantation procedures. Since little is known about the behavior of this highly porous material during material removal operations, the main objective of this study was to develop a framework capable of evaluating the effect of cutting speed, cutting depth, and feed rate on the interplay between porosity and cutting force signatures, as experienced during microslot cutting experiments. The comparisons performed between optically determined porosity and cutting force profiles by means of standard random data analysis metrics (correlation coefficient, power spectral density, and coherence) revealed that the presence of a material discontinuity has a prevalent effect on cutting force variation in the case of micromilling processes characterized by (1) less intensive machining regimes and (2) larger cutter/workpiece engagement zones. The proposed methodology is useful in selection of the investigative approach to be taken in assessment of the micromachining-related behavior of highly porous foams subjected to micromilling operations. © IMechE 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b2007f6b-4946-4d29-ac7d-0e5c1145ba7a ER - TY - JOUR TI - Engineering the optical properties of silicon using sub-wavelength structures DO - 10.1109/Group4.2013.6644476 AU - Halir, R. AU - Ortega-Moñux, A. AU - Maese-Novo, A. AU - Pérez-Galacho, D. AU - Zavargo-Peche, L. AU - Molina-Fernández, I. AU - Pérez, J.G.W. AU - Cheben, P. AU - Schmid, J.H. AU - Xu, D.-X. AU - Janz, S. AU - Fédéli, J.-M. T2 - IEEE International Conference on Group IV Photonics GFP T3 - 2013 IEEE 10th International Conference on Group IV Photonics, GFP 2013, 28 August 2013 through 30 August 2013, Seoul SN - 1949-2081 SN - 9781467358040 SP - 6644476 SP - 33 EP - 34 KW - Degree of freedom KW - Diffraction effects KW - Dispersion engineering KW - Multimode interference couplers KW - Sub-wave length grating KW - Sub-wavelength structures KW - Ultra-broadband KW - Waveguiding structures KW - Dispersion (waves) KW - Dispersions KW - Photonics KW - Silicon KW - Refractive index AB - In most integrated optics platforms, including silicon-on-insulator, only minor modifications in refractive index are possible. The geometry of the waveguiding structure is thus the only degree of freedom for the design of devices. The use of sub-wavelength gratings (SWGs), i.e. structures that are small enough to suppress diffraction effects, enables local engineering of both refractive index and dispersion, thereby opening new possibilities for device design. Here we present some of the recent advances in refractive index and dispersion engineering using silicon SWGs, focussing on ultra-broadband and compact multimode interference couplers and directional couplers. © 2013 IEEE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 7f2c0f52-495f-4a3c-8c5e-041b6f8f4f5e ER - TY - JOUR TI - Detection and discrimination of motion-defined form: Implications for the use of night vision devices DO - 10.1109/THMS.2013.2284911 AU - Allison, R.S. AU - Macuda, T. AU - Jennings, S. T2 - IEEE Transactions on Human-Machine Systems SN - 2168-2291 VL - 43 IS - 6 SP - 2284911 SP - 558 EP - 569 AB - Superimposed luminance noise is typical of imagery from devices used for low-light vision such as image intensifiers (i.e., night vision devices). In four experiments, we measured the ability to detect and discriminate motion-defined forms as a function of stimulus signal-to-noise ratio at a variety of stimulus speeds. For each trial, observers were shown a pair of image sequences- one containing dots in a central motion-defined target region that moves coherently against the surrounding dots, which moved in the opposite or in random directions, while the other sequence had the same random/uniform motion in both the center and surrounding parts. They indicated which interval contained the target stimulus in a two-interval forced-choice procedure. In the first experiment, simulated night vision images were presented with Poisson-distributed spatiotemporal image noise added to both the target and surrounding regions of the display. As the power of spatiotemporal noise was increased, it became harder for observers to detect the target, particularly at the lowest and highest dot speeds. The second experiment confirmed that these effects also occurred with low illumination in real night vision device imagery, a situation that produces similar image noise. The third experiment demonstrated that these effects generalized to Gaussian noise distributions and noise created by spatiotemporal decorrelation. In the fourth experiment, we found similar speed-dependent effects of luminance noise for the discrimination (as opposed to detection) of the shape of a motion-defined form. The results are discussed in terms of physiological motion processing and for the usability of enhanced vision displays under noisy conditions. © 2013 IEEE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 78924be3-e43b-43fb-83a1-5068f3593cbe ER - TY - JOUR TI - Raman based detection of Staphylococcus aureus utilizing single domain antibody coated nanoparticle labels and magnetic trapping DO - 10.1039/c3ay40652k AU - Drake, P. AU - Jiang, P.-S. AU - Chang, H.-W. AU - Su, S.-C. AU - Tanha, J. AU - Tay, L.-L. AU - Chen, P. AU - Lin, Y.-J. T2 - Analytical Methods SN - 1759-9660 VL - 5 IS - 16 SP - 4152 EP - 4158 KW - 4-mercaptobenzoic acids KW - Coated nanoparticles KW - Detection and quantifications KW - Gold Nanoparticles KW - Pathogenic bacterium KW - Single-domain antibodies KW - Staphylococcus aureus KW - Surface enhanced Raman spectroscopy KW - Antibodies KW - Bacteria KW - Chemical detection KW - Gold KW - Iron oxides KW - Metal nanoparticles KW - Raman spectroscopy KW - Transmission electron microscopy KW - Nanomagnetics AB - Nanoparticle labels were used to detect the pathogenic bacteria Staphylococcus aureus. Two different labels were employed. These consisted of nanoparticles based on iron-oxide for magnetic trapping and isolation of the bacteria and surface enhanced Raman spectroscopy (SERS) active gold nanoparticles (AuNPs) coated with 4-mercaptobenzoic acid for the detection and quantification of the bacteria. Both types of nanoparticles were conjugated with single domain antibodies that selectively bind to protein A on the surface of S. aureus. Transmission electron microscopy (TEM) image analysis showed the iron-oxide nanoparticles to have magnetic core diameters of 20 nm ± 3 nm and the gold nanoparticles to be 51 nm ± 2 nm in diameter. A response curve was obtained displaying a logarithmic dependency between the 1073 cm -1 peak intensity in the SERS spectra of the AuNPs and the concentration of S. aureus cells in the initial sample. The overall detection limit was estimated to be 1 S. aureus cell mL-1 in less than 10 min without culturing. © 2013 The Royal Society of Chemistry. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 44f8758e-881a-464b-9268-280a78a6cbf4 ER - TY - JOUR TI - Continuous anaerobic bioreactor with a fixed-structure bed (ABFSB) for wastewater treatment with low solids and low applied organic loading content DO - 10.1007/s00449-013-1108-y AU - Mockaitis, G. AU - Pantoja, J.L.R. AU - Rodrigues, J.A.D. AU - Foresti, E. AU - Zaiat, M. T2 - Bioprocess and Biosystems Engineering SN - 1615-7591 SP - 1 EP - 8 AB - This paper describes a new type of anaerobic bioreactor with a fixed-structure bed (ABFSB) in which the support for the biomass consists of polyurethane foam strips placed along the length of the bioreactor. This configuration prevents the accumulation of biomass or solids in the bed as well as clogging and channeling effects. In this study, complex synthetic wastewater with a chemical oxygen demand of 404.4 mg O2 L-1 is treated by the reactor. The ABFSB, which has a working volume of 4.77 L, was inoculated with anaerobic sludge obtained from an upflow anaerobic sludge blanket bioreactor. A removal efficiency of 78 % for organic matter and an effluent pH of 6.97 were achieved. An analysis of the organic volatile acids produced by the ABFSB indicated that it operated under stable conditions during an experimental run of 36 days. The stable and efficient operation of the bioreactor was compared with the configurations of other anaerobic bioreactors used for complex wastewater treatment. The results of the study indicate that the ABFSB is a technological alternative to packed-bed bioreactors. © 2013 Springer-Verlag Berlin Heidelberg. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ed892362-42e9-4c66-a1da-a06aa833196c ER - TY - JOUR TI - Historical perspective: Neon interatomic potentials from scattering data and crystalline properties [Volume 19, Issue 3, 1 April 1973, Pages 359-362] DO - 10.1016/j.cplett.2013.08.039 AU - Farrar, J.M. AU - Lee, Y.T. AU - Goldman, V.V. AU - Klein, M.L. T2 - Chemical Physics Letters SN - 0009-2614 DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 34be9deb-86b8-46e5-aed5-4e2fe2d78da3 ER - TY - JOUR TI - Analytical modeling of oxide thickness variation of metals under high temperature solid-particle erosion DO - 10.1142/S1793962314500020 AU - Chen, J. AU - Chen, K. AU - Liu, R. AU - Liang, M. T2 - International Journal of Modeling, Simulation, and Scientific Computing SN - 1793-9623 IS - 2 SP - 1 EP - 16 AB - The paper presents a study of model development for predicting the oxide thickness on metals under high temperature solid-particle erosion. The model is created based on the theory of solid-particle erosion that characterizes the erosion damage as deformation wear and cutting wear, incorporating the effect of the oxide scale on the eroded surface under high temperature erosion. Then the instantaneous oxide thickness is the result of the synergetic effect of erosion and oxidation. The developed model is applied on a Ni-based Al-containing (Ni-Al) alloy to investigate the oxide thickness variation with erosion duration of the alloy at high temperatures. The results show that the thickness of the oxide scale on the alloy surface increases with the exposure time and temperature when the surface is not attacked by particles. However, when particles impact on the alloy surface, the oxide thickness is reduced, although oxidation is continuing. This indicates that oxidation does not benefit the erosion resistance of this alloy at high temperatures due to the low growth rate of the oxide. © 2014 World Scientific Publishing Company. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 88b1e98f-1555-4a16-acaf-f1e78b7cc387 ER - TY - JOUR TI - From photons to phonons and back: A THz optical memory in diamond DO - 10.1103/PhysRevLett.111.243601 AU - England, D.G. AU - Bustard, P.J. AU - Nunn, J. AU - Lausten, R. AU - Sussman, B.J. T2 - Physical Review Letters SN - 0031-9007 VL - 111 IS - 24 SP - 243601 KW - Local synchronizations KW - Material dispersions KW - Optical phonon modes KW - Physical societies KW - Quantum technologies KW - Room temperature KW - Secure communications KW - Single quantum KW - Four wave mixing KW - Optical communication KW - Phonons KW - Photons KW - Quantum cryptography KW - Dispersions AB - Optical quantum memories are vital for the scalability of future quantum technologies, enabling long-distance secure communication and local synchronization of quantum components. We demonstrate a THz-bandwidth memory for light using the optical phonon modes of a room temperature diamond. This large bandwidth makes the memory compatible with down-conversion-type photon sources. We demonstrate that four-wave mixing noise in this system is suppressed by material dispersion. The resulting noise floor is just 7×10-3 photons per pulse, which establishes that the memory is capable of storing single quanta. We investigate the principle sources of noise in this system and demonstrate that high material dispersion can be used to suppress four-wave mixing noise in Λ-type systems. Published by the American Physical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5688d16e-4c65-4546-85c8-e06ec7ebe5a0 ER - TY - JOUR TI - Reduce, reuse and recycle: A green solution to Canada's medical isotope shortage DO - 10.1016/j.apradiso.2013.11.100 AU - Galea, R. AU - Ross, C. AU - Wells, R.G. T2 - Applied Radiation and Isotopes SN - 0969-8043 AB - Due to the unforeseen maintenance issues at the National Research Universal (NRU) reactor at Chalk River and coincidental shutdowns of other international reactors, a global shortage of medical isotopes (in particular technetium-99m, Tc-99m) occurred in 2009. The operation of these research reactors is expensive, their age creates concerns about their continued maintenance and the process results in a large amount of long-lived nuclear waste, whose storage cost has been subsidized by governments. While the NRU has since revived its operations, it is scheduled to cease isotope production in 2016. The Canadian government created the Non-reactor based medical Isotope Supply Program (NISP) to promote research into alternative methods for producing medical isotopes. The NRC was a member of a collaboration looking into the use of electron linear accelerators (LINAC) to produce molybdenum-99 (Mo-99), the parent isotope of Tc-99m. This paper outlines NRC's involvement in every step of this process, from the production, chemical processing, recycling and preliminary animal studies to demonstrate the equivalence of LINAC Tc-99m with the existing supply. This process stems from reusing an old idea, reduces the nuclear waste to virtually zero and recycles material to create a green solution to Canada's medical isotope shortage. Crown Copyright © 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d4661789-2c13-4dd5-9ad4-1e663f9e9648 ER - TY - JOUR TI - Optimization of stress-induced pockels effect in silicon waveguides for optical modulators DO - 10.1109/Group4.2013.6644453 AU - Aleali, Alireza AU - Xu, Danxia AU - Schmid, Jens H. AU - Cheben, Pavel AU - Ye, Winnie N. T2 - IEEE International Conference on Group IV Photonics GFP T3 - 2013 IEEE 10th International Conference on Group IV Photonics, GFP 2013, 28 August 2013 through 30 August 2013, Seoul SN - 1949-2081 SN - 9781467358040 SP - 6644453 SP - 109 EP - 110 KW - Electrooptic effects KW - Figure of merits KW - Pockels effect KW - Silicon waveguide KW - Stress-induced KW - Light modulators KW - Modulators KW - Photonics KW - Silicon KW - Strain KW - Waveguides KW - Optimization AB - A method for the optimization of strain-induced Pockels effect in silicon waveguides is proposed. We introduce a new figure of merit and show a 35% enhancement in FOM compared to most efficient reported devices. © 2013 IEEE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 69b7b6be-a329-4770-b0ec-1765ce033b29 ER - TY - JOUR TI - Multipodal and multilayer TiO2 nanotube arrays: Hierarchical structures for energy harvesting and sensing DO - 10.1557/opl.2013.584 AU - Mohammadpour, A. AU - Farsinezhad, S. AU - Hsieh, L.-H. AU - Shankar, K. T2 - 2013 MRS Spring Meeting - Symposium S – Nanostructured Metal Oxides for Advanced Applications T2 - Materials Research Society Symposium Proceedings; no. 1552 T3 - 2013 MRS Spring Meeting, 1 April 2013 through 5 April 2013, San Francisco, CA SN - 0272-9172 SN - 9781605115290 SP - 29 EP - 34 AB - Our ability to fabricate multipodal and multilayer TiO2 nanotube arrays enables us to increase performance and functionality in light harvesting devices such as excitonic solar cells and photocatalysts. Using a combination of simulations and experiments, we show that multilayer nanotube arrays enable photon management in the active toward enhancing the absorption and utilization of incident light. We show that the simultaneous utilization of TiO2 nanotubes with large (∼450 nm) and small (∼80 nm) diameters in stacked multilayer films increased light absorption and photocurrent in solar cells. Such enhanced light absorption is particularly desirable in the near-infrared region of the solar spectrum in which most excitonic solar cells suffer from poor quantum efficiencies and for blue photons at the TiO2 band-edge where significant room exists for improvement of photocatalytic quantum yields. Under AM 1.5 one sun illumination, multilayer nanotube arrays afforded us an approximately 20% improvement in photocurrent over single layer nanotube array films of the same thickness for N-719 sensitized liquid junction solar cells. Also, the possibility of multipodal TiO2 nanotube growth with different electrolyte recipes is presented. © 2013 Materials Research Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1c1d287a-20a1-4177-bebf-5f2bf2cf3b65 ER - TY - JOUR TI - Rolling silver nanowire electrodes: Simultaneously addressing adhesion, roughness, and conductivity DO - 10.1021/am403986f AU - Hauger, T.C. AU - Al-Rafia, S.M.I. AU - Buriak, J.M. T2 - ACS Applied Materials and Interfaces SN - 1944-8244 VL - 5 IS - 23 SP - 12663 EP - 12671 KW - Diffuse transmission KW - Indium tin oxide substrates KW - Organic light emitting diodes(OLEDs) KW - Organic photovoltaics KW - Polyethylene terephthalates (PET) KW - Silver nanowires KW - Spray coating KW - Transparent electrode KW - Adhesion KW - Coatings KW - Electric conductivity KW - Flexible electronics KW - Heat resistance KW - Nanowires KW - Organic light emitting diodes (OLED) KW - Rolling KW - Sheet resistance KW - Topology KW - Transparency KW - Electrodes AB - Silver nanowire mesh electrodes represent a possible mass-manufacturable route toward transparent and flexible electrodes for plastic-based electronics such as organic photovoltaics (OPVs), organic light emitting diodes (OLEDs), and others. Here we describe a route that is based upon spray-coated silver nanowire meshes on polyethylene terephthalate (PET) sheets that are treated with a straightforward combination of heat and pressure to generate electrodes that have low sheet resistance, good optical transmission, that are topologically flat, and adhere well to the PET substrate. The silver nanowire meshes were prepared by spray-coating a solution of silver nanowires onto PET, in air at slightly elevated temperatures. The as-prepared silver nanowire electrodes are highly resistive due to the poor contact between the individual silver nanowires. Light pressure applied with a stainless steel rod, rolled over the as-sprayed silver nanowire meshes on PET with a speed of 10 cm s-1 and a pressure of 50 psi, results in silver nanowire mesh arrays with sheet resistances of less than 20 Ω/□. Bending of these rolled nanowire meshes on PET with different radii of curvature, from 50 to 0.625 mm, showed no degradation of the conductivity of the electrodes, as shown by the constant sheet resistance before and after bending. Repeated bending (100 times) around a rod with a radius of curvature of 1 mm also showed no increase in the sheet resistance, demonstrating good adherence and no signs of delamination of the nanowire mesh array. The diffuse and direct transmittance of the silver nanowires (both rolled and as-sprayed) was measured for wavelengths from 350 to 1200 nm, and the diffuse transmission was similar to that of the PET substrate; the direct transmission decreases by about 7-8%. The silver nanowires were then incorporated into OPV devices with the following architecture: transparent electrode/PEDOT:PSS/P3HT:PC61BM/LiF/Al. While slightly lower in efficiency than the standard indium tin oxide substrate (ITO), the rolled silver nanowire electrodes had a very good device yield, showing that short circuits resulting from the silver nanowire electrodes can be successfully avoided by this rolling approach. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f2d2f6b8-0b42-4f54-9777-957bd5ed0022 ER - TY - JOUR TI - Rapid determination of silicone oil lubricant in elastomeric closures by ICP-OES DO - 10.1039/c3ay40754c AU - dos Santos, Éder José AU - Herrmann, Amanda Beatriz AU - Sturgeon, Ralph Edward AU - Azevedo Silva, Jessee Severo AU - Curtius, Adilson José T2 - Analytical Methods SN - 1759-9660 VL - 5 IS - 16 SP - 4263 EP - 4267 KW - External calibration KW - Extraction mixtures KW - Extraction solvents KW - Flame atomic absorption spectrometry KW - Inductively coupled plasma-optical emission spectrometry KW - Methyl iso-butyl ketones KW - Relative standard deviations KW - Standard solutions KW - Atomic absorption spectrometry KW - Extraction KW - Inductively coupled plasma KW - Interference suppression KW - Ketones KW - Mixtures KW - Optical emission spectroscopy KW - Silicones AB - A rapid method for determination of silicone oil in elastomeric closures of injection syringes by inductively coupled plasma optical emission spectrometry (ICP-OES) is presented. The silicone oil was extracted from the intact closure using a mixture of methyl isobutyl ketone and 1-pentanol, no further sample treatment was necessary. Quantitation was based on response from Si(i) at 288.158 nm using external calibration with standard solutions of silicone oil dissolved in the same extraction mixture. A supplemental flow of oxygen was used to decrease background interference, providing a detection limit (3s, n = 10) of 0.05 mg of silicone per L. The LOQ (10s, n = 10) was 0.15 mg silicone per L, equivalent to 3.8 μg silicone/sample of elastomeric closure, based on 25 mL of extraction solvent per closure. The same samples were also analyzed by high-resolution flame atomic absorption spectrometry (HR-CS F-AAS), providing results similar to those obtained by ICP-OES. Spike recoveries of 97-104% demonstrated the accuracy of the methodology. Precision, expressed as the relative standard deviation, was 0.7-3.0% under conditions of repeatability and 0.7-3.3% for reproducibility. This simple procedure has been adopted by the Institute of Technology of Paraná-TECPAR (Curitiba, Brazil). © 2013 The Royal Society of Chemistry. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : fc65b23f-07d1-4834-a532-de1f169a504f ER - TY - JOUR TI - G2C2 - I. Homogeneous photometry for galactic globular clusters in SDSS passbands DO - 10.1093/mnras/stt2002 AU - Vanderbeke, J. AU - West, M.J. AU - De Propris, R. AU - Peng, E.W. AU - Blakeslee, J.P. AU - Jordán, A. AU - Côté, P. AU - Gregg, M. AU - Ferrarese, L. AU - Takamiya, M. AU - Baes, M. T2 - Monthly Notices of the Royal Astronomical Society SN - 0035-8711 VL - 437 IS - 2 SP - stt2002 SP - 1725 EP - 1733 AB - We present g′ and z′ aperture photometry for 96 Galactic globular clusters, making this the largest homogeneous catalogue of photometry for these objects in the Sloan Digital Sky Survey (SDSS) filter system. For a subset of 56 clusters, we also provide photometry in r′ and i′. We carry out comparisons with previous photometry as well as with the SDSS data set. The data will be useful for a series of applications in Galactic and extragalactic astrophysics. Future papers will analyse the colour-metallicity relation, colour-magnitude diagrams and structural parameters. The compilation of results based on this data set will be collected in the Galactic Globular Cluster Catalog (G2C2). © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e7f3791e-00a4-483a-afdb-5f771824d6ac ER - TY - JOUR TI - Assessment and characterization of volcanic ash threat to gas turbine engine performance DO - 10.1115/GT2013-94079 AU - Davison, C.R. AU - Rutke, T. T2 - Proceedings of the ASME Turbo Expo T3 - ASME Turbo Expo 2013: Turbine Technical Conference and Exposition, GT 2013, 3 June 2013 through 7 June 2013, San Antonio, Tx SN - 9780791855133 VL - 2 KW - Airborne particle KW - Aircraft encounters KW - Carbon deposites KW - Engine inspection KW - Operational issues KW - Plinian eruption KW - Turbine cooling systems KW - Volcanic ash clouds KW - Aircraft accidents KW - Aviation KW - Cooling systems KW - Deposits KW - Engines KW - Exhibitions KW - Gas turbines KW - Hazards KW - Nozzles KW - Thermoelectric equipment KW - Turbomachine blades KW - Volcanoes AB - Multiple volcanoes erupt yearly propelling volcanic ash into the atmosphere and creating an aviation hazard. The plinian eruption type is most likely to create a significant aviation hazard. Plinian eruptions can eject large quantities of fine ash up to an altitude of 50,000 m (164,000 feet). While large airborne particles rapidly fall, smaller particles at reduced concentrations drift for days to weeks as they gradually descend and deposit on the ground. Very small particles, less than 1μm, can remain aloft for years. An average of three aircraft encounters with volcanic ash was reported every year between 1973 and 2003. Of these, 8 resulted in some loss of engine power, including a complete shutdown of all four engines on a Boeing 747. However, no crashes have been attributed to volcanic ash. The major forms of engine damage caused by volcanic ash are: 1. Deposition of ash on turbine nozzles and blades due to glassification 2. Erosion of compressor and turbine blades 3. Carbon deposits on fuel nozzles The combination of these effects can push the engine to surge and flame out. If a flame out occurs, engine restart may be possible. Less serious engine damage can also occur. In most cases the major damage will require an engine overhaul long before the minor damage becomes an operational issue, but under some conditions no sign of volcanic ash is evident and the turbine cooling system blockage could go unnoticed until an engine inspection is performed. Several organizations provide aircrew procedures to respond to encounters with a volcanic ash cloud. If a volcanic ash encounter is suspected, then an engine inspection, including borescope, should be performed with particular attention given to the turbine cooling system. Copyright © 2013 by Her Majesty the Queen in Right of Canada. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a8875030-995a-428f-b059-d6f554ee38a2 ER - TY - JOUR TI - Physical-layer security with multiuser scheduling in cognitive radio networks DO - 10.1109/TCOMM.2013.111213.130235 AU - Zou, Y. AU - Wang, X. AU - Shen, W. T2 - IEEE Transactions on Communications SN - 0090-6778 VL - 61 IS - 12 SP - 6678044 SP - 5103 EP - 5113 KW - Achievable secrecy rates KW - Cognitive base stations KW - Cognitive radio network KW - Cognitive transmissions KW - Diversity order KW - Multiuser scheduling KW - Physical-layer securities KW - Quality of Service constraints KW - Cognitive radio KW - Electric circuit breakers KW - Probability KW - Quality of service KW - Radio systems KW - Rayleigh fading KW - Scheduling AB - In this paper, we consider a cognitive radio network that consists of one cognitive base station (CBS) and multiple cognitive users (CUs) in the presence of multiple eavesdroppers, where CUs transmit their data packets to CBS under a primary user's quality of service (QoS) constraint while the eavesdroppers attempt to intercept the cognitive transmissions from CUs to CBS. We investigate the physical-layer security against eavesdropping attacks in the cognitive radio network and propose the user scheduling scheme to achieve multiuser diversity for improving the security level of cognitive transmissions with a primary QoS constraint. Specifically, a cognitive user (CU) that satisfies the primary QoS requirement and maximizes the achievable secrecy rate of cognitive transmissions is scheduled to transmit its data packet. For the comparison purpose, we also examine the traditional multiuser scheduling and the artificial noise schemes. We analyze the achievable secrecy rate and intercept probability of the traditional and proposed multiuser scheduling schemes as well as the artificial noise scheme in Rayleigh fading environments. Numerical results show that given a primary QoS constraint, the proposed multiuser scheduling scheme generally outperforms the traditional multiuser scheduling and the artificial noise schemes in terms of the achievable secrecy rate and intercept probability. In addition, we derive the diversity order of the proposed multiuser scheduling scheme through an asymptotic intercept probability analysis and prove that the full diversity is obtained by using the proposed multiuser scheduling. © 2013 IEEE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 200126c6-855f-45ad-872c-2a1af72da037 ER - TY - JOUR TI - Carded recycled carbon fiber mats for the production of thermoset composites via infusion/compression molding DO - 10.4271/2013-01-2208 AU - Andjelic, S. AU - Roberge, J. AU - Legros, N. AU - Khoun, L. AU - Schougaard, S.B. T2 - SAE Technical Papers T3 - SAE 2013 AeroTech Congress and Exhibition, AEROTECH 2013, 24 September 2013 through 26 September 2013, Montreal, QC VL - 7 KW - Aircraft industries KW - Carbon fiber reinforced KW - Composite plates KW - Fiber volume fractions KW - Flexural testing KW - Pyrolysis process KW - Thermoset composites KW - Ultrasound treatments KW - Exhibitions KW - Fibers KW - Mechanical properties KW - Molding KW - Pyrolysis KW - Recycling KW - Scanning electron microscopy KW - Tensile testing KW - Textile industry KW - Thermosets KW - Carbon fibers AB - The use of carbon fiber reinforced thermoset composites has doubled in the last decade raising questions about the waste generated from manufacturing and at end-of-life, especially in the aircraft industry. In this study, 2.5 cm long carbon fibers were recovered from thermoset composite waste using a commercial scale pyrolysis process. Scanning electron microscopy, density measurements, single filament tensile testing as well as micro-droplet testing were performed to characterize the morphology, mechanical properties, and surface adhesion of the fibers. The recycled fibers appeared to be mostly undamaged and clean, exhibiting comparable mechanical properties to virgin carbon fibers. A carding process followed by an ultrasound treatment produced randomly aligned recycled fiber mats. These mats were used to fabricate composite plates, with fiber volume fractions up to 40 %, by infusion / compression molding. The mechanical properties of the plates were evaluated by tensile and flexural testing, and were found to be comparable to an equivalent containing virgin carbon fibers. Copyright © 2013 SAE International. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 71a49a82-1093-4487-90e3-51591385c610 ER - TY - JOUR TI - Carbon nanotube modified optical fiber surface plasmon resonance sensor DO - 10.1109/IPCon.2013.6656680 AU - Zhang, Yang AU - Jakubinek, Michael AU - Simard, Benoit AU - Albert, Jacques T2 - 2013 IEEE Photonics Conference, IPC 2013 T3 - 2013 26th IEEE Photonics Conference, IPC 2013, September 8-12, 2013, Bellevue, WA SN - 9781457715075 SP - 6656680 SP - 548 EP - 549 AB - Single-wall carbon nanotube deposition on gold-coated plasmonic optical fiber sensors has been proposed and demonstrated. The effects of carbon nanotubes on the polarization-dependent coupling of light from the fiber to the coating and on the resulting refractometric sensor properties are experimentally investigated. © 2013 IEEE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f7317eb6-1c1e-4898-b2c7-410d21f1e062 ER - TY - JOUR TI - Reduced-scale experimental research on fires in tunnels with natural ventilation DO - 10.1016/j.proeng.2013.08.142 AU - Yuan, Z. AU - Lei, B. AU - Kashef, A. T2 - Procedia Engineering T3 - 9th Asia-Oceania Symposium on Fire Science and Technology, AOSFST 2012, 17 October 2012 through 20 October 2012, Hefei SN - 1877-7058 VL - 62 SP - 907 EP - 915 AB - The 1/15 reduced-scale experiments were conducted using the Froude number conservation to investigate smoke diffusion characteristics in tunnel fires with natural ventilation. The effects of some factors such as: heat release rate, shaft distance, shaft size, train blockage and smoke curtain were studied. A porous bed propane burner, placed on the tunnel floor, was used to simulate the fire source. A series of K-type thermocouples were used to measure tunnel ceiling smoke temperatures. A hotwire anemometer was used to measure smoke volume rate and smoke temperature in the ventilation shaft. The experimental results indicated that all factors, except for the smoke curtain, have no major effect on the dimensionless ceiling temperatures in the fire section of the tunnel. Moreover, the fire size and train blockage do not have a significant effect on the dimensionless ceiling temperatures in the non-fire section of the tunnel. Nevertheless, the dimensionless ceiling temperatures in the non-fire section of the tunnel decreased with the decrease of the shaft distance and the increase of the shaft size. When the smoke curtain is used in the tunnel, the dimensionless ceiling temperatures in the fire channel are higher than in the case when the smoke curtain is not used. Moreover, there is no smoke in the evacuation channel. The fire size and train blockage do not have a considerable effect on the dimensionless temperatures and smoke volume rates in the shaft. Nonetheless, the dimensionless smoke temperatures in the shaft decrease with the increase in the shaft distance or the shaft size. Moreover, dimensionless smoke flow rates through the shaft increase with the decrease in the shaft distance or the increase in the shaft size. © 2013 International Association for Fire Safety Science. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 585d19cd-0603-4a89-a53f-4e6c40772966 ER - TY - JOUR TI - Neutron scattering investigation of the d-d excitations below the Mott gap of CoO DO - 10.1103/PhysRevB.88.205117 AU - Cowley, R.A. AU - Buyers, W.J.L. AU - Stock, C. AU - Yamani, Z. AU - Frost, C. AU - Taylor, J.W. AU - Prabhakaran, D. T2 - Physical Review B - Condensed Matter and Materials Physics SN - 1098-0121 VL - 88 IS - 20 SP - 205117 AB - Neutron scattering is used to investigate the single-ion spin and orbital excitations below the Mott-Hubbard gap in CoO. Three excitations are reported at 0.870±0.009 eV, 1.84±0.03, and 2.30±0.15 eV. These were parametrized within a weak crystal field scheme with an intraorbital exchange of J(dd)=1.3±0.2 eV and a crystal field splitting 10Dq=0.94±0.10 eV. A reduced spin-orbit coupling of λ=-0.016±0.003 eV is derived from dilute samples of Mg0.97Co0.03O, measured to remove effects due to spin exchange and structural distortion parameters which break the cubic phase degeneracy of the orbital excitations complicating the inelastic spectrum. The peak at 1.84 eV, while reported using resonant x-ray and optical techniques, was absent or weak for nonresonant x-ray experiments and overlaps with the expected position of a 4A2 level. This transition is absent in the dipolar approximation but expected to have a finite quadrupolar matrix element that can be observed with neutron scattering techniques at larger momentum transfers. Our results agree with a crystal field analysis (in terms of Racah parameters and Tanabe-Sugano diagrams) and with previous calculations performed using local-density band theory for Mott insulating transition metal oxides. The results also demonstrate the use of neutron scattering for measuring dipole forbidden transitions in transition metal oxide systems. © 2013 American Physical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : eb2271e9-c179-49e0-a41a-054d80c2d817 ER - TY - JOUR TI - Electrochemical performance of NaCo2O4 as electrode for supercapacitors DO - 10.1016/j.cclet.2013.11.051 AU - Tang, H.-W. AU - Gao, N. AU - Chang, Z.-R. AU - Li, B. AU - Yuan, X.-Z. AU - Wang, H.-J. T2 - Chinese Chemical Letters SN - 1001-8417 AB - Sub-micron-scaled sodium cobalt oxide (NaCo2O4) powders are prepared by a solid-state reaction method. Characterization using X-ray diffraction indicates that the synthesized NaCo2O4 has a hexagonal layered structure. The electrochemical performance of the NaCo2O4 electrodes is investigated using cyclic voltammetry and galvanostatic charge/discharge in NaOH solution. The results show that the specific capacitance of the NaCo2O4 electrode reaches 337 F/g over the potential range of 0.15-0.65 V at a mass normalized current of 50 mA/g. Moreover, NaCo2O4 exhibits very good stability and cycling performance as a supercapacitor material. © 2013 Zhao-Rong Chang. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2eb74432-cc6f-4ff5-9f1a-9cc88daecd84 ER - TY - JOUR TI - The road to medical vibrational spectroscopy – a history DO - 10.1039/c3an90035e AU - Mantsch, Henry H. T2 - The Analyst SN - 0003-2654 SN - 1364-5528 VL - 138 IS - 14 SP - 3863 EP - 3870 KW - animal KW - diagnostic imaging KW - editorial KW - equipment KW - history KW - human KW - infrared spectrophotometry KW - medicine KW - Raman spectrometry KW - vibration KW - Animals KW - Diagnostic Imaging KW - History, 20th Century KW - History, 21st Century KW - Humans KW - Medicine KW - Spectrophotometry, Infrared KW - Spectrum Analysis, Raman KW - Vibration AB - The present Editorial chronicles the journey from classical infrared and Raman spectroscopy to medical vibrational spectroscopy, as experienced by a contemporary witness of the times. During the second half of the last century vibrational biospectroscopy became a topic of increasing global interest and has spawned a number of international conferences of which the most recent, SPEC 2012 – Shedding New Light on Disease, constitutes the basis of the present themed issue. DA - 2013/05/08 PY - 2013 PB - Royal Society of Chemistry LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8a23305e-d91d-4a18-bfd6-ceb3c83553aa ER - TY - JOUR TI - Efficacy of genetically modified Bt toxins alone and in combinations against pink bollworm resistant to Cry1Ac and Cry2Ab DO - 10.1371/journal.pone.0080496 AU - Tabashnik, B.E. AU - Fabrick, J.A. AU - Unnithan, G.C. AU - Yelich, A.J. AU - Masson, L. AU - Zhang, J. AU - Bravo, A. AU - Soberón, M. T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 11 SP - e80496 AB - Evolution of resistance in pests threatens the long-term efficacy of insecticidal proteins from Bacillus thuringiensis (Bt) used in sprays and transgenic crops. Previous work showed that genetically modified Bt toxins Cry1AbMod and Cry1AcMod effectively countered resistance to native Bt toxins Cry1Ab and Cry1Ac in some pests, including pink bollworm ( Pectinophora gossypiella ). Here we report that Cry1AbMod and Cry1AcMod were also effective against a laboratory-selected strain of pink bollworm resistant to Cry2Ab as well as to Cry1Ab and Cry1Ac. Resistance ratios based on the concentration of toxin killing 50% of larvae for the resistant strain relative to a susceptible strain were 210 for Cry2Ab, 270 for Cry1Ab, and 310 for Cry1Ac, but only 1.6 for Cry1AbMod and 2.1 for Cry1AcMod. To evaluate the interactions among toxins, we tested combinations of Cry1AbMod, Cry1Ac, and Cry2Ab. For both the resistant and susceptible strains, the net results across all concentrations tested showed slight but significant synergism between Cry1AbMod and Cry2Ab, whereas the other combinations of toxins did not show consistent synergism or antagonism. The results suggest that the modified toxins might be useful for controlling populations of pink bollworm resistant to Cry1Ac, Cry2Ab, or both. © 2013 Tabashnik et al. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9c39b302-f639-49b1-b93a-e20fa73f2856 ER - TY - JOUR TI - Immediate impacts on particulate and gaseous emissions from a T56 turbo-prop engine using a biofuel blend DO - 10.4271/2013-01-2131 AU - Chan, T.W. AU - Pham, V. AU - Chalmers, J. AU - Davison, C. AU - Chishty, W. AU - Poitras, P. T2 - SAE Technical Papers T3 - SAE 2013 AeroTech Congress and Exhibition, AEROTECH 2013, 24 September 2013 through 26 September 2013, Montreal, QC VL - 7 KW - Aviation industry KW - Biofuel blends KW - Black carbon KW - Critical component KW - Engine durability KW - Mass emissions KW - Mass reduction KW - Particle numbers KW - Carbon dioxide KW - Durability KW - Engines KW - Exhibitions KW - Jet fuel KW - Reduction KW - Biofuels AB - Adoption of hydro-processed esters and fatty acid biojet fuels is a critical component for the sustainability of the aviation industry. Aviation biofuels reduce pollution and provide alternatives to conventional fossil fuels. A study of the impacts of biofuels on emissions from a T56 turbo-prop engine was undertaken as a joint effort among several departments of the Government of Canada. In this study, particulate (including particle number and black carbon (BC) mass) and regulated gaseous emissions (CO2, CO, NO, NO 2, THC) were characterized with the engine operating on conventional F-34 jet fuel and jet fuel blended with camelina-based hydro-processed biojet fuel (C-HEFA) by 50% in volume. Emissions characterization, conducted after 20-hour ground engine durability tests, showed immediate significant reductions in particle number and BC mass when the engine was operated on the C-HEFA blend. Operating at high speed ground idle (HSGI) using the C-HEFA blend reduced particle number and BC mass emissions by 31% and 50%, respectively. At Take-off engine mode, particle number and BC mass reductions were 22% and 32%, respectively. In addition, particles generated from the C-HEFA blend were also observed to be slightly smaller than those generated from the conventional jet fuel by 2-4 nanometer (nm). CO emissions from the C-HEFA blend were lower by 4-6%. CO2 emissions from the C-HEFA blend were lower by approximately 1%, consistent with the difference in hydrocarbon ratios in the C-HEFA blend. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c3c7382a-3bf5-4bd7-90f4-b4aeb7c57783 ER - TY - JOUR TI - Quantum confinement in Si and Ge nanostructures: Effect of crystallinity DO - 10.1117/12.2036323 AU - Barbagiovanni, Eric G. AU - Lockwood, David J. AU - Costa Filho, Raimundo N. AU - Goncharova, Lyudmila V. AU - Simpson, Peter J. T2 - SPIE - International Society for Optical Engineering. Proceedings T3 - Photonics North 2013 Conference, 3 June 2013 through 5 June 2013, Ottawa, ON SN - 0277-786X SN - 9780819497918 VL - 8915 SP - 891515 KW - Confinement effects KW - Confinement potential KW - Crystallinities KW - Effective mass KW - Effective-mass theory KW - Experimental parameters KW - Oscillator strengths KW - Position-dependent effective mass KW - Amorphous materials KW - Germanium KW - Interface states KW - Nanostructures KW - Photonics KW - Quantum confinement KW - Semiconducting germanium KW - Silicon AB - We look at the relationship between the preparation method of Si and Ge nanostructures (NSs) and the structural, electronic, and optical properties in terms of quantum confinement (QC). QC in NSs causes a blue shift of the gap energy with decreasing NS dimension. Directly measuring the effect of QC is complicated by additional parameters, such as stress, interface and defect states. In addition, differences in NS preparation lead to differences in the relevant parameter set. A relatively simple model of QC, using a 'particle-in-a-box'-type perturbation to the effective mass theory, was applied to Si and Ge quantum wells, wires and dots across a variety of preparation methods. The choice of the model was made in order to distinguish contributions that are solely due to the effects of QC, where the only varied experimental parameter was the crystallinity. It was found that the hole becomes de-localized in the case of amorphous materials, which leads to stronger confinement effects. The origin of this result was partly attributed to differences in the effective mass between the amorphous and crystalline NS as well as between the electron and hole. Corrections to our QC model take into account a position dependent effective mass. This term includes an inverse length scale dependent on the displacement from the origin. Thus, when the deBroglie wavelength or the Bohr radius of the carriers is on the order of the dimension of the NS the carriers 'feel' the confinement potential altering their effective mass. Furthermore, it was found that certain interface states (Si-O-Si) act to pin the hole state, thus reducing the oscillator strength. © 2013 SPIE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 71f2cb9a-8f25-4916-9023-8ee2a9d0c077 ER - TY - JOUR TI - Microindentation creep of monophasic calcium-silicate-hydrates DO - 10.1016/j.cemconcomp.2013.11.011 AU - Nguyen, D.-T. AU - Alizadeh, R. AU - Beaudoin, J.J. AU - Pourbeik, P. AU - Raki, L. T2 - Cement and Concrete Composites SN - 0958-9465 AB - Microindentation creep results for monophasic synthetic C-S-H (C/S = 0.6-1.5), 1.4 nm tobermorite, jennite and calcium hydroxide at 11%RH are reported. Creep results for well hydrated cement paste and C3S 'composite' systems are also described. The significance of the co-linear behavior of creep modulus functions of indentation modulus and indentation hardness for C-S-H obtained by microindentation and nanoindentation methods is discussed. The porosity dependence of creep modulus and the general equivalence of density values determined by helium pycnometry and by calculations employing unit cell dimensions (obtained using X-ray crystallography techniques) are also discussed in terms of postulates for the existence of two types of C-S-H. Comment on the compatibility of the creep modulus data for 1.4 nm tobermorite and jennite with models of C-S-H present in cement paste is provided. © 2013 Elsevier Ltd. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8553f660-11ce-4f41-b9aa-1a4b739eb571 ER - TY - JOUR TI - Review of the punching shear behavior of concrete flat slabs in ambient and elevated temperature DO - 10.1260/2040-2317.4.4.259 AU - Ghoreishi, Mehrafarid AU - Bagchi, Ashutosh AU - Sultan, Mohamed A. T2 - Journal of Structural Fire Engineering SN - 2040-2317 VL - 4 IS - 4 SP - 259 EP - 279 KW - Elevated temperature KW - Fire safety KW - Flat slabs KW - Punching shear KW - Punching shear capacity KW - Punching shear strength KW - Slab-column connection KW - State-of-the art reviews KW - Columns (structural) KW - Fires KW - Office buildings KW - Reinforced concrete KW - Concretes AB - There are a number of benefits associated with two-way concrete flat slab construction for office buildings, parking garages and apartments - for example, reduced formwork, prompt erection, flexibility of partitions, and minimal increase in story heights. However, concrete flat slabs could be quite vulnerable to punching shear failure in the event of a fire. The objective of the present article is to provide a state of the art review of the existing research and the issues associated with concrete flat slabs in fire and elevated temperature. There are a number of experimental and analytical studies on the punching shear behavior of concrete flat slabs in ambient conditions, available in the literature. Based on these studies, it is found that punching shear capacity in ambient condition is affected by many factors, which may not remain constant during a fire exposure. Only a limited number of studies on concrete flat slabs for punching shear failure in fire are available. This paper reviews the available experimental and analytical studies, standards and codes to address the research gap in estimating of punching shear strength of concrete flat slab-column connections without shear reinforcement. DA - 2013/12/10 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2b7ae628-fae7-41a3-b3e4-07fed9e87aac ER - TY - JOUR TI - Experimental and theoretical study for tunnel fires with natural ventilation DO - 10.1007/s10694-013-0378-x AU - Yuan, Zhongyuan AU - Lei, Bo AU - Kashef, Ahmed T2 - Fire Technology SN - 0015-2684 SP - 1 EP - 16 KW - reduced-scaled experiment; natural ventilation; smoke temperature; smoke exhaust AB - Natural ventilation mode is a ventilation strategy to control fire-induced hot smoke and provide safe and secure egress routes in subway tunnels. The study was carried out in a 1/15 reduced-scale tunnel using Froude modeling technique to investigate the fire-induced smoke temperature distribution and smoke exhaust through vertical shafts located at the ceiling of the scaled tunnel. A porous bed burner placed on the tunnel floor was used to simulate the fire source and propane was used as the fuel. The temperature distributions under the tunnel ceiling were measured using a series of K-type thermocouples to analyze smoke temperature distribution characteristics. The smoke temperature and velocity in the ventilation shafts were also monitored using hot wire anemometers. The effect of fire size, shaft distance, shaft geometry, train blockage on ceiling temperature distributions and smoke exhaust from shafts were studied. Based on the one-dimensional theory, the ceiling temperature decay characteristics were studied. Finally, empirical equations for predicting ceiling temperature distributions and smoke exhaust in tunnel fires with a natural ventilation mode were derived. DA - 2013/12/18 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 00d7dffb-2898-414e-909b-63ba55099c14 ER - TY - JOUR TI - Microindentation creep of 45 year old hydrated Portland cement paste DO - 10.1680/adcr.12.00058 AU - Pourbeik, P. AU - Alizadeh, R. AU - Beaudoin, J.J. AU - Nguyen, D.-T. AU - Raki, L. T2 - Advances in Cement Research SN - 0951-7197 VL - 25 IS - 5 SP - 301 EP - 306 AB - Microindentation methods were used to study the creep behaviour of cement paste hydrated for 45 years. These old pastes were prepared having a wide range of water/cement ratios varying from 0.5 to 1.0. The porosity dependence of the indentation parameters (creep modulus, indentation modulus and indentation hardness) was determined and is discussed in the context of possible creep mechanisms. Microindentation creep was also determined for 3 year old cement paste and young paste hydrated for 3 and 7 days. Variation in creep behaviour of the cement pastes for the three age groups is discussed in terms of nanostructural differences. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 7e0dc1f9-9838-4ad3-97e5-586795ccf764 ER - TY - JOUR TI - Analysis of localized surface plasmon resonance in glass-supported gold nanoparticles with a hexagonal pattern DO - 10.1117/12.2042346 AU - Hajebifard, A. AU - Yuan, J. AU - Zou, S. AU - Berini, P. T2 - SPIE - International Society for Optical Engineering. Proceedings T3 - Photonics North 2013 Conference, 3 June 2013 through 5 June 2013, Ottawa, ON SN - 0277-786X SN - 9780819497918 VL - 8915 SP - 89151M KW - Absorbance spectrum KW - COMSOL KW - Embedding ratios KW - Gold nanoparticle KW - Localized surface plasmon resonance KW - Seeding growth KW - Block copolymers KW - Glass KW - Gold KW - Metal nanoparticles KW - Photonics KW - Plasmons KW - Refractive index KW - Self assembly KW - Surface plasmon resonance AB - An approach has been devised to create a hexagonal pattern of glass-supported gold nanoparticles (AuNPs) with controllable particle size and inter-particle spacing, by combining the self-assembly of block copolymer micelle-loaded metal precursors with a seeding growth method. Absorbance spectra as an optical response of the AuNP arrays were measured to obtain their LSPR peak position (λLSPR). There was a red shift in λLSPR with increasing cover medium refractive index for all fabricated and simulated arrays. A comparison between computed and measured λLSPR for a 33 nm AuNP array suggests that large nanoparticles produced by this fabrication method have ellipsoidal shapes rather than spherical ones, as in the case of small AuNP arrays. © 2013 SPIE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2704eff0-d925-4524-8b81-14bc434f1ee4 ER - TY - JOUR TI - Ultrafast relaxation dynamics of uracil probed via strong field dissociative ionization DO - 10.1021/jp408073d AU - Matsika, S. AU - Spanner, M. AU - Kotur, M. AU - Weinacht, T.C. T2 - The Journal of Physical Chemistry A SN - 1089-5639 VL - 117 IS - 48 SP - 12796 EP - 12801 KW - Central wavelength KW - Deep ultraviolet KW - Dissociative ionization KW - High-level ab initio calculations KW - Relaxation dynamics KW - State of the art KW - Strong field ionization KW - Ultrafast relaxation dynamics KW - Aromatic compounds KW - Dissociation KW - Ionization AB - We study the ultrafast relaxation dynamics of uracil excited to the first bright ππ* state (S2) by an ultrafast laser pulse in the deep ultraviolet (central wavelength λ0 = 260 nm). With a unique combination of strong field dissociative ionization measurements, state of the art strong field ionization calculations, and high level ab initio calculations of excited neutral and ionic states at critical points along the neutral potentials, we are able to gain a detailed picture of the relaxation dynamics of the molecule, which resolves earlier disagreements regarding measurements and calculations of the relaxation. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4bdc4221-5e86-4408-b1b9-b7b497212163 ER - TY - JOUR TI - Fundamental and torsional combination bands of two isomers of the OCS-CO2 complex in the CO2 ν3 region DO - 10.1021/jp312339w AU - Norooz Oliaee, J. AU - Dehghany, M. AU - Moazzen-Ahmadi, N. AU - McKellar, A.R.W. T2 - The Journal of Physical Chemistry A SN - 1089-5639 VL - 117 IS - 39 SP - 9605 EP - 9611 KW - Combination bands KW - Fundamental vibrations KW - Out-of-plane KW - Stretching region KW - Torsional frequency KW - Torsional modes KW - Tunable diode lasers KW - Weakly bound complexes KW - Freons KW - Isomers KW - Supersonic aerodynamics KW - Carbon dioxide AB - Spectra of two isomers of the weakly bound complex OCS-CO2 are observed in the region of the CO2 ν3 fundamental vibration (∼2349 cm-1), using an infrared tunable diode laser to probe a pulsed supersonic slit-jet expansion. Two bands are measured and analyzed for each isomer, the fundamental asymmetric stretch of the CO 2 component and a combination band involving this fundamental plus the intermolecular out-of-plane torsional mode. For one isomer, the corresponding torsional combination band is also detected in the OCS ν1 stretching region (∼2060 cm-1). The resulting torsional frequencies are found to be 18.8 and 15.9 cm-1 for isomers a and b of OCS-CO2, respectively. This may be the first time that such a combination band is observed for a higher-energy isomer of a weakly bound complex. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : feadff58-d60f-4490-9630-b6f8c9be75b3 ER - TY - JOUR TI - Stark effect in the benzene dimer DO - 10.1021/jp408076q AU - Schnell, M. AU - Bunker, P.R. AU - Von Helden, G. AU - Grabow, J.-U. AU - Meijer, G. AU - Van Der Avoird, A. T2 - The Journal of Physical Chemistry A SN - 1089-5639 VL - 117 IS - 50 SP - 13775 EP - 13778 KW - Ab initio calculations KW - Asymmetric top KW - Dynamics calculations KW - Equilibrium structures KW - Fourier transform microwave spectroscopy KW - Intermolecular potentials KW - Internal rotations KW - Torsional motion KW - Benzene KW - Dimers KW - Microwave spectroscopy KW - Molecules KW - Stark effect AB - Ab initio calculations of the six-dimensional intermolecular potential have shown the benzene dimer to be an asymmetric top molecule at equilibrium with one benzene moiety forming the "stem" and the other a "tilted cap" in a T-shaped structure. Internal rotation of the cap about its C 6 axis is essentially free; the barriers for cap tilting and for internal rotation of the stem about its C6 axis are hindered by successively higher barriers. In previous work we have validated these theoretical results using Fourier transform microwave spectroscopy in conjunction with dynamics calculations. We have also measured the Stark effect, and despite the fact that the equilibrium structure is that of an asymmetric top, the assigned transitions involving K = 0 exhibit a second-order Stark effect whereas those involving K = 1 exhibit a first-order Stark effect. This is typical for a symmetric-top molecule, but anomalous for an asymmetric-top molecule. We use symmetry arguments to explain how this asymmetric-top molecule can have a first-order Stark effect in certain states that have excitation of cap internal rotation. Cap internal rotation is essentially the twisting of the monomers relative to each other about the intermolecular axis, and such torsional motion occurs in other asymmetric top dimers such as benzene-CO and benzene-H2O. These latter dimers will also have levels that exhibit a first-order Stark effect, which we can explain using our symmetry arguments. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e08fc927-7701-49f4-afc8-aa42bf27d28a ER - TY - JOUR TI - A new look at the infrared spectrum of the weakly bound CO-N2 complex DO - 10.1021/jp407896d AU - Rezaei, M. AU - Michaelian, K.H. AU - Moazzen-Ahmadi, N. AU - McKellar, A.R.W. T2 - The Journal of Physical Chemistry A SN - 1089-5639 VL - 117 IS - 50 SP - 13752 EP - 13758 KW - Broad bands KW - Infrared spectrum KW - Inter-molecular forces KW - Nitrogen molecule KW - Pulsed supersonic expansions KW - Rotational levels KW - Van der Waals complex KW - Weakly bound complexes KW - Carbon monoxide KW - Chemical bonds KW - Molecules KW - Quantum cascade lasers KW - Supersonic aerodynamics KW - Van der Waals forces KW - Spectroscopy AB - A broad-band (2135-2165 cm-1) infrared spectrum of the CO-N 2 van der Waals complex is obtained, using a tunable quantum cascade laser to probe a pulsed supersonic expansion from a slit jet source. Analysis of the spectrum results in the characterization of four new 'stacks' of rotational levels for CO-orthoN2 (all in the vCO = 1 upper state) and five new stacks for CO-paraN2 (three in the upper state and two in the vCO = 0 lower state). This considerably expands our knowledge of a rather fundamental weakly bound complex and should lead to improved determinations of the intermolecular forces governing interactions between the carbon monoxide and nitrogen molecules. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 7aebe019-5a04-4143-871e-7c83d8adc263 ER - TY - JOUR TI - Efficient basis sets for non-covalent interactions in XDM-corrected density-functional theory DO - 10.1063/1.4832325 AU - Johnson, E.R. AU - Otero-De-La-Roza, A. AU - Dale, S.G. AU - Dilabio, G.A. T2 - Journal of Chemical Physics SN - 0021-9606 VL - 139 IS - 21 SP - 214109 KW - Basis sets KW - Density change KW - Development and applications KW - Diffuse functions KW - Dispersion modeling KW - Large system KW - Non-covalent interaction KW - Density functional theory KW - Dispersions KW - Polarization KW - Benchmarking AB - In the development and application of dispersion-corrected density-functional theory, the effects of basis set incompleteness have been largely mitigated through the use of very large, nearly-complete basis sets. However, the use of such large basis sets makes application of these methods inefficient for large systems. In this work, we examine a series of basis sets, including Pople-style, correlation-consistent, and polarization-consistent bases, for their ability to efficiently and accurately predict non-covalent interactions when used in conjunction with the exchange-hole dipole moment (XDM) dispersion model. We find that the polarization-consistent 2 (pc-2) basis sets, and two modifications thereof with some diffuse functions removed, give performance of comparable quality to that obtained with aug-cc-pVTZ basis sets, while being roughly 12 to 23 times faster computationally. The behavior is explained, in part, by the role of diffuse functions in recovering small density changes in the intermolecular region. The general performance of the modified basis sets is tested by application of XDM to standard intermolecular benchmark sets at, and away from, equilibrium. © 2013 AIP Publishing LLC. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 95814015-c066-48be-96a5-84bbb6b95803 ER - TY - JOUR TI - Diabetes-associated periodontitis molecular features in infrared spectra of gingival crevicular fluid DO - 10.1902/jop.2013.120665 AU - Xiang, X. AU - Duarte, P.M. AU - Lima, J.A. AU - Santos, V.R. AU - Goncxalves, T.D. AU - Miranda, T.S. AU - Liu, K.-Z. T2 - Journal of Periodontology SN - 0022-3492 VL - 84 IS - 12 SP - 1792 EP - 1800 AB - Background: It has been established previously that infrared spectroscopy (IRS) can be used to identify periodontitis-specific molecular signatures in gingival crevicular fluid (GCF) and to confirm clinical diagnoses. This follow-up study is designed to assess whether this novel technique is also able to differentiate diseased from healthy sites in patients with diabetes mellitus (DM) by analyzing the molecular fingerprints embedded in the GCF. Methods: A total of 65 patients with DM with moderate-to-severe chronic periodontitis (CP) was recruited, and 15 individuals without DM (65 sites) without periodontal diseases were used as control. Clinical examination and GCF samples were taken from a total of 351 sites, including periodontitis (109), gingivitis (115), and healthy (127) sites. Corresponding absorption spectra of GCF samples were acquired and processed, and the relative contributions of key functional groups in the infrared spectra were identified and analyzed. The qualitative assessment of clinical relevance of these GCF spectra was interpreted with multivariate statistical analysis: linear discriminant analysis (LDA). Results: Spectral analysis revealed several molecular signatures representing vibrations in protein (amide I and II), lipid ester, and sugar moieties in the GCF of patients with DM with CP and non-DM controls. The diagnostic accuracy for distinction between healthy and CP sites in patients with DM determined by LDA of GCF spectra was 95.3% for the training set of samples and 87.5% for the validation set. Additional LDA of GCF spectra from healthy sites of non-DM controls and patients with DM revealed 100% diagnostic accuracy for the training set and 86.7% for the validation set. The regions robotically selected by LDA for the two analyses were slightly different in that first LDA identified major regions clustered with the side chain vibrations originating from protein and DNA contents, whereas the second was predominantly the glycation and protein components. Conclusion: IRS is a feasible method to differentiate disease-specific molecular signatures in GCF in the presence of DM and to generate a complex biochemical profile of GCF to identify DM-specific spectral features. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c66896a8-a247-4839-92ed-ecb58db26609 ER - TY - JOUR TI - Quantum random bit generation using energy fluctuations in stimulated Raman scattering DO - 10.1364/OE.21.029350 AU - Bustard, P.J. AU - England, D.G. AU - Nunn, J. AU - Moffatt, D. AU - Spanner, M. AU - Lausten, R. AU - Sussman, B.J. T2 - Optics Express SN - 1094-4087 VL - 21 IS - 24 SP - 29350 EP - 29357 KW - Continuous variables KW - Critical resources KW - Information processing systems KW - Quantum fluctuation KW - Quantum random number generators KW - Raman-active materials KW - Random bit generations KW - Stokes pulse energy fluctuations KW - Data processing KW - Quantum electronics KW - Random number generation KW - Stimulated Raman scattering AB - Random number sequences are a critical resource in modern information processing systems, with applications in cryptography, numerical simulation, and data sampling. We introduce a quantum random number generator based on the measurement of pulse energy quantum fluctuations in Stokes light generated by spontaneously-initiated stimulated Raman scattering. Bright Stokes pulse energy fluctuations up to five times the mean energy are measured with fast photodiodes and converted to unbiased random binary strings. Since the pulse energy is a continuous variable, multiple bits can be extracted from a single measurement. Our approach can be generalized to a wide range of Raman active materials; here we demonstrate a prototype using the optical phonon line in bulk diamond. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5569fded-9af7-4fea-803e-a20eccccd4c8 ER - TY - JOUR TI - A simplified model for thermal-wave cavity self-consistent measurement of thermal diffusivity DO - 10.1063/1.4846255 AU - Shen, J. AU - Zhou, J. AU - Gu, C. AU - Neill, S. AU - Michaelian, K.H. AU - Fairbridge, C. AU - Astrath, N.G.C. AU - Baesso, M.L. T2 - Review of Scientific Instruments SN - 0034-6748 VL - 84 IS - 12 SP - 124902 KW - Absolute measurements KW - Distilled water KW - Liquid sample KW - Theoretical modeling KW - Thermal parameters KW - Thermal-wave cavity KW - Equipment KW - Instruments KW - Thermal diffusivity AB - A simplified theoretical model was developed for the thermal-wave cavity (TWC) technique in this study. This model takes thermal radiation into account and can be employed for absolute measurements of the thermal diffusivity of gas and liquid samples without any knowledge of geometrical and thermal parameters of the components of the TWC. Using this model and cavity-length scans, thermal diffusivities of air and distilled water were accurately and precisely measured as (2.191 ± 0.004) × 10-5 and (1.427 ± 0.009) × 10-7 m2 s-1, respectively, in very good agreement with accepted literature values. © 2013 Crown. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8cb6a9b9-2212-411b-bb5c-a2ac6c8a6667 ER - TY - JOUR TI - Reply DO - 10.1111/echo.12152-2 AU - Kumar, K. AU - Jassal, D.S. T2 - Echocardiography SN - 0742-2822 VL - 30 IS - 3 SP - 365 KW - anesthetic agent KW - hypertensive agent KW - inotropic agent KW - cardiopulmonary bypass KW - heart left ventricle filling pressure KW - heart muscle revascularization KW - heart surgery KW - human KW - letter KW - lung capillary pressure KW - morbidity KW - off pump surgery KW - perioperative period KW - postoperative period KW - priority journal KW - prognosis KW - pulmonary artery catheter KW - tissue Doppler imaging KW - transthoracic echocardiography KW - Blood Pressure Determination KW - Cardiac Surgical Procedures KW - Elasticity Imaging Techniques KW - Female KW - Humans KW - Male KW - Monitoring, Intraoperative KW - Stroke Volume KW - Ventricular Dysfunction, Left DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2e3dd61d-b0d8-4276-b584-cfc45adcbd89 ER - TY - JOUR TI - A novel dominant glossy mutation causes suppression of wax biosynthesis pathway and deficiency of cuticular wax in Brassica napus DO - 10.1186/1471-2229-13-215 AU - Pu, Y. AU - Gao, J. AU - Guo, Y. AU - Liu, T. AU - Zhu, L. AU - Xu, P. AU - Yi, B. AU - Wen, J. AU - Tu, J. AU - Ma, C. AU - Fu, T. AU - Zou, J. AU - Shen, J. T2 - BMC Plant Biology SN - 1471-2229 VL - 13 IS - 1 SP - 215 KW - Brassica KW - Brassica napus KW - Embryophyta AB - Background: The aerial parts of land plants are covered with cuticular waxes that limit non-stomatal water loss and gaseous exchange, and protect plants from ultraviolet radiation and pathogen attack. This is the first report on the characterization and genetic mapping of a novel dominant glossy mutant (BnaA.GL) in Brassica napus.Results: Transmission electron microscopy revealed that the cuticle ultrastructure of GL mutant leaf and stem were altered dramatically compared with that of wide type (WT). Scanning electron microscopy corroborated the reduction of wax on the leaf and stem surface. A cuticular wax analysis of the GL mutant leaves further confirmed the drastic decrease in the total wax content, and a wax compositional analysis revealed an increase in aldehydes but a severe decrease in alkanes, ketones and secondary alcohols. These results suggested a likely blockage of the decarbonylation step in the wax biosynthesis pathway. Genetic mapping narrowed the location of the BnaA.GL gene to the end of A9 chromosome. A single-nucleotide polymorphism (SNP) chip assay in combination with bulk segregant analysis (BSA) also located SNPs in the same region. Two SNPs, two single sequence repeat (SSR) markers and one IP marker were located on the flanking region of the BnaA.GL gene at a distance of 0.6 cM. A gene homologous to ECERIFERUM1 (CER1) was located in the mapped region. A cDNA microarray chip assay revealed coordinated down regulation of genes encoding enzymes of the cuticular wax biosynthetic pathway in the glossy mutant, with BnCER1 being one of the most severely suppressed genes.Conclusions: Our results indicated that surface wax biosynthesis is broadly affected in the glossy mutant due to the suppression of the BnCER1 and other wax-related genes. These findings offer novel clues for elucidating the molecular basis of the glossy phenotype. © 2013 Pu et al.; licensee BioMed Central Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c7d0e437-b572-43e2-ad3e-95ced38e8bce ER - TY - JOUR TI - Identifying purpose behind electoral tweets DO - 10.1145/2502069.2502070 AU - Mohammad, S.M. AU - Kiritchenko, S. AU - Martin, J. T2 - Proceedings of the 2nd International Workshop on Issues of Sentiment Discovery and Opinion Mining, WISDOM 2013 - Held in Conjunction with SIGKDD 2013 T3 - 2nd International Workshop on Issues of Sentiment Discovery and Opinion Mining, WISDOM 2013 - Held in Conjunction with SIGKDD 2013, 11 August 2013 through 11 August 2013, Chicago, IL SN - 9781450323321 SP - 1 KW - Emotion detection KW - Key Issues KW - Large dataset KW - National elections KW - Natural language applications KW - Question Answering KW - Single event KW - Data mining KW - Natural language processing systems AB - Tweets pertaining to a single event, such as a national election, can number in the hundreds of millions. Automatically analyzing them is beneficial in many downstream natural language applications such as question answering and summarization. In this paper, we propose a new task: identifying purpose behind electoral tweets|why do people post election-oriented tweets? We show that identifying purpose is related to sentiment and emotion detection, but yet significantly different. Detecting purpose has a number of applications including detecting the mood of the electorate, estimating the popularity of policies, identifying key issues of contention, and predicting the course of events. We create a large dataset of electoral tweets and annotate a few thousand tweets for purpose. We develop a system that automatically classifies electoral tweets as per their purpose, obtaining an accuracy of 44.58% on an 11-class task and an accuracy of 73.91% on a 3-class task (both accuracies well above the most-frequent-class baseline). We also show that resources developed for emotion detection are helpful for detecting purpose. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 34fa28d6-df63-4377-abcd-fb224ccefc0f ER - TY - JOUR TI - Genomic DNA enrichment using sequence capture microarrays: a novel approach to discover sequence nucleotide polymorphisms (SNP) in Brassica napus L DO - 10.1371/journal.pone.0081992 AU - Clarke, W.E. AU - Parkin, I.A. AU - Gajardo, H.A. AU - Gerhardt, D.J. AU - Higgins, E. AU - Sidebottom, C. AU - Sharpe, A.G. AU - Snowdon, R.J. AU - Federico, M.L. AU - Iniguez-Luy, F.L. T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 12 SP - e81992 AB - Targeted genomic selection methodologies, or sequence capture, allow for DNA enrichment and large-scale resequencing and characterization of natural genetic variation in species with complex genomes, such as rapeseed canola ( Brassica napus L., AACC, 2n=38). The main goal of this project was to combine sequence capture with next generation sequencing (NGS) to discover single nucleotide polymorphisms (SNPs) in specific areas of the B. napus genome historically associated (via quantitative trait loci -QTL- analysis) to traits of agronomical and nutritional importance. A 2.1 million feature sequence capture platform was designed to interrogate DNA sequence variation across 47 specific genomic regions, representing 51.2 Mb of the Brassica A and C genomes, in ten diverse rapeseed genotypes. All ten genotypes were sequenced using the 454 Life Sciences chemistry and to assess the effect of increased sequence depth, two genotypes were also sequenced using Illumina HiSeq chemistry. As a result, 589,367 potentially useful SNPs were identified. Analysis of sequence coverage indicated a four-fold increased representation of target regions, with 57% of the filtered SNPs falling within these regions. Sixty percent of discovered SNPs corresponded to transitions while 40% were transversions. Interestingly, fifty eight percent of the SNPs were found in genic regions while 42% were found in intergenic regions. Further, a high percentage of genic SNPs was found in exons (65% and 64% for the A and C genomes, respectively). Two different genotyping assays were used to validate the discovered SNPs. Validation rates ranged from 61.5% to 84% of tested SNPs, underpinning the effectiveness of this SNP discovery approach. Most importantly, the discovered SNPs were associated with agronomically important regions of the B. napus genome generating a novel data resource for research and breeding this crop species. © 2013 Clarke et al. DA - 2013 PY - 2013 LA - eng N1 - The authors affiliated with NRC were with the NRC Institute for Plant Biotechnology prior to April 1, 2012. C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8ac19dda-471a-42ee-b5bf-305d4a1c96c1 ER - TY - JOUR TI - Wide-field UV imaging: Current capabilities and performance requirements for future missions DO - 10.1016/j.asr.2013.11.033 AU - Côté, P. T2 - Advances in Space Research SN - 0273-1177 AB - I give a brief history of UV space telescopes, paying particularly attention to imaging facilities that operate at UV wavelengths. I examine a number of science drivers for space imaging at UV and blue-optical wavelengths (≲ 0.5 μm) for the coming decade, and discuss some possible synergies with future optical-IR imaging facilities, such as LSST and Euclid. While the present "Golden Age" of UV astronomy may be drawing to a close, an important new imaging facility - the Ultraviolet Imaging Telescope (UVIT) onboard Astrosat - should begin operations in 2014. This instrument will provide astronomers with a wide-field (Ω ∼ 0.2 deg2) UV imaging capability at an angular resolution (FWHM ∼1.5″-1.8″) that approaches those of ground-based optical telescopes. I also describe a proposed wide-field UV/blue-optical imaging telescope (CASTOR) that would provide HST-quality images over a ∼0.7 deg2 field in three broad filters covering the range 150-550 nm. Crown Copyright © 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 29a57ce3-efb1-4417-9459-a528626ade48 ER - TY - JOUR TI - Magnon breakdown in a two dimensional triangular lattice heisenberg antiferromagnet of multiferroic LuMnO3 DO - 10.1103/PhysRevLett.111.257202 AU - Oh, J. AU - Le, M.D. AU - Jeong, J. AU - Lee, J.-H. AU - Woo, H. AU - Song, W.-Y. AU - Perring, T.G. AU - Buyers, W.J.L. AU - Cheong, S.-W. AU - Park, J.-G. T2 - Physical Review Letters SN - 0031-9007 VL - 111 IS - 25 SP - 257202 KW - Heisenberg antiferromagnets KW - Inelastic neutrons KW - Linewidth broadening KW - Magnetic system KW - Nonlinear effect KW - Spin hamiltonian KW - Triangular lattice KW - Triangular lattice antiferromagnet KW - Inelastic neutron scattering KW - Two dimensional AB - The breakdown of magnons, the quasiparticles of magnetic systems, has rarely been seen. By using an inelastic neutron scattering technique, we report the observation of spontaneous magnon decay in multiferroic LuMnO3, a simple two dimensional Heisenberg triangular lattice antiferromagnet, with large spin S=2. The origin of this rare phenomenon lies in the nonvanishing cubic interaction between magnons in the spin Hamiltonian arising from the noncollinear 120 spin structure. We observed all three key features of the nonlinear effects as theoretically predicted: a rotonlike minimum, a flat mode, and a linewidth broadening, in our inelastic neutron scattering measurements of single crystal LuMnO3. Our results show that quasiparticles in a system hitherto thought of as "classical" can indeed break down. © 2013 American Physical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4e5473db-caf6-4979-a65a-275217819c73 ER - TY - JOUR TI - The large-scale structure of the halo of the Andromeda galaxy. I. Global stellar density, morphology and metallicity properties DO - 10.1088/0004-637X/780/2/128 AU - Ibata, Rodrigo A. AU - Lewis, Geraint F. AU - McConnachie, Alan W. AU - Martin, Nicolas F. AU - Irwin, Michael J. AU - Ferguson, Annette M. N. AU - Babul, Arif AU - Bernard, Edouard J. AU - Chapman, Scott C. AU - Collins, Michelle AU - Fardal, Mark AU - MacKey, A. D. AU - Navarro, Julio AU - Peñarrubia, Jorge AU - Rich, R. Michael AU - Tanvir, Nial AU - Widrow, Lawrence T2 - The Astrophysical Journal SN - 0004-637X VL - 780 IS - 2 SP - 128 AB - We present an analysis of the large-scale structure of the halo of the Andromeda galaxy, based on the Pan-Andromeda Archeological Survey (PAndAS), currently the most complete map of resolved stellar populations in any galactic halo. Despite the presence of copious substructures, the global halo populations follow closely power-law profiles that become steeper with increasing metallicity. We divide the sample into stream-like populations and a smooth halo component (defined as the population that cannot be resolved into spatially distinct substructures with PAndAS). Fitting a three-dimensional halo model reveals that the most metal-poor populations () are distributed approximately spherically (slightly prolate with ellipticity c/a = 1.09 ± 0.03), with only a relatively small fraction residing in discernible stream-like structures (f stream = 42%). The sphericity of the ancient smooth component strongly hints that the dark matter halo is also approximately spherical. More metal-rich populations contain higher fractions of stars in streams, with f stream becoming as high as 86% for . The space density of the smooth metal-poor component has a global power-law slope of γ = -3.08 ± 0.07, and a non-parametric fit shows that the slope remains nearly constant from 30 kpc to 300 kpc. The total stellar mass in the halo at distances beyond 2° is 1.1 × 1010 M, while that of the smooth component is 3 × 109 M. Extrapolating into the inner galaxy, the total stellar mass of the smooth halo is plausibly 8 × 109 M. We detect a substantial metallicity gradient, which declines from 〈[Fe/H]〉 = -0.7 at R = 30 kpc to 〈[Fe/H]〉 = -1.5 at R = 150 kpc for the full sample, with the smooth halo being 0.2 dex more metal poor than the full sample at each radius. While qualitatively in line with expectations from cosmological simulations, these observations are of great importance as they provide a prototype template that such simulations must now be able to reproduce in quantitative detail. DA - 2013/12/17 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 53d2b3e0-fa39-4860-a7d7-c45684b979b9 ER - TY - JOUR TI - Supermassive black holes and their host galaxies. II. the correlation with near-infrared luminosity revisited DO - 10.1088/0004-637X/780/1/70 AU - Läsker, Ronald AU - Ferrarese, Laura AU - van de Ven, Glenn AU - Shankar, Francesco T2 - The Astrophysical Journal SN - 0004-637X VL - 780 IS - 1 SP - 70 AB - We present an investigation of the scaling relations between supermassive black hole (SMBH) masses, M •, and their host galaxies' K-band bulge (L bul) and total (L tot) luminosities. The wide-field WIRCam imager at the Canada-France-Hawaii-Telescope was used to obtain the deepest and highest resolution near-infrared images available for a sample of 35 galaxies with securely measured M •, selected irrespective of Hubble type. For each galaxy, we derive bulge and total magnitudes using a two-dimensional image decomposition code that allows us to account, if necessary, for large- and small-scale disks, cores, bars, nuclei, rings, envelopes, and spiral arms. We find that the present-day M •-L bul and M •-L tot relations have consistent intrinsic scatter, suggesting that M • correlates equally well with bulge and total luminosity of the host. Our analysis provides only mild evidence of a decreased scatter if the fit is restricted to elliptical galaxies. The log-slopes of the M •-L bul and M •-L tot relations are 0.75 ± 0.10 and 0.92 ± 0.14, respectively. However, while the slope of the M •-L bul relation depends on the detail of the image decomposition, the characterization of M •-L tot does not. Given the difficulties and ambiguities of decomposing galaxy images into separate components, our results indicate that L tot is more suitable as a tracer of SMBH mass than L bul, and that the M •-L tot relation should be used when studying the co-evolution of SMBHs and galaxies. DA - 2013/12/12 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 66be38f5-67b2-455c-885b-25cffe53f6dd ER - TY - JOUR TI - Supermassive black holes and their host galaxies. I. Bulge luminosities from dedicated near-infrared data DO - 10.1088/0004-637X/780/1/69 AU - Läsker, Ronald AU - Ferrarese, Laura AU - van de Ven, Glenn T2 - The Astrophysical Journal SN - 0004-637X VL - 780 IS - 1 SP - 69 AB - In an effort to secure, refine, and supplement the relation between central supermassive black hole masses, M •, and the bulge luminosities of their host galaxies, L bul, we obtained deep, high spatial resolution K-band images of 35 nearby galaxies with securely measured M •, using the wide-field WIRCam imager at the Canada-France-Hawaii-Telescope. A dedicated data reduction and sky subtraction strategy was adopted to estimate the brightness and structure of the sky, a critical step when tracing the light distribution of extended objects in the near-infrared. From the final image product, bulge and total magnitudes were extracted via two-dimensional profile fitting. As a first order approximation, all galaxies were modeled using a simple Sérsic-bulge+exponential-disk decomposition. However, we found that such models did not adequately describe the structure that we observed in a large fraction of our sample galaxies which often include cores, bars, nuclei, inner disks, spiral arms, rings, and envelopes. In such cases, we adopted profile modifications and/or more complex models with additional components. The derived bulge magnitudes are very sensitive to the details and number of components used in the models, although total magnitudes remain almost unaffected. Usually, but not always, the luminosities and sizes of the bulges are overestimated when a simple bulge+disk decomposition is adopted in lieu of a more complex model. Furthermore, we found that some spheroids are not well fit when the ellipticity of the Sérsic model is held fixed. This paper presents the details of the image processing and analysis, while we discuss how model-induced biases and systematics in bulge magnitudes impact the M •-L bul relation in a companion paper. DA - 2013/12/12 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 122eb8aa-b061-4017-b848-7e267cc21758 ER - TY - JOUR TI - Nanomechanical AC susceptometry of an individual mesoscopic ferrimagnet DO - 10.1016/j.ssc.2013.08.006 AU - Losby, J. E. AU - Diao, Z. AU - Fani Sani, F. AU - Grandmont, D. T. AU - Belov, M. AU - Burgess, J. A. AU - Hiebert, W. K. AU - Freeman, M. R. T2 - Solid State Communications SN - 0038-1098 AB - A novel method for simultaneous detection of both DC and time-dependent magnetic signatures in individual mesoscopic structures has emerged from early studies in spin mechanics. Multifrequency nanomechanical detection of AC susceptibility and its harmonics highlights reversible nonlinearities in the magnetization response of a single yttrium iron garnet (YIG) element, separating them from hysteretic jumps in the DC magnetization. DA - 2013/08/17 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : cc717b00-bf08-479f-b6ee-edf79a7099ac ER - TY - JOUR TI - Determination of localized visibility in off-axis electron holography DO - 10.1016/j.ultramic.2013.11.005 AU - McLeod, Robert A. AU - Kupsta, Martin AU - Malac, Marek T2 - Ultramicroscopy SN - 0304-3991 VL - 138 SP - 4 EP - 12 KW - 2-D histograms KW - Coherence loss KW - Electron coherence KW - Fringe contrasts KW - Interference methods KW - Maximum intensities KW - Off-axis electron holography KW - Wavefront coherence KW - Electron holography KW - Electrons KW - Germanium KW - Gold KW - Graphic methods KW - Incoherent scattering KW - Titanium KW - Transmission electron microscopy KW - Underwater acoustics KW - Wavefronts KW - Visibility AB - Off-axis electron holography is a wavefront-split interference method for the transmission electron microscope that allows the phase shift and amplitude of the electron wavefront to be separated and quantitatively measured. An additional, third component of the holographic signal is the coherence of the electron wavefront. Historically, wavefront coherence has been evaluated by measurement of the holographic fringe visibility (or contrast) based on the minimum and maximum intensity values. We present a method based on statistical moments is presented that allows allow the visibility to be measured in a deterministic and reproducible fashion suitable for quantitative analysis. We also present an algorithm, based on the Fourier-ratio method, which allows the visibility to be resolved in two-dimensions, which we term the local visibility. The local visibility may be used to evaluate the loss of coherence due to electron scattering within a specimen, or as an aid in image analysis and segmentation. The relationship between amplitude and visibility may be used to evaluate the composition and mass thickness of a specimen by means of a 2-D histogram. Results for a selection of elements (C, Al, Si, Ti, Cr, Cu, Ge, and Au) are provided. All presented visibility metrics are biased at low-dose conditions by the presence of shot-noise, for which we provide methods for empirical normalization to achieve linear response. DA - 2013/11/23 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9e4a32bf-6268-4172-987b-0a41cbc6022f ER - TY - JOUR TI - SMPDB 2.0: big improvements to the small molecule pathway database DO - 10.1093/nar/gkt1067 AU - Jewison, Timothy AU - Su, Yilu AU - Disfany, Fatemeh Miri AU - Liang, Yongjie AU - Knox, Craig AU - MacIejewski, Adam AU - Poelzer, Jenna AU - Huynh, Jessica AU - Zhou, You AU - Arndt, David AU - Djoumbou, Yannick AU - Liu, Yifeng AU - Deng, Lu AU - Guo, An Chi AU - Han, Beomsoo AU - Pon, Allison AU - Wilson, Michael AU - Rafatnia, Shahrzad AU - Liu, Philip AU - Wishart, David S. T2 - Nucleic Acids Research SN - 0305-1048 VL - 42 IS - D1 SP - D478 EP - D484 AB - The Small Molecule Pathway Database (SMPDB, http://www.smpdb.ca) is a comprehensive, colorful, fully searchable and highly interactive database for visualizing human metabolic, drug action, drug metabolism, physiological activity and metabolic disease pathways. SMPDB contains >600 pathways with nearly 75% of its pathways not found in any other database. All SMPDB pathway diagrams are extensively hyperlinked and include detailed information on the relevant tissues, organs, organelles, subcellular compartments, protein cofactors, protein locations, metabolite locations, chemical structures and protein quaternary structures. Since its last release in 2010, SMPDB has undergone substantial upgrades and significant expansion. In particular, the total number of pathways in SMPDB has grown by >70%. Additionally, every previously entered pathway has been completely redrawn, standardized, corrected, updated and enhanced with additional molecular or cellular information. Many SMPDB pathways now include transporter proteins as well as much more physiological, tissue, target organ and reaction compartment data. Thanks to the development of a standardized pathway drawing tool (called PathWhiz) all SMPDB pathways are now much more easily drawn and far more rapidly updated. PathWhiz has also allowed all SMPDB pathways to be saved in a BioPAX format. Significant improvements to SMPDB's visualization interface now make the browsing, selection, recoloring and zooming of pathways far easier and far more intuitive. Because of its utility and breadth of coverage, SMPDB is now integrated into several other databases including HMDB and DrugBank. © 2013 The Author(s). Published by Oxford University Press. DA - 2013/11/06 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e305b799-2658-440d-ab04-3c7554ba7d28 ER - TY - JOUR TI - DrugBank 4.0: shedding new light on drug metabolism DO - 10.1093/nar/gkt1068 AU - Law, Vivian AU - Knox, Craig AU - Djoumbou, Yannick AU - Jewison, Tim AU - Guo, An Chi AU - Liu, Yifeng AU - Maciejewski, Adam AU - Arndt, David AU - Wilson, Michael AU - Neveu, Vanessa AU - Tang, Alexandra AU - Gabriel, Geraldine AU - Ly, Carol AU - Adamjee, Sakina AU - Dame, Zerihun T. AU - Han, Beomsoo AU - Zhou, You AU - Wishart, David S. T2 - Nucleic Acids Research SN - 0305-1048 VL - 42 IS - D1 SP - D1091 EP - D1097 AB - DrugBank (http://www.drugbank.ca) is a comprehensive online database containing extensive biochemical and pharmacological information about drugs, their mechanisms and their targets. Since it was first described in 2006, DrugBank has rapidly evolved, both in response to user requests and in response to changing trends in drug research and development. Previous versions of DrugBank have been widely used to facilitate drug and in silico drug target discovery. The latest update, DrugBank 4.0, has been further expanded to contain data on drug metabolism, absorption, distribution, metabolism, excretion and toxicity (ADMET) and other kinds of quantitative structure activity relationships (QSAR) information. These enhancements are intended to facilitate research in xenobiotic metabolism (both prediction and characterization), pharmacokinetics, pharmacodynamics and drug design/discovery. For this release, >1200 drug metabolites (including their structures, names, activity, abundance and other detailed data) have been added along with >1300 drug metabolism reactions (including metabolizing enzymes and reaction types) and dozens of drug metabolism pathways. Another 30 predicted or measured ADMET parameters have been added to each DrugCard, bringing the average number of quantitative ADMET values for Food and Drug Administration-approved drugs close to 40. Referential nuclear magnetic resonance and MS spectra have been added for almost 400 drugs as well as spectral and mass matching tools to facilitate compound identification. This expanded collection of drug information is complemented by a number of new or improved search tools, including one that provides a simple analyses of drug-target, -enzyme and -transporter associations to provide insight on drug-drug interactions. © 2013 The Author(s). Published by Oxford University Press. DA - 2013/11/06 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b5c49036-19da-464a-8476-920d7f2b9733 ER - TY - JOUR TI - Major substructure in the M31 outer halo: the south-west cloud DO - 10.1093/mnras/stt2139 AU - Bate, N. F. AU - Conn, A. R. AU - McMonigal, B. AU - Lewis, G. F. AU - Martin, N. F. AU - McConnachie, A. W. AU - Veljanoski, J. AU - Mackey, A. D. AU - Ferguson, A. M. N. AU - Ibata, R. A. AU - Irwin, M. J. AU - Fardal, M. AU - Huxor, A. P. AU - Babul, A. T2 - Monthly Notices of the Royal Astronomical Society SN - 0035-8711 VL - 437 IS - 4 SP - 3362 EP - 3372 AB - We undertake the first detailed analysis of the stellar population and spatial properties of a diffuse substructure in the outer halo ofM31. The South-West Cloud lies at a projected distance of ̃100 kpc from the centre of M31 and extends for at least ̃50 kpc in projection. We use Pan-Andromeda Archaeological Survey photometry of red giant branch stars to determine a distance to the South-West Cloud of 793+45 -45 kpc. The metallicity of the cloud is found to be [Fe/H] = -1.3 ± 0.1. This is consistent with the coincident globular clusters PAndAS-7 and PAndAS-8, which have metallicities determined using an independent technique of [Fe/H] = -1.35 ± 0.15. We measure a brightness for the Cloud of MV = -12.1 mag; this is ̃75 per cent of the luminosity implied by the luminosity-metallicity relation. Under the assumption that the South-West Cloud is the visible remnant of an accreted dwarf satellite, this suggests that the progenitor object was amongst M31's brightest dwarf galaxies prior to disruption. © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. DA - 2013/12/03 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 33553aa1-0da0-4892-ad87-acfa99923670 ER - TY - JOUR TI - The investigation of the triaxial residual stress in the friction stir welded lap joint using neutron diffraction DO - 10.4028/www.scientific.net/MSF.768-769.589 AU - Bach, Michael AU - Merati, Ali AU - Gharghouri, Michal AU - Rogge, Ronald AU - Bell, Robert AU - Wang, Xin T2 - International Conference on Residual Stresses 9 (ICRS 9) T2 - Materials Science Forum; Volume 768-769 T3 - 9th International Conference on Residual Stresses, ICRS 2012, October 7-9, 2012, Garmisch-Partenkirchen SN - 0255-5476 SN - 9783037858493 SP - 589 EP - 596 KW - Double pass KW - Friction stir KW - High strength aluminum alloys KW - Lap joint KW - Non-destructive technique KW - Principal directions KW - Stress variations KW - Test specimens KW - Friction stir welding KW - Hammers KW - Neutron diffraction KW - Nondestructive examination KW - Stress concentration KW - Welds KW - Residual stresses AB - A detailed study of the complex triaxial residual stress distribution of the double-pass friction stir welded (FSW) lap-joint between two different high strength aluminum alloy sheet materials was conducted. A non-destructive technique known as neutron diffraction was used to measure the internal residual stress distribution in the three principal direction of the lap-joint in the as-welded and hammer peened configurations to determine effects of hammer peening on redistribution of residual stresses across the weld. The residual stress variation across the weld in the transverse direction contained the highest values of tensile stress in all three principal directions. The residual stress in the hammer peened test specimen was in most cases reduced in all three principal directions. DA - 2013/09 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d15e1ce2-20f0-47d9-aed0-47cfee4bb750 ER - TY - JOUR TI - Si nanotubes ALD coated with TiO2, TiN or Al2O 3 as high performance lithium ion battery anodes DO - 10.1039/c3ta14302c AU - Lotfabad, Elmira Memarzadeh AU - Kalisvaart, Peter AU - Kohandehghan, Alireza AU - Cui, Kai AU - Kupsta, Martin AU - Farbod, Behdokht AU - Mitlin, David T2 - Journal of Materials Chemistry A SN - 2050-7488 VL - 2 IS - 8 SP - 2504 EP - 2516 AB - Silicon based hollow nanostructures are receiving significant scientific attention as potential high energy density anodes for lithium ion batteries. However their cycling performance still requires further improvement. Here we explore the use of atomic layer deposition (ALD) of TiO2, TiN and Al2O3 on the inner, the outer, or both surfaces of hollow Si nanotubes (SiNTs) for improving their cycling performance. We demonstrate that all three materials enhance the cycling performance, with optimum performance being achieved for SiNTs conformally coated on both sides with 1.5 nm of Li active TiO2. Substantial improvements are achieved in the cycling capacity retention (1700 mA h g-1vs. 1287 mA h g-1 for the uncoated baseline, after 200 cycles at 0.2 C), steady-state coulombic efficiency (∼100% vs. 97-98%), and high rate capability (capacity retention of 50% vs. 20%, going from 0.2 C to 5 C). TEM and other analytical techniques are employed to provide new insight into the lithiation cycling-induced failure mechanisms that turn out to be intimately linked to the microstructure and the location of these layers. DA - 2013/11/27 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8da40fde-f472-4d4a-b60c-859a5d00d51e ER - TY - JOUR TI - Chirp-wave expansion of the electron wavefunctions in atoms DO - 10.1016/j.cam.2013.12.016 AU - Torres, Edmanuel AU - Torres, Rafael T2 - Journal of Computational and Applied Mathematics SN - 0377-0427 VL - 263 SP - 218 EP - 224 KW - Basis sets KW - Chirp series KW - Electron wavefunctions KW - Fractional Fourier series KW - Fractional Fourier transforms KW - Gauge transformation KW - Infinite numbers KW - Natural oscillation KW - Atoms KW - Fourier series KW - Electrons AB - The description of the electron wavefunctions in atoms is generalized to the fractional Fourier series. This method introduces a continuous and infinite number of chirp basis sets with linear variation of the frequency to expand the wavefunctions, in which plane-waves are a special case. The chirp characteristics of each basis set can be adjusted through a single parameter. Thus, the basis set cutoff can be optimized variationally. The approach is tested with the expansion of the electron wavefunctions in atoms, and it is shown that chirp basis sets substantially improve the convergence in the description of the electron density. We have found that the natural oscillations of the electron core states are efficiently described in chirp-waves. DA - 2013/12/18 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1cda9b9c-e004-46da-ac2f-98729808e8da ER - TY - JOUR TI - Spectroelectrochemistry of FeIII- and CoIII- mimochrome VI artificial enzymes immobilized on mesoporous ITO electrodes DO - 10.1039/c3cc48489k AU - Vitale, R. AU - Lista, L. AU - Lau-Truong, S. AU - Tucker, R. T. AU - Brett, M. J. AU - Limoges, B. AU - Pavone, V. AU - Lombardi, A. AU - Balland, V. T2 - Chemical Communications SN - 1359-7345 VL - 50 IS - 15 SP - 1894 EP - 1896 AB - UV-visible absorption spectroelectrochemistry elucidated the different redox behaviours of FeIII- and CoIII-mimochrome VI artificial enzymes, adsorbed on mesoporous conductive films of ITO. The reduction of the ferric complex was rapid and reversible, while the cobaltic complex exhibited irreversible processes probably related to multiple coordination states. DA - 2013/12/03 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d5c2a56a-fd23-452f-a9ea-2cf6bc25cf66 ER - TY - JOUR TI - The calcium-sensing receptor R990G polymorphism is associated with increased risk of hypertriglyceridemia in obese Chinese DO - 10.1016/j.gene.2013.09.122 AU - He, Yong-han AU - Kong, Wei-lan AU - Wang, Guan AU - Zhao, Yue AU - Bi, Ming-xin AU - Na, Li-xin AU - Wang, Mao-qing AU - Perry, Ben AU - Li, Ying T2 - Gene SN - 0378-1119 VL - 533 IS - 1 SP - 67 EP - 71 KW - calcium sensing receptor KW - triacylglycerol KW - adult KW - aged KW - article KW - body mass KW - Chinese KW - controlled study KW - exon KW - female KW - gene frequency KW - genetic association KW - genetic polymorphism KW - genetic risk KW - genotype KW - high risk population KW - homozygosity KW - human KW - hypertriglyceridemia KW - major clinical study KW - male KW - obesity KW - pathogenesis KW - priority journal KW - triacylglycerol blood level AB - Background: We have demonstrated that the calcium-sensing receptor (CaSR) is involved in lipid metabolism; however, whether CaSR polymorphisms affect lipid metabolism in obesity is still unclear. The present study aimed to determine the effects of CaSR polymorphisms on HTG risk in obese Chinese. Methods: A total of 972 subjects with HTG and 1197 with normal triglyceride (NTG) were stratified by body mass index (BMI) into normal weight, overweight or obesity subgroups. After 12-h fasting, CaSR polymorphisms in exon 7 were determined in the blood. Serum lipids and glucose, as well as height, body weight and waist circumference were measured. The anthropometric and metabolic characteristics of the NTG subjects were re-evaluated 3. years later. Results: There were no genotypic or allelic distribution differences for the A986S or Q1011E polymorphisms between the NTG and HTG groups. However, the G/G genotypic and G allelic distributions of the CaSR R990G polymorphism in the HTG group were higher than the NTG group (p<. 0.001). After stratification, in obese subjects, the homozygous (G/G) distribution of the CaSR R990G polymorphism in the HTG group was significantly higher than in the NTG group (p= 0.001), and showed an increased risk of HTG at baseline [OR. = 2.55, 95% CI. = 1.65-3.92, p<. 0.006]. Interaction of the CaSR R990G polymorphism with BMI was associated with increased risk of HTG (β= 0.927, p< 0.001). Re-evaluation of the NTG subjects revealed significantly increased serum triglyceride levels in obese homozygous versus wildtype carriers (p< 0.05). Conclusions: These results suggest that the CaSR R990G polymorphism is associated with increased risk of HTG, especially in obese Chinese, and may be a potential genetic predictor of diseases related to HTG. •The CaSR polymorphisms were determined in 2169 subjects. DA - 2013/10/10 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1e6c2da1-a9a9-4624-ac00-78ac57e8f1ac ER - TY - JOUR TI - Pleurocidin, a novel antimicrobial peptide, induces human mast cell activation through the FPRL1 receptor DO - 10.1038/mi.2013.37 AU - Pundir, P. AU - Catalli, A. AU - Leggiadro, C. AU - Douglas, S. E. AU - Kulka, M. T2 - Mucosal Immunology SN - 1933-0219 VL - 7 IS - 1 SP - 177 EP - 187 AB - Pleurocidins are a novel family of α-helical cationic antimicrobial peptides (CAPs) that are structurally and functionally similar to cathelicidins, one of the major CAP families. As cathelicidins stimulate mast cell chemotaxis and mediator release, we postulated that pleurocidins similarly activate mast cells. A screen of 20 pleurocidin peptides revealed that some were capable of degranulating the human mast cell line LAD2 (Laboratory of Allergic Diseases 2). Pleurocidin NRC-04 caused LAD2 to adhere, migrate, degranulate, and release cysteinyl leukotrienes and prostaglandin D2. Moreover, pleurocidin increased intracellular Ca2+ mobilization in mast cells and induced the production of proinflammatory chemokines such as monocyte chemotactic protein-1/C-C motif chemokine ligand 2 (CCL2) and macrophage inflammatory protein-1β/CCL4. Our evaluation of possible cellular mechanisms suggested that G proteins, phosphoinositol-3 kinase (PI3K), phospholipase C (PLC), and phosphokinase C (PKC) were involved in pleurocidin-induced mast cell activation as evidenced by the inhibitory effects of pertussis toxin (G protein inhibitor), wortmanin (PI3K inhibitor), U-73122 (PLC inhibitor), and Ro-31-8220 (PKC inhibitor), respectively. We also found that human mast cells expressed the N-formyl-peptide receptor 1 (FPRL1) receptor and FPRL1-specific inhibitor affected pleurocidin-mediated activation of mast cell. Our finding that the novel CAP pleurocidin activated human mast cell through G protein-coupled receptor signaling suggests that this peptide might have immunomodulatory functions. © 2014 Society for Mucosal Immunology. DA - 2013/07/10 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1afa80d2-0481-4c5a-8cef-6f252b405d64 ER - TY - JOUR TI - Isolated microspore culture of oat (Avena sativa L.) for the production of doubled haploids : effect of pre-culture and post-culture conditions DO - 10.1007/s11240-013-0385-0 AU - Ferrie, A. M. R. AU - Irmen, K. I. AU - Beattie, A. D. AU - Rossnagel, B. G. T2 - Plant Cell, Tissue and Organ Culture SN - 0167-6857 VL - 116 IS - 1 SP - 89 EP - 96 KW - Avena sativa KW - Culture conditions KW - Doubled haploid KW - Media composition KW - Microspore culture KW - Microspore embryogenesis KW - Oat KW - Plant breeding programs KW - Cell culture KW - Plants (botany) KW - Seed AB - The production of doubled haploid (DH) plants from microspores is an important technique used in plant breeding programs and basic research. Although doubled haploidy efficiencies in wheat and barley are sufficient for breeding purposes, oat (Avena sativa L.) is considered recalcitrant. The objective of this project was to develop a protocol for the production of microspore-derived embryos of oat and further develop these embryos into fertile DH plants. A number of experiments were conducted evaluating the factors influencing microspore embryogenesis, i.e. donor plant conditions, pretreatments, media composition, and culture conditions. The initial studies yielded little response, and it was not until high microspore densities (106 microspores/mL and greater) were used that embryogenesis was achieved. Depending on the treatment, yields of over 5,000 embryos/106 microspores were obtained for breeding line 2000QiON43. The doubled haploidy protocol includes: a 0.3 M mannitol pretreatment of the tillers for 7 days, culture in W14 basal medium with a pH of 6.5-7.5, a microspore density of 106 microspores/mL, and continuous incubation at 28 °C incubation. The resulting embryos observed after 28 days were plated onto solidified W14 medium with 0.8 or 1.0 g/L activated charcoal. A colchicine treatment of 0.2 % colchicine for 4 h resulted in conversion of 80 % of the plants from haploid to DH. This protocol was successful for the production of oat microspore-derived embryos and DH green plants with minimal albinism. DH seed was produced and planted for evaluation in a field nursery. DA - 2013/09/29 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5a9526df-e02a-4e92-903a-a59bfa9ee24a ER - TY - JOUR TI - Lipid-coated gold nanoparticles promote lamellar body formation in A549 cells DO - 10.1016/j.bbalip.2013.01.018 AU - Wang, Meijing AU - Petersen, Nils O. T2 - Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids SN - 1388-1981 VL - 1831 IS - 6 SP - 1089 EP - 1097 KW - Phospholipid; 1-stearoyl-2-oleoyl-sn-glycero-3-phospho-(1′-rac-glycerol) (SOPG); Gold nanoparticle; Endocytosis; A549 cell; Lamellar bodies (LBs) AB - Gold nanoparticles (GNPs) have been applied as diagnostic and therapeutic agents because they can be targeted, localized, and be heated to cause cell death. However, their use has been limited by their relatively low biocompatibility. In this work, we coated the GNPs' surface by a biocompatible phospholipid bilayer composed of 1-stearoyl-2-oleoyl-sn-glycero-3-phospho- (1′-rac-glycerol) (SOPG). We tested their interaction with A549 cells to investigate their uptake and intracellular fate as well as the response of the cells to the presence of the GNPs. We used flow cytometry and confocal microscopy to show that the SOPG coated GNPs were readily taken up by the A549 cells. Transmission electron microscopy (TEM) images and fluorescence images further showed that the number of granular structures in the cells was increased following exposure to the lipid coated GNPs. Co-localization experiments demonstrated that SOPG coated GNPs localize in acidic compartments in a time dependent manner and that the number of these increase as the cells are exposed to the GNPs suggesting that they induce formation of lamellar bodies (LBs) which in A549 cells in turn can serve as a means of exporting the GNPs. DA - 2013/02/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c50f9637-19a3-4015-a607-e976bb497f33 ER - TY - JOUR TI - The DiskMass Survey: VII. the distribution of luminous and dark matter in spiral galaxies DO - 10.1051/0004-6361/201321390 AU - Martinsson, Thomas P. K. AU - Verheijen, Marc A. W. AU - Westfall, Kyle B. AU - Bershady, Matthew A. AU - Andersen, David R. AU - Swaters, Rob A. T2 - Astronomy and Astrophysics SN - 0004-6361 VL - 557 SP - A131 KW - Fundamental parameters KW - Imaging spectroscopy KW - Kinematics and dynamics KW - Spiral KW - Techniques KW - Kinematics KW - Luminance KW - Rotation KW - Stars KW - Structure (composition) KW - Galaxies AB - We present dynamically-determined rotation-curve mass decompositions of 30 spiral galaxies, which were carried out to test the maximum-disk hypothesis and to quantify properties of their dark-matter halos.We used measured vertical velocity dispersions of the disk stars to calculate dynamical mass surface densities (σdyn). By subtracting our observed atomic and inferred molecular gas mass surface densities from σdyn, we derived the stellar mass surface densities (σ+), and thus have absolute measurements of all dominant baryonic components of the galaxies. Using K-band surface brightness profiles (IK), we calculated the K-band mass-to-light ratio of the stellar disks (γ+ = σ+/IK) and adopted the radial mean (γ) for each galaxy to extrapolate σ+ beyond the outermost kinematic measurement. The derived γ of individual galaxies are consistent with all galaxies in the sample having equal γ. We find a sample average and scatter of -γ- = 0.31 α 0.07. Rotation curves of the baryonic components were calculated from their deprojected mass surface densities. These were used with circular-speed measurements to derive the structural parameters of the dark-matter halos, modeled as either a pseudo-isothermal sphere (pISO) or a Navarro-Frenk-White (NFW) halo. In addition to our dynamically determined mass decompositions, we also performed alternative rotation-curve decompositions by adopting the traditional maximumdisk hypothesis. However, the galaxies in our sample are submaximal, such that at 2.2 disk scale lengths (hR) the ratios between the baryonic and total rotation curves (F 2.2hR b ) are less than 0.75. We find this ratio to be nearly constant between 1-6hR within individual galaxies. We find a sample average and scatter of -F 2.2hR b - = 0.57 α 0.07, with trends of larger F 2.2hR b for more luminous and higher-surface-brightness galaxies. To enforce these being maximal, we need to scale γ+ by a factor 3.6 on average. In general, the dark-matter rotation curves are marginally better fit by a pISO than by an NFWhalo. For the nominal-γ+ (submaximal) case, we find that the derived NFW-halo parameters have values consistent with δCDM N-body simulations, suggesting that the baryonic matter in our sample of galaxies has only had a minor effect on the dark-matter distribution. In contrast, maximum-γ+ decompositions yield halo-concentration parameters that are too low compared to the δCDM simulations. DA - 2013/09/20 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 64d8faea-3d7c-4b0d-80ce-971a0639f3df ER - TY - JOUR TI - The Carina project. VI. The helium-burning variable stars DO - 10.1088/0004-637X/775/1/6 AU - Coppola, G. AU - Stetson, P. B. AU - Marconi, M. AU - Bono, G. AU - Ripepi, V. AU - Fabrizio, M. AU - Dall'Ora, M. AU - Musella, I. AU - Buonanno, R. AU - Ferraro, I. AU - Fiorentino, G. AU - Iannicola, G. AU - Monelli, M. AU - Nonino, M. AU - Pulone, L. AU - Thévenin, F. AU - Walker, A. R. T2 - The Astrophysical Journal SN - 0004-637X VL - 775 IS - 1 SP - 6 AB - We present new optical (BVI) time-series data for the evolved variable stars in the Carina dwarf spheroidal galaxy. The quality of the data and the observing strategy allowed us to identify 14 new variable stars. Eight out of the 14 are RR Lyrae (RRL) stars, 4 are Anomalous Cepheids (ACs), and 2 are geometrical variables. Comparison of the period distribution for the entire sample of RRLs with similar distributions in nearby dwarf spheroidal galaxies and in the Large Magellanic Cloud indicates that the old stellar populations in these systems share similar properties. This finding is also supported by the RRL distribution in the Bailey diagram. On the other hand, the period distribution and the Bailey diagram of ACs display significant differences among the above stellar systems. This evidence suggests that the properties of intermediate-age stellar populations might be affected both by environmental effects and structural parameters. We use the BV Period-Wesenheit (PW) relation of RRLs together with evolutionary prescriptions and find a true distance modulus of 20.09 ± 0.07 (intrinsic) ± 0.1 (statistical) mag that agrees quite well with similar estimates available in the literature. We identified four peculiar variables. Taking into account their position in the Bailey diagram and in the BV PW relation, two of them (V14 and V149) appear to be candidate ACs, while two (V158 and V182) might be peculiar RRLs. In particular, the variable V158 has a period and a V-band amplitude very similar to the low-mass RRL - RRLR-02792 - recently identified by Pietrzyński et al. in the Galactic bulge. DA - 2013/08/28 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 476c8977-f59e-4abd-9de7-46f06933deb0 ER - TY - JOUR TI - The PAndAS view of the andromeda satellite system. I. A Bayesian search for dwarf galaxies using spatial and color-magnitude information DO - 10.1088/0004-637X/776/2/80 AU - Martin, Nicolas F. AU - Ibata, Rodrigo A. AU - McConnachie, Alan W. AU - Mackey, A. Dougal AU - Ferguson, Annette M. N. AU - Irwin, Michael J. AU - Lewis, Geraint F. AU - Fardal, Mark A. T2 - The Astrophysical Journal SN - 0004-637X VL - 776 IS - 2 SP - 80 AB - We present a generic algorithm to search for dwarf galaxies in photometric catalogs and apply it to the Pan-Andromeda Archaeological Survey (PAndAS). The algorithm is developed in a Bayesian framework and, contrary to most dwarf galaxy search codes, makes use of both the spatial and color-magnitude information of sources in a probabilistic approach. Accounting for the significant contamination from the Milky Way foreground and from the structured stellar halo of the Andromeda galaxy, we recover all known dwarf galaxies in the PAndAS footprint with high significance, even for the least luminous ones. Some Andromeda globular clusters are also recovered and, in one case, discovered. We publish a list of the 143 most significant detections yielded by the algorithm. The combined properties of the 39 most significant isolated detections show hints that at least some of these trace genuine dwarf galaxies, too faint to be individually detected. Follow-up observations by the community are mandatory to establish which are real members of the Andromeda satellite system. The search technique presented here will be used in an upcoming contribution to determine the PAndAS completeness limits for dwarf galaxies. Although here tuned to the search of dwarf galaxies in the PAndAS data, the algorithm can easily be adapted to the search for any localized overdensity whose properties can be modeled reliably in the parameter space of any catalog. DA - 2013/10/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d4187df2-f1bd-4055-8dda-3511a2597de7 ER - TY - JOUR TI - The DiskMass Survey: VI. Gas and stellar kinematics in spiral galaxies from PPak integral-field spectroscopy DO - 10.1051/0004-6361/201220515 AU - Martinsson, Thomas P. K. AU - Verheijen, Marc A. W. AU - Westfall, Kyle B. AU - Bershady, Matthhew A. AU - Schechtman-Rook, Andrew AU - Andersen, David R. AU - Swaters, Rob A. T2 - Astronomy and Astrophysics SN - 0004-6361 VL - 557 SP - A130 KW - Fundamental parameters KW - Imaging spectroscopy KW - Kinematics and dynamics KW - Spiral KW - Techniques KW - Curve fitting KW - Dispersions KW - Galaxies KW - Ionization of gases KW - Kinematics KW - Luminance KW - Stars KW - Structure (composition) KW - Surveys KW - Velocity KW - Rotating disks AB - We present ionized-gas ([Oiii]λ5007 Å) and stellar kinematics (velocities and velocity dispersions) for 30 nearly face-on spiral galaxies out to as many as three K-band disk scale lengths (hR). These data have been derived from PPak integral-field-unit spectroscopy from 4980−5370 Å observed at a mean resolution of λ/Δλ = 7700 (σinst = 17 km s-1). These data are a fundamental product of our survey and will be used in companion papers to, e.g., derive the detailed (baryonic+dark) mass budget of each galaxy in our sample. Our presentation provides a comprehensive description of the observing strategy and data reduction, including a robust measurement and removal of shift, scale, and rotation effects in the data due to instrumental flexure. Using an in-plane coordinate system determined by fitting circular-speed curves to our velocity fields, we derive azimuthally averaged rotation curves and line-of-sight velocity dispersion (σLOS) and luminosity profiles for both the stars and [Oiii]-emitting gas. Along with a clear presentation of the data, we demonstrate: (1) The [Oiii] and stellar rotation curves exhibit a clear signature of asymmetric drift with a rotation difference that is 11% of the maximum rotation speed of the galaxy disk, comparable to measurements in the solar neighborhood in the Milky Way. (2) The e-folding length of the stellar velocity dispersion (hσ) is 2hR on average, as expected for a disk with a constant scale height and mass-to-light ratio, with a scatter that is notably smaller for massive, high-surface-brightness disks in the most luminous galaxies. (3) At radii larger than 1.5hR, σLOS tends to decline slower than the best-fitting exponential function, which may be due to an increase in the disk mass-to-light ratio, disk flaring, or disk heating by the dark-matter halo. (4) A strong correlation exists between the central vertical stellar velocity dispersion of the disks (σz,0) and their circular rotational speed at 2.2hR (V2.2hROiii), with a zero point indicating that galaxy disks are submaximal. Moreover, weak but consistent correlations exist between σz,0/V2.2hROiii and global galaxy properties such that disks with a fainter central surface brightness in bluer and less luminous galaxies of later morphological types are kinematically colder with respect to their rotational velocities. DA - 2013/09/20 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : eb8b93c0-2291-48de-a804-4338dc7d7c7f ER - TY - JOUR TI - A normal abundance of faint satellites in the fossil group NGC 6482 DO - 10.1051/0004-6361/201321288 AU - Lieder, S. AU - Mieske, S. AU - Sánchez-Janssen, R. AU - Hilker, M. AU - Lisker, T. AU - Tanaka, M. T2 - Astronomy and Astrophysics SN - 0004-6361 VL - 559 SP - A76 AB - A fossil group is considered the end product in a galaxy group's evolution. It is a massive central galaxy that dominates the luminosity budget of the group, and is the outcome of efficient merging between intermediate-luminosity members. Little is known, however, about the faint satellite systems of fossil groups. Here we present a Subaru/Suprime-Cam wide-field, deep imaging study in the B-and R-bands of the nearest fossil group NGC 6482 (Mtot ~ 4 × 1012M⊙), covering the virial radius out to 310 kpc. We performed detailed completeness estimations and selected group member candidates by a combination of automated object detection and visual inspection. A fiducial sample of 48 member candidates down to M R ~-10.5 mag is detected, making this study the deepest of a fossil group to now. We investigate the photometric scaling relations, the color-magnitude relation, and the luminosity function of our galaxy sample. We find evidence of recent and ongoing merger events among bright group galaxies. The color-magnitude relation is comparable to that of nearby galaxy clusters, and it exhibits significant scatter at the faintest luminosities. The completeness-corrected luminosity function is dominated by early-type dwarfs and is characterized by a faint end slope α =-1.32 ± 0.05. We conclude that the NGC 6482 fossil group shows photometric properties consistent with those of regular galaxy clusters and groups, including a normal abundance of faint satellites. DA - 2013/11/18 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4364c7be-8b62-4fb8-8e71-b7c3dcc4fbe4 ER - TY - JOUR TI - Composite spectra XIX: HD 208253, a long-period binary whose hot secondary has enhanced strontium and barium DO - 10.1002/asna.201311891 AU - Griffin, R. E. M. AU - Griffin, R. F. T2 - Astronomische Nachrichten SN - 0004-6337 VL - 334 IS - 7 SP - 661 EP - 672 KW - binaries: spectroscopic; stars: chemically peculiar; stars: fundamental parameters; stars: individual (HD 208253) AB - We separate and analyse the component spectra of the composite-spectrum binary HD 208253. We find that the cool primary is an evolving star of spectral type G7 III, while its hot secondary is an early-A dwarf. The giant is currently near the lowest point of the red-giant branch and is slightly less luminous than its dwarf companion. We provide a set of precise radial-velocity measurements for both stars. The double-lined orbit which we derive from them shows that the component mass ratio is close to unity (q = 1.05 ± 0.01). We deduce the physical properties of both stars, determine their respective masses to be 2.75 ± 0.07 Me (giant) and 2.62 ± 0.07 Me (dwarf), and show that the orbit's inclination is within a degree or two of 68°. The spectrum of the A-type component has quite component has quite narrow lines (we infer a rotational velocity of 18 km s-1), though since the period of the orbit is well over 1 year that component cannot be in synchronous rotation. An intriguing property of the dwarf is its enhanced Sr and Ba, though it does not exhibit the other spectral peculiarities that would signal a classical Am star. While by no means unique amongst the multitude of oddities exhibited by A and early-F stars, this dwarf which we have uncovered in a long-period binary offers valuable constraints and challenges to stellar-evolution theory. DA - 2013/08/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 040a3bd2-fa18-432e-a83c-68723730e472 ER - TY - JOUR TI - Characterization of atomic structure of oxide films on carbon steel in simulated concrete pore solutions using EELS DO - 10.1016/j.apsusc.2013.03.014 AU - Gunay, H. Burak AU - Ghods, Pouria AU - Isgor, O. Burkan AU - Carpenter, Graham J. C. AU - Wu, Xiaohua T2 - Applied Surface Science SN - 0169-4332 VL - 274 SP - 195 EP - 202 KW - Chloride KW - Concrete pore solutions KW - Film structure KW - Passive films KW - Pore solution KW - Simulated concrete pore solution KW - Transition layers KW - Valence state KW - Carbon steel KW - Chlorine compounds KW - Concretes KW - Corrosion KW - Electron energy loss spectroscopy KW - Oxide films AB - The atomic structure of oxide films formed on carbon steel that are exposed to highly alkaline simulated concrete pore solutions was investigated using Electron Energy Loss Spectroscopy (EELS). In particular, the effect of chloride exposure on film structure was studied in two types of simulated pore solutions: saturated calcium hydroxide (CH) and a solution prepared to represent typical concrete pore solutions (CP). It was shown that the films that form on carbon steel in simulated concrete pore solutions contained three indistinct layers. The inner oxide film had a structure similar to that of FeIIO, which is known to be unstable in the presence of chlorides. The outer oxide film mainly resembled Fe3O4 (FeIIO·Fe 2 IIIO3) in the CH solution and α-Fe 2 IIIO3/Fe3O4 in the CP solution. The composition of the transition layer between the inner and outer layers of the oxide film was mainly composed of Fe3O4 (FeIIO·Fe2 IIIO3). In the presence of chloride, the relative amount of the FeIII/Fe II increased, confirming that chlorides induce valence state transformation of oxides from FeII to FeIII, and the difference between the atomic structures of oxide film layers diminished. DA - 2013/03/13 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 45107555-9dc7-42ee-a7da-2d531c1ae4f7 ER - TY - JOUR TI - Nanoscale torsional optomechanics DO - 10.1063/1.4789442 AU - Kim, P. H. AU - Doolin, C. AU - Hauer, B. D. AU - MacDonald, A. J. R. AU - Freeman, M. R. AU - Barclay, P. E. AU - Davis, J. P. T2 - Applied Physics Letters SN - 0003-6951 VL - 102 IS - 5 SP - 53102 KW - Fiber-based systems KW - Integrated device KW - Microdisk whispering galleries KW - Nano scale KW - Noise floor KW - On chips KW - Optical fiber probe KW - Opto-mechanics KW - Optomechanical KW - Physical measurement KW - Torsional resonator KW - Optical fibers KW - Resonators KW - Nanotechnology DA - 2013/02/04 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2ee30056-84d3-4884-9e55-c708a792563b ER - TY - JOUR TI - Astronomical seeing and ground-layer turbulence in the Canadian high Arctic DO - 10.1093/mnras/stt729 AU - Hickson, P. AU - Gagné, R. AU - Pfrommer, T. AU - Steinbring, E. T2 - Monthly Notices of the Royal Astronomical Society SN - 0035-8711 VL - 433 IS - 1 SP - 307 EP - 312 AB - We report results of a two-year campaign of measurements, during arctic winter darkness, of optical turbulence in the atmospheric boundary layer above the Polar Environment Atmospheric Laboratory in northern Ellesmere Island (latitude +80° N). The data reveal that the ground-layer turbulence in the Arctic is often quite weak, even at the comparatively low 610 m altitude of this site. The median and 25th percentile ground-layer seeing, at a height of 20 m, are found to be 0.57 and 0.25 arcsec, respectively. When combined with a free-atmosphere component of 0.30 arcsec, the median and 25th percentile total seeing for this height is 0.68 and 0.42 arcsec, respectively. The median total seeing from a height of 7 m is estimated to be 0.81 arcsec. These values are comparable to those found at the best high-altitude astronomical sites. © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9fac92d5-e186-4fcd-bc39-2bff2291f01b ER - TY - JOUR TI - Toward quantum processing in molecules: A THz-bandwidth coherent memory for light DO - 10.1103/PhysRevLett.111.083901 AU - Bustard, P.J. AU - Lausten, R. AU - England, D.G. AU - Sussman, B.J. T2 - Physical Review Letters SN - 0031-9007 VL - 111 IS - 8 SP - 83901 KW - Classical physics KW - Hydrogen molecule KW - Molecular memory KW - Molecular state KW - Physical societies KW - Quantum photonics KW - Ultra-fast KW - Bandwidth KW - Light KW - Quantum theory KW - Molecules AB - The unusual features of quantum mechanics are enabling the development of technologies not possible with classical physics. These devices utilize nonclassical phenomena in the states of atoms, ions, and solid-state media as the basis for many prototypes. Here we investigate molecular states as a distinct alternative. We demonstrate a memory for light based on storing photons in the vibrations of hydrogen molecules. The THz-bandwidth molecular memory is used to store 100-fs pulses for durations up to ∼1 ns, enabling ∼104 operational time bins. The results demonstrate the promise of molecules for constructing compact ultrafast quantum photonic technologies. Published by the American Physical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6869ca0e-1204-43b4-b312-dbdd17202b47 ER - TY - JOUR TI - Lipopolysaccharide structure of Helicobacter pylori serogroup O:3 DO - 10.1016/j.carres.2013.03.008 AU - Altman, E. AU - Chandan, V. AU - Li, J. AU - Vinogradov, E. T2 - Carbohydrate Research SN - 0008-6215 VL - 378 SP - 139 EP - 143 KW - General architectures KW - Helicobacter pylori KW - Linear assembly KW - Lipopolysaccharides KW - LPS KW - MALDI-MS KW - MS KW - O-Chain KW - Nuclear magnetic resonance KW - Organic compounds KW - Structure (composition) KW - Synthesis (chemical) KW - Chains KW - bacterium lipopolysaccharide KW - dextran KW - heptane KW - oligosaccharide KW - oxygen KW - polysaccharide KW - analytic method KW - animal cell KW - article KW - bacterial strain KW - biodegradation KW - carbohydrate analysis KW - chemical composition KW - controlled study KW - Helicobacter pylori KW - mass spectrometry KW - matrix assisted laser desorption ionization time of flight mass spectrometry KW - nonhuman KW - nuclear magnetic resonance spectroscopy KW - priority journal KW - substitution reaction KW - Helicobacter pylori AB - In this study, we describe a re-investigation of the lipopolysaccharide structure of Helicobacter pylori serogroup O:3. Application of NMR and MS approaches to the analysis of oligosaccharides obtained through degradation of LPS from H. pylori serogroup O:3 by various methods confirmed that its general architecture was identical to that of LPS from H. pylori strains 26695 and SS1 and followed a sequential linear assembly of the α-1,6-glucan, DD-heptan, and O-chain components. Additionally, MALDI-MS analysis demonstrated that a significant proportion of H. pylori serogroup O:3 LPS was terminated with α-1,6-glucan and was not further substituted by DD-heptan and the O-chain polysaccharide. Crown Copyright © 2013 Published by Elsevier Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5cad97e7-db88-4c7d-9e14-ce6451c6dc77 ER - TY - CHAP TI - MBE growth of THz quantum cascade lasers DO - 10.1016/B978-0-12-387839-7.00028-2 AU - Wasilewski, Z.R. T2 - Molecular Beam Epitaxy SN - 9780123878397 SP - 631 EP - 655 DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 83f81806-73e1-463c-b8f8-45eb9faaa984 ER - TY - JOUR TI - Study on the measurement of soot particle size by laser induced incandescence AU - Li, H.-M. AU - He, X. AU - Zheng, L. AU - Liu, F.-S. AU - Wang, J.-X. T2 - Kung Cheng Je Wu Li Hsueh Pao/Journal of Engineering Thermophysics SN - 0253-231X VL - 34 IS - 7 SP - 1389 EP - 1392 KW - Coflow diffusion flames KW - Laser induced incandescence KW - Laser-based techniques KW - Particle diameters KW - Primary particle size KW - Soot concentration KW - Soot measurement KW - Transmission electron microscope KW - Particle size KW - Soot KW - Transmission electron microscopy KW - Dust AB - Soot is very harmful to the human health, which has drawn increasing attention. It has been shown that the toxicity of soot is directly related to the particle size. So it is very important to develop laser-based techniques to rapidly gain soot particle size information. LII (Laser Induced Incandescence) is considered a very promising method for soot measurement, and it can be used to determine soot concentration and particle size. In this paper, LII was used to infer primary particle size of soot at different axis positions in an ethylene/air laminar coflow diffusion flame. The results were compared with those from TEM (Transmission Electron Microscope) image analysis of thermophoretically sampled soot. It was shown that, along the flame axis, the particle diameter first increases and then decreases. Comparing the LII and probe sampling results, the trends agree well but the values differ slightly. Nevertheless, the effectiveness of the LII technique for soot particle sizing is found promising. DA - 2013 PY - 2013 LA - zho C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 06e14594-1e8f-4301-b2fc-28253b247cd7 ER - TY - JOUR TI - Zero-energy states of graphene triangular quantum dots in a magnetic field DO - 10.1103/PhysRevB.88.155429 AU - Güçlü, A.D. AU - Potasz, P. AU - Hawrylak, P. T2 - Physical Review B - Condensed Matter and Materials Physics SN - 1098-0121 VL - 88 IS - 15 SP - 155429 AB - We present a tight-binding theory of triangular graphene quantum dots (TGQD) with zigzag edge and broken sublattice symmetry in an external magnetic field. The lateral size quantization opens an energy gap, and broken sublattice symmetry results in a shell of degenerate states at the Fermi level. We derive a semianalytical form for zero-energy states in a magnetic field and show that the shell remains degenerate in a magnetic field, in analogy to the zeroth Landau level of bulk graphene. The magnetic field closes the energy gap and leads to the crossing of valence and conduction states with the zero-energy states, modulating the degeneracy of the shell. The closing of the gap with increasing magnetic field is present in all graphene quantum dot structures investigated irrespective of shape and edge termination. ©2013 American Physical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 50025b40-eb85-4a9a-908d-4e604ea28bc1 ER - TY - JOUR TI - Cancer systems biology in the genome sequencing era: Part 2, evolutionary dynamics of tumor clonal networks and drug resistance DO - 10.1016/j.semcancer.2013.06.001 AU - Wang, E. AU - Zou, J. AU - Zaman, N. AU - Beitel, L.K. AU - Trifiro, M. AU - Paliouras, M. T2 - Seminars in Cancer Biology SN - 1044-579X VL - 23 IS - 4 SP - 286 EP - 292 KW - bioinformatics KW - cancer resistance KW - carcinogenesis KW - computer analysis KW - gene duplication KW - gene regulatory network KW - gene sequence KW - genetic association KW - genetic heterogeneity KW - genome analysis KW - genomics KW - human KW - malignant neoplastic disease KW - molecular cloning KW - molecular dynamics KW - molecular model KW - mutational analysis KW - nonhuman KW - review KW - RNA sequence KW - signal transduction KW - systems biology KW - tumor microenvironment AB - A tumor often consists of multiple cell subpopulations (clones). Current chemo-treatments often target one clone of a tumor. Although the drug kills that clone, other clones overtake it and the tumor recurs. Genome sequencing and computational analysis allows to computational dissection of clones from tumors, while singe-cell genome sequencing including RNA-Seq allows profiling of these clones. This opens a new window for treating a tumor as a system in which clones are evolving. Future cancer systems biology studies should consider a tumor as an evolving system with multiple clones. Therefore, topics discussed in Part 2 of this review include evolutionary dynamics of clonal networks, early-warning signals (e.g., genome duplication events) for formation of fast-growing clones, dissecting tumor heterogeneity, and modeling of clone-clone-stroma interactions for drug resistance. The ultimate goal of the future systems biology analysis is to obtain a 'whole-system' understanding of a tumor and therefore provides a more efficient and personalized management strategies for cancer patients. © 2013 Published by Elsevier Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c8ddc772-fba7-451f-bd33-a83e75639745 ER - TY - JOUR TI - Atomic weights of the elements 2011 (IUPAC technical report) DO - 10.1351/PAC-REP-13-03-02 AU - Wieser, M.E. AU - Holden, N. AU - Coplen, T.B. AU - Böhlke, J.K. AU - Berglund, M. AU - Brand, W.A. AU - De Bièvre, P. AU - Gröning, M. AU - Loss, R.D. AU - Meija, J. AU - Hirata, T. AU - Prohaska, T. AU - Schoenberg, R. AU - O'Connor, G. AU - Walczyk, T. AU - Yoneda, S. AU - Zhu, X.-K. T2 - Pure and Applied Chemistry SN - 0033-4545 VL - 85 IS - 5 SP - 1047 EP - 1078 KW - Atomic weights KW - Atomic-weight intervals KW - Atomic-weight ranges KW - Conventional atomic-weight values KW - Half lives KW - Iupac inorganic chemistry divisions KW - Atoms KW - Bromine KW - Germanium KW - Indium KW - Inorganic compounds KW - Magnesium KW - Mercury (metal) KW - Chemical elements AB - The biennial review of atomic-weight determinations and other cognate data has resulted in changes for the standard atomic weights of five elements. The atomic weight of bromine has changed from 79.904(1) to the interval [79.901, 79.907], germanium from 72.63(1) to 72.630(8), indium from 114.818(3) to 114.818(1), magnesium from 24.3050(6) to the interval [24.304, 24.307], and mercury from 200.59(2) to 200.592(3). For bromine and magnesium, assignment of intervals for the new standard atomic weights reflects the common occurrence of variations in the atomic weights of those elements in normal terrestrial materials. © 2013 IUPAC. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 48d8a279-61fc-4bdd-bfdf-2db08818ccf4 ER - TY - JOUR TI - Espectrómetro de transformada de fourier implementado mediante guías de onda en espiral con base de silicio DO - 10.7149/OPA.46.2.99 AU - Velasco, Aitor V. AU - Cheben, Pavel AU - Bock, Przemek AU - Schmid, Jens H. AU - Lapointe, Jean AU - Delâge, André AU - Janz, Siegfried AU - Calvo, María L. AU - Xu, Dan-Xia AU - Florjańczyk, Mirosław T2 - Optica Pura y Aplicada SN - 0030-3917 VL - 46 IS - 2 SP - 99 EP - 103 AB - In this work we present the design, fabrication and characterization of a Fourier-Transform micro-spectrometer implemented with planar waveguides. The device comprises an array of 32 Mach-Zehnder interferometers with increasing optical path differences between the arms of the interferometer, reaching a resolution of 0.1 nm in a free spectral range of 1.6 nm. Silicon waveguides in a spiral structure have been used in the arms of the interferometer, reducing the footprint of the device below 12 mm2. DA - 2013 PY - 2013 C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f3d8cad6-1cc2-4033-b3d9-4cc937ca4950 ER - TY - JOUR TI - Detection of carbon monoxide and water absorption lines in an exoplanet atmosphere DO - 10.1126/science.1232003 AU - Konopacky, Q.M. AU - Barman, T.S. AU - Macintosh, B.A. AU - Marois, C. T2 - Science SN - 0036-8075 VL - 339 IS - 6126 SP - 1398 EP - 1401 KW - carbon dioxide KW - carbon monoxide KW - water KW - absorption KW - astronomy KW - atmospheric chemistry KW - atmospheric structure KW - carbon monoxide KW - chemical composition KW - gravity field KW - oxygen KW - planetary atmosphere KW - planetary evolution KW - spectral analysis KW - water KW - article KW - astronomy KW - atmosphere KW - chemical composition KW - cloud KW - energy KW - gravity KW - light KW - light scattering KW - mass KW - priority journal KW - signal noise ratio KW - temperature KW - water absorption KW - Atmosphere KW - Carbon Monoxide KW - Evolution, Planetary KW - Extraterrestrial Environment KW - Gravitation KW - Planets KW - Spectrum Analysis KW - Water AB - Determining the atmospheric structure and chemical composition of an exoplanet remains a formidable goal. Fortunately, advancements in the study of exoplanets and their atmospheres have come in the form of direct imaging - spatially resolving the planet from its parent star - which enables high-resolution spectroscopy of self-luminous planets in jovian-like orbits. Here, we present a spectrum with numerous, well-resolved molecular lines from both water and carbon monoxide from a massive planet orbiting less than 40 astronomical units from the star HR 8799. These data reveal the planet's chemical composition, atmospheric structure, and surface gravity, confirming that it is indeed a young planet. The spectral lines suggest an atmospheric carbon-to-oxygen ratio that is greater than that of the host star, providing hints about the planet's formation. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 95999e6b-e130-4cd5-988c-f472b7c73e86 ER - TY - JOUR TI - Electronic temperature in phonon-photon-phonon terahertz quantum cascade devices with high-operating temperature performance DO - 10.1117/12.2006874 AU - Scamarcio, G. AU - Patimisco, P. AU - Santacroce, M. V. AU - Tempesta, P. AU - Spagnolo, V. AU - Vitiello, M. S. AU - Dupont, E. AU - Fathololoumi, S. AU - Laframboise, S. R. AU - Razavipour, S. G. AU - Wasilewski, Z. AU - Ban, D. AU - Liu, H. C. T2 - Quantum Sensing and Nanophotonic Devices X T2 - SPIE - International Society for Optical Engineering. Proceedings; 8631 T3 - Quantum Sensing and Nanophotonic Devices X, February 3-7, 2013, San Francisco, CA, USA SN - 0277-786X SN - 9780819494009 SP - 86312C KW - Band-to-band photoluminescence KW - Electronic distribution KW - Electronic temperature KW - Experimental measurements KW - Lasing conditions KW - Quantum-cascade devices KW - Temperature performance KW - Terahertz quantum-cascade lasers KW - Cascade connections KW - Nanophotonics KW - Photoluminescence KW - Photoluminescence spectroscopy KW - Photons KW - Semiconductor quantum wells KW - Phonons AB - We report on the experimental measurement of active region lattice (T L) and electronic temperatures (T e) in terahertz quantum cascade devices based on the phonon-photon-phonon scheme, by means of microprobe band-to-band photoluminescence spectroscopy. Three mesa devices, differing for doping region and number of quantum wells composing the active region, have been investigated. With device on, under band alignment for lasing condition, we measured a difference (Te - TL) ∼ 40 K much smaller than the typical value (Te - TL ∼ 100 K) reported for resonantphonon THz QCLs. © 2013 SPIE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6061d98f-423c-4f07-bcb9-c755ada06ffa ER - TY - JOUR TI - Separation of rare oligodendrocyte progenitor cells from brain using a high-throughput multilayer thermoplastic-based microfluidic device DO - 10.1016/j.biomaterials.2013.04.014 AU - Didar, T.F. AU - Li, K. AU - Veres, T. AU - Tabrizian, M. T2 - Biomaterials SN - 0142-9612 VL - 34 IS - 22 SP - 5588 EP - 5593 KW - Cell sorting KW - Central nervous systems KW - Cutting edge technology KW - Membrane pore size KW - Micro-fluidic devices KW - Oligodendrocytes KW - Regenerative medicine KW - Separation efficiency KW - Cell culture KW - Fluidic devices KW - Multilayers KW - Reinforced plastics KW - Repair KW - Stem cells KW - Separation KW - myelin KW - animal cell KW - article KW - brain tissue KW - cell culture KW - cell differentiation KW - cell population KW - cell separation KW - cell size KW - cell viability KW - controlled study KW - flow rate KW - glia cell KW - in vitro study KW - microfluidics KW - nonhuman KW - oligodendrocyte progenitor cell KW - priority journal KW - rabbit KW - stem cell KW - Rattus AB - Despite the advances made in the field of regenerative medicine, the progress in cutting-edge technologies for separating target therapeutic cells are still at early stage of development. These cells are often rare, such as stem cells or progenitor cells that their overall properties should be maintained during the separation process for their subsequent application in regenerative medicine. This work, presents separation of oligodendrocyte progenitor cells (OPCs) from rat brain primary cultures using an integrated thermoplastic elastomeric (TPE)- based multilayer microfluidic device fabricated using hot-embossing technology. OPCs are frequently used in recovery, repair and regeneration of central nervous system after injuries. Indeed, their ability to differentiate invitro into myelinating oligodendrocytes, are extremely important for myelin repair. OPCs form 5-10% of the glial cells population. The traditional macroscale techniques for OPCs separation require pre-processing of cells and/or multiple time consuming steps with low efficiency leading very often to alteration of their properties. The proposed methodology implies to separate OPCs based on their smaller size compared to other cells from the brain tissue mixture. Using aforementioned microfluidic chip embedded with a 5μm membrane pore size and micropumping system, a separation efficiency more than 99% was achieved. This microchip was able to operate at flow rates up to 100μl/min, capable of separating OPCs from a confluent 75cm2 cell culture flask in less than 10min, which provides us with a high-throughput and highly efficient separation expected from any cell sorting techniques. © 2013 Elsevier Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a464c901-09af-45ee-8b68-c7ecb3a996af ER - TY - JOUR TI - High resolution infrared spectra of H2-Xe and D2-Xe van der Waals complexes DO - 10.1139/cjp-2012-0468 AU - McKellar, A.R.W. T2 - Canadian Journal of Physics SN - 0008-4204 VL - 91 IS - 11 SP - 957 EP - 962 KW - Experimental benchmarks KW - Fourier transform infrared spectrometer KW - High spectral resolution KW - High-resolution infrared spectra KW - Intermolecular potential energy KW - Low temperatures KW - Stretching vibrations KW - Van der Waals complex KW - Fourier transform infrared spectroscopy KW - Hydrogen KW - Spectral resolution KW - Stretching KW - Van der Waals forces AB - Spectra of weakly-bound hydrogen-xenon complexes are studied in equilibrium gas mixtures at relatively high spectral resolution (0.04 cm-1) using a long-path (112 m), low-temperature (140 K) absorption cell and a Fourier transform infrared spectrometer. The data cover the regions of the H 2 and D2 fundamental stretching vibrations in the mid-infrared (λ ∼ 2.4, 3.3 νm), and are greatly improved compared to the only previous observation. The results serve as a stringent experimental benchmark for testing theoretical hydrogen-xenon intermolecular potential energy models, as well as forming the basis for deriving an improved semi-empirical potential. © 2013 Published by NRC Research Press. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : bb5967e6-ec31-477a-9f72-74c06bd01666 ER - TY - JOUR TI - The complex nature of the nuclear star cluster in FCC 277 DO - 10.1093/mnras/stt414 AU - Lyubenova, M. AU - van den Bosch, R.C.E. AU - Côté, P. AU - Kuntschner, H. AU - van de Ven, G. AU - Ferrarese, L. AU - Jordán, A. AU - Infante, L. AU - Peng, E.W. T2 - Monthly Notices of the Royal Astronomical Society SN - 0035-8711 VL - 431 IS - 4 SP - 3364 EP - 3372 AB - Recent observations have shown that compact nuclear star clusters (NSCs) are present in up to 80 per cent of galaxies. However, detailed studies of their dynamical and chemical properties are confined mainly to spiral galaxy hosts, where they are more easily observed. In this paper, we present our study of the NSC in FCC 277, a nucleated elliptical galaxy in the Fornax cluster. We use a combination of adaptive optics assisted near-infrared integral field spectroscopy, Hubble Space Telescope imaging and literature long-slit data. We show that while the NSC does not appear to rotate within our detection limit of ~6 kms-1, rotation is detected at larger radii, where the isophotes appear to be discy, suggesting the presence of a nuclear disc. We also observe a distinct central velocity dispersion drop that is indicative of a dynamically cold rotating sub-system. Following the results of orbit-based dynamical modelling, corotating as well as counter-rotating stellar orbits are simultaneously needed to reproduce the observed kinematics. We find evidence for varying stellar populations, with the NSC and nuclear disc hosting younger and more metal rich stars than the main body of the galaxy. We argue that gas dissipation and some level of merging have likely played an important role in the formation of the nucleus of this intermediate-mass galaxy. This is in contrast to NSCs in low-mass early-type galaxies, which may have been formed primarily through the infall of star clusters. 2013 © The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : bc6fa15d-a915-4553-aa20-11725bada515 ER - TY - JOUR TI - Considerations for the wind tunnel simulation of tractor-trailer combinations: Correlation of full- and half-scale measurements DO - 10.4271/2013-01-2456 AU - Leuschen, J. T2 - SAE International Journal of Commercial Vehicles SN - 1946-391X VL - 6 IS - 2 SP - 529 EP - 538 KW - Commercial trucks KW - Drag curves KW - Flow regimes KW - Full-scale testing KW - National Research Council KW - Test sections KW - Wind-tunnel simulation KW - Yaw angles KW - Automobile testing KW - Computer simulation KW - Reynolds number KW - Tractors (agricultural) KW - Tractors (truck) KW - Truck trailers KW - Wind tunnels AB - The 9-meter wind tunnel of the National Research Council (NRC) of Canada is commonly employed in testing of class 8 tractors at full- and model-scales. In support of this work a series of tests of an identical model at full- and half-scale were performed to investigate some of the effects resulting from simulation compromises. Minimum Reynolds Number considerations drive the crucial decisions of what scale and speed to employ for testing. The full- and half-scale campaigns included Reynolds Number sweeps allowing conclusions to be reached on the minimum Reynolds number required for testing of fully-detailed commercial truck models. Furthermore the Reynolds sweeps were repeated at a variety of yaw angles to examine whether the minimum Reynolds Number was a function of yaw angle and the resulting flow regime changes. The test section of the NRC 9-meter wind tunnel is not sufficiently long to accommodate a full-scale tractor and a typical trailer length of 48′ or more. Most of full-scale testing is therefore conducted with a more manageable 28′ trailer. To quantify the effects of this simplification the half-scale model was tested with representations of 28′ and 48′ trailers. The changes in the baseline drag curves will be presented along with the effect of trailer devices, such as skirts, on the different lengths of trailer. Copyright © 2013 SAE International. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4cd24300-4250-462c-9382-34ffd7e6ef72 ER - TY - JOUR TI - Methane production from the microalga Scenedesmus sp. AMDD in a continuous anaerobic reactor DO - 10.1016/j.algal.2013.07.002 AU - Tartakovsky, B. AU - Matteau-Lebrun, F. AU - McGinn, P.J. AU - O'Leary, S.J.B. AU - Guiot, S.R. T2 - Algal Research SN - 2211-9264 VL - 2 IS - 4 SP - 394 EP - 400 AB - Methane production from the microalga Scenedesmus sp. AMDD digested in a continuously operated anaerobic reactor was studied under a range of conditions. Preliminary anaerobic toxicity assays revealed that methane yields and glucose consumption were inhibited by algae/sludge ratios in excess of 0.1 (g/g). Continuous digestions of microalgae at two hydraulic retention times (16 and 58days) and two influent concentrations of algal feed (11 and 20gTVSL-1) were evaluated. Based on the amount of degraded algal biomass, a methane yield of 0.4LCH4gTVS -1 was estimated. However, at a hydraulic retention time of 16days only 52-53% of the algal biomass was degraded, primarily due to the limited hydrolysis of the algal cellular material. An increase of retention time to 58days did not improve the degradation efficiency. Anaerobic decomposition of microalgae biomass appeared to affect composition of the microbial consortium in the digester, promoting the growth of sulfate-reducing bacteria leading to high levels of H2S in the biogas. © 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b060b6c7-cf6f-4dcf-9b8a-6ce5addb8625 ER - TY - JOUR TI - High-level semi-synthetic production of the potent antimalarial artemisinin DO - 10.1038/nature12051 AU - Paddon, C.J. AU - Westfall, P.J. AU - Pitera, D.J. AU - Benjamin, K. AU - Fisher, K. AU - McPhee, D. AU - Leavell, M.D. AU - Tai, A. AU - Main, A. AU - Eng, D. AU - Polichuk, D.R. AU - Teoh, K.H. AU - Reed, D.W. AU - Treynor, T. AU - Lenihan, J. AU - Jiang, H. AU - Fleck, M. AU - Bajad, S. AU - Dang, G. AU - Dengrove, D. AU - Diola, D. AU - Dorin, G. AU - Ellens, K.W. AU - Fickes, S. AU - Galazzo, J. AU - Gaucher, S.P. AU - Geistlinger, T. AU - Henry, R. AU - Hepp, M. AU - Horning, T. AU - Iqbal, T. AU - Kizer, L. AU - Lieu, B. AU - Melis, D. AU - Moss, N. AU - Regentin, R. AU - Secrest, S. AU - Tsuruta, H. AU - Vazquez, R. AU - Westblade, L.F. AU - Xu, L. AU - Yu, M. AU - Zhang, Y. AU - Zhao, L. AU - Lievense, J. AU - Covello, P.S. AU - Keasling, J.D. AU - Reiling, K.K. AU - Renninger, N.S. AU - Newman, J.D. T2 - Nature SN - 0028-0836 VL - 496 IS - 7446 SP - 528 EP - 532 KW - artemisinin KW - singlet oxygen KW - antimalarial agent KW - biological production KW - disease treatment KW - enzyme activity KW - malaria KW - yeast KW - article KW - chemical reaction KW - derivatization KW - drug potency KW - esterification KW - expressed sequence tag KW - extractive fermentation KW - fed batch fermentation KW - fermentation KW - open reading frame KW - oxidative stress KW - photochemistry KW - priority journal KW - protein expression KW - stereochemistry KW - Antimalarials KW - Artemisinins KW - Biosynthetic Pathways KW - Biotechnology KW - Fermentation KW - Genetic Engineering KW - Malaria, Falciparum KW - Molecular Sequence Data KW - Saccharomyces cerevisiae KW - Singlet Oxygen KW - Artemisia annua KW - Artesunate KW - Plasmodium falciparum KW - Saccharomyces cerevisiae AB - In 2010 there were more than 200 million cases of malaria, and at least 655,000 deaths. The World Health Organization has recommended artemisinin-based combination therapies (ACTs) for the treatment of uncomplicated malaria caused by the parasite Plasmodium falciparum. Artemisinin is a sesquiterpene endoperoxide with potent antimalarial properties, produced by the plant Artemisia annua. However, the supply of plant-derived artemisinin is unstable, resulting in shortages and price fluctuations, complicating production planning by ACT manufacturers. A stable source of affordable artemisinin is required. Here we use synthetic biology to develop strains of Saccharomyces cerevisiae (baker's yeast) for high-yielding biological production of artemisinic acid, a precursor of artemisinin. Previous attempts to produce commercially relevant concentrations of artemisinic acid were unsuccessful, allowing production of only 1.6 grams per litre of artemisinic acid. Here we demonstrate the complete biosynthetic pathway, including the discovery of a plant dehydrogenase and a second cytochrome that provide an efficient biosynthetic route to artemisinic acid, with fermentation titres of 25 grams per litre of artemisinic acid. Furthermore, we have developed a practical, efficient and scalable chemical process for the conversion of artemisinic acid to artemisinin using a chemical source of singlet oxygen, thus avoiding the need for specialized photochemical equipment. The strains and processes described here form the basis of a viable industrial process for the production of semi-synthetic artemisinin to stabilize the supply of artemisinin for derivatization into active pharmaceutical ingredients (for example, artesunate) for incorporation into ACTs. Because all intellectual property rights have been provided free of charge, this technology has the potential to increase provision of first-line antimalarial treatments to the developing world at a reduced average annual price. © 2013 Macmillan Publishers Limited. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9aebe1d1-653b-49bb-9405-12dec558216f ER - TY - JOUR TI - Optical fiber interferometer array for scanless Fourier-transform spectroscopy DO - 10.1364/OL.38.002262 AU - Velasco, Aitor V. AU - Cheben, Pavel AU - Florjańczyk, Mirosław AU - Schmid, Jens H. AU - Bock, Przemek J. AU - Lapointe, Jean AU - Delâge, André AU - Janz, Siegfried AU - Vachon, Martin AU - Calvo, María L. AU - Xu, Dan-Xia AU - Civiš, Svatopluk T2 - Optics Letters SN - 0146-9592 VL - 38 IS - 13 SP - 2262 EP - 2264 KW - Fourier transform spectrometers KW - Fourier transform spectroscopy KW - Ideal behavior KW - Optical fiber interferometers KW - Resolution limits KW - Scanning elements KW - Spatial heterodyne KW - Spectral inversion KW - Fourier transform infrared spectroscopy KW - Interferometers KW - Optical fibers KW - Optical fiber fabrication AB - We report a spatial heterodyne Fourier-transform spectrometer implemented with an array of optical fiber interferometers. This configuration generates a wavelength-dependent stationary interferogram from which the input spectrum is retrieved in a single shot without scanning elements. Furthermore, fabrication and experimental deviations from the ideal behavior of the device are corrected by spectral inversion algorithms. The spectral resolution of our system can be readily scaled up by incorporating longer optical fiber delays, providing a pathway toward surpassing current spectroscopy resolution limits. © 2013 Optical Society of America. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 86fcac4f-ba40-44ae-a357-f61bb874706f ER - TY - JOUR TI - Comparison of metrics to monitor and compensate for piezoceramic debonding in structural health monitoring DO - 10.1177/1475921712467490 AU - Mulligan, K.R. AU - Quaegebeur, N. AU - Ostiguy, P.-C. AU - Masson, P. AU - Létourneau, S. T2 - Structural Health Monitoring SN - 1475-9217 VL - 12 IS - 2 SP - 153 EP - 168 KW - Frequency domains KW - Health monitoring KW - Lumped parameter models KW - Mechanical resonance frequency KW - Piezoceramic KW - Piezoceramic transducer KW - Received signals KW - Resonance frequencies KW - Adhesives KW - Damping KW - Degradation KW - Electric admittance KW - Natural frequencies KW - Piezoelectric ceramics KW - Piezoelectric transducers KW - Structural health monitoring AB - This article investigates metrics to assess and compensate for the degradation of the adhesive layer of surface-bonded piezoceramic transducers for structural health-monitoring applications. Capacitance, resonance frequency, and modal damping parameters are derived from admittance curves using a lumped parameter model to monitor the degradation of the transducer adhesive layer. A pitch-catch configuration is then used to discriminate the effect of bonding degradation on actuation and sensing. It is shown that below the first mechanical resonance frequency of the piezoceramic transducers, the degradation causes a decrease in the amplitude of the transmitted and received signals, while above resonance, in addition to a decrease in the amplitude of the transmitted and received signals, a linear phase shift is observed. A signal-correction factor is proposed to adjust signals based on adhesive degradation evaluated using the measured modal damping. The benefits of the signal-correction factor are demonstrated in the frequency domain for both the A0 and S0 modes. © The Author(s) 2012. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 093e44ae-591e-45e4-b366-673ad9d10f5d ER - TY - JOUR TI - Lipid reassembly in asymmetric Langmuir-Blodgett/Langmuir-Schaeffer bilayers DO - 10.1021/la3040424 AU - Yuan, J. AU - Hao, C. AU - Chen, M. AU - Berini, P. AU - Zou, S. T2 - Langmuir SN - 0743-7463 VL - 29 IS - 1 SP - 221 EP - 227 KW - 1 ,2-dioleoyl-sn-glycero-3-phosphocholine KW - AFM KW - Bi-layer KW - Binary lipid mixtures KW - Contrast changes KW - Domain structure KW - Dye molecule KW - Fluid-phase KW - Force mapping KW - Gel domains KW - Gel phase KW - Glass substrates KW - Image contrasts KW - Langmuir-blodgett KW - Lipid molecules KW - Multimodal imaging KW - Novel route KW - Phase segregations KW - Reassembly KW - Rupture forces KW - Single components KW - Solid-liquid interfaces KW - Structure dependent KW - Ternary mixtures KW - TIRF imaging KW - Total internal reflection fluorescence microscopy KW - Amino acids KW - Atomic force microscopy KW - Binary mixtures KW - Fluorescence KW - Mica KW - Molecules KW - Refractive index KW - Substrates KW - Lipid bilayers KW - aluminum silicate KW - glass KW - lipid KW - mica KW - article KW - atomic force microscopy KW - chemistry KW - lipid bilayer KW - Aluminum Silicates KW - Glass KW - Lipid Bilayers KW - Lipids KW - Microscopy, Atomic Force AB - Molecular-reorganization-induced morphology alteration in asymmetric substrate-supported lipid bilayers (SLBs) was directly visualized by means of atomic force microscopy (AFM) and total internal reflection fluorescence (TIRF) microscopy. SLB samples were fabricated on mica-on-glass and glass substrates by Langmuir-Blodgett (LB)/Langmuir-Schaeffer (LS) using binary lipid mixtures, namely, 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC)/1,2-dipalmitoyl-sn- glycero-3-phosphocholine (DPPC) and ternary mixtures DOPC/DPPC/1,2-dioleoyl-sn- glycero-3-phospho-l-serine (DOPS), labeled with 0.2 mol % Texas Red 1,2-dihexadecanoyl-sn-glycero-3-phosphoethanolamine triethylammonium salt (TR-DHPE) dye. Phase segregations were characterized by TIRF imaging, and DPPC-enriched domain structures were also observed. Interestingly for ∼40% (n = 6) of the samples with binary mixtures in the LB leaflet and a single component in the LS leaflet, that is, (DOPC/DPPC)LB+DOPC LS, the contrast of the DPPC domains changed from the original dark (without dye) to bright (more TR dye partitioning) on TIRF images, returning to dark again. This contrast reverse was also correlated to AFM height images, where a DPPC-DPPC gel phase was spotted after the TIRF image contrast returned to dark. The rupture force mapping results measured on these binary mixture samples also confirmed unambiguously the formation of DPPC-DPPC gel domain components during the contrast change. The samples were tracked over 48 h to investigate the lipid molecule movements in both the DPPC domains and the DOPC fluid phase. The fluorescence contrast changes from bright to dark in SLBs indicate that the movement of dye molecules was independent of the movement of lipid molecules. In addition, correlated multimodal imaging using AFM, force mapping, and fluorescence provides a novel route to uncover the reorganization of lipid molecules at the solid-liquid interface, suggesting that the dynamics of dye molecules is highly structure dependent. © Published 2012 by the American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 04c91300-11c2-4777-a6b6-5e96bb9dd9f2 ER - TY - JOUR TI - Abundant cyanopolyynes as a probe of infall in the Serpens South cluster-forming region DO - 10.1093/mnras/stt1671 AU - Friesen, R. K. AU - Medeiros, L. AU - Schnee, S. AU - Bourke, T. L. AU - Di Francesco, J. AU - Gutermuth, R. AU - Myers, P. C. T2 - Monthly Notices of the Royal Astronomical Society SN - 0035-8711 VL - 436 IS - 2 SP - 1513 EP - 1529 KW - Astrochemistry KW - Star formation KW - ISM abundances KW - ISM radio lines AB - We have detected bright HC₇N J=21-20 emission towards multiple locations in the Serpens South cluster-forming region using the K-Band Focal Plane Array at the Robert C. Byrd Green Bank Telescope. HC7N is seen primarily towards cold filamentary structures that have yet to form stars, largely avoiding the dense gas associated with small protostellar groups and the main central cluster of Serpens South. Where detected, the HC₇N abundances are similar to those found in other nearby star-forming regions. Towards some HC₇N 'clumps', we find consistent variations in the line centroids relative to NH₃(1,1) emission, as well as systematic increases in the HC₇N non-thermal line widths, which we argue reveal infall motions on to dense filaments within Serpens South with minimum mass accretion rates of M ~2-5M⊙ Myr⁻¹. The relative abundance of NH₃ to HC₇N suggests that the HC₇N is tracing gas that has been at densities n ~10₇ cm⁻³ for time-scales t ≲ 1-2 × 10⁵yr. Since HC₇N emission peaks are rarely co-located with those of either NH₃ or continuum, it is likely that Serpens South is not particularly remarkable in its abundance of HC₇ N, but instead the serendipitous mapping of HC₇N simultaneously with NH₃ has allowed us to detect HC₇N at low abundances in regions where it otherwise may not have been looked for. This result extends the known star-forming regions containing significant HC₇N emission from typically quiescent regions, like the Taurus molecular cloud, to more complex, active environments. DA - 2013/10/15 PY - 2013 PB - Oxford University Press LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3e585df7-5478-4617-bf16-60542bdefd62 ER - TY - JOUR TI - BigBrain: An ultrahigh-resolution 3D human brain model DO - 10.1126/science.1235381 AU - Amunts, K. AU - Lepage, C. AU - Borgeat, L. AU - Mohlberg, H. AU - Dickscheid, T. AU - Rousseau, M.-É. AU - Bludau, S. AU - Bazin, P.-L. AU - Lewis, L.B. AU - Oros-Peusquens, A.-M. AU - Shah, N.J. AU - Lippert, T. AU - Zilles, K. AU - Evans, A.C. T2 - Science SN - 0036-8075 VL - 340 IS - 6139 SP - 1472 EP - 1475 KW - brain KW - histology KW - hominid KW - hypothesis testing KW - numerical model KW - article KW - brain KW - brain mapping KW - brain region KW - human KW - human tissue KW - model KW - neuroanatomy KW - primary motor cortex KW - priority journal KW - simulation KW - tissue section KW - ultrahigh resolution three dimensional model KW - Aged KW - Brain KW - Brain Mapping KW - Cerebral Cortex KW - Female KW - Humans KW - Image Processing, Computer-Assisted KW - Imaging, Three-Dimensional KW - Magnetic Resonance Imaging KW - Microtomy AB - Reference brains are indispensable tools in human brain mapping, enabling integration of multimodal data into an anatomically realistic standard space. Available reference brains, however, are restricted to the macroscopic scale and do not provide information on the functionally important microscopic dimension. We created an ultrahigh-resolution three-dimensional (3D) model of a human brain at nearly cellular resolution of 20 micrometers, based on the reconstruction of 7404 histological sections. "BigBrain" is a free, publicly available tool that provides considerable neuroanatomical insight into the human brain, thereby allowing the extraction of microscopic data for modeling and simulation. BigBrain enables testing of hypotheses on optimal path lengths between interconnected cortical regions or on spatial organization of genetic patterning, redefining the traditional neuroanatomy maps such as those of Brodmann and von Economo. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4a8c62e3-6d03-4044-b981-639e0d2a527b ER - TY - JOUR TI - Correlates of protection following vaccination of mice with gene deletion mutants of Francisella tularensis subspecies tularensis strain, SCHU S4 that elicit varying degrees of immunity to systemic and respiratory challenge with wild-type bacteria DO - 10.1016/j.molimm.2012.10.043 AU - Ryden, P. AU - Twine, S. AU - Shen, H. AU - Harris, G. AU - Chen, W. AU - Sjostedt, A. AU - Conlan, W. T2 - Molecular Immunology SN - 0161-5890 VL - 54 IS - 1 SP - 58 EP - 67 KW - cytokine KW - francisella tularensis vaccine KW - gamma interferon KW - live vaccine KW - monocyte chemotactic protein 1 KW - tumor necrosis factor alpha KW - unclassified drug KW - animal cell KW - animal experiment KW - animal model KW - animal tissue KW - antibody response KW - article KW - bacterial immunity KW - bacterial strain KW - drug mechanism KW - female KW - Francisella tularensis KW - gene deletion KW - immune response KW - immunization KW - mouse KW - nonhuman KW - nucleotide sequence KW - priority journal KW - Administration, Cutaneous KW - Administration, Inhalation KW - Animals KW - Bacterial Vaccines KW - Female KW - Francisella tularensis KW - Gene Deletion KW - Immunity KW - Immunity, Innate KW - Mice KW - Mice, Inbred BALB C KW - Organisms, Genetically Modified KW - Tularemia KW - Vaccination KW - Virulence KW - Bacteria (microorganisms) KW - Francisella KW - Francisella tularensis KW - Mus AB - Francisella tularensis subspecies tularensis is an extremely virulent facultative intracellular bacterial pathogen capable of causing significant mortality in humans when inhaled. Consequently, subspecies tularensis was developed as a biological weapon more than 50 years ago. To counter this threat the US Army empirically developed a live vaccine strain, F. tularensis LVS, from the less virulent holarctica subspecies. In human experiments LVS afforded substantial protection against transdermal challenge with clinical subspecies tularensis strain, SCHU S4, but lesser protection against infection initiated by inhalation of the pathogen. Several regulatory and clinical issues remain unresolved for this vaccine, including the absence of a robust correlate of protection. To try to address this, we have developed several defined gene deletion mutants of SCHU S4 that elicit varying degrees of protection in a mouse dermal or respiratory challenge model. In the present study, we have examined whether host immune responses to immunization with such live vaccine candidates can serve as correlates of protection. Antibody responses were unable to distinguish between effective and ineffective vaccine strains. However, several cytokine responses to vaccination showed some promise. Especially, serum levels of TNFα, IFNγ, and MCP-1 between days 4 and 7 after vaccination appear to correlate with protection against respiratory challenge. © 2012. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 61b90b2b-f56e-46c2-8fda-451932b3cf03 ER - TY - JOUR TI - Fully automatic expression-invariant face correspondence DO - 10.1007/s00138-013-0579-9 AU - Salazar, A. AU - Wuhrer, S. AU - Shu, C. AU - Prieto, F. T2 - Machine Vision and Applications SN - 0932-8092 SP - 1 EP - 21 AB - We consider the problem of computing accurate point-to-point correspondences among a set of human face scans with varying expressions. Our fully automatic approach does not require any manually placed markers on the scan. Instead, the approach learns the locations of a set of landmarks present in a database and uses this knowledge to automatically predict the locations of these landmarks on a newly available scan. The predicted landmarks are then used to compute point-to-point correspondences between a template model and the newly available scan. To accurately fit the expression of the template to the expression of the scan, we use as template a blendshape model. Our algorithm was tested on a database of human faces of different ethnic groups with strongly varying expressions. Experimental results show that the obtained point-to-point correspondence is both highly accurate and consistent for most of the tested 3D face models. © 2013 Springer-Verlag Berlin Heidelberg. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c44a3083-a9b7-4bf4-b60a-4081e5b4439b ER - TY - JOUR TI - HTC scientific computing in a distributed cloud environment DO - 10.1145/2465848.2465850 AU - Sobie, R. AU - Agarwal, A. AU - Gable, I. AU - Leavett-Brown, C. AU - Paterson, M. AU - Taylor, R. AU - Charbonneau, A. AU - Impey, R. AU - Podiama, W. T2 - ScienceCloud 2013 - Proceedings of the 4th ACM Workshop on Scientific Cloud Computing T3 - 4th ACM Workshop on Scientific Cloud Computing, ScienceCloud 2013, 17 June 2013 through 17 June 2013, New York, NY SP - 45 EP - 51 KW - Computing capacity KW - Computing system KW - Design and implementations KW - Distributed clouds KW - High-throughput computing KW - Scientific applications KW - Cloud computing KW - Infrastructure as a service (IaaS) KW - Distributed computer systems AB - This paper describes the use of a distributed cloud computing system for high-throughput computing (HTC) scientific applications. The distributed cloud computing system is composed of a number of separate Infrastructure-as-a-Service (IaaS) clouds that are utilized in a unified infrastructure. The distributed cloud has been in production-quality operation for two years with approximately 500,000 completed jobs where a typical workload has 500 simultaneous embarrassingly-parallel jobs that run for approximately 12 hours. We review the design and implementation of the system which is based on pre-existing components and a number of custom components. We discuss the operation of the system, and describe our plans for the expansion to more sites and increased computing capacity. © 2013 ACM. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : efd46617-11d9-4231-8e59-55c8f5bf51d0 ER - TY - JOUR TI - Theoretical and experimental insights into applicability of solid-state 93Nb NMR in catalysis DO - 10.1039/c3cp44016h AU - Papulovskiy, E. AU - Shubin, A.A. AU - Terskikh, V.V. AU - Pickard, C.J. AU - Lapina, O.B. T2 - Physical Chemistry Chemical Physics SN - 1463-9076 VL - 15 IS - 14 SP - 5115 EP - 5131 AB - Ab initio DFT calculations of 93Nb NMR parameters using the NMR-CASTEP code were performed for a series of over fifty individual niobates, and a good agreement has been found with experimental NMR parameters. New experimental and calculated 93Nb NMR data were obtained for several compounds, AlNbO4, VNb9O25, K 8Nb6O19 and Cs3NbO8, which are of particular interest for catalysis. Several interesting trends have been identified between 93Nb NMR parameters and the specifics of niobium site environments in niobates. These trends may serve as useful guidelines in interpreting 93Nb NMR spectra of complex niobium oxide systems, including amorphous samples and niobium-based multicomponent heterogeneous catalysts. Potential applications of 93Nb NMR to study solid polyoxoniobates are discussed. © 2013 The Owner Societies. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4970bc4a-632a-4364-9791-94fc325d3ad6 ER - TY - JOUR TI - Ground-state 12CO emission and a resolved jet at 115GHz (rest frame) in the radio-loud quasar 3C 318 DO - 10.1093/mnras/stt1530 AU - Heywood, I. AU - Martínez-Sansigre, A. AU - Willott, C.J. AU - Rawlings, S. T2 - Monthly Notices of the Royal Astronomical Society SN - 0035-8711 VL - 435 IS - 4 SP - stt1530 SP - 3376 EP - 3384 AB - An analysis of 44 GHz Very Large Array observations of the z = 1.574 radio-loud quasar 3C 318 has revealed emission from the redshifted J=1→0 transition of the CO molecule and spatially resolved the 6.3 kpc radio jet associated with the quasar at 115 GHz rest frame. The continuum-subtracted line emitter is spatially offset from the quasar nucleus by 0.33 arcsec (2.82 kpc in projection). This spatial offset has a significance of >8σ and, together with a previously published -400 km s-1 velocity offset measured in the J = 2→1 CO line relative to the systemic redshift of the quasar, rules out a circumnuclear starburst or molecular gas ring and suggests that the quasar host galaxy is either undergoing a major merger with a gas-rich galaxy or is otherwise a highly disrupted system. If the merger scenario is correct, then the event may be in its early stages, acting as the trigger for both the young radio jets in the quasar and a starburst in the merging galaxy. The total molecular gas mass in the spatially offset line emitter as measured from the ground-state CO line MH2 = 3.7 (±0.4) × 1010 (αCO/0.8)M⊙. Assuming that the line emitter can be modelled as a rotating disc, an inclination-dependent upper limit is derived for its dynamical mass Mdyn sin2(i) < 3.2 × 109M⊙, suggesting that for MH2 to remain less than Mdyn the inclination angle must be i < 16°. The far-infrared and CO luminosities of 246 extragalactic systems are collated from the literature for comparison. The high molecular gas content of 3C 318 is consistent with that of the general population of high-redshift quasars and submillimetre galaxies. © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : de0473c2-aa9f-492f-af6d-a88b17ef487c ER - TY - JOUR TI - The physico-mechanical stability of C-S-H/polyaniline nanocomposites DO - 10.1617/s11527-013-0168-4 AU - Khoshnazar, R. AU - Alizadeh, R. AU - Beaudoin, J.J. AU - Raki, L. T2 - Materials and Structures/Materiaux et Constructions SN - 1359-5997 SP - 1 EP - 9 AB - The formation and characterization of various types of organically modified C -S -H-based nanocomposites have recently been investigated. The engineering properties of this class of cementitious materials, however, have rarely been studied. The current work examines a new approach to the assessment of the mechanical performance of C -S -H/polyaniline nanocomposites prepared in situ using C -S -H systems having C/S ratios of 0.8 and 1.2. Test methods including X-ray diffraction and dynamic mechanical analysis were employed in order to evaluate the physical and mechanical stability of these polymer-modified C -S -H nanocomposites. The variations in the 002 basal spacing, storage modulus (E′) and internal friction (tan δ) of the C -S -H/polyaniline nanocomposites were examined upon the incremental removal of the interlayer water. It was suggested that the polyaniline molecules may reinforce the C -S -H lamellar structure as indicated by the magnitude of the decrease in the 002 basal-spacing during the dehydration. Moreover, the initial DMA response of the C -S -H/polyaniline nanocomposites appears to be improved. © 2013 RILEM. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 849e782a-dad6-4f56-a211-fc175cabf4b7 ER - TY - JOUR TI - Altruism during predation in an assassin bug DO - 10.1007/s00114-013-1091-9 AU - Dejean, A. AU - Revel, M. AU - Azémar, F. AU - UPS, INP AU - Roux, O. T2 - Naturwissenschaften SN - 0028-1042 VL - 100 IS - 10 SP - 913 EP - 922 KW - altruism KW - ant KW - cannibalism KW - conspecific KW - egg KW - feeding KW - host plant KW - hunger KW - insect KW - myrmecophyte KW - predation KW - prey capture KW - prey size KW - shelter KW - Allomerus decemarticulatus KW - Drosera KW - Hexapoda KW - Hirtella physophora KW - Reduviidae KW - Zelus AB - Zelus annulosus is an assassin bug species mostly noted on Hirtella physophora, a myrmecophyte specifically associated with the ant Allomerus decemarticulatus known to build traps on host tree twigs to ambush insect preys. The Z. annulosus females lay egg clutches protected by a sticky substance. To avoid being trapped, the first three instars of nymphs remain grouped in a clutch beneath the leaves on which they hatched, yet from time to time, they climb onto the upper side to group ambush preys. Long-distance prey detection permits these bugs to capture flying or jumping insects that alight on their leaves. Like some other Zelus species, the sticky substance of the sundew setae on their forelegs aids in prey capture. Group ambushing permits early instars to capture insects that they then share or not depending on prey size and the hunger of the successful nymphs. Fourth and fifth instars, with greater needs, rather ambush solitarily on different host tree leaves, but attract siblings to share large preys. Communal feeding permits faster prey consumption, enabling small nymphs to return sooner to the shelter of their leaves. By improving the regularity of feeding for each nymph, it likely regulates nymphal development, synchronizing molting and subsequently limiting cannibalism. © 2013 Springer-Verlag Berlin Heidelberg. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d1a0a10e-b398-455b-a8fe-2d1d3831ca01 ER - TY - JOUR TI - Transgenic production of omega-3 very long chain polyunsaturated fatty acids in plants: Accomplishment and challenge DO - 10.1016/j.bcab.2013.08.007 AU - Chen, Y. AU - Meesapyodsuk, D. AU - Qiu, X. T2 - Biocatalysis and Agricultural Biotechnology SN - 1878-8181 AB - Omega-3 very long chain polyunsaturated fatty acids (VLC-PUFAs or VLCPUFAs) such as eicosapentaenoic acid (EPA, 22:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) have important roles in human health. The current source of these fatty acids is oil from marine fish and oleaginous microorganisms. However, sustainability of this source is questionable due to the declining fish population in ocean as well as the high cost associated with the microbial culturing and oil extraction. Transgenic plants producing a high level of VLCPUFAs have been proposed to be a potential alternative source for these fatty acids. Detections of EPA and DHA in transgenic plants expressing heterologous desaturases and elongases as well as a PUFA synthase from VLCPUFA-producing microorganisms have indeed optimistically proven the concept. However, the yield of VLCPUFAs in transgenics is still low and the desirable composition of these fatty acids is not achieved. This mini-review discusses what has been done on the reconstitution of VLCPUFA-biosynthetic pathways in transgenics and what kind of challenges and possible solutions could be in producing VLCPUFAs in plants. © 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5ff8e58c-aa69-4411-b8ed-49a68aeee3ee ER - TY - JOUR TI - Femtosecond laser desorption of thin polymer films from a dielectric surface AU - Mercadier, L. AU - Peng, J. AU - Sultan, Y. AU - Rayner, D.M. AU - Corkum, P.B. T2 - CLEO: Science and Innovations, CLEO_SI 2013 T3 - CLEO: Science and Innovations, CLEO_SI 2013, 9 June 2013 through 14 June 2013, San Jose, CA SN - 9781557529725 KW - Beam geometry KW - Dielectric surface KW - Thin polymer films KW - Two ways KW - Atomic force microscopy KW - Semiconducting films KW - Ultrashort pulses KW - Polymer films AB - We desorb polymer films from fused silica with a femtosecond laser and characterize the results by atomic force microscopy. Our study as a function of beam geometry and energy reveals two ways of achieving spatially controlled nanodesorption. © OSA 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a9adb067-0b83-40e3-ae31-574cd3824b32 ER - TY - JOUR TI - Enhancement of amorphous phase formation in alumina-YSZ coatings deposited by suspension plasma spray process DO - 10.1016/j.surfcoat.2012.10.054 AU - Tarasi, F. AU - Medraj, M. AU - Dolatabadi, A. AU - Oberste-Berghaus, J. AU - Moreau, C. T2 - Surface and Coatings Technology SN - 0257-8972 VL - 220 SP - 191 EP - 198 KW - Alumina-YSZ KW - Amorphous phase KW - Amorphous phase formation KW - Ceramic composites KW - In-flight particle characteristics KW - Influence of spray parameters KW - Larger particle sizes KW - Suspension plasma sprays KW - Alumina KW - Coatings KW - Deposition KW - Plasma jets KW - Plasma spraying KW - Preheating KW - Amorphous materials AB - In the present work on pseudo-eutectic alumina-yttria stabilized zirconia (YSZ) composite, the influence of spray parameters on amorphous phase formation during suspension plasma spray deposition is investigated. Several variables were evaluated as the most probable key factors influencing the amorphous phase formation. These variables include powder feed size, in-flight particle characteristics (temperature and velocity), spraying robot travel speed, preheating the substrate, number of deposition passes and the presence of bond coat. It was found that larger particle size, higher robot speed and substrate preheating lead to larger amounts of amorphous phase. Moreover, it is shown that particle velocity and temperature need to be reasonably low to get greater amorphous content while the presence of a bond coat has no significant influence on the amorphous phase formation. In contrast, increasing the number of deposition passes is detrimental to this phase. This work also discusses some correlations observed between the amorphous phase content and the in-flight particle characteristics and coating grain sizes. © 2012 Elsevier B.V. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : fa42066e-e033-464e-8383-7122ed72b64e ER - TY - CHAP TI - Learning in the presence of large fluctuations : a study of aggregation and correlation DO - 10.1007/978-3-642-37382-4_4 AU - Paquet, Eric AU - Viktor, Herna Lydia AU - Guo, Hongyu T2 - New Frontiers in Mining Complex Patterns : First International Workshop, NFMCP 2012, Held in Conjunction with ECML/PKDD 2012, Bristol, UK, September 24, 2012, Rivesed Selected Papers T2 - Lecture Notes In Computer Science; 7765 T3 - 1st International Workshop on New Frontiers in Mining Complex Patterns (NFMCP 2012), held in conjunction with European Conference on Machine Learning and Principles and Practice of Knowledge Discovery in Databases (ECML-PKDD 2012), September 24, 2012, Bristol, United Kingdom SN - 0302-9743 SN - 978-3-642-37381-7 SN - 978-3-642-37382-4 VL - 7765 LNAI SP - 49 EP - 63 KW - Analysis of data KW - Average values KW - Central Limit Theorem KW - Correlation-based Analysis and Covariance KW - Financial Data Analysis KW - Relational learning KW - Set of rules KW - Stable distributions KW - Database systems KW - Oil spills KW - Gaussian distribution AB - Consider a scenario where one aims to learn models from data being characterized by very large fluctuations that are neither attributable to noise nor outliers. This may be the case, for instance, when predicting the potential future damages of earthquakes or oil spills, or when conducting financial data analysis. If follows that, in such a situation, the standard central limit theorem does not apply, since the associated Gaussian distribution exponentially suppresses large fluctuations. In this paper, we present an analysis of data aggregation and correlation in such scenarios. To this end, we introduce the Lévy, or stable, distribution which is a generalization of the Gaussian distribution. Our theoretical conclusions are illustrated with various simulations, as well as against a benchmarking financial database. We show which specific strategies should be adopted for aggregation, depending on the stability exponent of the Lévy distribution. Our results indicate that the correlation in between two attributes may be underestimated if a Gaussian distribution is erroneously assumed. Secondly, we show that, in the scenario where we aim to learn a set of rules to estimate the level of stability of a stock market, the Lévy distribution produces superior results. Thirdly, we illustrate that, in a multi-relational database mining setting, aggregation using average values may be highly unsuitable. © 2013 Springer-Verlag. DA - 2013 PY - 2013 PB - Springer Berlin Heidelberg LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9fed2d6f-2322-4574-badd-32de49521bcb ER - TY - JOUR TI - Metallic transfer films studied in situ and ex situ: The case of cold-sprayed Al-Al2O3 AU - Michael Shockley, J. AU - Descartes, S. AU - Irissou, E. AU - Legoux, J.-G. AU - Chromik, R.R. T2 - Tribology and Lubrication Technology SN - 1545-858X VL - 69 IS - 9 SP - 28 EP - 31 KW - Cold-sprayed KW - Ex situ analysis KW - Metallic transfers KW - Nano-structured KW - Nanocrystalline aluminum KW - Transfer film KW - Tribological performance KW - Wear tracks KW - Composite coatings KW - Mechanical properties KW - Aluminum AB - The presence of A12O3 particles in the composite coating promoted the formation of nanostructured aluminum in the transfer film, which contributed to its stability, as observed by in situ tribometry. This was linked to lower wear rates and more stable friction compared to the unreinforced cold sprayed aluminum. Here, the combination of in situ tribometry and ex situ analysis was a useful approach to reveal mechanisms specifically related to the transfer film, which were responsible for improved tribological performance. Other questions remain, which will be subject of future work, regarding the microstructural evolution in the wear track, mechanical properties of the third bodies, and the role of A1203 particles in the dynamic formation of nanocrystalline aluminum. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : dd6f9794-fa86-4a25-ba69-e9c0b601672e ER - TY - JOUR TI - Dependence of the triple point temperature of neon on isotopic composition and its implications for the ITS-90 DO - 10.1063/1.4821378 AU - Pavese, F. AU - Steur, P.P.M. AU - Hermier, Y. AU - Hill, K.D. AU - Kim, J.S. AU - Lipiński, L. AU - Nagao, K. AU - Nakano, T. AU - Peruzzi, A. AU - Sparasci, F. AU - Szmyrka-Grzebyk, A. AU - Tamura, O. AU - Tew, W.L. AU - Valkiers, S. AU - Van Geel, J. T2 - TEMPERATURE: ITS MEASUREMENT AND CONTROL IN SCIENCE AND INDUSTRY, VOLUME 8: Proceedings of the Ninth International Temperature Symposium T2 - AIP Conference Proceedings; no. 1552 T3 - 9th International Temperature Symposium on Temperature: Its Measurement and Control in Science and Industry, ITS 2012, 19 March 2012 through 23 March 2012, Los Angeles, CA SN - 0094-243X SN - 1551-7616 SN - 9780735411784 SP - 192 EP - 197 AB - The paper summarizes the results of an International Project started in 2003 aimed at formulating a correction for the variability of isotopic composition found in 'natural' neon, and presently not taken into account by the ITS-90 definition, whose consequent ambiguity leads to a combined uncertainty uc = 160 μK, whereas uc = 30-50 μK for the rest of the budget. After a very short summary of the Project results (a detailed Final Report will be published later) recommendations for the correction function are presented, in agreement with both the experimental data and the theoretical calculations. © 2013 AIP Publishing LLC. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 7316cd37-78bc-42b1-9dbb-9766effd8dd9 ER - TY - JOUR TI - Effect of nucleation and plasticization on the stereocomplex formation between enantiomeric poly(lactic acid)s DO - 10.1016/j.polymer.2013.08.031 AU - Saeidlou, S. AU - Huneault, M.A. AU - Li, H. AU - Park, C.B. T2 - Polymer (United Kingdom) SN - 0032-3861 VL - 54 IS - 21 SP - 5762 EP - 5770 KW - Crystalline morphologies KW - Crystallization behavior KW - Heterogeneous nucleation KW - High melting point KW - Isothermal crystallization temperature KW - Spherulitic morphology KW - Stereocomplex formation KW - Stereocomplexes KW - Blending KW - Complexation KW - Crystallization kinetics KW - Differential scanning calorimetry KW - Lactic acid KW - Morphology KW - Optical data storage KW - Optical microscopy KW - Polypropylenes KW - Nucleation AB - The effect of nucleation and plasticization on the stereocomplex formation between poly(l-lactic acid) (PLLA) and poly(d-lactic acid) (PDLA) was investigated in blends where PDLA is added as a minor phase in a major phase of PLLA. The use of small amounts of PDLA is aimed at creating a high melting point stereocomplex phase that in turn can serve as nucleating agent for the major phase of PLLA. Blends containing 5% PDLA with talc or organic phosphonate as nucleants and polyethylene glycol as plasticizer were prepared via melt-blending. Their crystallization behavior was investigated through Differential Scanning Calorimetry (DSC) using various thermal histories. Two peculiar stereocomplex melting endotherms were found. The peak temperature and enthalpy of these two endotherms were correlated to prior isothermal crystallization temperature. The different endotherms were also associated with two different crystalline morphologies observed by optical microscopy and referred to as Network and Spherulitic morphologies. The influence of plasticization and of heterogeneous nucleation on these morphologies was investigated through optical microscopy and calorimetric observations. © 2013 Elsevier Ltd. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 7be08d47-e5cf-4b4a-8530-0c087913df9f ER - TY - JOUR TI - Centrifugation-induced water-tunable photonic colloidal crystals with narrow diffraction bandwidth and highly sensitive detection of SCN- DO - 10.1021/am302804b AU - Ma, C. AU - Jiang, Y. AU - Yang, X. AU - Wang, C. AU - Li, H. AU - Dong, F. AU - Yang, B. AU - Yu, K. AU - Lin, Q. T2 - ACS Applied Materials and Interfaces SN - 1944-8244 VL - 5 IS - 6 SP - 1990 EP - 1996 KW - Colloidal crystals KW - Electromagnetic spectra KW - Highly sensitive detections KW - Ion detection KW - Narrow size distributions KW - Photonic bandgap (PBG) KW - Polymeric microsphere KW - Stimuli-responsive KW - Centrifugation KW - Diffraction KW - Hydrogen bonds KW - Hydrophilicity KW - Ions KW - Microspheres KW - Polymers KW - Polystyrenes KW - Self assembly KW - Spontaneous emission KW - Hydrogels AB - Novel opal hydrogels with water-tunable photonic bandgap (PBG) exhibiting responses to external stimuli were self-assembled from polystyrene-co-poly(N,N- dimethylacrylamide) (PS-co-PDMAA) microspheres. The polymeric microspheres with narrow size distribution were successfully prepared in water, consisting of two regions. The inner region is rich in PS which is hard and hydrophobic; the outer region is rich in PDMAA which is soft and hydrophilic. The self-assembly of the PS-co-PDMAA hydrogel microspheres is ready induced by centrifugation and resulted in highly ordered three-dimensional (3D) photonic colloidal crystals (PCCs). With an increase of the amount of water, the PBG of the opal hydrogels shifted from the visible to near-infrared region of the electromagnetic spectrum. The maximum shift of diffraction peak positions could be larger than 500 nm with narrow full width at half maximum (FWHM) in the range of 20 to 40 nm only. The change in color was visible to the naked eye. The remarkable sensitivity to water of the lattice spacing of the opal hydrogels was repeatable after centrifugation. These observations are attributed to a reproducible degree of hydration of the hydrophilic outer region of the polymeric microspheres. Furthermore, the diffraction of the opal hydrogels was particularly sensitive to the presence of thiocyanate (SCN-) ions. The interaction between SCN- ions and DMAA repeat units is argued to block hydrogen bonds between DMAA and water molecules. Our PS-co-PDMAA opal hydrogels could be a practical system for diffraction-based detections. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 41ee19d5-cd52-4c25-8e72-10163b85767c ER - TY - JOUR TI - Simulation of conjugate heat transfer using the Lattice Boltzmann Method DO - 10.1080/10407782.2012.725009 AU - Tarokh, A. AU - Mohamad, A.A. AU - Jiang, L. T2 - Numerical Heat Transfer; Part A: Applications SN - 1040-7782 VL - 63 IS - 3 SP - 159 EP - 178 KW - Cold streams KW - Computational domains KW - Conjugate heat transfer KW - Energy equation KW - Extended surfaces KW - Finite thermal conductivity KW - Finite thickness KW - Fluid phasis KW - Lattice Boltzmann method KW - Lattice boltzmann methods (LBM) KW - Rate of heat transfer KW - Two-stream KW - Heat transfer KW - Computational fluid dynamics AB - The Lattice Boltzmann Method (LBM) is utilized to investigate conjugate heat transfer. Hot and cold streams enter the computational domain, and heat transfer takes place between the two streams through a finite thickness and finite thermal conductivity wall. The main objective of the work is to demonstrate that LBM can solve conjugate heat transfer by using one energy equation for solid and fluid phases. The flux continuity insures automatically. Furthermore, the effects of extended surfaces were investigated on the rate of heat transfer and pressure drop. © 2013 Copyright Taylor and Francis Group, LLC. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9e5ce91d-70ba-4f6e-80c4-2cd58167d79b ER - TY - JOUR TI - Polymer peel-off mask for high-resolution surface derivatization, neuron placement and guidance DO - 10.1002/bit.24887 AU - Martinez, Dolores AU - Py, Christopher AU - Denhoff, Mike AU - Monette, Robert AU - Comas, Tanya AU - Krantis, Anthony AU - Mealing, Geoffrey T2 - Biotechnology and Bioengineering SN - 0006-3592 VL - 110 IS - 8 SP - 2236 EP - 2241 KW - chemical patterning; process guidance; dry lift-off; neural network AB - We present a dry lift-off method using a chemically resistant spin-on plastic, polyimide, to pattern surfaces with high accuracy and resolution. Using well-known lithographic and reactive ion etching techniques, the spin-on polymer is patterned over a silicon dioxide surface. The plastic efficiently adheres to the silicon dioxide surface during the chemical modification and is readily lifted-off following the derivatization process, permitting highly reliable surface derivatization. The verticality of the reactive ion etch enables sub-micrometer features to be patterned, down to 0.8μm. The technique is used to pattern neurons on silicon dioxide surfaces: efficient neuron placement over a 4mm area is shown for patterns larger than 50μm while process guidance is shown for 10μm patterns. DA - 2013/05/29 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5f776607-e59c-47e8-9e25-d6d65854d521 ER - TY - JOUR TI - Rearrangements and addition reactions of biarylazacyclooctynones and the implications to copper-free click chemistry DO - 10.1039/c3ob40683k AU - Chigrinova, M. AU - McKay, C.S. AU - Beaulieu, L.-P.B. AU - Udachin, K.A. AU - Beauchemin, A.M. AU - Pezacki, J.P. T2 - Organic and Biomolecular Chemistry SN - 1477-0520 VL - 11 IS - 21 SP - 3436 EP - 3441 KW - Bio-conjugation KW - Copper-free clicks KW - Highly strained KW - Living systems KW - Tetracyclic products KW - Chemistry KW - Positive ions KW - Addition reactions AB - Highly strained biarylazacyclooctynone (BARAC) and analogous bioconjugation reagents were shown to undergo novel rearrangement and addition reactions leading to tetracyclic products. This may limit their practical applicability as bioorthogonal reporters for imaging biomolecules within living systems. This journal is © The Royal Society of Chemistry. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5400c140-99bb-4d42-abd0-04e481c7888c ER - TY - JOUR TI - Effect of duty cycle and applied current frequency on plasma electrolytic oxidation (PEO) coating growth behavior DO - 10.1016/j.surfcoat.2013.03.041 AU - Dehnavi, V. AU - Luan, B.L. AU - Shoesmith, D.W. AU - Liu, X.Y. AU - Rohani, S. T2 - Surface and Coatings Technology SN - 0257-8972 VL - 226 SP - 100 EP - 107 KW - Alkaline electrolytes KW - Concentration distributions KW - Duty cycle KW - Electrical parameter KW - Elemental distribution KW - Frequency KW - Plasma electrolytic oxidation KW - Pulsed direct current KW - Aluminum KW - Ceramic coatings KW - Energy dispersive spectroscopy KW - Oxidation KW - Plasmas KW - Scanning electron microscopy KW - Electrolysis AB - Ceramic coatings were created on the surface of 6061 aluminum alloy using a plasma electrolytic oxidation (PEO) process employing a pulsed direct current (DC) power mode in an alkaline electrolyte. The effect of electrical parameters including frequency and duty cycle on the microdischarge behavior and coating growth was investigated at constant current. Surface features of coatings were studied using scanning electron microscopy. Energy dispersive spectroscopy was employed to investigate elemental distribution on the coating surfaces and cross-sections. Applying lower duty cycles was found to result in increased breakdown voltages and microdischarges with higher spatial density and lower intensity. Further, applying a lower duty cycle was also found to promote the uniformity of silicon distribution in the coating. Based on these new findings, a new conceptual model is proposed to explain the concentration distribution of Si on the surface of coatings prepared at different duty cycles. © 2013 . DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : de47f0a1-00c9-44a0-8033-38d15eba8890 ER - TY - JOUR TI - Comparison of realizations of Re-C fixed points filled and measured at NPL and NRC DO - 10.1063/1.4819645 AU - Todd, A.D.W. AU - Lowe, D.H. AU - Dong, W. AU - Woods, D.J. T2 - TEMPERATURE: ITS MEASUREMENT AND CONTROL IN SCIENCE AND INDUSTRY, VOLUME 8: Proceedings of the Ninth International Temperature Symposium T2 - AIP Conference Proceedings; no. 1552 T3 - 9th International Temperature Symposium on Temperature: Its Measurement and Control in Science and Industry, ITS 2012, 19 March 2012 through 23 March 2012, Los Angeles, CA SN - 0094-243X SN - 1551-7616 SN - 9780735411784 SP - 797 EP - 801 AB - A Re-C fixed point was filled at the National Physical Laboratory (NPL), UK and its melting temperature compared to a fixed point that had been filled previously at NPL. Both of these fixed points were of the hybrid type and used a purified graphite foil between the sacrificial graphite sleeve and the outer crucible. The melting temperatures of these two fixed points were compared and found to agree within the comparison uncertainties. Another Re-C fixed point was filled at the National Research Council (NRC), Canada. This fixed point was also of the hybrid type but contained carbon-composite sheet as the liner between the sleeve and the outer crucible. The melting temperatures of the fixed point filled at NPL and the one filled at NRC were compared and found to agree within the uncertainties of the comparison. When the ITS-90 temperatures at the Re-C melting point (∼ 2474 °C) measured at NPL were compared to those measured at NRC they were also found to agree within the uncertainties of their respective scales. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e3fffc97-f5e5-4900-a03d-3ecea9f96868 ER - TY - CHAP TI - Isometrically invariant description of deformable objects based on the fractional heat equation DO - 10.1007/978-3-642-40246-3_17 AU - Paquet, Eric AU - Viktor, Herna Lydia T2 - Computer Analysis of Images and Patterns : 15th International Conference, CAIP 2013, York, UK, August 27-29, 2013, Proceedings, Part II T2 - Lecture Notes In Computer Science; 8048 T3 - 15th International Conference on Computer Analysis of Images and Patterns (CAIP 2013), August 27-29, 2013, York, United Kingdom SN - 0302-9743 SN - 0302-9743 SN - 978-3-642-40245-6 SN - 978-3-642-40246-3 SP - 135 EP - 143 KW - Fractional KW - Heat equation KW - Isometry KW - Kernel KW - Path integral KW - Geometry KW - Heat transfer KW - Image analysis KW - Random processes KW - Partial differential equations AB - Recently, a number of researchers have turned their attention to the creation of isometrically invariant shape descriptors based on the heat equation. The reason for this surge in interest is that the Laplace-Beltrami operator, associated with the heat equation, is highly dependent on the topology of the underlying manifold, which may lead to the creation of highly accurate descriptors. In this paper, we propose a generalisation based on the fractional heat equation. While the heat equation enables one to explore the shape with a Markovian Gaussian random walk, the fractional heat equation explores the manifold with a non-Markovian Lévy random walk. This generalisation provides two advantages. These are, first, that the process has a memory of the previously explored geometry and, second, that it is possible to correlate points or vertices which are not part of the same neighbourhood. Consequently, a highly accurate, contextual shape descriptor may be obtained. © 2013 Springer-Verlag. DA - 2013 PY - 2013 PB - Springer Berlin Heidelberg LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1d17627a-da37-4b8b-a51e-c4498afb89bf ER - TY - JOUR TI - Performance of thermally sprayed Si/mullite/BSAS environmental barrier coatings exposed to thermal cycling in water vapor environment DO - 10.1016/j.surfcoat.2012.11.043 AU - Cojocaru, C.V. AU - Lévesque, D. AU - Moreau, C. AU - Lima, R.S. T2 - Surface and Coatings Technology SN - 0257-8972 VL - 216 SP - 215 EP - 223 KW - Air plasma sprayed KW - Bond coats KW - BSAS KW - Controlled conditions KW - Crack-healing KW - Crack-resistant KW - Deposition conditions KW - Elastic modulus values KW - Environmental barrier coatings KW - Functionally graded KW - High temperature KW - High temperature structural applications KW - High-temperature water KW - Hot zone KW - Influence of water KW - Microstructural characteristics KW - SiC substrates KW - Silicon-based ceramics KW - Structural and mechanical properties KW - Thermal cycle testing KW - Thermal exposure KW - Top-coats KW - Water vapor atmosphere KW - Aluminosilicates KW - Ceramic matrix composites KW - Cracks KW - Elastic moduli KW - Gas turbines KW - High temperature applications KW - Signal encoding KW - Silicate minerals KW - Silicon KW - Silicon carbide KW - Thermal barrier coatings KW - Thermal cycling KW - Vapors KW - Sprayed coatings AB - The ongoing development of environmental barrier coatings (EBCs) offers the prospect to implement the full potential of silicon-based ceramic matrix composites (CMCs) for high temperature structural applications, more specifically the hot zones of gas turbine engines. The current state-of-the-art EBC system comprises a Si bond coat, a mullite (Al6Si2O13) interlayer and a barium-strontium aluminosilicate (BSAS) (Ba1-xSrxAl2Si2O8; 025 KW - Labrador Sea KW - NAO KW - PIP25 KW - Atmospheric pressure KW - Ocean currents KW - Phytoplankton KW - Sediments KW - Submarine geology KW - Sea ice KW - climate effect KW - climate modeling KW - diatom KW - environmental conditions KW - ice cover KW - ice drift KW - isoprenoid KW - marine sediment KW - North Atlantic Oscillation KW - sea ice KW - Atlantic Ocean KW - Canada KW - Labrador Sea KW - Newfoundland KW - Newfoundland and Labrador KW - Bacillariophyta AB - The recent rapid decline in Arctic sea ice cover has increased the need to improve the accuracy of the sea ice component in climate models and to provide detailed long-term sea ice concentration records, which are only available via proxy data. Recently, the highly branched isoprenoid IP25, identified in marine sediments underlying seasonal sea ice, has emerged as a potential sea ice specific proxy for past sea ice cover. We tested the reliability of this biomarker as a sea ice proxy against observational sea ice data (sea ice concentrations from the global HadISST1 database) and against a more established sea ice proxy (sea ice diatom abundance in sediments) in the South-West (SW) Labrador Sea. Furthermore, our study location at the southern margin of Arctic sea ice drift provided a new environmental setting in which to further test the novel PIP25 index. Our two study sites are located North-East (NE) and South-East (SE) of Newfoundland where box cores covering the last ca 100-150 years were collected. IP25 concentrations are nearly an order of magnitude higher and sea ice diatoms more abundant in sediments from NE of Newfoundland, where sea ice prevails 2-4 months per year compared to the sediments SE of Newfoundland, where conditions are generally ice-free year round. The IP25 fluxes NE of Newfoundland agree well with multi-decadal North Atlantic Oscillation (NAO) trends in the study area, which in previous studies have been shown to affect the climatic and sea ice conditions in the region. When assessed against observational sea ice data, IP25 appears to be a more sensitive indicator of sea ice variability in this setting compared to sea ice diatoms and proved to be a robust and reliable proxy for reconstructing low-frequency variability in past sea ice concentrations. The PIP25 index results clearly differ from the observed sea ice data underlining that caution needs to be exercised when using the index in different environmental settings. © 2013 Elsevier Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d2a3995f-c176-42cf-b9ab-ea477d2abb72 ER - TY - JOUR TI - Ultrafast photoinduced dynamics of halogenated cyclopentadienes: Observation of geminate charge-transfer complexes in solution DO - 10.1039/c3cp44295k AU - Wolf, T.J.A. AU - Schalk, O. AU - Radloff, R. AU - Wu, G. AU - Lang, P. AU - Stolow, A. AU - Unterreiner, A.-N. T2 - Physical Chemistry Chemical Physics SN - 1463-9076 VL - 15 IS - 18 SP - 6673 EP - 6683 KW - cyclopentane derivative KW - article KW - chemistry KW - gas KW - halogenation KW - quantum theory KW - solution and solubility KW - ultraviolet radiation KW - X ray photoelectron spectroscopy KW - Cyclopentanes KW - Gases KW - Halogenation KW - Photoelectron Spectroscopy KW - Quantum Theory KW - Solutions KW - Ultraviolet Rays AB - The photoinduced dynamics of the fully halogenated cyclopentadienes C 5Cl6 and C5Br6 have been investigated in solution and gas phase by femtosecond time-resolved spectroscopy. Both in solution and in gas phase, homolytic dissociation into a halogen radical and a C5X5 (X = Cl, Br) radical was observed. In liquid phase, solvent-dependent formation of charge transfer complexes between geminate radicals was observed for the first time. These complexes were found to be surprisingly stable and offered the opportunity to follow the dynamics of specific radical pairs. In the case of C 5Cl6 in trichloroethanol, a reaction of the chlorine radical with molecules from the solvent cage was observed. © 2013 the Owner Societies. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f3b61df6-1d96-471a-9a22-9df9a30e76b3 ER - TY - JOUR TI - Difference in the relative response of the alanine dosimeter to megavoltage x-ray and electron beams DO - 10.1088/0031-9155/58/10/3259 AU - Anton, M. AU - Kapsch, R.-P. AU - Krauss, A. AU - Von Voigts-Rhetz, P. AU - Zink, K. AU - McEwen, M. T2 - Physics in Medicine and Biology SN - 0031-9155 VL - 58 IS - 10 SP - 3259 EP - 3282 KW - Alanine dosimeters KW - Calorimetric measurements KW - Electron detectors KW - Experimental datum KW - Measurement and analysis KW - Monte Carlo simulations KW - Relative uncertainty KW - Uncertainty budget KW - Amino acids KW - Dosimeters KW - Dosimetry KW - Electron beams KW - Monte Carlo methods KW - Quality assurance KW - X rays KW - Uncertainty analysis KW - alanine KW - article KW - comparative study KW - electron KW - methodology KW - Monte Carlo method KW - radiometry KW - X ray KW - Alanine KW - Electrons KW - Monte Carlo Method KW - Radiometry KW - X-Rays AB - In order to increase the usefulness of the alanine dosimeter as a tool for quality assurance measurements in radiotherapy using MV x-rays, the response with respect to the dose to water needs to be known accurately. This quantity is determined experimentally relative to 60Co for 4, 6, 8, 10, 15 and 25 MV x-rays from two clinical accelerators. For the calibration, kQ factors for ionization chambers with an uncertainty of 0.31% obtained from calorimetric measurements were used. The results, although not inconsistent with a constant difference in response for all MV x-ray qualities compared to 60Co, suggest a slow decrease from approximately 0.996 at low energies (4-6 MV) to 0.989 at the highest energy, 25 MV. The relative uncertainty achieved for the relative response varies between 0.35% and 0.41%. The results are confirmed by revised experimental data from the NRC as well as by Monte Carlo simulations using a density correction for crystalline alanine. By comparison with simulated and measured data, also for MeV electrons, it is demonstrated that the weak energy dependence can be explained by a transition of the alanine dosimeter (with increasing MV values) from a photon detector to an electron detector. An in-depth description of the calculation of the results and the corresponding uncertainty components is presented in an appendix for the interested reader. With respect to previous publications, the uncertainty budget had to be modified due to new evidence and to changes of the measurement and analysis method used at PTB for alanine/ESR. © 2013 Institute of Physics and Engineering in Medicine. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f05dd163-7837-4dd1-81b7-c87dd1894068 ER - TY - JOUR TI - An approach to fatigue damage estimation of helicopter rotating components using computational intelligence techniques AU - Cheung, C. AU - Rocha, B. AU - Valdés, J.J. AU - Stefani, A. AU - Li, M. T2 - Annual Forum Proceedings - AHS International T3 - 69th American Helicopter Society International Annual Forum 2013, 21 May 2013 through 23 May 2013 SN - 1552-2938 SN - 9781627486514 VL - 2 SP - 1034 EP - 1041 KW - Computational intelligence techniques KW - Dynamic component KW - Fatigue damage estimation KW - Operational flights KW - Rainflow cycle counting KW - Real aircraft KW - Remaining life prediction KW - Time signals KW - Artificial intelligence KW - Military helicopters KW - Flight control systems AB - In this paper we present a computational intelligence approach to estimate fatigue usage in rotating components based on real aircraft data (Australian Black Hawk S-70A-9 flight load survey data). The load time signal for the main rotor pushrod in forward level flight is first predicted using only input data from the flight state and control system parameters through a computational intelligence model. The subsequent fatigue usage is then estimated using adaptations of standard techniques, such as the Rainflow cycle counting method. More accurate fatigue accumulation and remaining life predictions can possibly be made considering the real operational flight load spectra and not just based on design mission estimations, accounting for the change in use of platforms during their in-service lives. This approach is particularly devoted to rotating components and avoids the use of additional sensors, specifically challenging when dynamic components are considered. Copyright© (2013) by the American Helicopter Society International. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 60427844-93d0-4a24-aecd-92a999f3d324 ER - TY - JOUR TI - Thermo-active elastomer composite for optical heating in microfluidic systems DO - 10.1002/smll.201202151 AU - Geissler, M. AU - Voisin, B. AU - Clime, L. AU - Le Drogoff, B. AU - Veres, T. T2 - Small SN - 1613-6810 VL - 9 IS - 5 SP - 654 EP - 659 KW - As doping KW - Elastomer composites KW - IR thermography KW - Laser lights KW - Mass fraction KW - Micro fluidic system KW - Optical heating KW - Temperature response KW - Infrared imaging KW - Single-walled carbon nanotubes (SWCN) KW - Thermoplastic elastomers KW - Fluidic devices AB - Single-walled carbon nanotubes are used as doping agents to form thermo-active composites with an elastomeric block-copolymer. Thermal imaging reveals that the temperature response upon irradiation with NIR laser light is dependent (among other things) on the mass fraction of the nanotubes in the polymer matrix. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 80acd65f-056b-4b15-94c7-ecbcd5b44cac ER - TY - JOUR TI - High-resolution Fourier-transform spectrometer chip with microphotonic silicon spiral waveguides DO - 10.1364/OL.38.000706 AU - Velasco, Aitor V. AU - Cheben, Pavel AU - Bock, Przemek J. AU - Delâge, André AU - Schmid, Jens H. AU - Lapointe, Jean AU - Janz, Siegfried AU - Calvo, María L. AU - Xu, Dan-Xia AU - Florjańczyk, Mirosław AU - Vachon, Martin T2 - Optics Letters SN - 0146-9592 VL - 38 IS - 5 SP - 706 EP - 708 KW - Amplitude errors KW - Compact devices KW - Fabrication imperfections KW - Fourier transform spectrometers KW - Free spectral range KW - High resolution KW - Interferograms KW - Microphotonic waveguides KW - Optical delay KW - Optical path delays KW - Output waveguides KW - Retrieval algorithms KW - Si wire waveguide KW - Spiral waveguides KW - Transformation matrices KW - Wavelength resolution KW - Fourier transform infrared spectroscopy KW - Linear transformations KW - Silicon KW - Spectrometers KW - Waveguides KW - silicon KW - algorithm KW - article KW - equipment KW - Fourier analysis KW - interferometry KW - laser KW - photon KW - spectroscopy KW - Algorithms KW - Fourier Analysis KW - Interferometry KW - Lasers KW - Photons KW - Silicon KW - Spectrum Analysis AB - We reporta stationary Fourier-transform spectrometer chip implemented in silicon microphotonic waveguides. The device comprises an array of 32 Mach-Zehnder interferometers (MZIs) with linearly increasing optical path delays between the MZI arms across the array. The optical delays are achieved by using Si-wire waveguides arranged in tightly coiled spirals with a compact device footprint of 12 mm2. Spectral retrieval is demonstrated in a single measurement of the stationary spatial interferogram formed at the output waveguides of the array, with a wavelength resolution of 40 pm within a free spectral range of 0.75 nm. The phase and amplitude errors arising from fabrication imperfections are compensated using a transformation matrix spectral retrieval algorithm. © 2013 Optical Society of America. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : fe5e501a-8449-47a3-8d9d-54698dab37d8 ER - TY - JOUR TI - Failure mechanisms and damage model of ductile cast iron under low-cycle fatigue conditions DO - 10.4271/2013-01-0391 AU - Wu, Xijia AU - Quan, Tony AU - Sloss, Clayton T2 - SAE Technical Papers T3 - SAE 2013 World Congress and Exhibition, 16 April 2013 through 18 April 2013, Detroit, MI VL - 2 KW - Fractographic observations KW - Inelastic deformation KW - Intergranular embrittlement KW - Nonlinear interactions KW - Stress strain behaviours KW - Synergetic interactions KW - Temperature conditions KW - Thermo-mechanical damages KW - Coalescence KW - Constitutive models KW - Embrittlement KW - Fatigue damage KW - Plasticity KW - Strain rate KW - Surface defects KW - Textures KW - Creep AB - Strain-controlled low-cycle fatigue (LCF) experiments were conducted on ductile cast iron at total strain rates of 1.2/min, 0.12/min and 0.012/min in a temperature range of RT 800°C. An integrated creep-fatigue (ICF) life prediction framework is proposed, which embodies a deformation mechanism based constitutive model and a thermomechanical damage model. The constitutive model is based on the decomposition of inelastic deformation into plasticity and creep mechanisms, which can describe both rate-independent and rate-dependent cyclic responses under wide strain rate and temperature conditions. The damage model takes into consideration of i) plasticity-induced fatigue, ii) intergranular embrittlement, iii) creep and iv) oxidation. Each damage form is formulated based on the respective physical mechanism/strain. The overall damage accumulation follows a nonlinear interaction mechanism that represents the nucleation and propagation of a surface crack in coalescence with internally distributed damages (cracks/voids). For ductile cast iron (DCI), the model predicates that the room temperature deformation and LCF life are primarily driven by cyclic plasticity; but at 400°C, albeit the deformation is mainly plasticity, its LCF is limited by intergranular embrittlement. When the temperature is increased above 600°C, rate-dependent stress-strain behaviour manifests due to creep, and the synergetic interaction of creep with oxidation dominates the LCF process. As a result of such interaction, a crossover-behaviour between room temperature and high-temperature (>600°C) strain-life relationships may occur, as observed in the experiments. The model prediction corroborates with the LCF test results and fractographic observations on the test coupons, which further substantiates the validity of the model. DA - 2013/04/08 PY - 2013 PB - SAE International LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5c5b967b-1277-4d66-9c42-f13846cb6a46 ER - TY - JOUR TI - III-V access waveguides using atomic layer deposition DO - 10.1117/12.2004310 AU - Mnaymneh, K. AU - Frédérick, S AU - Dalacu, D. AU - Lapointe, J AU - Poole, P.J. AU - Williams, R.L. T2 - Advanced Fabrication Technologies for Micro/Nano Optics and Photonics VI T2 - SPIE - International Society for Optical Engineering. Proceedings; 8613 T3 - Advanced Fabrication Technologies for Micro/Nano Optics and Photonics VI, 5 February 2013 through 6 February 2013, San Francisco, CA SN - 0277-786X SN - 9780819493828 SP - 86130D KW - Compound semiconductors KW - Critical parts KW - Optically Active KW - Photonic circuitry KW - Photonic crystal membranes KW - Quantum photonics KW - Selective area epitaxy KW - Silicon-on-insulators KW - Atomic layer deposition KW - Deposition KW - Quantum chemistry KW - Refractive index KW - Technology KW - Photonics AB - Normally, the larger refractive index contrast of silicon-on-insulator (SOI) photonics used for transporting highly confined optical modes is not available in compound semiconductor systems because the optically active layer rests upon an epitaxial support layer having a similar refractive index. Here, a semiconductor-under-insulator (SUI) technology for compound semiconductor membrane photonic circuitry is presented. It will be shown that such a technology can facilitate the transport of highly confined optical modes in compound semiconductor systems and is anticipated to be a critical part of future scalable quantum photonics applications. © 2013 Copyright SPIE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2a2d27b2-5688-4627-8929-55fb6952a2ee ER - TY - JOUR TI - On the depolarization asymmetry seen in giant radio lobes DO - 10.1007/s10509-012-1310-4 AU - Bell, M.B. AU - Comeau, S.P. T2 - Astrophysics and Space Science SN - 0004-640X VL - 344 IS - 1 SP - 205 EP - 210 AB - The depolarization asymmetry seen in double-lobed radio sources, referred to as the Laing-Garrington (L-G) effect where more rapid depolarization is seen in the lobe with no visible jet as the wavelength increases, can be explained either by internal differences between the two lobes, or by an external Faraday screen that lies in front of only the depolarized lobe. If the jet one-sidedness is due to relativistic beaming the depolarization asymmetry must be due to an intervening Faraday screen. If it is intrinsic the depolarization asymmetry must be related to internal differences in the lobes. For a random viewing angle distribution, which must be the case here where un-beamed lobe radiation dominates, jet one-sidedness is unrelated to viewing angle and therefore cannot be used either to estimate the viewing angle or to imply beaming. The outflow speed in the kpc jet is notoriously difficult to determine. However, although it has not yet been proven conclusively, we assume in this paper that the speed in the outer jet of several Fanaroff-Riley Class 1 (FRI) sources exhibiting the L-G effect is close to the 0. 1c reported by several other investigators. For these sources we find that the jet one-sidedness cannot be explained by beaming and therefore must be intrinsic. In these FRI sources the L-G effect must be due to differences that originate inside the lobes themselves, with the outer regions of the relevant lobe acting as a Faraday screen. Although it is not known if the flow in the outer jets of FRII sources also slows to this speed it is suggested that the explanation of the L-G effect is likely to be the same in both types. This argument is strengthened by the recent evidence that FRII galaxies have very large viewing angles, which in turn implies that the L-G model cannot work regardless of the jet velocity. It may therefore be too soon to completely rule out internal depolarization in the lobes as the true explanation for the L-G effect. © 2012 Springer Science+Business Media Dordrecht. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 41cbf4c2-4896-430a-93f6-067983923249 ER - TY - JOUR TI - Conserved glycolipid termini in capsular polysaccharides synthesized by ATP-binding cassette transporterdependent pathways in Gram-negative pathogens DO - 10.1073/pnas.1222317110 AU - Willis, L.M. AU - Stupak, J. AU - Richards, M.R. AU - Lowary, T.L. AU - Li, J. AU - Whitfield, C. T2 - Proceedings of the National Academy of Sciences of the United States of America SN - 0027-8424 VL - 110 IS - 19 SP - 7868 EP - 7873 KW - ABC transporter KW - glycerophospholipid KW - glycolipid KW - glycosaminoglycan polysulfate KW - polysaccharide KW - polysialic acid KW - amino acid sequence KW - article KW - bacterial capsule KW - biosynthesis KW - Escherichia coli KW - hydrophobicity KW - lipid analysis KW - molecular weight KW - Neisseria meningitidis KW - nonhuman KW - priority journal KW - proton nuclear magnetic resonance KW - capsule assembly KW - polysaccharide export KW - Adenosine Triphosphate KW - ATP-Binding Cassette Transporters KW - Bacterial Capsules KW - Biological Transport KW - Escherichia coli KW - Glycolipids KW - Gram-Negative Bacteria KW - Magnetic Resonance Spectroscopy KW - Mass Spectrometry KW - Methylation KW - Mutation KW - Neisseria meningitidis KW - Polysaccharides KW - Virulence Factors AB - Bacterial capsules are surface layers made of long-chain polysaccharides. They are anchored to the outer membrane of many Gramnegative bacteria, including pathogens such as Escherichia coli, Neisseriameningitidis, Haemophilus influenzae, andPasteurella multocida. Capsules protect pathogens from host defenses including complement- mediated killing and phagocytosis and therefore represent a major virulence factor. Capsular polysaccharides are synthesized by enzymes located in the inner (cytoplasmic) membrane and are then translocated to the cell surface.Whereas the enzymes that synthesize the polysaccharides have been studied in detail, the structure and biosynthesis of the anchoring elements have not been definitively resolved. Here we determine the structure of the glycolipid attached to the reducing terminus of the polysialic acid capsular polysaccharides from E. coli K1 and N. meningitidis group B and the heparosan-like capsular polysaccharide from E. coli K5. All possess the same unique glycolipid terminus consisting of a lyso-phosphatidylglycerol moiety with a β-linked poly-(3-deoxy-D-manno-oct-2-ulosonic acid) (poly-Kdo) linker attached to the reducing terminus of the capsular polysaccharide. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f820ac5a-63c5-40ff-8c30-857e9f9cbb2e ER - TY - JOUR TI - Synthesis of high-purity LiMn2O4 with enhanced electrical properties from electrolytic manganese dioxide treated by sulfuric acid-assisted hydrothermal method DO - 10.1007/s10008-013-2199-8 AU - Guo, D. AU - Chang, Z. AU - Li, B. AU - Tang, H. AU - Yuan, X.-Z. AU - Wang, H. T2 - Journal of Solid State Electrochemistry SN - 1432-8488 VL - 17 IS - 11 SP - 2849 EP - 2856 KW - Cath-ode materials KW - Electrochemical reactions KW - Electrolytic manganese dioxides KW - High-temperature solid-phase KW - Lithium-ion battery KW - Lithium-ion battery cathodes KW - Spinel lithium manganese oxides KW - Sulfuric acid-assisted hydrothermal KW - Cathodes KW - Crystal impurities KW - Cyclic voltammetry KW - Diffusion KW - Electric properties KW - Electrochemical impedance spectroscopy KW - Lithium KW - Lithium alloys KW - Lithium batteries KW - Lithium compounds KW - Oxides KW - Scanning electron microscopy KW - Sulfuric acid KW - X ray diffraction KW - Manganese oxide AB - Using sulfuric acid-assisted hydrothermal treatment, β-MnO2 particles were obtained from the electrolytic manganese dioxide (EMD). Via high-temperature solid-phase reactions, spinel lithium manganese oxides (LiMn2O4) were produced using the obtained β-MnO 2 particles as precursor mixed with LiOH·H2O for the lithium-ion battery cathodes. Atomic absorption (AAS) shows that after the hydrothermal treatment, the contents of impurity ions, such as Na+, K+, Ca2+, and Mg2+, caused by the limitation of preparation technology of EMD are greatly reduced. X-ray diffraction and scanning electron microscopy show that β-MnO2 is highly alloyed consisting of nano sticks. Spinel lithium manganese (LiMn2O 4) synthesized by the β-MnO2 precursor has high crystallinity with a well 111 face grow and presents a regular and micron-sized octagonal crystal. When used as cathode materials for lithium-ion batteries, LiMn2O4 synthesized by the β-MnO2 precursor has greater discharge capacity, better cycle performance, and better high-rate capability when compared with LiMn2O4 synthesized by the EMD precursor. Cyclic voltammetry and electrochemical impedance spectroscopy indicate that LiMn2O4 synthesized by the β-MnO2 precursor has better electrochemical reaction reversibility, greater peak current, higher lithium-ion diffusion coefficient, and lower electrochemical impedance. © 2013 Springer-Verlag Berlin Heidelberg. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4f9cfbbf-04a8-415e-b9a5-295ce21816fc ER - TY - JOUR TI - Graphene versus multi-walled carbon nanotubes for electrochemical glucose biosensing DO - 10.3390/ma6031011 AU - Zheng, D. AU - Vashist, S.K. AU - Dykas, M.M. AU - Saha, S. AU - Al-Rubeaan, K. AU - Lam, E. AU - Luong, J.H.T. AU - Sheu, F.-S. T2 - Materials SN - 1996-1944 VL - 6 IS - 3 SP - 1011 EP - 1027 KW - 3-aminopropyltriethoxysilane KW - Direct electron transfer KW - Electrochemical glucose sensors KW - Glassy carbon electrodes KW - Glucose oxidases (GOx) KW - Interfering substances KW - Pathological level KW - Pathophysiological KW - Glass membrane electrodes KW - Glucose KW - Glucose oxidase KW - Glucose sensors KW - Metabolites KW - Multiwalled carbon nanotubes (MWCN) KW - Graphene AB - A simple procedure was developed for the fabrication of electrochemical glucose biosensors using glucose oxidase (GOx), with graphene or multi-walled carbon nanotubes (MWCNTs). Graphene and MWCNTs were dispersed in 0.25% 3-aminopropyltriethoxysilane (APTES) and drop cast on 1% KOH-pre-treated glassy carbon electrodes (GCEs). The EDC (1-ethyl-(3-dimethylaminopropyl) carbodiimide)-activated GOx was then bound covalently on the graphene- or MWCNT-modified GCE. Both the graphene- and MWCNT-based biosensors detected the entire pathophysiological range of blood glucose in humans, 1.4-27.9 mM. However, the direct electron transfer (DET) between GOx and the modified GCE's surface was only observed for the MWCNT-based biosensor. The MWCNT-based glucose biosensor also provided over a four-fold higher current signal than its graphene counterpart. Several interfering substances, including drug metabolites, provoked negligible interference at pathological levels for both the MWCNT- and graphene-based biosensors. However, the former was more prone to interfering substances and drug metabolites at extremely pathological concentrations than its graphene counterpart. © 2013 by the authors. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 99416130-3392-4976-8d08-922d691f53a7 ER - TY - JOUR TI - Coherent manipulation of three-spin states in a GaAs/AlGaAs triple dot device DO - 10.1002/pssc.201200655 AU - Studenikin, S. AU - Aers, G. AU - Granger, G. AU - Gaudreau, L. AU - Kam, A. AU - Zawadzki, P. AU - Wasilewski, Z.R. AU - Sachrajda, A. T2 - Physica Status Solidi (C) Current Topics in Solid State Physics SN - 1862-6351 VL - 10 IS - 5 SP - 752 EP - 755 KW - Charge configuration KW - Coherent manipulation KW - Electron spin state KW - GaAs/AlGaAs KW - Initialization points KW - Stability diagram KW - Three-spin states KW - Triple quantum KW - Magnetic moments KW - Semiconductor quantum dots KW - Spin dynamics AB - In this paper we describe our recent experiments on coherent manipulation of electron spin states formed in a highly tunable GaAs/AlGaAs triple quantum dot device. The coherent evolution of spin states is achieved by using fast pulses from an initialization point in the (201) charge configuration region of the stability diagram. We demonstrate the versatility of the triple dot system capable of tuning to different regimes controlled by the width of the (111) region and pulse parameters. In particular we observe Δ'1/2-Q3/2 (analogue of S-T+ in a double dot) and Δ'1/2-Δ1/2 exchange driven oscillations from both sides of the stability diagram involving all three spins. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : bf826c43-1703-4d14-93ed-84c47bb77abc ER - TY - JOUR TI - HVOF Coating case study for power plant process control ball valve application DO - 10.1007/s11666-013-9978-8 AU - Vernhes, L. AU - Lee, D.A. AU - Poirier, D. AU - Li, D. AU - Klemberg-Sapieha, J.E. T2 - Journal of Thermal Spray Technology SN - 1059-9630 VL - 22 IS - 7 SP - 1184 EP - 1192 KW - Carbide precipitation KW - Chromium carbide KW - Cohesive failures KW - Failure mechanism KW - Power plant process KW - Self-fluxing alloys KW - Supercritical steam KW - Temperature variation KW - Carbides KW - Chromate coatings KW - Cracks KW - Decarburization KW - Failure (mechanical) KW - High temperature applications KW - Power plants KW - HVOF thermal spraying AB - This case study is the result of an investigation on HVOF 80/20 Cr 3C2-NiCr coating failure of on-off metal-seated ball valve (MSBV) used in supercritical steam lines in a power plant and solution. HVOF 80/20 Cr3C2-NiCr coating is used to protect thousands of MSBVs without incident. However, in this case, the valves are challenged with exposure to rapid high-pressure and -temperature variations resulting in a unique situation where the coating experiences cracking and cohesive failure. It was found that carbide precipitation is a major factor causing embrittlement of the coating. Once the coating toughness and ductility is reduced, thermal, mechanical, and residual stresses can initiate and propagate cracks more easily, causing coating failure when exposed to thermal shock. To alleviate the above mentioned issues, possible coating alternatives were then evaluated. © 2013 ASM International. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : caacd262-21ec-4b9c-9d07-706c663dc7d4 ER - TY - JOUR TI - Stable structures of tantalum at high temperature and high pressure DO - 10.1103/PhysRevB.88.054102 AU - Yao, Y. AU - Klug, D.D. T2 - Physical Review B - Condensed Matter and Materials Physics SN - 1098-0121 VL - 88 IS - 5 SP - 54102 AB - Knowledge of the structures of Ta that appear at high pressures and high temperatures is critical for addressing the recent controversies regarding the phase diagram and melting temperatures of this refractory metal. Structural searches based on a density functional metadynamics method were therefore employed to obtain candidate structures at high-pressure and finite-temperature conditions. A structural transformation from the initial body-centered cubic phase of Ta stable under ambient conditions to an orthorhombic structure with the space group Pnma is predicted. The Pnma structure is shown to be energetically more favorable and more reasonable than other candidate structures considered previously, since it was also confirmed to be mechanically and dynamically stable by phonon and metadynamics calculations. However, a recently proposed hexagonal-ω phase for dense Ta is found to be mechanically and dynamically unstable when anharmonic effects are characterized by high-temperature, self-consistent phonon calculations. © 2013 American Physical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5c83b337-58f9-40bc-85a3-326751b65a67 ER - TY - JOUR TI - Fluorescence lifetime imaging of alterations to cellular metabolism by domain 2 of the Hepatitis C virus core protein DO - 10.1371/journal.pone.0066738 AU - Mazumder, N. AU - Lyn, R.K. AU - Singaravelu, R. AU - Ridsdale, A. AU - Moffatt, D.J. AU - Hu, C.-W. AU - Tsai, H.-R. AU - McLauchlan, J. AU - Stolow, A. AU - Kao, F.-J. AU - Pezacki, J.P. T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 6 SP - e66738 KW - core protein KW - fat droplet KW - green fluorescent protein KW - reduced nicotinamide adenine dinucleotide phosphate KW - virus RNA KW - article KW - cell metabolism KW - coherent anti Stokes Raman scattering microscopy KW - correlation analysis KW - enzyme activity KW - fluorescence KW - genetic transfection KW - glycolysis KW - hepatitis C KW - Hepatitis C virus KW - hepatoma cell KW - human KW - human cell KW - lipogenesis KW - liver metabolism KW - metabolic regulation KW - microscopy KW - mitochondrial energy transfer KW - molecular imaging KW - protein conformation KW - protein expression KW - protein function KW - protein localization KW - Raman spectrometry AB - Hepatitis C virus (HCV) co-opts hepatic lipid pathways to facilitate its pathogenesis. The virus alters cellular lipid biosynthesis and trafficking, and causes an accumulation of lipid droplets (LDs) that gives rise to hepatic steatosis. Little is known about how these changes are controlled at the molecular level, and how they are related to the underlying metabolic states of the infected cell. The HCV core protein has previously been shown to independently induce alterations in hepatic lipid homeostasis. Herein, we demonstrate, using coherent anti-Stokes Raman scattering (CARS) microscopy, that expression of domain 2 of the HCV core protein (D2) fused to GFP is sufficient to induce an accumulation of larger lipid droplets (LDs) in the perinuclear region. Additionally, we performed fluorescence lifetime imaging of endogenous reduced nicotinamide adenine dinucleotides [NAD(P)H], a key coenzyme in cellular metabolic processes, to monitor changes in the cofactor's abundance and conformational state in D2-GFP transfected cells. When expressed in Huh-7 human hepatoma cells, we observed that the D2-GFP induced accumulation of LDs correlated with an increase in total NAD(P)H fluorescence and an increase in the ratio of free to bound NAD(P)H. This is consistent with an approximate 10 fold increase in cellular NAD(P)H levels. Furthermore, the lifetimes of bound and free NAD(P)H were both significantly reduced - indicating viral protein-induced alterations in the cofactors' binding and microenvironment. Interestingly, the D2-expressing cells showed a more diffuse localization of NAD(P)H fluorescence signal, consistent with an accumulation of the co-factor outside the mitochondria. These observations suggest that HCV causes a shift of metabolic control away from the use of the coenzyme in mitochondrial electron transport and towards glycolysis, lipid biosynthesis, and building of new biomass. Overall, our findings demonstrate that HCV induced alterations in hepatic metabolism is tightly linked to alterations in NAD(P)H functional states. © 2013 Mazumder et al. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b7d5af0f-1a8f-4937-b1e9-a16abc21a2fd ER - TY - JOUR TI - Two mass distributions in the L 1641 molecular clouds: The Herschel connection of dense cores and filaments in Orion A DO - 10.1088/2041-8205/777/2/L33 AU - Polychroni, D. AU - Schisano, E. AU - Elia, D. AU - Roy, A. AU - Molinari, S. AU - Martin, P. AU - André, Ph. AU - Turrini, D. AU - Rygl, K.L.J. AU - Di Francesco, J. AU - Benedettini, M. AU - Busquet, G. AU - Di Giorgio, A.M. AU - Pestalozzi, M. AU - Pezzuto, S. AU - Arzoumanian, D. AU - Bontemps, S. AU - Hennemann, M. AU - Hill, T. AU - Könyves, V. AU - Men'Shchikov, A. AU - Motte, F. AU - Nguyen-Luong, Q. AU - Peretto, N. AU - Schneider, N. AU - White, G. T2 - The Astrophysical Journal Letters SN - 2041-8205 VL - 777 IS - 2 SP - L33 AB - We present Herschel survey maps of the L 1641 molecular clouds in Orion A. We extracted both the filaments and dense cores in the region. We identified which of the dense sources are proto- or pre-stellar, and studied their association with the identified filaments. We find that although most (71%) of the pre-stellar sources are located on filaments there, is still a significant fraction of sources not associated with such structures. We find that these two populations (on and off the identified filaments) have distinctly different mass distributions. The mass distribution of the sources on the filaments is found to peak at 4 M⊙ and drives the shape of the core mass function (CMF) at higher masses, which we fit with a power law of the form dN/dlogM ∝ M-1.4 ± 0.4. The mass distribution of the sources off the filaments, on the other hand, peaks at 0.8 M⊙ and leads to a flattening of the CMF at masses lower than ∼4 M⊙. We postulate that this difference between the mass distributions is due to the higher proportion of gas that is available in the filaments, rather than in the diffuse cloud. © 2013. The American Astronomical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4570a2ac-2650-4e47-a732-096882d6bc59 ER - TY - JOUR TI - Chemical structure of the carbohydrate backbone of the lipopolysaccharide from Piscirickettsia salmonis DO - 10.1016/j.carres.2013.04.010 AU - Vinogradov, E. AU - Frimmelova, M. AU - Toman, R. T2 - Carbohydrate Research SN - 0008-6215 VL - 378 SP - 108 EP - 113 KW - Backbone structures KW - Chemical degradation KW - LPS KW - Methylation analysis KW - MS KW - Piscirickettsia salmonis KW - Pseudaminic acid KW - Structural information KW - Alkylation KW - Chemical analysis KW - Mass spectrometry KW - Nuclear magnetic resonance KW - Structure (composition) KW - Carbohydrates KW - arabinose derivative KW - carbohydrate derivative KW - formic acid derivative KW - lipid A KW - lipopolysaccharide KW - monosaccharide KW - oligosaccharide KW - polymer KW - article KW - carbohydrate analysis KW - carbon nuclear magnetic resonance KW - chemical structure KW - degradation KW - mass spectrometry KW - methylation KW - nonhuman KW - Piscirickettsia salmonis KW - piscirickettsiosis KW - priority journal KW - proton nuclear magnetic resonance KW - Piscirickettsia salmonis KW - Salmonidae AB - Elucidation of the carbohydrate backbone structure of the lipopolysaccharide (LPS) from Piscirickettsia salmonis, the etiological agent of the salmonid rickettsial septicemia, is described. Structural information was established by a combination of monosaccharide and methylation analyses of LPS, and by NMR and mass spectrometries of oligosaccharides obtained through the use of various chemical degradations of the native polymer. The following structure of the backbone sugars was determined on the basis of the combined data from these experiments: (Equation presented) The presence of two consecutive residues of diacetylated pseudaminic acid (Pse5,7Ac, 5,7-diacetamido-3,5,7,9-tetradeoxy- L-glycero-L-manno-non-2-ulosonic acid) in the LPS appears to be unique among polysaccharides containing this acidic sugar. Similarly, the presence of 4-aminoarabinose (Ara4N, 4-amino-4-deoxy-L-arabinopyranose) on O-4 of the α-GlcN1P of the lipid A moiety is a unique feature of this LPS. © 2013 Elsevier Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e53126ff-01ee-4fca-af74-1275b6eaf4c5 ER - TY - JOUR TI - Morphology and expression status investigations of specific surface markers on B-cell chronic lymphocytic leukemia cells DO - 10.1002/jemt.22278 AU - Niu, S. AU - Chan, R. AU - Berini, P. AU - Wang, C. AU - Zou, S. T2 - Microscopy Research and Technique SN - 1059-910X VL - 76 IS - 11 SP - 1147 EP - 1153 AB - The morphology of cells and expression status of specific surface markers [cluster of differentiation (CD)], such as CD5, CD19, CD20, CD38, and CD45, have long been considered as the essential indicators for the diagnosis and prognosis of B-cell chronic lymphocytic leukemia (B-CLL). Clinically, it is difficult to simultaneously obtain cell morphology and distribution of surface markers with flow cytometry, especially for some surrogate markers such as CD38. Here, as an alternative and complementary prognostic method, fluorescence microscopy and image processing method are introduced to directly visualize the cells from patients and to quantitatively determine the expression status of surface markers. In this study, the morphological parameters of B-CLL cells were measured to establish the correlation between the cellular morphology and the surface marker expression. It was clear that the CD38+ and CD38- B-CLL cells from the same CD38+ patients had hardly any size differences; however, an increase in perimeter was observed for CD38- patients. Moreover, the expression level of the receptors on the cell was independent of the cell size. There was no evidence showing that the expression intensities of CD19 and CD38 were related to each other for the CD38+ B-CLL cells. On the same cells, CD5 was more selectively expressed on the cell membrane; however, the expression patterns suggested that the cell membrane of CD38- B-CLL cells contained the least expression level of CD19. © 2013 Wiley Periodicals, Inc. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4bc8017a-facf-41c0-8bd4-fc779b02927b ER - TY - JOUR TI - Structural analysis of a novel cyclohexylamine oxidase from brevibacterium oxydans IH-35A DO - 10.1371/journal.pone.0060072 AU - Mirza, I.A. AU - Burk, D.L. AU - Xiong, B. AU - Iwaki, H. AU - Hasegawa, Y. AU - Grosse, S. AU - Lau, P.C.K. AU - Berghuis, A.M. T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 3 SP - e60072 KW - alicyclic amine KW - aliphatic amine KW - cyclohexanone KW - cyclohexylamine oxidase KW - flavine adenine nucleotide KW - oxidoreductase KW - unclassified drug KW - unspecific monooxygenase KW - article KW - bacterial gene KW - binding site KW - Brevibacterium KW - brevibacterium oxydans KW - chaA gene KW - conformational transition KW - crystal structure KW - enzyme purification KW - enzyme specificity KW - enzyme structure KW - Escherichia coli KW - gene expression KW - hydrophobicity KW - molecular cloning KW - molecular dynamics KW - nonhuman KW - nucleotide sequence KW - structure analysis KW - Bacterial Proteins KW - Brevibacterium KW - Oxidoreductases Acting on CH-NH Group Donors KW - Substrate Specificity KW - Escherichia coli KW - Microbacterium oxydans AB - Cyclohexylamine oxidase (CHAO) is a flavoprotein first described in Brevibacterium oxydans strain IH-35A that carries out the initial step of the degradation of the industrial chemical cyclohexylamine to cyclohexanone. We have cloned and expressed in Escherichia coli the CHAO-encoding gene (chaA) from B. oxydans, purified CHAO and determined the structures of both the holoenzyme form of the enzyme and a product complex with cyclohexanone. CHAO is a 50 kDa monomer with a PHBH fold topology. It belongs to the flavin monooxygenase family of enzymes and exhibits high substrate specificity for alicyclic amines and sec-alkylamines. The overall structure is similar to that of other members of the flavin monooxygenase family, but lacks either of the C- or N-terminal extensions observed in these enzymes. Active site features of the flavin monooxygenase family are conserved in CHAO, including the characteristic aromatic cage. Differences in the orientations of residues of the CHAO aromatic cage result in a substrate-binding site that is more open than those of its structural relatives. Since CHAO has a buried hydrophobic active site with no obvious route for substrates and products, a random acceleration molecular dynamics simulation has been used to identify a potential egress route. The path identified includes an intermediate cavity and requires transient conformation changes in a shielding loop and a residue at the border of the substrate-binding cavity. These results provide a foundation for further studies with CHAO aimed at identifying features determining substrate specificity and for developing the biocatalytic potential of this enzyme. © 2013 Mirza et al. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 41152c5d-26ca-490f-9021-801aa8d0258f ER - TY - JOUR TI - Direct heteroarylation of β-protected dithienosilole and dithienogermole monomers with thieno[3,4-c]pyrrole-4,6-dione and furo[3,4-c]pyrrole-4,6-dione DO - 10.1039/c3py21138j AU - Mercier, L.G. AU - Aïch, B.R. AU - Najari, A. AU - Beaupré, S. AU - Berrouard, P. AU - Pron, A. AU - Robitaille, A. AU - Tao, Y. AU - Leclerc, M. T2 - Polymer Chemistry SN - 1759-9954 VL - 4 IS - 20 SP - 5252 EP - 5260 KW - Arylation reactions KW - Bulk heterojunction solar cells KW - Cross coupling reactions KW - Cross-linked materials KW - Cross-linked polymers KW - Heteroarylation KW - Organic solar cell KW - Polymerization reaction KW - Crosslinking KW - Heterojunctions KW - Monomers KW - Polymerization KW - Polymers KW - Solar cells KW - Aromatic compounds AB - Direct C-H bond arylation reactions between heteroarenes and aryl halides provide an atom-economical and "green" alternative to standard cross-coupling reactions (Stille, Suzuki, etc.). Unfortunately, this reaction is not selective and more than one type of C-H bond may react, which, during polymerization reactions, can lead to cross-linked materials. This paper reports the preparation of PDTSiTPD and PDTGeTPD, which have exhibited high efficiencies in organic solar cells, using direct (hetero)arylation polymerization methodologies. In order to circumvent side reactions leading to cross-linked polymers, a number of new dithieno[3,2-b:2′,3′-d]silole (DTSi) monomers were prepared where the β-positions were blocked with alkyl chains and the alkyl groups on the heteroatom were modified. Co-polymers were synthesized with N-alkylthieno[3,4-c]pyrrole-4,6-dione (TPD) and the oxygen congener, N-alkylfuro[3,4-c]pyrrole-4,6-dione (FPD). However, the resulting polymers were not planar, and conjugation of the backbone was disrupted. An efficiency of 1.7% was achieved in bulk heterojunction solar cells (BHJ-SCs). © 2013 The Royal Society of Chemistry. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 839f7551-819c-4ce2-a95e-e15908d3e107 ER - TY - JOUR TI - Acceptance testing and commissioning of a flight simulator for rotorcraft simulation fidelity research DO - 10.1177/0954410012439816 AU - White, M.D. AU - Perfect, P. AU - Padfield, G.D. AU - Gubbels, A.W. AU - Berryman, A.C. T2 - Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering SN - 0954-4100 VL - 227 IS - 4 SP - 663 EP - 686 KW - Certification standards KW - Fidelity KW - Flight KW - Modelling and simulations KW - Research environment KW - Rotorcraft KW - Rotorcraft industry KW - University of Liverpool KW - Accident prevention KW - Environmental impact KW - Flight simulators KW - Helicopter rotors KW - Helicopter services KW - Research aircraft KW - Rotors KW - Simulators KW - Research AB - The rotorcraft industry faces a number of challenges today regarding the replacement of ageing airframes, an expansion in the operational roles of helicopters and a requirement to improve safety whilst reducing the environmental impact of rotorcraft operations. The quantification of simulation fidelity underpins the confidence required for the expanding use of modelling and simulation to develop solutions to these challenges in a timely and cost-efficient manner. Current simulator certification standards do not provide a fully quantitative method for assessing simulation fidelity, especially in a research environment. This article details the commissioning and acceptance process of the new research flight simulation facility at the University of Liverpool, HELIFLIGHT-R, and its subsequent use in a research project 'Lifting Standards: A Novel Approach to the Development of Fidelity Criteria for Rotorcraft Flight Simulators' aimed at developing new predicted and perceptual measures of simulator fidelity. Some initial results from both piloted simulation and flight tests using the Bell 412 Advanced Systems Research Aircraft are reported within the context of the rotorcraft simulation fidelity project. © IMechE 2012. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ad33f80f-5a94-4655-ad80-c1091c069e53 ER - TY - JOUR TI - Complex long-range magnetic ordering in the Mn-bearing dugganite Pb 3TeMn3P2O14 DO - 10.1016/j.jssc.2013.05.019 AU - Silverstein, H.J. AU - Sharma, A.Z. AU - Cruz-Kan, K. AU - Zhou, H.D. AU - Huq, A. AU - Flacau, R. AU - Wiebe, C.R. T2 - Journal of Solid State Chemistry SN - 0022-4596 VL - 204 SP - 102 EP - 107 KW - Antiferromagnetics KW - Dugganite KW - Langasites KW - Long range magnetic order KW - Magnetic transitions KW - Magnetization measurements KW - Magnetoelectric couplings KW - Neutron scattering measurements KW - Antiferromagnetic materials KW - Neutron scattering KW - Silicon KW - Lead AB - Spin liquids, multiferroics, and doubly-chiral helical structures are just some of the exotic magnetic states found in the langasite compounds. A subclass of the langasite group, the Te6+-containing dugganites, has also shown exotic magnetism including magnetoelectric coupling, coexisting complex long-ranged ordered structures, and low-field induced magnetic transitions. Here, we present the first detailed structural study of Pb3TeMn 3P2O14 as well as the first neutron scattering measurements. This material undergoes long-range magnetic ordering, similar to the multiferroic Ba3NbFe3Si2O14, at TN=6.6 K, which is consistent with previous magnetization measurements. However unlike any other langasite or dugganite studied to date, we present evidence of a large, pseudohexagonal incommensurate supercell that alters the nuclear and magnetic structures away from the langasite ideal. © 2013 Elsevier Inc. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0fbe9fcb-d9fa-4718-ae74-d49d587ce237 ER - TY - JOUR TI - A relation between the warm neutral and ionized media observed in the Canadian Galactic plane survey DO - 10.1088/2041-8205/773/1/L11 AU - Foster, T. AU - Kothes, R. AU - Brown, J. C. T2 - The Astrophysical Journal Letters SN - 2041-8205 VL - 773 IS - 1 SP - L11 AB - We report on a comparison between 21 cm rotation measure (RM) and the optically thin atomic hydrogen column density (N H I (τ → 0)) measured toward unresolved extragalactic sources in the Galactic plane of the northern sky. H I column densities integrated to the Galactic edge are measured immediately surrounding each of nearly 2000 sources in 1 arcmin 21 cm line data, and are compared to RMs observed from polarized emission of each source. RM data are binned in column density bins 4 × 10²⁰ cm⁻² wide, and one observes a strong relationship between the number of hydrogen atoms in a 1 cm² column through the plane and the mean RM along the same line of sight and path length. The relationship is linear over one order of magnitude (from 0.8 to 14 × 10²¹ atoms cm ⁻²) of column densities, with a constant RM/NH I ∼ -23.2 ± 2.3 rad m⁻²/10²¹ atoms cm⁻², and a positive RM of 45.0 ± 13.8 rad m⁻² in the presence of no atomic hydrogen. This slope is used to calculate a mean volume-averaged magnetic field in the second quadrant of 〈B 〉 ∼1.0 ± 0.1 μG directed away from the Sun, assuming an ionization fraction of 8% (consistent with the warm-neutral medium; WNM). The remarkable consistency between this field and 〈B〉 = 1.2 μG found with the same RM sources and a Galactic model of dispersion measures (DMs) suggests that electrons in the partially ionized WNM are mainly responsible for pulsar DMs, and thus the partially ionized WNM is the dominant form of the magneto-ionic interstellar medium. © 2013. The American Astronomical Society. All rights reserved.. DA - 2013/07/26 PY - 2013 PB - IOP Publishing LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ec54b1b9-40e1-4114-91f4-ef07330d21e1 ER - TY - JOUR TI - Corrosion inhibition of Al-B4C metal matrix composites in a NaCl solution by benzotriazole DO - 10.1016/j.matchemphys.2013.01.021 AU - Han, Y.-M. AU - Gallant, D. AU - Chen, X.-G. T2 - Materials Chemistry and Physics SN - 0254-0584 VL - 139 IS - 1 SP - 187 EP - 195 KW - Corrosion inhibition KW - Corrosion inhibition efficiency KW - Electrochemical impedance KW - Electrochemical techniques KW - Freundlich adsorption isotherms KW - Infrared reflections KW - Inhibition efficiency KW - Metal matrix composites KW - Adsorption KW - Aluminum KW - Corrosion KW - Efficiency KW - Metallic matrix composites KW - Corrosion inhibitors AB - Benzotriazole (BTAH) was used for the first time to inhibit the corrosion of Al-B4C composites in a NaCl solution. Its corrosion inhibition effect was systematically investigated as a function of BTAH concentrations, volume fractions of B4C particles and immersion time by using potentiodynamic polarization, electrochemical impedance and infrared reflection adsorption spectroscopy techniques. It was found that BTAH is a good corrosion inhibitor for the Al-B4C MMCs in a 3.5 g L-1 NaCl solution, and its inhibition efficiency increased with increasing BTAH concentration. For the same BTAH concentration and immersion time, higher B 4C volume fraction leads to higher corrosion inhibition efficiency. The inhibition efficiency of benzotriazole was also influenced by the immersion time: the inhibition efficiency increases with the immersion time in the first 18 h. However, prolonging the immersion time leads to a decrease in the inhibition efficiency. As the BTAH was an inhibitor with a cathodic character and it inhibited corrosion by physically adsorbing on B4C particles at the composite surface, it obeyed the Freundlich adsorption isotherm. © 2013 Elsevier B.V. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f8bfcfce-ca0d-484d-9cda-06926bfb65d5 ER - TY - JOUR TI - Geometry, chirality, topology and electron-electron interactions in the quadruple quantum dot molecule DO - 10.1016/j.ssc.2013.08.011 AU - Ozfidan, I. AU - Trojnar, A.H. AU - Korkusinski, M. AU - Hawrylak, P. T2 - Solid State Communications SN - 0038-1098 VL - 172 SP - 15 EP - 19 KW - Electronic transport KW - Exact diagonalization method KW - Extended Hubbard model KW - Fermi statistics KW - Matrix elements KW - Number of electrons KW - Quantum dot molecules KW - Topological phase KW - Chirality KW - Electron-electron interactions KW - Electronic properties KW - Geometry KW - Molecules KW - Semiconductor quantum dots KW - Stars KW - Topology KW - Stereochemistry AB - We present a theory of electronic properties of a quadruple quantum dot molecule (QQD) which focuses on geometry, chirality, and electron-electron interactions. The QQD is described by the extended Hubbard model solved using exact diagonalization method in real and Fourier space. The energy spectrum of a QQD is analysed as a function of the number of electrons Ne, for ring, linear, or star geometry. We discuss the interplay of chirality, topology, and Fermi statistics for a half-filled ring QQD charged with either additional electron or hole. We show that the chirality leads to the appearance of a topological phase and an effective gauge field stabilizing the spin polarised state. The spin polarised state with extra electron (hole) and spin unpolarised state at half-filling lead to spin blockade in transport through the ring-like QQD but not through a linear nor star QQD molecule. We demonstrate that the ground state can be tuned between a total spin S=1/2 and S=3/2 by changing the strength of on-site interactions or tuning the tunnelling matrix element. © 2013 Elsevier Ltd. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 904aac97-8c49-42ed-8394-248086dee69c ER - TY - JOUR TI - Structurally unique interaction of RBD-like and PH domains is crucial for yeast pheromone signaling DO - 10.1091/mbc.E12-07-0516 AU - Yerko, V. AU - Sulea, T. AU - Ekiel, I. AU - Harcus, D. AU - Baardsnes, J. AU - Cyglera, M. AU - Whiteway, M. AU - Wu, C. T2 - Molecular Biology of the Cell SN - 1059-1524 VL - 24 IS - 3 SP - 409 EP - 420 KW - mitogen activated protein kinase kinase KW - pheromone KW - protein Ste11 KW - protein Ste5 KW - scaffold protein KW - ubiquitin KW - unclassified drug KW - amino acid sequence KW - article KW - binding site KW - cell cycle arrest KW - cellular distribution KW - crystal structure KW - mutational analysis KW - nonhuman KW - priority journal KW - protein binding KW - protein domain KW - protein expression KW - protein folding KW - protein function KW - protein motif KW - protein protein interaction KW - protein structure KW - Saccharomyces cerevisiae KW - Schizosaccharomyces pombe KW - signal transduction KW - Adaptor Proteins, Signal Transducing KW - Amino Acid Substitution KW - Binding Sites KW - Genes, Mating Type, Fungal KW - MAP Kinase Kinase Kinases KW - Models, Molecular KW - Mutagenesis, Site-Directed KW - Peptide Mapping KW - Pheromones KW - Protein Binding KW - Protein Interaction Domains and Motifs KW - Protein Structure, Secondary KW - Protein Transport KW - Saccharomyces cerevisiae KW - Saccharomyces cerevisiae Proteins KW - Signal Transduction AB - The Ste5 protein forms a scaffold that associates and regulates the components of the mitogen-activated protein (MAP) kinase cascade that controls mating-pheromone-mediated signaling in the yeast Saccharomyces cerevisiae. Although it is known that the MEK kinase of the pathway, Ste11, associates with Ste5, details of this interaction have not been established. We identified a Ras-binding-domain-like (RBL) region in the Ste11 protein that is required specifically for the kinase to function in the mating pathway. This module is structurally related to domains in other proteins that mediate Ras-MAP kinase kinase kinase associations; however, this RBL module does not interact with Ras, but instead binds the PH domain of the Ste5 scaffold. Structural and functional studies suggest that the key role of this PH domain is to mediate the Ste5-Ste11 interaction. Overall these two evolutionarily conserved modules interact with each other through a unique interface, and thus in the pheromone pathway the structural context of the RBL domain contribution to kinase activation has been shifted through a change of its interaction partner from Ras to a PH domain. © 2013 Jo et al. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1cf42cc6-57a0-4184-8b0b-93553c98b856 ER - TY - JOUR TI - The capsular polysaccharide and lipopolysaccharide structures of two carbapenem resistant Klebsiella pneumoniae outbreak isolates DO - 10.1016/j.carres.2012.12.018 AU - Kubler-Kielb, J. AU - Vinogradov, E. AU - Ng, W.-I. AU - MacZynska, B. AU - Junka, A. AU - Bartoszewicz, M. AU - Zelazny, A. AU - Bennett, J. AU - Schneerson, R. T2 - Carbohydrate Research SN - 0008-6215 VL - 369 SP - 6 EP - 9 KW - Capsular polysaccharides KW - CRKP KW - Klebsiella pneumoniae KW - KPC KW - LPS KW - National Institutes of Health KW - O-specific polysaccharides KW - Therapeutic solutions KW - Organic compounds KW - Structure (composition) KW - Synthesis (chemical) KW - Bacteria KW - carbapenem KW - lipopolysaccharide KW - polysaccharide KW - article KW - bacterium isolate KW - carbohydrate analysis KW - Klebsiella pneumoniae KW - methylation KW - molecular typing KW - nonhuman KW - nuclear magnetic resonance spectroscopy KW - polyacrylamide gel electrophoresis KW - priority journal KW - silver staining KW - Anti-Bacterial Agents KW - Carbapenems KW - Drug Resistance, Bacterial KW - Klebsiella pneumoniae KW - Lipopolysaccharides KW - Polysaccharides, Bacterial KW - Klebsiella pneumoniae AB - Carbapenem resistant Klebsiella pneumoniae (CRKP) are isolated with increasing frequency, especially from immunocompromized patients. The capsular polysaccharide (CPS) types of CPKP were not determined. Investigation of two CRKP isolates from a 2011 outbreak at the Clinical Center, the National Institutes of Health, identified a new capsular type shared by the two isolates, similar to K. pneumonia K19 and K34 but structurally different than any published K. pneumoniae CPS repeating unit: The LPS of the two isolates was found to have no O-specific polysaccharide and the chemical structure of the core oligosaccharides agreed with the published data. If this structure type will be prevalent among CPKP isolates, our findings could facilitate rapid diagnosis and help to develop new therapeutic solutions to this antibiotic resistant pathogen. © 2013 Elsevier Inc. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f4dba8af-edfa-4602-bcbe-a58074b33bce ER - TY - JOUR TI - Determination of total mercury in biological tissue by isotope dilution ICPMS after UV photochemical vapor generation DO - 10.1016/j.talanta.2013.09.024 AU - Liu, R. AU - Xu, M. AU - Shi, Z. AU - Zhang, J. AU - Gao, Y. AU - Yang, L. T2 - Talanta SN - 0039-9140 VL - 117 SP - 371 EP - 375 KW - Biological samples KW - Certified reference materials KW - Chemical vapor generation KW - External calibration KW - Isotope dilution inductively coupled plasma mass spectrometry KW - Isotope dilutions KW - Pneumatic nebulization KW - Sample preparation procedure KW - Formic acid KW - Inductively coupled plasma KW - Inductively coupled plasma mass spectrometry KW - Isotopes KW - Mass spectrometry KW - Mercury (metal) KW - Vapors KW - Tissue AB - A method is developed for the determination of trace mercury in biological samples using photo chemical vapor generation (PVG) and isotope dilution inductively coupled plasma mass spectrometry (ID ICPMS) detection. Biological tissues were solubilized in formic acid. Subsequently, the sample solutions were exposed to an ultraviolet (UV) source for the reduction of mercury into vapor species prior to ICPMS measurements. The formic acid served not only as a tissue solubilizer in the sample preparation procedure, but also as a photochemical reductant for mercury in the PVG process. The problem arising from the opaque formic acid digested solution was efficiently solved by using ID method. The optimum conditions for sample treatment and PVG were investigated. A limit of detection (LOD) of 0.5 pg g-1, based on an external calibration, provided 350-fold improvement over that obtained by utilizing conventional pneumatic nebulization sample introduction. Method validation was demonstrated by the determination of total mercury in several biological tissue certified reference materials (CRMs). The results were in good agreement with the certified values. © 2013 Elsevier B.V. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a7824315-623b-42c8-839a-3c2b608fb93f ER - TY - CHAP TI - Contemporary research on E-business technology and strategy: International Conference, iCETS 2012 Tianjin, China, august 29-31, 2012 revised selected papers AU - Khachidze, V. AU - Wang, T. AU - Siddiqui, S. AU - Liu, V. AU - Cappuccio, S. AU - Lim, A. T2 - Communications in Computer and Information Science SN - 1865-0929 SN - 9783642344466 VL - 332 DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3f94cd1b-8ce1-4672-9ca1-426720e0b585 ER - TY - JOUR TI - Tracing electron beams in the sun's corona with radio dynamic imaging spectroscopy DO - 10.1088/2041-8205/763/1/L21 AU - Chen, B. AU - Bastian, T.S. AU - White, S.M. AU - Gary, D.E. AU - Perley, R. AU - Rupen, M. AU - Carlson, B. T2 - The Astrophysical Journal Letters SN - 2041-8205 VL - 763 IS - 1 SP - L21 AB - We report observations of type III radio bursts at decimeter wavelengths (type IIIdm bursts) - signatures of suprathermal electron beams propagating in the low corona - using the new technique of radio dynamic imaging spectroscopy provided by the recently upgraded Karl G. Jansky Very Large Array. For the first time, type IIIdm bursts were imaged with high time and frequency resolution over a broad frequency band, allowing electron beam trajectories in the corona to be deduced. Together with simultaneous hard X-ray and extreme ultraviolet observations, we show that these beams emanate from an energy release site located in the low corona at a height below ∼15 Mm, and propagate along a bundle of discrete magnetic loops upward into the corona. Our observations enable direct measurements of the plasma density along the magnetic loops, and allow us to constrain the diameter of these loops to be less than 100 km. These overdense and ultra-thin loops reveal the fundamentally fibrous structure of the Sun's corona. The impulsive nature of the electron beams, their accessibility to different magnetic field lines, and the detailed structure of the magnetic release site revealed by the radio observations indicate that the localized energy release is highly fragmentary in time and space, supporting a bursty reconnection model that involves secondary magnetic structures for magnetic energy release and particle acceleration. © 2013. The American Astronomical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e595569a-2141-408a-ba2c-5f3600a66f36 ER - TY - JOUR TI - Structural studies of the cell wall polysaccharides from three strains of Lactobacillus helveticus with different autolytic properties: DPC4571, BROI, and LH1 DO - 10.1016/j.carres.2013.05.020 AU - Vinogradov, E. AU - Valence, F. AU - Maes, E. AU - Jebava, I. AU - Chuat, V. AU - Lortal, S. AU - Grard, T. AU - Guerardel, Y. AU - Sadovskaya, I. T2 - Carbohydrate Research SN - 0008-6215 VL - 379 SP - 7 EP - 12 KW - 2D-NMR spectroscopy KW - Autolytic properties KW - Cell wall polysaccharides KW - Cell-wall components KW - Intracellular enzyme KW - Lactobacillus helveticus KW - Methylation analysis KW - Structural studies KW - Alkylation KW - Antigen-antibody reactions KW - Cells KW - Enzymatic hydrolysis KW - Nuclear magnetic resonance spectroscopy KW - Polysaccharides KW - Strain KW - Structure (composition) KW - Cytology KW - autolysin KW - peptidoglycan KW - polysaccharide KW - teichoic acid KW - article KW - autolysis KW - bacterial strain KW - cell wall KW - chemical structure KW - hydrolysis KW - Lactobacillus helveticus KW - methylation KW - nonhuman KW - nuclear magnetic resonance spectroscopy KW - priority journal KW - protein structure KW - Lactobacillus helveticus AB - Lactobacillus helveticus is traditionally used in dairy industry as a starter or an adjunct culture for manufacture of cheese and some types of fermented milk. Its autolysis releases intracellular enzymes which is a prerequisite for optimum cheese maturation, and is known to be strain dependent. Autolysis is caused by an enzymatic hydrolysis of the cell wall peptidoglycan (PG) by endogenous peptidoglycan hydrolases (PGHs) or autolysins. Origins of differences in autolytic properties of different strains are not fully elucidated. Regulation of autolysis possibly depends on the structure of the cell wall components other than PG, particularly polysaccharides. In the present work, we screened six L. helveticus strains with different autolytic properties: DPC4571, BROI and LH1. We established, for the first time, that cell walls (CWs) of these strains contained polysaccharides, different from their CW teichoic acids. Cell wall polysaccharides of three strains were purified, and their chemical structures were established by 2D NMR spectroscopy and methylation analysis. The structures of their repeating units are presented. © 2013 Elsevier Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 41b1fb8c-f014-4077-8ab1-a34915352453 ER - TY - JOUR TI - Star clusters in M31. V. Evidence for self-enrichment in old M31 clusters from integrated spectroscopy DO - 10.1088/2041-8205/776/1/L7 AU - Schiavon, R.P. AU - Caldwell, N. AU - Conroy, C. AU - Graves, G.J. AU - Strader, J. AU - Macarthur, L.A. AU - Courteau, S. AU - Harding, P. T2 - The Astrophysical Journal Letters SN - 2041-8205 VL - 776 IS - 1 SP - L7 AB - In the past decade, the notion that globular clusters (GCs) are composed of coeval stars with homogeneous initial chemical compositions has been challenged by growing evidence that they host an intricate stellar population mix, likely indicative of a complex history of star formation and chemical enrichment. Several models have been proposed to explain the existence of multiple stellar populations in GCs, but no single model provides a fully satisfactory match to existing data. Correlations between chemistry and global parameters such as cluster mass or luminosity are fundamental clues to the physics of GC formation. In this Letter, we present an analysis of the mean abundances of Fe, Mg, C, N, and Ca for 72 old GCs from the Andromeda galaxy. We show for the first time that there is a correlation between the masses of GCs and the mean stellar abundances of nitrogen, spanning almost two decades in mass. This result sheds new light on the formation of GCs, providing important constraints on their internal chemical evolution and mass loss history. © 2013. The American Astronomical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ea07ae8b-2e3d-4da8-8957-295c7cf5092b ER - TY - JOUR TI - Synthesis and properties of LiMn2O4 from hydrazine hydrate reduced electrolytic manganese dioxide DO - 10.1016/j.ssi.2013.02.009 AU - Guo, D. AU - Chang, Z. AU - Li, B. AU - Tang, H. AU - Yuan, X.-Z. AU - Wang, H. T2 - Solid State Ionics SN - 0167-2738 VL - 237 SP - 34 EP - 39 KW - Cath-ode materials KW - Electrochemical impedance KW - Electrolytic manganese dioxides KW - Hydrazine hydrate KW - Lithium-ion battery KW - Lithium-ion battery cathodes KW - Manganese dioxide KW - Spinel lithium manganese oxides KW - Cathodes KW - Crystal impurities KW - Cyclic voltammetry KW - Diffusion KW - Electrochemical impedance spectroscopy KW - Hydrates KW - Hydration KW - Hydrazine KW - Lithium KW - Lithium batteries KW - Manganese KW - Scanning electron microscopy KW - Synthesis (chemical) KW - X ray diffraction KW - Lithium alloys AB - Using N2H4·H2O as reductant γ-Mn3O4 particles were obtained from the electrolytic manganese dioxide (EMD). Via high temperature solid-phase reactions, spinel lithium manganese oxide (LiMn2O4) was produced using the obtained γ-Mn3O4 as precursor mixed with LiOH×H2O for the lithium ion battery cathodes. Atomic absorption (AAS) shows that after the liquid-phase reduction reaction the impurity ions, such as Na+, K+, Ca2 +, and Mg2 +, are greatly reduced. X-ray diffraction (XRD) and scanning electron microscopy (SEM) show that γ-Mn3O4 has high crystallinity and uniform size-distribution. Spinel lithium manganese (LiMn2O4) synthesized by the γ-Mn3O 4 precursor has a high crystallinity and the (111) face grows perfectly with a regular and micron-sized octagonal crystal. The electrochemical tests show that LiMn2O4 synthesized by the γ-Mn3O4 precursor has greater discharge capacity, better cycle performance, and better high-rate capability compared with LiMn2O4 synthesized by the EMD precursor. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) indicate that LiMn2O4 synthesized by the γ-Mn3O 4 precursor has a better electrochemical reaction reversibility, greater peak current, higher lithium-ion diffusion coefficient, and lower electrochemical impedance. Furthermore, this synthesis process is simple, of low-cost, and easy for a large-scale production. © 2013 Elsevier B.V. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e5255ea2-2bd2-4ce0-b535-1a780f387546 ER - TY - JOUR TI - Characterization of AA5754 alloy for identification of Barlat's YLD2000-2D yield criterion AU - Dion-Martin, O. AU - Fafard, M. AU - Ahmed, R. AU - D'Amours, G. T2 - TMS Annual Meeting T3 - Characterization of Minerals, Metals, and Materials 2013 - TMS 2013 Annual Meeting and Exhibition, 3 March 2013 through 7 March 2013, San Antonio, TX SN - 9781118605646 SP - 55 EP - 65 KW - AA5754 KW - Aluminum plates KW - Anisotropic behaviors KW - Bulge KW - Constitutive law KW - Material parameter KW - Work hardening curves KW - Yld2000-2d KW - Aluminum alloys KW - Exhibitions KW - Strain hardening KW - Tensile testing KW - Characterization AB - The optimization of aluminum sheet and tube forming needs the use of large strain finite elements software. The precision of the predicted results from those simulations depends mainly on the quality of constitutive law of the material used. In order to improve quality of these simulations, Barlat has suggested a new yield function named YLD2000-2d. This criterion describes the anisotropic behavior of the rolled aluminum plates. This work consists of characterizing the AA5754 alloy and estimating the material parameters needed for the YLD2000-2d criterion in LS-DYNA. In order to get these parameters, various mechanical testing were performed such as bulge and tensile tests. Moreover, the bulge test was also used to obtain an estimation of work hardening curve in large strain condition, up to 50%. The objective of this paper is to share the experimental results of the characterization of AA5754 aluminum alloy. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 756ac0fd-ab14-4178-8765-db10ad09ef14 ER - TY - JOUR TI - Interesting evidence for a low-level oscillation superimposed on the local Hubble flow DO - 10.1007/s10509-012-1344-7 AU - Bell, M.B. T2 - Astrophysics and Space Science SN - 0004-640X VL - 344 IS - 2 SP - 471 EP - 477 AB - Historically the velocity scatter seen on local Hubble plots has been attributed to the peculiar velocities of individual galaxies. Although most galaxies also have uncertainties in their distances, when galaxies with accurate distances are used recent studies have found that these supposed peculiar velocities may have preferred, or discrete, values. Here we report the interesting result that when these discrete components are identified and removed from the radial velocities of the SNeIa galaxies studied in the Hubble Key Project, there is evidence for a residual oscillation, or ripple, superimposed on the Hubble flow. This oscillation has a wavelength near 40 Mpc and, because its amplitude is small compared to that of the scatter in velocities, it becomes visible only after the discrete components are removed. This result is interesting because even if this ripple has been produced by a selection effect, the fact that it is only revealed after the discrete velocities are removed implies that the discrete velocities are real. Alternatively, if no selection effect can be identified to explain the ripple, then both the discrete velocities and the ripple together become very difficult to explain by chance and these results could then have interesting cosmological consequences. © 2013 Springer Science+Business Media Dordrecht. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1a11dbf5-0c20-4378-b7ca-6556899fb6bc ER - TY - JOUR TI - A study of geological evaluation indicators for the exploitation potential of marine natural gas hydrates: Theory and methodology DO - 10.3787/j.issn.1000-0976.2013.07.002 AU - Wu, N. AU - Huang, L. AU - Su, Z. AU - Yang, S. AU - Wang, H. AU - Liang, J. AU - Lu, H. T2 - Natural Gas Industry SN - 1000-0976 VL - 33 IS - 7 SP - 11 EP - 17 KW - Experimental simulations KW - Exploitation potentials KW - Geological evaluation KW - Geological parameters KW - Index KW - Marine KW - Marine hydrate deposits KW - Reservoir characteristic KW - Hydration KW - Natural gas KW - Natural gas deposits KW - Production engineering KW - Reservoirs (water) KW - Gas hydrates AB - There are good prospects of natural gas hydrate resources on the northern slope of the South China Sea. However, whether or not the gas hydrate will play a part in our energy strategy lies in whether or not it can be effectively extracted. Such real production will mostly rely on the full assessment of gas production potential from the marine hydrate deposits. Unfortunately, the relevant research costs are surprisingly high in the field tests alone, while the experimental simulation of hydrate production under high pressures is limited to a small scale presently, and can not fully characterize the gas production potential on a substantial reservoir scale. Thus it is the only way for hydrate production engineers to establish mining plans and calculate gas production potentials through numerical simulation. Because the gas production potential, however, is closely related to the complexity and dissimilarities of the hydrate reservoir characteristics, the production capacities must be evaluated by using different production methods for different types of hydrate reservoirs, which will inevitably raise the research cost. Therefore, based on the response relationship between hydrate production potential and different geological parameters of hydrate reservoirs, this paper discussed the geological parameters, which are most closely related to the gas production potential. Thus, a set of the objectives, contents and methods were presented for the geological evaluation indexes of marine hydrate production potential, providing the theory and methodology for the rapid evaluation of gas production potential in the marine gas hydrate reservoirs. DA - 2013 PY - 2013 LA - zho C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 7aa1347b-23e4-4dd8-910b-7b2be5a139e9 ER - TY - JOUR TI - B4-B1 phase transition of GaN under isotropic and uniaxial compression DO - 10.1103/PhysRevB.88.014113 AU - Yao, Y. AU - Klug, D.D. T2 - Physical Review B - Condensed Matter and Materials Physics SN - 1098-0121 VL - 88 IS - 1 SP - 14113 AB - The question raised recently about the mechanisms of the pressure-induced B4-B1 transition of GaN is investigated using a density functional-based metadynamics method. A homogeneous deformation path through a tetragonal intermediate structure is found to be energetically favorable under hydrostatic pressure conditions. This transition path is initialized by the soft phonon modes that appear along the transverse acoustic branches near the transition point. However, under certain nonhydrostatic pressure conditions an elastic instability replaces the phonon instability to become a dominant mechanism for the structural transformation of GaN. The phase transition would avoid the tetragonal path when a uniaxial stress is applied on the c axis but follows a different path through a hexagonal intermediate structure. The selection of the transformation mechanisms, determined by specific stress conditions applied, highlights the important role the competition between phonon and elastic instabilities plays in the reconstructive phase transitions. © 2013 American Physical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f426f128-91b7-4701-aa55-36c8ecf6320c ER - TY - JOUR TI - High throughput multilayer microfluidic particle separation platform using embedded thermoplastic-based micropumping DO - 10.1039/c3lc50181g AU - Didar, T.F. AU - Li, K. AU - Tabrizian, M. AU - Veres, T. T2 - Lab on a Chip - Miniaturisation for Chemistry and Biology SN - 1473-0197 VL - 13 IS - 13 SP - 2615 EP - 2622 KW - elastomer KW - polycarbonate KW - polystyrene KW - thermoplastic elastomer KW - unclassified drug KW - article KW - cell selection KW - erythrocyte KW - fluorescence KW - in vitro study KW - microfluidics KW - osteoblast KW - particle size KW - priority journal AB - We present an integrated thermoplastic elastomer (TPE) based multilayer microfluidic device with an embedded peristaltic micropump and through-holes membrane for high throughput particle sorting and separation. Fluidic and pneumatic layers of the device were fabricated using hot-embossing lithography and commercially available polycarbonate membranes were succcessfully sandwiched between two thermoplastic elastomer fluidic layers integrated to a peristaltic micropumping layer. The integrated peristaltic micropump induces turbulence at the top-microfluidic layer ring which successfully avoids particle aggregation and membrane blocking even at nanorange size. We present herein the general design of the device structure and pumping characteristics for three devices with membrane pore sizes of 10 μm, 5 μm and 800 nm. By using this design we have successfully demonstrated a separation efficiency as high as 99% of polystyrene microbeads with different sizes and most importantly the separation of 390 nm particles from 2 μm beads was achieved. Using this device, we were also able to separate red blood cells with size of about 6-8 μm from osteoblasts typically larger than 10 μm to demonstrate the potential applicability of this platform for biological samples. The produced microfluidic chip operating at flow rates up to 100 μl min-1 allows us to achieve efficient high-throughput sorting and separation of target particles/cells. © 2013 The Royal Society of Chemistry. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : db196cb7-58bc-4fc6-8be4-c783d2d3c8b6 ER - TY - JOUR TI - Palliser's promise: Brassica carinata, An emerging western Canadian crop for delivery of new bio-industrial oil feedstocks DO - 10.1016/j.bcab.2013.09.012 AU - Marillia, E.-F. AU - Francis, T. AU - Falk, K.C. AU - Smith, M. AU - Taylor, D.C. T2 - Biocatalysis and Agricultural Biotechnology SN - 1878-8181 AB - The global demand for vegetable-based oils continues to rise, while the availability of highly productive arable farm land is becoming progressively limited. To meet the requirements of the future, it will be essential to develop new and improved temperate oilseed cultivars adapted to less-than-optimum acreage. An example is the brown soil zone in the semi-arid marginal land area of the south-western Canadian prairies known as Palliser's Triangle, which is not well-suited to the growth of crops like canola. Brassica carinata is a species that is well-adapted to growth in semi-arid regions and is highly drought-tolerant. It is being developed as a new crop platform dedicated to the production of bio-industrial oil feedstocks, most notably oils enriched in the very long-chain fatty acids (VLCFAs) erucic and nervonic. VLCFA-enriched B. carinata oils have applications in the manufacture of bio-jet fuels, bio-diesel, enhanced oil recovery (EOR) surfactants, bio-plastics and many other products. The contributions of B. carinata oil products to both bio-based aviation fuels and to the more-efficient extraction of recalcitrant fossil fuel resources for maximum return at drill sites will help to create a more sustainable energy sector. B. carinata breeding and biotechnology efforts are being combined to establish this crop as a bio-industrial oil platform and this chapter highlights recent progress in this regard. © 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 69f519fe-3263-4cd4-815c-7098a8ea57cc ER - TY - JOUR TI - Crystalline domain size and faulting in the new NIST SRM 1979 zinc oxide DO - 10.1017/S0885715613001188 AU - Cline, J.P. AU - Leoni, M. AU - Black, D. AU - Henins, A. AU - Bonevich, J.E. AU - Whitfield, P.S. AU - Scardi, P. T2 - Powder Diffraction SN - 0885-7156 VL - 28 IS - SUPPL.2 SP - S22 EP - S32 AB - A NIST SRM certified to address the issue of crystallite size measurement through a line profile analysis has been under development for several years. In order to prepare the feedstock for the SRM, nano-crystalline zinc oxide was produced from thermal decomposition of zinc oxalate. The thermal processing parameters were chosen to yield particles in two size ranges, one with a distribution centered at approximately 15 nm and another centered at 60 nm. Certification data were collected on a NIST-built diffractometer equipped with a Johansson incident beam monochromator and scintillation detector. Data were analyzed using whole powder pattern modeling to determine microstructural data. The analysis shows domains to be in the form of discs of a fairly small aspect ratio. While both materials exhibit the effects of stacking faults through broadening of specific hkl reflections, their presence in the 60 nm is more difficult to discern. Images of the crystallites obtained with transmission electron microscopy are consistent with the results from the X-ray diffraction analyses. © 2013 JCPDS-ICDD. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 26df7b88-3c9a-4273-865b-118ad00c2b8c ER - TY - JOUR TI - Assessment of multidrug resistance on cell coculture patterns using scanning electrochemical microscopy DO - 10.1073/pnas.1214809110 AU - Kuss, S. AU - Polcari, D. AU - Geissler, M. AU - Brassard, D. AU - Mauzeroll, J. T2 - Proceedings of the National Academy of Sciences of the United States of America SN - 0027-8424 VL - 110 IS - 23 SP - 9249 EP - 9254 KW - ferrocene derivative KW - ferrocenemethanol KW - multidrug resistance protein 1 KW - ruthenium complex KW - unclassified drug KW - article KW - cancer cell KW - cell culture KW - cell structure KW - controlled study KW - electrochemistry KW - female KW - HeLa cell KW - human KW - human cell KW - kinetics KW - multidrug resistance KW - priority journal KW - protein localization KW - quantitative analysis KW - scanning electrochemical microscopy KW - target cell KW - uterine cervix cancer KW - HeLa cells KW - microelectrode KW - MRP1 KW - Cell Culture Techniques KW - Drug Resistance, Multiple KW - Female KW - Ferrous Compounds KW - HeLa Cells KW - Humans KW - Microelectrodes KW - Microscopy, Fluorescence KW - Microscopy, Scanning Probe KW - Multidrug Resistance-Associated Proteins AB - The emergence of resistance to multiple unrelated chemotherapeutic drugs impedes the treatment of several cancers. Although the involvement of ATP-binding cassette transporters has long been known, there is no in situ method capable of tracking this transporter- related resistance at the single-cell level without interfering with the cell's environment or metabolism. Here, we demonstrate that scanning electrochemical microscopy (SECM) can quantitatively and noninvasively track multidrug resistance-related protein 1- dependent multidrug resistance in patterned adenocarcinoma cervical cancer cells. Nonresistant human cancer cells and their multidrug resistant variants are arranged in a side-by-side format using a stencil-based patterning scheme, allowing for precise positioning of target cells underneath the SECM sensor. SECM measurements of the patterned cells, performed with ferrocenemethanol and [Ru(NH3)6]3+ serving as electrochemical indicators, are used to establish a kinetic "map" of constant-height SECM scans, free of topography contributions. The concept underlying the work described herein may help evaluate the effectiveness of treatment administration strategies targeting reduced drug efflux. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : fcc2b639-e891-4e35-bed1-4f7e76890995 ER - TY - JOUR TI - Inductively coupled plasma mass spectrometry-based immunoassay: A review DO - 10.1002/mas.21391 AU - Liu, R. AU - Wu, P. AU - Yang, L. AU - Hou, X. AU - Lv, Y. T2 - Mass Spectrometry Reviews SN - 0277-7037 AB - The last 10 years witnessed the emerging and growing up of inductively coupled plasma mass spectrometry (ICPMS)-based immunoassay. Its high sensitivity and multiplex potential have made ICPMS a revolutionary technique for bioanalyte quantification after element-tagged immunoassay. This review focuses on the major developments and the applications of ICPMS-based immunoassay, with emphasis on methodological innovations. The ICPMS-based immunoassay with elemental tags of metal ions, nanoparticles, and metal containing polymers was discussed in detail. The recent development of multiplex assay, mass cytometry, suspension array, and surface analysis demonstrated the versatility and great potential of this technique. ICPMS-based immunoassay has become one of the key methods in bioanalysis. © 2013 Wiley Periodicals, Inc. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9775aec9-b0ee-4913-90e6-d7f76871c5e0 ER - TY - JOUR TI - Mechanical and microstructural characterization of cold-sprayed Ti-6Al-4V after heat treatment DO - 10.1007/s11666-013-9945-4 AU - Vo, P. AU - Irissou, E. AU - Legoux, J.-G. AU - Yue, S. T2 - Journal of Thermal Spray Technology SN - 1059-9630 VL - 22 IS - 6 SP - 954 EP - 964 KW - After-heat treatment KW - As-sprayed conditions KW - Cold spray KW - Dense coating KW - Fracture surfaces KW - High hardness KW - Micro-structural characterization KW - Microstructural changes KW - Aluminum KW - Crystal microstructure KW - Hardness KW - Heat treatment KW - Helium KW - Mechanical properties KW - Microstructure KW - Nitrogen KW - Sprayed coatings KW - Tensile strength KW - Tensile testing KW - Titanium alloys KW - Aluminum coatings AB - The cold spray of Ti-6Al-4V coatings deposited on Ti-6Al-4V substrates has been investigated. Coatings were produced using nitrogen and helium as propellant gases and subsequently heat treated with various temperature-time conditions. The microstructure was characterized by SEM and optical microscopy while mechanical properties were measured by microhardness and tensile testing. It is shown that coatings sprayed with nitrogen gas were relatively porous in comparison to the nearly completely dense coatings obtained with helium gas. In the as-sprayed condition, coatings displayed high hardness but low tensile strength. Heat treatments at temperatures of 600 C and higher resulted in a decrease in hardness due to microstructural changes within the particles including recovery, recrystallization, and/or phase transformation. However, an increase in tensile strength was attributed to improved inter-particle bonding due to an observed change from brittle to ductile features on the fracture surface. The highest strength coating produced was a helium-sprayed coating annealed at 600 C, which featured a tensile strength ~85% of the minimum required bulk value and coating/substrate microstructures similar to the as-received powder/substrate microstructures. © 2013 ASM International. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6fcdae95-1ac9-43ab-b2a9-f709778e35c3 ER - TY - JOUR TI - Resolved debris discs around a stars in the herschel DEBRIS survey DO - 10.1093/mnras/sts117 AU - Booth, M. AU - Kennedy, G. AU - Sibthorpe, B. AU - Matthews, B.C. AU - Wyatt, M.C. AU - Ducĥene, G. AU - Kavelaars, J.J. AU - Rodriguez, D. AU - Greaves, J.S. AU - Koning, A. AU - Vican, L. AU - Rieke, G.H. AU - Su, K.Y.L. AU - Moro-Mart́in, A. AU - Kalas, P. T2 - Monthly Notices of the Royal Astronomical Society SN - 0035-8711 VL - 428 IS - 2 SP - 1263 EP - 1280 AB - The majority of debris discs discovered so far have only been detected through infrared excess emission above stellar photospheres. While disc properties can be inferred from unresolved photometry alone under various assumptions for the physical properties of dust grains, there is a degeneracy between disc radius and dust temperature that depends on the grain size distribution and optical properties. By resolving the disc we can measure the actual location of the dust. The launch of Herschel, with an angular resolution superior to previous far-infrared telescopes, allows us to spatially resolve more discs and locate the dust directly. Here we present the nine resolved discs around A stars between 20 and 40 pc observed by the Disc Emission via a Bias-free Reconnaissance in the Infrared/Submillimetre (DEBRIS) survey. We use these data to investigate the disc radii by fitting narrowringmodels to images at 70, 100 and 160μm and by fitting blackbodies to full spectral energy distributions. We do this with the aim of finding an improved way of estimating disc radii for unresolved systems. The ratio between the resolved and blackbody radii varies between 1 and 2.5. This ratio is inversely correlated with luminosity and any remaining discrepancies are most likely explained by differences to the minimum size of grain in the size distribution or differences in composition. We find that three of the systems are well fit by a narrow ring, two systems are borderline cases and the other four likely require wider or multiple rings to fully explain the observations, reflecting the diversity of planetary systems. © 2012 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ae411f65-b50e-4f2d-af5f-2ccd368b5741 ER - TY - JOUR TI - Signaling network assessment of mutations and copy number variations predict breast cancer subtype-specific drug targets DO - 10.1016/j.celrep.2013.08.028 AU - Zaman, N. AU - Li, L. AU - Jaramillo, M. AU - Sun, Z. AU - Tibiche, C. AU - Banville, M. AU - Collins, C. AU - Trifiro, M. AU - Paliouras, M. AU - Nantel, A. AU - O'Connor-McCourt, M. AU - Wang, E. T2 - Cell Reports SN - 2211-1247 VL - 5 IS - 1 SP - 216 EP - 223 KW - antineoplastic agent KW - bms 536924 KW - bosutinib KW - docetaxel KW - erlotinib KW - nutlin 3 KW - protein kinase B inhibitor KW - rapamycin KW - rdea 119 KW - tamoxifen KW - tanespimycin KW - tcs 2312 KW - tozasertib KW - unclassified drug KW - article KW - breast cancer KW - cancer cell KW - cancer classification KW - cell proliferation KW - cell survival KW - copy number variation KW - drug sensitivity KW - drug targeting KW - exome KW - gene identification KW - gene mutation KW - gene sequence KW - genetic screening KW - human KW - human cell KW - mutation KW - priority journal KW - signal transduction KW - tumor gene AB - Individual cancer cells carry a bewildering number ofdistinct genomic alterations (e.g., copy number variations and mutations), making it a challenge touncover genomic-driven mechanisms governing tumorigenesis. Here, we performed exome sequencing on several breast cancer cell lines that represent two subtypes, luminal and basal. We integrated these sequencing data and functional RNAi screening data (for the identification of genes that are essential for cell proliferation and survival) onto a human signaling network. Two subtype-specific networks that potentially represent core-signaling mechanisms underlying tumorigenesis were identified. Within both networks, we found that genes were differentially affected in different cell lines; i.e., in some cell lines a gene was identified through RNAi screening, whereas in others it was genomically altered. Interestingly, we found that highly connected network genes could be used to correctly classify breast tumors into subtypes on the basis of genomic alterations. Further, the networks effectively predicted subtype-specific drug targets, which were experimentally validated. © 2013 The Authors. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6f7d4adc-37d5-4bf8-9e45-130377e20eb8 ER - TY - JOUR TI - The open cluster NGC 2437 (Messier 46) DO - 10.1086/669823 AU - Davidge, T.J. T2 - Publications of the Astronomical Society of the Pacific SN - 0004-6280 VL - 125 IS - 924 SP - 115 EP - 125 AB - The stellar content of the open cluster NGC 2437 (Messier 46) is investigated using moderately deep u*, g′, and r′ MegaCam images. When compared with solar metallicity isochrones, the (g′; u′ - g′) and (r′; g′ - r′) CMDs are consistent with an age log(tyr) = 8:35 ± 0:15, a distance modulus μ0 = 11:05 ± 0:05, and a color excess E(B - V) = 0:115 ± 0:035. The r′ luminosity function (LF) of main sequence stars in the magnitude range r′ < 17 (i.e., masses ~0:8 Mȯ) has a shape that follows solar neighborhood star counts. However, at fainter magnitudes, the cluster LF is flat, in contrast with what would be expected from solar neighborhood counts. The clustering properties of stars in NGC 2437 are investigated by examining the two-point angular correlation functions of main sequence stars in different brightness ranges. Main sequence stars fainter than r′ = 17 are less centrally concentrated than brighter stars and are found over a larger area of the sky, suggesting that there is a corona of faint main sequence stars around NGC 2437. Based on the flat LF and extended spatial distribution of faint stars, it is concluded that NGC 2437 is actively shedding stars with masses ~0:8 Mȯ.© 2013. The Astronomical Society of the Pacific. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 7fa862d6-ddcf-42cd-87e5-4e2e369080f7 ER - TY - JOUR TI - The SCUBA-2 cosmology legacy survey: Blank-Field number counts of 450-μm-selected galaxies and their contribution to the cosmic infrared background DO - 10.1093/mnras/stt352 AU - Geach, J.E. AU - Chapin, E.L. AU - Coppin, K.E.K. AU - Dunlop, J.S. AU - Halpern, M. AU - Smail, I. AU - van der Werf, P. AU - Serjeant, S. AU - Farrah, D. AU - Roseboom, I. AU - Targett, T. AU - Arumugam, V. AU - Asboth, V. AU - Blain, A. AU - Chrysostomou, A. AU - Clarke, C. AU - Ivison, R.J. AU - Jones, S.L. AU - Karim, A. AU - Mackenzie, T. AU - Meijerink, R. AU - Michałowski, M.J. AU - Scott, D. AU - Simpson, J.M. AU - Swinbank, A.M. AU - Alexander, D.M. AU - Almaini, O. AU - Aretxaga, I. AU - Best, P. AU - Chapman, S. AU - Clements, D.L. AU - Conselice, C. AU - Danielson, A.L.R. AU - Eales, S. AU - Edge, A.C. AU - Gibb, A.G. AU - Hughes, D. AU - Jenness, T. AU - Knudsen, K.K. AU - Lacey, C.G. AU - Marsden, G. AU - McMahon, R. AU - Oliver, S.J. AU - Page, M.J. AU - Peacock, J.A. AU - Rigopoulou, D. AU - Robson, E.I. AU - Spaans, M. AU - Stevens, J. AU - Webb, T.M.A. AU - Willott, C. AU - Wilson, C.D. AU - Zemcov, M. T2 - Monthly Notices of the Royal Astronomical Society SN - 0035-8711 VL - 432 IS - 1 SP - 53 EP - 61 AB - The first deep blank-field 450 μm map (1σ ≈ 1.3 mJy) from the Submillimetre Common- User Bolometer Array-2 SCUBA-2 Cosmology Legacy Survey (S2CLS), conducted with the James Clerk Maxwell Telescope (JCMT) is presented. Our map covers 140 arcmin2 of the Cosmological Evolution Survey field, in the footprint of the Hubble Space Telescope (HST) Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey. Using 60 submillimetre galaxies detected at ≥3.75σ, we evaluate the number counts of 450-μm-selected galaxies with flux densities S450 > 5 mJy. The 8 arcsec JCMT beam and high sensitivity of SCUBA-2 now make it possible to directly resolve a larger fraction of the cosmic infrared background (CIB, peaking at λ ~ 200 μm) into the individual galaxies responsible for its emission than has previously been possible at this wavelength. At S450 > 5 mJy, we resolve (7.4 ± 0.7) x 10-2 MJy sr-1 of the CIB at 450 μm (equivalent to 16 ± 7 per cent of the absolute brightness measured by the Cosmic Background Explorer at this wavelength) into point sources. A further ~40 per cent of the CIB can be recovered through a statistical stack of 24 μm emitters in this field, indicating that the majority (≈60 per cent) of the CIB at 450 μm is emitted by galaxies with S450 > 2 mJy. The average redshift of 450 μm emitters identified with an optical/near-infrared counterpart is estimated to be 〈z〉 = 1.3, implying that the galaxies in the sample are in the ultraluminous class (LIR ≈ 1.1 x 1012 L⊙). If the galaxies contributing to the statistical stack lie at similar redshifts, then the majority of the CIB at 450 μm is emitted by galaxies in the luminous infrared galaxy (LIRG) class with LIR > 3.6 x 1011 L⊙. © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b6606106-7d9b-4ed9-bc04-4f2a1855b99d ER - TY - JOUR TI - A possible divot in the size distribution of the Kuiper Belt's scattering objects DO - 10.1088/2041-8205/764/1/L2 AU - Shankman, C. AU - Gladman, B. J. AU - Kaib, N. AU - Kavelaars, J. J. AU - Petit, J. M. T2 - The Astrophysical Journal Letters SN - 2041-8205 VL - 764 IS - 1 SP - L2 AB - Via joint analysis of a calibrated telescopic survey, which found scattering Kuiper Belt objects, and models of their expected orbital distribution, we explore the scattering-object (SO) size distribution. Although for D > 100 km the number of objects quickly rise as diameters decrease, we find a relative lack of smaller objects, ruling out a single power law at greater than 99% confidence. After studying traditional "knees" in the size distribution, we explore other formulations and find that, surprisingly, our analysis is consistent with a very sudden decrease (a divot) in the number distribution as diameters decrease below 100 km, which then rises again as a power law. Motivated by other dynamically hot populations and the Centaurs, we argue for a divot size distribution where the number of smaller objects rises again as expected via collisional equilibrium. Extrapolation yields enough kilometer-scale SOs to supply the nearby Jupiter-family comets. Our interpretation is that this divot feature is a preserved relic of the size distribution made by planetesimal formation, now "frozen in" to portions of the Kuiper Belt sharing a "hot" orbital inclination distribution, explaining several puzzles in Kuiper Belt science. Additionally, we show that to match today's SO inclination distribution, the supply source that was scattered outward must have already been vertically heated to the of order 10°. DA - 2013/01/22 PY - 2013 PB - IOP Publishing LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : dae4af3b-4333-480e-bc0d-e3c323aa02f1 ER - TY - JOUR TI - Fine structure of a biexciton in a single quantum dot with a magnetic impurity DO - 10.1103/PhysRevB.87.205311 AU - Trojnar, A.H. AU - Korkusinski, M. AU - Mendes, U.C. AU - Goryca, M. AU - Koperski, M. AU - Smolenski, T. AU - Kossacki, P. AU - Wojnar, P. AU - Hawrylak, P. T2 - Physical Review B - Condensed Matter and Materials Physics SN - 1098-0121 VL - 87 IS - 20 SP - 205311 AB - We show theoretically and experimentally that the ground state of a biexciton in a CdTe self-assembled quantum dot with a magnetic Mn impurity exhibits a fine structure due to electron-electron Coulomb and electron-Mn exchange interactions. Results of exact diagonalization of the microscopic biexciton-manganese-ion model predict a pattern of three pairs of states in the ground-state manifold, each pair labeled by the projection of Mn spin. We show that the fine structure determines the ordering of the biexciton emission maxima and can be derived from the biexciton and exciton emission spectra. Theoretical predictions are successfully compared with measured biexciton and exciton emission spectra of a single CdTe dot with a Mn ion in its center. © 2013 American Physical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9e9f665c-070f-4940-afca-4cd0b606e431 ER - TY - JOUR TI - Immobilization of glucose oxidase into a nanoporous TiO2 film layered on metallophthalocyanine modified vertically-aligned carbon nanotubes for efficient direct electron transfer DO - 10.1016/j.bios.2013.02.029 AU - Cui, H.-F. AU - Zhang, K. AU - Zhang, Y.-F. AU - Sun, Y.-L. AU - Wang, J. AU - Zhang, W.-D. AU - Luong, J.H.T. T2 - Biosensors and Bioelectronics SN - 0956-5663 VL - 46 SP - 113 EP - 118 KW - Amperometric response KW - Bioelectrocatalytic KW - Carbon nanotubes (CNT) KW - Detection sensitivity KW - Direct electron transfer KW - Iron phthalocyanines KW - Metallophthalocyanines KW - Nano-porous TiO KW - Carbon nanotubes KW - Glucose KW - Glucose oxidase KW - Glucose sensors KW - Oxygen KW - Scanning electron microscopy KW - Titanium dioxide KW - Electron transitions KW - glucose KW - glucose oxidase KW - iron phthalocyanine KW - metallophthalocyanine KW - multi walled nanotube KW - nanoparticle KW - nitrogen KW - phthalocyanine derivative KW - titanium dioxide nanoparticle KW - unclassified drug KW - amperometry KW - article KW - chemical reaction KW - cyclic potentiometry KW - direct electron transfer KW - electric conductivity KW - enzyme electrode KW - enzyme immobilization KW - enzyme stability KW - limit of detection KW - nanoanalysis KW - nanochemistry KW - oxidation kinetics KW - porosity KW - response time KW - scanning electron microscopy KW - sensitivity analysis KW - surface property KW - Aspergillus niger KW - Biosensing Techniques KW - Electrodes KW - Enzymes, Immobilized KW - Ferrous Compounds KW - Glucose KW - Glucose Oxidase KW - Indoles KW - Nanotubes, Carbon KW - Porosity KW - Sensitivity and Specificity KW - Titanium AB - Glucose oxidase (GOD) was adsorbed into a nanoporous TiO2 film layered on the surface of an iron phthalocyanine (FePc) vertically-aligned carbon nanotube (CNT) modified electrode. A Nafion film was then dropcast on the electrode's surface to improve operational and storage stabilities of the GOD-based electrode. Scanning electron microscopy (SEM) micrographs revealed the formation of FePc and nanoporous TiO2 nanoparticles along the sidewall and the tip of CNTs. Cyclic voltammograms of the GOD electrode in neutral PBS exhibited a pair of well-defined redox peaks, attesting the direct electron transfer of GOD (FAD/FADH2) with the underlying electrode. The potential of glucose electro-oxidation under nitrogen was ~+0.12V with an oxidation current density of 65.3μAcm-2 at +0.77V. Voltammetric and amperometric responses were virtually unaffected by oxygen, illustrating an efficient and fast direct electron transfer. The modification of the CNT surface with FePc resulted in a biosensor with remarkable detection sensitivity with an oxygen-independent bioelectrocatalysis. In deaerated PBS, the biosensor displayed average response time of 12s, linearity from 50μM to 4mM, and a detection limit of 30μM (S/N=3) for glucose. © 2013 Elsevier B.V. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c66e7c67-a146-4dfe-bf21-872d11418657 ER - TY - JOUR TI - Phonon lifetime investigation of anharmonicity and thermal conductivity of UO2 by neutron scattering and theory DO - 10.1103/PhysRevLett.110.157401 AU - Pang, J.W.L. AU - Buyers, W.J.L. AU - Chernatynskiy, A. AU - Lumsden, M.D. AU - Larson, B.C. AU - Phillpot, S.R. T2 - Physical Review Letters SN - 0031-9007 VL - 110 IS - 15 SP - 157401 KW - Anharmonicities KW - First-principles simulations KW - Inelastic neutrons KW - Longitudinal optics KW - Phonon lifetimes KW - Phonon physics KW - Quantitative correspondence KW - Phonons KW - Thermal conductivity AB - Inelastic neutron scattering measurements of individual phonon lifetimes and dispersion at 295 and 1200 K have been used to probe anharmonicity and thermal conductivity in UO2. They show that longitudinal optic phonon modes carry the largest amount of heat, in contrast to past simulations and that the total conductivity demonstrates a quantitative correspondence between microscopic and macroscopic phonon physics. We have further performed first-principles simulations for UO2 showing semiquantitative agreement with phonon lifetimes at 295 K, but larger anharmonicity than measured at 1200 K. © 2013 American Physical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3c729046-fc3a-40d5-81bb-7f9e664ab797 ER - TY - JOUR TI - Electronic temperatures of terahertz quantum cascade active regions with phonon scattering assisted injection and extraction scheme DO - 10.1364/OE.21.010172 AU - Patimisco, P. AU - Scamarcio, G. AU - Santacroce, M.V. AU - Spagnolo, V. AU - Vitiello, M.S. AU - Dupont, E. AU - Laframboise, S.R. AU - Fathololoumi, S. AU - Razavipour, G.S. AU - Wasilewski, Z. T2 - Optics Express SN - 1094-4087 VL - 21 IS - 8 SP - 10172 EP - 10181 KW - Active regions KW - Electronic temperature KW - Ground level KW - Optical phonon scattering KW - Population ratio KW - Quantum cascades KW - Quantum-cascade devices KW - Resonant phonon KW - Optical lattices KW - Quantum well lasers KW - Phonon scattering KW - article KW - equipment KW - equipment design KW - equipment failure KW - light KW - methodology KW - radiation scattering KW - terahertz radiation KW - thermography KW - Equipment Design KW - Equipment Failure Analysis KW - Light KW - Scattering, Radiation KW - Terahertz Radiation KW - Thermography AB - We measured the lattice and subband electronic temperatures of terahertz quantum cascade devices based on the optical phonon-scattering assisted active region scheme. While the electronic temperature of the injector state (j=4) significantly increases by △T=Te 4 -TL ∼40 K, in analogy with the reported values in resonant phonon scheme (△T ∼70-110 K), both the laser levels (j=2,3) remain much colder with respect to the latter (by a factor of 3-5) and share the same electronic temperature of the ground level (j=1). The electronic population ratio n2/n1 shows that the optical phonon scattering efficiently depopulates the lower laser level (j=2) up to an electronic temperature Te ∼180 K. © 2013 Optical Society of America. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4c9a4e1b-ce0c-4fed-ac1a-1d87c72fc57e ER - TY - JOUR TI - Numerical and experimental studies on the new design concept of hydroforming dies for complex tubes DO - 10.1016/j.matdes.2012.12.075 AU - Bihamta, R. AU - D'Amours, G. AU - Bui, Q.-H. AU - Guillot, M. AU - Rahem, A. AU - Fafard, M. T2 - Materials and Design SN - 0261-3069 VL - 47 SP - 766 EP - 778 KW - Axial feeding KW - Complex geometries KW - New design KW - Numerical and experimental study KW - Numerical results KW - Numerical verification KW - Transportation industry KW - Tube hydroforming KW - Two parameter KW - Metal forming KW - Tubes (components) KW - Dies AB - Recently, the tube hydroforming (THF) process has found a remarkable role in the production of tubular parts especially for the transportation industry. In prior research, there were only two parameters, i.e. hydroforming pressure and axial feeding, to play with to obtain a part without any problems like bursting and wrinkling. However, for parts with complex geometries it is sometimes impossible to produce them by changing only these two variables.In this paper a new concept to design THF dies is presented and verified by numerical and experimental studies. By application of this concept, dies will have three parts instead of two, and consequently the tube will be preformed by the die closing before the start of the hydroforming step. The numerical verifications confirmed that without this modification, the production of most of the workpieces with complex geometries is difficult, if not impossible. The numerical results showed good agreement with the performed experiments. © 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 77138ad7-e518-453a-bc40-02175523301f ER - TY - JOUR TI - Carrier molecules for use in veterinary vaccines DO - 10.1016/j.vaccine.2012.11.067 AU - Gerdts, V. AU - Mutwiri, G. AU - Richards, J. AU - Hurk, S.V.D.L.V.D. AU - Potter, A.A. T2 - Vaccine SN - 0264-410X VL - 31 IS - 4 SP - 596 EP - 602 KW - alginic acid KW - chitosan KW - CpG oligodeoxynucleotide KW - DNA vaccine KW - drug carrier KW - gamma interferon KW - glycoconjugate KW - glycoconjugate vaccine KW - Haemophilus vaccine KW - hepatitis B surface antigen KW - immunoglobulin A KW - immunoglobulin G1 KW - immunoglobulin G2 KW - immunoglobulin M KW - immunostimulating agent KW - influenza vaccine KW - interleukin 2 KW - interleukin 6 KW - liposome KW - nanoparticle KW - peptide vaccine KW - poly[di(sodium carboxylatoethylphenoxy] phosphazene KW - poly[di(sodium carboxylatophenoxy)] polyphosphazene KW - polyglactin KW - polymer KW - polysaccharide vaccine KW - starch KW - unclassified drug KW - vaccine KW - Wart virus vaccine KW - Actinobacillus pleuropneumoniae KW - antigen presenting cell KW - atrophic rhinitis KW - bacterial load KW - Bordetella bronchiseptica KW - bronchopneumonia KW - CD8+ T lymphocyte KW - cost effectiveness analysis KW - cytokine production KW - cytotoxic T lymphocyte KW - dendritic cell KW - Haemophilus influenzae type b KW - human KW - Human papillomavirus type 16 KW - immunization KW - immunogenicity KW - mucosal immunity KW - Neisseria meningitidis KW - nonhuman KW - Pasteurella multocida infection KW - priority journal KW - review KW - Streptococcus pneumoniae KW - virus like agent KW - Animals KW - Glycoconjugates KW - Nanoparticles KW - Vaccination KW - Vaccines KW - Vaccines, Conjugate KW - Vaccines, Subunit KW - Vaccines, Virus-Like Particle AB - The practice of immunization of animals and humans has been carried out for centuries and is generally accepted as the most cost effective and sustainable method of infectious disease control. Over the past 20 years there have been significant changes in our ability to produce antigens by conventional extraction and purification, recombinant DNA and synthesis. However, many of these products need to be combined with carrier molecules to generate optimal immune responses. This review covers selected topics in the development of carrier technologies for use in the veterinary vaccine field, including glycoconjugate and peptide vaccines, microparticle and nanoparticle formulations, and finally virus-like particles. © 2012. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ae945c23-371e-467a-a9fd-4b5aa6ba079d ER - TY - JOUR TI - Neisseria gonorrhoeae-derived heptose elicits an innate immune response and drives HIV-1 expression DO - 10.1073/pnas.1303738110 AU - Malott, R.J. AU - Keller, B.O. AU - Gaudet, R.G. AU - McCaw, S.E. AU - Lai, C.C.L. AU - Dobson-Belaire, W.N. AU - Hobbs, J.L. AU - Michael, F.S. AU - Cox, A.D. AU - Moraes, T.F. AU - Gray-Owen, S.D. T2 - Proceedings of the National Academy of Sciences of the United States of America SN - 0027-8424 VL - 110 IS - 25 SP - 10234 EP - 10239 KW - heptose KW - heptose monophosphate KW - HldA protein KW - lipid A KW - toll like receptor 4 KW - toll like receptor 5 KW - unclassified drug KW - article KW - CD4+ T lymphocyte KW - Human immunodeficiency virus 1 KW - innate immunity KW - mouse KW - mutagenesis KW - Neisseria gonorrhoeae KW - nonhuman KW - phenotype KW - priority journal KW - transposon KW - coinfection KW - inflammation KW - microbial-associated molecular pattern KW - pathogen-associated molecular pattern KW - sexually transmitted disease KW - Bacterial Proteins KW - CD4-Positive T-Lymphocytes KW - Coinfection KW - Female KW - Gonorrhea KW - Heptoses KW - HIV Infections KW - HIV Long Terminal Repeat KW - HIV-1 KW - Humans KW - Jurkat Cells KW - Male KW - Neisseria gonorrhoeae KW - Toll-Like Receptor 5 AB - Clinical and epidemiological synergy exists between the globally important sexually transmitted infections, gonorrhea and HIV. Neisseria gonorrhoeae, which causes gonorrhea, is particularly adept at driving HIV-1 expression, but the molecular determinants of this relationship remain undefined. N. gonorrhoeae liberates a soluble factor that potently induces expression from the HIV-1 LTR in coinfected cluster of differentiation 4-positive (CD4+) T lymphocytes, but this factor is not a previously described innate effector. A genomewide mutagenesis approach was undertaken to reveal which component(s) of N. gonorrhoeae induce HIV-1 expression in CD4+ T lymphocytes. A mutation in the ADP-heptose biosynthesis gene, hldA, rendered the bacteria unable to induce HIV-1 expression. The hldA mutant has a truncated lipooligosaccharide structure, contains lipid A in its outer membrane, and remains bioactive in a TLR4 reporterbased assay but did not induce HIV-1 expression. Mass spectrometry analysis of extensively fractionated N. gonorrhoeae-derived supernatants revealed that the LTR-inducing fraction contained a compound having a mass consistent with heptose-monophosphate (HMP). Heptose is a carbohydrate common in microbes but is absent from the mammalian glycome. Although ADP-heptose biosynthesis is common among Gram-negative bacteria, and heptose is a core component of most lipopolysaccharides, N. gonorrhoeae is peculiar in that it effectively liberates HMP during growth. This N. gonorrhoeaederived HMP activates CD4+ T cells to invoke an NF-κB-dependent transcriptional response that drives HIV-1 expression and viral production. Our study thereby shows that heptose is a microbial-specific product that is sensed as an innate immune agonist and unveils the molecular link between N. gonorrhoeae and HIV-1. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 48de0760-5db0-49c4-827b-b4f74f2ff779 ER - TY - JOUR TI - Design and fabrication of an integrated dual-mode ultrasonic probe DO - 10.1016/j.ultras.2012.11.009 AU - Ono, Y. AU - Qu, Z. AU - Wu, K.-T. T2 - Ultrasonics SN - 0041-624X VL - 53 IS - 3 SP - 637 EP - 641 KW - Dual modes KW - Liquid sample KW - Longitudinal waves KW - Measurement sensitivity KW - Mode conversions KW - Piezoelectric film KW - Probe design KW - Pulse echoes KW - Ultrasonic probe KW - Viscous liquids KW - Conversion efficiency KW - Probes KW - Shear waves KW - Silicones KW - Substrates KW - Ultrasonic testing KW - Ultrasonic transducers KW - Nanocomposites AB - In this paper, we present an integrated dual-mode ultrasonic probe that is capable of transmitting and receiving longitudinal and shear waves (LW and SW, respectively) simultaneously. The probe consists of a thick piezoelectric film LW ultrasonic transducer and a substrate with a specific shape. An SW is generated inside the substrate by mode conversion. In the probe design, two factors were theoretically investigated: impedance matching between the substrate and the material being measured to improve measurement sensitivity and mode conversion efficiency at the slanted face of the substrate. The developed probe was tested with a selected silicone liquid sample to demonstrate its capability to measure the properties of a viscous liquid using both LW and SW. © 2013 Elsevier B.V. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6235d3bc-fa01-4978-9894-743898fe5eee ER - TY - JOUR TI - Towards scalable photonics via quantum storage DO - 10.1117/12.2012487 AU - Nunn, J. AU - Langford, N.K. AU - Kolthammer, W.S. AU - Champion, T.F.M. AU - Sprague, M.R. AU - Michelberger, P.S. AU - Jin, X.-M. AU - England, D.G. AU - Walmsley, I.A. T2 - SPIE - International Society for Optical Engineering. Proceedings T3 - Advances in Slow and Fast Light VI, 3 February 2013 through 5 February 2013, San Francisco, CA SN - 0277-786X SN - 9780819494054 VL - 8636 SP - 863612 KW - Experimental demonstrations KW - Optical quantum-information processing KW - Quantum Computing KW - Quantum memory KW - Quantum-information processing KW - Single photons KW - Single-photon source KW - Time-bandwidth products KW - Digital storage KW - Photons KW - Quantum computers KW - Quantum optics KW - Raman scattering KW - Synchronization KW - Quantum theory AB - Single photons are a vital resource for optical quantum information processing. efficient and deterministic single photon sources do not yet exist, however. To date, experimental demonstrations of quantum processing primitives have been implemented using non-deterministic sources combined with heralding and/or postselection. Unfortunately, even for eight photons, the data rates are already so low as to make most experiments impracticable. It is well known that quantum memories, capable of storing photons until they are needed, are a potential solution to this 'scaling catastrophe'. Here, we analyze two protocols for generating multiphoton states using quantum memories, showing how the production rates can be enhanced by many orders of magnitude. We identify the time-bandwidth product as a key figure of merit in this connection. © 2013 SPIE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 67096ae9-446b-493e-8d04-ce9996c61047 ER - TY - JOUR TI - Graphene-based integrated electronic, photonic and spintronic circuit DO - 10.1117/12.2016607 AU - Potasz, P. AU - Güçlü, A.D. AU - Ozfidan, I. AU - Korkusinski, M. AU - Hawrylak, P. T2 - SPIE - International Society for Optical Engineering. Proceedings T3 - 2013 Micro- and Nanotechnology Sensors, Systems, and Applications V Conference, 29 April 2013 through 3 May 2013, Baltimore, MD SN - 0277-786X VL - 8725 SP - 87250G KW - Electric and magnetic fields KW - Electrical field KW - Electronic nanodevices KW - Ferromagnetic orders KW - Integrated electronics KW - Semiconductor nanoparticles KW - Spatial confinement KW - Spintronic circuits KW - Absorption spectroscopy KW - Energy gap KW - Graphene KW - Magnetic moments KW - Magnetic properties KW - Magnetoelectronics KW - Nanostructured materials KW - Nanotechnology KW - Optical properties KW - Photons KW - Semiconductor quantum dots KW - Sensors KW - Solids KW - Photonic integration technology AB - To create carbon-based nanoscale integrated electronic, photonic, and spintronic circuit one must demonstrate the three functionalities in a single material, graphene quantum dots (GQDs), by engineering lateral size, shape, edges, number of layers and carrier density. We show theoretically that spatial confinement in GQDs opens an energy gap tunable from UV to THz, making GQDs equivalent to semiconductor nanoparticles. When connected to leads, GQDs act as single-electron transistors. The energy gap and absorption spectrum can be tuned from UV to THz by size and edge engineering and by external electric and magnetic fields. The sublattice engineering in, e.g., triangular graphene quantum dots (TGQDs) with zigzag edges generates a finite magnetic moment. The magnetic moment can be controlled by charging, electrical field, and photons. Addition of a single electron to the charge-neutral system destroys the ferromagnetic order, which can be restored by absorption of a photon. This allows for an efficient spin-photon conversion. These results show that graphene quantum dots have potential to fulfill the three functionalities: electronic, photonic, and spintronic, realized with different materials in current integrated circuits, as well as offer new functionalities unique to graphene. © 2013 SPIE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9b2e54bd-2c21-4484-b783-4cf3d03fe6b9 ER - TY - JOUR TI - SWG dispersion engineering for ultra-broadband photonic devices DO - 10.1117/12.2017229 AU - Halir, Robert AU - Maese-Novo, Alejandro AU - Romero-García, Sebastián AU - Pérez-Galacho, Diego AU - Zavargo-Peche, Luis AU - Ortega-Moñux, Alejandro AU - Molina-Fernández, Íñigo AU - Wangüemert-Pérez, J. Gonzalo AU - Cheben, Pavel T2 - SPIE - International Society for Optical Engineering. Proceedings T3 - Integrated Photonics: Materials, Devices, and Applications II, 24 April 2013 through 26 April 2013, Grenoble SN - 0277-786X SN - 9780819495648 VL - 8767 SP - 87670R KW - Broadband device KW - Dispersion engineering KW - Multi-mode interference KW - Passive waveguides KW - Silicon on insulator KW - Sub-wave length grating KW - Diffraction gratings KW - Directional couplers KW - Dispersion (waves) KW - Optical waveguides KW - Photonics KW - Refractive index KW - Silicon on insulator technology KW - Ultra-wideband (UWB) KW - Dispersions AB - In most integrated optics platforms device design is restricted to variations in the lateral dimensions, and a small set of etch depths. Sub-wavelength gratings (SWGs) in silicon-on-insulator enable engineering of refractive index in a wide range. SWGs exhibit a pitch smaller than the wavelength of light propagating through them, thereby suppressing diffraction and acting as a homogenous medium with an equivalent refractive index controlled by the duty-cycle. Here, we propose to not only engineer refractive index, but to control SWG dispersion. We use this concept to design ultra-broadband directional couplers (DCs) and multimode interference couplers (MMIs) with a fivefold bandwidth enhancement compared to conventional devices. © 2013 SPIE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b3b60622-4aac-4011-a1aa-559e022e0891 ER - TY - JOUR TI - Spatial-spectral coupling in hyperspectral CARS microscopy image formation DO - 10.1117/12.2004217 AU - Barlow, A.M. AU - Popov, K. AU - Andreana, M. AU - Moffatt, D.J. AU - Ridsdale, A. AU - Slepkov, A.D. AU - Ramunno, L. AU - Stolow, A. T2 - Progress in Biomedical Optics and Imaging - Proceedings of SPIE T3 - Three-Dimensional and Multidimensional Microscopy: Image Acquisition and Processing XX, 5 February 2013 through 7 February 2013, San Francisco, CA SN - 1605-7422 SN - 9780819493583 VL - 8589 SP - 85890T KW - Cars microscopies KW - Coherence imaging KW - Coherent anti-Stokes Raman scattering microscopy KW - Kramers-Kronig transformation KW - Nonlinear microscopy KW - Numerical calculation KW - Three dimensional images KW - Three dimensional space KW - Coherent scattering KW - Image acquisition KW - Three dimensional KW - Time domain analysis KW - Raman spectroscopy AB - Hyperspectral coherent anti-Stokes Raman scattering (CARS) microscopy has provided an imaging tool for extraction of 3-dimensional volumetric information, as well as chemically-sensitive spectral information. These techniques have been used in a variety of different domains including biophysics, geology, and material science. The measured CARS spectrum results from interference between the Raman response of the sample and a non-resonant background. We have collected four dimensional data sets (three spatial dimensions, plus spectra) and extracted Raman response from the CARS spectrum using a Kramers-Kronig transformation. However, the three dimensional images formed by a CARS microscope are distorted by interference, some of which arises because of the Gouy phase shift. This type of interference comes from the axial position of the Raman resonant object in the laser focus. We studied how the Gouy phase manifests itself in the spectral domain by investigating microscopic diamonds and nitrobenzene droplets in a CARS microscope. Through experimental results and numerical calculation using finite-diference time-domain (FDTD) methods, we were able to demonstrate the relationship between the spatial configuration of the sample and the CARS spectral response in three dimensional space. © 2013 Copyright SPIE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 57a4a789-7d7a-4cb0-bcb8-e46eb6d01982 ER - TY - JOUR TI - Collaborative computing technologies and systems DO - 10.1016/j.jss.2013.03.058 AU - Yong, J. AU - Shen, W. AU - James, A. T2 - Journal of Systems and Software SN - 0164-1212 VL - 86 IS - 7 SP - 1725 EP - 1726 DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c4c3e17d-37bd-4d94-851b-e91f2738c768 ER - TY - JOUR TI - Hidden in plain sight: low-literacy adults in a developed country overcoming social and educational challenges through mobile learning support tools DO - 10.1007/s00779-013-0748-x AU - Munteanu, C. AU - Molyneaux, H. AU - Maitland, J. AU - McDonald, D. AU - Leung, R. AU - Fournier, H. AU - Lumsden, J. T2 - Personal and Ubiquitous Computing SN - 1617-4909 SP - 1 EP - 15 AB - Illiteracy is often associated with people in developing countries. However, an estimated 50 % of adults in a developed country such as Canada lack the literacy skills required to cope with the challenges of today's society; for them, tasks such as reading, understanding, basic arithmetic, and using everyday items are a challenge. Many community-based organizations offer resources and support for these adults, yet overall functional literacy rates are not improving. This is due to a wide range of factors, such as poor retention of adult learners in literacy programs, obstacles in transferring the acquired skills from the classroom to the real life, personal attitudes toward learning, and the stigma of functional illiteracy. In our research we examined the opportunities afforded by personal mobile devices in providing learning and functional support to low-literacy adults. We present the findings of an exploratory study aimed at investigating the reception and adoption of a technological solution for adult learners. ALEX© is a mobile application designed for use both in the classroom and in daily life in order to help low-literacy adults become increasingly literate and independent. Such a solution complements literacy programs by increasing users' motivation and interest in learning, and raising their confidence levels both in their education pursuits and in facing the challenges of their daily lives. We also reflect on the challenges we faced in designing and conducting our research with two user groups (adults enrolled in literacy classes and in an essential skills program) and contrast the educational impact and attitudes toward such technology between these. Our conclusions present the lessons learned from our evaluations and the impact of the studies' specific challenges on the outcome and uptake of such mobile assistive technologies in providing practical support to low-literacy adults in conjunction with literacy and essential skills training. © 2013 Her Majesty the Queen in Right of Canada. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 986e82bd-4e29-4a68-b2d6-a6a2d50ffbf7 ER - TY - JOUR TI - Extragalactic number counts at 100 μm, free from cosmic variance DO - 10.1093/mnrasl/sls002 AU - Sibthorpe, B. AU - Ivison, R.J. AU - Massey, R.J. AU - Roseboom, I.G. AU - van der Werf, P.P. AU - Matthews, B.C. AU - Greaves, J.S. T2 - Monthly Notices of the Royal Astronomical Society: Letters SN - 1745-3925 VL - 428 IS - 1 SP - L6 EP - L10 AB - We use data from the Disc Emission via a Bias-free Reconnaissance in the Infrared/ Submillimetre (DEBRIS) survey, taken at 100 μm with the Photoconductor Array Camera and Spectrometer instrument on board the Herschel Space Observatory, to make a cosmic variance independent measurement of the extragalactic number counts. These data consist of 323 small-area mapping observations performed uniformly across the sky, and thus represent a sparse sampling of the astronomical sky with an effective coverage of ~2.5 deg2. We find our cosmic variance independent analysis to be consistent with previous count measurements made using relatively small area surveys. Furthermore, we find no statistically significant cosmic variance on any scale within the errors of our data. Finally, we interpret these results to estimate the probability of galaxy source confusion in the study of debris discs. © 2012 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b880d409-ebdb-43af-976f-1af5a8668892 ER - TY - JOUR TI - Isolation of scFv antibody fragments against HER2 and CEA tumor antigens from combinatorial antibody libraries derived from cancer patients DO - 10.1016/j.biologicals.2013.05.004 AU - Ayat, H. AU - Burrone, O.R. AU - Sadghizadeh, M. AU - Jahanzad, E. AU - Rastgou, N. AU - Moghadasi, S. AU - Arbabi, M. T2 - Biologicals SN - 1045-1056 VL - 41 IS - 6 SP - 345 EP - 354 AB - Tumor cells expressing HER-2/neu and CEA antigens are potentially ideal targets for antibody-targeted therapy. In this study, two large human combinatorial libraries have been generated from the lymph nodes of breast cancer patients that express HER2 and CEA antigens in their tumors. These 'immune' libraries have been constructed in two different formats of scFv, differing in the length of the peptide linker connecting the two variable VH and VL domains. Libraries derived from these patients may contain a larger pool of anti-tumor antigen antibodies and are useful repertoire for isolating scFvs against any tumor markers. The results of this study showed that we were successful in obtaining human scFvs against HER-2/neu and CEA. For HER-2, cell-panning strategy was performed and resulted in two scFv binders that detected the complete HER-2 receptor on the cell membrane and internalized to the cells. Also, preliminary ELISA data showed that several anti-CEA scFv binders were isolated by panning. © 2013 The International Alliance for Biological Standardization. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2b8ff120-3ed3-4d33-8e76-eb887ad15840 ER - TY - JOUR TI - Cancer systems biology in the genome sequencing era: Part 1, dissecting and modeling of tumor clones and their networks DO - 10.1016/j.semcancer.2013.06.002 AU - Wang, E. AU - Zou, J. AU - Zaman, N. AU - Beitel, L.K. AU - Trifiro, M. AU - Paliouras, M. T2 - Seminars in Cancer Biology SN - 1044-579X VL - 23 IS - 4 SP - 279 EP - 285 KW - apoptosis KW - breast cancer KW - breast carcinogenesis KW - cancer cell KW - cancer prognosis KW - cancer survival KW - cancer systems biology KW - cell proliferation KW - cell subpopulation KW - cell survival KW - chromosome breakage KW - copy number variation KW - disease marker KW - gene mutation KW - human KW - molecular cloning KW - oncology KW - review KW - RNA sequence KW - signal transduction KW - single cell analysis KW - systems biology AB - Recent tumor genome sequencing confirmed that one tumor often consists of multiple cell subpopulations (clones) which bear different, but related, genetic profiles such as mutation and copy number variation profiles. Thus far, one tumor has been viewed as a whole entity in cancer functional studies. With the advances of genome sequencing and computational analysis, we are able to quantify and computationally dissect clones from tumors, and then conduct clone-based analysis. Emerging technologies such as single-cell genome sequencing and RNA-Seq could profile tumor clones. Thus, we should reconsider how to conduct cancer systems biology studies in the genome sequencing era. We will outline new directions for conducting cancer systems biology by considering that genome sequencing technology can be used for dissecting, quantifying and genetically characterizing clones from tumors. Topics discussed in Part 1 of this review include computationally quantifying of tumor subpopulations; clone-based network modeling, cancer hallmark-based networks and their high-order rewiring principles and the principles of cell survival networks of fast-growing clones. © 2013 Published by Elsevier Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3811a93e-f5a0-459d-9859-e55b9fdbd845 ER - TY - JOUR TI - Applications of flexible ultrasonic transducer array for defect detection at 150 °C DO - 10.3390/s130100975 AU - Shih, J.-L. AU - Wu, K.-T. AU - Jen, C.-K. AU - Chiu, C.-H. AU - Tzeng, J.-C. AU - Liaw, J.-W. T2 - Sensors (Switzerland) SN - 1424-8220 VL - 13 IS - 1 SP - 975 EP - 983 KW - Defect detection KW - Flexible ultrasonic transducer KW - Pitch-catch KW - Pulse-echo mode KW - PZT KW - Total focusing method KW - Antenna phased arrays KW - Composite films KW - Defects KW - Nondestructive examination KW - Sol-gel process KW - Sol-gels KW - Thickness measurement KW - Transducers KW - Ultrasonic transducers KW - Inspection AB - In this study, the feasibility of using a one dimensional 16-element flexible ultrasonic transducer (FUT) array for nondestructive testing at 150 °C is demonstrated. The FUT arrays were made by a sol-gel sprayed piezoelectric film technology; a PZT composite film was sprayed on a titanium foil of 75 μm thickness. Since the FUT array is flexible, it was attached to a steel pipe with an outer diameter of 89 mm and a wall thickness of 6.5 mm at 150 °C. Using the ultrasonic pulse-echo mode, pipe thickness measurements could be performed. Moreover, using the ultrasonic pulse-echo and pitch-catch modes of each element of FUT array, the defect detection was performed on an Al alloy block of 30 mm thickness with a side-drilled hole (SDH) of φ3 mm at 150 °C. In addition, a post-processing algorithm based on the total focusing method was used to process the full matrix of these A-scan signals of each single transmitter and multi-receivers, and then the phase-array image was obtained to indicate this defect- SDH. Both results show the capability of FUT array being operated at 150 °C for the corrosion and defect detections. © 2013 by the authors; licensee MDPI, Basel, Switzerland. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3884cd6b-4260-457e-9e8c-32bfbaccbc34 ER - TY - JOUR TI - Subwavelength grating Fourier-transform interferometer array in silicon-on-insulator DO - 10.1002/lpor.201300063 AU - Bock, Przemek J. AU - Cheben, Pavel AU - Velasco, Aitor V. AU - Schmid, Jens H. AU - Delâge, André AU - Florjańczyk, Mirosław AU - Lapointe, Jean AU - Xu, Dan-Xia AU - Vachon, Martin AU - Janz, Siegfried AU - Calvo, María L. T2 - Laser and Photonics Reviews SN - 1863-8880 VL - 7 IS - 6 SP - L67 EP - L70 KW - Calibration measurements KW - Fourier transform spectrometers KW - Free spectral range KW - Interferometer arrays KW - Optical path difference KW - Sub-wave length grating KW - Sub-wavelength KW - Subwavelength grating waveguides KW - Circular waveguides KW - Diffraction gratings KW - Errors KW - Fabrication KW - Fourier transform infrared spectroscopy KW - Interferometry KW - Light extinction KW - Mach-Zehnder interferometers KW - Planar waveguides KW - Silicon on insulator technology KW - Spectral resolution KW - Spectrometers KW - Electric losses AB - A planar waveguide Fourier-transform spectrometer with densely arrayed Mach-Zehnder interferometers is demonstrated. Subwavelength gratings are used to produce an optical path difference without waveguide bends. The fabricated device comprises of an array of 32 Mach-Zehnder interferometers, which produce a spatial interferogram without any moving parts, yielding a spectral resolution of 50 pm and a free-spectral range of 0.78 nm. As a result of similar propagation losses in subwavelength grating waveguides and conventional strip waveguides, loss imbalance is minimized and high interferometic extinction ratio of -25 to -30 dB is obtained. Furthermore, phase and amplitude errors arising from normal fabrication variation are compensated by the spectral retrieval process using calibration measurements. A planar waveguide Fourier-transform spectrometer with densely arrayed Mach-Zehnder interferometers is demonstrated. Subwavelength gratings are used to produce an optical path difference without waveguide bends. The fabricated device comprises of an array of 32 Mach-Zehnder interferometers, which produce a spatial interferogram without any moving parts, yielding a spectral resolution of 50 pm and a free-spectral range of 0.78 nm. As a result of similar propagation losses in subwavelength grating waveguides and conventional strip waveguides, loss imbalance is minimized and high interferometic extinction ratio of -25 to -30 dB is obtained. Furthermore, phase and amplitude errors arising from normal fabrication variation are compensated by the spectral retrieval process using calibration measurements. © 2013 by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 069d7203-a1d6-4c1d-b809-85237371b0d2 ER - TY - JOUR TI - Rate equation analysis of three phonon-photon-phonon terahertz quantum cascade lasers AU - Razavipour, S. G. AU - Dupont, E. AU - Fathololoumi, S. AU - Wasilewski, Z. R. AU - Laframboise, S. R. AU - Liu, H. C. AU - Ban, D. T2 - CLEO: QELS_Fundamental Science, CLEO:QELS FS 2013 T3 - CLEO: QELS_Fundamental Science, CLEO:QELS FS 2013, 9 June 2013 through 14 June 2013, San Jose, CA SN - 9781557529725 AB - A rate equation model is presented to analyze the performance of terahertz quantum cascade lasers based on consecutive phonon-photon-phonon emissions. Devices lased up to 128.5, 138, and 144 K at 2.5, 3.2 and 2.6 THz, respectively. © Optical Society of America. DA - 2013/06 PY - 2013 PB - The Optical Society LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 67f72046-155c-4660-8d33-2f98fb145325 ER - TY - JOUR TI - Structure of the capsular polysaccharides and lipopolysaccharides from Haemophilus parasuis strains ER-6P (serovar 15) and Nagasaki (serovar 5) DO - 10.1016/j.carres.2013.04.023 AU - Perry, M.B. AU - MacLean, L.L. AU - Gottschalk, M. AU - Aragon, V. AU - Vinogradov, E. T2 - Carbohydrate Research SN - 0008-6215 VL - 378 SP - 91 EP - 97 KW - Capsular polysaccharides KW - Capsule KW - Gram-negative bacteria KW - Haemophilus parasuis KW - Lipooligosaccharides KW - Lipopolysaccharides KW - Upper respiratory tract KW - Virulent strains KW - Bacteria KW - Chains KW - Mass spectrometry KW - Nuclear magnetic resonance spectroscopy KW - Polysaccharides KW - Strain KW - bacterial polysaccharide KW - bacterium lipopolysaccharide KW - dextro glycero dextro manno heptose KW - galactosamine KW - galactose KW - glucose KW - glycoprotein KW - l glycero dextro manno heptose KW - monosaccharide KW - n glycoloylneuraminic acid KW - neuraminic acid KW - sephadex KW - unclassified drug KW - article KW - bacterial cell KW - bacterial strain KW - chemical structure KW - dephosphorylation KW - gel chromatography KW - Haemophilus parasuis KW - mass spectrometry KW - molecular mimicry KW - nonhuman KW - nuclear magnetic resonance spectroscopy KW - polyacrylamide gel electrophoresis KW - priority journal KW - proton nuclear magnetic resonance KW - serotype KW - terminal sequence KW - Animalia KW - Bacteria (microorganisms) KW - Haemophilus parasuis KW - Negibacteria KW - Pasteurellaceae KW - Suidae AB - Haemophilus parasuis is a Gram-negative bacterium from the family Pasteurellaceae and a swine pathogen. H. parasuis is found in the upper respiratory tract of piglets and produces Glässer's disease, an invasive disease characterized by polyserositis. H. parasuis contains a short lipopolysaccharide (LPS) or lipooligosaccharide (LOS) reported to play a partial role in interaction with host cells. The presence of capsule has been phenotypically demonstrated in certain H. parasuis strains and its role in virulence has been suggested, but the chemical structure of the surface polysaccharides of this bacterium was unknown. The structure of capsular polysaccharide (CPS) and LOS from virulent strains ER-6P and Nagasaki was studied by NMR spectroscopy, mass spectrometry and chemical methods. CPS from both strains had the same main chain with disaccharide repeating unit, substituted with α-Neu5R-(2-3)-α-GalNAc-(1-P-(strain ER-6P) or α-Neu5R-(2-3)-α-Gal-(1-P-strain Nagasaki) side chains, where R is the N-acetyl or N-glycolyl group. Glycolyl-neuraminic acid is widely found in animal glycoproteins, but it apparently has not been found in bacteria before, and might be important for the biology of this microorganism. Ac and Gc were present in equal amounts in the strain ER-6P but Nagasaki contained only about 20% of Gc substituent. Both strains produced the same LPS of a rough type with a single phosphorylated Kdo linking core and lipid A parts. LOS structure was similar to some strains of H. influenzae and contained a globotetraose terminal sequence. Crown Copyright © 2013 Published by Elsevier Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5606ea52-980a-4370-a6f4-25da606052b2 ER - TY - JOUR TI - Virtual endoscopy in neurosurgery: A review DO - 10.1227/NEU.0b013e31827393c9 AU - Neubauer, A. AU - Wolfsberger, S. T2 - Neurosurgery SN - 0148-396X VL - 72 IS - SUPPL. 1 SP - A97 EP - A106 KW - anastomosis KW - angioscopy KW - clinical feature KW - endocrine surgery KW - human KW - hypophysis KW - intraoperative period KW - neuroendoscopy KW - neurosurgery KW - nose surgery KW - paranasal sinus KW - patient safety KW - priority journal KW - review KW - simulator KW - virtual endoscopy KW - Computer Simulation KW - Humans KW - Imaging, Three-Dimensional KW - Neuroendoscopy KW - Preoperative Care KW - User-Computer Interface KW - Ventriculostomy AB - Virtual endoscopy is the computerized creation of images depicting the inside of patient anatomy reconstructed in a virtual reality environment. It permits interactive, noninvasive, 3-dimensional visual inspection of anatomical cavities or vessels. This can aid in diagnostics, potentially replacing an actual endoscopic procedure, and help in the preparation of a surgical intervention by bridging the gap between plain 2-dimensional radiologic images and the 3-dimensional depiction of anatomy during actual endoscopy. If not only the endoscopic vision but also endoscopic handling, including realistic haptic feedback, is simulated, virtual endoscopy can be an effective training tool for novice surgeons. In neurosurgery, the main fields of the application of virtual endoscopy are third ventriculostomy, endonasal surgery, and the evaluation of pathologies in cerebral blood vessels. Progress in this very active field of research is achieved through cooperation between the technical and the medical communities. While the technology advances and new methods for modeling, reconstruction, and simulation are being developed, clinicians evaluate existing simulators, steer the development of new ones, and explore new fields of application. This review introduces some of the most interesting virtual reality systems for endoscopic neurosurgery developed in recent years and presents clinical studies conducted either on areas of application or specific systems. In addition, benefits and limitations of single products and simulated neuroendoscopy in general are pointed out. Copyright © 2012 by the Congress of Neurological Surgeons. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2fc0e318-4c2a-4bf1-9cd9-d27662322633 ER - TY - JOUR TI - Comparison of lipopolysaccharide structures of Bordetella pertussis clinical isolates from pre- and post-vaccine era DO - 10.1016/j.carres.2013.05.002 AU - AlBitar-Nehme, S. AU - Basheer, S.M. AU - Njamkepo, E. AU - Brisson, J.-R. AU - Guiso, N. AU - Caroff, M. T2 - Carbohydrate Research SN - 0008-6215 VL - 378 SP - 56 EP - 62 KW - Bordetella pertussis KW - Clinical isolates KW - Evolution KW - Gram-negative bacteria KW - Lipopolysaccharides KW - MALDI-mass spectrometry KW - Physico-chemical analysis KW - Vaccine strains KW - Chemical analysis KW - Epitopes KW - Mass spectrometry KW - Monoclonal antibodies KW - Polysaccharides KW - Structure (composition) KW - Vaccines KW - lipid A KW - lipopolysaccharide KW - pertussis vaccine KW - article KW - bacterial strain KW - bacterium isolate KW - Bordetella pertussis KW - carbohydrate analysis KW - mass spectrometry KW - molecular model KW - nonhuman KW - physical chemistry KW - polyacrylamide gel electrophoresis KW - priority journal KW - thin layer chromatography KW - Bordetella pertussis KW - Negibacteria AB - Endotoxins are lipopolysaccharides (LPS), and major constituents of the outer membrane of Gram-negative bacteria. Bordetella pertussis LPS were the only major antigens, of this agent of whooping-cough, that were not yet analyzed on isolates from the pre- and post-vaccination era. We compared here the LPS structures of four clinical isolates with that of the vaccine strain BP 1414. All physico-chemical analyses, including SDS-PAGE, TLC, and different MALDI mass spectrometry approaches were convergent. They helped demonstrating that, on the contrary to some other B. pertussis major antigens, no modification occurred in the dodecasaccharide core structure, as well as in the whole LPS molecules. These results are rendering these major antigens good potential vaccine components. Molecular modeling of this conserved LPS structure also confirmed the conclusions of previous experiments leading to the production of anti-LPS monoclonal antibodies and defining the main epitopes of these major antigens. © 2013 Elsevier Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a9c346d2-f034-4969-8781-276ab8ebf0a8 ER - TY - JOUR TI - The Next Generation Virgo Cluster Survey. IV. NGC 4216: A bombarded spiral in the virgo cluster DO - 10.1088/0004-637X/767/2/133 AU - Paudel, S. AU - Duc, P.-A. AU - Côté, P. AU - Cuillandre, J.-C. AU - Ferrarese, L. AU - Ferriere, E. AU - Gwyn, S.D.J. AU - Mihos, J.C. AU - Vollmer, B. AU - Balogh, M.L. AU - Carlberg, R.G. AU - Boissier, S. AU - Boselli, A. AU - Durrell, P.R. AU - Emsellem, E. AU - Macarthur, L.A. AU - Mei, S. AU - Michel-Dansac, L. AU - Van Driel, W. T2 - The Astrophysical Journal SN - 0004-637X VL - 767 IS - 2 SP - 133 AB - The final stages of mass assembly of present-day massive galaxies are expected to occur through the accretion of multiple satellites. Cosmological simulations thus predict a high frequency of stellar streams resulting from this mass accretion around the massive galaxies in the Local Volume. Such tidal streams are difficult to observe, especially in dense cluster environments, where they are readily destroyed. We present an investigation into the origins of a series of interlaced narrow filamentary stellar structures, loops and plumes in the vicinity of the Virgo Cluster, edge-on spiral galaxy, NGC 4216 that were previously identified by the Blackbird telescope. Using the deeper, higher-resolution, and precisely calibrated optical CFHT/MegaCam images obtained as part of the Next Generation Virgo Cluster Survey (NGVS), we confirm the previously identified features and identify a few additional structures. The NGVS data allowed us to make a physical study of these low surface brightness features and investigate their origin. The likely progenitors of the structures were identified as either already cataloged Virgo Cluster Catalog dwarfs or newly discovered satellites caught in the act of being destroyed. They have the same g-i color index and likely contain similar stellar populations. The alignment of three dwarfs along an apparently single stream is intriguing, and we cannot totally exclude that these are second-generation dwarf galaxies being born inside the filament from the debris of an original dwarf. The observed complex structures, including in particular a stream apparently emanating from a satellite of a satellite, point to a high rate of ongoing dwarf destruction/accretion in the region of the Virgo Cluster where NGC 4216 is located. We discuss the age of the interactions and whether they occurred in a group that is just falling into the cluster and shows signs of the so-called pre-processing before it gets affected by the cluster environment, or in a group which already ventured toward the central regions of Virgo Cluster. In any case, compared to the other spiral galaxies in the Virgo Cluster, but also to those located in lower density environments, NGC 4216 seems to suffer an unusually heavy bombardment. Further studies will be needed to determine whether, given the surface brightness limit of our survey, about 29 mag arcsec-2, the number of observed streams around that galaxy is as predicted by cosmological simulations or conversely, whether the possible lack of similar structures in other galaxies poses a challenge to the merger-based model of galaxy mass assembly. © 2013. The American Astronomical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0a34d8b8-8a3d-4c68-bad8-de51f3bf6ef6 ER - TY - JOUR TI - HyDEn: A hybrid steganocryptographic approach for data encryption using randomized error-correcting DNA codes DO - 10.1155/2013/634832 AU - Tulpan, D. AU - Regoui, C. AU - Durand, G. AU - Belliveau, L. AU - Léger, S. T2 - BioMed Research International SN - 2314-6133 VL - 2013 SP - 634832 KW - article KW - data analysis KW - DNA sequence KW - DNA steganography KW - error KW - genetic code KW - hybrid DNA encryption KW - process design AB - This paper presents a novel hybrid DNA encryption (HyDEn) approach that uses randomized assignments of unique error-correcting DNA Hamming code words for single characters in the extended ASCII set. HyDEn relies on custom-built quaternary codes and a private key used in the randomized assignment of code words and the cyclic permutations applied on the encoded message. Along with its ability to detect and correct errors, HyDEn equals or outperforms existing cryptographic methods and represents a promising in silico DNA steganographic approach. © 2013 Dan Tulpan et al. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : bb1f9f72-5bfb-4169-a52e-7efec828e6e6 ER - TY - JOUR TI - A GSP double auction for smart exchange DO - 10.1109/CSCWD.2013.6581032 AU - Ghonaim, W. AU - Ghenniwa, H. AU - Shen, W. T2 - Proceedings of the 2013 IEEE 17th International Conference on Computer Supported Cooperative Work in Design, CSCWD 2013 T3 - 2013 IEEE 17th International Conference on Computer Supported Cooperative Work in Design, CSCWD 2013, 27 June 2013 through 29 June 2013, Whistler, BC SN - 9781467360852 SP - 6581032 SP - 621 EP - 626 KW - Bidding languages KW - Double auction KW - GSP auction KW - Preference elicitation KW - prefernce deduction KW - Reverse auction KW - strategic rules KW - Winner determination KW - Electronic commerce KW - Interactive computer systems KW - Sustainable development KW - Online systems AB - The emerging dynamics of the digital e-markets are creating many opportunities with the vast growth and potential of online services and mobile technology. However, the sustainability of e-markets is uncertain due to industry and operational risks. While industry threats extend to the rapidly shifting powers, fuzzy dynamics, and fierce rivalry, this work examines an overlooked operational risk that relates to the fact present e-markets often constrain e-traders from strategic conduct. Such denial incites adverse reactions that cause e-market failures. In contrast, Smith invisible hand realizes the efficiency of the flexible strategic choice in free markets. Conveying strategies as rules may, also, accelerate the bidding lifecycles due to the automatic preference deduction of rules by the smart exchange. This work presents the RBBL rule based bidding language that enables free expressions of strategic rules in the bid structure, while proposing the GSPM generalized second price truthful matching double auction that computes stable, efficient and tractable outcomes with market profitability. The introduced smart exchange deliberates on the RBBL rules for automatic preference deduction while using the GSPM for winner determination, hence, improves sustainability with the rapid and stable e-trades, social efficiency, and self-prosperity of free choice. © 2013 IEEE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e1717380-627b-41f3-aa8a-4ca8f05192be ER - TY - JOUR TI - Editorial DO - 10.1007/s11666-013-9900-4 AU - Marple, B.R AU - Agarwal, A. AU - Hyland, M.M. AU - Lau, Y.-C. AU - Li, C.-J. AU - Lima, R.S. AU - McDonald, A. AU - Toma, F.-L. T2 - Journal of Thermal Spray Technology SN - 1059-9630 VL - 22 IS - 2-Mar SP - 81 EP - 82 DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b9992ce4-5bae-4896-a519-6e83aea13675 ER - TY - JOUR TI - Microscopic investigation of platinum deposition in PEMFC cross-sections using AFM and SEM DO - 10.1149/2.130306jes AU - Helmly, S. AU - Hiesgen, R. AU - Morawietz, T. AU - Yuan, X.-Z. AU - Wang, H. AU - Friedrich, K.A. T2 - Journal of the Electrochemical Society SN - 0013-4651 VL - 160 IS - 6 SP - F687 EP - F697 KW - Conductive AFM KW - Crystallite growth KW - Membrane degradation KW - Platinum depositions KW - Polymer decomposition KW - Postmortem analysis KW - Proton exchange membrane fuel cell (PEMFCs) KW - Pt deposition KW - Atomic force microscopy KW - Cathodes KW - Deposition KW - Membranes KW - Platinum KW - Scanning electron microscopy KW - Proton exchange membrane fuel cells (PEMFC) AB - Atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to investigate platinum (Pt) deposition in the membrane of degraded proton exchange membrane fuel cells (PEMFCs). This study focuses on Pt distribution and microscopic aspects of accelerated membrane degradation. To facilitate post-mortem analysis, a 4-cell stack was specially designed with cells composed of two membranes. Considerable Pt deposition was observed in both membranes and at their interface. Significant crystallite growth in the form of a Pt band and membrane thinning was present in the membrane at the cathode side, which supports the hypothesis that Pt deposition accelerates polymer decomposition. Furthermore, a large continuous area of Pt crystals across the whole cathode membrane was detected. In addition, conductive AFM measurements revealed electronic connections across the membrane. These results indicate the formation of electronic short-circuits in the cell due to the accumulation of Pt particles, which has not been previously reported. Moreover, AFM proved to be more sensitive to detect Pt deposits and its effects than SEM. © 2013 The Electrochemical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2b05cac9-bfe9-498e-a33a-452ffa47870a ER - TY - JOUR TI - On the discovery of the diffuse interstellar bands DO - 10.1098/rspa.2012.0604 AU - McCall, B.J. AU - Griffin, R.E. T2 - Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences SN - 1364-5021 VL - 469 IS - 2151 SP - 20120604 KW - Diffuse interstellar bands KW - Lick observatory KW - Long lasting KW - Mary Lea Heger KW - Systematic research KW - Buildings KW - History KW - Observatories KW - Research KW - Astronomy AB - This contribution attempts to reconstruct the precise history of the discovery of one of astronomy's longlasting enigmas, the so-called diffuse interstellar bands (DIBs). While systematic research into the DIBs was initiated by Merrill in 1936, the first pointers to abnormal features in the spectra of distant stars were published some 15 years earlier by Mary Lea Heger, who researched them at Lick Observatory while a student.We have examined Heger's observing notebooks from her doctoral work in 1919-1920. We have also digitized her 1919 photographic plates, and compared the spectra that she measured with modern ones. Our conclusion is that Heger was indeed the first to observe and draw attention to the two absorption features at 5780Å and 5797Å that subsequently came to be recognized as DIBs, thereby initiating a substantial field of research that now embraces several hundred such features, all of whose provenance is unsolved even to this day. © 2013 The Author(s). DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f9eb2334-91eb-4312-8f7e-c6611baef897 ER - TY - JOUR TI - Evaluation of novel seat cushions to mitigate helicopter aircrew exposure to vibration AU - Wickramasinghe, V. AU - Chen, Y. T2 - Annual Forum Proceedings - AHS International T3 - 69th American Helicopter Society International Annual Forum 2013, 21 May 2013 through 23 May 2013 SN - 1552-2938 SN - 9781627486514 VL - 1 SP - 484 EP - 493 KW - Helicopter aircrews KW - Impedance properties KW - Long term exposure KW - Low-cost solution KW - Polyurethane materials KW - Research studies KW - Seat cushions KW - Vibration level KW - Air cushioning KW - Energy absorption KW - Helicopters KW - Aircraft seats AB - Undesired vibration transmitted through the helicopter seats has been known to cause fatigue and discomfort to the aircrew in the short-term as well as neck strain and back pain injuries due to long-term exposure. This research study investigated the use of novel energy absorbing cushion materials integrated into helicopter seats to mitigate the aircrew whole-body exposure to high vibration levels. Replacing the cushion material on a helicopter seat was a low cost solution with less certification effort that provided a reduction in the vibration transmitted to the aircrew. Novel energy absorbing cushion material, namely, the Hybrid Air Cushioning System known as Mitigator and a viscoelastic polyurethane material known as Sorbothane, were evaluated using flight tests on the NRC Bell-412 helicopter. The test results confirmed that the aircrew vibration levels can be effectively reduced through proper optimization of the seat cushion impedance properties. In particular, integration of the Hybrid Air Cushioning System into the seat significantly reduced the 1/rev peak while marginally reducing the 4/rev peak that resulted in an overall reduction in the aircrew vibration. Copyright © 2013 by the American Helicopter Society International, Inc. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 16aa4e32-ee2e-413c-8bd4-cb3f86368f1c ER - TY - JOUR TI - Characterization of nickel diffusion and its effect on the microstructure of nickel PM steels DO - 10.1007/s11661-012-1417-9 AU - Tougas, B. AU - Blais, C. AU - Chagnon, F. AU - Pelletier, S. T2 - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science SN - 1073-5623 VL - 44 IS - 2 SP - 754 EP - 765 KW - Concentration maps KW - Diffusion mechanisms KW - Grain-boundary diffusion KW - Heterogeneous microstructure KW - Microstructures and properties KW - Sintered parts KW - Volume diffusion coefficients KW - Wavelength dispersive X-rays KW - Diffusion KW - Grain boundaries KW - Microstructure KW - Nickel powder metallurgy KW - Powder metallurgy KW - Steel KW - Nickel AB - Admixing pure elements to powder mixes can cause the formation of heterogeneous microstructures in sintered parts. For instance, nickel is renowned for forming nickel-rich areas (NRA) in powder metallurgy (PM) nickel steels due to its poor diffusivity in iron matrix (or lattice). The present work is aimed at characterizing the principal diffusion mechanisms of nickel and their influence on microstructures and properties of PM nickel steels. A new wavelength dispersive X-ray spectrometry (WDS) approach linking line scans and X-ray maps to concentration maps is proposed. Grain boundary and volume diffusion coefficients of admixed nickel have been determined in PM nickel steels using Suzuoka's equation. Results also show that nickel distributes itself in the iron matrix mainly by surface and grain boundary diffusion. © 2012 The Minerals, Metals & Materials Society and ASM International. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b2e97fcd-17b9-4304-b480-6d2cc22913bc ER - TY - JOUR TI - Human serum activates CIDEB-mediated lipid droplet enlargement in hepatoma cells DO - 10.1016/j.bbrc.2013.10.080 AU - Singaravelu, R. AU - Lyn, R.K. AU - Srinivasan, P. AU - Delcorde, J. AU - Steenbergen, R.H. AU - Tyrrell, D.L. AU - Pezacki, J.P. T2 - Biochemical and Biophysical Research Communications SN - 0006-291X VL - 441 IS - 2 SP - 447 EP - 452 AB - Human hepatocytes constitutively express the lipid droplet (LD) associated protein cell death-inducing DFFA-like effector B (CIDEB). CIDEB mediates LD fusion, as well as very-low-density lipoprotein (VLDL) maturation. However, there are limited cell culture models readily available to study CIDEB's role in these biological processes, as hepatoma cell lines express negligible levels of CIDEB. Recent work has highlighted the ability of human serum to differentiate hepatoma cells. Herein, we demonstrate that culturing Huh7.5 cells in media supplemented with human serum activates CIDEB expression. This activation occurs through the induced expression of PGC-1α, a positive transcriptional regulator of CIDEB. Coherent anti-Stokes Raman scattering (CARS) microscopy revealed a correlation between CIDEB levels and LD size in human serum treated Huh7.5 cells. Human serum treatment also resulted in a rapid decrease in the levels of adipose differentiation-related protein (ADRP). Furthermore, individual overexpression of CIDEB was sufficient to down-regulate ADRP protein levels. siRNA knockdown of CIDEB revealed that the human serum mediated increase in LD size was CIDEB-dependent. Overall, our work highlights CIDEB's role in LD fusion, and presents a new model system to study the PGC-1α/CIDEB pathway's role in LD dynamics and the VLDL pathway. © 2013 Elsevier Inc. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9389930c-d268-4a19-a3cb-c5303e7692e9 ER - TY - JOUR TI - Haffner 16: A young moving group in the making DO - 10.1086/673379 AU - Davidge, T.J. AU - Carrasco, E.R. AU - Winge, C. AU - Pessev, P. AU - Neichel, B. AU - Vidal, F. AU - Rigaut, F. T2 - Publications of the Astronomical Society of the Pacific SN - 0004-6280 VL - 125 IS - 932 SP - 1181 EP - 1190 AB - The photometric properties of main sequence (MS) and pre-main sequence (PMS) stars in the young cluster Haffner 16 are examined using images recorded with the Gemini South Adaptive Optics Imager (GSAOI) and corrected for atmospheric blurring by the Gemini Multi-Conjugate Adapative Optics System (GeMS). A rich population of PMS stars is identified, and comparisons with isochrones suggest an age ≲10 Myr, assuming a distance modulus of 13.5 (D = 5 kpc). This age is consistent with that estimated from the lower cutoff of the MS on the K-band luminosity function and is ~2 Myr younger than the age found from bright MS stars at visible wavelengths. When compared with the solar neighborhood, Haffner 16 is roughly a factor of 2 deficient in objects with subsolar masses. PMS objects in the cluster are also more uniformly distributed on the sky than bright MS stars. It is suggested that Haffner 16 is dynamically evolved and that it is shedding protostars with subsolar masses. Young low mass clusters like Haffner 16 are one possible source of PMS stars in the field. The cluster will probably evolve on time scales of ~100-1000 Myr into a diffuse moving group with a mass function that is very different from that which prevailed early in its life. © 2013. The Astronomical Society of the Pacific. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c4fedaf7-8e0c-46d6-86de-afbe6054e7c8 ER - TY - JOUR TI - A method for detecting forward scattering signals on-chip with a photonic-microfluidic integrated device DO - 10.1364/BOE.4.001051 AU - Watts, B.R. AU - Zhang, Z. AU - Xu, C.-Q. AU - Cao, X. AU - Lin, M. T2 - Biomedical Optics Express SN - 2156-7085 VL - 4 IS - 7 SP - 1051 EP - 1060 KW - Design modifications KW - False positive rates KW - Forward scatters KW - Integrated device KW - Integrated microfluidic devices KW - Optimal excitation KW - Polystyrene beads KW - Side scatter signal KW - Geometry KW - Photoexcitation KW - Polystyrenes KW - Signal detection KW - article KW - device fabrication KW - device testing KW - experimental design KW - fluorescence imaging KW - free space detection KW - laboratory diagnosis KW - light scattering KW - limit of detection KW - microfluidic analysis KW - optical excitation KW - optics KW - scatter detection AB - A photonic integrated microfluidic device is demonstrated to perform optical excitation and forward scatter collection all on-chip in a planar format. Integrated on-chip optics formed a tailored beam geometry for optimal excitation of particles while a special design modification allowed for on-chip forward collection with the beam shaping capabilities. A notch was placed in the lens system that caused a dark spot on the facet of a collection waveguide while not affecting the beam geometry at the point of interrogation. The modified device with the ability to form a 10 μm beam geometry was demonstrated to detect the forward scatter from blank 5 μm diameter polystyrene beads. Free-space collection of side scatter signals was performed simultaneously with the on-chip collection and the designs demonstrated and enhanced SNR while the reliability of detection was determined to be appropriate for many applications. Excellent performance was confirmed via a false positive rate of 0.4%, a missed events rate of 6.8%, and a coincident rate of 96.3% as determined between simultaneously performed free-space and on-chip detection schemes. © 2013 Optical Society of America. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b60201b1-f4c3-46bb-a8e9-c184a1b35768 ER - TY - JOUR TI - Two- and three-electron pauli spin blockade in series-coupled triple quantum dots DO - 10.1103/PhysRevLett.110.016803 AU - Amaha, S. AU - Izumida, W. AU - Hatano, T. AU - Teraoka, S. AU - Tarucha, S. AU - Gupta, J.A. AU - Austing, D.G. T2 - Physical Review Letters SN - 0031-9007 VL - 110 IS - 1 SP - 16803 KW - Sequential tunneling KW - Spin blockade KW - Triple quantum KW - Triplet state KW - Electrons KW - Magnetic moments KW - Semiconductor quantum dots KW - Spin dynamics KW - Electrospinning AB - We investigate two- and three-electron spin blockade in three vertical quantum dots (QDs) coupled in series. Two-electron spin blockade is found in a region where sequential tunneling through all QDs is forbidden but tunneling involving virtual hopping through an empty QD is allowed. It is observed only for the hole cycle with a distinct bias threshold for access to the triplet state. Three-electron spin blockade involving the quadruplet state is observed for nonequibilium conditions where sequential tunneling is allowed and the triplet state is accessible. Our results shine light on the importance of the nonequibilium conditions to obtain sufficient population of triplet and quadruplet states necessary for spin blockade. © 2013 American Physical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9d7c77a0-7b14-4030-87e2-ff569375bcbd ER - TY - JOUR TI - Efficient optical pumping and high optical depth in a hollow-core photonic-crystal fibre for a broadband quantum memory DO - 10.1088/1367-2630/15/5/055013 AU - Sprague, M.R. AU - England, D.G. AU - Abdolvand, A. AU - Nunn, J. AU - Jin, X.-M. AU - Steven Kolthammer, W. AU - Barbieri, M. AU - Rigal, B. AU - Michelberger, P.S. AU - Champion, T.F.M. AU - Russell, P.S.J. AU - Walmsley, I.A. T2 - New Journal of Physics SN - 1367-2630 VL - 15 SP - 55013 KW - Broadband pulse KW - High-efficiency KW - Hollow-core photonic-crystal KW - Light-matter coupling KW - Multiphoton quantum KW - Nonlinear optical effects KW - Quantum memory KW - Room temperature KW - Computer simulation KW - Optical fibers KW - Optical waveguides KW - Quantum theory KW - Optical pumping AB - The generation of large multiphoton quantum states - for applications in computing, metrology and simulation - requires a network of high-efficiency quantum memories capable of storing broadband pulses. Integrating these memories into a fibre offers a number of advantages towards realizing this goal: strong light-matter coupling at low powers, simplified alignment and compatibility with existing photonic architectures. Here, we introduce a large-core kagome-structured hollow-core fibre as a suitable platform for an integrated fibre-based quantum memory with a warm atomic vapour. We demonstrate, for the first time, efficient optical pumping in such a system, where 90 ± 1% of atoms are prepared in the ground state. We measure high optical depths (3 × 104) and narrow homogeneous linewidths (6 ± 2 MHz) that do not exhibit significant transit-time broadening, showing that we can prepare a Λ-level system in a pure state. Our results establish that kagome fibres are suitable for implementing a broadband, room-temperature quantum memory, as well as a range of nonlinear optical effects. © IOP Publishing and Deutsche Physikalische Gesellschaft. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : bfdd8b17-dd65-48fd-ad75-23526319dc42 ER - TY - JOUR TI - The role of the Kramers-Henneberger atom in the higher-order Kerr effect DO - 10.1088/1367-2630/15/8/083012 AU - Richter, Maria AU - Patchkovskii, Serguei AU - Morales, Felipe AU - Smirnova, Olga AU - Ivanov, Misha T2 - New Journal of Physics SN - 1367-2630 VL - 15 SP - 83012 KW - Driving field KW - External fields KW - Generalized models KW - Intensity-dependent KW - Kerr response KW - Non-linear response KW - Strong field ionization KW - The standard model KW - Atomic spectroscopy KW - Atoms KW - Optical Kerr effect AB - We discuss the connection between strong-field ionization, saturation of the Kerr response and the formation of the Kramers-Henneberger (KH) atom and long-living excitations in intense infrared (IR) external fields. We present a generalized model for the intensity-dependent response of atoms in strong IR laser fields, describing deviations in the nonlinear response at the frequency of the driving field from the standard model. We show that shaping the driving laser pulse allows one to reveal signatures of the excited KH states in the Kerr response of an individual atom. © IOP Publishing and Deutsche Physikalische Gesellschaft. DA - 2013/08/06 PY - 2013 PB - Institute of Physics LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 816a6bc4-d47a-4471-bea1-2fe142b2eb52 ER - TY - JOUR TI - Confocal scanner for highly sensitive photonic transduction of nanomechanical resonators DO - 10.7567/APEX.6.065202 AU - Diao, Zhu AU - Losby, Joseph E. AU - Sauer, Vincent T. K. AU - Westwood, Jocelyn N. AU - Freeman, Mark R. AU - Hiebert, Wayne K. T2 - Applied Physics Express SN - 1882-0778 VL - 6 IS - 6 SP - 65202 KW - Confocal laser scanning KW - Coupling efficiency KW - Doubly clamped beam KW - Free-space optical KW - Nanomechanical resonators KW - Nanophotonic circuits KW - Orders of magnitude KW - Resonant response KW - Bacteriophages KW - Nanophotonics KW - Resonators KW - Coupled circuits AB - We show that a simple confocal laser scanning system can be used to couple light through grating couplers into nanophotonic circuits. The coupling efficiency is better than 15% per coupler. Our technique avoids using multi-axis fibre stages and is especially advantageous when the nanophotonic circuit is kept in vacuum, e.g., for nanomechanical resonator displacement transduction. This was demonstrated by recording the resonant response of a nanomechanical doubly clamped beam embedded in a race-track optical cavity. The nanophotonic transduction offers an increase of two orders of magnitude in transduction responsivity compared with conventional free-space optical interferometry. DA - 2013/06/04 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5f7dd8aa-8ce0-4029-8d72-fab36ffc563d ER - TY - JOUR TI - Substrate integrated waveguide-fed tapered slot antenna with smooth performance characteristics over an ultra-wide bandwidth AU - Locke, Lisa S. AU - Bornemann, Jens AU - Claude, Stéphane T2 - Applied Computational Electromagnetics Society Journal SN - 1054-4887 VL - 28 IS - 5 SP - 454 EP - 462 KW - Cross-polarization level KW - Finite integration technique KW - Gain KW - Half power beam widths KW - Linear tapered slot antennas KW - Performance characteristics KW - Antipodal tapered slot antennas KW - Alumina KW - Antenna feeders KW - Design KW - Microwave circuits KW - Substrate integrated waveguides KW - Ultra-wideband AB - We present an ultra-wide extended K-band (18 GHz - 30 GHz) planar linear tapered slot antenna (LTSA) design. From a parametric study involving eight designs, the best compromise LTSA is selected in terms of flattest gain and beam width and most symmetric beam width. The design is antipodal with alumina (ε = 10) substrate and fed with substrate integrated waveguide (SIW). Regular corrugations improve cross-polarization, input return loss, and gain. Numerical simulations use finite element analysis and time domain finite integration technique field solvers. The resulting design has half power beam widths (HPBW) of only ± 3.2° and ± 2.5° variation in frequency in the E- and H-planes, respectively. Cross-polarization levels at boresight are 35.7 dB at 18 GHz and 17.4 dB at 30 GHz, return loss is better than -11.7 dB and gain is 9.23 dB with ± 0.40 dB variation with frequency. Alternatively, for imaging systems requiring efficient illumination of a reflector or focusing elements, a second resulting design shows near-perfect beam symmetiy with HPBWE/HPBWH = 0.91. These two LTSAs are good candidates for dual-polarization focal plane array feed applications in astronomy imaging. DA - 2013/05 PY - 2013 UR - http://www.ece.uvic.ca/~jbornema/Journals/115-13aces-lbc.pdf LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 08011102-dac8-4dfc-a799-59561146ede0 ER - TY - JOUR TI - Inkjet application, chromatography, and mass spectrometry of sugars on nanostructured thin films DO - 10.1007/s00216-013-7131-7 AU - Kirchert, Simone AU - Wang, Zhen AU - Taschuk, Michael T. AU - Jim, Steven R. AU - Brett, Michael J. AU - Morlock, Gertrud E. T2 - Analytical and Bioanalytical Chemistry SN - 1618-2642 VL - 405 IS - 23 SP - 7195 EP - 7203 KW - Derivatizations KW - Electrospray ionization mass spectrometry KW - Glancing Angle Deposition KW - High performance thin layer chromatography KW - Miniaturized layers KW - Quantitation KW - Ultrathin-layer chromatographies KW - Vapor-deposition techniques KW - Deposition KW - Ink jet printers KW - Mass spectrometry KW - Physical vapor deposition KW - RNA KW - Sugars KW - Chromatography KW - Theobroma cacao AB - Ultrathin-layer chromatography (UTLC) potentially offers faster analysis, reduced solvent and sample volumes, and lower costs. One novel technique for producing UTLC plates has been glancing angle deposition (GLAD), a physical vapor deposition technique capable of aligning macropores to produce interesting separation properties. To date, however, GLAD-UTLC plates have been restricted to model dye systems, rather than realistic analytes. This study demonstrates the transfer of high-performance thin-layer chromatography (HPTLC) sugar analysis methods to GLAD-UTLC plates using the office chromatography framework. A consumer inkjet printer was used to apply very sharp low volume (3-30 nL) bands of water-soluble analytes (lactose, sucrose, and fructose). Analytic performance measurements extrapolated the limits of detection to be 3-5 ng/zone, which was experimentally proven down to 60-70 ng/band, depending on the sugar. This qualitative analysis of sugars in a commercially available chocolate sample is the first reported application of GLAD-UTLC to food samples. The potential utility of GLAD-UTLC is further exemplified by successful coupling with electrospray ionization mass spectrometry for the first time to characterize underivatized sugars. DA - 2013/09/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4458f52c-9f80-4fac-b32a-95d35d2f8d5b ER - TY - JOUR TI - Antiperlecan antibodies are novel accelerators of immune-mediated vascular injury DO - 10.1111/ajt.12168 AU - Cardinal, H. AU - Dieudé, M. AU - Brassard, N. AU - Qi, S. AU - Patey, N. AU - Soulez, M. AU - Beillevaire, D. AU - Echeverry, F. AU - Daniel, C. AU - Durocher, Y. AU - Madore, F. AU - Hébert, M. J. T2 - American Journal of Transplantation SN - 1600-6135 VL - 13 IS - 4 SP - 861 EP - 874 KW - acute rejection KW - antibody KW - calcineurin inhibitor KW - CD4 antigen KW - immunoglobulin G KW - perlecan KW - animal experiment KW - antibody titer KW - apoptosis KW - blood vessel injury KW - endothelium cell KW - graft recipient KW - graft survival KW - immune mediated injury KW - immunoglobulin A nephropathy KW - kidney allograft rejection KW - kidney transplantation KW - neointima KW - protein function AB - Acute vascular rejection (AVR) is characterized by immune-mediated vascular injury and heightened endothelial cell (EC) apoptosis. We reported previously that apoptotic ECs release a bioactive C-terminal fragment of perlecan referred to as LG3. Here, we tested the possibility that LG3 behaves as a neoantigen, fuelling the production of anti-LG3 antibodies of potential importance in regulating allograft vascular injury. We performed a case-control study in which we compared anti-LG3 IgG titers in kidney transplant recipients with AVR (n = 15) versus those with acute tubulo-interstitial rejection (ATIR) (n = 15) or stable graft function (n = 30). Patients who experienced AVR had elevated anti-LG3 titers pre and posttransplantation compared to subjects with ATIR or stable graft function (p < 0.05 for both mediators). Elevated pretransplant anti-LG3 titers (OR: 4.62, 95% CI: 1.08-19.72) and pretransplant donor-specific antibodies (DSA) (OR 4.79, 95% CI: 1.03-22.19) were both independently associated with AVR. To address the functional role of anti-LG3 antibodies in AVR, we turned to passive transfer of anti-LG3 antibodies in an animal model of vascular rejection based on orthotopic aortic transplantation between fully MHC-mismatched mice. Neointima formation, C4d deposition and allograft inflammation were significantly increased in recipients of an ischemic aortic allograft passively transferred with anti-LG3 antibodies. Collectively, these data identify anti-LG3 antibodies as novel accelerators of immune-mediated vascular injury and obliterative remodeling. DA - 2013/02/22 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b4f72186-6ae3-4377-9fd9-c8f6465dddd7 ER - TY - JOUR TI - Effect of peptide secondary structure on adsorption and adsorbed film properties DO - 10.1016/j.actbio.2013.01.018 AU - Binazadeh, M. AU - Zeng, H. AU - Unsworth, L. D. T2 - Acta Biomaterialia SN - 1742-7061 VL - 9 IS - 5 SP - 6403 EP - 6413 KW - Non-specific protein adsorption; Secondary structure; Poly-l-lysine; Circular dichroism; Quartz crystal microbalance with dissipation AB - Protein adsorption at the biomaterial-tissue interface is of utmost importance to the widespread application of engineered materials. The present study asked what role the secondary structures of peptides play in their adsorption, as well as how these structures affect the physicochemical properties of the final adsorbed layer. To this end, α-helices and β-sheets were induced in poly-l-lysine, and their adsorption to Au surfaces was monitored using quartz crystal microbalance with dissipation. It was observed that secondary structures played an important role in governing both the adsorption process and the final film properties. Higher initial adsorption rates were obtained for α-helices compared with β-sheets, regardless of solution salt concentration. Adsorption half-time for β-sheets was greater than that for α-helices, and the final amount adsorbed on β-sheet was significantly higher than that on α-helix. The adsorbed amount and adsorption half-time decreased with increasing salt concentration, suggesting that electrostatic interactions played a role. It was found that the differences in Zeta potential coupled with the apparent effect of surface contact area differences between α-helix and β-sheet conformations are ultimately responsible for these different peptide adsorption behaviours at the Au interface. The initial adsorption rate of α-helix increased with salt concentrations up to 50 mM, whereas β-sheet initial adsorption rates increased with salt concentrations up to 500 mM. Viscosities for films formed from α-helices were about twice those of β-sheets films, regardless of solution ionic strength. It was evident that the peptide secondary structures influence all aspects of their adsorption, as well as affecting the adsorbed film properties. DA - 2013/01/29 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d835be9f-e49d-4a9a-977f-8c1cf4dc9b9e ER - TY - JOUR TI - Chemical insight into the origin of red and blue photoluminescence arising from freestanding silicon nanocrystals DO - 10.1021/nn4000644 AU - Dasog, Mita AU - Yang, Zhenyu AU - Regli, Sarah AU - Atkins, Tonya M. AU - Faramus, Angelique AU - Singh, Mani P. AU - Muthuswamy, Elayaraja AU - Kauzlarich, Susan M. AU - Tilley, Richard D. AU - Veinot, Jonathan G. C. T2 - ACS Nano SN - 1936-0851 VL - 7 IS - 3 SP - 2676 EP - 2685 KW - silicon nanocrystals; photoluminescence; surface functionalization; nitrogen AB - Silicon nanocrystals (Si NCs) are attractive functional materials. They are compatible with standard electronics and communications platforms and are biocompatible. Numerous methods have been developed to realize size-controlled Si NC synthesis. While these procedures produce Si NCs that appear identical, their optical responses can differ dramatically. Si NCs prepared using high-temperature methods routinely exhibit photoluminescence agreeing with the effective mass approximation (EMA), while those prepared via solution methods exhibit blue emission that is somewhat independent of particle size. Despite many proposals, a definitive explanation for this difference has been elusive for no less than a decade. This apparent dichotomy brings into question our understanding of Si NC properties and potentially limits the scope of their application. The present contribution takes a substantial step forward toward identifying the origin of the blue emission that is not expected based upon EMA predictions. It describes a detailed comparison of Si NCs obtained from three of the most widely cited procedures as well as the conversion of red-emitting Si NCs to blue emitters upon exposure to nitrogen-containing reagents. Analysis of the evidence is consistent with the hypothesis that the presence of trace nitrogen and oxygen even at the parts per million level in Si NCs gives rise to the blue emission. DA - 2013/02/08 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 99345083-e7c6-4cb7-b50c-c878f5515c4c ER - TY - JOUR TI - Solution-processed zinc phosphide (α-Zn3P2) colloidal semiconducting nanocrystals for thin film photovoltaic applications DO - 10.1021/nn4034234 AU - Luber, Erik J. AU - Mobarok, Md Hosnay AU - Buriak, Jillian M. T2 - ACS Nano SN - 1936-0851 VL - 7 IS - 9 SP - 8136 EP - 8146 KW - Core-shell KW - earth-abundant KW - Photovoltaics KW - Semiconductor nanocrystals KW - Solution-processed KW - Zinc phosphide KW - Heterojunctions KW - Molybdenum oxide KW - Nanocrystals KW - Nanoparticles KW - Photoelectron spectroscopy KW - Photoelectrons KW - Quantum confinement KW - Synthesis (chemical) KW - Thin films KW - Transmission electron microscopy KW - X ray diffraction KW - X ray photoelectron spectroscopy KW - Zinc AB - Zinc phosphide (Zn3P2) is a promising earth-abundant material for thin film photovoltaic applications, due to strong optical absorption and near ideal band gap. In this work, crystalline zinc phosphide nanoparticles are synthesized using dimethylzinc and tri-n-octylphosphine as precursors. Transmission electron microscopy and X-ray diffraction data show that these nanoparticles have an average diameter of ∼8 nm and adopt the crystalline structure of tetragonal α-Zn3P2. The optical band gap is found to increase by 0.5 eV relative to bulk Zn 3P2, while there is an asymmetric shift in the conduction and valence band levels. Utilizing layer-by-layer deposition of Zn 3P2 nanoparticle films, heterojunction devices consisting of ITO/ZnO/Zn3P2/MoO3/Ag are fabricated and tested for photovoltaic performance. The devices are found to exhibit excellent rectification behavior (rectification ratio of 600) and strong photosensitivity (on/off ratio of ∼10²). X-ray photoelectron spectroscopy and ultraviolet photoemission spectroscopy analyses reveal the presence of a thin 1.5 nm phosphorus shell passivating the surface of the Zn3P 2 nanoparticles. This shell is believed to form during the nanoparticle synthesis. DA - 2013/08/12 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ae7f8f26-1d83-4169-9e87-cebfd4b01348 ER - TY - JOUR TI - Using nuances of emotion to identify personality AU - Mohammad, Saif M. AU - Kiritchenko, Svetlana T2 - Proceedings of the ICWSM Workshop on Computational Personality Recognition T3 - ICWSM Workshop on Computational Personality Recognition, July 2013, Boston, MA AB - Past work on personality detection has shown that frequency of lexical categories such as first person pronouns, past tense verbs, and sentiment words have significant correlations with personality traits. In this paper, for the first time, we show that fine affect (emotion) categories such as that of excitement, guilt, yearning, and admiration are significant indicators of personality. Additionally, we perform experiments to show that the gains provided by the fine affect categories are not obtained by using coarse affect categories alone or with specificity features alone. We employ these features in five SVM classifiers for detecting five personality traits through essays. We find that the use of fine emotion features leads to statistically significant improvement over a competitive baseline, whereas the use of coarse affect and specificity features does not. DA - 2013/07/01 PY - 2013 PB - AAAI Publications LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0d2da4fd-27fd-42f1-a867-d3de866ad8ea ER - TY - JOUR TI - NRC-Canada : building the state-of-the-art in sentiment analysis of tweets AU - Mohammad, Saif M. AU - Kiritchenko, Svetlana AU - Zhu, Xiaodan T2 - Proceedings of the Seventh International Workshop on Semantic Evaluation Exercises T3 - SemEval-2013, June 2013, Atlanta, GA AB - In this paper, we describe how we created two state-of-the-art SVM classifiers, one to detect the sentiment of messages such as tweets and SMS (message-level task) and one to detect the sentiment of a term within a message (term-level task). Among submissions from 44 teams in a competition, our submissions stood first in both tasks on tweets, obtaining an F-score of 69.02 in the message-level task and 88.93 in the term-level task. We implemented a variety of surface-form, semantic, and sentiment features. We also generated two large word–sentiment association lexicons, one from tweets with sentiment-word hashtags, and one from tweets with emoticons. In the message-level task, the lexicon-based features provided a gain of 5 F-score points over all others. Both of our systems can be replicated using freely available resources. DA - 2013/07/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1ba3cbfc-a41f-4b46-a1c4-a30ed0c346b9 ER - TY - JOUR TI - NMR metabolomics analysis of the effects of 5-lipoxygenase inhibitors on metabolism in glioblastomas DO - 10.1021/pr400026q AU - Morin, Pier Jr AU - Ferguson, Dean AU - Leblanc, Luc M. AU - Hébert, Martin J. G. AU - Paré, Aurélie F. AU - Jean-François, Jacques AU - Surette, Marc E. AU - Touaibia, Mohamed AU - Cuperlovic-Culf, Miroslava T2 - Journal of Proteome Research SN - 1535-3893 VL - 12 IS - 5 SP - 2165 EP - 2176 KW - Drug discovery; NMR Metabolomics; Caffeic acid phenethyl ester; 5-lipoxygenase inhibitors; Glioblastoma multiforme; Antioxidant and antiradical activity AB - Changes across metabolic networks are emerging as an integral part of cancer development and progression. Increasing comprehension of the importance of metabolic processes as well as metabolites in cancer is stimulating exploration of novel, targeted treatment options. Arachidonic acid (AA) is a major component of phospholipids. Through the cascade catalyzed by cyclooxygenases and lipoxygenases, AA is also a precursor to cellular signaling molecules as well as molecules associated with a variety of diseases including cancer. 5-Lipoxygenase catalyzes the transformation of AA into leukotrienes (LT), important mediators of inflammation. High-throughput analysis of metabolic profiles was used to investigate the response of glioblastoma cell lines to treatment with 5-lipoxygenase inhibitors. Metabolic profiling of cells following drug treatment provides valuable information about the response and metabolic alterations induced by the drug action and give an indication of both on-target and off-target effects of drugs. Four different 5-lipoxygenase inhibitors and antioxidants were tested including zileuton, caffeic acid, and its analogues caffeic acid phenethyl ester and caffeic acid cyclohexethyl ester. A NMR approach identified metabolic signatures resulting from application of these compounds to glioblastoma cell lines, and metabolic data were used to develop a better understanding of the mode of action of these inhibitors. DA - 2013/04/05 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ece1ba28-0395-4f13-9c87-f011aaea97c8 ER - TY - JOUR TI - Density-functional theory, finite-temperature classical maps, and their implications for foundational studies of quantum systems DO - 10.1088/1742-6596/442/1/012030 AU - Dharma-Wardana, M. W. C. T2 - Journal of Physics: Conference Series T3 - 6th International Workshop on Decoherence, Information, Complexity and Entropy: Spacetime - Matter - Quantum Mechanics - From the Planck Scale to Emergent Phenomena, DICE 2012, September 17-21, 2012, Castiglioncello, Tuscany, Italy SN - 1742-6588 VL - 442 IS - 1 SP - 12030 KW - De Broglie wavelength KW - Decoherence models KW - Density distributions KW - Hohenberg-Kohn theorem KW - Local correlations KW - Macroscopic systems KW - Pair distribution functions KW - Pauli exclusion effects KW - Density functional theory KW - Quantum electronics KW - Quantum optics AB - The advent of the Hohenberg-Kohn theorem in 1964, its extension to finite-T, Kohn-Sham theory, and relativistic extensions provide the well-established formalism of density-functional theory (DFT). This theory enables the calculation of all static properties of quantum systems without the need for an n-body wavefunction ψ. DFT uses the one-body density distribution instead of ψ. The more recent time-dependent formulations of DFT attempt to describe the time evolution of quantum systems without using the time-dependent wavefunction. Although DFT has become the standard tool of condensed-matter computational quantum mechanics, its foundational implications have remained largely unexplored. While all systems require quantum mechanics (QM) at T=0, the pair-distribution functions (PDFs) of such quantum systems have been accurately mapped into classical models at effective finite-T, and using suitable non-local quantum potentials (e.g., to mimic Pauli exclusion effects). These approaches shed light on the quantum → hybrid → classical models, and provide a new way of looking at the existence of non- local correlations without appealing to Bell's theorem. They also provide insights regarding Bohmian mechanics. Furthermore, macroscopic systems even at 1 Kelvin have de Broglie wavelengths in the micro-femtometer range, thereby eliminating macroscopic cat states, and avoiding the need for ad hoc decoherence models. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c3c20ad8-2112-41a6-9095-41bee10f006a ER - TY - JOUR TI - Effect of an in-plane magnetic field on microwave photoresistance and Shubnikov-de Haas effect in high-mobility GaAs/AlGaAs quantum wells DO - 10.1088/1742-6596/456/1/012004 AU - Bogan, A. AU - Hatke, A. T. AU - Studenikin, S. A. AU - Sachrajda, A. AU - Zudov, M. A. AU - Pfeiffer, L. N. AU - West, K. W. T2 - Journal of Physics: Conference Series T3 - 20th International Conference on the Application of High Magnetic Fields in Semiconductor Physics, HMF 2012, July 22-27, 2012, Chamonix Mont Blanc SN - 1742-6588 VL - 456 IS - 1 SP - 12004 KW - GaAs/AlGaAs quantum well KW - High mobility KW - High tilt angle KW - In-plane magnetic fields KW - Microwave-induced resistance oscillations KW - Photoresistance KW - Quantum scattering KW - Shubnikov-de Haas oscillations KW - Electric resistance KW - Magnetic fields KW - Semiconductor quantum wells KW - Shubnikov-de Haas effect KW - Microwave oscillators AB - A recent study of the decay of microwave-induced resistance oscillations (MIRO) in GaAs/AlGaAs quantum wells due to an in-plane magnetic field B ∥ has revealed the dominant role of a quadratic-in-B ∥ correction to the quantum scattering rate. In the present study, we examine the evolution of Shubnikov-de Haas oscillations (SdHO) with increasing tilt angle in the same sample. Even though we find that the SdHO also diminish at high tilt angles, this decay is qualitatively different from that of MIRO, possibly indicating a different physical origin. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c9a4b717-dff0-4559-8d84-0ba57fff9e5e ER - TY - JOUR TI - Phase diagram and magnetic structures of the Co-bearing dugganites Pb3TeCo3A2O14 (A = V, P) DO - 10.1088/0953-8984/25/24/246004 AU - Silverstein, H. J. AU - Sharma, A. Z. AU - Stoller, A. J. AU - Cruz-Kan, K. AU - Flacau, R. AU - Donaberger, R. L. AU - Zhou, H. D. AU - Manuel, P. AU - Huq, A. AU - Kolesnikov, A. I. AU - Wiebe, C. R. T2 - Journal of Physics Condensed Matter SN - 0953-8984 VL - 25 IS - 24 SP - 246004 KW - Applied magnetic fields KW - Langasites KW - Magnetic behaviour KW - Magnetic state KW - Magnetic susceptibility measurements KW - Multiferroic properties KW - Nonmagnetics KW - Super cell KW - Magnetic structure KW - Magnetic susceptibility KW - Oligomers KW - Phase diagrams KW - Lead compounds AB - Exhibiting rich magnetic behaviour and potentially multiferroic properties, the dugganites, a Te6+ containing subgroup of the langasite series, are an attractive family of compounds for future study. It was recently shown that Pb-bearing members of the dugganite series undergo distortions away from the P321 symmetry that is characteristic of the langasites. Here, we detail the consequences these distortions have on the magnetism exhibited by Pb 3TeCo3V2O14 and Pb 3TeCo3P2O14, solving the magnetic structures of both compounds with respect to a new supercell. Using neutron scattering and magnetic susceptibility measurements, we show that small applied magnetic fields can seriously perturb the delicate magnetic states in both of these systems. This is further demonstrated by presenting how doping P 5+ onto the nonmagnetic V5+ site completely changes the magnetic structure from either of the end series members. Finally, it is shown using inelastic neutron scattering and magnetic susceptibility measurements that Pb3TeCo3V2O14 can be characterized using a model for isosceles trimers, which do not exist in the previously reported P321 subcell. DA - 2013/05/24 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : dfe91cf4-6ef4-4363-b262-3011e092b6e7 ER - TY - JOUR TI - Vector space model for adaptation in statistical machine translation AU - Chen, Boxing AU - Kuhn, Roland AU - Foster, George T2 - Proceedings of the 51st Annual Meeting of the Association for Computational Linguistics T2 - Annual Meeting of the Association for Computational Linguistics T3 - 2013 North American Chapter of the Association for Computational Linguistics: Human Language Technologies, June 9-15, 2013, Atlanta, GA SP - P13-1126 AB - This paper proposes a new approach to domain adaptation in statistical machine translation (SMT) based on a vector space model (VSM). The general idea is first to create a vector profile for the in-domain development (“dev”) set. This profile might, for instance, be a vector with a dimensionality equal to the number of training subcorpora; each entry in the vector reflects the contribution of a particular subcorpus to all the phrase pairs that can be extracted from the dev set. Then, for each phrase pair extracted from the training data, we create a vector with features defined in the same way, and calculate its similarity score with the vector representing the dev set. Thus, we obtain a decoding feature whose value represents the phrase pair’s closeness to the dev. This is a simple, computationally cheap form of instance weighting for phrase pairs. Experiments on large scale NIST evaluation data show improvements over strong baselines: +1.8 BLEU on Arabic to English and +1.4 BLEU on Chinese to English over a non-adapted baseline, and significant improvements in most circumstances over baselines with linear mixture model adaptation. An informal analysis suggests that VSM adaptation may help in making a good choice among words with the same meaning, on the basis of style and genre. DA - 2013/07/01 PY - 2013 PB - ACL LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d1f017c8-aab2-4739-88a6-53999a36d713 ER - TY - JOUR TI - Core/shell metal/heterogeneous oxide nanocapsules: the empirical formation law and tunable electromagnetic losses DO - 10.1021/jp4015417 AU - Zhang, X. F. AU - Huang, H. AU - Dong, X. L. T2 - The Journal of Physical Chemistry C SN - 1932-7447 VL - 117 IS - 16 SP - 8563 EP - 8569 KW - Arc discharge KW - Dielectric oxides KW - Dielectric shells KW - Electromagnetic loss KW - Frequency ranges KW - Interfacial couplings KW - Magnetic metals KW - Oxide powder KW - Electromagnetism KW - Nanocapsules KW - Powder metals KW - Electric discharges AB - We report an empirical thermodynamic law for the synthesis of core/shell metal/heterogeneous oxide nanocapsules, such as Fe/SiO2, Ni/SiO 2, Fe/B2O3, Ni/B2O3, Fe/Al2O3, Fe/MnO2, Fe/Y2O 3, Fe/CeO2, and Fe/La2O3, by arc-discharge evaporating a compressed mixture of Fe (or Ni) powders and the oxide powders of shell components. By integrating such dielectric oxide shells and magnetic metal cores in each particle, the electromagnetic losses can be artificially manipulated at the whole S-band, C-band, X-band, and Ku frequency ranges. The microscopic origins of the controllability of electromagnetic losses are ascribed to the specific matching and interfacial coupling between the magnetic cores and dielectric shells. DA - 2013/03/28 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : fddbc45b-efae-4acc-9717-f06376880caa ER - TY - JOUR TI - Water-halogen interactions in chlorine and bromine clathrate hydrates: An example of multidirectional halogen bonding DO - 10.1021/jp402399r AU - Udachin, Konstantin A. AU - Alavi, Saman AU - Ripmeester, John A. T2 - The Journal of Physical Chemistry C SN - 1932-7447 VL - 117 IS - 27 SP - 14176 EP - 14182 KW - Effective diameter KW - Hydrate structures KW - Multi-directional KW - Structural details KW - Tetragonal structure KW - Van der Waals radius KW - Water oxygen atoms KW - X-ray structural determination KW - Chlorine KW - Crystal structure KW - Hydration KW - Molecules KW - X rays KW - Hydrates AB - There are unresolved questions in our understanding of the clathrate hydrates with halogen molecule guests. In this work, we describe the synthesis and single crystal X-ray structural determination of cubic structure I (sI) Cl2, tetragonal structure III (sIII) Br2, and mixed cubic sI Cl2-Br2 clathrate hydrate phases. Unlike the previous X-ray structural determination of the pure chlorine clathrate hydrate by Pauling and Marsh (Proc. Nat. Acad. Sci. USA1952, 38, 112), we report that 32.5% of the clathrate small cages are occupied by Cl2 molecules. Pure Br 2 produces the unique tetragonal sIII clathrate hydrate whose structure is refined from single-crystal measurements, identifying disordered Br2 guest positions in cages and giving structural details not previously identified. In mixed sI clathrate hydrate of Cl2 and Br2, we observed that Br2 guests fit into the large sI cages. The introduction of Br2 in the Cl2 hydrate lattice causes severe distortions because of strong Br⋯OH2 interactions. In these three hydrate structures, based on accepted van der Waals radii, the effective diameters of the clathrate hydrate cages are smaller than the size of the Cl2 and Br2 guest molecules. The accommodation of these guests in the cages and the short O⋯Cl and O⋯Br contact distances reveal halogen bonding between the water oxygen atoms and the dihalogen guests. The X-ray structural determinations of the length of the Cl-Cl and Br-Br bonds of the Cl2 and Br2 guests show significant librational shortening compared to free Cl2 and Br2 molecules. DA - 2013/06/11 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 208ce3b3-f37b-4132-8d17-b1b19fb07a8d ER - TY - JOUR TI - Identification of nonequivalent framework oxygen species in metal-organic frameworks by 17O solid-state NMR DO - 10.1021/jp403512m AU - He, Peng AU - Xu, Jun AU - Terskikh, Victor V. AU - Sutrisno, Andre AU - Nie, Heng-Yong AU - Huang, Yining T2 - The Journal of Physical Chemistry C SN - 1932-7447 VL - 117 IS - 33 SP - 16953 EP - 16960 KW - Current performance KW - Isotopic enrichment KW - Metal organic framework KW - Metalorganic frameworks (MOFs) KW - Nano-porous materials KW - Spectral signature KW - Structural characterization KW - Synthetic approach KW - Crystalline materials KW - Isotopes KW - Java programming language KW - Nuclear magnetic resonance spectroscopy KW - Porous materials KW - Solid state physics KW - Oxygen AB - Metal-organic frameworks (MOFs) are a class of novel nanoporous materials with many potential applications. Structural characterization is important because understanding the relationship between the properties of these industrially relevant materials and their structures allows one to develop new applications and improve current performance. Oxygen is one of the most important elements in many MOFs and exists in various forms. Ideally, 17O solid-state NMR (SSNMR) should be an excellent tool for characterizing various oxygen species. However, the major obstacles that prevent applying 17O SSNMR to MOF characterization are the synthetic effort needed for 17O isotopic enrichment and the associated high cost. In this work, we successfully prepared several prototypical 17O-enriched MOFs, including Zr-UiO-66, MIL-53(Al), CPO-27-Mg (or Mg-MOF-74), and microporous α-Mg3(HCOO)6. Depending on the target MOF, different isotopic enrichment methods were used to effectively incorporate 17O from 17O-enriched H2O. Using these 17O-enriched MOFs, we were able to acquire 17O SSNMR spectra at a magnetic field of 21.1 T. They provide distinct spectral signatures of various key oxygen species commonly seen in representative MOFs. We demonstrate that 17O SSNMR can be used to differentiate chemically and, under favorite circumstances, crystallographically nonequivalent oxygens and to follow the phase transitions. The synthetic approaches for preparation of 17O-enriched sample described in this paper are fairly simple and cost-effective. DA - 2013/06/19 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 85b7973f-7678-41f5-b9e9-1e6530701131 ER - TY - JOUR TI - Initial processes of proton transfer in salicylideneaniline studied by time-resolved photoelectron spectroscopy DO - 10.1021/jp4016036 AU - Sekikawa, Taro AU - Schalk, Oliver AU - Wu, Guorong AU - Boguslavskiy, Andrey E. AU - Stolow, Albert T2 - The Journal of Physical Chemistry A SN - 1089-5639 VL - 117 IS - 14 SP - 2971 EP - 2979 KW - Excitation wavelength KW - Excited state reactions KW - Excited-state dynamics KW - Excited-state intramolecular proton transfer KW - Femtosecond time-resolved KW - Ground-state molecules KW - Time dependent density functional theory KW - Time-resolved photoelectron spectroscopy KW - Density functional theory KW - Excited states KW - Photoelectron spectroscopy KW - Proton transfer KW - Ground state KW - aniline derivative KW - salicylideneaniline KW - X ray photoelectron spectroscopy KW - Aniline Compounds KW - Quantum Theory KW - Schiff Bases AB - Excited-state intramolecular proton transfer (ESIPT) in salicylideneaniline (SA) and selected derivatives substituted in the para position of the anilino group have been investigated by femtosecond time-resolved photoelectron spectroscopy (TRPES) and time-dependent density functional theory (TDDFT). SA has a twisted structure at the energetic minimum of the ground state, but ESIPT is assumed to take place through a planar structure, although this has not been fully established. The TRPES studies revealed that the excited-state dynamics within the S1 band varied significantly with excitation wavelength. At finite temperatures, the ground state was found to sample a broad range of torsional angles, from planar to twisted. At lower photon energies (370 nm), only the planar ground-state molecules were excited, and the excited-state reaction took place within 50 fs. At higher energies (350 and 330 nm), predominantly twisted ground-state molecules were excited: they had to planarize before ESIPT could occur. This process was found to be slower in methylated SA but did not change significantly in the brominated and nitrated SAs. These substitution effects on the decay dynamics can be explained by modifications of the potential barriers, as predicted by the TDDFT calculations, and support the mechanism of a twisting motion of the anilino ring prior to ESIPT. The contribution of another pathway leading to internal conversion within the enol form was found to be minor at the excitation wavelengths considered here. DA - 2013/03/15 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : dff91493-9513-407a-a06f-0888e78bd660 ER - TY - JOUR TI - On the condensed phase ring-closure of vinylheptafulvalene and ring-opening of gaseous dihydroazulene DO - 10.1021/jp400616c AU - Schalk, Oliver AU - Broman, Søren L. AU - Petersen, Michael Å. AU - Khakhulin, Dmitry V. AU - Brogaard, Rasmus Y. AU - Nielsen, Mogens Brøndsted AU - Boguslavskiy, Andrey E. AU - Stolow, Albert AU - Sølling, Theis I. T2 - The Journal of Physical Chemistry A SN - 1089-5639 VL - 117 IS - 16 SP - 3340 EP - 3347 KW - Ab initio computations KW - Biexponential decay KW - Cis-trans Isomerization KW - Condensed phase KW - Internal rotations KW - Ring opening reaction KW - Time-resolved photoelectron spectroscopy KW - Transient absorption KW - Photoelectron spectroscopy KW - cyclopentane derivative KW - dihydroazulene KW - X ray photoelectron spectroscopy KW - Azulenes KW - Cyclopentanes KW - Photoelectron Spectroscopy AB - Dihydroazulenes are interesting because of their photoswitching behavior. While the ring-opening to vinylheptafulvalene (VHF) is light induced, the back reaction is known to proceed thermally. In the present paper, we show the first gas phase study of the ring-opening reaction of 2-phenyl-1,8a-dihydroazulene-1, 1-dicarbonitrile (Ph-DHA) by means of time-resolved photoelectron spectroscopy which permits us to follow the ring-opening process. Moreover, we investigated s-trans-Ph-VHF in a series of transient absorption experiments, supported by ab initio computations, to understand the origin of the absence of light-induced ring-closure. The transient absorption results show a biexponential decay governed by a hitherto unknown state. This state is accessed within 1-2 ps and return to the ground state is probably driven through a cis-trans isomerization about the exocyclic C1=C2 double bond. The rapid decrease in potential energy disfavors internal rotation to s-cis-Ph-VHF, the structure that would precede the ring-closure reaction. DA - 2013/04/04 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : be6f4011-ba6f-4143-9067-fdd1cecbf18b ER - TY - JOUR TI - CO dimer: the infrared spectrum revisited DO - 10.1021/jp312337v AU - Rezaei, Mojtaba AU - Sheybani-Deloui, S. AU - Moazzen-Ahmadi, N. AU - Michaelian, K. H. AU - McKellar, A. R. W. T2 - The Journal of Physical Chemistry A SN - 1089-5639 VL - 117 IS - 39 SP - 9612 EP - 9620 KW - Broad bands KW - Infrared spectrum KW - Intermolecular vibrations KW - Rotational levels KW - Rotational temperature KW - Splittings KW - Supersonic jet expansion KW - Very low frequency KW - Isomers KW - Quantum cascade lasers KW - Supersonic aerodynamics KW - Spectroscopy AB - A broad-band (2135-2200 cm-¹) infrared spectrum of the CO dimer is recorded using a tunable quantum cascade laser to probe a supersonic jet expansion with an effective rotational temperature of about 2.5 K. Analysis of the spectrum reveals the first known levels of the excited state (vCO = 1) with A+ symmetry and establishes that resonant vibrational splittings are small (<0.2 cm-¹) for both the C-bonded and O-bonded dimer isomers. The spectrum extends over a surprisingly large range, with somewhat reduced intensity above 2150 cm-¹. A total of 28 new "stacks" of rotational levels having A- symmetry are assigned for vCO = 1 on the basis of combination differences, adding to the 8 stacks previously known, and extending up to 51 cm-¹ above the vCO = 1 origin. Assignments are given for the first 13 stacks of vCO = 1 in terms of the very low frequency geared bending intermolecular vibration. DA - 2013/02/15 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d0af8ec1-51fa-4f6c-b32d-b0487dbbe041 ER - TY - JOUR TI - Substituent effects on dynamics at conical intersections: Cycloheptatrienes DO - 10.1021/jp309875m AU - Schalk, Oliver AU - Boguslavskiy, Andrey E. AU - Schuurman, Michael S. AU - Brogaard, Rasmus Y. AU - Unterreiner, Andreas N. AU - Wrona-Piotrowicz, Anna AU - Werstiuk, Nick H. AU - Stolow, Albert T2 - The Journal of Physical Chemistry A SN - 1089-5639 VL - 117 IS - 40 SP - 10239 EP - 10247 KW - Conical intersection KW - Large-amplitude motion KW - Non-adiabatic dynamics KW - Non-adiabatic transitions KW - Photoelectron anisotropy KW - Time-resolved photoelectron spectroscopy KW - Unsaturated hydrocarbons KW - Vibrational dynamics KW - Dynamics KW - Photoelectron spectroscopy KW - Quantum chemistry KW - Wave packets KW - Excited states AB - Using selective methyl substitution, we study the effects of vibrational dynamics at conical intersections in unsaturated hydrocarbons. Here, we investigate the excited state nonadiabatic dynamics of cycloheptatriene (CHT) and its relation to dynamics in other polyenes by comparing CHT with 7-methyl CHT, 7-ethyl CHT, and perdeuterated CHT using time-resolved photoelectron spectroscopy and photoelectron anisotropy. Our results suggest that, upon ππ-excitation to the bright 2A″ state, we observe an early intersection with the dark 2A′ state close to the Franck-Condon region with evidence of wavepacket bifurcation. This indicates that the wavepacket evolves on both states, likely along a planarization coordinate, with the majority of the flux undergoing nonadiabatic transition via conical intersections within 100 fs following light absorption. In CHT, large amplitude motion along the planarization coordinate improves the intra-ring π-overlap, yielding a delocalized electronic density. However, substitutions in 7 position, chosen to modify the inertia of the planarization motion, did not markedly alter the first step in the sequential kinetic scheme. This suggests that there is a crossing of potential energy surfaces before planarization is achieved and, thus, nonadiabatic transition likely takes place far away from a local minimum. DA - 2013/09/09 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4838f116-1768-458c-9fef-1800e68b1bf9 ER - TY - JOUR TI - Zero-point tunneling splittings in compounds with multiple hydrogen bonds calculated by the rainbow instanton method DO - 10.1021/jp4073608 AU - Smedarchina, Zorka AU - Siebrand, Willem AU - Fernández-Ramos, Antonio T2 - The Journal of Physical Chemistry A SN - 1089-5639 VL - 117 IS - 43 SP - 11086 EP - 11100 KW - Binary complexes KW - Handling systems KW - Low temperatures KW - Stationary configurations KW - Sudden approximation KW - Theoretical methods KW - Tunneling splittings KW - Zero temperatures KW - Carrier mobility KW - Hydrogen bonds KW - Isotopes KW - Molecules KW - Complexation AB - Zero-point tunneling splittings are calculated, and the values are compared with the experimentally observed values for four compounds in which the splittings are due to multiple-proton transfer along hydrogen bonds. These compounds are three binary complexes, namely, the formic acid and benzoic acid dimer and the 2-pyridone-2-hydroxypyridine complex, in which the protons move in pairs, and the calix[4]arene molecule, in which they move as a quartet. The calculations make use of and provide a test for the newly developed rainbow approximation for the zero-temperature instanton action which governs the tunneling splitting (as well as the transfer rate). This approximation proved to be much less drastic than the conventional adiabatic and sudden approximations, leading to a new general approach to approximate the instanton action directly. As input parameters the method requires standard electronic-structure data and the Hessians of the molecule or complex at the stationary configurations only; the same parameters also yield isotope effects. Compared to our earlier approximate instanton method, the rainbow approximation offers an improved treatment of the coupling of the tunneling mode to the other vibrations. Contrary to the conventional instanton approach based on explicit evaluation of the instanton trajectory, both methods bypass this laborious procedure, which renders them very efficient and capable of handling systems that thus far have not been handled by other theoretical methods. Past results for model systems have shown that the method should be valid for a wide range of couplings. The present results for real compounds show that it gives a satisfactory account of tunneling splittings and isotope effects in systems with strong coupling that enhances tunneling, thus demonstrating its applicability to low-temperature proton dynamics in systems with multiple hydrogen bonds. DA - 2013/10/04 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6bdd1766-d3fe-4263-b23a-ba36a63a2a50 ER - TY - JOUR TI - Identity verification based on haptic handwritten signature : novel fitness functions for GP framework DO - 10.1109/HAVE.2013.6679618 AU - Alsulaiman, Fawaz A. AU - Valdes, Julio J. AU - El Saddik, Abdulmotaleb T3 - 2013 IEEE International Symposium on Haptic Audio Visual Environments and Games (HAVE 2013), Oct 26-27, 2013, Istanbul, Turkey SN - 978-1-4799-0848-6 SP - 98 EP - 102 AB - Fitness functions are the evaluation measures driving evolutionary processes towards solutions. In this paper, three fitness functions are proposed for solving the unbalanced dataset problem in Haptic-based handwritten signatures using genetic programming (GP). The use of these specifically designed fitness functions produced simpler analytical expressions than those obtained with currently available fitness measures, while keeping comparable classification accuracy. The functions introduced in this paper capture explicitly the nature of unbalanced data, exhibit better dimensionality reduction and have better False Rejection Rate. DA - 2013/11/01 PY - 2013 PB - IEEE LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 71ef8fa7-ac7f-4144-b873-1ae61c9c3d5b ER - TY - JOUR TI - ¹H NMR metabolomics analysis of the effect of dichloroacetate and allopurinol on breast cancers DO - 10.1016/j.jpba.2013.08.017 AU - Lefort, Natalie AU - Brown, Amy AU - Lloyd, Vett AU - Ouellette, Rodney AU - Touaibia, Mohamed AU - Culf, Adrian S. AU - Cuperlovic-Culf, Miroslava T2 - Journal of Pharmaceutical and Biomedical Analysis SN - 0731-7085 AB - Metabolomics analysis was used to determine the effect of two well known, non-proprietary metabolic modulators, dichloroacetate and allopurinol on breast cancer cell lines. Dichloroacetate, a pyruvate dehydrogenase kinase inhibitor and allopurinol, a xanthine oxidase/dehydrogenase inhibitor, have been previously explored as chemotherapeutics showing potential in some cancer subtypes while at the same time leading to unexpected increase in proliferation in others. In this work, metabolic effects of these drugs, applied singly and in combination, were explored in three different breast cell lines including cancer cells, MDA-MB-231 and MCF-7 and normal control cell line, MCF-10A. The metabolic changes induced by these drugs were monitored by ¹H NMR metabolic profiling. Analyses were performed on complete spectral data as well as quantified metabolic data in intracellular fractions and extracellular media leading to the determination of the most significantly affected metabolites. The effect of dichloroacetate and allopurinol is the most apparent in the metabolic profile of extracellular media. In MCF-7 cells, dichloroacetate treatment is dominant with only a minor observed influence of allopurinol in combined treatment. In MDA-MB-231 cells, both allopurinol and DCA lead to a metabolic shift with the allopurinol change dominating the effect of combined treatment. Results show the power of metabolomics as a tool for fast molecular profiling of drug effects in cells. In summary, treatments of breast cancer cells with DCA and allopurinol result in larger changes in metabolites found in extracellular medium than intracellular pools. DA - 2013/09/08 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : cf147b86-583f-4699-afa3-d1a8e1cb10d7 ER - TY - JOUR TI - Effect of reverse polarity on space charge evolution in polypropylene with different concentration of natural and synthetic nano clay AU - Abou-Dakka, Mahmoud AU - Chen, Yaoren T2 - 2013 Annual Report: Conference on Electrical Insulation and Dielectric Phenomena T3 - 2013 IEEE Conference on Electrical Insulation and Dielectric Phenomena (CEIDP 2013), October 20-23, 2013, Chenzhen, China AB - The space charge evolution in the Polypropylene (PP) loaded with two types of nanoparticles, synthetic and natural clay with weekly reversing polarity was studied. The sapce charge in these two polymer nanocomposites (PNCs) were measured with the PEA technique after he each period of poling. The charge distribution in the host materials was substantially smaller after reverse polarity compared to dc negative polarity. This could be related to the mitigation of charge bay the compatibilizers added to the host materials. The charge accumulation measured after the negative periods were lower than the positive periods. The PNC with 2-wt& of synthtic clay stocks lots of charges after the end of the positive periods. Then, it will not be optimal concentration as it was for dc poling. It is found out that the two optimal concentrations for reverse polarity were 4-wt% (PPI-S4%) for the synthetic PNC and the 2-wt% (PPI-N2%) for the natural PNC. With reverse polarity and before the 12th week of poling all filled and unfilled materials stock charges of the same order. The unfilled materials show increasing of charges that crosses the values of filled materials, except the PPA-S3%, after the 12 weeks of poling with reverse polarity. More poling time is necessary to investigate the effect of long term poling on the charge evolution and investigate the continuous increase of charge in the unfilled materials. DA - 2013/10/23 PY - 2013 PB - IEEE Dielectrics and Electrical Insulation Society LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 58e04c6a-f4bf-4474-b358-aedd2fbc3172 ER - TY - JOUR TI - Reinforced plastics and aerogels by nanocrystalline cellulose DO - 10.1007/s11051-013-1636-z AU - Leung, Alfred C. W. AU - Lam, Edmond AU - Chong, Jonathan AU - Hrapovic, Sabahudin AU - Luong, John H. T. T2 - Journal of Nanoparticle Research SN - 1388-0764 VL - 15 IS - 5 SP - 1636 KW - Nanocrystalline cellulose; Nanofiller; Nanocomposite; Nanomaterials; Nanoparticles; Renewable biomass; Cellulose AB - Nanocrystalline cellulose (NCC), a rigid rod-like nanoscale material, can be produced from cellulosic biomass in powder, liquid, or gel forms by acid and chemical hydrolysis. Owing to its unique and exceptional physicochemical properties, the incorporation of a small amount of NCC into plastic enhances the mechanical strength of the latter by several orders of magnitudes. Carbohydrate-based NCC poses no serious environmental concerns, providing further impetus for the development and applications of this green and renewable biomaterial to fabricate lightweight and biodegradable composites and aerogels. Surface functionalization of NCC remains the main focus of NCC research to tailor its properties for dispersion in hydrophilic or hydrophobic media. It is of uttermost importance to develop tools and protocols for imaging of NCC in a complex matrix and quantify its reinforcement effect. DA - 2013/04/13 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 834835c0-b5b4-491f-a452-9168d5983e17 ER - TY - JOUR TI - Infrared spectra of the Ne-C2D4 and Ar-C2D4 complexes DO - 10.1016/j.jms.2013.05.013 AU - Rezaei, M. AU - Michaelian, K. H. AU - McKellar, A. R. W. AU - Moazzen-Ahmadi, N. T2 - Journal of Molecular Spectroscopy SN - 0022-2852 VL - 289 SP - 21 EP - 25 KW - Direct measurement KW - Fundamental bands KW - Hindered internal rotations KW - Infrared spectrum KW - Rotational constants KW - Supersonic jets KW - Tunneling splittings KW - Vibrational shift KW - Argon KW - Ethylene KW - Neon KW - Quantum cascade lasers KW - Spectroscopy KW - Supersonic aerodynamics KW - van der Waals AB - Spectra of Ne-C2D4 and Ar-C2D4 are studied in the ν11 fundamental band region of C 2D4 (≈2200 cm-¹) using a tuneable quantum cascade laser to probe a pulsed supersonic slit jet expansion. The spectra are those of perpendicular bands of near-prolate asymmetric rotors, but with a doubling of transitions due to tunneling. These tunneling splittings are due to hindered internal rotation of C2D4 around its C-C axis, and are more prominent for Ne-C2D4 than for Ar-C2D4. The analysis yields the first direct measurement of the A rotational constants for these complexes, and shows that the vibrational shifts are very small (<0.3 cm-¹). Attempts to observe the spectrum of He-C2D4 were not successful. DA - 2013/06/07 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2fff085a-340b-4afd-904f-241b19e322fa ER - TY - JOUR TI - Probing ultrafast dynamics with time-resolved multi-dimensional coincidence imaging: butadiene DO - 10.1080/09500340.2013.801525 AU - Hockett, Paul AU - Ripani, Enrico AU - Rytwinski, Andrew AU - Stolow, Albert T2 - Journal of Modern Optics SN - 0950-0340 VL - 60 IS - 17 SP - 1409 EP - 1425 KW - ultrafast dynamics, coincidence imaging, butadiene, photoionization, time-resolved photoelectron spectroscopy (TRPES), time-resolved photoelectron angular distributions (TRPADs) AB - Time-resolved coincidence imaging of photoelectrons and photoions represents the most complete experimental measurement of ultrafast excited state dynamics, a multi-dimensional measurement for a multi-dimensional problem. Here we present the experimental data from recent coincidence imaging experiments, undertaken with the aim of gaining insight into the complex ultrafast excited-state dynamics of 1,3-butadiene initiated by absorption of 200 nm light. We discuss photoion and photoelectron mappings of increasing dimensionality, and focus particularly on the time-resolved photoelectron angular distributions (TRPADs), expected to be a sensitive probe of the electronic evolution of the excited state and to provide significant information beyond the time-resolved photoelectron spectrum (TRPES). Complex temporal behaviour is observed in the TRPADs, revealing their sensitivity to the dynamics while also emphasising the difficulty of interpretation of these complex observables. From the experimental data some details of the wavepacket dynamics are discerned relatively directly, and we make some tentative comparisons with existing ab initio calculations in order to gain deeper insight into the experimental measurements; finally, we sketch out some considerations for taking this comparison further in order to bridge the gap between experiment and theory. © 2013 Copyright Crown Copyright 2013. Reproduced with the permission of the National Research Council of Canada. DA - 2013/06/20 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3a504ec3-2d6d-46d8-a318-3244d986e5c1 ER - TY - JOUR TI - Photometry, colorimetry and radiometry: Issues and applications DO - 10.1080/09500340.2013.846064 AU - Bullough, John D. AU - Zwinkels, Joanne C. T2 - Journal of Modern Optics SN - 0950-0340 VL - 60 IS - 14 SP - 1099 DA - 2013/11/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0a1fe4bb-b524-4ac6-b95b-cab97a972fe9 ER - TY - JOUR TI - Near-infrared photoluminescence of orange color standards: then and now DO - 10.1080/09500340.2013.818171 AU - Zwinkels, Joanne C. AU - Noël, Mario AU - Hillman, Sean T2 - Journal of Modern Optics SN - 0950-0340 VL - 60 IS - 14 SP - 1115 EP - 1123 AB - The presence of near-infrared (NIR) photoluminescence has been recently reported in some of the second series of Ceramic Color Standards (CCSII) that are widely used in the calibration and performance evaluation of color measuring instruments. The impact of this photoluminescence effect can cause significant colorimetric errors particularly for broadband measurements using a detector with high spectral responsivity in the NIR region. The magnitude of this effect has been demonstrated for specific color standards and specific instrument systems but has not been unambiguously quantified to allow general predictions or absolute comparisons of different instrument designs or different ceramic tiles. Here we present absolute NIR photoluminescence measurements on three different formulations of the CCSII orange ceramic color standard using the National Research Council of Canada (NRC) Reference Spectrofluorimeter whose spectral range has been recently extended to 1000 nm. The validation for this extended spectral range is shown by comparison of an independent method of instrument calibration using a different combination of physical standards. It is convincingly shown that the two different leaded formulations of this ceramic orange standard issued in 2000 and 2011 have no significant photoluminescence and thus can be used for calibration with any type of spectrophotometer design whereas the unleaded formulation issued in 2011 has significant NIR photoluminescence and should not be used for instrument calibration and validation over an extended range into the NIR for certain spectrophotometers with relatively high throughput in the NIR region, such as a spectrophotometer with polychromatic illumination mode using a xenon source or with monochromatic illumination mode using a Si detector. It is shown that for colorimetric applications, the impact of this NIR fluorescence is only significant for the latter spectrophotometer design with broadband detection with a Si or spectrally flat detector and is negligible with a narrowband PMT detector. These calculated colorimetric results are also consistent with previously estimated colorimetric errors for this type of orange CCSII ceramic tile used to transfer calibration between these two types of detector systems. © 2013 Crown copyright © National Research Council Canada. DA - 2013/08/08 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d6a17767-7a16-4ef9-b075-892b2fbc4fbd ER - TY - JOUR TI - Coincidence and covariance data acquisition in photoelectron and -ion spectroscopy. I. Formal theory DO - 10.1080/09500340.2013.839837 AU - Mikosch, Jochen AU - Patchkovskii, Serguei T2 - Journal of Modern Optics SN - 0950-0340 VL - 60 IS - 17 SP - 1426 EP - 1438 AB - We derive a formal theory of noisy Poisson processes with multiple outcomes. We obtain simple, compact expressions for the probability distribution function of arbitrarily complex composite events and its moments. We illustrate the utility of the theory by analyzing properties of coincidence and covariance photoelectron-photoion detection involving single-ionization events. The results and techniques introduced in this work are directly applicable to more general coincidence and covariance experiments, including multiple ionization and multiple-ion fragmentation pathways. DA - 2013/10/28 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 54fefe6d-2bf4-439c-9923-e9cf9ca58a53 ER - TY - JOUR TI - Towards a sustainable smart e-marketplace: a stable, efficient and responsive smart exchange with strategic conduct AU - Ghonaim, Wafa AU - Ghenniwa, Hamada AU - Shen, Weiming T2 - ICAART 2013 - Proceedings of the 5th International Conference on Agents and Artificial Intelligence T3 - 5th International Conference on Agents and Artificial Intelligence, ICAART 2013, February 15-18, 2013, Barcelona, Spain SN - 9789898565389 VL - 2 SP - 338 EP - 345 KW - Bidding languages KW - Double auction KW - GSP auction KW - GSP matching KW - Preference elicitation KW - Preference formulation KW - Reverse GSP auction KW - Strategic rules KW - Winner determination KW - Artificial intelligence KW - Game theory KW - Commerce AB - The landscapes of e-marketplaces are changing profoundly, evident in the phenomenal growth and potential of online services, consumers, and enabling mobile technologies. However, it is unleashing grave concerns about sustainability due to the fierce competitions, fuzzy dynamics and rapidly shifting powers. While it is attributed to the game-theoretic economics and computation complexities of the decentralized combinatorial allocation problem, this work establishes, denying e-traders expressing fair strategic choice is unfounded of adverse strategic risk. In fact, free market dynamics realize impact of smart learning on strategic conduct. The fact strategic rules enable faster consumer-to-market bidding lifecycle is another compelling factor. Hence, the work introduces the novel rule-based bidding language and GSPM double auction for the smart exchange that facilitates expressions of strategic rules, while uniquely exploits forward and reverse GSP auctions for efficient, tractable, stable, and budget balanced e-marketplace. The e-marketplace deliberates on rules for effective preference elicitation, while bringing self-prosperity in socially efficient ecosystem. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ffb4ee65-4e11-4849-91da-3831dc8fa38d ER - TY - JOUR TI - Coincidence and covariance data acquisition in photoelectron and -ion spectroscopy. II. Analysis and applications DO - 10.1080/09500340.2013.839840 AU - Mikosch, Jochen AU - Patchkovskii, Serguei T2 - Journal of Modern Optics SN - 0950-0340 VL - 60 IS - 17 SP - 1439 EP - 1451 AB - We use an analytical theory of noisy Poisson processes, developed in the preceding companion publication, to compare coincidence and covariance measurement approaches in photoelectron and -ion spectroscopy. For non-unit detection efficiencies, coincidence data acquisition (DAQ) suffers from false coincidences. The rate of false coincidences grows quadratically with the rate of elementary ionization events. To minimize false coincidences for rare event outcomes, very low event rates may hence be required. Coincidence measurements exhibit high tolerance to noise introduced by unstable experimental conditions. Covariance DAQ on the other hand is free of systematic errors as long as stable experimental conditions are maintained. In the presence of noise, all channels in a covariance measurement become correlated. Under favourable conditions, covariance DAQ may allow orders of magnitude reduction in measurement times. Finally, we use experimental data for strong-field ionization of 1,3-butadiene to illustrate how fluctuations in experimental conditions can contaminate a covariance measurement, and how such contamination can be detected. DA - 2013/10/28 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 7f8ab715-623e-4348-80e7-6186cad49d31 ER - TY - JOUR TI - The effect of oxygen, nitrogen and carbon on the microstructure and compression properties of titanium foams DO - 10.1557/jmr.2013.114 AU - Lefebvre, Louis-Philippe AU - Baril, Eric AU - De Camaret, Laurent T2 - Journal of Materials Research SN - 0884-2914 VL - 28 IS - 17 SP - 2453 EP - 2460 AB - This paper presents the effect of oxygen, nitrogen, and carbon concentration on the microstructure and properties of titanium foams produced with a powder metallurgy process. Oxygen and nitrogen reduce the ductility and increase the compression yield strength of CpTi foams. The effect of nitrogen appears to be similar to the effect of oxygen, a trend different from the ones reported in the literature for dense titanium in tension, where the effect of nitrogen is recognized to be significantly more important than the effect of oxygen. For carbon, the levels investigated were above the room temperature solubility limit of carbon in α-Ti and titanium carbides were observed in the microstructure. The volume fraction of carbides observed in the microstructure increased with carbon content. The effect of the carbides on the compression properties and ductility of the titanium foams is, however, small compared to the effect of oxygen and nitrogen. © Crown Copyright, Published by the Materials Research Society 2013. DA - 2013/05/14 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8de79dcd-4c39-40e1-a25a-e16edfa1cc10 ER - TY - JOUR TI - A high capacity silicon-graphite composite as anode for lithium-ion batteries using low content amorphous silicon and compatible binders DO - 10.1039/c3ta10883j AU - Yim, Chae-Ho AU - Courtel, Fabrice M. AU - Abu-Lebdeh, Yaser T2 - Journal of Materials Chemistry A SN - 2050-7488 VL - 1 IS - 28 SP - 8234 EP - 8243 KW - Amorphous powders KW - Crystalline silicons KW - Different binders KW - Good capacity retentions KW - Irreversible capacity KW - Lithium-ion battery KW - Reversible capacity KW - Silicon oxide layers KW - Anodes KW - Ball milling KW - Binders KW - Graphite KW - Lithium batteries KW - Lithium compounds KW - Milling (machining) KW - Nanocrystalline silicon KW - Powders KW - Silicon oxides KW - Amorphous silicon AB - In this study, silicon-graphite composites were prepared and investigated as anode materials for Li-ion batteries with small amounts of silicon and different binders. The silicon powders were prepared by ball-milling crystalline silicon for 100 h and 200 h. After 200 h, an average silicon particle size of 0.73 μm was obtained and XRD measurements confirmed the formation of an amorphous powder embedded within nanocrystalline regions. XPS analysis of the silicon samples showed that silicon particles were covered with a native silicon oxide layer that grows during ball-milling. Battery cycling of the silicon powders in half cells showed that the powder ball milled for 200 h gave the lowest first-cycle irreversible capacity and the highest reversible capacity reaching over 500 mA h g-1 after 50 cycles at C/12. Composites were made using graphite and only 5 wt% silicon powders. The silicon was found to be uniformly dispersed into the composites as evidenced by X-ray mapping and SEM. When tested in half cells using different binders, it was found that the polyetherimide binder showed the highest capacity reaching 514 mA h g -1 after 350 cycles at C/12, which is 1.6 times greater than commercial graphite anode. High rate cycling showed good capacity retention reaching half the capacity at 5 C. DA - 2013/05/30 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b707b12e-b0e5-435f-935a-c95c66caecb8 ER - TY - JOUR TI - Echelle diffractive grating based wavelength interrogator for potential aerospace applications DO - 10.1109/JLT.2013.2263278 AU - Guo, Honglei AU - Xiao, Gaozhi AU - Mrad, Nezih AU - Yao, Jianping T2 - Journal of Lightwave Technology SN - 0733-8724 VL - 31 IS - 13 SP - 6516513 SP - 2099 EP - 2105 KW - Echelle diffractive gratings KW - Fiber Bragg Grating Sensors KW - Impact damage detection KW - interrogator KW - Measurement resolution KW - Practical implementation KW - Structural health monitoring (SHM) KW - Wavelength interrogator KW - Aerospace applications KW - Damage detection KW - Electric sensing devices KW - Fiber Bragg gratings KW - Fiber optic sensors KW - Structural health monitoring KW - Diffraction gratings AB - Operational load monitoring and impact damage detection are the two critical aspects of aerospace structural health monitoring (SHM). Fiber Bragg grating (FBG) sensors have demonstrated great potential in both. But the currently available interrogation systems can only handle one of the two types of SHM capabilities offered by FBG sensors. In addition, the practical implementation of FBG sensor systems in aerospace vehicles requires the interrogator to be small size, light weight, and low-power consuming. In this paper, we present an Echelle diffractive grating (EDG) based interrogation system for FBG sensors, which possesses two operation modes, i.e., the sweeping mode for operational load monitoring and the parked mode for impact damage detection. Experimental results show that this interrogator offers better than 1-pm measurement resolution and 10-pm repeatability. In addition, the interrogation system is very compact and weighs less than 60 g (excluding the electronic controller). It also has the potential to achieve a measurement speed of 300 kHz and be powered by a battery. DA - 2013/07/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 14eb3aa9-11b6-4208-83bf-36690db7b59b ER - TY - JOUR TI - Bacillus anthracis cell wall peptidoglycan but not lethal or edema toxins produces changes consistent with disseminated intravascular coagulation in a rat model DO - 10.1093/infdis/jit247 AU - Qiu, Ping AU - Li, Yan AU - Shiloach, Joseph AU - Cui, Xizhong AU - Sun, Junfeng AU - Trinh, Loc AU - Kubler-Kielb, Joanna AU - Vinogradov, Evgeny AU - Mani, Haresh AU - Al-Hamad, Mariam AU - Fitz, Yvonne AU - Eichacker, Peter Q. T2 - Journal of Infectious Diseases SN - 0022-1899 VL - 208 IS - 6 SP - 978 EP - 989 KW - anthrax infection; sepsis; coagulopathy; thrombocytopenia; Bacillus anthracis; disseminated intravascular coagulation; peptidoglycan; lethal toxin; edema toxin AB - Background. Disseminated intravascular coagulation (DIC) appears to be important in the pathogenesis of Bacillus anthracis infection, but its causes are unclear. Although lethal toxin (LT) and edema toxin (ET) could contribute, B. anthracis cell wall peptidoglycan (PGN), not the toxins, stimulates inflammatory responses associated with DIC.Methods and Results. To better understand the pathogenesis of DIC during anthrax, we compared the effects of 24-hour infusions of PGN, LT, ET, or diluent (control) on coagulation measures 6, 24, or 48 hours after infusion initiation in 135 rats. No control recipient died. Lethality rates (approximately 30%) did not differ among PGN, LT, and ET recipients (P =. 78). Thirty-three of 35 deaths (94%) occurred between 6 and 24 hours after the start of challenge. Among challenge components, PGN most consistently altered coagulation measures. Compared with control at 6 hours, PGN decreased platelet and fibrinogen levels and increased prothrombin and activated partial thromboplastin times and tissue factor, tissue factor pathway inhibitor, protein C, plasminogen activator inhibitor (PAI), and thrombin-antithrombin complex levels, whereas LT and ET only decreased the fibrinogen level or increased the PAI level (P ≤. 05). Nearly all effects associated with PGN infusion significantly differed from changes associated with toxin infusion (P ≤. 05 for all comparisons except for PAI level).Conclusion. DIC during B. anthracis infection may be related more to components such as PGN than to LT or ET. © 2013 The Author. DA - 2013/06/03 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e9593893-0ea4-491e-90a5-60fbd2839c4f ER - TY - JOUR TI - A typology of clean technology commercialization accelerators DO - 10.1016/j.jengtecman.2013.10.006 AU - Malek, Kourosh AU - Maine, Elicia AU - McCarthy, Ian P. T2 - Journal of Engineering and Technology Management SN - 0923-4748 AB - Accelerators are a type of incubation program that are concerned with attracting, supporting and developing new ventures. Although there is significant enthusiasm for accelerators and their potential benefits, there is limited research on how their core capabilities can vary. In response, we develop a typology of accelerator capabilities taking into account their strategy, governance, business model, operations and finance. To develop the typology we carried out a benchmark analysis of six clean energy commercialization accelerators (CECAs). From this we verified and illustrated the dimensions of our typology and identified four types of accelerator capabilities: R&D focused, technology enabled, market enabled, and network enabled. We then use a seventh accelerator case to illustrate how our typology can be used to describe, understand and prescribe appropriate capabilities for a CECA. We conclude our paper by explaining the research and practice implications of our research. Crown Copyright © 2013. DA - 2013/10/05 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : bb10406e-f88a-46c2-bdb4-63c6e60ad760 ER - TY - JOUR TI - Ordered gold nanoparticle arrays on glass and their characterization DO - 10.1016/j.jcis.2013.07.070 AU - Yuan, Jie AU - Hajebifard, Akram AU - George, Christeen AU - Berini, Pierre AU - Zou, Shan T2 - Journal of Colloid and Interface Science SN - 0021-9797 VL - 410 SP - 1 EP - 10 KW - Gold nanoparticles (AuNPs); Localized surface plasmon resonance (LSPR); Self-assembly; Diblock copolymer; Seeding growth AB - Using self-assembly of block copolymer micelle loaded metal precursors, combined with a seeding growth route, we have developed a novel approach to create ordered metal nanoparticle (NP) arrays of controllable size over large areas (~80mm2) on solid substrates. Atomic force microscopy (AFM), UV-Vis extinction spectrophotometry, and theoretical simulations were systematically carried out to determine the size and pattern of NP arrays, and locate the localized surface plasmon resonance (LSPR) peak. By tuning the molar ratios of precursors, hexagonal arrays of AuNPs of mean heights of 5.2±0.6nm, 8.3±1.7nm, and 10.0±2.1nm were obtained by self-assembly of poly(styrene-b-2-vinyl pyridine) micelle-loaded gold salt on glass. Further seeding growth was then used to enlarge the AuNPs to heights of 25.7 and 33nm and decrease the edge-to-edge inter-particle spacing. The optical response of AuNP arrays was determined by measuring and computing their absorbance spectra as a function of the cover medium refractive index over the range from 1 to 1.55; the measured spectra agree very well with the computations. The resonance wavelength red-shifts as the medium refractive index increases and the bulk sensitivity of the arrays increases with increasing AuNP size. When the edge-to-edge inter-particle spacing decreased to ~50nm, coupling of adjacent AuNPs became apparent, as a shoulder which developed in the spectra. Also, the AuNPs were found to be embedded in the substrate glass by about ~20-30%, as determined by comparing the experimental and computed bulk sensitivities. The fabrication technique devised is suitable for low-cost mass-manufacturing of large area arrays of ordered high-quality AuNPs on a substrate for biosensor or other applications. © 2013 . DA - 2013/08/12 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 982c9596-3ba1-4d6c-9867-ab7f58c6496c ER - TY - JOUR TI - Communication: Spectroscopic evidence for a planar cyclic CO trimer DO - 10.1063/1.4793220 AU - Rezaei, Mojtaba AU - Sheybani-Deloui, S. AU - Moazzen-Ahmadi, N. AU - Michaelian, K. H. AU - McKellar, A. R. W. T2 - Journal of Chemical Physics SN - 0021-9606 VL - 138 IS - 7 SP - 71102 KW - Blue shift KW - Cyclic CO KW - High-resolution spectra KW - Intermolecular separations KW - Spectroscopic evidence KW - Theoretical calculations KW - Trimer structure KW - Dimers AB - A high-resolution spectrum in the region of 2144 cm-1 is assigned to the previously elusive CO trimer. In spite of interference from the CO dimer and some remaining unexplained details, there is strong evidence for a planar, cyclic, C-bonded trimer structure, with C3h symmetry and 4.42 Å intermolecular separation, in agreement with theoretical calculations. A modest vibrational blueshift of +0.85 cm-1 is observed for the CO trimer, as compared to +0.71 cm-1 for the C-bonded form of the dimer. DA - 2013/02/15 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e29e2c6b-2630-4a6a-95dd-4fb229236d48 ER - TY - JOUR TI - A comprehensive experimental and theoretical study of H2-CO spectra DO - 10.1063/1.4791712 AU - Jankowski, Piotr AU - Surin, L. A. AU - Potapov, A. AU - Schlemmer, S. AU - McKellar, A. R. W. AU - Szalewicz, Krzysztof T2 - Journal of Chemical Physics SN - 0021-9606 VL - 138 IS - 8 SP - 84307 KW - Analytic expressions KW - Coupled-cluster methods KW - Experimental investigations KW - Experimental spectra KW - Extrapolation procedure KW - Interaction energies KW - Quadruple excitations KW - Vibrational wave functions KW - Calculations KW - Microwave spectroscopy KW - Potential energy surfaces KW - Quantum chemistry KW - Spectroscopy KW - Iterative methods AB - A detailed description of a new ab initio interaction potential energy surfaces for the H2-CO complex computed on a six-dimensional grid (i.e., including the dependence on the H-H and C-O separations) is presented. The interaction energies were first calculated using the coupled-cluster method with single, double, and noniterative triple excitations and large basis sets, followed by an extrapolation procedure. Next, a contribution from iterative triple and noniterative quadruple excitations was added from calculations in smaller basis sets. The resulting interaction energies were then averaged over the ground-state and both ground- and first-excited-states vibrational wave functions of H2 and CO, respectively. The two resulting four-dimensional potential energy surfaces were fitted by analytic expressions. Theoretical infrared spectra calculated from these surfaces have already been shown [P. Jankowski, A. R. W. McKellar, and K. Szalewicz, Science 336, 1147 (2012)] to agree extremely well, to within a few hundredth of wavenumber, with the experimental spectra of the para and orthoH2-CO complex. In the latter case, this agreement enabled an assignment of the experimental spectrum, ten years after it had been measured. In the present paper, we provide details concerning the development of the surfaces and the process of spectral line assignment. Furthermore, we assign some transitions for paraH2-CO that have not been assigned earlier. A completely new element of the present work are experimental investigations of the orthoH2-CO complex using microwave spectroscopy. Vast parts of the measured spectrum have been interpreted by comparisons with the infrared experiments, including new low-temperature ones, and theoretical spectrum. Better understanding of the spectra of both para and orthoH2-CO complexes provides a solid foundation for a new search of the bound H2-CO complex in space. DA - 2013/02/27 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 785b5eb3-eb19-46e3-b9d5-897d2b19298d ER - TY - JOUR TI - Pressure induced dimer to ionic insulator and metallic structural changes in Al2Br6 DO - 10.1063/1.4793314 AU - Yao, Yansun AU - Klug, Dennis D. T2 - Journal of Chemical Physics SN - 0021-9606 VL - 138 IS - 9 SP - 94501 KW - Electron phonon couplings KW - Experimental datum KW - Fermi surface nesting KW - First-principles density-functional method KW - High-pressure phase transitions KW - Mechanically stable KW - Structural transformation KW - Superconducting critical temperatures KW - Dimers KW - Electronic structure KW - Phonons KW - Aluminum AB - High-pressure phase transitions in Al2Br6 were theoretically investigated using first principles density functional methods. A structural transformation from the initial molecular solid phase to a planar polymeric phase is predicted near 0.4 GPa that is accompanied with a substantial volume drop. A unique feature of this phase transition is that the hcp lattice of Br atoms remains unchanged during the transition, whereas the Al atoms are displaced from the original tetrahedral sites to the octahedral sites. The calculated phonon spectra indicate that the predicted phase is mechanically stable at 1 atm, and therefore it may be quench-recovered to ambient conditions and exist as a metastable form. A second structural transformation is predicted to occur at around 80 GPa, and also at this point, the AlBr3 reaches a metallic state. The electronic structure of the metallic phase features soft phonon modes and Fermi surface nesting in the Brillouin zone, which leads to localized electron-phonon coupling. By comparing with the experimental data available for high-pressure BI3, the superconducting critical temperature Tc for the metallic phase of AlBr3 is estimated to be at 0.5 K or above. DA - 2013/03/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e79870db-6a87-4d20-b251-58d685dbedb0 ER - TY - JOUR TI - Communication: selection rules for tunneling splitting of vibrationally excited levels DO - 10.1063/1.4813002 AU - Siebrand, Willem AU - Smedarchina, Zorka AU - Fernández-Ramos, Antonio T2 - Journal of Chemical Physics SN - 0021-9606 VL - 139 IS - 2 SP - 21101 KW - Excited levels KW - Ground level KW - Malonaldehyde KW - Selection Rules KW - Splittings KW - Tunneling splittings KW - Vibrationally excited KW - Zero-point KW - Excited states AB - Five symmetry-based selection rules are formulated that relate the tunneling splitting of a vibrationally excited level to that of the ground level in molecules with a symmetric double-minimum potential. The rules, which explain why excited levels frequently have smaller splittings than zero-point levels, are used to interpret the observed and calculated splittings in malonaldehyde. DA - 2013/07/08 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 370dfbfd-7b62-42a4-88ab-253b57b35912 ER - TY - JOUR TI - The quantitative determination of laser-induced molecular axis alignment DO - 10.1063/1.4812787 AU - Mikosch, Jochen AU - Bisgaard, Christer Z. AU - Boguslavskiy, Andrey E. AU - Wilkinson, Iain AU - Stolow, Albert T2 - Journal of Chemical Physics SN - 0021-9606 VL - 139 IS - 2 SP - 24304 KW - Angular dependence KW - Confidence interval KW - Experimental datum KW - Maximum-likelihood classification KW - Polyatomic molecules KW - Quantitative determinations KW - Quantitative knowledge KW - Strong field ionization KW - Alignment KW - Molecular dynamics KW - Probes KW - Angular distribution AB - Experiments in the gas phase usually involve averaging observables over a random molecular axis alignment distribution. This deleterious averaging limits insights gained by probes of molecular dynamics, but can be overcome by prealigning molecular axes using laser-alignment methods. However, the transformation from the laboratory frame to the molecular frame of reference requires quantitative knowledge of the axis alignment distribution. The latter is often hard to obtain directly from experimental data, particularly for polyatomic molecules. Here we describe a general maximum-likelihood classification procedure for non-adiabatic numerical alignment simulations with free parameters that employs experimental data from an alignment-dependent probe. This method delivers (i) the most probable molecular frame angular dependence of the probe, and (ii) the most likely laboratory frame axis alignment distribution of the sample, each with a confidence interval. This procedure was recently used for studies of angle- and channel-resolved strong field ionization of 1,3-butadiene in the molecular frame [Mikosch, Phys. Rev. Lett. 110, 023004 (2013)], used here as an illustrative example. © 2013 Crown. DA - 2013/07/10 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 45f9d650-6f3b-4184-a8cd-af5b592290b3 ER - TY - JOUR TI - Posttranslational modification of flagellin flaB in Shewanella oneidensis DO - 10.1128/JB.00015-13 AU - Sun, Linlin AU - Jin, Miao AU - Ding, Wen AU - Yuan, Jie AU - Kelly, John AU - Gao, Haichun T2 - Journal of Bacteriology SN - 0021-9193 VL - 195 IS - 11 SP - 2550 EP - 2561 KW - cysteine KW - flagellin KW - lysine KW - protein FlaB KW - protein PseB KW - protein PseC KW - serine KW - bacterial strain KW - bacterium mutant KW - controlled study KW - glycosylation KW - liquid chromatography KW - methylation KW - protein isolation KW - protein processing KW - Salmonella enterica KW - Shewanella oneidensis KW - Amino Acid Sequence KW - Amino Acid Substitution KW - Bacterial Proteins KW - Chromatography, Liquid KW - Flagella KW - Genetic Complementation Test KW - Glycosylation KW - Mass Spectrometry KW - Mutagenesis, Site-Directed KW - Mutation KW - Polysaccharides KW - Protein Processing, Post-Translational KW - Recombinant Fusion Proteins KW - Tandem Mass Spectrometry AB - Shewanella oneidensis is a highly motile organism by virtue of a polar, glycosylated flagellum composed of flagellins FlaA and FlaB. In this study, the functional flagellin FlaB was isolated and analyzed with nano-liquid chromatography-mass spectrometry (MS) and tandem MS. In combination with the mutational analysis, we propose that the FlaB flagellin protein from S. oneidensis is modified at five serine residues with a series of novel O-linked posttranslational modifications (PTMs) that differ from each other by 14 Da. These PTMs are composed in part of a 274-Da sugar residue that bears a resemblance to the nonulosonic acids. The remainder appears to be composed of a second residue whose mass varies by 14 Da depending on the PTM. Further investigation revealed that synthesis of the glycans initiates with PseB and PseC, the first two enzymes of the Pse pathway. In addition, a number of lysine residues are found to be methylated by SO4160, an analogue of the lysine methyltransferase of Salmonella enterica serovar Typhimurium. DA - 2013/03/29 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 32c95948-d4eb-4871-a7c4-aa51276a066c ER - TY - JOUR TI - Generating extractive summaries of scientific paradigms AU - Qazvinian, Vahed AU - Radev, Dragomir R. AU - Mohammad, Saif M. AU - Dorr, Bonnie AU - Zajic, David AU - Whidby, Michael AU - Moon, Taesun T2 - Journal of Artificial Intelligence Research SN - 1076-9757 VL - 46 SP - 165 EP - 201 KW - Automatically generated KW - Community detection KW - Dependency parsing KW - Large amounts KW - Scientific articles KW - Scientific literature KW - Scientific paradigm KW - Set of questions KW - Data mining KW - Dynamic positioning KW - Natural language processing systems AB - Researchers and scientists increasingly find themselves in the position of having to quickly understand large amounts of technical material. Our goal is to effectively serve this need by using bibliometric text mining and summarization techniques to generate summaries of scientific literature. We show how we can use citations to produce automatically generated, readily consumable, technical extractive summaries. We first propose C-LexRank, a model for summarizing single scientific articles based on citations, which employs community detection and extracts salient information-rich sentences. Next, we further extend our experiments to summarize a set of papers, which cover the same scientific topic. We generate extractive summaries of a set of Question Answering (QA) and Dependency Parsing (DP) papers, their abstracts, and their citation sentences and show that citations have unique information amenable to creating a summary. DA - 2013/02/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6ff31eea-c26d-4f61-975a-39229415d238 ER - TY - JOUR TI - Photopolymerizable organically modified holographic glass with enhanced thickness for spectral filters DO - 10.1063/1.4775787 AU - Velasco, A. V. AU - Calvo, M. L. AU - Cheben, P. T2 - Journal of Applied Physics SN - 0021-8979 VL - 113 IS - 3 SP - 33101 KW - Extinction ratios KW - High refractive index KW - Holographic grating recording KW - Holographic notch filters KW - Optical qualities KW - Spectral bandwidth KW - Spectral filters KW - Synthesis method KW - Volume gratings KW - Volume holographic KW - Diffraction gratings KW - Glass KW - Refractive index KW - Holography AB - A novel formulation and synthesis method to overcome the thickness limitations in samples of photopolymerizable glasses with high refractive index species is presented. The reported method allows the recording of volume holographic diffraction gratings in samples of ∼500 μm thickness with a high optical quality and low scattering. Holographic grating recording is performed in a single coherent light exposure step, resulting in volume gratings of high optical quality. A holographic notch filter implemented in a 500 μm thick photopolymerizable glass with a spectral bandwidth below 0.3 nm and an excellent filter extinction ratio of <-27 dB is also demonstrated. DA - 2013/01/15 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ae2997a5-2508-4e40-9dbf-9597081f9518 ER - TY - JOUR TI - Manipulated electromagnetic losses by integrating chemically heterogeneous components in Fe-based core/shell architecture DO - 10.1063/1.4792669 AU - Huang, Hao AU - Zhang, Xue-Feng AU - Lv, Bo AU - Xue, Fang-Hong AU - Shah, Asif AU - Su, Lei AU - Yan, Jing-Guo AU - Yao, Man AU - Dong, Xing-Long T2 - Journal of Applied Physics SN - 0021-8979 VL - 113 IS - 8 SP - 84312 KW - Dielectric behavior KW - Electromagnetic loss KW - Formation mechanism KW - Heterogeneous component KW - Heterogeneous cores KW - Metal nanostructure KW - Microwave absorption KW - Tunable components KW - Chemical vapor deposition KW - Nanocapsules KW - Thermodynamics KW - Electric discharges AB - Existing techniques for stabilizing and functionalizing metal nanostructures required precise control of complex procedures and probably introduce undesirable impurities. We herein report an arc-discharge chemical vapor deposition strategy for the synthesis of chemically heterogeneous core/shell metal/oxide nanocapsules Fe/TiFe2O4, Fe/MnFe2O4, and Fe/Al2O3. A universal formation mechanism based on the co-effect of oxygen potential and surface energy is further proposed, derived from fundamental thermodynamics. Such core/shell nanocapsules, integrated with tunable components, present an effective manipulability of microwave absorption at expected frequency, originating from the various dielectric behaviors of the heterogeneous oxide shells. DA - 2013/02/27 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8d15b618-6c32-4af0-ac10-ba7fa982d5c4 ER - TY - JOUR TI - Effect of oscillator strength and intermediate resonance on the performance of resonant phonon-based terahertz quantum cascade lasers DO - 10.1063/1.4795614 AU - Fathololoumi, S. AU - Dupont, E. AU - Wasilewski, Z. R. AU - Chan, C. W. I. AU - Razavipour, S. G. AU - Laframboise, S. R. AU - Huang, S. AU - Hu, Q. AU - Ban, D. AU - Liu, H. C. T2 - Journal of Applied Physics SN - 0021-8979 VL - 113 IS - 11 SP - 113109 KW - Density matrix formalism KW - Device optimization KW - Devices under tests KW - Electric field domain KW - Electrical instability KW - Oscillator strengths KW - Radiative transitions KW - Terahertz quantum-cascade lasers KW - Optimization KW - Design AB - We experimentally investigated the effect of oscillator strength (radiative transition diagonality) on the performance of resonant phonon-based terahertz quantum cascade lasers that have been optimized using a simplified density matrix formalism. Our results show that the maximum lasing temperature (T max) is roughly independent of laser transition diagonality within the lasing frequency range of the devices under test (3.2-3.7 THz) when cavity loss is kept low. Furthermore, the threshold current can be lowered by employing more diagonal transition designs, which can effectively suppress parasitic leakage caused by intermediate resonance between the injection and the downstream extraction levels. Nevertheless, the current carrying capacity through the designed lasing channel in more diagonal designs may sacrifice even more, leading to electrical instability and, potentially, complete inhibition of the devices lasing operation. We propose a hypothesis based on electric-field domain formation and competition/switching of different current-carrying channels to explain observed electrical instability in devices with lower oscillator strengths. The study indicates that not only should designers maximize Tmax during device optimization but also they should always consider the risk of electrical instability in device operation. DA - 2013/03/20 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 42a89c03-276e-440f-9310-9f2e21b6b756 ER - TY - JOUR TI - An indirectly pumped terahertz quantum cascade laser with low injection coupling strength operating above 150 K DO - 10.1063/1.4807580 AU - Razavipour, S. G. AU - Dupont, E. AU - Fathololoumi, S. AU - Chan, C. W. I. AU - Lindskog, M. AU - Wasilewski, Z. R. AU - Aers, G. AU - Laframboise, S. R. AU - Wacker, A. AU - Hu, Q. AU - Ban, D. AU - Liu, H. C. T2 - Journal of Applied Physics SN - 0021-8979 VL - 113 IS - 20 SP - 203107 KW - Coupling strengths KW - Fabricated device KW - Injection currents KW - Metal-metal waveguides KW - Non-equilibrium Green's function KW - Oscillator strengths KW - Population inversions KW - Terahertz quantum-cascade lasers KW - Gallium arsenide KW - Gold KW - Semiconducting gallium KW - Quantum cascade lasers AB - We designed and demonstrated a terahertz quantum cascade laser based on indirect pump injection to the upper lasing state and phonon scattering extraction from the lower lasing state. By employing a rate equation formalism and a genetic algorithm, an optimized active region design with four-well GaAs / Al0.25 Ga0.75 As cascade module was obtained and epitaxially grown. A figure of merit which is defined as the ratio of modal gain versus injection current was maximized at 150 K. A fabricated device with a Au metal-metal waveguide and a top n+ GaAs contact layer lased at 2.4 THz up to 128.5 K, while another one without the top n+ GaAs lased up to 152.5 K (1.3ω/kB). The experimental results have been analyzed with rate equation and nonequilibrium Green's function models. A high population inversion is achieved at high temperature using a small oscillator strength of 0.28, while its combination with the low injection coupling strength of 0.85 meV results in a low current. The carefully engineered wavefunctions enhance the quantum efficiency of the device and therefore improve the output optical power even with an unusually low injection coupling strength. DA - 2013/05/29 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8241dee6-ff57-401f-9626-fe7fcbd7ffc7 ER - TY - JOUR TI - Microbial communities in low permeability, high pH uranium mine tailings: characterization and potential effects DO - 10.1111/jam.12180 AU - Bondici, V. F. AU - Lawrence, J. R. AU - Khan, N. H. AU - Hill, J. E. AU - Yergeau, E. AU - Wolfaardt, G. M. AU - Warner, J. AU - Korber, D. R. T2 - Journal of Applied Microbiology SN - 1364-5072 VL - 114 IS - 6 SP - 1671 EP - 1686 KW - biotransformation, ecology, microbial diversity, uranium tailings AB - Aims: To describe the diversity and metabolic potential of microbial communities in uranium mine tailings characterized by high pH, high metal concentration and low permeability. Methods and Results: To assess microbial diversity and their potential to influence the geochemistry of uranium mine tailings using aerobic and anaerobic culture-based methods, in conjunction with next generation sequencing and clone library sequencing targeting two universal bacterial markers (the 16S rRNA and cpn60 genes). Growth assays revealed that 69% of the 59 distinct culturable isolates evaluated were multiple-metal resistant, with 15% exhibiting dual-metal hypertolerance. There was a moderately positive correlation coefficient (R = 0·43, P < 0·05) between multiple-metal resistance of the isolates and their enzyme expression profile. Of the isolates tested, 17 reduced amorphous iron, 22 reduced molybdate and seven oxidized arsenite. Based on next generation sequencing, tailings depth was shown to influence bacterial community composition, with the difference in the microbial diversity of the upper (0-20 m) and middle (20-40 m) tailings zones being highly significant (P < 0·01) from the lower zone (40-60 m) and the difference in diversity of the upper and middle tailings zone being significant (P < 0·05). Phylotypes closely related to well-known sulfate-reducing and iron-reducing bacteria were identified with low abundance, yet relatively high diversity. Conclusions: The presence of a population of metabolically-diverse, metal-resistant micro-organisms within the tailings environment, along with their demonstrated capacity for transforming metal elements, suggests that these organisms have the potential to influence the long-term geochemistry of the tailings. Significance and Impact of the study: This study is the first investigation of the diversity and functional potential of micro-organisms present in low permeability, high pH uranium mine tailings. DA - 2013/03/19 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0a829e73-1ed6-42d1-b6cc-1e74c478585a ER - TY - JOUR TI - Selective hydride generation-cryotrapping-ICP-MS for arsenic speciation analysis at picogram levels: analysis of river and sea water reference materials and human bladder epithelial cells DO - 10.1039/c3ja50021g AU - Matoušek, Tomáš AU - Currier, Jenna M. AU - Trojánková, Nikola AU - Saunders, R. Jesse AU - Ishida, María C. AU - González-Horta, Carmen AU - Musil, Stanislav AU - Mester, Zoltán AU - Stýblo, Miroslav AU - Dědina, Jiří T2 - Journal of Analytical Atomic Spectrometry SN - 0267-9477 VL - 28 IS - 9 SP - 1456 EP - 1465 KW - Absorption spectrometry KW - Arsenic speciation analysis KW - Epithelial cells KW - Hydride generations KW - Limits of detection KW - Pre-concentration KW - Speciation analysis KW - Amino acids KW - Atomic absorption spectrometry KW - Hydrides KW - Inductively coupled plasma KW - Liquid chromatography KW - Mass spectrometers KW - Seawater KW - Inductively coupled plasma mass spectrometry AB - An ultra-sensitive method for arsenic (As) speciation analysis based on selective hydride generation (HG) with preconcentration by cryotrapping (CT) and inductively coupled plasma-mass spectrometry (ICP-MS) detection is presented. Determination of the valency of the As species is performed by selective HG without prereduction (trivalent species only) or with l-cysteine prereduction (sum of tri- and pentavalent species). Methylated species are resolved on the basis of thermal desorption of the formed methyl substituted arsines after collection at -196 °C. Limits of detection of 3.4, 0.06, 0.14 and 0.10 pg mL-¹ (ppt) were achieved for inorganic As, mono-, di- and trimethylated species, respectively, from a 500 μL sample. Speciation analysis of river water (NRC SLRS-4 and SLRS-5) and sea water (NRC CASS-4, CASS-5 and NASS-5) reference materials certified to contain 0.4 to 1.3 ng mL-¹ total As was performed. The concentrations of methylated As species in tens of pg mL-¹ range obtained by HG-CT-ICP-MS systems in three laboratories were in excellent agreement and compared well with results of HG-CT-atomic absorption spectrometry and anion exchange liquid chromatography-ICP-MS; sums of detected species agreed well with the certified total As content. The HG-CT-ICP-MS method was successfully used for analysis of microsamples of exfoliated bladder epithelial cells isolated from human urine. Here, samples of lysates of 25 to 550 thousand cells contained typically tens of pg up to ng of iAs species and from single to hundreds of pg of methylated species, well within detection power of the presented method. A significant portion of As in the cells was found in the form of the highly toxic trivalent species. DA - 2013/06/21 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 923ecd03-7d5d-455d-8902-4c47c95a8717 ER - TY - JOUR TI - Effects of precursor treatment on the structure and electrochemical properties of spinel LiMn2O4 cathode DO - 10.1016/j.jallcom.2013.02.164 AU - Tang, Hongwei AU - Chang, Zhaorong AU - Zhao, Haili AU - Yuan, Xiao-Zi AU - Wang, Haijiang AU - Gao, Shuyan T2 - Journal of Alloys and Compounds SN - 0925-8388 VL - 566 SP - 16 EP - 21 KW - Cathode materials KW - Different treatments KW - Discharge rates KW - Electrochemical performance KW - Good capacity retentions KW - Initial discharge capacities KW - Lithium manganates KW - Two-step drying method KW - Electric discharges KW - Hydrazine KW - Lithium compounds KW - Morphology KW - Lithium alloys AB - As a precursor of spinel LiMn2O4 cathode, manganese oxide is prepared by co-precipitation via a two-step drying method. The effects of precursor treatment on the structure, morphology, and electrochemical performance of the synthesized spinel LiMn2O4 are studied using contrasting experiments involving the addition of hydrazine, N 2, and H2O2. The tests show that different treatments have a great effect on the crystal structure, morphology, tap density, and electrochemical performance of LiMn2O4. When the precursor is treated by adding hydrazine and pure N2, the synthesized LiMn2O4 shows an integral lattice, uniform particle size, a pure spinel phase with an ordered octahedral crystal structure, and high tap density (2.23 g cm-3). The electrochemical results show that spinel LiMn2O4 exhibits higher specific capacity and better cyclic stability than other samples, especially at an elevated temperature and high discharge current. The initial discharge capacity of the electrode is 110.8 mAh g-1 at a rate of 3 C, and exhibits a good capacity retention of 96.4% after 30 cycles; at a rate of 5 C, the initial discharge capacity is 107.5 mAh g-1, with a capacity retention of 87.3% after 50 cycles. DA - 2013/03/13 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f2680c57-6997-429f-9ba8-e12a2d7042af ER - TY - JOUR TI - Spectroscopy of dimers, trimers and larger clusters of linear molecules DO - 10.1080/0144235X.2013.813799 AU - Moazzen-Ahmadi, N. AU - McKellar, A. R. W. T2 - International Reviews in Physical Chemistry SN - 0144-235X VL - 32 IS - 4 SP - 611 EP - 650 KW - Cluster, dimer, trimer, van der Waals, intermolecular forces, infrared, high resolution AB - Rotationally resolved spectra of van der Waals clusters provide the most direct, precise and unambiguous experimental probe of intermolecular potential energy surfaces, particularly in the lower energy range of attractive forces. The spectroscopy of such weakly bound complexes is reviewed with a focus on those containing only the following five small linear molecules: N2O, CO2, OCS, CS2 and C2H2. Even with this limitation, there are over 30 such complexes for which high-resolution spectroscopic results are now available in the microwave, millimetre wave and infrared regions. Dimers formed from these five species tend to be planar with slipped parallel structures, though there are some exceptions. Trimers tend to be barrel-shaped, that is, non-planar with approximately parallel monomers. Larger clusters are almost invariably non-planar and sometimes highly symmetric. Three significant themes emerge here. First, the possibility of determining low-frequency intermolecular vibrational modes by means of mid-infrared combination bands. Second, the increasing number of complexes for which more than one structural form, or isomer, is observed. And finally, the growing amenability of even 'large' clusters (say, tetramers and larger) to spectroscopic study. All three factors help to probe potential energy surfaces more completely in regions away from the global minimum. DA - 2013/07/16 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : cc3e767d-1b55-4d31-805d-d76c632c4bfb ER - TY - JOUR TI - Review of confederation bridge ice forces: Winter 2008-2010 AU - Frederking, Robert AU - Li, Lian-Feng AU - Kubat, Ivana T2 - International Journal of Offshore and Polar Engineering SN - 1053-5381 VL - 23 IS - 1 SP - 1 EP - 8 KW - Conical structures KW - Data acquisition system KW - Ice interactions KW - Interaction process KW - Measurement system KW - Tilt measurement KW - Bridge piers KW - Loading KW - Meteorological problems KW - Offshore structures KW - Standards KW - Data set KW - Ice core KW - Ice-structure interaction KW - Videography KW - Wind forcing AB - Ice interactions with the Confederation Bridge for the winters 2008, 2009 and 2010 have been studied. Ice conditions for these winters were characterized as two average winters and one very mild winter. Tilt data from piers P23 and P24 in response to ice and wind actions were recorded by a data acquisition system. Video records of ice interactions with pier P23 and overall ice conditions adjacent to piers P23 and P24 allowed ice conditions and interaction processes to be related to tilt measurements. Wind data were analyzed to correct for the tilt caused by wind actions on the bridge. Limit stress and limit force events were identified. An ice loading scenario that transitioned from limit force to limit stress resulted in the highest ice forces over the three years of monitoring, with forces of 3.1 MN and 4.3 MN at P23 and P24, respectively. ISO 19906 Arctic offshore structures can provide reasonable predictions of ice forces for ice actively failing on a conical structure. DA - 2013/03/01 PY - 2013 UR - http://www.isope.org/publications/journals/ijope-23-1/abst-23-1-p001-vs06.pdf LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9d2b8aa4-358a-41e0-8696-eecaf2dda2ee ER - TY - JOUR TI - Assessment of hydrodynamic impacts from tidal power lagoons in the Bay of Fundy DO - 10.1016/j.ijome.2013.05.006 AU - Cornett, Andrew AU - Cousineau, Julien AU - Nistor, Ioan T2 - International Journal of Marine Energy SN - 2214-1669 VL - 1 SP - 33 EP - 54 KW - Circulation patterns KW - Human activities KW - Hydrodynamic impacts KW - Hydrodynamic model KW - Modelling systems KW - Potential change KW - Tidal lagoon KW - Energy resources KW - Hydrodynamics KW - Numerical models KW - Ocean currents KW - Tidal power KW - Tides KW - Water levels KW - Lakes KW - Electricity generation KW - Energy resource KW - Hydrodynamics KW - Hydroelectric power KW - Resource management AB - The Bay of Fundy located in eastern Canada is home to some of the world's largest tides. Currently there is renewed interest in harnessing these very large tides for power generation in ways that avoid upsetting ecosystems, infrastructure and human activities that are presently well adapted to existing conditions. This paper investigates the hydrodynamic impacts due to tidal power lagoons, an approach to power generation that involves temporarily storing seawater behind a circular engineered dyke and generating power by gradually releasing the impounded seawater through conventional low-head hydroelectric turbines. This paper describes a study in which a two-dimensional, depth-averaged hydrodynamic model based on the TELEMAC modelling system was developed, calibrated, and applied to analyze, predict, and quantify the potential changes in tidal hydrodynamics (water levels, tide range, circulation patterns and tidal currents) throughout the Bay of Fundy and Gulf of Maine due to the presence of a single tidal lagoon and multiple lagoons operating at various locations in the upper Bay of Fundy. The sensitivity of the hydrodynamic impacts to changes in lagoon type, size, location, the number of lagoons, and their operating mode have also been investigated. The methods employed in this study and the main findings are presented and discussed herein. These results will help inform future decisions concerning development of the vast tidal energy resources in the Bay of Fundy. © 2013 Elsevier Ltd. All rights reserved. DA - 2013/04 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2bf5cb19-0225-46e4-93b4-c05964bbae0c ER - TY - JOUR TI - Sodium tungstate as electrolyte additive to improve high-temperature performance of nickel-metal hydride batteries DO - 10.1016/j.ijhydene.2013.02.047 AU - Shangguan, Enbo AU - Li, Jing AU - Chang, Zhaorong AU - Tang, Hongwei AU - Li, Bao AU - Yuan, Xiao-Zi AU - Wang, Haijiang T2 - International Journal of Hydrogen Energy SN - 0360-3199 VL - 38 IS - 12 SP - 5133 EP - 5138 KW - Charge/discharge test KW - Cycle stability KW - Electrochemical impedance KW - High temperature performance KW - Nickel hydroxide electrode KW - Performance improvements KW - Sodium tungstate KW - Cyclic voltammetry KW - Electrochemical impedance spectroscopy KW - Electrolytes KW - Nickel cadmium batteries KW - Tungsten compounds KW - Sodium AB - Sodium tungstate (Na2WO4) used as new electrolyte additive to enhance the high-temperature performance of Nickel-metal hydride (Ni-MH) battery is investigated in this paper. The effects of Na 2WO4 on nickel hydroxide electrodes are investigated using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and a charge/discharge test. It is found that the Ni-MH cell with the conventional KOH electrolyte containing 1 wt.% Na2WO4 additive exhibits higher discharge retention and better cycling performance than the cell without Na2WO4 additive at both 25 °C and 70 °C. These performance improvements are ascribed to the enhancement of oxygen evolution overvoltage and lower electrochemical impedance, as indicated by CV and EIS. The results suggest that the proposed approach be an effective way to improve the high temperature performance of Ni-MH batteries. DA - 2013/03/14 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1e56bde6-f8de-41de-a81e-108b53f90e43 ER - TY - JOUR TI - Enhancement of the high-temperature performance of advanced nickel-metal hydride batteries with NaOH electrolyte containing NaBO2 DO - 10.1016/j.ijhydene.2013.06.005 AU - Shangguan, Enbo AU - Wang, Jianling AU - Li, Jing AU - Dan, Guo AU - Chang, Zhaorong AU - Yuan, Xiao-Zi AU - Wang, Haijiang T2 - International Journal of Hydrogen Energy SN - 0360-3199 VL - 38 IS - 25 SP - 10616 EP - 10624 KW - Conventional batteries KW - Cycle stability KW - Electrochemical impedance KW - Nickel metal hydride battery KW - Oxygen evolution overpotential KW - Sodium metaborate KW - Steady state polarization KW - Nickel cadmium batteries KW - Oxygen KW - Sodium KW - Electrolytes AB - In this paper, an alternative approach to improve the high-temperature performance of nickel-metal hydride (Ni-MH) batteries is proposed by introducing NaOH electrolyte with sodium metaborate (NaBO2) additives. Compared with conventional batteries using KOH electrolyte, the in-house prepared batteries with proposed electrolytes exhibit an enhanced discharge capacity, improved high-rate discharge ability, increased cycle stability and reduced self-discharge rate at an elevated temperature (70 °C). The charge acceptance of these Ni-MH batteries at 70 °C is over 96% at a charge/discharge rate of 1 C. These performance improvements are ascribed to the increased oxygen evolution overpotential, slower oxygen evolution rate and lower electrochemical impedance, as indicated by CV, steady-state polarization measurements and EIS. The results suggest that the proposed approach be an effective way to improve the high-temperature performance of Ni-MH batteries. DA - 2013/07/09 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : fa3324dc-40f4-4ad0-a1ef-49f97ceee98f ER - TY - JOUR TI - Effect of KOH concentration on the oxygen reduction kinetics catalyzed by heat-treated co-pyridine/C electrocatalysts AU - Qiao, Jinli AU - Xu, Li AU - Ding, Lei AU - Shi, Penghui AU - Zhang, Lei AU - Baker, Ryan AU - Zhang, Jiujun T2 - International Journal of Electrochemical Science SN - 1452-3981 VL - 8 IS - 1 SP - 1189 EP - 1208 AB - Using a simple thermal method, a non-noble metal electrocatalyst (Co-N-S/C) is successfully synthesized and its' composition is analyzed using EDX. The electrochemical activity of such a catalyst is also tested using surface electrochemical methods. Three one-electron transfer redox processes in the studied potential range are identified, where only one such a process is associated with the catalyst's ORR activity. The effect of KOH on the Co-N-S/C catalyzed ORR kinetics is investigated using the rotating disk electrode technique in a concentration range of 0.05 to 6.0M. Several ORR kinetic parameters such as overall electron transfer number (n), the product of electron transfer number and coefficient in ORR rate determining step (αnα), and the exchange current density (iO2/H2O°) are estimated. The results show that values of n at different KOH concentrations are close to 4.0, suggesting that Co-N-S/C catalyzed ORR is a 4-electron transfer process from O2 to H2O. KOH concentration has an insignificant effect on the value of n, however, a significant effect is observed on both values of αnα and iO2/H2O°. (αnα decreases while that of iO2/H2O° increases with increasing KOH concentration). DA - 2013/01/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b5048249-3939-4fee-a7d0-c1048dc18643 ER - TY - JOUR TI - Assessing performance in brain tumor resection using a novel virtual reality simulator DO - 10.1007/s11548-013-0905-8 AU - Gélinas-Phaneuf, Nicholas AU - Choudhury, Nusrat AU - Al-Habib, Ahmed R. AU - Cabral, Anne AU - Nadeau, Etienne AU - Mora, Vincent AU - Pazos, Valerie AU - Debergue, Patricia AU - DiRaddo, Robert AU - Del Maestro, Rolando F. T2 - International Journal of Computer Assisted Radiology and Surgery SN - 1861-6410 VL - 9 IS - 1 SP - 1 EP - 9 KW - NeuroTouch KW - virtual reality simulation KW - Haptic feedback KW - Brain tumor resection KW - Neurosurgical oncology KW - performance metrics AB - Purpose: NeuroTouch is a virtual reality (VR) simulator developed for neurosurgical skill training. Validation demonstrating that the system is useful and reliable is required for formal adoption into training curriculums. Face and content validity have been demonstrated for some neurosurgical simulators, but construct validity remains difficult to establish. A pilot validation study was conducted for a NeuroTouch training exercise. Methods: Participants completed the internal resection of a simulated convexity meningioma and filled out questionnaires to provide feedback on the experience. Performance metrics included volume of tissues removed, tool path lengths, duration of excessive forces applied and efficient use of the aspirator. Results were analyzed according to participants' level of training, gender, handedness, surgical experience in meningioma removal and hours/week playing musical instruments or video games. Results: Seventy-two participants (10 medical students, 18 junior residents and 44 senior residents) were enrolled. Analyses demonstrated statistically significant increase in tumor removed and efficiency of ultrasonic aspirator use between medical students and residents, but not between junior and senior residents. After covariate adjustment for the number of meningioma cases operated on, multivariate analysis of the level of training became nonsignificant. Participants judged the exercise appropriate and realistic, desiring use of the system in current training programs. Conclusion: We have conducted a pilot validation study for the NeuroTouch tumor resection scenario and demonstrated for the first time, face, content and construct validity of a VR neurosurgical simulation exercise. Future full-scale studies will be conducted in noncompetitive settings and incorporate expert participants. DA - 2013/06/20 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b37b2ec9-3a8a-4715-a07b-f4bac7f180a5 ER - TY - JOUR TI - High resolution Fourier-transform microspectroscopy based on spiral silicon waveguides DO - 10.1109/ICTON.2013.6602863 AU - Velasco, Aitor V. AU - Cheben, Pavel AU - Calvo, Maria L. AU - Florjańczyk, Miroslaw AU - Bock, Przemek J. AU - Delâge, André AU - Schmid, Jens H. AU - Lapointe, Jean AU - Janz, Siegfried AU - Xu, Dan-Xia AU - Vachon, Martin T2 - ICTON 2013: 15th International Conference on Transparent Optical Networks, June 23-27, 2013, Cartagena, Spain : conference proceedings T2 - International Conference on Transparent Optical Networks : [proceedings]; 6602863 T3 - 15th International Conference on Transparent Optical Networks, ICTON 2013, June 23-27, 2013, Cartagena, Spain SN - 2162-7339 SN - 9781479906826 SP - 6602863 KW - Fabrication imperfections KW - Fourier transform spectrometers KW - Machzehnder interferometers (MZI) KW - Optical path difference KW - Silicon microphotonics KW - spectral retrieval KW - Transformation matrices KW - Fourier transform infrared spectroscopy KW - Linear transformations KW - Transparent optical networks AB - We report a spatial heterodyne Fourier-transform spectrometer consisting of an array of Mach-Zehnder interferometers (MZI) implemented in silicon microphotonics. Optical path differences between the MZI arms increase linearly along the array, generating a wavelength-dependent interferogram which enables the retrieval of the source spectrum with a single measurement. Optical delays were implemented with Si-wire waveguides arranged in tightly coiled spirals to achieve a high resolution in a reduced footprint. Our spectral retrieval algorithm compensates phase and amplitude errors arising from fabrication imperfections by using a transformation matrix based on the calibration data. A wavelength resolution of 40 pm within a free spectral range of 0.75 nm is demonstrated. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : bdc4fe7d-0d56-4bc0-806b-635a0ab7661e ER - TY - JOUR TI - Quantitative vibrational dynamics of the metal site in a tin porphyrin: an IR, NRVS, and DFT study DO - 10.1021/ic401152b AU - Leu, Bogdan M. AU - Zgierski, Marek Z. AU - Bischoff, Christian AU - Li, Ming AU - Hu, Michael Y. AU - Zhao, Jiyong AU - Martin, Steve W. AU - Alp, Esen Ercan AU - Scheidt, W. Robert T2 - Inorganic Chemistry SN - 0020-1669 VL - 52 IS - 17 SP - 9948 EP - 9953 AB - We used a newer, synchrotron-based, spectroscopic technique (nuclear resonance vibrational spectroscopy, NRVS) in combination with a more traditional one (infrared absorption, IR) to obtain a complete, quantitative picture of the metal center vibrational dynamics in a six-coordinated tin porphyrin. From the NRVS 119Sn site-selectivity and the sensitivity of the IR signal to 112Sn/119Sn isotope substitution, we identified the frequency of the antisymmetric stretching of the axial bonds (290 cm -1) and all the other vibrations involving Sn. Experimentally authenticated density functional theory (DFT) calculations aid the data interpretation by providing detailed normal mode descriptions for each observed vibration. These results may represent a starting point toward the characterization of the local vibrational dynamics of the metallic site in tin porphyrins and compounds with related structures. The quantitative complementariness between IR, NRVS, and DFT is emphasized. DA - 2013/08/20 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c1721578-f5c1-4573-932a-8b02822c6c63 ER - TY - JOUR TI - Elimination of mass-exchange errors in the NRC watt balance DO - 10.1109/TIM.2012.2225957 AU - Sanchez, Carlos A. AU - Wood, Barry M. AU - Inglis, Dave AU - Robinson, Ian A. T2 - IEEE Transactions on Instrumentation and Measurement SN - 0018-9456 VL - 62 IS - 6 SP - 6355670 SP - 1506 EP - 1511 KW - Electromagnetic forces KW - Electronic kilogram KW - Measurements of KW - National Research Council Canada KW - Planck constants KW - Electrical engineering KW - Instruments KW - Errors AB - We report on the evaluation, correction, and subsequent elimination of the mass-exchange errors in the National Research Council (NRC) of Canada watt balance. Two effects arising from mass exchanges during the weighing phase initially produced significant systematic errors in the measurements of the Planck constant (h). These effects were estimated, and corresponding corrections were applied to measurements of h made at NRC between August and September of 2011. The effect due to the tilting of the beam required an estimated correction of (0.238 ± 0.018) μJ/s(J s) , and the effect due to the tilting of the flat, which supports the beam, required an estimated correction of (-0.636 ± 0.056) μJsJs). After the initial measurements were completed, we made several modifications to the balance which achieved a reduction of the two errors to negligible levels. A second set of measurements, made with the modified apparatus in May and June of 2012, shows very good agreement with the first measurements. DA - 2013/11/16 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 93549ae8-61aa-4a4b-bd35-2b18aaac2629 ER - TY - JOUR TI - Low-frequency quantum-based AC power standard at NRC Canada DO - 10.1109/TIM.2013.2240952 AU - Djokić, Branislav V. T2 - IEEE Transactions on Instrumentation and Measurement SN - 0018-9456 VL - 62 IS - 6 SP - 6471821 SP - 1699 EP - 1703 KW - Digital sampling KW - Inductive voltage divider KW - ITS evaluation KW - National Research Council of Canada KW - Output voltages KW - Programmable Josephson voltage standard KW - Calibration KW - Electric instrument transformers KW - Electric transformers KW - Voltage dividers KW - Josephson junction devices AB - A low-frequency AC power standard based on the programmable Josephson voltage standard (PJVS) has been developed at the National Research Council of Canada. At the step voltages, PJVS provides quantum accuracy. Differential digital sampling is used to extend the quantum accuracy to the AC power standard output voltage and current, nominally 120 V and 5 A. The paper describes the power standard and its evaluation. DA - 2013/03/07 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 153d0825-65fc-41f8-9647-48929634e400 ER - TY - JOUR TI - High-current CT calibration using a sampling current ratio bridge DO - 10.1109/TIM.2013.2253975 AU - Rietveld, Gert AU - Jol, Leendert AU - van den Brom, Helko E. AU - So, Eddy T2 - IEEE Transactions on Instrumentation and Measurement SN - 0018-9456 VL - 62 IS - 6 SP - 6506958 SP - 1693 EP - 1698 KW - Alternating current KW - Current ratios KW - Digital sampling KW - Phase displacement KW - Phase error KW - Ratio error KW - Electric current measurement KW - Electric instrument transformers AB - A measurement setup is developed for the accurate ratio measurement of ac current transformers (CTs) for primary currents up to 5 kA. A unique property of the system is the use of high-quality digitizers for sampling of the secondary current signals and step-down transformers with different current ratios. This allows for accurate comparison of CTs even when their nominal ratios are not equal. The calibration results of the key components in the setup show that the sampling current ratio bridge has a ratio uncertainty of better than 2 μ A/A in magnitude and 0.8 μrad in phase for CT-under-test current ratios that do not differ by more than a factor of 5 from one of the ratios in the reference CT. The linearity of the bridge for input currents changing between 1% and 120% of nominal input current is better than 4 μ A/A in magnitude and 0.5 μ rad in phase. DA - 2013/04/22 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8d79cfd1-f093-482a-9533-7e6929d252be ER - TY - JOUR TI - Effect of additives on the performance of cross-linked polyethylene subjected to long term single and periodically reversed polarity DC voltage DO - 10.1109/TDEI.2013.6508769 AU - Abou-Dakka, M. AU - Bulinski, A. AU - Bamji, S. S. T2 - IEEE Transactions on Dielectrics and Electrical Insulation SN - 1070-9878 VL - 20 IS - 2 SP - 6508769 SP - 654 EP - 663 KW - Crosslinked polyethylene KW - Electric field enhancement KW - Electric insulation performance KW - Polarity reversal KW - Space charge measurements KW - Thermal step method KW - XLPE KW - Electric space charge KW - Forestry AB - The performance of cross-linked polyethylene with and without tree-retarding additives, aged with single and reversed polarity DC voltage was investigated. Under single polarity field of a 50 kV/mm, cross-linked polyethylene without the tree retardant (XLPE) showed significantly longer time to breakdown than the material with a tree retardant (TR-XLPE). This is attributed to the difference in how the two materials accumulate and retain space charge. In the case of polarity reversals, TR-XLPE showed better performance than XLPE. This seeming contradiction was studied by measuring the dynamics of space charge evolution with time. The Thermal Step Method (TSM) of space charge measurements was used. It showed that after the polarity reversal the TSM current rapidly inversed in the TR-XLPE but not in the XLPE. This implies more rapid charge dissipation in TR-XLPE. The retained charges cause the electric field enhancement in the material when the polarity is reversed. Thus, after each polarity reversal XLPE was subjected to higher local electric stress for a longer time and thus broke down sooner than TR-XLPE. For both materials the space charge decreased faster when the polarity was changed from negative to positive than vice versa. This could be explained by more efficient electron than holes injection. Since the control of the power flow in DC networks requires reversals of voltage polarity, their detrimental effect on XLPE-insulated equipment, such as cables, cannot be avoided. The effect could be mitigated by the application of carefully designed additives. However, as the present study indicates, additives that improve insulation performance under polarity reversals can be harmful under single polarity voltage. DA - 2013/04 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : da8fff6a-d9f3-4835-8151-04f25e7368a6 ER - TY - JOUR TI - Three-dimensional spine model reconstruction using one-class SVM regularization DO - 10.1109/TBME.2013.2272657 AU - Lecron, Fabian AU - Boisvert, Jonathan AU - Mahmoudi, Saïd AU - Labelle, Hubert AU - Benjelloun, Mohammed T2 - IEEE Transactions on Biomedical Engineering SN - 0018-9294 VL - 60 IS - 11 SP - 6557062 SP - 3256 EP - 3264 KW - 3D reconstruction KW - Biomedical applications KW - One-class support vector machines (OCSVM) KW - scoliosis KW - State-of-the-art methods KW - Statistical shape model KW - Gaussian distribution KW - Hospital data processing KW - Medical applications KW - Support vector machines KW - accuracy KW - algorithm KW - anatomic model KW - image reconstruction KW - sensitivity analysis KW - statistical shape model KW - validity AB - Statistical shape models have become essential for medical image registration or segmentation and are used in many biomedical applications. These models are often based on Gaussian distributions learned from a training set. We propose in this paper a shape model which does not rely on the estimation of a Gaussian distribution, but on similarities computed with a kernel function. Our model takes advantage of the one-class support vector machine (OCSVM) to do so. In this context, we propose in this paper a method for reconstructing the spine of scoliotic patients using OCSVM regularization. Current state-of-the-art methods use conventional statistical shape models, and the reconstruction is commonly processed by minimizing a Mahalanobis distance. Nevertheless, when a shape differs significantly from the statistical model, the associated Mahalanobis distance often overstates the need for statistical regularization. We show that OCSVM regularization is more robust and is less sensitive to weak landmarks definition and is hardly influenced by the presence of outliers in the training data. The proposed OCSVM model applied to 3-D spine reconstruction was evaluated on real patient data, and results showed that our approach allows precise reconstruction. DA - 2013/07/10 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e3ad19b5-e670-4b90-b58c-817120035848 ER - TY - JOUR TI - Validation of strain gauges for structural health monitoring with bayesian belief networks DO - 10.1109/JSEN.2012.2217954 AU - Liu, Zheng AU - Mrad, Nezih T2 - IEEE Sensors Journal SN - 1530-437X VL - 13 IS - 1 SP - 6298926 SP - 400 EP - 407 KW - Aluminum plates KW - Discretizations KW - Multiple sensors KW - Sensor configurations KW - Sensor data KW - Sensor redundancy KW - Sensor validation KW - State of health KW - Training data KW - Validation process KW - Virtual sensor KW - Decision theory KW - Loading KW - Strain gages AB - The application of structural health monitoring (SHM) often employs multiple sensors to monitor the state of health and usage of the structures. The fault of any sensor may lead to an inaccurate or even incorrect inference with the collected sensor data, which will accordingly create a negative impact on higher-level decisions for maintenance and services. Thus, sensor validation becomes a critical process to the performance of the whole SHM system. This paper presents the use of Bayesian belief network to validate the reading of strain gauges on an aluminum plate for loading monitoring. The Bayesian belief network is constructed with the training data. The factors investigated in this paper, which may affect the validation process, include sensor configuration, sensor redundancy, and sensor data range for the discretization. The feasibility of using a Bayesian belief network for SHM sensor validation is demonstrated with the experimental results. DA - 2013/09/11 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5e70402a-f499-4503-82cb-51339fb4a561 ER - TY - JOUR TI - Direct and sensitive phase readout for integrated waveguide sensors DO - 10.1109/JPHOT.2013.2276747 AU - Halir, R. AU - Vivien, L. AU - Le Roux, X. AU - Xu, D.-X. AU - Cheben, P. T2 - IEEE Photonics Journal SN - 1943-0655 VL - 5 IS - 4 SP - 6575104 KW - Average sensitivities KW - Conventional detection KW - Integrated optical sensors KW - Integrated waveguides KW - Intensity variations KW - Optical phase changes KW - Phase detection KW - Transmittance function KW - Chemical detection KW - Sensitivity analysis AB - Integrated optical affinity sensors based on Mach-Zehnder interferometers (MZIs) enable sensitive and label-free detection of chemical and biological molecules. However, since MZIs transduce optical phase changes into sinusoidal intensity variations, they exhibit a variable sensitivity that vanishes at the extrema of the transmittance function. Moreover, the direction of phase change cannot be unambiguously determined with these sensors. Here, we present a coherent detection scheme based on integrated optics that enables unambiguous readout of the optical phase with a constant sensitivity. Our approach furthermore cancels the effect of imperfections in the sensor hardware using a blind calibration scheme. We experimentally show completely linear readout of the optical phase, with a fourfold enhancement of average sensitivity compared to conventional detection. DA - 2013/08/06 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5b81a947-f93f-4093-b1b2-fb10f98f4caf ER - TY - JOUR TI - Optimal relay selection for physical-layer security in cooperative wireless networks DO - 10.1109/JSAC.2013.131011 AU - Zou, Yulong AU - Wang, Xianbin AU - Shen, Weiming T2 - IEEE Journal on Selected Areas in Communications SN - 0733-8716 VL - 31 IS - 10 SP - 6601774 SP - 2099 EP - 2111 KW - Cooperative wireless networks KW - Decode-and-forward protocols KW - Diversity order KW - Eavesdropping attacks KW - Physical-layer securities KW - Probability expressions KW - Probability performance KW - Relay selection KW - Numerical methods KW - Security systems KW - Optimization AB - In this paper, we explore the physical-layer security in cooperative wireless networks with multiple relays where both amplify-and-forward (AF) and decode-and-forward (DF) protocols are considered. We propose the AF and DF based optimal relay selection (i.e., AFbORS and DFbORS) schemes to improve the wireless security against eavesdropping attack. For the purpose of comparison, we examine the traditional AFbORS and DFbORS schemes, denoted by T-AFbORS and T-DFbORS, respectively. We also investigate a so-called multiple relay combining (MRC) framework and present the traditional AF and DF based MRC schemes, called T-AFbMRC and T-DFbMRC, where multiple relays participate in forwarding the source signal to destination which then combines its received signals from the multiple relays. We derive closed-form intercept probability expressions of the proposed AFbORS and DFbORS (i.e., P-AFbORS and P-DFbORS) as well as the T-AFbORS, T-DFbORS, T-AFbMRC and T-DFbMRC schemes in the presence of eavesdropping attack. We further conduct an asymptotic intercept probability analysis to evaluate the diversity order performance of relay selection schemes and show that no matter which relaying protocol is considered (i.e., AF and DF), the traditional and proposed optimal relay selection approaches both achieve the diversity order M where M represents the number of relays. In addition, numerical results show that for both AF and DF protocols, the intercept probability performance of proposed optimal relay selection is strictly better than that of the traditional relay selection and multiple relay combining methods. © 2013 IEEE. DA - 2013/10 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c054d0a9-0279-4196-aea2-79ec5bb2e7ad ER - TY - JOUR TI - Modeling of single-section quantum dot mode-locked lasers: impact of group velocity dispersion and self phase modulation DO - 10.1109/JQE.2013.2285115 AU - Jiao, Zhejing AU - Zhang, Rong AU - Zhang, Xiupu AU - Liu, Jiaren AU - Lu, Zhenguo T2 - IEEE Journal of Quantum Electronics SN - 0018-9197 VL - 49 IS - 12 SP - 1008 EP - 1015 KW - Dispersion length KW - High peak power KW - Kerr-lens effect KW - Mode-locked laser KW - Pulse evolution KW - Pulse-train generation KW - Traveling wave KW - Traveling wave model KW - Group velocity dispersion KW - Laser accessories KW - Quantum dot lasers KW - Self phase modulation KW - Locks (fasteners) AB - A short pulse train with pulsewidth < 1 ps was generated in a quantum dot mode-locked laser (QD MLL). Due to the short dispersion length, it is required to include group-velocity dispersion (GVD) in modeling pulse train generation and evolution from QD MLLs. On the other hand, Kerr effect is also required to consider due to high peak power density in the laser cavity, and its induced self-phase modulation (SPM) also contributes to the pulse evolution. In this paper, a time domain traveling wave model, including the effect of GVD and SPM, combined with rate equations, is established to model the pulse evolution in a single-section QD MLL. It is shown that the pulse evolution calculated by this model is in reasonable agreement with the experiments. The contribution to the pulse evolution by the GVD and SPM impact is discussed. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b55515e7-3fba-4e25-9b4d-ac451f0f6a7d ER - TY - JOUR TI - Hepatitis C virus induced up-regulation of microRNA-27: a novel mechanism for hepatic steatosis DO - 10.1002/hep.26634 AU - Singaravelu, Ragunath AU - Chen, Ran AU - Lyn, Rodney K. AU - Jones, Daniel M. AU - O'Hara, Shifawn AU - Rouleau, Yanouchka AU - Cheng, Jenny AU - Srinivasan, Prashanth AU - Nasheri, Neda AU - Russell, Rodney S. AU - Tyrrell, D. Lorne AU - Pezacki, John Paul T2 - Hepatology SN - 0270-9139 VL - 59 IS - 1 SP - 98 EP - 108 AB - MicroRNAs (miRNAs) are small RNAs that posttranscriptionally regulate gene expression. Their aberrant expression is commonly linked with diseased states, including hepatitis C virus (HCV) infection. Herein, we demonstrate that HCV replication induces the expression of miR-27 in cell culture and in vivo HCV infectious models. Overexpression of the HCV proteins core and NS4B independently activates miR-27 expression. Furthermore, we establish that miR-27 overexpression in hepatocytes results in larger and more abundant lipid droplets, as observed by coherent anti-Stokes Raman scattering (CARS) microscopy. This hepatic lipid droplet accumulation coincides with miR-27b's repression of peroxisome proliferator-activated receptor (PPAR)-α and angiopoietin-like protein 3 (ANGPTL3), known regulators of triglyceride homeostasis. We further demonstrate that treatment with a PPAR-α agonist, bezafibrate, is able to reverse the miR-27b-induced lipid accumulation in Huh7 cells. This miR-27b-mediated repression of PPAR-α signaling represents a novel mechanism of HCV-induced hepatic steatosis. This link was further demonstrated in vivo through the correlation between miR-27b expression levels and hepatic lipid accumulation in HCV-infected SCID-beige/Alb-uPa mice. Conclusion: Collectively, our results highlight HCV's up-regulation of miR-27 expression as a novel mechanism contributing to the development of hepatic steatosis. DA - 2013/11/19 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 418a6f6b-8d62-48da-ad74-7a4ac9da9798 ER - TY - JOUR TI - The antigen-binding site of an N-propionylated polysialic acid-specific antibody protective against group B meningococci is consistent with extended epitopes DO - 10.1093/glycob/cwt031 AU - Johal, Asha R. AU - Jarrell, Harold C. AU - Letts, James A. AU - Khieu, Nam Huan AU - Landry, Roxanne C. AU - Jachymek, Wojciech AU - Yang, Qingling AU - Jennings, Harold J. AU - Brisson, Jean-Robert AU - Evans, Stephen V. T2 - Glycobiology SN - 0959-6658 VL - 23 IS - 8 SP - 946 EP - 954 KW - epitope KW - polysaccharide KW - polysialic acid KW - conformational transition KW - crystal structure KW - Escherichia coli KW - immunological tolerance KW - molecular docking KW - molecular recognition KW - Neisseria meningitidis AB - Monoclonal antibodies 13D9 and 6B9 are both specific for N-propionylated polysialic acid (NPrPSA); however, while 13D9 is protective against meningitis caused by group B meningococci and Escherichia coli capsular type K1 infection, 6B9 is not. The crystal structures of the Fabs from the two antibodies determined at 2.06 and 2.45 Å resolutions, respectively, reveal markedly different combining sites, where only the surface of 13D9 is consistent with the recognition of extended helical epitopes known to exist in the capsular polysaccharides of etiological agents of meningitis. Interestingly, complementarity determining region H2 on 13D9 lies in a non-canonical conformation that docking studies show is a critical feature in the generation of negative free energy of binding. Finally, the model of extended NPrPSA decasaccharide bound to 13D9 derived from docking studies is consistent with saturation transfer difference nuclear magnetic resonance experiments. Together, these results provide further evidence that extended epitopes have the ability to break immune tolerance associated with the polysialic acid capsule of these pathogens. DA - 2013/05/22 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 51164426-3a10-4d2f-997f-fa5e80dd729a ER - TY - JOUR TI - Leveraging metabolomics to assess the next generation of temozolomide-based therapeutic approaches for glioblastomas DO - 10.1016/j.gpb.2013.04.003 AU - St-Coeur, Patrick-Denis AU - Touaibia, Mohamed AU - Cuperlovic-Culf, Miroslava AU - Morin, Pier Jr T2 - Genomics, Proteomics and Bioinformatics SN - 1672-0229 VL - 11 IS - 4 SP - 199 EP - 206 KW - Glioblastoma multiforme; Temozolomide; Signaling cascades; Cancer therapeutics; Cancer diagnosis AB - Glioblastoma multiforme (GBM) is the most common adult primary tumor of the central nervous system. The current standard of care for glioblastoma patients involves a combination of surgery, radiotherapy and chemotherapy with the alkylating agent temozolomide. Several mechanisms underlying the inherent and acquired temozolomide resistance have been identified and contribute to treatment failure. Early identification of temozolomide-resistant GBM patients and improvement of the therapeutic strategies available to treat this malignancy are of uttermost importance. This review initially looks at the molecular pathways underlying GBM formation and development with a particular emphasis placed on recent therapeutic advances made in the field. Our focus will next be directed toward the molecular mechanisms modulating temozolomide resistance in GBM patients and the strategies envisioned to circumvent this resistance. Finally, we highlight the diagnostic and prognostic value of metabolomics in cancers and assess its potential usefulness in improving the current standard of care for GBM patients. DA - 2013/06/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0e4d550d-27a8-4b38-b60a-e76cb853870a ER - TY - JOUR TI - Model-based ex situ diagnostics of water fluxes in catalyst layers of polymer electrolyte fuel cells DO - 10.1002/fuce.201200072 AU - Liu, J. AU - Gazzarri, J. AU - Eikerling, M. T2 - Fuel Cells SN - 1615-6846 VL - 13 IS - 2 SP - 134 EP - 142 KW - Catalyst Layer Modeling; Extraction of Effective Transport Properties; Partial Liquid Saturation; Polymer Electrolyte Fuel Cell; Water Flux Response Function AB - The ability to predict the electrochemical performance of the cathode catalyst layer in a polymer electrolyte fuel cell hinges on a precise knowledge of water distribution and fluxes. Water transport mechanisms that must be accounted for include vapor diffusion, liquid water permeation and vaporization exchange. In order to facilitate experimental efforts to this effect, we propose an ex situ model of water fluxes in catalyst layers. The model formulation is similar to transmission line models that are widely used in the analysis of electrochemical impedance spectra of porous composite electrodes. Focusing in this article on steady state and isothermal conditions, we rationalize the response function between defined environmental conditions, i.e. gas pressures, partial vapor pressures and temperature, which are defined at the boundaries of the catalyst layer, and the net water flux. This response function provides diagnostic capabilities to isolate and extract water transport parameters of catalyst layers from measurements of water fluxes through membrane electrode assemblies or half cell systems. An important asset of the model is the ability to analyze catalyst layer transport properties under partial saturation. DA - 2013/02/18 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 62f9b7aa-309f-411f-b5bb-e43fe67957ce ER - TY - JOUR TI - Distribution of colonization and antimicrobial resistance genes in campylobacter jejuni isolated from chicken DO - 10.1089/fpd.2012.1271 AU - Thibodeau, Alexandre AU - Fravalo, Philippe AU - Garneau, Philippe AU - Masson, Luke AU - Laurent-Lewandowski, Sylvette AU - Quessy, Sylvain AU - Harel, Josée AU - Letellier, Ann T2 - Foodborne Pathogens and Disease SN - 1535-3141 VL - 10 IS - 4 SP - 382 EP - 391 AB - Campylobacter jejuni is an important worldwide foodborne pathogen commonly found as a commensal organism in poultry that can reach high numbers within the gut after colonization. Although information regarding some genes involved in colonization is available, little is known about their distribution in strains isolated specifically from chickens and whether there is a linkage between antimicrobial resistance (AMR) and colonization genes. To assess the distribution and relevance of genes associated with chicken colonization and AMR, a C. jejuni microarray was created to detect 254 genes of interest in colonization and AMR including variants. DNA derived from chicken-specific Campylobacter isolates collected in 2003 (n=29) and 2008 (n=28) was hybridized to the microarray and compared. Hybridization results showed variable colonization-associated gene presence. Acquired AMR genes were low in prevalence whereas chemotaxis receptors, arsenic resistance genes, as well as genes from the cell envelope and flagella functional groups were highly variable in their presence. Strains clustered into two groups, each linked to different control strains, 81116 and NCTC11168. Clustering was found to be independent of collection time. We also show that AMR weakly associated with the CJ0628 and arsR genes. Although other studies have implicated numerous genes associated with C. jejuni chicken colonization, our data on chicken-specific isolates suggest the opposite. The enormous variability in presumed colonization gene prevalence in our chicken isolates suggests that many are of lesser importance than previously thought. Alternatively, this also suggests that combinations of genes may be required for natural colonization of chicken intestines. DA - 2013/03/19 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 463077dd-433a-447e-a858-331188237ad1 ER - TY - JOUR TI - Evolution of methane during gas hydrate dissociation DO - 10.1016/j.fluid.2013.08.017 AU - Bagherzadeh, S. Alireza AU - Alavi, Saman AU - Ripmeester, John A. AU - Englezos, Peter T2 - Fluid Phase Equilibria SN - 0378-3812 VL - 358 SP - 114 EP - 120 KW - Methane hydrate; Dissociation process; Nano-bubble formation; Molecular dynamics AB - We simulated decomposition of structure I methane hydrate (H) with all cages filled in contact with two reservoirs (pools) of liquid water (W) which in turn are in contact with either two methane gas reservoirs (G), or with vacuum (V), under constant volume-constant energy conditions. By adding gas or empty spaces to the simulation box we allow the released methane to diffuse out of the liquid phase and into the gas phase similar to what happens during methane hydrate dissociation. The evolution of the released methane molecules during the hydrate dissociation process was carefully monitored. We found that some of the released methane gas reaches the gas phase and contributes to the increase of gas pressure on the hydrate phase. As the hydrate dissociates, liquid water phase becomes supersaturated with methane, methane molecules aggregate, and spherical regions of high concentration of methane form which we identify as "nano-bubbles". These nano-bubbles grew to a specific size range which depends on simulation conditions and remained stable in the liquid phase for the duration of the simulations (5. ns). DA - 2013/08/26 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 644a728c-85ab-43e1-a0a9-9401e3028a6c ER - TY - JOUR TI - Studying the RNA silencing pathway with the p19 protein DO - 10.1016/j.febslet.2013.01.036 AU - Danielson, Dana C. AU - Pezacki, John Paul T2 - FEBS Letters SN - 0014-5793 VL - 587 IS - 8 SP - 1198 EP - 1205 KW - p19 protein; Viral suppressors of RNA silencing; Small RNA detection; miRNA-122; Protein engineering; Heterologous expression AB - The origins of the RNA silencing pathway are in defense against invading viruses and in response, viruses have evolved counter-measures to interfere with the host pathway. The p19 protein is expressed by tombusviruses as a suppressor of RNA silencing and functions to sequester small RNA duplexes, thereby preventing induction of the pathway. p19 exhibits size-specific and sequence-independent binding of its small RNA ligands, binding with high affinity to duplexes 20-22 nucleotides long. p19's binding specificity and its ability to sequester small RNAs has made it a unique protein-based tool for probing the molecular mechanisms of the highly complex RNA silencing pathway in a variety of systems. Furthermore, protein engineering of this 'molecular caliper' promises novel applications in biotechnology and medicine where small RNA molecules are of remarkable interest given their potent gene regulatory abilities. DA - 2013/01/29 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3afd45c8-dd39-499c-9b86-4a166474cd7e ER - TY - JOUR TI - Expression of a type 2 diacylglycerol acyltransferase from Thalassiosira pseudonana in yeast leads to incorporation of docosahexaenoic acid B-oxidation intermediates into triacylglycerol DO - 10.1111/febs.12537 AU - Xu, Jingyu AU - Kazachkov, Michael AU - Jia, Yunhua AU - Zheng, Zhifu AU - Zou, Jitao T2 - FEBS Journal SN - 1742-464X VL - 280 IS - 23 SP - 6162 EP - 6172 KW - docosahexaenoic acid KW - eicosapentaenoic acid KW - triacylglycerol KW - type 2 diacylglycerol acyltransferase KW - β-oxidation AB - Glycerolipids of the marine diatom Thalassiosira pseudonana are enriched particularly with eicosapentaenoic acid (EPA), and also with an appreciable level of docosahexaenoic acid (DHA). The present study describes the functional characterization of a type 2 diacylglycerol acyltransferase (DGAT2, EC 2.3.1.20) from T. pseudonana, designated TpDGAT2, which catalyzes the final step of triacylglycerol (TAG) synthesis. Heterologous expression of this gene restored TAG formation in a yeast mutant devoid of TAG biosynthesis. TpDGAT2 was also shown to exert a large impact on the fatty acid profile of TAG. Its expression caused a 10-12% increase of 18:1 and a concomitant decrease of 16:0 relative to that of AtDGAT1(Arabidopsis thaliana). Furthermore, in the presence of the very-long-chain polyunsaturated fatty acids (VLCPUFA) EPA and DHA, TAG formed by TpDGAT2 displayed three- to six-fold increases in the percentage of VLCPUFA relative to that of AtDGAT1 even though TpDGAT2 conferred much lower TAG-synthetic activities than Arabidopsis DGAT1. Strikingly, when fed DHA, the yeast mutant expressing TpDGAT2 incorporated high levels of EPA and DHA isomers derived from DHA β-oxidation. In contrast, no such phenomenon occurred in the cells expressing AtDGAT1. These results suggested that, in addition to the role in breaking down storage lipids, yeast peroxisomes also contribute to lipid synthesis by recycling acyl-CoAs when a fatty acyl assembly system is available to capture and utilize the fatty acyl pools generated via β-oxidation. Our study hence illustrated a case where the efficiency and substrate preference of an acyltransferase can elicit far reaching metabolic adjustments that affect TAG composition. DA - 2013/10/16 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 746e094a-5bc5-4306-a354-d688bc612ffe ER - TY - JOUR TI - The three pillars of photo-initiated quantum molecular dynamics DO - 10.1039/c3fd90021e AU - Stolow, Albert T2 - Faraday Discussions SN - 1359-6640 VL - 163 SP - 9 EP - 32 AB - Studies of the interaction of light with matter, based on spectroscopy and diffraction, yielded a microscopic view of nature. The detailed structure of molecules and solids emerged from this effort and led to many of the advances of the 20th century, with the 'structure-function' paradigm being perhaps paramount. This static view of Nature is a necessary but insufficient advance and, in the 21st century, we will need to develop microscopic yet dynamical views of Nature. We consider here issues in Photo-initiated Quantum Molecular Dynamics raised by Faraday Discussions 163, in the context of three main categories or 'pillars' of light-matter interaction: energy/time, phase/coherence, intensity. DA - 2013/07/18 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6de9e07f-f69a-49e5-bdcb-aa3329cd34e0 ER - TY - JOUR TI - Influence of lipoplex surface charge on siRNA delivery: application to the in vitro downregulation of CXCR4 HIV-1 co-receptor DO - 10.1517/14712598.2013.743526 AU - Lavigne, Carole AU - Slater, Kathryn AU - Gajanayaka, Niranjala AU - Duguay, Christian AU - Arnau Peyrotte, Erika AU - Fortier, Germaine AU - Simard, Martin AU - Kell, Arnold J. AU - Barnes, Michael L. AU - Thierry, Alain R. T2 - Expert Opinion on Biological Therapy SN - 1471-2598 VL - 13 IS - 7 SP - 973 EP - 985 KW - anti-HIV therapy, CXCR4, lipoplex charge, nanodelivery system, Neutraplex, siRNA delivery AB - Objective: Cationic lipidic formulations have been successfully used to deliver small interfering RNA (siRNA) into cells but they show limitations for in vivo application due to their cytotoxicity and instability in the presence of serum. To overcome these limitations, the authors developed an anionic lipid-based carrier named Neutraplex (Nx). Here, they wanted to investigate the influence of the lipoplex (Lx) surface charge on cytotoxicity, delivery and silencing activity of siRNAs. Methods: The efficiency of three Nx formulations (cationic, close to neutrality and anionic) to deliver anti-CXCR4 siRNAs in MAGI cells was investigated and compared with the cationic commercial transfection reagent Lipofectamine RNAiMAX. Cellular uptake and intracellular localization of a fluorescent siRNA was monitored in live cells using fluorescence microscopy and silencing activity was measured by flow cytometry and RT-PCR analysis. Results: The authors found that the Lx surface charge influenced cellular uptake and silencing activity of siRNA in cell cultures. Although cationic Lx formulations were the most efficient carriers to deliver active silencing siRNAs, negatively charged lipoplexes were taken up by cells, delivered active siRNAs and presented low cytotoxicity. Conclusions: Altogether, the findings support further investigation for in vivo delivery of therapeutic siRNAs using Nx. Furthermore, this study indicates that anionic delivery systems may have potential for in vivo RNAi therapeutics. DA - 2013/07 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : fe44888f-f9c7-478a-be32-92890ad06f90 ER - TY - JOUR TI - The dynamophore : localization of excited state dynamics studied by time-resolved photoelectron spectroscopy DO - 10.1051/epjconf/20134102037 AU - Schalk, O. AU - Boguslavskiy, A. E. AU - Schuurman, M. S. AU - Stolow, A. T2 - XVIIIth International Conference on Ultrafast Phenomena T2 - EPJ Web of Conferences; 41 T3 - 18th International Conference on Ultrafast Phenomena, UP 2012, July 8-13, 2012, Lausanne, Switzerland SN - 2101-6275 SN - 9782759809561 SP - 2037 AB - Photoinduced dynamics tend to localize at a confined region of a molecule, called dynamophore. Here, we show examples from time-resolved photoelectron spectroscopy DA - 2013/03/13 PY - 2013 PB - EDP Sciences LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b58516f8-ef3c-4ff0-88b1-239c9af56a14 ER - TY - JOUR TI - Initial processes of proton transfer in salicylideneaniline studied by time-resolved photoelectron spectroscopy DO - 10.1051/epjconf/20134102031 AU - Sekikawa, Taro AU - Schalk, Oliver AU - Wu, Guorong AU - Boguslavskiy, Andrey E. AU - Stolow, Albert T2 - EPJ Web of Conferences; 41 T3 - 18th International Conference on Ultrafast Phenomena, UP 2012, July 8-13, 2012, Lausanne, Switzerland SN - 2101-6275 SN - 9782759809561 SP - 2031 AB - Excited state intramolecular proton transfer (ESIPT) in salicylideneaniline (SA) and selected derivatives substituted in para-position of the anilino group has been investigated by femtosecond time-resolved photoelectron spectroscopy (TRPES) and time-dependent density functional theory (TDDFT). The planarity of the molecule was found to be a key parameter to describe ESIPT. © Owned by the authors, published by EDP Sciences, 2013. DA - 2013/03/13 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d7c34083-0c7e-44df-8dc7-e6a89bd194aa ER - TY - JOUR TI - Internal conversion vs. intersystem crossing: what drives the dynamics of cyclic α,β-Enones? DO - 10.1051/epjconf/20134105029 AU - Schalk, O. AU - Lang, P. AU - Schuurman, M.S. AU - Wu, G. AU - Bradler, M. AU - Riedle, E. AU - Stolow, A. T2 - XVIIIth International Conference on Ultrafast Phenomena T2 - EPJ Web of Conferences; 41 T3 - 18th International Conference on Ultrafast Phenomena, UP 2012, July 8-13, 2012, Lausanne, Switzerland SN - 2101-6275 SN - 9782759809561 SP - 5029 AB - The origin of ultrafast intersystem crossing and its competitiveness with singlet pathways was studied in cyclic α,β-enones by transient absorption, time-resolved photoelectron spectroscopy and ab initio calculations. © Owned by the authors, published by EDP Sciences, 2013. DA - 2013/03/13 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 066eff76-f8f5-46af-9741-aac1c89ae907 ER - TY - JOUR TI - When does an electron exit a tunneling barrier? DO - 10.1051/epjconf/20134102019 AU - Shafir, D. AU - Soifer, H. AU - Bruner, B. D. AU - Dagan, M. AU - Mairesse, Y. AU - Patchkovskii, S. AU - Ivanov, M. Y. AU - Smirnova, O. AU - Dudovich, N. T2 - EPJ Web of Conferences T3 - XVIIIth International Conference on Ultrafast Phenomena, UP 2012, July 8-13, 2012, Lausanne, Switzerland SN - 978-2-7598-0956-1 VL - 41 SP - 02019 AB - We probe the dynamics of tunnel ionization via high harmonic generation. We characterize the ionization dynamics in helium atoms, and apply our approach to resolve subtle differences in ionization from different orbitals of a CO 2 molecule. © Owned by the authors, published by EDP Sciences, 2013. DA - 2013/03/13 PY - 2013 PB - EDP Sciences LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c22bf364-9fac-4464-930f-f4224b22bbe6 ER - TY - JOUR TI - Fractographic examination of coupons representing aircraft structural joints with and without hole cold expansion DO - 10.1016/j.engfailanal.2012.12.008 AU - Yanishevsky, Marko AU - Li, Gang AU - Shi, Guoqin AU - Backman, David T2 - Engineering Failure Analysis SN - 1350-6307 VL - 30 SP - 74 EP - 90 KW - Aircraft structural joints; Failure analysis; Hole cold expansion; Interference fit fasteners; Spectrum fatigue testing AB - In an effort to establish the potential benefits of hole cold expansion and interference fit fasteners for long term fatigue performance, coupons representing three types of aircraft structural joints were designed, manufactured and assembled. These joints, manufactured using 7075-T6 aluminium alloys for main members and 7075-T73 for doublers or spacers, were representative of: No Load Transfer joints, simulating " non-structural" joints, such as brackets, supports for conduits, fuel lines, and wire bundles. Medium Load Transfer joints, simulating symmetrical doubler, stiffener and rib joints; and High Load Transfer joints, simulating symmetrical splices in major load carrying members. The joints were assembled using Hi-Lok™ interference fit fasteners, with and without hole cold expansion, and were fatigue tested to complete failure using a representative mission mix service load spectrum for a coastal patrol aircraft wing fatigue sensitive location. The failure surfaces were examined with the aid of an optical microscope at various magnifications. The fractographic descriptions for the three types of joints examined document the crack nucleation sites, mechanisms of crack formation, and extent of damage at catastrophic failure, including the effects of manufacturing, such as direction of hole cold expansion and direction of interference fit fastener insertion. Examination of fracture surfaces for fractographic evidence provides researchers and engineers with valuable insights into the failure process, which will enable them to perform more accurate and representative life predictions of joint performance. © 2013 Elsevier Ltd. DA - 2013/01/08 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f7240ef0-5d40-4249-ad91-f7280108a93b ER - TY - JOUR TI - Cracks formation and residual stress in chromium carbide overlays DO - 10.1016/j.engfailanal.2013.01.050 AU - Ma, Liang AU - Huang, Cheng AU - Jiang, Jiaren AU - Hui, Rob AU - Xie, Yongsong AU - Liu, Zhong-Sheng T2 - Engineering Failure Analysis SN - 1350-6307 VL - 31 SP - 320 EP - 337 KW - Chromium carbide overlays; Solidification cracks; Welding process; Finite element method; Thermal expansion and shrinkage AB - A chromium carbide overlay is often welded on the surfaces that are subject to severe wear attack, of mining equipment in order to prolong its service time. The welding causes unequal and unsynchronized thermal expansion/shrinkage between the overlay and its substrate, leading to a significant level of thermal strain/stress in the overlay. When the stress level at any location becomes higher than material strength, at that location a crack will start to form and propagate, resulting in partial release of stress. The residual stress varying by location can lead to delamination and spalling of chunks of the overlay. This paper tries to give better understanding of cracks-formation and residual stress, covering the driving force for cracks formation and residual stress, the locations where cracks initiate, the directions towards to which the cracks propagate, the resulting patterns of the cracks and the residual stress at the interfaces between the overlay and its substrate. The approach to realize this is through mechanics modeling and simulation plus experimental observations. The practical significance of this work lies in its values to improvement of welding processes and the basis for evaluating overlay quality. DA - 2013/02/15 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 377606fd-a4d7-4c38-977c-88243f826094 ER - TY - JOUR TI - Photoluminescence efficiency of germanium dots self-assembled on oxides DO - 10.1149/05301.0185ecst AU - Lockwood, David J. AU - Rowell, Nelson L. AU - Barbagiovanni, Eric G. AU - Goncharova, Lyudmila V. AU - Simpson, Peter J. AU - Berbezier, Isabelle AU - Amiard, Guillaume AU - Favre, Luc AU - Ronda, Antoine AU - Faustini, Marco AU - Grosso, David T2 - Graphene, Ge/III-V, and Emerging Materials for Post CMOS Applications 5 T2 - ECS Transactions; 53 T3 - 223rd ECS Meeting, 5th International Symposium on Graphene, Ge/III-V and Emerging Materials For Post-CMOS Applications, May 12-17, 2013, Toronto, ON, Canada SN - 1938-5862 SN - 9781607683742 SP - 185 EP - 206 KW - Absolute intensity KW - Efficiency curves KW - Energy dependence KW - Near-infrared bands KW - Photoluminescence efficiency KW - Self-assembled Ge quantum dots KW - Thermal-annealing KW - Transmission electron KW - Atomic force microscopy KW - Germanium KW - Graphene KW - Molecular beam epitaxy KW - Photoluminescence KW - Size distribution AB - Self-assembled Ge quantum dots were formed by in-situ thermal annealing of a thin amorphous Ge layer deposited by molecular beam epitaxy either on a thin porous TiO2 layer grown on SiO2 on Si(001) or directly on the SiO2 layer itself. For samples with dot diameters ranging from 10 to 35 nm, the dot photoluminescence (PL) appeared primarily as a wide near-infrared band peaked near 800 meV. The peak energy of the PL band reflects the average dot size and its shape depends on the dot size distribution. Using tight binding and effective mass theoretical models, we have analyzed the PL spectrum in terms of the dot size distribution. The observed size distribution determined from transmission electron and atomic force microscopy allowed the determination of the nonlinear increase in the PL efficiency with decreasing dot diameter. Although the absolute intensities of the PL from the samples vary, the calculated efficiency curves are all well fitted by straight lines on a log-log plot, with essentially the same slope for all samples, thereby demonstrating that under the weak confinement regime investigated here there is a universal power-law increase in PL efficiency with decreasing dot size. Knowing this generic PL efficiency, we show that it is possible to evaluate the size distribution of Ge dots from their PL energy dependence. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8934a368-0a5d-46cb-82c2-f40664ee75a4 ER - TY - JOUR TI - (Invited) Fast and slow light-emitting silicon-germanium nanostructures DO - 10.1149/05304.0003ecst AU - Lockwood, David J. AU - Wu, Xiaohua AU - Baribeau, Jean-Marc AU - Mala, Selina A. AU - Modi, Nikhil AU - Tsybeskov, Leonid T2 - Nanocrystal Embedded Dielectrics for Electronic and Photonic Devices T2 - ECS Transactions; 53 T3 - 223rd ECS Meeting, Nanocrystal Embedded Dielectrics for Electronic and Photonic Devices, May 12-16, 2013, Toronto, ON, Canada SN - 1938-5862 SN - 9781607683773 SP - 3 EP - 16 KW - Carrier recombination KW - Electron-hole droplets KW - Excitation intensity KW - Ge concentrations KW - Hetero interfaces KW - Light emitting devices KW - Linear dependence KW - SiGe quantum wells KW - Nanocrystals KW - Photonic devices KW - Semiconductor quantum wells KW - Silicon alloys KW - Three dimensional KW - Germanium AB - Epitaxially-grown three-dimensional Si/SiGe nanostructures (NSs) produce photoluminescence (PL) and electroluminescence in the desired spectral range of 1.3-1.6 μm. We show that by controlling and modifying such Ge-rich SiGe nanoclusters during growth it is possible to fabricate very fast (PL lifetime <20 ns) and hence more efficient SiGe light-emitting devices. The results presented here demonstrate that in such Si/SiGe 3D NSs with a nominal Ge concentration approaching ∼35% the PL peaked near 0.78 eV strongly depends on the Si/SiGe heterointerface abruptness. In other Si/SiGe NS/quantum-well samples with a Ge concentration approaching ∼40%, we find two PL bands peaked at ∼0.8 eV and ∼0.9 eV at low temperatures. The PL peaked at 0.8 eV rises and decays slowly, and it quickly saturates as the excitation intensity increases. In contrast, the PL peaked at 0.9 eV shows a much shorter lifetime and exhibits a linear dependence versus excitation intensity. The slow/delayed PL at 0.8 eV is attributed to carrier recombination at the SiGe NS/Si transition layer while the faster and more efficient PL at 0.9 eV is associated with SiGe quantum wells. More complicated and similarly fast (∼10-7 s) decays are observed at very high excitation intensities due to electron-hole droplet formation. The physics of carrier recombination in these Si/SiGe NSs is discussed. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c4579eca-6ea0-4023-a30b-b332292e497a ER - TY - JOUR TI - Spinel NixCo2-xO4 as a bifunctional air electrode for zinc-air batteries DO - 10.1149/04529.0105ecst AU - Yuan, Xiao Zi AU - Qu, Wei AU - Zhang, Xinge AU - Yao, Peter AU - Fahlman, Jason T2 - Batteries and Energy Technology (General) – 221st ECS Meeting T2 - ECS Transactions; 45 T3 - 221st ECS Meeting, Symposium on Batteries and Energy Technology Joint General Session, May 6-10, 2012, Seattle, WA, USA SN - 1938-5862 SN - 9781623320522 SP - 105 EP - 112 KW - Air electrodes KW - Cycling properties KW - Electrocatalytic properties KW - Oxygen evolution reaction KW - Oxygen reduction reaction KW - Rotating ring-disk electrode KW - Transfer pathway KW - Zinc-air battery KW - Design KW - Electrolytic reduction KW - Sol-gel process KW - X ray diffraction KW - Electrodes AB - Spinel NixCo2-xO4 powder was prepared through a sol-gel method and characterized by X-ray diffraction (XRD). The electrocatalytic properties of NixCo2-xO4/C composites towards the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) were studied using rotating ring-disk electrode (RDE) technique and Koutecky-Levich theory in 1 M, 3M, and 6 M KOH electrolytes. The results show that the synthesized spinel NixCo2- xO4 exhibits activities for both ORR and OER. The OER Tafel slope is around 60mVdec -1 at a low overpotential, and the ORR process is dominated by a 4-electron transfer pathway. Cell test demonstrates that the ORR activity of non-carbon NixCo2-xO4 air electrode reached 56mA cm -2 at a potential of 0.9V and the OER activity reached 62mA cm -2 at a potential of 2.2V for the first cycle However, the ORR cycling property is not satisfying due to flooding issues. This can probably be solved by an advanced air electrode design. Copyright 2013 by The Electrochemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 51d1d748-0eb0-4674-9e1f-e8f7edd90e26 ER - TY - JOUR TI - Galvanic corrosion associated with Al-B4C composites/SS304 and Al-B4C composites/AA6061 couples in NaCl and H3BO 3 solutions DO - 10.1016/j.electacta.2013.01.115 AU - Han, Yu-Mei AU - Gallant, Danick AU - Chen, X.-Grant T2 - Electrochimica Acta SN - 0013-4686 VL - 94 SP - 134 EP - 142 KW - Neutron absorber material KW - Solution composition KW - Zero resistance ammeter KW - Boric acid KW - Cathodes KW - Coupling agents KW - Dissimilar materials KW - Metallic matrix composites KW - Nuclear industry KW - Aluminum AB - Al-B4C composites are neutron absorber materials utilized in the nuclear industry that are often assembled to structural materials AA6061 or SS304, which increases the likelihood of galvanic corrosion, especially under wet storage conditions. This study investigates the galvanic corrosion behavior that may occur between Al-B4C composites and AA6061 or SS304 in NaCl and H3BO3 solutions using a zero resistance ammeter (ZRA). The effects of dissimilar materials (e.g., B4C content), immersion solution, and ratio of the coupled material areas are reported. In the NaCl solution, depending on the nature of the coupling agent (SS304 or AA6061), the composite or base alloy always acts as an anode and the measured galvanic currents are directly proportional to the cathode area. In contrast, in the H3BO3 solution, the composites preferentially dissolve in the presence of SS304, while AA6061 protects the metal matrix composites from dissolution. Although galvanic corrosion is controlled by oxygen diffusion at the cathode in both NaCl and H3BO3 solutions, its intensity is appreciably lower in the H3BO3 solution than in the NaCl solution. The B4C content is also found to play a key role in galvanic corrosion; its influence is modulated by the solution composition and the materials to which the composite is galvanically coupled. DA - 2013/01/29 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0bf3f417-ccc8-4523-9941-79b02144aed6 ER - TY - JOUR TI - Graphene-TiO2 composite supported Pt electrocatalyst for oxygen reduction reaction DO - 10.1016/j.electacta.2013.05.155 AU - Tiido, Kristiina AU - Alexeyeva, Nadezda AU - Couillard, Martin AU - Bock, Christina AU - MacDougall, Barry R. AU - Tammeveski, Kaido T2 - Electrochimica Acta SN - 0013-4686 VL - 107 SP - 509 EP - 517 KW - Electrocatalytic activity KW - Electrocatalytic behavior KW - Functionalized graphene KW - Oxygen Reduction KW - Oxygen reduction reaction KW - Pt nanoparticles KW - Pt-based catalyst KW - Rotating disk electrodes KW - Catalyst activity KW - Cyclic voltammetry KW - Electrolytic reduction KW - Graphene KW - Oxides KW - Rotating disks KW - Scanning electron microscopy KW - Titanium dioxide KW - Transmission electron microscopy KW - Platinum AB - A nano-sized Pt catalyst supported onto titanium dioxide functionalized graphene nanosheets (TiO2-FGSs) was prepared using the polyol method and utilized for a catalyst activity investigation toward the oxygen reduction reaction (ORR). The electrochemical and microscopic studies were carried out using a 40 wt.% Pt/TiO2-FGS catalyst. Cyclic voltammetry and the rotating disk electrode experiments were performed in 0.5 M H2 SO4 and 0.1 M KOH solutions in order to investigate the electrocatalytic behavior of the prepared catalysts. The composite catalyst samples were characterized by scanning electron microscopy and transmission electron microscopy showing a good dispersion of the Pt particles on the surface of the graphene supported TiO2 particles. The average Pt particle size was 11 ± 2 nm. The values of specific activity and other kinetic parameters were determined from the Tafel plots taking into account the real electroactive area of each electrode. The electrodes exhibited a relatively high electrocatalytic activity for the four-electron reduction of oxygen to water. DA - 2013/06/19 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f370d4d6-2e9e-436c-9701-6dee6a6b1d0e ER - TY - JOUR TI - Synthesis of highly active SnO2-CNTs supported Pt-on-Au composite catalysts through site-selective electrodeposition for HCOOH electrooxidation DO - 10.1016/j.electacta.2013.08.189 AU - Wang, Jianshe AU - Xi, Jingyu AU - Zhang, Lei AU - Zhang, Jiujun AU - Guo, Xun AU - Zhao, Jianhong AU - Song, Chengying AU - Wang, Liucheng T2 - Electrochimica Acta SN - 0013-4686 VL - 112 SP - 480 EP - 485 KW - Electrochemical measurements KW - Glassy carbon electrodes KW - High performance composites KW - Morphology and composition KW - Site selective KW - Thermal transformations KW - Excitons KW - Formic acid KW - Glass membrane electrodes KW - Gold deposits KW - High resolution transmission electron microscopy KW - Synthesis (chemical) KW - Tin KW - X ray diffraction KW - Platinum AB - In this paper, site-selective electrodeposition method is developed to prepare Pt-on-Au composite catalysts for HCOOH electrooxidation. In the synthesis, Au nanoparticles are prepared through reduction of NaAuCl4 by Sn(OH)2 supported on carbon nanotubes and after thermal transformation of Sn(OH)2 to SnO2, composite supports (Au/SnO2-CNTs) were obtained. By adjusting the potential of Au/SnO2-CNTs coated glassy carbon electrode, Pt entities are selectively deposited on Au particles to form SnO2-CNTs supported Pt-on-Au composite catalysts. The morphology and composition of the formed composite catalysts are characterized by instrument techniques such as X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). The site-selectivity of Pt electrodeposition on Au is confirmed by electrochemical measurements. The composite catalysts are tested to have high Pt mass activity toward HCOOH oxidation reaction, demonstrating that the synthesis method developed in this paper has promising potential for developing high performance composite catalysts. The Pt content effect on the catalytic activity is also tested for catalyst performance optimization. DA - 2013/09/14 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 7f943310-f9cc-40b1-b75c-df51d99799bf ER - TY - JOUR TI - Assessment of three techniques for delivering stem cells to the heart using PET and MR imaging DO - 10.1186/2191-219X-3-72 AU - Elhami, Esmat AU - Dietz, Bryson AU - Xiang, Bo AU - Deng, Jixian AU - Wang, Fei AU - Chi, Chao AU - Goertzen, Andrew L. AU - Mzengeza, Shadreck AU - Freed, Darren AU - Arora, Rakesh C. AU - Tian, Ganghong T2 - EJNMMI Research SN - 2191-219X VL - 3 AB - Background: Stem cell therapy has a promising potential for the curing of various degenerative diseases, including congestive heart failure (CHF). In this study, we determined the efficacy of different delivery methods for stem cell administration to the heart for the treatment of CHF. Both positron emission tomography (PET) and magnetic resonance imaging (MRI) were utilized to assess the distribution of delivered stem cells. Methods: Adipose-derived stem cells of male rats were labeled with super-paramagnetic iron oxide (SPIO) and 18 F-fluorodeoxyglucose (FDG). The left anterior descending coronary artery (LAD) of the female rats was occluded to induce acute ischemic myocardial injury. Immediately after the LAD occlusion, the double-labeled stem cells were injected into the ischemic myocardium (n = 5), left ventricle (n = 5), or tail vein (n = 4). In another group of animals (n = 3), the stem cells were injected directly into the infarct rim 1 week after the LAD occlusion. Whole-body PET images and MR images were acquired to determine biodistribution of the stem cells. After the imaging, the animals were euthanized and retention of the stem cells in the vital organs was determined by measuring the cDNA specific to the Y chromosome. Results: PET images showed that retention of the stem cells in the ischemic myocardium was dependent on the cell delivery method. The tail vein injection resulted in the least cell retention in the heart (1.2% ± 0.6% of total injected cells). Left ventricle injection led to 3.5% ± 0.9% cell retention and direct myocardial injection resulted in the highest rate of cell retention (14% ± 4%) in the heart. In the animals treated 1 week after the LAD occlusion, rate of cell retention in the heart was only 4.5% ±1.1%, suggesting that tissue injury has a negative impact on cell homing. In addition, there was a good agreement between the results obtained through PET-MR imaging and histochemical measurements. Conclusion: PET-MR imaging is a reliable technique for noninvasive tracking of implanted stem cells in vivo. Direct injection of stem cells into the myocardium is the most effective way for cell transplantation to the heart in heart failure models. DA - 2013/10/28 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4701d240-bf02-468b-bc46-3b3a0e3be676 ER - TY - JOUR TI - Temperature effects on kinetics of paralytic shellfish toxin elimination in Atlantic surfclams, Spisula solidissima DO - 10.1016/j.dsr2.2013.05.014 AU - Bricelj, V. Monica AU - Cembella, Allan D. AU - Laby, David T2 - Deep-Sea Research Part II: Topical Studies in Oceanography SN - 0967-0645 AB - Surfclams, Spisula solidissima, pose a particular health risk for human consumption as they are characterized by accumulation of extremely high levels of toxins associated with paralytic shellfish poisoning (PSP), slow toxin elimination and an extremely high post-ingestive capacity for toxin bioconversion. Surfclam populations experience a wide range of temperatures along the NW Atlantic continental shelf, and are undergoing range contraction that has been attributed to global warming. In this study the influence of temperature (5, 12 and 21 °C) on detoxification kinetics of individual PSP toxins in two tissue compartments of juvenile surfclams (∼35 mm shell length) was determined under controlled laboratory conditions, over prolonged (2.4 months) depuration. Clams were toxified with a representative regional Gulf of Maine isolate of the dinoflagellate Alexandrium fundyense of known toxin profile, allowing tracking of changes in toxin composition and calculated toxicity in surfclam tissues. The visceral mass detoxified at all temperatures, although toxin loss rate increased with increasing temperature. In contrast, total toxin content and calculated toxicities in other tissues remained constant or even increased during depuration, suggesting a physiological or biochemical toxin-retention mechanism in this tissue pool and temperature-independent detoxification. In vivo toxin compositional changes in surfclam tissues found in this study provide evidence of specific toxin conversion pathways, involving both reductive and decarbamoylation pathways. We conclude that such toxin biotransformations, especially in non-visceral tissues, may introduce a discrepancy in describing kinetics of total toxicity (in saxitoxin equivalents [STXeq]) of S. solidissima over prolonged detoxification. Nevertheless, use of total toxicity values generated by routine regulatory monitoring based upon mouse bioassays or calculated from chemical analytical determination of molar toxin concentrations is adequate for first-order modeling of toxin kinetics in this species. Furthermore, the differential detoxification response of viscera and other tissues in relation to temperature emphasizes the need for two-compartment modeling to describe the fate of PSP toxins in this species. Finally, key parameters were identified that may prove useful in hindcasting the timing of toxic blooms or new toxin input in deep offshore waters where routine monitoring of toxic phytoplankton is impractical. DA - 2013/05/18 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 88393707-85f1-4f81-bf68-66b27e866f96 ER - TY - JOUR TI - Macromolecular structure comparison and docking: an algorithmic review DO - 10.2174/1381612811319120006 AU - Paquet, Eric AU - Viktor, Herna L. T2 - Current Pharmaceutical Design SN - 1381-6128 VL - 19 IS - 12 SP - 2183 EP - 2193 KW - Macromolecular structures, docking, protein-protein interaction, alignment, algorithms, drug designers, comparison, Bayesian framework, kernel-based methods, projection-based techniques AB - The comparison of macromolecular structures, in terms of functionalities, is a crucial step when aiming to identify potential docking sites. Drug designers require the identification of such docking sites for the binding of two proteins, in order to form a stable complex. This paper presents a review of current approaches to macromolecular structure comparison and docking, following an algorithmic approach. We describe techniques based on the Bayesian framework, kernel-based methods, projection-based techniques and spectral approaches. We introduce the use of quantum particle swarm optimization, in order to aid us to find the most appropriate docking sites. We discuss the importance of the heat and Schrödinger equations to address the non-rigid nature of proteins and highlight the strengths and limitations of the various methods. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2581777b-164c-4529-a40d-ccf6df4af3c1 ER - TY - JOUR TI - Structural assessment of anhydrous sulfates with high field 33S solid state NMR and first principles calculations DO - 10.1039/c3ce41233d AU - Pallister, Peter J. AU - Moudrakovski, Igor L. AU - Enright, Gary D. AU - Ripmeester, John A. T2 - CrystEngComm SN - 1466-8033 VL - 15 IS - 43 SP - 8808 EP - 8822 AB - A combination of solid state NMR, first principles calculations and single crystal XRD was applied to relate solid state 33S NMR parameters obtained from a series of anhydrous sulfates of the elements of groups I-III. Operating at high magnetic field of 21.14 T provides a dramatic improvement in the quality of spectra due to significantly enhanced sensitivity and a reduction of second order quadrupolar effects. Experimental 33S NMR spectra for most studied sulfates are dominated by quadrupolar interactions with the quadrupolar parameters unique for each compound. Magnetic shielding constants and quadrupolar parameters for sulfur were calculated using plane wave pseudo-potential density functional theory as implemented in the CASTEP computational package. The calculated NMR parameters are in very good agreement with the experimental results and help in assignment of the stationary spectra. The results demonstrate that such a combined computational-experimental solid state NMR approach can aid in an assessment and improved interpretation of the crystallographic data. DA - 2013/10/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e19f27c5-3878-4c95-af85-75471ddf79ed ER - TY - CHAP TI - USNCCM-11: computational fluid mechanics for free and moving boundary problems DO - 10.1016/j.compfluid.2013.09.023 AU - Rao, Rekha R. AU - Roberts, S. A. AU - Noble, David R. AU - Anderson, Patrick D. AU - Hétu, Jean-François T2 - Computers and Fluids SN - 0045-7930 VL - 87 SP - 1 DA - 2013/10/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 11f96928-d1ce-471f-9130-27137294a752 ER - TY - JOUR TI - An immersed boundary-body conformal enrichment method for thermal flow problems DO - 10.1016/j.compfluid.2013.10.026 AU - Ilinca, F. AU - Hétu, J.-F. T2 - Computers and Fluids SN - 0045-7930 VL - 88 SP - 616 EP - 628 KW - Body conformal enrichments KW - Complex conjugates KW - Finite-element discretization KW - Immersed boundary methods KW - Interface elements KW - Level-set function KW - Multiple materials KW - Solution algorithms KW - Cylinder configurations KW - Cylinders (shapes) KW - Finite element method KW - Heat flux KW - Heat transfer KW - Thermodynamic properties KW - Turbulent flow KW - Interfaces (materials) AB - Solving the flow around objects with complex shapes may involve extensive meshing work that has to be repeated each time a change in the geometry is needed. The same problem arises if one need to solve the heat transfer involving multiple materials whose interface is complex or changes with time. Time consuming meshing can be avoided when the solution algorithm can tackle grids that do not fit the shape of the interface between different materials. This work presents the extension of a recently proposed immersed boundary-body conformal enrichment (IB-BCE) method to the solution of the heat transfer. The method produces solutions of the temperature field satisfying accurately the continuity of the normal heat flux at interfaces between materials with different thermal properties. As for the isothermal flow problems, the fluid/solid interface is defined using a level-set function and the finite element discretization of interface elements is enriched with additional degrees of freedom which are eliminated at element level. The method is first validated in the case of heat conduction in two solids with different thermal properties. Then, solutions are shown for the more complex conjugate heat transfer between water and aluminum for two configurations: steady state flow inside a channel obstructed by a heated cylinder and transient flow around a heated cylinder. For each problem the solutions obtained using the proposed immersed boundary method are compared with solutions on body-conformal meshes having comparable mesh size distribution. The proposed approach is very accurate and effective in capturing the sharp discontinuity in the normal temperature gradient at the interface. DA - 2013/10/30 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 37a16683-495e-40dc-a4c9-da0853e7206f ER - TY - JOUR TI - B-spline surface based concept design module for applications in virtual reality environment DO - 10.3722/cadaps.2013.247-263 AU - Pungotra, Harish AU - Knopf, George K. AU - Canas, Roberto T2 - Computer-Aided Design and Applications SN - 1686-4360 VL - 10 IS - 2 SP - 247 EP - 263 KW - concept design, deformable model, virtual reality, blending matrices AB - Over the past decade, B-spline modeling has become the standard mathematical model for representing freeform or organic objects in CAD/CAM systems. Using a Bspline surface to represent the virtual model in a haptic concept design module helps to streamline the exchange of the information with existing CAD/CAM systems. Bspline surfaces also help increase visual realism because these represent continuous surface. At the same time, physically based virtual deformable models provide a sense of realism to the user. However, the algorithms used for interaction with the virtual model should be efficient to maintain acceptable level of virtual realism and perceive the simulation as continuous with no time lag. This paper presents a B-spline surface based concept design framework, which can be used to generate various concepts, evaluate these concepts, and provide user training. The proposed framework assumes that all deformable models are represented as B-spline surfaces. The tools used to interact with the deformable models can be implicit surface, tessellated surface, Bspline surface, or point-based. The technique exploits blending matrices for the Bspline surface that are independent of the control point positions and, hence, can be pre-calculated prior to haptic interaction. Once determined, the pre-calculated blending matrices are used to generate discrete points on the B-spline surface. Mass spring system is used to incorporate material properties to the virtual objects. Practical illustrations of the concept design framework are presented for modeling and evaluation of concepts and provide training to the intended user segment. DA - 2013/08/09 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a4ead78f-227f-4e83-933a-527d656029a4 ER - TY - JOUR TI - An alternative methodology to represent B-spline surface for applications in virtual reality environment DO - 10.3722/cadaps.2013.711-726 AU - Pungotra, Harish AU - Knopf, George K. AU - Canas, Roberto T2 - Computer-Aided Design and Applications SN - 1686-4360 VL - 10 IS - 4 SP - 711 EP - 726 KW - B-spline representation KW - Collision detection KW - Computational costs KW - Deformable object KW - Mass spring systems KW - Physics-based modeling KW - Physics-based models KW - Virtual-reality environment KW - Blending KW - Deformation KW - Matrix algebra KW - Virtual reality KW - Interpolation AB - B-spline representation is one of the main methods for free-form surface modeling and has become the standard for CAD systems. However, in Virtual Reality (VR) environment, when a B-spline surface deforms, the blending functions need to be continuously computed. The high computational cost of continuously calculating the blending functions for merging, collision detection and physics-based deformation system, while the model is deforming, restricts the use of B-spline representation in a VR environment. This paper presents an alternative methodology to represent B-spline surface patches for an interactive VR environment. A uniformly discretized B-spline surface patch can be represented by a set of control points and two precalculated B-spline blending matrices. The proposed technique exploits the fact that these B-spline blending matrices are independent of the position of control points and therefore can be pre-calculated. The blending matrices enable the algorithm to merge B-spline surface patches, accurately check the collision, and generate nodes for the mass spring system to determine deformation using the physics-based model. This technique does away with the need to calculate computationally intensive blending functions for the Bspline surfaces, and inverse of large matrices during the run-time. DA - 2013/08/09 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a637c6f4-d172-40b9-bbf9-e06a10e31140 ER - TY - JOUR TI - Computing lexical contrast DO - 10.1162/COLI_a_00143 AU - Mohammad, Saif M. AU - Dorr, Bonnie J. AU - Hirst, Graeme AU - Turney, Peter D. T2 - Computational Linguistics SN - 0891-2017 VL - 39 IS - 3 SP - 556 EP - 589 AB - Knowing the degree of semantic contrast between words has widespread application in natural language processing, including machine translation, information retrieval, and dialogue systems. Manually created lexicons focus on opposites, such as hot and cold. Opposites are of many kinds such as antipodals, complementaries, and gradable. Existing lexicons often do not classify opposites into the different kinds, however. They also do not explicitly list word pairs that are not opposites but yet have some degree of contrast in meaning, such as warm and cold or tropical and freezing. We propose an automatic method to identify contrasting word pairs that is based on the hypothesis that if a pair of words, A and B, are contrasting, then there is a pair of opposites, C and D, such that A and C are strongly related and B and D are strongly related. (For example, there exists the pair of opposites hot and cold such that tropical is related to hot, and freezing is related to cold.) We will call this the contrast hypothesis. We begin with a large crowdsourcing experiment to determine the amount of human agreement on the concept of oppositeness and its different kinds. In the process, we flesh out key features of different kinds of opposites. We then present an automatic and empirical measure of lexical contrast that relies on the contrast hypothesis, corpus statistics, and the structure of a Roget-like thesaurus. We show how, using four different data sets, we evaluated our approach on two different tasks, solving "most contrasting word" questions and distinguishing synonyms from opposites. The results are analyzed across four parts of speech and across five different kinds of opposites. We show that the proposed measure of lexical contrast obtains high precision and large coverage, outperforming existing methods. DA - 2013/07/16 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 7cfdb17a-8fca-4cdc-a63a-083d58385d6d ER - TY - JOUR TI - Thermal, oxygen barrier and mechanical properties of polylactide-organoclay nanocomposites DO - 10.1016/j.compscitech.2013.03.015 AU - Yourdkhani, Mostafa AU - Mousavand, Tahereh AU - Chapleau, Nathalie AU - Hubert, Pascal T2 - Composites Science and Technology SN - 0266-3538 VL - 82 SP - 47 EP - 53 KW - Clay concentration KW - Clay dispersion KW - Dispersion quality KW - Melt intercalation KW - Optimum concentration KW - Oxygen permeability KW - Poly lactide KW - Contact angle KW - Dispersions KW - Organoclay KW - Oxygen permeable membranes KW - Polyesters KW - Transmission electron microscopy KW - Nanocomposites AB - Polylactide (PLA) nanocomposites reinforced with commercially available organoclays, Nanomer I.28E and Nanomer I.34TCN, were prepared using a melt intercalation technique. In this work, two different clay concentrations (2 and 4. wt.%) were considered. The morphology of the resulting nanocomposites was observed by TEM micrographs while the interaction between polymer and clay was measured by FTIR analysis and contact angle measurements. Better dispersion quality and interaction with the polymer matrix was observed for I.34TCN organoclay. The effect of clay dispersion and its interaction with PLA was investigated by measuring the thermal, oxygen barrier and mechanical properties of the prepared nanocomposites; consequently, higher improvements were observed in the properties of nanocomposites containing I.34TCN compared to the I.28E counterpart. Besides, 2. wt.% clay content was found as an optimum concentration for enhancing the different properties of the resulting nanocomposites with respect to neat PLA. However, higher improvements in oxygen permeability and tensile modulus were achieved by embedding 4. wt.% organoclay into the PLA matrix. DA - 2013/03/28 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3e2141bc-0429-462e-bb87-1d57901011bc ER - TY - JOUR TI - Polyphenylene sulfide (PPS) composites reinforced with recycled carbon fiber DO - 10.1016/j.compscitech.2013.05.005 AU - Stoeffler, Karen AU - Andjelic, Stefan AU - Legros, Nathalie AU - Roberge, Judith AU - Schougaard, Steen B. T2 - Composites Science and Technology SN - 0266-3538 VL - 84 SP - 65 EP - 71 KW - Carbon fiber reinforced KW - E. Extrusion KW - Impact property KW - Mechanical and physical properties KW - Polymer Matrix Composites (PMCs) KW - Polymeric matrices KW - Polyphenylene sulfides KW - Thermoset composites KW - Aerospace industry KW - Mechanical properties KW - Polypropylenes KW - Thermogravimetric analysis KW - Thermosets KW - Recycling AB - Recycled carbon fibers were reclaimed by commercial scale pyrolysis from carbon fiber reinforced thermoset composite waste generated by the aerospace industry. The mechanical and physical properties of the reclaimed carbon fibers were shown to be comparable to those of aerospace grade virgin carbon fibers. The recycled carbon fibers were integrated into a polyphenylene sulfide (PPS) thermoplastic resin by twin screw compounding followed by injection molding. Composites containing 20. wt.% and 40. wt.% recycled carbon fibers were produced. Overall, the fibers were found to be uniformly dispersed in the polymeric matrix. The tensile, flexural and impact properties of the composites were evaluated. The recycled carbon fiber reinforced PPS composites exhibited comparable mechanical properties to equivalent compounds produced using industrial grades of short virgin carbon fiber. In addition, thermogravimetric analysis showed that the introduction of recycled carbon fibers was not detrimental to the inherent thermal stability of PPS. DA - 2013/05/16 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 330e55af-8312-415e-b260-a3d968e13e2e ER - TY - JOUR TI - Multidisciplinary characterization of new shield with metallic nanoparticles for composite aircrafts DO - 10.1016/j.compositesb.2013.02.043 AU - Jalali, M. AU - Molière, T. AU - Michaud, A. AU - Wuthrich, R. T2 - Composites Part B: Engineering SN - 1359-8368 VL - 50 SP - 309 EP - 317 KW - Aeronautic applications KW - Aircraft structure KW - High frequency HF KW - Mechanical behavior KW - Personal electronic devices KW - Polymer Matrix Composites (PMCs) KW - Aerodynamics KW - Aerospace applications KW - Aircraft manufacture KW - Airframes KW - Electromagnetic pulse KW - Electromagnetic shielding KW - Electron microscopy KW - Mechanical testing KW - Optical microscopy KW - Polymer matrix composites KW - Thermoanalysis AB - Because of major advantages (e.g. weight saving, maintenance advantages), the airframe manufacturers use more and more Polymer Matrix Composites (PMCs) in different parts of aircraft structures. But PMCs have a substantial disadvantage of low conductivity and therefore low Electromagnetic (EM) Shielding. Electromagnetic Interference (EMI) sources are all around and inside aircraft and can potentially threat the immunity of aircraft. Metallic meshes have been used to overcome this shortage. However in high frequencies most of the mentioned methods loose their performances. Regrettably on one side most of the present and upcoming systems onboard of aircraft are functional in mentioned range of frequencies. On the other side, passengers use more and more Personal Electronic Devices (PEDs) onboard of aircraft. Interferences caused by PEDs are also in the same range of frequencies. Measured susceptibility caused by PEDs is higher in composite aircrafts comparing to metallic ones. To overcome this back door lack of composite aircrafts, design of a new light weight shield particularly for aeronautic application is needed. Metallic nanoparticles have a great potential to be used as new EM shields for aerospace applications, particularly in high frequencies. Without multidisciplinary characterization of new shield, the application onboard would be suspended. Here the encouraging results of EM characterization are presented. Thermal, microscopy and mechanical tests are also performed. Based on acquired results in this work, thermal and mechanical behaviors as well as distribution of particles are all acceptable. The promising results obtained in this work can assure the designers on using metallic nanoparticles as a new shield for protection of composite aircrafts. DA - 2013/03/14 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f245f41f-2b5a-4876-9c04-209abe848b7b ER - TY - JOUR TI - Effects of dietary cholesterol on astaxanthin transport in plasma of Atlantic salmon (Salmo salar) DO - 10.1016/j.cbpb.2013.02.007 AU - Chimsung, N. AU - Lall, S. P. AU - Tantikitti, C. AU - Verlhac-Trichet, V. AU - Milley, J. E. T2 - Comparative Biochemistry and Physiology - B Biochemistry and Molecular Biology SN - 1096-4959 VL - 165 IS - 1 SP - 73 EP - 81 KW - high density lipoprotein cholesterol KW - low density lipoprotein cholesterol KW - very low density lipoprotein KW - absorption KW - blood sampling KW - density gradient centrifugation KW - dietary intake KW - fish KW - nonhuman KW - polyacrylamide gel electrophoresis KW - separation technique KW - sucrose density gradient centrifugation KW - Animals KW - Cholesterol, Dietary KW - Cholesterol, VLDL KW - Lipoproteins KW - Lipoproteins, HDL KW - Xanthophylls AB - The effect of dietary cholesterol on astaxanthin (Ax) absorption and transport in the plasma of Atlantic salmon was investigated. Under controlled conditions, three experimental diets, non-pigmented diet (NPD), NPD with 40mg Axkg-1, and NPD with 40mg Axkg-1 and 2% cholesterol, were fed to juvenile salmon reared in sea water. After 12weeks, blood was collected and plasma separated for analysis of plasma Ax and cholesterol content. In addition, plasma samples from each group of fish were fractionated into lipoproteins using a sucrose density gradient and ultracentrifugation. The apolipoprotein components of VLDL, LDL and HDL from each sample fraction were separated using SDS-PAGE. The addition of 2% cholesterol to the Ax-containing diet significantly increased the concentration of Ax and cholesterol in fish plasma. The protein-rich fraction was found to be the major carrier of Ax in salmon plasma. Cholesterol supplementation significantly increased Ax in plasma and VLDL as well as increasing plasma cholesterol. The VLDL fraction showed the most significant change in fish fed diet supplemented with cholesterol resulting in higher levels of Ax in this lipoprotein. The results clearly show that dietary cholesterol had a significant effect on the Ax transport process in the blood. DA - 2013/03/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 02c1e43f-ec53-44e5-a143-f5289b14d3e2 ER - TY - JOUR TI - Bacterial community evidence for anaerobic degradation of petroleum hydrocarbons in cold climate groundwater DO - 10.1016/j.coldregions.2012.10.013 AU - Yeung, C. William AU - Van Stempvoort, Dale R. AU - Spoelstra, John AU - Bickerton, Greg AU - Voralek, John AU - Greer, Charles W. T2 - Cold Regions Science and Technology SN - 0165-232X VL - 86 SP - 55 EP - 68 KW - DGGE KW - Hydrocarbon contamination KW - Hydrocarbon degradation KW - Microbial diversity KW - Nitrate reduction KW - Biodegradation KW - Bioremediation KW - Chemical analysis KW - Electrophoresis KW - Fuel tanks KW - Genes KW - Groundwater pollution KW - Hydrocarbons KW - Manganese KW - Nitrates KW - Petroleum chemistry KW - RNA KW - Hydrochemistry KW - Anoxic conditions KW - Bacterium KW - Biodegradation KW - Community structure KW - Fractured medium KW - Microbial community KW - Reduction KW - Sulfate KW - Canada KW - Canadian Shield KW - Northwest Territories KW - Bacteria (microorganisms) KW - Geobacter KW - Pseudomonas KW - Thiobacillus AB - There is currently limited scientific data to assess whether groundwater bacterial communities in fractured rock environments can degrade petroleum hydrocarbon plumes in cold regions. The former Colomac Mine is located in the Canadian Shield in the Northwest Territories (mean annual air temperature of -. 5°C) and is currently listed on the Federal Contaminated Sites inventory. Groundwater in fractured rock beneath the former fuel tank-farm at the mine site is contaminated by petroleum hydrocarbons. The objectives of this study were to investigate the bacterial community structure in the groundwater associated with hydrocarbon contamination, and to probe for potential anaerobic microbial processes involved in intrinsic bioremediation. Groundwater monitoring wells previously installed at the site were used to collect samples for chemical, isotopic and microbial analyses. Denaturing gradient gel electrophoresis (DGGE) analysis identified a relatively high bacterial diversity in the least contaminated locations, but as the hydrocarbon contamination increased, bacterial diversity decreased. Sequence analysis of the 16S rRNA gene demonstrated that the bacteria belonged to a wide range of genera, such as Pseudomonas, Thiobacillus, and Geobacter, all of which have been associated with the anaerobic degradation of hydrocarbons. Two putative nitrate-reducing genes were detected in samples with high nitrate reducing activity. Both chemical and microbiological results indicated the presence of microbial anaerobic processes by using nitrate, manganese(IV), ferric iron and sulfate as electron acceptors and suggest that these anaerobic processes play an important role in the biodegradation of dissolved petroleum hydrocarbons in the groundwater at the Colomac site. Our results also revealed that more than one biogeochemical process linked to hydrocarbon degradation could be present in a single borehole and these processes could vary spatially at this site. DA - 2013/11/14 PY - 2013 LA - eng N1 - Erratum published in volume 89, page 48, May 2013. DOI: 10.1016/j.coldregions.2013.01.007 C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 25d67768-c808-4c0f-88c2-94c5bbb4501c ER - TY - JOUR TI - Revisiting the Sanderson pressure-area curve: Defining parameters that influence ice pressure DO - 10.1016/j.coldregions.2013.08.005 AU - Timco, G. W. AU - Sudom, D. T2 - Cold Regions Science and Technology SN - 0165-232X VL - 95 SP - 53 EP - 66 KW - Contact areas KW - Geometric area KW - Ice interactions KW - Ice properties KW - Ice-structure interaction KW - Number of datum KW - Offshore KW - Pressure area KW - Aspect ratio KW - Design KW - Offshore structures KW - Pressure KW - Sea ice KW - Structure (composition) KW - Loading AB - There is a strong perception in the ice mechanics community that during ice-structure interaction, the ice pressure always decreases as the area of contact increases. This understanding is often based on the pressure-area plot published by Sanderson (1988), which combines a large number of data sources and ice interaction situations on a single plot and shows a definite decrease in pressure with increasing area. This paper examines the data sources in the Sanderson plot as well as some more recent data, and discusses the definitions of global, local, spatial and process pressure-area. It is found that the pressure over a defined local geometric area or over the full global ice contact area can either show no dependence on area or a decrease with increasing area, depending on the interaction scenario. Factors other than area are examined to determine their influence on pressure including the loading rate, aspect ratio, ice failure mode, and ice properties. It is shown that in many cases, these factors are more important than the area in predicting ice pressure. The theory of Palmer et al. (2009) provides a reasonable explanation for some of the observed trends in pressure-area behavior. Examples from field data are provided to illustrate the application of pressure-area relationships for offshore structures in icy waters. DA - 2013/08/22 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1ff5874c-b939-4bca-aa67-1b493afa4179 ER - TY - JOUR TI - Modulation of fatty acid synthase enzyme activity and expression during hepatitis C virus replication DO - 10.1016/j.chembiol.2013.03.014 AU - Nasheri, Neda AU - Joyce, Michael AU - Rouleau, Yanouchka AU - Yang, Pengyu AU - Yao, Shao AU - Tyrrell, D. Lorne AU - Pezacki, John Paul T2 - Chemistry and Biology SN - 1074-5521 VL - 20 IS - 4 SP - 570 EP - 582 AB - The hepatitis C virus (HCV) induces alterations of host cells to facilitate its life cycle. Fatty acid synthase (FASN) is a multidomain enzyme that plays a key role in the biosynthesis of fatty acids and is upregulated during HCV infection. Herein, we applied activity-based protein profiling (ABPP) that allows for the identification of differentially active enzymes in complex proteomic samples, to study the changes in activity of FASN during HCV replication. For this purpose, we used an activity-based probe based on the FASN inhibitor Orlistat, and observed an increase in the activity of FASN in the presence of a subgenomic and a genomic HCV replicon as well as in chimeric SCID/Alb-uPA mice infected with HCV genotype 1a. To study the molecular basis for this increase in FASN activity, we overexpressed individual HCV proteins in Huh7 cells and observed increased expression and activity of FASN in the presence of core and NS4B, as measured by western blots and ABPP, respectively. Triglyceride levels were also elevated in accordance with FASN expression and activity. Lastly, immunofluorescence and ABPP imaging analyses demonstrated that while the abundance and activity of FASN increases significantly in the presence of HCV, its localization does not change. Together these data suggest that the HCV-induced production of fatty acids and neutral lipids is provided by an increase in FASN abundance and activity that is sufficient to allow HCV propagation without transporting FASN to the replication complexes. DA - 2013/04/18 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2cf64c45-974d-483b-957d-7d1003fad928 ER - TY - JOUR TI - A combined ultra-wideline solid-state NMR and DFT study of 137Ba electric field gradient tensors in barium compounds DO - 10.1016/j.cplett.2013.02.040 AU - O'Dell, Luke A. AU - Moudrakovski, Igor L. T2 - Chemical Physics Letters SN - 0009-2614 VL - 565 SP - 56 EP - 60 KW - Crystallographic sites KW - DFT calculation KW - DFT study KW - Electric field gradient tensors KW - NMR spectrum KW - Pulse sequence KW - Solid state NMR KW - Density functional theory KW - Electric fields KW - Nuclear magnetic resonance spectroscopy KW - Barium compounds AB - Ultra-wideline 137Ba solid-state (SS) NMR spectra have been obtained from a series of five barium compounds (BaSO4, BaMoO 4, Ba(CH3COO)2, Ba(OH)2· 8H2O and α-Ba2P2O7), using the broadband WURST-QCPMG pulse sequence and magnetic field of 21.1 T. The signals from the two distinct crystallographic sites in α-Ba2P 2O7 are resolved, with one of them demonstrating a C Q of 42.3 ± 0.3 MHz, the largest obtained for 137Ba in a powder. The quadrupolar parameters reported in this work are in excellent agreement with the DFT calculations and correlate well with those previously reported by Hamaed et al. (2010) [24]. DA - 2013/02/26 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : fb22e484-68e6-4a91-bfd0-51a1a8808e2c ER - TY - JOUR TI - Infrared spectrum of the CS2 tetramer: observation of a structure with D2d symmetry DO - 10.1016/j.cplett.2013.03.074 AU - Rezaei, M. AU - Norooz Oliaee, J. AU - Moazzen-Ahmadi, N. AU - McKellar, A. R. W. T2 - Chemical Physics Letters SN - 0009-2614 VL - 570 SP - 12 EP - 15 KW - Energy isomers KW - Fundamental bands KW - High resolution KW - Infrared spectrum KW - Intermolecular potentials KW - Jet expansion KW - Spectroscopic detection KW - Symmetric rotors KW - Isomers KW - Nitrogen oxides KW - Spectroscopy KW - Supersonic aerodynamics KW - Oligomers AB - Infrared spectra of carbon disulfide clusters are studied in the region of the CS2 ν3 fundamental band (≈1535 cm-1), using a tuneable diode laser to probe a pulsed supersonic slit jet expansion. A symmetric rotor parallel band at 1551.438 cm-1 is assigned to CS2 tetramer. The likely structure is a staggered and tilted barrel with D2d symmetry, similar to the previously observed oblate tetramer of nitrous oxide, and in reasonable agreement with that calculated from an empirical CS2 intermolecular potential function. This is the first high-resolution spectroscopic detection of CS2 tetramer, and the calculations suggest that there could be other low energy isomers of (CS2)4 which are not yet observed. DA - 2013/04/03 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 758cf5b8-0db0-470b-bc3f-043ecc236711 ER - TY - JOUR TI - The structure and optical absorption of single source precursors for II-VI quantum dots DO - 10.1016/j.cplett.2013.03.029 AU - Wang, Xinqin AU - Zeng, Qun AU - Shi, Jing AU - Jiang, Gang AU - Yang, Mingli AU - Liu, Xiangyang AU - Enright, Gary AU - Yu, Kui T2 - Chemical Physics Letters SN - 0009-2614 VL - 568-569 SP - 125 EP - 129 KW - Blue-shifted KW - Cadmium selenides KW - Covalent bonding KW - Density functional theory calculations KW - HOMO-LUMO transitions KW - II-VI quantum dots KW - Ligand-free KW - Single-source precursor KW - Cadmium compounds KW - Cadmium sulfide KW - Chemical bonds KW - Density functional theory KW - Electron transitions KW - Electronic structure KW - Semiconducting selenium compounds KW - Light absorption AB - Starting from its measured structure, the electronic structures and optical absorptions of CdSe single source precursor, cadmium bis(diselenophosphinate) (CSP), have been studied by means of density functional theory calculations. In contrast to covalent bonding in ligand-free cadmium selenide, the Cd-Se bonds in CSP are featured by the coordination of the 4p electrons of Se atoms, resulting in low net charge on Cd and blue shifted electron transitions. The ligands not only stabilize the CdSe core but also affect the HOMO-LUMO transition. Computations were extended to the corresponding ZnSe and CdS complexes and came to similar conclusions. DA - 2013/03/19 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b9215333-b5e6-4893-ace0-18f58c025b1b ER - TY - JOUR TI - Reprint of: Neon interatomic potentials from scattering data and crystalline properties DO - 10.1016/j.cplett.2013.08.059 AU - Farrar, J. M. AU - Lee, Y. T. AU - Goldman, V. V. AU - Klein, M. L. T2 - Chemical Physics Letters SN - 0009-2614 VL - 589 SP - 14 EP - 16 AB - Interatomic potentials for Ne2 derived from recent differential elastic scattering cross section measurements and properties of solid neon are presented. Cross sections and second virial coefficients are calculated with the proposed potentials and comparisons with experiment are made. The Ne2 potential derived from scattering data only is shown to provide a good fit to the solid state data. DA - 2013/08/21 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 21eeec90-385e-4070-87e0-971cd7462bb8 ER - TY - JOUR TI - Electronic spectra and excited-state dynamics of 4-fluoro-N,N- dimethylaniline DO - 10.1016/j.cplett.2013.09.028 AU - Fujiwara, Takashige AU - Reichardt, Christian AU - Vogt, R. Aaron AU - Crespo-Hernández, Carlos E. AU - Zgierski, Marek Z. AU - Lim, Edward C. T2 - Chemical Physics Letters SN - 0009-2614 VL - 586 SP - 70 EP - 75 KW - Dual fluorescence KW - Electronic spectrum KW - Electronic transition KW - Excited-state dynamics KW - Intramolecular charge transfers KW - Room temperature KW - Thermal equilibriums KW - Twisted intra-molecular charge transfers KW - Physical chemistry KW - Charge transfer AB - Concerted ultrafast time-resolved spectroscopic experiments and ab initio computational (TDDFT) studies of the electronic transitions of 4-fluoro-N,N-dimethylaniline (FDMA) have been performed to investigate the mechanism of photo-induced intramolecular charge transfer (ICT). The compound FDMA shows dual fluorescence from a ππ state and a closely-lying twisted intramolecular charge transfer (TICT) state in both n-hexane and acetonitrile. The very similar lifetimes observed for the two emission bands indicate that the ππ* and the TICT states are effectively in thermal equilibrium at room temperature. DA - 2013/09/18 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 02a63f88-05c4-415e-99e6-57f4aef8c2a4 ER - TY - JOUR TI - New interpretation of proton and deuteron tunneling in 2′- methylacetophenone DO - 10.1016/j.cplett.2013.09.020 AU - Fernández-Ramos, Antonio AU - Siebrand, Willem AU - Smedarchina, Zorka T2 - Chemical Physics Letters SN - 0009-2614 VL - 586 SP - 61 EP - 66 KW - First principles KW - Interconversions KW - Proton tunneling KW - Rotamers KW - Transition rates KW - Rate constants KW - Protons AB - The enol-keto transition rate constants in 2′-methylacetophenone observed by Grellmann et al. [3] are calculated from first principles. The results reinterpret the proposed mechanism and show that proton tunneling is preceded by dissociation of a substrate-solvent complex rather than by rotamer interconversion. DA - 2013/10/24 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 7c332cb3-8a8a-41e2-9f75-db3d40bc8ad6 ER - TY - JOUR TI - Effect of ammonia gas addition to the synthesis environment of single-walled carbon nanotubes on their surface chemistry DO - 10.1016/j.cej.2013.06.062 AU - Shahverdi, Ali AU - Soucy, Gervais AU - Simard, Benoit AU - Mostaghimi, Javad T2 - Chemical Engineering Journal SN - 1385-8947 VL - 230 SP - 80 EP - 92 KW - Ammonia chemisorption KW - Ammonia decomposition KW - Concentration profiles KW - Induction thermal plasma KW - Semiconducting tubes KW - Single-walled carbon nanotubes (SWCNTs) KW - Singlewalled carbon nanotube (SWCNT) KW - Two-step reaction mechanisms KW - Chemical modification KW - Computer simulation KW - Infrared spectroscopy KW - Kinetics KW - Numerical models KW - Reaction intermediates KW - Surface chemistry KW - Synthesis (chemical) KW - Thermogravimetric analysis AB - This study evaluates the effect of ammonia gas addition on synthesis environment and surface chemistry of single-walled carbon nanotubes (SWCNTs) produced by induction thermal plasma system (ITP). The experiments were carried out based on the opposed-flow injection of ammonia into the ITP reactor used for mass production of SWCNTs containing soot. The influence of in situ ammonia injection on the SWCNT final products was closely examined by Raman spectroscopy at three wavelengths, coupled thermogravimetry-infrared spectroscopy (TG-FTIR) and solid-phase infrared spectroscopy. The results clearly indicated the surface modification of SWCNTs where the metallic tubes had a greater tendency than the semiconducting tubes to react with ammonia at high temperature. To better understand the reaction system and predict the concentration profile of the intermediates and the product species from thermal decomposition of ammonia in the ITP reactor, a numerical simulation was developed including both the detailed kinetic of ammonia decomposition and turbulent mixing in the reaction system. By comparing the experimental and simulation results, a two-step reaction mechanism is suggested for this in situ SWCNTs chemistry in which the reaction of atomic hydrogen and amidogen radicals with SWCNTs, is followed by the ammonia chemisorption. DA - 2013/06/26 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f9d1c3a7-9fd0-4795-9a79-8e57057714c1 ER - TY - JOUR TI - Misalignment of magnetic fields and outflows in protostellar cores DO - 10.1088/0004-637X/768/2/159 AU - Hull, Charles L. H. AU - Plambeck, Richard L. AU - Bolatto, Alberto D. AU - Bower, Geoffrey C. AU - Carpenter, John M. AU - Crutcher, Richard M. AU - Fiege, Jason D. AU - Franzmann, Erica AU - Hakobian, Nicholas S. AU - Heiles, Carl AU - Houde, Martin AU - Hughes, A. Meredith AU - Jameson, Katherine AU - Kwon, Woojin AU - Lamb, James W. AU - Looney, Leslie W. AU - Matthews, Brenda C. AU - Mundy, Lee AU - Pillai, Thushara AU - Pound, Marc W. AU - Stephens, Ian W. AU - Tobin, John J. AU - Vaillancourt, John E. AU - Volgenau, N. H. AU - Wright, Melvyn C. H. T2 - The Astrophysical Journal SN - 0004-637X VL - 768 IS - 2 SP - 159 AB - We present results of λ1.3 mm dust-polarization observations toward 16 nearby, low-mass protostars, mapped with ∼2.″5 resolution at CARMA. The results show that magnetic fields in protostellar cores on scales of ∼1000 AU are not tightly aligned with outflows from the protostars. Rather, the data are consistent with scenarios where outflows and magnetic fields are preferentially misaligned (perpendicular), or where they are randomly aligned. If one assumes that outflows emerge along the rotation axes of circumstellar disks, and that the outflows have not disrupted the fields in the surrounding material, then our results imply that the disks are not aligned with the fields in the cores from which they formed. DA - 2013/04/25 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3a522c08-fd5c-49fc-a05f-2cb19eac5633 ER - TY - JOUR TI - Most observations of σ Ori E: challenging the centrifugal breakout narrative DO - 10.1088/0004-637X/769/1/33 AU - Townsend, R. H. D. AU - Rivinius, Th. AU - Rowe, J. F. AU - Moffat, A. F. J. AU - Matthews, J. M. AU - Bohlender, D. AU - Neiner, C. AU - Telting, J. H. AU - Guenther, D. B. AU - Kallinger, T. AU - Kuschnig, R. AU - Rucinski, S. M. AU - Sasselov, D. AU - Weiss, W. W. T2 - The Astrophysical Journal SN - 0004-637X VL - 769 IS - 1 SP - 33 AB - We present results from three weeks' photometric monitoring of the magnetic helium-strong star σ Ori E using the Microvariability and Oscillations of Stars microsatellite. The star's light curve is dominated by twice-per-rotation eclipse-like dimmings arising when magnetospheric clouds transit across and occult the stellar disk. However, no evidence is found for any abrupt centrifugal breakout of plasma from the magnetosphere, either in the residual flux or in the depths of the light minima. Motivated by this finding we compare the observationally inferred magnetospheric mass against that predicted by a breakout analysis. The large discrepancy between the values leads us to argue that centrifugal breakout does not play a significant role in establishing the magnetospheric mass budget of σ Ori E. DA - 2013/05/02 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c468f727-442d-4511-b474-bfc4e98968e2 ER - TY - JOUR TI - Herschel reveals massive cold clumps in NGC 7538 DO - 10.1088/0004-637X/773/2/102 AU - Fallscheer, C. AU - Reid, M. A. AU - Di Francesco, J. AU - Martin, P. G. AU - Hill, T. AU - Hennemann, M. AU - Nguyen-Luong, Q. AU - Motte, F. AU - Men'Shchikov, A. AU - André, Ph. AU - Ward-Thompson, D. AU - Griffin, M. AU - Kirk, J. AU - Konyves, V. AU - Rygl, K. L. J. AU - Sadavoy, S. AU - Sauvage, M. AU - Schneider, N. AU - Anderson, L. D. AU - Benedettini, M. AU - Bernard, J.-P. AU - Bontemps, S. AU - Ginsburg, A. AU - Molinari, S. AU - Polychroni, D. AU - Rivera-Ingraham, A. AU - Roussel, H. AU - Testi, L. AU - White, G. AU - Williams, J. P. AU - Wilson, C.D. AU - Wong, M. AU - Zavagno, A. T2 - The Astrophysical Journal SN - 0004-637X VL - 773 IS - 2 SP - 102 AB - We present the first overview of the Herschel observations of the nearby high-mass star-forming region NGC 7538, taken as part of the Herschel imaging study of OB young stellar objects (HOBYS) Key Programme. These PACS and SPIRE maps cover an approximate area of one square degree at five submillimeter and far-infrared wavebands. We have identified 780 dense sources and classified 224 of those. With the intention of investigating the existence of cold massive starless or class 0-like clumps that would have the potential to form intermediate- to high-mass stars, we further isolate 13 clumps as the most likely candidates for follow-up studies. These 13 clumps have masses in excess of 40 M ⊙and temperatures below 15 K. They range in size from 0.4 pc to 2.5 pc and have densities between 3 × 103 cm -3 and 4 × 104 cm-3. Spectral energy distributions are then used to characterize their energetics and evolutionary state through a luminosity-mass diagram. NGC 7538 has a highly filamentary structure, previously unseen in the dust continuum of existing submillimeter surveys. We report the most complete imaging to date of a large, evacuated ring of material in NGC 7538 which is bordered by many cool sources. DA - 2013/07/30 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6b27bffa-0ef3-4292-839f-9270f297c063 ER - TY - JOUR TI - Ionisation impact of high-mass stars on interstellar filaments: a Herschel study of the RCW 36 bipolar nebula in Vela C DO - 10.1051/0004-6361/201219423 AU - Minier, V. AU - Tremblin, P. AU - Hill, T. AU - Motte, F. AU - André, Ph. AU - Lo, N. AU - Schneider, N. AU - Audit, E. AU - White, G. J. AU - Hennemann, M. AU - Cunningham, M. AU - Deharveng, L. AU - Didelon, P. AU - Di Francesco, J. AU - Elia, D. AU - Giannini, T. AU - Nguyen Luong, Q. AU - Pezzuto, S. AU - Rygl, K. L. J. AU - Spinoglio, L. AU - Ward-Thompson, D. AU - Zavagno, A. T2 - Astronomy and Astrophysics SN - 0004-6361 VL - 550 SP - A50 KW - Dynamical phenomena KW - Far-infrared KW - Filamentary structures KW - H II regions KW - HERSCHEL KW - Herschel space observatories KW - High-mass stars KW - ISM: individual objects KW - ISM: structure KW - Molecular clouds KW - Molecular lines KW - Natural evolution KW - Southern Hemisphere KW - Star formations KW - Stars: massive KW - Submillimetre KW - Galaxies KW - Hydrodynamics KW - Ionization KW - Morphology AB - Context. Ionising stars reshape their original molecular cloud and impact star formation, leading to spectacular morphologies such as bipolar nebulae around H ii regions. Molecular clouds are structured in filaments where stars principally form, as revealed by the Herschel space observatory. The prominent southern hemisphere H ii region, RCW 36, is one of these bipolar nebulae. Aims. We study the physical connection between the filamentary structures of the Vela C molecular cloud and the bipolar morphology of RCW 36, providing an in-depth view of the interplay occurring between ionisation and interstellar structures (bright-rims and pillars) around an H ii region. Methods. We have compared Herschel observations in five far-infrared and submillimetre filters with the PACS and SPIRE imagers, to dedicated numerical simulations and molecular line mapping. Results. Our results suggest that the RCW 36 bipolar morphology is a natural evolution of its filamentary beginnings under the impact of ionisation. Conclusions. Such results demonstrate that, filamentary structures can be the location of very dynamical phenomena inducing the formation of dense clumps at the edge of H ii regions. Moreover, these results could apply to better understanding the bipolar nebulae as a consequence of the expansion of an H ii region within a molecular ridge or an interstellar filament. DA - 2013/01/24 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 86d757cd-9630-4598-9f48-b2308d30cb79 ER - TY - JOUR TI - 2011 HM102: discovery of a high-inclination L5 Neptune Trojan in the search for a post-Pluto New Horizons target DO - 10.1088/0004-6256/145/4/96 AU - Parker, Alex H. AU - Buie, Marc W. AU - Osip, David J. AU - Gwyn, Stephen D. J. AU - Holman, Matthew J. AU - Borncamp, David M. AU - Spencer, John R. AU - Benecchi, Susan D. AU - Binzel, Richard P. AU - DeMeo, Francesca E. AU - Fabbro, Sébastien AU - Fuentes, Cesar I. AU - Gay, Pamela L. AU - Kavelaars, J. J. AU - McLeod, Brian A. AU - Petit, Jean-Marc AU - Sheppard, Scott S. AU - Stern, S. Alan AU - Tholen, David J. AU - Trilling, David E. AU - Ragozzine, Darin A. AU - Wasserman, Lawrence H. AU - The Ice Hunters T2 - The Astronomical Journal SN - 0004-6256 VL - 145 IS - 4 SP - 96 KW - astronomy; Pluto; New Horizons; minor planets; asteroids AB - We present the discovery of a long-term stable L5 (trailing) Neptune Trojan in data acquired to search for candidate trans-Neptunian objects for the New Horizons spacecraft to fly by during an extended post-Pluto mission. This Neptune Trojan, 2011 HM102, has the highest inclination (29.°4) of any known member of this population. It is intrinsically brighter than any single L5 Jupiter Trojan at HV 8.18. We have determined its gri colors (a first for any L5 Neptune Trojan), which we find to be similar to the moderately red colors of the L4 Neptune Trojans, suggesting similar surface properties for members of both Trojan clouds. We also present colors derived from archival data for two L4 Neptune Trojans (2006 RJ103 and 2007 VL305), better refining the overall color distribution of the population. In this document we describe the discovery circumstances, our physical characterization of 2011 HM102, and this object's implications for the Neptune Trojan population overall. Finally, we discuss the prospects for detecting 2011 HM102 from the New Horizons spacecraft during its close approach in mid- to late-2013. DA - 2013/03/01 PY - 2013 PB - IOP Science LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d14f3389-b465-4b23-8255-790534fee394 ER - TY - JOUR TI - The Herschel view of the massive star-forming region NGC 6334 DO - 10.1051/0004-6361/201219971 AU - Russeil, D. AU - Schneider, N. AU - Anderson, L. D. AU - Zavagno, A. AU - Molinari, S. AU - Persi, P. AU - Bontemps, S. AU - Motte, F. AU - Ossenkopf, V. AU - André, Ph. AU - Arzoumanian, D. AU - Bernard, J.-Ph. AU - Deharveng, L. AU - Didelon, P. AU - Di Francesco, J. AU - Elia, D. AU - Hennemann, M. AU - Hill, T. AU - Könyves, V. AU - Li, J. Z. AU - Martin, P. G. AU - Nguyen Luong, Q. AU - Peretto, N. AU - Pezzuto, S. AU - Polychroni, D. AU - Roussel, H. AU - Rygl, K. L. J. AU - Spinoglio, L. AU - Testi, L. AU - Tigé, J. AU - Vavrek, R. AU - Ward-Thompson, D. AU - White, G. T2 - Astronomy and Astrophysics SN - 0004-6361 VL - 554 SP - A42 KW - Density distributions KW - Density structures KW - ISM : clouds KW - ISM: individual objects KW - Star-forming complexes KW - Star-forming region KW - Stars: formation KW - Using probabilities KW - Distribution functions KW - Gravitation KW - Probability distributions KW - Space applications KW - Turbulence AB - Aims. Fundamental to any theory of high-mass star formation are gravity and turbulence. Their relative importance, which probably changes during cloud evolution, is not known. By investigating the spatial and density structure of the high-mass star-forming complex NGC 6334 we aim to disentangle the contributions of turbulence and gravity. Methods. We used Herschel PACS and SPIRE imaging observations from the HOBYS key programme at wavelengths of 160, 250, 350, and 500 μm to construct dust temperature and column density maps. Using probability distribution functions (PDFs) of the column density determined for the whole complex and for four distinct sub-regions (distinguished on the basis of differences in the column density, temperature, and radiation field), we characterize the density structure of the complex. We investigate the spatial structure using the Δ-variance, which probes the relative amount of structure on different size scales and traces possible energy injection mechanisms into the molecular cloud. Results. The Δ-variance analysis suggests that the significant scales of a few parsec that were found are caused by energy injection due to expanding H ii regions, which are numerous, and by the lengths of filaments seen everywhere in the complex. The column density PDFs have a lognormal shape at low densities and a clearly defined power law at high densities for all sub-regions whose slope is linked to the exponent α of an equivalent spherical density distribution. In particular with α = 2.37, the central sub-region is largly dominated by gravity, caused by individual collapsing dense cores and global collapse of a larger region. The collapse is faster than free-fall (which would lead only to α = 2) and thus requires a more dynamic scenario (external compression, flows). The column density PDFs suggest that the different sub-regions are at different evolutionary stages, especially the central sub-region, which seems to be in a more evolved stage. DA - 2013/06/03 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6c4faeb8-5581-4e41-8ae1-9dbf6ccfe160 ER - TY - JOUR TI - Calcium-sensing receptor antagonist (calcilytic) NPS 2143 specifically blocks the increased secretion of endogenous Aβ42 prompted by exogenous fibrillary or soluble Aβ25-35 in human cortical astrocytes and neurons: therapeutic relevance to Alzheimer's disease DO - 10.1016/j.bbadis.2013.04.020 AU - Armato, Ubaldo AU - Chiarini, Anna AU - Chakravarthy, Balu AU - Chioffi, Franco AU - Pacchiana, Raffaelia AU - Colarusso, Enzo AU - Whitfield, James F. AU - Dal Prà, Ilaria T2 - Biochimica et Biophysica Acta - Molecular Basis of Disease SN - 0925-4439 VL - 1832 IS - 10 SP - 1634 EP - 1652 KW - Amyloid-β; Human astrocyte; Human neuron; NPS 2143; NPS R-568; Calcium-sensing receptor AB - The "amyloid-β (Aβ) hypothesis" posits that accumulating Aβ peptides (Aβs) produced by neurons cause Alzheimer's disease (AD). However, the Aβs contribution by the more numerous astrocytes remains undetermined. Previously we showed that fibrillar (f)Aβ25-35, an Aβ42 proxy, evokes a surplus endogenous Aβ42 production/accumulation in cortical adult human astrocytes. Here, by using immunocytochemistry, immunoblotting, enzymatic assays, and highly sensitive sandwich ELISA kits, we investigated the effects of fAβ25-35 and soluble (s)Aβ25-35 on Aβ42 and Aβ40 accumulation/secretion by human cortical astrocytes and HCN-1A neurons and, since the calcium-sensing receptor (CaSR) binds Aβs, their modulation by NPS 2143, a CaSR allosteric antagonist (calcilytic). The fAβ25-35-exposed astrocytes and surviving neurons produced, accumulated, and secreted increased amounts of Aβ42, while Aβ40 also accrued but its secretion was unchanged. Accordingly, secreted Aβ42/Aβ40 ratio values rose for astrocytes and neurons. While slightly enhancing Aβ40 secretion by fAβ25-35-treated astrocytes, NPS 2143 specifically suppressed the fAβ25-35-elicited surges of endogenous Aβ42 secretion by astrocytes and neurons. Therefore, NPS 2143 addition always kept Aβ42/Aβ40 values to baseline or lower levels. Mechanistically, NPS 2143 decreased total CaSR protein complement, transiently raised proteasomal chymotrypsin activity, and blocked excess NO production without affecting the ongoing increases in BACE1/β-secretase and γ-secretase activity in fAβ25-35-treated astrocytes. Compared to fAβ25-35, sAβ25-35 also stimulated Aβ42 secretion by astrocytes and neurons and NPS 2143 specifically and wholly suppressed this effect. Therefore, since NPS 2143 thwarts any Aβ/CaSR-induced surplus secretion of endogenous Aβ42 and hence further vicious cycles of Aβ self-induction/secretion/spreading, calcilytics might effectively prevent/stop the progression to full-blown AD. DA - 2013/04/26 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : cb87a459-a341-4fe0-90b4-1d793396fd82 ER - TY - JOUR TI - Fomalhaut b: independent analysis of the hubble space telescope public archive data DO - 10.1088/0004-637X/769/1/42 AU - Galicher, Raphaël AU - Marois, Christian AU - Zuckerman, B. AU - MacIntosh, Bruce T2 - The Astrophysical Journal SN - 0004-637X VL - 769 IS - 1 SP - 42 AB - The nature and even the existence of a putative planet-mass companion ("Fomalhaut b") to Fomalhaut has been debated since 2008. In the present paper, we reanalyze the multi-epoch ACS/STIS/WFC3 Hubble Space Telescope (HST) optical/near-infrared images on which the discovery and some other claims were based. We confirm that the HST images do reveal an object in orbit around Fomalhaut, but the detailed results from our analysis differ in some ways from previous discussions. In particular, we do not confirm flux variability over a two-year interval at 0.6 μm wavelength and we detect Fomalhaut b for the first time at the short wavelength of 0.43 μm. We find that the HST image of Fomalhaut b at 0.8 μm may be extended beyond the point-spread function. We cannot determine from our astrometry if Fomalhaut b will cross or not the dust ring. The optical through mid-infrared spectral energy distribution (SED) of Fomalhaut b cannot be explained as due to direct or scattered radiation from a massive planet. We consider two models to explain the SED: (1) a large circumplanetary disk around an unseen planet and (2) the aftermath of a collision during the past 50-150 yr of two Kuiper-Belt-like objects of radii ∼50 km. DA - 2013/05/03 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8772b977-0de8-4415-ab99-8143b1b4e76a ER - TY - JOUR TI - X-ray observations of the supernova remnant CTB 87 (G74.9+1.2): an evolved pulsar wind nebula DO - 10.1088/0004-637X/774/1/33 AU - Matheson, H. AU - Safi-Harb, S. AU - Kothes, R. T2 - The Astrophysical Journal SN - 0004-637X VL - 774 IS - 1 SP - 33 AB - Pulsar wind nebulae (PWNe) studies with the Chandra X-Ray Observatory have opened a new window to address the physics of pulsar winds, zoom on their interaction with their hosting supernova remnant (SNR) and interstellar medium, and identify their powering engines. We here present a new 70 ks, plus an archived 18 ks, Chandra ACIS observation of the SNR CTB 87 (G74.9+1.2), classified as a PWN with unusual radio properties and poorly studied in X-rays. We find that the peak of the X-ray emission is clearly offset from the peak of the radio emission by ∼100″ and located at the southeastern edge of the radio nebula. We detect a point source - the putative pulsar - at the peak of the X-ray emission and study its spectrum separately from the PWN. This new point source, CXOU J201609.2+371110, is surrounded by a compact nebula displaying a torus-like structure and possibly a jet. A more extended diffuse nebula is offset from the radio nebula, extending from the point source to the northwest for ∼250″. The spectra of the point source, compact nebula, and extended diffuse nebula are all well described by a power-law model with a photon index of 1.1 (0.7-1.6), 1.2 (0.9-1.4), and 1.7 (1.5-1.8), respectively, for a column density NH=1.38(1.21-1.57)×10²² cm⁻² (90% confidence). The total X-ray luminosity of the source is ∼1.6 × 10³⁴ erg s⁻¹ at an assumed distance of 6.1 kpc, with ∼2% and 6% contribution from the point source and compact nebula, respectively. The observed properties suggest that CTB 87 is an evolved (∼5-28 kyr) PWN, with the extended radio emission likely a "relic" PWN, as in Vela-X and G327.1-1.1. To date, however, there is no evidence for thermal X-ray emission from this SNR, and the SNR shell is still missing, suggesting expansion into a low-density medium ( n0<0.2D[sub 6.1][super -1/2] cm⁻³), likely caused by a stellar wind bubble blown by the progenitor star. DA - 2013/08/13 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2fc305ca-4af5-4c9d-afbd-a63fa9e82331 ER - TY - JOUR TI - Particle-physics constraints from the globular cluster M5: neutrino dipole moments DO - 10.1051/0004-6361/201322004 AU - Viaux, N. AU - Catelan, M. AU - Stetson, P. B. AU - Raffelt, G. G. AU - Redondo, J. AU - Valcarce, A. A. R. AU - Weiss, A. T2 - Astronomy and Astrophysics SN - 0004-6361 VL - 558 SP - A12 KW - Globular clusters: general KW - Globular clusters: individual KW - Hertzsprung-Russell and C-M diagrams KW - Neutrinos KW - Stars: evolution KW - Stars: Interiors KW - Dipole moment KW - Energy dissipation KW - Luminance KW - Neutrons KW - Plasmons AB - Stellar evolution is modified if energy is lost in a "dark channel" similar to neutrino emission. Comparing modified stellar evolution sequences with observations provides some of the most restrictive limits on axions and other hypothetical low-mass particles and on non-standard neutrino properties. In particular, a putative neutrino magnetic dipole moment μν enhances the plasmon decay process, postpones helium ignition in low-mass stars, and therefore extends the red giant branch (RGB) in globular clusters (GCs). The brightness of the tip of the RGB (TRGB) remains the most sensitive probe for μν and we revisit this argument from a modern perspective. Based on a large set of archival observations, we provide high-precision photometry for the Galactic GC M5 (NGC 5904) and carefully determine its TRGB position. On the theoretical side, we add the extra plasmon decay rate brought about by μν to the Princeton-Goddard-PUC (PGPUC) stellar evolution code. Different sources of uncertainty are critically examined. The main source of systematic uncertainty is the bolometric correction and the main statistical uncertainty derives from the distance modulus based on main-sequence fitting. (Other measures of distance, e.g., the brightness of RR Lyrae stars, are influenced by the energy loss that we wish to constrain.) The statistical uncertainty of the TRGB position relative to the brightest RGB star is less important because the RGB is well populated. We infer an absolute I-band brightness of MI = -4.17 ± 0.13 mag for the TRGB compared with the theoretical prediction of - 3.99 ± 0.07 mag, in reasonable agreement with each other. A significant brightness increase caused by neutrino dipole moments is constrained such that μν < 2.6 × 10-12 μB (68% CL), where μB ≡ e/2me is the Bohr magneton, and μν < 4.5 × 10-12 μB (95% CL). In these results, statistical and systematic errors have been combined in quadrature. DA - 2013/09/26 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ad7769c5-2c33-4b87-820e-eacec7896360 ER - TY - JOUR TI - High-resolution radio emission from RCW 49/Westerlund 2 DO - 10.1051/0004-6361/201321976 AU - Benaglia, P. AU - Koribalski, B. AU - Peri, C. S. AU - Martí, J. AU - Sánchez-Sutil, J. R. AU - Dougherty, S. M. AU - Noriega-Crespo, A. T2 - Astronomy and Astrophysics SN - 0004-6361 VL - 559 SP - A31 KW - Gamma rays: stars KW - ISM: individual objects KW - Open clusters and associations KW - Radio continuum: ISM KW - Stars: winds, outflows KW - Bandwidth KW - Infrared imaging KW - Optical waveguides KW - Telescopes AB - Aims. The HII region RCW49 and its ionizing cluster form an extensive, complex region that has been widely studied at infrared (IR) and optical wavelengths. The Molonglo 843 MHz and Australia Telescope Compact Array data at 1.4 and 2.4 GHz showed two shells. Recent high-resolution IR imaging revealed a complex dust structure and ongoing star formation. New high-bandwidth and high-resolution data of the RCW 49 field have been obtained to survey the radio emission at arcsec scale and investigate the smallscale features and nature of the HII region. Methods. Radio observations were collected with the new 2-GHz bandwidth receivers and the CABB correlator of the Australia Telescope Compact Array [ATCA], at 5.5 and 9.0 GHz. In addition, archival observations at 1.4 and 2.4 GHz have been re-reduced and re-analyzed in conjunction with observations in the optical, IR, X-ray, and gamma-ray regimes. Results. The new 2-GHz bandwidth data result in the most detailed radio continuum images of RCW 49 to date. The radio emission closely mimics the near-IR emission observed by Spitzer, showing pillars and filaments. The brightest continuum emission comes from the region known as the bridge. The overall flattish spectral index is typically consistent with a free-free emission mechanism. However, hints of nonthermal components are also present in the bridge. An interesting jet-like structure surrounded by a bubble feature whose nature is still unclear has been discovered close to the Westerlund 2 core. Two apparent bow shocks and a number of discrete sources have been detected as well in the surroundings of RCW 49. In addition, we also report on and discuss the possible detection of a hydrogen recombination line. Conclusions. The radio results support an association between the cm continuum and molecular emission. The detection of the radio recombination line kinematically favors a RCW49 distance of 6-7 kpc. If the negative spectral indices measured at the bridge should be confirmed to be caused by synchrotron emission, we propose a scenario where high-energy emission could be produced. Finally, the newly discovered jet-like structure appears to be an intriguing source that deserves a detailed study by itself. DA - 2013/10/31 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d0fef371-cace-4ef9-83b2-f17e3f0d1bbc ER - TY - JOUR TI - The luminosities of protostars in the Spitzer c2d and Gould Belt legacy clouds DO - 10.1088/0004-6256/145/4/94 AU - Dunham, Michael M. AU - Arce, Héctor G. AU - Allen, Lori E. AU - Evans Ii, Neal J. AU - Broekhoven-Fiene, Hannah AU - Chapman, Nicholas L. AU - Cieza, Lucas A. AU - Gutermuth, Robert A. AU - Harvey, Paul M. AU - Hatchell, Jennifer AU - Huard, Tracy L. AU - Kirk, Jason M. AU - Matthews, Brenda C. AU - Merín, Bruno AU - Miller, Jennifer F. AU - Peterson, Dawn E. AU - Spezzi, Loredana T2 - The Astronomical Journal SN - 0004-6256 VL - 145 IS - 4 SP - 94 AB - Motivated by the long-standing "luminosity problem" in low-mass star formation whereby protostars are underluminous compared to theoretical expectations, we identify 230 protostars in 18 molecular clouds observed by two Spitzer Space Telescope Legacy surveys of nearby star-forming regions. We compile complete spectral energy distributions, calculate Lbol for each source, and study the protostellar luminosity distribution. This distribution extends over three orders of magnitude, from 0.01 L☉ to 69 L☉, and has a mean and median of 4.3 L☉ and 1.3 L☉, respectively. The distributions are very similar for Class 0 and Class I sources except for an excess of low luminosity (Lbol ≲ 0.5 L☉) Class I sources compared to Class 0. 100 out of the 230 protostars (43%) lack any available data in the far-infrared and submillimeter (70 μm <λ < 850 μm) and have Lbol underestimated by factors of 2.5 on average, and up to factors of 8-10 in extreme cases. Correcting these underestimates for each source individually once additional data becomes available will likely increase both the mean and median of the sample by 35%-40%. We discuss and compare our results to several recent theoretical studies of protostellar luminosities and show that our new results do not invalidate the conclusions of any of these studies. As these studies demonstrate that there is more than one plausible accretion scenario that can match observations, future attention is clearly needed. The better statistics provided by our increased data set should aid such future work. DA - 2013/02/28 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6fd9a1ac-e575-4c42-81a3-dc1382463e38 ER - TY - JOUR TI - On a possible size/color relationship in the Kuiper Belt DO - 10.1088/0004-6256/146/4/75 AU - Pike, R. E. AU - Kavelaars, J. J. T2 - Astronomical Journal SN - 0004-6256 VL - 146 IS - 4 SP - 75 AB - Color measurements and albedo distributions introduce non-intuitive observational biases in size-color relationships among Kuiper Belt Objects (KBOs) that cannot be disentangled without a well characterized sample population with systematic photometry. Peixinho et al. report that the form of the KBO color distribution varies with absolute magnitude, H. However, Tegler et al. find that KBO color distributions are a property of object classification. We construct synthetic models of observed KBO colors based on two B-R color distribution scenarios: color distribution dependent on H magnitude (H-Model) and color distribution based on object classification (Class-Model). These synthetic B-R color distributions were modified to account for observational flux biases. We compare our synthetic B-R distributions to the observed "Hot" and "Cold" detected objects from the Canada-France Ecliptic Plane Survey and the Meudon Multicolor Survey. For both surveys, the Hot population color distribution rejects the H-Model, but is well described by the Class-Model. The Cold objects reject the H-Model, but the Class-Model (while not statistically rejected) also does not provide a compelling match for data. Although we formally reject models where the structure of the color distribution is a strong function of H magnitude, we also do not find that a simple dependence of color distribution on orbit classification is sufficient to describe the color distribution of classical KBOs. DA - 2013/08/21 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 69af767b-f058-4964-a5f6-56d6e6150646 ER - TY - JOUR TI - The RR Lyrae variables and horizontal branch of NGC 6656 (m22) DO - 10.1088/0004-6256/146/5/119 AU - Kunder, Andrea AU - Stetson, Peter B. AU - Cassisi, Santi AU - Layden, Andrew AU - Bono, Giuseppe AU - Catelan, Márcio AU - Walker, Alistair R. AU - Paredes Alvarez, Leonardo AU - Clem, James L. AU - Matsunaga, Noriyuki AU - Salaris, Maurizio AU - Lee, Jae-Woo AU - Chaboyer, Brian T2 - Astronomical Journal SN - 0004-6256 VL - 146 IS - 5 SP - 119 AB - The first calibrated broadband UBVI time-series photometry is presented for the RR Lyrae variable stars in NGC 6656 (M22), with observations spanning a range of 22 years. We have also redetermined the variability types and periods for the RR Lyrae stars identified previously by photographic observations, revising the number of fundamental-mode RR Lyrae variables (RR0) to 10 and the number of first-overtone variables (RR1) to 16. The mean periods of the RR0 and RR1 variables are 〈P〉RR0 = 0.66 ± 0.02 days and 〈P〉RR1 = 0.33 ± 0.01 days, respectively, supporting an Oosterhoff II classification for the cluster. The number ratio of RR1-type to all RR-type variables is N 1/NRR = 0.61, also consistent with an Oosterhoff II designation. Both the RR Lyrae stars' minimum light colors and the blue edge of the RR Lyrae instability strip suggest E( B - V) = 0.36 ± 0.02 mag toward M22. Regarding the HB morphology of M22, we find (B-R)/(B+V+R) = +0.97 ± 0.1 and at least one "gap" located in an unusual part of the blue HB, in the middle of the so-called hot HB stars. © 2013. The American Astronomical Society. All rights reserved. DA - 2013/10/07 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9cdb938b-a4c8-481a-b319-a93ba00d4853 ER - TY - JOUR TI - Atmospheric pressure plasma oxidation of AA6061-T6 aluminum alloy surface for strong and durable adhesive bonding applications DO - 10.1016/j.apsusc.2013.05.064 AU - Saleema, N. AU - Gallant, D. T2 - Applied Surface Science SN - 0169-4332 VL - 282 SP - 98 EP - 104 KW - Adhesive bonding KW - Atmospheric pressure plasmas KW - IRRAS KW - Plasma oxidation KW - SEM/EDX KW - Adhesion KW - Adhesive joints KW - Aluminum KW - Atmospheric pressure KW - Bond strength (materials) KW - Epoxy resins KW - Wetting AB - AA 6061-T6 aluminum alloy surface has been treated using atmospheric pressure helium-oxygen plasma at room temperature prior to bonding with a bi-component epoxy resin. The adhesive joint strengths were evaluated via single lap shear tests as prepared (pristine conditions) as well as following degradation by exposure to extreme temperature and humidity conditions (cataplasma conditions). Very high adhesion strength of 24 ± 1 MPa was achieved on surfaces after a very short exposure of the He/O2 plasma of only 15 s under pristine conditions resulting in cohesive failure of the adhesive itself. Best results were obtained under cataplasma conditions with adhesion strength of 22.6 ± 1 MPa by introducing a very simple pretreatment with scotch brite® prior to plasma exposure. With many different surface treatment methods being predominantly tested and evaluated, the adhesive bonding community may highly benefit from the present work as the treatment method uses very simple, economical and safe procedures in obtaining results comparable to benchmark methods such as Forest Products Laboratory (FPL) etch, anodization and so on. DA - 2013/05/31 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a3379eec-5445-4b47-95bb-0313f4b37b53 ER - TY - JOUR TI - Fast and intense photoluminescence in a SiGe nano-layer embedded in multilayers of Si/SiGe clusters DO - 10.1063/1.4813560 AU - Mala, S. A. AU - Tsybeskov, L. AU - Lockwood, D. J. AU - Wu, X. AU - Baribeau, J.-M. T2 - Applied Physics Letters SN - 0003-6951 VL - 103 IS - 3 SP - 33103 KW - Excitation energy density KW - Hetero-interfaces KW - Output intensity KW - PL property KW - Si/SiGe KW - Germanium KW - Multilayers KW - Silicon alloys KW - Photoluminescence AB - An intense photoluminescence (PL) peaking near 0.9 eV is emitted by a single Si1-xGex nanometer-thick layer (NL) with x ≈ 8% incorporated into Si/Si0.6Ge0.4 cluster multilayers (CMs). The SiGe NL PL does not saturate in output intensity with up to 50 mJ/cm^2 of excitation energy density, and it has nearly a 1000 times shorter lifetime compared to CM PL, which peaks at ∼0.8 eV. These dramatic differences in observed PL properties are attributed to different compositions and structures of the Si/SiGe NL and CM hetero-interfaces. DA - 2013/07/15 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : eeb36ef8-8678-498e-b08d-d7a39e618988 ER - TY - JOUR TI - Strain analysis of highly scalable single InAs/InP quantum dots in a stress-sensitive environment DO - 10.1063/1.4817758 AU - Mnaymneh, K. AU - Dalacu, D. AU - Poole, P. J. AU - Williams, R. L. T2 - Applied Physics Letters SN - 0003-6951 VL - 103 IS - 6 SP - 61901 KW - Computational studies KW - Emission spectrums KW - InAs/InP quantum dots KW - Pseudopotential calculation KW - Quantum information systems KW - Self assembled quantum dots KW - Single-photon source KW - Stress sensitive KW - Emission spectroscopy KW - Quantum optics KW - Semiconductor quantum dots AB - We perform an experimental and computational study of the effects of external stress and intermixing on single site-selected InAs/InP quantum dots in a highly scalable stress-sensitive environment. While such effects are well known for their ability to tune emission spectra, little is known on how they influence emission shell spacing, electron-hole effective mass renormalization, and the physical size of the embedded quantum dot, which are all important parameters affecting the intended functionality. We show excellent agreement between experiment and finite-element solutions of the coupled Navier and Schrödinger equations, including recent atomistic pseudopotential calculations in the literature. These results indicate that using single self-assembled quantum dots in highly scalable, stress-sensitive settings as active elements in future bottom-up nanosystems offers greater versatility to not only quantum information systems where they serve as scalable single-photon sources but also to ultra-sensing capabilities in future nano-electro-mechanical architectures. DA - 2013/08/05 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ab62bf39-7df5-48f8-b14b-cc7472589bcb ER - TY - JOUR TI - Highly polarized emission from electrical spin injection into an InGaAs quantum well with free carriers DO - 10.1063/1.4832460 AU - Li, C. H. AU - Kioseoglou, G. AU - Petrou, A. AU - Korkusinski, M. AU - Hawrylak, P. AU - Jonker, B. T. T2 - Applied Physics Letters SN - 0003-6951 VL - 103 IS - 21 SP - 212403 AB - We report on a highly polarized emission from InGaAs/GaAs-quantum well light-emitting diodes in which we inject spin-polarized electrons from an Fe/Schottky contact. The emission spectra consist of the e1h 1 free exciton (FX) and a feature 12 meV below FX attributed to band-to-band (BB) recombination. The FX exhibits a maximum circular polarization of 22%, with a magnetic-field dependence characteristic of spin injection from Fe. The BB emission on the other hand exhibits a polarization that is strongly bias and temperature dependent, with intriguing magnetic-field dependence: The polarization exhibits a maximum of 78% at 2.5 T and 2 K, then decreases linearly with field and reaches -78% at 7 T, attributed to magnetic-field dependent spin relaxation in the presence of excess electrons. DA - 2013/11/19 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c6a0ca30-4733-4101-a5b5-40e1852c4c04 ER - TY - JOUR TI - Substrate profiling of cyclohexylamine oxidase and its mutants reveals new biocatalytic potential in deracemization of racemic amines DO - 10.1007/s00253-013-5028-1 AU - Li, Guangyue AU - Ren, Jie AU - Iwaki, Hiroaki AU - Zhang, Dalong AU - Hasegawa, Yoshie AU - Wu, Qiaqing AU - Feng, Jinhui AU - Lau, Peter C. K. AU - Zhu, Dunming T2 - Applied Microbiology and Biotechnology SN - 0175-7598 SP - 1 EP - 9 AB - A cyclohexylamine oxidase (CHAO) of bacterial origin was previously shown to be a potentially useful catalyst in the deracemization of racemic primary amines. To further explore the properties and application of this enzyme, five single-amino acid substitution mutants (L199A, M226A, Y321A, Y321F, and L353M) were created based on superimposition of the tertiary structure of CHAO and the monoamine oxidase (MAO) B homolog. The substrate specificity of the purified wild-type and five mutant enzymes were examined towards 38 structurally diverse amines. All the enzymes exhibited better activity for primary amines than secondary and tertiary amines and in general exhibited high stereoselectivity. Among the mutant enzymes, M226A displayed an enhanced activity (5-400 %) towards most substrates, and L353M showed 7-445 % higher activity towards primary aliphatic amines with cycloalkane or aromatic moieties. Kinetic parameters revealed that both Y321 mutants showed higher catalytic efficiency towards cyclooctanamine, whereas the wild-type CHAO (wt CHAO) was most efficient towards cyclohexylamine. The wt CHAO or variant L353M in combination with a borane-ammonia complex as reducing agent was applied to the deracemization of 1-aminotetraline to give the (R)-enantiomer, a precursor of an antidepressant drug Norsertraline, in good yield (73-76 %), demonstrating their application potential in chiral amine synthesis. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3e21c4cd-8d5a-4853-b7a3-d0d8f2c2cdeb ER - TY - JOUR TI - Camphor pathway redux: functional recombinant expression of 2,5-and 3,6-diketocamphane monooxygenases of Pseudomonas putida ATCC 17453 with their cognate flavin reductase catalyzing Baeyer-Villiger reactions DO - 10.1128/AEM.03958-12 AU - Iwaki, Hiroaki AU - Grosse, Stephan AU - Bergeron, Hélène AU - Leisch, Hannes AU - Morley, Krista AU - Hasegawa, Yoshie AU - Lau, Peter C. K. T2 - Applied and Environmental Microbiology SN - 0099-2240 VL - 79 IS - 10 SP - 3282 EP - 3293 KW - Baeyer Villiger oxidation KW - Baeyer-Villiger reaction KW - Biochemical properties KW - Flavin adenine dinucleotide KW - Flavin mono nucleotides (FMN) KW - Pulsed field gel electrophoresis KW - Recombinant expression KW - Recombinant plasmid KW - Cams KW - DNA KW - Electrophoresis KW - Escherichia coli KW - Genes KW - Genetic engineering KW - Ketones KW - Oxygenation KW - Substrates KW - Camphor KW - bacteriology KW - bacterium KW - catalysis KW - electrokinesis KW - enzyme activity KW - gene expression KW - ketone KW - oxidation KW - plasmid KW - recombination KW - terpene AB - Whereas the biochemical properties of the monooxygenase components that catalyze the oxidation of 2,5-diketocamphane and 3,6-diketocamphane (2,5-DKCMO and 3,6-DKCMO, respectively) in the initial catabolic steps of (+) and (-) isomeric forms of camphor (CAM) metabolism in Pseudomonas putida ATCC 17453 are relatively well characterized, the actual identity of the flavin reductase (Fred) component that provides the reduced flavin to the oxygenases has hitherto been ill defined. In this study, a 37-kDa Fred was purified from a camphor-induced culture of P. putida ATCC 17453 and this facilitated cloning and characterization of the requisite protein. The active Fred is a homodimer with a subunit molecular weight of 18,000 that uses NADH as an electron donor (Km(32 μM), and it catalyzes the reduction of flavin mononucleotide (FMN) (Km=3.6 μM; kcat=283 s-¹) in preference to flavin adenine dinucleotide (FAD) (Km(19 μM; kcat(128 s-¹). Sequence determination of~40 kb of the CAM degradation plasmid revealed the locations of two isofunctional 2,5-DKCMO genes (camE25-1 for 2,5-DKCMO-1 and camE25-2 for 2,5-DKCMO-2) as well as that of a 3,6-DKCMO-encoding gene (camE36). In addition, by pulsed-field gel electrophoresis, the CAM plasmid was established to be linear and~533 kb in length. To enable functional assessment of the two-component monooxygenase system in Baeyer-Villiger oxidations, recombinant plasmids expressing Fred in tandem with the respective 2,5-DKCMO- and 3,6-DKCMO-encoding genes in Escherichia coli were constructed. Comparative substrate profiling of the isofunctional 2,5-DCKMOs did not yield obvious differences in Baeyer-Villiger biooxidations, but they are distinct from 3,6-DKCMO in the stereoselective oxygenations with various mono- and bicyclic ketone substrates. DA - 2013/03/22 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 13e011cb-87a2-4755-b6f4-95f98f5c7b9a ER - TY - JOUR TI - Potentiation of azole antifungals by 2-adamantanamine DO - 10.1128/AAC.00294-13 AU - LaFleur, Michael D. AU - Sun, Lingmei AU - Lister, Ida AU - Keating, John AU - Nantel, Andre AU - Long, Lisa AU - Ghannoum, Mahmoud AU - North, Jeffrey AU - Lee, Richard E. AU - Coleman, Ken AU - Dahl, Thomas AU - Lewis, Kim T2 - Antimicrobial Agents and Chemotherapy SN - 0066-4804 VL - 57 IS - 8 SP - 3585 EP - 3592 KW - 2 adamantanamine KW - amantadine derivative KW - antifungal agent KW - ergosterol KW - fluconazole KW - miconazole KW - rimantadine KW - transcriptome KW - unclassified drug KW - voriconazole KW - biofilm KW - Candida albicans KW - controlled study KW - drug efficacy KW - drug potentiation KW - drug screening KW - fungicidal activity KW - fungus growth KW - genetic analysis KW - guinea pig KW - human cell KW - human tissue KW - IC 50 KW - skin candidiasis AB - Azoles are among the most successful classes of antifungals. They act by inhibiting 14 lanosterol demethylase in the ergosterol biosynthesis pathway. Oropharyngeal candidiasis (OPC) occurs in about 90% of HIV-infected individuals, and 4 to 5%are refractory to current therapies, including azoles, due to the formation of resistant biofilms produced in the course of OPC. We reasoned that compounds affecting a different target may potentiate azoles to produce increased killing and an antibiofilm therapeutic. 2-Adamantanamine (AC17) was identified in a screen for compounds potentiating the action of miconazole against biofilms of Candida albicans. AC17, a close structural analog to the antiviral amantadine, did not affect the viability of C. albicans but caused the normally fungistatic azoles to become fungicidal. Transcriptome analysis of cells treated with AC17 revealed that the ergosterol and filamentation pathways were affected. Indeed, cells exposed to AC17 had decreased ergosterol contents and were unable to invade agar. In vivo, the combination of AC17 and fluconazole produced a significant reduction in fungal tissue burden in a guinea pig model of cutaneous candidiasis, while each treatment alone did not have a significant effect. The combination of fluconazole and AC17 also showed improved efficacy (P value of 0.018) compared to fluconazole alone when fungal lesions were evaluated. AC17 is a promising lead in the search for more effective antifungal therapeutics. DA - 2013/08 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e008d068-8f31-416f-b78a-c9f4bc42a576 ER - TY - JOUR TI - Effect of tertiary and secondary phosphines on low-temperature formation of quantum dots DO - 10.1002/anie.201300568 AU - Yu, Kui AU - Liu, Xiangyang AU - Zeng, Qun AU - Leek, Donald M. AU - Ouyang, Jianying AU - Whitmore, Kenneth Matthew AU - Ripmeester, John A. AU - Tao, Ye AU - Yang, Mingli T2 - Angewandte Chemie - International Edition SN - 1433-7851 VL - 52 IS - 18 SP - 4823 EP - 4828 KW - Diphenylphosphine KW - Feed molar ratio KW - Low temperature formation KW - Reproducibilities KW - Secondary phosphines KW - Semiconducting nanocrystals KW - Tri-n-octylphosphine KW - Coordination reactions KW - Density functional theory KW - Molecular modeling KW - Nanocrystals KW - Phosphorus compounds KW - Semiconductor quantum dots KW - Semiconducting selenium compounds KW - Phosphine derivative KW - Chemical structure KW - Cadmium KW - Cold Temperature KW - Models, Molecular KW - Oleic Acid KW - Phosphines AB - Getting to the TOP of things: The coordination of tri-n-octylphosphine (TOP) instead of diphenylphosphine (DPP) to cadmium oleate (Cd(OA)2) reveals how tertiary and secondary phosphines enhance the yield and reproducibility of the synthesis of nanocrystals by shifting the equilibrium of the reaction to the right (see picture). High Cd-to-Se and Se-to-TOP feed molar ratios facilitate the formation of Se[DOUBLE BOND]DPP by way of Se exchange from TOP to DPP. DA - 2013/03/25 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 08139141-a619-48ac-a62f-0144ec073b95 ER - TY - JOUR TI - Structure of the benzene dimer - governed by dynamics DO - 10.1002/anie.201300653 AU - Schnell, Melanie AU - Erlekam, Undine AU - Bunker, P. R. AU - von Helden, Gert AU - Grabow, Jens-Uwe AU - Meijer, Gerard AU - van der Avoird, Ad T2 - Angewandte Chemie - International Edition SN - 1433-7851 VL - 52 IS - 19 SP - 5180 EP - 5183 KW - Ab initio calculations KW - Hindered rotations KW - Internal rotations KW - Non-covalent interaction KW - Rotational spectra KW - Rotational spectroscopy KW - Splitting patterns KW - Theoretical models KW - Electron tunneling KW - Ions KW - Benzene AB - The benzene dimer, an important prototype for studying noncovalent interactions, exhibits characteristic splitting patterns in its rotational spectrum, which for a long time were not understood. A new theoretical model reveals their origin: a concerted internal motion involving sixfold hindered rotation tunneling of the molecule forming the stem of the T-shaped structure and tilt tunneling of the cap. DA - 2013/05/03 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 03dd2cbd-8b25-4aa3-b8e2-8cb595731364 ER - TY - JOUR TI - The formation mechanism of binary semiconductor nanomaterials: Shared by single-source and dual-source precursor approaches DO - 10.1002/anie.201304958 AU - Yu, Kui AU - Liu, Xiangyang AU - Zeng, Qun AU - Yang, Mingli AU - Ouyang, Jianying AU - Wang, Xinqin AU - Tao, Ye T2 - Angewandte Chemie - International Edition SN - 1433-7851 VL - 52 IS - 42 SP - 11034 EP - 11039 KW - Binary semiconductors KW - Colloidal semiconductor nanocrystals KW - Formation mechanism KW - Metal-ligand interactions KW - Nanocrystal formation mechanism KW - Phosphine chalcogenides KW - phosphines KW - Reaction mechanism KW - Inorganic compounds KW - Molecular modeling KW - Nuclear magnetic resonance spectroscopy KW - Semiconductor quantum dots KW - Phosphorus compounds AB - One thing in common: The formation of binary colloidal semiconductor nanocrystals from single- (M(EEPPh2)n) and dual-source precursors (metal carboxylates M(OOCR)n and phosphine chalcogenides such as E=PHPh2) is found to proceed through a common mechanism. For CdSe as a model system 31Pa NMR spectroscopy and DFT calculations support a reaction mechanism which includes numerous metathesis equilibriums and Se exchange reactions. DA - 2013/10/11 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0ec5e8ad-04e3-46bb-8093-73f4769a6e6f ER - TY - JOUR TI - Acid extraction for the determination of methyl mercury in biotissues by isotope dilution gas chromatography inductively coupled plasma-mass spectrometry DO - 10.1039/c3ay40909k AU - D'Ulivo, Lucia AU - Yang, Lu AU - Feng, Yong-Lai AU - Mester, Zoltán T2 - Analytical Methods SN - 1759-9660 VL - 5 IS - 24 SP - 7127 EP - 7131 AB - Methyl mercury (MeHg) is a common contaminant worldwide. Health authorities keep monitoring MeHg levels in biological and environmental samples to assess the corresponding exposure in the population. So far, a basic leaching has been mostly used for the MeHg extraction. In this study, it was demonstrated that methanesulfonic acid, commonly used for amino acid extraction, can be used for MeHg extraction. Species-specific isotope dilution was employed to achieve accurate results. The method was validated by analysis of dogfish liver certified reference material (DOLT-4). The derivatized extracts were then analyzed with gas chromatography-inductively coupled plasma-mass spectrometry (GC-ICP-MS). Results obtained for MeHg in DOLT-4 are in agreement with the certified value (t-test, P = 0.05), confirming that methanesulfonic acid extraction is suitable for extraction of MeHg in biological tissues. This new procedure could be of particular interest in biological and toxicological studies where a simultaneous determination of MeHg and certain amino acids is sometimes required. DA - 2013/10/14 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f92ef430-1aef-44ac-9dfa-edb1e654fe29 ER - TY - JOUR TI - Absolute quantification of peptides by isotope dilution liquid chromatography-inductively coupled plasma mass spectrometry and gas chromatography/mass spectrometry DO - 10.1021/ac400158u AU - Liu, Rui AU - Hou, Xiandeng AU - Lv, Yi AU - McCooeye, Margaret AU - Yang, Lu AU - Mester, Zoltán T2 - Analytical Chemistry SN - 0003-2700 VL - 85 IS - 8 SP - 4087 EP - 4093 KW - Absolute quantification KW - Calibration solutions KW - Gas chromatography/Mass spectrometry KW - Methane sulfonic acid KW - Peptide quantification KW - Relative standard deviations KW - Species-specific isotope dilution KW - Validation strategies KW - Amino acids KW - Chromatography KW - Inductively coupled plasma mass spectrometry KW - Isotopes KW - Spectrometry KW - Trace analysis KW - Peptides AB - Absolute quantitation of peptides/proteins in dilute calibration solutions used in various diagnostic settings is a major challenge. Here we report the absolute quantitation of peptides by non-species-specific isotope dilution liquid chromatography-inductively coupled plasma mass spectrometry (ID LC-ICPMS) based on stoichiometric Eu tagging. The method was validated by species-specific isotope dilution gas chromatography/mass spectrometry (GC/MS) analysis of constituent amino acids of the target peptide. Quantitative labeling of bradykinin peptide was accomplished with a commercially available 2′,2″-(10-(2-((2,5-dioxopyrrolidin-1-yl)oxy)-2-oxoethyl)-1,4,7, 10-tetraazacyclododecane-1,4,7-triyl) triacetic acid (DOTA-NHS-ester) and subsequently tagged with Eu. A 151Eu-enriched spike was used for the non-species-specific ID LC-ICPMS determination of bradykinin. The non-species-specific ID LC-ICPMS method was cross-validated by a species-specific ID GC/MS approach, which is based on the determination of phenylalanine in bradykinin to derive the concentration of the peptide in the sample. The hydrolysis of the peptide into amino acids was achieved by microwave digestion with 4 M methanesulfonic acid, and derivatization of phenylalanine with methyl chloroformate (MCF) was performed prior to its detection by GC/MS based on a 13C-enriched phenylalanine spike. The accuracy of the method was confirmed at various concentration levels with a typical precision of better than 5% relative standard deviation (RSD) at 20 pmol for non-species-specific ID LC-ICPMS and 500 pmol for species-specific ID GC/MS. A detection limit (3 SD) of 7.2 fmol estimated for ID LC-ICPMS with a 10 μL injection volume from three procedure blanks was obtained for bradykinin, confirming the suitability of the method for the direct determination of peptides at trace levels. To the best of our knowledge, the proposed method is the first ICPMS peptide quantification strategy which employs an independent validation strategy using species-specific ID GC/MS for amino acid quantitation. DA - 2013/03/14 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 05c246f7-e6c1-4a7b-9014-dba992398179 ER - TY - JOUR TI - Reduction of measurement uncertainty by experimental design in high-order (double, triple, and quadruple) isotope dilution mass spectrometry: application to GC-MS measurement of bromide DO - 10.1007/s00216-013-6724-5 AU - Pagliano, Enea AU - Mester, Zoltán AU - Meija, Juris T2 - Analytical and Bioanalytical Chemistry SN - 1618-2642 SP - 1 EP - 9 AB - Since its introduction a century ago, isotope dilution analysis has played a central role in developments of analytical chemistry. This method has witnessed many elaborations and developments over the years. To date, we have single, double, and even triple isotope dilution methods. In this manuscript, we summarize the conceptual aspects of isotope dilution methods and introduce the quadruple dilution and the concept of exact matching triple and quadruple dilutions. The comparison of isotope dilution methods is performed by determination of bromide ions in groundwater using novel ethyl-derivatization chemistry in conjunction with GC/MS. We show that the benefits of higher-order isotope dilution methods are countered with a greater need for careful experimental design of the isotopic blends. Just as for ID2MS, ID3MS and ID4MS perform best when the isotope ratio of one sample/spike blend is matched with that of a standard/spike blend (exact matching). © 2013 Her Majesty the Queen in Right of Canada. DA - 2013/03 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6226de5b-010e-45d8-a677-737e83b62cb5 ER - TY - JOUR TI - Papal chemistry challenge DO - 10.1007/s00216-013-7157-x AU - Meija, Juris T2 - Analytical and Bioanalytical Chemistry SN - 1618-2642 VL - 405 IS - 22 SP - 6897 EP - 6898 KW - International union of pure and applied chemistries KW - Scientific communication KW - Systematic naming KW - Mass spectrometry KW - Surface analysis KW - Chemical elements AB - The article presents a quiz for readers to identify a certain element using a clue given in it. While searching for the sacred treasure, Robert Langdon of The Da Vinci Code encountered a cryptic clue: 'a knight whose funeral was presided over by a Pope.' Not much different from Langdon's, the clue for this challenge is: 'this element is Pope.' As with the election of a new Pope, once discovery of a new chemical element is officially recognized, a new name is adopted. The christening of an element, however, does not happen overnight as the assumption of regnal names by pontiffs. The element 114 was discovered in 1999, this discovery was confirmed a decade later in 2009, the element was officially recognized in 2011. To facilitate the scientific communications regarding elements which lack a formal name, a nomenclature of systematic naming has been established by the International Union of Pure and Applied Chemistry (IUPAC), the International body in charge of christening all new chemical elements. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d1d607aa-387a-4e87-ab79-88cc02e8ba4b ER - TY - JOUR TI - Strained lattice with persistent atomic order in Pt3Fe 2 intermetallic core-shell nanocatalysts DO - 10.1021/nn4019009 AU - Prabhudev, Sagar AU - Bugnet, Matthieu AU - Bock, Christina AU - Botton, Gianluigi A. T2 - ACS Nano SN - 1936-0851 VL - 7 IS - 7 SP - 6103 EP - 6110 KW - Aberration-corrected scanning transmission electron microscopies KW - Compositional analysis KW - Enhanced catalytic activity KW - Lattice strain KW - Nanocatalysts KW - Oxygen reduction reaction KW - Scanning transmission electron microscopy KW - Two Dimensional (2 D) KW - Atoms KW - Catalyst activity KW - Degradation KW - Durability KW - Electrolytic reduction KW - Energy dispersive spectroscopy KW - Proton exchange membrane fuel cells (PEMFC) KW - Shells (structures) KW - Surface relaxation KW - Transmission electron microscopy KW - Two dimensional KW - X ray diffraction KW - Platinum AB - Fine-tuning nanocatalysts to enhance their catalytic activity and durability is crucial to commercialize proton exchange membrane fuel cells. The structural ordering and time evolution of ordered Pt3Fe2 intermetallic core-shell nanocatalysts for the oxygen reduction reaction that exhibit increased mass activity (228%) and an enhanced catalytic activity (155%) compared to Pt/C has been quantified using aberration-corrected scanning transmission electron microscopy. These catalysts were found to exhibit a static core-dynamic shell regime wherein, despite treating over 10 000 cycles, there is negligible decrease (9%) in catalytic activity and the ordered Pt 3Fe2 core remained virtually intact while the Pt shell suffered a continuous enrichment. The existence of this regime was further confirmed by X-ray diffraction and the compositional analyses using energy-dispersive spectroscopy. With atomic-scale two-dimensional (2-D) surface relaxation mapping, we demonstrate that the Pt atoms on the surface are slightly relaxed with respect to bulk. The cycled nanocatalysts were found to exhibit a greater surface relaxation compared to noncycled catalysts. With 2-D lattice strain mapping, we show that the particle was about -3% strained with respect to pure Pt. While the observed enhancement in their activity is ascribed to such a strained lattice, our findings on the degradation kinetics establish that their extended catalytic durability is attributable to a sustained atomic order. DA - 2013/06/17 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 747146e2-9b5a-4b16-91f0-23ba20313fb7 ER - TY - JOUR TI - Patient-specific scatter correction in clinical cone beam computed tomography imaging made possible by the combination of Monte Carlo simulations and a ray tracing algorithm DO - 10.3109/0284186X.2013.813641 AU - Thing, Rune S. AU - Bernchou, Uffe AU - Mainegra-Hing, Ernesto AU - Brink, Carsten T2 - Acta Oncologica SN - 0284-186X VL - 52 IS - 7 SP - 1477 EP - 1483 KW - calibration KW - computed tomography scanner KW - cone beam computed tomography KW - image quality KW - imaging system KW - Monte Carlo method KW - phantom KW - radiation dose distribution KW - radiation scattering KW - simulation AB - Purpose. Cone beam computed tomography (CBCT) image quality is limited by scattered photons. Monte Carlo (MC) simulations provide the ability of predicting the patient-specific scatter contamination in clinical CBCT imaging. Lengthy simulations prevent MC-based scatter correction from being fully implemented in a clinical setting. This study investigates the combination of using fast MC simulations to predict scatter distributions with a ray tracing algorithm to allow calibration between simulated and clinical CBCT images. Material and methods. An EGSnrc-based user code (egs-cbct), was used to perform MC simulations of an Elekta XVI CBCT imaging system. A 60keV x-ray source was used, and air kerma scored at the detector plane. Several variance reduction techniques (VRTs) were used to increase the scatter calculation efficiency. Three patient phantoms based on CT scans were simulated, namely a brain, a thorax and a pelvis scan. A ray tracing algorithm was used to calculate the detector signal due to primary photons. A total of 288 projections were simulated, one for each thread on the computer cluster used for the investigation. Results. Scatter distributions for the brain, thorax and pelvis scan were simulated within 2% statistical uncertainty in two hours per scan. Within the same time, the ray tracing algorithm provided the primary signal for each of the projections. Thus, all the data needed for MC-based scatter correction in clinical CBCT imaging was obtained within two hours per patient, using a full simulation of the clinical CBCT geometry. Conclusions. This study shows that use of MC-based scatter corrections in CBCT imaging has a great potential to improve CBCT image quality. By use of powerful VRTs to predict scatter distributions and a ray tracing algorithm to calculate the primary signal, it is possible to obtain the necessary data for patient specific MC scatter correction within two hours per patient. DA - 2013/10 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3c47f0e6-5a17-4f66-bf78-f6474b2aadd1 ER - TY - JOUR TI - Quantum memories and large-scale quantum coherence based on Raman interactions DO - 10.1109/PHOSST.2013.6614558 AU - Nunn, Josh AU - Sprague, Michael R. AU - Michelberger, Patrick S. AU - Champion, Tessa F. M. AU - Jin, Xian-Min AU - Langford, Nathan K. AU - Sussman, Benjamin J. AU - England, Duncan G. AU - Barbieri, Marco AU - Kolthammer, W. Steven AU - Walmsley, Ian A. T2 - Photonics Society Summer Topical Meeting Series, 2013 IEEE T3 - 2013 IEEE Photonics Society Summer Topical Meeting Series, PSSTMS 2013, July 8-10, 2013, Waikoloa, HI, USA SN - 9781467350594 SN - 1467350591 SP - 6614558 SP - 173 EP - 174 KW - Foundations of quantum mechanics KW - Fundamental research KW - Quantum coherence KW - Quantum correlations KW - Quantum technologies KW - Quantum-information processing KW - Raman interactions KW - Time-bandwidth products KW - Quantum electronics KW - Quantum optics KW - Quantum entanglement AB - Applied research into quantum technologies and fundamental research into the foundations of quantum mechanics run hand in hand, since our understanding of quantum correlations both advances, and is advanced by, our ability to control large quantum systems. The off-resonant Raman interaction of light with material systems provides a powerful tool both for quantum information processing, and for accessing macroscopic non-classical states of matter. We describe a recent demonstration of entanglement between the motion of separated diamond crystals at room temperature, and the implementation of quantum memories in cesium vapour that can store and retrieve photons on demand with a time-bandwidth product exceeding 2000, both based on Raman scattering. © 2013 IEEE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 807b5a32-6056-4072-8e01-2677024edf00 ER - TY - JOUR TI - Femtosecond laser nanomachining initiated by ultraviolet multiphoton ionization DO - 10.1364/OE.21.024185 AU - Yu, Xiaming AU - Bian, Qiumei AU - Chang, Zenghu AU - Corkum, P. B. AU - Lei, Shuting T2 - Optics Express SN - 1094-4087 VL - 21 IS - 20 SP - 24185 EP - 24190 KW - Combined pulse KW - Damage features KW - Damage threshold KW - Multiphoton ionization KW - Nanomachining KW - Near-infrared KW - Rate-equation models KW - Shorter wavelength KW - Fused silica KW - Photoionization KW - Ultrafast lasers KW - Ultrashort pulses AB - We report on the experimental results of 300 nm features generated on fused silica using a near-infrared (IR) femtosecond laser pulse initiated by an ultraviolet (UV) pulse. With both pulses at a short (~60 fs) delay, the damage threshold of the UV pulse is only 10% of its normal value. Considerable reduction of UV damage threshold is observed when two pulses are at ± 1.3 ps delay. The damage feature size of the combined pulses is similar to that of a single UV pulse. A modified rate equation model with the consideration of defect states is used to help explain these results. This concept can be applied to shorter wavelengths, e.g. XUV and X-ray, with the required fluence below their normal threshold. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d7d1ea1c-bbeb-4e1c-90ef-e5928c4d224c ER - TY - JOUR TI - Near-infrared femtosecond laser machining initiated by ultraviolet multiphoton ionization DO - 10.1063/1.4794946 AU - Yu, X. AU - Bian, Q. AU - Zhao, B. AU - Chang, Z. AU - Corkum, P. B. AU - Lei, S. T2 - Applied Physics Letters SN - 0003-6951 VL - 102 IS - 10 SP - 101111-1 EP - 101111-4 AB - We report on the experimental study of microstructures fabricated on the surface of fused silica by two femtosecond laser pulses, a tightly focused 266 nm beam followed by a loosely focused 800 nm beam. By setting the fluence of each pulse below the damage threshold, visible microstructures are fabricated using the combined beams. Our results suggest that the ultraviolet pulse generates seed electrons through multiphoton absorption, and the near-infrared pulse utilizes these electrons to cause damage by avalanche ionization. DA - 2013/03/14 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e5b4e4d3-6946-4e16-bb83-16bbe97f7096 ER - TY - JOUR TI - Molecular alignment using circularly polarized laser pulses DO - 10.1088/0953-4075/46/20/201001 AU - Smeenk, C. T. L. AU - Corkum, P. B. T2 - Journal of Physics B: Atomic, Molecular and Optical Physics SN - 0953-4075 SN - 1361-6455 VL - 46 IS - 20 SP - 201001-1 EP - 201001-4 AB - We show that circularly polarized femtosecond laser pulses produce field-free alignment in linear and planar molecules. We study the rotational wavepacket evolution of O2 and benzene created by circularly polarized light. For benzene, we align the molecular plane to the plane of polarization. For O2, we demonstrate that circular polarization yields a net alignment along the laser propagation axis at certain phases of the evolution. Circular polarization gives us the ability to control alignment of linear molecules outside the plane of polarization, providing new capabilities for molecular imaging. DA - 2013/10/15 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d4938ccc-7119-4738-98c7-5614fe8515a7 ER - TY - JOUR TI - High harmonic cutoff energy scaling and laser intensity measurement with a 1.8 μm laser source DO - 10.1080/09500340.2013.765067 AU - Shiner, A. D. AU - Trallero-Herrero, C. AU - Kajumba, N. AU - Schmidt, B. E. AU - Bertrand, J. B. AU - Kim, Kyung Taec AU - Bandulet, H.-C. AU - Comtois, D. AU - Kieffer, J.-C. AU - Rayner, D. M. AU - Corkum, P. B. AU - Légaré, F. AU - Villeneuve, D. M. T2 - Journal of Modern Optics SN - 0950-0340 SN - 1362-3044 VL - 60 IS - 17 SP - 1458 EP - 1465 KW - high harmonic generation; phase matching AB - High harmonic generation in gas targets leads to the production of attosecond pulses. The process of high harmonic generation requires that the gas be ionized by an intense femtosecond laser field. The highest photon energy produced is related to the laser intensity times the wavelength squared. This cutoff is reached only if good phase matching is achieved. Using a laser with a wavelength of 1800 nm, we estimate the laser intensity in the gas jet by recording the ion yield, and simultaneously record the high harmonic spectrum. We show that the cutoff energy matches the measured intensity, confirming that good phase matching is achieved to 100 eV. We also use the ion collector to characterize the spatial size of the gas jet and to measure the confocal parameter of the laser beam, parameters that are useful for numerical modelling. DA - 2013/02/12 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e08f91f7-9828-4a24-bfea-95c4e13d05c5 ER - TY - JOUR TI - Trajectory-resolved Coulomb focusing in tunnel ionization of atoms with intense, elliptically polarized laser pulses DO - 10.1103/PhysRevLett.111.023005 AU - Shafir, D. AU - Soifer, H. AU - Vozzi, C. AU - Johnson, A. S. AU - Hartung, A. AU - Dube, Z. AU - Villeneuve, D. M. AU - Corkum, P. B. AU - Dudovich, N. AU - Staudte, A. T2 - Physical Review Letters SN - 0031-9007 SN - 1079-7114 VL - 111 IS - 2 SP - 023005-1 EP - 023005-5 AB - In strong-field light-matter interactions, the strong laser field dominates the dynamics. However, recent experiments indicate that the Coulomb force can play an important role as well. In this Letter, we have studied the photoelectron momentum distributions produced from noble gases in elliptically polarized, 800 nm laser light. By performing a complete mapping of the three-dimensional electron momentum, we find that Coulomb focusing significantly narrows the lateral momentum spread. We find a surprisingly sensitive dependence of Coulomb focusing on the initial transverse momentum distribution, i.e., the momentum at the moment of birth of the photoelectron. We also observe a strong signature of the low-energy structure in the above threshold ionization spectrum. DA - 2013/07/09 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9ccabf44-683f-4c3d-8121-9ad3badec5c4 ER - TY - JOUR TI - Control of energy deposition in femtosecond laser dielectric interactions DO - 10.1063/1.4802820 AU - Peng, Jiahui AU - Grojo, David AU - Rayner, David M. AU - Corkum, Paul B. T2 - Applied Physics Letters SN - 0003-6951 VL - 102 IS - 16 SP - 161105-1 EP - 161105-3 AB - There are natural limits to the spatial resolution and the deposited energy densities that can be achieved in femtosecond laser dielectric modification. These arise because of the threshold-like nature of nonlinear absorption. We use two-pulse experiments to show that both limits can be exceeded by taking advantage of absorption seeded by free electrons or self-trapped excitons, depending on the pulse separation. DA - 2013/04/23 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d24af294-055b-48d8-b5a2-0114a625f6a6 ER - TY - JOUR TI - Femtosecond laser desorption of ultrathin polymer films from a dielectric surface DO - 10.1063/1.4817816 AU - Mercadier, Laurent AU - Peng, Jiahui AU - Sultan, Yasir AU - Davis, Thomas A. AU - Rayner, David M. AU - Corkum, Paul B. T2 - Applied Physics Letters SN - 0003-6951 VL - 103 IS - 6 SP - 061107-01 EP - 061107-04 AB - By focusing femtosecond pulses on the front and rear surface of a fused silica coverslip, we desorb 8-nm thick polymer films at submicron scale. To determine the role of the substrate in the desorption process, we measure the threshold for nonlinear absorption in fused silica and compare it to the threshold for desorption, taking into account the enhancement of the field at the dielectric-air interface. The results indicate that absorption of energy only occurs in the film. We then measure the beam radius in situ by the knife-edge technique and characterize the desorption by atomic force microscopy. The radius of the laser desorbed area is determined by the desorption threshold intensity and can be a factor of 5 smaller than the beam waist DA - 2013/08/06 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 389e40b7-1f07-4aab-a442-4bd554d30e97 ER - TY - JOUR TI - Petahertz optical oscilloscope DO - 10.1038/nphoton.2013.286 AU - Kim, Kyung Taec AU - Zhang, Chunmei AU - Shiner, Andrew D. AU - Schmidt, Bruno E. AU - Légaré, François AU - Villeneuve, D. M. AU - Corkum, P. B. T2 - Nature Photonics SN - 1749-4885 SN - 1749-4893 VL - 7 IS - 12 SP - 958 EP - 962 AB - The time-dependent field of an electromagnetic pulse can be measured if there is a fast enough gate. For terahertz radiation, femtosecond photoinjection of free carriers into a semiconductor in the presence of the terahertz radiation can serve as the gate1. For visible or infrared radiation, attosecond photoionization of a gas target in the presence of the optical field is a direct analogue2–8. Here, we show that nonlinear optical mixing9–13 in a medium in which attosecond pulses are being generated can also be used to measure the time-dependent field of an optical pulse. The gate is the phase accumulated by the recollision electron during the subcycle time interval between ionization and recombination. We show that the instantaneous field of an unknown pulse is imprinted onto the deflection of the attosecond extreme ultraviolet pulse using an all-optical set-up with a bandwidth up to 1 PHz. DA - 2013/11/03 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 83e82449-d2f5-4ced-bef7-9f2c3bf6135e ER - TY - JOUR TI - Photonic streaking of attosecond pulse trains DO - 10.1038/nphoton.2013.170 AU - Kim, Kyung Taec AU - Zhang, Chunmei AU - Ruchon, Thierry AU - Hergott, Jean-François AU - Auguste, Thierry AU - Villeneuve, D. M. AU - Corkum, P. B. AU - Quéré, F. T2 - Nature Photonics SN - 1749-4885 SN - 1749-4893 VL - 7 IS - 8 SP - 651 EP - 656 AB - High harmonic radiation, produced when intense laser pulses interact with matter, is composed of a train of attosecond pulses. Individual pulses in this train carry information on ultrafast dynamics that vary from one half-optical-cycle to the next. Here, we demonstrate an all-optical photonic streaking measurement that provides direct experimental access to each attosecond pulse by mapping emission time onto propagation angle. This is achieved by inducing an ultrafast rotation of the instantaneous laser wavefront at the focus. We thus time-resolve attosecond pulse train generation, and hence the dynamics in the nonlinear medium itself. We apply photonic streaking to harmonic generation in gases and directly observe, for the first time, the influence of non-adiabatic electron dynamics and plasma formation on the generated attosecond pulse train. These experimental and numerical results also provide the first evidence of the generation of attosecond lighthouses in gases, which constitute ideal sources for attosecond pump–probe spectroscopy. DA - 2013/07/07 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 14e8fa79-d378-404c-89c6-dfd29ec9c12b ER - TY - JOUR TI - Not so loosely bound rare gas atoms : finite-temperature vibrational fingerprints of neutral gold-cluster complexes DO - 10.1088/1367-2630/15/8/083003 AU - Ghiringhelli, Luca M. AU - Gruene, Philipp AU - Lyon, Jonathan T. AU - Rayner, David M. AU - Meijer, Gerard AU - Fielicke, André AU - Scheffler, Matthias T2 - New Journal of Physics SN - 1367-2630 VL - 15 IS - 8 SP - 1 EP - 23 AB - We present an experimental and theoretical study of the structure of small, neutral gold clusters—Au3, Au4 and Au7—'tagged' by krypton atoms. Infrared (IR) spectra of AuNcenterdotKrM complexes formed at 100 K are obtained via far-IR multiple photon dissociation in a molecular beam. The theoretical study is based on a statistical (canonical) sampling of the AuNcenterdotKrM complexes through ab initio molecular dynamics using density-functional theory in the generalized gradient approximation, explicitly corrected for long-range van-der-Waals (vdW) interactions. The choice of the functional is validated against higher-level first-principle methods. Thereby finite-temperature theoretical vibrational spectra are obtained that are compared with the experimental spectra. This enables us to identify which structures are present in the experimental molecular beam for a given cluster size. For Au2, Au3 and Au4, the predicted vibrational spectra of the Kr-complexed and pristine species differ. For Au7, the presence of Kr influences the vibrational spectra only marginally. This behavior is explained in terms of the formation of a weak chemical bond between Kr and small gold clusters that localizes the Kr atom at a defined adsorption site, whereas for bigger clusters the vdW interactions prevail and the Kr adatom is delocalized and orbits the gold cluster. In all cases, at temperatures as low as T = 100 K, vibrational spectra already display a notable anharmonicity and show, in comparison with harmonic spectra, different position of the peaks, different intensities and broadenings, and even the appearance of new peaks. DA - 2013/08/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6af4f89c-71d2-4f85-8161-d1384b4d1dca ER - TY - JOUR TI - Laser-induced orbital projection and diffraction of O-2 with velocity map imaging DO - 10.1080/09500340.2013.771755 AU - Comtois, D. AU - Bandulet, H.-C. AU - Spanner, M. AU - Pavičić, D. AU - Meckel, M. AU - Zeidler, D. AU - Pépin, H. AU - Dörner, R. AU - Kieffer, J.-C. AU - Villeneuve, D. M. AU - Corkum, P. B. AU - Staudte, A. T2 - Journal of Modern Optics SN - 0950-0340 SN - 1362-3044 VL - 60 IS - 17 SP - 1395 EP - 1408 KW - velocity map imaging; laser induced electron diffraction; orbital imaging AB - In a velocity map imaging spectrometer, we measured the electron momentum distributions from the ionization of O molecules with 800 nm wavelength, 40 fs laser pulses at a peak intensity of W cm. The molecules were aligned at 0, 45 and 90 relative to the laser polarization prior to ionization. We show that for all alignments the low momentum region – populated by direct electrons which do not recollide with the parent ion – is consistent with the ionized orbital being filtered and projected onto the continuum electron wave packet. In the high momentum region – populated by rescattered electrons – we observe that the pattern created by diffraction of the recolliding wave packet by the ion core disappears as the alignment gets closer to the laser field axis. We find that a two-slit diffraction model agrees well with the results for molecules aligned at 90, but only partially predicts the decrease in the diffraction signature for smaller alignment angles. DA - 2013/03/06 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c1b66326-d38b-49b0-ba27-5d7722c084c5 ER - TY - JOUR TI - Performance evaluation of 3D imaging systems based on GD&T DO - 10.1016/j.mfglet.2013.08.004 AU - Carrier, Benjamin AU - Mackinnon, David K. AU - Cournoyer, Luc T2 - Manufacturing Letters SN - 22138463 VL - 1 IS - 1 SP - 9 EP - 12 KW - 3D imaging systems KW - performance KW - characterization KW - geometrical and dimensional tolerancing KW - 3D metrology AB - We present a method for evaluating the performance of short-range non-contact 3D imaging systems. This method is intended to address the lack of internationally-recognized standards for the characterization of these systems. We begin by presenting characterization-specific terminology before introducing a geometrical and dimensional tolerancing-based approach for the characterization of these systems. This approach focuses on what these systems are typically used for rather than being designed specifically for specific classes of 3D imaging systems. A Portable Characterization Target (PCT) is then presented as an artifact that provides a simple way to perform the characterization of short-range non-contact 3D imaging systems. DA - 2013/09/11 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 09ce70c4-b092-4e22-92c9-cd5d5130a865 ER - TY - JOUR TI - Linked attosecond phase interferometry for molecular frame measurements DO - 10.1038/nphys2540 AU - Bertrand, J. B. AU - Wörner, H. J. AU - Salières, P. AU - Villeneuve, D. M. AU - Corkum, P. B. T2 - Nature Physics SN - 1745-2473 SN - 1745-2481 VL - 9 IS - 3 SP - 174 EP - 178 AB - High-harmonic spectroscopy uses attosecond techniques to measure single-atom or molecule photorecombination cross-sections. Whereas the amplitude of the extreme-ultraviolet light is easily measurable, the phase is more challenging to access. However, the phase contains information necessary for tomographic imaging of the molecular orbital wavefunction with attosecond–ångström resolution. Present techniques cannot simultaneously measure the phase as a function of molecular angle and photon frequency, which is necessary for a full reconstruction of the wavefunction. We overcome this limitation with an all-optical method that does not require any ad hoc assumptions about the phase. We apply it to record the full phase map of aligned bromine molecules relative to reference xenon atoms. It allows us to resolve, both spectrally and angularly, the participation of multiple molecular orbitals, and infer a phase of ionization. This method opens a path to time-resolved molecular orbital tomography. DA - 2013/02/10 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d4159260-1d24-4d9f-95fa-1c9c15e4a346 ER - TY - JOUR TI - Manipulation of quantum paths for space–time characterization of attosecond pulses DO - 10.1038/nphys2525 AU - Kim, Kyung Taec AU - Zhang, Chunmei AU - Shiner, Andrew D. AU - Kirkwood, Sean E. AU - Frumker, Eugene AU - Gariepy, Genevieve AU - Naumov, Andrei AU - Villeneuve, D. M. AU - Corkum, P. B. T2 - Nature Physics SN - 1745-2473 SN - 1745-2481 VL - 9 IS - 3 SP - 159 EP - 163 AB - Attosecond extreme-ultraviolet pulses have a complex space–time structure. However, at present, there is no method to observe this intricate detail; all measurements of the duration of attosecond pulses are, to some extent, spatially averaged. A technique for determining the full space–time structure would enable a detailed study of the highly nonlinear processes that generate these pulses as a function of intensity without averaging. Here, we introduce and demonstrate an all-optical method to measure the space–time characteristics of an isolated attosecond pulse. Our measurements show that intensity-dependent phase and quantum-path interference both play a key role in determining the pulse structure. In the generating medium, the attosecond pulse is strongly modulated in space and time. Propagation modifies but does not erase this modulation. Quantum-path interference of the single-atom response, previously obscured by spatial and temporal averaging, may enable measuring the laser-field-driven ion dynamics with sub-cycle resolution. DA - 2013/01/20 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f268392e-2620-40f9-811b-bf5ea64d448f ER - TY - JOUR TI - Small platinum cluster hydrides in the gas phase DO - 10.1021/jp405120u AU - Kerpal, Christian AU - Harding, Dan J. AU - Rayner, David M. AU - Fielicke, André T2 - The Journal of Physical Chemistry A SN - 1089-5639 SN - 1520-5215 VL - 117 IS - 34 SP - 8230 EP - 8237 AB - The reactions of small cationic platinum clusters (Pt2+–Pt7+) with molecular hydrogen were investigated, and the structures of the hydride complexes were analyzed using IR spectroscopy. We determined the relative reaction rates for the addition of the first H2 molecule to the platinum clusters, and we report the hydrogen saturation coverages observed at high H2 concentration. High H atom per Pt atom ratios were observed, similar to earlier measurements on other group-10 transition metals. The structures of the fully saturated complexes of Pt2+–Pt5+ were investigated using a combination of infrared multiple-photon dissociation (IR-MPD) spectroscopy in the frequency range of 550–2050 cm–1 and density functional theory-based calculations. We found molecularly bound hydrogen alongside bridge and often atop binding of hydrogen atoms for all of the low-energy structures, in contrast to earlier theoretical predictions. DA - 2013/07/31 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0118d8af-9035-42e2-af81-9f7f49f949f8 ER - TY - JOUR TI - Molecular motions of adsorbed CO2 on a tetrazole-functionalized PIM polymer studied with 13C NMR DO - 10.1021/jp4084234 AU - Moore, Jeremy K. AU - Guiver, Michael D. AU - Du, Naiying AU - Hayes, Sophia E. AU - Conradi, Mark S. T2 - The Journal of Physical Chemistry C SN - 1932-7447 SN - 1932-7455 VL - 117 IS - 44 SP - 22995 EP - 22999 KW - CO2; 13C NMR; in situ NMR; adsorption; membrane separation; PIM; tetrazole-functionalized AB - The CO2 adsorption in a polymer of intrinsic microporosity (PIM) functionalized by tetrazole (TZPIM) has been studied with in situ 13C nuclear magnetic resonance (NMR) spectroscopy at variable temperature and loading conditions. The CO2 molecules are seen to interact with tetrazole sites through physisorption. The adsorbed system was studied from 8 K to 385 K at two loadings of CO2. The 13C NMR resonance lineshapes and relaxation times have been analyzed to give insights into the adsorption process. The CO2 molecules undergo site to site hopping with accompanying CO2 reorientations while adsorbed on TZPIM, resulting in line narrowing starting near 100 K. Correspondingly, the spin echo T2 passes through a minimum at 100 K. The analysis indicates two kinds of adsorption sites are available. DA - 2013/10/15 PY - 2013 PB - American Chemical Society (ACS) LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 693dc3ca-eeb3-4db1-88c6-380db6ad16e6 ER - TY - JOUR TI - Artery phantoms for intravascular optical coherence tomography : diseased arteries DO - 10.1117/1.JBO.18.9.096010 AU - Bisaillon, Charles-Étienne AU - Lamouche, Guy T2 - Journal of Biomedical Optics SN - 1083-3668 VL - 18 IS - 9 SP - 096010-1 EP - 096010-6 KW - medical imaging; coherent optical systems; tissues; targets AB - We propose and test various strategies for the creation of artery phantoms mimicking different kinds of diseased arteries when imaged by intravascular optical coherence tomography (IVCT). We first review the method for making artery phantoms. We then describe the procedure to fabricate diseased artery phantoms with intima thickening, lipid pool, thin-capped fibroatheroma, calcification, and restenosis (homogeneous and layered) after stent apposition. For each case, a phantom is fabricated, an IVOCT image is obtained and the image is compared to that of a real artery. DA - 2013/09/10 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 7ca6b452-7794-46d3-a6aa-e8ad41527d74 ER - TY - JOUR TI - Distributed cavity phase calculation for a rectangular Ramsey cavity in NRC-FCs1 DO - 10.1109/EFTF-IFC.2013.6702294 AU - Marmet, Louis AU - Dube, Pierre AU - Shtin, Nicolas AU - Lopez, J. Maricio T2 - 2013 Joint European Frequency and Time Forum & International Frequency Control Symposium (EFTF/IFC) T3 - 2013 Joint European Frequency and Time Forum & International Frequency Control Symposium (EFTF/IFC), July 21-25, 2013, Prague, Czech Republic SN - 978-1-4799-0342-9 SP - 764 EP - 767 AB - A preliminary calculation of the frequency shifts resulting from the distributed phase of a rectangular cavity is used to model frequency measurements of the fountain clock NRC-FCs1. The calculation is based on a numerical evaluation of the cavity field made with a finite element EM solver. The frequency shift is obtained by solving the Bloch-equations numerically along the path of the atoms on the free-fall trajectories through the cavity. We study the frequency shifts as a function of the launch direction, the tilt of the physics package and offsets in the position of the MOT relative to the axis defined by the state-selection cavity and the Ramsey cavity. DA - 2013/07/25 PY - 2013 PB - IEEE LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a3aba777-ac9a-462b-b024-897e81d2b4ba ER - TY - JOUR TI - Quantifying the calibration uncertainty attributable to thermocouple inhomogeneity DO - 10.1063/1.4819595 AU - Hill, Kenneth D. AU - Gee, Douglas J. T2 - Temperature : Its Measurement and Control in Science and Industry T2 - AIP Conference Proceedings; no. 1552 T3 - 9th International Temperature Symposium (ITS9), March 19–23 2012, Los Angeles, California, USA SN - 0094-243X SN - 978-0-7354-1178-4 VL - 8 SP - 520 EP - 525 KW - Inhologeneity; Seebeck; thermocouple AB - Inhomogeneity in the Seebeck coefficient as a function of position along a thermocouple wire frequently dominates the uncertainty budgets of thermocouple calibration and use. The calibration process itself, simply through exposure to elevated temperatures for relatively modest times, generates both reversible and irreversible changes to the thermocouple that are a complex function of time, temperature, alloy composition, sheath structure, etc. We present data acquired using a salt bath at 250 °C to provide the step-function-like gradient that is our spatial probe of thermoelectric homogeneity. We show how the finite width of the step-function limits our ability to assess the "true" inhomogeneity of the thermocouple, and explore how the inhomogeneity impacts the calibration uncertainty attainable with the various thermal sources used for the calibration of thermocouples (based on their characteristic temperature gradients). DA - 2013/09/11 PY - 2013 PB - AIP Publishing LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4d7fc383-8e4d-4296-9bf5-ce0a6ab27921 ER - TY - JOUR TI - Fast luminescence in silicon-germanium nanostructures DO - 10.1149/05041.0035ecst AU - Lockwood, David J. AU - Wu, Xiaohua AU - Baribeau, Jean-Marc AU - Modi, Nikhil AU - Tsybeskov, Leonid T2 - Luminescence and Display Materials: Fundamentals and Applications T2 - ECS Transactions T3 - PRiME 2012: Pits and Pores 5: A Symposium in Honor of David Lockwood, October 7-12, 2012, Honolulu, Hawaii SN - 1938-5862 SN - 1938-6737 SN - 978-1-62332-077-5 SN - 978-1-60768-429-9 VL - 50 IS - 41 SP - 35 EP - 47 KW - Carrier recombination KW - CMOS Compatible KW - Light emitters KW - Light emitting devices KW - Si/SiGe KW - Silicon Germanium KW - Spectral range KW - Germanium KW - Light KW - Silicon alloys KW - Nanostructures AB - Epitaxially-grown three-dimensional Si/SiGe nanostructures produce photoluminescence and electroluminescence in the desired spectral range of 1.3-1.6 μm. We show that by controlling and modifying such Ge-rich SiGe nanoclusters during growth it is possible to fabricate very fast and hence more efficient SiGe light-emitting devices. The physics of carrier recombination in these Si/SiGe nanostructures is discussed. The present results provide another possible route toward CMOS compatible light emitters. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8c5096bb-75eb-4252-a75a-ebe00543dd02 ER - TY - JOUR TI - Diagnostic technique for smart maintenance of medium voltage power cables based on Depolarization Principle AU - Abou-Dakka, Mahmoud AU - McIntyre, Douglas T2 - Proceedings of the Fourth International Meeting on Dielectric Materials T3 - Fourth International Meeting on Dielectric Materials (IMDM'4), May 29-31, 2013, Marrakech, Morocco KW - Diagnostic KW - Polarization/depolarization KW - cable maintenance strategy AB - In this paper, after showing the evolution of the insulation condition with aging time and its link to water trees, the results obtained from performing the depolarization techniques in-field on a large number of cables will be presented. The link between age of cable and its condition will be discussed. This would make a large step toward the development of a smart maintenance strategy for planning the replacement strategy of power cables. DA - 2013/05/31 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8bf337b7-c4ca-4458-b54a-f4e2b32dfc7a ER - TY - JOUR TI - Water-use efficiency Code requirements reach public review stage AU - Green, Diane T2 - Construction Innovation SN - 1203-2743 VL - 18 IS - 2 AB - The fall 2013 public review provides an opportunity to comment on proposed changes to add water-use efficiency requirements to the National Plumbing Code of Canada 2015. The proposed changes are issued for public review by the Canadian Commission on Building and Fire Codes (CCBFC). DA - 2013/09/20 PY - 2013 PB - National Research Council Canada UR - http://www.nrc-cnrc.gc.ca/ci-ic/article/v18n2-3 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 791bef02-49be-479c-ad74-fdc4863e554f ER - TY - JOUR TI - Commission reviews standards for low lead in Canadian plumbing fittings AU - Green, Diane T2 - Construction Innovation SN - 1203-2743 VL - 18 IS - 2 AB - According to Health Canada, exposure to lead can be harmful to human health, even in small amounts. Everyone is exposed to trace amounts of it in air, soil, household dust and drinking water. Although drinking water is not the most significant source of exposure in Canada, lead can leach into the water system from the corrosion of pipes and fittings, especially if those fittings touch stagnant water. DA - 2013/09/20 PY - 2013 PB - National Research Council Canada UR - http://www.nrc-cnrc.gc.ca/ci-ic/article/v18n2-4 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f8d9682c-fd32-4acc-93f5-0f34c79f90a8 ER - TY - JOUR TI - Electrochemical characterization of anodic biofilm development in a microbial fuel cell DO - 10.1007/s10800-013-0537-2 AU - Martin, Edith AU - Savadogo, Oumarou AU - Guiot, Serge R. AU - Tartakovsky, Boris T2 - Journal of Applied Electrochemistry SN - 0021-891X SN - 1572-8838 VL - 43 IS - 5 SP - 533 EP - 540 KW - MFC; Anodic biofilm; Cyclic voltammetry; EIS; Internal resistance AB - Electrochemical impedance spectroscopy, cyclic voltammetry, and polarization tests were used to monitor the progress of the anode colonization by electrode-reducing microorganisms in a single-chamber membraneless microbial fuel cell seeded with anaerobic sludge. The electrochemical methods showed that an increase in microbial fuel cell power output coincided with a progressive decrease of the anode internal resistance and a more negative open circuit potential. Two redox systems were observed in cyclic voltammograms shortly after microbial fuel cell startup, while a redox system with a peak around −330 mV (vs. Ag/AgCl) was predominant in the mature biofilm. The redox systems were also dependent on the external resistance chosen for microbial fuel cell operation. This suggests that within the diverse microbial populations several species are capable of electron transfer to the anode, and that the microorganisms with the highest electron transfer rate become predominant. Furthermore, the growth of these electrode-reducing microorganisms can be accelerated by optimizing the microbial fuel cell electrical load. DA - 2013/02/26 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : badc355d-f4a2-4a24-8718-57f8d111ab72 ER - TY - JOUR TI - An improved current-comparator-based power standard with an uncertainty of 2.5 μw/VA (k = 1) DO - 10.1109/TIM.2013.2239015 AU - So, E. AU - Arseneau, R. AU - Angelo, D. T2 - IEEE Transactions on Instrumentation and Measurement SN - 0018-9456 VL - 62 IS - 6 SP - 6466383 SP - 1704 EP - 1709 KW - Current comparators KW - High-accuracy KW - Power bridges KW - Power factors KW - Power standard KW - Sinusoidal conditions KW - uncertainty KW - Voltage ranges KW - Comparators (optical) KW - Electric power factor KW - Electric power measurement KW - Uncertainty analysis AB - An improved power standard derived from a current comparator power bridge for calibrating active/reactive power and energy meters under sinusoidal conditions is described. Measurements can be made at any power factor from zero lag through unity to zero lead, at positive or negative power, at 120 V, 5 A, and 50 or 60 Hz. The improved power standard has an estimated uncertainty of not more than 2.5 μW/VA at k = 1. Special high-accuracy current and voltage range extenders have been incorporated to extend the current and voltage ranges up to 200 A and 1200 V, respectively. © 2013 IEEE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 70f0f594-4aa7-4932-8f8f-bdfb00b9143a ER - TY - JOUR TI - Studies of variability in proto-planetary nebulae. II. Light and velocity curve analyses of Iras 22272+5435 and 22223+4327 DO - 10.1088/0004-637X/766/2/116 AU - Hrivnak, B.J. AU - Lu, W. AU - Sperauskas, J. AU - Van Winckel, H. AU - Bohlender, D. AU - Začs, L. T2 - The Astrophysical Journal SN - 0004-637X VL - 766 IS - 2 SP - 116 AB - We have carried out a detailed observational study of the light, color, and velocity variations of two bright, carbon-rich proto-planetary nebulae, IRAS 22223+4327 and 22272+5435. The light curves are based upon our observations from 1994 to 2011, together with published data by Arkhipova and collaborators. They each display four significant periods, with primary periods for IRAS 22223+4327 and 22272+5435 being 90 and 132 days, respectively. For each of them, the ratio of secondary to primary period is 0.95, a value much different from that found in Cepheids, but which may be characteristic of post-asymptotic giant branch (AGB) stars. Fewer significant periods are found in the smaller radial velocity data sets, but they agree with those of the light curves. The color curves generally mimic the light curves, with the objects reddest when faintest. A comparison in seasons when there exist contemporaneous light, color, and velocity curves reveals that the light and color curves are in phase, while the radial velocity curves are ∼0.25 P out of phase with the light curves. Thus they differ from what is seen in Cepheids, in which the radial velocity curve is 0.50 P out of phase with the light curve. Comparison of the observed periods and amplitudes with those of post-AGB pulsation models shows poor agreement, especially for the periods, which are much longer than predicted. These observational data, particularly the contemporaneous light, color, and velocity curves, provide an excellent benchmark for new pulsation models of cool stars in the post-AGB, proto-planetary nebula phase. © 2013. The American Astronomical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng N1 - Erratum published in volume 777, issue 1, article 80, 2013. DOI: 10.1088/0004-637X/777/1/80 C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 67c8619d-bebb-41a2-90c0-f97091f8ae8e ER - TY - JOUR TI - Plant and bird presence strongly influences the microbial communities in soils of Admiralty Bay, Maritime Antarctica DO - 10.1371/journal.pone.0066109 AU - Teixeira, L.C.R.S. AU - Yeargeau, E. AU - Balieiro, F.C. AU - Piccolo, M.C. AU - Peixoto, R.S. AU - Greer, C.W. AU - Rosado, A.S. T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 6 SP - e66109 KW - nitrogen KW - RNA 16S KW - Acidobacteria KW - Antarctica KW - article KW - Colobanthus quitensis KW - community structure KW - controlled study KW - Deschampsia antarctica KW - environmental factor KW - Firmicutes KW - greenhouse effect KW - microarray analysis KW - microbial community KW - nitrogen concentration KW - nonhuman KW - penguin KW - plant KW - polymerase chain reaction KW - population abundance KW - rhizosphere KW - sampling KW - soil microflora KW - species distribution KW - taxon AB - Understanding the environmental factors that shape microbial communities is crucial, especially in extreme environments, like Antarctica. Two main forces were reported to influence Antarctic soil microbes: birds and plants. Both birds and plants are currently undergoing relatively large changes in their distribution and abundance due to global warming. However, we need to clearly understand the relationship between plants, birds and soil microorganisms. We therefore collected rhizosphere and bulk soils from six different sampling sites subjected to different levels of bird influence and colonized by Colobanthus quitensis and Deschampsia antarctica in Admiralty Bay, King George Island, Maritime Antarctic. Microarray and qPCR assays targeting 16S rRNA genes of specific taxa were used to assess microbial community structure, composition and abundance and analyzed with a range of soil physico-chemical parameters. The results indicated significant rhizosphere effects in four out of the six sites, including areas with different levels of bird influence. Acidobacteria were significantly more abundant in soils with little bird influence (low nitrogen) and in bulk soil. In contrast, Actinobacteria were significantly more abundant in the rhizosphere of both plant species. At two of the sampling sites under strong bird influence (penguin colonies), Firmicutes were significantly more abundant in D. antarctica rhizosphere but not in C. quitensis rhizosphere. The Firmicutes were also positively and significantly correlated to the nitrogen concentrations in the soil. We conclude that the microbial communities in Antarctic soils are driven both by bird and plants, and that the effect is taxa-specific. © 2013 Teixeira et al. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 20afb806-eb78-4b2c-9ad2-2bf924cce7dc ER - TY - JOUR TI - Correlating infall with deuterium fractionation in dense cores DO - 10.1088/0004-637X/777/2/121 AU - Schnee, S. AU - Brunetti, N. AU - Di Francesco, J. AU - Caselli, P. AU - Friesen, R. AU - Johnstone, D. AU - Pon, A. T2 - The Astrophysical Journal SN - 0004-637X VL - 777 IS - 2 SP - 121 AB - We present a survey of HCO+ (3-2) observations pointed toward dense cores with previous measurements of N(N2D+)/N(N 2H+). Of the 26 cores in this survey, 5 show the spectroscopic signature of outward motion, 9 exhibit neither inward nor outward motion, 11 appear to be infalling, and 1 is not detected. We compare the degree of deuterium fractionation with infall velocities calculated from the HCO + spectra and find that those cores with [D]/[H] > 0.1 are more likely to have the signature of inward motions than cores with smaller [D]/[H] ratios. Infall motions are also much more common in cores with masses exceeding their thermal Jeans masses. The fastest infall velocity measured belongs to one of the two protostellar cores in our survey, L1521F, and the observed motions are typically on the order of the sound speed. © 2013. The American Astronomical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8596564e-d3a4-4291-bfb0-f215e51b79bf ER - TY - JOUR TI - Nanoscale structuring of tungsten tip yields most coherent electron point-source DO - 10.1088/1367-2630/15/7/073038 AU - Mutus, J.Y. AU - Livadaru, L. AU - Urban, R. AU - Pitters, J. AU - Peter Legg, A. AU - Salomons, M.H. AU - Cloutier, M. AU - Wolkow, R.A. T2 - New Journal of Physics SN - 1367-2630 VL - 15 SP - 73038 KW - Coherence properties KW - Emission current KW - Extraction voltage KW - High-aspect ratio KW - Holographic measurement KW - Low energy electrons KW - Point source microscopes KW - Virtual sources KW - Aspect ratio KW - Electrons KW - Optical microscopy KW - Tungsten AB - This report demonstrates the most spatially-coherent electron source ever reported. A coherence angle of 14.3 ± 0.5° was measured, indicating a virtual source size of 1.7 ± 0.6 Å using an extraction voltage of 89.5 V. The nanotips under study were crafted using a spatially-confined, field-assisted nitrogen etch which removes material from the periphery of the tip apex resulting in a sharp, tungsten-nitride stabilized, high-aspect ratio source. The coherence properties are deduced from holographic measurements in a low-energy electron point source microscope with a carbon nanotube bundle as sample. Using the virtual source size and emission current the brightness normalized to 100 kV is found to be 7.9 × 108 A sr-1 cm2. © IOP Publishing and Deutsche Physikalische Gesellschaft. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a351e2f9-8e8e-49d5-bc52-a71e353dead0 ER - TY - JOUR TI - A MegaCam survey of outer halo satellites. II. Blue stragglers in the lowest stellar density systems DO - 10.1088/0004-637X/774/2/106 AU - Santana, F.A. AU - Muñoz, R.R. AU - Geha, M. AU - Côté, P. AU - Stetson, P. AU - Simon, J.D. AU - Djorgovski, S.G. T2 - The Astrophysical Journal SN - 0004-637X VL - 774 IS - 2 SP - 106 AB - We present a homogeneous study of blue straggler stars across 10 outer halo globular clusters, 3 classical dwarf spheroidal galaxies, and 9 ultra-faint galaxies based on deep and wide-field photometric data taken with MegaCam on the Canada-France-Hawaii Telescope. We find blue straggler stars to be ubiquitous among these Milky Way satellites. Based on these data, we can test the importance of primordial binaries or multiple systems on blue straggler star formation in low-density environments. For the outer halo globular clusters, we find an anti-correlation between the specific frequency of blue stragglers and absolute magnitude, similar to that previously observed for inner halo clusters. When plotted against density and encounter rate, the frequency of blue stragglers is well fit by a single trend with a smooth transition between dwarf galaxies and globular clusters; this result points to a common origin for these satellites' blue stragglers. The fraction of blue stragglers stays constant and high in the low encounter rate regime spanned by our dwarf galaxies, and decreases with density and encounter rate in the range spanned by our globular clusters. We find that young stars can mimic blue stragglers in dwarf galaxies only if their ages are 2.5 ± 0.5 Gyr and they represent ∼1%-7% of the total number of stars, which we deem highly unlikely. These results point to mass-transfer or mergers of primordial binaries or multiple systems as the dominant blue straggler formation mechanism in low-density systems. © 2013. The American Astronomical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c84bd68a-2ad6-4ef9-a8fd-187a67ba0ca0 ER - TY - JOUR TI - A pixel is an artifact: On the necessity of zero-filling in Fourier imaging DO - 10.1002/cmr.a.21256 AU - Zhu, X. AU - Tomanek, B. AU - Sharp, J. T2 - Concepts in Magnetic Resonance Part A: Bridging Education and Research SN - 1546-6086 VL - 42 A IS - 2 SP - 32 EP - 44 AB - MR imaging data is sometimes presented in a "patchwork quilt" format with individual pixels visible as squares of uniform intensity. This phenomenon often arises by default from an image space convolution (performed implicitly by the graphics system) used to convert the sparse point sampling of the spatial domain offered by the discrete Fourier transform (DFT) into a sufficiently dense sampling to allow assignment of an intensity value to each addressable point on the display device. Typical examples are fMRI maps, spectroscopic images and zoomed-in views. These square patches are image structure not present in the object, i.e., artifacts. This form of image display is studied by both an image analysis method and by Fourier analysis. Image formation by display of the 2D DFT of an acquired k-space matrix as a 2D pixel array is a poor reconstruction because it does not ensure a faithful representation of the spatial frequency content actually present in the data. By analysis of the visual appearance of 2D pixel arrays we show that there are two principal effects: (a) attenuation of higher spatial frequencies (i.e., low-pass filtering); (b) introduction of artifactual high frequency image structure. These effects can lead to very poor performance with an artifact/signal ratio of over 200% in the corners of 2D k-space. Generated k-space maps demonstrate that both detrimental effects increase radially in k-space. The simple remedy is to zero-fill (resulting in image interpolation) until individual pixels become invisible in the displayed image. Alternatively, data modeling may be used. © 2013 Wiley Periodicals, Inc. DA - 2013/03/19 PY - 2013 PB - Wiley LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e7a23ead-93f8-44c2-9a37-4749bb206d99 ER - TY - JOUR TI - Aerodynamic characterization of a thin, high-performance airfoil for use in ground fluids testing DO - 10.2514/6.2013-2933 AU - Broeren, A.P. AU - Lee, S. AU - Clark, C. T2 - 5th AIAA Atmospheric and Space Environments Conference T3 - 5th AIAA Atmospheric and Space Environments Conference, 24 June 2013 through 27 June 2013, San Diego, CA KW - Aero-dynamic performance KW - Aerodynamic characterization KW - Aerodynamic effect KW - Anti-icing fluids KW - Flow disturbances KW - Laminar separation bubble KW - National Research Council of Canada KW - Wind-tunnel testing KW - Contamination KW - Data visualization KW - Ice KW - Laminar flow KW - Pelletizing KW - Reynolds number KW - Wind tunnels KW - Aerodynamics AB - The FAA has worked with Transport Canada and others to develop allowance times for aircraft operating in ice-pellet precipitation. Wind-tunnel testing has been carried out to better understand the flowoff characteristics and resulting aerodynamic effects of anti-icing fluids contaminated with ice pellets using a thin, high-performance wing section at the National Research Council of Canada Propulsion and Icing Wind Tunnel. The objective of this paper is to characterize the aerodynamic behavior of this wing section in order to better understand the adverse aerodynamic effects of anti-icing fluids and ice-pellet contamination. Aerodynamic performance data, boundary-layer surveys and flow visualization were conducted at a Reynolds number of approximately 6.0×106 and a Mach number of 0.12. The clean, baseline model exhibited leading-edge stall characteristics including a leading-edge laminar separation bubble and minimal or no separation on the trailing edge of the main element or flap. These results were consistent with expected 2-D aerodynamics and showed no anomalies that could adversely affect the evaluation of anti-icing fluids and ice-pellet contamination on the wing. Tests conducted with roughness and leading-edge flow disturbances helped to explain the aerodynamic impact of the anti-icing fluids and contamination. The stalling characteristics of the wing section with fluid and contamination appear to be driven at least partially by the effects of a secondary wave of fluid that forms near the leading edge as the wing is rotated in the simulated takeoff profile. These results have provided a much more complete understanding of the adverse aerodynamic effects of anti-icing fluids and ice-pellet contamination on this wing section. This is important since these results are used, in part, to develop the ice-pellet allowance times that are applicable to many different airplanes. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c4b96a58-1332-4bad-816d-63ec3df224ce ER - TY - JOUR TI - Distortion and residual stress measurements of induction hardened AISI 4340 discs DO - 10.1016/j.matchemphys.2013.07.012 AU - Yi, J. AU - Gharghouri, M. AU - Bocher, P. AU - Medraj, M. T2 - Materials Chemistry and Physics SN - 0254-0584 VL - 142 IS - 1 SP - 248 EP - 258 KW - Hardened layers KW - Hardening depth KW - Hardness levels KW - Induction hardening KW - Lattice spacing KW - Neutron scattering and diffraction KW - Orthogonal directions KW - Stress calculations KW - Hardness KW - Heat treatment KW - Induction heating KW - Metals KW - Neutron diffraction KW - Residual stresses KW - Stress concentration KW - X ray diffraction KW - Hardening AB - 10 Induction hardened discs with two initial hardness levels were used for exploring the influences of the variation of initial hardness as well as induction hardening (IH) recipes on the heat treatment distortions and hardening depth. The results show that for the same initial hardness, the larger the energy input, the higher the distortion size as well as the hardening depth. For a given induction hardening recipe, the increase in initial hardness leads to a deeper hardening depth but a smaller distortion. One disc was selected for the residual stress investigation in three orthogonal directions by neutron diffraction (ND). The corresponding stress-free lattice spacing d0 was measured from the same material using both ND and X-ray diffraction (XRD) methods. The ND results show that the variation of d0 in the hardened layer is significant and should be taken into account for stress calculation. However, regarding the core region, the d0 value measured by XRD is more reliable. Accordingly, a combination of the ND-measured d0 profiles in the hardened layer and the XRD-measured d0 value in the core was adopted for the determination of residual stress distributions. © 2013 Elsevier B.V. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e45080cc-3d18-4adc-833f-4e0f9a1502b1 ER - TY - JOUR TI - Analytical technologies for influenza virus-like particle candidate vaccines: Challenges and emerging approaches DO - 10.1186/1743-422X-10-141 AU - Thompson, C.M. AU - Petiot, E. AU - Lennaertz, A. AU - Henry, O. AU - Kamen, A.A. T2 - Virology Journal SN - 1743-422X VL - 10 SP - 141 KW - influenza vaccine KW - influenza virus like particle vaccine KW - unclassified drug KW - virus protein KW - cell strain HEK293 KW - DNA vector KW - electron microscopy KW - enzyme activity KW - enzyme linked immunosorbent assay KW - HeLa cell KW - immunodiffusion KW - Influenza virus KW - insect cell KW - protein analysis KW - reversed phase high performance liquid chromatography KW - review KW - Vero cell KW - virion KW - virus hemagglutination KW - virus strain KW - Western blotting KW - Orthomyxoviridae AB - Influenza virus-like particle vaccines are one of the most promising ways to respond to the threat of future influenza pandemics. VLPs are composed of viral antigens but lack nucleic acids making them non-infectious which limit the risk of recombination with wild-type strains. By taking advantage of the advancements in cell culture technologies, the process from strain identification to manufacturing has the potential to be completed rapidly and easily at large scales. After closely reviewing the current research done on influenza VLPs, it is evident that the development of quantification methods has been consistently overlooked. VLP quantification at all stages of the production process has been left to rely on current influenza quantification methods (i.e. Hemagglutination assay (HA), Single Radial Immunodiffusion assay (SRID), NA enzymatic activity assays, Western blot, Electron Microscopy). These are analytical methods developed decades ago for influenza virions and final bulk influenza vaccines. Although these methods are time-consuming and cumbersome they have been sufficient for the characterization of final purified material. Nevertheless, these analytical methods are impractical for in-line process monitoring because VLP concentration in crude samples generally falls out of the range of detection for these methods. This consequently impedes the development of robust influenza-VLP production and purification processes. Thus, development of functional process analytical techniques, applicable at every stage during production, that are compatible with different production platforms is in great need to assess, optimize and exploit the full potential of novel manufacturing platforms. © 2013 Thompson et al.; licensee BioMed Central Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c21848bf-d808-44a0-a341-ec9e862aad69 ER - TY - JOUR TI - Impact of water quality on the bacterial populations and off-flavours in recirculating aquaculture systems DO - 10.1111/1574-6941.12053 AU - Auffret, M. AU - Yergeau, E. AU - Pilote, A. AU - Proulx, E. AU - Proulx, D. AU - Greer, C.W. AU - Vandenberg, G. AU - Villemur, R. T2 - FEMS Microbiology Ecology SN - 0168-6496 VL - 84 IS - 2 SP - 235 EP - 247 KW - 2 methylisoborneol KW - 2-methylisoborneol KW - bornane derivative KW - fresh water KW - geosmin KW - naphthol derivative KW - aquaculture KW - bacterium KW - biofiltration KW - gene expression KW - nitrification KW - phosphate KW - population structure KW - species diversity KW - turbidity KW - water quality KW - animal KW - aquaculture KW - article KW - bacterium KW - chemistry KW - genetics KW - isolation and purification KW - metabolism KW - microbiology KW - nitrification KW - rainbow trout KW - water quality KW - Animals KW - Aquaculture KW - Bacteria KW - Bornanes KW - Fresh Water KW - Naphthols KW - Nitrification KW - Oncorhynchus mykiss KW - Water Quality KW - Bacteria (microorganisms) KW - Myxococcales KW - Nannocystis KW - Sorangium AB - A variety of factors affecting water quality in recirculating aquaculture systems (RAS) are associated with the occurrence of off-flavours. In this study, we report the impact of water quality on the bacterial diversity and the occurrence of the geosmin-synthesis gene (geoA) in two RAS units operated for 252 days. Unit 2 displayed a higher level of turbidity and phosphate, which affected the fresh water quality compared with unit 1. In the biofilter, nitrification is one of the major processes by which high water quality is maintained. The bacterial population observed in the unit 1 biofilter was more stable throughout the experiment, with a higher level of nitrifying bacteria compared with the unit 2 biofilter. Geosmin appeared in fish flesh after 84 days in unit 2, whereas it appeared in unit 1 after 168 days, but at a much lower level. The geoA gene was detected in both units, 28 days prior to the detection of geosmin in fish flesh. In addition, we detected sequences associated with Sorangium and Nannocystis (Myxococcales): members of these genera are known to produce geosmin. These sequences were observed at an earlier time in unit 2 and at a higher level than in unit 1. This study confirms the advantages of new molecular methods to understand the occurrence of geosmin production in RAS. © 2012 Federation of European Microbiological Societies. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : fd104f1e-da77-411a-8098-73a8d2412f6f ER - TY - JOUR TI - Dynamical magnetic and nuclear polarization in complex spin systems: Semi-magnetic II-VI quantum dots DO - 10.1088/1367-2630/15/6/063039 AU - Abolfath, R.M. AU - Trojnar, A. AU - Roostaei, B. AU - Brabec, T. AU - Hawrylak, P. T2 - New Journal of Physics SN - 1367-2630 VL - 15 SP - 63039 KW - Dipole interaction KW - Electron spin transfer KW - Hyperfine interactions KW - II-VI quantum dots KW - Nuclear polarization KW - Nuclear-spin polarization KW - Radiative recombination KW - Spin-polarized excitons KW - Excitons KW - Polarization KW - Semiconductor quantum dots KW - Spin dynamics KW - Magnetism AB - Dynamical magnetic and nuclear polarization in complex spin systems is discussed on the example of transfer of spin from exciton to the central spin of magnetic impurity in a quantum dot in the presence of a finite number of nuclear spins. The exciton is described in terms of electron and heavy-hole spins interacting via exchange interaction with magnetic impurity, via hyperfine interaction with a finite number of nuclear spins and via dipole interaction with photons. The time evolution of the exciton, magnetic impurity and nuclear spins is calculated exactly between quantum jumps corresponding to exciton radiative recombination. The collapse of the wavefunction and the refilling of the quantum dot with a new spin-polarized exciton is shown to lead to the build up of magnetization of the magnetic impurity as well as nuclear spin polarization. The competition between electron spin transfer to magnetic impurity and to nuclear spins simultaneous with the creation of dark excitons is elucidated. The technique presented here opens up the possibility of studying optically induced dynamical magnetic and nuclear polarization in complex spin systems. © 2013 IOP Publishing and Deutsche Physikalische Gesellschaft. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0d6d92e0-53c8-4a49-88a9-533e51e039f6 ER - TY - JOUR TI - Verification of icephobic/anti-icing properties of a superhydrophobic surface DO - 10.1021/am400429q AU - Wang, Y. AU - Xue, J. AU - Wang, Q. AU - Chen, Q. AU - Ding, J. T2 - ACS Applied Materials and Interfaces SN - 1944-8244 VL - 5 IS - 8 SP - 3370 EP - 3381 KW - ice-repellent KW - Impact dynamics KW - Sliding angle KW - Super-hydrophobic surfaces KW - Superhydrophilic surface KW - Superhydrophobic KW - Surface wettability KW - Water contact angle KW - Adhesion KW - Atmospheric humidity KW - Coatings KW - Contact angle KW - High speed photography KW - Ice KW - Surface properties KW - Temperature KW - Wetting KW - Hydrophobicity AB - Four aluminum surfaces with wettability varied from superhydrophilic to superhydrophobic were prepared by combining an etching and a coating process. The surface wettability was checked in terms of water contact angle (CA) and sliding angle (SA) under different humidity at -10 C. High-speed photography was applied to study water droplet impact dynamics on these surfaces. It was found that single and successive water droplets could rebound on the superhydrophobic surface and roll off at a tilt angle larger than 30 under an extremely condensing weather condition (-10 C and relative humidity of 85-90%). In addition, the superhydrophobic surface showed a strong icephobic property, the ice adhesion on this surface was only 13% of that on the superhydrophilic surface, though they had a similar nano/microtopological structure. Moreover, this superhydrophobic surface displayed an excellent durability of the icephobic property. The ice adhesion only increased to 20% and 16% of that on the superhydrophobic surface after the surface was undergone 20 icing/ice-breaking cycles and 40 icing/ice-melting cycles, respectively. Surface profile and XPS studies on these surfaces indicated a minor damage of the surface nano/microstructure and the coating layer upon these multiple ice-breaking and ice-melting processes. Therefore, this superhydrophobic surface could be a good candidate for icephobic applications. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0309377e-958f-4bb7-8628-f27804b6bc9f ER - TY - JOUR TI - Increased microbial activity and nitrogen mineralization coupled to changes in microbial community structure in the rhizosphere of Bt corn DO - 10.1016/j.apsoil.2013.03.010 AU - Velasco, A.G.V. AU - Kowalchuk, G.A. AU - Mañero, F.J.G. AU - Ramos, B. AU - Yergeau, E. AU - García, J.A.L. T2 - Applied Soil Ecology SN - 0929-1393 VL - 68 SP - 46 EP - 56 AB - The interactions between plant roots and soil microorganisms are essential for the function and stability of ecosystems, primary agricultural production and plant health. Despite the importance of soil microbes the response of these microbes to large-scale cultivation of genetically modified (GM) crops is still poorly understood. This study evaluated the potential impact of two lines of transgenic Bt maize on rhizosphere microorganisms. A time-course field experiment was conducted over a period of two years in two fields in Guadalajara (Spain) with monthly sampling from April to September. Rhizosphere soil was collected from transgenic (TG) and unmodified (WT) maize plants from each field and sampling time for the analysis of several important functional and structural soil quality parameters. Total microbial activity, as determined by H3-Thymidine and C14-Leucine incorporation, was found to be higher in the rhizospheres of the transgenic plants. Similarly, differences in potential ammonification and nitrification were observed in the second year of the study. In contrast, bacterial and fungal microbial catabolic abilities, as determined by Biolog ECO and FF plate analyses, respectively, were more influenced by sampling time than the transgenic nature of the plants. Microbial community structure was also studied by bacterial and phylum-specific PCR-DGGE and PCR cloning approaches. In general, differences were again more pronounced between sampling times, as opposed to between TG versus WT plants, although marked differences were observed within the Betaproteobacteria between plant lines. For the first time it describes the presence of Iamiaceae family in soil, specifically to TG plant rhizosphere. To summarize, the study showed that some important properties of rhizopshere microbes may be impacted by Bt maize cultivation and highlighted the fact that such potential effects need to be viewed within the context of seasonal and spatial variability. © 2013 Elsevier B.V. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 353b0214-235b-4c94-b889-0cb9a4c7832e ER - TY - JOUR TI - Morphological and rheological properties of PET/clay nanocomposites DO - 10.1007/s00397-012-0667-1 AU - Ghanbari, A. AU - Heuzey, M.-C. AU - Carreau, P.J. AU - Ton-That, M.-T. T2 - Rheologica Acta SN - 0035-4511 VL - 52 IS - 1 SP - 59 EP - 74 AB - This work investigates the effects of clay chemistry and concentration on the morphology and rheology of polyethylene terephthalate (PET)/clay nanocomposites. The complex viscosity of the PET nanocomposites exhibited a more solid-like behavior, in contrast to the matrix that had a frequency-independent viscosity. In addition, at high frequencies where the behavior of the matrix should be dominant, a lower complex viscosity of the nanocomposites was observed due to PET degradation in the presence of the organoclays. The high-frequency data were used to estimate the matrix degradation using the Maron-Pierce equation. The apparent molecular weight of the PET matrix was found to decrease from 65 kg/mol for the neat PET to 30 kg/mol for a PET nanocomposite containing 8 wt% Cloisite® 30B. The apparent yield stress in the nanocomposites was determined using the Herschel-Bulkley model. Yield stress increased with the level of exfoliation and clay concentration, from ~0 to 166 Pa when the clay concentration increased from 2 to 8 wt%. © 2012 Springer-Verlag Berlin Heidelberg. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 976c50b8-1981-4a30-a3db-d1ca91e8ef2b ER - TY - JOUR TI - Selective pharmacological modulation of pyramidal neurons and interneurons in the CA1 region of the rat hippocampus DO - 10.3389/fphar.2013.00024 AU - Martina, M. AU - Comas, T. AU - Mealing, G.A.R. T2 - Frontiers in Pharmacology SN - 1663-9812 VL - 4-Mar SP - Article 24 KW - AMPA receptor KW - dizocilpine KW - memantine KW - n methyl dextro aspartic acid receptor KW - n methyl dextro aspartic acid receptor 1 KW - n methyl dextro aspartic acid receptor 2A KW - n methyl dextro aspartic acid receptor 2B KW - n methyl dextro aspartic acid receptor 2C KW - animal cell KW - animal tissue KW - article KW - cell structure KW - cellular distribution KW - concentration response KW - controlled study KW - dose response KW - drug antagonism KW - excitatory postsynaptic potential KW - hippocampal CA1 region KW - hyperpolarization KW - inhibitory postsynaptic potential KW - interneuron KW - membrane steady potential KW - nerve cell stimulation KW - neurotransmission KW - nonhuman KW - patch clamp KW - protein expression KW - pyramidal nerve cell KW - rat KW - stratum radiatum AB - The hippocampus is a complex network tightly regulated by interactions between excitatory and inhibitory neurons. In neurodegenerative disorders where cognitive functions such as learning and memory are impaired this excitation-inhibition balance may be altered. Interestingly, the uncompetitive N-methyl-D-aspartate receptor (NMDAR) antagonist memantine, currently in clinical use for the treatment of Alzheimer's disease, may alter the excitation-inhibition balance in the hippocampus. However, the specific mechanism by which memantine exerts this action is not clear. To better elucidate the effect of memantine on hippocampal circuitry, we studied its pharmacology on NMDAR currents in both pyramidal cells (PCs) and interneurons (Ints) in the CA1 region of the hippocampus. Applying whole-cell patch-clamp methodology to acute rat hippocampal slices, we report that memantine antagonism is more robust in PCs than in Ints. Using specific NMDAR subunit antagonists, we determined that this selective antagonism of memantine is attributable to specific differences in the molecular make-up of the NMDARs in excitatory and inhibitory neurons. These findings offer new insight into the mechanism of action and therapeutic potential of NMDA receptor pharmacology in modulating hippocampal excitability. © 2013 Martina, Comas and Mealing. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4f56b050-b79b-4207-98e0-ffb72b4c50a6 ER - TY - JOUR TI - Detecting concept relations in clinical text: Insights from a state-of-the-art model DO - 10.1016/j.jbi.2012.11.006 AU - Zhu, X. AU - Cherry, C. AU - Kiritchenko, S. AU - Martin, J. AU - de Bruijn, B. T2 - Journal of Biomedical Informatics SN - 1532-0464 VL - 46 IS - 2 SP - 275 EP - 285 KW - Electronic health record KW - Knowledge sources KW - Medical concepts KW - NAtural language processing KW - Real-world scenario KW - Semantic relations KW - State of the art KW - Text mining KW - Algorithms KW - Artificial intelligence KW - Data mining KW - Medical problems KW - Semantics KW - Natural language processing systems KW - accuracy KW - article KW - data extraction KW - human KW - kernel method KW - priority journal KW - semantics AB - This paper addresses an information-extraction problem that aims to identify semantic relations among medical concepts (problems, tests, and treatments) in clinical text. The objectives of the paper are twofold. First, we extend an earlier one-page description (appearing as a part of [5]) of a top-ranked model in the 2010 I2B2 NLP Challenge to a necessary level of details, with the belief that feature design is the most crucial factor to the success of our system and hence deserves a more detailed discussion. We present a precise quantification of the contributions of a wide variety of knowledge sources. In addition, we show the end-to-end results obtained on the noisy output of a top-ranked concept detector, which could help construct a more complete view of the state of the art in the real-world scenario. As the second major objective, we reformulate our models into a composite-kernel framework and present the best result, according to our knowledge, on the same dataset. © 2012. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6e865eaf-0f5a-43e7-82f4-ae2d16f652c5 ER - TY - JOUR TI - Data mining based fault isolation with FMEA rank: A case study of APU fault identification DO - 10.1109/ICPHM.2013.6621454 AU - Yang, C. AU - Létourneau, S. AU - Yang, Y. AU - Liu, J. T2 - PHM 2013 - 2013 IEEE International Conference on Prognostics and Health Management, Conference Proceedings T3 - 2013 IEEE International Conference on Prognostics and Health Management, PHM 2013, 24 June 2013 through 27 June 2013, Gaithersburg, MD SN - 9781467357227 SP - 6621454 AB - FMEA (Failure Mode and Effects Analysis), which was developed to enhance the reliability of complex systems, is a standard method to characterize and document product and process problems and a systematic method for fault identification/isolation in maintenance industry. Fault identification for a given failure effect or mode is a reactive process. Usually, a failure has occurred and it needs to identify which component is the root cause or to isolate the fault to a specific contributing component. Traditional method is to conduct TSM (Trouble Shooting Manuals)-based fault isolation, which is complicated, expensive, and time-consuming. To efficiently perform fault isolation, this paper proposed data mining-based framework for fault isolation by using FMEA information to rank data-driven models. In this paper, we present the proposed framework along with a case study for APU fau It identification. © 2013 IEEE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 507d51da-6ccb-4e5b-8a8c-efe05b65175f ER - TY - JOUR TI - Identification of the common antigenic determinant shared by Streptococcus pneumoniae serotypes 33A, 35A, and 20 capsular polysaccharides DO - 10.1016/j.carres.2013.08.001 AU - Lin, F.L. AU - Vinogradov, E. AU - Deng, C. AU - Zeller, S. AU - Green, B.A. AU - Jansen, K.U. AU - Pavliak, V. T2 - Carbohydrate Research SN - 0008-6215 VL - 380 SP - 101 EP - 107 KW - Acetyl transferase KW - Antigenic determinant KW - Capsular polysaccharides KW - Serotypes KW - Streptococcus pneumoniae KW - Acetylation KW - Body fluids KW - Polysaccharides KW - Antigens KW - acyltransferase KW - bacterial polysaccharide KW - disaccharide KW - epitope KW - monosaccharide KW - acetylation KW - anion exchange chromatography KW - article KW - capillary electrophoresis KW - chemical structure KW - linkage analysis KW - nonhuman KW - nuclear magnetic resonance spectroscopy KW - priority journal KW - serotype KW - Streptococcus pneumoniae AB - In order to better understand cross-reactions of serogroup 33 polysaccharides and the typing sera, the structure of pneumococcal capsular polysaccharide serotype 33A was elucidated. Serotype 33A has been shown to have an identical polysaccharide backbone as that of serotype 33F, with two additional sites of O-acetylation at C5, and C6 of the 3-β-Galf residue in serotype 33A. This finding is consistent with the presence of an additional functional acetyltransferase gene (wcjE) in the cps biosynthetic locus of serotype 33A compared to 33F. The identical polysaccharide backbone with at least one common O-acetylation site (C2 of 5-β-Galf) shared by serotype 33A and 33F polysaccharides is proposed to be the epitope recognized by typing serum 33b. In addition, a 5,6-di-O-acetylated →3)-β-d-Galf5,6Ac- (1→3)-β-d-Glcp-(1→ disaccharide unit, a common structural motif present in serotypes 33A, 20, and 35A polysaccharides, is proposed to be the antigenic determinant recognized by typing serum 20b. © 2013 Published by Elsevier Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 55658aee-e11f-448c-85f0-80d20dcafbd5 ER - TY - JOUR TI - A magnetic confinement versus rotation classification of massive-star magnetospheres DO - 10.1093/mnras/sts344 AU - Petit, V. AU - Owocki, Department of Physics and Astronomy AU - Wade, Department of Physics AU - Cohen, D.H. AU - Sundqvist, J.O. AU - Gagne, M. AU - Máiz Apellaniz, J. AU - Oksala, M.E. AU - Bohlender, D.A. AU - Rivinius, T. AU - Henrichs, H.F. AU - Alecian, E. AU - Townsend, R.H.D. AU - Ud-Doula, A. AU - Collaboration, M. T2 - Monthly Notices of the Royal Astronomical Society SN - 0035-8711 VL - 429 IS - 1 SP - 398 EP - 422 AB - Building on results from the Magnetism in Massive Stars (MiMeS) project, this paper shows how a two-parameter classification of massive-star magnetospheres in terms of the magnetic wind confinement (which sets the Alfv́en radius RA) and stellar rotation (which sets the Kepler co-rotation radius RK) provides a useful organization of both observational signatures and theoretical predictions. We compile the first comprehensive study of inferred and observed values for relevant stellar and magnetic parameters of 64 confirmed magnetic OB stars with Teff> 16 kK. Using these parameters, we locate the stars in the magnetic confinement-rotation diagram, a log-log plot of RK versus RA. This diagram can be subdivided into regimes of centrifugal magnetospheres (CM), with RA > RK, versus dynamical magnetospheres (DM), with RK > RA. We show how key observational diagnostics, like the presence and characteristics of Ha emission, depend on a star-s position within the diagram, as well as other parameters, especially the expected wind mass-loss rates. In particular, we identify two distinct populations of magnetic stars with Ha emission: namely, slowly rotating O-type stars with narrow emission consistent with a DM, and more rapidly rotating B-type stars with broader emission associated with a CM. For O-type stars, the high mass-loss rates are sufficient to accumulate enough material for line emission even within the relatively short free-fall time-scale associated with a DM: this high mass-loss rate also leads to a rapid magnetic spindown of the stellar rotation. For the B-type stars, the longer confinement of a CMis required to accumulate sufficient emitting material from their relatively weak winds, which also lead to much longer spindown time-scales. Finally, we discuss how other observational diagnostics, e.g. variability of UV wind lines or X-ray emission, relate to the inferred magnetic properties of these stars, and summarize prospects for future developments in our understanding of massive-star magnetospheres©2012 The Authors. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9038428b-a295-47a6-bf77-75a63b9b9e4d ER - TY - JOUR TI - Variable stars in the globular cluster NGC 2808 DO - 10.1088/0004-6256/145/2/33 AU - Kunder, A. AU - Stetson, P.B. AU - Catelan, M. AU - Walker, A.R. AU - Amigo, P. T2 - Astronomical Journal SN - 0004-6256 VL - 145 IS - 2 SP - 33 AB - The first calibrated broadband BVI time-series photometry is presented for the variable stars in NGC 2808, with observations spanning a range of 28 years. We have also redetermined the variability types and periods for the variable stars identified previously by Corwin et al., revising the number of probable fundamental-mode RR Lyrae variables (RR0) to 11 and the number of first-overtone variables (RR1) to five. Our observations were insufficient to discern the nature of the previously identified RR1 star, V24, and the tentatively identified RR1 star, V13. These two variables are ∼0.8 mag brighter than the RR Lyrae variables, appear to have somewhat erratic period and/or luminosity changes, and lie inside the RR Lyrae instability strip. Curiously, all but one of the RR Lyrae stars studied in this relatively metal-rich cluster exhibit the Blazhko phenomenon, an effect thought to occur with higher frequency in metal-poor environments. The mean periods of the RR0 and RR1 variables are 〈P〉RR0 = 0.56 ± 0.01 d and 0.30 ± 0.02 d, respectively, supporting an Oosterhoff I classification of the cluster. On the other hand, the number ratio of RR1-to-RR0-type variables is high, though not unprecedented, for an Oosterhoff I cluster. The RR Lyrae variables have no period shifts at a given amplitude compared to the M3 variables, making it unlikely that these variables are He enhanced. Using the recent recalibration of the RR Lyrae luminosity scale by Catelan & Cortés, a mean distance modulus of (m-M)V = 15.57 ± 0.13 mag for NGC 2808 is obtained, in good agreement with that determined here from its type II Cepheid and SX Phoenicis population. Our data have also allowed the discovery of two new candidate SX Phoenicis stars and an eclipsing binary in the blue straggler region of the NGC 2808 color-magnitude diagram. © 2013. The American Astronomical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a02e87af-4cf9-455f-b211-7aa8d8922557 ER - TY - JOUR TI - Microwave-enhanced dephasing time in a HgCdTe film DO - 10.1063/1.4773178 AU - Wei, L.M. AU - Gao, K.H. AU - Liu, X.Z. AU - Yu, G. AU - Wang, Q.W. AU - Lin, T. AU - Guo, S.L. AU - Wei, Y.F. AU - Yang, J.R. AU - He, L. AU - Dai, N. AU - Chu, J.H. AU - Austing, D.G. T2 - Applied Physics Letters SN - 0003-6951 VL - 102 IS - 1 SP - 12108 KW - Anti-localization effects KW - Dephasing KW - Heating mechanisms KW - HgCdTe KW - HgCdTe films KW - Microwave field KW - Microwave power KW - Electron gas KW - Mercury compounds AB - The antilocalization effect in a compensated HgCdTe film is observed. With an applied microwave field, both the zero-magnetic-field conductance and the dephasing time are enhanced nonlinearly with microwave power. The observation concerning the dephasing time is inconsistent with a heating mechanism. Such behavior is also in contrast to the microwave-induced suppression of weak-antilocalization and dephasing time seen for a two-dimensional electron gas of the anodic-oxidized HgCdTe. The nonlinear increase in zero-magnetic-field conductance is consistent with a microwave-assisted-hopping mechanism. The increased dephasing time can be explained qualitatively by the microwave-assisted-hopping mechanism and a microwave-induced increase in the electron density. © 2013 American Institute of Physics. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 123cb098-6d23-4590-bdc2-ee4caf861bdc ER - TY - JOUR TI - The effect of drying method on ordinary Portland cement surfaces during the early stages of hydration DO - 10.1617/s11527-012-9878-2 AU - Makar, J.M. AU - Sato, T. T2 - Materials and Structures/Materiaux et Constructions SN - 1359-5997 VL - 46 IS - 1-Feb SP - 1 EP - 12 KW - Different solvents KW - Drying methods KW - Ettringites KW - High-resolution scanning electron microscopies KW - Nano scale KW - Ordinary Portland cement KW - Quantitative image analysis KW - Secondary electrons KW - SEM image KW - Small sample statistics KW - Solvent exchanges KW - Surface area KW - Surface feature KW - Dissolution KW - Electron microscopy KW - High resolution electron microscopy KW - Hydrated lime KW - Hydration KW - Nanotechnology KW - Scanning electron microscopy KW - Solvents AB - During the early stages of ordinary Portland cement (OPC) hydration, ettringite, calcium hydroxide and C-S-H form on the OPC surface while nanoscale pits are formed in the exposed surface areas. In order to study these features using high resolution electron microscopy, samples must be appropriately dried to remove unbound water. The work reported here compares the effects of freeze-drying to drying by solvent exchange using four different solvents on the surface features of OPC after four hours of hydration in order to determine whether the solvent exchange process produces nanoscale changes in the surface features that can be detected using high resolution scanning electron microscopy (SEM). A quantitative image analysis of secondary electron SEM images was performed and the results analyzed using small sample statistics. They suggest that all of the solvent exchange methods damage the OPC surface and produce surface structures not seen in the freeze-dried samples. Caution is therefore warranted in the use of solvent exchange in the preparation of samples for the study of the dissolution of OPC surfaces. © 2012 RILEM. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ed27bbab-c884-45fa-86c8-9278bc871021 ER - TY - JOUR TI - Multiplexed electrokinetic sample fractionation, preconcentration and elution for proteomics DO - 10.1039/c3lc50401h AU - Hua, Y. AU - Jemere, A.B. AU - Dragoljic, J. AU - Harrison, D.J. T2 - Lab on a Chip - Miniaturisation for Chemistry and Biology SN - 1473-0197 VL - 13 IS - 13 SP - 2651 EP - 2659 KW - [2 (methacryloyloxy)ethyl] trimethylammonium chloride KW - fluorescein isothiocyanate KW - polymer KW - unclassified drug KW - article KW - electroosmosis KW - electrospray mass spectrometry KW - elution KW - fluorescence KW - microfluidics KW - polymerization KW - priority journal KW - proteomics KW - solid phase extraction AB - Both 6 and 8-channel integrated microfluidic sample pretreatment devices capable of performing "in space" sample fractionation, collection, preconcentration and elution of captured analytes via sheath flow assisted electrokinetic pumping are described. Coatings and monolithic polymer beds were developed for the glass devices to provide cationic surface charge and anodal electroosmotic flow for delivery to an electrospray emitter tip. A mixed cationic ([2-(methacryloyloxy)ethyl] trimethylammonium chloride) (META) and hydrophobic butyl methacrylate-based monolithic porous polymer, photopolymerized in the 6- or 8-fractionation channels, was used to capture and preconcentrate samples. A 0.45 wt% META loaded bed generated comparable anodic electroosmotic flow to the cationic polymer PolyE-323 coated channel segments in the device. The balanced electroosmotic flow allowed stable electrokinetic sheath flow to prevent cross contamination of separated protein fractions, while reducing protein/peptide adsorption on the channel walls. Sequential elution of analytes trapped in the SPE beds revealed that the monolithic columns could be efficiently used to provide sheath flow during elution of analytes, as demonstrated for neutral carboxy SNARF (residual signal, 0.08% RSD, n = 40) and charged fluorescein (residual signal, 2.5% n = 40). Elution from monolithic columns showed reproducible performance with peak area reproducibility of ∼8% (n = 6 columns) in a single sequential elution and the run-to-run reproducibility was 2.4-6.7% RSD (n = 4) for elution from the same bed. The demonstrated ability of this device design and operation to elute from multiple fractionation beds into a single exit channel for sample analysis by fluorescence or electrospray mass spectrometry is a crucial component of an integrated fractionation and assay system for proteomics. © 2013 The Royal Society of Chemistry. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2e5ff108-10d6-4b3a-bc85-ed566f0d8519 ER - TY - JOUR TI - Investigation of corrosion behavior of wrought Co-Cr-W super alloys AU - Zhang, X.Z. AU - Liu, R. AU - Chen, K.Y. AU - Yao, M.X. T2 - NACE - International Corrosion Conference Series T3 - Corrosion 2013, 17 March 2013 through 21 March 2013, Orlando, FL SN - 0361-4409 SN - 9781627481458 AB - The corrosion behavior of two wrought Co-Cr-W superalloys is studied under both polarization immersion tests. The corrosive media, Green Death solution, is used in both tests. Potentiodynamic polarization and cyclic polarization testes are performed to investigate general and localized corrosion resistance of these alloys. Immersion tests of the two alloys are conducted in Green Death solution to determine Critical Pitting Temperature (CPT), mass loss, thickness change and the Extreme Value (minimum thickness) using Extreme Value Analysis (EVA) model derived from the Gumbel Distribution. A Scanning Electron Microscope (SEM) with Energy Dispersive X-ray (EDX) spectrum is utilized to analyze the chemical composition of the corrosion products (pits). The presence of carbides generates potential in the electrochemical reaction, causing corrosion of the alloys in the solution. The larger the carbide volume fraction, the more the pits are formed in the alloy. Carbide size also affects maximum pit depths; the larger the carbide size, the bigger and deeper the pits. The EDX analysis results of pits show large amount of oxygen in the carbide phase and a small amount of oxygen in the solid solution phase. The Cr-rich carbides react with oxygen forming Cr-rich carbonates which are easily brittle, loose and broken. © 2013 by NACE International. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c364aa86-3b70-4dca-b7c1-b0b65020e7ef ER - TY - JOUR TI - Strongly magnetic iron nanoparticles improve the fiagnosis of small tumours in the reticuloendothelial system by magnetic resonance imaging DO - 10.1371/journal.pone.0056572 AU - Ferguson, P.M. AU - Feindel, K.W. AU - Slocombe, A. AU - MacKay, M. AU - Wignall, T. AU - Delahunt, B. AU - Tilley, R.D. AU - Hermans, I.F. T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 2 SP - e56572 KW - superparamagnetic iron oxide nanoparticle KW - animal cell KW - animal experiment KW - animal model KW - article KW - breast cancer KW - cancer cell KW - controlled study KW - diagnostic accuracy KW - diagnostic test accuracy study KW - image analysis KW - image display KW - in vivo study KW - lymph node metastasis KW - micrometastasis KW - mouse KW - nonhuman KW - nuclear magnetic resonance imaging KW - outcome assessment KW - reticuloendothelial neoplasm KW - sensitivity and specificity KW - spleen KW - tumor diagnosis KW - tumor localization KW - Animals KW - Breast Neoplasms KW - Cell Line, Tumor KW - Contrast Media KW - Female KW - Humans KW - Iron KW - Magnetic Resonance Imaging KW - Magnetite Nanoparticles KW - Metal Nanoparticles KW - Mice KW - Mononuclear Phagocyte System AB - Despite advances in non-invasive medical imaging, accurate nodal staging of malignancy continues to rely on surgery. Superparamagnetic iron oxide nanoparticles (IONP) with lymphotropic qualities have shown some promise as contrast agents for MRI of the lymph nodes, but recent large-scale studies failed to show consistent detection of tumours below 5 mm. Herein we compare imaging of splenic and lymph node tissue using iron/iron oxide core/shell nanoparticles (Fe NP) that have superior magnetic qualities to IONP, to determine whether improved negative contrast in T2-weighted MRI can enhance the diagnosis of small tumours in the reticuloendothelial system. To provide an in vivo pre-clinical model of human lymph node micrometastases, breast cancer cells were injected into the spleens of mice, providing localised areas of tumour growth. MR images of groups of tumour-bearing and sham-treated animals were generated using a 1.5 T imaging system and analysed by two independent, blinded radiologists. Fe NP improved the sensitivity and specificity of MRI when compared to IONP, enabling accurate detection of tumours as small as 1-3 mm. The use of Fe NP as contrast agents have the potential to improve the diagnostic accuracy of MRI in cancer patients, leading to more rapid and effective treatment. © 2013 Ferguson et al. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3a6d9115-a203-4320-b743-c3a79c46e657 ER - TY - JOUR TI - Relating centromeric topography in fixed human chromosomes to -satellite DNA and CENP-B distribution DO - 10.1159/000348744 AU - Khan, W.A. AU - Chisholm, R. AU - Tadayyon, S. AU - Subasinghe, A. AU - Norton, P. AU - Samarabandu, J. AU - Johnston, L.J. AU - Knoll, J.H. AU - Rogan, P.K. T2 - Cytogenetic and Genome Research SN - 1424-8581 VL - 139 IS - 4 SP - 234 EP - 242 KW - centromere protein B KW - satellite DNA KW - article KW - atomic force microscopy KW - centromere KW - comparative study KW - controlled study KW - DNA sequence KW - fluorescence microscopy KW - fluorescent lighting KW - human KW - human cell KW - human chromosome KW - metaphase chromosome KW - priority journal KW - protein localization KW - Cell Line, Tumor KW - Centromere KW - Centromere Protein B KW - Chromatin KW - Chromosomes, Human, Pair 17 KW - DNA Probes KW - DNA, Satellite KW - Fluorescent Antibody Technique KW - Humans KW - In Situ Hybridization, Fluorescence KW - Lymphocytes KW - Metaphase KW - Microscopy, Atomic Force KW - Tissue Fixation AB - Despite extensive analyses on the centromere and its associated proteins, detailed studies of centromeric DNA structure have provided limited information about its topography in condensed chromatin. We have developed a method with correlative fluorescence light microscopy and atomic force microscopy that investigates the physical and structural organization of -satellite DNA sequences in the context of its associated protein, CENP-B, on human metaphase chromosome topography. Comparison of centromeric DNA and protein distribution patterns in fixed homologous chromosomes indicates that CENP-B and -satellite DNA are distributed distinctly from one another and relative to observed centromeric ridge topography. Our approach facilitates correlated studies of multiple chromatin components comprising higher-order structures of human metaphase chromosomes. © 2013 S. Karger AG, Basel. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 36ff577c-e59c-4f70-b977-cbfca7751a4a ER - TY - JOUR TI - Sialyltransferase inhibitors : consideration of molecular shape and charge/hydrophobic interactions DO - 10.1016/j.carres.2012.12.017 AU - Kumar, Rishi AU - Nasi, Ravindranath AU - Bhasin, Milan AU - Khieu, Nam Huan AU - Hsieh, Margaret AU - Gilbert, Michel AU - Jarrell, Harold AU - Zou, Wei AU - Jennings, Harold J. T2 - Carbohydrate Research SN - 0008-6215 VL - 378 SP - 45 EP - 55 KW - 1,2,3-Triazole KW - 2-Deoxy-2 KW - Click chemistry KW - Sialic acids KW - Sialyltransferase KW - Sialyltransferease inhibitors> KW - 2-Deoxy-2,3-dehydro-acetylneuraminic acid KW - Amino acids KW - Bacteria KW - Binding energy KW - Carboxylic acids KW - Hydrophobicity KW - Molecules KW - Nitrogen compounds KW - Sulfur compounds KW - Synthesis (chemical) KW - Enzyme inhibition KW - 1,2,3 triazole derivative KW - benzoic acid derivative KW - cytidine KW - cytidine phosphate n acetylneuraminic acid KW - phosphate KW - sialyltransferase KW - sulfanilamide KW - sulfonamide KW - article KW - binding affinity KW - Campylobacter jejuni KW - chemical structure KW - click chemistry KW - competitive inhibition KW - enzyme inhibition KW - glycosylation KW - hydrogen bond KW - hydrophobicity KW - molecular docking KW - molecular interaction KW - priority journal KW - Campylobacter jejuni AB - In order to evaluate the importance of molecular shape of inhibitor molecules and the charge/H-bond and hydrophobic interactions, we synthesized three types of molecules and tested them against a sialyltransferase. The first type of compounds were designed as substrate mimics in which the phosphate in CMP-Neu5NAc was replaced by a non-hydrolysable, uncharged 1,2,3-triazole moiety. The second type of compound contained a 2-deoxy-2,3-dehydro-acetylneuraminic moiety which was linked to cytidine through its carboxylic acid and amide linkers. In the third type of compound the sialyl phosphate was substituted by an aryl sulfonamide which was then linked to cytidine. Inhibition study of these cytidine conjugates against Campylobacter jejuni sialyltransferase Cst 06 showed that the first type of molecules are competitive inhibitors, whereas the other two could only inhibit the enzyme non-competitively. The results indicate that although the binding specificity may be guided by molecular shape and H-bond interaction, the charge and hydrophobic interactions contributed most to the binding affinity. DA - 2013/01/10 PY - 2013 PB - Elsevier Ltd. LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c6ebca10-a135-4907-acf2-aa07fc9fad31 ER - TY - JOUR TI - Proximity, knowledge transfer, and innovation in technology-based M&As DO - 10.1109/HICSS.2013.457 AU - Ensign, P.C. AU - Chreim, S. AU - Persaud, A. AU - Lin, C.-D. T2 - Proceedings of the Annual Hawaii International Conference on System Sciences T3 - 46th Annual Hawaii International Conference on System Sciences, HICSS 2013, 7 January 2013 through 10 January 2013, Wailea, Maui, HI SN - 1530-1605 SN - 9780769548920 SP - 6480275 SP - 3563 EP - 3572 KW - Knowledge transfer KW - Management interventions KW - Qualitative study KW - Technology-based KW - Three dimensions KW - Systems science KW - Knowledge management AB - This paper presents the findings from a qualitative study on the extent to which three dimensions of proximity-geographic, cognitive, and organizational-impact knowledge transfer and innovation post-M&A. Findings show that the elements of proximity substantially influence both knowledge transfer and innovation although the nature of the impact varies and is influenced by the type of management interventions or lack thereof post-M&A. © 2012 IEEE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 51acbb07-dfa7-481f-8a21-8edaa41e7492 ER - TY - JOUR TI - Density functional theory investigation of the binding interactions between phosphoryl, carbonyl, imino, and thiocarbonyl ligands and the pentaaqua nickel(II) complex: Coordination affinity and associated parameters DO - 10.1002/qua.24524 AU - Da Costa, L.M. AU - Stoyanov, S.R. AU - Damasceno, R.N. AU - De M. Carneiro, J.W. T2 - International Journal of Quantum Chemistry SN - 0020-7608 VL - 113 IS - 24 SP - 2621 EP - 2628 KW - DFT KW - EDA KW - Electron withdrawing group KW - Electron-donating group KW - Energy decomposition analysis KW - Interaction enthalpies KW - Metal-ligand interactions KW - Substituent effect KW - Binding energy KW - Chlorine compounds KW - Density functional theory KW - Metals KW - Nitrogen oxides KW - Positive ions KW - Ligands AB - Density Functional Theory (UB3LYP/6-311++G(d,p)) calculations of the affinity of the pentaaqua nickel(II) complex for a set of phosphoryl [Oï£P(H)(CH3)(PhR)], imino [HNï£C(CH 3)(PhR)], thiocarbonyl [Sï£C(CH3)(PhR)] and carbonyl [Oï£C(CH3)(PhR)] ligands were performed, where Rï£NH2, OCH3, OH, CH3, H, Cl, CN, and NO2 is a substituent at the para-position of a phenyl ring.The affinity of the pentaaqua nickel(II) complex for these ligands was analized and quantified in terms of interaction enthalpy (ΔH), Gibbs free energy (ΔG298), geometric and electronic parameters of the resultant octahedral complexes. The ΔH and ΔG298 results show that the ligand coordination strength increases in the following order: carbonyl < thiocarbonyl < imino < phosphoryl. This coordination strength order is also observed in the analysis of the metal-ligand distances and charges on the ligand atom that interacts with the Ni(II) cation. The electronic character of the substituent R is the main parameter that affects the strength of the metal-ligand coordination. Ligands containing electron-donating groups (NH 2, OCH3, OH) have more exothermic ΔH and ΔG298 than ligands with electron-withdrawing groups (Cl, CN, NO2). The metal-ligand interaction decomposed by means of the energy decomposition analysis (EDA) method shows that the electronic character of the ligand modulates all the components of the metal-ligand interaction. The absolute softness of the free ligands is correlated with the covalent contribution to the instantaneous interaction energy calculated using the EDA method. © 2013 Wiley Periodicals, Inc. The interactions between metal cations and biomolecules are extensively studied in bioinorganic and coordination chemistry. Transition metal ions are present in many enzymes, metalloproteins, peptide hormones, and nucleic acids and are fundamental for their biological functions. In this work, the affinity of the pentaaqua nickel(II) complex toward a set of para-substituted ligands is evaluated. The electronic nature of the ligand modulates the magnitude of the electrostatic, covalent, and repulsion components of the interaction. © 2013 Wiley Periodicals, Inc. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ef2d8d79-85c2-48e2-98b4-a9a99eb4bb34 ER - TY - JOUR TI - Ultra-deep hubble space telescope imaging of the small magellanic cloud: The initial mass function of stars with M ≲ 1 M DO - 10.1088/0004-637X/763/2/110 AU - Kalirai, J.S. AU - Anderson, J. AU - Dotter, A. AU - Richer, H.B. AU - Fahlman, G.G. AU - Hansen, B.M.S. AU - Hurley, J. AU - Reid, I.N. AU - Rich, R.M. AU - Shara, M.M. T2 - The Astrophysical Journal SN - 0004-637X VL - 763 IS - 2 SP - 110 AB - We present a new measurement of the stellar initial mass function (IMF) based on ultra-deep, high-resolution photometry of >5000 stars in the outskirts of the Small Magellanic Cloud (SMC) galaxy. The Hubble Space Telescope (HST) Advanced Camera for Surveys observations reveal this rich, cospatial population behind the foreground globular cluster 47 Tuc, which we targeted for 121 HST orbits. The stellar main sequence of the SMC is measured in the F606W, F814W color-magnitude diagram down to 30th magnitude, and is cleanly separated from the foreground star cluster population using proper motions. We simulate the SMC population by extracting stellar masses (single and unresolved binaries) from specific IMFs and converting those masses to luminosities in our bandpasses. The corresponding photometry for these simulated stars is drawn directly from a rich cloud of 4 million artificial stars, thereby accounting for the real photometric scatter and completeness of the data. Over a continuous and well-populated mass range of M = 0.37-0.93 M(e.g., down to a 75% completeness limit at F606W = 28.7), we demonstrate that the IMF is well represented by a single power-law form with slope α = -1.90 ( +0.15 0.10) (3σ error) (e.g., dN/dM M α). This is shallower than the Salpeter slope of α = -2.35, which agrees with the observed stellar luminosity function at higher masses. Our results indicate that the IMF does not turn over to a more shallow power-law form within this mass range. We discuss implications of this result for the theory of star formation, the inferred masses of galaxies, and the (lack of a) variation of the IMF with metallicity. © 2013. The American Astronomical Society. All rights reserved.. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 195a1fb3-39ca-494f-b400-994d4041bfd0 ER - TY - JOUR TI - Comparing the white dwarf cooling sequences in 47 tuc and NGC 6397 DO - 10.1088/0004-637X/778/2/104 AU - Richer, H.B. AU - Goldsbury, R. AU - Heyl, J. AU - Hurley, J. AU - Dotter, A. AU - Kalirai, J.S. AU - Woodley, K.A. AU - Fahlman, G.G. AU - Rich, R.M. AU - Shara, M.M. T2 - The Astrophysical Journal SN - 0004-637X VL - 778 IS - 2 SP - 104 AB - Using deep Hubble Space Telescope imaging, color-magnitude diagrams are constructed for the globular clusters 47 Tuc and NGC 6397. As expected, because of its lower metal abundance, the main sequence of NGC 6397 lies well to the blue of that of 47 Tuc. A comparison of the white dwarf cooling sequences of the two clusters, however, demonstrates that these sequences are indistinguishable over most of their loci - a consequence of the settling out of heavy elements in the dense white dwarf atmosphere and the near equality of their masses. Lower quality data on M4 continues this trend to a third cluster whose metallicity is intermediate between these two. While the path of the white dwarfs in the color-magnitude diagram is nearly identical in 47 Tuc and NGC 6397, the numbers of white dwarfs along the path are not. This results from the relatively rapid relaxation in NGC 6397 compared to 47 Tuc and provides a cautionary note that simply counting objects in star clusters in random locations as a method of testing stellar evolutionary theory is likely dangerous unless dynamical considerations are included. © 2013. The American Astronomical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : df3c663a-b7e8-4571-a3e3-7a916b5f532d ER - TY - JOUR TI - R-Spondin 2 signalling mediates susceptibility to fatal infectious diarrhoea DO - 10.1038/ncomms2816 AU - Papapietro, O. AU - Teatero, S. AU - Thanabalasuriar, A. AU - Yuki, K.E. AU - Diez, E. AU - Zhu, L. AU - Kang, E. AU - Dhillon, S. AU - Muise, A.M. AU - Durocher, Y. AU - Marcinkiewicz, M.M. AU - Malo, D. AU - Gruenheid, S. T2 - Nature Communications SN - 2041-1723 VL - 4 SP - 1898 KW - alpha smooth muscle actin KW - beta actin KW - beta catenin KW - cyclin D1 KW - matrilysin KW - messenger RNA KW - Myc protein KW - protein KW - spondin 2 KW - unclassified drug KW - Wnt protein KW - coliform bacterium KW - diarrheal disease KW - homeostasis KW - infectious disease KW - ion KW - molecular analysis KW - pathogen KW - physiological response KW - rodent KW - signal KW - animal experiment KW - article KW - Citrobacter rodentium KW - colon mucosa KW - diarrhea KW - gene expression KW - gene locus KW - genetic susceptibility KW - infection sensitivity KW - ion transport KW - mouse KW - nonhuman KW - signal transduction KW - single nucleotide polymorphism AB - Citrobacter rodentium is a natural mouse pathogen widely used as a model for enteropathogenic and enterohemorrhagic Escherichia coli infections in humans. While C. rodentium causes self-limiting colitis in most inbred mouse strains, it induces fatal diarrhoea in susceptible strains. The physiological pathways as well as the genetic determinants leading to susceptibility have remained largely uncharacterized. Here we use a forward genetic approach to identify the R-spondin2 gene as a major determinant of susceptibility to C. rodentium infection. Robust induction of R-spondin2 expression during infection in susceptible mouse strains causes a potent Wnt-mediated proliferative response of colonic crypt cells, leading to the generation of an immature and poorly differentiated colonic epithelium with deficiencies in ion-transport components. Our data demonstrate a previously unknown role of R-spondins and Wnt signalling in susceptibility to infectious diarrhoea and identify R-spondin2 as a key molecular link between infection and intestinal homoeostasis. © 2013 Macmillan Publishers Limited. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 19b9b7cd-0df0-485b-8bcd-880af9665472 ER - TY - JOUR TI - Morphological aspects of injected polypropylene/clay nanocomposite materials DO - 10.1002/pen.23334 AU - Salah, H.B.H. AU - Daly, H.B. AU - Denault, J. AU - Perrin, F. T2 - Polymer Engineering and Science SN - 0032-3888 VL - 53 IS - 5 SP - 905 EP - 913 KW - Clay intercalation KW - Clay nanocomposites KW - Crystallization behavior KW - Injection-molded specimens KW - Low-molecular weight KW - Molecular chain orientation KW - Morphological aspects KW - Transmission electron microscopy (TEM) KW - Coupling agents KW - Crystallization KW - Differential scanning calorimetry KW - Molecular weight KW - Nanocomposites KW - Polypropylenes KW - Scanning electron microscopy KW - Transmission electron microscopy KW - X ray diffraction KW - Injection molding AB - Polypropylene (PP) clay nanocomposites were injection-molded using two different coupling agents based on maleic anhydride-grafted PP (MA-g-PP) and two clay loadings. The morphological aspects of these materials were studied by depth profiling. Molecular chain and clay orientations were characterized using attenuated total reflectance-infrared analysis and transmission electron microscopy (TEM). Both clay platelets and PP molecular chain orientations were found to decrease from the surface toward the core of the injection-molded specimens. Clay intercalation, characterized by both complementary X-ray diffraction and TEM, was found to be significantly influenced by both the characteristics of the coupling agent used and the type of residual stresses generated at each layer across the thickness of the injection-molded parts. The use of low-molecular weight (Mw) MA-g-PP led to a uniform intercalation but with no further exfoliation. The use of higher molecular weight MA-g-PP led to a heterogeneous intercalation with some signs of exfoliation. The crystallization behavior of PP clay nanocomposites studied by differential scanning calorimetry showed an increase in the level of crystallinity from the surface to the core of the specimens; these results were also confirmed by scanning electron microscopy. Copyright © 2012 Society of Plastics Engineers. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4a18513f-6679-4b51-ba1b-45d746004cbc ER - TY - JOUR TI - Genome-wide transcriptional profiling and enrichment mapping reveal divergent and conserved roles of Sko1 in the Candida albicans osmotic stress response DO - 10.1016/j.ygeno.2013.06.002 AU - Marotta, D.H. AU - Nantel, A. AU - Sukala, L. AU - Teubl, J.R. AU - Rauceo, J.M. T2 - Genomics SN - 0888-7543 VL - 102 IS - 4 SP - 363 EP - 371 KW - phosphotransferase KW - protein hog1 KW - unclassified drug KW - article KW - Candida albicans KW - computer model KW - controlled study KW - DNA binding motif KW - enzyme activity KW - gene KW - gene function KW - gene mapping KW - genetic conservation KW - genetic regulation KW - genetic transcription KW - genetic variability KW - genome analysis KW - microarray analysis KW - nonhuman KW - osmotic stress KW - priority journal KW - real time polymerase chain reaction KW - signal transduction KW - Sko1 gene KW - Candida albicans KW - Saccharomyces cerevisiae AB - Candida albicans maintains both commensal and pathogenic states in humans. Here, we have defined the genomic response to osmotic stress mediated by transcription factor Sko1. We performed microarray analysis of a sko1δ/δ mutant strain subjected to osmotic stress, and we utilized gene sequence enrichment analysis and enrichment mapping to identify Sko1-dependent osmotic stress-response genes. We found that Sko1 regulates distinct gene classes with functions in ribosomal synthesis, mitochondrial function, and vacuolar transport. Our in silico analysis suggests that Sko1 may recognize two unique DNA binding motifs. Our C. albicans genomic analyses and complementation studies in Saccharomyces cerevisiae showed that Sko1 is conserved as a regulator of carbohydrate metabolism, redox metabolism, and glycerol synthesis. Further, our real time-qPCR results showed that osmotic stress-response genes that are dependent on the kinase Hog1 also require Sko1 for full expression. Our findings reveal divergent and conserved aspects of Sko1-dependent osmotic stress signaling. © 2013 Elsevier Inc. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5e2639a2-199a-426f-9079-e1d8c282ffa5 ER - TY - JOUR TI - Experimental characterization of contaminants in engine lubricants using surface plasmon resonance sensing DO - 10.1108/00368791311292828 AU - Aghayan, H.R. AU - Bordatchev, E.V. AU - Yang, J. T2 - Industrial Lubrication and Tribology SN - 0036-8792 VL - 65 IS - 1 SP - 61 EP - 68 KW - Automotive components industry KW - Bayesian classification KW - Design/methodology/approach KW - Dielectric permittivities KW - Engine components KW - Engine lubricants KW - Experimental characterization KW - Incidence angles KW - Online condition monitoring KW - Online monitoring KW - Resonance angle KW - SPR sensors KW - Surface plasmon resonance sensing KW - Surface plasmons KW - Absorption refrigeration KW - Characterization KW - Condition monitoring KW - Contamination KW - Coolants KW - Engines KW - Gasoline KW - Impurities KW - Lubricants KW - Pattern recognition KW - Permittivity KW - Plasmons KW - Reflection KW - Refractive index KW - Water KW - Water absorption KW - Surface plasmon resonance AB - Purpose - The purpose of this paper is to develop new knowledge in experimental characterization of contaminants in engine lubricants, using surface plasmon resonance (SPR) sensing that can be applicable for on-line condition monitoring of lubricant quality and engine component performance. Design/methodology/approach - The effect of change in optical properties (e.g. transparency, absorption, and refractive index) of engine lubricants caused by the introduction of contaminants, such as gasoline, coolant, and water, on the surface plasmon resonance characteristics is analyzed experimentally. In SPR measurement, variations in both the refractive index and absorption cause changes in the SPR curve, which is the dependence of reflectivity vs incidence angle. The SPR characteristics (e.g. refractivity) of engine lubricant contaminated by gasoline, water and coolant at different concentration are measured as a function of resonance angle and analyzed with respect to different concentration (1%-10%) of contaminants. Also, pattern recognition analysis between fresh and used engine lubricants is performed, to show applicability of Bayesian classification methodology for on-line monitoring and predicting engine lubricant condition. Findings - It was shown experimentally that attenuation of surface plasmons due to introduction of contaminants to the engine lubricant leads to a noticeable change in resonance angle and reflectivity minimum of the SPR curve due to an increase in the dielectric permittivity. In addition, the changes in the SPR characteristics were observed between fresh and used engine lubricant, causing resonance angle and reflectivity minimum of the SPR curve to shift. Practical implications - The knowledge generated in this study lays the informational basis to further develop an on-line system for engine lubricant condition monitoring using miniaturized SPR sensors fully suitable for on board applications. Originality/value - SPR characterization is originally applied for analysis of optical properties of engine lubricants caused by the introduction of contaminants, such as gasoline, coolant, and water. © Emerald Group Publishing Limited. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f7c76e14-887a-4294-9e71-8d15bdbb0276 ER - TY - JOUR TI - First results of the SONS survey : submillimetre detections of debris discs DO - 10.1093/mnras/stt1293 AU - Panić, O. AU - Holland, W. S. AU - Wyatt, M. C. AU - Kennedy, G. M. AU - Matthews, B. C. AU - Lestrade, J. F. AU - Sibthorpe, B. AU - Greaves, J. S. AU - Marshall, J. P. AU - Phillips, N. M. AU - Tottle, J. T2 - Monthly Notices of the Royal Astronomical Society SN - 0035-8711 VL - 435 IS - 2 SP - 1037 EP - 1046 AB - New detections of debris discs at submillimetre wavelengths present highly valuable complementary information to prior observations of these sources at shorter wavelengths. Characterization of discs through spectral energy distribution modelling including the submillimetre fluxes is essential for our basic understanding of disc mass and temperature, and presents a starting point for further studies using millimetre interferometric observations. In the framework of the ongoing SCUBA-2 Observations of Nearby Stars, the instrument SCUBA-2 on the James Clerk Maxwell Telescope was used to provide measurements of 450 and 850 μm fluxes towards a large sample of nearby main-sequence stars with debris discs detected previously at shorter wavelengths. We present the first results from the ongoing survey, concerning 850 μm detections and 450 μm upper limits towards 10 stars, the majority of which are detected at submillimetre wavelengths for the first time. One, or possibly two, of these new detections is likely a background source. We fit the spectral energy distributions of the star+disc systems with a blackbody emission approach and derive characteristic disc temperatures. We use these temperatures to convert the observed fluxes to disc masses. We obtain a range of disc masses from 0.001 to 0.1M, values similar to the prior dust mass measurements towards debris discs. There is no evidence for evolution in dust mass with age on the main sequence, and indeed the upper envelope remains relatively flat at ~0.5M at all ages. The inferred disc masses are lower than those from disc detections around pre-main-sequence stars, which may indicate a depletion of solid mass. This may also be due to a change in disc opacity, though limited sensitivity means that it is not yet known what fraction of pre-main-sequence stars have discs with dust masses similar to debris disc levels. New, high-sensitivity detections are a path towards investigating the trends in dust mass evolution. DA - 2013/08/30 PY - 2013 PB - Oxford University Press on behalf of the Royal Astronomical Society LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4cea719f-606f-4908-a0ae-bd846acb370d ER - TY - JOUR TI - Ice-phobic coatings based on silicon-oil-infused polydimethylsiloxane DO - 10.1021/am400704z AU - Zhu, L. AU - Xue, J. AU - Wang, Y. AU - Chen, Q. AU - Ding, J. AU - Wang, Q. T2 - ACS Applied Materials and Interfaces SN - 1944-8244 VL - 5 IS - 10 SP - 4053 EP - 4062 KW - hydrophobic KW - Hydrophobic properties KW - Ice adhesion strength KW - ice-phobic KW - Low surface energy KW - Polydimethylsiloxane PDMS KW - Silicon oil KW - Water contact angle KW - Adhesion KW - Aluminum coatings KW - Bond strength (materials) KW - Contact angle KW - High speed photography KW - Hydrophobicity KW - Microchannels KW - Plastic coatings KW - Polydimethylsiloxane KW - Polymers KW - Silicon KW - Silicones KW - Surfaces KW - Ice AB - A simple and low-cost technique for the preparation of silicon-oil-infused polydimethylsiloxane (PDMS) coatings with different silicon oil contents have been developed and studied. This material is designed for ice-phobic applications, and thus a high hydrophobic property of PDMS is maintained by avoiding any polar groups such as C=O and OH in the structure. Therefore, the polymer main chain was attached with vinyl and Si-H groups to obtain a cross-linking capability, meanwhile to ensure a nonpolar chemical structure. Its ice-phobic property has been investigated in terms of ice adhesion strength (tensile and shear), water contact angle, icing dynamics using high-speed photography and morphology using TEM, SEM and AFM. The prepared coating surface shows a low surface energy and very low ice adhesion strength of 50 kPa, only about 3% of the value on a bare aluminum (Al) surface. In the silicon oil infused PDMS coatings, the low surface energy of the silicon oil and PDMS, and the high mobility of silicon oil played an important role on the ice-phobic property. Both of these factors offer the surface a large water contact angle and hence a small contact area, leading to the formation of a loose ice layer. In addition, the oil infused polymer structure significantly reduces the contact area of the ice with solid substrate since the ice mostly contacts with the mobile oil. This leads to a very weak interaction between the substrate and ice, consequently significantly reduces the ice adhesion strength on the surface. Therefore, such material could be a good candidate for ice-phobic coatings on which the accumulated ice may be easily removed by a nature force, such as wind, gravity, and vibration. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : edf61182-8b35-4210-98a9-865c9a41b3c3 ER - TY - CHAP TI - Special track on bioinformatics AU - Tulpan, D. AU - Lecca, P. AU - Palakal, M.J. T2 - Proceedings of the ACM Symposium on Applied Computing T3 - 28th Annual ACM Symposium on Applied Computing, SAC 2013, 18 March 2013 through 22 March 2013, Coimbra SN - 9781450316569 SP - 1312 EP - 1313 DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 846509c9-40ff-42c6-a0df-273cb3ef6198 ER - TY - JOUR TI - Repeatability and reproducibility of the ISO/TS 19700 steady state tube furnace DO - 10.1016/j.firesaf.2012.10.002 AU - Purser, J.A. AU - Purser, D.A. AU - Stec, A.A. AU - Moffatt, C. AU - Hull, T.R. AU - Su, J.Z. AU - Bijloos, M. AU - Blomqvist, P. T2 - Fire Safety Journal SN - 0379-7112 VL - 55 SP - 22 EP - 34 KW - ISO TS 19700 KW - Repeatability KW - Reproducibilities KW - Toxic KW - Tube furnaces KW - Carbon dioxide KW - Furnaces KW - Polymers KW - Toxicity KW - Tubes (components) KW - Laboratories AB - The ISO/TS 19700 steady state tube furnace is designed to measure the yields of combustion products, and in particular toxic combustion products, under a range of different specified decomposition conditions occurring in full-scale compartment fires. In order to establish the repeatability and reproducibility of the method, a Round Robin inter-laboratory study and statistical analysis has been carried out involving three laboratories. Pre-existing data from a fourth laboratory have also been considered where appropriate. Samples of different polymers (PMMA, LDPE, PA6.6 and rigid PVC) were tested under two fire conditions: well-ventilated flaming at 650 °C and post-flashover under-ventilated flaming at 825 °C, with each laboratory performing three replicate runs on each polymer under each condition. The results showed good agreement between laboratories and against calculated stoichiometric maxima, demonstrating satisfactory levels of repeatability and reproducibility for key combustion gases. These included O2 consumption, and the yields of CO2, CO, HCN and HCl. A number of amendments to the standard have been recommended as a result of minor procedural issues arising during preliminary work. © 2012 Elsevier Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a460b76b-247e-483b-9736-b887a801b31e ER - TY - JOUR TI - One- and two-magnon and exciton Raman scattering in antiferromagnetic CoF2: Experiment and theory DO - 10.3938/jkps.63.817 AU - Meloche, E. AU - Cottam, M.G. AU - Lockwood, D.J. T2 - Journal of the Korean Physical Society SN - 0374-4884 VL - 63 IS - 3 SP - 817 EP - 820 AB - Experimental data are reported for the temperature and polarization dependence of the oneand two-magnon Raman light scattering in the rutile-structure antiferromagnet CoF2. The correspondingn Stokes and anti-Stokes Raman spectra are measured, emphasizing the temperature and polarization variations of the one-magnon frequency, line width, and integrated intensity. A Green's function method is employed to derive the excitation energies and their intensities over a broad range of temperatures (below the Néel temperature = 38 K) for a spin S = 3/2 anisotropic antiferromagnet with strong spin-orbit coupling. The exchange terms are analyzed using the random-phase approximation while single-ion anisotropy terms are treated exactly by generating a closed set of coupled Green's function equations. Good overall agreement between theory and experiment is obtained. © 2013 The Korean Physical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d24d81d3-d9f0-497d-ad90-18f2687124d8 ER - TY - JOUR TI - Small-scale structure in fluid cholesterol-lipid bilayers DO - 10.1016/j.cocis.2013.07.001 AU - Rheinstädter, M.C. AU - Mouritsen, O.G. T2 - Current Opinion in Colloid and Interface Science SN - 1359-0294 VL - 18 IS - 5 SP - 440 EP - 447 KW - Correlation function KW - Liquid-ordered phase KW - Molecular modeling studies KW - Neutron diffraction studies KW - Quantitative assessments KW - Raft KW - Small-scale structures KW - Structured liquids KW - Cell membranes KW - Computer simulation KW - Lipid bilayers KW - Neutron diffraction KW - Neutron scattering KW - Cholesterol KW - cholesterol KW - lipid KW - cell function KW - cell membrane KW - chemical structure KW - computer simulation KW - controlled study KW - lipid bilayer KW - lipid raft KW - membrane permeability KW - molecular dynamics KW - molecular model KW - neutron diffraction KW - neutron scattering KW - protein domain KW - review KW - small scale structure KW - thickness AB - Cholesterol is the single most abundant molecule in animal plasma membranes, in the range of 20-30. mol%, where it is known to modulate the lipid-bilayer component of the membrane and lead to increased mechanical stability, lower permeability, larger thickness, and a distinct lateral organization. The phase equilibria of membranes with cholesterol and the associated large- and small-scale structure have turned out to be a particularly elusive problem. With the proposal that lipid domains and so-called 'rafts', characterized by high local levels of cholesterol in a liquid-ordered phase, are important for a wide range of cellular functions, an understanding and a quantitative assessment of the nature of these cholesterol-induced structures and their types of ordering have become urgent. Recent progress in neutron diffraction studies of lipid-cholesterol model membranes has now revealed details of the lateral ordering, and combined with earlier molecular model studies a picture emerges of the membrane as a locally structured liquid with small ordered 'domains' of a highly dynamic nature. © 2013 Elsevier Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 41f9ae2f-3fd2-466d-afe0-e9e2f4ea376b ER - TY - JOUR TI - Solid state complex chemistry: Formation, structure, and properties of homoleptic tetracyanamidogermanates RbRE[Ge(CN2)4] (RE = La, Pr, Nd, Gd) DO - 10.1021/ic401201w AU - Kalmutzki, M. AU - Enseling, D. AU - Wren, J.E.C. AU - Kroeker, S. AU - Terskikh, V.V. AU - Jüstel, T. AU - Meyer, H.-J. T2 - Inorganic Chemistry SN - 0020-1669 VL - 52 IS - 21 SP - 12372 EP - 12382 AB - Tetracyanamidometallates with the general formula RbRE[T(CN 2)4] (RE = La, Pr, Nd, Gd; T = Si, Ge) were prepared by solid state metathesis reactions starting from stoichiometric mixtures of RECl3, A2[TF6], and Li2(CN 2). Reactions were studied by differential thermal analysis that showed ignition temperatures between 360 and 390 C for the formation of RbGd[T(CN2)4] with T = Si and Ge. The powder diffraction patterns of RbRE[Ge(CN2)4] were indexed isotypically to the already known RbRE[Si(CN2)4] compound. IR spectra of RbLa[Ge(CN2)4] were measured and compared with those of RbLa[Si(CN2)4]. 73Ge, 87Rb, and 139La solid state NMR measurements and density functional theory calculations were used to verify the novel homoleptic [Ge(CN2) 4]4- ion. Luminescence properties of Eu3+, Ce3+, and Tb3+ doped samples are reported. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 630e56d9-be6d-487d-ad42-893ab7526a94 ER - TY - JOUR TI - Improving the strength and corrosion resistance of 316L stainless steel for biomedical applications using cold spray DO - 10.1016/j.surfcoat.2012.11.061 AU - Al-Mangour, B. AU - Mongrain, R. AU - Irissou, E. AU - Yue, S. T2 - Surface and Coatings Technology SN - 0257-8972 VL - 216 SP - 297 EP - 307 KW - 316 L stainless steel KW - Analysis and characterization KW - Biomedical applications KW - Coating parameters KW - Cobalt-chromium alloys KW - Cold gas dynamic spray KW - Cold spray KW - Corrosion behavior KW - Electron back scatter diffraction KW - Hank's solution KW - Mild steel substrates KW - Potentiodynamic polarization tests KW - Room temperature KW - Stainless steel 316L KW - Stent KW - Tensile tests KW - Thinner coatings KW - Carbon steel KW - Chromium KW - Chromium alloys KW - Coatings KW - Cobalt KW - Diffusion KW - Ductility KW - Medical applications KW - Scanning electron microscopy KW - Stainless steel KW - Tensile testing KW - Corrosion resistance AB - Stainless steel 316L mixed with cobalt chromium alloy L605 powders has been cold sprayed onto mild steel substrate. As spraying Co-Cr alone is difficult, three different proportions (by volume of Co-Cr, 25%, 33.3% and 50%) were used in this study. Analysis and characterization of sprayed depositions were performed through scanning electron microscopy, electron backscatter diffraction, microhardness, and tensile tests at room temperature. The porosity of the coating was low for both the 25% and 33.3% coating (about 0.9-1.5%). However, the 50% coating had a much poorer deposition rate leading to a much thinner coating using the same coating parameters; the porosity was much higher (about 4.5%). The ductility of the annealed 25% and 33.3% specimens reached approximately 20% and 18% respectively after annealing, but the 50% specimen was too thin to be tested. The corrosion behavior was evaluated using potentiodynamic polarization tests carried at Hank's solution as an electrolyte. It was found that corrosion resistances of the metal-metal mixture were higher than that of pure stainless steel. © 2012 Elsevier B.V. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6740a912-293d-41d0-a6d4-e8006952f843 ER - TY - JOUR TI - Crack detection using induction thermography during high temperature testing DO - 10.1117/12.2015488 AU - Genest, M. AU - Dudzinski, D.C. AU - Dawag, L. AU - Kersey, R.K. T2 - SPIE - International Society for Optical Engineering. Proceedings T3 - Thermosense: Thermal Infrared Applications XXXV, 30 April 2013 through 1 May 2013, Baltimore, MD SN - 0277-786X SN - 9780819494962 VL - 8705 SP - 87050P KW - Crack growth curves KW - Detection capability KW - Elevated temperature KW - Engineering applications KW - Replication method KW - Scanning electronic microscopy KW - Thermo mechanical fatigues (TMF) KW - Total fatigue lives KW - Crack detection KW - Fatigue of materials KW - Induction heating KW - Infrared devices KW - Infrared radiation KW - Inspection KW - Thermography (imaging) KW - Thermography (temperature measurement) KW - Cracks AB - Thermo-mechanical fatigue (TMF) tests and strain to crack (SC) tests at elevated temperature are important aspects to the total fatigue life for many engineering applications. During a TMF test, crack inspections are commonly done in a disruptive manner using an acetate replication method; and post-test crack evaluations are done using both optical and scanning electronic microscopy methods. Similarly, inspections during a typical SC test are also performed in a disruptive manner. This paper demonstrates that infrared imaging can be used as an in-situ inspection approach to detect crack during TMF and SC tests at high temperature. It is also demonstrated that this technique allows for the reduction or elimination of the need for downtime that is typically required for disruptive inspection. The results obtained by induction thermography are compared to those obtained via traditional methods and post-test evaluation. The induction thermography inspections were carried out at several temperatures and showed that the temperature used during the test does not influence the crack detection capability. It is demonstrated that induction thermography can detect cracks smaller than 500 μm and has potential for monitoring and generating a crack growth curve. © 2013 SPIE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8d665dad-6b4e-406e-b829-b6b44a1600cb ER - TY - JOUR TI - Linkage between bacterial and fungal rhizosphere communities in hydrocarbon-contaminated soils is related to plant phylogeny DO - 10.1038/ismej.2013.149 AU - Bell, T.H. AU - El-Din Hassan, S. AU - Lauron-Moreau, A. AU - Al-Otaibi, F. AU - Hijri, M. AU - Yergeau, E. AU - St-Arnaud, M. T2 - ISME Journal SN - 1751-7362 AB - Phytoremediation is an attractive alternative to excavating and chemically treating contaminated soils. Certain plants can directly bioremediate by sequestering and/or transforming pollutants, but plants may also enhance bioremediation by promoting contaminant-degrading microorganisms in soils. In this study, we used high-throughput sequencing of bacterial 16S rRNA genes and the fungal internal transcribed spacer (ITS) region to compare the community composition of 66 soil samples from the rhizosphere of planted willows (Salix spp.) and six unplanted control samples at the site of a former petrochemical plant. The Bray-Curtis distance between bacterial communities across willow cultivars was significantly correlated with the distance between fungal communities in uncontaminated and moderately contaminated soils but not in highly contaminated (HC) soils (>2000 mg kg-1 hydrocarbons). The mean dissimilarity between fungal, but not bacterial, communities from the rhizosphere of different cultivars increased substantially in the HC blocks. This divergence was partly related to high fungal sensitivity to hydrocarbon contaminants, as demonstrated by reduced Shannon diversity, but also to a stronger influence of willows on fungal communities. Abundance of the fungal class Pezizomycetes in HC soils was directly related to willow phylogeny, with Pezizomycetes dominating the rhizosphere of a monophyletic cluster of cultivars, while remaining in low relative abundance in other soils. This has implications for plant selection in phytoremediation, as fungal associations may affect the health of introduced plants and the success of co-inoculated microbial strains. An integrated understanding of the relationships between fungi, bacteria and plants will enable the design of treatments that specifically promote effective bioremediating communities.The ISME Journal advance online publication, 29 August 2013; doi:10.1038/ismej.2013.149. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2b6bd53d-aba8-4783-a0c4-3791046fa23a ER - TY - JOUR TI - Synthesims of 7-oxabicyclo[2.2.1]heptanes and 8-oxabicyclo[3.2.1]octanes from C-glycosides via an intramolecular cyclization DO - 10.1021/jo3024973 AU - Zou, W. AU - Vembaiyan, K. T2 - Journal of Organic Chemistry SN - 0022-3263 VL - 78 IS - 6 SP - 2703 EP - 2709 KW - Anomeric configuration KW - C-glycosides KW - Chemical yields KW - Enamine intermediates KW - Epimerization KW - Intramolecular cyclizations KW - Nucleophilic substitutions KW - Pyrrolidines KW - Cyclization KW - Heptane KW - Stereoselectivity KW - Sugars KW - 7 oxabicyclo [2 2 1] heptane KW - 8 oxabicyclo [3 2 1]octane KW - glycoside KW - heptane KW - octane KW - pyrrolidine derivative KW - unclassified drug KW - bicyclo compound KW - C glycoside KW - C-glycoside KW - cycloheptane derivative KW - cyclooctane derivative KW - monosaccharide KW - article KW - chemical reaction KW - chemical structure KW - cyclization KW - epimerization KW - nucleophilicity KW - stereochemistry KW - synthesis KW - chemistry KW - cyclization KW - stereoisomerism KW - Bicyclo Compounds KW - Cyclization KW - Cycloheptanes KW - Cyclooctanes KW - Molecular Structure KW - Monosaccharides KW - Stereoisomerism AB - A simple and effective method for the synthesis of 7-oxabicyclo[2.2.1] heptanes and 8-oxabicyclo[3.2.1]octanes from acetonyl C-glycoside substrates is described, which involves an intramolecular cyclization reaction through a nucleophilic substitution at C-5 or C-6 of C-glycosides by a 2′-enamine intermediate formed in the presence of pyrrolidine. Because anomeric epimerization occurs under these conditions, C-glycoside substrates with either anomeric configuration were converted to the same product(s) in same stereoselectivity and similar chemical yield. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8859ff11-0861-49b5-82f3-ed151ee60d6d ER - TY - JOUR TI - In vivo neutralization of α-Cobratoxin with high-affinity llama single-domain antibodies (VHHs) and a VHH-Fc antibody DO - 10.1371/journal.pone.0069495 AU - Richard, G. AU - Meyers, A.J. AU - McLean, M.D. AU - Arbabi-Ghahroudi, M. AU - MacKenzie, R. AU - Hall, J.C. T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 7 SP - e69495 KW - antibody KW - cobrotoxin KW - single variable domain antibody KW - single variable domain Fc antibody KW - snake venom antiserum KW - unclassified drug KW - animal cell KW - animal experiment KW - animal model KW - antibody affinity KW - article KW - controlled study KW - drug efficacy KW - drug penetration KW - envenomation KW - female KW - humoral immunity KW - in vivo study KW - lethality KW - male KW - molecular weight KW - mouse KW - Nicotiana benthamiana KW - nonhuman KW - protein expression KW - protein purification AB - Small recombinant antibody fragments (e.g. scFvs and VHHs), which are highly tissue permeable, are being investigated for antivenom production as conventional antivenoms consisting of IgG or F(ab')2 antibody fragments do not effectively neutralize venom toxins located in deep tissues. However, antivenoms composed entirely of small antibody fragments may have poor therapeutic efficacy due to their short serum half-lives. To increase serum persistence and maintain tissue penetration, we prepared low and high molecular mass antivenom antibodies. Four llama VHHs were isolated from an immune VHH-displayed phage library and were shown to have high affinity, in the low nM range, for α-cobratoxin (α-Cbtx), the most lethal component of Naja kaouthia venom. Subsequently, our highest affinity VHH (C2) was fused to a human Fc fragment to create a VHH2-Fc antibody that would offer prolonged serum persistence. After in planta (Nicotiana benthamiana) expression and purification, we show that our VHH2-Fc antibody retained high affinity binding to α-Cbtx. Mouse α-Cbtx challenge studies showed that our highest affinity VHHs (C2 and C20) and the VHH2-Fc antibody effectively neutralized lethality induced by α-Cbtx at an antibody:toxin molar ratio as low as ca. 0.75×:1. Further research towards the development of an antivenom therapeutic involving these anti-α-Cbtx VHHs and VHH2-Fc antibody molecules should involve testing them as a combination, to determine whether they maintain tissue penetration capability and low immunogenicity, and whether they exhibit improved serum persistence and therapeutic efficacy. © 2013 Richard et al. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2684e8b0-3433-4c7d-b8ff-e86f85e0ad0d ER - TY - JOUR TI - A Herschel * and APEX census of the reddest sources in Orion: Searching for the youngest protostars DO - 10.1088/0004-637X/767/1/36 AU - Stutz, A. M. AU - Tobin, J. J. AU - Stanke, T. AU - Megeath, S. T. AU - Fischer, W. J. AU - Robitaille, T. AU - Henning, T. AU - Ali, B. AU - di Francesco, J. AU - Furlan, E. AU - Hartmann, L. AU - Osorio, M. AU - Wilson, T. L. AU - Allen, L. AU - Krause, O. AU - Manoj, P. T2 - The Astrophysical Journal SN - 0004-637X VL - 767 IS - 1 SP - 36 KW - ISM clouds KW - Star formation KW - Low-mass stars KW - Protostars AB - We perform a census of the reddest, and potentially youngest, protostars in the Orion molecular clouds using data obtained with the PACS instrument on board the Herschel Space Observatory and the LABOCA and SABOCA instruments on APEX as part of the Herschel Orion Protostar Survey (HOPS). A total of 55 new protostar candidates are detected at 70 μm and 160 μm that are either too faint (m24 > 7 mag) to be reliably classified as protostars or undetected in the Spitzer/MIPS 24 μm band. We find that the 11 reddest protostar candidates with log λFλ70/λF λ24 > 1.65 are free of contamination and can thus be reliably explained as protostars. The remaining 44 sources have less extreme 70/24 colors, fainter 70 μm fluxes, and higher levels of contamination. Taking the previously known sample of Spitzer protostars and the new sample together, we find 18 sources that have log λFλ70/ λFλ24 > 1.65; we name these sources "PACS Bright Red sources," or PBRs. Our analysis reveals that the PBR sample is composed of Class 0 like sources characterized by very red spectral energy distributions (SEDs; Tbol < 45 K) and large values of sub-millimeter fluxes (Lsmm/Lbol > 0.6%). Modified blackbody fits to the SEDs provide lower limits to the envelope masses of 0.2-2 M⊙ and luminosities of 0.7-10 L⊙. Based on these properties, and a comparison of the SEDs with radiative transfer models of protostars, we conclude that the PBRs are most likely extreme Class 0 objects distinguished by higher than typical envelope densities and hence, high mass infall rates. © 2013. The American Astronomical Society. All rights reserved. DA - 2013/04/10 PY - 2013 PB - IOP Publishing LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 73a357df-8748-4fbd-98e0-ede432bf12ee ER - TY - JOUR TI - Surface-enhanced Raman and optical scattering in coupled plasmonic nanoclusters DO - 10.1080/09500340.2013.821535 AU - Tay, Li-Lin AU - Hulse, John T2 - Journal of Modern Optics SN - 0950-0340 VL - 60 IS - 14 SP - 1107 EP - 1114 KW - Plasmonics KW - surface-enhanced Raman scattering KW - gold nanoparticle KW - nanocluster structure KW - hot-spot AB - Optical excitation of small Au nanoparticle (NP) clusters of appropriate wavelength is known to generate intense electromagnetic fields localized uniquely at NP junction sites within the nanoclusters. These intense and localized field hot-sites can induce intense surface-enhanced Raman scattering (SERS) of molecules residing at the junction hot-sites. In this paper, we present a series of electromagnetic simulations, experimental SERS and extinction data obtained from small self-assembled Au NP clusters coated to saturation with a Raman reporter molecule. Our experimental data show that the SERS enhancement factor remains relatively constant despite the heterogeneity of the nanocluster and this is supported by the simulation results. Furthermore, our simulation results show significant variations in the localized electric field intensities of the junction hot-sites in different nanocluster geometries. This explains the observation that increasing the number of hot-sites does not necessarily result in a higher SERS enhancement factor. DA - 2013/08/15 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d1324025-bad7-4b28-934e-5818a12163a3 ER - TY - JOUR TI - Quantitative proteomic investigation employing stable isotope labeling by peptide dimethylation on proteins of strawberry fruit at different ripening stages DO - 10.1016/j.jprot.2013.09.004 AU - Li, L. AU - Song, J. AU - Kalt, W. AU - Forney, C. AU - Tsao, R. AU - Pinto, D. AU - Chisholm, K. AU - Campbell, L. AU - Fillmore, S. AU - Li, X. T2 - Journal of Proteomics SN - 1874-3919 VL - 94 SP - 219 EP - 239 KW - aconitate hydratase KW - actin KW - acyltransferase KW - adenosine kinase KW - allergen KW - aquaporin KW - ascorbate peroxidase KW - aspartic proteinase KW - carbonate dehydratase KW - cystatin KW - erbium KW - heat shock protein 70 KW - lipid transfer protein KW - methionine synthase KW - methyltransferase KW - nucleoside diphosphate kinase KW - oligomycin KW - oxidoreductase KW - oxygenase KW - pectinesterase KW - peptide KW - phosphoglucomutase KW - phosphoglycerate dehydrogenase KW - prohibitin KW - protein KW - pyruvate decarboxylase KW - stable isotope KW - transaldolase KW - uridine diphosphate KW - uridine diphosphate glucose KW - article KW - biosynthesis KW - controlled study KW - energy metabolism KW - fruit ripening KW - isotope labeling KW - nonhuman KW - peptide dimethylation KW - priority journal KW - protein analysis KW - protein degradation KW - protein expression KW - protein folding KW - protein methylation KW - protein synthesis KW - proteomics KW - strawberry KW - stress AB - A quantitative proteomic investigation of strawberry fruit ripening employing stable isotope labeling by peptide dimethylation was conducted on 'Mira' and 'Honeoye' strawberry fruit. Postharvest physiological quality indices, including volatile production, total phenolics, total anthocyanins, antioxidant capacity, soluble solids and titratable acidity, were also characterized in white, pink and red fruit. More than 892 and 848 proteins were identified and quantified in the 'Mira' and 'Honeoye' fruit, respectively, using at least two peptides for each protein identification. Using the normalized ratio of protein abundance changes, proteins that changed two-fold or more were identified as proteins that are up- or down-regulated during fruit ripening. Among the quantified proteins, 111 proteins were common to both cultivars and represented five significant clusters based on quantitative changes. Among the up-regulated proteins were proteins involved in metabolic pathways including flavonoid/anthocyanin biosynthesis, volatile biosynthesis, antioxidant metabolism, stress responses and allergen formation. Proteins that decreased during fruit ripening were found to be responsible for methionine metabolism, antioxidant-redox, energy metabolism and protein synthesis. Our results show that strawberry ripening is a highly complex system involving multi-physiological processes made possible through changes in protein expression. This study provides new insights on the regulation of proteins during strawberry fruit ripening that lay the foundation for further targeted studies. Biological significance: Research on the postharvest physiology and biochemistry of strawberry fruit as a model of non-climacteric fruit ripening has been conducted for many years. However, the mechanism(s) for the initiation and metabolic regulation of non-climacteric fruit ripening remains unknown. Little information on strawberry fruit ripening is available at the proteome level. This paper is the first report of a quantitative proteomic investigation of strawberry fruit ripening employing stable isotope labeling by peptide dimethylation. Postharvest physiological quality indices, including volatile production, total phenolics, total anthocyanins, antioxidant capacity, soluble solids and titratable acidity, were also characterized in ripening fruit. Significant biological changes associated with ripening were revealed and proteins that change significantly under these conditions were identified. Therefore, our study links the biological events of strawberry fruit ripening with proteomic information and provides insights into possible mechanisms of regulation. Proteins that changed during ripening were analyzed through function analysis, which provides new insights into metabolic changes occurring during ripening. Findings from this paper not only provide proteome information on fruit ripening, but also pave the way for further quantitative studies using SMR to investigate certain proteins and pathways involved in fruit ripening. © 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 82737e80-26cd-4723-b723-11fc2ba99b9e ER - TY - JOUR TI - Symmetry of the fornix using diffusion tensor imaging DO - 10.1002/jmri.24424 AU - Sboto-Frankenstein, U.N. AU - Lazar, T. AU - Bolster, R.B. AU - Thind, S. AU - Dreessen de Gervai, P. AU - Gruwel, M.L. AU - Smith, S.D. AU - Tomanek, B. T2 - Journal of Magnetic Resonance Imaging SN - 1053-1807 AB - Purpose: To: 1) Present fornix tractography in its entirety for 20 healthy individuals to assess variability. 2) Provide individual and groupwise whole tract diffusion parameter symmetry assessments prior to clinical application. 3) Compare whole tract diffusion parameter assessments with tract-based spatial statistics (TBSS). Materials and Methods: Diffusion tensor imaging (DTI) data were acquired on a 3T Siemens magnetic resonance imaging (MRI) system using a single-shot spin echo planar imaging (EPI) sequence. Individual fornix tractography was conducted and whole tract diffusion parameter symmetries assessed. Whole tract results were compared with asymmetry contrasts conducted with voxelwise statistical analysis of diffusion parameters using TBSS. Results: The fornix tract could be visualized in its entirety including the columns, body, crura, and fimbria. Contrary to the crus and body, there were some tractography inconsistencies of the columns and fimbria across subjects. Although whole tract diffusion parameter asymmetries were nonsignificant, fractional anisotropy (FA) values bordered on statistical significance (P = 0.052). Using TBSS, significant FA asymmetries were identified (P ≤ 0.01, corrected). Conclusion: The findings demonstrate consistency of fornix tractography as well as some variability in the columns and fimbria. While parametric assessment demonstrates diffusion parameter symmetry, permutation-based TBSS analysis reveals significant FA asymmetries in the crura and fimbriae. © 2013 Wiley Periodicals, Inc. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2c5dda53-51b4-4ecd-80b9-1ed1f4bef13c ER - TY - JOUR TI - Modeling and process control of MOCVD growth of InAlGaAs MQW structures on InP DO - 10.1016/j.jcrysgro.2013.10.019 AU - Pitts, O.J. AU - Benyon, W. AU - SpringThorpe, A.J. T2 - Journal of Crystal Growth SN - 0022-0248 AB - We have developed a model which integrates calculation of InAlGaAs multiple quantum well (MQW) transition energies using the envelope function approximation with a statistical analysis of the PL emission wavelength, net strain and MQW period measured for a variety of MQW designs grown by MOCVD. The model relates the measured MQW parameters directly to MOCVD process parameters, allowing an accurate prediction of the process parameters required to grow a specified MQW design. This greatly reduces the need to grow and characterize individual calibration layers. The difference of the measured and predicted MQW parameters is recorded run-to-run over time, which allows process variability to be analyzed across a number of process parameters with intentional variations to grow different MQW designs. Crown Copyright © 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 86b72ee3-90c2-4493-a3a8-4fb274c70252 ER - TY - JOUR TI - Inhomogeneous transport in model hydrated polymer electrolyte supported ultrathin films DO - 10.1021/nn401624p AU - Damasceno Borges, D. AU - Franco, A.A. AU - Malek, K. AU - Gebel, G. AU - Mossa, S. T2 - ACS Nano SN - 1936-0851 VL - 7 IS - 8 SP - 6767 EP - 6773 KW - Classical molecular dynamics KW - Electrochemical activities KW - Fuel-cell catalyst layers KW - Hydrophilic/hydrophobic KW - Molecular dynamics simulations KW - Polymer electrolyte membranes KW - Technological activity KW - transport/nanostructure interplay KW - Catalysts KW - Fuel cells KW - Hydration KW - Molecular dynamics KW - Polyelectrolytes KW - Transport properties KW - Ultrathin films AB - The structure of polymer electrolyte membranes, e.g., Nafion, inside fuel cell catalyst layers has significant impact on the electrochemical activity and transport phenomena that determine cell performance. In those regions, Nafion can be found as an ultrathin film, coating the catalyst and the catalyst support surfaces. The impact of the hydrophilic/hydrophobic character of these surfaces on the structural formation of the films and, in turn, on transport properties has not been sufficiently explored yet. Here, we report classical molecular dynamics simulations of hydrated Nafion thin films in contact with unstructured supports, characterized by their global wetting properties only. We have investigated structure and transport in different regions of the film and found evidence of strongly heterogeneous behavior. We speculate about the implications of our work on experimental and technological activity. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0c637e89-dfd0-40ca-9f38-826e989ca1f3 ER - TY - JOUR TI - Impact of surfactants on Pb (Zr0.53Ti0.47) O3 nanocrystal formation DO - 10.1016/j.matlet.2012.10.033 AU - Wan, Q. AU - Gu, Q. AU - Xing, J. AU - Chen, J. T2 - Materials Letters SN - 0167-577X VL - 92 SP - 52 EP - 56 KW - Growth conditions KW - High resolution transmission electronic microscopy KW - Nano meter range KW - Nanocrystal formation KW - PZT KW - Single-crystalline KW - Triton X-100 KW - Tween-20 KW - Lead KW - Nanocrystals KW - Nanorods KW - Sintering KW - Sol-gel process KW - X ray diffraction KW - Zirconium KW - Surface active agents AB - In this article, we studied how surfactants can impact Pb (Zr 0.53Ti0.47) O3 (PZT) nanocrystal formation to result in interesting nanohexagon and nanorod shapes of PZT crystal. The PZT nanohexagons/nanorods with typical diameters and bounding lengths within the nanometer range were synthesized by sintering the mixture of PZT crystals. After annealing at 800 °C for 3 h, PZT nanohexagons were formed with Tween 20. Using the same sol-gel method and growth condition but with Tween 20 replaced by Triton X-100, PZT nanocrystals were formed having nanorod shapes. Their single-crystalline nanostructures and compositions were confirmed by high resolution transmission electronic microscopy (HR-TEM), X-ray diffraction (XRD) and Raman Spectra. The results of this study demonstrated new insight on how surfactants impact the morphology of PZT formation. © 2012 Elsevier B.V. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 99bc1a22-4b2f-4a59-aa31-5a202aaeee3d ER - TY - JOUR TI - Performance of cast-iron-pipe bell-spigot joints subjected to overburden pressure and ground movement DO - 10.1061/(ASCE)PS.1949-1204.0000125 AU - Rajani, B. AU - Abdel-Akher, A. T2 - Journal of Pipeline Systems Engineering and Practice SN - 1949-1190 VL - 4 IS - 2 SP - 98 EP - 114 KW - Asphalt coatings KW - Experimental test KW - Ground movement KW - Joint rotations KW - Material non-linearity KW - Mechanistic models KW - Overburden pressures KW - Pipe inspection KW - Cast iron pipe KW - Iron KW - Pipe joints KW - Bells AB - Bell split, in which a shard is separated from the bell end of a bell-spigot joint, is a predominant failure mode (in addition to longitudinal facture) that is observed in lead-caulked bell-spigot joints of large-diameter cast-iron pipes installed between 1850 and the early 1960s. This paper addresses three specific issues related to this type of failure of lead-caulked bell-spigot joints: (1) the extent to which cast-iron pipe joints can rotate without inducing stress in the bell; (2) the behavior of the bell-spigot lead-caulked joints; and (3) an estimate of the degree of settlement that two or more contiguous segments of jointed cast-iron pipe can tolerate before failure. The procedures described in this paper were motivated by the need to understand and explain the circumstances that lead to this failure mode in large-diameter cast-iron pipes. A mechanistic model accounts for lead material nonlinearity, wet and dry joint conditions encountered in water and gas pipelines, respectively, and existence or absence of asphalt coating on the outer pipe surface. The model is validated against experimental tests conducted in the mid-1930s on lead-caulked bell-spigot joints and is subsequently used to develop another model to predict the cumulative joint response of two or more contiguous pipesegments resting on an elastic medium and subject to overburden pressure followed by ground movement.Illustrative analyses of 400 and 1,200 mm diameter pipes clearly show that the extent to which a pipejoint can rotate without failure when subjected to ground movement gets smaller as the pipes become larger. The models developed in this paper to characterize joint behavior can be used to monitor pipe joint condition if actual joint rotations are measured when conducting pipe inspection © 2013 American Society of Civil Engineers. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f83b90ac-f007-4e3c-9621-d194591b5fc5 ER - TY - JOUR TI - Geniposide regulates glucose-stimulated insulin secretion possibly through controlling glucose metabolism in INS-1 cells DO - 10.1371/journal.pone.0078315 AU - Liu, J. AU - Guo, L. AU - Yin, F. AU - Zhang, Y. AU - Liu, Z. AU - Wang, Y. T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 10 SP - e78315 KW - 2 oxoglutaric acid KW - adenosine triphosphate KW - geniposide KW - glucose KW - pyruvate carboxylase KW - animal cell KW - article KW - cell protection KW - diabetes mellitus KW - enzyme activation KW - enzyme regulation KW - enzyme synthesis KW - gluconeogenesis KW - glucose metabolism KW - glucose transport KW - immunoblotting KW - insulin release KW - nonhuman KW - nucleotide sequence KW - pancreas islet beta cell KW - protein analysis KW - protein blood level KW - protein expression KW - protein function KW - rat AB - Glucose-stimulated insulin secretion (GSIS) is essential to the control of metabolic fuel homeostasis. The impairment of GSIS is a key element of β-cell failure and one of causes of type 2 diabetes mellitus (T2DM). Although the KATP channel-dependent mechanism of GSIS has been broadly accepted for several decades, it does not fully describe the effects of glucose on insulin secretion. Emerging evidence has suggested that other mechanisms are involved. The present study demonstrated that geniposide enhanced GSIS in response to the stimulation of low or moderately high concentrations of glucose, and promoted glucose uptake and intracellular ATP levels in INS-1 cells. However, in the presence of a high concentration of glucose, geniposide exerted a contrary role on both GSIS and glucose uptake and metabolism. Furthermore, geniposide improved the impairment of GSIS in INS-1 cells challenged with a high concentration of glucose. Further experiments showed that geniposide modulated pyruvate carboxylase expression and the production of intermediates of glucose metabolism. The data collectively suggest that geniposide has potential to prevent or improve the impairment of insulin secretion in β-cells challenged with high concentrations of glucose, likely through pyruvate carboxylase mediated glucose metabolism in β-cells. © 2013 Liu et al. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5dc68ed3-4220-4397-90d5-e49480f9bbe0 ER - TY - JOUR TI - Head-and-face shape variations of U.S. civilian workers DO - 10.1016/j.apergo.2013.01.008 AU - Zhuang, Ziquing AU - Shu, Chang AU - Xi, Pencheng AU - Bergman, Michael AU - Joseph, Michael T2 - Applied Ergonomics SN - 0003-6870 VL - 44 IS - 5 SP - 775 EP - 784 KW - Anthropometric; 3D scan; Head-and-face modeling; Shape analysis; Respirator design AB - The objective of this study was to quantify head-and-face shape variations of U.S. civilian workers using modern methods of shape analysis. The purpose of this study was based on previously highlighted changes in U.S. civilian worker head-and-face shape over the last few decades - touting the need for new and better fitting respirators - as well as the study's usefulness in designing more effective personal protective equipment (PPE) - specifically in the field of respirator design. The raw scan three-dimensional (3D) data for 1169 subjects were parameterized using geometry processing techniques. This process allowed the individual scans to be put in correspondence with each other in such a way that statistical shape analysis could be performed on a dense set of 3D points. This process also cleaned up the original scan data such that the noise was reduced and holes were filled in. The next step, statistical analysis of the variability of the head-and-face shape in the 3D database, was conducted using Principal Component Analysis (PCA) techniques. Through these analyses, it was shown that the space of the head-and-face shape was spanned by a small number of basis vectors. Less than 50 components explained more than 90% of the variability. Furthermore, the main mode of variations could be visualized through animating the shape changes along the PCA axes with computer software in executable form for Windows XP. The results from this study in turn could feed back into respirator design to achieve safer, more efficient product style and sizing. Future study is needed to determine the overall utility of the point cloud-based approach for the quantification of facial morphology variation and its relationship to respirator performance. DA - 2013/01/21 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0fcd58ef-3683-412e-9872-36f3fe085e1e ER - TY - JOUR TI - Tip apex shaping of gas field ion sources DO - 10.1016/j.ultramic.2013.03.013 AU - Pitters, J.L. AU - Urban, R. AU - Vesa, C. AU - Wolkow, R.A. T2 - Ultramicroscopy SN - 0304-3991 VL - 131 SP - 56 EP - 60 KW - Acceleration effects KW - Cold field emissions KW - Emission properties KW - Field ion microscopy KW - Gas field ion sources KW - Helium ion beams KW - Operating voltage KW - Single-atom tips KW - Atoms KW - Etching KW - Full width at half maximum KW - Helium KW - Ion sources KW - Gas industry KW - helium KW - nitrogen KW - article KW - chemical procedures KW - controlled study KW - electron microscopy KW - etching process KW - evaporation KW - gas field KW - image analysis KW - ionization KW - molecular dynamics KW - molecular imaging KW - molecular size KW - pressure measurement KW - procedures KW - single atom tip shaping KW - surface property AB - A procedure to control W(111) tip shape during etching to a single atom is described. It is demonstrated that the base of a single atom tip (SAT) can be shaped in order to alter the final operating voltage and emission opening angle of single atom tips for use as gas field ion sources or electron cold field emission sources. The operating voltages for single atom tips varied between 5 and 17. kV during helium ion beam generation. The emission properties of SATs were evaluated by fitting SAT images and measuring the full width at half maximum (FWHM) of the helium ion images. The FWHM is related to the linear opening angle and was evaluated as a function of SAT operating voltage. The results show that a forward focussing effect is observed such that the spot size decreases faster than is expected solely from an acceleration effect, indicating an affect from the tip shape. These results have consequences in designing gas field ion sources where etching is used to prepare the emitter. © 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d63008e2-090f-4f90-8f62-65e77a3a8335 ER - TY - JOUR TI - Profiling of cytokine and chemokine responses using multiplex bead array technology DO - 10.1007/978-1-62703-589-7_16 AU - Harris, G. AU - Chen, W. T2 - Methods in Molecular Biology SN - 1064-3745 SN - 9781627035880 VL - 1061 SP - 265 EP - 278 KW - chemokine KW - CXCL3 chemokine KW - cytokine KW - interleukin 1beta KW - interleukin 6 KW - keratinocyte derived chemokine KW - macrophage inflammatory protein 1beta KW - monocyte chemotactic protein 1 KW - RANTES KW - tumor necrosis factor alpha KW - animal tissue KW - article KW - blood analysis KW - controlled study KW - immunology test kit KW - lung lavage KW - microarray analysis KW - mouse KW - multiplex bead array assay KW - nonhuman KW - priority journal KW - quantitative analysis KW - supernatant KW - technology KW - tissue culture KW - tissue homogenate AB - Multiplex bead array technology expands upon the principles of the enzyme-linked immunosorbent assay by allowing the simultaneous quantification of a large number of cytokines and chemokines within a single sample. This allows for the researcher more freedom to investigate complex immune responses both in vivo and in vitro. Here we describe the detailed assay protocol and technical tips for simultaneous quantification of multiple cytokines and chemokines in mouse biological fluids such as sera, bronchoalveolar lavage fluid, tissue homogenate supernatant, and tissue culture supernatant, using a multiplex bead array assay. © 2013 Springer Science+Business Media, LLC. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1dd8edd8-90ee-4d6b-a704-1cdf800d7e3a ER - TY - JOUR TI - Improving the formability of stainless steel 321 through multistep deformation for hydroforming applications AU - Anderson, M. AU - Gholipour, J. AU - Bridier, F. AU - Bocher, P. AU - Jahazi, M. AU - Savoie, J. AU - Wanjara, P. T2 - Transactions of the Canadian Society for Mechanical Engineering SN - 0315-8977 VL - 37 IS - 1 SP - 39 EP - 52 KW - Aerospace alloys KW - Heat treatment parameters KW - Intermediate heat treatment KW - Micro-structure evolutions KW - Multistep forming KW - Strain-induced martensite KW - Tube hydroforming KW - Uniaxial tensile testing KW - Alloys KW - Austenitic stainless steel KW - Automotive industry KW - Formability KW - Heat treatment KW - Microstructure KW - Stainless steel KW - Stress relief KW - Tensile testing KW - Tubes (components) KW - Deformation AB - Tube hydroforming (THF) is a well established process in the automotive industry and its application is being extended to the aerospace for manufacturing complex geometries. However, most of the alloys used in aerospace are high in strength and low in formability, which renders the application of THF more challenging. The objective of this paper is to present a method to increase the formability of an austenitic stainless steel. A multistep forming process was simulated through interrupted uniaxial tensile testing experiments to study the influence of the latter process on formability. The tensile test was divided into several deformation steps with a stress relief heat treatment after each forming step. The results indicated that the application of intermediate heat treatments considerably increased the formability of the stainless steel 321 alloy (SS321). Microstructure evolution as a function of deformation or heat treatment parameters was also investigated and revealed the formation of strain-induced martensite after the first deformation and heat treatment cycle without any deleterious effect on formability enhancement. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e20de9b8-5dfb-4cc7-b6df-e3ab2ecc4926 ER - TY - JOUR TI - Exoplanets from the arctic: The first wide-field survey at 80°N DO - 10.1088/0004-6256/145/3/58 AU - Law, N.M. AU - Carlberg, R. AU - Salbi, P. AU - Ngan, W.-H.W. AU - Ahmadi, A. AU - Steinbring, E. AU - Murowinski, R. AU - Sivanandam, S. AU - Kerzendorf, W. T2 - Astronomical Journal SN - 0004-6256 VL - 145 IS - 3 SP - 58 AB - Located within 10° of the North Pole, northern Ellesmere Island offers continuous darkness in the winter months. This capability can greatly enhance the detection efficiency of planetary transit surveys and other time domain astronomy programs. We deployed two wide-field cameras at 80°N, near Eureka, Nunavut, for a 152 hr observing campaign in 2012 February. The 16 megapixel camera systems were based on commercial f/1.2 lenses with 70 mm and 42 mm apertures, and they continuously imaged 504 and 1295 deg2, respectively. In total, the cameras took over 44,000 images and produced better than 1% precision light curves for approximately 10,000 stars. We describe a new high-speed astrometric and photometric data reduction pipeline designed for the systems, test several methods for the precision flat fielding of images from very-wide-angle cameras, and evaluate the cameras' image qualities. We achieved a scintillation-limited photometric precision of 1%-2% in each 10 s exposure. Binning the short exposures into 10 minute chunks provided a photometric stability of 2-3 mmag, sufficient for the detection of transiting exoplanets around the bright stars targeted by our survey. We estimate that the cameras, when operated over the full Arctic winter, will be capable of discovering several transiting exoplanets around bright (mV < 9.5) stars. © 2013. The American Astronomical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 38e7268f-99bb-4bee-9410-4d6d7c08dc0f ER - TY - JOUR TI - Enhancement of bone consolidation in mandibular distraction osteogenesis: A contemporary review of experimental studies involving adjuvant therapies DO - 10.1016/j.bjps.2013.03.030 AU - Hong, P. AU - Boyd, D. AU - Beyea, S.D. AU - Bezuhly, M. T2 - Journal of Plastic, Reconstructive and Aesthetic Surgery SN - 1748-6815 VL - 66 IS - 7 SP - 883 EP - 895 KW - adiponectin KW - alendronic acid KW - bone morphogenetic protein 2 KW - bone morphogenetic protein 4 KW - calcium hydroxide KW - calcium sulfate KW - deferoxamine KW - erythropoietin KW - fibroblast growth factor KW - icariin KW - nerve growth factor KW - osteogenic protein 1 KW - simvastatin KW - somatomedin C KW - tissue inhibitor of metalloproteinase 1 KW - zoledronic acid KW - angiogenesis KW - bone development KW - bone regeneration KW - distraction osteogenesis KW - electrostimulation KW - extracorporeal lithotripsy KW - gene therapy KW - human KW - hyperbaric oxygen KW - low intensity pulsed ultrasound KW - low level laser therapy KW - mandibular distraction osteogenesis KW - mechanical stimulation KW - membrane guided regeneration KW - mesenchymal stem cell KW - nonhuman KW - ossification KW - priority journal KW - protein expression KW - protein function KW - review KW - systematic review KW - ultrasound KW - Adjuvants, Pharmaceutic KW - Alendronate KW - Animals KW - Bone Morphogenetic Protein 4 KW - Bone Regeneration KW - Disease Models, Animal KW - Dogs KW - Electric Stimulation Therapy KW - Erythropoietin KW - Genetic Therapy KW - Mandible KW - Nerve Growth Factor KW - Osteogenesis KW - Osteogenesis, Distraction KW - Rabbits KW - Rats KW - Risk Assessment KW - Stem Cell Transplantation KW - Treatment Outcome AB - Background One of the major disadvantages of mandibular distraction osteogenesis (MDO) is the prolonged time required for consolidation of the regenerate bone. The objective of the present study is to perform a contemporary review of various adjuvant therapies to enhance bone consolidation in MDO. Methods A PubMed search for articles related to MDO, along with the references of those articles, was performed. Inclusion and exclusion criteria were applied to all experimental studies assessing adjuvant therapies to enhance bone consolidation. Results A total of 1414 titles and abstracts were initially reviewed; 61 studies were included for full review. Many studies involved growth factors, hormones, pharmacological agents, gene therapy, and stem cells. Other adjuvant therapies included mechanical stimulation, laser therapy, and hyperbaric oxygen. Majority of the studies demonstrated positive bone healing effects and thus adjuvant therapies remain a viable strategy to enhance and hasten the consolidation period. Conclusion Although most studies have demonstrated promising results, many questions still remain, such as optimal amount, timing, and delivery methods required to stimulate the most favorable bone regeneration. As well, further studies comparing various adjuvant therapies and documentation of long-term adverse effects are required prior to clinical application. © 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : cff5a645-eee7-492c-af6d-6c47c00c1c75 ER - TY - JOUR TI - A critical perspective on molecular electronic junctions: There is plenty of room in the middle DO - 10.1039/c2cp43516k AU - McCreery, R.L. AU - Yan, H. AU - Bergren, A.J. T2 - Physical Chemistry Chemical Physics SN - 1463-9076 VL - 15 IS - 4 SP - 1065 EP - 1081 AB - The promise of molecular electronic devices stems from the possibilities offered by the rich electronic structure of organic molecules. The use of molecules as functional components in microelectronic devices has long been envisioned to augment or even replace silicon. However, the understanding of what controls charge transport in these devices involves complexities stemming from numerous variables that are often interactive and exert a controlling influence on transport, confounding the role of the molecular component. This perspective discusses various aspects of molecular electronics, from the initial "vision quests" of single molecule, functional electronic elements, to the molecular tunnel junctions that have been studied and characterized in-depth. Aspects of energy level alignment are discussed in the context of charge transport mechanisms, as are important electronic interactions when molecules are bonded to conducting "contacts". In addition, integration of molecular components with microelectronic processing is considered, as are the prospects for functional, real-world devices. © the Owner Societies 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9e5b94e6-63d7-4f81-8e03-d73c1243b9bd ER - TY - JOUR TI - Density-functional theory with dispersion-correcting potentials for methane: Bridging the efficiency and accuracy gap between high-level wave function and classical molecular mechanics methods DO - 10.1021/ct4003114 AU - Torres, E. AU - Dilabio, G.A. T2 - Journal of Chemical Theory and Computation SN - 1549-9618 VL - 9 IS - 8 SP - 3342 EP - 3349 AB - Large clusters of noncovalently bonded molecules can only be efficiently modeled by classical mechanics simulations. One prominent challenge associated with this approach is obtaining force-field parameters that accurately describe noncovalent interactions. High-level correlated wave function methods, such as CCSD(T), are capable of correctly predicting noncovalent interactions, and are widely used to produce reference data. However, high-level correlated methods are generally too computationally costly to generate the critical reference data required for good force-field parameter development. In this work we present an approach to generate Lennard-Jones force-field parameters to accurately account for noncovalent interactions. We propose the use of a computational step that is intermediate to CCSD(T) and classical molecular mechanics, that can bridge the accuracy and computational efficiency gap between them, and demonstrate the efficacy of our approach with methane clusters. On the basis of CCSD(T)-level binding energy data for a small set of methane clusters, we develop methane-specific, atom-centered, dispersion-correcting potentials (DCPs) for use with the PBE0 density-functional and 6-31+G(d,p) basis sets. We then use the PBE0-DCP approach to compute a detailed map of the interaction forces associated with the removal of a single methane molecule from a cluster of eight methane molecules and use this map to optimize the Lennard-Jones parameters for methane. The quality of the binding energies obtained by the Lennard-Jones parameters we obtained is assessed on a set of methane clusters containing from 2 to 40 molecules. Our Lennard-Jones parameters, used in combination with the intramolecular parameters of the CHARMM force field, are found to closely reproduce the results of our dispersion-corrected density-functional calculations. The approach outlined can be used to develop Lennard-Jones parameters for any kind of molecular system. © Published 2013 by the American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 142c2b15-09fc-49b3-9171-e410d4a45ba6 ER - TY - JOUR TI - On the density profile of the globular cluster M92 DO - 10.1088/0004-6256/145/4/103 AU - Di Cecco, A. AU - Zocchi, A. AU - Varri, A.L. AU - Monelli, M. AU - Bertin, G. AU - Bono, G. AU - Stetson, P.B. AU - Nonino, M. AU - Buonanno, R. AU - Ferraro, I. AU - Iannicola, G. AU - Kunder, A. AU - Walker, A.R. T2 - Astronomical Journal SN - 0004-6256 VL - 145 IS - 4 SP - 103 AB - We present new number density and surface brightness profiles for the globular cluster M92 (NGC 6341). These profiles are calculated from optical images collected with the CCD mosaic camera MegaCam at the Canada-France-Hawaii Telescope and with the Advanced Camera for Surveys on the Hubble Space Telescope. The ground-based data were supplemented with the Sloan Digital Sky Survey photometric catalog. Special care was taken to discriminate candidate cluster stars from field stars and to subtract the background contamination from both profiles. By examining the contour levels of the number density, we found that the stellar distribution becomes clumpy at radial distances larger than ∼13′, and there is no preferred orientation of contours in space. We performed detailed fits of King and Wilson models to the observed profiles. The best-fit models underestimate the number density inside the core radius. Wilson models better represent the observations, in particular in the outermost cluster regions: the good global agreement of these models with the observations suggests that there is no need to introduce an extra-tidal halo to explain the radial distribution of stars at large radial distances. The best-fit models for the number density and the surface brightness profiles are different, even though they are based on the same observations. Additional tests support the evidence that this fact reflects the difference in the radial distribution of the stellar tracers that determine the observed profiles (main-sequence stars for the number density, bright evolved stars for the surface brightness). © 2013. The American Astronomical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 849e92ea-2d35-4fff-8eb6-8f37b4b89719 ER - TY - JOUR TI - Oxide films in laser additive manufactured Inconel 718 DO - 10.1016/j.actamat.2013.07.039 AU - Zhang, Y.N. AU - Cao, X. AU - Wanjara, P. AU - Medraj, M. T2 - Acta Materialia SN - 1359-6454 VL - 61 IS - 17 SP - 6562 EP - 6576 KW - Additive Manufacturing KW - Continuous waves KW - Failure mechanism KW - Fracture surfaces KW - Laser depositions KW - Parent materials KW - Tensile fracture surfaces KW - Thermo dynamic analysis KW - Alloying elements KW - Deposition KW - Fiber lasers KW - Hydrogen embrittlement KW - Inert gases KW - Intermetallics KW - Manufacture KW - Niobium KW - Niobium compounds KW - Scanning electron microscopy KW - Sodium compounds KW - Soldering alloys KW - Tensile strength KW - Tensile testing KW - Thermoanalysis KW - Welding KW - Wetting KW - Oxide films AB - A continuous-wave 5 kW fiber laser welding system was used in conduction mode to deposit Inconel® alloy 718 (IN718) by employing filler wire on as-serviced IN718 parent material (PM) substrates. The direct laser deposited (DLD) coupons and as-serviced IN718 PM were then evaluated through tensile testing. To understand the failure mechanisms, the tensile fracture surfaces of the as-serviced IN718 PM, DLD and DLD-PM samples were analyzed using scanning electron microscopy. The fracture surfaces revealed the presence of both Al 2O3 and Cr2O3 films, although the latter was reasoned to be the main oxide in IN718. Both the experimental observations and thermodynamic analysis indicated that oxidation of some alloying elements in IN718 cannot be completely avoided during manufacturing, whether in the liquid state under vacuum (for casting, the electron beam melting, welding and/or deposition) or with inert gas protection (for welding or laser deposition). The exposed surface of the oxide film on the fracture surface has poor wetting with the metal and thus can constitute a lack of bonding or a crack with either the metal and/or another non-wetted side of the oxide film. On the other hand, the wetted face of the oxide film has good atom-to-atom contact with the metal and may nucleate some intermetallic compounds, such as Laves, Ni3Nb-δ, Nb-rich MC and γ′ compounds. The potential of their nucleation on Cr 2O3 was assessed using planar disregistry. Coherent planes were found between these intermetallics and Cr2O3. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5a03ad02-3906-406a-864f-c83f6beecfa8 ER - TY - JOUR TI - Pasteurella multocida heddleston serovar 3 and 4 strains share a common lipopolysaccharide biosynthesis locus but display both inter- and intrastrain lipopolysaccharide heterogeneity DO - 10.1128/JB.00779-13 AU - Harper, M. AU - St.Michael, F. AU - John, M. AU - Vinogradov, E. AU - Steen, J.A. AU - van Dorsten, L. AU - Turni, C. AU - Blackall, P.J. AU - Adler, B. AU - Cox, A.D. AU - Boycea, J.D. T2 - Journal of Bacteriology SN - 0021-9193 VL - 195 IS - 21 SP - 4854 EP - 4864 KW - bacterium lipopolysaccharide KW - galactosyltransferase KW - glycosyltransferase KW - article KW - bacterial growth KW - bacterium isolation KW - biosynthesis KW - carbohydrate analysis KW - controlled study KW - crystal structure KW - DNA sequence KW - electrospray mass spectrometry KW - Escherichia coli KW - gene locus KW - gene mutation KW - genotype KW - missense mutation KW - mutagenesis KW - nonhuman KW - nonsense mutation KW - nuclear magnetic resonance spectroscopy KW - nucleotide sequence KW - Pasteurella multocida KW - priority journal KW - promoter region KW - serotype AB - Pasteurella multocida is a Gram-negative multispecies pathogen and the causative agent of fowl cholera, a serious disease of poultry which can present in both acute and chronic forms. The major outer membrane component lipopolysaccharide (LPS) is both an important virulence factor and a major immunogen. Our previous studies determined the LPS structures expressed by different P. multocida strains and revealed that a number of strains belonging to different serovars contain the same LPS biosynthesis locus but express different LPS structures due to mutations within glycosyltransferase genes. In this study, we report the full LPS structure of the serovar 4 type strain, P1662, and reveal that it shares the same LPS outer core biosynthesis locus, L3, with the serovar 3 strains P1059 and Pm70. Using directed mutagenesis, the role of each glycosyltransferase gene in LPS outer core assembly was determined. LPS structural analysis of 23 Australian field isolates that contain the L3 locus revealed that at least six different LPS outer core structures can be produced as a result of mutations within the LPS glycosyltransferase genes. Moreover, some field isolates produce multiple but related LPS glycoforms simultaneously, and three LPS outer core structures are remarkably similar to the globo series of vertebrate glycosphingolipids. Our in-depth analysis showing the genetics and full range of P. multocida lipopolysaccharide structures will facilitate the improvement of typing systems and the prediction of the protective efficacy of vaccines. © 2013, American Society for Microbiology. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 51877006-391d-4266-8d02-4bf699f69b80 ER - TY - JOUR TI - Genome-based bioinformatic prediction of major histocompatibility complex (MHC) epitopes DO - 10.1007/978-1-62703-589-7_19 AU - Foote, S.J. T2 - Methods in Molecular Biology SN - 1064-3745 SN - 9781627035880 VL - 1061 SP - 309 EP - 322 KW - epitope KW - algorithm KW - article KW - bioinformatics KW - CD8+ T lymphocyte KW - computer program KW - data base KW - gene inactivation KW - gene sequence KW - genome KW - major histocompatibility complex KW - mouse KW - nonhuman KW - nucleotide sequence KW - priority journal KW - protein localization AB - Over the last 12 years, a large amount of knowledge has been accumulated on various aspects of Major Histocompatibility Complex (MHC) molecules. In conjunction, numerous algorithms and tools have been developed to screen protein molecules for these MHC receptor sites. By combining these computational tools and databases with genomic sequence information that is now widely available for a vast range of organisms, it is possible to screen whole genomes for MHC epitopes. By prescreening these genomes, it allows the researcher to narrow down possible protein targets for further analysis by traditional tools such as gene knockouts and animal efficacy studies. © 2013 Springer Science+Business Media, LLC. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 63c00b39-b263-47ba-b784-e42d3327509f ER - TY - JOUR TI - Cerebral endothelial expression of Robo1 affects brain infiltration of polymorphonuclear neutrophils during mouse stroke recovery DO - 10.1016/j.nbd.2013.02.014 AU - Gangaraju, S. AU - Sultan, K. AU - Whitehead, S.N. AU - Nilchi, L. AU - Slinn, J. AU - Li, X. AU - Hou, S.T. T2 - Neurobiology of Disease SN - 0969-9961 VL - 54 SP - 24 EP - 31 KW - glucose KW - oxygen KW - receptor protein KW - ROBO1 protein KW - Slit protein KW - Slit1 protein KW - unclassified drug KW - animal experiment KW - animal model KW - animal tissue KW - article KW - brain blood vessel KW - brain cortex KW - brain ischemia KW - brain tissue KW - cell migration KW - cerebrovascular accident KW - controlled study KW - convalescence KW - endothelium cell KW - human KW - human cell KW - in vitro study KW - inflammation KW - middle cerebral artery occlusion KW - mouse KW - neutrophil chemotaxis KW - nonhuman KW - priority journal KW - protein expression KW - reperfusion KW - sham procedure KW - umbilical vein endothelial cell KW - vascular endothelium KW - Animals KW - Blotting, Western KW - Brain KW - Chemotaxis, Leukocyte KW - Disease Models, Animal KW - Endothelial Cells KW - HEK293 Cells KW - Humans KW - Immunohistochemistry KW - Mice KW - Mice, Inbred C57BL KW - Nerve Tissue Proteins KW - Neutrophils KW - Receptors, Immunologic KW - Stroke KW - Transfection AB - Increased brain infiltration of polymorphonuclear neutrophils (PMNs) occurs early after stroke and is important in eliciting brain inflammatory response during stroke recovery. In order to understand the molecular mechanism of PMN entry, we investigated the expression and requirement for Slit1, a chemorepulsive guidance cue, and its cognate receptor, Robo1, in a long-term recovery mouse model of cerebral ischemia. The expression levels of Robo1 were significantly decreased bilaterally at 24. h following reperfusion. Robo1 expression levels remained suppressed in the ipsilateral cortex until 28. d post MCAO-reperfusion, while the levels of Robo1 in the contralateral cortex recovered to the level of sham-operated mouse by 7. d reperfusion. Circulating PMNs express high levels of Slit1, but not Robo1. Influx of PMNs into the ischemic core area occurred early (24. h) after cerebral ischemia, when endothelial Robo1 expression was significantly reduced in the ischemic brain, indicating that Robo1 may form a repulsive barrier to PMN entry into the brain parenchyma. Indeed, blocking Slit1 on PMNs in a transwell migration assay in combination with an antibody blocking of Robo1 on human umbilical vein endothelial cells (HUVEC) significantly increased PMN transmigration during oxygen glucose deprivation, an in vitro model of ischemia. Collectively, in the normal brain, the presence of Slit1 on PMNs, and Robo1 on cerebral endothelial cells, generated a repulsive force to prevent the infiltration of PMNs into the brain. During stroke recovery, a transient reduction in Robo1 expression on the cerebral endothelial cells allowed the uncontrolled infiltration of Slit1-expressing PMNs into the brain causing inflammatory reactions. © 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3aaa48e4-57b4-4a3c-8cbc-f096f92a97c2 ER - TY - JOUR TI - Seds: The spitzer extended deep survey. Survey design, photometry, and deep irac source counts DO - 10.1088/0004-637X/769/1/80 AU - Ashby, M.L.N. AU - Willner, S.P. AU - Fazio, G.G. AU - Huang, J.-S. AU - Arendt, R. AU - Barmby, P. AU - Barro, G. AU - Bell, E.F. AU - Bouwens, R. AU - Cattaneo, A. AU - Croton, D. AU - Davé, R. AU - Dunlop, J.S. AU - Egami, E. AU - Faber, S. AU - Finlator, K. AU - Grogin, N.A. AU - Guhathakurta, P. AU - Hernquist, L. AU - Hora, J.L. AU - Illingworth, G. AU - Kashlinsky, A. AU - Koekemoer, A.M. AU - Koo, D.C. AU - Labbé, I. AU - Li, Y. AU - Lin, L. AU - Moseley, H. AU - Nandra, K. AU - Newman, J. AU - Noeske, K. AU - Ouchi, M. AU - Peth, M. AU - Rigopoulou, D. AU - Robertson, B. AU - Sarajedini, V. AU - Simard, L. AU - Smith, H.A. AU - Wang, Z. AU - Wechsler, R. AU - Weiner, B. AU - Wilson, G. AU - Wuyts, S. AU - Yamada, T. AU - Yan, H. T2 - The Astrophysical Journal SN - 0004-637X VL - 769 IS - 1 SP - 80 AB - The Spitzer Extended Deep Survey (SEDS) is a very deep infrared survey within five well-known extragalactic science fields: the UKIDSS Ultra-Deep Survey, the Extended Chandra Deep Field South, COSMOS, the Hubble Deep Field North, and the Extended Groth Strip. SEDS covers a total area of 1.46 deg 2 to a depth of 26 AB mag (3σ) in both of the warm Infrared Array Camera (IRAC) bands at 3.6 and 4.5 μm. Because of its uniform depth of coverage in so many widely-separated fields, SEDS is subject to roughly 25% smaller errors due to cosmic variance than a single-field survey of the same size. SEDS was designed to detect and characterize galaxies from intermediate to high redshifts (z = 2-7) with a built-in means of assessing the impact of cosmic variance on the individual fields. Because the full SEDS depth was accumulated in at least three separate visits to each field, typically with six-month intervals between visits, SEDS also furnishes an opportunity to assess the infrared variability of faint objects. This paper describes the SEDS survey design, processing, and publicly-available data products. Deep IRAC counts for the more than 300,000 galaxies detected by SEDS are consistent with models based on known galaxy populations. Discrete IRAC sources contribute 5.6 ± 1.0 and 4.4 ± 0.8 nW m-2 sr-1 at 3.6 and 4.5 μm to the diffuse cosmic infrared background (CIB). IRAC sources cannot contribute more than half of the total CIB flux estimated from DIRBE data. Barring an unexpected error in the DIRBE flux estimates, half the CIB flux must therefore come from a diffuse component. © 2013. The American Astronomical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4bb6c817-3faf-4dc2-b2b8-ca2222500d52 ER - TY - JOUR TI - Requirement of the lipopolysaccharide O-chain biosynthesis gene wxocB for type III secretion and virulence of Xanthomonas oryzae pv. Oryzicola DO - 10.1128/JB.02299-12 AU - Wang, L. AU - Vinogradov, E.V. AU - Bogdanove, A.J. T2 - Journal of Bacteriology SN - 0021-9193 VL - 195 IS - 9 SP - 1959 EP - 1969 KW - exopolysaccharide KW - lipopolysaccharide KW - novobiocin KW - phytoalexin KW - resveratrol KW - antibiotic resistance KW - article KW - biosynthesis KW - mutant KW - nonhuman KW - oxidative stress KW - pathogenesis KW - plant cell KW - priority journal KW - structure analysis KW - virulence KW - wild type KW - Xanthomonas oryzae KW - Bacterial Proteins KW - Bacterial Secretion Systems KW - Gene Expression Regulation, Bacterial KW - Glucosyltransferases KW - Lipopolysaccharides KW - Molecular Structure KW - Mutation KW - Oryza sativa KW - Plant Diseases KW - Protein Transport KW - Virulence KW - Xanthomonas KW - Bacteria (microorganisms) KW - Xanthomonas KW - Xanthomonas oryzae pv. oryzicola AB - Xanthomonas oryzae pv. oryzicola causes bacterial leaf streak of rice. A mutant disrupted in wxocB, predicted to encode an enzyme for lipopolysaccharide (LPS) synthesis, was previously shown to suffer reduced virulence. Here, we confirm a role for wxocB in virulence and demonstrate its requirement for LPS O-chain assembly. Structure analysis indicated that wild-type LPS contains a polyrhamnose O chain with irregular, variant residues and a core oligosaccharide identical to that of other Xanthomonas spp. and that the wxocB mutant lacks the O chain. The mutant also showed moderate impairment in exopolysaccharide (EPS) production, but comparison with an EPS-deficient mutant demonstrated that this impairment could not account entirely for the reduced virulence. The wxocB mutant was not detectably different from the wild type in its induction of pathogenesis- related rice genes, type II secretion competence, flagellar motility, or resistance to two phytoalexins or resveratrol, and it was more, not less, resistant to oxidative stress and a third phytoalexin, indicating that none of these properties is involved. The mutant was more sensitive to SDS and to novobiocin, so increased sensitivity to some host-derived antimicrobials cannot be ruled out. However, the mutant showed a marked decrease in type III secretion into plant cells. This was not associated with any change in expression of genes for type III secretion or the ability to attach to plant cells in suspension. Thus, virulence of the wxocB mutant is likely reduced due primarily to a direct, possibly structural, effect of the loss of the O chain on type III delivery of effector proteins. © 2013, American Society for Microbiology. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 35c878b6-c385-4c2f-b08e-9ead5d2fff2e ER - TY - JOUR TI - The impact of SO2 on post combustion carbon dioxide capture in bed of silica sand through hydrate formation DO - 10.1016/j.ijggc.2013.02.008 AU - Daraboina, N. AU - Ripmeester, J. AU - Englezos, P. T2 - International Journal of Greenhouse Gas Control SN - 1750-5836 VL - 15 SP - 97 EP - 103 KW - Carbon dioxide capture KW - Geological sequestration of CO KW - Hydrate formation conditions KW - Hydrate formation process KW - Hydrate nucleation KW - Sequestration KW - Thermodynamics and kinetics KW - THF KW - Carbon capture KW - Carbon dioxide KW - Flue gases KW - Hydration KW - Impurities KW - Nucleation KW - Porous materials KW - Removal KW - Sulfur dioxide KW - Gas hydrates KW - carbon dioxide KW - carbon sequestration KW - combustion KW - gas hydrate KW - P-T conditions KW - porous medium KW - silica KW - sulfur dioxide KW - thermodynamics AB - Hydrate crystallization technology is one of the novel approaches for capturing carbon dioxide from flue gases. The presence of impurities such as SO2, NO2, H2S can influence the CO2 hydrate formation process. In the present work the impact of SO2 on hydrate equilibrium was investigated using the isothermal pressure search method. The hydrate equilibrium shifted to low pressures and high temperatures in the presence of small amount SO2. For example the hydrate formation pressure shifted from 7.7MPa to 7.25MPa at 273.75K. In addition, the presence of SO2 enhanced the initial hydrate formation rate and final moles of gas consumed 16h after the hydrate nucleation. The CO2 and SO2 gases were preferentially incorporated into the hydrate phase. The presence of SO2 helps the thermodynamics and kinetics of the hydrate formation process. Therefore complete removal of this SO2 impurity is not necessary; in fact it aids both thermodynamically and kinetically for hydrate formation, which indeed is a positive factor for the capture and geological sequestration of CO2 in the form of hydrates. The addition of THF reduces the CO2/N2/SO2 hydrate formation conditions (from 7.25MPa to 0.15MPa at 273.75K), which is practically important for reducing high compression costs. Moreover, the presence of THF decreases the hydrate nucleation time but reduces the hydrate formation rate significantly. © 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1c4fedac-1a27-489b-89e1-821f81938bed ER - TY - JOUR TI - In situ tribometry of cold-sprayed Al-Al2O3 composite coatings DO - 10.1016/j.surfcoat.2012.04.099 AU - Shockley, J.M. AU - Strauss, H.W. AU - Chromik, R.R. AU - Brodusch, N. AU - Gauvin, R. AU - Irissou, E. AU - Legoux, J.-G. T2 - Surface and Coatings Technology SN - 0257-8972 VL - 215 SP - 350 EP - 356 KW - Cold spray KW - Mechanically mixed layers KW - Metal matrix composite coatings KW - Situ tribologies KW - Third body KW - Aluminum coatings KW - Cladding (coating) KW - Composite coatings KW - Friction KW - Interfaces (materials) KW - Wear of materials KW - Aluminum AB - An in situ tribometer utilizing a transparent hemispherical counterface was used to conduct sliding wear tests on Al-Al2O3 composite coatings deposited by cold spray. Direct observation of the wear interface via the slider allowed for correlation to be identified between the formation of transfer film and friction changes, wear rates, and the evolution of subsurface structures. It was revealed that the presence of hard particles in the Al-Al2O3 coating stabilized the transfer film, characterized by less plastic flow and fewer instances of hole formation at the interface. This increase in stability correlated with lower wear rates, stable friction, and the formation of a mechanically mixed layer (MML) in the worn subsurface. © 2012 Elsevier B.V. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 779ca94d-3ecb-4829-8d10-17e56c54fd74 ER - TY - JOUR TI - Analysis of a ferric uptake regulator (Fur) knockout mutant in Aeromonas salmonicida subsp. salmonicida DO - 10.1016/j.vetmic.2012.10.038 AU - Ebanks, R.O. AU - Goguen, M. AU - Knickle, L. AU - Dacanay, A. AU - Leslie, A. AU - Ross, N.W. AU - Pinto, D.M. T2 - Veterinary Microbiology SN - 0378-1135 VL - 162 IS - 2-Apr SP - 831 EP - 841 KW - ferric uptake regulator KW - iron KW - outer membrane protein C KW - siderophore KW - Aeromonas hydrophila KW - Aeromonas salmonicida KW - amino acid sequence KW - article KW - autoregulation KW - bacterial gene KW - bacterial growth KW - bacterial strain KW - Escherichia coli KW - gene deletion KW - nonhuman KW - open reading frame KW - protein analysis KW - protein purification KW - proteomics KW - reverse transcription polymerase chain reaction KW - sequence analysis KW - wild type KW - Aeromonas hydrophila KW - Aeromonas salmonicida KW - Aeromonas salmonicida subsp. salmonicida KW - Bacteria (microorganisms) KW - Escherichia coli KW - Salmonidae AB - Aeromonas salmonicida subsp. salmonicida is the etiological agent of furunculosis; a serious infectious disease in aquaculture raised salmonids. Iron acquisition has been shown to be critical for the survival of pathogenic bacteria during the course of infection. Previous work has demonstrated that A. salmonicida expresses iron-repressible IROMP proteins, suggesting the presence of iron acquisition systems that are under the control of a ferric uptake regulator (Fur). In this study, the A. salmonicida fur has been sequenced and a fur deletion strain generated. The A. salmonicida fur gene has an open reading frame of 428. bp, coding for a protein of 143 amino acids, and with high homology to previously described Fur proteins. The Fur protein product had a 94% sequence identity and 96% sequence similarity to the Aeromonas hydrophila Fur protein product. Transcription of the A. salmonicida fur gene was not regulated by the iron status of the bacterium and is not autoregulated, as in Escherichia coli. Proteomic analysis of the A. salmonicida fur mutant, fails to repress iron-regulated outer membrane proteins in the presence of iron. The A. salmonicida fur::KO mutant shows significantly reduced pathogenicity compared to the wild-type parental strain. In addition, the A. salmonicida fur mutant provides an important tool for further investigation of the iron acquisition mechanisms utilized by A. salmonicida. © 2012 Elsevier B.V.. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 156e9412-7ed7-4717-aace-673678c1f363 ER - TY - JOUR TI - Increased sky coverage with optimal correction of tilt and tilt-anisoplanatism modes in laser-guide-star multiconjugate adaptive optics DO - 10.1364/JOSAA.30.000604 AU - Correia, C. AU - Véran, J.-P. AU - Herriot, G. AU - Ellerbroek, B. AU - Wang, L. AU - Gilles, L. T2 - Journal of the Optical Society of America A: Optics and Image Science, and Vision SN - 1084-7529 VL - 30 IS - 4 SP - 604 EP - 615 KW - Atmospheric tomography KW - Double integrator KW - Multi-conjugate adaptive optics systems KW - Multiconjugate adaptive optics KW - Natural guide star KW - Optimal correction KW - Optimal stochastic control KW - Thirty Meter Telescope KW - Mineralogy KW - Optimization KW - Stars AB - Laser-guide-star multiconjugate adaptive optics (MCAO) systems require natural guide stars (NGS) to measure tilt and tilt-anisoplanatism modes. Making optimal use of the limited number of photons coming from such, generally dim, sources is mandatory to obtain reasonable sky coverage, i.e., the probability of finding asterisms amenable to NGS wavefront (WF) sensing for a predefined WF error budget. This paper presents a Strehl-optimal (minimum residual variance) spatiotemporal reconstructor merging principles of modal atmospheric tomography and optimal stochastic control theory. Simulations of NFIRAOS, the first light MCAO system for the thirty-meter telescope, using ~500 typical NGS asterisms, show that the minimum-variance (MV) controller delivers outstanding results, in particular for cases with relatively dim stars (down to magnitude 22 in the H-band), for which lowtemporal frame rates (as low as 16 Hz) are required to integrate enough flux. Over all the cases tested ~21 nm rms median improvement in WF error can be achieved with the MV compared to the current baseline, a type-II controller based on a double integrator. This means that for a given level of tolerable residual WF error, the sky coverage is increased by roughly 10%, a quite significant figure. The improvement goes up to more than 20% when compared with a traditional single-integrator controller. © 2013 Optical Society of America. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9a9bd92c-449a-4321-8650-2ea7f95d7b49 ER - TY - JOUR TI - Optical properties of charged quantum dots doped with a single magnetic impurity DO - 10.1103/PhysRevB.88.115306 AU - Mendes, U.C. AU - Korkusinski, M. AU - Trojnar, A.H. AU - Hawrylak, P. T2 - Physical Review B - Condensed Matter and Materials Physics SN - 1098-0121 VL - 88 IS - 11 SP - 115306 AB - We present a microscopic theory of the optical properties of self-assembled quantum dots doped with a single magnetic manganese (Mn) impurity and containing a controlled number of electrons. The single-particle electron and heavy-hole electronic shells are described by two-dimensional harmonic oscillators. The electron-electron, electron-hole Coulomb as well as the short-range electron spin-Mn spin and hole spin-Mn spin contact exchange interactions are included. The electronic states of the photoexcited electron-hole-Mn complex and of the final electron-Mn complex are expanded in a finite number of configurations and the full interacting Hamiltonian is diagonalized numerically. The emission spectrum is predicted as a function of photon energy for a given number of electrons and different number of confined electronic quantum dot shells. We show how emission spectra allow to identify the number of electronic shells, the number of electrons populating these shells and, most importantly, their spin. We show that electrons not interacting directly with the spin of Mn ion do so via electron-electron interactions. This indirect interaction is a strong effect even when Mn impurity is away from the quantum dot center. © 2013 American Physical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9e9ca83a-fe1e-4855-aac6-c5c465ef1bf8 ER - TY - JOUR TI - Synthesis and characterization of a structure H hydrate formed with carbon dioxide and 3,3-dimethyl-2-butanone DO - 10.1039/c2cc37717a AU - Tezuka, K. AU - Shen, R. AU - Watanabe, T. AU - Takeya, S. AU - Alavi, S. AU - Ripmeester, J.A. AU - Ohmura, R. T2 - Chemical Communications SN - 1359-7345 VL - 49 IS - 5 SP - 505 EP - 507 KW - 2 butanone KW - carbon dioxide KW - pinacolone KW - unclassified drug KW - article KW - molecular dynamics KW - molecular interaction KW - synthesis KW - X ray diffraction AB - Experiments were carried out to synthesize and characterize a structure H clathrate hydrate containing CO2 and 3,3-dimethyl-2-butanone (pinacolone) by means of phase equilibrium and powder X-ray diffraction measurements. Molecular dynamics simulations of this structure H hydrate were performed to understand the nature of guest-host molecular interactions. © 2013 The Royal Society of Chemistry. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0fb24ad3-0f8e-4162-abcb-ed54b7d463f9 ER - TY - JOUR TI - The effective g-factor in In0.53Ga0.47As/In 0.52Al0.48As quantum well investigated by magnetotransport measurement DO - 10.1063/1.4776236 AU - Liu, X. Z. AU - Xu, Y. G. AU - Yu, G. AU - Wei, L. M. AU - Lin, T. AU - Guo, S. L. AU - Chu, J. H. AU - Zhou, W. Z. AU - Zhang, Y. G. AU - Lockwood, David J. T2 - Journal of Applied Physics SN - 0021-8979 VL - 113 IS - 3 SP - 33704 KW - Dephasing KW - Dephasing rates KW - Effective band gap KW - Effective g-factor KW - High mobility KW - In-plane magnetic fields KW - Magneto-transport measurement KW - Micro-roughness KW - Shubnikov-de Haas oscillations KW - Tilt angle KW - Weak antilocalization KW - Zeeman splittings KW - Zero-field spin splitting KW - Carrier concentration KW - Gallium KW - Semiconductor quantum wells AB - The magneotransport properties of a high carrier concentration and high mobility 20-nm thick In0.53Ga0.47As/In 0.52Al0.48As quantum well (QW) are investigated by tilt angle dependent Shubnikov-de Haas oscillations and by weak antilocalization (WAL) in an in-plane magnetic field. The effective g-factor g* and zero field spin splitting Δ 0 are extracted from tilt angle dependent beating pattern. We found that g* shows a dramatic reduction with increasing carrier density due to the increased effective band gap. Furthermore, an anomalously rapid suppression of the WAL effect with increasing in-plane magnetic field B|| is observed. This reveals that the total dephasing rate is not solely contributed by Zeeman splitting. The microroughness scattering in the QW is proposed to be another factor to cause the dephasing and thus responsible for this effect. © 2013 American Institute of Physics. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3ae71c45-cca9-4b15-9e77-9edfe3f0cb72 ER - TY - JOUR TI - A bobsleigh ice friction model AU - Lozowski, E. AU - Szilder, K. AU - Poirier, L. T2 - Proceedings of the International Offshore and Polar Engineering Conference T3 - 23rd International Offshore and Polar Engineering Conference, ISOPE 2013, 30 June 2013 through 5 July 2013, Anchorage, AK SN - 1098-6189 SN - 9781880653999 SP - 1259 EP - 1267 KW - Bobsleigh KW - Effect of pressure KW - Frictional melting KW - Hydrodynamic regime KW - Moored structures KW - Structural forces KW - Surface transportation KW - Theory KW - Friction KW - Ice KW - Models KW - Physics KW - Sailing vessels KW - Sea ice KW - SportS KW - Lubrication AB - Ice friction affects us in many ways, from slippery roads to winter sports. In cold regions, ice friction influences ice interaction with itself, which determines the motion of ice floes. It also influences the structural forces resulting from ice interactions with fixed and moored structures and with floating vessels. Ice friction also affects surface transportation over snow and ice. This paper addresses only one aspect of ice friction in winter sports, but it is potentially relevant to other applications, particularly surface transportation over ice. The model of ice friction described here is for a steel bobsleigh runner sliding on ice at high velocity. The model describes ice friction in the fully-lubricated, hydrodynamic regime, where a layer of meltwater completely separates the ice and slider surfaces. The effect of any contact between asperities on both surfaces is neglected. Friction results from a ploughing force, arising from ice deformation, crushing and extrusion, and from the shear stress in the lubricating Couette flow. The model takes into account frictional melting, heat conduction into the ice and the lateral squeeze flow of the lubricating liquid. The effect of pressure on the melting temperature is also accounted for. Sensitivity testing of the numerical model has been conducted to examine the influence of such factors as runner dimensions, sliding speed, ice temperature and g-forces. A comparison with recent measurements of bobsled ice friction made by one of the authors is encouraging, suggesting that the model has identified and adequately represented the most essential physical processes. Copyright © 2013 by the International Society of Offshore and Polar Engineers (ISOPE). DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6db43f35-ec17-4293-9ffe-5d8f637a0dc3 ER - TY - JOUR TI - Discovery of a new member of the inner oort cloud from the Next Generation Virgo Cluster Survey DO - 10.1088/2041-8205/775/1/L8 AU - Chen, Ying-Tung AU - Kavelaars, J. J. AU - Gwyn, Stephen AU - Ferrarese, Laura AU - Côté, Patrick AU - Jordán, Andrés AU - Suc, Vincent AU - Cuillandre, Jean-Charles AU - Ip, Wing-Huen T2 - The Astrophysical Journal Letters SN - 2041-8205 VL - 775 IS - 1 SP - L8 AB - We report the discovery of 2010 GB174, a likely new member of the Inner Oort Cloud (IOC). 2010 GB174 is 1 of 91 trans-Neptunian objects and Centaurs discovered in a 76 deg2 contiguous region imaged as part of the Next Generation Virgo Cluster Survey (NGVS) - a moderate ecliptic latitude survey reaching a mean limiting magnitude of g′ ≃ 25.5 - using MegaPrime on the 3.6 m Canada-France-Hawaii Telescope. 2010 GB 174 is found to have an orbit with a semi-major axis of a ≃ 350.8 AU, an inclination of i ≃ 21.°6, and a pericenter of q ∼ 48.5 AU. This is the second largest perihelion distance among known solar system objects. Based on the sky coverage and depth of the NGVS, we estimate the number of IOC members with sizes larger than 300 km (HV ≤ 6.2 mag) to be ≃ 11, 000. A comparison of the detection rate from the NGVS and the PDSSS (a characterized survey that "rediscovered" the IOC object Sedna) gives, for an assumed a power-law luminosity function for IOC objects, a slope of α ≃ 0.7 ± 0.2. With only two detections in this region this slope estimate is highly uncertain. DA - 2013/09/20 PY - 2013 PB - IOP Publishing LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 17c27420-ec83-46cf-879b-9e3322a14343 ER - TY - JOUR TI - External and internal corrosion of large-diameter cast iron mains DO - 10.1061/(ASCE)IS.1943-555X.0000135 AU - Rajani, B. AU - Kleiner, Y. T2 - Journal of Infrastructure Systems SN - 1076-0342 VL - 19 IS - 4 SP - 486 EP - 495 AB - Deterioration in cast iron mains manifests itself in the form of corrosion. External corrosion is typically found to occur in pipes buried in corrosive soils while internal corrosion is dependent on water chemistry and flow characteristics. In the literature, corrosion of cast ron pipes (external and internal) is typically characterized by corrosion pit depth even though corroded area and corroded pit volume as well as pit location may enhance this characterization. Knowledge of these corrosion pit properties permits the assessment of its structural integrity. Typically, internal and external corrosion pits and corroded areas are observed to occur in many irregular shapes and sizes, which make their characterization a challenge. This paper describes extreme value statistical models that can be used to estimate external and internal corrosion pit depths in cast iron pipes using indirect properties or parameters. The goal of these corrosion models is to be able to predict corrosion pit depth based on available data with an acceptable degree of confidence. The external corrosion model is calibrated using external corrosion ata collected by ThamesWater Utilities Ltd (TWUL) and subsequently validated with data obtained from the inspection of four cast iron pipe lengths. The internal corrosion model was calibrated using internal corrosion data but sufficient appropriate data was not available for its validation. © 2013 American Society of Civil Engineers. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e30c052a-792e-4eb4-b17e-6d567c52fd4e ER - TY - JOUR TI - Hydroxyl anion conducting membranes poly(vinyl alcohol)/ poly(diallyldimethylammonium chloride) for alkaline fuel cell applications: Effect of molecular weight DO - 10.1016/j.electacta.2013.07.182 AU - Zhang, J. AU - Zhou, T. AU - Qiao, J. AU - Liu, Y. T2 - Electrochimica Acta SN - 0013-4686 VL - 111 SP - 351 EP - 358 KW - Alkaline anion-exchange membranes KW - Dense network structures KW - Hydroxide conductivities KW - Molecular weight effect KW - Poly (vinyl alcohol) (PVA) KW - Poly(diallyldimethylammonium chloride) KW - Single cell performance KW - Thermal gravity analysis KW - Alkaline fuel cells KW - Biomechanics KW - Chlorine compounds KW - Convergence of numerical methods KW - Fourier transform infrared spectroscopy KW - Ions KW - Mechanical properties KW - Membranes KW - Molecular weight KW - Polyvinyl alcohols KW - Scanning electron microscopy KW - Stability KW - Clarification AB - Hydroxyl anion conducting membranes have been developed using poly(vinyl alcohol) (PVA) as polymermatrix by incorporation of poly(diallyldimethylammonium chloride) (PDDA) as anion charge carriers. PDDA of four different molecular weight (namely PDDA-HMw, PDDA-MMw, PDDA-LMw and PDDA-ULMw) was incorporated in order to clarifying the effect of molecular weight on membrane performances. The membranes are characterized in detail by FTIR spectroscopy, scanning electron microscopy (SEM), thermal gravity analysis (TG), mechanical property, AC impedance technique, water uptake, swelling ratio, oxidation and alkaline stability to evaluate their applicability in alkaline fuel cells. The OH -conductivity of the membranes was found to be increased with increasing molecular weight of PDDA, and the maximum OH-conductivity of 0.027 S cm-1was achieved for PVA/PDDA-HMw membrane. ThePVA/PDDA-HMw membrane also showed the best mechanical property and excellent thermal stability due to the most compact and dense network structure. All the membranes showed relatively highoxidative stability in 30% H2O2and strong alkaline stability in 2 M KOH for 624 h at room temperature. The fuel cell performances of the MEAs with these membranes were 18.2, 23.4, 28.5 and 35.1 mW cm-2using H2and O2gases at 25°C. The long-term stability of single-cell performance showed that the PVA/PDDA membrane could approximately last 80 h on the fuel cell with only a slight decrease of 0.1 V in cell potential. © 2013 Elsevier Ltd. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 88179986-8809-4f07-8daf-7ab68760bb26 ER - TY - JOUR TI - Gender differences in the relationship between smoking and frailty: Results from the Beijing longitudinal study of aging DO - 10.1093/gerona/gls166 AU - Wang, C. AU - Song, X. AU - Mitnitski, A. AU - Yu, P. AU - Fang, X. AU - Tang, Z. AU - Shi, J. AU - Rockwood, K. T2 - Journals of Gerontology - Series A Biological Sciences and Medical Sciences SN - 1079-5006 VL - 68 IS - 3 SP - 338 EP - 346 KW - age KW - aged KW - article KW - China KW - cohort analysis KW - educational status KW - female KW - frail elderly KW - health status KW - human KW - longitudinal study KW - male KW - marriage KW - mortality KW - multivariate analysis KW - sex difference KW - smoking KW - Age Factors KW - Aged KW - Aged, 80 and over KW - China KW - Cohort Studies KW - Educational Status KW - Female KW - Frail Elderly KW - Health Status KW - Humans KW - Longitudinal Studies KW - Male KW - Marital Status KW - Mortality KW - Multivariate Analysis KW - Sex Factors KW - Smoking AB - Background. Smoking is common in China, where the population is aging rapidly. This study evaluated the relationship between smoking and frailty and their joint association with health and survival in older Chinese men and women.Methods.Data came from the Beijing Longitudinal Study of Aging, a representative cohort study with a 15-year follow-up. Community-dwelling people (n = 3257) aged more than 55 years at baseline were followed between 1992 and 2007, during which time 51% died. A frailty index (FI) was constructed from 28 self-reported health deficits.Results.Almost half (1,485 people; 45.6%) of the participants reported smoking at baseline (66.8% men, 25.3% women). On average, male smokers were frailer (FI = 0.17±0.13) than male nonsmokers (FI = 0.13±0.10; p =. 038). No such differences were seen in women. Men who smoked had the lowest survival probability; female nonsmokers had the highest. Compared with female nonsmokers, the risk of death for male smokers was 1.58 (95% CI = 1.41-1.95; p <. 001), adjusted for age and education. Across all FI values, female smokers and male nonsmokers had comparable survival rates.Conclusion.Smoking was associated with an increased rate of both worsening health and mortality. At all levels of health status, as defined by deficit accumulation, women who smoked lost the survival advantage conferred by their sex. © 2012 The Author. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c6780428-4d29-411c-960d-5a6b189f70ce ER - TY - JOUR TI - Twenty years of performance-based fire protection design: Challenges faced and a look ahead DO - 10.1177/1042391513484911 AU - Alvarez, A. AU - Meacham, B.J. AU - Dembsey, N.A. AU - Thomas, J.R. T2 - Journal of Fire Protection Engineering SN - 1042-3915 VL - 23 IS - 4 SP - 249 EP - 276 KW - Authority having jurisdictions KW - Engineering analysis KW - Engineering perspective KW - Engineering process KW - Fire safety engineering KW - Literature reviews KW - Performance based design KW - Protection designs KW - Engineering KW - Fire extinguishers KW - Fire protection KW - Tools KW - Structural design AB - A review of two decades of worldwide experience using standards, codes and guidelines related to performance-based fire protection design for buildings has identified shortcomings in the interpretation, application and implementation of the performance-based design process, apparent inconsistency in the resulting levels of performance achieved and several opportunities to enhance the process. In a constantly evolving building environment, technical challenges have to be overcome because fire safety engineering still depends greatly on knowledge gained from scientific and engineering research across a broad range of disciplines (e.g., better understanding of the fire phenomena, the behavior and response of the building occupants/contents/structure to the fire, tools for engineering analysis and all the necessary data needed to support tool application). Political challenges also need to be considered as performance-based fire protection design requires the approval of the authority having jurisdiction and other involved stakeholders, at several of its different steps (design, construction, original usage, modifications of usage). The review presented here has been undertaken from an engineering perspective rather than a regulatory perspective. Two key outcomes of this engineering review are that several of the challenges that have been identified are strongly linked to the application of generic guidance to specific problems, which results in critical details being missed, and that some of the engineering issues are treated within a political context, while they should be addressed as purely technical issues. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5d6547bc-69c3-4bc4-8d6e-52e9dadb51c8 ER - TY - JOUR TI - Graph theory based model for learning path recommendation DO - 10.1016/j.ins.2013.04.017 AU - Durand, G. AU - Belacel, N. AU - Laplante, F. T2 - Information Sciences SN - 0020-0255 VL - 251 SP - 10 EP - 21 KW - Complex task KW - Educational data minings (EDM) KW - Efficient learning KW - Learning designs KW - Learning objects KW - Learning paths KW - Design KW - Graph theory KW - Recommender systems KW - Soft computing KW - Learning systems AB - Learning design, the activity of designing a learning path, can be a complex task, especially for learners. A learning design recommendation system would help self-learners find appropriate learning objects and build efficient learning paths during their learning journey. Educational Data Mining (EDM) has provided an impressive amount of novelties related to learning object recommendation systems. However, most of the solutions proposed thus far do not take into account eventual competency dependencies among learning objects and/or are not designed for large repositories of interdependent learning objects. We propose a model to build a learning design recommendation system based on graph theory. From this model, we propose, implement and test an approach using the concept of cliques to recommend learning paths. © 2013 Published by Elsevier Inc. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 66b1c4d6-a766-4588-85ac-ed409c1a93c7 ER - TY - JOUR TI - Understanding the effects of backpressure on PEM fuel cell reactions and performance DO - 10.1016/j.jelechem.2012.09.033 AU - Zhang, J. AU - Song, C. AU - Baker, R. AU - Zhang, L. T2 - Journal of Electroanalytical Chemistry SN - 1572-6657 VL - 688 SP - 130 EP - 136 KW - Back pressures KW - Exchange current densities KW - Gas partial pressure KW - Limiting current density KW - PEM fuel cell KW - Performance enhancements KW - Reversible thermodynamics KW - Semi-empirical approach KW - Current density KW - Electric conductivity KW - Kinetics KW - Mass transfer KW - Open circuit voltage KW - Reaction kinetics KW - Proton exchange membrane fuel cells (PEMFC) AB - The effects of the operating backpressure on PEM fuel cell reactions and performance are analyzed using both theoretical and semi-empirical approaches. The change in fuel cell operation backpressure can affect the reversible thermodynamic voltage, exchange current density of the electrode reactions, the membrane conductivity, as well as mass transfer limiting current densities. Backpressure can affect the fuel cell open circuit voltage (OCV) by affecting theoretical potential, mixed O2-Pt voltage drop as well as the H 2 crossover induced voltage drop. The magnitude of the fuel cell voltage change with backpressure in both electrode kinetic and mass transfer ranges is determined mainly by both the fuel cell reaction exchange current densities and the mass transfer limiting current densities. Theoretical modeling indicates that when the fuel cell is controlled at a low backpressure or backpressure range, the change in backpressure will lead to a larger fuel cell voltage change than that of a fuel cell controlled at a high backpressure range. Overall, an increase in the fuel cell backpressure will result in a performance enhancement such as higher open circuit voltage, and kinetic cell voltages at higher backpressures. However, negative effects such as high crossover, sealing problems, parasitic power losses, higher cost for compression and enlarged volume of the fuel cell system can occur with a higher operating backpressure. © 2012 Published by Elsevier B.V. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 429a41ec-ad2d-48fc-a311-d9d9f477319e ER - TY - JOUR TI - Electron doping evolution of the magnetic excitations in BaFe 2-xNixAs2 DO - 10.1103/PhysRevB.88.144516 AU - Luo, H. AU - Lu, X. AU - Zhang, R. AU - Wang, M. AU - Goremychkin, E.A. AU - Adroja, D.T. AU - Danilkin, S. AU - Deng, G. AU - Yamani, Z. AU - Dai, P. T2 - Physical Review B - Condensed Matter and Materials Physics SN - 1098-0121 VL - 88 IS - 14 SP - 144516 AB - We use inelastic neutron scattering (INS) spectroscopy to study the magnetic excitations spectra throughout the Brillouin zone in electron-doped iron pnictide superconductors BaFe2-xNixAs2 with x=0.096,0.15,0.18. While the x=0.096 sample is near optimal superconductivity with Tc=20 K and has coexisting static incommensurate magnetic order, the x=0.15,0.18 samples are electron overdoped with reduced Tc of 14 and 8 K, respectively, and have no static antiferromagnetic (AF) order. In previous INS work on undoped (x=0) and electron optimally doped (x=0.1) samples, the effect of electron doping was found to modify spin waves in the parent compound BaFe2As2 below ∼100 meV and induce a neutron spin resonance at the commensurate AF ordering wave vector that couples with superconductivity. While the new data collected on the x=0.096 sample confirm the overall features of the earlier work, our careful temperature dependent study of the resonance reveals that the resonance suddenly changes its Q width below Tc similar to that of the optimally hole-doped iron pnictides Ba0.67K0.33Fe 2As2. In addition, we establish the dispersion of the resonance and find it to change from commensurate to transversely incommensurate with increasing energy. Upon further electron doping to overdoped iron pnictides with x=0.15 and 0.18, the resonance becomes weaker and transversely incommensurate at all energies, while spin excitations above ∼100 meV are still not much affected. Our absolute spin excitation intensity measurements throughout the Brillouin zone for x=0.096,0.15,0.18 confirm the notion that the low-energy spin excitation coupling with itinerant electron is important for superconductivity in these materials, even though the high-energy spin excitations are weakly doping dependent. © 2013 American Physical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b1b82129-a828-41df-b4be-1151a0a0f059 ER - TY - JOUR TI - Multi-scale modeling and synthesis of polyester ionomers DO - 10.1039/c3cp44285c AU - Nikolić, D. AU - Moffat, K.A. AU - Farrugia, V.M. AU - Kobryn, A.E. AU - Gusarov, S. AU - Wosnick, J.H. AU - Kovalenko, A. T2 - Physical Chemistry Chemical Physics SN - 1463-9076 VL - 15 IS - 16 SP - 6128 EP - 6138 AB - Simulations of microphase separation are carried out using the dissipative particle dynamics (DPD). By varying the concentration and temperature of resin solutions we explore mesomorphologies supported by the all-atom models. We found that for a low degree of functionalization the homogeneously distributed ionomers self-assemble into spherical micelles at solid loads below 31 wt%, subject to the activation energy barrier for the gradual growth of pre-micellar aggregates. Computed optimum aggregation numbers exhibit sensitivity to both the temperature-dependent interfacial tension and the ionic content and compare well with the experimental observations. This journal is © the Owner Societies. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4f143a14-98bd-4714-bd65-bcc675fc0426 ER - TY - JOUR TI - Avoided quantum criticality and magnetoelastic coupling in BaFe 2-xNixAs2 DO - 10.1103/PhysRevLett.110.257001 AU - Lu, X. AU - Gretarsson, H. AU - Zhang, R. AU - Liu, X. AU - Luo, H. AU - Tian, W. AU - Laver, M. AU - Yamani, Z. AU - Kim, Y.-J. AU - Nevidomskyy, A.H. AU - Si, Q. AU - Dai, P. T2 - Physical Review Letters SN - 0031-9007 VL - 110 IS - 25 SP - 257001 KW - Antiferromagnetics KW - Magnetoelastic couplings KW - Quantum critical points KW - Quantum criticality KW - Superconducting state KW - Synchrotron x rays KW - Temperature separation KW - Zero temperatures KW - Antiferromagnetism KW - Separation KW - Superconductivity KW - Nickel AB - We study the structural and magnetic orders in electron-doped BaFe 2-xNixAs2 by high-resolution synchrotron x-ray and neutron scatterings. Upon Ni doping x, the nearly simultaneous tetragonal-to-orthorhombic structural (Ts) and antiferromagnetic (TN) phase transitions in BaFe2As2 are gradually suppressed and separated, resulting in Ts>TN with increasing x, as was previously observed. However, the temperature separation between Ts and TN decreases with increasing x for x≥0.065, tending toward a quantum bicritical point near optimal superconductivity at x≈0.1. The zero-temperature transition is preempted by the formation of a secondary incommensurate magnetic phase in the region 0.0882;0.104, resulting in a finite value of TN≈Tc+10 K above the superconducting dome around x≈0.1. Our results imply an avoided quantum critical point, which is expected to strongly influence the properties of both the normal and superconducting states. © 2013 American Physical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ba14c6ec-f12b-44d0-a299-be0d47963905 ER - TY - JOUR TI - The nonlinear Rashba effect in Hg0.77Cd0.23Te inversion layers probed by weak antilocalization analysis DO - 10.1063/1.4772643 AU - Liu, X. Z. AU - Yu, G. AU - Wei, L. M. AU - Lin, T. AU - Xu, Y. G. AU - Yang, J. R. AU - Wei, Y. F. AU - Guo, S. L. AU - Chu, J. H. AU - Rowell, N. L. AU - Lockwood, D. J. T2 - Journal of Applied Physics SN - 0021-8979 VL - 113 IS - 1 SP - 13704 KW - Anti-localization effects KW - Gate voltages KW - High mobility KW - High-electron-density KW - Interband coupling KW - Magneto-transport measurement KW - P-type KW - Rashba effects KW - Rashba spin orbit interaction KW - Rashba spin splitting KW - Weak antilocalization KW - Carrier concentration KW - Electron density measurement KW - Electron gas KW - Inversion layers AB - The Rashba spin-orbit interaction of the two-dimensional electron gas with high mobility in the inversion layer of p-type Hg0.77Cd 0.23Te is investigated by magnetotransport measurements. Both the Rashba spin splitting and Rashba coefficient are extracted by analysis of the weak anti-localization effect using the Golub model. It is found that both the splitting and coefficient increase with increasing electron density (∼3.0-6.0 × 1015 m-2), i.e., with the gate voltage. A self-consistent Schrodinger-Poisson calculation is performed and suggests that the nonlinear Rashba effect caused by the weakening of interband coupling, especially at high electron density, dominates this system. © 2013 American Institute of Physics. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : bacfa18b-eae6-47e1-848b-64cfb7ec023f ER - TY - JOUR TI - The ACS LCID project. Ix. Imprints of the early universe in the radial variation of the star formation history of dwarf galaxies DO - 10.1088/0004-637X/778/2/103 AU - Hidalgo, S.L. AU - Monelli, M. AU - Aparicio, A. AU - Gallart, C. AU - Skillman, E.D. AU - Cassisi, S. AU - Bernard, E.J. AU - Mayer, L. AU - Stetson, P. AU - Cole, A. AU - Dolphin, A. T2 - The Astrophysical Journal SN - 0004-637X VL - 778 IS - 2 SP - 103 AB - Based on Hubble Space Telescope observations from the Local Cosmology from Isolated Dwarfs project, we present the star formation histories, as a function of galactocentric radius, of four isolated Local Group dwarf galaxies: two dSph galaxies, Cetus and Tucana, and two transition galaxies (dTrs), LGS-3 and Phoenix. The oldest stellar populations of the dSphs and dTrs are, within the uncertainties, coeval (∼13 Gyr) at all galactocentric radii. We find that there are no significative differences between the four galaxies in the fundamental properties (such as the normalized star formation rate or age-metallicity relation) of their outer regions (radii greater than four exponential scale lengths); at large radii, these galaxies consist exclusively of old (≳ 10.5 Gyr) metal-poor stars. The duration of star formation in the inner regions varies from galaxy to galaxy, and the extended central star formation in the dTrs produces the dichotomy between dSph and dTr galaxy types. The dTr galaxies show prominent radial stellar population gradients: The centers of these galaxies host young (≲ 1 Gyr) populations, while the age of the last formation event increases smoothly with increasing radius. This contrasts with the two dSph galaxies. Tucana shows a similar, but milder, gradient, but no gradient in age is detected Cetus. For the three galaxies with significant stellar population gradients, the exponential scale length decreases with time. These results are in agreement with outside-in scenarios of dwarf galaxy evolution, in which a quenching of the star formation toward the center occurs as the galaxy runs out of gas in the outskirts. © 2013. The American Astronomical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5fbe6efd-1935-4b7d-b98d-ba008d4b06d9 ER - TY - JOUR TI - Effects of amino acid deletion and substitution on the chemical properties, biological activities of the frog peptide palustrin-OG1 DO - 10.2174/0929866511320070012 AU - Xie, Y.-G. AU - Liu, Y.-F. AU - Luan, C. AU - Han, F.-F. AU - Lai, R. AU - Groleau, D. AU - Feng, J. AU - Wang, Y.-Z. T2 - Protein and Peptide Letters SN - 0929-8665 VL - 20 IS - 7 SP - 813 EP - 819 KW - alanine KW - antiinfective agent KW - cysteine KW - OG1 peptide KW - OG2 peptide KW - OG2A peptide KW - OG2N peptide KW - OG2W peptide KW - tryptophan KW - unclassified drug KW - amino acid deletion KW - amino acid substitution KW - animal cell KW - article KW - bacterial cell wall KW - bacterial kinetics KW - bactericidal activity KW - biological activity KW - cell damage KW - controlled study KW - drug cytotoxicity KW - erythrocyte KW - Escherichia coli KW - hemolysis KW - hydrophobicity KW - membrane damage KW - minimum inhibitory concentration KW - nonhuman KW - peripheral blood mononuclear cell KW - protein function KW - protein modification KW - Pseudomonas aeruginosa KW - Salmonella enterica KW - Salmonella typhimurium KW - Staphylococcus aureus AB - Palustrin-OG1 (OG1) is a host defense peptide isolated from the frog Odorrana grahami. In this study, we analyzed the chemical properties, antimicrobial activities and cytotoxicities of OG1 and its derivatives to identify the most promising peptide as an antimicrobial agent. By increasing the net positive charge, amphipathicity and decreasing the mean hydrophobicity of OG1, the derivative named as OG2 exerted higher antimicrobial activity against bacteria but lower cytotoxicity against both porcine erythrocytes and peripheral blood mononuclear cells than did OG1 (P<0.01). After substitution of Cys residues of OG2 by Ala or Trp residues, two derivatives named as OG2A and OG2W were less effective against bacteria and induced greater hemolysis than did OG2, indicating the importance of Cys residues. The substitution of the C-terminal Thr of OG2 resulted OG2N, which decreased the cytotoxicity and improved killing kinetics against gram-positive bacteria by the rapid damage of cell wall and membrane. © 2013 Bentham Science Publishers. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1b3c005c-3db2-424c-9ee4-1c4a744e8645 ER - TY - JOUR TI - Transparent anodic TiO2 nanotube arrays on plastic substrates for disposable biosensors and flexible electronics DO - 10.1166/jnn.2013.7409 AU - Farsinezhad, S. AU - Mohammadpour, A. AU - Dalrymple, A.N. AU - Geisinger, J. AU - Kar, P. AU - Brett, M.J. AU - Shankar, K. T2 - Journal of Nanoscience and Nanotechnology SN - 1533-4880 VL - 13 IS - 4 SP - 2885 EP - 2891 KW - Anodizations KW - Metal oxides KW - Polymer substrate KW - Self-Organized KW - Thin-film depositions KW - Transparent KW - Troponin KW - Bioassay KW - Biosensors KW - Deposition KW - Film growth KW - Ion sources KW - Nanotubes KW - Polyimides KW - Polymeric films KW - Refractive index KW - Titanium KW - Titanium dioxide KW - Substrates KW - nanotube KW - plastic KW - titanium KW - titanium dioxide KW - article KW - chemistry KW - electronics KW - fluorescence KW - genetic procedures KW - immunoassay KW - Biosensing Techniques KW - Electronics KW - Fluorescence KW - Immunoassay KW - Nanotubes KW - Plastics KW - Titanium AB - Exploitation of anodically formed self-organized TiO2 nanotube arrays in mass-manufactured, disposable biosensors, rollable electrochromic displays and flexible large-area solar cells would greatly benefit from integration with transparent and flexible polymeric substrates. Such integration requires the vacuum deposition of a thin film of titanium on the desired substrate, which is then anodized in suitable media to generate TiO2 nanotube arrays. However the challenges associated with control of Ti film morphology, nanotube array synthesis conditions, and film adhesion and transparency, have necessitated the use of substrate heating during deposition to temperatures of at least 300 °C and as high as 500 °C to generate highly ordered open-pore nanotube arrays, thus preventing the use of polymeric substrates. We report on a film growth technique that exploits atomic peening to achieve high quality transparent TiO2 nanotube arrays with lengths up to 5.1 μm at room temperature on polyimide substrates without the need for substrate heating or substrate biasing or a Kauffman ion source. The superior optical quality and uniformity of the nanotube arrays was evidenced by the high specular reflectivity and the smooth pattern of periodic interferometric fringes in the transmission spectra of the nanotube arrays, from which the wavelength-dependent effective refractive index was extracted for the air-TiO2 composite medium. A fluorescent immunoassay biosensor constructed using 5.1 μm-long transparent titania nanotube arrays (TTNAs) grown on Kapton substrates detected human cardiac troponin I at a concentration of 0.1 μg ml-1. Copyright © 2013 American Scientific Publishers. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b8e2caa4-bbff-48c9-b526-2a9bbbe8c5b7 ER - TY - JOUR TI - Optimum extraction of polysaccharides from Opuntia dillenii and evaluation of its antioxidant activities DO - 10.1016/j.carbpol.2013.05.057 AU - Yang, Q. AU - Chen, H. AU - Zhou, X. AU - Zhang, J. T2 - Carbohydrate Polymers SN - 0144-8617 VL - 97 IS - 2 SP - 736 EP - 742 KW - Anti-oxidant activities KW - Antioxidant capacity KW - Box-Behnken design KW - Extraction conditions KW - Extraction temperatures KW - Extraction time KW - Opuntia dillenii KW - Response surface methodology KW - Agents KW - Optimization KW - Polysaccharides KW - Surface properties KW - Extraction KW - Opuntia KW - Opuntia dillenii AB - Response surface methodology (RSM) was applied to optimize the extraction of crude polysaccharides from Opuntia dillenii (Ker-Gaw) Haw. A three-level, four-variable Box-Behnken design was employed to obtain the best possible combination of extraction temperature (80-90°C), extraction time (50-70 min), number of extraction cycle (1-3 times), and ratio of water to raw material (8:1-12:1, v/w) for maximum yield of crude polysaccharide. Besides, the antioxidant capacity of crude polysaccharide was evaluated by DPPH assay. The results showed that optimized extraction conditions were extraction temperature 85°C, extraction time 63.7 min, extraction 2 times and ratio of water to raw material 11.14:1. Under these conditions, the experimental yield was 27.36 ± 0.21%, which is well in close agreement with the value (27.44%) predicted by RSM model. Pharmacological test showed that O. dillenii crude polysaccharides had a good antioxidant activity. © 2013 Elsevier Ltd. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8fc6d886-bbaf-4e31-ae5f-b82822ef77e7 ER - TY - JOUR TI - Limb-specific emotional modulation of cervical spinal cord neurons DO - 10.3758/s13415-013-0154-x AU - McIver, T.A. AU - Kornelsen, J. AU - Smith, S.D. T2 - Cognitive, Affective and Behavioral Neuroscience SN - 1530-7026 VL - 13 IS - 3 SP - 464 EP - 472 AB - Emotional stimuli receive prioritized attentional and motoric processing in the brain. Recent data have indicated that emotional stimuli enhance activity in the cervical spinal cord as well. In the present study, we used fMRI to investigate the specificity of this emotion-dependent spinal cord activity. We examined whether the limb depicted in a passively viewed image (upper vs. lower) differentially influenced activity in the cervical segments that innervate the upper limbs, and whether this effect was enhanced by emotion. Participants completed four fMRI runs: neutral-upper limb, neutral-lower limb, negative-upper limb, and negative-lower limb. The results indicated main effects of limb and emotion, with upper limbs and negative stimuli eliciting greater activity than lower limbs and neutral stimuli, respectively. For upper-limb runs, negative stimuli evoked more activity than did neutral stimuli. Additionally, negative stimuli depicting upper limbs produced stronger responses than did negative stimuli depicting lower limbs. These results suggest that emotional stimuli augment limb-specific responses in the spinal cord. © 2013 Psychonomic Society, Inc. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f84eb604-6b2d-4915-bd52-2942fb9bafa2 ER - TY - JOUR TI - Water in star-forming regions with Herschel (WISH): III. Far-infrared cooling lines in low-mass young stellar objects DO - 10.1051/0004-6361/201220028 AU - Karska, A. AU - Herczeg, G. J. AU - Van Dishoeck, E. F. AU - Wampfler, S. F. AU - Kristensen, L. E. AU - Goicoechea, J. R. AU - Visser, R. AU - Nisini, B. AU - San José-García, I. AU - Bruderer, S. AU - Śniady, P. AU - Doty, S. AU - Fedele, D. AU - Yildiz, U. A. AU - Benz, A. O. AU - Bergin, E. AU - Caselli, P. AU - Herpin, F. AU - Hogerheijde, M. R. AU - Johnstone, D. AU - Jørgensen, J. K. AU - Liseau, R. AU - Tafalla, M. AU - Van Der Tak, F. AU - Wyrowski, F. T2 - Astronomy and Astrophysics SN - 0004-6361 VL - 552 SP - A141 KW - infrared: ISM KW - ISM: jets and outflows KW - stars: protostars KW - molecular processes KW - astrochemistry AB - Context.Understanding the physical phenomena involved in the earlierst stages of protostellar evolution requires knowledge of the heating and cooling processes that occur in the surroundings of a young stellar object. Spatially resolved information from its constituent gas and dust provides the necessary constraints to distinguish between different theories of accretion energy dissipation into the envelope. Aims. Our aims are to quantify the far-infrared line emission from low-mass protostars and the contribution of different atomic and molecular species to the gas cooling budget, to determine the spatial extent of the emission, and to investigate the underlying excitation conditions. Analysis of the line cooling will help us characterize the evolution of the relevant physical processes as the protostar ages. Methods.Far-infrared Herschel-PACS spectra of 18 low-mass protostars of various luminosities and evolutionary stages are studied in the context of the WISH key program. For most targets, the spectra include many wavelength intervals selected to cover specific CO, H2O, OH, and atomic lines. For four targets the spectra span the entire 55-200 μm region. The PACS field-of-view covers ∼47′′ with the resolution of 9.4′′. Results. Most of the protostars in our sample show strong atomic and molecular far-infrared emission. Water is detected in 17 out of 18 objects (except TMC1A), including 5 Class I sources. The high-excitation H2O 818-707 63.3 μm line (Eu/kB = 1071 K) is detected in 7 sources. CO transitions from J = 14-13 up to J = 49-48 are found and show two distinct temperature components on Boltzmann diagrams with rotational temperatures of ∼350 K and ∼700 K. H 2O has typical excitation temperatures of ∼150 K. Emission from both Class 0 and I sources is usually spatially extended along the outflow direction but with a pattern that depends on the species and the transition. In the extended sources, emission is stronger off source and extended on =10 000 AU scales; in the compact sample, more than half of the flux originates within 1000 AU of the protostar. The H2O line fluxes correlate strongly with those of the high-J CO lines, both for the full array and for the central position, as well as with the bolometric luminosity and envelope mass. They correlate less strongly with OH fluxes and not with [Oi] fluxes. In contrast, [Oi] andOH often peak together at the central position. Conclusions.The PACS data probe at least two physical components. The H2O and CO emission very likely arises in non-dissociative (irradiated) shocks along the outflow walls with a range of pre-shock densities. Some OH is also associated with this component, most likely resulting from H2O photodissociation. UV-heated gas contributes only a minor fraction to the CO emission observed by PACS, based on the strong correlation between the shock-dominated CO 24-23 line and the CO 14-13 line. [Oi] and some of the OH emission probe dissociative shocks in the inner envelope. The total far-infrared cooling is dominated by H2O and CO, with the fraction contributed by [Oi] increasing for Class I sources. Consistent with previous studies, the ratio of total far-infrared line emission over bolometric luminosity decreases with the evolutionary state DA - 2013/04/17 PY - 2013 PB - EDP SCiences LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4298f9f2-e8b7-446b-ad55-d1270dcca789 ER - TY - CHAP TI - LIDAR and RADAR Observations DO - 10.1002/9783527653218.ch9 AU - Pelon, J. AU - Vali, G. AU - Ancellet, G. AU - Ehret, G. AU - Flamant, P.H. AU - Haimov, S. AU - Heymsfield, G. AU - Leon, D. AU - Mead, J.B. AU - Pazmany, A.L. AU - Protat, A. AU - Wang, Z. AU - Wolde, M. T2 - Airborne Measurements for Environmental Research: Methods and Instruments SN - 9783527409969 SP - 457 EP - 526 DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : bdc7986a-6efa-4d7b-a10b-b30e88f92660 ER - TY - JOUR TI - Feasibility study on grinding of titanium alloys with electroplated CBN wheels DO - 10.4028/www.scientific.net/AMR.797.73 AU - Shi, Z.D. AU - Attia, H. T2 - Advanced Materials Research T3 - 16th International Symposium on Advances in Abrasive Technology, ISAAT 2013 and 17th Chinese Conference of Abrasive Technology, CCAT 2013, 23 September 2013 through 26 September 2013, Hangzhou SN - 1022-6680 SN - 9783037858257 VL - 797 SP - 73 EP - 78 KW - Experimental investigations KW - Feasibility studies KW - Grinding fluids KW - Ground surfaces KW - Material removal rate KW - Specific materials KW - Surface grinding KW - Wheel cleaning KW - Abrasives KW - Creep KW - Grinding (machining) KW - Loading KW - Surface cleaning KW - Surface roughness KW - Titanium alloys KW - Wheels AB - An experimental investigation is reported on the grinding of a titanium alloy using electroplated CBN wheels with water-based grinding fluid and wheel surface cleaning fluid applied at high pressures. This work was motivated by applying grinding fluid and wheel surface cleaning fluid both at high pressures for avoiding wheel loading, which is commonly seen in titanium alloy grinding. The objective is to explore the feasibility to grind titanium alloys with electroplated CBN wheels and high pressure wheel surface cleaning fluid for enhancing material removal rates. Straight surface grinding experiments were conducted on titanium alloy blocks in both shallow depth of cut and creep-feed modes. Grinding power, forces, and surface roughness were measured. Specific material removal rates of 8 mm2/s in shallow cut mode and 3 mm2/s at a depth of cut as high as 3 mm in creep-feed mode were achieved without burning and smearing of ground surfaces. It was showed that it is feasible to grind titanium alloys with electroplated CBN wheels at enhanced removal rates by applying grinding and wheel cleaning fluid at high pressures. © (2013) Trans Tech Publications, Switzerland. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : bdf54f78-9298-4dc5-b723-a0c5b0adafad ER - TY - JOUR TI - Defining the functional potential and active community members of a sediment microbial community in a high-arctic hypersaline subzero spring DO - 10.1128/AEM.00153-13 AU - Lay, C.-Y. AU - Mykytczuk, N.C.S. AU - Yergeau, É. AU - Lamarche-Gagnon, G. AU - Greer, C.W. AU - Whyte, L.G. T2 - Applied and Environmental Microbiology SN - 0099-2240 VL - 79 IS - 12 SP - 3637 EP - 3648 KW - Metagenomic analysis KW - Microbial communities KW - Microbial components KW - Microbial populations KW - Oligotrophic conditions KW - Permafrost environment KW - Stress response genes KW - Sub-zero temperatures KW - Ammonia KW - Genes KW - Metabolism KW - Methane KW - Microorganisms KW - RNA KW - Sulfur KW - Sulfur compounds KW - complementary DNA KW - primer DNA KW - RNA 16S KW - adaptation KW - discharge KW - environmental stress KW - enzyme activity KW - fluvial deposit KW - genetic analysis KW - hypersaline environment KW - metabolism KW - microbial community KW - nutrient cycling KW - oxidation KW - population structure KW - terrestrial ecosystem KW - archaeon KW - Arctic KW - article KW - Bacteroidetes KW - cold KW - cyanobacterium KW - DNA sequence KW - genetics KW - metagenome KW - microbiology KW - molecular genetics KW - natural spring KW - nucleotide sequence KW - Proteobacteria KW - salinity KW - sediment KW - Archaea KW - Arctic Regions KW - Bacteroidetes KW - Base Sequence KW - Cold Temperature KW - Cyanobacteria KW - DNA Primers KW - DNA, Complementary KW - Geologic Sediments KW - Metagenome KW - Molecular Sequence Data KW - Natural Springs KW - Proteobacteria KW - RNA, Ribosomal, 16S KW - Salinity KW - Sequence Analysis, DNA KW - Canada AB - The Lost Hammer (LH) Spring is the coldest and saltiest terrestrial spring discovered to date and is characterized by perennial discharges at subzero temperatures (-5°C), hypersalinity (salinity, 24%), and reducing (≈-165mV), microoxic, and oligotrophic conditions. It is rich in sulfates (10.0%, wt/wt), dissolved H2S/sulfides (up to 25ppm), ammonia (≈381μM), and methane (11.1g day-1). To determine its total functional and genetic potential and to identify its active microbial components, we performed metagenomic analyses of the LH Spring outlet microbial community and pyrosequencing analyses of the cDNA of its 16S rRNA genes. Reads related to Cyanobacteria (19.7%), Bacteroidetes (13.3%), and Proteobacteria (6.6%) represented the dominant phyla identified among the classified sequences. Reconstruction of the enzyme pathways responsible for bacterial nitrification/ denitrification/ammonification and sulfate reduction appeared nearly complete in the metagenomic data set. In the cDNA profile of the LH Spring active community, ammonia oxidizers (Thaumarchaeota), denitrifiers (Pseudomonas spp.), sulfate reducers (Desulfobulbus spp.), and other sulfur oxidizers (Thermoprotei) were present, highlighting their involvement in nitrogen and sulfur cycling. Stress response genes for adapting to cold, osmotic stress, and oxidative stress were also abundant in the metagenome. Comparison of the composition of the functional community of the LH Spring to metagenomes from other saline/ subzero environments revealed a close association between the LH Spring and another Canadian high-Arctic permafrost environment, particularly in genes related to sulfur metabolism and dormancy. Overall, this study provides insights into the metabolic potential and the active microbial populations that exist in this hypersaline cryoenvironment and contributes to our understanding of microbial ecology in extreme environments. © 2013, American Society for Microbiology. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 10066444-a0de-4d4f-8826-203bb06c265a ER - TY - JOUR TI - Electrochemical behavior of nanostructured nickel phthalocyanine (NiPc/C) for oxygen reduction reaction in alkaline media DO - 10.1007/s10800-012-0503-4 AU - Ding, L. AU - Xin, Q. AU - Zhou, X. AU - Qiao, J. AU - Li, H. AU - Wang, H. T2 - Journal of Applied Electrochemistry SN - 0021-891X VL - 43 IS - 1 SP - 43 EP - 51 KW - Activity enhancement KW - Alkaline electrolytes KW - Alkaline media KW - Catalyst structures KW - Electrocatalytic activity KW - Electrochemical behaviors KW - Electron transfer mechanisms KW - Half-wave potential KW - Heat treatment temperature KW - Heat-treatment effects KW - Linear sweep voltammetry KW - Milling procedures KW - Nano-structured KW - Nanoparticle catalysts KW - Nickel phthalocyanines KW - Number of electrons KW - Onset potential KW - Oxygen reduction reaction KW - Remarkable impact KW - Rotating disk electrodes KW - XPS analysis KW - Catalysts KW - Cyclic voltammetry KW - Electrolytes KW - Electrolytic reduction KW - Electron transitions KW - Nitrogen compounds KW - Photoelectrons KW - Proton exchange membrane fuel cells (PEMFC) KW - Rotating disks KW - Synthesis (chemical) KW - Thermogravimetric analysis KW - Transmission electron microscopy KW - X ray diffraction KW - X ray photoelectron spectroscopy KW - Nickel AB - Carbon-supported nickel phthalocyanine (NiPc/C) nanoparticle catalysts have been synthesized by a simple solvent-impregnation and milling procedure, then heat-treated at 600, 700, 800 and 900 °C to optimize their activity for the oxygen reduction reaction (ORR). The electrocatalytic activity and electron transfer mechanism of NiPc/C catalysts were demonstrated in oxygen-saturated alkaline electrolyte by cyclic voltammetry, linear sweep voltammetry as well as rotating disk electrode techniques, respectively. The results show that the heat-treatment temperature has a remarkable impact on the ORR activity of NiPc/C. An onset potential of 0.05 V and a half-wave potential of -0.15 V are achieved in 0.1 M KOH after the catalyst was heat-treated at 800 °C. In addition to an increase in ORR kinetics, the number of electrons transferred for ORR also increased from 2.2 to 2.8 with increasing heat-treatment temperature from 600 to 800 °C. To understand the heat-treatment effect, X-ray diffraction, transmission electron microscopy, thermogravimetric analysis, and X-ray photoelectron spectroscopy (XPS) were used to identify the catalyst structure and composition. From XPS analysis, pyridinic-N and graphitic-N were clearly observed after the sample was heat-treated at 800 °C. Both of these species might be assigned to sites catalytically active toward the ORR leading to activity enhancement. © 2012 Springer Science+Business Media Dordrecht. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : dd38680b-30b2-4efb-b0e0-320f762789fa ER - TY - JOUR TI - Collapsin response mediator protein 3 deacetylates histone H4 to mediate nuclear condensation and neuronal death DO - 10.1038/srep01350 AU - Hou, S.T. AU - Jiang, S.X. AU - Aylsworth, A. AU - Cooke, M. AU - Zhou, L. T2 - Scientific Reports SN - 2045-2322 VL - 3 SP - 1350 KW - Dpysl4 protein, mouse KW - glutamic acid KW - histone KW - histone deacetylase KW - nerve protein KW - transcription factor E2F1 KW - tubulin KW - acetylation KW - animal KW - article KW - cell death KW - cell line KW - cell nucleus KW - drug effect KW - female KW - gene expression regulation KW - gene silencing KW - genetics KW - human KW - metabolism KW - mouse KW - nerve cell KW - protein binding KW - protein transport KW - ultrastructure KW - Acetylation KW - Animals KW - Cell Death KW - Cell Line KW - Cell Nucleus KW - E2F1 Transcription Factor KW - Female KW - Gene Expression Regulation KW - Gene Knockdown Techniques KW - Glutamic Acid KW - Histone Deacetylases KW - Histones KW - Humans KW - Mice KW - Nerve Tissue Proteins KW - Neurons KW - Protein Binding KW - Protein Transport KW - Tubulin AB - CRMP proteins play critical regulatory roles during semaphorin-mediated neurite outgrowth, neuronal differentiation and death. Albeit having a high degree of structure and sequence resemblance to that of liver dihydropyrimidinase, purified rodent brain CRMPs do not hydrolyze dihydropyrimidinase substrates. Here we found that mouse CRMP3 has robust histone H4 deacetylase activity. During excitotoxicity-induced mouse neuronal death, calpain-cleaved, N-terminally truncated CRMP3 undergoes nuclear translocation to cause nuclear condensation through deacetylation of histone H4. CRMP3-mediated deacetylation of H4 leads to de-repression of the E2F1 gene transcription and E2F1-dependent neuronal death. These studies revealed a novel mechanism of CRMP3 in neuronal death. Together with previous well established bodies of literature that inhibition of histone deacetylase activity provides neuroprotection, we envisage that inhibition of CRMP3 may represent a novel therapeutic approach towards excitotoxicity-induced neuronal death. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8310cefe-ddef-4f25-97e6-cd6dab878a39 ER - TY - JOUR TI - Maintaining health by balancing microbial exposure and prevention of infection: The hygiene hypothesis versus the hypothesis of early immune challenge DO - 10.1016/S0195-6701(13)60007-9 AU - Kramer, A. AU - Bekeschus, S. AU - Bröker, B.M. AU - Schleibinger, H. AU - Razavi, B. AU - Assadian, O. T2 - Journal of Hospital Infection SN - 0195-6701 VL - 83 IS - SUPPL. 1 SP - S29 EP - S34 KW - antiinflammatory activity KW - article KW - asthma KW - atopy KW - autoimmune disease KW - bacterial flora KW - Crohn disease KW - cross infection KW - early immune challenge hypothesis KW - enteritis KW - exposure KW - hay fever KW - Helicobacter infection KW - Heligmosomoides polygyrus KW - helper cell KW - host parasite interaction KW - host pathogen interaction KW - human KW - hygiene hypothesis KW - hypothesis KW - immune response KW - immunological tolerance KW - immunoregulation KW - immunostimulation KW - infection KW - infection prevention KW - inflammation KW - innate immunity KW - microbial colonization KW - microorganism KW - nonhuman KW - parasite KW - phylogeny KW - regulatory T lymphocyte KW - Schistosoma KW - Schistosoma mansoni KW - Th1 cell KW - Th17 cell KW - Toxoplasma gondii KW - Trichuris suis KW - Autoimmune Diseases KW - Health KW - Humans KW - Hygiene Hypothesis KW - Hypersensitivity KW - Incidence AB - The human immune system is inseparably bonded to an individual's personal micro-biome from birth to death. Since the beginning of life, commensal relationships have ensured the survival of micro- and macro-organisms within complex relationships. However, technological advances and altered lifestyle imposed new rules for this interaction during recent decades. It has been observed that reduced exposure to micro-organisms and parasites results in decreased morbidity and mortality, but is also associated with a rising prevalence of atopic disorders and autoimmune diseases, mostly in industrialized countries. This inverse relationship is described by the 'hygiene hypothesis', put forward in 1989, yet this term only imperfectly describes these observations, as excessive hygiene or hygienic measures may not directly be the central cause. The lack of appropriate immune stimulation during early childhood with the consequence of disturbed alignment in the sequence of encountering self- or non-self-antigens might account in the rise of atopy and autoimmune disease. For this reason we propose the term 'early immune challenge hypothesis'. This concept highlights the importance of immune priming in early life in the context of genetic, social, geographic, cultural, and economic background. Moreover, it emphasizes the central role of 'training' of regulatory T-cells through sufficient microbial exposure, leading to a robust, healthy balance between inflammation and anti-inflammation or immune tolerance. Insufficient exposure might result in abnormal immune regulatory development. Finally, it incorporates the idea of encountering 'old friends' - organisms that shaped our immune system during human phylogeny. This article gives a comprehensive overview of the relationship between microbial exposure, and the incidence of asthma and hay fever is outlined. Although the outcomes of these studies originally were interpreted in the framework of the hygiene hypothesis, they may suit the concept of the hypothesis of early immune challenge even better. Moreover, recent studies have revealed that TH or TReg imbalances in disease may be partially corrected by the administration of helminthic or bacterial extracts. © 2013 The Healthcare Infection Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : cf19fc41-9fb2-469e-8ad0-099dcacb71c5 ER - TY - JOUR TI - Freeform Laser Consolidated H13 and CPM 9V Tool Steels DO - 10.1007/s13632-013-0061-0 AU - Xue, L. AU - Chen, J. AU - Wang, S.-H. T2 - Metallography, Microstructure, and Analysis SN - 2192-9262 VL - 2 IS - 2 SP - 67 EP - 78 KW - Additive Manufacturing KW - AISI H13 KW - CPM 9V KW - Freeforms KW - Rapid tooling KW - Carbides KW - Manufacture KW - Wear resistance KW - Tool steel AB - As a novel computer-aided materials additive manufacturing process, the freeform laser consolidation (LC) can directly produce functional shapes (features or structures) through a "layer-upon-layer" deposition. In this research, LC processability of both H13 and CPM 9V tool steels and their mechanical performance thus obtained were investigated. Both laser-consolidated tool steels were metallurgically sound with no crack, exhibiting layer-wise refined solidified structures with dominated martensite and small amount of retained austenite, as well as composition-dependent carbides. Laser-consolidated H13 could outperform its wrought counterpart mechanically as measured by tensile strength/strain, and bonding strength as well as sliding wear resistance; laser-consolidated CPM 9V could provide excellent sliding wear resistance superior to the conventional widely used tool steel (such as wrought D2). These unique microstructures and mechanical properties could be tailored for niche applications in additive manufacturing of tools, molds, and dies. © 2013 Her Majesty the Queen in Right of Canada. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c6f547a0-c9d6-43b1-be2d-53096a7efc02 ER - TY - JOUR TI - Initial thickness measurements and insights into crystal growth of methane hydrate film DO - 10.1002/aic.13987 AU - Li, S.-L. AU - Sun, C.-Y. AU - Liu, B. AU - Feng, X.-J. AU - Li, F.-G. AU - Chen, L.-T. AU - Chen, G.-J. T2 - AIChE Journal SN - 0001-1541 VL - 59 IS - 6 SP - 2145 EP - 2154 KW - Bubble in waters KW - Bubble surface KW - Different sizes KW - Hydrate shells KW - Initial thickness KW - Lateral growth KW - Methane hydrates KW - Three-dimensional growth KW - Crystal growth KW - Film thickness KW - Gas hydrates KW - Hydration KW - Methane KW - Thickness gages KW - Thickness measurement KW - Three dimensional KW - Film growth AB - The initial thickness of methane hydrate film was directly measured by suspending a single methane bubble in water at 274.0, 276.0, and 278.0 K. The results show that the initial hydrate film thickness decreases from tens of micrometers to about 10 μm with the subcooling increased from 0.5 K to about 3 K. When subcooling is higher than 1.0 K, all initial film thickness data measured under different temperatures vary inversely with the subcooling. Notable three-dimensional growths of hydrate crystals of different sizes and shapes at film front and emergence of new crystal were clearly observed at lower subcooling that resulting in the rougher surface of hydrate film and uncertainty of initial thickness measurement under lower subcooling. The hydrate film growth was dominated by film growth in thickness, not by lateral growth at low subcooling. The growth in thickness of hydrate shell covering one whole bubble surface was also investigated. © 2013 American Institute of Chemical Engineers (AIChE). DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 52414d52-4a26-4552-b3c5-841bf9a7fbb5 ER - TY - JOUR TI - Effects of thioredoxin: Sumo and intein on soluble fusion expression of an antimicrobial peptide OG2 in escherichia coli AU - Xie, Y.-G. AU - Luan, C. AU - Zhang, H.-W. AU - Han, F.-F. AU - Feng, J. AU - Choi, Y-J. AU - Groleau, D. AU - Wang, Y.-Z. T2 - Protein and Peptide Letters SN - 0929-8665 VL - 20 IS - 1 SP - 54 EP - 60 KW - intein KW - polypeptide antibiotic agent KW - polypeptide antibiotic agent OG2 KW - SUMO protein KW - thioredoxin KW - unclassified drug KW - affinity chromatography KW - article KW - chemical structure KW - controlled study KW - enzyme release KW - Escherichia coli KW - expression vector KW - hemolysis KW - molecular cloning KW - nonhuman KW - polymerase chain reaction KW - process optimization KW - protein expression KW - protein purification KW - Animals KW - Anti-Infective Agents KW - Antimicrobial Cationic Peptides KW - Erythrocytes KW - Escherichia coli KW - Hemolytic Agents KW - Inteins KW - Ranidae KW - Recombinant Fusion Proteins KW - Small Ubiquitin-Related Modifier Proteins KW - Staphylococcus aureus KW - Swine KW - Thioredoxins AB - OG2 is a modified antimicrobial peptide of Palustrin-OG1 (OG1), which is derived from Odorrana grahami frog. OG2 has shown much higher selective antimicrobial activity and lower hemolytic activity than OG1, indicating OG2 may be a promising antimicrobial agent. In this study, we investigated three fusion partners, including thioredoxin, Mxe GyrA intein, and small ubiquitin-like modifier (SUMO), each fused with OG2, and examined their effects on the expression level and solubility of OG2 in Escherichia coli. The codon-optimized OG2 gene was cloned into pET32a (+) and pTWIN1 for fusion with thioredoxin and Mxe GyrA intein, respectively. In addition, the SUMO-OG2 gene was amplified by splice overlap extension PCR method and was cloned into pET30a (+). All recombinant plasmids were then transformed into E. coli BL21(DE3)pLysS, and the expressed fusion proteins were verified. Upon isopropyl α-D-1- thiogalactopyranoside (IPTG) induction, OG2 fused with thioredoxin (Trx-OG2) showed the highest yield as a soluble fusion protein (50 mg/L), followed by Mxe GyrA intein (44 mg/L) and SUMO (11 mg/L). The thioredoxin-fused protein (Trx-OG2) was then purified by nickel-nitrilotriacetic acid chromatography and desalted by Sephadex G25. The OG2 released by both tobacco etch virus protease and enterokinase from Trx-OG2 showed strong antimicrobial activity against Staphylococcus aureus ATCC25923. Copyright © 2012 Bentham Science Publishers. All Rights Reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 71d61e3e-3517-4438-a81a-475c6f4fb1da ER - TY - JOUR TI - Redshift 6.4 host galaxies of 108 solar mass black holes: Low star formation rate and dynamical mass DO - 10.1088/0004-637X/770/1/13 AU - Willott, C.J. AU - Omont, A. AU - Bergeron, J. T2 - The Astrophysical Journal SN - 0004-637X VL - 770 IS - 1 SP - 13 AB - We present Atacama Large Millimeter Array observations of rest-frame far-infrared continuum and [C II] line emission in two z = 6.4 quasars with black hole masses of 108 M ⊙. CFHQS J0210-0456 is detected in the continuum with a 1.2 mm flux of 120 ± 35 μJy, whereas CFHQS J2329-0301 is undetected at a similar noise level. J2329-0301 has a star formation rate limit of <40 M ⊙ yr-1, considerably below the typical value at all redshifts for this bolometric luminosity. Through comparison with hydro simulations, we speculate that this quasar is observed at a relatively rare phase where quasar feedback has effectively shut down star formation in the host galaxy. [C II] emission is also detected only in J0210-0456. The ratio of [C II] to far-infrared luminosity is similar to that of low-redshift galaxies of comparable luminosity, suggesting that the previous finding of an offset in the relationships between this ratio and far-infrared luminosity at low and high redshifts may be partially due to a selection effect due to the limited sensitivity of previous continuum data. The [C II] line of J0210-0456 is relatively narrow (FWHM = 189 ± 18 km s-1), indicating a dynamical mass substantially lower than expected from the local black hole-velocity dispersion correlation. The [C II] line is marginally resolved at 0.″7 resolution with the blue and red wings spatially offset by 0.″5 (3 kpc) and a smooth velocity gradient of 100 km s-1 across a scale of 6 kpc, possibly due to the rotation of a galaxy-wide disk. These observations are consistent with the idea that stellar mass growth lags black hole accretion for quasars at this epoch with respect to more recent times. © 2013. The American Astronomical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 72a45b48-b76d-42c9-afa5-df95e3d0894d ER - TY - JOUR TI - Compressed sensing reconstruction improves sensitivity of variable density spiral fMRI DO - 10.1002/mrm.24621 AU - Holland, D.J. AU - Liu, C. AU - Song, X. AU - Mazerolle, E.L. AU - Stevens, M.T. AU - Sederman, A.J. AU - Gladden, L.F. AU - D'Arcy, R.C.N. AU - Bowen, C.V. AU - Beyea, S.D. T2 - Magnetic Resonance in Medicine SN - 0740-3194 VL - 70 IS - 6 SP - 1634 EP - 1643 AB - Purpose Functional MRI (fMRI) techniques that can provide excellent blood oxygen level dependent contrast, rapid whole brain imaging, and minimal spatial distortion are in demand. This study explored whether fMRI sensitivity can be improved through the use of compressed sensing (CS) reconstruction of variable density spiral fMRI. Methods Three different CS-reconstructed 1-shot variable density spirals were explored (corresponding to 28%, 35%, and 46% under-sampling), and compared with conventional 1-shot and 2-shot Archimedean spirals acquired using matched echo time and volume repetition time. fMRI maps were reconstructed with or without CS MRI and sensitivity was compared using identically matched voxels. Results The results demonstrated that an l 1-norm based CS reconstruction only led to an increase in functional contrast when applied to 28% under-sampled data. A whole brain t-contrast map revealed that 2-shot uniformly sampled spiral and 28% under-sampled spiral data reconstructed with CS yield equivalent sensitivity, even with matched echo time and volume repetition time Conclusion VD spiral exhibits a useful operating range, in the region of 25-30% under-sampling, for which CS reconstruction can be used to increase the sensitivity of fMRI to brain activity. Using CS, VD acquisitions achieve the same sensitivity as 2-shot Archimedean acquisitions, but require only a single shot. Magn Reson Med 70:1634-1643, 2013. © 2013 Wiley Periodicals, Inc. Copyright © 2013 Wiley Periodicals, Inc. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 464c9cb7-797a-4b46-80bb-be56f68ddeec ER - TY - JOUR TI - The very young type Ia supernova 2013dy: Discovery, and strong carbon absorption in early-time spectra DO - 10.1088/2041-8205/778/1/L15 AU - Zheng, W. AU - Silverman, J.M. AU - Filippenko, A.V. AU - Kasen, D. AU - Nugent, P.E. AU - Graham, M. AU - Wang, X. AU - Valenti, S. AU - Ciabattari, F. AU - Kelly, P.L. AU - Fox, O.D. AU - Shivvers, I. AU - Clubb, K.I. AU - Cenko, S.B. AU - Balam, D. AU - Howell, D.A. AU - Hsiao, E. AU - Li, W. AU - Howie Marion, G. AU - Sand, D. AU - Vinko, J. AU - Wheeler, J.C. AU - Zhang, J. T2 - The Astrophysical Journal Letters SN - 2041-8205 VL - 778 IS - 1 SP - L15 AB - The Type Ia supernova (SN Ia) 2013dy in NGC 7250 (d ≈ 13.7 Mpc) was discovered by the Lick Observatory Supernova Search. Combined with a prediscovery detection by the Italian Supernova Search Project, we are able to constrain the first-light time of SN 2013dy to be only 0.10 ± 0.05 days (2.4 ± 1.2 hr) before the first detection. This makes SN 2013dy the earliest known detection of an SN Ia. We infer an upper limit on the radius of the progenitor star of R 0 ≲ 0.25 R ⊙, consistent with that of a white dwarf. The light curve exhibits a broken power law with exponents of 0.88 and then 1.80. A spectrum taken 1.63 days after first light reveals a C II absorption line comparable in strength to Si II. This is the strongest C II feature ever detected in a normal SN Ia, suggesting that the progenitor star had significant unburned material. The C II line in SN 2013dy weakens rapidly and is undetected in a spectrum 7 days later, indicating that C II is detectable for only a very short time in some SNe Ia. SN 2013dy reached a B-band maximum of MB = -18.72 ± 0.03 mag ∼17.7 days after first light. © 2013. The American Astronomical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8048ad61-cb22-4c80-bbcc-637d87e8e20e ER - TY - JOUR TI - Effect of template size on the synthesis of mesoporous carbon spheresand their supported Fe-based ORR electrocatalysts DO - 10.1016/j.electacta.2013.07.037 AU - Zhang, L. AU - Kim, J. AU - Dy, E. AU - Ban, S. AU - Tsay, K.-C. AU - Kawai, H. AU - Shi, Z. AU - Zhang, J. T2 - Electrochimica Acta SN - 0013-4686 VL - 108 SP - 814 EP - 819 KW - Catalyst deposition KW - Mesoporous carbon KW - Mesoporous carbon supports KW - ORR electrocatalysts KW - Oxygen reduction reaction KW - Support materials KW - Template effects KW - Ultrasonic spray pyrolysis KW - Carbon KW - Catalyst activity KW - Catalyst supports KW - Electrocatalysts KW - Electrolytic reduction KW - Model predictive control KW - Proton exchange membrane fuel cells (PEMFC) KW - Spray pyrolysis KW - Synthesis (chemical) KW - Mesoporous materials AB - Three mesoporous carbon spheres (MPCs) are synthesized using three different templates with sizes of22, 35 and 50 nm, respectively. These three MPC materials are then used as catalyst supports to formthree catalysts (Fe-N X/MPC22, Fe-NX/MPC35, and Fe-NX/MPC50) for oxygen reduction reaction (ORR).SEM images show that after catalyst deposition on the synthesized mesoporous carbon, the sphericalmorphology of mesoporous carbon is well maintained. EDX measurements show that the average Fecontent in the formed mesoporous carbon supported catalysts is very close to the initial synthesis valueof 5 wt%. BET and linear scanning voltammetry are used for characterizing the surface area and electro-chemical properties of the synthesized MPC support materials to study the effect of template size (orpore size). The results show that mesoporous carbon with template size of 50 nm has the largest BETsurface area (2125 m2/g). The measurement results show that all ORR activities of these three MPC sup-ported catalysts are higher than that of commercially available carbon supported one, demonstratingthe advantage of MPC support. Among these three catalysts, the performance order is Fe-N X/MPC50 > Fe-NX/MPC35 > Fe-NX/MPC22, showing the effect of template size on the ORR activity of the catalyst, i.e., theORR activity increases when the template size (or MPC pore size) is increased. The results also clearlyindicate that the mesopores in the range of 22-50 nm can still affect the ORR activity, suggesting thatmesopores are also important in the formation of ORR active sites besides micropores. © 2013 Published by Elsevier Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 75f993a4-ceeb-4a99-9ad8-ac2ea29e980b ER - TY - JOUR TI - Adenosine monophosphate forms ordered arrays in multilamellar lipid matrices: insights into assembly of nucleic acid for primitive life DO - 10.1371/journal.pone.0062810 AU - Toppozini, L. AU - Dies, H. AU - Deamer, D. W. AU - Rheinstädter, M. C. T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 5 SP - e62810 KW - adenosine phosphate KW - dimyristoylphosphatidylcholine KW - nucleic acid KW - phosphate KW - ribose KW - Bragg peak KW - crystal structure KW - mathematical phenomena KW - molecular biology KW - molecule lateral organization KW - multilamellar phospholipid matrix KW - nucleic acid assembly KW - nucleic acid structure KW - nucleic acid structure, metabolism and function KW - phospholipid bilayer KW - polymerization KW - radiation scattering KW - structure analysis AB - A fundamental question of biology is how nucleic acids first assembled and then were incorporated into the earliest forms of cellular life 4 billion years ago. The polymerization of nucleotides is a condensation reaction in which phosphodiester bonds are formed. This reaction cannot occur in aqueous solutions, but guided polymerization in an anhydrous lipid environment could promote a non-enzymatic condensation reaction in which oligomers of single stranded nucleic acids are synthesized. We used X-ray scattering to investigate 5′-adenosine monophosphate (AMP) molecules captured in a multilamellar phospholipid matrix composed of dimyristoylphosphatidylcholine. Bragg peaks corresponding to the lateral organization of the confined AMP molecules were observed. Instead of forming a random array, the AMP molecules are highly entangled, with the phosphate and ribose groups in close proximity. This structure may facilitate polymerization of the nucleotides into RNA-like polymers. DA - 2013/05/07 PY - 2013 PB - PLOS LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 85156115-3a21-4196-8cce-cbcdf7c9893c ER - TY - JOUR TI - Antioxidant canolol production from a renewable feedstock via an engineered decarboxylase DO - 10.1039/c3gc40748a AU - Morley, Krista L. AU - Grosse, Stephan AU - Leisch, Hannes AU - Lau, Peter C. K. T2 - Green Chemistry SN - 1463-9262 VL - 15 IS - 12 SP - 3312 EP - 3317 AB - Canolol (4-vinylsyringol, VS), a potent antioxidant and an alkylperoxyl radical scavenger originally discovered in crude canola oil (rapeseed), is produced by decarboxylation of sinapic acid (SA) during canola seed roasting. Chemical syntheses of VS from SA require thermal or microwave induced decarboxylation in the presence of a base. A laboratory-evolved enzyme, designated SA decarboxylase (SAD), was developed in this study. In a biphasic bioreactor system, SAD was shown to produce VS from SA extracts prepared from canola meal with an overall yield of 3.0 mg VS per g of canola meal. In addition, we investigated the application of VS in polymerization to produce polyvinylsyringol (PVS) as a potential biodegradable polymer. The characteristics of PVS determined by thermogravimetric analysis, differential scanning calorimetry and nanoindentation tests are described. © 2013 The Royal Society of Chemistry. DA - 2013/10/03 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 62d77990-938d-4fa8-be95-3413ac2dc21b ER - TY - JOUR TI - Ecotoxicological assessment of a high energetic and insensitive munitions compound : 2,4-Dinitroanisole (DNAN) DO - 10.1016/j.jhazmat.2013.08.043 AU - Dodard, Sabine G. AU - Sarrazin, Manon AU - Hawari, Jalal AU - Paquet, Louise AU - Ampleman, Guy AU - Thiboutot, Sonia AU - Sunahara, Geoffrey I. T2 - Journal of Hazardous Materials SN - 0304-3894 VL - 262 SP - 143 EP - 150 KW - 2 ,4 ,6-trinitrotoluene KW - 2 ,4-dinitroanisole KW - Ecotoxicity KW - Ecotoxicological assessment KW - Environmental risk assessment KW - Experimental conditions KW - Microtox KW - Pseudokirchneriella subcapitata KW - Algae KW - Ammunition KW - Aromatic compounds KW - Environmental impact KW - Explosives KW - Risk assessment KW - Toxicity KW - 2,4 dinitroanisole KW - aromatic nitro compound KW - nitrobenzene derivative KW - unclassified drug KW - bacterium KW - bioluminescence KW - concentration (composition) KW - decision making KW - dose-response relationship KW - earthworm KW - ecotoxicology KW - environmental impact KW - environmental risk KW - grass KW - green alga KW - risk assessment KW - toxicity test KW - trinitrotoluene KW - algal growth KW - article KW - avoidance behavior KW - bioavailability KW - bioluminescence KW - biotransformation KW - concentration response KW - earthworm KW - ecotoxicity KW - Eisenia andrei KW - environmental impact KW - fluid balance KW - growth inhibition KW - nonhuman KW - oxidative phosphorylation KW - perennial ryegrass KW - Pseudokirchneriella subcapitata KW - Vibrio fischeri AB - The high explosive nitroaromatic 2,4-dinitroanisole (DNAN) is less shock sensitive than 2,4,6-trinitrotoluene (TNT), and is proposed as a TNT replacement for melt-cast formulations. Before using DNAN in munitions and potentially leading to environmental impact, the present study examines the ecotoxicity of DNAN using selected organisms. In water, DNAN decreased green algae Pseudokirchneriella subcapitata growth (EC50=4.0mg/L), and bacteria Vibrio fischeri bioluminescence (Microtox, EC50=60.3mg/L). In soil, DNAN decreased perennial ryegrass Lolium perenne growth (EC50=7mg/kg), and is lethal to earthworms Eisenia andrei (LC50=47mg/kg). At sub-lethal concentrations, DNAN caused an avoidance response (EC50=31mg/kg) by earthworms. The presence of DNAN and 2-amino-4-nitroanisole in earthworms and plants suggested a role of these compounds in DNAN toxicity. Toxicity of DNAN was compared to TNT, tested under the same experimental conditions. These analyses showed that DNAN was equally, or even less deleterious to organism health than TNT, depending on the species and toxicity test. The present studies provide baseline toxicity data to increase the understanding of the environmental impact of DNAN, and assist science-based decision makers for improved management of potential DNAN contaminated sites. © 2013. DA - 2013/08/23 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d2998754-2cb7-4801-9ff5-a510027642f8 ER - TY - JOUR TI - Texture based segmentation method to detect atherosclerotic plaque from optical tomography images DO - 10.1117/12.2032197 AU - Prakash, A. AU - Hewko, M. AU - Sowa, M. AU - Sherif, S. T2 - Progress in Biomedical Optics and Imaging - Proceedings of SPIE T3 - Optical Coherence Tomography and Coherence Techniques VI Conference, 13 May 2013 through 15 May 2013, Munich SN - 1605-7422 SN - 9780819496515 VL - 8802 SP - 88020S KW - atherosclerosis KW - Atherosclerotic plaque KW - Cardio-vascular disease KW - High frame rate KW - plaque KW - Plaque detection KW - Texture-based segmentations KW - Visual detection KW - Diseases KW - Image processing KW - Image segmentation KW - Image texture KW - Photography KW - Textures KW - Tissue KW - Optical tomography AB - Optical coherence tomography (OCT) imaging has been widely employed in assessing cardiovascular disease. Atherosclerosis is one of the major cause cardio vascular diseases. However visual detection of atherosclerotic plaque from OCT images is often limited and further complicated by high frame rates. We developed a texture based segmentation method to automatically detect plaque and non plaque regions from OCT images. To verify our results we compared them to photographs of the vascular tissue with atherosclerotic plaque that we used to generate the OCT images. Our results show a close match with photographs of vascular tissue with atherosclerotic plaque. Our texture based segmentation method for plaque detection could be potentially used in clinical cardiovascular OCT imaging for plaque detection. © OSA-2013 SPIE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ac505922-337b-44c6-b15d-cee90391bd9c ER - TY - JOUR TI - Evaluating the pathogenic potential of environmental Escherichia coli by using the caenorhabditis elegans infection model DO - 10.1128/AEM.03501-12 AU - Merkx-Jacques, A. AU - Coors, A. AU - Brousseau, R. AU - Masson, L. AU - Mazza, A. AU - Tien, Y.-C. AU - Topp, E. T2 - Applied and Environmental Microbiology SN - 0099-2240 VL - 79 IS - 7 SP - 2435 EP - 2445 KW - Caenorhabditis elegans KW - Clinical isolates KW - Environmental isolates KW - Human health risks KW - Pathogenic potential KW - Recreational water KW - Siderophore receptors KW - Virulence factors KW - Bioassay KW - Encoding (symbols) KW - Genes KW - Plants (botany) KW - Potable water KW - Escherichia coli KW - virulence factor KW - abundance KW - bioassay KW - commensal KW - detection method KW - diarrheal disease KW - digestive system disorder KW - fecal coliform KW - gene expression KW - health risk KW - infectious disease KW - nematode KW - pathogen KW - protein KW - virulence KW - water quality KW - watershed KW - animal KW - animal model KW - article KW - Caenorhabditis elegans KW - Canada KW - DNA microarray KW - Escherichia coli KW - Escherichia coli infection KW - genetics KW - genotype KW - human KW - isolation and purification KW - microarray analysis KW - microbiology KW - mortality KW - pathogenicity KW - survival KW - Animals KW - Caenorhabditis elegans KW - Environmental Microbiology KW - Escherichia coli KW - Escherichia coli Infections KW - Genotype KW - Humans KW - Microarray Analysis KW - Models, Animal KW - Oligonucleotide Array Sequence Analysis KW - Ontario KW - Survival Analysis KW - Virulence Factors KW - Canada KW - Ontario [Canada] KW - Caenorhabditis elegans KW - Escherichia coli AB - The detection and abundance of Escherichia coli in water is used to monitor and mandate the quality of drinking and recreational water. Distinguishing commensal waterborne E. coli isolates from those that cause diarrhea or extraintestinal disease in humans is important for quantifying human health risk. A DNA microarray was used to evaluate the distribution of virulence genes in 148 E. coli environmental isolates from a watershed in eastern Ontario, Canada, and in eight clinical isolates. Their pathogenic potential was evaluated with Caenorhabditis elegans, and the concordance between the bioassay result and the pathotype deduced by genotyping was explored. Isolates identified as potentially pathogenic on the basis of their complement of virulence genes were significantly more likely to be pathogenic to C. elegans than those determined to be potentially nonpathogenic. A number of isolates that were identified as nonpathogenic on the basis of genotyping were pathogenic in the infection assay, suggesting that genotyping did not capture all potentially pathogenic types. The detection of the adhesin-encoding genes sfaD, focA, and focG, which encode adhesins; of iroN2, which encodes a siderophore receptor; of pic, which encodes an autotransporter protein; and of b1432, which encodes a putative transposase, was significantly associated with pathogenicity in the infection assay. Overall, E. coli isolates predicted to be pathogenic on the basis of genotyping were indeed so in the C. elegans infection assay. Furthermore, the detection of C. elegans-infective environmental isolates predicted to be nonpathogenic on the basis of genotyping suggests that there are hitherto-unrecognized virulence factors or combinations thereof that are important in the establishment of infection. © 2013, American Society for Microbiology. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 97d297a8-6a8b-473f-ba78-8a557bf21b7a ER - TY - JOUR TI - Identification of genes involved in the biosynthesis of the third and fourth sugars of the Methanococcus maripaludis archaellin N-linked tetrasaccharide DO - 10.1128/JB.00668-13 AU - Ding, Y. AU - Jones, G.M. AU - Uchida, K. AU - Aizawa, S.-I. AU - Robotham, A. AU - Logan, S.M. AU - Kelly, J. AU - Jarrell, K.F. T2 - Journal of Bacteriology SN - 0021-9193 VL - 195 IS - 18 SP - 4094 EP - 4104 KW - carbohydrate KW - methyltransferase KW - article KW - bioinformatics KW - biosynthesis KW - controlled study KW - gene KW - gene deletion KW - gene identification KW - glycosylation KW - mass spectrometry KW - Methanococcus maripaludis KW - mmp1084 gene KW - mmp1085 gene KW - mmp1086 gene KW - mmp1087 gene KW - nonhuman KW - priority journal KW - Archaeal Proteins KW - Carbohydrate Sequence KW - Computational Biology KW - Gene Deletion KW - Genes, Archaeal KW - Glycosylation KW - Mass Spectrometry KW - Membrane Proteins KW - Methanococcus KW - Methyltransferases KW - Multigene Family KW - Polysaccharides KW - Protein Processing, Post-Translational KW - Reverse Transcriptase Polymerase Chain Reaction KW - Threonine KW - Transferases AB - N-glycosylation is a protein posttranslational modification found in all three domains of life. Many surface proteins in Archaea, including S-layer proteins, pilins, and archaellins (archaeal flagellins) are known to contain N-linked glycans. In Methanococcus maripaludis, the archaellins are modified at multiple sites with an N-linked tetrasaccharide with the structure Sug-1,4-β-ManNAc3NAmA6Thr-1,4-β-GlcNAc3NAcA-1,3-β-GalNAc, where Sug is the unique sugar (5S)-2-acetamido-2,4-dideoxy-5-Omethyl-α-L-erythro-hexos-5-ulo-1,5-pyranose. In this study, four genes-mmp1084, mmp1085, mmp1086, and mmp1087-were targeted to determine their potential involvement of the biosynthesis of the sugar components in the N-glycan, based on bioinformatics analysis and proximity to a number of genes which have been previously demonstrated to be involved in the N-glycosylation pathway. The genes mmp1084 to mmp1087 were shown to be cotranscribed, and in-frame deletions of each gene as well as a Δmmp1086Δmmp1087 double mutant were successfully generated. All mutants were archaellated and motile. Mass spectrometry examination of purified archaella revealed that in Δmmp1084 mutant cells, the threonine linked to the third sugar of the glycan was missing, indicating a putative threonine transferase function of MMP1084. Similar analysis of the archaella of the Δmmp1085 mutant cells demonstrated that the glycan lacked the methyl group at the C-5 position of the terminal sugar, indicating that MMP1085 is a methyltransferase involved in the biosynthesis of this unique sugar. Deletion of the remaining two genes, mmp1086 and mmp1087, either singularly or together, had no effect on the structure of the archaellin N-glycan. Because of their demonstrated involvement in the N-glycosylation pathway, we designated mmp1084 as aglU and mmp1085 as aglV. © 2013, American Society for Microbiology. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 064506c3-1ae4-416c-8195-7a16be705625 ER - TY - JOUR TI - A 3D meso-scale analysis of angle-ply laminates DO - 10.1080/15376494.2012.676712 AU - Zhang, Y. AU - Xia, Z. AU - Ellyin, F. T2 - Mechanics of Advanced Materials and Structures SN - 1537-6494 VL - 20 IS - 10 SP - 801 EP - 810 KW - Angle ply laminate KW - damage KW - Material non-linearity KW - Mesomechanics KW - Nonlinear viscoelastic material KW - Numerical results KW - Periodic boundary conditions KW - Smeared crack KW - Boundary conditions KW - Composite materials KW - Cracks KW - Finite element method KW - Three dimensional KW - Viscoelasticity KW - Laminates AB - A 3D two-cell representation of laminates with periodic fiber arrays is established and the corresponding periodic boundary conditions are presented. The matrix is described by a nonlinear viscoelastic material model and the fiber by an elastic one. Matrix cracking is modeled by a "smeared crack" method. The modeling of material nonlinearity, crack initiation, and growth, with appropriate periodic boundary conditions, are incorporated into a finite element model (FEM). Numerical results for five different angle-ply laminates under tensile loading are presented. The results are found to be in fair agreement with the available test data. © 2013 Taylor and Francis Group, LLC. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e6341277-8c12-419f-9c25-a6131920baa9 ER - TY - JOUR TI - Structure of a sugar N -formyltransferase from campylobacter jejuni DO - 10.1021/bi4009006 AU - Thoden, J.B. AU - Goneau, M.-F. AU - Gilbert, M. AU - Holden, H.M. T2 - Biochemistry SN - 0006-2960 VL - 52 IS - 35 SP - 6114 EP - 6126 KW - Amino acid residues KW - Campylobacter jejuni KW - Carbonyl carbon KW - Catalytic efficiencies KW - Enzymatic activities KW - Gram-negative bacteria KW - Tetrahydrofolates KW - X-ray structure KW - Amino acids KW - Biochemistry KW - Carbon KW - Catalysis KW - Enzymes KW - Bacteria KW - amino acid KW - carbon KW - carbonyl derivative KW - folinic acid KW - galactose KW - glucose KW - histidine KW - n formyltransferase KW - O antigen KW - sugar KW - tetrahydrofolic acid KW - thymidine diphosphate KW - transferase KW - unclassified drug KW - article KW - biosynthesis KW - Campylobacter jejuni KW - catalysis KW - enzyme activity KW - enzyme assay KW - enzyme structure KW - mutation KW - nonhuman KW - outer membrane KW - priority journal KW - X ray AB - The O-antigens, which are components of the outer membranes of Gram-negative bacteria, are responsible for the wide species variations seen in nature and are thought to play a role in bacterial virulence. They often contain unusual dideoxysugars such as 3,6-dideoxy-3-formamido-d-glucose (Qui3NFo). Here, we describe a structural and functional investigation of the protein C8J-1081 from Campylobacter jejuni 81116, which is involved in the biosynthesis of Qui3NFo. Specifically, the enzyme, hereafter referred to as WlaRD, catalyzes the N-formylation of dTDP-3,6-dideoxy-3-amino-d-glucose (dTDP-Qui3N) using N10-formyltetrahydrofolate as the carbon source. For this investigation, seven X-ray structures of WlaRD, in complexes with various dTDP-linked sugars and cofactors, were determined to resolutions of 1.9 Å or better. One of the models, with bound N10-formyltetrahydrofolate and dTDP, represents the first glimpse of an N-formyltransferase with its natural cofactor. Another model contains the reaction products, tetrahydrofolate and dTDP-Qui3NFo. In combination, the structures provide snapshots of the WlaRD active site before and after catalysis. On the basis of these structures, three amino acid residues were targeted for study: Asn 94, His 96, and Asp 132. Mutations of any of these residues resulted in a complete loss of enzymatic activity. Given the position of His 96 in the active site, it can be postulated that it functions as the active site base to remove a proton from the sugar amino group as it attacks the carbonyl carbon of the N-10 formyl group of the cofactor. Enzyme assays demonstrate that WlaRD is also capable of utilizing dTDP-3,6-dideoxy-3-amino-d-galactose (dTDP-Fuc3N) as a substrate, albeit at a much reduced catalytic efficiency. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d5786577-2561-4ca9-919d-573c7d994d4a ER - TY - JOUR TI - Thermochromic and photovoltaic properties of an alternating copolymer of dithieno[3,2-b:2′,3′-d]thiophene and thieno[3,4-c]pyrrole-4,6-dione DO - 10.1002/macp.201200468 AU - Li, Z. AU - Malenfant, P. AU - Tao, Y. AU - Ding, J. T2 - Macromolecular Chemistry and Physics SN - 1022-1352 VL - 214 IS - 4 SP - 447 EP - 452 KW - Alternating copolymer KW - Building blockes KW - Bulk heterojunction KW - Chlorobenzene solution KW - Electron-deficient KW - Electron-donating KW - Electron-rich KW - Electronwithdrawing KW - General designs KW - Main chains KW - Organic solar cell KW - Peak shift KW - Photovoltaic applications KW - Photovoltaic property KW - Polymer main chain KW - Polymer materials KW - Polymer photovoltaics KW - Polymer Solar Cells KW - Power conversion efficiencies KW - Steric effect KW - Steric hindrances KW - Thermo-chromic KW - Thermochromic effects KW - Chemical reactions KW - Conjugated polymers KW - Conversion efficiency KW - Electrons KW - Fluorescence spectroscopy KW - Heterojunctions KW - Solar cells KW - Thiophene KW - Polymer blends AB - The synthesis of a new alternating conjugated polymer, PDTTTPD, based on electron-donating dithieno[3,2-b:2′,3′-d]thiophene (DTT) and electron-withdrawing thieno[3,4-c]pyrrole-4,6-dione (TPD) units is reported. This polymer shows strong thermochromic effect in chlorobenzene with a peak shift up to 170 nm. This phenomenon is studied with fluorescence spectroscopy and related to the steric hindrance along the polymer main chain. Polymer solar cells are fabricated from its blends with PC71BM, and shows modest power conversion efficiency up to 2.1%. The low efficiency is due to the low short-circuit current, which is also attributed to the steric effect. Based on these results, a general design rule for polymer photovoltaic material with controlled backbone conformation is proposed. A new alternating conjugated polymer, PDTTTPD, based on electron-rich dithieno[3,2-b:2′,3′-d] thiophene (DTT) and electron-deficient thieno[3,4-c]pyrrole-4,6-dione (TPD) building blocks is designed and synthesized. PDTTTPD shows strong thermochromic effect in chlorobenzene solution and modest PCE of 2.1% in organic solar cell devices due to the steric hindrance induced twisting of the conjugated main chain. A general design rule is then suggested to control the main chain conformation of polymer materials for photovoltaic applications. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 274551de-d1fe-4570-b5da-ab12e0bae829 ER - TY - JOUR TI - Effect of metal ions on the reactions of the cumyloxyl radical with hydrogen atom donors. Fine control on hydrogen abstraction reactivity determined by Lewis acid-base interactions DO - 10.1021/ja309579t AU - Salamone, M. AU - Mangiacapra, L. AU - Dilabio, G.A. AU - Bietti, M. T2 - Journal of the American Chemical Society SN - 0002-7863 VL - 135 IS - 1 SP - 415 EP - 423 KW - 1 ,4-cyclohexadienes KW - Alkoxyl radicals KW - Carbon-centered radicals KW - Donor ability KW - Donor substrates KW - Heteroatoms KW - Hydrogen abstraction KW - Hydrogen abstraction reaction KW - Hydrogen atoms KW - Lewis acid-base interaction KW - Lewis acidity KW - Lone pair KW - Metal salt KW - Tertiary amine KW - Time-resolved kinetic study KW - Transition state KW - Abstracting KW - Acetonitrile KW - Amines KW - Metal ions KW - Rate constants KW - Substrates KW - Hydrogen KW - 1,4 cyclohexadiene KW - acetonitrile KW - alkoxy radical KW - amine KW - cumyloxyl radical KW - hydrogen KW - inorganic salt KW - Lewis acid KW - Lewis base KW - lithium ion KW - lithium perchlorate KW - magnesium ion KW - magnesium perchlorate KW - metal ion KW - radical KW - sodium ion KW - unclassified drug KW - acid base balance KW - acidity KW - article KW - chemical reaction KW - chemical reaction kinetics KW - concentration response KW - hydrogen bond KW - molecular interaction KW - molecular stability KW - photolysis KW - Alcohols KW - Hydrogen KW - Ions KW - Lewis Acids KW - Lewis Bases KW - Lithium KW - Magnesium KW - Molecular Structure AB - A time-resolved kinetic study on the effect of metal ions (Mn+) on hydrogen abstraction reactions from C-H donor substrates by the cumyloxyl radical (CumO•) was carried out in acetonitrile. Metal salt addition was observed to increase the CumO• β-scission rate constant in the order Li+ > Mg2+ > Na+. These effects were explained in terms of the stabilization of the β-scission transition state determined by Lewis acid-base interactions between Mn+ and the radical. When hydrogen abstraction from 1,4-cyclohexadiene was studied in the presence of LiClO4 and Mg(ClO4)2, a slight increase in rate constant (k H) was observed indicating that interaction between Mn+ and CumO• can also influence, although to a limited extent, the hydrogen abstraction reactivity of alkoxyl radicals. With Lewis basic C-H donors such as THF and tertiary amines, a decrease in kH with increasing Lewis acidity of Mn+ was observed (kH(MeCN) > k H(Li+) > kH(Mg2+)). This behavior was explained in terms of the stronger Lewis acid-base interaction of M n+ with the substrate as compared to the radical. This interaction reduces the degree of overlap between the α-C-H σ* orbital and a heteroatom lone-pair, increasing the C-H BDE and destabilizing the carbon centered radical formed after abstraction. With tertiary amines, a >2-order of magnitude decrease in kH was measured after Mg(ClO 4)2 addition up to a 1.5:1 amine/Mg(ClO4) 2 ratio. At higher amine concentrations, very similar kH values were measured with and without Mg(ClO4)2. These results clearly show that with strong Lewis basic substrates variations in the nature and concentration of Mn+ can dramatically influence k H, allowing for a fine control of the substrate hydrogen atom donor ability, thus providing a convenient method for C-H deactivation. The implications and generality of these findings are discussed. © 2012 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 05285608-318a-4270-98cd-6be420cb26da ER - TY - JOUR TI - Genome mining for new α-Amylase and Glucoamylase encoding sequences and high level expression of a Glucoamylase from Talaromyces stipitatus for potential raw starch hydrolysis DO - 10.1007/s12010-013-0460-3 AU - Xiao, Zhizhuang AU - Wu, Meiqun AU - Grosse, Stephan AU - Beauchemin, Manon AU - Lévesque, Michelle AU - Lau, Peter C. K. T2 - Applied Biochemistry and Biotechnology SN - 0273-2289 VL - 172 IS - 1 SP - 73 EP - 86 KW - Fungal genomes KW - Amylase KW - Glucoamylase KW - Cold starch hydrolysis KW - Genome mining KW - Triticale KW - Potato starch KW - Pichia pastoris KW - Biocatalysts KW - Biorefinery AB - Mining fungal genomes for glucoamylase and α-amylase encoding sequences led to the selection of 23 candidates, two of which (designated TSgam-2 and NFamy-2) were advanced to testing for cooked or raw starch hydrolysis. TSgam-2 is a 66-kDa glucoamylase recombinantly produced in Pichia pastoris and originally derived for Talaromyces stipitatus. When harvested in a 20-L bioreactor at high cell density (OD600 > 200), the secreted TSgam-2 enzyme activity from P. pastoris strain GS115 reached 800 U/mL. In a 6-L working volume of a 10-L fermentation, the TSgam-2 protein yield was estimated to be ∼8 g with a specific activity of 360 U/mg. In contrast, the highest activity of NFamy-2, a 70-kDa α-amylase originally derived from Neosartorya fischeri, and expressed in P. pastoris KM71 only reached 8 U/mL. Both proteins were purified and characterized in terms of pH and temperature optima, kinetic parameters, and thermostability. TSgam-2 was more thermostable than NFamy-2 with a respective half-life (t1/2) of >300 min at 55 °C and >200 min at 40 °C. The kinetic parameters for raw starch adsorption of TSgam-2 and NFamy-2 were also determined. A combination of NFamy-2 and TSgam-2 hydrolyzed cooked potato and triticale starch into glucose with yields, 71-87 %, that are competitive with commercially available α-amylases. In the hydrolysis of raw starch, the best hydrolysis condition was seen with a sequential addition of 40 U of a thermostable Bacillus globigii amylase (BgAmy)/g starch at 80 °C for 16 h, and 40 U TSgam-2/g starch at 45 °C for 24 h. The glucose released was 8.7 g/10 g of triticale starch and 7.9 g/10 g of potato starch, representing 95 and 86 % of starch degradation rate, respectively. © 2013 Her Majesty the Queen in Right of Canada. DA - 2013/09/08 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c86908ed-5c34-4e93-8e1d-a84f9eb53361 ER - TY - JOUR TI - Bilayer molecular electronics: All-carbon electronic junctions containing molecular bilayers made with "click" chemistry DO - 10.1021/ja4065443 AU - Sayed, S.Y. AU - Bayat, A. AU - Kondratenko, M. AU - Leroux, Y. AU - Hapiot, P. AU - McCreery, R.L. T2 - Journal of the American Chemical Society SN - 0002-7863 VL - 135 IS - 35 SP - 12972 EP - 12975 KW - Click reaction KW - Current voltage KW - Diazonium reduction KW - Electronic junctions KW - Molecular junction KW - Redox-active KW - Reproducibilities KW - Top contact KW - Molecules KW - Carbon KW - alkane derivative KW - alkyne derivative KW - carbon KW - diazonium compound KW - article KW - bilayer membrane KW - chemical structure KW - click chemistry KW - molecular electronics KW - molecule KW - oxidation reduction reaction KW - reduction AB - Bilayer molecular junctions were fabricated by using the alkyne/azide "click" reaction on a carbon substrate, followed by deposition of a carbon top contact in a crossbar configuration. The click reaction on an alkyne layer formed by diazonium reduction permitted incorporation of a range of molecules into the resulting bilayer, including alkane, aromatic, and redox-active molecules, with high yield (>90%) and good reproducibility. Detailed characterization of the current-voltage behavior of bilayer molecular junctions indicated that charge transport is consistent with tunneling, but that the effective barrier does not strongly vary with molecular structure for the series of molecules studied. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 61bb708f-c20b-49e9-83a3-22dc9070ba54 ER - TY - JOUR TI - Stable all-nitrogen metallic salt at terapascal pressures DO - 10.1103/PhysRevLett.111.175502 AU - Sun, J. AU - Martinez-Canales, M. AU - Klug, D.D. AU - Pickard, C.J. AU - Needs, R.J. T2 - Physical Review Letters SN - 0031-9007 VL - 111 IS - 17 SP - 175502 KW - Ab initio molecular dynamics simulation KW - Equation of state KW - Extreme conditions KW - Fundamental physics KW - Layered Structures KW - Modulated structures KW - P-T phase diagram KW - Phonon calculation KW - Calculations KW - Equations of state KW - High pressure engineering KW - Molecular dynamics KW - Phase diagrams KW - Nitrogen AB - The phase diagram and equation of state of dense nitrogen are of interest in understanding the fundamental physics and chemistry under extreme conditions, including planetary processes, and in discovering new materials. We predict several stable phases of nitrogen at multi-TPa pressures, including a P4/nbm structure consisting of partially charged N2δ+ pairs and N5δ- tetrahedra, which is stable in the range 2.5-6.8 TPa. This is followed by a modulated layered structure between 6.8 and 12.6 TPa, which also exhibits a significant charge transfer. The P4/nbm metallic nitrogen salt and the modulated structure are stable at high pressures and temperatures, and they exhibit strongly ionic features and charge density distortions, which is unexpected in an element under such extreme conditions and could represent a new class of nitrogen materials. The P-T phase diagram of nitrogen at TPa pressures is investigated using quasiharmonic phonon calculations and ab initio molecular dynamics simulations. © 2013 American Physical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2ff980be-33f0-4858-bbb8-ee6fe1f2dda7 ER - TY - JOUR TI - Finite element-based modeling of machining-induced residual stresses in Ti-6Al-4V under finish turning conditions DO - 10.1016/j.procir.2013.06.066 AU - Abboud, E. AU - Shi, B. AU - Attia, H. AU - Thomson, V. AU - Mebrahtu, Y. T2 - Procedia CIRP T3 - 14th CIRP Conference on Modeling of Machining Operations, CIRP CMMO 2013, 13 June 2013 through 14 June 2013, Turin SN - 2212-8271 VL - 8 SP - 63 EP - 68 KW - Cutting speed KW - Edge radius KW - FE modeling KW - Feed-rates KW - Finite-element predictions KW - Numerical investigations KW - Surface residual stress KW - Surface temperatures KW - Atmospheric temperature KW - Cutting KW - Cutting tools KW - Finite element method KW - Machining centers KW - Titanium KW - Titanium alloys KW - Turning KW - X ray diffraction KW - Residual stresses AB - Residual stresses (RS) imparted during the finishing stages of machining constitute an essential measure of surface integrity and an acceptance criterion for the safety of critical aerospace parts. To build a predictive tool for machining-induced residual stresses in titanium alloy Ti-6Al-4V, a finite element-based model of orthogonal cutting is developed using DEFORM-2D. A full factorial orthogonal cutting experiment is conducted using sharp tools to investigate the effect of feed rate (f) and cutting speed (v) on residual stresses under finish-turning conditions. For every cutting condition, machining forces are measured using a piezoelectric dynamometer, surface temperatures in the vicinity of the cutting zone are captured with an infra-red camera, and surface residual stresses in the cutting direction are measured by X-ray diffraction (XRD). Experimental results for forces, temperatures and RS are used to validate the finite element model. Once a high confidence level in finite element predictions is obtained, a numerical investigation of the effects of cutting tool edge radius (r) and cutting speed on RS is carried out. Within the investigated range of parameters, residual stresses are found to be compressive in nature. It is observed that residual stresses become more compressive with increasing feed rate and less compressive with increasing edge radius or cutting speed. Copyright © 2013 Elsevier B.V. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : cd1daa59-1f03-4303-bc56-8f472fad4405 ER - TY - JOUR TI - Translational biomarker discovery in clinical metabolomics: An introductory tutorial DO - 10.1007/s11306-012-0482-9 AU - Xia, J. AU - Broadhurst, D.I. AU - Wilson, M. AU - Wishart, D.S. T2 - Metabolomics SN - 1573-3882 VL - 9 IS - 2 SP - 280 EP - 299 KW - acylcarnitine KW - amino acid KW - biological marker KW - prostate specific antigen KW - analytic method KW - analytical parameters KW - article KW - bioinformatics KW - clinical chemistry KW - clinical practice KW - computer program KW - confidence interval KW - data processing KW - diagnostic test KW - discriminant analysis KW - gold standard KW - heart disease KW - human KW - inborn error of metabolism KW - intermethod comparison KW - machine learning KW - malignant neoplastic disease KW - mathematical computing KW - metabolite KW - metabolomics KW - neurologic disease KW - newborn screening KW - partial least squares regression KW - predictive value KW - principal component analysis KW - process development KW - process model KW - process optimization KW - prognosis KW - protein analysis KW - protein blood level KW - protein function KW - protein processing KW - protein secretion KW - receiver operating characteristic KW - reliability KW - risk assessment KW - sample size KW - screening test KW - sensitivity and specificity KW - standard KW - statistical analysis KW - validation process AB - Metabolomics is increasingly being applied towards the identification of biomarkers for disease diagnosis, prognosis and risk prediction. Unfortunately among the many published metabolomic studies focusing on biomarker discovery, there is very little consistency and relatively little rigor in how researchers select, assess or report their candidate biomarkers. In particular, few studies report any measure of sensitivity, specificity, or provide receiver operator characteristic (ROC) curves with associated confidence intervals. Even fewer studies explicitly describe or release the biomarker model used to generate their ROC curves. This is surprising given that for biomarker studies in most other biomedical fields, ROC curve analysis is generally considered the standard method for performance assessment. Because the ultimate goal of biomarker discovery is the translation of those biomarkers to clinical practice, it is clear that the metabolomics community needs to start "speaking the same language" in terms of biomarker analysis and reporting-especially if it wants to see metabolite markers being routinely used in the clinic. In this tutorial, we will first introduce the concept of ROC curves and describe their use in single biomarker analysis for clinical chemistry. This includes the construction of ROC curves, understanding the meaning of area under ROC curves (AUC) and partial AUC, as well as the calculation of confidence intervals. The second part of the tutorial focuses on biomarker analyses within the context of metabolomics. This section describes different statistical and machine learning strategies that can be used to create multi-metabolite biomarker models and explains how these models can be assessed using ROC curves. In the third part of the tutorial we discuss common issues and potential pitfalls associated with different analysis methods and provide readers with a list of nine recommendations for biomarker analysis and reporting. To help readers test, visualize and explore the concepts presented in this tutorial, we also introduce a web-based tool called ROCCET (ROC Curve Explorer & Tester, http://www. roccet. ca). ROCCET was originally developed as a teaching aid but it can also serve as a training and testing resource to assist metabolomics researchers build biomarker models and conduct a range of common ROC curve analyses for biomarker studies. © 2012 The Author(s). DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5dcc16ab-ed71-4b75-8adb-a720da50580e ER - TY - JOUR TI - Immunogenic and protective properties of GP5 and M structural proteins of porcine reproductive and respiratory syndrome virus expressed from replicating but nondisseminating adenovectors DO - 10.1186/1297-9716-44-17 AU - Roques, E. AU - Girard, A. AU - St-Louis, M.-C. AU - Massie, B. AU - Gagnon, C.A. AU - Lessard, M. AU - Archambault, D. T2 - Veterinary Research SN - 0928-4249 VL - 44 IS - 1 SP - 17 KW - Arterivirus KW - Porcine respiratory and reproductive syndrome virus KW - Suidae KW - Sus AB - Porcine reproductive and respiratory syndrome virus (PRRSV) is responsible for significant economic losses in the porcine industry. Currently available commercial vaccines do not allow optimal and safe protection. In this study, replicating but nondisseminating adenovectors (rAdV) were used for the first time in pigs for vaccinal purposes. They were expressing the PRRSV matrix M protein in fusion with either the envelope GP5 wild-type protein (M-GP5) which carries the major neutralizing antibody (NAb)-inducing epitope or a mutant form of GP5 (M-GP5m) developed to theoretically increase the NAb immune response. Three groups of fourteen piglets were immunized both intramuscularly and intranasally at 3-week intervals with rAdV expressing the green fluorescent protein (GFP, used as a negative control), M-GP5 or M-GP5m. Two additional groups of pigs were primed with M-GP5m-expressing rAdV followed by a boost with bacterially-expressed recombinant wild-type GP5 or were immunized twice with a PRRSV inactivated commercial vaccine. The results show that the rAdV expressing the fusion proteins of interest induced systemic and mucosal PRRSV GP5-specific antibody response as determined in an ELISA. Moreover the prime with M-GP5m-expressing rAdV and boost with recombinant GP5 showed the highest antibody response against GP5. Following PRRSV experimental challenge, pigs immunized twice with rAdV expressing either M-GP5 or M-GP5m developed partial protection as shown by a decrease in viremia overtime. The lowest viremia levels and/or percentages of macroscopic lung lesions were obtained in pigs immunized twice with either the rAdV expressing M-GP5m or the PRRSV inactivated commercial vaccine. © 2013 Roques et al.; licensee BioMed Central Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1144b022-eced-4e81-b1f1-4180ad1d6795 ER - TY - JOUR TI - Recent star formation in the Lupus clouds as seen by Herschel DO - 10.1051/0004-6361/201219511 AU - Rygl, K.L.J. AU - Benedettini, M. AU - Schisano, E. AU - Elia, D. AU - Molinari, S. AU - Pezzuto, S. AU - André, Ph. AU - Bernard, J.P. AU - White, G.J. AU - Polychroni, D. AU - Bontemps, S. AU - Cox, N.L.J. AU - Di Francesco, J. AU - Facchini, A. AU - Fallscheer, C. AU - Di Giorgio, A.M. AU - Hennemann, M. AU - Hill, T. AU - Könyves, V. AU - Minier, V. AU - Motte, F. AU - Nguyen-Luong, Q. AU - Peretto, N. AU - Pestalozzi, M. AU - Sadavoy, S. AU - Schneider, N. AU - Spinoglio, L. AU - Testi, L. AU - Ward-Thompson, D. T2 - Astronomy and Astrophysics SN - 0004-6361 VL - 549 SP - L1 KW - Gould belt KW - HERSCHEL KW - Infrared: ISM KW - ISM: individual objects KW - Pre-main sequences KW - Spitzer KW - Star formation rates KW - Star formations KW - Stars: formation KW - Stars: protostars KW - Young stellar objects KW - Surveys KW - Stars AB - We present a study of the star formation histories of the Lupus I, III, and IV clouds using the Herschel 70-500μm maps obtained by the Herschel Gould Belt Survey Key Project. By combining the new Herschel data with the existing Spitzer catalog we obtained an unprecedented census of prestellar sources and young stellar objects in the Lupus clouds, which allowed us to study the overall star formation rate (SFR) and efficiency (SFE). The high SFE of Lupus III, its decreasing SFR, and its large number of pre-main sequence stars with respect to proto-and prestellar sources, suggest that Lupus III is the most evolved cloud, and after having experienced a major star formation event in the past, is now approaching the end of its current star-forming cycle. Lupus I is currently undergoing a large star formation event, apparent by the increasing SFR, the large number of prestellar objects with respect to more evolved objects, and the high percentage of material at high extinction (e.g., above AVA ≈ A 8A mag). Also Lupus IV has an increasing SFR; however, the relative number of prestellar sources is much lower, suggesting that its star formation has not yet reached its peak. © 2012 ESO. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5407bcde-8f7f-4707-9b43-61ec094d9493 ER - TY - JOUR TI - Altered network communication following a neuroprotective drug treatment DO - 10.1371/journal.pone.0054478 AU - Vincent, K. AU - Tauskela, J.S. AU - Mealing, G.A. AU - Thivierge, J.-P. T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 1 SP - e54478 KW - neuroprotective agent KW - animal cell KW - animal tissue KW - article KW - brain cell KW - brain function KW - brain mapping KW - cell density KW - controlled study KW - drug mechanism KW - extracellular space KW - in vitro study KW - ischemic preconditioning KW - nerve cell network KW - nonhuman KW - rat KW - reaction time KW - synaptic transmission KW - theoretical study KW - 4-Aminopyridine KW - Animals KW - Bicuculline KW - Brain KW - Brain Mapping KW - Electroencephalography KW - Nerve Net KW - Neural Pathways KW - Neurons KW - Neuroprotective Agents KW - Rats KW - Rattus AB - Preconditioning is defined as a range of stimuli that allow cells to withstand subsequent anaerobic and other deleterious conditions. While cell protection under preconditioning is well established, this paper investigates the influence of neuroprotective preconditioning drugs, 4-aminopyridine and bicuculline (4-AP/bic), on synaptic communication across a broad network of in vitro rat cortical neurons. Using a permutation test, we evaluated cross-correlations of extracellular spiking activity across all pairs of recording electrodes on a 64-channel multielectrode array. The resulting functional connectivity maps were analyzed in terms of their graph-theoretic properties. A small-world effect was found, characterized by a functional network with high clustering coefficient and short average path length. Twenty-four hours after exposure to 4-AP/bic, small-world properties were comparable to control cultures that were not treated with the drug. Four hours following drug washout, however, the density of functional connections increased, while path length decreased and clustering coefficient increased. These alterations in functional connectivity were maintained at four days post-washout, suggesting that 4-AP/bic preconditioning leads to long-term effects on functional networks of cortical neurons. Because of their influence on communication efficiency in neuronal networks, alterations in small-world properties hold implications for information processing in brain systems. The observed relationship between density, path length, and clustering coefficient is captured by a phenomenological model where connections are added randomly within a spatially-embedded network. Taken together, results provide information regarding functional consequences of drug therapies that are overlooked in traditional viability studies and present the first investigation of functional networks under neuroprotective preconditioning. © 2013 Vincent et al. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a38f723d-d0ec-4882-8b8b-e0e0105df631 ER - TY - JOUR TI - Solid-state transformation of iron-rich intermetallic phases in Al-Cu 206 cast alloys during solution heat treatment DO - 10.1007/s11661-013-1726-7 AU - Liu, K. AU - Cao, X. AU - Chen, X.-G. T2 - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science SN - 1073-5623 VL - 44 IS - 8 SP - 3494 EP - 3503 KW - Chinese script KW - D. transmission electron microscopes (TEM) KW - Differential scanning calorimeters KW - Electron back-scattered diffraction KW - Intermetallic phasis KW - Normal solutions KW - Solid state transformations KW - Solution heat treatment KW - Alloys KW - Aluminum KW - Cast iron KW - Copper alloys KW - Differential scanning calorimetry KW - Heat treatment KW - Scanning electron microscopy KW - Transmission electron microscopy KW - Iron alloys AB - The solid-state transformation of the iron-rich intermetallic phases in Al-Cu 206 cast alloys during the solution heat treatment was studied by using Scanning Electron Microscope (SEM), Electron Back Scattered Diffraction (EBSD), Differential Scanning Calorimeter (DSC), and Transmission Electron Microscope (TEM). At a normal solution treatment temperature of 793 K (520 C), no visible variation is observed for the β-Fe phase solidified from the Al alloy melt. With increasing soaking time, however, the Chinese script α-Fe becomes unstable and progressively transforms into platelet β-Fe, termed as solid-state-transformed (STed) β-Fe to distinguish it from the β-Fe directly solidified from the Al alloy melt. The STed β-Fe preferentially nucleates on the α-Fe and then grows from the α-Fe/Al interface into α-Fe and/or Al matrix with a much higher growth rate in the α-Fe. The incomplete solid-state transformation from α-Fe into STed β-Fe leads to the fragmentation of the α-Fe. The formation of the STed β-Fe with increasing size and volume fraction after longer soaking time can deteriorate the tensile properties. © 2013 The Minerals, Metals & Materials Society and ASM International. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 24c2cc69-87ea-4454-977a-45074c82f440 ER - TY - JOUR TI - Intrinsic role of FoxO3a in the development of CD8+ T Cell memory DO - 10.4049/jimmunol.1200639 AU - Tzelepis, F. AU - Joseph, J. AU - Haddad, E.K. AU - MacLean, S. AU - Dudani, R. AU - Agenes, F. AU - Peng, S.L. AU - Sekaly, R.-P. AU - Sad, S. T2 - Journal of Immunology SN - 0022-1767 VL - 190 IS - 3 SP - 1066 EP - 1075 KW - actin KW - BIM protein KW - cytokine KW - lysosome associated membrane protein 1 KW - protein Bid KW - PUMA protein KW - RAG1 protein KW - transcription factor FKHRL1 KW - animal cell KW - animal experiment KW - animal model KW - antigen presentation KW - apoptosis KW - article KW - CD8+ T lymphocyte KW - cell expansion KW - cell survival KW - controlled study KW - cytokine release KW - degranulation KW - effector cell KW - female KW - listeriosis KW - lymphocyte function KW - memory T lymphocyte KW - mouse KW - nonhuman KW - pre T lymphocyte KW - priority journal KW - protein analysis KW - protein deficiency KW - protein expression KW - protein function KW - wild type KW - Animals KW - Antigen Presentation KW - Antigens, Bacterial KW - Apoptosis KW - Apoptosis Regulatory Proteins KW - CD8-Positive T-Lymphocytes KW - Cytokines KW - Cytotoxicity, Immunologic KW - Female KW - Forkhead Transcription Factors KW - Homeodomain Proteins KW - Immunologic Memory KW - L-Selectin KW - Listeria monocytogenes KW - Listeriosis KW - Lymphocyte Activation KW - Lymphocyte Subsets KW - Lymphokines KW - Lysosome-Associated Membrane Glycoproteins KW - Membrane Proteins KW - Mice KW - Mice, Inbred C57BL KW - Ovalbumin KW - Proto-Oncogene Proteins KW - Receptors, Interleukin-7 KW - Tumor Suppressor Proteins AB - CD8+ T cells undergo rapid expansion during infection with intracellular pathogens, which is followed by swift and massive culling of primed CD8+ T cells. The mechanisms that govern the massive contraction and maintenance of primed CD8+ T cells are not clear. We show in this study that the transcription factor, FoxO3a, does not influence Ag presentation and the consequent expansion of CD8+ T cell response during Listeria monocytogenes infection, but plays a key role in the maintenance of memory CD8+ T cells. The effector function of primed CD8+ T cells as revealed by cytokine secretion and CD107a degranulation was not influenced by inactivation of FoxO3a. Interestingly, FoxO3a-deficient CD8+ T cells displayed reduced expression of proapoptotic molecules BIM and PUMA during the various phases of response, and underwent reduced apoptosis in comparison with wild-type cells. A higher number of memory precursor effector cells and memory subsets was detectable in FoxO3a-deficient mice compared with wild-type mice. Furthermore, FoxO3a-deficient memory CD8+ T cells upon transfer into normal or RAG1-deficient mice displayed enhanced survival. These results suggest that FoxO3a acts in a cell-intrinsic manner to regulate the survival of primed CD8+ T cells. Copyright © 2013 by The American Association of Immunologists, Inc. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 7abb551f-c5ff-42ba-8b21-d9f8088bf917 ER - TY - JOUR TI - Stiction-free fabrication of lithographic nanostructures on resist-supported nanomechanical resonators DO - 10.1116/1.4821194 AU - Diao, Z. AU - Losby, J.E. AU - Burgess, J.A.J. AU - Sauer, V.T.K. AU - Hiebert, W.K. AU - Freeman, M.R. T2 - Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures SN - 1071-1023 VL - 31 IS - 5 SP - 51805 KW - Electron beam patterning KW - Fabrication process KW - Hydrofluoric acid etching KW - Nanomechanical device KW - Nanomechanical resonators KW - Silicon-on-insulator substrates KW - Surface micromachined structure KW - Wide temperature ranges KW - Hydrofluoric acid KW - Magnetic moments KW - Magnetostatics KW - Nanostructures KW - Resonators KW - Thermomechanical treatment KW - Fabrication AB - The authors report a highly flexible process for nanostructure lithography to incorporate specific functions in micro- and nanomechanical devices. The unique step involves electron beam patterning on top of released, resist-supported, surface micromachined structures, hence avoiding hydrofluoric acid etching of sensitive materials during the device release. The authors demonstrate the process by creating large arrays of nanomechanical torque magnetometers on silicon-on-insulator substrates. The fabricated devices show a thermomechanical noise-limited magnetic moment sensitivity in the range of 5 × 106 μB at room temperature and can be utilized to study both magnetostatics and dynamics in nanomagnets across a wide temperature range. The fabrication process can be generalized for the deposition and patterning of a wide range of materials on micro-/nanomechanical resonators. © 2013 Crown. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 98c5f1ee-742d-4bdc-9274-bb6dbc13c901 ER - TY - JOUR TI - Clathrin- and arp2/3-independent endocytosis in the fungal pathogen Candida albicans DO - 10.1128/mBio.00476-13 AU - Epp, E. AU - Nazarova, E. AU - Regan, H. AU - Douglas, L.M. AU - Konopka, J.B. AU - Vogel, J. AU - Whiteway, M. T2 - mBio SN - 2161-2129 VL - 4 IS - 5 SP - e00476-13 AB - Clathrin-mediated endocytosis (CME) is conserved among eukaryotes and has been extensively analyzed at a molecular level. Here, we present an analysis of CME in the human fungal pathogen Candida albicans that shows the same modular structure as those in other fungi and mammalian cells. Intriguingly, C. albicans is perfectly viable in the absence of Arp2/3, an essential component of CME in other systems. In C. albicans, Arp2/3 function remains essential for CME as all 15 proteins tested that participate in CME, including clathrin, lose their characteristic dynamics observed in wild-type (WT) cells. However, since arp2/3 cells are still able to endocytose lipids and fluid-phase markers, but not the Ste2 and Mup1 plasma membrane proteins, there must be an alternate clathrin-independent pathway we term Arp2/3-independent endocytosis (AIE). Characterization of AIE shows that endocytosis in arp2 mutants relies on actin cables and other Arp2/3-independent actin structures, as inhibition of actin functions prevented cargo uptake in arp2/3 mutants. Transmission electron microscopy (TEM) showed that arp2/3 mutants still formed invaginating tubules, cell structures whose proper functions are believed to heavily rely on Arp2/3. Finally, Prk1 and Sjl2, two proteins involved in patch disassembly during CME, were not correctly localized to sites of endocytosis in arp2 mutants, implying a role of Arp2/3 in CME patch disassembly. Overall, C. albicans contains an alternative endocytic pathway (AIE) that relies on actin cable function to permit clathrin-independent endocytosis (CIE) and provides a system to further explore alternate endocytic routes that likely exist in fungal species. © 2013 Epp et al. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : bbb3afb1-df72-4c28-8b12-a4204ad07654 ER - TY - JOUR TI - Synthesis, characterization and evaluation of unsupported porous NiS 2 sub-micrometer spheres as a potential hydrodesulfurization catalyst DO - 10.1016/j.apcata.2012.10.030 AU - Mondal, D. AU - Villemure, G. AU - Li, G. AU - Song, C. AU - Zhang, J. AU - Hui, R. AU - Chen, J. AU - Fairbridge, C. T2 - Applied Catalysis A: General SN - 0926-860X VL - 450 SP - 230 EP - 236 KW - Adsorption/desorption KW - Colloidal silica KW - Dibenzothiophenes KW - Direct synthesis KW - Energy dispersive X ray spectroscopy KW - First-order reaction rate constant KW - HDS of DBT KW - Hydrodesulfurization catalysts KW - Model compound KW - Nano-structured KW - Porous structures KW - Silica removal KW - Single phase KW - Single-step KW - Special properties KW - Submicrometers KW - Surface area KW - Ultrasonic spray pyrolysis KW - XRD KW - Rate constants KW - Scanning electron microscopy KW - Silica KW - Spray pyrolysis KW - Transmission electron microscopy KW - X ray diffraction KW - X ray spectroscopy KW - Hydrodesulfurization AB - Nanostructured NiS2 has attracted interest due to its wide applications and special properties. Synthesis of a pure phase NiS2 in a single step has been a challenge. In this work, a new method for direct synthesis of uniform NiS2/SiO2 sub microspheres has been developed by ultrasonic spray pyrolysis. Colloidal silica was used as a sacrificial template to create the porous structure. After silica removal, hollow, porous NiS2 nano spheres were obtained. The product was characterized by using scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction (XRD), transmission electron microscopy and N2 adsorption/desorption isotherm. XRD confirmed the formation of single phase pyrite NiS2. It was found that the porous spherical NiS2 has a surface area of ca. 300 m2 g-1. The HDS catalytic activity of NiS2 was evaluated using a model compound, dibenzothiophene (DBT). It showed a first order reaction rate constant of 1.51 × 10-4 s-1 g cata-1 at 320 °C for HDS of DBT, which is significantly promising for further exploration. © 2012 Published by Elsevier B.V. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a7832f6f-46bb-46fc-ad12-8f516fe2ded6 ER - TY - JOUR TI - Microstructure and hardness of fiber laser deposited Inconel 718 using filler wire DO - 10.1007/s00170-013-5171-y AU - Zhang, Y.N. AU - Cao, X. AU - Wanjara, P. T2 - International Journal of Advanced Manufacturing Technology SN - 0268-3768 SP - 1 EP - 13 AB - A continuous wave 5 kW fiber laser welding system was used to deposit INCONEL® alloy 718 (IN718) layers in conduction mode by applying filler wire with a composition similar to the parent metal, which was extracted directly from a scrapped, service-exposed IN718 aerospace component. The quality of the deposits was characterized in both the as-deposited and fully heat-treated conditions in terms of the macrostructure, defects, microstructure, and hardness. Integral deposits with no visible porosity were obtained using the fiber laser deposition technique. In the as-deposited clad zone, weld metal liquation cracking led to the presence of minor microcracks in the lower layer beads near the layer interface. The crack healing behavior observed after post-clad heat treatment of the IN718 deposits supports the marked potential of using the laser deposition technique by filler wire addition to manufacture and repair/remanufacture superalloy components for aerospace applications. © 2013 Her Majesty the Queen in Right of Canada as represented by: National Research Council Canada. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0239ee87-07dd-4a93-9523-84b03132045b ER - TY - JOUR TI - Spring wheat yield in the semiarid Canadian prairies: Effects of precipitation timing and soil texture over recent 30 years DO - 10.1016/j.fcr.2013.05.013 AU - He, Y. AU - Wei, Y. AU - DePauw, R. AU - Qian, B. AU - Lemke, R. AU - Singh, A. AU - Cuthbert, R. AU - McConkey, B. AU - Wang, H. T2 - Field Crops Research SN - 0378-4290 VL - 149 SP - 329 EP - 337 KW - clay soil KW - crop production KW - crop yield KW - drought resistance KW - growing season KW - prairie KW - precipitation (climatology) KW - semiarid region KW - soil texture KW - soil water KW - wheat KW - Canada KW - Triticum aestivum AB - The large year-to-year and site-to-site variation in wheat production on rain-fed semiarid areas of the Canadian prairies is mainly due to the timing and amount of precipitation and soil water holding capacity. Here, we identify the critical periods of growing season precipitation on wheat yield and then utilize this information to analyze which type of soil texture had higher drought resistance and higher grain yield when precipitation was more than sufficient. Thirty years (1982-2011) of grain yield data on two sites located in the same rain-fed area with different soil texture types were used in our analysis. To seek the critical periods of precipitation on yield, correlation over the whole growing season between precipitation and yield was first analyzed. By doing this, we calculated not only when the precipitation occurs that was most related to yield but also the duration of this period. To further understand these cause-and-effect interrelationships, a modern version of path analysis - Structural Equation Modeling (SEM) was used. The result of SEM was satisfactory since 67% of yield variation can be explained by only 3 exogenous variables (early and late precipitation and fertilizer N) and 2 intermediate variables (thousand kernel weight and kernel nitrogen concentration). Results showed that early precipitation (from seeding to anthesis) was most critical for high grain yield in our study area. Clay soil has a higher drought tolerance efficiency and lower drought susceptibility index. Grain yield was higher on the clay soil than on the silt loam soil in most dry and wet years. We conclude that early precipitation had a deterministic effect on grain yield. The clay soil has a more stable yield under current fertilizer rates and the climate conditions in our study area. These results may lead to a better understanding of the crop-environmental interactions enabling breeders to analyze their experimental trials with regard to the broad environments that they target. © 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : df7435dc-477b-4fdf-b9f8-e1a0092abc34 ER - TY - JOUR TI - Derivation and new analysis of a hydrodynamic model of speed skate ice friction AU - Lozowski, E.P. AU - Szilder, K. T2 - International Journal of Offshore and Polar Engineering SN - 1053-5381 VL - 23 IS - 2 SP - 104 EP - 111 KW - Hydrodynamic friction KW - Hydrodynamic model KW - Lubrication equation KW - Mathematical derivation KW - Mutatis-mutandis KW - Physical variables KW - Theory KW - Thermohydrodynamics KW - Fluid dynamics KW - Friction KW - Ice KW - Models KW - Physics KW - Sensitivity analysis KW - Tribology KW - Recreational facilities KW - friction KW - hydrodynamics KW - ice KW - measurement method KW - numerical model KW - sensitivity analysis KW - theoretical study KW - thermodynamics AB - This paper presents the mathematical derivation of a new model of speed skate ice friction. The model acronym is FAST, which stands for friction algorithm using speed skate thermohydrodynamics. Mutatis mutandis, it is applicable to other ice friction problems in the hydrodynamic friction regime. This paper updates and corrects an earlier publication of the model that omitted the full derivation of the lubrication equation (Penny et al., 2007). It also updates the ice hardness equation based on new measurements, and it presents a more thorough exploration of the model results and its sensitivity to the variation of physical variables. © by The International Society of Offshore and Polar Engineers. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2baf3ef6-24c5-40a6-bc40-1016b30a853f ER - TY - JOUR TI - Formation and phase selection of iron-rich intermetallics in Al-4.6Cu-0.5Fe cast alloys DO - 10.1007/s11661-012-1419-7 AU - Liu, K. AU - Cao, X. AU - Chen, X.-G. T2 - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science SN - 1073-5623 VL - 44 IS - 2 SP - 682 EP - 695 KW - Alloy compositions KW - Chinese script KW - Cooling rates KW - Electron back-scattered diffraction KW - Industrial casting KW - Phase selection KW - Solidification sequence KW - Solidification structure KW - Aluminum KW - Cast iron KW - Cerium alloys KW - Cooling KW - Copper alloys KW - Differential scanning calorimetry KW - Iron KW - Iron alloys KW - Manganese KW - Silicon KW - Solidification KW - Transmission electron microscopy KW - Intermetallics AB - The solidification structures of Al-Cu 206 cast alloys at a high iron level of 0.5 pct were systematically studied by means of differential scanning calorimetry, electron backscattered diffraction, and transmission electron microscopy. The full solidification sequences of the 206 cast alloys at 0.5 pct Fe were established. The influences of both alloy composition (i.e., Si and Mn contents) and cooling rate on the formation and phase selection of the iron-rich intermetallics have been systematically explored. At a cooling rate of 12 K/min, it was found that one of the three iron-rich phases, i.e., Chinese script Alm(FeMn) and α-Fe, or platelet Al3(FeMn), may precipitate as the dominant iron-rich intermetallic, depending on Si and Mn contents. However, the dominant Chinese script iron-rich intermetallics, Al m(FeMn) and/or α-Fe, can be fully obtained for the 206 Al-Cu cast alloys at 0.5 pct Fe above a threshold cooling rate that can easily be obtained in normal industrial casting conditions, indicating that there is a significant potential of designing and developing new 206 Al-Cu cast alloys with a high tolerant iron content. © 2012 Reprinted with permission of Her Majesty the Queen in Right of Canada, as represented by the Minister of Natural Resources. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a2d466db-9117-48ac-a257-716d413f6891 ER - TY - JOUR TI - Perturbing the metabolic dynamics of myo-inositol in developing Brassica napus seeds through in vivo methylation impacts its utilization as phytate precursor and affects downstream metabolic pathways DO - 10.1186/1471-2229-13-84 AU - Dong, J. AU - Yan, W. AU - Bock, C. AU - Nokhrina, K. AU - Keller, W. AU - Georges, F. T2 - BMC Plant Biology SN - 1471-2229 VL - 13 IS - 1 SP - 84 KW - Animalia KW - Brassica napus KW - Brassica napus var. napus KW - Mesembryanthemum KW - Mesembryanthemum crystallinum KW - inositol KW - phytic acid KW - article KW - germination KW - growth, development and aging KW - metabolism KW - methylation KW - plant seed KW - rapeseed KW - Brassica napus KW - Germination KW - Inositol KW - Metabolic Networks and Pathways KW - Methylation KW - Phytic Acid KW - Seeds AB - Background: myo-Inositol (Ins) metabolism during early stages of seed development plays an important role in determining the distributional relationships of some seed storage components such as the antinutritional factors, sucrose galactosides (also known as raffinose oligosaccharides) and phytic acid (PhA) (myo-inositol 1,2,3,4,5,6-hexakisphosphate). The former is a group of oligosaccharides, which plays a role in desiccation at seed maturation. They are not easily digested by monogastric animals, hence their flatulence-causing properties. Phytic acid is highly negatively charged, which chelates positive ions of essential minerals and decreases their bioavailability. It is also a major cause of phosphate-related water pollution. Our aim was to investigate the influence of competitive diversion of Ins as common substrate on the biosynthesis of phytate and sucrose galactosides. Results: We have studied the initial metabolic patterns of Ins in developing seeds of Brassica napus and determined that early stages of seed development are marked by rapid deployment of Ins into a variety of pathways, dominated by interconversion of polar (Ins phosphates) and non-polar (phospholipids) species. In a time course experiment at early stages of seed development, we show Ins to be a highly significant constituent of the endosperm and seed coat, but with no phytate biosynthesis occurring in either tissue. Phytate accumulation appears to be confined mainly within the embryo throughout seed development and maturation. In our approach, the gene for myo-inositol methyltransferase (IMT), isolated from Mesembryanthemum crystallinum (ice plant), was transferred to B. napus under the control of the seed-specific promoters, napin and phaseolin. Introduction of this new metabolic step during seed development prompted Ins conversion to the corresponding monomethyl ether, ononitol, and affected phytate accumulation. We were able to produce homozygous transgenic lines with 19% - 35% average phytate reduction. Additionally, changes in the raffinose content and related sugars occurred along with enhanced sucrose levels. Germination rates, viability and other seed parameters were unaffected by the IMT transgene over-expression. Conclusions: Competitive methylation of Ins during seed development reduces seed antinutritional components and enhances its nutritional characteristics while maintaining adequate phosphate reserves. Such approach should potentially raise the canola market value and likely, that of other crops. © 2013 Dong et al.; licensee BioMed Central Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 952f9839-0719-43f8-95db-67a231ae27f1 ER - TY - JOUR TI - Towards a physical picture of star formation quenching: The photometric properties of recently quenched galaxies in the sloan digital sky survey DO - 10.1093/mnras/sts489 AU - Mendel, T.J. AU - Simard, L. AU - Ellison, S.L. AU - Patton, D.R. T2 - Monthly Notices of the Royal Astronomical Society SN - 0035-8711 VL - 429 IS - 3 SP - 2212 EP - 2227 AB - We select a sample of young passive galaxies from the Sloan Digital Sky Survey data release 7 in order to study the processes that quench star formation in the local universe. Quenched galaxies are identified based on the contribution of A-type stars to their observed (central) spectra and relative lack of ongoing star formation; we find that such systems account for roughly 2.5 per cent of all galaxies with log(M/M⊙)≥ = 9.5, and have a space density of ~2.2×10-4 Mpc-3.We show that quenched galaxies span a range of morphologies, but visual classifications suggest that they are predominantly early-type systems. Their visual early-type classification is supported by quantitative structural measurements (śersic indices) that show a notable lack of disc-dominated galaxies, suggesting that any morphological transformation associated with galaxies' transition from star forming to passive - e.g. the formation of a stellar bulge - occurs contemporaneously with the decline of their star formation activity. We show that there is no clear excess of optical active galactic nuclei (AGN) in quenched galaxies, suggesting that: (i) AGN feedback is not associated with the majority of quenched systems or (ii) that the observability of quenched galaxies is such that the quenching phase in general outlives any associated nuclear activity. Comparison with classical post-starburst galaxies shows that both populations show similar signatures of bulge growth, and we suggest that the defining characteristic of post-starburst galaxies is the efficiency of their bulge growth rather than a particular formation mechanism. © 2011 The authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a1b269ad-8745-41e5-b536-d8527e3574ad ER - TY - JOUR TI - Effects of heat-treatment and pyridine addition on the catalytic activity of carbon-supported cobalt-phthalocyanine for oxygen reduction reaction in alkaline electrolyte AU - Dai, X. AU - Qiao, J. AU - Zhou, X. AU - Shi, J. AU - Xu, P. AU - Zhang, L. AU - Zhang, J. T2 - International Journal of Electrochemical Science SN - 1452-3981 VL - 8 IS - 3 SP - 3160 EP - 3175 AB - Carbon-supported non-precious metal (cobalt) catalysts, namely Py-CoPc/C, where Py is the pyridine and Pc is the phthalocyanine, are synthesized for oxygen reduction reaction (ORR) using combined solvent-impregnation and high-temperature treatment process. The heat-treatment effect on the catalysts' activity toward ORR is examined using catalysts obtained at 600, 700, 800, and 900°C, respectively. The effect of pyridine addition on the ORR activity is also studied. It is found that the formed Py-CoPc/C catalysts all show the higher ORR activities than that of CoPc/C catalyst, and the catalyst obtained at 700°C treatment gives the best activity for the ORR in 0.1M KOH solution, which are tested using both CV and RDE techniques. XRD, TEM as well as XPS are employed to study the crystal structures, morphologies and surface structure changes of the synthesized Py-CoPc/C catalysts. Both XRD and TEM analysis indicate the formation of different amounts of Co-NX-C active site at different heat-treatment temperatures, which is well correlated with the catalysts' ORR activities. XPS results suggest that the pyridinic-N and graphitic-N groups are both responsible for the enhanced ORR activity, and the catalyst formed at 700°C treatment shows the most amount of these two groups, leading to the most active ORR catalyst. © 2013 by ESG. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 443da1bb-2db4-4553-b5ac-64cef7b8713d ER - TY - JOUR TI - Characteristics of H13 tool steel coatings by pulsed Nd:YAG laser cladding AU - Wang, S. AU - Chen, J. AU - Xue, L. T2 - TMS Annual Meeting T3 - 142nd Annual Meeting and Exhibition: Linking Science and Technology for Global Solutions, TMS 2013, 3 March 2013 through 7 March 2013, San Antonio, TX SN - 9781118605813 SP - 201 EP - 208 KW - Carbon steel substrates KW - Dendritic structures KW - H13 tool steel KW - Hot-work tool steel KW - Phase identification KW - Plastic injection molding KW - Pulsed Nd:YAG laser KW - Tensile residual stress KW - Carbon steel KW - Coatings KW - Die casting KW - Exhibitions KW - Laser cladding KW - Protective coatings KW - Rapid solidification KW - Steel testing KW - Tool steel KW - Tribology KW - Wear resistance KW - X ray diffraction KW - Neodymium lasers AB - AISI H13 hot-work tool steel has a wide application for mold/die of die casting, hot forging, hot extrusion, hot stamping and plastic injection molding, due to its high toughness, high hot hardness and high thermal fatigue resistance. Laser cladding, a material additive technology, can be used to apply various functional coatings and to repair/reconfigure tool/die. H13 tool steel was successfully laser-clad on carbon steel substrates at room temperature. The microstructure of as-clad coating showed a refined dendritic structure due to fast cooling and rapid solidification. X-ray diffraction (XRD) phase identification revealed that the coating consisted of a majority of martensite phase plus certain amount of retained austenite phase (∼ 20 vol%). Tensile residual stresses were measured in the as-clad H13 coating. The average value of Vickers hardness in the as-clad coating is about 575 Hv0.05. Wear resistance evaluation using pin-on-disc sliding wear testing showed that the wear resistance of as-clad H13 steel coating was similar to or slightly better than that of hardened wrought H13 steel (HRC 54) plate under the wear test condition used in this study, but the wear mechanisms are significantly different. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 706518ff-2353-46a1-a381-b5c40c450572 ER - TY - JOUR TI - Phased microphone array measurements of a bombardier aircraft scaled model AU - Syms, G.F. AU - Mamou, M. T2 - 19th AIAA/CEAS Aeroacoustics Conference T3 - 19th AIAA/CEAS Aeroacoustics Conference, 27 May 2013 through 29 May 2013, Berlin SN - 9781624102134 SP - 247 KW - Aerodynamic wind tunnel model KW - Aircraft manufacturers KW - Bombardier aerospaces KW - Calibration procedure KW - Collaborative research KW - Conventional beamforming KW - National Research Council KW - Post-processing procedure KW - Aeroacoustics KW - Aerodynamics KW - Aircraft models KW - Calibration KW - Microphones KW - Acoustic noise AB - Aerodynamic testing of high fidelity models is a standard practice for aircraft manufacturers. With the development of phased microphone array technology, aeroacoustics can become an integral part of the design process of an airplane. In 2012, the National Research Council Canada and Bombardier Aerospace carried out a collaborative research program focusing on measuring the sound generated by a high-fidelity aerodynamic wind tunnel model. The noise of various configurations was measured at combinations of three wind speeds and three microphone array polar orientations above the model. Several calibration reference noise waveforms were explored to determine the most effective in a highly reverberant hard-walled test section. The calibration data analysis showed that meaningful beamform maps above 30kHz could be generated when a pulsed sine wave was applied as the reference noise signal in the calibration process. For the model configurations tested, slat noise dominated the sound maps processed using either conventional beamforming or CLEAN-PSF. The wing flap edge noise as well as the contributions from the main gear were also discernible. For each configuration, one data point was taken while the microphone array was rotating instead of stationary. The computationally intense post-processing procedure for these data provided a detailed map of the sources due to reduced spatial aliasing. The sound levels measured with the rotating array were at a slightly lower magnitude owing to the averaging of the source over its full directivity pattern. Future work includes implementing a calibration procedure for the rotating array and improving the signal-to-noise ratio of the signals so that shorter microphone time histories can be used to extract directivity information from the datasets of the rotating array. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 73e9c373-6af2-442f-9fa6-34af9a3ef0a2 ER - TY - JOUR TI - Hyperfine-structure splitting of the 716 nm R(90)3-10 molecular iodine transition DO - 10.1364/JOSAB.30.001317 AU - Huet, N. AU - Krins, S. AU - Dubé, P. AU - Bastin, T. T2 - Journal of the Optical Society of America B: Optical Physics SN - 0740-3224 VL - 30 IS - 5 SP - 1317 EP - 1321 KW - Atomic species KW - Dispersive signals KW - Experimental values KW - Frequency reference KW - Fully compatible KW - Hyperfine constants KW - Molecular iodine KW - Ti: Sapphire laser KW - Atoms KW - Experiments KW - Laser cooling KW - Iodine AB - We report on the hyperfine-structure splitting of the 716 nm R(90)3-10 molecular iodine transition.We show that this particular iodine line provides a very useful frequency reference in the context of a laser cooling experiment of iron atoms, an atomic species that has so far never been laser cooled and trapped to our knowledge. We provide experimental values for the hyperfine constants ΔeQq and ΔC of the investigated iodine transition. Dispersive signals of this transition are also presented and used to lock the frequency of a Ti:sapphire laser. The reported stabilization performance is fully compatible with the requirements of a laser cooling experiment of iron atoms. © 2013 Optical Society of America. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 07ff2cb9-89b1-42fb-8a05-1e8c12e8be16 ER - TY - JOUR TI - Investigation of a postprocessing method to tailor the mechanical properties of carbon nanotube/polyamide fibers DO - 10.1002/app.39713 AU - Palardy, G. AU - Trudel-Boucher, D. AU - Hubert, P. T2 - Journal of Applied Polymer Science SN - 0021-8995 VL - 130 IS - 6 SP - 4375 EP - 4382 KW - Capillary rheometer KW - Melt-compounding KW - Multi-walled nanotubes KW - Nanostructured polymers KW - Postprocessing methods KW - Thermal and electrical properties KW - Thermoplastic fibers KW - Twin screw extrusion KW - Carbon KW - Chains KW - Electric properties KW - Extrusion KW - Fibers KW - Mechanical properties KW - Multiwalled carbon nanotubes (MWCN) KW - Polyamides KW - Polymers KW - X ray diffraction KW - Spinning (fibers) AB - The incorporation of carbon nanotubes to thermoplastic fibers can potentially improve mechanical, thermal and electrical properties. In this article, a methodology to tailor the mechanical properties of carbon nanotube/nylon fibers is presented. Multiwalled nanotubes (MWNT) were combined to polyamide 12 through melt compounding and twin-screw extrusion. Pellets containing between 0 and 5.0 wt % MWNT were extruded and subsequently melt spun with a capillary rheometer to produce filaments. To further promote the alignment of the polymer chains and MWNTs, postdrawing parameters were systematically investigated: temperature, drawing speed and elongation. The best improvements in terms of elastic modulus and yield strength were measured at 140°C and 500% elongation, whereas drawing speed was shown to have a negligible effect. It was confirmed through electron microscopy and X-ray diffraction that these enhancements were mainly induced by the alignment of the polymer chains along the fibers' axis. Copyright © 2013 Wiley Periodicals, Inc. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5362caba-861c-4643-9a56-303c15636ccf ER - TY - JOUR TI - On the effect of the orientation of sheet rolling direction in shot peen forming DO - 10.1016/j.jmatprotec.2013.01.003 AU - Gariépy, A. AU - Larose, S. AU - Perron, C. AU - Bocher, P. AU - Lévesque, M. T2 - Journal of Materials Processing Technology SN - 0924-0136 VL - 213 IS - 6 SP - 926 EP - 938 KW - 2024-T3 KW - Accurate prediction KW - Finite Element KW - Finite element simulations KW - Initial stress KW - Manufacturing process KW - Maximum deflection KW - Numerical results KW - Orthotropy KW - Peen forming KW - Plastic anisotropy KW - Radii of curvature KW - Rolling direction KW - Sheet material KW - Sheet rolling KW - Shot peen KW - Wing skins KW - Aerospace industry KW - Anisotropy KW - Compressive stress KW - Residual stresses KW - Shot peening AB - Peen forming is commonly used in the aerospace industry to shape large and thin panels, such as wing skins. This manufacturing process uses shot peening to introduce unbalanced compressive stresses near the surface of the component. These stresses tend to bend the panel and, when optimized, lead to the desired contour. Sheet materials often exhibit both elastic and plastic anisotropy, which can alter the development of curvatures. Since peen forming relies on compressive stresses to upset equilibrium, resulting curvatures may also be affected by initial stresses in the part. In this work, the influence of the rolling direction orientation with respect to the sample was investigated experimentally and numerically for the first time for aluminium alloy 2024-T3 specimens. Although maximum deflections were only slightly dependent on the rolling direction orientation, it was found that radii of curvature varied by as much as 10% with respect to this parameter. Finite element simulations allowed quantification of the individual effects of non-equibiaxial initial stresses and elastic orthotropy. It was found that these factors can significantly influence curvature development. Comparison of experimental and numerical results suggested that plastic anisotropy should also be taken into account in future studies. The tools developed in this study show promises for the accurate prediction of peen forming process for large scale components. © 2013 Elsevier B.V. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 76a563a8-16c6-4ccb-979c-e14e35529e79 ER - TY - JOUR TI - Fabrication of binary opal lattices in microfluidic devices DO - 10.1021/cm401472j AU - Malekpourkoupaei, A. AU - Kostiuk, L.W. AU - Harrison, D.J. T2 - Chemistry of Materials SN - 0897-4756 VL - 25 IS - 19 SP - 3808 EP - 3815 KW - Colloidal self-assembly KW - Micro-fluidic devices KW - Microfluidic chip KW - Particle numbers KW - Protein separations KW - Rotation methods KW - Sedimentation process KW - Silica particles KW - Fabrication KW - Fluidic devices KW - Mathematical models KW - Microfluidics KW - Nanopores KW - Polystyrenes KW - Self assembly KW - Stoichiometry KW - Silica AB - We have studied growth and fabrication of opal lattices made from polystyrene and silica particles by an on-chip colloidal self-assembly (CSA) approach. An optical microscopy method was used to analyze the lattice growth behavior. A mathematical model was also adopted and modified to describe the growth behavior of the silica system. On the basis of these studies, silica and polystyrene systems demonstrate different growth dynamics that originate from a sedimentation process in the microfluidic chip reservoir fractionating large and small particles. Binary lattices of silica particles were fabricated by a periodic chip rotation method. The effect of particle number ratio on the opal stoichiometry was also studied for the polystyrene system. By increasing the number ratio from 2.5 to 11, different structural stoichiometries were achieved. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d58cf067-55e9-4066-af64-274df25f1d56 ER - TY - JOUR TI - Tocopherol activity correlates with its location in a membrane: A new perspective on the antioxidant vitamin e DO - 10.1021/ja312665r AU - Marquardt, D. AU - Williams, J.A. AU - Kučerka, N. AU - Atkinson, J. AU - Wassall, S.R. AU - Katsaras, J. AU - Harroun, T.A. T2 - Journal of the American Chemical Society SN - 0002-7863 VL - 135 IS - 20 SP - 7523 EP - 7533 KW - Antioxidant mechanisms KW - Hydrocarbon matrix KW - Hydrophobic-hydrophilic KW - Lipid acyl-chains KW - Measurements of KW - Oxidation kinetics KW - Physical locations KW - Reactive oxygen species KW - Cytology KW - Lipid bilayers KW - Neutron diffraction KW - Ultraviolet spectroscopy KW - Physical addresses KW - alpha tocopherol KW - hydrocarbon KW - hydrogen KW - hydroxyl group KW - reactive oxygen metabolite KW - tocopherol KW - antioxidant activity KW - hydration KW - hydrophilicity KW - hydrophobicity KW - lipid bilayer KW - lipid membrane KW - lipid oxidation KW - membrane structure KW - neutron diffraction KW - nuclear magnetic resonance spectroscopy KW - review KW - ultraviolet spectroscopy AB - We show evidence of an antioxidant mechanism for vitamin E which correlates strongly with its physical location in a model lipid bilayer. These data address the overlooked problem of the physical distance between the vitamin's reducing hydrogen and lipid acyl chain radicals. Our combined data from neutron diffraction, NMR, and UV spectroscopy experiments all suggest that reduction of reactive oxygen species and lipid radicals occurs specifically at the membrane's hydrophobic-hydrophilic interface. The latter is possible when the acyl chain "snorkels" to the interface from the hydrocarbon matrix. Moreover, not all model lipids are equal in this regard, as indicated by the small differences in vitamin's location. The present result is a clear example of the importance of lipid diversity in controlling the dynamic structural properties of biological membranes. Importantly, our results suggest that measurements of aToc oxidation kinetics, and its products, should be revisited by taking into consideration the physical properties of the membrane in which the vitamin resides. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 439a0a03-56d5-4ac9-981f-7ec9500f26a3 ER - TY - JOUR TI - Modeling noncovalent radical-molecule interactions using conventional density-functional theory: Beware erroneous charge transfer DO - 10.1021/jp3084309 AU - Johnson, E.R. AU - Salamone, M. AU - Bietti, M. AU - Dilabio, G.A. T2 - The Journal of Physical Chemistry A SN - 1089-5639 VL - 117 IS - 5 SP - 947 EP - 952 KW - Coulombic attractions KW - DFT method KW - Donor-acceptor complex KW - Fractional charges KW - Hartree-Fock exchanges KW - Highest occupied molecular orbital KW - Noncovalent KW - Charge transfer KW - Density functional theory KW - Molecular orbitals KW - Molecules AB - Conventional density-functional theory (DFT) has the potential to overbind radical-molecule complexes because of erroneous charge transfer. We examined this behavior by exploring the ability of various DFT approximations to predict fractional charge transfer and by quantifying the overbinding in a series of complexes. It is demonstrated that too much charge is transferred from molecules to radicals when the radical singly unoccupied molecular orbitals are predicted to be erroneously too low in energy relative to the molecule highest occupied molecular orbitals, leading to excessive Coulombic attraction. In this respect, DFT methods formulated with little or no Hartree-Fock exchange perform most poorly. The present results illustrate that the charge-transfer problem is much broader than may have been previously expected and is not limited to conventional (i.e., molecule-molecule) donor-acceptor complexes. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 87f40a51-7a0e-45b1-9ab8-3c61a7dc4e3e ER - TY - JOUR TI - Does a prestellar core always become protostellar? Tracing the evolution of cores from the prestellar to protostellar phase DO - 10.1093/mnras/stt006 AU - Anathpindika, S. AU - Francesco, J.D. T2 - Monthly Notices of the Royal Astronomical Society SN - 0035-8711 VL - 430 IS - 3 SP - 1854 EP - 1866 AB - Recently, a subset of starless cores whose thermal Jeans mass is apparently overwhelmed by the mass of the core has been identified, e.g. the core L183. In the literature, massive cores such as this one are often referred to as 'super-Jeans cores'. As starless cores are perhaps on the cusp of forming stars, a study of their dynamics will improve our understanding of the transition from the prestellar to the protostellar phase. In this work, we use non-magnetic polytropes belonging originally to the family of the Isothermal sphere. For the purpose, perturbations were applied to individual polytropes, first by replacing the isothermal gas with a gas that was cold near the centre of the polytrope and relatively warm in the outer regions, and secondly, through a slight compression of the polytrope by raising the external confining pressure. Using this latter configuration, we identify thermodynamic conditions under which a core is likely to remain starless. In fact, we also argue that the attribute 'super-Jeans' is subjective and that these cores do not formally violate the Jeans stability criterion. On the basis of our test results, we suggest that gas temperature in a star-forming cloud is crucial towards the formation and evolution of a core. Simulations in this work were performed using the particle-based smoothed particle hydrodynamics algorithm. However, to establish numerical convergence of the results we suggest similar tests with a grid scheme, such as the adaptive mesh refinement. © 2013 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3a18e12d-3ef4-4130-87a4-6505319bb7ca ER - TY - JOUR TI - Disorder and defect formation mechanisms in molecular-beam-epitaxy grown silicon epilayers DO - 10.1016/j.tsf.2012.11.140 AU - Akbari-Sharbaf, A. AU - Baribeau, J.-M. AU - Wu, X. AU - Lockwood, D.J. AU - Fanchini, G. T2 - Thin Solid Films SN - 0040-6090 VL - 527 SP - 38 EP - 44 KW - Molecular beam epitaxy; Disordered silicon; Defects; Electron spin resonance; Microstructure AB - We investigate the role of disorder, stress and crystallite size in determining the density of defects in disordered and partially ordered silicon thin films deposited at low or moderate temperatures by molecular beam epitaxy. We find that the paramagnetic defect density measured by electron spin resonance (ESR) is strongly dependent on the growth temperature of the films, decreasing from ~ 2·1019 cm- 3 at 98 C to ~ 1·10 18 cm- 3 at 572 C. The physical nature of the defects is strongly dependent on the range of order in the films: ESR spectra consistent with dangling bonds in an amorphous phase are observed at the lowest temperatures, while the ESR signal gradually becomes more anisotropic as medium-range order improves and the stress level (measured both by X-ray diffraction and Raman spectroscopy) is released in more crystalline films. Anisotropic ESR spectra consistent with paramagnetic defects embedded in an epitaxial phase are observed at the highest growth temperature (572 C). DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1185aa14-f6fc-4162-8687-597caedc8ad3 ER - TY - JOUR TI - Nickel, cobalt, and manganese oxide composite as an electrode material for electrochemical supercapacitors DO - 10.1007/s11581-013-0872-7 AU - Wang, G. AU - Liu, L. AU - Zhang, L. AU - Zhang, J. T2 - Ionics SN - 0947-7047 VL - 19 IS - 4 SP - 689 EP - 695 KW - Co-oxides KW - Composite electrode KW - Electrochemical supercapacitor KW - Mn oxides KW - Ni oxide KW - Capacitors KW - Manganese KW - Nickel KW - Precipitation (chemical) KW - Scanning electron microscopy KW - X ray diffraction KW - Electrochemical electrodes AB - A composite material, Ni1/3Co1/3Mn1/3(OH)2, is synthesized by chemical precipitation method for supercapacitors' electrode material. Physical characterizations using x-ray diffraction, energy-dispersive x-ray, and scanning electron microscopy show that Ni1/3Co1/3Mn1/3(OH)2 possesses an amorphous structure and higher specific surface area (268. 5 m2 g-1), which lead to a high initial specific capacitance of 1,403 F g-1 in the potential window of 0-1. 5 V. It may be a potential electrode material for future supercapacitor when its cycling stability and rate performance are addressed. © 2013 Springer-Verlag Berlin Heidelberg. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 97a57f78-0245-4520-8d75-c862619d03b1 ER - TY - JOUR TI - Using small-angle neutron scattering to detect nanoscopic lipid domains DO - 10.1016/j.chemphyslip.2013.02.012 AU - Pan, J. AU - Heberle, F.A. AU - Petruzielo, R.S. AU - Katsaras, J. T2 - Chemistry and Physics of Lipids SN - 0009-3084 VL - 170-171 SP - 19 EP - 32 KW - lipid KW - cell membrane KW - lipid composition KW - membrane model KW - Monte Carlo method KW - morphology KW - neutron scattering KW - phase separation KW - priority journal KW - review AB - The cell plasma membrane is a complex system, which is thought to be capable of exhibiting non-random lateral organization. Studies of live cells and model membranes have yielded mechanisms responsible for the formation, growth, and maintenance of nanoscopic heterogeneities, although the existence and mechanisms that give rise to these heterogeneities remain controversial. Small-angle neutron scattering (SANS) is a tool ideally suited to interrogate lateral heterogeneity in model membranes, primarily due to its unique spatial resolution (i.e., ∼5-100 nm) and its ability to resolve structure with minimal perturbation to the membrane. In this review we examine several methods used to analyze the SANS signal arising from freely suspended unilamellar vesicles containing lateral heterogeneity. Specifically, we discuss an analytical model for a single, round domain on a spherical vesicle. We then discuss a numerical method that uses Monte Carlo simulation to describe systems with multiple domains and/or more complicated morphologies. Also discussed are several model-independent approaches that are sensitive to membrane heterogeneity. The review concludes with several recent applications of SANS to the study of membrane raft mixtures. © 2013 Elsevier Ireland Ltd. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 810abc7a-99ce-446c-9808-e06f625c6eed ER - TY - JOUR TI - Immunization against a saccharide epitope accelerates clearance of experimental gonococcal infection DO - 10.1371/journal.ppat.1003559 AU - Gulati, S. AU - Zheng, B. AU - Reed, G.W. AU - Su, X. AU - Cox, A.D. AU - St. Michael, F. AU - Stupak, J. AU - Lewis, L.A. AU - Ram, S. AU - Rice, P.A. T2 - PLoS Pathogens SN - 1553-7366 VL - 9 IS - 8 SP - e1003559 KW - bacterial vaccine KW - glycosyltransferase KW - immunoglobulin A KW - immunoglobulin G KW - immunoglobulin M KW - monoclonal antibody 2C7 KW - multi antigenic peptide 1 KW - unclassified drug KW - article KW - bacterial clearance KW - bactericidal activity KW - colony forming unit KW - controlled study KW - enzyme linked immunosorbent assay KW - female KW - fractionation KW - gonorrhea KW - human KW - immune response KW - immunization KW - mouse KW - Neisseria gonorrhoeae KW - nonhuman KW - passive immunization KW - polymerase chain reaction KW - serum bactericidal antibody assay AB - The emergence of ceftriaxone-resistant strains of Neisseria gonorrhoeae may herald an era of untreatable gonorrhea. Vaccines against this infection are urgently needed. The 2C7 epitope is a conserved oligosaccharide (OS) structure, a part of lipooligosaccharide (LOS) on N gonorrhoeae. The epitope is expressed by 94% of gonococci that reside in the human genital tract (in vivo) and by 95% of first passaged isolates. Absence of the 2C7 epitope shortens the time of gonococcal carriage in a mouse model of genital infection. To circumvent the limitations of saccharide immunogens in producing long lived immune responses, previously we developed a peptide mimic (called PEP1) as an immunologic surrogate of the 2C7-OS epitope and reconfigured it into a multi-antigenic peptide, (MAP1). To test vaccine efficacy of MAP1, female BALB/c mice were passively immunized with a complement-dependent bactericidal monoclonal antibody specific for the 2C7 epitope or were actively immunized with MAP1. Mice immunized with MAP1 developed a TH1-biased anti-LOS IgG antibody response that was also bactericidal. Length of carriage was shortened in immune mice; clearance occurred in 4 days in mice passively administered 2C7 antibody vs. 6 days in mice administered control IgG3λ mAb in one experiment (p = 0.03) and 6 vs. 9 days in a replicate experiment (p = 0.008). Mice vaccinated with MAP1 cleared infection in 5 days vs. 9 days in mice immunized with control peptide (p = 0.0001 and p = 0.0002, respectively in two replicate experiments). Bacterial burden was lower over the course of infection in passively immunized vs. control mice in both experiments (p = 0.008 and p = 0.0005); burdens were also lower in MAP1 immunized mice vs. controls (p<0.0001) and were inversely related to vaccine antibodies induced in the vagina (p = 0.043). The OS epitope defined by mAb 2C7 may represent an effective vaccine target against gonorrhea, which is rapidly becoming incurable with currently available antibiotics. © 2013 Gulati et al. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6f8c0c0b-a459-43e1-828d-6a75b235feed ER - TY - JOUR TI - Single-mode 2.65 μm InGaAsSb/AlInGaAsSb laterally coupled distributed-feedback diode lasers for atmospheric gas detection DO - 10.1364/OE.21.001317 AU - Briggs, R.M. AU - Frez, C. AU - Bagheri, M. AU - Borgentun, C.E. AU - Gupta, J.A. AU - Witinski, M.F. AU - Anderson, J.G. AU - Forouhar, S. T2 - Optics Express SN - 1094-4087 VL - 21 IS - 1 SP - 1317 EP - 1323 KW - Absorption lines KW - Current thresholds KW - Distributed-feedback KW - Gas detection KW - InGaAsSb KW - Isotopologues KW - Modal characteristics KW - Multi-quantum well structures KW - Output power KW - Second orders KW - Single longitudinal mode KW - Single mode KW - Single mode emission KW - Molecular beam epitaxy KW - Ridge waveguides KW - Semiconductor lasers KW - Distributed feedback lasers AB - We demonstrate index-coupled distributed-feedback diode lasers at 2.65 μm that are capable of tuning across strong absorption lines of HDO and other isotopologues of H2O. The lasers employ InGaAsSb/AlInGaAsSb multi-quantum-well structures grown by molecular beam epitaxy on GaSb, and single-mode emission is generated using laterally coupled second-order Bragg gratings etched alongside narrow ridge waveguides. We verify nearcritical coupling of the gratings by analyzing the modal characteristics of lasers of different length. With an emission facet anti-reflection coating, 2-mm-long lasers exhibit a typical current threshold of 150 mA at 20 °C and are capable of emitting more than 25 mW in a single longitudinal mode, which is significantly higher than the output power reported for losscoupled distributed-feedback lasers operating at similar wavelengths. © 2013 Optical Society of America. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : feb1eff6-dd15-4a2e-8c33-1ec69e031e94 ER - TY - JOUR TI - Nonlocal effect and dimensions of Cooper pairs measured by low-energy muons and polarized neutrons in type-I superconductors DO - 10.1103/PhysRevB.87.104508 AU - Kozhevnikov, V. AU - Suter, A. AU - Fritzsche, H. AU - Gladilin, V. AU - Volodin, A. AU - Moorkens, T. AU - Trekels, M. AU - Cuppens, J. AU - Wojek, B.M AU - Prokscha, T. AU - Morenzoni, E. AU - Nieuwenhuys, G.J. AU - Van Bael, M.J. AU - Temst, K. AU - Van Haesendonck, C AU - Indekeu, J.O. T2 - Physical Review B - Condensed Matter and Materials Physics SN - 1098-0121 VL - 87 IS - 10 SP - 104508 AB - The Pippard coherence length ξ0 (the size of a Cooper pair) in two extreme type-I superconductors (In and Sn) was determined directly through high-resolution measurement of the nonlocal electrodynamic effect combining low-energy muon spin rotation spectroscopy and polarized neutron reflectometry. The renormalization factor Z=mcp*/2m (mcp* and m are the mass of the Cooper pair and the electron, respectively) resulting from the electron-phonon interaction, and the temperature-dependent London penetration depth λL(T) were determined as well. An expression linking ξ0, Z, and λL(0) is introduced and experimentally verified. This expression allows one to determine experimentally the Pippard coherence length in any superconductor, independent of whether the superconductor is local or nonlocal, conventional or unconventional. © 2013 American Physical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 918a4572-c279-4239-9754-b996fea6ccc4 ER - TY - JOUR TI - A minocycline derivative reduces nerve injury-induced allodynia, LPS-induced prostaglandin E2 microglial production and signaling via toll-like receptors 2 and 4 DO - 10.1016/j.neulet.2013.03.014 AU - Bastos, L.F.S. AU - Godin, A.M. AU - Zhang, Y. AU - Jarussophon, S. AU - Ferreira, B.C.S. AU - Machado, R.R. AU - Maier, S.F. AU - Konishi, Y. AU - de Freitas, R.P. AU - Fiebich, B.L. AU - Watkins, L.R. AU - Coelho, M.M. AU - Moraes, M.F.D. T2 - Neuroscience Letters SN - 0304-3940 VL - 543 SP - 157 EP - 162 KW - calcium KW - divalent cation KW - hydroxy 1,12 pyrazolinominocycline KW - magnesium ion KW - minocycline KW - prostaglandin E2 KW - pyrazoline derivative KW - toll like receptor 2 KW - toll like receptor 4 KW - unclassified drug KW - allodynia KW - animal cell KW - animal experiment KW - animal model KW - animal tissue KW - antibacterial activity KW - antiinflammatory activity KW - article KW - cell viability KW - chelation KW - controlled study KW - female KW - genetic transfection KW - human KW - in vitro study KW - kidney cell KW - microglia KW - mouse KW - nerve injury KW - neuropathic pain KW - nonhuman KW - priority journal KW - sham procedure KW - single drug dose KW - treatment duration KW - treatment outcome KW - Animals KW - Anti-Inflammatory Agents, Non-Steroidal KW - Cells, Cultured KW - Dinoprostone KW - Female KW - Humans KW - Hyperalgesia KW - Lipopolysaccharides KW - Mice KW - Mice, Inbred C57BL KW - Microglia KW - Minocycline KW - Neuralgia KW - Physical Stimulation KW - Rats KW - Rats, Wistar KW - Sciatic Nerve KW - Signal Transduction KW - Toll-Like Receptor 2 KW - Toll-Like Receptor 4 KW - Touch AB - Many studies have shown that minocycline, an antibacterial tetracycline, suppresses experimental pain. While minocycline's positive effects on pain resolution suggest that clinical use of such drugs may prove beneficial, minocycline's antibiotic actions and divalent cation (Ca2+; Mg2+) chelating effects detract from its potential utility. Thus, we tested the antiallodynic effect induced by a non-antibacterial, non-chelating minocycline derivative in a model of neuropathic pain and performed an initial investigation of its anti-inflammatory effects in vitro. Intraperitoneal minocycline (100mg/kg) and 12S-hydroxy-1,12-pyrazolinominocycline (PMIN; 23.75mg/kg, 47.50mg/kg or 95.00mg/kg) reduce the mechanical allodynia induced by chronic constriction injury of mouse sciatic nerve. PMIN reduces the LPS-induced production of PGE2 by primary microglial cell cultures. Human embryonic kidney cells were transfected to express human toll-like receptors 2 and 4, and the signaling via both receptors stimulated with PAM3CSK4 or LPS (respectively) was affected either by minocycline or PMIN. Importantly, these treatments did not affect the cell viability, as assessed by MTT test. Altogether, these results reinforce the evidence that the anti-inflammatory and experimental pain suppressive effects induced by tetracyclines are neither necessarily linked to antibacterial nor to Ca2+ chelating activities. This study supports the evaluation of the potential usefulness of PMIN in the management of neuropathic pain, as its lack of antibacterial and Ca2+ chelating activities might confer greater safety over conventional tetracyclines. © 2013 Elsevier Ireland Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : af84025d-8c30-4609-9eec-136753e51296 ER - TY - JOUR TI - Incommensurate dynamic correlations in the quasi-two-dimensional spin liquid BiCu2PO6 DO - 10.1103/PhysRevB.88.024402 AU - Plumb, K.W. AU - Yamani, Z. AU - Matsuda, M. AU - Shu, G.J. AU - Koteswararao, B. AU - Chou, F.C. AU - Kim, Y.-J. T2 - Physical Review B - Condensed Matter and Materials Physics SN - 1098-0121 VL - 88 IS - 2 SP - 24402 AB - We report detailed inelastic neutron-scattering measurements on single crystals of the frustrated two-leg ladder BiCu2PO6, whose ground state is described as a spin liquid phase with no long-range order down to 6 K. Two branches of steeply dispersing long-lived spin excitations are observed with excitation gaps of Δ1=1.90(9) meV and Δ2=3.95(8) meV. Significant frustrating next-nearest-neighbor interactions along the ladder leg drive the minimum of each excitation branch to incommensurate wave vectors ζ1=0.574π and ζ2=0.553π for the lower and upper energy branches, respectively. The temperature dependence of the excitation spectrum near the gap energy is consistent with thermal activation into singly and doubly degenerate excited states. The observed magnetic excitation spectrum as well as earlier thermodynamic data could be consistently explained by the presence of strong anisotropic interactions in the ground-state Hamiltonian. © 2013 American Physical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0136e6d1-9381-4a2a-9f3b-99145878fcb5 ER - TY - JOUR TI - Interfacial vs. internalwater transport resistance of sulfonated hydrocarbon proton-exchange membranes DO - 10.1149/2.009303eel AU - Zhao, N. AU - Edwards, D. AU - Shi, Z. AU - Holdcroft, S. T2 - ECS Electrochemistry Letters SN - 2162-8726 VL - 2 IS - 3 SP - F22 EP - F24 KW - Common knowledge KW - Hydrophilic domains KW - Hydrophilic surfaces KW - Interfacial resistances KW - Proton exchange membranes KW - Proton-exchange membrane KW - Transport resistance KW - Water permeation KW - Hydrophilicity KW - Proton exchange membrane fuel cells (PEMFC) KW - Vapors KW - Membranes AB - Liquid-Vapor Water Permeation (LVP) through sulfonated poly(etheretherketone) (sPEEK) proton exchange membranes, measured upon exposure of membranes to liquid water on one side and water vapor on the other, is lower than for Nafion membranes. Thickness-dependent measurements reveal that both internal and interfacial resistances to water transport are larger for sPEEK membranes, despite sPEEK membranes possessing larger water contents and possessing more hydrophilic surfaces. This report brings to attention the importance of organized hydrophilic domains on net water transport, not just within the membrane, which is common knowledge, but also at its surface. © 2013 The Electrochemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 7d85b0f4-cc53-44ed-a397-06b3e8ff7646 ER - TY - JOUR TI - Modal survey test and model correlation of the CASSIOPE spacecraft DO - 10.1111/j.1747-1567.2011.00783.x AU - Wickramasinghe, V. AU - Chen, Y. AU - Zimcik, D. AU - Tremblay, P. AU - Dahl, H. AU - Walkty, I. T2 - Experimental Techniques SN - 0732-8818 VL - 37 IS - 6 SP - 15 EP - 23 KW - Analysis softwares KW - Coupled loads analysis KW - Environmental loads KW - Experimental modal analysis KW - Experimental modal tests KW - Modal test KW - Multi-input multi-output KW - Qualification test KW - Finite element method KW - Forecasting KW - Iterative methods KW - MIMO systems KW - Modal analysis KW - Structural dynamics KW - Surveys KW - Vibrations (mechanical) KW - Spacecraft AB - A comprehensive modal survey test based on multi-input multi-output experimental modal analysis techniques was conducted on the flight model of the CASSIOPE spacecraft in the final stages of integration, which included all of the payload and bus instruments and electronics boxes. The multiple-input excitation for the spacecraft was generated using two portable electrodynamic modal shakers installed on the top and bottom of the spacecraft to distribute the excitation energy and the response was measured using 81 miniature accelerometers. Advanced modal analysis software was used to extract modal parameters from the measured data and critical modes were compared with predictions from the finite element model. Most modes identified through the experimental data compared favorably with the predictions. Nevertheless, some differences were large enough to require iterative update of the finite element model. The structural dynamics information from the updated finite element model was used to plan the mechanical vibration qualification test and predict the response of the spacecraft to the launch vehicle environmental loads through coupled loads analysis to provide confidence in the structural integrity of the spacecraft design. This paper describes the details of the methodology used to perform the successful experimental modal test to efficiently extract the critical modes of the spacecraft to correlate with the model. © 2011, Society for Experimental Mechanics. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 56d3645a-aeac-44e3-8ab0-1843ec4880fc ER - TY - JOUR TI - Prioritization of therapeutic targets of inflammation using proteomics, bioinformatics, and in silico cell-cell interactomics DO - 10.1007/978-1-62703-589-7_21 AU - Haqqani, A.S. AU - Stanimirovic, D.B. T2 - Methods in Molecular Biology SN - 1064-3745 SN - 9781627035880 VL - 1061 SP - 345 EP - 360 KW - intercellular adhesion molecule 1 KW - neutralizing antibody KW - vascular cell adhesion molecule 1 KW - amino acid sequence KW - article KW - bioinformatics KW - cell activation KW - cell communication and cell contact KW - cell interaction KW - cell surface KW - computer program KW - endothelium cell KW - human KW - human cell KW - inflammation KW - leukocyte KW - liquid chromatography KW - mass spectrometry KW - priority journal KW - protein analysis KW - protein folding KW - protein protein interaction KW - protein secretion KW - proteomics KW - T lymphocyte activation AB - Leukocyte extravasation is a multistep process, involving the movement of leukocytes out of the circulatory system, through vascular endothelium and to the site of tissue damage or infection. Protein-protein interactions play key roles in the extravasation process and have been attractive therapeutic targets for inhibiting inflammation using blocking (or neutralizing) antibodies. These targets include protein-protein interactions between cytokines (or chemokines) and their receptors on leukocytes and between adhesions molecules involving leukocyte-endothelium contacts. A number of therapeutics against these targets are currently used in clinic for treatment of inflammatory disorders, however, they are associated with side-effects partly due to the off-target actions (i.e., nonspecific targets). There is a need for novel targets involved in the leukocyte extravasation process that are specific to leukocyte subsets or to individual inflammatory disorder, and are amenable for drug development (i.e., duggable). In this chapter, we describe a methodology to identify novel "druggable" targets involving protein-protein interactions between activated leukocytes and endothelial cells using a combination of proteomics, bioinformatics and in silico interactomics. The result is a prioritized list of protein-protein interactions in a network consisting of leukocyte-endothelial cell communication and contacts. These prioritized targets can be pursued for the development of therapeutics such as neutralizing antibodies and for their validation through preclinical testing. The method described here provides the workflow to identify and clinically target important cell-cell interactions that are specific/selective for particular inflammatory disorders and to improve currently available therapies. © 2013 Springer Science+Business Media, LLC. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b0a2f6de-18a9-400a-8ad4-b4c725b29ebe ER - TY - JOUR TI - Journal Impact Factors: Their relevance and their influence on society-published scientific journalsk DO - 10.2138/am.2013.4357 AU - Putirka, K. AU - Kunz, M. AU - Swainson, I. AU - Thomson, J. T2 - American Mineralogist SN - 0003-004X VL - 98 IS - 5-Jun SP - 1055 EP - 1065 KW - asymmetric information KW - bibliography KW - geochemistry KW - mineralogy KW - petrology KW - publishing AB - We examine the nature and temporal trends of science journal publishing, and seek to explain why some journals have higher Journal Impact Factors (JIF) than others. The investigation has implications for how we assess the importance of scientific contributions. National Laboratories run by the U.S. Department of Energy, for example, compare JIF across disciplines, while some academic institutions look at JIF when evaluating publication records. Problematic to these policies are several results, which have long been known in the medical and biological sciences, and are shown here to apply to the Earth sciences as well. In particular, citations are distributed almost logarithmically in any given issue of a journal, and so JIFs say nothing about the actual number of citations acquired by any given paper. In the area of mineralogy and petrology, for example, 25% of articles in a typical issue will capture >50% of all citations that accrue to that issue. For some issues the asymmetry is greater; we use such citation asymmetry to develop a classification for journals as "super elite," "elite," "influential," and "minor." We also find that JIFs are inherently larger for large disciplines, in part because as the size of a discipline increases (as measured by total papers published), the top journals benefit to a greater extent than other journals. For this and other reasons, JIF cannot be compared across disciplines. A heretofore unknown and disconcerting result is the incredible growth in JIFs for commercially published journals compared to their society-published counterparts-a growth that coincides with the advent of electronic distribution models (e.g., bundling) that were instituted by commercial publishers at the beginning of the 21st century. Journals, which only a decade ago had similar JIFs, and were viewed as being scientifically equivalent, now have very different JIFs. These contrasts may nucleate feedback loops (as authors look to higher JIF journals in which to publish) that threaten the health of society-published journals. Our analysis however, shows that in spite of growing contrasts in JIF, many society-published journals still provide a greater value (JIF/cost) compared to their commercially published counterparts. While we acknowledge that citations and citation rates can be useful tools to compare scientific influence and importance, the results of this and other bibliometric studies cause us to conclude that in the evaluation of science and scientists, it is a grave error to substitute numerical values for human judgment. And if professional societies are to continue to play a significant role in science publication, it is incumbent upon scientists-now more than ever-to send their best works to society-published journals. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b29de1bb-e046-4ac5-826c-9ea9dc47f9eb ER - TY - JOUR TI - Instantaneous in-flame measurement of soot volume fraction, primary particle diameter, and aggregate radius of gyration via auto-compensating laser-induced incandescence and two-angle elastic light scattering DO - 10.1007/s00340-013-5539-6 AU - Crosland, B.M. AU - Thomson, K.A. AU - Johnson, M.R. T2 - Applied Physics B: Lasers and Optics SN - 0946-2171 VL - 112 IS - 3 SP - 381 EP - 393 AB - A new combination of soot diagnostics employing two-angle elastic light scattering and laser-induced incandescence is described that is capable of producing non-intrusive, instantaneous, and simultaneous, in situ measurements of soot volume fraction, primary particle size, and aggregate radius of gyration within flames. Controlled tests of the new apparatus on a well-characterized laminar flame show good agreement with existing measurements in the literature. From a detailed and comprehensive Monte Carlo uncertainty analysis of the results, it was found that the uncertainty in all three measured parameters is dominated by knowledge of soot properties and aggregation behavior. The soot volume fraction uncertainty is dominated by uncertainty in the soot refractive index light absorption function; the primary particle diameter uncertainty is dominated by uncertainty in the fractal prefactor; while the uncertainty in the aggregate radius of gyration is dominated by the uncertainty in the width of the distribution of aggregate sizes. DA - 2013/07/25 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : df876502-3885-4aec-8ef6-2400b43e6559 ER - TY - JOUR TI - Fecal source tracking in water using a mitochondrial DNA microarray DO - 10.1016/j.watres.2012.09.011 AU - Vuong, N.-M. AU - Villemur, R. AU - Payment, P. AU - Brousseau, R. AU - Topp, E. AU - Masson, L. T2 - Water Research SN - 0043-1354 VL - 47 IS - 1 SP - 16 EP - 30 KW - DNA micro-array KW - Fecal KW - PCR clamping KW - Peptide nucleic acid KW - Quantitative PCR KW - Source tracking KW - DNA KW - Extraction KW - Fish KW - Mitochondria KW - Oligonucleotides KW - Peptides KW - Probes KW - RNA KW - Tissue KW - Water pollution KW - Polymerase chain reaction KW - mitochondrial DNA KW - RNA 12S KW - RNA 16S KW - transfer RNA KW - array KW - deer KW - discriminant analysis KW - domestic species KW - environmental monitoring KW - genome KW - identification method KW - mitochondrial DNA KW - nucleic acid KW - polymerase chain reaction KW - watershed KW - animal tissue KW - article KW - cat KW - controlled study KW - cow KW - coyote KW - deer KW - DNA extraction KW - DNA microarray KW - DNA sequence KW - dog KW - duck KW - emu KW - fecal coliform KW - feces KW - feces analysis KW - gene amplification KW - gene sequence KW - gene targeting KW - genetic identification KW - genetic variability KW - goat KW - horse KW - human KW - limit of detection KW - moose KW - mouse KW - muskrat KW - nonhuman KW - nucleotide sequence KW - oligonucleotide probe KW - ostrich KW - pigeon KW - polymerase chain reaction KW - poultry KW - priority journal KW - quail KW - quantitative analysis KW - rabbit KW - raccoon KW - reindeer KW - sheep KW - swine KW - turkey (bird) KW - water pollution KW - water sampling KW - watershed KW - Animals KW - DNA, Mitochondrial KW - Enterobacteriaceae KW - Environmental Monitoring KW - Feces KW - Humans KW - Oligonucleotide Array Sequence Analysis KW - RNA, Ribosomal KW - RNA, Ribosomal, 16S KW - RNA, Transfer KW - Species Specificity KW - Water Pollutants KW - Animalia KW - Cervidae AB - A mitochondrial-based microarray (mitoArray) was developed for rapid identification of the presence of 28 animals and one family (cervidae) potentially implicated in fecal pollution in mixed activity watersheds. Oligonucleotide probes for genus or subfamily-level identification were targeted within the 12S rRNA - Val tRNA - 16S rRNA region in the mitochondrial genome. This region, called MI-50, was selected based on three criteria: 1) the ability to be amplified by universal primers 2) these universal primer sequences are present in most commercial and domestic animals of interest in source tracking, and 3) that sufficient sequence variation exists within this region to meet the minimal requirements for microarray probe discrimination. To quantify the overall level of mitochondrial DNA (mtDNA) in samples, a quantitative-PCR (Q-PCR) universal primer pair was also developed. Probe validation was performed using DNA extracted from animal tissues and, for many cases, animal-specific fecal samples. To reduce the amplification of potentially interfering fish mtDNA sequences during the MI-50 enrichment step, a clamping PCR method was designed using a fish-specific peptide nucleic acid. DNA extracted from 19 water samples were subjected to both array and independent PCR analyses. Our results confirm that the mitochondrial microarray approach method could accurately detect the dominant animals present in water samples emphasizing the potential for this methodology in the parallel scanning of a large variety of animals normally monitored in fecal source tracking. © 2012 Elsevier Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b76c73b1-8b05-4445-8bb5-87400332ac74 ER - TY - JOUR TI - Effects of SWCNTs on mechanical and thermal performance of epoxy at elevated temperatures DO - 10.1007/s10853-013-7584-2 AU - Ashrafi, B. AU - Backman, D. AU - Johnston, A. AU - Martinez-Rubi, Y. AU - Simard, B. T2 - Journal of Materials Science SN - 0022-2461 VL - 48 IS - 21 SP - 7664 EP - 7672 KW - After-heat treatment KW - Elevated temperature KW - Heat-treated specimens KW - Operating temperature KW - Thermal and mechanical properties KW - Thermal Performance KW - Thermoset polymers KW - Ultimate tensile strength KW - Dynamic mechanical analysis KW - Glass KW - Heat treatment KW - Mechanical properties KW - Single-walled carbon nanotubes (SWCN) KW - Tensile strength KW - Tensile testing KW - Thermogravimetric analysis KW - Thermosets KW - Nanocomposites AB - A property which limits the breadth of application of thermoset polymers and their composites is their relatively low maximum operating temperatures. This work investigates the potential application of both functionalized single-walled carbon nanotubes (f-SWCNTs) based on negative charging, and unfunctionalized SWCNTs (u-SWCNTs) to increase the mechanical and thermal performance of a high-temperature aerospace-grade epoxy with a glass transition temperature of approximately 270 C. Thermal and mechanical properties of the baseline epoxy and nanocomposites containing a low content of SWCNTs (0.2 % by weight) were characterized through thermogravimetric analyses, tensile tests, and dynamic mechanical analyses. Tensile tests were performed both at room temperature and at 80 C. Further, room temperature tensile tests were performed on untreated and heat-treated specimens. The heat treatment was performed at 300 C, slightly above the resin glass transition temperature. Results demonstrate that f-SWCNTs are effective in improving the mechanical and thermal performance of the epoxy. No significant improvement was observed for u-SWCNT nanocomposites. For the nanocomposite with f-SWCNTs, the ultimate tensile strength and strain to failure at room temperature (80 C) increased by 20 % (8 %) and 71 % (77 %), respectively, as compared to the baseline epoxy. The f-SWCNT nanocomposite, unlike other examined materials, exhibited a stress-strain necking behavior at 80 C, an indication of increased ductility. After heat treatment, these properties further improved relative to the neat epoxy (160 % increase in ultimate tensile strength and 270 % increase in strain to failure). This work suggests the potential to utilize f-SWCNTs based on negative charging to enhance high-temperature thermoset performance. © 2013 Her Majesty the Queen in Right of Canada. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2db13fb7-dbb9-491a-81ca-e6eae0693fa7 ER - TY - JOUR TI - Nafion®/ODF-silica composite membranes for medium temperature proton exchange membrane fuel cells DO - 10.1016/j.jpowsour.2013.01.178 AU - Treekamol, Y. AU - Schieda, M. AU - Robitaille, L. AU - MacKinnon, S.M. AU - Mokrini, A. AU - Shi, Z. AU - Holdcroft, S. AU - Schulte, K. AU - Nunes, S.P. T2 - Journal of Power Sources SN - 0378-7753 AB - A series of composite membranes were prepared by dispersing fluorinated polyoxadiazole oligomer (ODF)-functionalized silica nanoparticles in a Nafion® matrix. Both melt-extrusion and solvent casting processes were explored. Ion exchange capacity, conductivity, water uptake and dimensional stability, thermal stability and morphology were characterized. The inclusion of functionalized nanoparticles proved advantageous, mainly due to a physical crosslinking effect and better water retention, with functionalized nanoparticles performing better than the pristine silica particles. For the same filler loading, better nanoparticle dispersion was achieved for solvent-cast membranes, resulting in higher proton conductivity. Filler agglomeration, however, was more severe for solvent-cast membranes at loadings beyond 5 wt.%. The composite membranes showed excellent thermal stability, allowing for operation in medium temperature PEM fuel cells. Fuel cell performance of the composite membranes decreases with decreasing relative humidity, but good performance values are still obtained at 34% RH and 90 °C, with the best results obtained for solvent cast membranes loaded with 10 wt.% ODF-functionalized silica. Hydrogen crossover of the composite membranes is higher than that for pure Nafion® membranes, possibly due to porosity resulting from suboptimal particle-matrix compatibility. © 2013 [Author/Employing Institution]. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2277e61f-7827-4bdf-bf70-a7940548afd6 ER - TY - JOUR TI - Multivariate factor analysis of heavy minerals concentrate from Athabasca oil sands tailings by X-ray photoelectron spectroscopy DO - 10.1002/sia.5201 AU - Marshall, Gregory M. AU - Kingston, David M. AU - Moran, Kevin AU - Mercier, Patrick H. J. T2 - Surface and Interface Analysis SN - 0142-2421 VL - 46 IS - 4 SP - 197 EP - 209 KW - multivariate analysis; XPS chemical imaging; oil sands; mineralogy; Varimax rotation AB - Multivariate factor analysis of X-ray photoelectron spectroscopy data acquired from Athabasca oil sands heavy minerals concentrate was used to identify the primary mineral components and their physical associations. Using large-area spectroscopy, a principal components analysis (PCA) and Varimax rotation of the PCA spectral loadings matrix demonstrated that the most significant factors index the mineral chemistry by virtue of the within-factor spectral correlations. Analysis of the Varimax rotated factor scores indicated the physical character of several mineral associations. Emphasis is placed on the high-value materials, namely, zircon and the titanium-bearing minerals. In spectral imaging mode, Varimax rotation in the spatial domain applied to a PCA noise-reduced data reconstruction was used to render component images illustrating the spatial distribution of selected mineral chemistries. The component images also revealed evidence of surface species consistent with pyrite weathering. Data are supported with optical microscopy and energy-dispersive X-ray spectroscopy. Our work demonstrates the utility of multivariate spectroscopic techniques in the analysis of complex mineral chemistry. DA - 2013/02/03 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ab8787b2-d9c2-4a4c-8fea-53107703aa79 ER - TY - JOUR TI - Performance of a Carboxydothermus hydrogenoformansimmobilizing membrane reactor for syngas upgrading into hydrogen DO - 10.1016/j.ijhydene.2012.11.038 AU - Zhao, Y. AU - Haddad, M. AU - Cimpoia, R. AU - Liu, Z. AU - Guiot, S.R. T2 - International Journal of Hydrogen Energy SN - 0360-3199 VL - 38 IS - 5 SP - 2167 EP - 2175 KW - Abiotic membranes KW - Carboxydothermus hydrogenoformans KW - CO conversion KW - Co loading KW - Dissolved co KW - Hollow fiber membrane bioreactor KW - Hollow fiber membranes KW - Liquid velocities KW - Low concentrations KW - Membrane bioreactor KW - Membrane permeability KW - Membrane reactor KW - Operational conditions KW - Pure culture KW - Reactor performance KW - Sessile growths KW - Shearing stress KW - Shell-side KW - Syn-gas KW - Three orders of magnitude KW - Total biomass KW - Transfer rates KW - Volatile suspended solids KW - Biofilms KW - Bioreactors KW - Carbon monoxide KW - Fischer-Tropsch synthesis KW - Fouling KW - Hydrogen KW - Internet protocols KW - Liquids KW - Loading KW - Mass transfer KW - Membrane fouling KW - Synthesis gas KW - Membranes AB - Hydrogen conversion of CO by a pure culture of Carboxydothermus hydrogenoformans was investigated and optimized in a lab-scale hollow fiber membrane bioreactor (HFMBR). The reactor was operated under strict anaerobic, extremely thermophilic (70 °C) conditions with a continuous supply of gas, for four months. Reactor performance was evaluated under various operational conditions, such as liquid velocity (vliq) (13, 65 and 130 m h -1), temperature (70, 65, and 60 °C), CO pressure (from 1 to 2.5 atm) and CO loading rate (from 1.3 to 16:5 mol Lrxr -1 d-1). Overall, results indicated a relatively constant H2 yield of 92 ± 4% (mol mol-1) regardless of the operational condition tested. Permeation across the colonized membrane was improved by three orders of magnitude as compared to the abiotic membrane, because of dissolved CO concentration was constantly maintained low in the liquid on the shell side of the membrane as continually depleted by the microorganisms. Once the biofilm was sufficiently developed, a maximum CO conversion activity of 0.44 mol CO g-1 volatile suspended solid (VSS) d-1 was achieved at a pCO of 2 atm or above and a vliq of 65 m h-1. However, this highest activity represented only 15% of the maximal activity potential of the strain under non-limiting conditions, attributed to the low concentration of dissolved CO (0.01-0.07 mM) present in the HFMBR liquid. Higher vliq (130 m h-1) produced shearing stress, which detached a significant portion of the biofilm from the membrane, and/or prevented less sessile growth (57% total biomass as biofilm, as opposed to 84-86% at lower vliq). One may deduce from this work that the volumetric CO conversion performance of such a membrane bioreactor would be at the most in the range of 5 mol CO Lrxr -1 d-1. Overall, the CO conversion performance in the HFMBR was biokinetically limited, when not limited by gaseliquid mass transfer. Additionally, over time, membrane fouling and aging decreased membrane permeability such that the CO transfer rate would be the most limiting factor in the long run. Crown Copyright © 2012, Hydrogen Energy Publications, LLC. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 11ee5c87-3f45-4b5a-b6ae-db5ebe37ffe2 ER - TY - JOUR TI - A review on the laminar flame speed and ignition delay time of Syngas mixtures DO - 10.1016/j.ijhydene.2013.10.068 AU - Lee, H.C. AU - Jiang, L.Y. AU - Mohamad, A.A. T2 - International Journal of Hydrogen Energy SN - 0360-3199 AB - Syngas has shown great success in Integrated Gasification Combined Cycle (IGCC) technology for providing cleaner and higher efficiency energy production with minimal environment impact. Thus, it is promising that Syngas is able to replace the conventional fossil fuel resources, while at the same time minimizing pollutants. The drawback of traditional Gas Turbines that burn Syngas is that they use diffusion flame combustion technology that suffers from low efficiency and high emissions. Recently, Lean premixed combustion technique has emerged as a promising solution, but the variation of hydrogen fraction in Syngas has prohibited its usage. Besides, other gases such as CO2, N2, H2O, NH3, and CH4 in Syngas have adverse effects on the combustion characteristics. To address these issues, better understanding of the Syngas's fundamental combustion properties are vital. Hence, recent works published on Syngas combustion at lean-premixed and Gas Turbine relevant conditions are reviewed, classified according to their objectives, and remarks were concluded. © 2013 Hydrogen Energy Publications, LLC. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a3653114-2d33-45b7-b4f3-fcdbc17b9941 ER - TY - JOUR TI - Characterization of CpdC, a large-ring lactone-hydrolyzing enzyme from Pseudomonas sp. strain HI-70, and its use as a fusion tag facilitating overproduction of proteins in Escherichia coli DO - 10.1128/AEM.02435-13 AU - Xu, Y. AU - Grosse, S. AU - Iwaki, H. AU - Hasegawa, Y. AU - Lau, P.C.K. T2 - Applied and Environmental Microbiology SN - 0099-2240 VL - 79 IS - 22 SP - 7091 EP - 7100 KW - Carbon-carbon bond KW - Catalytic efficiencies KW - Degradation pathways KW - Expression in Escherichia coli KW - Global carbon cycle KW - Inclusion bodies KW - Pentadecalactone KW - Proof of concept KW - Bacteria KW - Dimers KW - Esters KW - Hydrolases KW - Proteins KW - Escherichia coli KW - bacterium KW - carbon cycle KW - coliform bacterium KW - enzyme activity KW - gene expression KW - homogeneity KW - hydrolysis KW - molecular analysis KW - plasmid KW - protein KW - solubilization AB - There are few entries of carbon-carbon bond hydrolases (EC 3.7.1.-) in the ExPASy database. In microbes, these enzymes play an essential role in the metabolism of alicyclic or aromatic compounds as part of the global carbon cycle. CpdC is aω-pentadecalactone hydrolase derived from the degradation pathway of cyclopentadecanol or cyclopentadecanone by Pseudomonas sp. strain HI-70. CpdC was purified to homogeneity and characterized. It is active as a dimer of 56,000 Da with a subunit molecular mass of 33,349. Although CpdC has the highest activity and reaction rate (kcat) towardω-pentadecalactone, its catalytic efficiency favors lauryl lactone as a substrate. The melting temperature (Tm) of CpdC was estimated to be 50.9±0.1°C. The half-life of CpdC at 35°C is several days. By virtue of its high level of expression in Escherichia coli, the intact CpdC-encoding gene and progressive 3=-end deletions were employed in the construction of a series of fusion plasmid system. Although we found them in inclusion bodies, proof-of-concept of overproduction of three microbial cutinases of which the genes were otherwise expressed poorly or not at all in E. coli was demonstrated. On the other hand, two antigenic proteins, azurin and MPT63, were readily produced in soluble form. © 2013, American Society for Microbiology. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d829a439-96a0-4919-b8e8-7257b3cff992 ER - TY - JOUR TI - Force spectroscopy measurements show that cortical neurons exposed to excitotoxic agonists stiffen before showing evidence of bleb damage DO - 10.1371/journal.pone.0073499 AU - Zou, S. AU - Chisholm, R. AU - Tauskela, J.S. AU - Mealing, G.A. AU - Johnston, L.J. AU - Morris, C.E. T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 8 SP - e73499 KW - calcium ion KW - glutamic acid KW - hypotonic solution KW - myosin adenosine triphosphatase KW - n methyl dextro aspartic acid KW - sodium channel KW - sodium ion KW - spectrin KW - veratridine KW - water KW - actin myosin interaction KW - animal cell KW - animal experiment KW - animal model KW - animal tissue KW - article KW - atomic force microscopy based force spectroscopy KW - bilayer membrane KW - bleb damage KW - brain cell KW - brain injury KW - brain ischemia KW - calcium transport KW - cell damage KW - cell stiffening KW - cell swelling KW - cell volume KW - controlled study KW - elasticity KW - excitotoxicity KW - exposure KW - female KW - hydrostatic pressure KW - measurement KW - membrane damage KW - nerve cell necrosis KW - nonhuman KW - osmosis KW - positive feedback KW - rat KW - sodium transport KW - spectroscopy KW - traumatic brain injury KW - water transport AB - In ischemic and traumatic brain injury, hyperactivated glutamate (N-methyl-D-aspartic acid, NMDA) and sodium (Nav) channels trigger excitotoxic neuron death. Na+, Ca++ and H2O influx into affected neurons elicits swelling (increased cell volume) and pathological blebbing (disassociation of the plasma membrane's bilayer from its spectrin-actomyosin matrix). Though usually conflated in injured tissue, cell swelling and blebbing are distinct processes. Around an injury core, salvageable neurons could be mildly swollen without yet having suffered the bleb-type membrane damage that, by rendering channels leaky and pumps dysfunctional, exacerbates the excitotoxic positive feedback spiral. Recognizing when neuronal inflation signifies non-lethal osmotic swelling versus blebbing should further efforts to salvage injury-penumbra neurons. To assess whether the mechanical properties of osmotically-swollen versus excitotoxically-blebbing neurons might be cytomechanically distinguishable, we measured cortical neuron elasticity (gauged via atomic force microscopy (AFM)-based force spectroscopy) upon brief exposure to hypotonicity or to excitotoxic agonists (glutamate and Nav channel activators, NMDA and veratridine). Though unperturbed by solution exchange per se, elasticity increased abruptly with hypotonicity, with NMDA and with veratridine. Neurons then invariably softened towards or below the pre-treatment level, sometimes starting before the washout. The initial channel-mediated stiffening bespeaks an abrupt elevation of hydrostatic pressure linked to NMDA or Nav channel-mediated ion/H2O fluxes, together with increased [Ca++]int-mediated submembrane actomyosin contractility. The subsequent softening to below-control levels is consistent with the onset of a lethal level of bleb damage. These findings indicate that dissection/identification of molecular events during the excitotoxic transition from stiff/swollen to soft/blebbing is warranted and should be feasible. © 2013 Zou et al. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 666541e7-16a7-432b-a7d7-630cc8034238 ER - TY - JOUR TI - Atomic force microscopy studies of conductive nanostructures in solid polymer electrolytes DO - 10.1016/j.electacta.2013.04.147 AU - Hiesgen, R. AU - Helmly, S. AU - Morawietz, T. AU - Yuan, X.-Z. AU - Wang, H. AU - Friedrich, K.A. T2 - Electrochimica Acta SN - 0013-4686 VL - 110 SP - 292 EP - 305 AB - The conductivity of three different sulfonated polymer electrolyte membranes (PEM), two perfluorinated membranes, Nafion® and Aquivion®, and JST, a non-perfluorinated aromatic block copolymer, were compared using advanced material-sensitive and conductive atomic force microscopy (AFM). All of the membranes required activation by a current flow to reach significant conductivity for the AFM analysis, indicating the existence of a highly resistive surface skin layer. The two perfluorinated sulfonic acid membranes, a membrane with long side-chains (Nafion ®) and a membrane with short side-chains (Aquivion ®), exhibited similar properties. A lamellar surface structure, with polymer bundles or micelles in a parallel orientation, was also found for the Aquivion® membrane. AFM high-resolution current images, performed under a continuous current flow, were used to distinguish between the conducting network and the subsurface phase distribution at the membrane surface. The connected subnets of the JST membrane were approximately 100-200 nm in size, whereas those for the perfluorinated membrane surfaces were 200-300 nm in size. The conductive areas of the Aquivion® and JST membranes exhibited larger homogeneous conducting areas, corresponding to the smaller correlation lengths of ionic phase separation. Membrane cross sections were analyzed to elucidate the structure of the bulk ionic network of the Nafion ® membrane, before and after operation. The existence of extended water layers in the bulk, even before operation, was confirmed.© 2013 Elsevier Ltd. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ca3e0740-3b41-4a68-a884-eba145626f91 ER - TY - JOUR TI - Biodiagnostics using oriented and aligned inorganic semiconductor nanotubes and nanowires DO - 10.1166/jnn.2013.7771 AU - Kar, P. AU - Shankar, K. T2 - Journal of Nanoscience and Nanotechnology SN - 1533-4880 VL - 13 IS - 7 SP - 4473 EP - 4496 KW - Arrays KW - Biodiagnostics KW - Electrical measurement KW - ELectrochemical methods KW - Inorganic nanotubes KW - MALDI TOF MS KW - Nanomechanical KW - Optical interferometry KW - Cellular arrays KW - Electric properties KW - Electrochemistry KW - Field effect transistors KW - Fluorescence KW - Nanorods KW - Nanotubes KW - Nanowires KW - Biosensors KW - inorganic compound KW - nanotube KW - chemistry KW - conductometry KW - equipment KW - equipment design KW - equipment failure KW - genetic procedures KW - nanotechnology KW - review KW - semiconductor KW - Biosensing Techniques KW - Conductometry KW - Equipment Design KW - Equipment Failure Analysis KW - Inorganic Chemicals KW - Nanotechnology KW - Nanotubes KW - Semiconductors AB - The simplicity of synthesis of deterministically positioned inorganic semiconductor nanorods (NRs) and nanotubes (NTs) coupled with their chemical stability, high surface area, controllable optical properties and tunable surface functionality, have sparked worldwide research efforts towards biodiagnostic applications. Biosensors based on oriented and aligned one-dimensional (1-D) inorganic semiconductor nanostructures have demonstrated remarkable detection sensitivity, high throughput and label-free operability. In comparison to suspensions of nanoparticles and discrete randomly oriented nanowires, nanowire (NW) and nanotube arrays offer continuous charge transport pathways, a major advantage for all-electrical detection and in exploiting electrokinetic effects. We review highly sensitive biosensors based on oriented and aligned NTs/NRs/NWs employing conventional detection methods, inclusive of fluorescence, electrochemistry and electromechanical sensing as well as detection methods unique to nanowires such as field-effect transistors. Entirely new types of sensing applications such as the impaling of living cells to monitor cellular events in situ, and substrates with electrically controlled wetting for surface-assisted laser desorption and ionization are emerging to take advantage of the unique properties of nanowire arrays. Concurrently, we explain the semiconductor materials and architectures employed, and the functionalization procedures used to construct the biosensors. Aligned semiconductor array-based approaches are critically examined in relation to prevailing technologies to get a sense of the exclusive niches that nanotube/nanorod array biosensors inhabit. The versatility of the detection principles that nanowire/nanotube arrays are compatible with are enabling hybrid approaches where combinations of detection methods are used. Such advantages offset the complexity associated with changing the status quo with respect to the current state-of-the-art in biodiagnostic platforms and devices. Copyright © 2013 American Scientific Publishers All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 332a9551-7d7a-40eb-9002-94792d8f4211 ER - TY - JOUR TI - Impact of human presence on secondary organic aerosols derived from ozone-initiated chemistry in a simulated office environment DO - 10.1021/es3050828 AU - Fadeyi, M.O. AU - Weschler, C.J. AU - Tham, K.W. AU - Wu, W.Y. AU - Sultan, Z.M. T2 - Environmental Science and Technology SN - 0013-936X VL - 47 IS - 8 SP - 3933 EP - 3941 KW - Air handling systems KW - Fast mobility particle sizers KW - Identical conditions KW - Indoor pollutants KW - Mass concentration KW - Office environments KW - Ozone concentration KW - Secondary organic aerosols KW - Aerosols KW - Experiments KW - Monoterpenes KW - Ozone KW - limonene KW - ozone KW - terpene KW - aerosol KW - atmospheric pollution KW - concentration (composition) KW - estimation method KW - experimental study KW - human activity KW - indoor air KW - ozone KW - simulation KW - ultraviolet radiation KW - adult KW - air pollution KW - article KW - chemical reaction KW - concentration (parameters) KW - controlled study KW - environmental exposure KW - human KW - microclimate KW - photometry KW - pollutant KW - secondary organic aerosol KW - work environment AB - Several studies have documented reductions in indoor ozone levels that occur as a consequence of its reactions with the exposed skin, hair and clothing of human occupants. One would anticipate that consumption of ozone via such reactions would impact co-occurring products derived from ozone's reactions with various indoor pollutants. The present study examines this possibility for secondary organic aerosols (SOA) derived from ozone-initiated chemistry with limonene, a commonly occurring indoor terpene. The experiments were conducted at realistic ozone and limonene concentrations in a 240 m3 chamber configured to simulate a typical open office environment. During an experiment the chamber was either unoccupied or occupied with 18-20 workers. Ozone and particle levels were continuously monitored using a UV photometric ozone analyzer and a fast mobility particle sizer (FMPS), respectively. Under otherwise identical conditions, when workers were present in the simulated office the ozone concentrations were approximately two-thirds and the SOA mass concentrations were approximately one-half of those measured when the office was unoccupied. This was observed whether new or used filters were present in the air handling system. These results illustrate the importance of accounting for occupancy when estimating human exposure to pollutants in various indoor settings. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5848f3a5-9481-4510-b71a-3a42b616aabe ER - TY - JOUR TI - Comparative analysis of photocaged RGDS peptides for cell patterning DO - 10.1002/jbm.a.34381 AU - Goubko, C.A. AU - Basak, A. AU - Majumdar, S. AU - Jarrell, H. AU - Khieu, N.H. AU - Cao, X. T2 - Journal of Biomedical Materials Research - Part A SN - 1549-3296 VL - 101 A IS - 3 SP - 787 EP - 796 KW - 2-nitrobenzyl KW - Biological applications KW - Cell-patterning KW - Comparative analysis KW - Modeling predictions KW - Physiological properties KW - RGDS peptides KW - Solid phase synthesis KW - Biological materials KW - Cell adhesion KW - Cell membranes KW - Docking KW - Photochemical reactions KW - Rate constants KW - Peptides KW - alpha v beta 3 integrin receptor KW - arginylglycylaspartylserine KW - benzyl derivative KW - integrin receptor KW - unclassified drug KW - article KW - cell adhesion KW - cell patterning KW - cellular parameters KW - controlled study KW - enzyme linked immunosorbent assay KW - hydrogel KW - molecular docking KW - molecular interaction KW - molecular model KW - molecular stability KW - photolysis KW - photosensitivity KW - physiology KW - protein binding KW - protein function KW - protein synthesis KW - solid KW - Animals KW - Cell Adhesion KW - Coated Materials, Biocompatible KW - Humans KW - Integrin alphaVbeta3 KW - Molecular Docking Simulation KW - Oligopeptides KW - Photochemical Processes KW - Protein Binding AB - Photocaged RGDS is a cell nonadhesive tetrapeptide that can be activated with light to become cell-adhesive. Such molecules can find useful applications in controlling cell adhesion for biological study, drug development, and in forming dynamic, adhesion-controlled biomaterials. Herein, we prepared RGDS peptide photocaged either on the Arg-Gly backbone amide nitrogen atom (R[-]GDS) or Asp side chain carboxyl (RG[D]S). A critical comparison of the peptides' chemical and physiological properties relevant for biological applications was carried out. It was observed that RG[D]S was synthesized more readily via automated solid-phase synthesis, underwent uncaging with a rate constant 3-fold higher than R[-]GDS, and was more stable in aqueous solution. Automated docking studies were performed to examine the interactions of various caged RGDS peptides with cell surface integrin receptor to identify suitable locations for the photosensitive 2-nitrobenzyl (NB) group for biological applications. A competitive binding ELISA method compared the ability of various peptides to bind to αVβ3 cell integrin receptors and the data were found to be consistent with the modeling predictions. Finally, the application of our caged RGDS peptides in controlling cell adhesion to form cell patterns on a hydrogel material was presented. © 2012 Wiley Periodicals, Inc. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 367e3077-7e3f-400a-92ab-c4b26b9e95f9 ER - TY - JOUR TI - Influence of the reaction stoichiometry on the mechanical and thermal properties of SWCNT-modified epoxy composites DO - 10.1088/0957-4484/24/26/265701 AU - Ashrafi, B. AU - Martinez-Rubi, Y. AU - Khoun, L. AU - Yourdkhani, M. AU - Kingston, C.T. AU - Hubert, P. AU - Simard, B. AU - Johnston, A. T2 - Nanotechnology SN - 0957-4484 VL - 24 IS - 26 SP - 265701 KW - Cross-link densities KW - Diaminodiphenylsulfone KW - Mechanical and thermal properties KW - Overall properties KW - Reaction stoichiometry KW - Single-walled carbon nanotube (SWCNTs) KW - Thermal and mechanical properties KW - Ultimate tensile strength KW - Curing KW - Epoxy resins KW - Fracture toughness KW - Mechanical properties KW - Raman spectroscopy KW - Resins KW - Scanning electron microscopy KW - Single-walled carbon nanotubes (SWCN) KW - Tensile strength KW - Thermodynamic properties KW - Stoichiometry AB - Previous studies suggest that carbon nanotubes (CNTs) have a considerable influence on the curing behavior and crosslink density of epoxy resins. This invariably has an important effect on different thermal and mechanical properties of the epoxy network. This work focuses on the important role of the epoxy/hardener mixing ratio on the mechanical and thermal properties of a high temperature aerospace-grade epoxy (MY0510 Araldite as an epoxy and 4,4′-diaminodiphenylsulfone as an aromatic hardener) modified with single-walled carbon nanotubes (SWCNTs). The effects of three different stoichiometries (stoichiometric and off-stoichiometric) on various mechanical and thermal properties (fracture toughness, tensile properties, glass transition temperature) of the epoxy resin and its SWCNT-modified composites were obtained. The results were also supported by Raman spectroscopy and scanning electron microscopy (SEM). For the neat resin, it was found that an epoxy/hardener molar ratio of 1:0.8 provides the best overall properties. In contrast, the pattern in property changes with the reaction stoichiometry was considerably different for composites reinforced with unfunctionalized SWCNTs and reduced SWCNTs. A comparison among composites suggests that a 1:1 molar ratio considerably outperforms the other two ratios examined in this work (1:0.8 and 1:1.1). This composition at 0.2 wt% SWCNT loading provides the highest overall mechanical properties by improving fracture toughness, ultimate tensile strength and ultimate tensile strain of the epoxy resin by 40%, 34%, 54%, respectively. © 2013 IOP Publishing Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a2ac634e-58e2-48dc-82b8-9eae3f81149a ER - TY - JOUR TI - Components of the cultivated red seaweed Chondrus crispus enhance the immune response of Caenorhabditis elegans to Pseudomonas aeruginosa through the pmk-1, daf-2/daf-16, and skn-1 pathways DO - 10.1128/AEM.01927-13 AU - Liu, Jianghua AU - Hafting, Jeff AU - Critchley, Alan T. AU - Banskota, Arjun H. AU - Prithiviraj, Balakrishnan T2 - Applied and Environmental Microbiology SN - 0099-2240 VL - 79 IS - 23 SP - 7343 EP - 7350 AB - Marine macroalgae are rich in bioactive compounds that can, when consumed, impart beneficial effects on animal and human health. The red seaweed Chondrus crispus has been reported to have a wide range of health-promoting activities, such as antitumor and antiviral activities. Using a Caenorhabditis elegans infection model, we show that C. crispus water extract (CCWE) enhances host immunity and suppresses the expression of quorum sensing (QS) and the virulence factors of Pseudomonas aeruginosa (strain PA14). Supplementation of nematode growth medium with CCWE induced the expression of C. elegans innate immune genes, such as irg-1, irg-2, F49F1.6, hsf-1, K05D8.5, F56D6.2, C29F3.7, F28D1.3, F38A1.5 ZK6.7, lys-1, spp-1, and abf-1, by more than 2-fold, while T20G5.7 was not affected. Additionally, CCWE suppressed the expression of PA14 QS genes and virulence factors, although it did not affect the growth of the bacteria. These effects correlated with a 28% reduction in the PA14-inflicted killing of C. elegans. Kappa-carrageenan (K-CGN), a major component of CCWE, was shown to play an important role in the enhancement of host immunity. Using C. elegans mutants, we identified that pmk-1, daf-2/daf-16, and skn-1 are essential in the K-CGN-induced host immune response. In view of the conservation of innate immune pathways between C. elegans and humans, the results of this study suggest that water-soluble components of C. crispus may also play a health-promoting role in higher animals and humans. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : cabe6783-95dd-4387-acd0-f56aa8a64df7 ER - TY - JOUR TI - Continuum variability of deeply embedded protostars as a probe of envelope structure DO - 10.1088/0004-637X/765/2/133 AU - Johnstone, D. AU - Hendricks, B. AU - Herczeg, G.J. AU - Bruderer, S. T2 - The Astrophysical Journal SN - 0004-637X VL - 765 IS - 2 SP - 133 AB - Stars may be assembled in large growth spurts; however the evidence for this hypothesis is circumstantial. Directly studying the accretion at the earliest phases of stellar growth is challenging because young stars are deeply embedded in optically thick envelopes, which have spectral energy distributions that peak in the far-IR, where observations are difficult. In this paper, we consider the feasibility of detecting accretion outbursts from these younger stars by investigating the timescales for how the protostellar envelope responds to changes in the emission properties of the central source. The envelope heats up in response to an outburst, brightening at all wavelengths and with the emission peak moving to shorter wavelengths. The timescale for this change depends on the time for dust grains to heat and re-emit photons and the time required for the energy to escape the inner, optically thick portion of the envelope. We find that the dust response time is much shorter than the photon propagation time and thus the timescale over which the emission varies is set by time delays imposed by geometry. These times are hours to days near the peak of the spectral energy distribution and weeks to months in the sub-mm. The ideal location to quickly detect continuum variability is therefore in the mid- to far-IR, near the peak of the spectral energy distribution, where the change in emission amplitude is largest. Searching for variability in sub-mm continuum emission is also feasible, though with a longer time separation and a weaker relationship between the amount of detected emission amplitude and change in central source luminosity. Such observations would constrain accretion histories of protostars and would help to trace the disk/envelope instabilities that lead to stellar growth. © 2013. The American Astronomical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f026beba-78d9-44e9-8e43-f30f376b28d8 ER - TY - JOUR TI - Fabrication of titanium/fluorapatite composites and in vitro behavior in simulated body fluid DO - 10.1016/j.jmst.2013.01.013 AU - Ye, H. AU - Liu, X.Y. AU - Hong, H. T2 - Journal of Materials Science and Technology SN - 1005-0302 VL - 29 IS - 6 SP - 523 EP - 532 KW - Biological environments KW - Carbonated apatite KW - Fluorapatites KW - In-vitro KW - In-vitro bioactivity KW - Induced nucleation KW - Simulated body fluids KW - Surface conditions KW - Bioactivity KW - Calcium carbonate KW - Fluorine KW - Phosphorus compounds KW - Powder metallurgy KW - Titanium KW - Sintering AB - Titanium/fluorapatite (Ti/FA) composites with various FA additions were fabricated by powder metallurgy. The decomposition of FA during sintering was accelerated by the presence of Ti. The main reaction products of FA and Ti were identified as CaO, Ti phosphides, and CaTiO3. The addition of FA significantly inhibited the densification of Ti. The in vitro bioactivity of the composites was evaluated in a simulated body fluid (SBF). After immersion into the SBF, all the Ti/FA composites induced nucleation and growth of bone-like carbonated apatite on the surface. Co-precipitation of CaCO3 and Mg(OH)2 was also detected on the surface of the composite with high FA addition at an early stage of immersion. Furthermore, the release of fluorine ions from the composite was confirmed, which could promote bone regeneration and retard the formation of caries in the biological environment. The in vitro behavior was attributed to multiple factors, including the surface conditions and the constituents of the composite. The results demonstrated that the Ti/FA composites were bioactive in nature even with a low FA addition and they could introduce the benefit of fluorine ions in the service. © 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f702fbbb-3f96-4fb5-9256-14b7e9a23579 ER - TY - JOUR TI - A general approach for robust integrated polarization rotators DO - 10.1117/12.2016845 AU - Alonso-Ramos, C. AU - Halir, R. AU - Ortega-Moñux, A. AU - Cheben, P. AU - Vivien, L. AU - Molina-Fernández, I. AU - Marris-Morini, D. AU - Janz, S. AU - Xu, D.-X. AU - Schmid, J. T2 - SPIE - International Society for Optical Engineering. Proceedings T3 - Integrated Optics: Physics and Simulations, 17 April 2013 through 18 April 2013, Prague SN - 0277-786X SN - 9780819495839 VL - 8781 SP - 878109 KW - Analytical conditions KW - Conventional approach KW - Fabrication tolerances KW - Polarization diversity KW - Polarization phase KW - Polarization rotation KW - Polarization rotator KW - Thermooptic effects KW - Errors KW - Fabrication KW - Integrated optics KW - Light extinction KW - Optical communication KW - Phase shift KW - Phase shifters KW - Polarization AB - Integrated polarization rotators suffer from very high sensitivity to fabrication errors. A polarization rotator scheme that substantially increases fabrication tolerances is proposed. In the proposed scheme, two tunable polarization phase shifters are used to connect three rotator waveguide sections. By means of properly setting the polarization phase shifters, fabrication errors are compensated and perfect polarization rotation is achieved. Analytical conditions are shown that determine the maximum deviation that can be corrected with the proposed scheme. A design example is discussed, where the thermo-optic effect is used to provide the required tunable polarization phase shifting. Calculated 40dB extinction ratio is shown in presence of fabrication errors that would yield a 4dB extinction ratio in the conventional approach. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4fcc02bb-3873-4535-af42-deed789f040e ER - TY - JOUR TI - Global and local mechanical properties of autogenously laser welded Ti-6Al-4V DO - 10.1007/s11661-013-2106-z AU - Cao, X. AU - Kabir, A.S.H. AU - Wanjara, P. AU - Gholipour, J. AU - Birur, A. AU - Cuddy, J. AU - Medraj, M. T2 - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science SN - 1073-5623 SP - 1 EP - 15 AB - Ti-6Al-4V sheets, 3.2-mm in thickness, were butt welded using a continuous wave 4 kW Nd:YAG laser welding system. The effect of two main process parameters, laser power and welding speed, on the joint integrity was characterized in terms of the joint geometry, defects, microstructure, hardness, and tensile properties. In particular, a digital image correlation technique was used to determine the local tensile properties of the welds. It was determined that a wide range of heat inputs can be used to fully penetrate the Ti-6Al-4V butt joints during laser welding. At high laser power levels, however, significant defects such as underfill and porosity, can occur and cause marked degradation in the joint integrity and performance. At low welding speeds, however, significant porosity occurs due to its growth and the potential collapse of instable keyholes. Intermediate to relatively high levels of heat input allow maximization of the joint integrity and performance by limiting the underfill and porosity defects. In considering the effect of the two main defects on the joint integrity, the underfill defect was found to be more damaging to the mechanical performance of the weldment than the porosity. Specifically, it was determined that the maximum tolerable underfill depth for Ti-6Al-4V is approximately 6 pct of the workpiece thickness, which is slightly stricter than the value of 7 pct specified in AWS D17.1 for fusion welding in aerospace applications. Hence, employing optimized laser process parameters allows the underfill depth to be maintained within the tolerable limit (6 pct), which in turn prevents degradation in both the weld strength and ductility. To this end, the ability to maintain weld ductility in Ti-6Al-4V by means of applying a high energy density laser welding process presents a significant advantage over conventional arc welding for the assembly of aerospace components. © 2013 The Minerals, Metals & Materials Society and ASM International. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9981fcb9-3c81-42a7-a1b2-edc9cd070a1e ER - TY - JOUR TI - Photonic fractional-order differentiator using an soi microring resonator with an MMI coupler DO - 10.1109/LPT.2013.2266252 AU - Shahoei, H. AU - Xu, D.-X. AU - Schmid, J.H. AU - Yao, J. T2 - IEEE Photonics Technology Letters SN - 1041-1135 VL - 25 IS - 15 SP - 6523070 SP - 1408 EP - 1411 KW - Fractional order KW - Fractional order differentiator KW - Input polarization KW - Microring resonator KW - Multimode interference couplers KW - Optical Differentiator KW - Resonance wavelengths KW - Silicon photonics KW - Integrated optics KW - Phase shift KW - Phase shifters KW - Photonics KW - Optical resonators AB - An optically tunable fractional order temporal differentiator implemented using a silicon-on-isolator microring resonator with a multimode interference (MMI) coupler is proposed and experimentally demonstrated. Through changing the input polarization state, the self coupling coefficient and the loss factor of the designed ring resonator with the MMI coupler are changed. Correspondingly, the coupling regime is changed. Through changing the coupling regime from over-coupled to under-coupled regime, the phase shift in the resonance wavelength is changed from <π to >π. This tunable phase shift is used to implement a tunable fractional order photonic differentiator with an order tunable from <1 to > 1. The proposed fractional order differentiator is demonstrated experimentally. A Gaussian pulse with a bandwidth of 45 GHz is temporally differentiated with a tunable order of 0.37, 0.67, 1, 1.2, and 1.3. © 1989-2012 IEEE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : dea43f32-e767-4098-9175-ff1ba7c4473f ER - TY - JOUR TI - A common pathway for O-linked protein-glycosylation and synthesis of capsule in Acinetobacter baumannii DO - 10.1111/mmi.12300 AU - Lees-Miller, R.G. AU - Iwashkiw, J.A. AU - Scott, N.E. AU - Seper, A. AU - Vinogradov, E. AU - Schild, S. AU - Feldman, M.F. T2 - Molecular Microbiology SN - 0950-382X VL - 89 IS - 5 SP - 816 EP - 830 KW - glycoprotein KW - glycosyltransferase KW - pentasaccharide KW - Acinetobacter baumannii KW - article KW - bacterial capsule KW - bacterial virulence KW - biosynthesis KW - capsule biosynthesis KW - gene locus KW - glycoprotein synthesis KW - mass spectrometry KW - microbial attenuation KW - mouse KW - mutagenesis KW - nonhuman KW - nuclear magnetic resonance KW - priority journal KW - protein analysis KW - protein assembly KW - protein glycosylation KW - protein polymerization KW - protein structure KW - protein transport KW - reversed phase liquid chromatography KW - Acinetobacter baumannii KW - Bacteria (microorganisms) KW - Mus AB - Multi-drug resistant strains of Acinetobacter baumannii are increasingly being isolated in hospitals worldwide. Among the virulence factors identified in this bacterium there is a general O-glycosylation system that appears to be important for biofilm formation and virulence, and the capsular polysaccharide, which is essential for resistance to complement killing. In this work, we identified a locus that is responsible for the synthesis of the O-pentasaccharide found on the glycoproteins. Besides the enzymes required for the assembly of the glycan, additional proteins typically involved in polymerization and transport of capsule were identified within or adjacently to the locus. Mutagenesis of PglC, the initiating glycosyltransferase prevented the synthesis of both glycoproteins and capsule, resulting in abnormal biofilm structures and attenuated virulence in mice. These results, together with the structural analysis of A. baumannii 17978 capsular polysaccharide via NMR, demonstrated that the pentasaccharides that decorate the glycoproteins are also the building blocks for capsule biosynthesis. Two linked subunits, but not longer glycan chains, were detected on proteins via MS. The discovery of a bifurcated pathway for O-glycosylation and capsule synthesis not only provides insight into the biology of A. baumannii but also identifies potential novel candidates for intervention against this emerging pathogen. © 2013 John Wiley & Sons Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a62261a8-857f-4a76-826f-810b35930d86 ER - TY - JOUR TI - Susceptibility-weighted imaging in the experimental autoimmune encephalomyelitis model of multiple sclerosis indicates elevated deoxyhemoglobin, iron deposition and demyelination DO - 10.1177/1352458512460602 AU - Nathoo, N. AU - Agrawal, S. AU - Wu, Y. AU - Haylock-Jacobs, S. AU - Yong, V.W. AU - Foniok, T. AU - Barnes, S. AU - Obenaus, A. AU - Dunn, J.F. T2 - Multiple Sclerosis SN - 1352-4585 VL - 19 IS - 6 SP - 721 EP - 731 KW - deoxyhemoglobin KW - iron KW - myelin KW - allergic encephalomyelitis KW - animal experiment KW - animal model KW - animal tissue KW - article KW - cerebellum KW - controlled study KW - demyelination KW - disease model KW - female KW - gray matter KW - inflammation KW - lumbar spinal cord KW - mouse KW - multiple sclerosis KW - nonhuman KW - signal processing KW - susceptibility weighted imaging KW - white matter AB - Background: Susceptibility-weighted imaging (SWI) is an iron-sensitive magnetic resonance imaging (MRI) method that has shown iron-related lesions in multiple sclerosis (MS) patients. The contribution of deoxyhemoglobin to the signals seen in SWI has not been well characterized in MS. Objectives: To determine if SWI lesions (seen as focal hypointensities) exist in the experimental autoimmune encephalomyelitis (EAE) animal model of MS, and to determine whether the lesions relate to iron deposits, inflammation, demyelination, and/or deoxyhemoglobin in the vasculature. Methods: We performed SWI on the lumbar spinal cord and cerebellum of EAE and control mice (both complete Freund's adjuvant/pertussis toxin (CFA/PTX)-immunized and naive). We also performed SWI on mice before and after perfusion (to remove blood from vessels). SWI lesions were counted and their locations were compared to histology for iron, myelin and inflammation. Results: SWI lesions were found to exist in the EAE model. Many lesions seen by SWI were not present after perfusion, especially at the grey/white matter boundary of the lumbar spinal cord and in the cerebellum, indicating that these lesion signals were associated with deoxyhemoglobin present in the lumen of vessels. We also observed SWI lesions in the white matter of the lumbar spinal cord that corresponded to iron deposition, inflammation and demyelination. In the cerebellum, SWI lesions were present in white matter tracts, where we found histological evidence of inflammatory perivascular cuffs. Conclusions: SWI lesions exist in EAE mice. Many lesions seen in SWI were a result of deoxyhemoglobin in the blood, and so may indicate areas of hypoxia. A smaller number of SWI lesions coincided with parenchymal iron, demyelination, and/or inflammation. © The Author(s) 2012. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9a3034e2-7db6-40d4-9754-1c7a3e554f7d ER - TY - JOUR TI - Molecular strong field ionization and high harmonic generation: A selection of computational illustrations DO - 10.1016/j.chemphys.2011.12.016 AU - Spanner, M. AU - Patchkovskii, S. T2 - Chemical Physics SN - 0301-0104 VL - 414 SP - 10 EP - 19 AB - Strong field ionization (SFI) and high harmonic generation (HHG) are the central processes that enable attosecond physics. To date, most theoretical investigations of SFI and HHG rely on semiclassical methods, most notably the strong field approximation (SFA), which treats the continuum states of the liberated electron as plane waves. SFA is a very successful conceptual model for atoms and small molecules, and leads to an intuitively satisfying picture of HHG (i.e. the three-step model). However, as SFI and HHG experiments enter the regime of polyatomic molecules, many approximations made in SFA-type models can no longer be ignored even for a qualitatively correct understanding. In this contribution, we present a selection of results from our efforts toward ab initio modeling of strong field processes in molecular systems. The method is applicable to single-electron ionization and HHG of gas-phase polyatomic molecular targets. © 2012 Elsevier B.V. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 962b9ecb-94c2-41ff-93b5-0620762ff037 ER - TY - JOUR TI - Gene function hypotheses for the Campylobacter jejuni glycome generated by a logic-based approach DO - 10.1016/j.jmb.2012.10.014 AU - Sternberg, M.J.E. AU - Tamaddoni-Nezhad, A. AU - Lesk, V.I. AU - Kay, E. AU - Hitchen, P.G. AU - Cootes, A. AU - Van Alphen, L.B. AU - Lamoureux, M.P. AU - Jarrell, H.C. AU - Rawlings, C.J. AU - Soo, E.C. AU - Szymanski, C.M. AU - Dell, A. AU - Wren, B.W. AU - Muggleton, S.H. T2 - Journal of Molecular Biology SN - 0022-2836 VL - 425 IS - 1 SP - 186 EP - 197 KW - glucuronosyltransferase KW - heptose guanosyltransferase KW - heptose kinase KW - methyltransferase KW - sedoheptulose isomerase KW - sugar transferase KW - unclassified drug KW - article KW - Campylobacter jejuni KW - DNA microarray KW - gene expression KW - gene function KW - knockout gene KW - machine learning KW - nonhuman KW - priority journal KW - serotype KW - Artificial Intelligence KW - Bacterial Capsules KW - Biosynthetic Pathways KW - Campylobacter jejuni KW - Gene Knockout Techniques KW - Genes, Bacterial KW - Glycomics KW - Logic KW - Metabolomics KW - Models, Biological KW - Molecular Sequence Annotation KW - Mutation KW - Oligonucleotide Array Sequence Analysis KW - Phenotype KW - Polysaccharides, Bacterial KW - Systems Biology KW - Campylobacter jejuni AB - Increasingly, experimental data on biological systems are obtained from several sources and computational approaches are required to integrate this information and derive models for the function of the system. Here, we demonstrate the power of a logic-based machine learning approach to propose hypotheses for gene function integrating information from two diverse experimental approaches. Specifically, we use inductive logic programming that automatically proposes hypotheses explaining the empirical data with respect to logically encoded background knowledge. We study the capsular polysaccharide biosynthetic pathway of the major human gastrointestinal pathogen Campylobacter jejuni. We consider several key steps in the formation of capsular polysaccharide consisting of 15 genes of which 8 have assigned function, and we explore the extent to which functions can be hypothesised for the remaining 7. Two sources of experimental data provide the information for learning - the results of knockout experiments on the genes involved in capsule formation and the absence/presence of capsule genes in a multitude of strains of different serotypes. The machine learning uses the pathway structure as background knowledge. We propose assignments of specific genes to five previously unassigned reaction steps. For four of these steps, there was an unambiguous optimal assignment of gene to reaction, and to the fifth, there were three candidate genes. Several of these assignments were consistent with additional experimental results. We therefore show that the logic-based methodology provides a robust strategy to integrate results from different experimental approaches and propose hypotheses for the behaviour of a biological system. © 2012 Elsevier Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c567c96c-e878-4326-b202-05390750300b ER - TY - JOUR TI - Potential shortfall of pyramided transgenic cotton for insect resistance management DO - 10.1073/pnas.1216719110 AU - Brévault, T. AU - Heuberger, S. AU - Zhang, M. AU - Ellers-Kirk, C. AU - Ni, X. AU - Masson, L. AU - Li, X. AU - Tabashnik, B.E. AU - Carrière, Y. T2 - Proceedings of the National Academy of Sciences of the United States of America SN - 0027-8424 VL - 110 IS - 15 SP - 5806 EP - 5811 KW - Cry1Ab toxin KW - Cry1Ac toxin KW - article KW - controlled study KW - cotton KW - cross resistance KW - Diatracea saccharalis KW - Helicoverpa armigera KW - Helicoverpa punctigera KW - Helicoverpa zea KW - heliothis virescens KW - insect resistance KW - Lepidoptera KW - nonhuman KW - Pectinophora gossypiella KW - plant growth KW - plant leaf KW - Plutella xylostella KW - priority journal KW - seasonal variation KW - simulation KW - species KW - survival KW - transgenic plant KW - trichoplusia ni KW - Alleles KW - Animals KW - Bacillus thuringiensis KW - Bacterial Proteins KW - Crops, Agricultural KW - Endotoxins KW - Gossypium KW - Hemolysin Proteins KW - Inhibitory Concentration 50 KW - Insecticide Resistance KW - Insecticides KW - Moths KW - Pest Control, Biological KW - Plants, Genetically Modified KW - Bacillus thuringiensis KW - Gossypium hirsutum KW - Helicoverpa zea KW - Hexapoda AB - To delay evolution of pest resistance to transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt), the "pyramid" strategy uses plants that produce two or more toxins that kill the same pest. In the United States, this strategy has been adopted widely, with two-toxin Bt cotton replacing one-toxin Bt cotton. Although two-toxin plants are likely to be more durable than one-toxin plants, the extent of this advantage depends on several conditions. One key assumption favoring success of two-toxin plants is that they kill insects selected for resistance to one toxin, which is called "redundant killing." Here we tested this assumption for a major pest, Helicoverpa zea, on transgenic cotton producing Bt toxins Cry1Ac and Cry2Ab. Selection with Cry1Ac increased survival on two-toxin cotton, which contradicts the assumption. The concentration of Cry1Ac and Cry2Ab declined during the growing season, which would tend toexacerbate this problem. Furthermore, analysis of results from 21 selection experiments with eight species of lepi-dopteran pests indicates that some cross-resistance typically occurs between Cry1A and Cry2A toxins. Incorporation of empirical data into simulation models shows that the observed deviations from ideal conditions could greatly reduce the benefits of the pyramid strategy for pests like H. zea, which have inherently low susceptibility to Bt toxins and have been exposed extensively to one of the toxins in the pyramid before two-toxin plants are adopted. For such pests, the pyramid strategy could be improved by incorporating empirical data on deviations from ideal assumptions about redundant killing and cross-resistance. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 92241b52-beb5-427b-82b5-73bf60dcf050 ER - TY - JOUR TI - Understanding chair absorption characteristics using the perimeter-to-area method DO - 10.1016/j.apacoust.2013.03.009 AU - Bradley, J.S. AU - Choi, Y.-J. AU - Jeong, D.-U. T2 - Applied Acoustics SN - 0003-682X VL - 74 IS - 9 SP - 1060 EP - 1068 KW - Absorption characteristics KW - Absorption co-efficient KW - Common source KW - Measurements of KW - Perimeter-to-area KW - Physical characteristics KW - Sound absorption KW - Sound absorption characteristic KW - Auditoriums KW - Sound insulating materials KW - Acoustic wave absorption AB - Measurements of the sound absorption of several blocks of chairs with varied perimeter-to-area (P/A) ratios were used to examine how chair absorption coefficients are related to their physical characteristics. Because the P/A method combines the results of several samples of each type of chair, a more accurate understanding can be obtained of how the physical properties of the chairs are related to their sound absorption characteristics. Unoccupied chairs are shown to have a wide range of characteristics and it is necessary to test each type of chair to accurately predict their effect in an auditorium. However, the absorption characteristics of occupied chairs are strongly influenced by the absorption of the occupants and an approximate average sound absorption characteristic can be useful for predicting the effect of occupied chairs in an auditorium. Although the variations of sound absorption with row spacing are related to P/A, the variations are quite different than when simply changing the P/A for chair samples with constant row spacing. Both chair underpass height and chair back height affect the absorption characteristics of theater chairs, but the effects can be influenced by the presence of carpet under the chairs or by occupants in the chairs. Common sources of increased sound absorption in each octave band are identified and discussed. © 2013 Elsevier B.V.All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9cd7e9a9-291f-40f2-9c85-6f90c2e8652a ER - TY - JOUR TI - Acute toxicities of saxitoxin, neosaxitoxin, decarbamoyl saxitoxin and gonyautoxins 1&4 and 2&3 to mice by various routes of administration DO - 10.1016/j.toxicon.2013.09.013 AU - Munday, R. AU - Thomas, K. AU - Gibbs, R. AU - Murphy, C. AU - Quilliam, M.A. T2 - Toxicon SN - 0041-0101 VL - 76 SP - 77 EP - 83 KW - decarbamoylsaxitoxin KW - gonyautoxin KW - neosaxitoxin KW - saxitoxin KW - acute toxicity KW - animal experiment KW - article KW - calibration KW - female KW - LD 50 KW - mortality KW - mouse KW - nonhuman KW - priority journal KW - toxicity equivalence factor KW - toxicological parameters AB - Saxitoxin and its derivatives, the paralytic shellfish toxins (PSTs), are known to be toxic to humans, and maximum permitted levels in seafood have been established by regulatory authorities in many countries. Until recently, the mouse bioassay was the reference method for determining the levels of these toxins in seafood, but this has now been superseded by chemical methods of analysis. The latter methods are able to determine the levels of many PSTs in shellfish, but for risk assessment an estimate of the relative toxicities of the individual components of the PST mixture is required. The relative toxicities are expressed as "Toxicity Equivalence Factors" (TEFs). At present, TEFs are based on relative specific activities in the mouse bioassay, rather than on acute toxicity determinations, as measured by median lethal doses (LD50s). In the present study, the median lethal doses of saxitoxin, neosaxitoxin, decarbamoyl saxitoxin and equilibrium mixtures of gonyautoxins 1&4 and gonyautoxins 2&3 have been determined by intraperitoneal injection, gavage and feeding. The results indicate that specific activities in the MBA do not consistently correlate with acute toxicities by any of the routes of administration, and TEFs, particularly for neosaxitoxin, require revision. © 2013 Elsevier Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 381421a0-0db8-4a4e-87af-2096bd8a6044 ER - TY - JOUR TI - Relationship between soot volume fraction and LII signal in AC-LII: effect of primary soot particle diameter polydispersity DO - 10.1007/s00340-012-5330-0 AU - Liu, F. AU - Smallwood, G.J. T2 - Applied Physics B: Lasers and Optics SN - 0946-2171 SP - 1 EP - 13 AB - Theoretical analysis and numerical calculations were conducted to investigate the relationship between soot volume fraction and laser-induced incandescence (LII) signal within the context of the auto-compensating LII technique. The emphasis of this study lies in the effect of primary soot particle diameter polydispersity. The LII model was solved for a wide range of primary soot particle diameters from 2 to 80 nm. For a log-normally distributed soot particle ensemble encountered in a typical laminar diffusion flame at atmospheric pressure, the LII signals at 400 and 780 nm were calculated. To quantify the effects of sublimation and differential conduction cooling on the determined soot volume fraction in auto-compensating LII, two new quantities were introduced and demonstrated to be useful in LII study: an emission intensity distribution function and a scaled soot volume fraction. When the laser fluence is sufficiently low to avoid soot mass loss due to sublimation, accurate soot volume fraction can be obtained as long as the LII signals are detected within the first 200 ns after the onset of the laser pulse. When the laser fluence is in the high fluence regime to induce significant sublimation, however, the LII signals should be detected as early as possible even before the laser pulse reaches its peak when the laser fluence is sufficiently high. The analysis method is shown to be useful to provide guidance for soot volume fraction measurements using the auto-compensating LII technique. © 2013 Her Majesty the Queen in Right of Canada. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c7dd07e3-975a-4ee5-acf2-2f553030bb49 ER - TY - JOUR TI - UV-induced atomization of gaseous mercury hydrides for atomic fluorescence spectrometric detection of inorganic and organic mercury after high performance liquid chromatographic separation DO - 10.1039/c3ja30363b AU - Huang, K. AU - Xu, K. AU - Hou, X. AU - Jia, Y. AU - Zheng, C. AU - Yang, L. T2 - Journal of Analytical Atomic Spectrometry SN - 0267-9477 VL - 28 IS - 4 SP - 510 EP - 515 KW - Analytical results KW - Atomic fluorescence KW - Atomic fluorescence spectrometry KW - Experimental conditions KW - Limits of detection KW - Liquid chromatographic separations KW - Relative standard deviations KW - Spectrometric detection KW - Atomization KW - Chromatography KW - Fluorescence spectroscopy KW - High performance liquid chromatography KW - Hydrides KW - Tissue KW - Mercury (metal) AB - A novel, simple, low power, low temperature (<45 °C) and high efficiency atomization technique using ultraviolet (UV) radiation was proposed for the atomization of gaseous mercury hydrides for their determination by atomic fluorescence spectrometry (AFS). This technique was used for the detection of inorganic mercury (Hg2+) and organic mercury (MeHg + and EtHg+) after high performance liquid chromatographic separation. In the proposed method, with 0.5% (m/v) KBH4 used as a reductant, inorganic mercury was reduced to elemental mercury, whereas the organic mercury species formed their respective volatile organic mercury hydrides (MeHgH and EtHgH) which were flushed to the UV atomizer for atomization and AFS detection. Under the optimized experimental conditions, the limits of detection were found to be 0.38, 0.41 and 0.56 μg L-1, and the relative standard deviations (n = 3) were 1.1%, 2.6% and 1.4% for Hg 2+, MeHg+ and EtHg+, respectively. The accuracy of the proposed method was validated by analyzing a certified reference sample (fish muscle tissue) with a satisfactory analytical result, and two water samples with recoveries in the range of 93.8-97.4%.© The Royal Society of Chemistry 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 179ba68b-51fd-405f-ad62-3e94e5d72ea5 ER - TY - JOUR TI - The ACS Virgo cluster survey. XVII. The spatial alignment of globular cluster systems with early-type host galaxies DO - 10.1088/0004-637X/769/2/145 AU - Wang, Q. AU - Peng, E.W. AU - Blakeslee, J.P. AU - Côté, P. AU - Ferrarese, L. AU - Jordán, A. AU - Mei, S. AU - West, M.J. T2 - The Astrophysical Journal SN - 0004-637X VL - 769 IS - 2 SP - 145 AB - We study the azimuthal distribution of globular clusters (GCs) in early-type galaxies and compare them to their host galaxies using data from the ACS Virgo Cluster Survey. We find that in host galaxies with visible elongation (ε > 0.2) and intermediate to high luminosities (Mz < -19), the GCs are preferentially aligned along the major axis of the stellar light. The red (metal-rich) GC subpopulations show strong alignment with the major axis of the host galaxy, which supports the notion that these GCs are associated with metal-rich field stars. The metal-rich GCs in lenticular galaxies show signs of being more strongly associated with disks rather than bulges. Surprisingly, we also find that the blue (metal-poor) GCs can also show the same correlation. If the metal-poor GCs are part of the early formation of the halo and built up through mergers, then our results support a picture where halo formation and merging occur anisotropically, and that the present-day major axis is an indicator of the preferred merging axis. © 2013. The American Astronomical Society. All rights reserved.. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ef2f4315-1543-42af-9199-908f910ec0fe ER - TY - JOUR TI - A key role of microRNA-29b for the suppression of colon cancer cell migration by American ginseng DO - 10.1371/journal.pone.0075034 AU - Poudyal, D. AU - Cui, X. AU - Le, P.M. AU - Hofseth, A.B. AU - Windust, A. AU - Nagarkatti, M. AU - Nagarkatti, P.S. AU - Schetter, A.J. AU - Harris, C.C. AU - Hofseth, L.J. T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 10 SP - e75034 KW - gelatinase A KW - hexane KW - microRNA 29b KW - Panax quinquefolius extract KW - plant extract KW - unclassified drug KW - antineoplastic activity KW - article KW - cancer inhibition KW - cell migration KW - colon cancer KW - human KW - human cell KW - molecular mechanics KW - nonhuman KW - Panax quinquefolius KW - protein function KW - protein targeting KW - regulatory mechanism AB - Metastasis of colon cancer cells increases the risk of colon cancer mortality. We have recently shown that American ginseng prevents colon cancer, and a Hexane extract of American Ginseng (HAG) has particularly potent anti-inflammatory and anti-cancer properties. Dysregulated microRNA (miR) expression has been observed in several disease conditions including colon cancer. Using global miR expression profiling, we observed increased miR-29b in colon cancer cells following exposure to HAG. Since miR-29b plays a role in regulating the migration of cancer cells, we hypothesized that HAG induces miR-29b expression to target matrix metalloproteinase-2 (MMP-2) thereby suppressing the migration of colon cancer cells. Results are consistent with this hypothesis. Our study supports the understanding that targeting MMP-2 by miR-29b is a mechanism by which HAG suppresses the migration of colon cancer cells. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 08efc757-5631-4d93-8567-fdbfaec20db7 ER - TY - JOUR TI - Mesoporous carbons supported non-noble metal Fe-N X electrocatalysts for PEM fuel cell oxygen reduction reaction DO - 10.1007/s10800-012-0497-y AU - Monteverde Videla, A.H.A. AU - Zhang, L. AU - Kim, J. AU - Zeng, J. AU - Francia, C. AU - Zhang, J. AU - Specchia, S. T2 - Journal of Applied Electrochemistry SN - 0021-891X VL - 43 IS - 2 SP - 159 EP - 169 KW - Exchange current densities KW - Hollow core-mesoporous shell carbons KW - Mesoporosity KW - Mesoporous carbon KW - Non-noble metal catalysts KW - Oxygen reduction reaction KW - Performance improvements KW - Ultrasonic spray pyrolysis KW - Carbon KW - Electrolysis KW - Electrolytic reduction KW - Mesoporous materials KW - Microporosity KW - Nitrogen KW - Precious metals KW - Proton exchange membrane fuel cells (PEMFC) KW - Rotating disks KW - Spray pyrolysis KW - Ultrasonic applications KW - Electrocatalysts AB - Three types of iron-nitrogen-containing non-noble metal catalysts, supported on an ultrasonic spray pyrolysis mesoporous carbon (USPMC), a hollow core mesoporous shell carbon (HCMSC), and a standard carbon (Ketjen Black CJ600, KB), respectively, are synthesized using a wet-impregnation method. The morphologies and structure as well as composition of the synthesized carbon supports and their corresponding supported Fe-N X catalysts (namely Fe-N X /USPMC, Fe-N X /HCMSC, and Fe-N X /KB, respectively) are physically characterized using EDX, SEM, FESEM, and BET analysis, respectively. The catalytic activities of these three electrocatalysts toward oxygen reduction reaction (ORR) are measured using rotating disk electrode technique in O2-saturated 0.5 M H2SO4 solution. The catalyzed ORR exchange current densities are also obtained using the Tafel method based on the measured data. Among these three electrocatalysts, Fe-N X /HCMSC can give the best ORR performance, which is correlated to its higher nitrogen, mesopore, and micropore contents, compared to the other electrocatalysts. It is rationalized that the performance improvement of these electrocatalysts may be achieved as long as an optimal relationship among mesopores, micropores, and even macropores for increasing both ORR kinetics and reactant gases accessibility to the active sites can be found. © 2012 Springer Science+Business Media Dordrecht. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5198d8ae-d07c-4b57-8930-79dd1f12c8c6 ER - TY - JOUR TI - Prediction of the active layer nanomorphology in polymer solar cells using molecular dynamics simulation DO - 10.1021/am400566f AU - Ashrafi Khajeh, A.R. AU - Shankar, K. AU - Choi, P. T2 - ACS Applied Materials and Interfaces SN - 1944-8244 VL - 5 IS - 11 SP - 4617 EP - 4624 KW - Active Layer KW - Bulk heterojunction KW - Cylindrical structure KW - Degree of polymerization KW - Flory-Huggins interaction parameter KW - Molecular dynamics simulations KW - Nanomorphologies KW - Polymer solar cell (PSCs) KW - Heterojunctions KW - Molecular dynamics KW - Molecular mechanics KW - Nanostructured materials KW - Solar cells KW - Block copolymers AB - Active layer nanomorphology is a major factor that determines the efficiency of bulk heterojunction polymer solar cells (PSCs). Synthesizing diblock copolymers in which acceptor and donor materials are the constituent blocks is the most recent method to control the structure of the active layer. In the current work, a computational method is proposed to predict the nanomorphology of the active layer consisting of a diblock copolymer. Diblock copolymers have a tendency to self-organize and form well-defined nanostructures. The shape of the structure depends on the Flory-Huggins interaction parameter (i.e., χ), the total degree of polymerization (N) and volume fractions of the constituent blocks (φi). In this work, molecular dynamics (MD) simulations were used to calculate χ parameters for two different block copolymers used in PSCs: P3HT-b-poly(S8A 2)-C60 and P3HT-b-poly(n-butyl acrylate-stat-acrylate perylene) also known as P3HT-b-PPerAcr. Such calculations indicated strong segregation of blocks into cylindrical structure for P3HT-b-poly(S 8A2)-C60 and intermediate segregation into cylindrical structure for P3HT-b-PPerAcr. Experimental results of P3HT-b-poly(S8A2)-C60 and P3HT-b-PTP4AP, a diblock copolymer having very similar structure to P3HT-b-PPerAcr, validate our predictions. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f8754202-7ced-4757-a133-bd16b0bd9ae0 ER - TY - JOUR TI - Coiled-coil-mediated grafting of bioactive vascular endothelial growth factor DO - 10.1016/j.actbio.2013.02.032 AU - Murschel, F. AU - Liberelle, B. AU - St-Laurent, G. AU - Jolicoeur, M. AU - Durocher, Y. AU - De Crescenzo, G. T2 - Acta Biomaterialia SN - 1742-7061 VL - 9 IS - 6 SP - 6806 EP - 6813 KW - chimeric protein KW - homodimer KW - vasculotropin KW - vasculotropin 165 KW - article KW - assay KW - biological activity KW - cell survival KW - controlled study KW - human KW - human cell KW - immobilization KW - in vitro study KW - phenotype KW - priority journal KW - protein binding KW - surface plasmon resonance KW - Mammalia AB - Chimeric growth factors may represent a powerful alternative to their natural counterparts for the functionalization of tissue-engineered scaffolds and applications in regenerative medicine. Their rational design should provide a simple, readily scalable production strategy while improving retention at the site of action. In that endeavor, we here report the synthesis of a chimeric protein corresponding to human vascular endothelial growth factor 165 being N-terminally fused to an E5 peptide tag (E5-VEGF). E5-VEGF was successfully expressed as a homodimer in mammalian cells. Following affinity purification, in vitro surface plasmon resonance biosensing and cell survival assays confirmed diffusible E5-VEGF ability to bind to its receptor ectodomains, while observed morphological phenotypes confirmed its anti-apoptotic features. Additional surface plasmon resonance assays highlighted that E5-VEGF could be specifically captured with high stability when interacting with covalently immobilized K5 peptide (a synthetic peptide designed to bind to the E5 moiety of chimeric hVEGF). This immobilization strategy was applied to glass substrates and chimeric hVEGF was shown to be maintained in a functionally active state following capture. Altogether, our data demonstrated that stable hVEGF capture can be performed via coiled-coil interactions without impacting hVEGF bioactivity, thus opening up the way to future applications in the field of tissue engineering and regenerative medicine. © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2562da32-8212-437f-b13a-7ddcf3d6e668 ER - TY - JOUR TI - Advanced oxidation using Fe₃O₄ magnetic nanoparticles and its application in mercury speciation analysis by high performance liquid chromatography-cold vapor generation atomic fluorescence spectrometry DO - 10.1039/c3an00010a AU - Ai, Xi AU - Wang, Yu AU - Hou, Xiandeng AU - Yang, Lu AU - Zheng, Chengbin AU - Wu, Li T2 - Analyst SN - 0003-2654 VL - 138 IS - 12 SP - 3494 EP - 3501 AB - A novel, green and efficient post-column oxidation method using Fe₃O₄4 magnetic nanoparticles (MNPs) was developed to on-line convert hydride generation/cold vapor generation (HG/CV) inactive species to their active species without microwave/UV irradiation. It was applied to high performance liquid chromatography HG/CV atomic fluorescence spectrometry (HPLC-HG/CV-AFS) to enable sensitive speciation analysis of both HG/CV inactive and active species. Inorganic mercury (Hg²⁺), methylmercury (MeHg), ethylmercury (EtHg) and phenylmercury (PhHg) were selected as model compounds to validate the methodology. Separation of these mercury species was accomplished on a RP-C18 column with a mixture of acetonitrile and water (10 : 90) at pH 6.8 containing 0.12% (m/v) l-cysteine as the mobile phase. In the presence of 0.6% (v/v) H₂O₂, on-line conversion of the organomercury species eluted from the HPLC column to Hg²⁺ was obtained using the advanced oxidation method at pH 2.0. Optimum conditions for the separation, oxidation and cold vapor generation were carefully investigated. The limits of detection (LODs) were 0.7, 1.1, 0.8 and 0.9 μg L-1 (as Hg) for Hg²⁺, MeHg, EtHg and PhHg, respectively, corresponding to 14, 22, 16 and 18 pg absolute detection limits for Hg²⁺, MeHg, EtHg and PhHg by using a 20 μL sample loop, which are comparable to or better than those previously reported. National Research Council Canada DORM-2 fish muscle tissue and several real water samples were analyzed to validate the accuracy of the proposed method. DA - 2013/03/05 PY - 2013 PB - Royal Society of Chemistry LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ecc82532-349e-44b0-98ef-8d1062b83e69 ER - TY - JOUR TI - Resolving multiple non-equivalent metal sites in magnesium-containing metal-organic frameworks by natural abundance 25Mg solid-state NMR spectroscopy DO - 10.1002/chem.201300113 AU - Xu, J. AU - Terskikh, V.V. AU - Huang, Y. T2 - Chemistry - A European Journal SN - 0947-6539 VL - 19 IS - 14 SP - 4432 EP - 4436 KW - 3QMAS KW - Local environments KW - Metal organic framework KW - Metal sites KW - Natural abundance KW - Solid state NMR KW - Solid-state NMR spectroscopy KW - Theoretical calculations KW - Crystalline materials KW - Magic angle spinning KW - Microporous materials KW - Solid state physics KW - Nuclear magnetic resonance spectroscopy AB - In a spin: Directly differentiating multiple Mg sites in Mg-containing MOFs by 25Mg solid-state NMR spectroscopy is very challenging at natural abundance. By performing 25Mg two-dimensional triple-quantum magic-angle spinning solid-state NMR experiments at a magnetic field of 21.1 T at natural abundance, four non-equivalent Mg sites with very similar local environments in α-Mg3(HCOO)6 were unambiguously resolved (see figure). Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e240162e-7471-419c-a4ef-7515f6262725 ER - TY - JOUR TI - Quantification of superparamagnetic iron oxide using inversion recovery balanced steady-state free precession DO - 10.1016/j.mri.2013.03.010 AU - Pelot, N.A. AU - Bowen, C.V. T2 - Magnetic Resonance Imaging SN - 0730-725X VL - 31 IS - 6 SP - 953 EP - 960 KW - superparamagnetic iron oxide KW - algorithm KW - animal experiment KW - article KW - artifact KW - calibration KW - feasibility study KW - in vitro study KW - in vivo study KW - inversion recovery balanced steady state free precession KW - mathematical model KW - mouse KW - nonhuman KW - nuclear magnetic resonance imaging KW - priority journal KW - quantitative analysis KW - simulation AB - Cellular and molecular MRI trafficking studies using superparamagnetic iron oxide (SPIO) have greatly improved non-invasive investigations of disease progression and drug efficacy, but thus far, these studies have largely been restricted to qualitative assessment of hypo- or hyperintense areas near SPIO. In this work, SPIO quantification using inversion recovery balanced steady-state free precession (IR-bSSFP) was demonstrated at 3T by extracting R2 values from a monoexponential model (P. Schmitt et al., 2004). A low flip angle was shown to reduce the apparent recovery rate of the IR-bSSFP time course, thus extending the dynamic range of quantification. However, low flip angle acquisitions preclude the use of traditional methods for combining RF phase-cycled images to reduce banding artifacts arising from off-resonance due to B0 inhomogeneity. To achieve R2 quantification of SPIO, we present a new algorithm applicable to low flip angle IR-bSSFP acquisitions that is specifically designed to identify on-resonance acquisitions. We demonstrate in this work, using both theoretical and empirical methods, that the smallest estimated R2 from multiple RF phase-cycled acquisitions correspond well to the on-resonance time course. Using this novel minimum R2 algorithm, homogeneous R2 maps and linear R2 calibration curves were created up to 100μg(Fe)/mL with 20° flip angles, despite substantial B0 inhomogeneity. In addition, we have shown this technique to be feasible for pre-clinical research: the minimum R2 algorithm was resistant to off-resonance in a single slice mouse R2 map, whereas maximum intensity projection resulted in banding artifacts and overestimated R2 values. With the application of recent advances in accelerated acquisitions, IR-bSSFP has the potential to quantify SPIO in vivo, thus providing important information for oncology, immunology, and regenerative medicine MRI studies. © 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 88173c8d-1ef5-497f-9c5c-645981b87c7f ER - TY - JOUR TI - Lap shear strength and fatigue behavior of friction stir spot welded dissimilar magnesium-to-aluminum joints with adhesive DO - 10.1016/j.msea.2012.11.039 AU - Chowdhury, S.H. AU - Chen, D.L. AU - Bhole, S.D. AU - Cao, X. AU - Wanjara, P. T2 - Materials Science and Engineering A SN - 0921-5093 VL - 562 SP - 53 EP - 60 KW - Adhesive interlayers KW - Al alloys KW - Anthropogenic greenhouse gas emissions KW - Automotive sector KW - Dissimilar weld KW - Failure energy KW - Fatigue behavior KW - Fatigue failure mode KW - Fatigue failures KW - Fatigue properties KW - Friction stir KW - Friction stir spot welding KW - Fuel efficiency KW - Interfacial layer KW - Lap shear strength KW - Lightweighting KW - Loading direction KW - Mg alloy KW - Motor vehicle KW - Pull-out failure KW - Spot welded KW - Stir zones KW - Structural applications KW - Adhesives KW - Aluminum KW - Cyclic loads KW - Failure modes KW - Fatigue of materials KW - Gas emissions KW - Greenhouse gases KW - Magnesium KW - Magnesium alloys KW - Spot welding KW - Stress concentration KW - Welding KW - Welds KW - Aluminum alloys AB - Lightweighting is currently considered as an effective way in improving fuel efficiency and reducing anthropogenic greenhouse gas emissions. The structural applications of lightweight magnesium and aluminum alloys in the aerospace and automotive sectors unavoidably involve welding and joining while guaranteeing the safety and durability of motor vehicles. The objective of this study was to evaluate the lap shear strength and fatigue properties of friction stir spot welded (FSSWed) dissimilar AZ31B-H24 Mg alloy and Al alloy (AA) 5754-O in three combinations, i.e., (top) Al/Mg (bottom), Al/Mg with an adhesive interlayer, and Mg/Al with an adhesive interlayer. For all the dissimilar Mg-to-Al weld combinations, FSSW induced an interfacial layer in the stir zone (SZ) that was composed of intermetallic compounds of Al3Mg2 and Al12Mg17, which led to an increase in hardness. Both Mg/Al and Al/Mg dissimilar adhesive welds had significantly higher lap shear strength, failure energy and fatigue life than the Al/Mg dissimilar weld without adhesive. Two different types of fatigue failure modes were observed. In the Al/Mg adhesive weld, at high cyclic loads nugget pull-out failure occurred due to fatigue crack propagation circumferentially around the nugget. At low cyclic loads, fatigue failure occurred in the bottom Mg sheet due to the stress concentration of the keyhole leading to crack initiation followed by propagation perpendicular to the loading direction. In the Mg/Al adhesive weld, nugget pull-out failure mode was primarily observed at both high and low cyclic loads. © 2012 Elsevier B.V. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9a4f782c-d482-42e7-8f17-ba933674c0b3 ER - TY - JOUR TI - Reactions of the cumyloxyl and benzyloxyl radicals with tertiary amides. hydrogen abstraction selectivity and the role of specific substrate-radical hydrogen bonding DO - 10.1021/jo400535u AU - Salamone, M. AU - Milan, M. AU - Dilabio, G.A. AU - Bietti, M. T2 - Journal of Organic Chemistry SN - 0022-3263 VL - 78 IS - 12 SP - 5909 EP - 5917 KW - Hydrogen abstraction reaction KW - Hydrogen bond interaction KW - Intramolecular hydrogen KW - N ,N-Dimethylacetamide KW - N ,N-Dimethylformamide KW - Rate-limiting formation KW - Theoretical investigations KW - Time-resolved kinetic study KW - Amides KW - Functional groups KW - Hydrogen bonds KW - Organic solvents KW - Substrates KW - Abstracting KW - acetic acid derivative KW - aliphatic amine KW - amide KW - benzyloxyl radical KW - carbon KW - cumyloxyl radical KW - dimethyl sulfoxide KW - hydrogen KW - hydroxyl radical KW - n,n dimethylacetamide KW - n,n dimethylformamide KW - oxygen KW - tertiary amine KW - unclassified drug KW - article KW - calculation KW - chemical reaction kinetics KW - chemical structure KW - controlled study KW - density functional theory KW - dissociation constant KW - enzyme specificity KW - hydrogen bond KW - mathematical computing KW - molecular interaction KW - phase transition KW - stereochemistry AB - A time-resolved kinetic study in acetonitrile and a theoretical investigation of hydrogen abstraction reactions from N,N-dimethylformamide (DMF) and N,N-dimethylacetamide (DMA) by the cumyloxyl (CumO•) and benzyloxyl (BnO•) radicals was carried out. CumO • reacts with both substrates by direct hydrogen abstraction. With DMF, abstraction occurs from the formyl and N-methyl C-H bonds, with the formyl being the preferred abstraction site, as indicated by the measured k H/kD ratios and by theory. With DMA, abstraction preferentially occurs from the N-methyl groups, whereas abstraction from the acetyl group represents a minor pathway, in line with the computed C-H BDEs and the kH/kD ratios. The reactions of BnO• with both substrates were best described by the rate-limiting formation of hydrogen-bonded prereaction complexes between the BnO• α-C-H and the amide oxygen, followed by intramolecular hydrogen abstraction. This mechanism is consistent with the very large increases in reactivity measured on going from CumO• to BnO• and with the observation of kH/kD ratios close to unity in the reactions of BnO•. Our modeling supports the different mechanisms proposed for the reactions of CumO• and BnO • and the importance of specific substrate/radical hydrogen bond interactions, moreover providing information on the hydrogen abstraction selectivity. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e9fe8d3f-7635-41cb-921e-9cd360c3570c ER - TY - JOUR TI - Magnesium and magnesium-silicide coated silicon nanowire composite anodes for lithium-ion batteries DO - 10.1039/c2ta00769j AU - Kohandehghan, A. AU - Kalisvaart, P. AU - Kupsta, M. AU - Zahiri, B. AU - Amirkhiz, B.S. AU - Li, Z. AU - Memarzadeh, E.L. AU - Bendersky, L.A. AU - Mitlin, D. T2 - Journal of Materials Chemistry A SN - 2050-7488 VL - 1 IS - 5 SP - 1600 EP - 1612 KW - Coulombic efficiency KW - Degradation mechanism KW - Electrical contacts KW - Electrochemical cycling stability KW - Electrolyte decomposition KW - Lithium-ion battery anodes KW - Magnesium silicides KW - Quantitative information KW - Anodes KW - Coated materials KW - Degradation KW - Lithium batteries KW - Magnesium KW - Polyethylene oxides KW - Silicides KW - Silicon KW - Transmission electron microscopy KW - Nanowires AB - We synthesized composites consisting of silicon nanowires (SiNWs) coated with magnesium (Mg) and magnesium silicide (Mg2Si) for lithium-ion battery anodes and studied their electrochemical cycling stability and degradation mechanisms. Compared to bare SiNWs, both Mg- and Mg 2Si-coated materials show significant improvement in coulombic efficiency during cycling, with pure Mg coating being slightly superior by ∼1% in each cycle. XPS measurements on cycled nanowire forests gave quantitative information on the composition of the SEI layer and showed lower Li2CO3 and higher polyethylene oxide content for coated nanowires, thus revealing a passivating effect towards electrolyte decomposition. Extensive characterization of the microstructure before and after cycling was carried out by scanning- and transmission electron microscopy aided by focused ion beam cross-sectioning. The formation of large voids between the nanowire assembly and the substrate during cycling, causing the nanowires to lose electrical contact with the substrate, is identified as an important degradation mechanism. © 2013 The Royal Society of Chemistry. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3278cb69-eee9-4827-9356-239d17ca1aa2 ER - TY - JOUR TI - Effect of surface hydrophilicity on the formation of Nafion thin films inside PEMFC catalyst layers: A computational study DO - 10.1149/04523.0101ecst AU - Damasceno Borges, D. AU - Malek, K. AU - Mossa, S. AU - Gebel, G. AU - Franco, A.A. T2 - ECS Transactions T3 - Symposium on Fuel Cell Membranes, Electrode Binders, and MEA Performance - 221st ECS Meeting, 6 May 2012 through 10 May 2012, Seattle, WA SN - 1938-5862 SN - 9781623320423 VL - 45 IS - 23 SP - 101 EP - 108 KW - Computational studies KW - Continuous surface KW - Electrochemical activities KW - Perfluorosulfonic acid KW - Structural formation KW - Surface hydrophilicity KW - Transport phenomena KW - Water distributions KW - Binders KW - Catalyst activity KW - Computer simulation KW - Hydrophilicity KW - Molecular dynamics KW - Polymers KW - Ultrathin films KW - Water supply systems KW - Proton exchange membrane fuel cells (PEMFC) AB - Structure of Nafion inside Polymer Electrolyte Membrane Fuel Cells (PEMFC) catalyst layers is suspected to have a significant impact on the electrochemical activity and transport phenomena that determine the overall cell performances. In those regions, Nafion can be found as an ultra-thin film, coating the catalyst and the catalyst support surfaces. The impact of the hydrophilic character of these surfaces on the structural formation of the films has not been explored in details yet. Here, we report about our Molecular Dynamic computer simulations studies of the formation of Nafion thin films in contact with unstructured continuous surfaces, characterized by their global wetting properties only. We investigate changes of morphology and nanostructure of the perfluorosulfonic acid polymer as a result of water and polymersurface affinities. Charge and water distributions are also analyzed. Possible impact of Nafion thin film self-assembly on the actual activity properties of realistic catalysts layers is shortly discussed. © The Electrochemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5158d962-a03f-49ff-bb9c-91452facc81e ER - TY - JOUR TI - Radio continuum surveys with square kilometre array pathfinders DO - 10.1017/pas.2012.020 AU - Norris, R.P. AU - Afonso, J. AU - Bacon, D. AU - Beck, R. AU - Bell, M. AU - Beswick, R.J. AU - Best, P. AU - Bhatnagar, S. AU - Bonafede, A. AU - Brunetti, G. AU - Budavári, T. AU - Cassano, R. AU - Condon, J.J. AU - Cress, C. AU - Dabbech, A. AU - Feain, I. AU - Fender, R. AU - Ferrari, C. AU - Gaensler, B.M. AU - Giovannini, G. AU - Haverkorn, M. AU - Heald, G. AU - Van Der Heyden, K. AU - Hopkins, A.M. AU - Jarvis, M. AU - Johnston-Hollitt, M. AU - Kothes, R. AU - Van Langevelde, H. AU - Lazio, J. AU - Mao, M.Y. AU - Martínez-Sansigre, A. AU - Mary, D. AU - McAlpine, K. AU - Middelberg, E. AU - Murphy, E. AU - Padovani, P. AU - Paragi, Z. AU - Prandoni, I. AU - Raccanelli, A. AU - Rigby, E. AU - Roseboom, I.G. AU - Röttgering, H. AU - Sabater, J. AU - Salvato, M. AU - Scaife, A.M.M. AU - Schilizzi, R. AU - Seymour, N. AU - Smith, D.J.B. AU - Umana, G. AU - Zhao, G.-B. AU - Zinn, P.-C. T2 - Publications of the Astronomical Society of Australia SN - 1323-3580 VL - 30 IS - 1 SP - e020 AB - In the lead-up to the Square Kilometre Array (SKA) project, several next-generation radio telescopes and upgrades are already being built around the world. These include APERTIF (The Netherlands), ASKAP (Australia), e-MERLIN (UK), VLA (USA), e-EVN (based in Europe), LOFAR (The Netherlands), MeerKAT (South Africa), and the Murchison Widefield Array. Each of these new instruments has different strengths, and coordination of surveys between them can help maximise the science from each of them. A radio continuum survey is being planned on each of them with the primary science objective of understanding the formation and evolution of galaxies over cosmic time, and the cosmological parameters and large-scale structures which drive it. In pursuit of this objective, the different teams are developing a variety of new techniques, and refining existing ones. To achieve these exciting scientific goals, many technical challenges must be addressed by the survey instruments. Given the limited resources of the global radio-astronomical community, it is essential that we pool our skills and knowledge. We do not have sufficient resources to enjoy the luxury of re-inventing wheels. We face significant challenges in calibration, imaging, source extraction and measurement, classification and cross-identification, redshift determination, stacking, and data-intensive research. As these instruments extend the observational parameters, we will face further unexpected challenges in calibration, imaging, and interpretation. If we are to realise the full scientific potential of these expensive instruments, it is essential that we devote enough resources and careful study to understanding the instrumental effects and how they will affect the data. We have established an SKA Radio Continuum Survey working group, whose prime role is to maximise science from these instruments by ensuring we share resources and expertise across the projects. Here we describe these projects, their science goals, and the technical challenges which are being addressed to maximise the science return. © 2013 Astronomical Society of Australia. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0f952ae7-8e52-46c2-b4b9-560784c73e8a ER - TY - JOUR TI - Epoxy-coated bars as corrosion control in cracked reinforced concrete DO - 10.1002/maco.201106319 AU - Lõpez-Calvo, H.Z. AU - Montes-Garcia, P. AU - Kondratova, I. AU - Bremner, T.W. AU - Thomas, M.D.A. T2 - Materials and Corrosion SN - 0947-5117 VL - 64 IS - 7 SP - 599 EP - 608 KW - Adhesion test KW - Corrosion current densities KW - Corrosion potentials KW - Cracked concretes KW - Epoxy coatings KW - Adhesion KW - Chlorine compounds KW - Coatings KW - Concrete slabs KW - Corrosion KW - Cracks KW - Epoxy resins KW - Reinforcement KW - Software testing KW - Concretes AB - One of the most common corrosion protection methods in reinforcing concrete bars is the application of fusion-bonded epoxy coatings. Although considerable research has been carried out on the performance of epoxy-coated bars (ECR), there are still many uncertainties about their performance in cracked concrete. In this experimental program, reinforcing steel bars with six types of epoxy coatings embedded in concrete slabs with a 0.4 mm wide preformed crack intersecting the reinforcing steel at right angles were tested. Results of corrosion potentials, corrosion current density, coating adhesion tests, chloride content, and visual examination after 68 months of exposure to a simulated marine environment are reported. Results revealed that under the studied conditions the ECR did not provide total protection of steel reinforcement in cracked concrete. Their use however, tended to reduce significantly the damage caused by the chloride-induced corrosion when compared with the uncoated bars embedded in concrete with similar characteristics. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 40c0ee03-d9b9-492a-9e07-9638cfff1ef9 ER - TY - JOUR TI - The distance to NGC 1316 (Fornax A): Yet another curious case DO - 10.1051/0004-6361/201220756 AU - Cantiello, M. AU - Grado, A. AU - Blakeslee, J.P. AU - Raimondo, G. AU - Di Rico, G. AU - Limatola, L. AU - Brocato, E. AU - Della Valle, M. AU - Gilmozzi, R. T2 - Astronomy and Astrophysics SN - 0004-6361 VL - 552 SP - A106 KW - Galaxies: clusters: individual: NGC 1316 KW - Galaxies: distances and redshifts KW - Galaxies: elliptical and lenticular , CD KW - Galaxies: peculiar KW - Galaxies: photometry KW - Galaxies: stellar content KW - Calibration KW - Mobility aids for blind persons KW - Photometry KW - Population statistics KW - Stars KW - Galaxies AB - Aims. The distance of NGC 1316, the brightest galaxy in the Fornax cluster, provides an interesting test for the cosmological distance scale. First, because Fornax is the second largest cluster of galaxies within ≠25 Mpc after Virgo and, in contrast to Virgo, has a small line-of-sight depth; and second, because NGC 1316 is the single galaxy with the largest number of detected Type Ia supernovae (SNe Ia), giving the opportunity to test the consistency of SNe Ia distances both internally and against other distance indicators. Methods. We measure surface brightness fluctuations (SBF) in NGC 1316 from ground- and space-based imaging data. The sample provides a homogeneous set of measurements over a wide wavelength interval. The SBF magnitudes, coupled with empirical and theoretical absolute SBF calibrations, are used to estimate the distance to the galaxy. We also present the first B-band SBF measurements of NGC 1316 and use them together with the optical and near-IR SBF data to analyze the properties of field stars in the galaxy. Results. We obtain mag, or d = 20.8 ± 0.5(stat.) ± 1.5(sys.) Mpc. When placed in a consistent Cepheid distance scale, our result agrees with the distances from other indicators. On the other hand, our distance is ~17% larger than the most recent estimate based on SNe Ia. Possible explanations for this disagreement are the uncertain level of internal extinction, and/or calibration issues. Concerning the stellar population analysis, we confirm the results from other spectro-photometric indicators: the field stars in NGC 1316 are dominated by a component with roughly solar metallicity and intermediate age. A non-negligible mismatch exists between B-band SBF models and data. We confirm that such behavior can be accounted for by an enhanced percentage of hot horizontal branch stars. Conclusions. Our study of the SBF distance to NGC 1316, and the comparison with distances from other indicators, raises some concern about the homogeneity between the calibrations of different indicators. If not properly placed in the same reference scale, significant differences can occur, with dramatic impact on the cosmological distance ladder. Our results on the stellar populations properties show that SBF data over a broad wavelength interval are an efficient means of studying the properties of unresolved systems in peculiar cases like NGC 1316. © 2013 ESO. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : fa861dd0-4166-412e-8de7-ab72876b0598 ER - TY - JOUR TI - Picomolar inhibition of cholera toxin by a pentavalent ganglioside GM1os-calix[5]arene DO - 10.1039/c3ob40515j AU - Garcia-Hartjes, J. AU - Bernardi, S. AU - Weijers, C.A.G.M. AU - Wennekes, T. AU - Gilbert, M. AU - Sansone, F. AU - Casnati, A. AU - Zuilhof, H. T2 - Organic and Biomolecular Chemistry SN - 1477-0520 VL - 11 IS - 26 SP - 4340 EP - 4349 KW - Binding domain KW - Calix[5]arene KW - Causative agents KW - Cholera toxin KW - Epithelial cells KW - Inhibition assays KW - Multivalency effects KW - Valencies KW - Positive ions KW - Chemistry AB - Cholera toxin (CT), the causative agent of cholera, displays a pentavalent binding domain that targets the oligosaccharide of ganglioside GM1 (GM1os) on the periphery of human abdominal epithelial cells. Here, we report the first GM1os-based CT inhibitor that matches the valency of the CT binding domain (CTB). This pentavalent inhibitor contains five GM1os moieties linked to a calix[5]arene scaffold. When evaluated by an inhibition assay, it achieved a picomolar inhibition potency (IC50 = 450 pM) for CTB. This represents a significant multivalency effect, with a relative inhibitory potency of 100000 compared to a monovalent GM1os derivative, making GM1os-calix[5]arene one of the most potent known CTB inhibitors. This journal is © The Royal Society of Chemistry 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e27d4c2a-b951-4934-9b06-cd5bc8b51466 ER - TY - JOUR TI - Characterization and optimization of vibration-assisted drilling of fibre reinforced epoxy laminates DO - 10.1016/j.cirp.2013.03.097 AU - Sadek, A. AU - Attia, M.H. AU - Meshreki, M. AU - Shi, B. T2 - CIRP Annals - Manufacturing Technology SN - 0007-8506 VL - 62 IS - 1 SP - 91 EP - 94 KW - Cutting energy KW - Cutting temperature KW - Fibre-reinforced epoxy KW - Hole quality KW - Intermittent cutting KW - Mechanical defects KW - Process parameters KW - Vibration assisted drilling KW - Axial flow KW - Composite materials KW - Defects KW - Drilling KW - Optimization AB - Vibration-assisted drilling (VAD) can reduce thermal and mechanical defects associated with drilling of composites. Machinability maps are presented to establish the effect of the process parameters (speed, feed, frequency, and amplitude) in the low frequency-high amplitude regime (<200 Hz, <0.6 mm) on the hole quality attributes. The optimized VAD conditions can reduce the cutting temperature by 50% and the axial force by 40% and produce delamination-free holes, without affecting productivity. It is demonstrated that the intermittent cutting in VAD redistributes the cutting energy over the engagement cycles. This enhances the tool cooling and substantially reduces the axial force component. © 2013 CIRP. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : cfab2aaf-6fac-4b8f-bfd5-0093c5fb5153 ER - TY - JOUR TI - Review of flexural strength of multi-year ice AU - Frederking, R. AU - Sudom, D. T2 - Proceedings of the International Offshore and Polar Engineering Conference T3 - 23rd International Offshore and Polar Engineering Conference, ISOPE 2013, 30 June 2013 through 5 July 2013, Anchorage, AK SN - 1098-6189 SN - 9781880653999 SP - 1087 EP - 1093 KW - Absolute values KW - Beam tests KW - Field test KW - First-year sea ices KW - Fresh-water KW - Ice floes KW - Multi-year ices KW - Small area KW - Sea ice KW - Bending strength AB - Flexural strength from dedicated beam tests and ramming of multi-year floes has been compared. Flexural strength of multi-year ice from beam tests indicates the strength decreases as the size of the beams increases and this is important in comparing flexural strength data from various sources. In terms of relative flexural strength; from strongest to weakest is fresh-water ice, multi-year ice and first-year sea ice. Ship ramming results provide comparative results for flexural strength, even if the absolute values are greater than would be expected given the thickness of the ice. Colder ice floes have greater flexural strength. The MV Arctic ramming tests indicate that multi-year floes in a small area can be quite variable in thickness, temperature and flexural strength. Copyright © 2013 by the International Society of Offshore and Polar Engineers (ISOPE). DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ddbbc431-8e91-40cd-9eab-3c8d4166e007 ER - TY - JOUR TI - Optically pumped rolled-up InAs/InGaAsP quantum dash lasers at room temperature DO - 10.1088/0268-1242/28/9/094007 AU - Dastjerdi, M.H.T. AU - Djavid, M. AU - Arafin, S. AU - Liu, X. AU - Bianucci, P. AU - Mi, Z. AU - Poole, P.J. T2 - Semiconductor Science and Technology SN - 0268-1242 VL - 28 IS - 9 SP - 94007 KW - Continuous Wave KW - Coupling factor KW - InAs quantum dots KW - Optical cavities KW - Optical performance KW - Optically pumped KW - Quantum dashes KW - Room temperature KW - Magnetic materials KW - Semiconductor devices KW - Optical pumping AB - We have investigated the fabrication and optical performance of free-standing rolled-up InGaAsP tube optical cavities, wherein self-organized InAs quantum dots or dashes are incorporated as the gain media. Such tubular optical cavities are formed when the coherently strained InAs/InGaAsP quantum dot/dash nanomembrane is selectively released from the host substrate. We have achieved lasing from rolled-up InAs/InGaAsP quantum dash microtubes at room temperature under continuous wave optical pumping. The measured threshold is ∼6 W, and the Purcell factor and the spontaneous emission coupling factor are estimated to be ∼6.54 and ∼0.87, respectively. © 2013 IOP Publishing Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a3823c88-9f85-49ed-a724-a446ed796465 ER - TY - JOUR TI - Definitions of terms relating to mass spectrometry (IUPAC Recommendations 2013) DO - 10.1351/PAC-REC-06-04-06 AU - Murray, K.K. AU - Boyd, R.K. AU - Eberlin, M.N. AU - John Langley, G. AU - Li, L. AU - Naito, Y. T2 - Pure and Applied Chemistry SN - 0033-4545 VL - 85 IS - 7 SP - 1515 EP - 1609 KW - Accelerator mass spectrometry KW - Definitions KW - IUPAC analytical Chemistry division KW - Mass spectroscopy KW - Rapid expansion KW - Tandem mass spectrometry KW - Terms KW - Glossaries KW - Molecular structure KW - Physical chemistry KW - Terminology KW - Vacuum technology KW - Mass spectrometry AB - This document contains recommendations for terminology in mass spectrometry. Development of standard terms dates back to 1974 when the IUPAC Commission on Analytical Nomenclature issued recommendations on mass spectrometry terms and definitions. In 1978, the IUPAC Commission on Molecular Structure and Spectroscopy updated and extended the recommendations and made further recommendations regarding symbols, acronyms, and abbreviations. The IUPAC Physical Chemistry Division Commission on Molecular Structure and Spectroscopy's Subcommittee on Mass Spectroscopy revised the recommended terms in 1991 and appended terms relating to vacuum technology. Some additional terms related to tandem mass spectrometry were added in 1993 and accelerator mass spectrometry in 1994. Owing to the rapid expansion of the field in the intervening years, particularly in mass spectrometry of biomolecules, a further revision of the recommendations has become necessary. This document contains a comprehensive revision of mass spectrometry terminology that represents the current consensus of the mass spectrometry community. © 2013 IUPAC. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 24a37fd8-163e-42fd-9ae4-babf85dc49af ER - TY - JOUR TI - Microbial expression profiles in the rhizosphere of willows depend on soil contamination DO - 10.1038/ismej.2013.163 AU - Yergeau, E. AU - Sanschagrin, S. AU - Maynard, C. AU - St-Arnaud, M. AU - Greer, C.W. T2 - ISME Journal SN - 1751-7362 AB - The goal of phytoremediation is to use plants to immobilize, extract or degrade organic and inorganic pollutants. In the case of organic contaminants, plants essentially act indirectly through the stimulation of rhizosphere microorganisms. A detailed understanding of the effect plants have on the activities of rhizosphere microorganisms could help optimize phytoremediation systems and enhance their use. In this study, willows were planted in contaminated and non-contaminated soils in a greenhouse, and the active microbial communities and the expression of functional genes in the rhizosphere and bulk soil were compared. Ion Torrent sequencing of 16S rRNA and Illumina sequencing of mRNA were performed. Genes related to carbon and amino-acid uptake and utilization were upregulated in the willow rhizosphere, providing indirect evidence of the compositional content of the root exudates. Related to this increased nutrient input, several microbial taxa showed a significant increase in activity in the rhizosphere. The extent of the rhizosphere stimulation varied markedly with soil contamination levels. The combined selective pressure of contaminants and rhizosphere resulted in higher expression of genes related to competition (antibiotic resistance and biofilm formation) in the contaminated rhizosphere. Genes related to hydrocarbon degradation were generally more expressed in contaminated soils, but the exact complement of genes induced was different for bulk and rhizosphere soils. Together, these results provide an unprecedented view of microbial gene expression in the plant rhizosphere during phytoremediation.The ISME Journal advance online publication, 26 September 2013; doi:10.1038/ismej.2013.163. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0be8da17-c11a-4f35-9161-a151d37eadde ER - TY - JOUR TI - Quercetin deformable liposome: Preparation and efficacy against ultraviolet B induced skin damages in vitro and in vivo DO - 10.1016/j.jphotobiol.2013.07.014 AU - Liu, D. AU - Hu, H. AU - Lin, Z. AU - Chen, D. AU - Zhu, Y. AU - Hou, S. AU - Shi, X. T2 - Journal of Photochemistry and Photobiology B: Biology SN - 1011-1344 VL - 127 SP - 8 EP - 17 KW - 3,4 methylenedioxyamphetamine KW - cholesterol KW - cholic acid KW - liposome KW - malonaldehyde KW - phosphatidylcholine KW - polysorbate 80 KW - quercetin KW - reactive oxygen metabolite KW - sorbitan laurate KW - animal cell KW - animal experiment KW - article KW - cell membrane KW - cell protection KW - cell viability KW - controlled study KW - dermatitis KW - drug delivery system KW - drug efficacy KW - drug formulation KW - drug release KW - drug solubility KW - drug synthesis KW - elasticity KW - encapsulation KW - histopathology KW - in vitro study KW - in vivo study KW - keratinocyte KW - lipid peroxidation KW - male KW - nonhuman KW - oxidative stress KW - particle size KW - priority journal KW - rat KW - skin defect KW - skin edema KW - stratum corneum KW - ultraviolet B radiation KW - ultraviolet irradiation KW - zeta potential AB - Ultraviolet (UV) radiation has deleterious effects on cells through direct damage to DNA or through increasing generation of reactive oxygen species (ROS). The flavonol quercetin (Qu) provides cellular protection against UV radiation and the current investigation was carried out to develop a deformable liposome formulation of Qu to enhance its delivery into human skin and to improve its anti-UVB effect. The influence of surfactants (including Span 20, Tween 80 and sodium cholate) on the properties of Qu deformable liposomes was investigated. Liposomes composed of Qu, phosphatidylcholine (PC), cholesterol (Chol), and Tween 80 showed high entrapment efficiencies (80.41 ± 4.22%), small particle sizes (132 ± 14 nm), high elasticity (10.48 ± 0.71), and prolonged drug release. The cell viability in UVB-irradiated HaCaT cells increased to 89.89 ± 4.5% at 24 h and 78.8 ± 3.19% at 48 h following treatment with Qu defomable liposomes. The ROS and malondialdehyde (MDA) level were also reduced. The penetration rate was 3.8-fold greater than that of the Qu suspension. Moreover, the edema and inflammation was alleviated by Qu deformable liposomes. These results showed the potential of deformable liposomes to enhance the anti-UVB effects of Qu both in vitro and in vivo. © 2013 Elsevier B.V. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 54320dd5-68fe-4e5b-99f7-abaf9344106d ER - TY - JOUR TI - Thermo-responsive photoluminescent polymer brushes device as a platform for selective detection of Cr(vi) DO - 10.1039/c3py00669g AU - Yang, X. AU - Jiang, Y. AU - Shen, B. AU - Chen, Y. AU - Dong, F. AU - Yu, K. AU - Yang, B. AU - Lin, Q. T2 - Polymer Chemistry SN - 1759-9954 VL - 4 IS - 22 SP - 5591 EP - 5596 KW - Environmental Monitoring KW - Fluorescent molecules KW - Laboratory analysis KW - Photo-luminescent properties KW - Photoluminescence intensities KW - Quaternary ammonium KW - Selective detection KW - Thermoresponsive polymer KW - Chromium compounds KW - Sensors KW - Dendrimers AB - In this work, we first report a thermo-responsive photoluminescent polymer brushes device as a platform for the selective and sensitive detection of Cr(vi). Positively charged fluorescent molecules of a quaternary ammonium tetraphenylethylene derivative (d-TPE) are immobilized in the thermo-responsive polymer brushes of p(NIPAM-co-AAc) by Coulombic force, which leads to the observation of an immobilized induced emission (IIE) phenomenon. The emission intensity of the d-TPE labelled film is improved hundreds of times compared with a d-TPE aqueous solution. As a result, we obtain a novel thermo-responsive polymer brushes device with excellent photoluminescent properties. The photoluminescence (PL) intensity of the device exhibits a linear and reversible response from 4 to 60 °C and shows a high PL quenching for the sensitive and selective detection of Cr(vi) rather than Cr(iii). The limit of detection can reach as low as 0.05 ppm, which indicates a promising sensor device for environmental monitoring, laboratory analysis and various other applications. This journal is © The Royal Society of Chemistry. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1aaacb1b-1fe1-41ac-ba44-dc7dad9f94db ER - TY - JOUR TI - Natural fiber composites DO - 10.1155/2013/569020 AU - Hamada, H. AU - Denault, J. AU - Mohanty, A.K. AU - Li, Y. AU - Aly-Hassan, M.S. T2 - Advances in Mechanical Engineering SN - 1687-8132 VL - 2013 SP - 569020 DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 42ea947b-c084-4e19-86ca-6aeedbd693a7 ER - TY - JOUR TI - A graph-partitioning framework for aligning hierarchical topic structures to presentations DO - 10.1109/TASL.2013.2244084 AU - Zhu, X. AU - Cherry, C. AU - Penn, G. T2 - IEEE Transactions on Audio, Speech and Language Processing SN - 1558-7916 VL - 21 IS - 5 SP - 6423823 SP - 1102 EP - 1112 KW - Graph Partitioning KW - minimum-cut KW - Semantic structures KW - Spoken document KW - Topic structures KW - Alignment KW - Graph theory KW - Mapping KW - Semantics KW - Indexing (of information) AB - This paper studies the problem of imposing an existing hierarchical semantic structure onto a corresponding spoken document in which the structures are embedded, with the goal of indexing such documents for easier access. We propose a graph-partitioning framework to solve a semantic tree-to-string alignment problem through optimizing a normalized-cut criterion. We present models with different modeling capabilities and time complexities in this framework and provide experimental evidence of their performance. We relate graph partitioning to conventional dynamic time warping (DTW) as it applies to this problem, and show that the proposed framework can naturally include topic segmentation to accommodate cohesion constraints. © 2006-2012 IEEE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 99243c1f-859f-4955-b0de-037cca9c4599 ER - TY - JOUR TI - Electrochemical behavior of Zn/Zn(II) couples in aprotic ionic liquids based on pyrrolidinium and imidazolium cations and bis(trifluoromethanesulfonyl) imide and dicyanamide anions DO - 10.1016/j.electacta.2012.11.023 AU - Xu, M. AU - Ivey, D.G. AU - Xie, Z. AU - Qu, W. T2 - Electrochimica Acta SN - 0013-4686 VL - 89 SP - 756 EP - 762 KW - Aprotic KW - Aqueous electrolyte KW - Bis(trifluoromethane sulfonyl)imide KW - Dicyanamide KW - Dicyanamide anion KW - Electroactive species KW - Electrochemical behaviors KW - Electrode mechanism KW - Electrode reaction mechanisms KW - Electrode reactions KW - Exchange current densities KW - Imidazolium KW - Imidazolium cation KW - Overpotential KW - Pyrrolidinium KW - Room temperature ionic liquids KW - Shedding light KW - Single electron KW - Single-step KW - Strong dependences KW - Tafel analysis KW - Two-electron transfer KW - Cyclic voltammetry KW - Electrolytes KW - Ionic liquids KW - Negative ions KW - Positive ions KW - Potentiodynamic polarization KW - Redox reactions KW - Secondary batteries KW - Zinc AB - Motivated by the potential of using room temperature ionic liquids (RTILs) as electrolytes to replace traditional aqueous electrolytes for Zn-anode secondary batteries, Zn/Zn(II) redox reactions have been studied in four aprotic RTILs based on pyrrolidinium ([Pyrr]+) and imidazolium ([Im] +) cations, and bis(trifluoromethanesulfonyl)imide ([TFSI] -) and dicyanamide ([DCA]-) anions. Cyclic voltammetry results suggest a smaller overpotential for Zn redox in [Im]+ cation based and [DCA]- anion based RTILs than in [Pyrr]+ and [TFSI]- based RTILs. Potentiodynamic polarization experiments indicate a strong dependence of the electrode reaction mechanism for the Zn species on the RTIL anions. In [TFSI]- based RTILs, Zn2+ ions are the electroactive species, with the electrode reaction being a single-step, two-electron transfer process. In [DCA]- based RTILs, two-step, single-electron reactions account for the electrode mechanism. The exchange current densities derived from Tafel analysis for the Zn species in the four RTILs are greater than 10-3 mA/cm2, with the [Im]+ cation based RTIL possessing the highest value of 9.9 × 10-3 mA/cm2. The results obtained will assist in obtaining a better understanding of the electrochemical behavior of Zn in RTILs, shedding light on the development of RTILs for Zn-anode secondary batteries. © 2012 Elsevier Ltd. All Rights Reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 34a4d2f8-5bba-4b3d-bf74-60fc307fd66a ER - TY - JOUR TI - Microwave-assisted acid digestion protocol for the determination of methionine and selenomethionine in selenium-enriched yeast by species specific isotope dilution GC-MS DO - 10.1039/c2ay25498k AU - Yang, L. AU - Maxwell, P. AU - Mester, Z. T2 - Analytical Methods SN - 1759-9660 VL - 5 IS - 2 SP - 525 EP - 529 KW - Analytes KW - As extraction KW - Certified reference materials KW - Certified values KW - Conventional acids KW - Extraction efficiencies KW - Extraction time KW - Focused microwaves KW - GC-MS analysis KW - Methane sulfonic acid KW - Methyl chloroformate KW - Microwave assisted KW - Microwave extraction KW - Microwave-assisted acid digestion KW - Protein digestion KW - Real-time production KW - Selenized yeast KW - Selenomethionine KW - Simultaneous determinations KW - Species-specific isotope dilution KW - Standard deviation KW - Amino acids KW - Food products KW - Isotopes KW - Microwaves KW - Selenium KW - Selenium compounds KW - Yeast AB - A quantitative and fast microwave assisted protein digestion method is described for the simultaneous determination of methionine (Met) and selenomethionine (SeMet) in yeast. Extraction of Met and SeMet from the selenized yeast was performed in a focused microwave system using methanesulfonic acid (MSA). The effects of parameters such as extraction time, temperature, power and sample mass on the extraction efficiencies of Met and SeMet were investigated. Species specific isotope dilution (ID) calibration using 13C enriched Met and SeMet spikes was employed to obtain accurate results. Analytes were derivatized with methyl chloroformate and extracted into chloroform prior to species specific ID GC-MS analysis. Using a 20 minute extraction time at 165 °C and 6 ml of 4 M MSA was found to be efficient for both analytes based on a 50 mg sample mass. Under these conditions, concentrations of 5862 ± 32 and 3366 ± 60 μg g -1 (one standard deviation, n = 3) for Met and SeMet, respectively, were obtained in SELM-1 yeast certified reference material (CRM). The obtained results are in good agreement with the certified values of 5758 ± 277 and 3448 ± 146 μg g-1 (expanded uncertainty, k = 2). Compared to previous MSA reflux digestion, this newly proposed method offers dramatic reduction in extraction time from 8-16 hours of the conventional MSA reflux to 20 minutes by microwave extraction, significantly improving the sample throughput. Additionally, the microwave extraction is fully automated and uses 75% less reagent (MSA) than the conventional acid reflux setup. The developed method is suitable for quasi real time production monitoring of Met and SeMet in Se enriched yeast and other food products. This journal is © 2013 The Royal Society of Chemistry. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b52cb201-8fab-4b10-a677-7f094d4bff97 ER - TY - JOUR TI - Bacterial growth at -15 °C; molecular insights from the permafrost bacterium Planococcus halocryophilus Or1 DO - 10.1038/ismej.2013.8 AU - Mykytczuk, N.C.S. AU - Foote, S.J. AU - Omelon, C.R. AU - Southam, G. AU - Greer, C.W. AU - Whyte, L.G. T2 - ISME Journal SN - 1751-7362 VL - 7 IS - 6 SP - 1211 EP - 1226 KW - adaptation KW - bacterium KW - cytology KW - fatty acid KW - genomics KW - growth rate KW - metabolism KW - microcosm KW - osmosis KW - permafrost KW - phenotypic plasticity KW - physiology KW - synergism KW - Bacteria (microorganisms) KW - Planococcus (bacterium) AB - Planococcus halocryophilus strain Or1, isolated from high Arctic permafrost, grows and divides at -15 °C, the lowest temperature demonstrated to date, and is metabolically active at -25 °C in frozen permafrost microcosms. To understand how P. halocryophilus Or1 remains active under the subzero and osmotically dynamic conditions that characterize its native permafrost habitat, we investigated the genome, cell physiology and transcriptomes of growth at -15 °C and 18% NaCl compared with optimal (25 °C) temperatures. Subzero growth coincides with unusual cell envelope features of encrustations surrounding cells, while the cytoplasmic membrane is significantly remodeled favouring a higher ratio of saturated to branched fatty acids. Analyses of the 3.4 Mbp genome revealed that a suite of cold and osmotic-specific adaptive mechanisms are present as well as an amino acid distribution favouring increased flexibility of proteins. Genomic redundancy within 17% of the genome could enable P. halocryophilus Or1 to exploit isozyme exchange to maintain growth under stress, including multiple copies of osmolyte uptake genes (Opu and Pro genes). Isozyme exchange was observed between the transcriptome data sets, with selective upregulation of multi-copy genes involved in cell division, fatty acid synthesis, solute binding, oxidative stress response and transcriptional regulation. The combination of protein flexibility, resource efficiency, genomic plasticity and synergistic adaptation likely compensate against osmotic and cold stresses. These results suggest that non-spore forming P. halocryophilus Or1 is specifically suited for active growth in its Arctic permafrost habitat (ambient temp. ~ -16 °C), indicating that such cryoenvironments harbor a more active microbial ecosystem than previously thought. © 2013 International Society for Microbial Ecology. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : fbb007e5-aa3e-41ae-9246-f6137033b1a3 ER - TY - JOUR TI - Ab initio potential energy and dipole moment surfaces for CS2: Determination of molecular vibrational energies DO - 10.1021/jp309651r AU - Pradhan, E. AU - Carreón-Macedo, J.-L. AU - Cuervo, J.E. AU - Schröder, M. AU - Brown, A. T2 - The Journal of Physical Chemistry A SN - 1089-5639 VL - 117 IS - 32 SP - 6925 EP - 6931 KW - Ab initio potentials KW - Current potential KW - Dipole moment surfaces KW - Generic interfaces KW - Ground state potential KW - Low energy regions KW - Neural network method KW - Vibrational energies KW - Dipole moment KW - Neural networks KW - Potential energy KW - Potential energy surfaces KW - Quantum chemistry AB - The ground state potential energy and dipole moment surfaces for CS 2 have been determined at the CASPT2/C:cc-pVTZ,S:aug-cc-pV(T+d)Z level of theory. The potential energy surface has been fit to a sum-of-products form using the neural network method with exponential neurons. A generic interface between neural network potential energy surface fitting and the Heidelberg MCTDH software package is demonstrated. The potential energy surface has also been fit using the potfit procedure in MCTDH. For fits to the low-energy regions of the potential, the neural network method requires fewer parameters than potfit to achieve high accuracy; global fits are comparable between the two methods. Using these potential energy surfaces, the vibrational energies have been computed for the four most abundant CS2 isotopomers. These results are compared to experimental and previous theoretical data. The current potential energy surfaces are shown to accurately reproduce the low-lying vibrational energies within a few wavenumbers. Hence, the potential energy and dipole moments surfaces will be useful for future study on the control of quantum dynamics in CS2. © 2012 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9f0c9597-7ce4-41d6-bbd9-d48da1e7acc4 ER - TY - JOUR TI - The concept of 2D gated imaging for particle sizing in a laminar diffusion flame DO - 10.1007/s00340-013-5507-1 AU - Hadef, R. AU - Geigle, K.P. AU - Zerbs, J. AU - Sawchuk, R.A. AU - Snelling, D.R. T2 - Applied Physics B: Lasers and Optics SN - 0946-2171 SP - 1 EP - 14 AB - In this work, time-resolved laser-induced incandescence (TiRe LII) has been employed to measure primary particle diameters of soot in an atmospheric laminar ethylene diffusion flame. The generated data set complements existing data determined in one single location and takes advantage of the good spatial resolution of the ICCD detection. Time resolution is achieved by shifting the camera gate along the LII decay. One key input parameter for the analysis of time-resolved LII is the local flame temperature. This was determined on a grid throughout the flame by coherent anti-Stokes Raman scattering. The accurate temperature data, in combination with other published data from this flame, are well suited for soot model validation purposes while we showed feasibility of a shifted gate approach to deduce 2D particle sizes in the chosen standard flame. © 2013 Springer-Verlag Berlin Heidelberg. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 13f06dcc-23ec-48c5-a95f-b130eb9b27aa ER - TY - JOUR TI - The importance of water transport on short-side chain perfluorosulfonic acid membrane fuel cells operating under low relative humidity DO - 10.1016/j.jpowsour.2013.05.176 AU - Zhao, N. AU - Edwards, D. AU - Lei, C. AU - Wang, K. AU - Li, J. AU - Zhang, Y. AU - Holdcroft, S. AU - Shi, Z. T2 - Journal of Power Sources SN - 0378-7753 AB - Polarization curves of fuel cells incorporating PFSA short-side chain (SSC) ionomer membranes having ion exchange capacity (IEC) 1.30, 1.37, 1.43 and 1.50 meq g-1 and NRE-211 are compared. Under low humidity conditions, fuel cells incorporating SSC membranes show higher performance than NRE-211. SSC PFSA membranes possessing an IEC of 1.37 meq g-1 exhibit the highest performance. Differences in fuel cell polarization curves are due to differences in the high frequency resistance, which in turn is found related to ex-situ measurements of both the effective proton mobility and the rate of water flux through the membrane, which also exhibit a maximum for membranes of IEC 1.37 meq g-1. Water permeation and proton mobility are shown to be inherently linked, but it is found that simply increasing the membrane's IEC does not necessarily translate to increased water transport and effective proton mobility, despite the increased water content. © 2013 Crown Copyright and Elsevier Inc. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 27833002-e68a-44e7-b0a2-eb7920eb64a1 ER - TY - JOUR TI - Methods and applications of serological proteome analysis DO - 10.1007/978-1-62703-589-7_5 AU - Fulton, K.M. AU - Martin, S.S. AU - Wolfraim, L. AU - Twine, S.M. T2 - Methods in Molecular Biology SN - 1064-3745 SN - 9781627035880 VL - 1061 SP - 97 EP - 112 KW - proteome KW - tularemia vaccine KW - article KW - blood analysis KW - immunoblotting KW - immunoreactivity KW - isoelectric focusing KW - mouse KW - nonhuman KW - polyacrylamide gel electrophoresis KW - priority journal KW - protein analysis KW - serological proteome analysis KW - serology KW - two dimensional gel electrophoresis KW - vaccination KW - Western blotting AB - The study of the humoral response to infectious diseases and chronic diseases, such as cancer, is important for many reasons, including understanding the host response to disease, identification of protective antigens, vaccine development, and discovery of biomarkers for early diagnosis. During the past decade, proteomic approaches, such as serological proteome analysis (SERPA), have been used to identify the repertoire of immunoreactive proteins in various diseases. In this chapter, we provide an outline of the SERPA approach, using the analysis of sera from mice vaccinated with a live attenuated tularemia vaccine as an example. © 2013 Springer Science+Business Media, LLC. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c1a20eb1-f7aa-4d65-b03c-c6f930aef793 ER - TY - JOUR TI - Herschel * Observations of the W3 GMC: Clues to the formation of clusters of high-mass stars DO - 10.1088/0004-637X/766/2/85 AU - Rivera-Ingraham, A. AU - Martin, P.G. AU - Polychroni, D. AU - Motte, F. AU - Schneider, N. AU - Bontemps, S. AU - Hennemann, M. AU - Men'Shchikov, A. AU - Luong, Q.N. AU - André, Ph. AU - Arzoumanian, D. AU - Bernard, J.-Ph. AU - Di Francesco, J. AU - Elia, D. AU - Fallscheer, C. AU - Hill, T. AU - Li, J.Z. AU - Minier, V. AU - Pezzuto, S. AU - Roy, A. AU - Rygl, K.L.J. AU - Sadavoy, S.I. AU - Spinoglio, L. AU - White, G.J. AU - Wilson, C.D. T2 - The Astrophysical Journal SN - 0004-637X VL - 766 IS - 2 SP - 85 AB - The W3 GMC is a prime target for the study of the early stages of high-mass star formation. We have used Herschel data from the HOBYS key program to produce and analyze column density and temperature maps. Two preliminary catalogs were produced by extracting sources from the column density map and from Herschel maps convolved to 500 μm resolution. Herschel reveals that among the compact sources (FWHM < 0.45 pc), W3 East, W3 West, and W3 (OH) are the most massive and luminous and have the highest column density. Considering the unique properties of W3 East and W3 West, the only clumps with ongoing high-mass star formation, we suggest a "convergent constructive feedback" scenario to account for the formation of a cluster with decreasing age and increasing system/source mass toward the innermost regions. This process, which relies on feedback by high-mass stars to ensure the availability of material during cluster formation, could also lead to the creation of an environment suitable for the formation of Trapezium-like systems. In common with other scenarios proposed in other HOBYS studies, our results indicate that an active/dynamic process aiding in the accumulation, compression, and confinement of material is a critical feature of the high-mass star/cluster formation, distinguishing it from classical low-mass star formation. The environmental conditions and availability of triggers determine the form in which this process occurs, implying that high-mass star/cluster formation could arise from a range of scenarios: from large-scale convergence of turbulent flows to convergent constructive feedback or mergers of filaments. © 2013. The American Astronomical Society. All rights reserved.. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 300215e8-7554-463a-b6bb-4798fb51c222 ER - TY - JOUR TI - Optimization of MOCVD-diffused p-InP for planar avalanche photodiodes DO - 10.1016/j.jcrysgro.2013.09.053 AU - Pitts, O.J. AU - Hisko, M. AU - Benyon, W. AU - Raymond, S. AU - SpringThorpe, A.J. T2 - Journal of Crystal Growth SN - 0022-0248 AB - We investigate the materials properties and dark currents of planar InP/InGaAs avalanche photodiodes (APDs) in which the p-dopant, Zn, is introduced by diffusion in an MOCVD reactor using dimethylzinc (DMZn) as the source. APD dark currents are compared with low-temperature photoluminescence (PL), electrochemical capacitance-voltage (ECV) and secondary ion mass spectroscopy (SIMS) measurements of layers diffused under the same set of conditions. Device dark currents exhibit both surface-related and bulk contributions, with the bulk contribution appearing as a step increase in the current near the punch-through voltage. The bulk dark current contribution depends on the diffusion process parameters and is correlated with the total Zn incorporation and the intensities of the InP and InGaAs PL peaks. A variation of three orders of magnitude is observed in the bulk dark current contribution as diffusion conditions are varied. © 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 456522a6-ecd0-4908-b537-6c5bad042da1 ER - TY - JOUR TI - Hydrogen absorption into titanium under cathodic polarization: An in-situ neutron reflectometry and EIS study DO - 10.1149/2.020309jes AU - Vezvaie, M. AU - Noël, J.J. AU - Tun, Z. AU - Shoesmith, D.W. T2 - Journal of the Electrochemical Society SN - 0013-4651 VL - 160 IS - 9 SP - C414 EP - C422 KW - Absorption kinetics KW - Diffusion process KW - Electronic defects KW - Hydrogen absorption KW - Hydrogen penetration KW - Neutron reflectometry KW - Redox transformations KW - Scattering length density KW - Cathodic polarization KW - Deuterium KW - Electrochemical impedance spectroscopy KW - Film growth KW - Grain boundaries KW - Heavy water KW - Neutron reflection KW - Oxide films KW - Titanium KW - Titanium dioxide KW - Hydrogen AB - Hydrogen (deuterium) absorption into sputter-coated titanium (Ti) film electrodes during cathodic polarization in heavy water (D2O) was monitored using in-situ neutron reflectometry (NR) and electrochemical impedance spectroscopy (EIS). The scattering length density (SLD) of Ti metal increased with increasing cathodic polarization, due to the penetration of deuterium through the surface oxide and into the underlying metal. The rate of D absorption estimated from the NR data showed a pattern with four distinctive regions separated by potential boundaries between -0.35 and -0.4 VSCE and around ∼-0.6 VSCE. EIS results support division of the behavior into these potential ranges. Hydrogen absorption by Tiwas observed at potentials <∼-0.35 VSCE, where the capacitance and resistance of the TiO2 layer dramatically changed. At this point, the D content of the film quickly achieved a level of ∼900 ppm by weight (atom ratio D:Ti ∼ 0.04). Decreased absorption kinetics were observed over the potential region from ∼-0.40 VSCE to -0.6 VSCE, indicating that D absorption was controlled either by a diffusion process through the TiO 2 layer or by the formation of blocking hydrides at the Ti/TiO 2 interface, at the base of the defective locations in the oxide through which the hydrogen was entering. Significant increases in the current density and SLD of the Ti film at potentials more negative than -0.6 V SCE were assigned to widespread hydrogen absorption and TiH x growth within the metal. These observations are consistent with hydrogen ingress through the oxide film, probably via weak points containing electronic defects and disorder, such as grain boundaries and triple points, at potentials as mild as ∼-0.4 VSCE, and with hydrogen penetration through continuous, intact oxide via the previously published redox transformation mechanism, at potentials more negative than -0.6 VSCE. © 2013 The Electrochemical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9d815a00-de1b-4b09-a2a7-51fa03a5dcc0 ER - TY - JOUR TI - Polarization management for silicon photonic integrated circuits DO - 10.1002/lpor.201200023 AU - Dai, D. AU - Liu, L. AU - Gao, S. AU - Xu, D.-X. AU - He, S. T2 - Laser and Photonics Reviews SN - 1863-8880 VL - 7 IS - 3 SP - 303 EP - 328 KW - Nonlinear KW - Photonic integrated circuits KW - Polarization dependent loss KW - Polarization division multiplexing (PDM) KW - Polarization independence KW - Rotator KW - Silicon photonic integrated circuits KW - Splitter KW - Nanophotonics KW - Nanowires KW - Optical interconnects KW - Optical waveguides KW - Photonic devices KW - Photonic integration technology KW - Photonics KW - Polarization KW - Ridge waveguides KW - Silicon KW - Waveguides KW - Multiplexing AB - Polarization management is very important for photonic integrated circuits (PICs) and their applications. Due to geometrical anisotropy and fabrication inaccuracies, the characteristics of the guided transverse-electrical (TE) and transverse-magnetic (TM) modes are generally different. Polarization-dependent dispersion and polarization-dependent loss are such manifestations in PICs. These issues become more severe in high index contrast structures such as nanophotonic waveguides made of silicon-on-insulator (SOI), which has been regarded as a good platform for optical interconnects because of the compatibility with CMOS processing. Recently, polarization division multiplexing (PDM) with coherent detection using silicon photonics has also attracted much attention. This trend further highlights the importance of polarization management in silicon PICs. The authors review their work on polarization management for silicon PICs using the polarization independence and polarization diversity methods. Polarization issues and solutions in PICs made of SOI nanowires and ridge waveguides are discussed. © 2012 by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1c2c995d-c711-4843-abc5-7bb3c4a3a4ad ER - TY - JOUR TI - Proteomics analysis suggests broad functional changes in potato leaves triggered by phosphites and a complex indirect mode of action against Phytophthora infestans DO - 10.1016/j.jprot.2013.03.010 AU - Lim, S. AU - Borza, T. AU - Peters, R.D. AU - Coffin, R.H. AU - Al-Mughrabi, K.I. AU - Pinto, D.M. AU - Wang-Pruski, G. T2 - Journal of Proteomics SN - 1874-3919 VL - 93 SP - 207 EP - 223 AB - Phosphite (salts of phosphorous acid; Phi)-based fungicides are increasingly used in controlling oomycete pathogens, such as the late blight agent Phytophthora infestans. In plants, low amounts of Phi induce pathogen resistance through an indirect mode of action. We used iTRAQ-based quantitative proteomics to investigate the effects of phosphite on potato plants before and after infection with P. infestans. Ninety-three (62 up-regulated and 31 down-regulated) differentially regulated proteins, from a total of 1172 reproducibly identified proteins, were identified in the leaf proteome of Phi-treated potato plants. Four days post-inoculation with P. infestans, 16 of the 31 down-regulated proteins remained down-regulated and 42 of the 62 up-regulated proteins remained up-regulated, including 90% of the defense proteins. This group includes pathogenesis-related, stress-responsive, and detoxification-related proteins. Callose deposition and ultrastructural analyses of leaf tissues after infection were used to complement the proteomics approach. This study represents the first comprehensive proteomics analysis of the indirect mode of action of Phi, demonstrating broad effects on plant defense and plant metabolism. The proteomics data and the microscopy study suggest that Phi triggers a hypersensitive response that is responsible for induced resistance of potato leaves against P. infestans. Biological significance: Phosphie triggers complex functional changes in potato leaves that are responsible for the induced resistance against Phytophthora infestans.This article is part of a Special Issue entitled: Translational Plant Proteomics. © 2013 Elsevier B.V. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4ca6f188-38ab-49a4-9b57-46886d1b1b6e ER - TY - JOUR TI - Over-expression of x-linked inhibitor of apoptosis protein modulates multiple aspects of neuronal Ca2+ signaling DO - 10.1007/s11064-013-0989-0 AU - Grant, J. AU - Parker, K. AU - Moore, C.S. AU - Keddy, P.G.W. AU - Mayne, M. AU - Robertson, G.S. T2 - Neurochemical Research SN - 0364-3190 VL - 38 IS - 4 SP - 847 EP - 856 KW - benzyloxycarbonylvalylalanylaspartyl fluoromethyl ketone KW - calcium ion KW - glutamic acid KW - n methyl dextro aspartic acid receptor KW - thapsigargin KW - voltage gated calcium channel KW - X linked inhibitor of apoptosis KW - animal cell KW - animal tissue KW - article KW - brain cortex KW - brain nerve cell KW - calcium cell level KW - calcium signaling KW - controlled study KW - embryo KW - female KW - male KW - mouse KW - neuromodulation KW - neuroprotection KW - nonhuman KW - priority journal KW - protein analysis KW - protein expression KW - protein function KW - receptor upregulation KW - transgenic mouse KW - transient transfection KW - wild type KW - Animals KW - Apoptosis KW - Calcium KW - Calcium Signaling KW - Glutamic Acid KW - Mice KW - Mice, Inbred C57BL KW - Mice, Transgenic KW - Neurons KW - Neuroprotective Agents KW - Oligopeptides KW - Thapsigargin KW - X-Linked Inhibitor of Apoptosis Protein KW - Mus KW - Mus musculus AB - X-linked inhibitor of apoptosis (XIAP) protects and preserves the function of neurons in both in vitro and in vivo models of excitotoxicity. Since calcium (Ca2+) overload is a pivotal event in excitotoxic neuronal cell death, we have determined whether XIAP over-expression influences Ca 2+-signaling in primary cultures of mouse cortical neurons. Using cortical neuron cultures derived from wild-type (Wt) mice transiently transfected with XIAP or from transgenic mice that over-express XIAP, we show that XIAP opposes the rise in intracellular Ca2+ concentration by a variety of triggers. Relative to control neurons, XIAP over-expression produced a slight, but significant, elevation of resting Ca2+ concentrations. By contrast, the rise in intracellular Ca2+ concentrations produced by N-methyl-d-aspartate receptor stimulation and voltage gated Ca2+ channel activation were markedly attenuated by XIAP over-expression. The release of Ca2+ from intracellular stores induced by the sarco/endoplasmic reticulum Ca2+ ATPase inhibitor thapsigargin was also inhibited in neurons transiently transfected with XIAP. The pan-caspase inhibitor zVAD did not, however, diminish the rise in intracellular Ca2+ concentrations elicited by l-glutamate suggesting that XIAP influences Ca2+ signaling in a caspase-independent manner. Taken together, these findings demonstrate that the ability of XIAP to block excessive rises in intracellular Ca2+ by a variety of triggers may contribute to the neuroprotective effects of this anti-apoptotic protein. © 2013 Springer Science+Business Media New York. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a12b692b-d897-4e5e-ac6f-5c5b56fa5f3b ER - TY - JOUR TI - Thermomechanical fatigue crack growth from laser drilled holes in single crystal nickel based superalloy DO - 10.1016/j.ijfatigue.2013.06.006 AU - Kersey, R.K. AU - Staroselsky, A. AU - Dudzinski, D.C. AU - Genest, M. T2 - International Journal of Fatigue SN - 0142-1123 VL - 55 SP - 183 EP - 193 KW - Crack growth prediction KW - Crystallographic orientations KW - Crystallographic plane KW - Experimental techniques KW - Notch KW - Number of cycles to failure KW - Single crystal nickel based superalloy KW - Thermo mechanical fatigues (TMF) KW - Crack detection KW - Crack propagation KW - Single crystals KW - Superalloys KW - Cracks AB - The test results undergoing thermomechanical fatigue of single crystal PWA1484 crack growth showed that the life of TMF specimens with notches (in this case laser drilled holes) is 4 times shorter than the number of cycles to failure observed on smooth gage section specimens (without holes) under the same loading conditions. Such a significant change in number of cycles to failure must be accounted in any damage tolerant turbine airfoil design system. The detailed fractographic analysis demonstrated that all cracks start crystallographically along the {1 1 1} octahedral crystallographic planes and later change to mixed mode fracture. Most of the crack propagation takes place at the low temperature portion of the cycle in the out-of-phase test; however there is noticeable damage accumulation during the high temperature compressive load portion of the cycle. Crack propagation under TMF loading conditions is considerably faster than corresponding isothermal LCF crack growth tested at the temperature and similar loading conditions of the tensile part of the TMF cycle. As results show, the applicability of the LEFM methods for single crystal TMF crack growth prediction is limited and at least should consist of mixed mode crack analysis. A new method for detecting cracks during a TMF test using induction thermography was employed. This method, coined the Active Inferred Crack Detection System (AICD), demonstrated high effectiveness in following crack progression under cyclic loading making it well suited to perform TMF crack growth testing. Using this experimental technique we also investigated the effect of secondary crystallographic orientation on crack propagation. © 2013 Elsevier Ltd. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1624bb0d-b6ec-40ae-b111-119e2392e00c ER - TY - JOUR TI - Estimating probability of detection from in-service inspection data DO - 10.5589/q13-008 AU - Khan, M. AU - Liao, M. T2 - Canadian Aeronautics and Space Journal SN - 0008-2821 VL - 59 IS - 2 SP - 59 EP - 69 KW - Hit and miss KW - In-service datum KW - In-service inspection KW - Laboratory environment KW - Non destructive inspection KW - POD method KW - Probability of detection KW - Real structure KW - Cracks KW - Estimation KW - Inspection KW - Crack detection AB - Due to the complexity of real structures and in-service environment, the probability of detection (POD) curve generated from a laboratory environment and simple coupon samples may not be representative of in-service nondestructive inspection capability and experience. A study was carried out to assess the capability of a recent Berens model to estimate the POD using in-service inspection data. This paper presents the Berens model as well as the results of five case studies, where two types of mean POD curves were estimated and compared with each other. The first POD estimation used the standard POD method, described in the Military Handbook 1823, and used both hit and miss (detected and nondetected cracks) data. The second POD estimation used the Berens model and only hit (detected cracks) and percentage of crack detection (number of detected cracks per number of inspected sites) data. It is shown that the a90 values estimated by the Berens model are close to those from the first POD approach, especially when the percentage of crack detection is known. The study demonstrated the possibility of using the Berens model for estimating an "effective" POD curve from in-service data, where often not all data required by the standard POD approach are available. © 2013 Government of Canada. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 77707708-b9dc-4202-bd30-2bee13dcee63 ER - TY - JOUR TI - Nanocomposites of nanocrystalline cellulose for enzyme immobilization DO - 10.1007/s10570-012-9805-2 AU - Incani, V. AU - Danumah, C. AU - Boluk, Y. T2 - Cellulose SN - 0969-0239 VL - 20 IS - 1 SP - 191 EP - 200 KW - Acid groups KW - Biosensing applications KW - Carbodiimides KW - Carbon chains KW - Cationic polyethylenimine KW - Chemical affinities KW - Gold nanoparticle KW - Metallic nanoparticles KW - Nanocrystalline cellulose KW - Natural cellulose fibers KW - Renewable sources KW - Surface area KW - Biosensors KW - Carbon KW - Carboxylic acids KW - Cellulose derivatives KW - Glucose sensors KW - Gold KW - Metal nanoparticles KW - Nanocomposites KW - Synthesis (chemical) KW - Enzyme immobilization KW - Carboxylic Acids KW - Cellulose Derivatives KW - Composites KW - Crystallites KW - Gold Compounds KW - Sensors KW - Synthesis AB - We describe the synthesis, characterization and use of a composite material made of a renewable source and metallic nanoparticles for biosensing applications. Nanocrystalline cellulose (NCC) is a product isolated from natural cellulose fibers, which is of approximately 100 nm long and 10 nm wide in size. We augmented the surface area and tailored the chemical affinity of NCC by optimally dressing it with gold nanoparticles (AuNPs). The deposition of AuNPs on NCC was controlled by using cationic polyethylenimine (PEI) at different pHs. AuNPs were thiol-functionalized using different linkers prior to enzyme immobilization. The enzyme (glucose oxidase or GOx) was conjugated on the composite by carbodiimide coupling, and subsequent activation of linker-carboxylic acid group. Our results showed that GOx was attached to the surface of the NCC nanocomposite. Moreover, the amount of GOx loaded onto the support depended on the length of the thiol-linker used. The lower value (20. 3 mg/mg of support) was obtained with the longer thiol-linker (11 carbon chain) compared to 25. 2 mg/mg of support for the smaller thiol-linker (3 carbon chain). © 2012 Springer Science+Business Media Dordrecht. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 905d30f0-dff0-424f-978b-b06e0f0ac257 ER - TY - JOUR TI - PCSK9 Prosegment chimera as novel inhibitors of LDLR degradation DO - 10.1371/journal.pone.0072113 AU - Luna Saavedra, Y.G. AU - Zhang, J. AU - Seidah, N.G. T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 8 SP - e72113 KW - immunoglobulin G1 KW - low density lipoprotein receptor KW - PCSK9 inhibitor KW - proteinase inhibitor KW - recombinant Fcpro protein KW - recombinant protein KW - unclassified drug KW - amino terminal sequence KW - article KW - carboxy terminal sequence KW - cell strain HEK293 KW - cell strain HepG2 KW - controlled study KW - down regulation KW - enzyme active site KW - enzyme activity KW - human KW - human cell KW - in vitro study KW - protein binding KW - protein degradation KW - protein domain KW - protein expression KW - protein function KW - protein protein interaction KW - protein secretion AB - The proprotein convertase PCSK9, a target for the treatment of hypercholesterolemia, is a negative regulator of the LDL receptor (LDLR) leading to its degradation in endosomes/lysosomes and up-regulation of plasma LDL-cholesterol levels. The proprotein convertases, a family of nine secretory serine proteases, are first synthesized as inactive zymogens. Except for PCSK9, all other convertases are activated following the autocatalytic excision of their inhibitory N-terminal prosegment. PCSK9 is unique since the mature enzyme exhibits a cleaved prosegment complexed with the catalytic subunit and has no protease activity towards other substrates. Similar to other convertases, we hypothesized that the in trans presence of the PCSK9 prosegment would interfere with PCSK9's activity on the LDLR. Since the prosegment cannot be secreted alone, we engineered a chimeric protein using the Fc-region of human IgG1 fused to the PCSK9 prosegment. The expression of such Fcpro-fusion protein in HEK293 and HepG2 cells resulted in a secreted protein that binds PCSK9 and markedly inhibits its activity on the LDLR. This was observed by either intracellular co-expression of PCSK9 and Fcpro or by an extracellular in vitro co-incubation of Fcpro with PCSK9. Structure-function studies revealed that the inhibitory function of Fcpro does not require the acidic N-terminal stretch (residues 31-58) nor the C-terminal Gln152 of the prosegment. Fcpro likely interacts with the prosegment and/or catalytic subunit of the prosegment≡PCSK9 complex thereby allosterically modulating its function. Our data suggest a novel strategic approach for the design and isolation of PCSK9 inhibitors. © 2013 Luna Saavedra et al. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e14dd102-92ae-4cc3-90c3-996e1fa83227 ER - TY - JOUR TI - Method for isolation and molecular characterization of extracellular microvesicles released from brain endothelial cells DO - 10.1186/2045-8118-10-4 AU - Haqqani, A.S. AU - Delaney, C.E. AU - Tremblay, T.-L. AU - Sodja, C. AU - Sandhu, J.K. AU - Stanimirovic, D.B. T2 - Fluids and Barriers of the CNS SN - 2045-8118 VL - 10 IS - 1 SP - 4 KW - ALIX protein KW - biological marker KW - CD81 antigen KW - CD9 antigen KW - insulin receptor KW - low density lipoprotein KW - low density lipoprotein receptor related protein KW - protein KW - tetraspanin KW - transferrin receptor KW - tumor susceptibility gene 101 protein KW - unclassified drug KW - article KW - blood brain barrier KW - brain endothelium cell KW - cell isolation KW - cell vacuole KW - endothelium cell KW - exosome KW - human KW - human cell KW - mass spectrometry KW - priority journal KW - protein analysis KW - protein function KW - protein localization KW - proteomics AB - Background: In addition to possessing intracellular vesicles, eukaryotic cells also produce extracellular microvesicles, ranging from 50 to 1000 nm in diameter that are released or shed into the microenvironment under physiological and pathological conditions. These membranous extracellular organelles include both exosomes (originating from internal vesicles of endosomes) and ectosomes (originating from direct budding/shedding of plasma membranes). Extracellular microvesicles contain cell-specific collections of proteins, glycoproteins, lipids, nucleic acids and other molecules. These vesicles play important roles in intercellular communication by acting as carrier for essential cell-specific information to target cells. Endothelial cells in the brain form the blood-brain barrier, a specialized interface between the blood and the brain that tightly controls traffic of nutrients and macromolecules between two compartments and interacts closely with other cells forming the neurovascular unit. Therefore, brain endothelial cell extracellular microvesicles could potentially play important roles in 'externalizing' brain-specific biomarkers into the blood stream during pathological conditions, in transcytosis of blood-borne molecules into the brain, and in cell-cell communication within the neurovascular unit.Methods: To study cell-specific molecular make-up and functions of brain endothelial cell exosomes, methods for isolation of extracellular microvesicles using mass spectrometry-compatible protocols and the characterization of their signature profiles using mass spectrometry -based proteomics were developed.Results: A total of 1179 proteins were identified in the isolated extracellular microvesicles from brain endothelial cells. The microvesicles were validated by identification of almost 60 known markers, including Alix, TSG101 and the tetraspanin proteins CD81 and CD9. The surface proteins on isolated microvesicles could potentially interact with both primary astrocytes and cortical neurons, as cell-cell communication vesicles. Finally, brain endothelial cell extracellular microvesicles were shown to contain several receptors previously shown to carry macromolecules across the blood brain barrier, including transferrin receptor, insulin receptor, LRPs, LDL and TMEM30A.Conclusions: The methods described here permit identification of the molecular signatures for brain endothelial cell-specific extracellular microvesicles under various biological conditions. In addition to being a potential source of useful biomarkers, these vesicles contain potentially novel receptors known for delivering molecules across the blood-brain barrier. © 2013 Haqqani et al.; licensee BioMed Central Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 84ee0a32-72ff-428b-84d1-c577647c89eb ER - TY - JOUR TI - A first look at the AURIGA-CALIFORNIA giant molecular cloud with Herschel and the CSO: Census of the young stellar objects and the dense gas DO - 10.1088/0004-637X/764/2/133 AU - Harvey, P.M. AU - Fallscheer, C. AU - Ginsburg, A. AU - Terebey, S. AU - André, P. AU - Bourke, T.L. AU - Di Francesco, J. AU - Könyves, V. AU - Matthews, B.C. AU - Peterson, D.E. T2 - The Astrophysical Journal SN - 0004-637X VL - 764 IS - 2 SP - 133 AB - We have mapped the Auriga/California molecular cloud with the Herschel PACS and SPIRE cameras and the Bolocam 1.1 mm camera on the Caltech Submillimeter Observatory with the eventual goal of quantifying the star formation and cloud structure in this giant molecular cloud (GMC) that is comparable in size and mass to the Orion GMC, but which appears to be forming far fewer stars. We have tabulated 60 compact 70/160 μm sources that are likely pre-main-sequence objects and correlated those with Spitzer and WISE mid-IR sources. At 1.1 mm, we find 18 cold, compact sources and discuss their properties. The most important result from this part of our study is that we find a modest number of additional compact young objects beyond those identified at shorter wavelengths with Spitzer. We also describe the dust column density and temperature structure derived from our photometric maps. The column density peaks at a few × 1022 cm-2 (NH2) and is distributed in a clear filamentary structure along which nearly all of the pre-main-sequence objects are found. We compare the young stellar object surface density to the gas column density and find a strong nonlinear correlation between them. The dust temperature in the densest parts of the filaments drops to ∼10 K from values ∼14-15 K in the low-density parts of the cloud. We also derive the cumulative mass fraction and probability density function of material in the cloud, which we compare with similar data on other star-forming clouds. © 2013. The American Astronomical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e6bc7b8f-6733-4ce1-a3a1-2057b6800d9a ER - TY - JOUR TI - Characterization of a trifunctional glucosyltransferase essential for Moraxella catarrhalis lipooligosaccharide assembly DO - 10.1093/glycob/cwt042 AU - Luke-Marshall, N.R. AU - Edwards, K.J. AU - Sauberan, S. AU - St. Michael, F. AU - Vinogradov, E.V. AU - Cox, A.D. AU - Campagnari, A.A. T2 - Glycobiology SN - 0959-6658 VL - 23 IS - 8 SP - 1013 EP - 1021 KW - glucosyltransferase KW - lipooligosaccharide KW - amino terminal sequence KW - article KW - bacterial strain KW - biosynthesis KW - carbohydrate synthesis KW - carboxy terminal sequence KW - catalysis KW - Escherichia coli KW - Moraxella catarrhalis KW - nonhuman KW - nucleotide sequence KW - Pasteurella multocida KW - phenotype KW - priority journal KW - protein domain KW - protein motif KW - Streptococcus pyogenes AB - The human respiratory tract pathogen Moraxella catarrhalis expresses lipooligosaccharides (LOS), glycolipid surface moieties that are associated with enhanced colonization and virulence. Recent studies have delineated the major steps required for the biosynthesis and assembly of the M. catarrhalis LOS molecule. We previously demonstrated that the glucosyltransferase enzyme Lgt3 is responsible for the addition of at least one glucose (Glc) molecule, at the β-(1-4) position, to the inner core of the LOS molecule. Our data further suggested a potential multifunctional role for Lgt3 in LOS biosynthesis. The studies reported here demonstrate that the Lgt3 enzyme possesses two glycosyltransferase domains (A1 and A2) similar to that of other bifunctional glycosyltransferase enzymes involved in surface polysaccharide biosynthesis in Escherichia coli, Pasteurella multocida and Streptococcus pyogenes. Each Lgt3 domain contains a conserved DXD motif, shown to be involved in the catalytic activity of other glycosyltransferases. To determine the function of each domain, A1 (N-terminal), A2 (C-terminal) and double A1A2 site-directed DAD to AAA mutants were constructed and the resulting LOS phenotypes of these modified strains were analyzed. Our studies indicate that the Lgt3 N-terminal A1 catalytic domain is responsible for the addition of the first β-(1-3) Glc to the first Glc on the inner core. The C-terminal catalytic domain A2 then adds the β-(1-4) Glc and the β-(1-6) Glc, confirming the bifunctional nature of this domain. The results from these experiments demonstrate that Lgt3 is a novel, multifunctional transferase responsible for the addition of three Glcs with differing linkages onto the inner core of M. catarrhalis LOS. © 2013 The Author 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f70abfce-d6e3-4d3a-8b63-900c9d4c2fe1 ER - TY - JOUR TI - A modified protocol for retrograde cerebral perfusion: Magnetic resonance spectroscopy in pigs DO - 10.1093/ejcts/ezs505 AU - Yang, Y. AU - Yang, L. AU - Sun, J. AU - Gruwel, M.L. AU - Deslauriers, R. AU - Ye, J. T2 - European Journal of Cardio-thoracic Surgery SN - 1010-7940 VL - 43 IS - 5 SP - ezs505 SP - 1065 EP - 1071 KW - adenosine triphosphate KW - creatine phosphate KW - animal cell KW - animal experiment KW - animal tissue KW - article KW - brain level KW - brain perfusion KW - brain protection KW - cell pH KW - clinical effectiveness KW - clinical protocol KW - controlled study KW - deep hypothermic circulatory arrest KW - experimental pig KW - inferior cava vein KW - nonhuman KW - nuclear magnetic resonance spectroscopy KW - priority journal KW - retrograde cerebral perfusion KW - warming KW - water content KW - Adenosine Triphosphate KW - Animals KW - Body Temperature KW - Brain Chemistry KW - Cardiopulmonary Bypass KW - Hydrogen-Ion Concentration KW - Hypothermia, Induced KW - Magnetic Resonance Imaging KW - Perfusion Imaging KW - Phosphocreatine KW - Phosphorus Isotopes KW - Random Allocation KW - Swine AB - Objectives: Retrograde cerebral perfusion (RCP) has been employed to protect the brain during cardiovascular surgery, requiring temporary hypothermic circulatory arrest (HCA). However, the protocol used for RCP remains to be modified if prolonged HCA is expected. The aim of this study was to determine the efficacy of a modified protocol for this purpose. Methods: After establishment of HCA at 15°C, 14 pigs were subjected to 90-min RCP using either the conventional protocol (i.e. alpha-stat strategy, 25-mmHg perfusion pressure and occluded inferior vena cava, Group I, n = 7) or the new protocol (i.e. pH-stat strategy, 40-mmHg perfusion pressure and unoccluded inferior vena cava, Group II, n = 7). After being rewarmed to 37°C, pigs were perfused for another 60 min. Phosphorus-31 magnetic resonance spectroscopy was used to track the changes of brain high-energy phosphates [i.e. adenosine triphosphate and phosphocreatine (PCr)] and intracellular pH (pHi). At the end, brain water content was measured. Results: During RCP, high-energy phosphates decreased in both groups, whereas adenosine triphosphate decreased much faster in Group I (10.4 ± 4.3 vs 30.4 ± 4.4% of the baseline, P = 0.007, 60-min RCP). After rewarming, the recovery of high-energy phosphates and pHi was much slower in Group I (PCr: 55.7 ± 9.1 vs 78.4 ± 5.1% of the baseline, P = 0.046; adenosine triphosphate: 26.6 ± 10.6 vs 64.8 ± 4.6% of the baseline, P = 0.007; pHi: 6.5 ± 0.4 vs 7.1 ± 0.1, P = 0.021 at 30-min normothermic perfusion after rewarming). Brain tissue water content was significantly higher in Group I (81.1 ± 0.4 vs 79.5 ± 0.4%, P = 0.016). Conclusions: Application of the modified RCP protocol significantly improved cerebral energy conservation during HCA and accelerated energy recovery after rewarming. © The Author 2012. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 70251240-a810-4a60-8ea9-195fc4a3310a ER - TY - JOUR TI - In Vivo detection of human TRPV6-rich tumors with anti-cancer peptides derived from soricidin DO - 10.1371/journal.pone.0058866 AU - Bowen, Chris V. AU - DeBay, Drew AU - Ewart, Stephen H. AU - Gallant, Pamela AU - Gormley, Sean AU - Ilenchuk, T. Toney AU - Iqbal, Umar AU - Lutes, Tyler AU - Martina, Marzia AU - Mealing, Geoffrey AU - Merkley, Nadine AU - Sperker, Sandra AU - Moreno, Maria J. AU - Rice, Christopher AU - Syvitski, Raymond T. AU - Stewart, John M. T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 3 SP - e58866 AB - Soricidin is a 54-amino acid peptide found in the paralytic venom of the northern short-tailed shrew (Blarina brevicauda) and has been found to inhibit the transient receptor potential of vallinoid type 6 (TRPV6) calcium channels. We report that two shorter peptides, SOR-C13 and SOR-C27, derived from the C-terminus of soricidin, are high-affinity antagonists of human TRPV6 channels that are up-regulated in a number of cancers. Herein, we report molecular imaging methods that demonstrate the in vivo diagnostic potential of SOR-C13 and SOR-C27 to target tumor sites in mice bearing ovarian or prostate tumors. Our results suggest that these novel peptides may provide an avenue to deliver diagnostic and therapeutic reagents directly to TRPV6-rich tumors and, as such, have potential applications for a range of carcinomas including ovarian, breast, thyroid, prostate and colon, as well as certain leukemia's and lymphomas. DA - 2013/03/15 PY - 2013 PB - PLOS LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 45f91680-00ea-4763-8ce9-6880089e2685 ER - TY - JOUR TI - Experimental investigation of load distribution in a composite girder bridge at elastic versus inelastic states DO - 10.1016/j.engstruct.2012.10.034 AU - Razaqpur, A.G. AU - Shedid, M. AU - Nofal, M. T2 - Engineering Structures SN - 0141-0296 VL - 49 SP - 707 EP - 718 KW - Bridge design KW - Bridge elements KW - Bridge model KW - Calculated values KW - Composite girder bridges KW - Distribution characteristics KW - Distribution factor KW - Elastic limit KW - Experimental investigations KW - Flexure KW - Highway bridge design KW - Internal forces KW - Live loads KW - Load distribution factor KW - Load distributions KW - Loading tests KW - Maximum moments KW - Reinforced KW - Scale models KW - Slab-on-girder bridge KW - Steel girder KW - Traffic loads KW - Beams and girders KW - Bridges KW - Composite bridges KW - Concrete slabs KW - Concretes KW - Numerical analysis KW - Steel KW - Loading KW - bridge KW - composite KW - concrete structure KW - design method KW - experimental study KW - failure analysis KW - flexure KW - loading KW - reinforced concrete KW - steel structure AB - Bridge design and evaluation involve the determination of the internal forces and moments that each bridge element must resist. In slab-on-girder bridges, the moment and shear caused by traffic loads are normally determined using load distribution factors. These factors are derived based on results of analytical models, numerical analyses, as well as actual loading tests, but there appears to be scant experimental data to gauge their accuracy, particularly beyond the elastic limit state. To address the scarcity of the experimental data and to understand how the distribution characteristics of concrete slab on steel girder composite bridges change with the advent of yielding and inelasticity, a 1/3 scale model of a hypothetical composite bridge was tested to failure in this study.Extensive measurements were taken during the test to allow better understanding of the response of slab-on-girder bridges as well as their live load distribution characteristics at all stages of loading up to failure. The experimentally determined distribution factors for the tested bridge model are compared with the calculated values based on the Canadian Highway Bridge Design Standard, and the code values are found to overestimate the maximum moment in the interior loaded girder by about 22% and 33% at the elastic and the inelastic states, respectively. © 2012 Elsevier Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 24e8aa98-9dc8-4897-a5cb-3860d35635d3 ER - TY - JOUR TI - In situ TEM study of stability of TaRhx diffusion barriers using a novel sample preparation method DO - 10.1016/j.micron.2013.11.002 AU - Dalili, N. AU - Li, P. AU - Kupsta, M. AU - Liu, Q. AU - Ivey, D.G. T2 - Micron SN - 0968-4328 AB - The atomic diffusion mechanisms associated with metallurgical failure of TaRhx diffusion barriers for Cu metallizations were studied by in situ transmission electron microscopy (TEM). The issues related to in situ heating of focused ion beam (FIB) prepared cross-sectional TEM samples that contain Cu thin films are discussed. The Cu layer in Si/(13 nm)TaRhx /Cu stacks showed grain growth and formation of voids at temperatures exceeding 550 °C. For Si/(43 nm)TaRhx /Cu stacks, grain growth of Cu was delayed to higher temperatures, i.e., 700 °C, and void formation was not observed. Extensive surface diffusion of Cu, however, preceded bulk diffusion. Therefore, a 10 nm film of electron beam evaporated C was deposited on both sides of the TEM lamellae to limit surface diffusion. This processing technique allowed for direct observation of atomic diffusion and reaction mechanisms across the TaRhx interface. Failure occurred by nucleation of orthorhombic RhSi particles at the Si/TaRhx interface. Subsequently, the barrier at areas adjacent to RhSi particles was depleted in Rh. This created lower density areas in the barrier, which facilitated diffusion of Cu to the Si substrate to form Cu3Si. The morphology of an in situ annealed lamella was compared with an ex situ bulk annealed sample, which showed similar reaction morphology. The sample preparation method developed in this study successfully prevented surface diffusion/delamination of the Cu layer and can be employed to understand the metallurgical failure of other potential diffusion barriers. © 2013 Elsevier Ltd. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a2a6b8c5-8374-42bc-9be1-b7343f234b6b ER - TY - JOUR TI - Core-shell nanoparticles as prodrugs: Possible cytotoxicological and biomedical impacts of batch-to-batch inconsistencies DO - 10.1016/j.jcis.2012.08.065 AU - França, R. AU - Zhang, X.-F. AU - Veres, T. AU - Yahia, L. AU - Sacher, E. T2 - Journal of Colloid and Interface Science SN - 0021-9797 VL - 389 IS - 1 SP - 292 EP - 297 KW - Amine oxidation KW - Batch-to-batch chemical inconsistency KW - Bond scissions KW - Chemical variations KW - Core-shell nanoparticles KW - Drug carrier KW - Prodrugs KW - Side reactions KW - Targeted drug delivery KW - Cytotoxicity KW - Drug delivery KW - Magnetite KW - Nanoparticles KW - Silica KW - Surface chemistry KW - Surface reactions KW - Magnetite nanoparticles KW - drug carrier KW - magnetite nanoparticle KW - reagent KW - silane KW - silicon dioxide KW - article KW - catalyst KW - chemical analysis KW - chemical reaction KW - chemical structure KW - cytotoxicity KW - medical research KW - oxidation KW - priority journal KW - surface property KW - Drug Carriers KW - Ferumoxytol KW - Humans KW - Nanoparticles KW - Oxidation-Reduction KW - Prodrugs KW - Silanes KW - Silicon Dioxide KW - Surface Properties AB - Numerous samples of magnetite@silica and magnetite@silica@silane core-shell nanoparticles, previously used as prodrugs, were prepared by an experienced chemist, using the same identical equipment and the same lots of reagents. Their surface analyses showed batch-to-batch chemical variations: no two batches were found to have the same surface chemistries, showing unexpected Si-O bond scission and amine oxidation. Because the preparations used reactions recognized to be mild, and bond scission and oxidation were never previously reported for similar reactions on larger surfaces, the Fe3O4 nanoparticles that form the nanoparticle core appear to have acted as catalysts for these side reactions. The intended use of these nanoparticles, as drug carriers, is discussed in terms of cytotoxicological and biomedical consequences. © 2012 Elsevier Inc. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4f42a3e6-1f47-4888-bed1-69d5a38c9584 ER - TY - JOUR TI - The scuba-2 cosmology legacy survey: Demographics of the 450-μm population DO - 10.1093/mnras/stt1577 AU - Roseboom, I.G. AU - Dunlop, J.S. AU - Cirasuolo, M. AU - Geach, J.E. AU - Smail, I. AU - Halpern, M. AU - Van der Werf, P. AU - Almaini, O. AU - Arumugam, V. AU - Asboth, V. AU - Auld, R. AU - Blain, A. AU - Bremer, M.N. AU - Bock, J. AU - Bowler, R.A.A. AU - Buitrago, F. AU - Chapin, E. AU - Chapman, S. AU - Chrysostomou, A. AU - Clarke, C. AU - Conley, A. AU - Coppin, K.E.K. AU - Danielson, A.L.R. AU - Farrah, D. AU - Glenn, J. AU - Hatziminaoglou, E. AU - Ibar, E. AU - Ivison, R.J. AU - Jenness, T. AU - van Kampen, E. AU - Karim, A. AU - Mackenzie, T. AU - Marsden, G. AU - Meijerink, R. AU - Michałowski, M.J. AU - Oliver, S.J. AU - Page, M.J. AU - Pearson, E. AU - Scott, D. AU - Simpson, J.M. AU - Smith, D.J.B. AU - Spaans, M. AU - Swinbank, A.M. AU - Symeonidis, M. AU - Targett, T. AU - Valiante, E. AU - Viero, M. AU - Wang, L. AU - Willott, C.J. AU - Zemcov, M. T2 - Monthly Notices of the Royal Astronomical Society SN - 0035-8711 VL - 436 IS - 1 SP - 430 EP - 448 AB - We investigate the multiwavelength properties of a sample of 450-μm-selected sources from the SCUBA-2 Cosmology Legacy Survey. A total of 69 sources were identified above 4σ in deep SCUBA-2 450-μm observations overlapping the UDS and COSMOS fields and covering 210 arcmin2 to a typical depth of σ450 = 1.5mJy. Reliable cross-identifications are found for 58 sources (84 per cent) in Spitzer and Hubble Space Telescope WFC3/IR data. The photometric redshift distribution (dN/dz) of 450-μm-selected sources is presented, showing a broad peak in the redshift range 1 < z < 3 and a median of z = 1.4. Combining the SCUBA-2 photometry with Herschel SPIRE data from HerMES, the submm spectral energy distribution (SED) is examined via the use of modified blackbody fits, yielding aggregate values for the IR luminosity, dust temperature and emissivity of (LIR) = 1012 ± 0.8 L, (TD) = 42 ± 11K and (βD) = 1.6 ± 0.5, respectively. The relationship between these SED parameters and the physical properties of galaxies is investigated, revealing correlations between TD and LIR and between βD and both stellar mass and effective radius. The connection between the star formation rate (SFR) and stellar mass is explored, with 24 per cent of 450-μm sources found to be 'starbursts', i.e. displaying anomalously high specific SFRs. However, both the number density and observed properties of these 'starburst' galaxies are found to be consistent with the population of normal star-forming galaxies. © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 974a5a2b-0549-462a-8dad-9a4fe4ca10fd ER - TY - JOUR TI - An exponential decline at the bright end of the z = 6 galaxy luminosity function DO - 10.1088/0004-6256/145/1/4 AU - Willott, C.J. AU - McLure, R.J. AU - Hibon, P. AU - Bielby, R. AU - McCracken, H.J. AU - Kneib, J.-P. AU - Ilbert, O. AU - Bonfield, D.G. AU - Bruce, V.A. AU - Jarvis, M.J. T2 - Astronomical Journal SN - 0004-6256 VL - 145 IS - 1 SP - 4 AB - We present the results of a search for the most luminous star-forming galaxies at redshifts z ≈ 6 based on Canada-France-Hawaii Telescope Legacy Survey data. We identify a sample of 40 Lyman break galaxies (LBGs) brighter than magnitude z′ = 25.3 across an area of almost 4 deg 2. Sensitive spectroscopic observations of seven galaxies provide redshifts for four, of which only two have moderate to strong Lyα emission lines. All four have clear continuum breaks in their spectra. Approximately half of the LBGs are spatially resolved in 0.7 arcsec seeing images, indicating larger sizes than lower luminosity galaxies discovered with the Hubble Space Telescope, possibly due to ongoing mergers. The stacked optical and infrared photometry is consistent with a galaxy model with stellar mass 10 10 M⊙. There is strong evidence for substantial dust reddening with a best-fit A V = 0.75 and A V > 0.48 at 2σ confidence, in contrast to the typical dust-free galaxies of lower luminosity at this epoch. The spatial extent and spectral energy distribution suggest that the most luminous z ≈ 6 galaxies are undergoing merger-induced starbursts. The luminosity function of z = 5.9 star-forming galaxies is derived. This agrees well with previous work and shows strong evidence for an exponential decline at the bright end, indicating that the feedback processes that govern the shape of the bright end are occurring effectively at this epoch. © 2013. The American Astronomical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 939c5b3c-8c4d-44a1-8614-e7db1f290d07 ER - TY - JOUR TI - A Stochastic XFEM Model to Study Delamination in PPS/Glass UD Composites: Effect of Uncertain Fracture Properties DO - 10.1007/s10443-013-9342-7 AU - Motamedi, D. AU - Milani, A.S. AU - Komeili, M. AU - Bureau, M.N. AU - Thibault, F. AU - Trudel-Boucher, D. T2 - Applied Composite Materials SN - 0929-189X SP - 1 EP - 18 AB - A nonlinear extended finite element (XFEM) modeling framework under a stochastic cohesive zone is presented for realistic prediction of delamination in polyphenylene sulfide (PPS)/glass composites in mode I of fracture. The cohesive zone model adopts damage evolution of the material based on a bilinear traction-separation law, the critical energy release rate and the J-integral method to formulate the delamination interface under stochastic fracture properties. To demonstrate the application of the approach, numerical predictions are compared to experimental data using Double Cantilever Beam (DCB) tests. In particular, it is shown how the XFEM model can be used to capture test non-repeatability due to uncertain fracture properties, which is often the case during the characterization of composites using standard fracture tests. © 2013 Springer Science+Business Media Dordrecht. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a295199c-6700-41b6-a607-cd69d874ea70 ER - TY - JOUR TI - Investigating the candidacy of LPS-based glycoconjugates to prevent invasive meningococcal disease: conjugates based on core oligosaccharides DO - 10.1007/s10719-013-9500-z AU - St. Michael, F. AU - Cairns, C.M. AU - Filion, A.L. AU - Biolchi, A. AU - Brunelli, B. AU - Giuliani, M. AU - Richards, J.C. AU - Cox, A.D. T2 - Glycoconjugate Journal SN - 0282-0080 SP - 1 EP - 15 AB - In this study we have prepared glycoconjugates with core oligosaccharides (OS) from the lipopolysaccharide (LPS) of Neisseria meningitidis, thus avoiding the neo-epitopes of the deacylated lipid A region of the derived LPS molecule identified in our previous studies. A comprehensive investigation was performed with glycoconjugates prepared from the most extended to the most truncated core OS still maintaining the conserved inner core epitope. As previously, we have established reproducible bactericidal killing of the homologous antigen elaborating strain, but a failure to kill wild-type strains. In these studies it was evident that the linker molecules used in the conjugation methodologies were dominating the immune response. However, when galE core OS based conjugates were prepared without utilizing linkers, via direct reductive amination, we failed to generate an immune response to even the homologous antigen. We also identified that immunisation with the galE antigen via linker methodologies provoked an immune response that was dependent upon key residues of the conserved inner core OS structure, whereas the immune responses to lgtB and lgtA antigens did not involve the inner core OS. This comprehensive study has, despite our best efforts, cast significant doubt as to the utility of the conserved inner core region of the meningococcal LPS as a potential vaccine antigen. © 2013 Her Majesty the Queen in Right of Canada. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9bebb747-c4e1-4206-9358-62a79edf2615 ER - TY - JOUR TI - Normal adaptation of Candida albicans to the murine gastrointestinal tract requires Efg1p-dependent regulation of metabolic and host defense genes DO - 10.1128/EC.00236-12 AU - Pierces, J.V. AU - Dignard, D. AU - Whiteway, M. AU - Kumamoto, C.A. T2 - Eukaryotic Cell SN - 1535-9778 VL - 12 IS - 1 SP - 37 EP - 49 KW - DNA binding protein KW - EFG1 protein, Candida albicans KW - fungal protein KW - superoxide dismutase KW - transcription factor KW - transcriptome KW - animal KW - article KW - Bagg albino mouse KW - Candida albicans KW - cecum KW - DNA microarray KW - fungal gene KW - fungus hyphae KW - gastrointestinal tract KW - gene expression KW - gene expression regulation KW - genetics KW - growth, development and aging KW - host pathogen interaction KW - ileum KW - lipid metabolism KW - metabolism KW - microbiology KW - mouse KW - physiology KW - upregulation KW - Animals KW - Candida albicans KW - Cecum KW - DNA-Binding Proteins KW - Fungal Proteins KW - Gastrointestinal Tract KW - Gene Expression KW - Gene Expression Regulation, Fungal KW - Genes, Fungal KW - Host-Pathogen Interactions KW - Hyphae KW - Ileum KW - Lipid Metabolism KW - Mice KW - Mice, Inbred BALB C KW - Oligonucleotide Array Sequence Analysis KW - Superoxide Dismutase KW - Transcription Factors KW - Transcriptome KW - Up-Regulation KW - Candida albicans KW - Murinae KW - Mus AB - Although gastrointestinal colonization by the opportunistic fungal pathogen Candida albicans is generally benign, severe systemic infections are thought to arise due to escape of commensal C. albicans from the gastrointestinal (GI) tract. The C. albicans transcription factor Efg1p is a major regulator of GI colonization, hyphal morphogenesis, and virulence. The goals of this study were to identify the Efg1p regulon during GI tract colonization and to compare C. albicans gene expression during colonization of different organs of the GI tract. Our results identified significant differences in gene expression between cells colonizing the cecum and ileum. During colonization, efg1- null mutant cells expressed higher levels of genes involved in lipid catabolism, carnitine biosynthesis, and carnitine utilization than did colonizing wild-type (WT) cells. In addition, during laboratory growth, efg1- null mutant cells grew to a higher density than WT cells. The efg1- null mutant grew in depleted medium, while WT cells could grow only if the depleted medium was supplemented with carnitine, a compound that promotes the metabolism of fatty acids. Altered gene expression and altered growth capability support the ability of efg1- cells to hypercolonize naïve mice. Also, Efg1p was shown to be important for transcriptional responses to the stresses present in the cecum environment. For example, during colonization, SOD5, encoding a superoxide dismutase, was highly upregulated in an Efg1p-dependent manner. Ectopic expression of SOD5 in an efg1- null mutant increased the fitness of the efg1- null mutant cells during colonization. These data show that EFG1 is an important regulator of GI colonization. © American Society for Microbiology. All Rights Reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 14854058-cb1e-45b8-804c-bac4199a5bc0 ER - TY - JOUR TI - IL-10 produced by trophoblast cells inhibits phagosome maturation leading to profound intracellular proliferation of Salmonella enterica Typhimurium DO - 10.1016/j.placenta.2013.06.003 AU - Nguyen, T. AU - Robinson, N. AU - Allison, S.E. AU - Coombes, B.K. AU - Sad, S. AU - Krishnan, L. T2 - Placenta SN - 0143-4004 VL - 34 IS - 9 SP - 765 EP - 774 KW - agar KW - bacterial protein KW - beta galactosidase KW - cytokine KW - interleukin 10 KW - interleukin 10 antibody KW - interleukin 6 KW - lysosome associated membrane protein 1 KW - pathogenicity island 1 gene effector protein KW - Rab protein KW - Rab5 protein KW - unclassified drug KW - animal experiment KW - article KW - bacterial load KW - bacterial strain KW - bacterium colony KW - biogenesis KW - cell division KW - cell line KW - cell lysate KW - cell maturation KW - cell proliferation KW - cellular distribution KW - colony forming unit KW - confocal microscopy KW - controlled study KW - cytokine production KW - cytokine response KW - enzyme release KW - female KW - growth inhibition KW - HeLa cell KW - human KW - human cell KW - in vitro study KW - in vivo study KW - internalization KW - lysosome KW - macrophage KW - mouse KW - mutant KW - nonhuman KW - pathogenicity island KW - phagocytosis KW - phagosome KW - priority journal KW - protein localization KW - Salmonella typhimurium KW - trophoblast KW - Western blotting AB - Introduction Salmonella enterica Typhimurium (ST) is a phagosomal pathogen that can infect placental trophoblast cells leading to abortion and severe maternal illness. It is unclear how the trophoblast cells promote profound bacterial proliferation. Methods The mechanism of internalization, intracellular growth and phagosomal biogenesis in ST-infected human epithelial (HeLa), macrophage (THP-1) and trophoblast-derived cell lines (JEG-3, BeWo and HTR-8) was studied. Specific inhibitors were used to block bacterial internalization. Phagosomal maturation was determined by confocal microscopy, Western-blotting and release of lysosomal β-galactosidase by infected cells. Bacterial colony forming units were determined by plating infected cell lysates on agar plates. Results ST proliferated minimally in macrophages but replicated profoundly within trophoblast cells. The ST-ΔinvA (a mutant of Salmonella pathogenicity island-1 gene effector proteins) was unable to infect epithelial cells, but was internalized by scavenger receptors on trophoblasts and macrophages. However, ST was contrastingly localized in early (Rab5+) or late (LAMP1+) phagosomes within trophoblast cells and macrophages respectively. Furthermore trophoblast cells (unlike macrophages) did not exhibit phagoso-lysosomal fusion. ST-infected macrophages produced IL-6 whereas trophoblast cells produced IL-10. Neutralizing IL-10 in JEG-3 cells accelerated phagolysomal fusion and reduced proliferation of ST. Placental bacterial burden was curtailed in vivo in anti-IL-10 antibody treated and IL-10-deficient mice. Discussion Macrophages phagocytose but curtail intracellular replication of ST in late phagosomes. In contrast, phagocytosis by trophoblast cells results in an inappropriate cytokine response and proliferation of ST in early phagosomes. Conclusion IL-10 production by trophoblast cells that delays phagosomal maturation may facilitate proliferation of pathogens in placental cells. © 2013 Elsevier Ltd. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : fbc072e1-b52b-4dfb-aaa1-6a048f90f6ce ER - TY - JOUR TI - Alkaline polymer electrolyte membranes for fuel cell applications DO - 10.1039/c3cs60053j AU - Wang, Y.-J. AU - Qiao, J. AU - Baker, R. AU - Zhang, J. T2 - Chemical Society Reviews SN - 0306-0012 VL - 42 IS - 13 SP - 5768 EP - 5787 AB - In this review, we examine the most recent progress and research trends in the area of alkaline polymer electrolyte membrane (PEM) development in terms of material selection, synthesis, characterization, and theoretical approach, as well as their fabrication into alkaline PEM-based membrane electrode assemblies (MEAs) and the corresponding performance/durability in alkaline polymer electrolyte membrane fuel cells (PEMFCs). Respective advantages and challenges are also reviewed. To overcome challenges hindering alkaline PEM technology advancement and commercialization, several research directions are then proposed. © 2013 The Royal Society of Chemistry. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1e79f943-577d-4a4c-b5a3-c03f91c307b9 ER - TY - JOUR TI - Comparison of T2 and T2 *-weighted MR molecular imaging of a mouse model of glioma DO - 10.1186/1471-2342-13-20 AU - Blasiak, Barbara AU - Barnes, Samuel AU - Foniok, Tadeusz AU - Rushforth, David AU - Matyas, John AU - Ponjevic, Dragana AU - Weglarz, Wladyslaw P. AU - Tyson, Randy AU - Iqbal, Umar AU - Abulrob, Abedelnasser AU - Sutherland, Garnette R. AU - Obenaus, Andre AU - Tomanek, Boguslaw T2 - BMC Medical Imaging SN - 1471-2342 VL - 13 IS - 1 SP - 20 AB - Background: Standard MRI has been used for high-grade gliomas detection, albeit with limited success as it does not provide sufficient specificity and sensitivity to detect complex tumor structure. Therefore targeted contrast agents based on iron oxide, that shorten mostly T2 relaxation time, have been recently applied. However pulse sequences for molecular imaging in animal models of gliomas have not been yet fully studied. The aim of this study was therefore to compare contrast-to-noise ratio (CNR) and explain its origin using spin-echo (SE), gradient echo (GE), GE with flow compensation (GEFC) as well as susceptibility weighted imaging (SWI) in T2 and T2* contrast-enhanced molecular MRI of glioma.Methods: A mouse model was used. U87MGdEGFRvIII cells (U87MG), derived from a human tumor, were injected intracerebrally. A 9.4 T MRI system was used and MR imaging was performed on the 10 day after the inoculation of the tumor. The CNR was measured prior, 20 min, 2 hrs and 24 hrs post intravenous tail administration of glioma targeted paramagnetic nanoparticles (NPs) using SE, SWI, GE and GEFC pulse sequences.Results: The results showed significant differences in CNR among all pulse sequences prior injection. GEFC provided higher CNR post contrast agent injection when compared to GE and SE. Post injection CNR was the highest with SWI and significantly different from any other pulse sequence.Conclusions: Molecular MR imaging using targeted contrast agents can enhance the detection of glioma cells at 9.4 T if the optimal pulse sequence is used. Hence, the use of flow compensated pulse sequences, beside SWI, should to be considered in the molecular imaging studies. DA - 2013/07/18 PY - 2013 PB - BioMed Central LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2fb8b122-647a-46ee-857d-8ffad1a7fb8b ER - TY - JOUR TI - Anion conducting poly(vinyl alcohol)/poly(diallyldimethylammonium chloride) membranes with high durable alkaline stability for polymer electrolyte membrane fuel cells DO - 10.1016/j.jpowsour.2013.02.059 AU - Qiao, J. AU - Zhang, J. T2 - Journal of Power Sources SN - 0378-7753 VL - 237 SP - 1 EP - 4 KW - Alkaline anion-exchange membranes KW - Chemical cross-linking KW - Diallyldimethylammonium chlorides KW - Hydrocarbon membrane KW - Hydroxide conductivities KW - Membrane electrode assemblies KW - Poly (vinyl alcohol) (PVA) KW - Poly(diallyldimethylammonium chloride) KW - Chlorine compounds KW - Crosslinking KW - Ions KW - Proton exchange membrane fuel cells (PEMFC) KW - Membranes AB - Novel and highly durable alkaline anion-exchange membranes, PVA/PDDA-OH-, are synthesized using a combined thermal and chemical cross-linking method. In the synthesis, poly(vinyl alcohol) (PVA) is used as polymer matrix and poly(diallyldimethylammonium chloride) (PDDA) as anion charge carriers. The resulting membrane exhibits a high hydroxide conductivity of 0.025 S cm-1 at a polymer composition PVA/PDDA being 1:0.5 by mass. A promising H2/O2 fuel cell peak power density of 32.7 mW cm-2 is reached for MEA fabricated with this PVA/PDDA-OH- at 25 °C. The membrane also shows a strong alkaline stability in 8 M KOH at 80 °C for 360 h. This is considered a new record for the fully cation-free hydrocarbon membranes for the use in alkaline fuel cell, seeing that PVA/PDDA-OH- is made simply of aliphatic skeletons. © 2013 Elsevier B.V. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9ca6d256-13df-433e-811f-1bbaa306d383 ER - TY - JOUR TI - Generation of a near infra-red guide star catalog for thirty-meter telescope observations DO - 10.1007/s12036-013-9176-6 AU - Subramanian, S. AU - Subramaniam, A. AU - Simard, L. AU - Gillies, K. AU - Ramaprakash, A.N. AU - Anupama, G.C. AU - Stalin, C.S. AU - Ravindranath, S. AU - Reddy, B.E. T2 - Journal of Astrophysics and Astronomy SN - 0250-6335 VL - 34 IS - 2 SP - 175 EP - 192 AB - The requirements for the production of a near Infra-Red Guide Star Catalog (IRGSC) for Thirty Meter Telescope (TMT) observations are identified and presented. A methodology to compute the expected J band magnitude of stellar sources from their optical (g, r, i) magnitudes is developed. The computed and observed J magnitudes of sources in three test fields are compared and the methodology developed is found to be satisfactory for the magnitude range, JVega = 16-22 mag. From this analysis, we found that for the production of final TMT IRGSC (with a limiting magnitude of JVega = 22 mag), we need g, r, i bands optical data which go up to i AB ~ 23 mag. Fine tuning of the methodology developed, such as using Spectral Energy Distribution (SED) template fitting for optimal classification of stars in the fainter end, incorporating spectral libraries in the model, to reduce the scatter, and modification of the existing colour-temperature relation to increase the source density are planned for the subsequent phase of this work. © 2013 Indian Academy of Sciences. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1729046b-289c-4645-8665-f11c2b51c4a6 ER - TY - JOUR TI - Dynamics of Ag+ ions in RbAg4I5 probed indirectly via 87Rb solid-state NMR DO - 10.1021/jp3125928 AU - Spencer, T.L. AU - O'Dell, L.A. AU - Moudrakovski, I. AU - Goward, G.R. T2 - The Journal of Physical Chemistry C SN - 1932-7447 VL - 117 IS - 19 SP - 9558 EP - 9565 KW - Close proximity KW - Indirect methods KW - Ion conducting materials KW - Powder patterns KW - Powdered samples KW - Quadrupole moments KW - Solid state NMR KW - Temperature window KW - Activation energy KW - Computer software KW - Metal ions KW - Nuclear magnetic resonance spectroscopy KW - Ionic conduction AB - Solid-state 87Rb NMR has been used to determine the ionic hopping rate of Ag+ ions in a powdered sample of α-RbAg 4I5 as a function of temperature from 20 to 250 C. In this phase, Rb is a stationary framework atom, which does not take part in ionic conduction in this material. At the same time 87Rb has a large quadrupole moment, making 87Rb NMR capable of detecting mobile species in close proximity. Simulation of the static 87Rb NMR powder pattern under the influence of Ag+ motion was performed using the EXPRESS software. Lineshape simulations were used to extract an ionic hopping rate for each temperature, and changes in the line shape were correlated to changes in ion mobility, which increases with temperature. Ag+ hopping rates were found to be in the range of 7.0 ± 0.5 kHz to 30 ± 2 kHz within the temperature window of 20 to 100 C, resulting in an activation energy of 17 ± 3 kJ/mol (0.18 ± 0.03 eV), for silver ion hopping. This result is in agreement with previous studies, suggesting that this indirect method of detecting ion mobility can be extended to other ion conducting materials. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ae362b15-e497-4a17-8024-c12c24e51024 ER - TY - JOUR TI - Single-molecule approaches to prion protein misfolding DO - 10.4161/pri.23303 AU - Yu, H. AU - Dee, D.R. AU - Woodside, M.T. T2 - Prion SN - 1933-6896 VL - 7 IS - 2 SP - 140 EP - 146 KW - oligomer KW - prion protein KW - atomic force microscopy KW - energy KW - fluorescence correlation spectroscopy KW - fluorescence resonance energy transfer KW - human KW - molecular dynamics KW - molecular probe KW - molecule KW - nonhuman KW - optical tweezers KW - prion disease KW - protein aggregation KW - protein analysis KW - protein conformation KW - protein folding KW - protein misfolding KW - protein structure KW - review KW - single molecule probe AB - The structural conversion of the prion protein PrP into a transmissible, misfolded form is the central element of prion disease, yet there is little consensus as to how it occurs. Key aspects of conversion into the diseased state remain unsettled, from details about the earliest stages of misfolding such as the involvement of partially- or fully-unfolded intermediates to the structure of the infectious state. Part of the difficulty in understanding the structural conversion arises from the complexity of the underlying energy landscapes. Single-molecule methods provide a powerful tool for probing complex folding pathways as in prion misfolding, because they allow rare and transient events to be observed directly. We discuss recent work applying single-molecule probes to study misfolding in prion proteins, and what it has revealed about the folding dynamics of PrP that may underlie its unique behavior. We also discuss single-molecule studies probing the interactions that stabilize non-native structures within aggregates, pointing the way to future work that may help identify the microscopic events triggering pathogenic conversion. Although single-molecule approaches to misfolding are relatively young, they have a promising future in prion science. © 2013 Landes Bioscience. © 2013 Landes Bioscience. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6e292684-08ac-4ba8-b2c9-580d385c7db6 ER - TY - JOUR TI - Direct optical determination of interfacial transport barriers in molecular tunnel junctions DO - 10.1021/ja403123a AU - Fereiro, J.A. AU - McCreery, R.L. AU - Bergren, A.J. T2 - Journal of the American Chemical Society SN - 0002-7863 VL - 135 IS - 26 SP - 9584 EP - 9587 KW - Direct measurement KW - Energy thresholds KW - Interfacial transport KW - Internal photoemission KW - Molecular absorption KW - Optical determination KW - Organic components KW - Photocurrent spectrum KW - Synthesis (chemical) KW - Chemistry KW - absorption KW - article KW - chemical structure KW - electron KW - energy KW - molecular electronics KW - molecule KW - temperature dependence KW - X ray photoelectron spectroscopy AB - Molecular electronics seeks to build circuitry using organic components with at least one dimension in the nanoscale domain. Progress in the field has been inhibited by the difficulty in determining the energy levels of molecules after being perturbed by interactions with the conducting contacts. We measured the photocurrent spectra for large-area aliphatic and aromatic molecular tunnel junctions with partially transparent copper top contacts. Where no molecular absorption takes place, the photocurrent is dominated by internal photoemission, which exhibits energy thresholds corresponding to interfacial transport barriers, enabling their direct measurement in a functioning junction. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b8f5574c-4d3b-46c0-9cfb-c29cb8415501 ER - TY - JOUR TI - Numerical and experimental investigation of the resistance performance of an icebreaking cargo vessel in pack ice conditions DO - 10.3744/JNAOE.2013.5.1.116 AU - Kim, M.-C. AU - Lee, S.-K. AU - Lee, W.-J. AU - Wang, J. T2 - International Journal of Naval Architecture and Ocean Engineering SN - 2092-6782 VL - 5 IS - 1 SP - 116 EP - 131 KW - Experimental investigations KW - Finite element models KW - Hydrodynamic loads KW - Model testing KW - National Research Council KW - Numerical challenges KW - Pack ice KW - Penalty methods KW - Experiments KW - Finite element method KW - Fluid structure interaction KW - Numerical methods KW - Ship model tanks KW - Ships KW - Ice AB - The resistance performance of an icebreaking cargo vessel in pack ice conditions was investigated numerically and experimentally using a recently developed finite element (FE) model and model tests. A comparison between numerical analysis and experimental results with synthetic ice in a standard towing tank was carried out. The comparison extended to results with refrigerated ice to examine the feasibility of using synthetic ice. Two experiments using two different ice materials gave a reasonable agreement. Ship-ice interaction loads are numerically calculated based on the fluid structure interaction (FSI) method using the commercial FE package LS-DYNA. Test results from model testing with synthetic ice at the Pusan National University towing tank, and with refrigerated ice at the National Research Council's (NRC) ice tank, are used to validate and benchmark the numerical simulations. The designed icegoing cargo vessel is used as a target ship for three concentrations (90%, 80%, and 60%) of pack ice conditions. Ice was modeled as a rigid body but the ice density was the same as that in the experiments. The numerical challenge is to evaluate hydrodynamic loads on the ship's hull; this is difficult because LS-DYNA is an explicit FE solver and the FSI value is calculated using a penalty method. Comparisons between numerical and experimental results are shown, and our main conclusions are given. © SNAK, 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : dac91e3d-6fad-4c56-829b-a350fcde5952 ER - TY - JOUR TI - Experimental and numerical study of the effects of the oxygen index on the radiation characteristics of laminar coflow diffusion flames DO - 10.1016/j.combustflame.2012.12.005 AU - Fuentes, Andrès AU - Henríquez, Rodrigo AU - Nmira, Fatiha AU - Liu, Fengshan AU - Consalvi, Jean-Louis T2 - Combustion and Flame SN - 0010-2180 VL - 160 IS - 4 SP - 786 EP - 795 KW - Co-flow KW - Coflow diffusion flames KW - Correlated-k models KW - Ethylene diffusion flames KW - Experimental and numerical studies KW - Flame height KW - Fuel flow rates KW - Laminar diffusion flames KW - Measured values KW - Narrow bands KW - Nondimensional KW - Oxidizer stream KW - Oxygen concentrations KW - Oxygen index KW - Radiation characteristics KW - Radiative fluxes KW - Rate of increase KW - Semi-empirical KW - Smoke point KW - Soot formations KW - Soot model KW - Soot oxidation KW - Soot volume fraction KW - Two-equation KW - Two-regime KW - Vertical distributions KW - Volumetric flow rate KW - Acetylene KW - Diffusion KW - Ethylene KW - Flow rate KW - Forecasting KW - Heat radiation KW - Oxygen KW - Radiation effects KW - Smoke KW - Soot KW - Volume fraction KW - Dust KW - ethylene KW - oxygen KW - article KW - chemical parameters KW - diffusion coefficient KW - fire KW - flow rate KW - laminar coflow diffusion flame KW - oxidation KW - oxygen index KW - prediction KW - priority journal KW - radiation KW - stoichiometry KW - temperature AB - The oxygen concentration in the oxidizer stream (O₂+N₂) of laminar coflow ethylene diffusion flames is varied from 17% to 35% in order to study its influence on the flame height, the soot formation/oxidation processes, the smoke point characteristics, and the vertical distributions of radiative flux at a distance of 6.85cm from the flame axis. Measured values for all the investigated parameters are compared with the predictions provided by a numerical model based on a two-equation semiempirical acetylene-based soot model and on the statistical narrow-band correlated-k model to compute thermal radiation. Predictions are in overall reasonable agreement with the experiments for oxygen indices in the range 19-35%, whereas all the investigated parameters are significantly underestimated for an oxygen index of 17%. Measured flame heights based on CH* emission below, at, or slightly above the smoke point, as well as predicted stoichiometric flame heights, are found to be proportional to ζ=Vf[D∞ln(1+1/S)]-1(T∞/Tad)0.67, where Vf, D∞, S, and Tad are the volumetric flow rate of ethylene, the diffusion coefficient at ambient temperature, the stoichiometric molecular air-to-fuel ratio, and the adiabatic flame temperature. Soot formation processes are found to increase with the oxygen index, leading to higher values of the maximum soot volume fraction and the peak integrated soot volume fraction. In addition, the latter is reached at a nondimensional height (normalized by ζ of approximately 0.05, regardless of the oxygen index within the investigated range. Two regimes are evidenced: The first regime, occurring for oxygen indices lower than 25%, is dominated by soot oxidation and is characterized by an enhancement in both the maximum soot volume fraction and the fuel flow rate at the smoke point with the oxygen index. The second regime, occurring for oxygen indices higher than 25%, is dominated by soot formation; the rate of increase in the maximum soot volume fraction with the oxygen concentration is lower than in the first regime, whereas the fuel flow rate at the smoke point decreases. Finally, the peak of radiative flux increases with the oxygen index, but its rate of increase is also found to be considerably reduced for oxygen indices greater than 25%. DA - 2013/01/19 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8c274256-74ce-445b-90b0-3da04cb77c37 ER - TY - JOUR TI - Low cost hydrogen fuel cell DO - 10.1149/04523.0109ecst AU - Dara, M.S. AU - Lam, A AU - Fatih, K. AU - Wilkinson, D.P. T2 - ECS Transactions T3 - Symposium on Fuel Cell Membranes, Electrode Binders, and MEA Performance - 221st ECS Meeting, 6 May 2012 through 10 May 2012, Seattle, WA SN - 1938-5862 SN - 9781623320423 VL - 45 IS - 23 SP - 109 EP - 119 KW - Carbon cathode KW - Conventional fuel KW - Cost saving KW - Liquid electrolytes KW - Low costs KW - Maximum power density KW - Binders KW - Hydrogen fuels KW - Platinum KW - Fuel cells AB - In this paper a hydrogen fuel cell is operated in the absence of a membrane at 60°C. The fuel cell was fed a nonhumidified hydrogen fuel and a 2 M Fe(ClO4)3, 0.22M Fe(ClO4)2, and 0.2 M HClO4 oxidant catholyte. A 3-D carbon cathode in conjunction with a 0.5 M HClO4 liquid electrolyte was used to eliminate the membrane. Nonoptimized maximum power density upwards of 220 mW/cm2 was achieved with a total Pt content of the fuel cell as low as 0.05 mg/cm2. Elimination of the PEM and reduction in total fuel cell Pt-catalyst content are expected to offer significant cost savings over conventional fuel cell technology. © The Electrochemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b20e2c58-5f23-4cd5-bdab-c3b25d76abd8 ER - TY - JOUR TI - Variable stiffness smart structure systems to mitigate seismic induced building damages DO - 10.1002/eqe.2204 AU - Duerr, K. AU - Tesfamariam, S. AU - Wickramasinghe, V. AU - Grewal, A. T2 - Earthquake Engineering and Structural Dynamics SN - 0098-8847 VL - 42 IS - 2 SP - 221 EP - 237 KW - Building damage KW - Building structure KW - Earthquake events KW - Induced damage KW - Performance improvements KW - Performance indicators KW - Performance level KW - Retrofit techniques KW - Return periods KW - Seismic excitations KW - Seismic hazards KW - Seismic Performance KW - Seismic retrofits KW - Semiactive control KW - Smart spring KW - Smart structure system KW - Steel buildings KW - Variable stiffness KW - Variable stiffness devices KW - Benchmarking KW - Buildings KW - Intelligent structures KW - Retrofitting KW - Seismic design KW - Stiffness KW - Earthquakes KW - building KW - earthquake damage KW - earthquake prediction KW - seismic design KW - seismic hazard KW - seismic retrofit KW - stiffness AB - Upgrading noncode conforming buildings to mitigate seismic induced damages is important in moderate to high seismic hazard regions. The damage, can be mitigated by using conventional (e.g. FRP wrapping) and emerging (e.g. smart structures) retrofit techniques. A model for the structure to be retrofitted should include relevant performance indicators. This paper proposes a variable stiffness smart structure device known as the Smart Spring to be integrated on building structures to mitigate seismic induced damage. The variable stiffness capability is of importance to structures that exhibit vertical (e.g. soft storey) irregularities and to meet different performance levels under seismic excitation. To demonstrate the utility of the proposed retrofitting technique, a four-storey steel building is modelled in MATLAB and appropriate performance indicators are chosen. Various return period seismic hazards are generated from past earthquake event records to predict the structure's performance. The performance improvement because of the retrofitting of building structures using the variable stiffness device is presented. © 2012 John Wiley & Sons, Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 76f46641-53de-44ed-a7c0-145558f2e9bf ER - TY - JOUR TI - Microstructure and fatigue properties of a friction stir lap welded magnesium alloy DO - 10.1007/s11661-013-1728-5 AU - Naik, B.S. AU - Chen, D.L. AU - Cao, X. AU - Wanjara, P. T2 - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science SN - 1073-5623 VL - 44 IS - 8 SP - 3732 EP - 3746 AB - Friction stir welding (FSW), being an enabling solid-state joining technology, can be suitably applied for the assembly of lightweight magnesium (Mg) alloys. In this investigation, friction stir lap welded (FSLWed) joints of AZ31B-H24 Mg alloy were characterized in terms of the welding defects, microstructure, hardness, and fatigue properties at various combinations of tool rotational rates and welding speeds. It was observed that the hardness decreased from the base metal (BM) to the stir zone (SZ) across the heat-affected zone (HAZ) and thermomechanically affected zone (TMAZ). The lowest value of hardness appeared in the SZ. With increasing tool rotational rate or decreasing welding speed, the average hardness in the SZ decreased owing to increasing grain size, and a Hall-Petch-type relationship was established. Fatigue fracture of the lap welds always occurred at the interface between the SZ and TMAZ on the advancing side where a larger hooking defect was present (in comparison with the retreating side). The welding parameters had a significant influence on the hook height and the subsequent fatigue life. A relatively "cold" weld, conducted at a rotational rate of 1000 rpm and welding speed of 20 mm/s, gave rise to almost complete elimination of the hooking defect, thus considerably (over two orders of magnitude) improving the fatigue life. Fatigue crack propagation was basically characterized by the formation of fatigue striations concomitantly with secondary cracks. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 7b19bab6-46cc-4bb5-bc8a-9eb25988f72a ER - TY - JOUR TI - Oligomerization and hemolytic properties of the C-terminal domain of pyolysin, a cholesterol-dependent cytolysin DO - 10.1139/bcb-2012-0065 AU - Pokrajac, L. AU - Harris, J.R. AU - Sarraf, N. AU - Palmer, M. T2 - Biochemistry and Cell Biology SN - 0829-8211 VL - 91 IS - 2 SP - 59 EP - 66 KW - C-terminal domains KW - Hemolysis KW - Hemolytic activity KW - Membrane binding KW - Membrane insertion KW - Monomer structures KW - Proteolytic fragments KW - Pyolysin KW - Cell membranes KW - Cholesterol KW - Cytology KW - Monomers KW - Oligomerization KW - Reaction kinetics KW - Toxic materials KW - Oligomers KW - cholesterol KW - cytolysin KW - oligomer KW - protein pyolysin KW - unclassified drug KW - article KW - carboxy terminal sequence KW - hemolysis KW - oligomerization KW - protein binding KW - protein domain AB - Pyolysin (PLO) belongs to the homologous family of the cholesterol- dependent cytolysins (CDCs), which bind to cell membranes containing cholesterol to form oligomeric pores of large size. The CDC monomer structure consists of 4 domains. Among these, the C-terminal domain 4 has been implicated in membrane binding of the monomer, while the subsequent processes of oligomerization and membrane insertion have primarily been assigned to other domains of the molecule. Recombinantly expressed or proteolytic fragments that span domain 4 of the CDCs streptolysin O and perfringolysin O bind to membranes but fail to oligomerize, and they inhibit the activity of the respective wild-type toxins. We report here that the isolated domain 4 of pyolysin (PLO-D4) not only binds to membranes but also forms oligomers with itself, as well as hybrid oligomers with the full-length toxin. As expected, the pure PLO-D4 oligomers are devoid of pore-forming activity. Surprisingly, however, within hybrid oligomers, PLO-D4 not only fails to inhibit, but even amplifies the hemolytic activity of the full-length toxin, to an extent similar to that of doubling the amount of the full-length toxin alone. We propose that this amplification may be related to the kinetics of the oligomerization reaction. Overall, our findings indicate a greater role of domain 4 in the oligomerization of CDCs than previously demonstrated. © 2013 Published by NRC Research Press. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b1b5f7ee-0004-4101-bf31-b35c0a2e8e9b ER - TY - JOUR TI - Histograms of fuzzy oriented gradients for face recognition DO - 10.1109/ICCAT.2013.6522006 AU - Salhi, A.I. AU - Kardouchi, M. AU - Belacel, N. T2 - International Conference on Computer Applications Technology, ICCAT 2013 T3 - 2013 International Conference on Computer Applications Technology, ICCAT 2013, 20 January 2013 through 22 January 2013, Sousse SN - 9781467352857 SP - 6522006 KW - Dimensional vectors KW - Feature dimensions KW - Feature vectors KW - HFOG KW - High dimensional feature KW - Histogram of oriented gradients (HOG) KW - HOG KW - Oriented gradients KW - Computer applications KW - Fuzzy sets KW - Graphic methods KW - Statistical methods KW - Face recognition AB - Efficient face descriptors require a careful equilibration between accuracy and feature dimension. In recent years Histogram of Oriented Gradient (HOG) starts to be used in the face recognition task. However the best recognition rate for HOG requires a high dimensional feature. In this paper, we will incorporate fuzzy concept to HOG aiming to achieve a good recognition rate with a low feature vector dimension. The proposed Histogram of Fuzzy Oriented Gradient is applied to the face recognition task. Experimental results on ORL database have demonstrated that HFOG outperforms the original HOG with a lower dimensional vector. © 2013 IEEE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e488d603-ebe2-47c6-98c1-b0c84f31a721 ER - TY - JOUR TI - Review of phosphocholine substituents on bacterial pathogen glycans: Synthesis, structures and interactions with host proteins DO - 10.1016/j.molimm.2013.05.237 AU - Young, N.M. AU - Foote, S.J. AU - Wakarchuk, W.W. T2 - Molecular Immunology SN - 0161-5890 VL - 56 IS - 4 SP - 563 EP - 573 KW - C reactive protein KW - citicoline KW - glycan KW - major histocompatibility antigen class 2 KW - phosphorylcholine KW - protein KW - teichoic acid KW - toll like receptor 4 KW - adaptive immunity KW - Haemophilus influenzae KW - Histophilus somni KW - innate immunity KW - Morganella morganii KW - nonhuman KW - Pasteurella multocida KW - priority journal KW - protein protein interaction KW - protein structure KW - protein synthesis KW - review KW - Streptococcus pneumoniae AB - Among the non-carbohydrate components of glycans, the addition of phosphocholine (ChoP) to the glycans of pathogens occurs more rarely than acetylation or methylation, but it has far more potent biological consequences. These arise from ChoP's multiple interactions with host proteins, which are important at all stages of the infection process. These stages include initial adherence to cells, encountering the host's innate immune system and then the adaptive immune system. Thus, in the initial stages of an infection, ChoP groups are an asset to the pathogen, but they can turn into a disadvantage subsequently. In this review, we have focussed on structural aspects of these phenomena. We describe the biosynthesis of the ChoP modification, the structures of the pathogen glycans known to carry ChoP groups and the host proteins that recognize ChoP. © 2013 The Authors. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 461798e6-f7eb-4b15-89db-b8a9291baf50 ER - TY - JOUR TI - Hydrocarbon-degrading potential of microbial communities from Arctic plants DO - 10.1111/jam.12020 AU - Ferrera-Rodríguez, O. AU - Greer, C.W. AU - Juck, D. AU - Consaul, L.L. AU - Martínez-Romero, E. AU - Whyte, L.G. T2 - Journal of Applied Microbiology SN - 1364-5072 VL - 114 IS - 1 SP - 71 EP - 83 KW - hydrocarbon KW - RNA 16S KW - arctic environment KW - bacterium KW - biodegradation KW - hydrocarbon KW - microbial community KW - phytoremediation KW - rhizosphere KW - soil microorganism KW - taxonomy KW - Actinobacteria KW - Arctic plant KW - article KW - bacterial count KW - bacterial gene KW - Bacteroidetes KW - Firmicutes KW - gene sequence KW - incubation temperature KW - microbial community KW - Mycobacterium KW - nonhuman KW - nucleotide sequence KW - phylogeny KW - plant KW - Proteobacteria KW - Pseudomonas KW - rhizosphere KW - Canada KW - Canadian Arctic KW - Ellesmere Island KW - Eureka KW - Nunavut KW - Queen Elizabeth Islands KW - Actinobacteria KW - Arthrobacter KW - Bacteria (microorganisms) KW - Bacteroidetes KW - Eriophorum scheuchzeri KW - Firmicutes KW - Intrasporangiaceae KW - Mycobacterium KW - Nocardia KW - Oxyria digyna KW - Potentilla rubricaulis KW - Proteobacteria KW - Pseudomonas KW - Puccinellia angustata KW - Rhodococcus KW - Salix arctica AB - Aims: To explore rhizospheric microbial communities from Arctic native plant species evaluating their bacterial hydrocarbon-degrading capacities. Methods and Results: Eriophorum scheuchzeri, Potentilla cf. rubricaulis, Oxyria digyna, Salix arctica and Puccinellia angustata plant species were collected at Eureka (Canadian high Arctic) along with their rhizospheric soil samples. Their bacterial community fingerprints (16S rRNA gene, DGGE) were distinctive encompassing members from the phyla: Bacteroidetes, Firmicutes, Actinobacteria and Proteobacteria. Isolated diesel-degrading bacteria belonged to the phyla Actinobacteria and Proteobacteria. Strains of Mycobacterium, Nocardia, Rhodococcus, Intrasporangiaceae, Leifsoni and Arthrobacter possessed alkB and Pseudomonas possessed both ndoB and xylE gene sequences. Two Rhodococcus strains mineralized [1-14C] hexadecane at 5 and -5°C. From the rhizosphere of P. angustata, larger numbers of hydrocarbon-degrading bacteria were isolated than from other plant rhizosphere samples and all three genes alkB (from Actinobacteria), ndoB and xylE (from Pseudomonas) were detected by PCR. Conclusions: (i) Arctic plants have unique rhizospheric bacterial communities. (ii) P. angustata has potential for phytoremediation research at high Arctic soils. (iii) Isolated bacteria mineralized hydrocarbons at ambient low temperatures. Significance and Impact of the Study: To the best of our knowledge, this is the first rhizospheric exploration examining the phytoremediation potential of five Arctic plants and evaluating their microbial hydrocarbon-degrading capacities. © 2012 The Society for Applied Microbiology. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : fa0c9b98-f435-4090-aaa3-364df781956e ER - TY - JOUR TI - Diversity and toxicity of the diatom Pseudo-nitzschia Peragallo in the Gulf of Maine, Northwestern Atlantic Ocean DO - 10.1016/j.dsr2.2013.06.022 AU - Fernandes, L.F. AU - Hubbard, K.A. AU - Richlen, M.L. AU - Smith, J. AU - Bates, S.S. AU - Ehrman, J. AU - Léger, C. AU - Mafra Jr., L.L. AU - Kulis, D. AU - Quilliam, M. AU - Libera, K. AU - McCauley, L. AU - Anderson, D.M. T2 - Deep-Sea Research Part II: Topical Studies in Oceanography SN - 0967-0645 AB - Multiple species in the toxic marine diatom genus Pseudo-nitzschia have been identified in the Northwestern Atlantic region encompassing the Gulf of Maine (GOM), including the Bay of Fundy (BOF). To gain further knowledge of the taxonomic composition and toxicity of species in this region, Pseudo-nitzschia isolates (n=146) were cultured from samples collected during research cruises that provided broad spatial coverage across the GOM and the southern New England shelf, herein referred to as the GOM region, during 2007-2008. Isolates, and cells in field material collected at 28 stations, were identified using electron microscopy (EM). Eight species (P. americana, P. fraudulenta, P. subpacifica, P. heimii, P. pungens, P. seriata, P. delicatissima and P. turgidula), and a novel form, P. sp. GOM, were identified. Species identity was confirmed by sequencing the large subunit of the ribosomal rDNA (28S) and the internal transcribed spacer 2 (ITS2) for six species (36 isolates). Phylogenetic analyses (including neighbor joining, maximum parsimony, and maximum likelihood estimates and ITS2 secondary structure analysis) and morphometric data supported the placement of P. sp. GOM in a novel clade that includes morphologically and genetically similar isolates from Australia and Spain and is genetically most similar to P. pseudodelicatissima and P. cuspidata. Seven species (46 isolates) were grown in nutrient-replete batch culture and aliquots consisting of cells and growth medium were screened by Biosense ASP ELISA to measure total domoic acid (DA) produced (intracellular+extracellular); P. americana and P. heimii were excluded from all toxin analyses as they did not persist in culture long enough for testing. All 46 isolates screened produced DA in culture and total DA varied among species (e.g., 0.04-320 ng ml-1 for P. pungens and P. sp. GOM isolates) and among isolates of the same species (e.g., 0.24-320 ng ml-1 for P. sp. GOM). The 15 most toxic isolates corresponded to P. seriata, P. sp. GOM and P. pungens, and fg DA cell-1 was determined for whole cultures (cells and medium) using ELISA and liquid chromatography (LC) with fluorescence detection (FLD); for seven isolates, toxin levels were also estimated using LC with mass spectrometry and ultraviolet absorbance detection. P. seriata was the most toxic species (up to 3500 fg cell-1) and was observed in the GOM region during all cruises (i.e., during the months of April, May, June and October). P. sp. GOM, observed only during September and October 2007, was less toxic (19-380 fg cell-1) than P. seriata but more toxic than P. pungens var. pungens (0.4 fg cell-1). Quantitation of DA indicated that concentrations measured by LC and ELISA were positively and significantly correlated; the lower detection limit of the ELISA permitted quantification of toxicity in isolates that were found to be non-toxic with LC methods. The confirmation of at least seven toxic species and the broad spatial and temporal distribution of toxic Pseudo-nitzschia spp. have significant implications for the regional management of nearshore and offshore shellfisheries. © 2013 Elsevier Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 16d37ad0-58f0-4274-a621-319a8e3295cd ER - TY - JOUR TI - Biochemical characterization of a polysialyltransferase from Mannheimia haemolytica A2 and comparison to other bacterial polysialyltransferases DO - 10.1371/journal.pone.0069888 AU - Lindhout, T. AU - Bainbridge, C.R. AU - Costain, W.J. AU - Gilbert, M. AU - Wakarchuk, W.W. T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 7 SP - e69888 KW - bacterial enzyme KW - glycan KW - glycoprotein KW - hybrid protein KW - maltose binding protein KW - polysialic acid KW - polysialyltransferase KW - recombinant enzyme KW - unclassified drug KW - article KW - binding site KW - carbohydrate analysis KW - cell migration KW - cell surface KW - comparative study KW - DNA sequence KW - enzyme activity KW - enzyme analysis KW - enzyme kinetics KW - enzyme stability KW - enzyme synthesis KW - Escherichia coli KW - Mannheimia haemolytica KW - Neisseria meningitidis KW - neuroprogenitor cell KW - nonhuman KW - nucleotide sequence KW - pH KW - protein expression KW - protein localization KW - protein modification KW - solubility KW - stem cell KW - suicide substrate KW - thermostability KW - wound healing AB - Polysialic acids are bioactive carbohydrates found in eukaryotes and some bacterial pathogens. The bacterial polysialyltransferases (PSTs), which catalyze the synthesis of polysialic acid capsules, have previously been identified in select strains of Escherichia coli and Neisseria meningitidis and are classified in the Carbohydrate-Active enZYmes Database as glycosyltransferase family GT-38. In this study using DNA sequence analysis and functional characterization we have identified a novel polysialyltransferase from the bovine/ovine pathogen Mannheimia haemolytica A2 (PSTMh). The enzyme was expressed in recombinant form as a soluble maltose-binding-protein fusion in parallel with the related PSTs from E. coli K1 and N. meningitidis group B in order to perform a side-by-side comparison. Biochemical properties including solubility, acceptor preference, reaction pH optima, thermostability, kinetics, and product chain length for the enzymes were compared using a synthetic fluorescent acceptor molecule. PSTMh exhibited biochemical properties that make it an attractive candidate for chemi-enzymatic synthesis applications of polysialic acid. The activity of PSTMh was examined on a model glycoprotein and the surface of a neuroprogenitor cell line where the results supported its development for use in applications to therapeutic protein modification and cell surface glycan remodelling to enable cell migration at implantation sites to promote wound healing. The three PSTs examined here demonstrated different properties that would each be useful to therapeutic applications. © 2013 Lindhout et al. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8e519624-1cfd-4675-bfa0-d3f56edf563d ER - TY - JOUR TI - High crystallinity binuclear iron phthalocyanine catalyst with enhanced performance for oxygen reduction reaction DO - 10.1016/j.jpowsour.2012.12.018 AU - Hu, X. AU - Xia, D. AU - Zhang, L. AU - Zhang, J. T2 - Journal of Power Sources SN - 0378-7753 VL - 231 SP - 91 EP - 96 KW - Good stability KW - High crystallinity KW - High electrical conductivity KW - Iron phthalocyanines KW - Macrocyles KW - Methanol Oxidation KW - Oxygen Reduction KW - Oxygen reduction currents KW - Oxygen reduction reaction KW - Transmission electron microscopy tem KW - Uniform coating KW - Electric conductivity KW - Electrocatalysts KW - Methanol KW - Multiwalled carbon nanotubes (MWCN) KW - Transmission electron microscopy KW - Electrolytic reduction AB - High crystallinity binuclear iron phthalocyanine coated onto multi-walled carbon nanotubes (bi-FePc/MWNT), was synthesized. Transmission electron microscopy (TEM) confirms that the crystalline bi-FePc forms a uniform coating on the carbon nanotubes with a thickness of about 20 nm. The plane of the macrocyle is perpendicular to the surface of the nanotube and the stacking axis of the bi-FePc molecules, which is the direction of high electrical conductivity, is found to be parallel to the substrate. The bi-FePc/MWNT show activity of 1.43 mA cm-2 at 0.66 V versus NHE indicating good activity and the current is stable for 14 h as electrocatalyst in oxygen reduction reactions (ORR) indicating good stability; the oxygen reduction current does not change in the presence of methanol showing the binuclear iron phthalocyanine coated onto multi-walled carbon nanotubes specifically catalyzes oxygen reduction and not methanol oxidation. © 2012 Elsevier B.V. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d9c7918f-79b4-4f42-9acb-077977c80d69 ER - TY - JOUR TI - Microbial electrolysis cell scale-up for combined wastewater treatment and hydrogen production DO - 10.1016/j.biortech.2012.12.062 AU - Gil-Carrera, L. AU - Escapa, A. AU - Mehta, P. AU - Santoyo, G. AU - Guiot, S.R. AU - Morán, A. AU - Tartakovsky, B. T2 - Bioresource Technology SN - 0960-8524 VL - 130 SP - 584 EP - 591 KW - Anodic compartment KW - Applied voltages KW - COD removal KW - COD removal rate KW - Domestic wastewater KW - Gas diffusion cathode KW - Hydraulic retention time KW - MEC KW - Membraneless KW - Microbial electrolysis cells KW - Municipal wastewaters KW - Organic load KW - Process scale-up KW - Real-time optimization KW - Removal efficiencies KW - Scale-up KW - Synthetic waste water KW - Algorithms KW - Electric reactors KW - Electrolytic cells KW - Energy utilization KW - Wastewater treatment KW - Hydrogen production KW - hydrogen KW - algorithm KW - chemical oxygen demand KW - electrokinesis KW - energy use KW - hydrogen KW - microbial activity KW - optimization KW - pollutant removal KW - real time KW - wastewater KW - water treatment KW - algorithm KW - article KW - chemical oxygen demand KW - electric potential KW - electrical equipment KW - energy consumption KW - gas diffusion KW - microbial electrolysis cell KW - priority journal KW - reactor KW - scale up KW - waste component removal KW - waste water management KW - Biological Oxygen Demand Analysis KW - Electrolysis KW - Hydrogen KW - Industrial Microbiology KW - Waste Water KW - Water Purification AB - This study demonstrates microbial electrolysis cell (MEC) scale-up from a 50. mL to a 10. L cell. Initially, a 50. mL membraneless MEC with a gas diffusion cathode was operated on synthetic wastewater at different organic loads. It was concluded that process scale-up might be best accomplished using a " reactor-in-series" concept. Consequently, 855. mL and 10. L MECs were built and operated. By optimizing the hydraulic retention time (HRT) of the 855. mL MEC and individually controlling the applied voltages of three anodic compartments with a real-time optimization algorithm, a COD removal of 5.7. g LR-1d-1 and a hydrogen production of 1.0-2.6. L LR-1d-1 was achieved. Furthermore, a two MECs in series 10. L setup was constructed and operated on municipal wastewater. This test showed a COD removal rate of 0.5. g LR-1d-1, a removal efficiency of 60-76%, and an energy consumption of 0.9. Wh. per. g of COD removed. © 2012. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1b1806f0-6229-4670-b06c-18fac438a1d5 ER - TY - JOUR TI - Regular frequency patterns in the young δ Scuti star HD 261711 observed by the CoRoT and MOST satellites DO - 10.1051/0004-6361/201220934 AU - Zwintz, K. AU - Fossati, L. AU - Guenther, D.B. AU - Ryabchikova, T. AU - Baglin, A. AU - Themessl, N. AU - Barnes, T.G. AU - Matthews, J.M. AU - Auvergne, M. AU - Bohlender, D. AU - Chaintreuil, S. AU - Kuschnig, R. AU - Moffat, A.F.J. AU - Rowe, J.F. AU - Rucinski, S.M. AU - Sasselov, D. AU - Weiss, W.W. T2 - Astronomy and Astrophysics SN - 0004-6361 VL - 552 SP - A68 KW - Stars: individual KW - Stars: oscillation KW - Stars: variables: delta scuti KW - Techniques: photometric KW - Techniques: spectroscopic KW - Fourier series KW - Photometry KW - Satellites KW - Spectroscopy KW - Spectrum analysis KW - Stars AB - Context. The internal structure of pre-main-sequence (PMS) stars is poorly constrained at present. This could change significantly through high-quality asteroseismological observations of a sample of such stars. Aims. We concentrate on an asteroseismological study of HD 261711, a rather hot δ Scuti-type pulsating member of the young open cluster NGC 2264 located at the blue border of the instability region. HD 261711 was discovered to be a PMS δ Scuti star using the time series photometry obtained by the MOST satellite in 2006. Methods. High-precision, time-series photometry of HD 261711 was obtained by the MOST and CoRoT satellites in four separate new observing runs that are put into context with the star's fundamental atmospheric parameters obtained from spectroscopy. Frequency Analysis was performed using Period04. The spectral analysis was performed using equivalent widths and spectral synthesis. Results. With the new MOST data set from 2011/12 and the two CoRoT light curves from 2008 and 2011/12, the δ Scuti variability was confirmed and regular groups of frequencies were discovered. The two pulsation frequencies identified in the data from the first MOST observing run in 2006 are confirmed and 23 new δ Scuti-type frequencies were discovered using the CoRoT data. Weighted average frequencies for each group were determined and are related to l = 0 and l = 1 p-modes. Evidence for amplitude modulation of the frequencies in two groups is seen. The effective temperature (Teff) was derived to be 8600 ± 200 K, log g is 4.1 ± 0.2, and the projected rotational velocity (υsini) is 53 ± 1 km s-1. Using our Teff value and the radius of 1.8 ± 0.5 R⊙ derived from spectral energy distribution (SED) fitting, we get a luminosity log L/L ⊙ of 1.20 ± 0.14 which agrees well to the seismologically determined values of 1.65 R⊙ and, hence, a log L/L ⊙ of 1.13. The radial velocity of 14 ± 2 km s -1 we derived for HD 261711, confirms the star's membership to NGC 2264. Conclusions. Our asteroseismic models suggest that HD 261711 is a δ Scuti-type star close to the zero-age main sequence (ZAMS) with a mass of 1.8 to 1.9 M⊙. With an age of about 10 million years derived from asteroseismology, the star is either a young ZAMS star or a late PMS star just before the onset of hydrogen-core burning. The observed splittings about the l = 0 and 1 parent modes may be an artifact of the Fourier derived spectrum of frequencies with varying amplitudes. © 2013 ESO. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a27a9a9a-2a5c-4690-b808-546df1ba4260 ER - TY - JOUR TI - Real-time diagnosis of gas-assisted hot embossing process by ultrasound DO - 10.1002/pen.23465 AU - Cheng, C.-C. AU - Wu, C.-L. AU - Wu, K.-T. AU - Yang, S.-Y. T2 - Polymer Engineering and Science SN - 0032-3888 VL - 53 IS - 10 SP - 2175 EP - 2182 KW - Gas pressures KW - Gas-assisted hot embossing KW - High temperature ultrasonic transducers KW - Plastic plates KW - Real-time diagnosis KW - V-cut pattern KW - Sheet molding compounds KW - Ultrasonic transducers KW - Ultrasonics KW - Gases AB - An integrated high temperature ultrasonic transducer (HTUT) sensor has been utilized for diagnosis of gas-assisted hot embossing process to fabricate V-cut patterns real-time, nonintrusively and nondestructively. The progression of the process, including plastic plate soften, gas introducing, cooling, and plate detachment inside the chamber, was clearly observed using ultrasound. Ultrasonic velocity could not only indicate the four steps of process, but also evaluate the replicating degree of the V-cut patterns on surface of plastic plate under various temperature and gas pressure settings. The experimental results indicate that the heights of V-cut patterns increase with temperature and gas pressure. © 2013 Society of Plastics Engineers. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b291a016-e504-462c-a263-a39502231c42 ER - TY - JOUR TI - Structural health monitoring of bonded composite repairs-A critical comparison between ultrasonic Lamb wave approach and surface mounted crack sensor approach DO - 10.1016/j.compositesb.2012.11.002 AU - Habib, F. AU - Martinez, M. AU - Artemev, A. AU - Brothers, M. T2 - Composites Part B: Engineering SN - 1359-8368 VL - 47 SP - 26 EP - 34 KW - Bonded repairs KW - Boolean operators KW - Conductive paints KW - Crack sensors KW - Disbond KW - Electrical signal KW - Fiber substrates KW - Hot spot KW - Monitoring system KW - Non destructive testing KW - Three-layer KW - Ultrasonic lamb waves KW - Ultrasound methods KW - Adhesive joints KW - Boron KW - Carbon fibers KW - Cracks KW - Debonding KW - Mechanical testing KW - Nondestructive examination KW - Sensors KW - Structural health monitoring KW - Ultrasonic waves KW - Ultrasonics KW - Ultrasonic applications AB - The effectiveness of the Lamb waves Acoustic-Ultrasound Structural Health Monitoring (SHM) technique for the determination of the adhesive joint failure was evaluated and compared to that of another SHM technique: Surface Mountable Crack Sensor (SMCS). A commercially available Acoustic-Ultrasound system was used. The SMCS consists of a "hot spot" monitoring system based on a three-layer electrically insulating and conductive paint. An electrical signal is used as a boolean operator for the characterization of the passage of damage through the sensor and the underlying material. The coupons consisted of carbon fiber substrates with boron patches bonded to them. The advantages and disadvantages of both techniques are discussed. It has been demonstrated that the Lamb waves Acoustic-Ultrasound technique possesses the capability to identify and quantify damage in a bonded repair. The SMCS proved to be a successful SHM technique for the monitoring of the formation of a disbond at the edges of the patch. All results were validated using the C-Scan ultrasound method. © 2012 Elsevier Ltd. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4d2dea73-2a07-47d6-955d-2617729c3011 ER - TY - JOUR TI - Modeling grain size and strain rate in linear friction welded Waspaloy DO - 10.1007/s11661-013-1767-y AU - Chamanfar, A. AU - Jahazi, M. AU - Gholipour, J. AU - Wanjara, P. AU - Yue, S. T2 - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science SN - 1073-5623 VL - 44 IS - 9 SP - 4230 EP - 4238 KW - Deformation temperatures KW - High temperature deformation KW - Isothermal compressions KW - Linear friction KW - Microstructural investigation KW - Ni-base superalloys KW - Recrystallized grain sizes KW - Strain rate sensitivity KW - Activation energy KW - Compression testing KW - Crystal microstructure KW - Deformation KW - Dynamic recrystallization KW - Friction welding KW - Grain size and shape KW - Nickel KW - Strain rate AB - The high-temperature deformation behavior of the Ni-base superalloy, Waspaloy, using uniaxial isothermal compression testing was investigated at temperatures above the γ′ solvus, 1333 K, 1373 K, 1413 K (1060 C, 1100 C, 1140 C) for constant true strain rates of 0.001, 0.01, 0.1, 1 s -1 and up to a true strain of 0.83. Flow softening and microstructural investigation indicated that dynamic recrystallization took place during deformation. For the investigated conditions, the strain rate sensitivity factor and the activation energy of hot deformation were 0.199 and 462 kJ/mol, respectively. Constitutive equations relating the dynamic recrystallized grain size to the deformation temperature and strain rate were developed and used to predict the grain size and strain rate in linear friction-welded (LFWed) Waspaloy. The predictions were validated against experimental findings and data reported in the literature. It was found that the equations can reliably predict the grain size of LFWed Waspaloy. Furthermore, the estimated strain rate was in agreement with finite element modeling data reported in the literature. © 2013 The Minerals, Metals & Materials Society and ASM International. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : eabdda50-4c43-463d-a2ab-d8d3f47d880b ER - TY - JOUR TI - Resonant laser-induced breakdown spectroscopy (RLIBS) analysis of traces through selective excitation of aluminum in aluminum alloys DO - 10.1039/c3ja30308j AU - Rifai, K. AU - Vidal, F. AU - Chaker, M. AU - Sabsabi, M. T2 - Journal of Analytical Atomic Spectrometry SN - 0267-9477 VL - 28 IS - 3 SP - 388 EP - 395 KW - Atomic transition KW - Detection threshold KW - Energy per pulse KW - Fluences KW - Laser wavelength KW - Limits of detection KW - Low concentrations KW - Off-resonance KW - Optical emissions KW - Optimal conditions KW - Particle collision KW - Selective excitations KW - Threshold fluences KW - Aluminum KW - Atomic emission spectroscopy KW - Optical parametric oscillators KW - Resonance KW - Silicon KW - Magnesium AB - We investigated laser-induced breakdown spectroscopy for the detection of traces of magnesium and silicon contained in aluminum alloys by using the same 5 ns optical parametric oscillator laser pulse to ablate the sample and excite selectively an atomic transition of vaporized aluminum (Al I 309.27 nm). The excitation energy of aluminum is then transferred to all components of the gas/plasma phase via particle collisions. The optical emission of the trace elements as a function of the laser wavelength exhibits a high peak when the laser is tuned exactly to the aluminum transition. The on-resonance signal-to-noise ratio of magnesium (Mg 285.21 nm) was maximized near the off-resonance threshold fluence for detection of the magnesium line (∼1.78 J cm-2). The detection threshold of the magnesium line decreases below 1.0 J cm-2 when the laser is on resonance for a sample of aluminum alloy containing 150 ppm of magnesium. Under optimal conditions, the limits of detection of magnesium and silicon in aluminum alloy were found to be 0.75 ppm and 80 ppm, respectively, compared to 39 ppm and 5000 ppm, respectively, when the laser was off resonance at the same fluence. The limits of detection obtained by using low fluences and low energy per pulse are similar to those obtained using conventional LIBS but with much higher fluences and higher energy per pulse. The main advantage of this technique is that it allows measuring simultaneously relatively low concentrations of several trace elements while minimizing the damage to the sample. © 2013 The Royal Society of Chemistry. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f8bcb6b3-be52-4224-8c86-649be8e5a6fd ER - TY - JOUR TI - Optimal dye-quencher pairs for the design of an "activatable" nanoprobe for optical imaging DO - 10.1039/c3pp50118c AU - Simard, B. AU - Tomanek, B. AU - Van Veggel, F.C.J.M. AU - Abulrob, A. T2 - Photochemical and Photobiological Sciences SN - 1474-905X VL - 12 IS - 10 SP - 1824 EP - 1829 AB - Optical imaging offers high sensitivity and portability at low cost. The design of an optimal "activatable" imaging agent could greatly decrease the background noise and increase specificity of the signal. Five different molecules have been used to quench basal fluorescence of an enzyme substrate labeled with Cy5, Cy5.5 or IR800 at a distance of 8 amino acids (32 Å): a 6 nm gold nanoparticle (NP), a 20 nm and a 30 nm iron oxide (FeO) NP, the black hole quencher BHQ-3 and the IRdye quencher QC-1. The quenching efficiencies were 99% for QC1-IR800, 98% for QC1-Cy5.5, 96% for 30 nm FeO NP-Cy5.5, 89% for BHQ3-Cy5, 84% for BHQ3-Cy5.5, 77-90% for 6 nm gold NP-Cy5.5, depending on the number of dyes around the NP, 79% for 20 nm FeO NP-Cy5.5 and 77% for Cy5.5-Cy5. Signal activation upon cleavage by the matrix metalloproteinase MMP9 was proportional to the quenching efficiencies, ranging from 3-fold with Cy5.5-Cy5 to 67-fold with QC1-IR800. This independent work reports on the properties of the dyes and quenchers explaining the superior performance of QC-1 and 30 nm FeO NPs. © 2013 The Royal Society of Chemistry and Owner Societies. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 08eea232-6283-4b95-9f34-55eb64c0ae7d ER - TY - JOUR TI - Alignment between flattened protostellar infall envelopes and ambient magnetic fields DO - 10.1088/0004-637X/770/2/151 AU - Chapman, N.L. AU - Davidson, J.A. AU - Goldsmith, P.F. AU - Houde, M. AU - Kwon, W. AU - Li, Z.-Y. AU - Looney, L.W. AU - Matthews, B. AU - Matthews, T.G. AU - Novak, G. AU - Peng, R. AU - Vaillancourt, J.E. AU - Volgenau, N.H. T2 - The Astrophysical Journal SN - 0004-637X VL - 770 IS - 2 SP - 151 AB - We present 350 μm polarization observations of four low-mass cores containing Class 0 protostars: L483, L1157, L1448-IRS2, and Serp-FIR1. This is the second paper in a larger survey aimed at testing magnetically regulated models for core-collapse. One key prediction of these models is that the mean magnetic field in a core should be aligned with the symmetry axis (minor axis) of the flattened young stellar object inner envelope (aka pseudodisk). Furthermore, the field should exhibit a pinched or hourglass-shaped morphology as gravity drags the field inward toward the central protostar. We combine our results for the four cores with results for three similar cores that were published in the first paper from our survey. An analysis of the 350 μm polarization data for the seven cores yields evidence of a positive correlation between mean field direction and pseudodisk symmetry axis. Our rough estimate for the probability of obtaining by pure chance a correlation as strong as the one we found is about 5%. In addition, we combine together data for multiple cores to create a source-averaged magnetic field map having improved signal-to-noise ratio, and this map shows good agreement between mean field direction and pseudodisk axis (they are within 15°). We also see hints of a magnetic pinch in the source-averaged map. We conclude that core-scale magnetic fields appear to be strong enough to guide gas infall, as predicted by the magnetically regulated models. Finally, we find evidence of a positive correlation between core magnetic field direction and bipolar outflow axis. © 2013. The American Astronomical Society. All rights reserved.. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 7204ca20-1ddd-43aa-97ee-7c357c89f59b ER - TY - JOUR TI - A novel branching pattern in the lipopolysaccharide expressed by non-typeable Haemophilus influenzae strain 1232 DO - 10.1016/j.carres.2013.03.011 AU - Vitiazeva, V. AU - Li, J. AU - Hood, D.W. AU - Richard Moxon, E. AU - Schweda, E.K.H. T2 - Carbohydrate Research SN - 0008-6215 VL - 378 SP - 114 EP - 122 KW - D-glycero-D-manno-Heptose KW - Haemophilus influenzae KW - Lipopolysaccharides KW - LosA1 KW - Sialyllacto-N-neotetraose KW - Capillary electrophoresis KW - Electrospray ionization KW - Nuclear magnetic resonance spectroscopy KW - Mass spectrometry KW - heptose KW - lipopolysaccharide KW - oligosaccharide KW - sialic acid KW - tetrasaccharide KW - article KW - bacterial strain KW - capillary electrophoresis KW - carbohydrate analysis KW - deacylation KW - dephosphorylation KW - electrospray mass spectrometry KW - Haemophilus influenzae KW - high performance liquid chromatography KW - hydrolysis KW - methylation KW - nuclear magnetic resonance spectroscopy KW - priority journal KW - sequence analysis KW - sialylation KW - tandem mass spectrometry KW - Haemophilus influenzae AB - We report the novel branching pattern in lipopolysaccharide (LPS) expressed by non-typeable Haemophilus influenzae (NTHi) strain 1232. The strain expressed the β-D-Glcp-(1→4)-[α-D-Galp-(1→4)-β-D-Galp- (1→7)]-D-α-D-Hepp-(1→6)-β-D-Glcp chain linked to the proximal heptose (HepI) of the conserved triheptosyl inner-core moiety of NTHi LPS: L-α-D-HepIIIp-(1→2)-[PEtn→6]-L-α-D-HepIIp-(1→3)- L-α-DHepIp-( 1→5)-[PPEtn→4]-α-Kdop-(2→6)-lipid A. The structure has been elucidated using NMR spectroscopy, electrospray ionization mass spectrometry (ESI-MS) and capillary electrophoresis coupled to electrospray ionization tandem mass spectrometry (CE-ESI-MSn) on O-deacylated LPS and core oligosaccharide (OS) materials, as well as HPLC-ESI-MSn on permethylated, dephosphorylated OS. It was also found that a tetrasaccharide unit bearing sialic acid [α-Neu5Ac-(2→3)-β-D-Galp-(1→4)- β-D-GlcNAcp-(1→3)-β-D-Galp-(1→] could substitute O-4 of the β-D-Glcp linked to HepI. In addition, the distal heptose (HepIII) was substituted by PCho→6-β-D-Galp-(1→ at the O-2 position. © 2013 Published by Elsevier Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 865e9dc6-3703-427e-b742-a099cd4a40e6 ER - TY - JOUR TI - On the effect of the peening trajectory in shot peen forming DO - 10.1016/j.finel.2013.02.003 AU - Gariépy, A. AU - Larose, S. AU - Perron, C. AU - Bocher, P. AU - Lévesque, M. T2 - Finite Elements in Analysis and Design SN - 0168-874X VL - 69 SP - 48 EP - 61 KW - Deformed shape KW - Different geometry KW - Finite Element KW - Local curvature KW - Manufacturing process KW - Model parameters KW - Peen forming KW - Small-scale tests KW - Aerospace industry KW - Boundary conditions KW - Rockets KW - Shot peening KW - Trajectories AB - Peen forming is a manufacturing process commonly used in the aerospace industry to shape large and thin panels such as wing and fuselage skins and rocket panels. Due to the large size of the components, this process is generally performed by moving the parts through a peening enclosure or by moving peening equipment following a trajectory on the parts. Previous research on peen forming simulation has rarely considered the influence of the peening pattern on the resulting deformed shape. The purpose of this work was therefore to evaluate experimentally and numerically this effect using small scale tests. A simple model was proposed to simulate incremental deflections as the shot stream traveled over the samples. Model parameters were calibrated experimentally and then applied to a different geometry for validation. Finite element analyses correctly predicted the complex radius distribution arising from the peening path and the constraints applied to the sample during peening. © 2013 Published by Elsevier B.V. DA - 2013 PY - 2013 LA - eng N1 - Erratum published in volume 74, page 111, October 2013. DOI: 10.1016/j.finel.2013.07.006 C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 7d035bcf-b2cf-4c8f-aba4-69ad6cc6fde6 ER - TY - JOUR TI - Properties of excitons in quantum dots with a weak confinement DO - 10.12693/APhysPolA.124.781 AU - Gołasa, K. AU - Molas, M. AU - Goryca, M. AU - Kazimierczuk, T. AU - Smoleński, T. AU - Koperski, M. AU - Golnik, A. AU - Kossacki, P. AU - Potemski, M. AU - Wasilewski, Z.R. AU - Babiński, A. T2 - Acta Physica Polonica A SN - 0587-4246 VL - 124 IS - 5 SP - 781 EP - 784 AB - Statistical properties of neutral excitons, biexcitons and trions confined to natural quantum dots formed in the InAs/GaAs wetting layer are reported. The correlation of the trion binding energy and the biexciton binding energy was found. Magnetospectroscopic measurements of the excitons revealed also the correlation of excitonic effective g* factor of an exciton with the biexciton binding energy. The qualitative picture of the effect of quantum Confinement on the observed correlations is presented. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 37414ad9-daf2-497e-836e-5eb259f2a2b2 ER - TY - JOUR TI - Design and performance of a resistor multiplexing readout circuit for a SiPM detector DO - 10.1109/TNS.2013.2251661 AU - Goertzen, A.L. AU - Zhang, X. AU - McClarty, M.M. AU - Berg, E.J. AU - Liu, C.-Y. AU - Kozlowski, P. AU - Retiere, F. AU - Ryner, L. AU - Sossi, V. AU - Stortz, G. AU - Thompson, C.J. T2 - IEEE Transactions on Nuclear Science SN - 0018-9499 VL - 60 IS - 3 SP - 6495512 SP - 1541 EP - 1549 KW - LYSO KW - Multiplexing networks KW - Operating temperature KW - Positron emission tomography (PET) KW - Scintillation crystals KW - Scintillator crystals KW - Signal multiplexing KW - Silicon photomultiplier KW - Multiplexing KW - Optimization KW - Photomultipliers KW - Pixels KW - Positron emission tomography KW - Readout systems KW - Resistors KW - Scintillation counters KW - Silicon KW - Detectors AB - A silicon photomultiplier (SiPM)-based positron emission tomography (PET) detector was developed using a resistor network charge division multiplexing circuit for detector readout. The detector consists of a lutetium-yttrium oxy-orthosilicate (LYSO) scintillation crystal array, an SiPM array detector (SPMArray 4, SensL Inc., Cork, Ireland) and the resistor multiplexing network implemented in a through-hole package to facilitate changing of resistor values. For purposes of optimizing the readout circuit, the LYSO array used was a 4 × 4 crystal array with crystal size mm on a pitch of 3.37 mm, matched to the SiPM pixel size 3.17 × 3.17 × 10 mm3. Flood image, energy resolution, photopeak amplitude, timing resolution, and signal time-pickoff measurements were performed using standard NIM electronics. The resistor network values were optimized through an iterative process. The performance of the detector was evaluated over a range of temperatures from 23 °C to 60 °C by heating the detector. The ability of the detector to resolve crystals smaller than the SiPMpixel pitch was evaluated using a dual-layer LYSO array with crystals of 1.67-mm pitch. The optimal resistor network values were found to be 100 ω along the rows connecting the SiPM pixels and 56 ω for the columns. For these resistor value settings, the average energy resolution for the central four crystals in the array at 23.5 °C was 13.3% ± 0.3% and degraded to 16.3% ± 0.3% at 60 °C. The photopeak amplitude decreased by 2%/°C, and the timing resolution degraded from 3.43 ± 0.22 ns to 4.64 ± 0.25 ns for a 350-750-keV energy window over this temperature range. The signal time-pickoff point shifted earlier by 2.7 ns as the temperature increased, an effect likely due to changes in the signal shape with temperature. The detector was able to resolve all 113 crystals in the dual-layer LYSO array. These results demonstrate that the resistor multiplexing readout circuit functions well for reading out SiPM array based detectors, which use scintillator crystal arrays much smaller than the SiPM pixel pitch. The reduced number of output signals achieved through this signal multiplexing greatly reduces the number of signal cables required. In addition, the ability of this detector to function over a wide range of temperatures offers significant flexibility in defining the system operating temperature set point. © 1963-2012 IEEE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c7f9bc60-471e-4983-a839-4103bea5bcfe ER - TY - JOUR TI - A cloud-based approach for smart facilities management DO - 10.1109/ICPHM.2013.6621459 AU - Laut, D. AU - Liu, J. AU - Majumdar, S. AU - Nandy, B. AU - St-Hilaire, M. AU - Yang, C.S. T2 - PHM 2013 - 2013 IEEE International Conference on Prognostics and Health Management, Conference Proceedings T3 - 2013 IEEE International Conference on Prognostics and Health Management, PHM 2013, 24 June 2013 through 27 June 2013, Gaithersburg, MD SN - 9781467357227 SP - 6621459 AB - One of the problems with the current practices in the various domains of facility management is that each facility is managed by its stake holder in isolation from the management of other similar facilities. However, with the advent of new technologies such as cloud computing, we have an opportunity to unify the management of multiple geographically dispersed facilities. To that end, this paper presents our joint research efforts on cloud-based smart facility management. More precisely, we present a cloud-based platform in order to manage sensor-based bridge infrastructures and smart machinery. Although the paper focuses on these two applications, the proposed cloud-based platform is designed to support/manage a multitude of smart facilities. © 2013 IEEE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 700dbb97-cd6d-4790-bea7-323ea041c559 ER - TY - JOUR TI - Antimicrobial peptides expressed in wheat reduce susceptibility to Fusarium head blight and powdery mildew DO - 10.4141/CJPS2012-125 AU - Badea, A. AU - Eudes, F. AU - Laroche, A. AU - Graf, R. AU - Doshi, K. AU - Amundsen, E. AU - Nilsson, D. AU - Puchalski, B. T2 - Canadian Journal of Plant Science SN - 0008-4220 VL - 93 IS - 2 SP - 199 EP - 208 KW - antimicrobial activity KW - bacterium KW - disease resistance KW - fungal disease KW - fungus KW - infectivity KW - molecular analysis KW - pathogen KW - peptide KW - plant defense KW - virus KW - wheat AB - Antimicrobial peptides (AMPs) have a broad spectrum of action against bacteria, fungi and viruses, which makes them attractive for building plant defense against a diversity of pathogens. Peptides MsrA2 and 10R were cloned in three genetic constructs for tissue-specific expressions in wheat, using either Lem1, GstA1WIR1a, or Ltp6 and LTP6 signal peptide targeting the lemma/palea, leaves and spikes, epicarp and endomembrane system, respectively. The minimal cassettes for these three genetic constructs and for Pat marker construct were co-delivered in immature wheat scutella using biolistics, and green plantlets were regenerated in presence of 5 mg L-1 glufosinate. Molecular screening confirmed one regenerated plant carried and expressed all transgenes (AMP+): one copy of 10R driven by Ltp6 promoter, one copy of msrA2 driven by GstA1Wir1a and two copies of msrA2 driven by Lem1. Its offspring and T3 generation were challenged with Fusarium graminearum and Blumeria graminis in a contained environment. A reduction of 50% in Fusarium head blight susceptibility was observed in T1, and was inherited through T3 generation. The latter, also presented a 53% reduction in Fusarium damaged kernels and 62% reduction in deoxynivalenol accumulation compared with wild cv. Fielder and sister lines AMP-. MsrA2 and 10R producing T3 lines showed an average significant reduction of 59% in powdery mildew susceptibility compared with cv. Fielder. Synthetic MsrA2 and 10R peptides were effective as in vivo antifungal peptides in wheat. The expression of antimicrobial peptides in plant cells or tissues may have great potential to limit pathogen infection or growth protecting wheat against a diversity of fungal diseases. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : af74a9d2-db47-4992-b948-abc93737ad4f ER - TY - JOUR TI - The debris disk around γ doradus resolved with Herschel DO - 10.1088/0004-637X/762/1/52 AU - Broekhoven-Fiene, H. AU - Matthews, B.C. AU - Kennedy, G.M. AU - Booth, M. AU - Sibthorpe, B. AU - Lawler, S.M. AU - Kavelaars, J.J. AU - Wyatt, M.C. AU - Qi, C. AU - Koning, A. AU - Su, K.Y.L. AU - Rieke, G.H. AU - Wilner, D.J. AU - Greaves, J.S. T2 - The Astrophysical Journal SN - 0004-637X VL - 762 IS - 1 SP - 52 AB - We present observations of the debris disk around γ Doradus, an F1V star, from the Herschel Key Programme DEBRIS (Disc Emission via Bias-free Reconnaissance in the Infrared/Submillimetre). The disk is well resolved at 70, 100, and 160 μm, resolved along its major axis at 250 μm, detected but not resolved at 350 μm, and confused with a background source at 500 μm. It is one of our best resolved targets and we find it to have a radially broad dust distribution. The modeling of the resolved images cannot distinguish between two configurations: an arrangement of a warm inner ring at several AU (best fit 4 AU) and a cool outer belt extending from ∼55 to 400 AU or an arrangement of two cool, narrow rings at ∼70 AU and ∼190 AU. This suggests that any configuration between these two is also possible. Both models have a total fractional luminosity of ∼10-5 and are consistent with the disk being aligned with the stellar equator. The inner edge of either possible configuration suggests that the most likely region to find planets in this system would be within ∼55 AU of the star. A transient event is not needed to explain the warm dust's fractional luminosity. © 2013. The American Astronomical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 914c437c-70c6-443c-91da-784d4fb40b9d ER - TY - JOUR TI - Extension of the B3LYP-dispersion-correcting potential approach to the accurate treatment of both inter- and intra-molecular interactions DO - 10.1007/s00214-013-1389-x AU - DiLabio, G.A. AU - Koleini, M. AU - Torres, E. T2 - Theoretical Chemistry Accounts SN - 1432-881X VL - 132 IS - 10 SP - 1 EP - 13 AB - We recently demonstrated that dispersion-correcting potentials (DCPs), which are atom-centered Gaussian-type functions that were developed for use with B3LYP (Torres and DiLabio in J Phys Chem Lett 3:1738-1744, 2012), greatly improved the ability of the underlying functional to predict non-covalent interactions. However, the recent application of the B3LYP-DCP approach to study the β-scission of the cumyloxyl radical led to a calculated barrier height that was over-estimated by ca. 8 kcal/mol. We demonstrate in the present work that the source of this error arises from the previously developed carbon atom DCPs, which erroneously alters the electron density in the C-C covalent-bonding region. In this work, we developed a new C-DCP with a form that was expected to less strongly influence the electron density in the covalent bonding region. Tests of the new C-DCP, in conjunction with previously published H-, N-, and O-DCPs, with B3LYP-DCP/6-31+G(2 d,2 p) on the S66, S22B, HSG-A, and HC12 databases of non-covalently interacting dimers showed that it is one of the most accurate methods available for treating intermolecular interactions, giving mean absolute errors (MAEs) of 0.19, 0.27, 0.16, and 0.18 kcal/mol, respectively. Additional testing on the S12L database of very large complexation systems gave an MAE of 2.6 kcal/mol, demonstrating that the B3LYP-DCP/6-31+G(2 d,2 p) approach to be one of the best-performing and most feasible methods for treating large systems containing significant non-covalent interactions. Finally, we showed that the modeling of C-C-making/C-C-breaking chemistry is well predicted using the newly developed DCPs. In addition to predicting a barrier height for the β-scission of the cumyloxyl radical, that is, within 1.7 kcal/mol of the high-level value, application of B3LYP-DCP/6-31+G(2 d,2 p) to 10 databases that include reaction barrier heights and energies, isomerization energies, and relative conformation energies gives performance that is among the best of all available dispersion-corrected density-functional theory approaches. © 2013 Springer-Verlag Berlin Heidelberg. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5bfe6e64-b875-4f5a-a160-f94891681f61 ER - TY - JOUR TI - The Canada-France high-z Quasar Survey: 1.2 mm observations DO - 10.1051/0004-6361/201221006 AU - Omont, A. AU - Willott, C.J. AU - Beelen, A. AU - Bergeron, J. AU - Orellana, G. AU - Delorme, P. T2 - Astronomy and Astrophysics SN - 0004-6361 VL - 552 SP - A43 KW - Galaxies : active KW - Galaxies: starbursts KW - Galaxies:high-redshift KW - Infrared: galaxies KW - Submillimeter: galaxies KW - Stars KW - Surveys KW - Galaxies AB - We report 250 GHz (1.2 mm) observations of a sample of 20 quasars at redshifts 5.8 < z < 6.5 from the Canada-France High-z Quasar Survey (CFHQS), using the Max-Planck-Millimeter-Bolometer (MAMBO) array at the 30-metre telescope of the Institut de Radioastronomie Millmétrique (IRAM). An rms sensitivity of ≲0.6 mJy was achieved for 65% of the sample, and of ≲ 1.0 mJy for 90%. Only one quasar, CFHQS J142952+544717, was robustly detected with S250 GHz = 3.46 ± 0.52 mJy. This indicates that one of the most powerful known starbursts at z ∼ 6 is associated with this radio-loud quasar. On average, the other CFHQS quasars, which have a mean optical magnitude fainter than the previously studied samples of z ∼ 6 quasars of the Sloan Digital Sky Survey (SDSS), have a mean 1.2 mm flux density S250 GHz = 0.41 ± 0.14 mJy; this average detection with a signal-to-noise (S/N) ratio of 2.9 is hardly meaningful. It would correspond to LFIR ≈ 0.94 ± 0.32 × 1012 L ·, and an average star formation rate of a few 100 M ·/yr, depending on the stellar initial mass function (IMF) and a possible contribution of an active galactic nucleus (AGN) to LFIR . This is consistent with previous findings of Wang et al. on the far-infrared emission of z ∼ 6 quasars and extends their results toward optically fainter sources. © 2013 ESO. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c91ee434-4af8-45bf-8ccc-ae00ecd42c17 ER - TY - JOUR TI - The mass, orbit, and tidal evolution of the Quaoar-Weywot system DO - 10.1016/j.icarus.2012.11.004 AU - Fraser, W.C. AU - Batygin, K. AU - Brown, M.E. AU - Bouchez, A. T2 - Icarus SN - 0019-1035 VL - 222 IS - 1 SP - 357 EP - 363 AB - Here we present new adaptive optics observations of the Quaoar-Weywot system. With these new observations we determine an improved system orbit. Due to a 0.39day alias that exists in available observations, four possible orbital solutions are available with periods of ∼11.6, ∼12.0, ∼12.4, and ∼12.8days. From the possible orbital solutions, system masses of 1.3-1.5±0.1×1021kg are found. These observations provide an updated density for Quaoar of 2.7-5.0gcm-3. In all cases, Weywot's orbit is eccentric, with possible values ∼0.13-0.16. We present a reanalysis of the tidal orbital evolution of the Quaoar-Weywot system. We have found that Weywot has probably evolved to a state of synchronous rotation, and has likely preserved its initial inclination over the age of the Solar System. We find that for plausible values of the effective tidal dissipation factor tides produce a very slow evolution of Weywot's eccentricity and semi-major axis. Accordingly, it appears that Weywot's eccentricity likely did not tidally evolve to its current value from an initially circular orbit. Rather, it seems that some other mechanism has raised its eccentricity post-formation, or Weywot formed with a non-negligible eccentricity. © 2012. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0cf1a3ef-d142-4b07-8baa-0a0c231728cb ER - TY - JOUR TI - Structural influence of hydrophobic diamine in sulfonated poly(sulfide sulfone imide) copolymers on medium temperature PEM fuel cell DO - 10.1016/j.polymer.2013.09.030 AU - Lee, Kang Hyuck AU - Lee, So Young AU - Shin, Dong Won AU - Wang, Chenyi AU - Ahn, Sang-Hyun AU - Lee, Kee-Jung AU - Guiver, Michael D. AU - Lee, Young Moo T2 - Polymer (United Kingdom) SN - 0032-3861 VL - 55 IS - 6 SP - 1317 EP - 1326 KW - Medium temperature PEMFC; Polymer electrolyte membrane; Sulfonated polyimide AB - Sulfonated poly(sulfide sulfone imide) copolymers containing flexible sulfide bond and six-membered imide ring were synthesized by random polycondensation. Two types of membranes were prepared by using sulfide (S-PSI) and sulfide sulfone (S-PSFI) based non-sulfonated diamines to investigate the effects of the hydrophobic component. IECw values were controlled to 1.51-1.94 meq g-1 depending on the degree of sulfonation (DS) which was in the range of 50-80%. The membrane series showed good thermal stability up to 310 °C and mechanical properties (tensile strength >30 MPa). Dimensional stabilities were excellent with 23-35% increases, even at 100 °C. Proton conductivities of membranes composed of different hydrophobic diamines display a relatively good correlation with water content and morphology. In fuel cell tests, the S-PSI60 membrane shows relatively high current density of 250 mA cm-2 at 0.6 V and maximum power density of 175 mW cm-2 at 120 °C, 35% RH, 1.5 atm. DA - 2013/09/25 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9bd4f3f5-99e0-4418-ac42-b10f7778d98c ER - TY - JOUR TI - Nonlinear dynamics and analysis of a four-bar linkage with clearance DO - 10.1007/s11465-013-0258-6 AU - Tang, Y. AU - Chang, Z. AU - Dong, X. AU - Hu, Y. AU - Yu, Z. T2 - Frontiers of Mechanical Engineering SN - 2095-0233 VL - 8 IS - 2 SP - 160 EP - 168 AB - In this paper, nonlinear dynamic behavior of a four-bar linkage considering clearance is studied. The dynamic model of the linkage with a clearance between coupler and rocker is developed firstly. Then the dynamic equations of this mechanism are solved by a numerical method. According to the calculated response, compliance, force and trajectory of pin in joint bearing are obtained. Effects of clearance magnitude and the relationship between a mechanism with clearance and without clearance are studied. By using Poincare Map, it is proved that strange attractors or chaos exist in the dynamic response. In addition, phenomena of chaos, periodic response and subharmonic response also can be found in the special condition. Bifurcation diagram is used to suggest that bifurcation and fractal phenomena exist in the dynamic response of this mechanism. © 2013 Higher Education Press and Springer-Verlag Berlin Heidelberg. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4fc2de13-b2c7-4430-b426-8f60ac0c0aac ER - TY - JOUR TI - Establishment of channel networks in a digital elevation model of the prairie region through hydrological correction and geomorphological assessment DO - 10.1080/07011784.2013.773788 AU - Zhang, H. AU - Huang, G.H. AU - Wang, D. T2 - Canadian Water Resources Journal SN - 0701-1784 VL - 38 IS - 1 SP - 12 EP - 23 KW - Canadian digital elevation datum KW - Digital elevation model KW - Hydrological corrections KW - Hydrological modeling KW - Quantitative evaluation KW - Saskatchewan , Canada KW - Spatial correlations KW - Watershed delineation KW - Digital instruments KW - Forestry KW - Geomorphology KW - Quality control KW - Surveying AB - Building channel networks in flat regions of digital elevation models (DEMs) is important for watershed delineation and hydrological modeling, particularly for areas with gently-sloped terrain, such as the Canadian Prairies. Existing drainage analysis methods cannot effectively address the spatial correlations of elevation across the flat regions, and the quality of the DEM-derived channel network is mainly evaluated through visual inspection. In this study a hydrological correction method is developed that integrates elevation information from both the existing digital channel network and the original DEM. A set of geomorphological indices is then introduced for quantitative evaluation of DEM-derived channel networks from the perspectives of flow direction and drainage pattern. Both the DEM correction and network assessment methods are implemented in a GIS environment. Their performance is demonstrated through a case study in southern Saskatchewan, Canada. The generated channel network is consistent with the known hydrological information and contains fewer parallel channels compared with existing methods. The developed methods could be valuable for a wide range of applications using the Canadian Digital Elevation Data (CDED) within the context of the Canadian Prairie region. © 2013 Canadian Water Resources Association. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : dd60c277-d749-47b7-b3ee-61b24897a471 ER - TY - JOUR TI - A Mouse model of acinetobacter baumannii-associated pneumonia using a clinically isolated hypervirulent strain DO - 10.1128/AAC.00944-13 AU - Harris, G. AU - Lee, R.K. AU - Lam, C.K. AU - Kanzaki, G. AU - Patel, G.B. AU - Xu, H.H. AU - Chen, W. T2 - Antimicrobial Agents and Chemotherapy SN - 0066-4804 VL - 57 IS - 8 SP - 3601 EP - 3613 AB - Acinetobacter baumannii is an important emerging pathogen in health care-acquired infections and is responsible for severe nosocomial and community-acquired pneumonia. Currently available mouse models of A. baumannii pneumonia show poor colonization with little to no extrapulmonary dissemination. Here, we describe a mouse model of A. baumannii pneumonia using a clinical isolate (LAC-4 strain) that reliably reproduces the most relevant features of human pulmonary A. baumannii infection and pathology. Using this model, we have shown that LAC-4 infection induced rapid bacterial replication in the lungs, significant extrapulmonary dissemination, and severe bacteremia by 24 h postintranasal inoculation. Infected mice showed severe bronchopneumonia and dilatation and inflammatory cell infiltration in the perivascular space. More significantly, 100% of C57BL/6 and BALB/c mice succumbed to 108 CFU of LAC-4 inoculation within 48 h. When this model was used to assess the efficacy of antimicrobials, all mice treated with imipenem and tigecycline survived a lethal intranasal challenge, with minimal clinical signs and body weight loss. Moreover, intranasal immunization of mice with formalin-fixed LAC-4 protected 40% of mice from a lethal (100-100% lethal dose) intraperitoneal challenge. Thus, this model offers a reproducible acute course of A. baumannii pneumonia without requiring additional manipulation of host immune status, which will facilitate the development of therapeutic agents and vaccines against A. baumannii pneumonia in humans. © 2013, American Society for Microbiology. All Rights Reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 644192bb-ef0c-46d0-aaaf-d49b53b943b7 ER - TY - JOUR TI - Synthesis of Pd and Nb-doped TiO 2 composite supports and their corresponding Pt-Pd alloy catalysts by a two-step procedure for the oxygen reduction reaction DO - 10.1016/j.jpowsour.2012.08.025 AU - Wang, Y.-J. AU - Wilkinson, D.P. AU - Guest, A. AU - Neburchilov, V. AU - Baker, R. AU - Nan, F. AU - Botton, G.A. AU - Zhang, J. T2 - Journal of Power Sources SN - 0378-7753 VL - 221 SP - 232 EP - 241 KW - Clusters KW - Composite support KW - Mass activity KW - Oxygen reduction reaction KW - PEM fuel cell KW - Alloys KW - Catalyst activity KW - Catalyst supports KW - Electric conductivity KW - Electrocatalysts KW - Electrolytic reduction KW - Niobium KW - Platinum KW - Platinum compounds KW - Proton exchange membrane fuel cells (PEMFC) KW - Rotating disks KW - Titanium dioxide KW - Platinum alloys AB - Several Pd-composite Nb 0.06Ti 0.94O 2 materials are synthesized by a two-step procedure, and employed as the Pt-Pd alloy catalyst support for the PEM fuel cell oxygen reduction reaction (ORR). These supports and their supported catalysts are characterized using analytical and electrochemical methods with respect to their material morphology, chemical/electrochemical stability, electronic conductivity as well as oxygen reduction reaction (ORR) mass activity/stability. For the supported Pt-Pd catalysts, the Pt-Pd nanoparticles adhered to both the Nb 0.06Ti 0.94O 2 and composited Pd surfaces to form Pt mPd n clusters. A possible synergetic interaction between the Pt-Pd alloy catalyst and its Pd-Nb 0.06Ti 0.94O 2 composite support is believed to exist which enhances the ORR activity of these catalysts. The electronic conductivity of Nb 0.06Ti 0.94O 2 can be greatly improved after forming composites with Pd to the desired levels required for electrocatalyst applications. Three supported Pt-Pd catalysts, 20 wt% Pt 0.62Pd 0.38/Pd 10wt%-(Nb 0.06Ti 0.94O 2) 90wt%, 20 wt% Pt 0.62Pd 0.38/Pd 30wt%-(Nb 0.06Ti 0.94O 2) 70wt%, and 20 wt% Pt 0.62Pd 0.38/Pd 50wt%-(Nb 0.06Ti 0.94O 2) 50wt%, are synthesized and tested using both cyclic voltammetric and rotating disk electrode techniques with respect to their surface electrochemistry, ORR mass activity, and electrochemical stability. All three catalysts show higher Pt mass activity (>130 mA mg Pt -1 at 0.9 V vs. RHE) than that of the baseline 47 wt% Pt C -1 carbon supported catalyst (110 mA mg Pt -1). However, the durability of these catalysts needs to be further improved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f94f32e5-8eb5-4313-9e81-2c09f331e295 ER - TY - JOUR TI - A dynamical signature of multiple stellar populations in 47 tucanae DO - 10.1088/2041-8205/771/1/L15 AU - Richer, H.B. AU - Heyl, J. AU - Anderson, J. AU - Kalirai, J.S. AU - Shara, M.M. AU - Dotter, A. AU - Fahlman, G.G. AU - Rich, R.M. T2 - The Astrophysical Journal Letters SN - 2041-8205 VL - 771 IS - 1 SP - L15 AB - Based on the width of its main sequence, and an actual observed split when viewed through particular filters, it is widely accepted that 47 Tucanae contains multiple stellar populations. In this contribution, we divide the main sequence of 47 Tuc into four color groups, which presumably represent stars of various chemical compositions. The kinematic properties of each of these groups are explored via proper motions, and a strong signal emerges of differing proper-motion anisotropies with differing main-sequence color; the bluest main-sequence stars exhibit the largest proper-motion anisotropy which becomes undetectable for the reddest stars. In addition, the bluest stars are also the most centrally concentrated. A similar analysis for Small Magellanic Cloud stars, which are located in the background of 47 Tuc on our frames, yields none of the anisotropy exhibited by the 47 Tuc stars. We discuss implications of these results for possible formation scenarios of the various populations. © 2013. The American Astronomical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b3df1257-39de-4ed5-8442-cc10f1ab86ca ER - TY - JOUR TI - Interconnected carbon nanosheets derived from hemp for ultrafast supercapacitors with high energy DO - 10.1021/nn400731g AU - Wang, H. AU - Xu, Z. AU - Kohandehghan, A. AU - Li, Z. AU - Cui, K. AU - Tan, X. AU - Stephenson, T.J. AU - King'Ondu, C.K. AU - Holt, C.M.B. AU - Olsen, B.C. AU - Tak, J.K. AU - Harfield, D. AU - Anyia, A.O. AU - Mitlin, D. T2 - ACS Nano SN - 1936-0851 VL - 7 IS - 6 SP - 5131 EP - 5141 KW - Carbon nanosheets KW - Electrochemical capacitor KW - Extreme current densities KW - High specific surface area KW - Hydrothermal carbonization KW - Multi-layered structure KW - Super capacitor KW - Supercapacitor application KW - Bast fibers KW - Biomass KW - Capacitance KW - Carbon KW - Energy storage KW - Hemp KW - Ionic liquids KW - Nanosheets KW - Electrolytic capacitors KW - Biomass KW - Capacitors KW - Carbon Fibers KW - Hemp KW - Ions KW - Liquids KW - Phloem KW - cannabis KW - graphite KW - nanomaterial KW - nitrogen KW - adsorption KW - article KW - chemistry KW - electric capacitance KW - electrochemistry KW - surface property KW - time KW - Adsorption KW - Cannabis KW - Electric Capacitance KW - Electrochemistry KW - Graphite KW - Nanostructures KW - Nitrogen KW - Surface Properties KW - Time Factors AB - We created unique interconnected partially graphitic carbon nanosheets (10-30 nm in thickness) with high specific surface area (up to 2287 m 2 g-1), significant volume fraction of mesoporosity (up to 58%), and good electrical conductivity (211-226 S m-1) from hemp bast fiber. The nanosheets are ideally suited for low (down to 0 C) through high (100 C) temperature ionic-liquid-based supercapacitor applications: At 0 C and a current density of 10 A g-1, the electrode maintains a remarkable capacitance of 106 F g-1. At 20, 60, and 100 C and an extreme current density of 100 A g-1, there is excellent capacitance retention (72-92%) with the specific capacitances being 113, 144, and 142 F g -1, respectively. These characteristics favorably place the materials on a Ragone chart providing among the best power-energy characteristics (on an active mass normalized basis) ever reported for an electrochemical capacitor: At a very high power density of 20 kW kg-1 and 20, 60, and 100 C, the energy densities are 19, 34, and 40 Wh kg-1, respectively. Moreover the assembled supercapacitor device yields a maximum energy density of 12 Wh kg-1, which is higher than that of commercially available supercapacitors. By taking advantage of the complex multilayered structure of a hemp bast fiber precursor, such exquisite carbons were able to be achieved by simple hydrothermal carbonization combined with activation. This novel precursor-synthesis route presents a great potential for facile large-scale production of high-performance carbons for a variety of diverse applications including energy storage. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9a408b85-8d4d-4e7f-9fe1-51a9ff2b68c4 ER - TY - JOUR TI - Electric-field-controlled antiferromagnetic domains in epitaxial BiFeO 3 thin films probed by neutron diffraction DO - 10.1103/PhysRevB.87.140405 AU - Ratcliff, W. AU - Yamani, Z. AU - Anbusathaiah, V. AU - Gao, T.R. AU - Kienzle, P.A. AU - Cao, H. AU - Takeuchi, I. T2 - Physical Review B - Condensed Matter and Materials Physics SN - 1098-0121 VL - 87 IS - 14 SP - 140405 AB - Direct evidence of controlling the population of magnetic domains in BiFeO3 thin films through electric field is reported using neutron diffraction. By fabricating BiFeO3 thin films on vicinal SrTiO 3 substrates, we have achieved ferroelectric monodomains as confirmed by piezoresponse force microscopy. The application of an electric field between the bottom SrRuO3 and the top electrode switches the ferroelectric domain state with concomitant changes in magnetic reflections observed with neutron diffraction, indicating changes in the antiferromagnetic domain populations. The observed magnetoelectric switching behavior by neutron diffraction is compared with the electric-field effect on the magneto-optical Kerr effect measurement on patterned pads of exchange coupled Co film deposited on top of the BiFeO3 films. The present result shows possible new directions for the realization of magnetoelectric devices. ©2013 American Physical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : bd01159d-4573-4358-b5c0-2c0d580a24fe ER - TY - JOUR TI - Optimal routing strategies for autonomous underwater vehicles in time-varying environment DO - 10.1016/j.robot.2013.08.010 AU - Eichhorn, M. T2 - Robotics and Autonomous Systems SN - 0921-8890 AB - This paper presents a mission system and the therein implemented algorithms for path planning in a time-varying environment based on graph methods. The basic task of the introduced path planning algorithms is to find a time-optimal path from a defined start position to a goal position with consideration of the time-varying ocean current for an autonomous underwater vehicle (AUV). Building on this, additional practice-oriented considerations in planning are discussed in this paper. Such points are the discussion of possible methods to accelerate the algorithms and the determination of the optimal departure time. The solutions and algorithms presented in this paper are focused on path planning requirements for the AUV "SLOCUM Glider". These algorithms are equally applicable to other AUVs or aerial mobile autonomous systems. © 2013 Elsevier B.V. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d93e0bd7-70fc-49e2-b03a-ed8db23ec9a7 ER - TY - JOUR TI - Static magnetic fields enhance lipid order in native plant plasma membrane DO - 10.1039/c3sm50355k AU - Poinapen, D. AU - Toppozini, L. AU - Dies, H. AU - Brown, D.C.W. AU - Rheinstädter, M.C. T2 - Soft Matter SN - 1744-683X VL - 9 IS - 29 SP - 6804 EP - 6813 KW - Correlation peaks KW - Field strengths KW - Fluid components KW - Molecular orders KW - Protein components KW - Protein structures KW - Silicon substrates KW - Static magnetic fields KW - Cell membranes KW - Proteins KW - X ray diffraction KW - Seed AB - We studied molecular order in native plant plasma membranes in the presence of static magnetic fields. Plasma membranes of seeds of the tomato plant were purified, extracted, and applied to a silicon substrate in a buffer suspension and their molecular structure was studied using X-ray diffraction. We observed correlation peaks that we assigned to the lipid and protein components of the plasma membrane. Two field strengths were available: B = 0.126 T and B = 0.208 T. While magnetic fields had no observable effect on protein structure, enhanced lipid order was observed, leading to an increase in the gel components and a decrease in the fluid component of the lipids. © 2013 The Royal Society of Chemistry. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8121ca59-9b4d-4fa2-83ee-5a85275cf412 ER - TY - JOUR TI - Reaction of lines of the rapid cycling brassica collection and Arabidopsis thaliana to four pathotypes of Plasmodiophora brassicae DO - 10.1094/PDIS-08-12-0752-RE AU - Sharma, K. AU - Gossen, B.D. AU - Greenshields, D. AU - Selvaraj, G. AU - Strelkov, S.E. AU - McDonald, M.R. T2 - Plant Disease SN - 0191-2917 VL - 97 IS - 6 SP - 720 EP - 727 AB - The clubroot reaction of five Rapid Cycling Brassica Collection (RCBC) lines (Brassica carinata, B. juncea, B. napus, B. oleracea, and B. rapa) and 84 lines of Arabidopsis thaliana to pathotypes 2, 3, 5, and 6 of Plasmodiophora brassicae (as classified on William's system) was assessed. Also, the reaction of the Arabidopsis lines to a single-spore isolate of each of pathotypes 3 and 6 was compared with that of a field isolate. Seedlings were inoculated with resting spores of P. brassicae, maintained at 25 and 20°C (day and night, respectively), and assessed for clubroot incidence and severity at 6 weeks after inoculation. Several lines of A. thaliana and RCBC exhibited a differential response to pathotype but none of the lines were immune. Among the RCBC lines, B. napus was resistant to all of the pathotypes; B. oleracea was resistant to pathotypes 2, 3, and 5; B carinata and B. rapa were resistant to pathotypes 2 and 5; and B. juncea was susceptible to pathotypes 5 and 6 and had an intermediate response to pathotypes 2 and 3. Line Ct- 1 of A. thaliana was highly resistant to pathotype 2, Pu2-23 was highly resistant to pathotype 5, and Ws-2 and Sorbo were highly resistant to pathotype 6. These results indicate that the lines of RCBC and A. thaliana have potential for use as model crops for a wide range of studies on clubroot, and could be used to differentiate these four pathotypes of P. brassicae. The reaction of the RCBC lines to pathotype 6 was highly correlated with response under field conditions but the reaction to the single-spore isolates of pathotypes 3 and 6 was not strongly correlated with reaction to the field collections in the Arabidopsis lines. © 2013 Department of Agriculture and Agri-Food, Government of Canada. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5c770006-5e10-4af0-85bb-64f743af4bb3 ER - TY - JOUR TI - Supercapacitors based on carbons with tuned porosity derived from paper pulp mill sludge biowaste DO - 10.1016/j.carbon.2013.01.079 AU - Wang, H. AU - Li, Z. AU - Tak, J.K. AU - Holt, C.M.B. AU - Tan, X. AU - Xu, Z. AU - Amirkhiz, B.S. AU - Harfield, D. AU - Anyia, A. AU - Stephenson, T. AU - Mitlin, D. T2 - Carbon SN - 0008-6223 VL - 57 SP - 317 EP - 328 KW - Activation process KW - Capacitance retention KW - Charge-discharge cycle KW - Hydrothermal carbonization KW - Ionic liquid electrolytes KW - Organic electrolyte KW - Paper manufacturing KW - Textural properties KW - Capacitance KW - Chemical activation KW - Electrolytes KW - Paper and pulp mills KW - Thermochemistry KW - Ionic liquids AB - Hydrothermal carbonization followed by chemical activation is utilized to convert paper pulp mill sludge biowaste into high surface area (up to 2980 m2 g-1) carbons. This synthesis process employs an otherwise unusable byproduct of paper manufacturing that is generated in thousands of tons per year. The textural properties of the carbons are tunable by the activation process, yielding controlled levels of micro and mesoporosity. The electrochemical results for the optimized carbon are very promising. An organic electrolyte yields a maximum capacitance of 166 F g-1, and a Ragone curve with 30 W h kg-1 at 57 W kg-1 and 20 W h kg-1 at 5450 W kg-1. Two ionic liquid electrolytes result in maximum capacitances of 180-190 F g-1 with up to 62% retention between 2 and 200 mV s-1. The ionic liquids yielded energy density-power density combinations of 51 W h kg-1 at 375 W kg -1 and 26-31 W h kg-1 at 6760-7000 W kg-1. After 5000 plus charge-discharge cycles the capacitance retention is as high at 91%. The scan rate dependence of the surface area normalized capacitance highlights the rich interplay of the electrolyte ions with pores of various sizes. © 2013 Elsevier Ltd. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a30cdd5b-2532-4632-bce1-f6f85b029d54 ER - TY - JOUR TI - Fast, Non-Competitive and Reversible Inhibition of NMDA-Activated Currents by 2-BFI Confers Neuroprotection DO - 10.1371/journal.pone.0064894 AU - Han, Z. AU - Yang, J.-L. AU - Jiang, S.X. AU - Hou, S.-T. AU - Zheng, R.-Y. T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 5 SP - e64894 KW - 2 (2 benzofuranyl) 2 imidazoline KW - alpha amino 3 hydroxy 5 methyl 4 isoxazolepropionic acid KW - calcium KW - imidazoline derivative KW - memantine KW - n methyl dextro aspartic acid KW - n methyl dextro aspartic acid receptor KW - unclassified drug KW - animal cell KW - article KW - brain cell KW - calcium transport KW - concentration response KW - controlled study KW - drug mechanism KW - drug receptor binding KW - drug selectivity KW - embryo KW - excitotoxicity KW - in vitro study KW - male KW - nerve cell culture KW - nerve cell excitability KW - neuroprotection KW - nonhuman KW - rat AB - Excessive activation of the N-methyl-D-aspartic acid (NMDA) type glutamate receptors (NMDARs) causes excitotoxicity, a process important in stroke-induced neuronal death. Drugs that inhibit NMDA receptor-mediated [Ca2+]i influx are potential leads for development to treat excitotoxicity-induced brain damage. Our previous studies showed that 2-(2-benzofu-ranyl)-2-imidazoline (2-BFI), an immidazoline receptor ligand, dose-dependently protects rodent brains from cerebral ischemia injury. However, the molecular mechanisms remain unclear. In this study, we found that 2-BFI transiently and reversibly inhibits NMDA, but not AMPA currents, in a dose-dependent manner in cultured rat cortical neurons. The mechanism of 2-BFI inhibition of NMDAR is through a noncompetitive fashion with a faster on (Kon = 2.19±0.33×10-9 M-1 sec-1) and off rate (Koff = 0.67±0.02 sec-1) than those of memantine, a gold standard for therapeutic inhibition NMDAR-induced excitotoxicity. 2-BFI also transiently and reversibly blocked NMDA receptor-mediated calcium entry to cultured neurons and provided long-term neuroprotection against NMDA toxicity in vitro. Collectively, these studies demonstrated a potential mechanism of 2-BFI-mediated neuroprotection and indicated that 2-BFI is an excellent candidate for repositioning as a drug for stroke treatment. © 2013 Han et al. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : cafe3662-db1c-4641-a272-5eb6be83012b ER - TY - JOUR TI - Sensitivity of air-coupled ultrasound and eddy current sensors to bearing fault detection AU - Dadouche, A. AU - Rezaei, A. AU - Singhe, V. AU - Dmochowski, W. AU - Bird, J.W. AU - Nitzsche, F. T2 - Tribology and Lubrication Technology SN - 1545-858X VL - 69 IS - 8 SP - 40 EP - 51 KW - Advanced signal processing KW - Air-Coupled Ultrasound Sensor KW - Air-coupled ultrasounds KW - Bearing fault detection KW - Eddy current sensors KW - Envelope Detection KW - Laboratory environment KW - Rolling Element Bearing KW - Ball bearings KW - Condition monitoring KW - Cracks KW - Electromagnetic field effects KW - Sensors KW - Signal processing KW - Testing KW - Ultrasonics KW - Vibration analysis KW - Ultrasonic applications AB - For decades, vibration and oil analysis have usually been used to detect early bearing faults and track their progression over time. Progress has been seen in condition monitoring through vibration analysis of rolling element bearings using improved sensors and advanced signal processing techniques. In this paper, the authors investigate the use of air-coupled ultrasound and eddy current sensors as diagnostic tools for the detection of bearing faults. A series of experiments was carried out in a laboratory environment: localized defects with different sizes were created intentionally on the test bearing components simulating evolving cracks or other related faults. The resulting data for a constant bearing speed and load have shown that both sensors are capable of detecting different types of defects located on the bearing components. The data from the air-coupled ultrasound and eddy current sensors were also compared with those obtained from an accelerometer. The test method and the processing technique are described and the spectra of the different signals are analyzed and discussed. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 36a3f1b1-7c9c-48ac-95cc-091f27ad02ed ER - TY - JOUR TI - Modeling of moving heat sources using meshless element free galerkin method AU - Pham, X.-T. AU - Pradinc, G. AU - Cao, X. AU - Fihey, J.-L. T2 - ASM Proceedings of the International Conference: Trends in Welding Research T3 - 9th International Conference on Trends in Welding Research, 4 June 2012 through 8 June 2012, Chicago, IL SN - 9781627089982 SP - 746 EP - 751 KW - Approximants KW - Element free Galerkin methods KW - Essential boundary conditions KW - Gaussian surface KW - Moving heat sources KW - Moving least squares KW - Rosenthal equation KW - Two dimensional model KW - Finite element method KW - Lagrange multipliers KW - Two dimensional KW - Welding KW - Heat conduction AB - This article deals with the quasi stationary-state solution of the two-dimensional Rosenthal equation for a moving heat source using a meshless element free Galerkin method. Node-based moving least square approximants are used to approximate the unknown function of temperature. Essential boundary conditions are enforced by using Lagrange multipliers. The results are obtained for a two-dimensional model with a Gaussian surface moving heat source and compared with the results of the finite-element method. Copyright © 2013 ASM International® All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 96bfebb4-668a-4388-9d41-27aac95cf857 ER - TY - JOUR TI - À la recherche du temps perdu: Extracting temporal relations from medical text in the 2012 i2b2 NLP challenge DO - 10.1136/amiajnl-2013-001624 AU - Cherry, C. AU - Zhu, X. AU - Martin, J. AU - de Bruijn, B. T2 - Journal of the American Medical Informatics Association SN - 1067-5027 VL - 20 IS - 5 SP - 843 EP - 848 KW - accuracy KW - article KW - data extraction KW - hospital discharge KW - human KW - machine learning KW - medical record KW - medical specialist KW - prediction KW - semantics KW - temporal analysis KW - time AB - Objective: An analysis of the timing of events is critical for a deeper understanding of the course of events within a patient record. The 2012 i2b2 NLP challenge focused on the extraction of temporal relationships between concepts within textual hospital discharge summaries. Materials and methods: The team from the National Research Council Canada (NRC) submitted three system runs to the second track of the challenge: typifying the time-relationship between pre-annotated entities. The NRC system was designed around four specialist modules containing statistical machine learning classifiers. Each specialist targeted distinct sets of relationships: local relationships, 'sectime'-type relationships, non-local overlap-type relationships, and non-local causal relationships. Results: The best NRC submission achieved a precision of 0.7499, a recall of 0.6431, and an F1 score of 0.6924, resulting in a statistical tie for first place. Post hoc improvements led to a precision of 0.7537, a recall of 0.6455, and an F1 score of 0.6954, giving the highest scores reported on this task to date. Discussion and conclusions: Methods for general relation extraction extended well to temporal relations, and gave top-ranked state-of-the-art results. Careful ordering of predictions within result sets proved critical to this success. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 66d4cef1-3ef2-475a-8142-f8f91780771a ER - TY - JOUR TI - Effects of scalloping on the mixing mechanisms of forced mixers with highly swirling core flow DO - 10.1115/1.4024043 AU - Wright, A. AU - Lei, Z. AU - Mahallati, A. AU - Cunningham, M. AU - Militzer, J. T2 - Journal of Engineering for Gas Turbines and Power SN - 0742-4795 VL - 135 IS - 7 SP - 71202 KW - Computational investigation KW - Mixing mechanisms KW - Pressure loss KW - Reduced pressure KW - Reynolds-Averaged Navier-Stokes KW - Separation bubble KW - Suction surfaces KW - Swirl angles KW - Computer simulation KW - Mixing KW - Molluscs KW - Navier Stokes equations KW - Vortex flow KW - Mixers (machinery) AB - This paper presents a detailed experimental and computational investigation of the effects of scalloping on the mixing mechanisms of a scaled 12-lobe turbofan mixer. Scalloping was achieved by eliminating approximately 70% of the lobe sidewall area. Measurements were made downstream of the mixer in a co-annular wind tunnel, and the simulations were carried out using an unstructured Reynolds averaged Navier-Stokes (RANS) solver, Numeca FINE/Hexa, with k-Ω SST model. In the core flow, the swirl angle was varied from 0 deg to 30 deg. At high swirl angles, a three-dimensional separation bubble was formed on the lobe's suction surface penetration region and resulted in the generation of a vortex at the lobe valley. The valley vortex quickly dissipated downstream. The mixer lobes removed most of the swirl, but scalloped lobes removed less swirl in the region of the scalloped notch. The residual swirl downstream of the scalloped mixer interacted with the vortices and improved mixing rates compared to the unscalloped mixer. Core flow swirl up to 10 deg provided improved mixing rates and reduced pressure and thrust losses for both mixers. As core flow swirl increased beyond 10 deg, the mixing rate continued to improve, but pressure and thrust losses declined compared to the zero swirl case. Lobe scalloping, in high swirl conditions, resulted in better mixing and improved pressure loss over the unscalloped mixer but at the expense of reduced thrust. Copyright © 2013 by ASME. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a2f34d67-ec0d-4aed-9136-6bdcf36b35d8 ER - TY - JOUR TI - Characterization of hospital-associated lineages of ampicillin-resistant Enterococcus faecium from clinical cases in dogs and humans DO - 10.3389/fmicb.2013.00245 AU - Tremblay, C.-L. AU - Charlebois, A. AU - Masson, L. AU - Archambault, M. T2 - Frontiers in Microbiology SN - 1664-302X VL - 4 IS - AUG SP - Article 245 AB - Ampicillin-resistant Enterococcus faecium (ARE) has rapidly emerged worldwide and is one of the most important pathogens. However, very few reports are available on ARE isolates from canine clinical cases. The objective characterize ARE strains of canine clinical origin from a veterinary teaching hospital in Canada and to compare strains. Ten ARE strains from dogs and humans were characterized by multilocus sequence typing (MLST), electrophoresis (PFGE), antibiotic susceptibility and biofilm activities, presence of rep-families, CRISPR genes. All ARE strains (n = 10) were resistant to ciprofloxacin and lincomycin. Resistances to tetracycline and to high concentrations of gentamicin, kanamycin and streptomycin (n = 5) were also observed. Canine be susceptible to vancomycin whereas resistance to this antibiotic was observed in human strains. PBP5 showing mutations at 25 amino acid positions. Fluoroquinolone resistance was attributable to ParC, Data demonstrated that all canine ARE were acm (collagen binding protein)-positive and that most harbored encoding for a cell wall adhesin. Biofilm formation was observed in two human strains but not in canine strains. families were observed per strain but no CRISPR sequences were found. A total of six STs (1, 18, 65, 202, 205, with one belonging to a new ST (ST803). These STs were identical or closely related to human hospital report describes for the first time the characterization of canine ARE hospital-associated strains in Canada importance of prudent antibiotic use in veterinary medicine to avoid zoonotic spread of canine ARE. © 2013 Tremblay, Charlebois, Masson and Archambault. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9d5869ef-3d4c-4634-b529-e089e99985d0 ER - TY - JOUR TI - Integrating logistical and technical criteria into a multiteam, competitive watershed model ranking procedure DO - 10.1061/(ASCE)HE.1943-5584.0000670 AU - Cunderlik, J.M. AU - Fleming, S.W. AU - Jenkinson, R.W. AU - Thiemann, M. AU - Kouwen, N. AU - Quick, M. T2 - Journal of Hydrologic Engineering SN - 1084-0699 VL - 18 IS - 6 SP - 641 EP - 654 KW - British Columbia KW - Canada KW - Forecasting system KW - Model comparison KW - Model performance KW - Performance rankings KW - UBCWM KW - Watershed models KW - WATFLOOD KW - Forecasting KW - Human resource management KW - Logistics KW - Project management KW - Watersheds KW - Computer simulation KW - forecasting method KW - hydrological modeling KW - ranking KW - watershed KW - British Columbia KW - Canada AB - A systematic and holistic watershed model comparison and selection process, integrating a full range of relevant criteria, is illustrated here. The process consists of screening for a set of candidate models on the basis of prerequisite model attributes; assessing hydrologic simulation performance using various conventional statistical metrics; assessing operational logistics performance, reflecting somewhat subjective but centrally important issues around relative feasibility and suitability of candidate models in the intended context of use; and integrating the hydrologic and operational performance results, which are each evaluated using a weighted-matrix approach, into a single coherent and comprehensive ranking system. The process was applied to evaluation of watershed models for operational hydroelectric inflow forecasting in British Columbia, Canada. An important feature of the study was its horse-race project management approach, involving a supervised competition between expert teams using different models but the same data sets. Four models passed the prescreening phase, and these were evaluated for three test basins representing contrasting geophysical regimes. The model selection process presented here is believed to be potentially very broadly useful. © 2013 American Society of Civil Engineers. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3a859845-1cae-47bd-9403-b1c5f06bb2f1 ER - TY - JOUR TI - Redox-gated three-terminal organic memory devices: Effect of composition and environment on performance DO - 10.1021/am4032828 AU - Das, B.C. AU - Pillai, R.G. AU - Wu, Y. AU - Mccreery, R.L. T2 - ACS Applied Materials and Interfaces SN - 1944-8244 VL - 5 IS - 21 SP - 11052 EP - 11058 KW - Conductance switching KW - Multi-state memory KW - Non-volatile memory KW - Resistive memory KW - Solid-state redox reactions KW - Conducting polymers KW - Electrolytes KW - Field effect transistors KW - Nonvolatile storage KW - Redox reactions KW - Vapors KW - Ions AB - The performance of redox-gated organic nonvolatile memory (NVM) based on conducting polymers was investigated by altering the polymer structure, composition, and local environment of three-terminal devices with a field-effect transistor (FET) geometry. The memory function was dependent on the presence of a redox active polymer with high conducting and low conducting states, the presence of a redox counter-reaction, and the ability to transport ions between the polymer and electrolyte phases. Simultaneous monitoring of both the "write" current and "readout" current revealed the switching dynamics of the devices and their dependence on the local atmosphere. Much faster and more durable response was observed in acetonitrile vapor than in a vacuum, indicating the importance of polar molecules for both ion motion and promotion of electrochemical reactions. The major factor determining "write" and "erase" speeds of redox-gated polymer memory devices was determined to be the rate of ion transport through the electrolyte layer to provide charge compensation for the conducting polarons in the active polymer layer. The results both confirm the mechanism of redox-gated memory action and identify the requirements of the conducting polymer, redox counter reaction, and electrolyte for practical applications as alternative solid-state nonvolatile memory devices. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 783e5536-4aa6-450a-9bac-514444befd01 ER - TY - JOUR TI - Identification of N-acylethanolamines in Dictyostelium discoideum and confirmation of their hydrolysis by fatty acid amide hydrolase DO - 10.1194/jlr.M032219 AU - Hayes, A.C. AU - Stupak, J. AU - Li, J. AU - Cox, A.D. T2 - Journal of Lipid Research SN - 0022-2275 VL - 54 IS - 2 SP - 457 EP - 466 KW - ethanolamine KW - fatty acid amidase KW - fatty acid amidase inhibitor KW - n acylethanolamine KW - recombinant enzyme KW - unclassified drug KW - article KW - controlled study KW - Dictyostelium discoideum KW - enzyme activity KW - enzyme inhibition KW - hydrolysis KW - in vitro study KW - in vivo study KW - lipid analysis KW - nonhuman KW - nucleotide sequence KW - phylogenetic tree KW - priority journal KW - signal transduction KW - Amidohydrolases KW - Animals KW - Computational Biology KW - Dictyostelium KW - Enzyme Inhibitors KW - Ethanolamines KW - Humans KW - Hydrolysis KW - Kinetics KW - Mice KW - Phylogeny AB - N-acylethanolamines (NAEs) are endogenous lipid-based signaling molecules best known for their role in the endocannabinoid system in mammals, but they are also known to play roles in signaling pathways in plants. The regulation of NAEs in vivo is partly accomplished by the enzyme fatty acid amide hydrolase (FAAH), which hydrolyses NAEs to ethanolamine and their corresponding fatty acid. Inhibition of FAAH has been shown to increase the levels of NAEs in vivo and to produce desirable phenotypes. This has led to the development of pharmaceutical-based therapies for a variety of conditions targeting FAAH. Recently, our group identified a functional FAAH homolog in Dictyostelium discoideum, leading to our hypothesis that D. discoideum also possesses NAEs. In this study, we provide a further characterization of FAAH and identify NAEs in D. discoideum for the first time. We also demonstrate the ability to modulate their levels in vivo through the use of a semispecific FAAH inhibitor and confirm that these NAEs are FAAH substrates through in vitro studies. We believe the demonstration of the in vivo modulation of NAE levels suggests that D. discoideum could be a good simple model organism in which to study NAE-mediated signaling. Copyright © 2013 by the American Society for Biochemistry and Molecular Biology, Inc. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 42653b13-2984-41c9-9a0a-28f087626843 ER - TY - JOUR TI - Morphology and properties of polymer/organoclay nanocomposites based on poly(ethylene terephthalate) and sulfopolyester blends DO - 10.1002/pi.4331 AU - Ghanbari, A. AU - Heuzey, M.-C. AU - Carreau, P.J. AU - Ton-That, M.-T. T2 - Polymer International SN - 0959-8103 VL - 62 IS - 3 SP - 439 EP - 448 KW - Characterization techniques KW - Clay particles KW - Cloisite 30b KW - Crystallinities KW - Dispersed phase KW - Gas barrier KW - Immiscible polymer blends KW - Melt blending KW - Organoclays KW - Oxygen permeability KW - Poly(ethylene terephthalate) (PET) KW - Rheometry KW - Scanning electrons KW - Tactoids KW - Blending KW - Differential scanning calorimetry KW - Dispersions KW - Ionomers KW - Nanocomposite films KW - Organoclay KW - Polyethylene terephthalates KW - Rheology KW - Scanning electron microscopy KW - Transmission electron microscopy KW - X ray diffraction KW - Nanocomposites AB - Poly(ethylene terephthalate) (PET) nanocomposite films containing two different organoclays, Cloisite 30B® (C30B) and Nanomer I.28E® (N28E), were prepared by melt blending. In order to increase the gallery spacing of the clay particles, a sulfopolyester (PET ionomer or PETi) was added to the nanocomposites via a master-batch approach. The morphological, thermal and gas barrier characteristics of the nanocomposite films were studied using several characterization techniques such as scanning electron microscopy, transmission electron microscopy, X-ray diffraction, differential scanning calorimetry, dynamic mechanical analysis, rheometry and oxygen permeability. PET and PETi were found to form immiscible polymer blends and the nanoparticles were preferentially located in the PETi dispersed phase. A better dispersion of clay was obtained for nanocomposites containing N28E with PETi. On the contrary, for nanocomposites containing C30B and PETi, the number of tactoids increased and the clay distribution and dispersion became worse than for C30B alone. Overall, the best properties were obtained for the PET/C30B nanocomposite without PETi. Higher crystallinity was found for all nanocomposite films in comparison to that of neat PET. © 2012 Society of Chemical Industry The effect of a sulfopolyester (poly(ethylene terephthalate) (PET) ionomer or PETi) on the properties of PET/clay nanocomposites was investigated. It was found that nanoclay particles have greater affinity for the PETi phase. © 2012 Society of Chemical Industry. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4b901701-c7fd-47ae-af4b-2266964227f1 ER - TY - JOUR TI - Conversion of bilayers of PS-b-PDMS block copolymer into closely packed, aligned silica nanopatterns DO - 10.1021/nn401968t AU - Wu, N.L.Y. AU - Harris, K.D. AU - Buriak, J.M. T2 - ACS Nano SN - 1936-0851 VL - 7 IS - 6 SP - 5595 EP - 5606 KW - Brush layers KW - Graphoepitaxy KW - Homopolymer blends KW - patterning KW - Solvent annealing KW - Blending KW - Block copolymers KW - Brushes KW - Microchannels KW - Monolayers KW - Plasmas KW - Self assembly KW - Silica KW - Silicones AB - Block copolymer (BCP) self-assembly is an effective and versatile approach for the production of complex nanopatterned interfaces. Monolayers of BCP films can be harnessed to produce a variety of different patterns, including lines, with specific spacings and order. In this work, bilayers of cylinder-forming polystyrene-block-polydimethylsiloxane block copolymer (PS-b-PDMS) were transformed into arrays of silica lines with half the pitch normally attained for conventional monolayers, with the PDMS acting as the source for the SiO x. The primary hurdle was ensuring the bilayer silica lines were distinctly separate; to attain the control necessary to prevent overlap, a number of variables related to the materials and self-assembly process were investigated in detail. Developing a detailed understanding of BCP film swelling during solvent annealing, blending of the PS-b-PDMS with PS homopolymer, utilization of a surface brush layer, and adjustment of the plasma exposure conditions, distinct and separate silica lines were prepared. On the microscale, the sample coverage of PS-b-PDMS bilayers was investigated and maximized to attain >95% bilayers under defined conditions. The bilayer BCP structures were also amenable to graphoepitaxy, and thus, dense and highly ordered arrays of silica line patterns with tightly controlled width and pitch were fabricated and distributed uniformly across a Si surface. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d1cb380a-1610-41db-a2ca-4af0f24e5230 ER - TY - JOUR TI - Influence of the process parameters on the spray pyrolysis technique, on the synthesis of gadolinium doped-ceria thin film DO - 10.1016/j.materresbull.2012.09.073 AU - Halmenschlager, C.M. AU - Neagu, R. AU - Rose, L. AU - Malfatti, C.F. AU - Bergmann, C.P. T2 - Materials Research Bulletin SN - 0025-5408 VL - 48 IS - 2 SP - 207 EP - 213 KW - A. Ceramics KW - Acetylacetonates KW - Ammonium nitrate KW - Annealing temperatures KW - Carbitol KW - Defect-free KW - Dense films KW - Doped-ceria KW - Electrochemical interface KW - Gadolinia doped ceria KW - Gas separation membrane KW - Heated substrates KW - Heating regimes KW - High thermal KW - Material deposition KW - Mono-crystals KW - Porous substrates KW - Postdeposition heat treatment KW - Precursor solutions KW - Process parameters KW - Secondary electron microscopy KW - Solvent composition KW - Spray-pyrolysis techniques KW - Ammonium compounds KW - Cerium KW - Cerium compounds KW - Coatings KW - Defects KW - Deposits KW - Electron microscopy KW - Ethanol KW - Gadolinium KW - Heat treatment KW - Phase interfaces KW - Porous silicon KW - Silica KW - Silicon wafers KW - Spray pyrolysis KW - Substrates KW - Surface properties KW - Thin films KW - Vapor deposition KW - Gas permeable membranes AB - This work presents the results of a process of optimization applied to gadolinia-doped ceria (Ce0.8Gd0.2O1.9-x, or CGO) thin films, deposited by spray pyrolysis (SP). Spray pyrolysis is a high thermal deposition method that combines material deposition and heat treatment. This combination is advantageous since the post-deposition heat treatment step is not necessary. However, stresses are solidified in the coating during the deposition, which may lead to the initiation of a crack in the coating. The aim of this work was to achieve thin, dense, and continuous CGO coatings, which may be used as gas separation membranes and as a solid state electrochemical interfaces. Dense, flat, low-defect substrates such as silica slides, silicon mono crystal wafers, and porous substrates were used as substrates in this work. Cerium ammonium nitrate and gadolinium acetylacetonate were dissolved in ethanol and butyl carbitol to form a precursor solution that was sprayed on the heated substrates. Process parameters such as solvent composition, deposition rate and different heating regimes were analyzed. The microstructure was analyzed by secondary electron microscopy (SEM) and was found that thin, dense, and defect-free films could be produced on dense and porous substrates. The results obtained show that it is possible to obtain a CGO dense film deposited by spray pyrolysis. X-ray diffraction (XRD) analysis showed that the films were crystalline after the deposition without requiring post-deposition heat treatment. The crystallite size does not vary significantly as a function of the annealing temperature. © 2012 Elsevier Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 55a451dd-2fc2-4d67-915d-66566bd1814f ER - TY - JOUR TI - Reactions of the phthalimide N-oxyl radical (PINO) with activated phenols: The contribution of π-stacking interactions to hydrogen atom transfer rates DO - 10.1021/jo302483s AU - D'Alfonso, C. AU - Bietti, M. AU - Dilabio, G.A. AU - Lanzalunga, O. AU - Salamone, M. T2 - Journal of Organic Chemistry SN - 0022-3263 VL - 78 IS - 3 SP - 1026 EP - 1037 KW - 2 ,4 ,6-trimethylphenol KW - Aromatic rings KW - Degree of Charge Transfer KW - Deuterium kinetic isotope effect KW - Hammett correlation KW - Hydrogen transfer KW - Hydrogen-atom transfer KW - Laser flash photolysis KW - Marcus cross-relations KW - N-oxyl radicals KW - Phenolic antioxidant KW - Phthalimide KW - Radical scavenging KW - Solvent effects KW - Stacking interaction KW - Theoretical calculations KW - Charge transfer KW - Deuterium KW - Free radical reactions KW - Hydrogen KW - Kinetics KW - Rate constants KW - Phenols KW - 2,2,5,7,8 pentamethylchroman 6 ol derivative KW - 2,6 di tert butyl 4 substituted phenol derivative KW - 2,6-dimethylphenol derivative KW - antioxidant KW - deuterium KW - hydrogen KW - phenol derivative KW - phthalimide derivative KW - phthalimide n oxyl radical KW - radical KW - scavenger KW - unclassified drug KW - article KW - chemical interaction KW - chemical structure KW - photolysis KW - transport kinetics AB - The kinetics of reactions of the phthalimide N-oxyl radical (PINO) with a series of activated phenols (2,2,5,7,8-pentamethylchroman-6-ol (PMC), 2,6-dimethyl- and 2,6-di-tert-butyl-4-substituted phenols) were investigated by laser flash photolysis in CH3CN and PhCl in order to establish if the reactions with PINO can provide a useful tool for evaluating the radical scavenging ability of phenolic antioxidants. On the basis of the small values of deuterium kinetic isotope effects, the relatively high and negative ρ values in the Hammett correlations and the results of theoretical calculations, we suggest that these reactions proceed by a hydrogen atom transfer (HAT) mechanism having a significant degree of charge transfer resulting from a π-stacked conformation between PINO and the aromatic ring of the phenols. Kinetic solvent effects were analyzed in detail for the hydrogen transfer from 2,4,6-trimethylphenol to PINO and the data obtained are in accordance with the Snelgrove-Ingold equation for HAT. Experimental rate constants for the reactions of PINO with activated phenols are in accordance with those predicted by applying the Marcus cross relation. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2be74efe-8693-4e05-a8cf-7aded57725ab ER - TY - JOUR TI - Numerical and experimental study of tube hydroforming for aerospace applications DO - 10.4028/www.scientific.net/KEM.554-557.1779 AU - Mojarad Farimani, S. AU - Champliaud, H. AU - Gholipour, J. AU - Savoie, J. AU - Wanjara, P. T2 - Key Engineering Materials T3 - 16th ESAFORM Conference on Material Forming, ESAFORM 2013, 22 April 2013 through 24 April 2013, Aveiro SN - 1013-9826 SN - 9783037857199 VL - 554-557 SP - 1779 EP - 1786 KW - Aerospace alloys KW - Data acquisition system KW - Deformation measurements KW - Finite element simulations KW - Friction conditions KW - Numerical and experimental study KW - Thickness variation KW - Tube hydroforming KW - Aerospace applications KW - Experiments KW - Finite element method KW - Strain KW - Tubes (components) KW - Loading AB - In the tube hydroforming (THF) process, a pressurized fluid is used to expand a thin walled tube inside a closed die in order to fill the die cavity. THF has many advantages that render this process interesting for different industries such as automotive and aerospace. In this work, to investigate the effect of different process parameters, such as the friction condition, tube thickness and end-feeding on the final product, THF experiments were performed on stainless steel 321 (SS 321) tubes using a round-to-square die. Experimental loading paths were obtained via the data acquisition system of the hydroforming press, which is fully instrumented. An automated deformation measurement system, Argus®, was used to measure the strains on the hydroformed tubes. The THF process was simulated using Ls-Dyna software. The variation in the strain and thickness measured from the experiments were compared to the simulation results at critical sections. Comparison of the results from the finite element (FE) simulations and experiments showed good agreement, indicating that the approach can be used for predicting the final shape and thickness variations of the hydroformed parts for more complex shapes in aerospace applications. Copyright © 2013 Trans Tech Publications Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8e5af5ea-0744-492f-9378-11c3c9786e79 ER - TY - JOUR TI - Diffuse surface calibration method to improve accuracy and dynamic range of aerosol elastic light scattering measurements DO - 10.1007/s00340-013-5357-x AU - Crosland, B.M. AU - Johnson, M.R. AU - Thomson, K.A. T2 - Applied Physics B: Lasers and Optics SN - 0946-2171 SP - 1 EP - 6 AB - A new method to calibrate detectors for elastic light scattering (ELS) measurement based on diffuse scattering from a Lambertian surface is presented. The method produces a calibration signal that is approximately seven orders of magnitude larger than a propane gas Rayleigh scattering calibration. The method also allows for calibration of detectors such as photodiodes, which are not sensitive enough to detect Rayleigh scattering for calibration but possess characteristics desirable for the measurement of soot ELS. Since the method is only suitable for backward scattering calibrations, transfer of calibration data from a backward- to a forward-oriented detector is accomplished with a secondary laser and integrating sphere. In demonstration experiments, calibration constants for photomultiplier tube (PMT) detectors obtained using both Rayleigh scattering and diffuse surface scattering agreed within experimental uncertainties as did measurements of in-flame scattering coefficients obtained with PMTs and photodiodes. However, achievable uncertainties with the diffuse-surface calibration approach were significantly reduced. More importantly, by enabling the use of photodiode detectors in ELS measurements, the new method facilitates operation at higher photon fluxes resulting in improved signal-to-noise ratios, reduced influence of photon shot noise, and the ability to achieve higher dynamic range in transient measurements. © 2013 Her Majesty the Queen in Right of Canada. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3aa3eebd-6966-4523-987b-cf0d1a7aaba5 ER - TY - JOUR TI - Texture analysis of optical coherence tomography speckle for characterizing biological tissues in vivo DO - 10.1364/OL.38.001280 AU - Lindenmaier, A.A. AU - Conroy, L. AU - Farhat, G. AU - DaCosta, R.S. AU - Flueraru, C. AU - Vitkin, I.A. T2 - Optics Letters SN - 0146-9592 VL - 38 IS - 8 SP - 1280 EP - 1282 KW - Cervical cancers KW - Characterizing biological tissues KW - Early cancer detection KW - Gamma distribution function KW - Intrinsic textures KW - Speckle intensity KW - Texture analysis KW - Tissue pathology KW - Histology KW - Speckle KW - Textures KW - Tumors KW - Optical tomography KW - animal KW - article KW - cell transformation KW - female KW - human KW - methodology KW - mouse KW - optical coherence tomography KW - pathology KW - tumor cell line KW - uterine cervix tumor KW - Animals KW - Cell Line, Tumor KW - Cell Transformation, Neoplastic KW - Female KW - Humans KW - Mice KW - Tomography, Optical Coherence KW - Uterine Cervical Neoplasms AB - We demonstrate a method for differentiating tissue disease states using the intrinsic texture properties of speckle in optical coherence tomography (OCT) images of normal and tumor tissues obtained in vivo. This approach fits a gamma distribution function to the nonlog-compressed OCT image intensities, thus allowing differentiation of normal and tumor tissues in an ME-180 human cervical cancer mouse xenograft model. Quantitative speckle intensity distribution analysis thus shows promise for identifying tissue pathologies, with potential for early cancer detection in vivo. © 2013 Optical Society of America. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1a279aed-726c-47ae-9e0a-d316a69a25ff ER - TY - JOUR TI - Effect of cooling rate on iron-rich intermetallic phases in 206 cast alloys AU - Liu, K. AU - Cao, X. AU - Chen, X.-G. T2 - TMS Light Metals T3 - Light Metals 2012 - TMS 2013 Annual Meeting and Exhibition, 3 March 2013 through 7 March 2013, San Antonio, TX SN - 0147-0809 SN - 9781118605721 IS - Light Metals 2013 - At the TMS 2013 Annual Meeting and Exhibition SP - 311 EP - 316 KW - Cast alloys KW - Cooling rates KW - Critical cooling rate KW - Differential scanning calorimeters KW - Intermetallic phase KW - Intermetallic phasis KW - Solidification characteristics KW - Temperature increase KW - Aluminum KW - Cast iron KW - Cerium alloys KW - Cooling KW - Copper alloys KW - Differential scanning calorimetry KW - Exhibitions KW - Iron KW - Iron alloys KW - Platelets KW - Scanning electron microscopy KW - Solidification KW - Thermoanalysis KW - Intermetallics AB - The effect of cooling rate on the solidification characteristics of the iron-rich intermetallics in 206 cast alloys with iron contents up to 0.5 wt% was investigated. The iron-rich intermetallics were analyzed and characterized by using Scanning Electron Microscopy (SEM), Differential Scanning Calorimeter (DSC) and Thermal Analysis (TA). It was found that Chinese script α-Fe and platelet β-Fe phases are the two main iron-rich intermetallics up to 0.3 wt% Fe. With increasing cooling rate, the precipitate temperature increases for α-Fe but decreases for β-Fe and eventually the formation of the β-Fe will be completely suppressed. At 0.5 wt% Fe, two extra iron-rich intermetallics, Chinese script Alm(FeMn) and platelet Al 3(FeMn) are experimentally observed. With increasing cooling rate, the Al3(FeMn) or Al6(FeMn) phases that precipitated at relatively low cooling rate can be replaced by Alm(FeMn) and α-Fe. The critical cooling rate to effectively suppress the formation of the platelet β-Fe and obtain dominant Chinese script α-Fe or Al m(FeMn) decreases with increasing iron level. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : deb13959-7172-4cef-b14b-1bfcbf28207f ER - TY - JOUR TI - Reporting performance in organic photovoltaic devices DO - 10.1021/nn402883g AU - Luber, E.J. AU - Buriak, J.M. T2 - ACS Nano SN - 1936-0851 VL - 7 IS - 6 SP - 4708 EP - 4714 KW - Experimental procedure KW - Hole transport layers KW - Inorganic semiconductors KW - Organic photovoltaic devices KW - Organic photovoltaics KW - Power conversion efficiencies KW - Statistical significance KW - Statistical treatment KW - Heterojunctions KW - Research AB - Research into organic photovoltaics (OPVs) is rapidly growing worldwide because it offers a route to low temperature, inexpensive processing of lightweight, flexible solar cells that can be mass manufactured cheaply. Unlike silicon or other inorganic semiconductors (e.g., CdTe, CIGs), OPVs are complicated by the requirement of having multiple materials and layers that must be integrated to enable the cell to function. The enormous number of research hours required to optimize all aspects of OPVs and to integrate them successfully is typically boiled down to one number-the power conversion efficiency (PCE) of the device. The PCE is the value by which comparisons are routinely made when modifications are made to devices; new bulk heterojunction materials, electron- and hole-transport layers, electrodes, plasmonic additives, and many other new advances are incorporated into OPV devices and compared with one, or a series of, control device(s). The concern relates to the statistical significance of this all-important efficiency/PCE value: is the observed change or improvement in performance truly greater than experimental error? If it is not, then the field can and will be misled by improper reporting of efficiencies, and future research in OPVs could be frustrated and, ultimately, irreversibly damaged. In this Perspective, the dangers of, for instance, cherry-picking of data and poor descriptions of experimental procedures, are outlined, followed by a discussion of a real data set of OPV devices, and how a simple and easy statistical treatment can help to distinguish between results that are indistinguishable experimentally, and those that do appear to be different. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 07757cfa-0103-4fbb-98eb-7ab6c6be783e ER - TY - JOUR TI - Commercial considerations for immunoproteomics DO - 10.1007/978-1-62703-589-7_22 AU - Ferguson, S.M. T2 - Methods in Molecular Biology SN - 1064-3745 SN - 9781627035880 VL - 1061 SP - 361 EP - 367 KW - article KW - commercial phenomena KW - immunoproteomics KW - outcome assessment KW - priority journal KW - proteomics KW - technology AB - The underlying drivers of scientific processes have been rapidly evolving, but the ever-present need for research funding is typically foremost amongst these. Successful laboratories are embracing this reality by making certain that their projects have commercial value right from the beginning of the project conception. Which factors to be considered for commercial success need to be well thought out and incorporated into a project plan with similar levels of detail as would be the technical elements. Specific examples of commercial outcomes in the field of Immunoproteomics are exemplified in this discussion. © 2013 Springer Science+Business Media, LLC. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3c32d666-e6b6-449e-9006-6cf3b3e4ab2a ER - TY - JOUR TI - Nuciferine prevents hepatic steatosis and injury induced by a high-fat diet in hamsters DO - 10.1371/journal.pone.0063770 AU - Guo, F. AU - Yang, X. AU - Li, X. AU - Feng, R. AU - Guan, C. AU - Wang, Y. AU - Li, Y. AU - Sun, C. T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 5 SP - e63770 KW - aporphine derivative KW - cholesterol KW - cytochrome P450 2E1 KW - fatty acid KW - high density lipoprotein cholesterol KW - low density lipoprotein cholesterol KW - nuciferine KW - triacylglycerol KW - tumor necrosis factor alpha KW - unclassified drug KW - very low density lipoprotein KW - adipose tissue KW - animal experiment KW - animal model KW - animal tissue KW - article KW - body weight KW - caloric intake KW - controlled study KW - down regulation KW - drug effect KW - dyslipidemia KW - fatty liver KW - food intake KW - gene expression KW - hamster KW - lipid diet KW - lipogenesis KW - lipolysis KW - liver injury KW - liver weight KW - male KW - metabolic syndrome X KW - nonhuman KW - protein secretion KW - reverse transcription polymerase chain reaction KW - supplementation KW - upregulation KW - Western blotting AB - Background:Nuciferine is a major active aporphine alkaloid from the leaves of N. nucifera Gaertn that possesses anti-hyperlipidemia, anti-hypotensive, anti-arrhythmic, and insulin secretagogue activities. However, it is currently unknown whether nuciferine can benefit hepatic lipid metabolism.Methodology/Principal Findings:In the current study, male golden hamsters were randomly divided into four groups fed a normal diet, a high-fat diet (HFD), or a HFD supplemented with nuciferine (10 and 15 mg/kg·BW/day). After 8 weeks of intervention, HFD-induced increases in liver and visceral adipose tissue weight, dyslipidemia, liver steatosis, and mild necroinflammation in hamsters were analyzed. Nuciferine supplementation protected against HFD-induced changes, alleviated necroinflammation, and reversed serum markers of metabolic syndrome in hamsters fed a HFD. RT-PCR and western blot analyses revealed that hamsters fed a HFD had up-regulated levels of genes related to lipogenesis, increased free fatty acid infiltration, and down-regulated genes involved in lipolysis and very low density lipoprotein secretion. In addition, gene expression of cytochrome P4502E1 and tumor necrosis factor-α were also increased in the HFD group. Nuciferine supplementation clearly suppressed HFD-induced alterations in the expression of genes involved in lipid metabolism.Conclusions/Significance:Nuciferine supplementation ameliorated HFD-induced dyslipidemia as well as liver steatosis and injury. The beneficial effects of nuciferine were associated with altered expression of hepatic genes involved in lipid metabolism. © 2013 Guo et al. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 846ebc09-ebdf-45e5-b512-d5f06b2408d2 ER - TY - JOUR TI - The rich globular cluster system of Abell 1689 and the radial dependence of the globular cluster formation efficiency DO - 10.1088/0004-637X/775/1/20 AU - Alamo-Martínez, K.A. AU - Blakeslee, J.P. AU - Jee, M.J. AU - Côté, P. AU - Ferrarese, L. AU - González-Lópezlira, R.A. AU - Jordán, A. AU - Meurer, G.R. AU - Peng, E.W. AU - West, M.J. T2 - The Astrophysical Journal SN - 0004-637X VL - 775 IS - 1 SP - 20 AB - We study the rich globular cluster (GC) system in the center of the massive cluster of galaxies Abell 1689 (z = 0.18), one of the most powerful gravitational lenses known. With 28 Hubble Space Telescope/Advanced Camera for Surveys orbits in the F814W bandpass, we reach a magnitude I 814 = 29 with ≳90% completeness and sample the brightest ∼5% of the GC system. Assuming the well-known Gaussian form of the GC luminosity function (GCLF), we estimate a total population of GCs within a projected radius of 400 kpc. As many as half of the GCs may comprise an intracluster component. Even with the sizable uncertainties, which mainly result from the uncertain GCLF parameters, this system is by far the largest GC population studied to date. The specific frequency SN is high, but not uncommon for central galaxies in massive clusters, rising from SN ≈ 5 near the center to ∼12 at large radii. Passive galaxy fading would increase SN by ∼20% at z = 0. We construct the radial mass profiles of the GCs, stars, intracluster gas, and lensing-derived total mass, and we compare the mass fractions as a function of radius. The estimated mass in GCs, = 3.9 × 1010 Mȯ, is comparable to ∼80% of the total stellar mass of the Milky Way. The shape of the GC mass profile appears intermediate between those of the stellar light and total cluster mass. Despite the extreme nature of this system, the ratios of the GC mass to the baryonic and total masses, and thus the GC formation efficiency, are typical of those in other rich clusters when comparing at the same physical radii. The GC formation efficiency is not constant, but varies with radius, in a manner that appears similar for different clusters; we speculate on the reasons for this similarity in profile. © 2013. The American Astronomical Society. All rights reserved.. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d1e3d55d-63f2-4db8-bbea-e22a3a967f2c ER - TY - JOUR TI - A comparison of microstructural strengthening for thermal creep and radiation damage resistance of titanium aluminide alloys DO - 10.1016/j.jnucmat.2013.03.020 AU - Zhu, H. AU - Wei, T. AU - Carr, D. AU - Harrison, R. AU - Edwards, L. AU - Seo, D. AU - Maruyama, K. T2 - Journal of Nuclear Materials SN - 0022-3115 VL - 438 IS - 1-Mar SP - 190 EP - 192 DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : fed01760-82e1-428e-8add-c7debd33d3e3 ER - TY - JOUR TI - Toward a mechanistic understanding of ionic self-complementary peptide self-assembly: Role of water molecules and ions DO - 10.1021/bm401077b AU - Kabiri, M. AU - Bushnak, I. AU - McDermot, M.T. AU - Unsworth, L.D. T2 - Biomacromolecules SN - 1525-7797 VL - 14 IS - 11 SP - 3943 EP - 3950 AB - Ionic self-complementary peptides are considered an important class of self-assembling peptides. In particular, RADARADARADARADA (RADA4) is well-known to form a relatively regular nanofiber structure that has been primarily studied in terms of its physicochemical properties, as related to its biomedical applications. However, the molecular level interactions that are involved in promoting the self-assembly of this peptide into nanofibers have not been fully elucidated. Herein, a thermodynamic analysis of the influences of peptide chemistry upon self-assembly is discussed for RADA4, RADA4-K5, and RADA4-S5. The regular nanofiber structure of the assembled peptides makes it a good candidate for isothermal titration calorimetry (ITC) studies for determining the propensity for self-assembly, the critical assembly concentration (CAC), and the role hydration and ion content play in the assembly of these peptides. First, solutions containing only RADA4-K5 did not self-assemble; illustrating even slight alterations in the asymmetric terminal amino acid chemistry affects assembly. The CAC of the remaining self-assembling peptides was between ∼0.1 and ∼0.15 mM. Interestingly, we found that self-assembly was entropically driven with hydrophobic forces being the main driving force for RADA4 and hydrogen bonding for RADA 4-S5. The role of water molecules and counterions in self-assembly was also highlighted: assembly of RADA4 led to desolvation of interfacial surfaces, whereas the net number of water molecules in the assembled complex increased upon RADA4-S5 self-assembly. Moreover, it was found that counterions did not seem to contribute significantly to self-assembly: a result in contrast to current concepts regarding the role of electrostatic interactions in self-assembly of RADA4-like peptides. A molecular level understanding of peptide self-assembly will allow for further engineering of peptides for a vast array of biomedical applications. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9b0befe3-e223-48ba-9208-e43977aafe1a ER - TY - JOUR TI - Immunoproteomics: Current technology and applications DO - 10.1007/978-1-62703-589-7_2 AU - Fulton, K.M. AU - Twine, S.M. T2 - Methods in Molecular Biology SN - 1064-3745 SN - 9781627035880 VL - 1061 SP - 21 EP - 57 KW - antigen KW - biological marker KW - cytokine KW - epitope KW - proteome KW - adaptive immunity KW - antigen antibody complex KW - antigen presenting cell KW - article KW - B lymphocyte KW - binding affinity KW - bioinformatics KW - cell surface KW - cytokine release KW - enzyme linked immunosorbent assay KW - human KW - humoral immunity KW - immune response KW - immunogenicity KW - immunoproteomics KW - major histocompatibility complex KW - matrix assisted laser desorption ionization time of flight mass spectrometry KW - nonhuman KW - peptide synthesis KW - polymerase chain reaction KW - priority journal KW - protein analysis KW - protein expression KW - protein processing KW - proteomics KW - T lymphocyte AB - The varied landscape of the adaptive immune response is determined by the peptides presented by immune cells, derived from viral or microbial pathogens or cancerous cells. The study of immune biomarkers or antigens is not new and classical methods such as agglutination, enzyme-linked immunosorbent assay, or Western blotting have been used for many years to study the immune response to vaccination or disease. However, in many of these traditional techniques, protein or peptide identification has often been the bottleneck. Recent advances in genomics and proteomics, has led to many of the rapid advances in proteomics approaches. Immunoproteomics describes a rapidly growing collection of approaches that have the common goal of identifying and measuring antigenic peptides or proteins. This includes gel based, array based, mass spectrometry, DNA based, or in silico approaches. Immunoproteomics is yielding an understanding of disease and disease progression, vaccine candidates, and biomarkers. This review gives an overview of immunoproteomics and closely related technologies that are used to define the full set of antigens targeted by the immune system during disease. © 2013 Springer Science+Business Media, LLC. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 83960f9c-4866-48c7-9188-e15dacb27b90 ER - TY - JOUR TI - Identity verification based on handwritten signatures with haptic information using genetic programming DO - 10.1145/2457450.2457453 AU - Alsulaiman, Fawaz A. AU - Sakr, Nizar AU - Valdes, Julio J. AU - El Saddik, Abdulmotaleb T2 - ACM Transactions on Multimedia Computing, Communications and Applications SN - 1551-6857 VL - 9 IS - 2 SP - 11 KW - Haptics; Biometrics; Genetic Programming; user verification; classification AB - In this article, haptic-based handwritten signature verification using Genetic Programming (GP) classification is presented. A comparison of GP-based classification with classical classifiers including support vector machine, k-nearest neighbors, naive Bayes, and random forest is conducted. In addition, the use of GP in discovering small knowledge-preserving subsets of features in high-dimensional datasets of haptic-based signatures is investigated and several approaches are explored. Subsets of features extracted from GP-generated models (analytic functions) are also exploited to determine the importance and relevance of different haptic data types (e.g., force, position, torque, and orientation) in user identity verification. The results revealed that GP classifiers compare favorably with the classical methods and use a much fewer number of attributes (with simple function sets). DA - 2013/05/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1451a431-40fb-496b-9d33-982b0b47a0cc ER - TY - JOUR TI - Hypocholesterolemic and hypotensive effects of a fruit-based functional beverage in spontaneously hypertensive rats fed with cholesterol-rich diet DO - 10.1016/j.jff.2013.05.007 AU - Gunathilake, K.D.P.P. AU - Wang, Y. AU - Rupasinghe, H.P.V. T2 - Journal of Functional Foods SN - 1756-4646 VL - 5 IS - 3 SP - 1392 EP - 1401 KW - Rattus AB - This study was designed to evaluate a polyphenols-rich fruit-based functional beverage on blood pressure, serum and liver lipid profiles in vivo. Sixty spontaneously hypertensive rats were divided into five groups and were fed with a AIN-93G-diet as the normal control (NC), high cholesterol diet as atherogenic control (AC), and the AC diet with three different beverage dosages (0.5. X, 1. X, 2. X), where X is the equivalence of two portion sizes for an adult (X = 10. mL/kg. BW/day) after dose translation. Blood pressure was measured during weeks 2 and 4 using a tail-cuff method. Systolic blood pressures were lowered by the beverage at the supplementation of 1. X/2. X after 2. week but not after 4. week. The oral administration of the beverage at 1. X/2. X significantly lowered liver cholesterol and total and non-HDL-cholesterol levels in the serum. Thus, the newly formulated beverage possessed hypolipidaemic effects while showing inconsistent effect in lowering the blood pressure. © 2013 The Authors. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e3955531-08fa-493f-9990-c1020d8fe56f ER - TY - JOUR TI - Correlated turbulence modelling: An advancing Fourier series method DO - 10.1016/j.jweia.2013.08.012 AU - Wall, A.S. AU - Zan, S.J. AU - Langlois, R.G. AU - Afagh, F.F. T2 - Journal of Wind Engineering and Industrial Aerodynamics SN - 0167-6105 VL - 123 SP - 155 EP - 162 KW - Aeroelastic phenomenon KW - Auto-spectra KW - Correlated flow KW - Correlations KW - Cross spectra KW - Fourier components KW - Fourier series method KW - Frequency domains KW - Flow fields KW - Fourier series KW - Time domain analysis AB - The simulation of correlated non-uniform flowfields in the time domain is required for the study of many time-dependent aeroelastic phenomena. A novel method for achieving representative spatially- and temporally-correlated flow simulation for a moving point in space, such as a point on a helicopter rotor, is discussed herein. This method uses the Fourier series to take frequency-domain information and from it reconstructs a time-domain velocity signal. It differs, however, from the traditional application in that the coefficients and phase angles for the Fourier components are modified at each time step to accommodate changing flowfield characteristics and achieve the correct correlations between one point in space and the next. This method is named the advancing Fourier series method. This paper covers the specifics of the method, including its advantages and disadvantages relative to other correlated flow modelling techniques. © 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3550ef99-6edc-4fa8-a299-f53342623e5c ER - TY - JOUR TI - Enrichment and characterization of glycopeptide epitopes from complex mixtures DO - 10.1007/978-1-62703-589-7_11 AU - Tessier, L. AU - Fulton, K.M. AU - Twine, S.M. T2 - Methods in Molecular Biology SN - 1064-3745 SN - 9781627035880 VL - 1061 SP - 181 EP - 195 KW - epitope KW - glycan KW - glycopeptide KW - glycoprotein KW - adaptive immunity KW - article KW - autoimmune disease KW - complex formation KW - electron transport KW - glycosylation KW - high performance liquid chromatography KW - immune system KW - innate immunity KW - mass spectrometry KW - priority journal KW - protein analysis KW - protein processing KW - tandem mass spectrometry AB - Antigen posttranslational modifications, including glycosylation, are recognized by the innate and adaptive arms of the immune system. Analytical approaches, including mass spectrometry and allied techniques, have allowed advances in the enrichment and identification of glyco-antigens, particularly T-cell epitopes. Similarly, major advances have been made in the identification, isolation, and detailed characterization of prokaryotic and eukaryotic glycoproteins and glycopeptides. In particular, peptide centric approaches are now capable of enriching low level glycopeptides from highly complex peptide mixtures. Similarly, advanced mass spectrometry methods allow identification of glycopeptides, characterization of glycans, and mapping of modification sites. Herein, we describe methods developed in our laboratory for the broad study of glycopeptides and illustrate how these approaches can be exploited to further our understanding of the identity and nature of glycopeptide epitopes in various diseases or auto immune disorders. © 2013 Springer Science+Business Media, LLC. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1738bb2e-5799-4638-9be2-68fcd9eb5df7 ER - TY - JOUR TI - Structure and biosynthetic locus of the lipopolysaccharide outer core produced by Pasteurella multocida serovars 8 and 13 and the identification of a novel phospho-glycero moiety DO - 10.1093/glycob/cws154 AU - Harper, M. AU - Michael, F.S. AU - Vinogradov, E. AU - John, M. AU - Steen, J.A. AU - Van Dorsten, L. AU - Boyce, J.D. AU - Adler, B. AU - Cox, A.D. T2 - Glycobiology SN - 0959-6658 VL - 23 IS - 3 SP - 286 EP - 294 KW - lipopolysaccharide KW - article KW - bacterial growth KW - bacterial strain KW - biosynthesis KW - chemical composition KW - chemical structure KW - genetic analysis KW - nonhuman KW - nucleotide sequence KW - Pasteurella multocida KW - priority journal KW - serotype KW - Actinobacillus pleuropneumoniae KW - Carbohydrate Conformation KW - Carbohydrate Sequence KW - Genes, Bacterial KW - Genetic Loci KW - Glycosyltransferases KW - Lipopolysaccharides KW - Pasteurella multocida KW - Actinobacillus pleuropneumoniae serovar 1 KW - Pasteurella multocida AB - Pasteurella multocida strains are classified into 16 Heddleston serovars on the basis of the lipopolysaccharide (LPS) antigens expressed on the surface of the bacteria. The LPS structure and the corresponding LPS outer core biosynthesis loci of strains belonging to serovars 1, 2, 3, 5, 9 and 14 have been characterized, revealing a clear structural basis for serovar classification. However, several of these serovars are genetically related, sharing the same LPS outer core biosynthesis locus, but producing different LPS molecules as a result of mutations within LPS assembly genes. In this article, we report that the P. multocida type strains belonging to serovars 8 and 13 share the same LPS outer core biosynthesis locus and produce structurally related LPS molecules. Structural analysis of the serovar 8 LPS revealed an inner core that is conserved among P. multocida strains and the following outer core structure: X-(1-6)-(1S)GalaNAC-(1-4-6)-α-Gal-(1-3)-β-Gal(PEtn)- (1-4)-L,D-α-Hep-(1-6) where X is a unique phospho-glycero moiety, 1-((4- aminobutyl)amino)-3-hydroxy-1-oxopropan-2-yl hydrogen phosphate, attached to the sixth position of (1S)GalaNAc. For serovar 13, the LPS structure is the same except for the absence of the terminal phospho-glycero moiety. Analysis of the common outer core biosynthesis locus from the serovar 8 and 13 type strains identified three genes that we predict are involved in the biosynthesis of this terminal moiety. Furthermore, bioinformatic comparisons with the characterized LPS outer core glycosyltransferases from Actinobacillus pleuropneumoniae serovar 1, strain 4074, allowed us to assign a function for each of the glycosyltransferases encoded within the serovar 8/13 LPS outer core biosynthesis locus. © The Author 2012. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a7c474f9-8440-4929-99de-03b404413851 ER - TY - JOUR TI - High-yield soluble expression and simple purification of the antimicrobial peptide OG2 using the intein system in Escherichia coli DO - 10.1155/2013/754319 AU - Xie, Y.-G. AU - Han, F.-F. AU - Luan, C. AU - Zhang, H.-W. AU - Feng, J. AU - Choi, Y.-J. AU - Groleau, D. AU - Wang, Y.-Z. T2 - BioMed Research International SN - 2314-6133 VL - 2013 SP - 754319 KW - bacterial protein KW - intein KW - og 2 protein KW - polypeptide antibiotic agent KW - unclassified drug KW - antimicrobial activity KW - article KW - Escherichia coli KW - molecular cloning KW - nonhuman KW - protein expression KW - protein purification AB - OG2 is a modified antimicrobial peptide, that is, derived from the frog peptide Palustrin-OG1. It has high antimicrobial activity and low cytotoxicity, and it is therefore promising as a therapeutic agent. Both prokaryotic (Escherichia coli) and eukaryotic (Pichia pastoris) production host systems were used to produce OG2 in our previous study; however, it was difficult to achieve high expression yields and efficient purification. In this study, we achieved high-yield OG2 expression using the intein fusion system. The optimized OG2 gene was cloned into the pTWIN1 vector to generate pTWIN-OG2-intein2 (C-terminal fusion vector) and pTWIN-intein1-OG2 (N-terminal fusion vector). Nearly 70% of the expressed OG2-intein2 was soluble after the IPTG concentration and induction temperature were decreased, whereas only 42% of the expressed of intein1-OG2 was soluble. Up to 75 mg of OG2-intein2 was obtained from a 1 l culture, and 85% of the protein was cleaved by 100 mM DTT. Intein1-OG2 was less amenable to cleavage due to the inhibition of cleavage by the N-terminal amino acid of OG2. The purified OG2 exhibited strong antimicrobial activity against E. coli K88. The intein system is the best currently available system for the cost-effective production of OG2. © 2013 Yong-Gang Xie et al. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 7cd1df62-bf19-4b8f-b8d7-26e00c8d6876 ER - TY - JOUR TI - Synthesis of novel mesoporous carbon spheres and their supported Fe-based electrocatalysts for PEM fuel cell oxygen reduction reaction DO - 10.1016/j.electacta.2013.06.126 AU - Zhang, L. AU - Kim, J. AU - Dy, E. AU - Ban, S. AU - Tsay, K.-C. AU - Kawai, H. AU - Shi, Z. AU - Zhang, J. T2 - Electrochimica Acta SN - 0013-4686 VL - 108 SP - 480 EP - 485 KW - Acid treatments KW - Acidic treatment KW - Electrochemical measurements KW - Mesoporous carbon KW - Oxygen reduction reaction KW - Support materials KW - Ultrasonic spray KW - Ultrasonic spray pyrolysis KW - Carbon KW - Electrocatalysts KW - Electrolytic reduction KW - Model predictive control KW - Precious metals KW - Proton exchange membrane fuel cells (PEMFC) KW - Spheres KW - Spray pyrolysis KW - Mesoporous materials AB - Mesoporous carbon spheres (MPCs) are synthesized using a template assisted ultrasonic spray pyrolysistechnique and explored as the support materials for non-noble metal electrocatalysts intended to beused for PEM fuel cell oxygen reduction reaction (ORR). TEM images show that MPCs synthesized are thehoneycomb-like carbon spheres with uniform nanosized pores. MPC's surface area thermal stability andaffinity to catalyst are improved by a second heat treatment and an acidic treatment confirmed by BET TGA and electrochemical measurements respectively. The synthesized Fe-Nxcatalyst with MPC supportshows an improved ORR activity when compared to the catalyst supported by commercially available Black Pearl 2000. © 2013 Published by Elsevier Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 98c8fab0-46b1-4b07-bdef-f15d4b236b94 ER - TY - JOUR TI - The comparative chemical evolution of an isolated dwarf galaxy: A vlt and keck spectroscopic survey of wlm DO - 10.1088/0004-637X/767/2/131 AU - Leaman, R. AU - Venn, K.A. AU - Brooks, A.M. AU - Battaglia, G. AU - Cole, A.A. AU - Ibata, R.A. AU - Irwin, M.J. AU - McConnachie, A.W. AU - Mendel, J.T. AU - Starkenburg, E. AU - Tolstoy, E. T2 - The Astrophysical Journal SN - 0004-637X VL - 767 IS - 2 SP - 131 AB - Building on our previous spectroscopic and photometric analysis of the isolated Local Group dwarf irregular (dIrr) galaxy WLM, we present a comparison of the metallicities of its red giant branch stars with respect to the well-studied Local Group dwarf spheroidal galaxies (dSphs) and Magellanic Clouds. We calculate a mean metallicity of [Fe/H] =-1.28 ± 0.02 and an intrinsic spread in metallicity of σ = 0.38 ± 0.04 dex, similar to the mean and spread observed in the massive dSph Fornax and the Small Magellanic Cloud. Thus, despite WLM's isolated environment, its global metallicity still follows expectations for mass and its global chemical evolution is similar to other nearby luminous dwarf galaxies (gas-rich or gas-poor). The data also show a radial gradient in [Fe/H] of d[Fe/H]/drc = -0.04 ± 0.04 dex , which is flatter than that seen in the unbiased and spatially extended surveys of dSphs. Comparison of the spatial distribution of [Fe/H] in WLM, the Magellanic Clouds, and a sample of Local Group dSphs shows an apparent dichotomy in the sense that the dIrrs have statistically flatter radial [Fe/H] gradients than the low angular momentum dSphs. The correlation between angular momentum and radial metallicity gradient is further supported when considering the Local Group dEs. This chemodynamic relationship offers a new and useful constraint for environment-driven dwarf galaxy evolution models in the Local Group. © 2013. The American Astronomical Society. All rights reserved.. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 66a9ff2e-2074-4f73-92cc-a1a134065d44 ER - TY - JOUR TI - Microstructure and tribological properties of solution-treated Tribaloy alloy DO - 10.1016/j.wear.2013.08.018 AU - Jiang, K. AU - Liu, R. AU - Chen, K. AU - Liang, M. T2 - Wear SN - 0043-1648 VL - 307 IS - 1-Feb SP - 22 EP - 27 KW - Elevated temperature KW - Laves-phase KW - Pin on disc tribometer KW - Sliding wear tests KW - Solid solution matrices KW - Solution treatments KW - Tribaloy alloy KW - Tribological properties KW - Alloys KW - Coatings KW - Microstructure KW - Sintering KW - Solid solutions KW - Temperature KW - Tribology KW - Wear of materials KW - Cerium alloys AB - A novel Tribaloy alloy, designated as T-400C9, has been developed for enhanced high-temperature oxidation resistance. This new alloy has been used as surface coating for environmental protection. One of the popular coating techniques, slurry coating, which is applied on T-400C, includes a sintering process at the temperature of solution treatment. This article presents a study of the influence of solution treatment on the microstructure and tribological properties of T-400C. The wear test is conducted on a temperature-controlled pin-on-disc tribometer at room temperature and elevated temperatures. The SEM/EDX analysis reveals that this treatment process promotes Laves phase precipitates within the solid solution matrix of this alloy. The sliding wear test demonstrates that the Laves phase precipitates enhance the wear resistance of this alloy. At high temperatures material oxidation affects the wear behavior of this alloy significantly. The worn surfaces are analyzed using SEM/EDX to help investigate the wear mechanisms of T-400C at high temperatures. © 2013 . DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6419d688-74a4-460e-80f6-6b3444947275 ER - TY - CHAP TI - Unraveling the Rhizosphere using the cpn 60 genomic marker and pyrosequencing DO - 10.1002/9781118297674.ch108 AU - Lazarovits, George AU - Turnbull, Amy L. AU - Haug, Brenda AU - Links, Matthew G. AU - Hill, Janet E. AU - Hemmingsen, Sean M. T2 - Molecular Microbial Ecology of the Rhizosphere SN - 9781118296172 VL - 2 SP - 1129 EP - 1136 KW - Potato KW - rhizosphere KW - pyrosequencing KW - bacteria KW - fungi KW - Rhizobium AB - The microbial communities of two distinct soils and of the rhizosphere, tuber-associated soil, and washed roots of potato plants grown in each soil were profiled by cpn60 gene-targeted metagenomics. DNA samples extracted from these sources were used as templates for PCR amplification of the cpn60 universal target regions present in each metagenomic sample. The cpn60 amplicons were analyzed by pyrosequencing. The 914,932 sequence reads obtained were aligned and assembled into unique cpn60 nucleotide sequences in an autonomous process that did not refer to a database of known cpn60 sequences. This process identified 27,222 unique nucleotide sequences, corresponding to 21,396 unique peptide sequences. The closest matches for each of these sequences in a database of cpn60 sequences, cpnDB, were determined. Bulk soil microbial richness [i.e., total number of unique operational taxonomic units (OTU)] was much greater than that of the plant-associated samples, as expected. The richness of the microbial communities associated with the plant samples ranged from 13% to 44% of that of the bulk soil in which it was grown. When only distinct peptide sequences derived from the nucleotide sequence OTU) were included, the apparent richness was reduced for all samples. If only OTU with higher relative abundances in the plant-associated sample than those in the bulk soil were considered, the apparent richness of the plant-associated microbial communities was significantly reduced. Clustering analysis identified OTU with distributions among the samples that strongly suggested a functional relationship with the plant. Classification of the reads observed in each sample the taxonomic level of bacterial Order revealed major differences between bulk soil and plant-associated communities. The distributions of a small number of OTU between samples suggest that these organisms had privileged relationships with the plant. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ab0650d7-29df-4217-bad6-4cd9d04a191b ER - TY - JOUR TI - Assessment of an experimental setup for high speed grinding using vitrified CBN wheels DO - 10.1504/IJAT.2013.057345 AU - Shi, Z. AU - Agapiou, J.S. AU - Attia, H. T2 - International Journal of Abrasive Technology SN - 1752-2641 VL - 6 IS - 2 SP - 132 EP - 146 KW - Grinding power KW - High speed grinding KW - HSG KW - Run outs KW - Vitrified CBN KW - Expansion KW - Grinding wheels KW - Nodular iron KW - Grinding (machining) AB - This paper is concerned with the assessment of an experimental setup for grinding experiments with a top wheel speed of 250 m/s. Among other considerations, high speed grinding is widely considered as a way for enhancing material removal rates by utilising large depths of cut and/or high workspeeds. Performing high speed grinding operations, however, presents challenges to the setup due to the high wheel speeds involved. An experimental setup was established in this study for high speed grinding of hardened nodular cast iron and steel using vitrified CBN wheels. This setup was assessed prior to grinding for wheel balancing and guarding, wheel core expansion and temperature rise, grinding fluid delivery, and idle power consumptions. It was found that high speed wheel rotations caused wheel expansion and temperature rise. A significant portion of the total power was consumed on actions other than material removals. The preliminary grinding tests indicated that the setup met the requirements for high speed grinding in general. Copyright © 2013 Inderscience Enterprises Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 665a198d-7a37-4523-8ef6-3af545345bf8 ER - TY - JOUR TI - Friction stir welded AZ31 magnesium alloy: Microstructure, texture, and tensile properties DO - 10.1007/s11661-012-1382-3 AU - Chowdhury, S.H. AU - Chen, D.L. AU - Bhole, S.D. AU - Cao, X. AU - Wanjara, P. T2 - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science SN - 1073-5623 VL - 44 IS - 1 SP - 323 EP - 336 KW - AZ31 magnesium alloy KW - Basal planes KW - Base alloys KW - Crystallographic textures KW - Fiber texture KW - Friction stir KW - Hardening capacities KW - Heat input KW - Mg alloy KW - Normal direction KW - Prismatic planes KW - Pyramidal planes KW - Recrystallized grains KW - Rolling direction KW - Rolling sheet KW - Rotational rates KW - Stir zones KW - Strain rate dependence KW - Strain-hardening exponent KW - Top surface KW - Transverse directions KW - Welding speed KW - Alloys KW - Ductility KW - Magnesium alloys KW - Recrystallization (metallurgy) KW - Textures KW - Welding KW - Friction stir welding AB - This study was aimed at characterizing the microstructure, texture and tensile properties of a friction stir welded AZ31B-H24 Mg alloy with varying tool rotational rates and welding speeds. Friction stir welding (FSW) resulted in the presence of recrystallized grains and the relevant drop in hardness in the stir zone (SZ). The base alloy contained a strong crystallographic texture with basal planes (0002) largely parallel to the rolling sheet surface and 1120 directions aligned in the rolling direction (RD). After FSW the basal planes in the SZ were slightly tilted toward the TD determined from the sheet normal direction (or top surface) and also slightly inclined toward the RD determined from the transverse direction (or cross section) due to the intense shear plastic flow near the pin surface. The prismatic planes (1010) and pyramidal planes (1011) formed fiber textures. After FSW both the strength and ductility of the AZ31B-H24 Mg alloy decreased with a joint efficiency in-between about 75 and 82 pct due to the changes in both grain structure and texture, which also weakened the strain rate dependence of tensile properties. The welding speed and rotational rate exhibited a stronger effect on the YS than the UTS. Despite the lower ductility, strain-hardening exponent and hardening capacity, a higher YS was obtained at a higher welding speed and lower rotational rate mainly due to the smaller recrystallized grains in the SZ arising from the lower heat input. © 2012 The Minerals, Metals & Materials Society and ASM International. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3345ae01-7ef0-4d4b-a4ac-c3f140c220fa ER - TY - JOUR TI - Assessing the performance of commercial and biological gas hydrate inhibitors using nuclear magnetic resonance microscopy and a stirred autoclave DO - 10.1016/j.fuel.2012.10.007 AU - Daraboina, N. AU - Moudrakovski, I.L. AU - Ripmeester, J.A. AU - Walker, V.K. AU - Englezos, P. T2 - Fuel SN - 0016-2361 VL - 105 SP - 630 EP - 635 KW - Antifreeze protein KW - Formation kinetics KW - Hydrate inhibitors KW - Hydrate nucleation KW - Inhibitor performance KW - Kinetic inhibitor KW - Magnetic resonance microscopy KW - Micro-imaging KW - Microliters KW - Potential inhibitors KW - Biogas KW - Hydrates KW - Kinetics KW - Magnetic resonance imaging KW - Pressure vessels KW - Hydration AB - The formation kinetics of methane/ethane/propane hydrate in the presence of kinetic inhibitors was investigated using 1H nuclear magnetic resonance imaging (MRI) as well as a more-traditional method using a stirred autoclave. These studies were facilitated by fabricating a multi-drop insert for 1H NMR micro-imaging, which allowed the comparison of the performance of microliter quantities of several inhibitors simultaneously and under the same conditions. Both methods showed that hydrate nucleation and growth were delayed significantly in the presence of inhibitors, which included two biological inhibitors (antifreeze proteins) and a commercial inhibitor. The results demonstrate that MRI is a useful tool for the visualization and evaluation of the performance of kinetic inhibitors on mixed gas hydrate formation. The MRI technique should prove especially valuable in the case of analysis of potential inhibitors, pre-commercialization, which are available in only limited quantities, such as biological inhibitors. This technique may also find utility in the exploration of differences in inhibitor performance, which may suggest distinct mechanisms of inhibitor action. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 911ac960-ffd7-4c25-8bbf-9dcd261a606b ER - TY - JOUR TI - Bidding specification language and winner determination for Grid computing scheduling DO - 10.1109/CSCWD.2013.6580980 AU - Aburukba, R.O. AU - Ghenniwa, H. AU - Shen, W. T2 - Proceedings of the 2013 IEEE 17th International Conference on Computer Supported Cooperative Work in Design, CSCWD 2013 T3 - 2013 IEEE 17th International Conference on Computer Supported Cooperative Work in Design, CSCWD 2013, 27 June 2013 through 29 June 2013, Whistler, BC SN - 9781467360852 SP - 6580980 SP - 305 EP - 312 KW - Bidding languages KW - Grid/Cloud computing KW - Resource-scheduling KW - Winner determination KW - Winner determination algorithm KW - Interactive computer systems KW - Scheduling KW - Specification languages KW - Surface measurement KW - Grid computing AB - In the Grid computing environment, computation, services, and storage belong to different organizations or individuals with different objectives. Entities in this domain are autonomous and self-interested; however, they are willingly to share their resources to achieve their individual and collective goals. In such open environment, the scheduling decision is a challenge given the decentralized nature of the environment. Each entity has specific requirements that need to achieve. This work analysis the environment structure for the Grid, proposes a bidding language that is expressive and a winner determination algorithm that is adequate for the Grid computing environment. © 2013 IEEE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 653061ee-0091-4dbe-bd9b-68db8a97bb3c ER - TY - JOUR TI - Nanoformulation of paclitaxel to enhance cancer therapy DO - 10.1177/0885328212446822 AU - Gu, Q. AU - Xing, J.Z. AU - Huang, M. AU - Zhang, X. AU - Chen, J. T2 - Journal of Biomaterials Applications SN - 0885-3282 VL - 28 IS - 2 SP - 298 EP - 307 KW - Cancer Chemotherapy KW - Nanoformulation KW - Paclitaxel KW - Pluronic copolymers KW - water-soluble KW - Chemotherapy KW - Copolymers KW - Diseases KW - Drug delivery KW - Enzyme inhibition KW - Loading KW - Nanoparticles KW - Synthesis (chemical) KW - Toxicity KW - Hydrogels KW - nanocarrier KW - paclitaxel KW - phosphate buffered saline KW - poloxamer KW - sorbitan palmitate KW - antineoplastic activity KW - aqueous solution KW - article KW - cancer cell culture KW - cancer therapy KW - cell killing KW - cell strain MCF 7 KW - cell viability KW - controlled study KW - cytotoxicity KW - drug delivery system KW - drug distribution KW - drug efficacy KW - drug formulation KW - drug solubility KW - drug structure KW - drug uptake KW - HeLa cell KW - high performance liquid chromatography KW - IC 50 KW - in vitro study KW - nanoencapsulation KW - nanopharmaceutics KW - nanotoxicology KW - particle size KW - physical chemistry KW - proton nuclear magnetic resonance KW - scanning electron microscopy KW - toxicity testing KW - transmission electron microscopy AB - Paclitaxel is a microtubule inhibitor causing mitotic arrest and is widely used in cancer chemotherapy. However, its poor water solubility restricts its direct clinical applications. In this article, we report paclitaxel-loaded nanoparticles that are water soluble and that can improve the drug's bio-distribution and therapeutic efficacy. Paclitaxel-loaded nanoparticles were synthesized by using Pluronic copolymers (F-68 and P-123) and surfactant (Span 40) as nanocarrier. The toxicity and cellular uptake of paclitaxel-loaded nanoparticles were evaluated. The paclitaxel-loaded nanoparticles can completely disperse into phosphate buffer saline to produce a clear aqueous suspension. Based on HPLC analysis, the drug-loading rate is 9.0 ± 0.1% while drug encapsulation efficiency is 99.0 ± 1.0%. The cytotoxicity assay was performed using breast cancer MCF-7 and cervical cancer Hela cells. For MCF-7 cells, the half maximal inhibitory concentrations (IC50) of paclitaxel-loaded nanoparticles and paclitaxel are 8.5 ± 0.3 and 14.0 ± 0.7 ng/mL at 48 hours and 3.5 ± 0.4 and 5.2 ± 0.5 ng/mL at 72 hours across several runs. IC50 of paclitaxel-loaded nanoparticles and paclitaxel for Hela cells are 5.0 ± 0.3 and 8.0 ± 0.3 ng/mL at 48 hours and 2.0 ± 0.1 and 6.5 ± 0.3 ng/mL at 72 hours. In-vitro studies show that the drug's nanoformulation gives obvious enhancements in the drug's efficiency at killing cancer cells over paclitaxel alone. Materials of the nanocarrier used for nanoformulation are approved with low toxicity according to the result of cell studies. Conclusion: paclitaxel-loaded nanoparticles greatly improved the physicochemical properties of paclitaxel without modifying its chemical structure, allowing for deep-site cancer drug delivery and enhancing the drug therapeutic efficiency. © 2012 The Author(s). DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a7598d29-2a77-4590-b984-33995bdeea61 ER - TY - JOUR TI - A study of transition-metal organometallic complexes combining 35Cl solid-state NMR spectroscopy and 35Cl NQR spectroscopy and first-principles DFT calculations DO - 10.1002/chem.201301268 AU - Johnston, K.E. AU - O'Keefe, C.A. AU - Gauvin, R.M. AU - Trébosc, J. AU - Delevoye, L. AU - Amoureux, J.-P. AU - Popoff, N. AU - Taoufik, M. AU - Oudatchin, K. AU - Schurko, R.W. T2 - Chemistry - A European Journal SN - 0947-6539 VL - 19 IS - 37 SP - 12396 EP - 12414 KW - Electric field gradients KW - First principles density functional theory (DFT) calculations KW - First-principles DFT calculations KW - Organo-metallic complexes KW - Solid-state NMR spectroscopy KW - Structural characterization KW - Structure determination KW - Transition-metal complex KW - Calculations KW - Chemical analysis KW - Chemical bonds KW - Chlorine KW - Density functional theory KW - Electric fields KW - Magnetic fields KW - Metal complexes KW - Nuclear magnetic resonance spectroscopy KW - Nuclear quadrupole resonance KW - Organometallics KW - Solid state physics KW - Tensors KW - Transition metals KW - Chlorine compounds AB - A series of transition-metal organometallic complexes with commonly occurring metal-chlorine bonding motifs were characterized using 35Cl solid-state NMR (SSNMR) spectroscopy, 35Cl nuclear quadrupole resonance (NQR) spectroscopy, and first-principles density functional theory (DFT) calculations of NMR interaction tensors. Static 35Cl ultra-wideline NMR spectra were acquired in a piecewise manner at standard (9.4 T) and high (21.1 T) magnetic field strengths using the WURST-QCPMG pulse sequence. The 35Cl electric field gradient (EFG) and chemical shielding (CS) tensor parameters were readily extracted from analytical simulations of the spectra; in particular, the quadrupolar parameters are shown to be very sensitive to structural differences, and can easily differentiate between chlorine atoms in bridging and terminal bonding environments. 35Cl NQR spectra were acquired for many of the complexes, which aided in resolving structurally similar, yet crystallographically distinct and magnetically inequivalent chlorine sites, and with the interpretation and assignment of 35Cl SSNMR spectra. 35Cl EFG tensors obtained from first-principles DFT calculations are consistently in good agreement with experiment, highlighting the importance of using a combined approach of theoretical and experimental methods for structural characterization. Finally, a preliminary example of a 35Cl SSNMR spectrum of a transition-metal species (TiCl4) diluted and supported on non-porous silica is presented. The combination of 35Cl SSNMR and 35Cl NQR spectroscopy and DFT calculations is shown to be a promising and simple methodology for the characterization of all manner of chlorine-containing transition-metal complexes, in pure, impure bulk and supported forms. Fast and furious: A series of transition-metal organometallic complexes with commonly occurring metal-chlorine bonding motifs were characterized using a combination of 35Cl solid-state NMR (SSNMR) spectroscopy, 35Cl nuclear quadrupole resonance (NQR) spectroscopy and first-principles density functional theory (DFT) calculations. Static 35Cl ultra-wideline NMR spectra were rapidly acquired in a piecewise manner at high magnetic field strengths. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9f51a1bd-43c6-42bc-8a99-e78319f65a3b ER - TY - JOUR TI - Simulation studies of the Cl- + CH3I SN2 nucleophilic substitution reaction: Comparison with ion imaging experiments DO - 10.1063/1.4795495 AU - Zhang, J. AU - Lourderaj, U. AU - Sun, R. AU - Mikosch, J. AU - Wester, R. AU - Hase, W.L. T2 - Journal of Chemical Physics SN - 0021-9606 VL - 138 IS - 11 SP - 114309 KW - Approximate agreement KW - Backward scattering KW - Energy partitioning KW - Isotropic scattering KW - Nucleophilic substitution reactions KW - Phase space theories KW - Rotational temperature KW - Scattering angle distribution KW - Imaging systems KW - Phase space methods KW - Scattering KW - Substitution reactions KW - Experiments AB - In the previous work of Mikosch Science 319, 183 (2008)10.1126/science. 1150238, ion imaging experiments were used to study the Cl- CH 3I → ClCH3 I- reaction at collision energies Erel of 0.39, 0.76, 1.07, and 1.9 eV. For the work reported here MP2(fc)ECPd direct dynamics simulations were performed to obtain an atomistic understanding of the experiments. There is good agreement with the experimental product energy and scattering angle distributions for the highest three Erel, and at these energies 80 or more of the reaction is direct, primarily occurring by a rebound mechanism with backward scattering. At 0.76 eV there is a small indirect component, with isotropic scattering, involving formation of the pre- and post-reaction complexes. All of the reaction is direct at 1.07 eV. Increasing Erel to 1.9 eV opens up a new indirect pathway, the roundabout mechanism. The product energy is primarily partitioned into relative translation for the direct reactions, but to CH 3Cl internal energy for the indirect reactions. The roundabout mechanism transfers substantial energy to CH3Cl rotation. At E rel 0.39 eV both the experimental product energy partitioning and scattering are statistical, suggesting the reaction is primarily indirect with formation of the pre- and post-reaction complexes. However, neither MP2 nor BhandHECPd simulations agree with experiment and, instead, give reaction dominated by direct processes as found for the higher collision energies. Decreasing the simulation Erel to 0.20 eV results in product energy partitioning and scattering which agree with the 0.39 eV experiment. The sharp transition from a dominant direct to indirect reaction as Erel is lowered from 0.39 to 0.20 eV is striking. The lack of agreement between the simulations and experiment for Erel 0.39 eV may result from a distribution of collision energies in the experiment andor a shortcoming in both the MP2 and BhandH simulations. Increasing the reactant rotational temperature from 75 to 300 K for the 1.9 eV collisions, results in more rotational energy in the CH3Cl product and a larger fraction of roundabout trajectories. Even though a ClCH3-I- post-reaction complex is not formed and the mechanistic dynamics are not statistical, the roundabout mechanism gives product energy partitioning in approximate agreement with phase space theory. © 2013 American Institute of Physics. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f7351875-a02d-4052-915f-3f0acd6dfefa ER - TY - JOUR TI - Transient gene expression in serum-free suspension-growing mammalian cells for the production of Foot-and-mouth disease virus empty capsids DO - 10.1371/journal.pone.0072800 AU - Mignaqui, A.C. AU - Ruiz, V. AU - Perret, S. AU - St-Laurent, G. AU - Singh Chahal, P. AU - Transfiguracion, J. AU - Sammarruco, A. AU - Gnazzo, V. AU - Durocher, Y. AU - Wigdorovitz, A. T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 8 SP - e72800 KW - polyethyleneimine KW - protein VP0 KW - protein VP1 KW - protein VP3 KW - pTT5 vector KW - recombinant subunit vaccine KW - subunit vaccine KW - unclassified drug KW - virus protein KW - virus vector KW - animal cell KW - animal experiment KW - article KW - cell growth KW - controlled study KW - cost effectiveness analysis KW - empty virus capsid KW - foot and mouth disease KW - Foot and mouth disease virus KW - gene KW - gene cassette KW - genetic transfection KW - human KW - human cell KW - male KW - mammal cell KW - mouse KW - nonhuman KW - p12A gene KW - P12A3C gene KW - transient expression KW - vaccine production KW - virus capsid KW - virus immunity KW - VP0 gene KW - vp1 gene KW - VP3 gene AB - Foot-and-mouth disease (FMD) is a highly contagious disease of cloven-hoofed animals. It produces severe economic losses in the livestock industry. Currently available vaccines are based on inactivated FMD virus (FMDV). The use of empty capsids as a subunit vaccine has been reported to be a promising candidate because it avoids the use of virus in the vaccine production and conserves the conformational epitopes of the virus. In this report, we explored transient gene expression (TGE) in serum-free suspension-growing mammalian cells for the production of FMDV recombinant empty capsids as a subunit vaccine. The recombinant proteins produced, assembled into empty capsids and induced protective immune response against viral challenge in mice. Furthermore, they were recognized by anti-FMDV bovine sera. By using this technology, we were able to achieve expression levels that are compatible with the development of a vaccine. Thus, TGE of mammalian cells is an easy to perform, scalable and cost-effective technology for the production of a recombinant subunit vaccine against FMDV. © 2013 Mignaqui et al. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c524b0e0-cbc3-4706-a42f-d658d07a7119 ER - TY - JOUR TI - Introduction to the immune system DO - 10.1007/978-1-62703-589-7_1 AU - McComb, S. AU - Thiriot, A. AU - Krishnan, L. AU - Stark, F. T2 - Methods in Molecular Biology SN - 1064-3745 SN - 9781627035880 VL - 1061 SP - 1 EP - 20 KW - cytokine KW - adaptive immunity KW - autoimmunity KW - bone marrow KW - cell function KW - cell size KW - cell type KW - human KW - immune system KW - immunity KW - immunocompetent cell KW - inflammation KW - innate immunity KW - liver KW - lymph node KW - lymph vessel KW - Peyer patch KW - priority journal KW - review KW - spleen KW - thymus KW - tonsil KW - tumor immunity AB - The immune system in a broad sense is a mechanism that allows a living organism to discriminate between "self" and "non-self." Examples of immune systems occur in multicellular organisms as simple and ancient as sea sponges. In fact, complex multicellular life would be impossible without the ability to exclude external life from the internal environment. This introduction to the immune system explores the cell types and soluble factors involved in immune reactions, as well as their location in the body during development and maintenance. Additionally, a description of the immunological events during an innate and adaptive immune reaction to an infection is discussed, as well as a brief introduction to autoimmunity and cancer immunity. © 2013 Springer Science+Business Media, LLC. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : bf830813-0e50-48db-91b0-803e5951479f ER - TY - JOUR TI - Structure and immunogenicity of the rough-type lipopolysaccharide from the periodontal pathogen Tannerella forsythia DO - 10.1128/CVI.00139-13 AU - Posch, G. AU - Andrukhov, O. AU - Vinogradov, E. AU - Lindner, B. AU - Messner, P. AU - Holst, O. AU - Schäffer, C. T2 - Clinical and Vaccine Immunology SN - 1556-6811 VL - 20 IS - 6 SP - 920 EP - 930 KW - bacterium lipopolysaccharide KW - galactose KW - glucosamine KW - interleukin 1 KW - interleukin 6 KW - mannose KW - phosphate KW - phosphoethanolamine KW - tumor necrosis factor alpha KW - article KW - carbohydrate analysis KW - controlled study KW - cytokine production KW - fetal calf serum KW - host pathogen interaction KW - human KW - human cell KW - immunogenicity KW - immunostimulation KW - macrophage activation KW - nonhuman KW - periodontium KW - priority journal KW - structure analysis KW - surface property KW - Tannerella forsythensis AB - Tannerella forsythia is a Gram-negative anaerobic organism that inhabits subgingival plaque biofilms and is covered with a so far unique surface layer composed of two glycoproteins. It belongs to the so-called "red complex" of bacteria comprising species that are associated with periodontal disease. While the surface layer glycoprotein glycan structure had been elucidated recently and found to be a virulence factor, no structural data on the lipopolysaccharide (LPS) of this organism were available. In this study, the T. forsythia LPS structure was partially elucidated by a combined mass spectrometry (MS) and nuclear magnetic resonance spectroscopy (NMR) approach and initial experiments to characterize its immunostimulatory potential were performed. The T. forsythia LPS is a complex, rough-type LPS with a core region composed of one 3-deoxy-D-manno-oct-2-ulosonic acid (Kdo) residue, three mannose residues, and two glucosamine residues. MS analyses of O-deacylated LPS proved that, in addition, one phosphoethanolamine residue and most likely one galactose-phosphate residue were present, however, their positions could not be identified. Stimulation of human macrophages with T. forsythia LPS resulted in the production of the proinflammatory cytokines interleukin-1 (IL-1), IL-6, and tumor necrosis factor alpha in a dose-dependent manner. The response to T. forsythia LPS was observed only upon stimulation in the presence of fetal calf serum (FCS), whereas no cytokine production was observed in the absence of FCS. This finding suggests that the presence of certain additional cofactors is crucial for the immune response induced by T. forsythia LPS. Copyright © 2013, American Society for Microbiology. All Rights Reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2fa3ed54-2681-4fb8-aab5-c9f80f479b37 ER - TY - JOUR TI - Compositional and material properties of rat bone after bisphosphonate and/or strontium ranelate drug treatment AU - Wu, Y. AU - Adeeb, S.M. AU - John Duke, M. AU - Munoz-Paniagua, D. AU - Doschak, M.R. T2 - Journal of Pharmacy and Pharmaceutical Sciences SN - 1482-1826 VL - 16 IS - 1 SP - 52 EP - 64 KW - calcium KW - phosphorus KW - risedronic acid KW - strontium KW - strontium ranelate KW - animal experiment KW - animal model KW - animal tissue KW - article KW - biomechanics KW - bone mass KW - bone strength KW - bone structure KW - combination chemotherapy KW - composite material KW - compressive strength KW - controlled study KW - cortical bone KW - drug efficacy KW - drug mechanism KW - electron probe microanalysis KW - female KW - growth plate KW - lumbar vertebra KW - micro-computed tomography KW - monotherapy KW - nonhuman KW - osteoporosis KW - ovariectomy KW - periosteum KW - rat KW - trabecular bone KW - treatment duration KW - Young modulus KW - Animals KW - Bone and Bones KW - Bone Density Conservation Agents KW - Calcium KW - Diphosphonates KW - Female KW - Hardness Tests KW - Osteoporosis KW - Ovariectomy KW - Phosphorus KW - Rats KW - Rats, Sprague-Dawley KW - Strontium KW - Thiophenes KW - X-Ray Microtomography AB - Purpose. We investigated elemental strontium and/or bisphosphonate drug incorporation upon the compositional and biomechanical properties of vertebral bone, in a rat model of Osteoporosis secondary to ovariectomy. Methods. Six month old female rats were ovariectomized (OVX) and divided into untreated OVXVehicle, OVX-RIS (Risedronate bisphosphonate [BP] treated), OVX-SrR (Strontium Ranelate [Protos®] treated), combination OVX-RIS+SrR, and sham-operated controls. After 16 weeks of treatment, rats were euthanized and lumbar vertebra were dissected. Micro-Computed Tomography (micro-CT), Electron Probe Micro-Analysis (EPMA), mechanical testing in compression and nano-indentation testing were then undertaken to evaluate bone morphometry, elemental composition, material properties and strength. Results. Bone Volume was significantly reduced in the OVX-Vehicle (133±10mm3) compared with OVX-RIS (169±22mm3), OVXSrR (145±2mm3), and OVX-RIS+SrR (172±3). EPMA mapped elemental Sr deposition to the periosteal surface of cortical bone (50-100 μm thick), endosteal trabecular surfaces (20 μm thick), as well as to both vertebral growth plates. The atomic ratios of (Ca+Sr)/P were significantly reduced with SrR treatment (2.4%- 6.6%), indicating Sr incorporation into bone mineral. No significant differences were measured in vertebral bone reduced modulus by nano-indentation. Conversely, all BP-dosed groups had significantly increased structural bone strength. Conclusions. Thus, we conclude that BP drugs dominate the conservation of trabecular geometry and structural strength in OP rats, whereas Sr drugs likely influence bone volume and material composition locally. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2ed26931-e133-4c1f-bc5e-37b699213a71 ER - TY - JOUR TI - A convenient and highly stereoselective method for synthesis of octahydropyrano[3,2-b]pyrrole derivatives DO - 10.1016/j.carres.2012.11.016 AU - Ma, X. AU - Tang, Q. AU - Ke, J. AU - Wang, H. AU - Zou, W. AU - Shao, H. T2 - Carbohydrate Research SN - 0008-6215 VL - 366 SP - 55 EP - 62 KW - Bicyclic compounds KW - Pyranose KW - Pyrrole derivatives KW - Pyrrolidines KW - Reductive amination KW - Sodium triacetoxyborohydride KW - Stereoselective method KW - Stereoselective synthesis KW - Amines KW - Cyclization KW - Sodium KW - Stereochemistry KW - Stereoselectivity KW - Aromatic compounds KW - 1 benzyl 6,7 bis(benzyloxy) 5 [(benzyloxy)methyl] 2 methyl octahydropyrano(3,2 b)pyrrole KW - 1 hydroxyethyl 6,7 bis(benzyloxy) 5 [(benzyloxy)methyl] 2 methyl octahydropyrano(3,2 b)pyrrole KW - 3,7 anhydro 5,6,8 tri o benzyl 2 deoxy dextro manno octos 4 ulose KW - 4,8 anhydro 6,7,9 tri o benzyl 1,3 dideoxy dextro manno nono 2,5 diulose KW - 6,7 bis(benzyloxy) 5 [(benzyloxy)methyl] 1 (2 methoxy phenethyl)octahydropyrano(3,2 b)pyrrole KW - 6,7 bis(benzyloxy) 5 [(benzyloxy)methyl] 1 (4 fluorophenethyl)octahydropyrano(3,2 b)pyrrole KW - 6,7 bis(benzyloxy) 5 [(benzyloxy)methyl] 1 (4 tolyl) octahydropyrano(3,2 b)pyrrole KW - 6,7 bis(benzyloxy) 5 [(benzyloxy)methyl] 1 [2 (4 fluorophenyl)ethyl] 2 methyl octahydropyrano(3,2 b)pyrrole KW - 6,7 bis(benzyloxy) 5 [(benzyloxy)methyl] 1 butyl 2 methyl octahydropyrano(3,2 b)pyrrole KW - 6,7 bis(benzyloxy) 5 [(benzyloxy)methyl] 1 butyl octahydropyrano(3,2 b)pyrrole KW - 6,7 bis(benzyloxy) 5 [(benzyloxy)methyl] 1 hexyl 2 methyl octahydropyrano(3,2 b)pyrrole KW - 6,7 bis(benzyloxy) 5 [(benzyloxy)methyl] 1 hexyl octahydropyrano(3,2 b)pyrrole KW - 6,7 bis(benzyloxy) 5 [(benzyloxy)methyl] 1 hydroxyethyl octahydropyrano(3,2 b)pyrrole KW - 6,7 bis(benzyloxy) 5 [(benzyloxy)methyl] 1 octyl octahydropyrano(3,2 b)pyrrole KW - 6,7 bis(benzyloxy) 5 [(benzyloxy)methyl] 2 methyl 1 (4 methylphenyl)octahydropyrano[3,2 b)pyrrole KW - 6,7 bis(benzyloxy) 5 [(benzyloxy)methyl] 2 methyl 1 (o tolyl) octahydropyrano(3,2 b)pyrrole KW - 6,7 bis(benzyloxy) 5 [(benzyloxy)methyl] 2 methyl 1 octyl octahydropyrano(3,2 b)pyrrole KW - 6,7 bis(benzyloxy) 5 [(benzyloxy)methyl] 2 methyl 1 phenyl octahydropyrano(3,2 b)pyrrole KW - pyrrole derivative KW - unclassified drug KW - amination KW - article KW - biological activity KW - carbohydrate analysis KW - chemical interaction KW - column chromatography KW - cyclization KW - diastereoisomer KW - nuclear Overhauser effect KW - oxidation KW - ozonolysis KW - priority journal KW - proton nuclear magnetic resonance KW - purification KW - stereochemistry KW - thin layer chromatography AB - The octahydropyrano[3,2-b]pyrrole derivatives are synthesized by a double reductive amination from pyranose derivatives of nono-2,5-diuloses and octos-4-uloses and various amines. The cyclization proceeded smoothly in the presence of sodium triacetoxyborohydride to produce a series of novel fused N-heterobicyclic compounds with high stereoselectivity. © 2012 Elsevier Ltd. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 463aad72-0870-4444-b5f0-7aed8ee87d25 ER - TY - JOUR TI - Solubility of cholesterol in lipid membranes and the formation of immiscible cholesterol plaques at high cholesterol concentrations DO - 10.1039/c3sm50700a AU - Barrett, M.A. AU - Zheng, S. AU - Toppozini, L.A. AU - Alsop, R.J. AU - Dies, H. AU - Wang, A. AU - Jago, N. AU - Moore, M. AU - Rheinstädter, M.C. T2 - Soft Matter SN - 1744-683X VL - 9 IS - 39 SP - 9342 EP - 9351 KW - Bi-layer KW - Cholesterol molecules KW - Dimyristoylphosphatidylcholine KW - High cholesterols KW - Lipid membranes KW - Monoclinic structures KW - Out-of-plane KW - Triclinic structures KW - Lipid bilayers KW - Molecules KW - X ray diffraction KW - Cholesterol AB - The molecular in-plane and out-of-plane structure of dimyristoylphosphatidylcholine (DMPC) membranes containing up to 60 mol% of cholesterol was studied using X-ray diffraction. Up to 37.5 mol% cholesterol could be dissolved in the membranes, resulting in a disordered lateral membrane structure. Highly ordered cholesterol structures were observed at cholesterol concentrations of more than 40 mol% cholesterol. These structures were characterized as immiscible cholesterol plaques, i.e., bilayers of cholesterol molecules coexisting with the lipid bilayer. The cholesterol molecules were found to form a monoclinic structure at 40 mol% cholesterol, which transformed into a triclinic arrangement at the highest concentration of 60 mol%. Monoclinic and triclinic structures were found to coexist at cholesterol concentrations between 50 and 55 mol%. © 2013 The Royal Society of Chemistry. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e3083277-ccd8-427f-abe1-ef2f9cf265f5 ER - TY - JOUR TI - Perspectives in molecular imaging using staging biomarkers and immunotherapies in alzheimer's disease DO - 10.1155/2013/589308 AU - Leclerc, B. AU - Abulrob, A. T2 - The Scientific World Journal SN - 1537-744X VL - 2013 SP - 589308 KW - ABC transporter KW - alpha 2 macroglobulin KW - amyloid beta protein KW - apolipoprotein E4 KW - biological marker KW - bleomycin hydrolase KW - CD33 antigen KW - clusterin KW - endothelial nitric oxide synthase KW - fluorodeoxyglucose KW - myeloperoxidase KW - oxidized low density lipoprotein receptor 1 KW - Pittsburgh compound B KW - presenilin 1 KW - presenilin 2 KW - sortilin KW - tau protein KW - thioflavine KW - urokinase KW - amyloid beta protein KW - biological marker KW - muscarinic receptor KW - Alzheimer disease KW - article KW - cerebrospinal fluid KW - early diagnosis KW - histopathology KW - human KW - molecular imaging KW - neuropathology KW - nonhuman KW - nuclear magnetic resonance imaging KW - positron emission tomography KW - risk factor KW - Alzheimer disease KW - disease course KW - hippocampus KW - immunotherapy KW - metabolism KW - molecular imaging KW - multimodality cancer therapy KW - pathology KW - pathophysiology KW - review KW - severity of illness index KW - Alzheimer Disease KW - Amyloid beta-Peptides KW - Biological Markers KW - Combined Modality Therapy KW - Disease Progression KW - Early Diagnosis KW - Hippocampus KW - Humans KW - Immunotherapy KW - Molecular Imaging KW - Receptors, Muscarinic KW - Risk Factors KW - Severity of Illness Index AB - Sporadic Alzheimer's disease (AD) is an emerging chronic illness characterized by a progressive pleiotropic pathophysiological mode of actions triggered during the senescence process and affecting the elderly worldwide. The complex molecular mechanisms of AD not only are supported by cholinergic, beta-amyloid, and tau theories but also have a genetic basis that accounts for the difference in symptomatology processes activation among human population which will evolve into divergent neuropathological features underlying cognitive and behaviour alterations. Distinct immune system tolerance could also influence divergent responses among AD patients treated by immunotherapy. The complexity in nature increases when taken together the genetic/immune tolerance with the patient's brain reserve and with neuropathological evolution from early till advance AD clinical stages. The most promising diagnostic strategies in today's world would consist in performing high diagnostic accuracy of combined modality imaging technologies using beta-amyloid 42 peptide-cerebrospinal fluid (CSF) positron emission tomography (PET), Pittsburgh compound B-PET, fluorodeoxyglucose-PET, total and phosphorylated tau-CSF, and volumetric magnetic resonance imaging hippocampus biomarkers for criteria evaluation and validation. Early diagnosis is the challenge task that needs to look first at plausible mechanisms of actions behind therapies, and combining them would allow for the development of efficient AD treatment in a near future. © 2013 Benoît Leclerc and Abedelnasser Abulrob. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 648aea45-e7ec-4a64-a170-7e4c32b05444 ER - TY - JOUR TI - Preliminary DIMM and MASS nighttime seeing measurements at PEARL in the Canadian High Arctic DO - 10.1086/671482 AU - Steinbring, E. AU - Millar-Blanchaer, M. AU - Ngan, W. AU - Murowinski, R. AU - Leckie, B. AU - Carlberg, R. T2 - Publications of the Astronomical Society of the Pacific SN - 0004-6280 VL - 125 IS - 929 SP - 866 EP - 877 AB - Results of deploying a differential image motion monitor (DIMM) and a DIMM combined with a multiaperture scintillation sensor (MASS/DIMM) are reported for campaigns in 2011 and 2012 on the roof of the Polar Environment Atmospheric Research Laboratory (PEARL). This facility is on a 610 m high ridge at latitude 80°N, near the Eureka weather station on Ellesmere Island, Canada. The median seeing at 8 m elevation is 0″.85 or better based on DIMM data alone, but is dependent on wind direction and likely includes a component due to the PEARL building itself. Results with MASS/DIMM yield a median seeing less than 0″.76. A semiempirical model of seeing versus ground wind speed is introduced which allows agreement between these datasets, and with previous boundary-layer profiling by lunar scintillometry from the same location. This further suggests that best 20th percentile seeing reaches 0″.53, of which typically 0″.30 is due to the free atmosphere. Some discussion for guiding future seeing instrumentation and characterization at this site is provided. © 2013. The Astronomical Society of the Pacific. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 983e6ef1-6165-43a5-8c48-d077cd97ceef ER - TY - JOUR TI - Phase behavior and domain size in sphingomyelin-containing lipid bilayers DO - 10.1016/j.bbamem.2013.01.007 AU - Petruzielo, R.S. AU - Heberle, F.A. AU - Drazba, P. AU - Katsaras, J. AU - Feigenson, G.W. T2 - Biochimica et Biophysica Acta - Biomembranes SN - 0005-2736 VL - 1828 IS - 4 SP - 1302 EP - 1313 KW - 2 oleoyl 1 palmitoylphosphatidylcholine KW - cholesterol KW - dioleoylphosphatidylcholine KW - sphingomyelin KW - analytic method KW - animal cell KW - article KW - artificial membrane KW - brain cell KW - cell function KW - differential scanning calorimetry KW - Forster resonance energy transfer KW - in vivo study KW - lipid bilayer KW - molecular size KW - molecular stability KW - neutron scattering KW - nonhuman KW - phase separation KW - priority journal KW - sensitivity analysis KW - swine KW - Calorimetry, Differential Scanning KW - Cholesterol KW - Fluorescence Resonance Energy Transfer KW - Lipid Bilayers KW - Neutrons KW - Phosphatidylcholines KW - Scattering, Radiation KW - Sphingomyelins KW - Sus AB - Membrane raft size measurements are crucial to understanding the stability and functionality of rafts in cells. The challenge of accurately measuring raft size is evidenced by the disparate reports of domain sizes, which range from nanometers to microns for the ternary model membrane system sphingomyelin (SM)/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC)/cholesterol (Chol). Using Förster resonance energy transfer (FRET) and differential scanning calorimetry (DSC), we established phase diagrams for porcine brain SM (bSM)/dioleoyl-sn-glycero-3-phosphocholine (DOPC)/Chol and bSM/POPC/Chol at 15 and 25 C. By combining two techniques with different spatial sensitivities, namely FRET and small-angle neutron scattering (SANS), we have significantly narrowed the uncertainty in domain size estimates for bSM/POPC/Chol mixtures. Compositional trends in FRET data revealed coexisting domains at 15 and 25 C for both mixtures, while SANS measurements detected no domain formation for bSM/POPC/Chol. Together these results indicate that liquid domains in bSM/POPC/Chol are between 2 and 7 nm in radius at 25 C: that is, domains must be on the order of the 2-6 nm Förster distance of the FRET probes, but smaller than the ~ 7 nm minimum cluster size detectable with SANS. However, for palmitoyl SM (PSM)/POPC/Chol at a similar composition, SANS detected coexisting liquid domains. This increase in domain size upon replacing the natural SM component (which consists of a mixture of chain lengths) with synthetic PSM, suggests a role for SM chain length in modulating raft size in vivo. © 2012 Elsevier B.V. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : fc863045-1748-40a4-afe4-8d16fc526021 ER - TY - JOUR TI - Catalytic epoxidation of C60 using Mo(O)2(acac) 2/tBuOOH DO - 10.1039/c2dt32523c AU - Anderson, R.E. AU - Barron, A.R. T2 - Dalton Transactions SN - 1477-9226 VL - 42 IS - 6 SP - 2186 EP - 2191 KW - Catalysed oxidation KW - Catalytic epoxidation KW - Mass spectra KW - Oxygenated derivatives KW - Oxygenated products KW - Product distributions KW - Reaction temperature KW - Chemistry KW - Inorganic compounds KW - Mass spectrometry AB - Highly oxygenated fullerenes, C60On with 1 ≤ n ≤ 13, have been prepared by the Mo(O)2(acac)2 catalysed oxidation of C60 with tBuOOH. Increasing the catalystC60 ratio or increasing the reaction temperature increases the yield as well shifting the product distribution to higher oxygenated products, in contrast, increasing the tBuOOH concentration shifts the product distribution in the opposite manner. The MALDI mass spectra of reactions containing the highest oxygenated products (n > 5) show additional peaks (not observed for C60 under the same MS conditions) due to the cage-opened products Cx (x = 54, 56, 58) along with their oxygenated derivatives, CxOn (x = 54, 56, 58; n = 1-3). This journal is © The Royal Society of Chemistry 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 35f48b33-59d9-4d5a-9985-b29473c60f6a ER - TY - JOUR TI - Behavior and response of lead-caulked bell-spigot joints in cast iron water mains DO - 10.1016/j.engstruct.2013.08.017 AU - Rajani, B. AU - Abdel-Akher, A. T2 - Engineering Structures SN - 0141-0296 VL - 56 SP - 2005 EP - 2013 KW - Anecdotal evidences KW - Annular space KW - Caulking KW - Linear modeling KW - Mechanistic models KW - Non-linear model KW - Pneumatic hammers KW - Spigot joints KW - Cast iron KW - Cast iron pipe KW - Hammers KW - Mathematical models KW - Pneumatics KW - Residual stresses KW - Tensile strength KW - Bells KW - joint KW - lead KW - modeling KW - pipe KW - stress AB - The annular space between bell and spigot joints for cast iron pipes installed between 1850 and the early 1960s in North America was typically caulked with lead. Lead was caulked unto place using hand-held or pneumatic hammers and special chisels. Historical anecdotal evidence suggests that some bells may have cracked during caulking, especially if the jointer was over zealous in hammering the lead in place or used pneumatic hammers with excessive pressure to produce a tight joint. This paper examines two mechanistic models, one linear and another non-linear, to estimate the levels of hoop stress induced in the bell as a consequence of lead caulking. Illustrative analyses of lead caulking joints in 16" and 48" diameter pipes show that the linear model tends to predict unrealistic high stresses while the non-linear model produced more realistic stresses. Tensile hoop stresses can reach as high as 25% of the tensile strength of cast iron if the joint caulker is over zealous in the hammering action. The non-linear model was also used to reproduce caulking-induced stresses in tests conducted on 20" diameter pipes by Prior in 1935. © 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a8d9fb96-576d-49c1-a321-76b7ae53ed98 ER - TY - JOUR TI - Absorbing gas around the wasp-12 planetary system DO - 10.1088/2041-8205/766/2/L20 AU - Fossati, L. AU - Ayres, T.R. AU - Haswell, C.A. AU - Bohlender, D. AU - Kochukhov, O. AU - Flöer, L. T2 - The Astrophysical Journal Letters SN - 2041-8205 VL - 766 IS - 2 SP - L20 AB - Near-UV observations of the planet host star WASP-12 uncovered the apparent absence of the normally conspicuous core emission of the Mg II h and k resonance lines. This anomaly could be due either to (1) a lack of stellar activity, which would be unprecedented for a solar-like star of the imputed age of WASP-12 or (2) extrinsic absorption, from the intervening interstellar medium (ISM) or from material within the WASP-12 system itself, presumably ablated from the extreme hot Jupiter WASP-12 b. HIRES archival spectra of the Ca II H and K lines of WASP-12 show broad depressions in the line cores, deeper than those of other inactive and similarly distant stars and similar to WASP-12's Mg II h and k line profiles. We took high-resolution ESPaDOnS and FIES spectra of three early-type stars within 20′ of WASP-12 and at similar distances, which show the ISM column is insufficient to produce the broad Ca II depression observed in WASP-12. The EBHIS H I column density map supports and strengthens this conclusion. Extrinsic absorption by material local to the WASP-12 system is therefore the most likely cause of the line core anomalies. Gas escaping from the heavily irradiated planet could form a stable and thick circumstellar disk/cloud. The anomalously low stellar activity index () of WASP-12 is evidently a direct consequence of the extra core absorption, so similar HK index deficiencies might signal the presence of translucent circumstellar gas around other stars hosting evaporating planets. © 2013. The American Astronomical Society. All rights reserved.. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c5f8216a-b8c3-487c-aa2a-1981442fe457 ER - TY - JOUR TI - Feasibility of nanocrystalline cellulose production by endoglucanase treatment of natural bast fibers DO - 10.1016/j.indcrop.2013.09.029 AU - Xu, Yali AU - Salmi, Jani AU - Kloser, Elisabeth AU - Perrin, Florence AU - Grosse, Stephan AU - Denault, Johanne AU - Lau, Peter C. K. T2 - Industrial Crops and Products SN - 0926-6690 VL - 51 SP - 381 EP - 384 KW - Aggregated networks KW - Endoglucanase treatments KW - Endoglucanases KW - Fungal enzymes KW - Nanocrystalline cellulose KW - Nanocrystalline cellulose(NCC) KW - Physical pre-treatment KW - Thermostable enzymes KW - Aspergillus KW - Atomic force microscopy KW - Cellulose derivatives KW - Cloning KW - Enzymes KW - Flax KW - Hemp fibers KW - Linen KW - Yarn KW - Fibers KW - assessment method KW - cellulose KW - crystallinity KW - enzyme activity KW - feasibility study KW - fungus KW - height KW - physicochemical property KW - temperature effect KW - Cellulose Derivatives KW - Endo Enzymes KW - Fibers KW - Flax KW - Glucanase KW - Linen KW - Yarn AB - Whereas straw management presents a continuing challenge among farmers, tremendous opportunities may exist within the natural fibers in terms of value- added products or chemicals. This research provides the first assessment and demonstration of feasibility of an enzyme-assisted production of nanocrystalline cellulose (NCC) from hemp and flax fibers. A newly cloned endoglucanase (AoEG), derived from Aspergillus oryzae and characterized to be a thermostable enzyme with a half-life of 50. h at 50. °C was used for the hydrolysis. Atomic force microscopy (AFM) imaging of NCC produced from acid swollen cellulose and flax fibers indicated that they form aggregated network, showing rod-like nanofibrils of about 10. nm in height, and 200. nm in length. The yield of NCC using physical pretreatment only or combined physical-chemical pretreatment was compared. The highest yield of NCC was obtained under the conditions of 300. mg of flax fiber treated by 100. IU enzyme at 50. °C for 24. h after pretreatment of the fibers by sonication-microwave in 2% NaOH solution. DA - 2013/09/22 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 821487fd-0e92-4eb0-972e-8bdc630b4e12 ER - TY - JOUR TI - Vesicular storage of glycine in glutamatergic terminals in mouse hippocampus DO - 10.1016/j.neuroscience.2013.03.007 AU - Muller, E. AU - Bakkar, W. AU - Martina, M. AU - Sokolovski, A. AU - Wong, A. Y. C. AU - Legendre, P. AU - Bergeron, R. T2 - Neuroscience SN - 0306-4522 VL - 242 SP - 110 EP - 127 KW - immunohistochemistry; sniffer patch technique; whole-cell patch-clamp; bafilomycin; 4-AP; synaptic transmission; vesicular release AB - Glycine acts as a neuromodulator to regions rich in glutamatergic synapses, such as the forebrain. However, recent evidences for synaptic release of glycine in hippocampal cultured neurons and synaptosomes argue for the existence of functional glycinergic synapses in the hippocampus. It is well established that GABA and glycine act in concert at inhibitory synapses, while the existence of synapses which utilize both glutamate and glycine is less common. The purpose of the present study was to investigate the distribution of glycine and its role in hippocampal neurotransmission. Using immunohistochemistry, we demonstrate that vesicular glycine is preferentially stored in glutamatergic, rather than GABAergic presynaptic terminals. Using the sniffer patch technique, we found that glycine could be released upon presynaptic activity. Furthermore, using whole-cell patch-clamp recordings, we show for the first time the presence of a postsynaptic strychnine-sensitive chloride current in response to presynaptic stimulation. The small amplitude of this current is likely due to the paucity of postsynaptic glycine receptors rather than a low level of glycine release. Taken together, our results suggest that glycine is stored in glutamatergic presynaptic terminals. It is likely that the major role of glycine that is released from presynaptic terminals is to modulate N-methyl-. d-aspartate receptor function but may also play a role in decreasing neuronal excitability by opposing glutamatergic neurotransmission in pathological states such as epilepsy or ischemia. DA - 2013/03/16 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1e8377d2-5b3d-428a-a53d-8437adfed286 ER - TY - JOUR TI - Theoretical study of Oxygen reduction reaction catalysts: From Pt to non-precious metal catalysts DO - 10.1007/978-1-4471-4911-8_11 AU - Chen, X. AU - Xia, D. AU - Shi, Z. AU - Zhang, J. T2 - Lecture Notes in Energy SN - 2195-1284 SN - 9781447149101 VL - 9 SP - 339 EP - 373 KW - Carbon based materials KW - Macrocyclic complex KW - Mobile power generation KW - Non-precious metal catalysts KW - Oxygen reduction reaction KW - Theoretical investigations KW - Theoretical modeling KW - Transitional metals KW - Catalysis KW - Electrocatalysis KW - Electrolysis KW - Electrolytic reduction KW - Environmental impact KW - Palladium compounds KW - Platinum KW - Precious metals KW - Proton exchange membrane fuel cells (PEMFC) KW - Catalysts AB - Fuel cells are regarded as one of the most promising candidates for stationary and mobile power generation due to their high energy yield and low environmental impact of hydrogen oxidation. The oxygen reduction reaction (ORR) at cathode is a very complex process and plays a crucial role during operation of the PEM fuel cells. However, its mechanism and the nature of intermediates involved remain vague. This chapter focuses on the recent theoretical modeling studies of ORR catalysts for PEMFC. Recent theoretical investigations on oxygen reduction electrocatalysts, such as Pt-based catalysts, non-Pt metal catalysts (Pd, Ir, CuCl), and non-precious metal catalysts (transitional metal macrocyclic complexes, conductive polymer materials, and carbon-based materials), are reviewed. The oxygen reduction mechanisms catalyzed by these catalysts are discussed based on the results. © Springer-Verlag London 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 57842140-1527-43c1-a652-3589818dc519 ER - TY - JOUR TI - Robust pose estimation with an outlier diagnosis based on a relaxation of rigid body constraints DO - 10.1115/1.4006624 AU - Lin, Y. AU - Tu, X.-W. AU - Xi, F. AU - Chan, V. T2 - Journal of Dynamic Systems, Measurement and Control, Transactions of the ASME SN - 0022-0434 VL - 135 IS - 1 SP - 14502 KW - 3D point measurement KW - Diagnosis methods KW - Error distributions KW - Gross errors KW - High breakdown point KW - Least squares methods KW - Measured points KW - Point data KW - Pose estimation KW - Preprocess KW - Relaxation methods KW - Rigid body KW - Rigid-body motion KW - Large eddy simulation KW - Rigid structures KW - Statistics AB - In this paper, we propose a novel outlier diagnosis method for robust pose estimation of rigid body motions from outlier contaminated 3D point measurements. Due to incorrect correspondences in a cluttered measuring environment, observed point data are contaminated by outliers, which are unusual gross errors that lie out of an overall error distribution. Standard least-squares methods for pose estimation are highly sensitive to outliers. For this reason, an outlier diagnosis method is developed to preprocess measured point data prior to pose estimation. This diagnosis method detects and removes outliers based on a relaxation method with rigid body constraints of a rigid body. Simulations and experiments prove the effectiveness and advantages of high breakdown point and ease of implementation. © 2013 American Society of Mechanical Engineers. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2613a27b-cce4-4512-a2bb-c6535213cd45 ER - TY - JOUR TI - Simultaneous multi-band detection of low surface brightness galaxies with markovian modeling DO - 10.1088/0004-6256/145/2/36 AU - Vollmer, B. AU - Perret, B. AU - Petremand, M. AU - Lavigne, F. AU - Collet, Ch. AU - Van Driel, W. AU - Bonnarel, F. AU - Louys, M. AU - Sabatini, S. AU - MacArthur, L.A. T2 - Astronomical Journal SN - 0004-6256 VL - 145 IS - 2 SP - 36 AB - We present to the astronomical community an algorithm for the detection of low surface brightness (LSB) galaxies in images, called MARSIAA (MARkovian Software for Image Analysis in Astronomy), which is based on multi-scale Markovian modeling. MARSIAA can be applied simultaneously to different bands. It segments an image into a user-defined number of classes, according to their surface brightness and surroundings - typically, one or two classes contain the LSB structures. We have developed an algorithm, called DetectLSB, which allows the efficient identification of LSB galaxies from among the candidate sources selected by MARSIAA. The application of the method to two and three bands simultaneously was tested on simulated images. Based on our tests, we are confident that we can detect LSB galaxies down to a central surface brightness level of only 1.5 times the standard deviation from the mean pixel value in the image background. To assess the robustness of our method, the method was applied to a set of 18 B- and I-band images (covering 1.3 deg2 in total) of the Virgo Cluster to which Sabatini et al. previously applied a matched-filter dwarf LSB galaxy search algorithm. We have detected all 20 objects from the Sabatini et al. catalog which we could classify by eye as bona fide LSB galaxies. Our method has also detected four additional Virgo Cluster LSB galaxy candidates undetected by Sabatini et al. To further assess the completeness of the results of our method, both MARSIAA, SExtractor, and DetectLSB were applied to search for (1) mock Virgo LSB galaxies inserted into a set of deep Next Generation Virgo Survey (NGVS) gri-band subimages and (2) Virgo LSB galaxies identified by eye in a full set of NGVS square degree gri images. MARSIAA/DetectLSB recovered 20% more mock LSB galaxies and 40% more LSB galaxies identified by eye than SExtractor/DetectLSB. With a 90% fraction of false positives from an entirely unsupervised pipeline, a completeness of 90% is reached for sources with re > 3″ at a mean surface brightness level of μg = 27.7 mag arcsec-2 and a central surface brightness of μ0 g = 26.7 mag arcsec-2. About 10% of the false positives are artifacts, the rest being background galaxies. We have found our proposed Markovian LSB galaxy detection method to be complementary to the application of matched filters and an optimized use of SExtractor, and to have the following advantages: it is scale free, can be applied simultaneously to several bands, and is well adapted for crowded regions on the sky. © 2013. The American Astronomical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : bccd52c6-8d2f-428e-a8b9-92824f37c192 ER - TY - JOUR TI - Effect of material model on finite element modeling of aerospace alloys DO - 10.4028/www.scientific.net/KEM.554-557.151 AU - Saboori, M. AU - Gholipour, J. AU - Champliaud, H. AU - Gakwaya, A. AU - Savoie, J. AU - Wanjara, P. T2 - Key Engineering Materials T3 - 16th ESAFORM Conference on Material Forming, ESAFORM 2013, 22 April 2013 through 24 April 2013, Aveiro SN - 1013-9826 SN - 9783037857199 VL - 554-557 SP - 151 EP - 156 KW - Constitutive law KW - Expansion tests KW - Friction conditions KW - Hydroforming KW - Hydroforming technology KW - Material characteristics KW - Thickness reduction KW - Tube bulge KW - Aerospace industry KW - Cerium alloys KW - Expansion KW - Experiments KW - Friction KW - Materials KW - Metal forming KW - Finite element method AB - Increasing acceptance and use of hydroforming technology within the aerospace industry requires a comprehensive understanding of critical issues such as the material characteristics, friction condition and hydroformability of the material. Moreover, the cost of experiments can be reduced by accurate finite element modeling (FEM) entails the application of adapted constitutive laws for reproducing with confidence the material behavior. In this paper, the effect of different constitutive laws on FEM of tubular shapes is presented. The free expansion process was considered for developing the FEM. Bulge height, thickness reduction and strains were determined at the maximum bulge height using different constitutive models, including Hollomon, Ludwik, Swift, Voce and Ludwigson. In order to minimize the effect of friction, the free expansion experiments were performed with no end feeding. The simulation results were compared with the experimental data to find the appropriate constitutive law for the free expansion process. Copyright © 2013 Trans Tech Publications Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 64b73ecd-946a-409a-b00c-8b837f3b154e ER - TY - JOUR TI - Sensitivity to white matter fMRI activation increases with field strength DO - 10.1371/journal.pone.0058130 AU - Mazerolle, E.L. AU - Gawryluk, J.R. AU - Dillen, K.N.H. AU - Patterson, S.A. AU - Feindel, K.W. AU - Beyea, S.D. AU - Stevens, M.T.R. AU - Newman, A.J. AU - Schmidt, M.H. AU - D'Arcy, R.C.N. T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 3 SP - e58130 KW - adult KW - article KW - controlled study KW - female KW - field strength KW - functional magnetic resonance imaging KW - gray matter KW - human KW - human experiment KW - image analysis KW - male KW - motor performance KW - normal human KW - radiological parameters KW - sensorimotor cortex KW - signal noise ratio KW - task performance KW - white matter AB - Functional magnetic resonance imaging (fMRI) activation in white matter is controversial. Given that many of the studies that report fMRI activation in white matter used high field MRI systems, we investigated the field strength dependence of sensitivity to white matter fMRI activation. In addition, we evaluated the temporal signal to noise ratio (tSNR) of the different tissue types as a function of field strength. Data were acquired during a motor task (finger tapping) at 1.5 T and 4 T. Group and individual level activation results were considered in both the sensorimotor cortex and the posterior limb of the internal capsule. We found that sensitivity increases associated with field strength were greater for white matter than gray matter. The analysis of tSNR suggested that white matter might be less susceptible to increases in physiological noise related to increased field strength. We therefore conclude that high field MRI may be particularly advantageous for fMRI studies aimed at investigating activation in both gray and white matter. © 2013 Mazerolle et al. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 94693025-f576-4938-8fda-31d7f2f6b6fb ER - TY - JOUR TI - Monoclonal antibodies recognizing the surface autolysin IspC of Listeria monocytogenes Serotype 4b: epitope localization, kinetic characterization, and cross-reaction studies DO - 10.1371/journal.pone.0055098 AU - Ronholm, J. AU - van Faassen, H. AU - MacKenzie, R. AU - Zhang, Z. AU - Cao, X. AU - Lin, M. T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 2 SP - e55098 KW - autolysin KW - epitope KW - immunogenic surface protein C KW - monoclonal antibody KW - monoclonal antibody M2773 KW - monoclonal antibody M2774 KW - monoclonal antibody M2775 KW - monoclonal antibody M2777 KW - monoclonal antibody M2778 KW - monoclonal antibody M2779 KW - monoclonal antibody M2780 KW - monoclonal antibody M2781 KW - monoclonal antibody M2785 KW - monoclonal antibody M2787 KW - monoclonal antibody M2790 KW - monoclonal antibody M2791 KW - monoclonal antibody M2792 KW - monoclonal antibody M2795 KW - monoclonal antibody M2797 KW - monoclonal antibody M2799 KW - monoclonal antibody M2800 KW - unclassified drug KW - amino terminal sequence KW - antibody affinity KW - antibody specificity KW - article KW - bacterium isolate KW - C terminal cell wall binding domain KW - controlled study KW - cross reaction KW - dissociation constant KW - enzyme linked immunosorbent assay KW - epitope mapping KW - kinetics KW - Listeria monocytogenes KW - mass spectrometry KW - molecular weight KW - nonhuman KW - nucleotide sequence KW - protein domain KW - protein localization KW - serotype KW - surface plasmon resonance KW - Amino Acid Sequence KW - Antibodies, Monoclonal KW - Antibody Specificity KW - Antigens, Bacterial KW - Bacterial Proteins KW - Binding Sites KW - Cell Wall KW - Cross Reactions KW - Enzyme-Linked Immunosorbent Assay KW - Epitopes KW - Kinetics KW - Listeria monocytogenes KW - Mass Spectrometry KW - Molecular Sequence Data KW - N-Acetylmuramoyl-L-alanine Amidase KW - Protein Binding KW - Sequence Alignment KW - Serotyping KW - Surface Plasmon Resonance AB - Listeria monocytogenes serotype 4b is responsible for a high percentage of fatal cases of food-borne infection. In a previous study, we created 15 monoclonal antibodies (MAbs) against a ~77 kDa antigen that is associated with the cell surface of live L. monocytogenes serotype 4b cells. Here we report an extensive characterization of these MAbs to further their development as diagnostic reagents. The ~77 kDa target antigen was identified by mass spectrometry and N-terminal sequencing to be IspC, a novel surface associated autolysin. Epitope localization experiments revealed that each of the 15 MAbs recognized the C-terminal cell-wall binding domain of IspC. The presence of IspC was shown to be highly conserved within L. monocytogenes serotype 4b, as evidenced by a strong reaction between anti-IspC MAbs and all 4b isolates. To determine the range of cross-reactivity with other L. monocytogenes serotypes ELISA was used to test each MAb against multiple isolates from each of the L. monocytogenes serotypes. Of the 15 MAbs, five: M2774, M2775, M2780, M2790 and M2797, showed specificity for L. monocytogenes serotype 4b and only cross reacted with serotype 4ab isolates. The kinetics of the interaction between each of the MAbs and IspC was measured using surface plasmon resonance. The MAbs M2773, M2792, M2775, M2797 and M2781 each had very low dissociation constants (4.5 × 10-9 to 1.2 × 10-8 M). While several of these antibodies have properties which could be useful in diagnostic tests, the combined high fidelity and affinity of M2775 for the IspC protein and serotype 4b isolates, makes it a particularly promising candidate for use in the development of a specific L. monocytogenes serotype 4b diagnostic test. © 2013 Ronholm et al. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 31baa45a-cbfd-455b-aac4-36bf566de3cd ER - TY - JOUR TI - Herschel -HIFI observations of high- J CO and isotopologues in star-forming regions: From low to high mass DO - 10.1051/0004-6361/201220472 AU - San José-García, I. AU - Mottram, J.C. AU - Kristensen, L.E. AU - Van Dishoeck, E.F. AU - Yildiz, U.A. AU - Van Der Tak, F.F.S. AU - Herpin, F. AU - Visser, R. AU - McCoey, C. AU - Wyrowski, F. AU - Braine, J. AU - Johnstone, D. T2 - Astronomy and Astrophysics SN - 0004-6361 VL - 553 SP - 128 KW - Astrochemistry KW - ISM: Kinematics and dynamics KW - ISM: molecules KW - Line: Profiles KW - Stars: formation KW - Stars: protostars KW - Dynamics KW - Luminance KW - Molecules KW - Stars AB - Context. Our understanding of the star formation process has traditionally been confined to certain mass or luminosity boundaries because most studies focus only on low-, intermediate-, or high-mass star-forming regions. Therefore, the processes that regulate the formation of these different objects have not been effectively linked. As part of the "Water In Star-forming regions with Herschel" (WISH) key programme, water and other important molecules, such as CO and OH, have been observed in 51 embedded young stellar objects (YSOs). The studied sample covers a range of luminosities from <1 to >10 5L⊙. Aims. We analyse the CO line emission towards a large sample of embedded protostars in terms of both line intensities and profiles. This analysis covers a wide luminosity range in order to achieve better understanding of star formation without imposing luminosity boundaries. In particular, this paper aims to constrain the dynamics of the environment in which YSOs form. Methods. Herschel-HIFI spectra of the 12CO J = 10-9, 13CO J = 10-9 and C18O J = 5-4, J = 9-8 and J = 10-9 lines were analysed for a sample of 51 embedded protostars. In addition, JCMT spectra of 12CO J = 3-2 and C18O J = 3-2 extend this analysis to cooler gas components. We focussed on characterising the shape and intensity of the CO emission line profiles by fitting the lines with one or two Gaussian profiles. We compared the values and results of these fits across the entire luminosity range covered by WISH observations. The effects of different physical parameters as a function of luminosity and the dynamics of the envelope-outflow system were investigated. Results. All observed CO and isotopologue spectra show a strong linear correlation between the logarithms of the line and bolometric luminosities across six orders of magnitude on both axes. This suggests that the high-J CO lines primarily trace the amount of dense gas associated with YSOs and that this relation can be extended to larger (extragalactic) scales. The majority of the detected 12CO line profiles can be decomposed into a broad and a narrow Gaussian component, while the C18O spectra are mainly fitted with a single Gaussian. For low- and intermediate-mass protostars, the width of the C18O J = 9-8 line is roughly twice that of the C18O J = 3-2 line, suggesting increased turbulence/infall in the warmer inner envelope. For high-mass protostars, the line widths are comparable for lower- and higher-J lines. A broadening of the line profile is also observed from pre-stellar cores to embedded protostars, which is due mostly to non-thermal motions (turbulence/infall). The widths of the broad 12CO J = 3-2 and J = 10-9 velocity components correlate with those of the narrow C18O J = 9-8 profiles, suggesting that the entrained outflowing gas and envelope motions are related but independent of the mass of the protostar. These results indicate that physical processes in protostellar envelopes have similar characteristics across the studied luminosity range. © ESO, 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 07cbddb1-fed0-46f9-956e-206a84606246 ER - TY - JOUR TI - First results from the herschel gould belt survey in taurus DO - 10.1093/mnras/stt561 AU - Kirk, J.M. AU - Ward-Thompson, D. AU - Palmeirim, P. AU - André, P. AU - Griffin, M.J. AU - Hargrave, P.J. AU - Könyves, V. AU - Bernard, J.-P. AU - Nutter, D.J. AU - Sibthorpe, B. AU - Di Francesco, J. AU - Abergel, A. AU - Arzoumanian, D. AU - Benedettini, M. AU - Bontemps, S. AU - Elia, D. AU - Hennemann, M. AU - Hill, T. AU - Men'shchikov, A. AU - Motte, F. AU - Nguyen-Luong, Q. AU - Peretto, N. AU - Pezzuto, S. AU - Rygl, K.L.J. AU - Sadavoy, S.I. AU - Schisano, E. AU - Schneider, N. AU - Testi, L. AU - White, G. T2 - Monthly Notices of the Royal Astronomical Society SN - 0035-8711 VL - 432 IS - 2 SP - 1424 EP - 1433 AB - The whole of the Taurus region (a total area of 52 deg2) has been observed by the Herschel Spectral and Photometric Imaging Receiver (SPIRE) and Photodetector Array Camera and Spectrometer (PACS) instruments at wavelengths of 70, 160, 250, 350 and 500 μm as part of the Herschel Gould Belt Survey. In this paper we present the first results from the part of the Taurus re gion that includes the Barnard 18 and L1536 clouds. A new source-finding routine, the Cardiff Source-finding AlgoRithm (CSAR), is introduced, which is loosely based on CLUMPFIND, but that also generates a structure tree, or dendrogram, which can be used to interpret hierarchical clump structure in a complex region. Sources were extracted from the data using the hierarchical version of CSAR and plotted on a mass-size diagram. We found a hierarchy of objects with sizes in the range 0.024-2.7 pc. Previous studies showed that gravitationally bound prestellar cores and unbound starless clumps appeared in different places on the mass-size diagram. However, it was unclear whether this was due to a lack of instrumental dynamic range or whether they were actually two distinct populations. The excellent sensitivity of Herschel shows that our sources fill the gap in the mass-size plane between starless and pre-stellar cores, and gives the first clear supporting observational evidence for the theory that unbound clumps and (gravitationally bound) prestellar cores are all part of the same population, and hence presumably part of the same evolutionary sequence. © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6e78273d-2c20-4a53-83d5-3627012843d5 ER - TY - JOUR TI - Three-mode electrochemical sensing of ultralow MicroRNA levels DO - 10.1021/ja308216z AU - Labib, M. AU - Khan, N. AU - Ghobadloo, S.M. AU - Cheng, J. AU - Pezacki, J.P. AU - Berezovski, M.V. T2 - Journal of the American Chemical Society SN - 0002-7863 VL - 135 IS - 8 SP - 3027 EP - 3038 KW - Cancer cells KW - Cancer classification KW - Direct detection KW - Dynamic range KW - Electrochemical sensing KW - High selectivity KW - Human serum KW - MicroRNAs KW - PCR amplification KW - Protein binding KW - Sequential analysis KW - Single electrodes KW - Wide dynamic range KW - Biochemistry KW - Electrochemical sensors KW - Polymerase chain reaction KW - RNA KW - Sensors KW - microRNA KW - microRNA 122 KW - microRNA 21 KW - microRNA 32 KW - protein p19 KW - unclassified drug KW - article KW - concentration (parameters) KW - electrochemical analysis KW - electrochemical detection KW - electrode KW - gene amplification KW - human KW - human tissue KW - hybridization KW - limit of detection KW - protein binding KW - protein localization KW - real time polymerase chain reaction KW - RNA analysis KW - sensor KW - Base Sequence KW - DNA Primers KW - Electrochemical Techniques KW - Humans KW - MicroRNAs KW - Nucleic Acid Hybridization KW - Real-Time Polymerase Chain Reaction AB - MicroRNAs (miRNAs) are an emerging class of biomarkers that are frequently deregulated in cancer cells and have shown great promise for cancer classification and prognosis. In this work, we developed a three-mode electrochemical sensor for detection and quantitation of ultralow levels of miRNAs in a wide dynamic range of measured concentrations. The sensor facilitates three detection modalities based on hybridization (H-SENS), p19 protein binding (P-SENS), and protein displacement (D-SENS). The combined three-mode sensor (HPD-SENS) identifies as low as 5 aM or 90 molecules of miRNA per 30 μL of sample without PCR amplification, and can be operated within the dynamic range from 10 aM to 1 μM. The HPD sensor is made on a commercially available gold nanoparticles-modified electrode and is suitable for analyzing multiple miRNAs on a single electrode. This three-mode sensor exhibits high selectivity and specificity and was used for sequential analysis of miR-32 and miR-122 on one electrode. In addition, the H-SENS can recognize miRNAs with different A/U and G/C content and distinguish between a fully matched miRNA and a miRNA comprising either a terminal or a middle single base mutation. Furthermore, the H- and P-SENS were successfully employed for direct detection and profiling of three endogenous miRNAs, including hsa-miR-21, hsa-miR-32, and hsa-miR-122 in human serum, and the sensor results were validated by qPCR. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5591f322-f823-4e82-bd15-e919edd403e2 ER - TY - JOUR TI - Multiplexed evaluation of serum and CSF pharmacokinetics of brain-targeting single-domain antibodies using a NanoLC-SRM-ILIS method DO - 10.1021/mp3004995 AU - Haqqani, A.S. AU - Caram-Salas, N. AU - Ding, W. AU - Brunette, E. AU - Delaney, C.E. AU - Baumann, E. AU - Boileau, E. AU - Stanimirovic, D. T2 - Molecular Pharmaceutics SN - 1543-8384 VL - 10 IS - 5 SP - 1542 EP - 1556 KW - FC44 antibody KW - FC5 antibody KW - nanobody KW - peptides and proteins KW - unclassified drug KW - animal cell KW - animal experiment KW - animal tissue KW - article KW - binding affinity KW - blood brain barrier KW - blood cerebrospinal fluid barrier KW - brain cell KW - brain endothelial cell KW - cerebrospinal fluid KW - controlled study KW - drug cerebrospinal fluid level KW - endothelium cell KW - fluorescence imaging KW - human KW - human cell KW - in vitro study KW - isotope labeling KW - limit of detection KW - limit of quantitation KW - male KW - microvascular endothelial cell KW - molecular weight KW - nonhuman KW - nucleotide sequence KW - outcome assessment KW - phage display KW - plasma half life KW - priority journal KW - treatment duration AB - FC5 and FC44 are single-domain antibodies (VHHs), selected by functional panning of phage-display llama VHH library for their ability to internalize human brain endothelial cells (BEC) and to transmigrate the in vitro BBB model. Quantification of brain delivery of FC5 and FC44 in vivo was challenging using classical methods because of their short plasma half-life and their loss of functionality with radioactive labeling. A highly sensitive (detection limit <2 ng/mL) and specific SRM-ILIS method to detect and quantify unlabeled VHHs in multiplexed assays was developed and applied to comparatively evaluate brain delivery of FC5 and FC44, and two control VHHs, EG2 and A20.1. FC5 and FC44 compared to control V HHs demonstrated significantly (p < 0.01) enhanced transport (50-100-fold) across rat in vitro BBB model as well as in vivo brain targeting assessed by optical imaging. The multiplexed SRM-ILIS analyses of plasma and CSF levels of codosed VHHs demonstrated that while all 4 VHHs have similar blood pharmacokinetics, only FC5 and FC44 show elevated CSF levels, suggesting that they are potential novel carriers for delivery of drugs and macromolecules across the BBB. © Published 2012 by the American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0d951595-1ff4-4447-965c-44d5a9dc3e9c ER - TY - JOUR TI - Bilayer thickness mismatch controls domain size in model membranes DO - 10.1021/ja3113615 AU - Heberle, F.A. AU - Petruzielo, R.S. AU - Pan, J. AU - Drazba, P. AU - Kučerka, N. AU - Standaert, R.F. AU - Feigenson, G.W. AU - Katsaras, J. T2 - Journal of the American Chemical Society SN - 0002-7863 VL - 135 IS - 18 SP - 6853 EP - 6859 KW - 1 ,2-dioleoyl-sn-glycero-3-phosphocholine KW - Experimental verification KW - Functional domains KW - Lateral phase separation KW - Lipid composition KW - Small-angle neutron scattering KW - Unilamellar vesicle KW - Unsaturated phospholipids KW - Lipid bilayers KW - Neutron scattering KW - Optical microscopy KW - Phase separation KW - Phospholipids KW - Signal transduction KW - Liquids KW - 1,2 distearoyl sn glycero 3 phosphocholine KW - 2 oleoyl 1 palmitoylphosphatidylcholine KW - cholesterol KW - dioleoylphosphatidylcholine KW - phospholipid KW - phosphorylcholine KW - unclassified drug KW - article KW - bilayer membrane KW - lipid composition KW - liquid KW - neutron scattering KW - thickness AB - The observation of lateral phase separation in lipid bilayers has received considerable attention, especially in connection to lipid raft phenomena in cells. It is widely accepted that rafts play a central role in cellular processes, notably signal transduction. While micrometer-sized domains are observed with some model membrane mixtures, rafts much smaller than 100 nm - beyond the reach of optical microscopy - are now thought to exist, both in vitro and in vivo. We have used small-angle neutron scattering, a probe free technique, to measure the size of nanoscopic membrane domains in unilamellar vesicles with unprecedented accuracy. These experiments were performed using a four-component model system containing fixed proportions of cholesterol and the saturated phospholipid 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC), mixed with varying amounts of the unsaturated phospholipids 1-palmitoyl-2-oleoyl-sn- glycero-3-phosphocholine (POPC) and 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC). We find that liquid domain size increases with the extent of acyl chain unsaturation (DOPC:POPC ratio). Furthermore, we find a direct correlation between domain size and the mismatch in bilayer thickness of the coexisting liquid-ordered and liquid-disordered phases, suggesting a dominant role for line tension in controlling domain size. While this result is expected from line tension theories, we provide the first experimental verification in free-floating bilayers. Importantly, we also find that changes in bilayer thickness, which accompany changes in the degree of lipid chain unsaturation, are entirely confined to the disordered phase. Together, these results suggest how the size of functional domains in homeothermic cells may be regulated through changes in lipid composition. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d5142ac4-9661-40c0-9dee-c340df802044 ER - TY - JOUR TI - Scattering detection using a photonic-microfluidic integrated device with on-chip collection capabilities DO - 10.1002/elps.201300195 AU - Watts, B.R. AU - Zhang, Z. AU - Xu, C.Q. AU - Cao, X. AU - Lin, M. T2 - Electrophoresis SN - 0173-0835 AB - SU-8-based photonic-microfluidic integrated devices with on-chip beam shaping and collection capabilities were demonstrated in a scattering detection and counting application. Through the proper deployment of the tailored beam geometries via the on-chip excitation optics, excellent CV values were measured for 1, 2, and 5 μm blank beads, 16.4, 11.0, and 12.5%, respectively, coupled with a simple free-space optical detection scheme. The performance of these devices was found dependent on the combination of on-chip, lens-shaped beam geometry and bead size. While very low CVs were obtained when the combination was ideal, a nonideal combination could still result in acceptable CVs for flow cytometry; the reliability was confirmed via devices being able to resolve separate populations of 2.0 and 5.0 μm beads from their mixture with low CV values of 15.9 and 18.5%, respectively. On-chip collection using integrated on-chip optical waveguides was shown to be very reliable in comparison with a free-space collection scheme, yielding a coincident rate of 94.2%. A CV as low as 19.2% was obtained from the on-chip excitation and collection of 5 μm beads when the on-chip lens-shaped beam had a 6.0-μm beam waist. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5cbc70d4-e27a-47dc-8134-a7813b5ea66f ER - TY - JOUR TI - Optimization of thermoplastic composites resistance welding parameters based on transient heat transfer finite element modeling DO - 10.1177/0892705711428657 AU - Talbot, E. AU - Hubert, P. AU - Dubé, M. AU - Yousefpour, A. T2 - Journal of Thermoplastic Composite Materials SN - 0892-7057 VL - 26 IS - 5 SP - 699 EP - 717 KW - Experimental datum KW - Finite element modeling KW - Finite element models KW - Heat transfer mechanism KW - Joints/joining KW - Mechanical performance KW - Thermoplastic composite KW - Transient heat transfer KW - Composite materials KW - Finite element method KW - Heat transfer KW - Optimization KW - Polymer matrix composites KW - Resistance welding KW - Thermoplastics KW - Three dimensional computer graphics KW - Welds KW - Three dimensional AB - The use of resistance welding technology to join thermoplastic composite aerospace structures is still contingent upon a better understanding of the heat transfer mechanisms occurring during welding, which govern the joint quality and mechanical performance. In this study, two-dimensional (2D) and three-dimensional (3D) transient heat transfer finite element models were developed to simulate resistance welding of thermoplastic composites. The 2D model was used to investigate the effect of the length of the exposed areas of the heating element to air (clamping distance) on the local overheating at the edges and the effects of the input power level on the thermal behavior of the welds. It is shown that controlling the clamping distance improves the thermal uniformity of the weld. The 3D model shows that heat conduction along the length of the laminates influences the thermal uniformity of the weld interface. An optimization chart is developed in order to minimize the undesirable edge effect and to define the conditions required to obtain a complete weld. The results of the 3D model are compared with experimental data. © The Author(s) 2011. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b9c41e04-79b2-4aae-9f2d-3a9435262ebb ER - TY - JOUR TI - Witnessing the differential evolution of disk galaxies in luminosity and size via gravitational lensing DO - 10.1088/0004-637X/777/1/1 AU - Bandara, K. AU - Crampton, D. AU - Peng, C. AU - Simard, L. T2 - The Astrophysical Journal SN - 0004-637X VL - 777 IS - 1 SP - 1 AB - We take advantage of the magnification in size and flux of a galaxy provided by gravitational lensing to analyze the properties of 62 strongly lensed galaxies from the Sloan Lens ACS (SLACS) Survey. The sample of lensed galaxies spans a redshift range of 0.20 ≤ z ≤ 1.20 with a median redshift of z = 0.61. We use the lens modeling code LENSFIT to derive the luminosities, sizes, and Sérsic indices of the lensed galaxies. The measured properties of the lensed galaxies show a primarily compact, "disk"-like population with the peaks of the size and Sérsic index distributions corresponding to ∼1.50 kpc and n ∼ 1, respectively. Comparison of the SLACS galaxies to a non-lensing, broadband imaging survey shows that a lensing survey allows us to probe a galaxy population that reaches ∼2 mag fainter. Our analysis allows us to compare the 〈z〉 = 0.61 disk galaxy sample (n ≤ 2.5) to an unprecedented local galaxy sample of ∼670, 000 SDSS galaxies at z ∼ 0.1; this analysis indicates that the evolution of the luminosity-size relation since z ∼ 1 may not be fully explained by a pure-size or pure-luminosity evolution but may instead require a combination of both. Our observations are also in agreement with recent numerical simulations of disk galaxies that show evidence of a mass-dependent evolution since z ∼ 1, where high-mass disk galaxies (M * > 109 M⊙) evolve more in size and low-mass disk galaxies (M * ≤ 109 M⊙) evolve more in luminosity. © 2013. The American Astronomical Society. All rights reserved.. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 37b39717-daa9-4f5a-bc55-8f2569d8f9c2 ER - TY - JOUR TI - Rolled-up 1.5 μm InAs quantum dot tube lasers and integrated nanophotonic circuits on Si DO - 10.1109/PHOSST.2013.6614486 AU - Mi, Z. AU - Dastjerdi, M.H.T. AU - Bianucci, P. AU - Tian, Z. AU - Zhong, Q. AU - Veerasubramanian, V. AU - Poole, P.J. AU - Kirk, A.G. AU - Plant, D.V. T2 - 2013 IEEE Photonics Society Summer Topical Meeting Series, PSSTMS 2013 T3 - 2013 IEEE Photonics Society Summer Topical Meeting Series, PSSTMS 2013, 8 July 2013 through 10 July 2013, Waikoloa, HI SN - 9781467350600 SP - 6614486 SP - 34 EP - 35 KW - Direct integration KW - Electronic component KW - Emission wavelength KW - High performance lasers KW - InAs quantum dots KW - Nanophotonic circuits KW - Nanoscale lasers KW - Telecom wavelengths KW - Optical communication KW - Semiconducting silicon KW - Semiconductor quantum dots KW - Silicon KW - Tubes (components) KW - Semiconductor lasers AB - Low threshold, ultrahigh speed micro- and nanoscale lasers that can be directly integrated with optoelectronic and electronic components on a CMOS chip are in demand for future chip-level optical communications. In this regard, rolled-up semiconductor tube optical cavities, formed when coherently strained nanomembranes are selectively released from the host substrate, have emerged as a promising approach to realize high performance lasers on Si. 1-3 We have investigated the design, fabrication, and characterization of InAs/InGaAsP quantum dot tube lasers. We report the first demonstration of semiconductor tube lasers that can operate at the telecom wavelength (∼ 1.5 μm). Such devices can exhibit an extremely low threshold (∼ 1.26 μW) and multiple emission wavelengths. The direct integration of quantum dot tube devices with Si waveguides has also been demonstrated. © 2013 IEEE. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ddb5420b-6199-4fe1-b9f7-b1cb34e4e10e ER - TY - JOUR TI - Electrochemical SERS study of a biomimetic membrane supported at a nanocavity patterned Ag electrode DO - 10.1016/j.electacta.2013.03.139 AU - Vezvaie, M. AU - Brosseau, C.L. AU - Lipkowski, J. T2 - Electrochimica Acta SN - 0013-4686 VL - 110 SP - 120 EP - 132 AB - Lipid bilayers in which two leaflets were made of dimyristoyl- phosphatidylcholine (DMPC) and hybrid bilayers with one leaflet composed of hydrogenated lipid and another leaflet of deuterium substituted molecules (d63-DMPC) were deposited on highly ordered nanocavity patterned Ag electrodes using LB-LS and vesicle fusion techniques. In situ electrochemical surface enhanced Raman scattering (EC-SERS) was then used to study potential driven changes in these model biological membranes. The nanocavity structures provided a SERS active substrate with uniformly distributed surface enhancement. To ensure that the bilayer was separated from the metal surface by a hydrophilic space layer, the electrodes were chemically modified with a self-assembled monolayer (SAM) of β-thioglucose (TG) molecules. The monolayer of TG ensured that the solid substrate surface was hydrophilic. The electrochemical properties of the bilayer were monitored by recording differential capacitance curves. EC-SERS indicated that at the silver surface modified by the monolayer of TG the lower leaflet (in contact with the support) is more ordered than the top leaflet that is contact with solution. However, both leaflets remained in the liquid crystalline (LC) state for the entire range of investigated potentials. The results of this study show that the DMPC bilayer at the nanocavity patterned Ag surface may be used as a good biomimetic membrane model in future SERS studies of membrane proteins. The information concerning the effect of the electrode potential on membrane stability may be useful for the development of biosensors.© 2013 Published by Elsevier Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 19b65e0a-fa77-41a0-8411-81b86d93f351 ER - TY - JOUR TI - Study of the formation of soot and its precursors in flames using optical diagnostics DO - 10.1016/j.proci.2012.09.004 AU - Desgroux, P. AU - Mercier, X. AU - Thomson, K.A. T2 - Proceedings of the Combustion Institute SN - 1540-7489 VL - 34 IS - 1 SP - 1713 EP - 1738 KW - Comparative measurements KW - Elastic light scattering KW - Flame KW - Laser induced fluorescence KW - Laser induced incandescence KW - Optical diagnostics KW - Polycyclic aromatic hydrocarbons (PAHS) KW - Soot precursors KW - Combustion KW - Dust KW - Optical properties KW - Polycyclic aromatic hydrocarbons KW - Supersonic aerodynamics KW - Soot AB - Soot particle emission from combustion processes is a significant environmental and health problem. Optical detection is clearly the only viable choice for in situ PAH and soot measurement in turbulent flames. This paper reviews the considerable progress made in optical diagnostics of soot and its precursors formed this last decade. Advances include the spectroscopy of polycyclic aromatic hydrocarbons (PAHs) and optical diagnostics for PAHs in flames, new approaches to identify the structure and composition of incipient soot, and the latest refinements for soot particle detection and quantification. Improvements of selective and quantitative PAH measurements have been made possible with supersonic expansion of flame extracted samples, coupled with laser induced fluorescence (jet-cooled LIF) and mass-spectroscopy combined with resonance enhanced or synchrotron selective photoionisation. More accurate description of all facets of soot particles properties (optical properties, morphology, and volume fraction) has guided recent research. In particular, optical exploration has led to new insight into soot inception, including the identification of particular soot precursors from large PAHs to nanoparticles passing through stacked PAHs, polymeric-like structures and aliphatic-linked PAHs. Despite the various improvements, the ultimate accuracy of the soot diagnostic methods such as laser induced incandescence, light extinction and elastic light scattering relies on our knowledge of the soot optical properties which may vary as a function of soot age in flames. Nonetheless, with well designed experiments, comparative measurement of sooting trends within or between flames can be acquired with accuracies needed for the validation of numerical simulations of soot formation. These optical methods have been successfully adopted to classify the sooting tendencies of a large number of hydrocarbons and to examine the effect of pressure on soot formation. The ultimate objective is certainly to use optical diagnostics to provide useful data for soot formation modelling in turbulent flames and under practical combustion. © 2012 The Combustion Institute. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b4e2782a-0505-41d2-a2e0-0d29f02e1080 ER - TY - JOUR TI - Default mode network functional connectivity altered in failed back surgery syndrome DO - 10.1016/j.jpain.2012.12.018 AU - Kornelsen, J. AU - Sboto-Frankenstein, U. AU - McIver, T. AU - Gervai, P. AU - Wacnik, P. AU - Berrington, N. AU - Tomanek, B. T2 - Journal of Pain SN - 1526-5900 VL - 14 IS - 5 SP - 483 EP - 491 KW - adult KW - aged KW - article KW - clinical article KW - controlled study KW - default mode network KW - failed back surgery syndrome KW - female KW - functional magnetic resonance imaging KW - human KW - independent component analysis KW - insula KW - male KW - nerve cell network KW - postcentral gyrus KW - prefrontal cortex KW - primary motor cortex KW - sensorimotor integration AB - The purpose of this study was to identify alterations in the default mode network of failed back surgery syndrome patients as compared to healthy subjects. Resting state functional magnetic resonance imaging was conducted at 3 Tesla and data were analyzed with an independent component analysis. Results indicate an overall reduced functional connectivity of the default mode network and recruitment of additional pain modulation brain regions, including dorsolateral prefrontal cortex, insula, and additional sensory motor integration brain regions, including precentral and postcentral gyri, for failed back surgery syndrome patients. Perspective: This article presents alterations in the default mode network of chronic low back pain patients with failed back surgery syndrome as compared to healthy participants. © 2013 by the American Pain Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 71e58c4f-7997-4f51-bd92-b7fd77ca1272 ER - TY - JOUR TI - The K1 capsular polysaccharide from Acinetobacter baumannii Is a potential therapeutic target via passive immunization DO - 10.1128/IAI.01184-12 AU - Russo, T.A. AU - Beanan, J.M. AU - Olson, R. AU - MacDonald, U. AU - Cox, A.D. AU - St. Michael, F. AU - Vinogradov, E.V. AU - Spellberg, B. AU - Luke-Marshall, N.R. AU - Campagnari, A.A. T2 - Infection and Immunity SN - 0019-9567 VL - 81 IS - 3 SP - 915 EP - 922 KW - epitope KW - K1 capsular polysaccharide KW - monoclonal antibody KW - polysaccharide KW - unclassified drug KW - Acinetobacter baumannii KW - animal experiment KW - animal model KW - article KW - bacterial capsule KW - bacterial clearance KW - bacterial growth KW - bacterial strain KW - bacterial survival KW - bactericidal activity KW - carbohydrate analysis KW - controlled study KW - immunogenicity KW - male KW - mass spectrometry KW - molecular mimicry KW - mouse KW - neutrophil KW - nonhuman KW - nuclear magnetic resonance KW - opsonization KW - passive immunization KW - priority journal KW - rat KW - seroprevalence KW - serotype KW - soft tissue infection KW - Acinetobacter baumannii KW - Acinetobacter Infections KW - Animals KW - Antibodies, Monoclonal KW - Bacterial Capsules KW - Bacterial Vaccines KW - Epitopes KW - Flow Cytometry KW - Gene Expression Regulation, Bacterial KW - Immunization, Passive KW - Magnetic Resonance Spectroscopy KW - Male KW - Mass Spectrometry KW - Mice KW - Rats KW - Rats, Long-Evans AB - The emergence of extremely resistant and panresistant Gram-negative bacilli, such as Acinetobacter baumannii, requires consideration of nonantimicrobial therapeutic approaches. The goal of this report was to evaluate the K1 capsular polysaccharide from A. baumannii as a passive immunization target. Its structure was determined by a combination of mass spectrometric and nuclear magnetic resonance (NMR) techniques. Molecular mimics that might raise the concern for autoimmune disease were not identified. Immunization of CD1 mice demonstrated that the K1 capsule is immunogenic. The monoclonal antibody (MAb) 13D6, which is directed against the K1 capsule from A. baumannii, was used to determine the seroprevalence of the K1 capsule in a collection of 100 A. baumannii strains. Thirteen percent of the A. baumannii isolates from this collection were seroreactive to MAb 13D6. Opsonization of K1-positive strains, but not K1-negative strains, with MAb 13D6 significantly increased neutrophil-mediated bactericidal activity in vitro (P < 0.05). Lastly, treatment with MAb 13D6 3 and 24 h after bacterial challenge in a rat soft tissue infection model resulted in a significant decrease in the growth/survival of a K1-positive strain compared to that of a K1-negative strain or to treatment with a vehicle control (P < 0.0001). These data support the proof of principle that the K1 capsule is a potential therapeutic target via passive immunization. Other serotypes require assessment, and pragmatic challenges exist, such as the need to serotype infecting strains and utilize serotype-specific therapy. Nonetheless, this approach may become an important therapeutic option with increasing antimicrobial resistance and a diminishing number of active antimicrobials. © 2013, American Society for Microbiology. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2736793c-658d-4053-acfa-cbe77b1f59a9 ER - TY - JOUR TI - Structural and optical properties of Si/Ge nanowire heterojunctions DO - 10.1149/05301.0215ecst AU - Tsybeskov, L. AU - Chang, H.-Y. AU - Mala, S. AU - Kamins, T.I. AU - Wu, X. AU - Lockwood, D.J. T2 - ECS Transactions T3 - 5th International Symposium on Graphene, Ge/III-V and Emerging Materials For Post-CMOS Applications - 223rd ECS Meeting, 12 May 2013 through 17 May 2013, Toronto, ON SN - 1938-5862 SN - 9781607683742 VL - 53 IS - 1 SP - 215 EP - 224 KW - Axial heterojunctions KW - Chemical compositions KW - Lateral expansion KW - Lattice-mismatched KW - Partial amorphization KW - Structural and optical properties KW - Structural defect KW - Vapor-liquid-solid techniques KW - Germanium KW - Graphene KW - Heterojunctions KW - Semiconductor quantum wells KW - Thermal expansion KW - Transmission electron microscopy KW - Vapors KW - Nanowires AB - In crystalline, dislocation-free, Si/Ge nanowire (NW) axial heterojunctions grown using the vapor-liquid-solid (VLS) technique, transmission electron microscopy (TEM) photoluminescence (PL) and Raman spectroscopy reveal a SiGe alloy transition layer with preferential chemical composition and strain. In addition to the lattice mismatch, strain due to the difference in Si and Ge thermal expansion is observed. We find, in agreement with theoretical predictions, that the strain can be partially relived by lateral nanowire expansion in the vicinity of the Si/Ge heteroj unction. In addition to the observed nanowire lateral expansion, the lattice mismatched induced strain could be relaxed by other mechanisms including intermixing, formation of structural defects and partial amorphization. The conclusions are supported by analytical TEM measurements. © The Electrochemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : de52388a-c038-4653-ad1f-80439c21537e ER - TY - JOUR TI - 2-Nitrobenzoate 2-Nitroreductase (NbaA) switches its substrate specificity from 2-Nitrobenzoic acid to 2,4-Dinitrobenzoic acid under oxidizing conditions DO - 10.1128/JB.02016-12 AU - Kim, Y.-H. AU - Song, W.-S. AU - Go, H. AU - Cha, C.-J. AU - Lee, C. AU - Yu, M.-H. AU - Lau, P.C.K. AU - Lee, K. T2 - Journal of Bacteriology SN - 0021-9193 VL - 195 IS - 2 SP - 480 EP - 192 KW - 2 nitrobenzoate 2 nitroreductase KW - 2 nitrobenzoic acid KW - 2,4 dinitrobenzoic acid KW - cysteine KW - dithiothreitol KW - nitrobenzoic acid derivative KW - nitroreductase KW - oligomer KW - reduced nicotinamide adenine dinucleotide phosphate KW - unclassified drug KW - anaerobic capacity KW - article KW - catalysis KW - disulfide bond KW - enzyme activity KW - enzyme modification KW - high performance liquid chromatography KW - nonhuman KW - nucleotide sequence KW - pH KW - polyacrylamide gel electrophoresis KW - priority journal KW - tandem mass spectrometry KW - temperature KW - thin layer chromatography KW - Pseudomonas fluorescens AB - 2-Nitrobenzoate 2-nitroreductase (NbaA) of Pseudomonas fluorescens strain KU-7 is a unique enzyme, transforming 2-nitrobenzoic acid (2-NBA) and 2,4-dinitrobenzoic acid (2,4-DNBA) to the 2-hydroxylamine compounds. Sequence comparison reveals that NbaA contains a conserved cysteine residue at position 141 and two variable regions at amino acids 65 to 74 and 193 to 216. The truncated mutant Δ65-74 exhibited markedly reduced activity toward 2,4-DNBA, but its 2-NBA reductionactivity was unaffected; however, both activities were abolished in the Δ193-216 mutant, suggesting that these regions are necessary for the catalysis and specificity of NbaA. NbaA showed different lag times for the reduction of 2-NBA and 2,4-DNBA with NADPH, and the reduction of 2,4-DNBA, but not 2-NBA, failed in the presence of 1mMdithiothreitol or under anaerobic conditions, indicating oxidative modification of the enzyme for 2,4-DNBA. The enzyme was irreversibly inhibited by 5,5'-dithio-bis-(2-nitrobenzoic acid) and ZnCl2, which bind to reactive thiol/thiolate groups, and was eventually inactivated during the formation of higherorder oligomers at high pH, high temperature, or in the presence of H2O2. SDS-PAGE and mass spectrometry revealed the formation of intermolecular disulfide bonds by involvement of the two cysteines at positions 141 and 194. Site-directed mutagenesis indicated that the cysteines at positions 39, 103, 141, and 194 played a role in changing the enzyme activity and specificity toward 2-NBA and 2,4-DNBA. This study suggests that oxidative modifications of NbaA are responsible for the differential specificity for the two substrates and further enzyme inactivation through the formation of disulfide bonds under oxidizing conditions. © 2013, American Society for Microbiology. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b0fd7e88-20f3-490a-81c1-b1203bdfa965 ER - TY - JOUR TI - Neutron scattering study of correlated phase behavior in Sr 2IrO4 DO - 10.1103/PhysRevB.87.144405 AU - Dhital, C. AU - Hogan, T. AU - Yamani, Z. AU - De La Cruz, C. AU - Chen, X. AU - Khadka, S. AU - Ren, Z. AU - Wilson, S.D. T2 - Physical Review B - Condensed Matter and Materials Physics SN - 1098-0121 VL - 87 IS - 14 SP - 144405 AB - Neutron diffraction measurements exploring the magnetic and structural phase behaviors of the candidate Jeff=1/2 Mott insulating iridate Sr2IrO4 are presented. Comparisons are drawn between the correlated magnetism in this single-layer system and its bilayer analog Sr 3Ir2O7, where both materials exhibit magnetic domains originating from crystallographic twinning and comparable moment sizes. Weakly temperature-dependent superlattice peaks violating the reported tetragonal space group of Sr2IrO4 are observed, supporting the notion of a lower structural symmetry arising from a high-temperature lattice distortion, and we use this to argue that moments orient along a unique in-plane axis demonstrating an orthorhombic symmetry in the resulting spin structure. Our results demonstrate that the correlated spin order and structural phase behaviors in both single-layer and bilayer Srn+1Ir nO3n+1 systems are remarkably similar and suggest comparable correlation strengths in each system. © 2013 American Physical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3a0d0fa8-d507-42d0-a013-e76960369363 ER - TY - JOUR TI - Interconversion of linearly viscoelastic material functions expressed as Prony series: A closure DO - 10.1007/s11043-012-9176-y AU - Luk-Cyr, J. AU - Crochon, T. AU - Li, C. AU - Lévesque, M. T2 - Mechanics of Time-Dependent Materials SN - 1385-2000 VL - 17 IS - 1 SP - 53 EP - 82 KW - Constitutive theory KW - Interconversions KW - Material symmetry KW - Prony series KW - Relaxation KW - Thermodynamics of irreversible process KW - Visco-elastic material KW - Algorithms KW - Creep KW - Viscoelasticity AB - Interconversion of viscoelastic material functions is a longstanding problem that has received attention since the 1950s. There is currently no accepted methodology for interconverting viscoelastic material functions due to the lack of stability and accuracy of the existing methods. This paper presents a new exact, analytical interconversion method for linearly viscoelastic material functions expressed as Prony series. The new algorithm relies on the equations of the thermodynamics of irreversible processes used for defining linearly viscoelastic constitutive theories. As a result, interconversion is made possible for unidimensional and tridimensional materials for arbitrary material symmetry. The algorithm has been tested over a broad range of cases and was found to deliver accurate interconversion in all cases. Based on its accuracy and stability, the authors believe that their algorithm provides a closure to the interconversion of linearly viscoelastic constitutive theories expressed with Prony series. © 2012 Springer Science+Business Media, B. V. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1a4011d5-ee3a-4ac0-ad23-ceba78a79969 ER - TY - JOUR TI - Amine-decorated nanocrystalline cellulose surfaces: Synthesis, characterization, and surface properties DO - 10.1139/cjc-2013-0165 AU - Hemraz, U.D. AU - Boluk, Y. AU - Sunasee, R. T2 - Canadian Journal of Chemistry SN - 0008-4042 VL - 91 IS - 10 SP - 974 EP - 981 KW - Aminated NCC KW - Covalent functionalizations KW - Nanocrystalline cellulose KW - Nanocrystalline cellulose(NCC) KW - Reactive functional groups KW - Surface Functionalization KW - Tempo oxidations KW - TEMPO-mediated oxidation KW - Amides KW - Amination KW - Carboxylation KW - Cellulose derivatives KW - Characterization KW - Fourier transform infrared spectroscopy KW - Functional groups KW - Medical applications KW - Oxidation KW - Photoelectrons KW - Surfaces KW - Synthesis (chemical) KW - X ray photoelectron spectroscopy KW - Surface reactions KW - Amides KW - Carboxylation KW - Cellulose KW - Cellulose Derivatives KW - Esca KW - Functional Groups KW - Oxidation KW - Photoelectrons KW - Surfaces KW - Synthesis KW - X Ray Spectroscopy AB - In this present work, terminal amino-functionalized nanocrystalline cellulose derivatives were prepared using a simple two-step protecting group-free protocol under aqueous reaction conditions at room temperature. Carboxylate groups were first introduced onto the surface of nanocrystalline cellulose (NCC) via a TEMPO-mediated oxidation. Then, reaction of surface-carboxylated NCC with bifunctional amines of small alkyl chain length by EDC/NHS-mediated coupling furnished the desired aminated NCC via an amide linkage. Surface covalent functionalization was confirmed by Fourier transform infrared spectroscopy, elemental analysis, and X-ray photoelectron spectroscopy. Size, surface charge, morphology, and thermal properties were obtained by various techniques. STEM images revealed no change in structure and morphology of the materials after TEMPO-mediated oxidation but a slight agglomeration was observed after surface covalent functionalization with diamines. While amide linkage confers stability, terminal primary amine groups on the surface of NCC represent a versatile reactive functional group for bioconjugation with other biomolecules for potential biomedical applications. © 2013 Published by NRC Research Press. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3ff24e1a-8954-4ab1-beb2-7795c06d98ff ER - TY - JOUR TI - Investigating the candidacy of a lipoteichoic acid-based glycoconjugate as a vaccine to combat Clostridium difficile infection DO - 10.1007/s10719-013-9489-3 AU - Cox, A.D. AU - St. Michael, F. AU - Aubry, A. AU - Cairns, C.M. AU - Strong, P.C.R. AU - Hayes, A.C. AU - Logan, S.M. T2 - Glycoconjugate Journal SN - 0282-0080 VL - 30 IS - 9 SP - 843 EP - 855 AB - A lipoteichoic acid has recently been shown to be conserved in the majority of strains from Clostridium difficile and as such is being considered as a possible vaccine antigen. In this study we examine the candidacy of the conserved lipoteichoic acid by demonstrating that it is possible to elicit antibodies against C. difficile strains following immunisation of rabbits and mice with glycoconjugates elaborating the conserved lipoteichoic acid antigen. The present study describes a conjugation strategy that utilises an amino functionality, present at approximately 33 % substitution of the N-acetyl-glucosamine residues within the LTA polymer repeating unit, as the attachment point for conjugation. A maleimide-thiol linker strategy with the maleimide linker on the carboxyl residues of the carrier protein and the thiol linker on the carbohydrate was employed. Immunisation derived antisera from rabbits and mice, recognised all strains of C. difficile vegetative cells examined, despite an immune response to the linkers also being observed. These sera recognised live cells in an immunofluorescence assay and were also able to recognise the spore form of the bacterium. This study has illustrated that the LTA polymer is a highly conserved surface polymer of C. difficile that is easily accessible to the immune system and as such merits consideration as a vaccine antigen to combat C. difficile infection. © 2013 Her Majesty the Queen in Right of Canada. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 37476df6-8a2b-41e8-84dc-e94719a45652 ER - TY - JOUR TI - Colloidal CuInSe2 nanocrystals: From gradient stoichiometry toward homogeneous alloyed structure mediated by conducting polymer P3HT DO - 10.1021/am3032212 AU - Liang, Y.N. AU - Yu, K. AU - Yan, Q. AU - Hu, X. T2 - ACS Applied Materials and Interfaces SN - 1944-8244 VL - 5 IS - 10 SP - 4100 EP - 4106 KW - Composition gradient KW - Copper-indium-selenide KW - Core shell structure KW - poly(3-hexyl thiophene) KW - Polymer-assisted KW - Quaternary compound KW - Single-step synthesis KW - Tri-n-octylphosphine KW - Coordination reactions KW - Copper KW - Indium KW - Nanocrystals KW - Stoichiometry KW - Synthesis (chemical) KW - Conducting polymers AB - We report, for the first time, the synthesis of colloidal copper indium selenide (CuInSe2) nanocrystals (NCs) possessing a gradient stoichiometry that is potentially tunable by the presence of a conducting polymer, i.e., poly(3-hexyl thiophene) (P3HT) in the synthesis medium. Dibenzyl ether (DBE) was used as a reaction medium, whereas copper acetylacetonate (Cu(acac)2), indium acetylacetonate (In(acac)3), and selenium powder were used as Cu, In, and Se sources, respectively. The Se precursor was tri-n-octylphosphine selenide (TOP-Se). Without the presence of P3HT, the resulting NCs consist of a p-type (Cu1+ rich) core and an n-type (In3+ rich) shell. Such a gradient stoichiometry was moderated to be substantially more homogeneous because the presence of P3HT is believed to have significantly reduced the reactivity difference between Cu(acac) 2 and In(acac)3, as well as and their respective monomers. Furthermore, the P3HT also acts as a surface coordination species, contributing to the readily preparation of conducting polymer-NCs hybrids by a single-step synthesis. The understandings of this work can serve as a guide for design and synthesis of conducting polymer-NCs hybrids based on various ternary or quaternary compound semiconductors with different core-shell composition gradient. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c215f983-9df2-4947-8ebf-c9a46af3fc10 ER - TY - JOUR TI - A methodological review of piezoelectric based acoustic wave generation and detection techniques for structural health monitoring DO - 10.1155/2013/928627 AU - Sun, Z. AU - Rocha, B. AU - Wu, K.-T. AU - Mrad, N. T2 - International Journal of Aerospace Engineering SN - 1687-5966 SP - 928627 KW - Acoustic wave generations KW - Aircraft operations KW - Condition based maintenance KW - Detection technique KW - Mechanical energies KW - Non destructive evaluation KW - Structural health monitoring (SHM) KW - Structure integrity KW - Acoustic waves KW - Acoustics KW - Nondestructive examination KW - Piezoelectric transducers KW - Structural health monitoring AB - Piezoelectric transducers have a long history of applications in nondestructive evaluation of material and structure integrity owing to their ability of transforming mechanical energy to electrical energy and vice versa. As condition based maintenance has emerged as a valuable approach to enhancing continued aircraft airworthiness while reducing the life cycle cost, its enabling structural health monitoring (SHM) technologies capable of providing on-demand diagnosis of the structure without interrupting the aircraft operation are attracting increasing R&D efforts. Piezoelectric transducers play an essential role in these endeavors. This paper is set forth to review a variety of ingenious ways in which piezoelectric transducers are used in today's SHM technologies as a means of generation and/or detection of diagnostic acoustic waves. © 2013 Zhigang Sun et al. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3c340499-571f-4fa0-9e1a-c3a3e888b935 ER - TY - JOUR TI - Virtual reality simulator: Demonstrated use in neurosurgical oncology DO - 10.1177/1553350612451354 AU - Clarke, D.B. AU - D'Arcy, R.C.N. AU - Delorme, S. AU - Laroche, D. AU - Godin, G. AU - Hajra, S.G. AU - Brooks, R. AU - Diraddo, R. T2 - Surgical Innovation SN - 1553-3506 VL - 20 IS - 2 SP - 190 EP - 197 KW - accuracy KW - adult KW - article KW - astrocytoma KW - brain edema KW - case report KW - computer assisted tomography KW - diffusion tensor imaging KW - female KW - finite element analysis KW - human KW - hypophysis adenoma KW - magnetic resonance angiography KW - meningioma KW - neurosurgery KW - nuclear magnetic resonance imaging KW - operating room KW - patient safety KW - simulator KW - surgical risk KW - surgical technique KW - surgical training KW - virtual reality KW - Brain Neoplasms KW - Computer Simulation KW - Education, Medical KW - Female KW - Frontal Lobe KW - Humans KW - Image Processing, Computer-Assisted KW - Magnetic Resonance Imaging KW - Meningeal Neoplasms KW - Meningioma KW - Middle Aged KW - Neurosurgical Procedures KW - Surgery, Computer-Assisted KW - User-Computer Interface AB - Background. The overriding importance of patient safety, the complexity of surgical techniques, and the challenges associated with teaching surgical trainees in the operating room are all factors driving the need for innovative surgical simulation technologies. Technical development. Despite these issues, widespread use of virtual reality simulation technology in surgery has not been fully implemented, largely because of the technical complexities in developing clinically relevant and useful models. This article describes the successful use of the NeuroTouch neurosurgical simulator in the resection of a left frontal meningioma. Conclusion. The widespread application of surgical simulation technology has the potential to decrease surgical risk, improve operating room efficiency, and fundamentally change surgical training. © The Author(s) 2012. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : fce4881f-bcec-4012-9039-fd0c141dc15e ER - TY - JOUR TI - A novel redox-precipitation method for the preparation of α-MnO 2 with a high surface Mn4+ concentration and its activity toward complete catalytic oxidation of o-xylene DO - 10.1016/j.cattod.2012.04.032 AU - Wu, Y. AU - Lu, Y. AU - Song, C. AU - Ma, Z. AU - Xing, S. AU - Gao, Y. T2 - Catalysis Today SN - 0920-5861 VL - 201 IS - 1 SP - 32 EP - 39 KW - Calcination temperature KW - Catalytic performance KW - Complete oxidation KW - Conventional methods KW - Conventional precipitation KW - Low temperatures KW - O-xylene KW - Oxidation of o-xylene KW - Porous structures KW - Potassium ions KW - Preparation conditions KW - Redox-precipitation KW - SEM/EDS KW - Space velocities KW - Spherical morphologies KW - Surface concentration KW - XRD KW - Calcination KW - Carbon dioxide KW - Catalyst activity KW - Catalytic oxidation KW - Ions KW - Manganese KW - Precipitation (chemical) KW - Surfaces KW - Volatile organic compounds KW - Xylene KW - Manganese oxide AB - A novel redox-precipitation method was developed for the preparation of α-MnO2, where Mn(NO3)2 and KOH were titrated into excess KMnO4 solution at pH 8. For comparison, MnO x was also prepared using a conventional precipitation method. These materials were characterized by XRD, BET, SEM/EDS, XPS, and H2-TPR techniques, and their catalytic activities were evaluated for the complete catalytic oxidation of a typical volatile organic compound (VOCs), o-xylene. The novel method produced open porous hierarchically structured microcrystalline α-MnO2 containing almost 100% Mn4+ ion on its surface. Whereas, the conventional precipitation method produced a mixture of MnO2 and Mn3O4 with a closely packed spherical morphology containing only 31% Mn4+ ion on its surface. It was found that α-MnO2 exhibited good low-temperature reducibility, and that it could convert 100% o-xylene into CO2 at 220 °C at a space velocity of 8000 h-1, 50 °C lower than the MnOx prepared by the conventional method. The surface concentration of Mn 4+ ion in α-MnO2 played a key role for its high catalytic activity for the complete oxidation of o-xylene. In addition, the open porous structure and the presence of small amount of potassium ion in the microcrystalline α-MnO2 channel may also be responsible for its excellent catalytic performance. Effects of pH and calcination temperature on its catalytic activity were investigated, and optimal preparation conditions were found. Durability of the α-MnO2 was also studied. © 2012 Elsevier B.V. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e436d88c-9ffb-4f81-ae5a-4201059e9bab ER - TY - JOUR TI - Stellar velocity dispersion measurements in high-luminosity quasar hosts and implications for the AGN black hole mass scale DO - 10.1088/0004-637X/773/2/90 AU - Grier, C.J. AU - Martini, P. AU - Watson, L.C. AU - Peterson, B.M. AU - Bentz, M.C. AU - Dasyra, K.M. AU - Dietrich, M. AU - Ferrarese, L. AU - Pogge, R.W. AU - Zu, Y. T2 - The Astrophysical Journal SN - 0004-637X VL - 773 IS - 2 SP - 90 AB - We present new stellar velocity dispersion measurements for four luminous quasars with the Near-Infrared Integral Field Spectrometer instrument and the ALTAIR laser guide star adaptive optics system on the Gemini North 8 m telescope. Stellar velocity dispersion measurements and measurements of the supermassive black hole (BH) masses in luminous quasars are necessary to investigate the coevolution of BHs and galaxies, trace the details of accretion, and probe the nature of feedback. We find that higher-luminosity quasars with higher-mass BHs are not offset with respect to the M BH-σ * relation exhibited by lower-luminosity active galactic nuclei (AGNs) with lower-mass BHs, nor do we see correlations with galaxy morphology. As part of this analysis, we have recalculated the virial products for the entire sample of reverberation-mapped AGNs and used these data to redetermine the mean virial factor 〈f〉 that places the reverberation data on the quiescent M BH-σ* relation. With our updated measurements and new additions to the AGN sample, we obtain 〈f〉 = 4.31 ± 1.05, which is slightly lower than, but consistent with, most previous determinations. © 2013. The American Astronomical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4b66dfb3-251f-4671-9b56-85ce5d1dc93c ER - TY - JOUR TI - Photo- and thermo-chemical vapor generation of mercury DO - 10.1039/c3ja50152c AU - Sturgeon, Ralph E. AU - Luong, V. T2 - Journal of Analytical Atomic Spectrometry SN - 0267-9477 VL - 28 IS - 10 SP - 1610 EP - 1619 KW - Certified reference materials KW - First order kinetics KW - Limit of detection KW - Matrix interference KW - Pseudo first-order kinetics KW - Replicate measurements KW - Second-order models KW - Thermal reduction KW - Formic acid KW - Reaction rates KW - Submarine geology KW - Vapors KW - Mercury (metal) AB - Photochemical vapor generation of both inorganic and methylmercury species can be achieved with equal efficiency when a sample reaction medium containing 2-10% formic acid is irradiated by low power (0.3 mW) deep UV LED sources with output in the range 245-260 nm. Whereas pseudo first order kinetics is evident for reduction of methylmercury, inorganic mercury does not conform to either first or second order models and the overall reaction rate is proportional to the concentration of formic acid but independent of that of mercury. Noteworthy, is that at room temperature, no reduction of either mercury species is achieved when radiation from 360 nm LEDs is used. A thermal reduction system operating at nominally 85 °C can also be used to reduce both mercury species in a 2% formic acid medium with the initial stages of the reaction being dominated by a first order kinetic process that is approximately 7-fold slower for methylmercury. Despite this disparity in reaction rates, direct speciation is not possible. Using a 10 cm quartz tube cell for cold vapor AAS measurement, a limit of detection of 0.68 ng absolute was achieved for mercury using a 9 min irradiation time with the deep UV LED sources. Precision of replicate measurement was 2.4% RSD for a sampled volume of 480 μl of a 200 ng ml -1 solution of Hg2+ (96 ng absolute) in 2% formic acid. The efficacy of the low power deep UV LED photoreactor was demonstrated by quantitation of total mercury in certified reference materials PACS-2 (marine sediment) and DOLT-4 (fish liver tissue) using the method of additions to compensate for matrix interferences. © The Royal Society of Chemistry 2013. DA - 2013/08/07 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 05ca8b74-9a8c-417a-bb78-5be5fd33009d ER - TY - JOUR TI - Social media as an organizational strategy: A case study of A&WMA's YPAC AU - Devillers, R. T2 - EM: Air and Waste Management Association's Magazine for Environmental Managers SN - 1088-9981 IS - MARCH SP - 24 EP - 26 DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : db9f707a-db1f-4521-a46d-73be6446758a ER - TY - JOUR TI - Tensile strength of friction stir spot welded dissimilar AA5754-to-AZ31B alloys AU - Cao, X. AU - Garnier, C. AU - Wanjara, P. T2 - ASM Proceedings of the International Conference: Trends in Welding Research T3 - 9th International Conference on Trends in Welding Research, 4 June 2012 through 8 June 2012, Chicago, IL SN - 9781627089982 SP - 572 EP - 579 KW - Automotive applications KW - Dissimilar joining KW - Friction stir spot welding KW - Friction stir welding(FSW) KW - Geometrical dimensions KW - Material combination KW - Resistant spot welding KW - Tensile shear strength KW - Aluminum alloys KW - Cerium alloys KW - Dissimilar materials KW - Friction stir welding KW - Joining KW - Magnesium alloys KW - Spot welding KW - Tools KW - Welding KW - Tensile strength AB - Friction stir welding (FSW) is a relatively new joining process. As a solid-state joining technique, FSW provides good potential for dissimilar materials, even for those considered to be "difficult" and "unweldable". As a variant, friction stir spot welding (FSSW) can have significant potential to replace riveting or resistant spot welding for aerospace and automotive applications. To date, limited work has been carried out on the FSSW of dissimilar material combinations. In this work, the tensile shear strength obtained is reported for a dissimilar 2-mm thick AA5754-to-AZ31 alloy system. The main process parameters investigated include tool rotation speed, tool plunge rate, dwell time and work-piece placement (i.e. either Al or Mg alloy on the top of the lap spot welds). The tensile shear strength is also compared with that obtained for similar AA5754-to-AA5754 and AZ31-to-AZ31 welds. Furthermore, the tensile shear strength is correlated with the joint geometrical dimensions and welding defects. Copyright © 2013 ASM International® All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 7e2d3567-482e-49b7-8298-2419de9ae46d ER - TY - JOUR TI - Pseudoelastic behavior of magnesium alloy during twinning-dominated cyclic deformation DO - 10.1016/j.msea.2013.02.021 AU - Lee, S.Y. AU - Gharghouri, M.A. T2 - Materials Science and Engineering A SN - 0921-5093 VL - 572 SP - 98 EP - 102 KW - Cyclic compression KW - Cyclic deformations KW - Detwinning KW - Intensity variations KW - Pseudoelastic behaviors KW - Pseudoelasticity KW - Situ neutron diffraction KW - Tension and compression KW - Magnesium KW - Magnesium alloys KW - Neutron diffraction KW - Twinning KW - Deformation AB - In- situ neutron diffraction has been used to examine the pseudoelastic behavior of an extruded Mg-8.5. wt.% Al alloy during twinning-dominated cyclic deformation in both tension and compression. Twinning activity is effectively tracked through the intensity variations of the diffraction peaks for some grain orientations. The results suggest that a fundamental difference in the pseudoelastic behavior between tension and compression cyclic loadings might be due to reversible detwinning-retwinning observed only during cyclic compression. © 2013 Elsevier B.V. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f1f07de0-4aa7-4001-84c9-3d373f12ec47 ER - TY - JOUR TI - From mice to women: The conundrum of immunity to infection during pregnancy DO - 10.1016/j.jri.2012.10.015 AU - Krishnan, L. AU - Nguyen, T. AU - McComb, S. T2 - Journal of Reproductive Immunology SN - 0165-0378 VL - 97 IS - 1 SP - 62 EP - 73 KW - CD15 antigen KW - gamma interferon KW - granulocyte colony stimulating factor KW - interleukin 12 KW - interleukin 1beta KW - interleukin 6 KW - interleukin 8 KW - macrophage inflammatory protein 1alpha KW - tumor necrosis factor alpha KW - adverse outcome KW - article KW - bacterial infection KW - blastocyst KW - Brucella abortus KW - Chlamydia KW - Chlamydophila KW - Chlamydophila abortus KW - Coxiella burnetii KW - cytokine production KW - cytokine response KW - Cytomegalovirus KW - decidualization KW - female KW - Fusobacterium nucleatum KW - gestational age KW - human KW - immunity KW - immunoreactivity KW - immunoregulation KW - infection resistance KW - influenza KW - Leishmania major KW - Listeria monocytogenes KW - listeriosis KW - macrophage KW - malaria KW - maternal disease KW - natural killer cell KW - neutrophil KW - nidation KW - nonhuman KW - parasitosis KW - pathogenesis KW - periodontitis KW - Plasmodium berghei KW - Plasmodium chabaudi KW - pregnancy KW - pregnancy outcome KW - priority journal KW - regulatory T lymphocyte KW - reproduction KW - Salmonella typhimurium KW - salmonellosis KW - Schistosoma mansoni KW - spontaneous abortion KW - T lymphocyte KW - Th1 cell KW - Th2 cell KW - Toxoplasma gondii KW - toxoplasmosis KW - Trypanosoma cruzi KW - virus infection KW - Animals KW - Disease Models, Animal KW - Female KW - Fetomaternal Transfusion KW - Humans KW - Immune Evasion KW - Mice KW - Placenta KW - Pregnancy KW - Pregnancy Complications, Infectious KW - Premature Birth KW - Transplantation Tolerance AB - Resistance to infection is the ability of the host to evoke a strong immune response sufficient to eliminate the infectious agent. In contrast, maternal tolerance to the fetus necessitates careful regulation of immune responses. Successful pregnancy requires the maternal host to effectively balance the opposing processes of maternal immune reactivity and tolerance to the fetus. However, this balance can be perturbed by infections which are recognized as the major cause of adverse pregnancy outcome including pre-term labor. Select pathogens also pose a serious threat of severe maternal illness. These include intracellular and chronic pathogens that have evolved immune evasive strategies. Murine models of intracellular bacteria and parasites that mimic pathogenesis of infection in humans have been developed. While human epidemiological studies provide insight into maternal immunity to infection, experimental infection in pregnant mice is a vital tool to unravel the complex molecular mechanisms of placental infection, congenital transmission and maternal illness. We will provide a comprehensive review of the pathogenesis of several infection models in pregnant mice and their clinical relevance. These models have revealed the immunological function of the placenta in responding to, and resisting infection. Murine feto-placental infection provides an effective way to evaluate new intervention strategies for managing infections during pregnancy, adverse fetal outcome and long-term effects on the offspring and mother. © 2012. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b294846f-9129-482c-9020-d52075016d19 ER - TY - JOUR TI - Microtomographic analysis of impact damage in FRP composite laminates: A comparative study DO - 10.1155/2013/521860 AU - Alemi-Ardakani, M. AU - Milani, A.S. AU - Yannacopoulos, S. AU - Bichler, L. AU - Trudel-Boucher, D. AU - Shokouhi, G. AU - Borazghi, H. T2 - Advances in Materials Science and Engineering SN - 1687-8434 VL - 2013 SP - 521860 KW - Close relationships KW - Comparative studies KW - Composite laminate KW - Different layers KW - High level applications KW - Non-destructive technique KW - Properties of fiber KW - Ultrasonic C-scanning KW - Ability testing KW - Glass fibers KW - Impact testing KW - Materials testing KW - Mechanical properties KW - Polypropylenes KW - Three dimensional computer graphics KW - Ultrasonic testing KW - Laminated composites AB - With the advancement of testing tools, the ability to characterize mechanical properties of fiber reinforced polymer (FRP) composites under extreme loading scenarios has allowed designers to use these materials in high-level applications more confidently. Conventionally, impact characterization of composite materials is studied via nondestructive techniques such as ultrasonic C-scanning, infrared thermography, X-ray, and acoustography. None of these techniques, however, enable 3D microscale visualization of the damage at different layers of composite laminates. In this paper, a 3D microtomographic technique has been employed to visualize and compare impact damage modes in a set of thermoplastic laminates. The test samples were made of commingled polypropylene (PP) and glass fibers with two different architectures, including the plain woven and unidirectional. Impact testing using a drop-weight tower, followed by postimpact four-point flexural testing and nondestructive tomographic analysis demonstrated a close relationship between the type of fibre architecture and the induced impact damage mechanisms and their extensions. © 2013 M. Alemi-Ardakani et al. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e33fdbbf-c3ef-4b10-a192-6f3fd755255b ER - TY - JOUR TI - Time-series BVi photometry for the globular cluster NGC 6981 DO - 10.1088/0004-6256/146/5/130 AU - Amigo, P. AU - Stetson, P.B. AU - Catelan, M. AU - Zoccali, M. AU - Smith, H.A. T2 - Astronomical Journal SN - 0004-6256 VL - 146 IS - 5 SP - 130 AB - We present new BVI photometry of the globular cluster NGC 6981, based mostly on ground-based CCD archival images. We present a new color-magnitude diagram (CMD) that reaches almost four magnitudes below the turn-off level. We performed new derivations of metallicity and morphological parameters of the evolved sequences, in good agreement with the results of previous authors, and obtain a value of [Fe/H] ≃ -1.50 in the new UVES scale. We also identify the cluster's blue straggler population. Comparing the radial distribution of these stars with the red giant branch population, we find that the blue stragglers are more centrally concentrated, as found in previous studies of blue stragglers in globular clusters. Taking advantage of the large field of view covered by our study, we analyzed the surface density profile of the cluster, and find extratidal main sequence stars out to r ≈ 14.′1, or about twice the tidal radius. We speculate that the presence of these stars may be due to tidal disruption in the course of NGC 6981's orbit, in which case tidal tails associated with the cluster may exist. We also take a fresh look at the variable stars in the cluster, recovering all previously known variables, including three SX Phoenicis stars. We also add three previously unknown RR Lyrae (one c-type and two ab-type) to the total census. Finally, comparing our CMD with unpublished data for M3 (NGC 5272), a cluster with a similar metallicity and horizontal branch morphology, we found that both objects are essentially coeval. © 2013. The American Astronomical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8fdefe67-43c2-4856-b78f-c08d53c330dd ER - TY - JOUR TI - Retraction: Plasma protein adsorption to zwitterionic poly (carboxybetaine methacrylate) modified surfaces: Chain chemistry and end-group effects on protein adsorption kinetics, adsorbed amounts and immunoblots DO - 10.1186/1559-4106-8-11 AU - Abraham, S. AU - Bahniuk, M.S. AU - Unsworth, L.D. T2 - Biointerphases SN - 1934-8630 VL - 8 IS - 1 DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c3e95a7d-07ca-4340-a6fb-2c2de1bc0cbc ER - TY - JOUR TI - Two radio supernova remnants discovered in the outer Galaxy DO - 10.1051/0004-6361/201220362 AU - Foster, T.J. AU - Cooper, B. AU - Reich, W. AU - Kothes, R. AU - West, J. T2 - Astronomy and Astrophysics SN - 0004-6361 VL - 549 SP - A107 KW - Basic parameters KW - Canadian galactic plane surveys KW - Flux densities KW - Future observations KW - Galactic plane KW - Interstellar mediums KW - ISM: general KW - ISM: supernova remnants KW - Line data KW - Line-of-sight KW - Low density KW - Milky ways KW - Multiwavelength data KW - Neutral hydrogen KW - Polarization parameters KW - Radio continuum KW - Spectral indices KW - Supernova remnants KW - Surface brightness KW - Galaxies KW - Hydrogen KW - Polarization KW - Surveys KW - Stars AB - Context. New and existing large-scale radio surveys of the Milky Way at centimetre wavelengths can play an important role in uncovering the hundreds of expected but missing supernova remnants in the Galaxy's interstellar medium. We report on the discovery of two supernova remnants (SNRs) designated G152.4-2.1 and G190.9-2.2, using Canadian Galactic Plane Survey data. Aims. The aims of this paper are, first, to present evidence that favours the classification of both sources as SNRs, and, second, to describe basic parameters (integrated flux density, spectrum, and polarization) as well as properties (morphology, line-of-sight velocity, distance and physical size) to facilitate and motivate future observations. Methods. Spectral and polarization parameters are derived from multiwavelength data from existing radio surveys carried out at wavelengths between 6 and 92 cm. In particular for the source G152.4-2.1 we also use new observations at 11 cm done with the Effelsberg 100 m telescope. The interstellar medium around the discovered sources is analyzed using 1-arcmin line data from neutral hydrogen (H i) and 45-arcsec 12CO(J = 1 → 0). Results. G152.4-2.1 is a barrel shaped SNR with two opposed radio-bright polarized flanks on the north and south. The remnant, which is elongated along the Galactic plane is evolving in a more-or-less uniform medium. G190.9-2.2 is also a shell-type remnant with east and west halves elongated perpendicular to the plane, and is evolving within a low-density region bounded by dense neutral hydrogen in the north and south, and molecular (12CO) clouds in the east and west. The integrated radio continuum spectral indices are-0.65 ± 0.05 and-0.66 ± 0.05 for G152.4-2.1 and G190.9-2.2 respectively. Both SNRs are approximately 1 kpc distant, with G152.4-2.1 being larger (32 × 30 pc in diameter) than G190.9-2.2 (18 × 16 pc). These two remnants are the lowest surface brightness SNRs yet catalogued at Σ1 GHz 2; 5 × 10-23 W m-2 Hz-1 sr-1. © 2013 ESO. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 17361a86-5b34-45ee-9245-08d3b60a98e7 ER - TY - JOUR TI - Adsorption of indole on kaolinite in nonaqueous media: Organoclay preparation and characterization, and 3D-RISM-KH molecular theory of solvation investigation DO - 10.1021/jp4064142 AU - Fafard, J. AU - Lyubimova, O. AU - Stoyanov, S.R. AU - Dedzo, G.K. AU - Gusarov, S. AU - Kovalenko, A. AU - Detellier, C. T2 - The Journal of Physical Chemistry C SN - 1932-7447 VL - 117 IS - 36 SP - 18556 EP - 18566 KW - Adsorbate-adsorbate interaction KW - Adsorption thermodynamics KW - Brunauer emmett tellers KW - Molecular theory of solvation KW - Organoclay preparation KW - Potential of mean force KW - Preferred orientations KW - Solvation free energies KW - Adsorbates KW - Adsorption KW - Heptane KW - Hydrogen bonds KW - Kaolinite KW - Monolayers KW - Oil sands KW - Organic solvents KW - Organoclay KW - Regression analysis KW - Sampling KW - Solvation KW - Solvents KW - Surfaces KW - Three dimensional KW - Toluene KW - Washing KW - Polycyclic aromatic hydrocarbons AB - Current oil sand mining operations in the Athabasca basin are predominantly aqueous-based. Extracts containing large amounts of fines lead to the formation of stable organoclay suspensions in froths giving lower yields and greater tailing wastes and making the development of more efficient extraction methods desirable from both economical and environmental perspectives. We examine an indole-kaolinite system as a model for these oil fines and their resistance to washing in nonaqueous solvents. The prepared organoclays show indole loading exclusively on the external surface of the clay. Micron-scaled vermicular structures, similar to natural kaolinite, are observed. Their formation is believed to be driven by strong adsorbate-adsorbate interactions. Indole is the primary adsorbate, as solvent adsorption is shown to be minimal based on both experimental and computational results. Isotherms are constructed and parameters calculated from linear regression analysis fitted to the Brunauer-Emmett-Teller equation. Monolayer quantities calculated match well to the theoretical amount calculated from surface areas measurements. Washing the organoclays with both toluene and isopropanol results in a 50% decrease of loaded organic material, leaving a monolayer equivalent of organic matter. The statistical-mechanical 3D-RISM-KH molecular theory of solvation is employed to perform full sampling of solvent orientations around a kaolinite platelet and gain insights into the preferred orientation and adsorption thermodynamics of indole on kaolinite in toluene and heptane solvents. In its preferred orientation, indole is hydrogen-bonded to one or two O atoms at the aluminum hydroxide surface of kaolinite. The calculated solvation free energy and potential of mean force for adsorption of indole and solvents on kaolinite in solution yield the increasing adsorption strength order of heptane < toluene < indole on the aluminum hydroxide surface. Multilayer adsorption profiles are predicted based on the integrated three-dimensional distribution functions of indole, toluene, and heptane. © 2013 American Chemical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e20c3b57-d5e3-4c4f-b3f5-2f88b005b916 ER - TY - JOUR TI - A Study of Pack Aluminizing Process for NiCrAlY Coatings Using Response Surface Methodology DO - 10.1007/s11665-013-0665-1 AU - Gao, F. AU - Huang, X. AU - Liu, R. AU - Yang, Q. T2 - Journal of Materials Engineering and Performance SN - 1059-9495 SP - 1 EP - 9 AB - Aluminizing process is widely used to provide additional Al deposition onto superalloy surface for enhanced oxidation and corrosion resistance. In this research, an aluminizing process-pack cementation process, is used to deposit Al onto the surface of NiCrAlY coatings for increasing environmental protection. The experiment is designed using Box-Behnken approach, in which three parameters, the Al content, Ni content of the pack powder, and the temperature of the process, are selected as factors; and the thickness and Al/Ni ratio of the coatings are selected as responses. The effects of the factors on the responses are analyzed and modeled empirically. It is found that these empirical models correlate well with the results from additional sets of experiment. These models can be used to produce aluminized NiCrAlY coatings with specific thicknesses and Al/Ni ratios. © 2013 ASM International. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b4add2f2-2ac9-4982-ad5c-07f736ad65d7 ER - TY - JOUR TI - Fatigue performance characterization of a composite butt joint configuration DO - 10.1016/j.compositesa.2013.04.001 AU - Li, G. T2 - Composites Part A: Applied Science and Manufacturing SN - 1359-835X VL - 51 SP - 43 EP - 55 KW - Butt joints KW - Damage evolution KW - Disbond defects KW - Failure mechanism KW - Fatigue performance KW - Joint configuration KW - Stiffness degradation KW - Tensile stiffness KW - Bolted joints KW - Butt welding KW - Fatigue testing KW - Locks (fasteners) KW - Stiffness KW - Surface defects KW - Fatigue damage AB - Fatigue performance characterization of a composite butt joint configuration was studied. The study focused on failure mode, damage evolution, and tensile stiffness degradation analyses. Effects of surface ply orientation, doubler thickness, joint attachment, and defect on the joint fatigue performance were evaluated. The bonded-bolted joints with two-row fasteners installed in each overlap section had an extremely high fatigue performance. For such a bonded-bolted joint configuration with thick doubler, a minor disbond defect improved, rather than reduced, the joint fatigue performance. This outcome was examined using the corresponding joint tensile stiffness degradation curves, and a dominant failure mechanism was identified based on damage characteristics. The study showed that the butt joint made using appropriate elements, such as a thick doubler with two-row fasteners installed in each bonded overlap section, could have very good fatigue performance regardless of the presence of a minor disbond defect. © 2013 Elsevier Ltd. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 06203200-5c53-4ddc-af78-f006901d8e1f ER - TY - JOUR TI - An analytical analysis of energy release rate in bonded composite joints in a mode i condition DO - 10.1016/j.compositesb.2012.01.082 AU - Li, G. AU - Li, C. T2 - Composites Part B: Engineering SN - 1359-8368 VL - 44 IS - 1 SP - 704 EP - 713 KW - Adhesive bond KW - Analytical analysis KW - Composite joint KW - Critical strain energy KW - Double cantilever beam models KW - Peel stress KW - Short beams KW - Test case KW - Theoretical result KW - Theoretical solutions KW - Mathematical techniques KW - Joints (structural components) AB - A complete analytical solution of mode I strain energy release rate, G I, was derived for bonded composite joints based on an augmented double cantilever beam (DCB) model. Good agreement was obtained between current and existing comparable theoretical solutions for this joint with a long adhesive bond. For a short bond length joint, the current solution can greatly reduce the degree of the mathematical singularity encountered in analyses of thick, short beams and avoid it entirely for thin, long beams. A correlation between the current theoretical and associated ASTM solutions was established. A bonded DCB laminate test case was conducted, and good agreement was obtained between the experimental and current theoretical results. Commentary was included regarding the tested critical strain energy release rate and the deduced critical adhesive peel stress. © 2012 Published by Elsevier Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 917d4eb8-73ab-4d97-8d81-6d928a5869fb ER - TY - JOUR TI - Room temperature single-crystal diffuse scattering and ab initio lattice dynamics in CaTiSiO5 DO - 10.1088/0953-8984/25/31/315402 AU - Gutmann, M.J. AU - Refson, K. AU - Zimmermann, M.V. AU - Swainson, I.P. AU - Dabkowski, A. AU - Dabkowska, H. T2 - Journal of Physics Condensed Matter SN - 0953-8984 VL - 25 IS - 31 SP - 315402 KW - Anti ferroelectrics KW - Density-functional perturbation theory KW - Diffuse scattering KW - High energy X ray KW - Phonon dispersion curves KW - Phonon dispersions KW - Scattering pattern KW - Static displacement KW - Acoustic dispersion KW - Ferroelectric materials KW - Lattice vibrations KW - Phonons KW - Solids KW - Strain measurement KW - Scattering AB - Single-crystal diffuse scattering data have been collected at room temperature on synthetic titanite using both neutrons and high-energy x-rays. A simple ball-and-springs model reproduces the observed diffuse scattering well, confirming its origin to be primarily due to thermal motion of the atoms. Ab initio phonons are calculated using density-functional perturbation theory and are shown to reproduce the experimental diffuse scattering. The observed diffuse x-ray and neutron scattering patterns are consistent with a summation of mode frequencies and displacement eigenvectors associated with the entire phonon spectrum, rather than with a simple, short-range static displacement. A band gap is observed between 600 and 700 cm-1 with only two modes crossing this region, both associated with antiferroelectric Ti-O motion along a. One of these modes (of B u symmetry), displays a large LO-TO mode-splitting (562-701.4 cm-1) and has a dominant component coming from Ti-O bond-stretching and, thus, the mode-splitting is related to the polarizability of the Ti-O bonds along the chain direction. Similar mode-splitting is observed in piezo- and ferroelectric materials. The calculated phonon dispersion model may be of use to others in future to understand the phase transition at higher temperatures, as well as in the interpretation of measured phonon dispersion curves. © 2013 IOP Publishing Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : efa0fc1f-8755-4ae2-b2de-e4d3df4bc5b6 ER - TY - JOUR TI - Nanomaterials-supported Pt catalysts for proton exchange membrane fuel cells DO - 10.1002/wene.47 AU - Saha, M.S. AU - Neburchilov, V. AU - Ghosh, D. AU - Zhang, J. T2 - Wiley Interdisciplinary Reviews: Energy and Environment SN - 2041-8396 VL - 2 IS - 1 SP - 31 EP - 51 KW - Catalyst layers KW - Catalyst synthesis KW - Fabrication process KW - Literature reviews KW - Membrane electrode assemblies KW - Novel methods KW - Pt catalysts KW - Nanostructured materials KW - Nanowires KW - Platinum KW - Proton exchange membrane fuel cells (PEMFC) KW - Catalyst supports AB - This paper reviews over 100 articles related to the development of nanotubes, nanofibers, and nanowires as catalyst supports for proton exchange membrane fuel cells. Several different novel methods for support and catalyst synthesis are discussed in detail. The fabrication processes for these nanomaterial-supported platinum (Pt) catalysts, catalyst layers, and membrane electrode assemblies are also reviewed. On the basis of the literature review, several research directions for catalyst cost reduction, catalytic activity, and durability enhancement are proposed in this paper. © 2012 John Wiley & Sons, Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 96494b5e-69f1-495b-b65b-daddbe55197b ER - TY - JOUR TI - A single N-acetylgalactosamine residue at threonine 106 modifies the dynamics and structure of interferon α2a around the glycosylation site DO - 10.1074/jbc.M112.413252 AU - Ghasriani, H. AU - Belcourt, P.J.F. AU - Sauvé, S. AU - Hodgson, D.J. AU - Brochu, D. AU - Gilbert, M. AU - Aubin, Y. T2 - Journal of Biological Chemistry SN - 0021-9258 VL - 288 IS - 1 SP - 247 EP - 254 KW - Enhancement measurements KW - Heteronuclear KW - High resolution KW - Isotopically labeled KW - O-linked glycoproteins KW - Structure and dynamics KW - Three-dimensional structure KW - Time-scales KW - Amino acids KW - Dynamics KW - Escherichia coli KW - Esterification KW - Glucose KW - Glycosylation KW - Nuclear magnetic resonance spectroscopy KW - Glycoproteins KW - alpha2a interferon KW - glycoprotein KW - monosaccharide KW - n acetylgalactosamine KW - n acetylgalactosamine[13c,15n]alpha2a interferon KW - threonine KW - unclassified drug KW - addition reaction KW - article KW - biological activity KW - human KW - in vitro study KW - isotope labeling KW - molecular dynamics KW - nonhuman KW - nuclear magnetic resonance spectroscopy KW - priority journal KW - protein analysis KW - protein glycosylation KW - protein metabolism KW - protein polymorphism KW - protein structure KW - protein synthesis KW - Acetylgalactosamine KW - Computational Biology KW - Disulfides KW - Escherichia coli KW - Glycoproteins KW - Glycosylation KW - Humans KW - Interferon-alpha KW - Interferons KW - Magnetic Resonance Spectroscopy KW - Models, Molecular KW - Molecular Conformation KW - Peptides KW - Polysaccharides KW - Protein Conformation KW - Recombinant Proteins KW - Threonine KW - Escherichia coli AB - Enzymatic addition of GalNAc to isotopically labeled IFNα2a produced in Escherichia coli yielded the O-linked glycoprotein GalNAcα-[ 13C,15N]IFNα2a. The three-dimensional structure of GalNAcα-IFNα2a has been determined in solution by NMR spectroscopy at high resolution. Proton-nitrogen heteronuclear Overhauser enhancement measurements revealed that the addition of a single monosaccharide unit at Thr-106 significantly slowed motions of the glycosylation loop on the nanosecond time scale. Subsequent addition of a Gal unit produced Gal(β1,3) GalNAcα[13C,15N]IFNα2a. This extension resulted in a further decrease in the dynamics of this loop. The methodology used here allowed the first such description of the structure and dynamics of an O-glycoprotein and opens the way to the study of this class of proteins. © 2013 by The American Society for Biochemistry and Molecular Biology, Inc. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a8489825-4f72-4abc-8993-a85c2b2984fa ER - TY - CHAP TI - Preface AU - Fulton, K.M. AU - Twine, S.M. T2 - Methods in Molecular Biology SN - 1064-3745 SN - 9781627035880 VL - 1061 KW - adaptive immunity KW - antigen antibody reaction KW - B lymphocyte KW - cell differentiation KW - editorial KW - enzyme linked immunosorbent assay KW - genomics KW - immune response KW - immunoproteomics KW - mass spectrometry KW - priority journal KW - proteomics KW - serology KW - T lymphocyte KW - Western blotting DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8a4a74c8-2a12-49ab-94d4-4dab651a7ee7 ER - TY - JOUR TI - A novel synthetic receptor-based immunoassay for influenza vaccine quantification DO - 10.1371/journal.pone.0055428 AU - Hashem, A. M. AU - Gravel, C. AU - Farnsworth, A. AU - Zou, W. AU - Lemieux, M. AU - Xu, K. AU - Li, C. AU - Wang, J. AU - Goneau, M.-F. AU - Merziotis, M. AU - He, R. AU - Gilbert, M. AU - Li, X. T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 2 SP - e55428 KW - alpha 2,3 sialyllactoside receptor KW - alpha 2,3 sialyltransferase KW - alpha 2,6 sialyllactoside receptor KW - alpha 2,6 sialyltransferase KW - n acetylneuraminic acid 2,3 lactose KW - n acetylneuraminic acid 2,6 lactose KW - n acetylneuraminic acid derivative KW - serum albumin KW - sialic acid KW - virus hemagglutinin KW - virus receptor KW - antigen specificity KW - avian influenza virus KW - enzyme linked immunosorbent assay KW - immunodiffusion KW - influenza KW - influenza vaccination KW - linkage analysis KW - nucleotide sequence KW - pH measurement KW - protein protein interaction KW - quantitative analysis KW - sensitivity analysis KW - sensitivity and specificity KW - sialylation KW - temperature measurement KW - Antigens, Viral KW - Azides KW - Birds KW - Enzyme-Linked Immunosorbent Assay KW - Glycosides KW - Hemagglutinin Glycoproteins, Influenza Virus KW - Immunodiffusion KW - Influenza A Virus, H1N1 Subtype KW - Influenza A Virus, H3N2 Subtype KW - Influenza in Birds KW - Influenza Vaccines KW - N-Acetylneuraminic Acid KW - Protein Denaturation KW - Protein Multimerization KW - Protein Structure, Quaternary KW - Sialyltransferases KW - Species Specificity AB - Vaccination is the most effective prophylactic method for preventing influenza. Quantification of influenza vaccine antigens is critically important before the vaccine is used for human immunization. Currently the vaccine antigen quantification relies on hemagglutinin content quantification, the key antigenic component, by single radial immunodiffusion (SRID) assay. Due to the inherent disadvantages associated with the traditional SRID; i.e. low sensitivity, low throughput and need for annual reagents, several approaches have been proposed and investigated as alternatives. Yet, most alternative methods cannot distinguish native hemagglutinin from denatured form, making them less relevant to antigenic analyses. Here, we developed a quantitative immunoassay based on the sialic acid binding property of influenza vaccine antigens. Specifically, we chemically synthesized human and avian influenza virus receptors analogues, N-acetylneuraminic acid-2,6-lactose and N-acetylneuraminic acid-2,3-lactose derivatives with an azidopropyl aglycon, using α-2,6- and α-2,3-sialyltransferases, respectively. The azido group of the two sialyllactose-derivatives was reduced and conjugated to mouse serum albumin through a squarate linkage. We showed that the synthetic α-2,6- and α-2,3-receptors selectively bound to human and avian-derived hemagglutinins, respectively, forming the basis of a new, and robust assay for hemagglutinin quantification. Hemagglutinin treated at high temperature or low pH was measured differentially to untreated samples suggesting native conformation is dependent for optimal binding. Importantly, this receptor-based immunoassay showed excellent specificity and reproducibility, high precision, less turnaround time and significantly higher sensitivity and throughput compared with SRID in analyzing multiple influenza vaccines. © 2013 Hashem et al. DA - 2013/02/12 PY - 2013 PB - PLos LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d692ba1d-c93b-442a-9928-ad2532609e32 ER - TY - JOUR TI - A critical evaluation of turbulence modeling in a model combustor DO - 10.1115/1.4023306 AU - Jiang, L. T2 - Journal of Thermal Science and Engineering Applications SN - 1948-5085 VL - 5 IS - 3 SP - 31002 KW - Combustion model KW - Conjugate heat transfer KW - Diffusion flame combustors KW - Eddy-viscosity turbulence KW - Reynolds stress models KW - Reynolds stress turbulence model KW - Second-moment closures KW - Turbulence kinetic energy KW - Carbon dioxide KW - Combustion KW - Combustors KW - Kinetics KW - Reynolds number KW - Viscosity KW - Turbulence models AB - Based on the previous benchmark studies on combustion, scalar transfer, and radiation models, a critical evaluation of turbulence models in a propane-air diffusion flame combustor with interior and exterior conjugate heat transfers has been performed. Results obtained from six turbulence models are presented and compared in detail with a comprehensive database obtained from a series of experimental measurements. It is found that the Reynolds stress model (RSM), a second moment closure, is superior over the five popular eddy-viscosity two-equation models. Although the main flow patterns are captured by all six turbulence models, only the RSM is able to successfully predict the lengths of both recirculation zones and give fairly accurate predictions for mean velocity, temperature, CO2 and CO mole fractions, as well as turbulence kinetic energy in the combustor chamber. In addition, the realizable k-ε (Rk-ε) model illustrates better performance than four other two-equation models and can provide comparable results to those from the RSM for the configuration and operating conditions considered in the present study. © 2013 by ASME. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8f97f103-1813-4c86-af7c-6e568a397faa ER - TY - JOUR TI - Simulations of pitch-heave limit-cycle oscillations at a transitional reynolds number DO - 10.2514/1.J052225 AU - Yuan, W. AU - Poirel, D. AU - Wang, B. T2 - AIAA Journal SN - 0001-1452 VL - 51 IS - 7 SP - 1716 EP - 1732 KW - Aerodynamic damping KW - Aeroelastic oscillations KW - Boundary-layer separation KW - Computational Fluid Dynamics codes KW - Limit cycle oscillations KW - Low Reynolds number KW - Nonlinear feedback coupling KW - Structural response KW - Aerodynamics KW - Airfoils KW - Computational fluid dynamics KW - Large eddy simulation KW - Reynolds number KW - Aeroelasticity AB - The present study investigates the nonlinear feedback coupling mechanism between unsteady low-Reynolds-number aerodynamics and structural response. Structural-response models addressing one-degree-of-freedom and two-degrees-of-freedom aeroelastic oscillations were coupled with an in-house-developed computational fluid dynamics code to perform large-eddy simulations for flows past a rigid airfoil in free-to-rotate and free-to-rotate-and-heave conditions at a low Reynolds number. As observed in the experiments, the numerical simulations confirmed the presence of self-sustained low-amplitude limit-cycle oscillations of a NACA 0012 airfoil. It was understood that this behavior in the transitional Reynolds-number regime resulted from the unsteadiness of the laminar boundary-layer separation and its delayed recovery when compared to the corresponding static conditions. The feedback coupling mechanism between the laminar-separation-bubble behavior and the structural response caused negative aerodynamic damping; thus, the aerodynamic forces did positive work and fed energy from the flow to the airfoil, sustaining the low-amplitude aeroelastic oscillations. The amplitude in pitch of the limit-cycle oscillations was of the order of 5-7 deg. As the operating angles of attack in unmanned-air-vehicle flights are within close range of the limit-cycle-oscillation occurrence, understanding and controlling the limit-cycle oscillation of the wings could ensure unmanned-air-vehicle stability so that it could acquire high-quality camera images and other data, for instance. Copyright © 2013 by Christopher Porter, R. Mark Rennie, Eric J. Jumper. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d8b37066-e8d7-4695-b75e-e04b4c09d4fd ER - TY - JOUR TI - A model of ice friction for a speed skate blade DO - 10.1007/s12283-013-0141-z AU - Lozowski, E. AU - Szilder, K. AU - Maw, S. T2 - Sports Engineering SN - 1369-7072 VL - 16 IS - 4 SP - 239 EP - 253 AB - The FAST 2.0i numerical model of ice friction was developed for an inclined speed skate blade. It describes ice friction at sliding velocities sufficiently high to produce a lubricating layer of meltwater, which completely separates the ice and slider surfaces (known as the hydrodynamic friction regime). Friction arises from ploughing a groove in the ice and from the shear stress in the lubricating Couette flow. The model takes into account frictional melting, heat conduction into the ice and the lateral squeeze flow of the lubricating liquid. We use the numerical model to calculate the ice-blade contacts, the parameters of the lubricating liquid layer, and the relative importance of the various contributions to the overall friction coefficient. We also use it to perform sensitivity studies and to predict the variation of ice friction during a typical skating stroke. The model results compare favorably with measurements of the ice friction coefficient during speed skating, made by others. © 2013 International Sports Engineering Association. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 31fc3810-4c0b-472b-b0ce-be3739569db4 ER - TY - JOUR TI - A synthetic peptide corresponding to a region of the human pericentriolar material 1 (PCM-1) protein binds β-amyloid (Aβ1-42) oligomers DO - 10.1111/jnc.12208 AU - Chakravarthy, B. AU - Ménard, M. AU - Brown, L. AU - Hewitt, M. AU - Atkinson, T. AU - Whitfield, J. T2 - Journal of Neurochemistry SN - 0022-3042 VL - 126 IS - 3 SP - 415 EP - 424 KW - amyloid beta protein[1-42] KW - oligomer KW - pericentriolar material 1 protein KW - polypeptide KW - unclassified drug KW - Alzheimer disease KW - apoptosis KW - article KW - controlled study KW - dot hybridization KW - enzyme linked immunosorbent assay KW - human KW - human cell KW - neuroblastoma cell KW - polyacrylamide gel electrophoresis KW - priority journal KW - protein binding KW - Aβ-binding peptides KW - Aβ1-42 oligomers KW - Alzheimer's disease KW - PCM-1 protein KW - Amino Acid Sequence KW - Amyloid beta-Peptides KW - Animals KW - Autoantigens KW - Blotting, Western KW - Cell Cycle Proteins KW - Cell Line, Tumor KW - Enzyme-Linked Immunosorbent Assay KW - Humans KW - Immunoblotting KW - Immunoprecipitation KW - Mice KW - Mice, Inbred C57BL KW - Mice, Transgenic KW - Molecular Sequence Data KW - Peptides KW - Protein Structure, Tertiary KW - Mus musculus AB - We have recently reported that a ~19-kDa polypeptide, rPK-4, is a protein kinase Cs inhibitor that is 89% homologous to the 1171-1323 amino acid region of the 228-kDa human pericentriolar material-1 (PCM-1) protein (Chakravarthy et al. 2012). We have now discovered that rPK-4 binds oligomeric amyloid-β peptide (Aβ)1-42 with high affinity. Most importantly, a PCM-1-selective antibody co-precipitated Aβ and amyloid β precursor protein (AβPP) from cerebral cortices and hippocampi from AD (Alzheimer's disease) transgenic mice that produce human AβPP and Aβ 1-42, suggesting that PCM-1 may interact with amyloid precursor protein/Aβ in vivo. We have identified rPK-4′s Aβ-binding domain using a set of overlapping synthetic peptides. We have found with ELISA, dot-blot, and polyacrylamide gel electrophoresis techniques that a ~ 5 kDa synthetic peptide, amyloid binding peptide (ABP)-p4-5 binds Aβ 1-42 at nM levels. Most importantly, ABP-p4-5, like rPK-4, appears to preferentially bind Aβ1-42 oligomers, believed to be the toxic AD-drivers. As expected from these observations, ABP-p4-5 prevented Aβ1-42 from killing human SH-SY5Y neuroblastoma cells via apoptosis. These findings indicate that ABP-p4-5 is a possible candidate therapeutic for AD. © Her Majesty the Queen in Right of Canada 2013. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d20fabd1-6e3c-47b4-8020-d5c673b761c1 ER - TY - JOUR TI - Atomistic theory of emission from dark excitons in self-assembled quantum dots DO - 10.1103/PhysRevB.87.115310 AU - Korkusinski, M. AU - Hawrylak, P. T2 - Physical Review B - Condensed Matter and Materials Physics SN - 1098-0121 VL - 87 IS - 11 SP - 115310 AB - We present atomistic theory of emission from dark excitons in self-assembled quantum dots. Using the atomistic tight-binding model coupled with the configuration-interaction approach, we calculate the emission spectrum of a dark exciton confined in a single, self-assembled quantum dot. We demonstrate that the dark exciton state is optically active and that it emits photons in the plane of the dot, polarized along its vertical axis. This finite radiative lifetime is due to the mixing of hole subbands and can be tuned over several orders of magnitude by engineering the size and shape of the quantum dot. Published by the American Physical Society. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 7511fde5-d701-4c45-ab7a-88843b501e10 ER - TY - JOUR TI - Electrochemical behavior of ruthenium-hexacyanoferrate modified glassy carbon electrode and catalytic activity towards ethanol electrooxidation DO - 10.5935/0103-5053.20130082 AU - Costa, W.M. AU - Cardoso, W.S. AU - Marques, E.P. AU - Bezerra, C.W.B. AU - Ferreira, A.Ap.P. AU - Song, C. AU - Zhang, J. AU - Marques, A.L.B. T2 - Journal of the Brazilian Chemical Society SN - 0103-5053 VL - 24 IS - 4 SP - 651 EP - 656 AB - Ruthenium-based hexacyanoferrate (RuHCF) thin film modified glassy carbon electrode was prepared by drop evaporation method. The RuHCF modified electrode exhibited four redox couples in strong acidic solution (pH 1.5) attributed to Fe(CN)6 3- ion and three ruthenium forms (Ru(II), Ru(III) and Ru(IV)), characteristic of ruthenium oxide compounds. The modified electrode displayed excellent electrocatalytic activity towards ethanol oxidation in the potential region where electrochemical processes Ru(III)-O-Ru(IV) and Ru(IV)-O-Ru(VI) occur. Impedance spectroscopy data indicated that the charge transfer resistance decreased with the increase of the applied potential and ethanol concentration, indicating the use of the RuHCF modified electrode as an ethanol sensor. Under optimized conditions, the sensor responded linearly and rapidly to ethanol concentration between 0.03 and 0.4 mol L-1 with a limit of detection of 0.76 mmol L-1, suggesting an adequate sensitivity in ethanol analyses. Printed in Brazil - ©2013 Sociedade Brasileira de Química. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6edfbab9-81a2-46af-9319-488968003073 ER - TY - JOUR TI - Nonlinear color-metallicity relations of globular clusters. IV. testing the nonlinearity scenario for color bimodality via HST/WFC3 u-band photometry of M84 (NGC 4374) DO - 10.1088/0004-637X/768/2/137 AU - Yoon, S.-J. AU - Sohn, S.T. AU - Kim, H.-S. AU - Chung, C. AU - Cho, J. AU - Lee, S.-Y. AU - Blakeslee, J.P. T2 - The Astrophysical Journal SN - 0004-637X VL - 768 IS - 2 SP - 137 AB - Color distributions of globular clusters (GCs) in most massive galaxies are bimodal. Assuming linear color-to-metallicity conversions, bimodality is viewed as the presence of merely two GC subsystems with distinct metallicities, which serves as a critical backbone of various galaxy formation theories. Recent studies, however, revealed that the color-metallicity relations (CMRs) often used to derive GC metallicities (e.g., CMRs of g-z, V-I, and C-T1) are in fact inflected. Such inflection can create bimodal color distributions if the underlying GC metallicity spread is simply broad as expected from the hierarchical merging paradigm of galaxy formation. In order to test the nonlinear-CMR scenario for GC color bimodality, the u-band photometry is proposed because the u-related CMRs (e.g., CMRs of u-g and u-z) are theoretically predicted to be least inflected and most distinctive among commonly used optical CMRs. Here, we present Hubble Space Telescope (HST)/WFC3 F336W (u-band) photometry of the GC system in M84, a giant elliptical in the Virgo galaxy cluster. Combining the u data with the existing HST ACS/WFC g and z data, we find that the u-z and u-g color distributions are different from the g-z distribution in a very systematic manner and remarkably consistent with our model predictions based on the nonlinear-CMR hypothesis. The results lend further confidence to the validity of the nonlinear-CMR scenario as an explanation for GC color bimodality. There are some GC systems showing bimodal spectroscopic metallicity, and in such systems the inflected CMRs often create stronger bimodality in the color domain. © 2013. The American Astronomical Society. All rights reserved. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 626fea4c-4d65-49eb-adff-2c3b037c1829 ER - TY - JOUR TI - How to reveal subsurface defects in Kevlar® composite materials after an impact loading using infrared vision and optical NDT techniques? DO - 10.1016/j.engfracmech.2013.02.030 AU - Bendada, A. AU - Sfarra, S. AU - Genest, M. AU - Paoletti, D. AU - Rott, S. AU - Talmy, E. AU - Ibarra-Castanedo, C. AU - Maldague, X. T2 - Engineering Fracture Mechanics SN - 0013-7944 VL - 108 SP - 195 EP - 208 KW - Active infrared thermography KW - Aerospace manufacturing KW - Detection capability KW - Digital speckle photography KW - In-service inspection KW - Integrated systems KW - Non destructive testing KW - Short wave infrared KW - Composite materials KW - Debonding KW - Defects KW - Holographic interferometry KW - Optical testing KW - Nondestructive examination AB - An integrated system between infrared vision and optical non-destructive testing techniques can be considered a viable, robust and reliable approach for both aerospace manufacturing and in-service inspections. In this paper, infrared vision is applied in different spectral bands on two impacted panels made of aramid-phenolic composite by applying two different methods, respectively: (1) near and short-wave infrared reflectography and transmittography, and (2) mid-wave active infrared thermography. Furthermore, optical methods, namely digital speckle photography and holographic interferometry, are used as well to highlight the damages due to the impacts on the samples. Some techniques provide more straightforward detection capabilities than others for different defect types. © 2013 Elsevier Ltd. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e3ac43a8-40af-429c-a033-1131967a1d22 ER - TY - JOUR TI - Measuring laser weldability of aluminium alloys using controlled restraint weldability test DO - 10.1179/1362171813Y.0000000137 AU - Coniglio, N. AU - Patry, M. T2 - Science and Technology of Welding and Joining SN - 1362-1718 VL - 18 IS - 7 SP - 573 EP - 580 KW - Al-Mg-Si alloys KW - Disk laser welding KW - Full penetration KW - Laser weldability KW - Solidification cracking KW - Solidification cracks KW - Weldability tests KW - Welding conditions KW - Aluminum alloys KW - Cracks KW - Laser beam welding KW - Silicon alloys KW - Solidification KW - Weldability KW - Testing AB - Al-Mg-Si alloys are known to be highly susceptible to solidification cracking. Weldability results of laminated AA6061-T6 plates are presented in this paper when welded in full penetration keyhole mode using a 1030 nm, 10 kW Yb:YAG disk laser welding source with different welding conditions. Making use of the controlled restraint weldability (CRW) cracking test, a boundary has been established between crack and no crack conditions for different preloads. The originality of the CRW test is the cross-shaped test coupon that partitions the pre-stress unequally along the welding path. The CRW is proven capable of ranking the solidification cracking behaviour of weld metals deposited under different welding conditions. © 2013 Crown in Right of Canada Published by Maney on behalf of the Institute. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 95bb5868-dfc2-405e-add2-c37187d8e02e ER - TY - JOUR TI - Aerobic biofilms grown from Athabasca watershed sediments are inhibited by increasing concentrations of bituminous compounds DO - 10.1128/AEM.02216-13 AU - Yergeau, Étienne AU - Lawrence, John R. AU - Sanschagrin, Sylvie AU - Roy, Julie L. AU - Swerhone, George D. W. AU - Korber, Darren R. AU - Greer, Charles W. T2 - Applied and Environmental Microbiology SN - 0099-2240 VL - 79 IS - 23 SP - 7398 EP - 7412 KW - Athabasca River; Biofilms; Next-generation sequencing; Oil sands; Sediments AB - Sediments from the Athabasca River and its tributaries naturally contain bitumen at various concentrations, but the impacts of this variation on the ecology of the river are unknown. Here, we used controlled rotating biofilm reactors in which we recirculated diluted sediments containing various concentrations of bituminous compounds taken from the Athabasca River and three tributaries. Biofilms exposed to sediments having low and high concentrations of bituminous compounds were compared. The latter were 29% thinner, had a different extracellular polysaccharide composition, 67% less bacterial biomass per μm2, 68% less cyanobacterial biomass per μm2, 64% less algal biomass per μm2, 13% fewer protozoa per cm2, were 21% less productive, and had a 33% reduced content in chlorophyll a per mm2 and a 20% reduction in the expression of photosynthetic genes, but they had a 23% increase in the expression of aromatic hydrocarbon degradation genes. Within the Bacteria, differences in community composition were also observed, with relatively more Alphaproteobacteria and Betaproteobacteria and less Cyanobacteria, Bacteroidetes, and Firmicutes in biofilms exposed to high concentrations of bituminous compounds. Altogether, our results suggest that biofilms that develop in the presence of higher concentrations of bituminous compounds are less productive and have lower biomass, linked to a decrease in the activities and abundance of photosynthetic organisms likely due to inhibitory effects. However, within this general inhibition, some specific microbial taxa and functional genes are stimulated because they are less sensitive to the inhibitory effects of bituminous compounds or can degrade and utilize some bitumen-associated compounds. DA - 2013/09/20 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a8e46933-9fc0-4680-b2f6-d44edc681e09 ER - TY - JOUR TI - Aerodynamics of a low-pressure turbine airfoil at low Reynolds numbers-Part II: Blade-wake interaction DO - 10.1115/1.4006320 AU - Mahallati, A. AU - Sjolander, S.A. T2 - Journal of Turbomachinery SN - 0889-504X VL - 135 IS - 1 SP - 11010 KW - Blade-wake interactions KW - Flow coefficients KW - Freestream turbulence intensity KW - Linear cascade KW - Low-pressure turbines KW - Profile loss KW - Reduced frequency KW - Reynolds KW - Suction surfaces KW - Time varying KW - Turbine airfoils KW - Unsteady effects KW - Wake-induced transitions KW - Airfoils KW - Reynolds number KW - Turbines KW - Wakes KW - Aerodynamics AB - Part II of this two-part paper presents the aerodynamic behavior of a low-pressure high-lift turbine airfoil, PakB, under the influence of incoming wakes. The periodic unsteady effects of wakes from a single upstream blade-row were measured in a low-speed linear cascade facility at Reynolds numbers of 25,000, 50,000 and 100,000 and at two freestream turbulence intensity levels of 0.4% and 4%. In addition, eight reduced frequencies between 0.53 and 3.2, at three flow coefficients of 0.5, 0.7 and 1.0 were examined. The complex wake-induced transition, flow separation and reattachment on the suction surface boundary layer were determined from an array of closely-spaced surface hot-film sensors. The wake-induced transition caused the separated boundary layer to reattach to the suction surface at all conditions examined. The time-varying profile losses, measured downstream of the cascade, increased with decreasing Reynolds number. The influence of increased freestream turbulence intensity was only evident in between wake-passing events at low reduced frequencies. At higher values of reduced frequency, the losses increased slightly and, for the cases examined here, losses were slightly larger at lower flow coefficients. An optimum wake-passing frequency was observed at which the profile losses were a minimum. © 2013 American Society of Mechanical Engineers. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5df3871c-a218-48e5-a5c2-a91151c88a4a ER - TY - JOUR TI - The whole annulus computations of particulate flow and erosion in an axial fan DO - 10.1115/1.4006564 AU - Yang, H. AU - Boulanger, J. T2 - Journal of Turbomachinery SN - 0889-504X VL - 135 IS - 1 SP - 11040 KW - Axial fans KW - Blade row KW - Computational costs KW - Down time KW - Dust particle KW - Erosion damage KW - Erosion patterns KW - Flow physics KW - Gas phase flow KW - Hostile environments KW - Intensive research KW - Lagrangian particle tracking KW - Life assessment KW - Maintenance cost KW - Multistage turbomachinery KW - Numerical algorithms KW - Numerical predictions KW - One-way couplings KW - Particulate flows KW - Power industry KW - Prediction methods KW - Sand erosion KW - Sand particles KW - Single blades KW - Stator-rotor interactions KW - Steady-state simulations KW - With inlets KW - Algorithms KW - Axial flow turbomachinery KW - Computational fluid dynamics KW - Digital storage KW - Forecasting KW - Erosion AB - Gas turbine engines operating in a hostile environment, polluted with sand or dust particles, are susceptible to erosion damage, mostly at the front axial fans and compressors. Accurately predicting the erosion pattern and rate due to sand ingestion is one of the major challenges faced by the transportation and power industries. Maintenance costs are scrutinized and intensive research efforts are currently deployed in predictive life assessment tools to minimize the overhaul down time. The conventional prediction methods were usually based on steady-state simulations of gas-phase flows through a single blade passage per blade row to reduce the computational cost. However, the multistage turbomachinery flows are intrinsically subject to unsteadiness, especially due to stator-rotor interactions, which may affect sand particle trajectories even if a one-way coupling method is considered. Furthermore, an unsteady stator-rotor interaction requires a whole-annulus model at great computational cost to avoid simplifications of the geometries or flow physics. To study the effects of the stator-rotor interaction on sand particle trajectories and erosion, an axial fan with inlet guide vanes is investigated, based on the whole annulus computations of both steady and unsteady gas-phase flows, each of which is then followed by a Lagrangian particle tracking step. A numerical algorithm for tracking particles driven by the unsteady gas-phase flow is presented. The comparison of the numerical predictions with the experimental data confirms the validity and necessity of the unsteady computational fluid dynamics (CFD) model in providing adequate predictions of sand erosion in the axial fan. © 2013 American Society of Mechanical Engineers. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 505bbf97-52ae-4828-ba56-186aa79e5dff ER - TY - JOUR TI - Aerodynamics of a low-pressure turbine airfoil at low Reynolds numbers-Part I: Steady flow measurements DO - 10.1115/1.4006319 AU - Mahallati, A. AU - McAuliffe, B.R. AU - Sjolander, S.A. AU - Praisner, T.J. T2 - Journal of Turbomachinery SN - 0889-504X VL - 135 IS - 1 SP - 11015 KW - Chord lengths KW - Experimental investigations KW - Freestream turbulence KW - Freestream turbulence intensity KW - Hot-film measurement KW - Inflow conditions KW - Laminar separations KW - Length scale KW - Linear cascade KW - Low Reynolds number KW - Low-pressure turbines KW - ON dynamics KW - Reynolds KW - Separated flows KW - Separation bubble KW - Statistical properties KW - Suction side KW - Suction surfaces KW - Transition phenomenon KW - Transition process KW - Turbulence intensity KW - Aerodynamics KW - Airfoils KW - Boundary layer flow KW - Turbines KW - Reynolds number AB - This two-part paper presents a detailed experimental investigation of the laminar separation and transition phenomena on the suction surface of a high-lift low-pressure turbine airfoil, PakB. The first part describes the influence of Reynolds number, freestream turbulence intensity and turbulence length scale on the PakB airfoil under steady inflow conditions. The present measurements are distinctive in that a closely-spaced array of hot-film sensors has allowed a very detailed examination of the suction surface boundary layer behavior. In addition, this paper presents a technique for interpreting the transition process in steady, and periodically unsteady, separated flows based on dynamic and statistical properties of the hot-film measurements. Measurements were made in a low-speed linear cascade facility at Reynolds numbers between 25,000 and 150,000 at three freestream turbulence intensity levels of 0.4%, 2%, and 4%. Two separate grids were used to generate turbulence intensity of 4% with integral length scales of about 10% and 40% of the airfoil axial chord length. While the higher levels of turbulence intensity promoted earlier transition and a shorter separation bubble, turbulence length scale did not have a noticeable effect on the transition process. The size of the suction side separation bubble increased with decreasing Reynolds number, and under low freestream turbulence levels the bubble failed to reattach at low Reynolds numbers. As expected, the losses increased with the length of the separation bubble, and increased significantly when the bubble failed to reattach. © 2013 American Society of Mechanical Engineers. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f2acc973-5c96-4c62-8216-7d3e21eebcfe ER - TY - JOUR TI - Simulating discriminative training for linear mixture adaptation in statistical machine translation AU - Foster, George AU - Chen, Boxing AU - Kuhn, Roland T2 - Proceedings of the XIV Machine Translation Summit (Nice, September 2–6, 2013) T3 - Machine Translation Summit XIV, September 2-6, 2013, Nice, France SP - 183 EP - 190 DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : bd605672-6e33-4b5e-b0d2-24cb16087955 ER - TY - JOUR TI - Laboratory investigation of breakwater crown wall comprised of permeable rock cages DO - 10.1142/9789814412216_0052 AU - Baker, Scott AU - Cornett, Andrew AU - Mahlujy, Keyvan T2 - Coastal Structures 2011 : Proceedings of the 6th International Conference T2 - Coastal structures : Proceedings of the International Conference T3 - Coastal Structures 2011, Sept. 5–9, 2011 , Yokohama, Japan SP - 599 EP - 610 AB - In this paper we explore the use of large permeable rock-filled cages as an innovative, economical and effective means of reducing overtopping on a large rubble-mound breakwater exposed to energetic breaking waves. The results of a physical modelling study demonstrate that significant reductions in wave overtopping can be achieved by erecting crown walls comprised of permeable rock-filled cages. The testing program included several different arrangements of rock cages and also included a sensitivity analysis with regards to rock cage permeability and interlocking friction. DA - 2013/01/01 PY - 2013 PB - World Scientific LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0dd6c45c-8ea6-4b2e-89d3-c24e78134545 ER - TY - JOUR TI - Type- and species-selective air etching of single-walled carbon nanotubes tracked with in situ Raman spectroscopy DO - 10.1021/nn402412t AU - Li-Pook-Than, Andrew AU - Lefebvre, Jacques AU - Finnie, Paul T2 - ACS Nano SN - 1936-0851 SN - 1936-086X VL - 7 IS - 8 SP - 6507 EP - 6521 KW - carbon nanotube combustion; air etching; in situ Raman spectroscopy; purification; chirality AB - The thermal oxidation of carbon nanotubes in air is investigated by in situ Raman spectroscopy. Etching rates are directly seen to be diameter, chirality, and type dependent. We directly track the evolution of bundled nanotube networks that undergo air etching from 300 to 600 °C. Some species are more robust than others. Changes to radial breathing mode (RBM) and G– peak structures suggest that metallic species etch away more rapidly, with smaller diameter semiconducting species etching more slowly and large diameter nanotubes, including semiconductors, etching last. The decay in integrated G and D band intensities is tracked and fit reasonably well with biexponential decay. The RBM evolution is better represented by a single exponential. All bands are fit to activation plots with RBMs showing significantly different rates. DA - 2013/07/09 PY - 2013 PB - ACS LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a2ee36a2-be32-4ca9-bdca-a39239689c7b ER - TY - JOUR TI - Critical role of gas phase diffusion and high efficiency in vertically aligned carbon nanotube forest growth DO - 10.1016/j.carbon.2013.04.007 AU - Vinten, P. AU - Marshall, P. AU - Quance, T. AU - Lefebvre, J. AU - Finnie, P. T2 - Carbon SN - 0008-6223 VL - 61 SP - 22 EP - 32 AB - Here the growth kinetics of vertically aligned carbon nanotube forests depend on the size of the patterned catalyst films from which they grow. Forests are grown using chemical vapor deposition on thin film catalyst islands patterned at the 100 μm scale on silicon wafers. The smaller the pattern, the faster the forest grows and the earlier it stops growing. Furthermore, the shape and structure of the forests, in particular the concavity of their top surface, also depend on the size of the catalyst islands. This result can be understood as a consequence of the high efficiency by which the acetylene source gas is converted into carbon nanotubes (here ∼30%) and a varying local amount of acetylene source gas available for growth. A diffusion model can explain the observed shape and structure of the forests and their growth kinetics by using experimentally measured parameters. This model also gives insight into the density and growth rate of carbon nanotube forests and suggests a mechanism that coordinates growth rates across the sample and, under certain conditions, can limit the fraction of catalyst nanoparticles that produce nanotubes. DA - 2013/04/10 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 446ea8e8-8c0d-45be-99a0-35cc199b8d00 ER - TY - JOUR TI - The effect of hydrogen addition on combustion and emission characteristics of an n-heptane fuelled HCCI engine DO - 10.1016/j.ijhydene.2013.06.084 AU - Guo, Hongsheng AU - Neill, W. Stuart T2 - International Journal of Hydrogen Energy SN - 0360-3199 VL - 38 IS - 26 SP - 11429 EP - 11437 KW - HCCI combustion; Hydrogen enrichment; Diesel combustion; Multi-zone model AB - The mechanisms of the influence of hydrogen enrichment on the combustion and emission characteristics of an n-heptane fuelled homogeneous charge compression ignition (HCCI) engine was numerically investigated using a multi-zone model. The model calculation successfully captured the most available experimental data. The results show that hydrogen addition retards combustion phasing of an n-heptane fuelled HCCI engine due to the dilution and chemical effects, with the dilution effect being more significant. It is because of the chemical effect that combustion duration is reduced at a constant compression ratio if an appropriate amount of hydrogen is added. As a result of retarded combustion phasing and reduced combustion duration, hydrogen addition increases indicated thermal efficiency at a constant combustion phasing. Hydrogen addition reduces indicated specific unburned hydrocarbon emissions, but slightly increases normalized unburned hydrocarbon emissions that are defined as the emissions per unit burned n-heptane mass. The increase in normalized unburned hydrocarbon emissions is caused by the presence of more remaining hydrocarbons that compete with hydrogen for some key radicals during high temperature combustion stage. At a given hydrogen addition level, N2O emissions increases with overly retarding combustion phasing, but hydrogen addition moderates this increase in N2O emissions. DA - 2013/07/17 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 09269947-9b4b-4ac8-b151-9fddf7db1b7e ER - TY - JOUR TI - Growth profile of Carboxydothermus hydrogenoformans on pyruvate DO - 10.1186/2191-0855-3-60 AU - Haddad, Mathieu AU - Cimpoia, Ruxandra AU - Zhao, Ya AU - Guiot, Serge R. T2 - AMB Express SN - 2191-0855 VL - 3 SP - 54123 SP - 1 EP - 5 KW - Carbon monoxide; Water-gas shift reaction; C. hydrogenormans; Pyruvate AB - Carboxydothermus hydrogenoformans is a thermophilic anaerobic strain most widely known for its ability to produce hydrogen (H2) when grown on carbon monoxide (CO). Although relatively well studied, growth characterization on pyruvate has never been assessed. The present work fully characterizes growth of the bacterium on pyruvate as a sole carbon source. C. hydrogenoformans demonstrated a growth rate of 0.03 h-1, with pyruvate consumption ranging between 0.21 and 0.48 mol · g-1 volatile suspended solid · d-1. A lag phase was also observed when switching from pyruvate to CO. When grown simultaneously on pyruvate and CO, pyruvate consumption was initiated upon CO depletion. This was attributed to pyruvate oxidation inhibition by CO, and not to a diauxic phenomenom. The strain also showed homoacetogenic activity. DA - 2013/10/01 PY - 2013 PB - Springer (Open Access) LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 23e27be8-bd14-46a0-aa78-372fff6e9915 ER - TY - JOUR TI - Towards high conductivity in anion-exchange membranes for alkaline fuel cells DO - 10.1002/cssc.201300320 AU - Li, Nanwen AU - Guiver, Michael D. AU - Binder, Wolfgang H. T2 - ChemSusChem SN - 1864-5631 VL - 6 IS - 8 SP - 1376 EP - 1383 KW - 1,2,3-triazole; click chemistry; fuel cells; hydrogen bonds; ion exchange AB - Quaternized poly(2,6-dimethylphenylene oxide) materials (PPOs) containing clicked 1,2,3-triazoles were first prepared through CuI-catalyzed “click chemistry” to improve the anion transport in anion-exchange membranes (AEMs). Clicked 1,2,3-triazoles incorporated into AEMs provided more sites to form efficient and continuous hydrogen-bond networks between the water/hydroxide and the triazole for anion transport. Higher water uptake was observed for these triazole membranes. Thus, the membranes showed an impressive enhancement of the hydroxide diffusion coefficient and, therefore, the anion conductivities. The recorded hydroxide conductivity was 27.8–62 mS cm−1 at 20 °C in water, which was several times higher than that of a typical PPO-based AEM (TMA-20) derived from trimethylamine (5 mS cm−1). Even at reduced relative humidity, the clicked membrane showed superior conductivity to a trimethylamine-based membrane. Moreover, similar alkaline stabilities at 80 °C in 1 M NaOH were observed for the clicked and non-clicked membranes. The performance of a H2/O2 single cell assembled with a clicked AEM was much improved compared to that of a non-clicked TMA-20 membrane. The peak power density achieved for an alkaline fuel cell with the synthesized membrane 1a(20) was 188.7 mW cm−2 at 50 °C. These results indicated that clicked AEM could be a viable strategy for improving the performance of alkaline fuel cells. DA - 2013/06/08 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 68c85398-4f64-4382-bc1e-73595eb1e2c6 ER - TY - JOUR TI - Polyamide thin-film composite membranes based on carboxylated polysulfone microporous support membranes for forward osmosis DO - 10.1016/j.memsci.2013.06.003 AU - Cho, Young Hoon AU - Han, Jungim AU - Han, Sungsoo AU - Guiver, Michael D. AU - Park, Ho Bum T2 - Journal of Membrane Science SN - 0376-7388 VL - 445 SP - 220 EP - 227 KW - Forward osmosis; Microporous Membrane; Desalination; Carboxylated Polysulfone AB - Due to its simple process and low energy consumption, forward osmosis (FO) has gained significant attention in the fields of portable hydration bags, desalination, landfill leachate treatment, and brine concentration. However, current state-of-the-art reverse osmosis (RO) membranes show relatively low water fluxes in FO processes due to high internal concentration polarization (ICP) and high mass transfer resistance in commercially available microporous support membranes. In this study, carboxylated polysulfones (CPSFs) were synthesized via direct polysulfone (PSF) functionalization and considered as hydrophilic, mechanically stable microporous support membranes. The incorporation of hydrophilic groups into hydrophobic polymer backbones often reduces mechanical strength due to excessive water swelling. However, the mechanical properties of CPSFs (degree of substitution, DS=0.49–0.85) were similar to those of pristine PSF, and they retained their hydrophilic nature. Microporous CPSF membranes were prepared in various conditions, and FO water fluxes and salt passages of polyamide thin-film/CPSF composite membranes were measured and compared with each other. CPSF-based FO membranes showed significantly higher water fluxes (water flux in FO mode: 18 L/m2 h, salt passage: 2.2 g/m2 h under 1 M MgCl2 as a draw solution, active layer facing DI water) than PSF-based FO membranes (10.5 L/m2 h, 1.5 g/m2 h at the same conditions), which might be due to enhanced hydrophilicity and reduced ICP. DA - 2013/06/13 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 97285ed8-bcce-4bdf-ae9a-e6b5f8af2814 ER - TY - JOUR TI - Determination of strontium isotope amount ratios in biological tissues using MS-ICPMS DO - 10.1039/C3AY00028A AU - Irrgeher, Johanna AU - Prohaska, Thomas AU - Sturgeon, Ralph E. AU - Mester, Zoltan AU - Yang, Lu T2 - Analytical Methods VL - 5 IS - 7 SP - 1687 EP - 1694 DA - 2013/02/18 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 79bc6eb9-7719-4b86-bed0-46207e9f5ef3 ER - TY - JOUR TI - Surface orientation of hydrophilic groups in sulfonated poly(ether ether ketone) membranes DO - 10.1016/j.jcis.2013.06.063 AU - He, Chenfeng AU - Guiver, Michael D. AU - Mighri, Frej AU - Kaliaguine, Serge T2 - Journal of Colloid and Interface Science SN - 0021-9797 VL - 409 SP - 193 EP - 203 KW - Surface molecular reorientation; Wetting; PEM; Sulfonated poly(ether ether ketone); SPEEK AB - Sulfonated poly(ether ether ketone) copolymers (SPEEK) with a range of sulfonate contents (SC 77–51%) were synthesized via nucleophilic substitution polycondensation from hydroquinone and sulfonated hydroquinone. Membranes obtained by solvent casting from dimethylacetamide onto glass surfaces were analyzed for surface behavior. The surfaces of a membrane were hydrophobic in air, but hydrophilic in water. This surface behavior was corroborated by water contact angle vs. time, using sessile drop measurements. Hydrophilic sulfonic group aggregates on SPEEK chain and various media contacting with the top or bottom surfaces of the membrane during the fabrication process caused differences in surface behavior. Angle-dependent XPS showed that there was a higher atomic S/C ratio of the bottom surface than on the corresponding top surface. The hydrophilic sulfonic groups were in higher concentration within the membrane, with the concentration gradually decreasing towards the surface for SPEEK-HQ-80 and SPEEK-HQ-70 membranes. Acidification with strong acid and higher temperature induced a more hydrophilic surface on a membrane than a milder acidification process. The depth profile at the membrane surface was examined by a combination of contact angle, XPS and ATR-FTIR. DA - 2013/07/03 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ad32046a-069b-4a1c-9e74-56ec4962d765 ER - TY - JOUR TI - Screening microalgae strains for their productivity in methane following anaerobic digestion DO - 10.1016/j.apenergy.2013.02.051 AU - Frigon, Jean-Claude AU - Matteau-Lebrun, Frédérique AU - Hamani Abdou, Rekia AU - McGinn, Patrick J. AU - O'Leary, Stephen J. B. AU - Guiot, Serge R. T2 - Applied Energy SN - 0306-2619 VL - 108 SP - 100 EP - 107 KW - Anaerobic digestion; Methane; Microalgae; Biofuel; Bioenergy; Scenedesmus AB - Interest in the use of microalgae for the production of biofuels has grown in recent years. Biomethane is a biofuel that can be obtained with high efficiency from anaerobic digestion of various organic feedstocks. In this study, a selection of freshwater (n = 15) and marine (n = 5) microalgae were tested in order to identify a microalgal strain that could be used as a model for large scale production of methane. Analysis of pH, volatile suspended solids and ammonium at the end of the assay ranged between 6.98–7.66, 16.0–25.9 g/L and 495–1622 mg/L respectively. No significant differences in these values were detected between freshwater and marine strains. There was no significant difference in the methane yield from freshwater microalgae (329 ± 43 mL CH4/g TVS) and marine microalgae (298 ± 83 mL CH4/g TVS) although it varied greatly within the tested strains. A statistical analysis of the microalgae grown under two different culture media showed that the type of medium was more determinant than the type of microalgae (freshwater or marine) for the methane yield, with 310 ± 35, 365 ± 25 and 303 ± 77 mL CH4/g TVS for the freshwater microalgae grown in Bold’s-3NV, f/2 and marine microalgae grown in f/2 media, respectively. The strains Scenedesmus sp.-AMDD, Isochrysis sp. and Scenedesmus dimorphus displayed the best methane yield with 410 ± 6, 408 ± 4 and 397 ± 10 mL CH4/g TVS, respectively. The strain Scenedesmus sp.-AMDD was chosen as a model strain for future work development with continuously fed digesters. DA - 2013/04/02 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1f20d484-b155-4fc2-bc2a-2d2cd5e16a54 ER - TY - JOUR TI - Practical correlation for thermal resistance of 45° sloped enclosed airspaces with downward heat flow for building applications DO - 10.1016/j.buildenv.2013.04.009 AU - Saber, Hamed H. T2 - Building and Environment SN - 0360-1323 VL - 65 SP - 154 EP - 169 KW - Reflective insulation; low emissivity material; thermal modelling; R-value correlation; airflow in enclosed airspace and heat transfer by convection; conduction and radiation AB - A table is provided in the 2009 ASHRAE Handbook of Fundamentals (Chapter 26) that contains the thermal resistances (R-values) of enclosed airspaces. The ASHRAE table provides the R-values for enclosed airspaces of different thicknesses, effective emittances, mean airspace temperatures, and temperature differences across the airspaces. This table is extensively used by modelers, architects and building designers in the design for the R-values of building enclosures. The effect of the airspace aspect ratio (length/thickness) on the R-value is not accounted for in the ASHRAE table. However, previous studies showed that the aspect ratio of the airspace can affect its R-value. In this paper, the previous studies that focused on determining the R-values for vertical enclosed airspaces and horizontal enclosed airspaces with upward and downward heat flow are extended to investigate the effect of the aspect ratio on the R-values of 45° sloped enclosed airspaces under downward heat flow for different airspace thicknesses and having a wide range of values for the effective emittance, mean temperature, and temperature differences across the airspaces. The predicted R-values are compared with those provided in the ASHRAE table. Considerations are also given to investigate the potential increase in the R-values of enclosed airspaces when a thin sheet is placed in the middle of the airspace and whose surfaces have different values of emissivity. Thereafter, practical correlation is developed for determining the R-values of 45° sloped enclosed airspaces for future use by modelers, architects and building designers. The simplicity of this correlation for the sloped enclosed airspaces along with those that were previously developed for vertical and horizontal airspaces suggests that these correlations could be included in the ASHRAE Handbook of Fundamentals. DA - 2013/07/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 693ab0bf-446c-44fa-b1c3-154b8e683d5d ER - TY - JOUR TI - Practical correlation for thermal resistance of horizontal enclosed airspaces with downward heat flow for building applications DO - 10.1177/1744259113498473 AU - Saber, Hamed H. T2 - Journal of Building Physics SN - 1744-2591 SN - 1744-2583 VL - 37 IS - 4 SP - 403 EP - 435 KW - Reflective insulation; low emissivity material; thermal modelling; R-value correlation; airflow in enclosed airspace; heat transfer by convection; conduction and radiation AB - The 2009 ASHRAE Handbook of Fundamentals (Chapter 26) provides a table that contains the thermal resistances (R-values) of enclosed airspaces for different values of airspace thickness, effective emittance, mean airspace temperature, and temperature differences across the airspace. This table is extensively used by modelers, architects, and building designers in the design for thermal resistance of building enclosures. The effect of the airspace aspect ratio (length/thickness) on the R-value is not accounted for in the ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) table. However, in previous studies, it was shown that the aspect ratio of the airspace can affect its R-value. In this article, the previous studies by the author who focused on determining the R-value for vertical enclosed airspaces and horizontal enclosed airspace under upward heat flow condition are extended to investigate the effect of the aspect ratio on the R-value of horizontal enclosed airspaces under a downward heat flow condition for different airspace thicknesses and having a wide range of values for effective emittance, mean temperature, and temperature differences across the airspaces. The R-values predicted from numerical simulation are compared with those provided in the ASHRAE table. Considerations were also given to investigate the potential increase in the R-values of enclosed airspaces when a thin sheet is placed horizontally in the middle of the airspace and whose surfaces have different values of emissivity. Thereafter, practical correlation was developed for determining the R-values of horizontal enclosed airspaces for future use by modelers, architects, and building designers. The simplicity of this correlation derived for horizontal airspaces under downward heat flow condition together with those that were previously developed for vertical airspaces and horizontal airspaces under upward heat flow condition suggests that these correlations could be included in the ASHRAE Handbook of Fundamentals. DA - 2013/08/01 PY - 2013 PB - SAGE LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f968d1cf-d4b6-4d8c-9fe1-224cbefd008f ER - TY - JOUR TI - Lipid phase separation and protein-ganglioside clustering in supported bilayers are induced by photorelease of ceramide DO - 10.1039/C3SM50240F AU - Ramirez, Daniel M. Carter AU - Kim, Young Ah AU - Bittman, Robert AU - Johnston, Linda J. T2 - Soft Matter VL - 9 IS - 19 SP - 4890 EP - 4899 AB - Photolysis of 6-bromo-7-hydroxycoumarinyl-caged ceramide was used to generate ceramide with spatial and temporal control in supported lipid bilayers prepared from mixtures of caged ceramide and phospholipids. The caged ceramide molecules are randomly distributed in fluid 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) bilayers, and upon photolysis with long wavelength UV light small ordered ceramide domains are formed that phase separate from the bulk fluid membrane. Irradiation of a spatially restricted area leads to the transient formation of ceramide-enriched gel phase domains that equilibrate via lipid diffusion with the surrounding unirradiated membrane. Photorelease of C16-ceramide in supported bilayers prepared from POPC, caged ceramide, and the ganglioside GM1 (90 : 10 : 1 molar ratio) results in partitioning of a ganglioside–protein complex into the ceramide-enriched domains, modeling some aspects of ceramide's behavior in cells. The photo-uncaging strategy used here for delivery of ceramide in bilayers provides a novel and useful alternative to the enzymatic generation of ceramide in sphingomyelin-containing membranes. The ability to control membrane phase separation behavior and the clustering of membrane-anchored proteins illustrates the potential of photo-uncaging for studying the compartmentalization of ceramide in cellular membranes. DA - 2013/04/04 PY - 2013 PB - RSC LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d1fd186f-eaef-415f-ad87-604d07746dd8 ER - TY - JOUR TI - Assessment of tungsten/rhenium thermocouples with metal-carbon eutectic fixed points up to 1500°C DO - 10.1063/1.4819607 AU - Gotoh, M. T2 - Temperature : its measurement and control in science and industry, volume 8: Proceedings of the Ninth International Temperature Symposium T2 - AIP Conference Proceedings; no. 1552 T3 - Ninth International Temperature Symposium, 19–23 March 2012, Los Angeles, California, USA SP - 587 EP - 590 KW - tungsten/rhenium thermocouple; Co-C eutectic point; Pd-C eutectic point AB - Four Type A thermocouples and two Type C thermocouples were calibrated at the Au fixed point and Co-C and Pd-C eutectic fixed points. The thermocouples were exposed to 1330 °C for a total of 100 hours. The maximum drift due to the exposure was found to be 4.8 °C. The fixed-point calibration EMF of these thermocouples deviated by less than 0.86% from the temperature specified by the standards ASTM E230-2003 for Type C and GOSTR 8.585-2001 for Type A. The length of one of Type A thermocouples A52 is longer than the others by 150mm. Making use of this provision it was possible to place annealed part of A52 to the temperature gradient part of calibration arrangement every time. Therefore observed aging effect was as low as 0.5 °C compared to the other thermocouples. DA - 2013/09/11 PY - 2013 LA - eng N1 - M. Gotoh was a visiting scientist at the time of publication C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4b9ddded-9514-4432-94ad-a51d6d7d8f40 ER - TY - JOUR TI - Practical correlations for thermal resistance of horizontal enclosed airspaces with upward heat flow for building applications DO - 10.1016/j.buildenv.2012.12.016 AU - Saber, Hamed H. T2 - Building and Environment SN - 0360-1323 VL - 61 SP - 169 EP - 187 KW - Reflective insulation; furred-airspace assembly; low emissivity material; thermal modelling; thermal resistance test method; R-value, heat flow meter; ASTM C-518; ASTM C-1363; airflow; heat transfer by convection; conduction and radiation AB - The thermal resistance (R-value) of an enclosed airspace depends on the emissivity of all surfaces that bound the airspace, the size and orientation of the airspace, the direction of heat transfer through the airspace, and the respective temperatures of all surfaces that define the airspace. A table is provided in the 2009 ASHRAE Handbook of Fundamentals (Chapter 26) that contains the R-values of enclosed airspaces. The ASHRAE table is extensively used by modellers, architects and building designers in the design for thermal resistance of building enclosures. This table provides R-values for enclosed airspaces for different values of airspace thickness, effective emittance, mean airspace temperature, and temperature differences across the airspace. The effect of the airspace aspect ratio (length/thickness) on the R-value is not accounted for in the ASHRAE table. However, in previous studies, it was shown that the aspect ratio of the airspace can affect its R-value. In this paper, previous studies undertaken by the author that focused on determining the R-value for vertical enclosed airspaces and horizontal enclosed airspaces with downward heat flow are extended to investigate the effect of the aspect ratio on the R-value of horizontal enclosed airspaces under an upward heat flow condition for different airspace thicknesses and having a wide range of values for effective emittance, mean temperature, and temperature differences across the horizontal airspaces. The R-values predicted from numerical simulation are compared with those provided in the ASHRAE table. Considerations were also given to investigate the potential increase in the R-values of enclosed airspaces when a thin sheet is placed horizontally in the middle of the airspace and whose surfaces have different values of emissivity. Thereafter, practical correlations are developed for determining the R-values of horizontal enclosed airspaces for future use by modellers, architects and building designers. The simplicity of these correlations for horizontal airspaces with upward heat flow along with those that were previously developed for vertical airspaces and horizontal airspaces with downward heat flow suggests that these correlations could be included in the ASHRAE Handbook of Fundamentals. DA - 2013/03/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2701de9e-b516-4c10-9732-c69869c671c3 ER - TY - JOUR TI - Energy retrofit using vacuum insulation panels: an alternative solution for enhancing the thermal performance of woodframe walls DO - 10.1177/1744259113505748 AU - Saber, Hamid H. AU - Maref, Wahid AU - Ganapathy, Gnanamurugan AU - Nicholls, Mike T2 - Journal of Building Physics SN - 1744-2591 SN - 1744-2583 SP - 1 EP - 34 KW - Vacuum Insulation Panel (VIP); heat transfer by conduction; convection and radiation; thermal insulation; retrofit; wood-framing AB - Field monitorings of thermal performance of residential 2 × 6 wood-frame wall systems that had been retrofitted using vacuum insulation panels (VIPs) and extruded polystyrene foam (XPS) panels were undertaken in May 2011 to May 2012 at the Field Exposure of Walls Facility (FEWF) of NRC-Construction. The main objective of this research was to measure the steady-state and transient thermal performance of three wall assemblies (4 ft × 6 ft), two of which incorporated VIPs within an XPS Tongue and Groove (T and G) configuration and VIPs within an XPS Clip-On (C-O) configuration, and a third assembly incorporating only XPS. The three wall assemblies were installed in the FEWF for 1-year cycle of exposure to outdoor natural weather conditions. The hygIRC-C model was used in this study. The results of the model calculations were in good agreement with the experimental data. Given that the VIPs could be punctured during the installation process or could fail during normal operating conditions, additional model calculations were used to predict the thermal resistance in cases where one or more VIPs failed. The model was also used to predict the yearly cumulative heat losses across these wall systems. It is important to point out that the aging effect and the effect of the thermal bridging due to envelope (i.e. skin) of the VIPs are not accounted for in this study. However, sensitivity analysis of the thickness and thermal conductivity of the VIP envelope was conducted to investigate the effect of these parameters on the effective thermal resistance of VIP. DA - 2013/10/15 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2474b62a-855b-434e-b39b-52a41e2f8193 ER - TY - JOUR TI - Large-scale arrays of nanomechanical sensors for biomolecular fingerprinting DO - 10.1016/j.snb.2012.09.070 AU - Guthy, C. AU - Belov, M. AU - Janzen, A. AU - Quitoriano, N. J. AU - Singh, A. AU - Wright, V. A. AU - Finley, E. AU - Kamins, T. I. AU - Evoy, S. T2 - Sensors and Actuators B: Chemical T3 - 14th International Meeting on Chemical Sensors, May 20 - 23, 2012, Nürnberg/Nuremberg, Germany SN - 09254005 VL - 187 SP - 111 EP - 117 KW - NEMS; Nanoresonators; Large-scale integration; Electronic noses AB - A review of activities involving the development of large arrays of nanomechanical resonators is presented. This review includes demonstration of the use of these arrays for the detection of biological targets. Both top-down and bottom-up approaches to the realization of such arrays were developed. Using a top-down approach, a nanomachining method for the fabrication of large arrays of doubly-clamped silicon carbonitride (SiCN) resonators with width as narrow as 16 nm and a yield approaching 100% was developed. The specific detection of protein-A using such resonator arrays functionalized with single domain antibody fragments (sdAb) was also demonstrated with femtogram-level mass sensitivity. A nano-imprinting based fabrication of these resonator arrays was also realized, opening up their potential for cost-effective manufacturing. On a bottom-up approach, resonant silicon nanowires were also produced using directed chemical vapor deposition methods. These bottom-up resonant nanowires were in turn successfully employed for the specific detection of streptavidin with attogram-level mass sensitivity. DA - 2013/10 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e80ea0f3-8eaa-4abc-a20d-f63d819ca1c9 ER - TY - JOUR TI - A feature-based method for NC machining time estimation DO - 10.1016/j.rcim.2012.10.001 AU - Liu, Changqing AU - Li, Yingguang AU - Wang, Wei AU - Shen, Weiming T2 - Robotics and Computer-Integrated Manufacturing SN - 07365845 VL - 29 IS - 4 SP - 8 EP - 14 KW - NC machining; Machining speed; Machining time estimation; Machining feature AB - Machining time estimation plays an important role in manufacturing process planning and scheduling. Existing NC machining time estimation methods are all based on material removal rates, NC programs, and machine characteristics. However, the machining condition which is related to the geometry-process information is also an important impact factor of the NC machining time estimation. As existing methods cannot satisfy the requirement of timeliness, accuracy and efficiency, this paper presents a feature-based method for NC machining time estimation. Experiment results show that the proposed approach is feasible and practical. It is particularly useful in real time manufacturing process planning and scheduling systems. DA - 2013/08 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 685d75d6-63b5-4a36-a1ab-b58a3c8d0cfe ER - TY - JOUR TI - Ceiling temperature distribution and smoke diffusion in tunnel fires with natural ventilation DO - 10.1016/j.firesaf.2013.09.019 AU - Kashef, Ahmed AU - Yuan, Zhongyuan AU - Lei, Bo T2 - Fire Safety Journal SN - 0379-7112 VL - 62 IS - Part C SP - 249 EP - 255 KW - Tunnel fire; natural ventilation; ceiling temperature distribution; smoke diffusion distance AB - A series of experimental tests was carried out in two 1/15 reduced-scale tunnels to investigate ceiling temperature distribution and smoke diffusion in tunnel fires with natural ventilation. Based on experimental results and the one-dimensional theory, formulas to predict the temperature distribution and smoke diffusion extent were developed. As the smoke was extracted through natural ventilation shafts, the tunnel was conceptually divided into two zones or sections: the fire and non-fire sections. In both sections, the smoke temperature can be expressed using the temperature decay formula and reference temperature formula. The temperature decay is an exponential function. The reference temperature in the fire section can be developed from the definition of the dimensionless temperature and a constant value that is different for different tunnels. The reference temperature in the non-fire section represents the relationship between the dimensionless reference temperature in the non-fire section and a constant value that is different for different tunnels. The smoke diffusion area represents the relationship between the dimensionless length of the smoke layer and the temperature decay at the location of smoke. DA - 2013/10/15 PY - 2013 LA - eng N1 - In Press, Corrected proof C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 70c3c1c3-b39f-4ece-a82d-27d22eb2cc04 ER - TY - JOUR TI - Risk-based decision making for sustainable and resilient infrastructure DO - 10.1061/9780784412848.162 AU - Lounis, Zoubir T2 - Structures Congress 2013: Bridging Your Passion With Your Profession T3 - Structures Congress 2013, May 2-4, 2013, Pittsburgh, Pennsylvania, United States SN - 978-0-7844-1284-8 SP - 1845 EP - 1856 KW - risk management; sustainable development; infrastructure; decision making AB - The design and preservation of civil infrastructure systems have been driven, for a long time, by cost minimization while maintaining system reliability at an acceptable level. The growing concerns with aging and deteriorating infrastructures and the need to ensure resilient and sustainable infrastructures and communities require the development and use of innovative construction materials and structural systems and management practices that yield infrastructure resiliency and achieve an adequate balance between social, economic and environmental sustainability and the emerging needs for sustainable and resilient infrastructure and communities. This paper discusses some key performance measures and approaches that can be used to assess resilience and sustainability and presents a risk-based decision-based approach to help decision-makers optimize the design, evaluation and management of infrastructures that considers all possible hazards and provides alternative risk mitigation strategies that can be evaluated using a cost-benefit analysis, and rational criteria are presented to support the selection of the most sustainable and resilient risk mitigation strategy indicators, such as safety, serviceability, costs, traffic disruption, greenhouse gas emissions, which can be used for life cycle design of highway bridges. An example, taken from the North American context, illustrates how different design and rehabilitation approaches can contribute to achieve the sustainability of a highway bridge. DA - 2013/04/30 PY - 2013 PB - American Society of Civil Engineers LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b2ddd42d-84f5-4c13-8756-e7da91079ad9 ER - TY - JOUR TI - Simultaneous optimization of pipe and pavement renewal scheduling DO - 10.1061/9780784412947.093 AU - Kleiner, Yehuda T2 - World Environmental and Water Resources Congress 2013: Showcasing the Future T3 - World Environmental and Water Resources Congress 2013, May 19-23, 2013, Cincinnati, Ohio SN - 978-0-7844-1294-7 SP - 967 EP - 974 KW - Renewal scheduling; pipe; pavement; deterioration; optimisation AB - Most urban distribution water mains are located under paved streets or roads. Despite an obvious interdependence between pipe and pavement deterioration, this interdependence has not yet been considered in frameworks that would optimize both simultaneously, which is the issue addressed in this paper. The deterioration processes of both pipe and pavement are considered to be deterministic, and some assumptions are made about the interactions between pipe breakage frequency and pavement condition. Total life cycle costs of both pipe and pavement are computed as the discounted costs of an infinite series of perpetual renewal cycles. Genetic Algorithm (GA) is used to find the (near) least cost strategy for scheduling multiple pipes and pavements in a network. DA - 2013/05/28 PY - 2013 PB - American Society of Civil Engineers LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 15c12000-da01-4ae0-bce1-0d7e1b024eb6 ER - TY - JOUR TI - Glyceryl trinitrate metabolism in the quail embryo by the glutathione S-transferases leads to a perturbation in redox status and embryotoxicity DO - 10.1016/j.cbpb.2013.04.001 AU - Bardai, Ghalib K. AU - Hales, Barbara F. AU - Sunahara, Geoffrey I. T2 - Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology SN - 1096-4959 VL - 165 IS - 3 SP - 153 EP - 164 KW - Glutathione; Nitrated proteins; N-acetylcysteine; Redox homeostasis; Embryotoxicity AB - Exposure of stage 9 quail (Coturnix coturnix japonica) embryos to glyceryl trinitrate (GTN) induces malformations that were associated in previous studies with an increase in protein nitration. Increased nitration suggests metabolism of GTN by the embryo. The goals of this study were to characterize the enzymes and co-factors required for GTN metabolism by quail embryos, and to determine the effects of in ovo treatment with N-acetyl cysteine (NAC), a precursor of glutathione (GSH), on GTN embryotoxicity. GTN treatment of quail embryos resulted in an increase in nitrite, a decrease in total GSH, and an increase in the ratio of NADP+/NADPH, indicating that redox balance may be compromised in exposed embryos. Glutathione S-transferases (GSTs; EC 2.5.1.18) purified from the whole embryo (Km 0.84 mM; Vmax 36 μM/min) and the embryonic eye (Km 0.20 mM; Vmax 30 μM/min) had GTN-metabolizing activity (1436 and 34 nmol/min/mg, respectively); the addition of ethacrynic acid, an inhibitor of GST activity, decreased GTN metabolism. Peptide sequencing of the GST isozymes indicated that alpha- or mu-type GSTs in the embryo and embryonic eye had GTN metabolizing activity. NAC co-treatment partially protected against the effects of GTN exposure. Thus, GTN denitration by quail embryo GSTs may represent a key initial step in the developmental toxicity of GTN. DA - 2013/04/12 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c9f62495-7fa9-4400-952f-240f327a634e ER - TY - JOUR TI - Predictable bacterial composition and hydrocarbon degradation in Arctic soils following diesel and nutrient disturbance DO - 10.1038/ismej.2013.1 AU - Bell, Terrence H. AU - Yergeau, Étienne AU - Maynard, Christine AU - Juck, David AU - Whyte, Lyle G. AU - Greer, Charles W. T2 - The ISME Journal SN - 1751-7362 SN - 1751-7370 VL - 7 IS - 6 SP - 1200 EP - 1210 KW - 16S rRNA; Arctic; betaproteobacteria; bioremediation; disturbance; nutrient amendment AB - Increased exploration and exploitation of resources in the Arctic is leading to a higher risk of petroleum contamination. A number of Arctic microorganisms can use petroleum for growth-supporting carbon and energy, but traditional approaches for stimulating these microorganisms (for example, nutrient addition) have varied in effectiveness between sites. Consistent environmental controls on microbial community response to disturbance from petroleum contaminants and nutrient amendments across Arctic soils have not been identified, nor is it known whether specific taxa are universally associated with efficient bioremediation. In this study, we contaminated 18 Arctic soils with diesel and treated subsamples of each with monoammonium phosphate (MAP), which has successfully stimulated degradation in some contaminated Arctic soils. Bacterial community composition of uncontaminated, diesel-contaminated and diesel+MAP soils was assessed through multiplexed 16S (ribosomal RNA) rRNA gene sequencing on an Ion Torrent Personal Genome Machine, while hydrocarbon degradation was measured by gas chromatography analysis. Diversity of 16S rRNA gene sequences was reduced by diesel, and more so by the combination of diesel and MAP. Actinobacteria dominated uncontaminated soils with 10 percent organic matter, while Proteobacteria dominated higher-organic matter soils, and this pattern was exaggerated following disturbance. Degradation with and without MAP was predictable by initial bacterial diversity and the abundance of specific assemblages of Betaproteobacteria, respectively. High Betaproteobacteria abundance was positively correlated with high diesel degradation in MAP-treated soils, suggesting this may be an important group to stimulate. The predictability with which bacterial communities respond to these disturbances suggests that costly and time-consuming contaminated site assessments may not be necessary in the future. DA - 2013/02/07 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a6c1fbcc-4174-434f-9687-c0ec11d39374 ER - TY - JOUR TI - Electrolyte formulations based on dinitrile solvents for high voltage Li-ion batteries DO - 10.1149/2.088306jes AU - Duncan, Hugues AU - Salem, Nuha AU - Abu-Lebdeh, Yaser T2 - Journal of the Electrochemical Society T3 - Meeting of the Electrochemical Society, May 6–10, 2012, Seattle, Washington SN - 0013-4651 SN - 1945-7111 VL - 160 IS - 6 SP - 343 SP - A838 EP - A848 AB - In this work, we have investigated the suitability of aliphatic dinitrile solvents with the chemical formula N≡C-(CH2)n-C≡N where n varies from 3 to 8 in single, binary (mixed with ethylene carbonate, EC) or ternary (mixed with EC and dimethyl carbonate, DMC) electrolyte solutions for the high voltage (4.7 V) LiMn1.5Ni0.5O4 cathode material in lithium batteries. We report that the conductivity of all the electrolyte solutions (with LiTFSI or LiBF4 as salt) decreases as a function of “n”, i.e. as the alkane chain become longer while the viscosity increases. The electrochemical stability window is about 7 V for the single electrolyte solutions and drops to 6–6.5 V for the binary and ternary ones. ATR IR spectra of all the electrolyte solutions indicate the presence of a strong interaction between Li ions and the different solvents. Li/LiMn1.5Ni0.5O4 half cell batteries assembled using dinitriles as the main solvent (50% by volume), LiBF4 salt and LiBOB co-salt show good performance only in the ternary solutions. Those with shorter alkane dinitriles with n = 4 and 5 retain the capacity better after 50 cycles than the longer ones with n = 6 and 8. Investigation of the surface of the cycled electrode by XPS reveals that DMC plays a great role in surface passivation at high voltages by preventing salt decomposition in ternary solutions. DA - 2013/03/29 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 431ad01c-3fb7-4610-923b-99d08c6a4c16 ER - TY - JOUR TI - Astronomy from 80 Degrees North on Ellesmere Island, Canada DO - 10.1017/S1743921312016869 AU - Steinbring, Eric T2 - Astrophysics from Antarctica T2 - Proceedings of the International Astronomical Union; no. 8, issue S288 T3 - International Astronomical Union Symposium 288: Astrophysics from Antarctica, August 2012, Beijing, China SN - 1743-9213 SN - 1743-9221 SP - 194 EP - 199 KW - arctic; site testing; telescopes; optical; submillimeter AB - Site testing carried out on Ellesmere Island over recent years has shown that mountainous coastal terrain there can provide high clear-sky fractions in the long dark season, with low precipitable water-vapour column and prospects for excellent seeing. This presents new possibilities for time-domain and survey-mode science in the northern hemisphere, allowing uninterrupted high-precision photometry in the optical/near-infrared, but also gains in the submillimetre/millimetre. Efforts underway at the Eureka research station, at 80 degrees latitude, are reviewed. This location provides year-round access to a nearby site being developed as a pathfinder observatory. A program of variable-star and transient searches involving a wide-field imaging system has begun, with some early results. Plans include extrasolar-planet hunting via transit surveys, and future directions are discussed. DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 09ec3903-efaf-4eae-bad6-4761c47e727e ER - TY - JOUR TI - Comparison of single and dual layer detector blocks for pre-clinical MRI–PET DO - 10.1016/j.nima.2012.07.062 AU - Thompson, Christopher AU - Stortz, Greg AU - Goertzen, Andrew AU - Berg, Eric AU - Retière, Fabrice AU - Kozlowski, Piotr AU - Ryner, Lawrence AU - Sossi, Vesna AU - Zhang, Xuezhu T2 - Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment T3 - PET/MR and SPECT/MR: New Paradigms for Combined Modalities in Molecular Imaging, May 26-30, 2012, ELBA Island, Italy SN - 01689002 VL - 702 SP - 56 EP - 58 KW - Pre-clinical PET; SiPM; Dual-layer pixelated detector AB - Dual or multi-layer crystal blocks have been proposed to minimise the radial blurring effect in PET scanners with small ring diameters. We measured two potential PET detector blocks' performance in a configuration which would allow 16 blocks in a ring which could be inserted in a small animal 7T MRI scanner. Two crystal sizes, 1.60×1.60 mm² and 1.20×1.20 mm², were investigated. Single layer blocks had 10 or 12 mm deep crystals, the dual layer blocks had 4 mm deep crystals on the top layer and 6 mm deep crystals on the bottom layer. The crystals in the dual layer blocks are offset by ½ of the crystal pitch to allow for purely geometric crystal identification. Both were read out with SensL 4×4 SiPM arrays. The software identifies 64 crystals in the single layer and either 85 or 113 crystals in the dual layer array, (either 49 or 64 in the lower layers and 36 or 49 in the upper layers). All the crystals were clearly visible in the crystal identification images and their resolvability indexes (average FWHM/crystal separation) were shown to range from 0.29 for the best single layer block to 0.33 for the densest dual layer block. The best coincidence response FWHM was 0.95 mm for the densest block at the centre of the field. This degraded to 1.83 mm at a simulated radial offset of 16 mm from the centre, while the single layer crystals blurred this result to 3.4 mm. The energy resolution was 16.4±2.2% averaged over the 113 crystals of the densest block. DA - 2013/02/21 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f4b3e568-3348-49f9-82d9-fb2d039c35f4 ER - TY - JOUR TI - Spatiotemporal modelling for policy analysis: application to sustainable management of whale-watching activities DO - 10.1016/j.marpol.2012.05.031 AU - Chion, Clément AU - Cantin, Guy AU - Dionne, Suzan AU - Dubeau, Benoit AU - Lamontagne, Philippe AU - Landry, Jacques-André AU - Marceau, Danielle AU - Martins, Cristiane C. A. AU - Ménard, Nadia AU - Michaud, Robert AU - Parrott, Lael AU - Turgeon, Samuel T2 - Marine Policy SN - 0308597X VL - 38 SP - 151 EP - 162 KW - Agent-based modelling; Spatiotemporal simulation; Whale-watching; Policy analysis; Sustainable management; Marine park AB - Anticipating the impacts of a new policy before implementation on a complex social–ecological system is a challenging task for managers and policymakers. This paper reports on the development and use of an agent-based model (ABM) dedicated to support marine park managers in their effort to devise policies to sustainably manage whale-watching activities. The ABM, called the Marine Mammal and Maritime Traffic Simulator (3MTSim), represents the spatiotemporal dynamics of marine mammals and navigation activities in and around the Saguenay–St. Lawrence Marine Park in Canada. In the context of updating the current regulations on whale-watching in the Marine Park, 3MTSim was run to evaluate the merits of a proposed set of rules compared to the current regulations. To do so, a set of variables related to policies’ impacts on the three spheres of sustainable development, namely the impact on whales (Environment), on whale-watching companies (Economy), and tourist experience (Society) was analysed. 3MTSim's simulations highlighted that the proposed rules are expected to improve the situation regarding whale conservation and tourist experience with only marginal impact on the whale-watching industry. In the proposed regulations, one rule is expected to be very influential on whale-watching activities. This rule limits to 10 the number of whale-watching boats allowed to stand within 926 m of any boat in observation mode. Assuming efficient law enforcement, 3MTSim predicts a significant decrease in overall boat concentration around whales in the Marine Park, which is one of the management objectives benefiting both whales and tourists. Interestingly, 3MTSim reveals that this rule could indirectly force some boats to observe second-choice whales present in higher abundance rather than some more attractive species scarcer in the region. This highlights the following management tradeoffs: Reducing boat exposure for the humpback whale and endangered blue whale is likely to increase it for the more abundant fin whale listed as of special concern (Canada's Species at Risk Act) and minke whale. This work demonstrates the utility of ABMs to support policy analysis in the context of sustainable management in a Marine Park. ABMs developed in close relationship with end-users are unarguably a tool of choice to manage complex social–ecological systems since they provide insight into phenomena hard or impossible to measure in the real system. Despite the labour intensive nature of their implementation, this investment is worth the effort. DA - 2013/03 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d54e9592-57bb-4265-a0a5-5607eb9db7ca ER - TY - JOUR TI - Evaluation of the absorption line blackbody distribution function of CO2 and H2O using the proper orthogonal decomposition and hyperbolic correlations DO - 10.1016/j.jqsrt.2012.07.009 AU - Liu, F. AU - Chu, H. AU - Zhou, H. AU - Smallwood, G. J. T2 - Journal of Quantitative Spectroscopy and Radiative Transfer T3 - Eurotherm Seminar 95: Computational Thermal Radiation in Participating Media IV, April 18-20, 2012, Nancy, France SN - 00224073 VL - 128 SP - 27 EP - 33 KW - Line-by-line; Spectral line based weight-sum-of-grey-gases model; Absorption line blackbody function; Proper orthogonal decomposition; Hyperbolic correlation AB - Databases of the absorption line blackbody distribution function (ALBDF) of CO2 and H2O were generated over a wide range of gas and blackbody temperatures and the full range of gas concentration from line-by-line (LBL) calculations using the latest version of HITEMP. Proper orthogonal decomposition (POD) and the hyperbolic correlations (HC) were then used for rapid calculation the ALBDF value at an arbitrary combination of gas and blackbody temperatures and gas concentration. A novel hyperbolic correlation for H2O was proposed to fully account for the self-broadening effect. The accuracy of POD and the HC was evaluated by comparing the ALBDF values and the total gas emissivities from these two approximate methods at several selected conditions against those from LBL calculations. POD is significantly more accurate than HC at essentially no extra computational costs. DA - 2013/10 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 7659ab33-95d2-4a6f-8038-43fd2a1c5fb0 ER - TY - JOUR TI - Gap tolerance allowance and robotic operational window for friction stir butt welding of AA6061 DO - 10.1016/j.jmatprotec.2012.10.010 AU - Wanjara, P. AU - Monsarrat, B. AU - Larose, S. T2 - Journal of Materials Processing Technology SN - 0924-0136 VL - 213 IS - 4 SP - 631 EP - 640 KW - Friction stir welding; AA6061-T6; Gap tolerance; Operational window; Kinetostatic analysis; Industrial robot AB - In this work, it was determined that with increasing weld pitch, the occurrence of a “lazy S” defect in the weld nugget of friction stir welded (FSWed) AA6061 became increasingly pronounced, though its impact on the bend performance of the weld was negligible. For a fixed weld pitch of 0.48, the effect of gap, i.e. the spacing between two sheets at the butt joint interface, on the joint quality of AA6061 was evaluated in terms of the welding defects, microstructure, hardness and bend performance. Fully penetrated welds without metallurgical defects such as wormholes were obtained up to a joint gap of 0.5 mm. Though the overall microhardness and bend performance of the welds remained unaffected until a joint gap of 0.8 mm, the decrease in the forge force during FSW beyond a joint gap value of 0.5 mm may represent a more critical limit in regards to the industrial application of the process; this is especially important when applying force control during processing to ensure a constant shoulder penetration in the material for addressing practical considerations, such as thickness variations in the assembly, clamping distortions and tool wear. Based on these results and using force amplitudes recorded during the welding experiments, a robotic scenario was synthesized with an appropriate operational window for continuous-path friction stir butt welding (FSBW) of 3.18-mm-thick sheets clamped to a 1 m × 1 m horizontal welding table. An appropriate industrial robot model was selected and the associated geometric workcell layout was developed for this application. This scenario was implemented in a physical prototype and used to successfully produce 1-m-long FSWed assemblies that exhibited good tensile mechanical performance. DA - 2013/04 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6775a243-4957-48ba-b8e5-d29d2327b4a4 ER - TY - JOUR TI - Comparison of three Co-C fixed points constructed using different crucible lining materials DO - 10.1063/1.4819568 AU - Todd, A. D. W. AU - Woods, D. J. T2 - Temperature : its measurement and control in science and industry, volume 8: Proceedings of the Ninth International Temperature Symposium T2 - AIP Conference Proceedings; 1552 T3 - Ninth International Temperature Symposium, 19–23 March 2012, Los Angeles, California, USA SN - 978-0-7354-1178-4 SP - 369 EP - 373 KW - high temperature fixed points; radiation thermometry; Co-C AB - The melting plateaus of three Co-C fixed points for radiation thermometry with different constructions were measured and compared. Two of the fixed points were of the hybrid type and contained either carbon composite cloth or pyrolytic graphite sheet between the graphite sleeve and the crucible wall. The third fixed point contained only the graphite sleeve. Little difference was found in the shapes of the melting curves between the fixed points. Given a comparison uncertainty of 37 mK (k = 1), there were, however, significant differences in the melting temperatures determined for each of the fixed points. Over three days of measurement, the melting temperature of the fixed point filled using the pyrolytic sheet drifted up by nearly 140 mK. DA - 2013/09/11 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : fa02e9ba-d814-40c3-8073-b6dbbd9e40ba ER - TY - JOUR TI - Solid-state 17O NMR of pharmaceutical compounds : salicylic acid and aspirin DO - 10.1021/jp405233f AU - Kong, Xianqi AU - Shan, Melissa AU - Terskikh, Victor AU - Hung, Ivan AU - Gan, Zhehong AU - Wu, Gang T2 - The Journal of Physical Chemistry B SN - 1520-6106 SN - 1520-5207 VL - 117 IS - 33 SP - 9643 EP - 9654 AB - We report solid-state NMR characterization of the 17O quadrupole coupling (QC) and chemical shift (CS) tensors in five site-specifically 17O-labeled samples of salicylic acid and o-acetylsalicylic acid (Aspirin). High-quality 17O NMR spectra were obtained for these important pharmaceutical compounds under both static and magic angle spinning (MAS) conditions at two magnetic fields, 14.0 and 21.1 T. A total of 14 17O QC and CS tensors were experimentally determined for the seven oxygen sites in salicylic acid and Aspirin. Although both salicylic acid and Aspirin form hydrogen bonded cyclic dimers in the solid state, we found that the potential curves for the concerted double proton transfer in these two compounds are significantly different. In particular, while the double-well potential curve in Aspirin is nearly symmetrical, it is highly asymmetrical in salicylic acid. This difference results in quite different temperature dependencies in 17O MAS spectra of the two compounds. A careful analysis of variabletemperature 17O MAS NMR spectra of Aspirin allowed us to obtain the energy asymmetry (ΔE) of the double-well potential, ΔE = 3.0 ± 0.5 kJ/mol. We were also able to determine a lower limit of ΔE for salicylic acid, ΔE > 10 kJ/mol. These asymmetrical features in potential energy curves were confirmed by plane-wave DFT computations, which yielded ΔE = 3.7 and 17.8 kJ/mol for Aspirin and salicylic acid, respectively. To complement the solid-state 17O NMR data, we also obtained solid-state 1H and 13C NMR spectra for salicylic acid and Aspirin. Using experimental NMR parameters obtained for all magnetic nuclei present in salicylic acid and Aspirin, we found that plane-wave DFT computations can produce highly accurate NMR parameters in welldefined crystalline organic compounds. DA - 2013/07/23 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8587d41a-7d86-4a7e-b35e-e9609b743dbe ER - TY - JOUR TI - Immersed boundary finite elements for 3D flow simulations in twin-screw extruders DO - 10.1016/j.compfluid.2012.06.025 AU - Hétu, J.-F. AU - Ilinca, F. T2 - Computers & Fluids T3 - Eleventh US National Congress on Computational Mechanics, Minisymposium: Computational Fluid Mechanics for Free and Moving Boundary Problems, July 25-28, 2011, Minneapolis, Minnesota, U.S.A. SN - 00457930 VL - 87 SP - 2 EP - 11 KW - Immersed boundary method; Twin-screw extruders; Finite elements; Non-body-conformal mesh; Body conformal enrichment AB - This paper presents applications of a recently proposed Immersed Boundary (IB) method to the solution of the flow around moving and complex shaped surfaces, in particular inside twin-screw extruders. Solving the flow around rotating screw elements implies significant changes in the computational topology at every time step. Using multiple meshes or adaptive methods to tackle these would require extensive meshing and interpolation work that has to be repeated each time step. Mesh generation and solution interpolation between successive grids may be costly and may introduce errors if the geometry changes significantly during the course of the computation. These drawbacks are avoided when the solution algorithm can tackle grids that do not fit the shape of immersed objects. In this work a fixed mesh is used covering both the fluid and solid regions, and the boundary of immersed objects is defined using a time dependent level-set function. The Body Conformal Enrichment (BCE) method is used to accurately impose boundary conditions on the surface of immersed bodies. The proposed algorithm enriches the finite element discretization of interface elements with additional degrees of freedom, the latter being eliminated at element level. Numerical applications are shown in which the flow inside twin-screw extruders is computed for multiple screw elements. A generalized non-Newtonian fluid is used to model molten polymer. Solutions will be shown for various rotation velocities of the screw as the viscosity depends on the shear rate. DA - 2013/10/25 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d757dad1-b491-4fa6-9a40-043d6c98fde1 ER - TY - JOUR TI - Calcium supplementation increases circulating cholesterol by reducing its catabolism via GPER and TRPC1-dependent pathway in estrogen deficient women DO - 10.1016/j.ijcard.2013.03.057 AU - Li, Songtao AU - Li, Ying AU - Ning, Hua AU - Na, Lixin AU - Niu, Yucun AU - Wang, Maoqing AU - Feng, Rennan AU - Liu, Liyan AU - Guo, Fuchuan AU - Hou, Shaoying AU - Chu, Xia AU - Wang, Yemei AU - Zhang, Yunbo AU - Zhang, Huaqi AU - Huang, Lina AU - Bi, Mingxin AU - Huang, Yifan AU - Hao, Liuyi AU - Zhao, Yan AU - Wang, Cheng AU - Wang, Yanwen AU - He, Yonghan AU - Sun, Changhao T2 - International Journal of Cardiology SN - 01675273 VL - 168 IS - 3 SP - 2548 EP - 2560 KW - Calcium supplementation; Cholesterol; Estrogen; G-Protein coupled estrogen receptor AB - Background: Limited studies have addressed the effects of calcium supplementation (CaS) on serum total cholesterol (TC) in postmenopausal women and the results are inconclusive. Moreover, the potential mechanisms through which CaS regulates cholesterol metabolism in the absence of estrogen are still sealed for the limitation of human being study. Methods: Cross-sectional survey, animal and in vitro experiments were conducted to investigate the effect of CaS on endogenous cholesterol metabolism in estrogen deficiency and identify its potential mechanisms. Ovariectomized rats were used to mimic estrogen deficiency. In vitro, HepG2 cell line was exposed to estradiol and/or calcium treatment. Results: We demonstrated that CaS significantly increased serum TC and the risk of hypercholesterolemia and myocardial infarction in postmenopausal women. Increased serum TC in estrogen deficiency was caused mainly by decreased cholesterol catabolism rather than increased synthesis. This was mediated by reduced 7α-hydroxylase resulting from increased liver intracellular Ca²⁺ concentrations, reduced intracellular basal cAMP and subsequent up-regulation of SREBP-1c and SHP expression. Estrogen had a protective role in preventing CaS-induced TC increase by activating the G-protein coupled estrogen receptor, which mediated the estrogen effect through the transient receptor potential canonical 1 cation channel. Conclusions: CaS increases endogenous serum TC via decreasing hepatic cholesterol catabolism in estrogen deficiency. G-protein coupled estrogen receptor is shown to be a key target in mediating CaS-induced TC increase. CaS should be monitored for the prevention of serum TC increase during menopause. DA - 2013/04/17 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ccb807c3-ff8e-46ff-9b6a-eea51d263619 ER - TY - JOUR TI - Synthesis and evaluation of L-Rhamnose 1C-Phosphonates as nucleotidylyltransferase inhibitors DO - 10.1021/jo401542s AU - Loranger, Matthew W. AU - Forget, Stephanie M. AU - Mccormick, Nicole E. AU - Syvitski, Raymond T. AU - Jakeman, David L. T2 - The Journal of Organic Chemistry SN - 0022-3263 SN - 1520-6904 VL - 78 IS - 19 SP - 9822 EP - 9833 AB - We report the synthesis of a series of phosphonates and ketosephosphonates possessing an l-rhamnose scaffold with varying degrees of fluorination. These compounds were evaluated as potential inhibitors of α-d-glucose 1-phosphate thymidylyltransferase (Cps2L), the first enzyme in Streptococcus pneumoniae l-rhamnose biosynthesis, and a novel antibiotic target. Enzyme–substrate and enzyme–inhibitor binding experiments were performed using water-ligand observed binding via gradient spectroscopy (WaterLOGSY) NMR for known sugar nucleotide substrates and selected phosphonate analogues. IC50 values were measured and Ki values were calculated for inhibitors. New insights were gained into the binding promiscuity of enzymes within the prokaryotic l-rhamnose biosynthetic pathway (Cps2L, RmlB–D) and into the mechanism of inhibition for the most potent inhibitor in the series, l-rhamnose 1C-phosphonate. DA - 2013/09/10 PY - 2013 PB - ACS Publications LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d9f6c1ac-fb26-44cf-a378-3c1d2f186d05 ER - TY - JOUR TI - Following the thermal activation of Au25(SR)18 clusters for catalysis by x-ray absorption spectroscopy DO - 10.1021/jp4063687 AU - Shivhare, Atal AU - Chevrier, Daniel M. AU - Purves, Randy W. AU - Scott, Robert W. J. T2 - The Journal of Physical Chemistry C SN - 1932-7447 SN - 1932-7455 VL - 117 IS - 39 SP - 20007 EP - 20016 AB - We show the thermal activation of phenylethanethiolate (L = SC₈H₉) and hexanethiolate (L = SC₆H₁₃) Au₂₅L₁₈ monolayer protected clusters (MPCs) on carbon black supports, followed by characterization with extended Xray absorption fine structure (EXAFS) spectroscopy and transmission electron microscopy (TEM). EXAFS analysis shows that the thiolate stabilizers can be partially removed from the surface under mild heating conditions without significant changes in the cluster size. The resulting clusters are shown to be catalytically active for the reduction catalysis of 4-nitrophenol. EXAFS and TEM data show that thermal treatment under air at 200 °C leads to nearly complete removal of all of the thiolate stabilizers with little to no growth in cluster size, while cluster sintering was seen at higher calcination temperatures. The maximum catalytic activity for Au₂₅(SC₈H₉)₁₈ MPCs was seen at 250 °C activation conditions. These results are consistent with results reported earlier for Au₂₅(SR)₁₈ clusters on ceria by Jin et al., who suggested that cluster integrity was maintained during mild activation conditions. Here, EXAFS data unambiguously show that while the cluster size does not grow significantly, such mild heating conditions do lead to nearly complete removal of the thiolate stabilizers. DA - 2013/09/06 PY - 2013 PB - ACS Publications LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2e9a8ad7-e680-43ca-b179-e586e38a8557 ER - TY - JOUR TI - Identification and characterization of interactions between abscisic acid and human heat shock protein 70 family members DO - 10.1093/jb/mvt067 AU - Kharenko, Olesya A. AU - Polichuk, Devin AU - Nelson, Ken M. AU - Abrams, Suzanne R. AU - Loewen, Michele C. T2 - Journal of Biochemistry SN - 0021-924X VL - 154 IS - 4 SP - 383 EP - 391 KW - abscisic acid; chemical proteomics; glucose-regulated protein 78; Heat shock protein 70; protein-ligand interaction AB - Abscisic acid (ABA) is a stress-inducible plant hormone comprising an inevitable component of the human diet. Recently, stress-induced accumulation of autocrine ABA was shown in humans, as well as ABA-mediated modulation of a number of disease-associated systems. Now, the application of a chemical proteomics approach to gain further insight into ABA mechanisms of action in mammalian cells is reported. An ABA mimetic photoaffinity probe was applied to intact mammalian insulinoma and embryonic cells, leading to the identification of heat shock protein 70 (HSP70) family members, (including GRP78 and HSP70-2) as putative human ABA-binding proteins. In vitro characterization of the ABA–HSP70 interactions yielded Kds in the 20–60 µM range, which decreased several fold in the presence of co-chaperone. However, ABA was found to have only variable- and co-chaperone-independent effects on the ATPase activity of these proteins. The potential implications of these ABA–HSP70 interactions are discussed with respect to the intracellular protein folding and extracellular receptor-like activities of these stress-inducible proteins. While mechanistic and functional relevance remain enigmatic, we conclude that ABA can bind to human HSP70 family members with physiologically relevant affinities and in a co-chaperone-dependent manner. DA - 2013/08/23 PY - 2013 PB - Oxford University Press LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 72f3b979-d37f-481f-bf4f-45feaef35002 ER - TY - JOUR TI - Gene expression profiles during embryo development in Brassica napus DO - 10.1111/pbr.12049 AU - Venglat, Prakash AU - Xiang, Daoquan AU - Yang, Hui AU - Wan, Lianglu AU - Tibiche, Chabane AU - Ross, Andrew AU - Wang, Edwin AU - Selvaraj, Gopalan AU - Datla, Raju T2 - Plant Breeding SN - 01799541 VL - 132 IS - 5 SP - 514 EP - 522 KW - Brassica napus; Embryogenesis; ESTs; Proteome - seed; Zygote AB - The seed in angiosperms is produced through coordinated development of the embryo, endosperm and seed coat. In dicots, most of the seed mass is taken up by the embryo with nutritional reserves stored in the cotyledons. During embryogenesis, well-coordinated developmental and genetic programmes establish the embryonic body plan, and the associated complex metabolic pathways result in the production of diverse nutrients and deposition of important seed storage reserves. To gain insights into the genetic programmes that operate during embryo development in Brassica napus L. (canola), an important oilseed crop, we performed gene and protein expression analyses. We used the key stages from single-cell zygote to mature embryo to generate comprehensive EST and proteome data sets. Analysis of these data sets identified 20 183 genes and 2607 proteins that are differentially expressed across different stages of embryo development. B. napus genes share high degree of homology with Arabidopsis and display stage-specific and shared expression patterns associated with developmental and metabolic pathways. Together, this study has generated useful new molecular and genomic resources for embryo development in B. napus. DA - 2013/03/26 PY - 2013 PB - John Wiley & Sons LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3a37cd0f-002d-48d3-91a3-743b0cad275b ER - TY - JOUR TI - Arabidopsis Clade I TGA factors regulate apoplastic defences against the bacterial pathogen Pseudomonas syringae through endoplasmic reticulum-based processes DO - 10.1371/journal.pone.0077378 AU - Wang, Lipu AU - Fobert, Pierre R. T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 9 SP - e77378:1 EP - e77378:13 AB - During the plant immune response, large-scale transcriptional reprogramming is modulated by numerous transcription (co) factors. The Arabidopsis basic leucine zipper transcription factors TGA1 and TGA4, which comprise the clade I TGA factors, have been shown to positively contribute to disease resistance against virulent strains of the bacterial pathogen Pseudomonas syringae. Despite physically interacting with the key immune regulator, NON-EXPRESSOR OF PATHOGENESIS-RELATED GENES 1 (NPR1), following elicitation with salicylic acid (SA), clade I function was shown to be largely independent of NPR1. Unlike mutants in NPR1, tga1-1 tga4-1 plants do not display reductions in steady-state levels of SA-pathway marker genes following treatment with this phenolic signaling metabolite or after challenge with virulent or avirulent P. syringae. By exploiting bacterial strains that have limited capacity to suppress Arabidopsis defence responses, the present study demonstrates that tga1-1 tga4-1 plants are compromised in basal resistance and defective in several apoplastic defence responses, including the oxidative burst of reactive oxygen species, callose deposition, as well as total and apoplastic PATHOGENESIS-RELATED 1 (PR-1) protein accumulation. Furthermore, analysis of npr1-1 and the tga1-1 tga4-1 npr1-1 triple mutant indicates that clade I TGA factors act substantially independent of NPR1 in mediating disease resistance against these strains of P. syringae. Increased sensitivity to the N-glycosylation inhibitor tunicamycin and elevated levels of endoplasmic reticulum (ER) stress marker genes encoding ER-resident chaperones in mutant seedlings suggest that loss of apoplastic defence responses is associated with aberrant protein secretion and implicate clade I TGA factors as positive regulators of one or more ER-related secretion pathways. DA - 2013/09/27 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : b686c8ab-e682-4081-adc5-a4eb44cd4641 ER - TY - JOUR TI - The development of a virtual simulator for training neurosurgeons to perform and perfect endoscopic endonasal transsphenoidal surgery DO - 10.1093/neurosurgery/73.suppl_1.S85 AU - Rosseau, Gail AU - Bailes, Julian AU - del Maestro, Rolando AU - Cabral, Anne AU - Choudhury, Nusrat AU - Comas, Olivier AU - Debergue, Patricia AU - De Luca, Gino AU - Hovdebo, Jordan AU - Jiang, Di AU - Laroche, Denis AU - Neubauer, Andre AU - Pazos, Valerie AU - Thibault, Francis AU - DiRaddo, Robert T2 - Neurosurgery SN - 0148-396X VL - 73 IS - 4 SP - S85 EP - S93 KW - computer simulation; endoscopy; neurosurgery; training; transsphenoidal; virtual reality AB - BACKGROUND: A virtual reality (VR) neurosurgical simulator with haptic feedback may provide the best model for training and perfecting surgical techniques for transsphenoidal approaches to the sella turcica and cranial base. Currently there are 2 commercially available simulators: NeuroTouch (Cranio and Endo) developed by the National Research Council of Canada in collaboration with surgeons at teaching hospitals in Canada, and the Immersive Touch. Work in progress on other simulators at additional institutions is currently unpublished. OBJECTIVE: This article describes a newly developed application of the NeuroTouch simulator that facilitates the performance and assessment of technical skills for endoscopic endonasal transsphenoidal surgical procedures as well as plans for collecting metrics during its early use. METHODS: The main components of the NeuroTouch-Endo VR neurosurgical simulator are a stereovision system, bimanual haptic tool manipulators, and high-end computers. The software engine continues to evolve, allowing additional surgical tasks to be performed in the VR environment. Device utility for efficient practice and performance metrics continue to be developed by its originators in collaboration with neurosurgeons at several teaching hospitals in the United States. Training tasks are being developed for teaching 1- and 2-nostril endonasal transsphenoidal approaches. Practice sessions benefit from anatomic labeling of normal structures along the surgical approach and inclusion (for avoidance) of critical structures, such as the internal carotid arteries and optic nerves. CONCLUSION: The simulation software for NeuroTouch-Endo VR simulation of transsphenoidal surgery provides an opportunity for beta testing, validation, and evaluation of performance metrics for use in neurosurgical residency training. DA - 2013/10/01 PY - 2013 PB - Congress of Neurological Surgeons LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e733b3fd-4410-4fea-981c-46c8cf75602f ER - TY - JOUR TI - Ring-opening polymerization of bile acid macrocycles by Candida antarctica lipase B DO - 10.1039/c3py00651d AU - Strandman, Satu AU - Tsai, I-Huang AU - Lortie, Robert AU - Zhu, X. X. T2 - Polymer Chemistry SN - 1759-9954 SN - 1759-9962 VL - 4 IS - 16 SP - 4312 EP - 4316 KW - Body temperature; Candida antarctica lipase B; Cholic acids; Functional moieties; Lipase-catalyzed; Macrocycles; Ring opening metathesis polymerization; Rubber-like elasticities AB - Lipase-catalyzed polymerization was explored as an alternative for Ru-catalyzed ring opening metathesis polymerization in the synthesis of polyesters bearing large functional moieties as part of the main chain. The selectivity of Candida antarctica lipase B (CALB) towards the functional groups of cholic acid (CA) was demonstrated, and the obtained CA-based polymers had relatively high molar masses, rubber-like elasticity, and glass transitions close to body temperature. DA - 2013/06/05 PY - 2013 PB - RSC Publishing LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : de349e4a-b174-41c1-b756-508c28bf1443 ER - TY - JOUR TI - Collapse of rectangular granular blocks AU - Babaei, M. H. AU - Dabros, T. AU - Savage, S. B. T2 - ISOPE 2012, Proceedings of the Twenty-Second International Offshore and Polar Engineering T2 - Proceedings of the Annual International Offshore and Polar Engineering Conference T3 - Twenty-Second (2012) International Offshore and Polar Engineering Conference, June 17-22, 2012, Rhodes, Greece SN - 1098-6189 SN - 9781880653944 SP - 418 EP - 424 KW - gravitational collapse; granular material; Mohr-Coulomb plasticity; two-phase flow; numerical modelling; stable heap AB - The collapse of bulk granular materials is of increasing importance in many applications in engineering and geophysics including processing of oil-sands and analysis of avalanches and landslides. The present work is primarily aimed at modelling of the deposition of tailings. This requires predicting the geometry of stable granular heaps, which poses a particular difficulty to available CFD models. In this paper we introduce a new plasticity model for the frictional stresses within the bulk granular material. The numerical simulations employ a two-fluid, one the granular material and the other the surrounding fluid, mixture approach to model the two-phase fluid-granular flow. Solution of the governing equations is carried out using COMSOL code. Results for two cases with small and large aspect ratios are presented. The results show the evolution of the internal flow and shape of the granular heap. The simulations examine the role of the height-to-length ratio on the final shapes. The results include comparisons between the present computations and available experimental measurements. DA - 2013/10/01 PY - 2013 PB - ISOPE UR - http://www.isope.org/publications/proceedings/ISOPE/ISOPE%202012/data/papers/vol2/2012-TPC-1138Babae.pdf LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 060470f3-d45b-4bb1-8fe8-a4e232fee075 ER - TY - JOUR TI - Phycobilisome composition in Chondrus crispus (Gigartinales, Rhodophyta) from a wild type strain and its vegetatively derived green mutant DO - 10.4490/algae.2013.28.1.121 AU - Cornish, M. Lynn AU - O'Leary, Stephen J. B. AU - Garbary, David J. T2 - ALGAE SN - 1226-2617 VL - 28 IS - 1 SP - 121 EP - 129 KW - Chondrus crispus; green mutant; phycobilisomes; phycoerythrin; pigmentation AB - Intact phycobilisomes from a wild-type red Chondrus crispus and its vegetatively derived green mutant were isolated by centrifugation through a discontinuous sucrose density gradient. Pigment composition was subsequently characterized by spectrophotometry. Vegetative thalli of the two strains grown together for six months in the laboratory resulted in different pigment profiles. Two pigmented phycobilisome bands appeared in the sucrose gradient of the wild-type alga, a purple coloured one, and a pink one, whereas only a single blue band appeared in the gradient of the green mutant. Spectrophotometric and fluorescence analyses identified the phycobiliprotein composition of the purple band as the typical phycoerythrin-phycocyanin-allophycocyanin complement in the wild-type, but there was no detectable phycoerythrin present in the blue band of the green mutant. Sodium dodecyl sulphate, preparative polyacrylamide gel electrophoresis analysis confirmed the presence of allophycocyanin subunits in all extracts, but firm evidence of an R-phycoerythrin linker polypeptide in the blue band was missing. These results highlight the ability of C. crispus to adapt to a phycoerythrin deficiency by adjusting light harvesting pigment ratios. DA - 2013/03/15 PY - 2013 PB - The Korean Society of Phycology LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d6b69197-89bb-48cf-88b9-baf364ec986d ER - TY - JOUR TI - Molecular mechanisms in the activation of Abscisic acid receptor PYR1 DO - 10.1371/journal.pcbi.1003114 AU - Dorosh, Lyudmyla AU - Kharenko, Olesya A. AU - Rajagopalan, Nandhakishore AU - Loewen, Michele C. AU - Stepanova, Maria T2 - PLoS Computational Biology SN - 1553-7358 VL - 9 IS - 6 SP - e1003114:1 EP - e1003114:17 KW - hondrus crispus; green mutant; phycobilisomes; phycoerythrin; pigmentation AB - The pyrabactin resistance 1 (PYR1)/PYR1-like (PYL)/regulatory component of abscisic acid (ABA) response (RCAR) proteins comprise a well characterized family of ABA receptors. Recent investigations have revealed two subsets of these receptors that, in the absence of ABA, either form inactive homodimers (PYR1 and PYLs 1–3) or mediate basal inhibition of downstream target type 2C protein phosphatases (PP2Cs; PYLs 4–10) respectively in vitro. Addition of ABA has been shown to release the apo-homodimers yielding ABA-bound monomeric holo-receptors that can interact with PP2Cs; highlighting a competitive-interaction process. Interaction selectivity has been shown to be mediated by subtle structural variations of primary sequence and ligand binding effects. Now, the dynamical contributions of ligand binding on interaction selectivity are investigated through extensive molecular dynamics (MD) simulations of apo and holo-PYR1 in monomeric and dimeric form as well as in complex with a PP2C, homology to ABA insensitive 1 (HAB1). Robust comparative interpretations were enabled by a novel essential collective dynamics approach. In agreement with recent experimental findings, our analysis indicates that ABA-bound PYR1 should efficiently bind to HAB1. However, both ABA-bound and ABA-extracted PYR1-HAB1 constructs have demonstrated notable similarities in their dynamics, suggesting that apo-PYR1 should also be able to make a substantial interaction with PP2Cs, albeit likely with slower complex formation kinetics. Further analysis indicates that both ABA-bound and ABA-free PYR1 in complex with HAB1 exhibit a higher intra-molecular structural stability and stronger inter-molecular dynamic correlations, in comparison with either holo- or apo-PYR1 dimers, supporting a model that includes apo-PYR1 in complex with HAB1. This possibility of a conditional functional apo-PYR1-PP2C complex was validated in vitro. These findings are generally consistent with the competitive-interaction model for PYR1 but highlight dynamical contributions of the PYR1 structure in mediating interaction selectivity suggesting added degrees of complexity in the regulation of the competitive-inhibition. DA - 2013/06/27 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 7d887851-e723-48e5-b166-c8dbab66b3b1 ER - TY - JOUR TI - Transcriptome analysis based on next-generation sequencing of non-model plants producing specialized metabolites of biotechnological interest DO - 10.1016/j.jbiotec.2013.04.004 AU - Xiao, Mei AU - Zhang, Ye AU - Chen, Xue AU - Lee, Eun-Jeong AU - Barber, Carla J. S. AU - Chakrabarty, Romit AU - Desgagné-Penix, Isabel AU - Haslam, Tegan M. AU - Kim, Yeon-Bok AU - Liu, Enwu AU - MacNevin, Gillian AU - Masada-Atsumi, Sayaka AU - Reed, Darwin W. AU - Stout, Jake M. AU - Zerbe, Philipp AU - Zhang, Yansheng AU - Bohlmann, Joerg AU - Covello, Patrick S. AU - De Luca, Vincenzo AU - Page, Johnathan E. AU - Ro, Dae-Kyun AU - Martin, Vincent J. J. AU - Facchini, Peter J. AU - Sensen, Christoph W. T2 - Journal of Biotechnology SN - 01681656 VL - 166 IS - 3 SP - 122 EP - 134 KW - Bioinformatics; Illumina GA sequencing; Plant specialized metabolites; RNA-seq; Roche-454 pyrosequencing; Transcriptomics AB - Plants produce a vast array of specialized metabolites, many of which are used as pharmaceuticals, flavors, fragrances, and other high-value fine chemicals. However, most of these compounds occur in non-model plants for which genomic sequence information is not yet available. The production of a large amount of nucleotide sequence data using next-generation technologies is now relatively fast and cost-effective, especially when using the latest Roche-454 and Illumina sequencers with enhanced base-calling accuracy. To investigate specialized metabolite biosynthesis in non-model plants we have established a data-mining framework, employing next-generation sequencing and computational algorithms, to construct and analyze the transcriptomes of 75 non-model plants that produce compounds of interest for biotechnological applications. After sequence assembly an extensive annotation approach was applied to assign functional information to over 800,000 putative transcripts. The annotation is based on direct searches against public databases, including RefSeq and InterPro. Gene Ontology (GO), Enzyme Commission (EC) annotations and associated Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway maps are also collected. As a proof-of-concept, the selection of biosynthetic gene candidates associated with six specialized metabolic pathways is described. A web-based BLAST server has been established to allow public access to assembled transcriptome databases for all 75 plant species of the PhytoMetaSyn Project (www.phytometasyn.ca). DA - 2013/04/16 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a43d35e7-92a4-45bc-87ee-9057d6e75a0f ER - TY - JOUR TI - An atypical pattern of accumulation of scopolamine and other tropane alkaloids and expression of alkaloid pathway genes in Hyoscyamus senecionis DO - 10.1016/j.plaphy.2013.05.007 AU - Dehghan, Esmail AU - Ahmadi, Farajollah Shahriari AU - Ravandi, Elnaz Ghotbi AU - Reed, Darwin W. AU - Covello, Patrick S. AU - Bahrami, Ahmad Reza T2 - Plant Physiology and Biochemistry SN - 09819428 VL - 70 SP - 188 EP - 194 KW - BSTFA; Expression profile; GC; GC-MS; Hyoscyamine 6β-hydroxylase (H6H); Hyoscyamus senecionis; IPTG; MS; ORF; PMT; Solanaceae; TMCS; TRI; TRII; Tropane alkaloids; X-Gal AB - A cDNA encoding hyoscyamine 6β-hydroxylase (H6H, EC 1.14.11.11), a bifunctional enzyme catalyzing the last two steps in the scopolamine biosynthetic pathway, was isolated from Hyoscyamus senecionis, a medicinal plant endemic to the Iranian plateau. Expression analysis indicates that Hsh6h is expressed in all tested organs of H. senecionis including roots, rhizomes, leaves, stems and flowers unlike the other tropane alkaloid producing species. In parallel to this, in leaves, levels of scopolamine, the product of H6H, were higher than the substrate hyoscyamine. These data suggest that not only does the conversion of hyoscyamine to scopolamine take place in the root, followed by translocation to aerial parts, but also accumulated hyoscyamine in the aerial parts may be converted to scopolamine by activity of HsH6H. Analysis of expression profiles of putrescine N-methyltransferase and tropinone reductase I and II genes also indicates the organ-independent expression of these genes. Here we also introduce H. senecionis as an important tropane alkaloid producing species with its thick underground parts as a source of hyoscyamine, while its leaves can be considered as a source of scopolamine. DA - 2013/05/18 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 762e16f0-aa89-4a27-8065-f51330f97759 ER - TY - JOUR TI - Evaluation of deep eutectic solvent–water binary mixtures for lipase-catalyzed lipophilization of phenolic acids DO - 10.1039/c3gc40899j AU - Durand, Erwann AU - Lecomte, Jérôme AU - Baréa, Bruno AU - Dubreucq, Eric AU - Lortie, Robert AU - Villeneuve, Pierre T2 - Green Chemistry SN - 1463-9262 SN - 1463-9270 VL - 15 IS - 8 SP - 2275 EP - 2282 AB - This work reports the first lipase-catalyzed reactions between substrates of different polarities using deep eutectic solvents as a medium. The model reaction consisted of a lipophilization process based on the alcoholysis of phenolic esters using immobilized Candida antarctica lipase B as a biocatalyst. Results showed that water could dramatically improve the lipase activity and change the reactivity of phenolic substrates. Indeed, very low conversions (<2%) were observed in pure DES, whereas in DES–water binary mixtures, quantitative conversions were achieved. After investigating the role of various parameters, such as the substrate concentration and ratio, pH or thermodynamic activity of water, the effect of the presence of water in pure DES based on urea or glycerol was discussed. In this paper, we propose new perspectives for the enzymatic modification of polar substrates using this novel generation of green, inexpensive and easy-to-handle solvents. DA - 2013/06/24 PY - 2013 PB - RSC Publishing LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e6a3284f-9cea-4304-9a43-9d3ee009a2dd ER - TY - JOUR TI - Fabrication and characterization of nanotemplated carbon monolithic material DO - 10.1021/am402030m AU - He, Xiaoyun AU - Nesterenko, Ekaterina P. AU - Nesterenko, Pavel N. AU - Brabazon, Dermot AU - Zhou, Lin AU - Glennon, Jeremy D. AU - Luong, John H. T. AU - Paull, Brett T2 - ACS Applied Materials & Interfaces SN - 1944-8244 SN - 1944-8252 VL - 5 IS - 17 SP - 8572 EP - 8580 KW - carbon monolith; electrochemical behavior; fullerene C60; nanotemplating AB - A novel hierarchical nanotemplated carbon monolithic rod (NTCM) was prepared using a novel facile nanotemplating approach. The NTCM was obtained using C60-fullerene modified silica gels as hard templates, which were embedded in a phenolic resin containing a metal catalyst for localized graphitization, followed by bulk carbonization, and template and catalyst removal. TEM, SEM, and BET measurements revealed that NTCM possessed an integrated open hierarchical porous structure, with a trimodal pore distribution. This porous material also possessed a high mesopore volume and narrow mesopore size distribution. During the course of carbonization, the C60 conjugated to aminated silica was partly decomposed, leading to the formation of micropores. The Raman signature of NTCM was very similar to that of multiwalled carbon nanotubes as exemplified by three major peaks as commonly observed for other carbon materials, i.e., the sp3 and sp2 carbon phases coexisted in the sample. Surface area measurements were obtained using both nitrogen adsorption/desorption isotherms (BET) and with a methylene blue binding assay, with BET results showing the NTCM material possessed an average specific surface area of 435 m2 g–1, compared to an area of 372 m2 g–1 obtained using the methylene blue assay. Electrochemical studies using NTCM modified glassy carbon or boron doped diamond (BDD) electrodes displayed quasi-reversible oxidation/reduction with ferricyanide. In addition, the BDD electrode modified with NTCM was able to detect hydrogen peroxide with a detection limit of below 300 nM, whereas the pristine BDD electrode was not responsive to this target compound. DA - 2013/08/06 PY - 2013 PB - ACS Publications LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8de63e78-f661-4fcb-b760-a791fe05d8f2 ER - TY - JOUR TI - Adsorption and desorption of Methylene blue on porous Carbon monoliths and nanocrystalline cellulose DO - 10.1021/am403222u AU - He, Xiaoyun AU - Male, Keith B. AU - Nesterenko, Pavel N. AU - Brabazon, Dermot AU - Paull, Brett AU - Luong, John H. T. T2 - ACS Applied Materials & Interfaces SN - 1944-8244 SN - 1944-8252 VL - 5 IS - 17 SP - 8796 EP - 8804 KW - activated carbon; adsorption; carbon monolith; desorption; kinetics; methylene blue; nanocrystalline cellulose AB - The dynamic batch adsorption of methylene blue (MB), a widely used and toxic dye, onto nanocrystalline cellulose (NCC) and crushed powder of carbon monolith (CM) was investigated using the pseudo-first- and -second-order kinetics. CM outperformed NCC with a maximum capacity of 127 mg/g compared to 101 mg/g for NCC. The Langmuir isotherm model was applicable for describing the binding data for MB on CM and NCC, indicating the homogeneous surface of these two materials. The Gibbs free energy of −15.22 kJ/mol estimated for CM unravelled the spontaneous nature of this adsorbent for MB, appreciably faster than the use of NCC (−4.47 kJ/mol). Both pH and temperature exhibited only a modest effect on the adsorption of MB onto CM. The desorption of MB from CM using acetonitrile was very effective with more than 94 % of MB desorbed from CM within 10 min to allow the reusability of this porous carbon material. In contrast, acetonitrile was less effective than ethanol in desorbing MB from NCC. The two solvents were incapable of completely desorbing MB on commercial granular coal-derived activated carbon. DA - 2013/08/09 PY - 2013 PB - ACS Publications LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 92dadc96-875c-42db-a950-95b3cfe81f64 ER - TY - JOUR TI - Anaerobic digestates are useful nutrient sources for microalgae cultivation : functional coupling of energy and biomass production DO - 10.1007/s10811-012-9968-0 AU - Bjornsson, William J. AU - Nicol, Robert W. AU - Dickinson, Kathryn E. AU - McGinn, Patrick J. T2 - Journal of Applied Phycology SN - 0921-8971 SN - 1573-5176 VL - 25 IS - 5 SP - 1523 EP - 1528 KW - Anaerobic digestates; Biomass; Nutrient recycling; Photosynthesis AB - We investigated the extent to which nitrogenous and phosphorus nutrients from liquid anaerobic digestates could be recycled for photosynthetic growth of a microalga, Scenedesmus sp. AMDD. Digestates recovered from the anaerobic digestion of cow manure and swine manure and a co-digestion of swine manure and algal biomass were diluted in distilled water and used for algal growth with and without supplemental CO2 addition. Nutrient assimilation and final biomass yield were retarded in all but the swine manure/algae co-digestate cultures supplemented with high CO2. Swine manure digestate cultures supplemented with the typical complement of micronutrients normally added with a commonly used growth medium or with Fe/EDTA failed to grow any better than unamended controls. When the culture medium was prepared by blending swine manure digestate with 25 or 50 % algal biomass digestate, diluting it with lake water or by supplementing with magnesium, nutrient assimilation and final algal biomass yields were maximized, indicating that magnesium was critically limiting for algal growth in swine manure digestates. Magnesium amendment thus appears to be essential if nutrients from swine manure digestates are recycled for algal growth. No such requirement is necessary for recycling nutrients from digestates generated wholly or in part from algal biomass. DA - 2013/01/12 PY - 2013 PB - Springer LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1ed7382f-ec6d-41ae-9cdf-aa34fd27a2c9 ER - TY - JOUR TI - New diacylglyceryltrimethylhomoserines from the marine microalga Nannochloropsis granulata and their nitric oxide inhibitory activity DO - 10.1007/s10811-012-9967-1 AU - Banskota, Arjun H. AU - Stefanova, Roumiana AU - Sperker, Sandra AU - McGinn, Patrick J. T2 - Journal of Applied Phycology SN - 0921-8971 SN - 1573-5176 VL - 25 IS - 5 SP - 1513 EP - 1521 KW - Betaine lipid; Diacylglyceryltrimethylhomoserine (DGTS); Inducible nitric oxide synthase; Microalgae; Nannochloropsis granulata; Nitric oxide AB - Chemical investigation of polar lipids from the marine eustigmatophyte microalga Nannochloropsis granulata led to the isolation of six betaine lipid diacylglyceryltrimethylhomoserine (DGTS), namely, (2S)-1,2-bis-O-eicosapentaenoylglyceryl-3-O-4′-(N,N,N-trimethyl)-homoserine (1), (2S)-1-O-eicosapentaenoyl-2-O-arachidonoylglyceryl-3-O-4′-(N,N,N-trimethyl)-homoserine (2), (2S)-1-O-eicosapentaenoyl-2-O-myristoylglyceryl-3-O-4′-(N,N,N-trimethyl)-homoserine (3), (2S)-1-O-eicosapentaenoyl-2-O-palmitoylglyceryl-3-O-4′-(N,N,N-trimethyl)-homoserine (4), (2S)-1-O-eicosapentaenoyl-2-O-palmitoleoylglyceryl-3-O-4′-(N,N,N-trimethyl)-homoserine (5), and (2S)-1-O-eicosapentaenoyl-2-O-linoleoylglyceryl-3-O-4′-(N,N,N-trimethyl)-homoserine (6). Structures of the isolated DGTSs were elucidated based on both spectroscopic technique and degradation methods. This is the first report of isolation of 1 in pure state, and 2–6 are all new compounds. The isolated betaine lipids showed dose-dependent nitric oxide (NO) inhibitory activity against lipopolysaccharide-induced nitric oxide production in RAW264.7 macrophage cells. Further study suggested that these betaine lipids (1–6) inhibit NO production in RAW264.7 macrophage cells through downregulation of inducible nitric oxide synthase expression, indicating the possible use as an anti-inflammatory agent. This is the first report of DGTS with anti-inflammatory activity. DA - 2013/01/08 PY - 2013 PB - Springer LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5e5e0377-b496-4685-8da3-7a0862bc0485 ER - TY - JOUR TI - Aeromonas salmonicida Ati2 is an effector protein of the type three secretion system DO - 10.1099/mic.0.067959-0 AU - Dallaire-Dufresne, Stéphanie AU - Barbeau, Xavier AU - Sarty, Darren AU - Tanaka, Katherine H. AU - Denoncourt, Alix M. AU - Lagüe, Patrick AU - Reith, Michael E. AU - Charette, Steve J. T2 - Microbiology SN - 1350-0872 SN - 1465-2080 VL - 159 IS - Pt_9 SP - 1937 EP - 1945 AB - The bacterium Aeromonas salmonicida, a fish pathogen, uses the type three secretion system (TTSS) to inject effector proteins into host cells to promote the infection. The study of the genome of A. salmonicida has revealed the existence of Ati2, a potential TTSS effector protein. In the present study, a structure–function analysis of Ati2 has been done to determine its role in the virulence of A. salmonicida. Biochemical assays revealed that Ati2 is secreted into the medium in a TTSS-dependent manner. Protein sequence analyses, molecular modelling and biochemical assays demonstrated that Ati2 is an inositol polyphosphate 5-phosphatase, which hydrolyses PtdIns(4,5)P2 and PtdIns(3,4,5)P3 in a way similar to VPA0450, a protein from Vibrio parahaemolyticus having high sequence similarity with Ati2. Mutants of Ati2 with altered amino acids at two different locations in the catalytic site displayed no phosphatase activity. Wild-type and mutant forms of Ati2 were cloned into expression systems for Dictyostelium discoideum, a soil amoeba used as an alternative host to study A. salmonicida virulence. Expression tests allowed us to demonstrate that Ati2 is toxic for the host cell in a catalytic-dependent manner. Finally, this study demonstrated the existence of a new TTSS effector protein in A. salmonicida. DA - 2013/07/07 PY - 2013 PB - Society for General Microbiology LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9d62a81a-69bc-49be-9084-7f73b27ea11b ER - TY - JOUR TI - The impact of nitric oxide toxicity on the evolution of the glutathione transferase superfamily : a proposal for an evolutionary driving force DO - 10.1074/jbc.M113.476135 AU - Bocedi, Alessio AU - Fabrini, Raffaele AU - Farrotti, Andrea AU - Stella, Lorenzo AU - Ketterman, Albert J. AU - Pedersen, Jens Z. AU - Allocati, Nerino AU - Lau, Peter C. K. AU - Grosse, Stephan AU - Eltis, Lindsay D. AU - Ruzzini, Antonio AU - Edwards, Thomas E. AU - Morici, Laura AU - Del Grosso, Erica AU - Guidoni, Leonardo AU - Bovi, Daniele AU - Bello, Mario Lo AU - Gederici, Giorgio AU - Parker, Michael W. AU - Board, Philip G. AU - Ricci, Giorgio T2 - Journal of Biological Chemistry SN - 0021-9258 SN - 1083-351X VL - 288 IS - 34 SP - 24936 EP - 24947 KW - Enzyme Inhibitors, Enzyme Structure, Enzymes, Evolution, Nitric Oxide, Dinitrosyl Iron Complex, Glutathione Transferase AB - Glutathione transferases (GSTs) are protection enzymes capable of conjugating glutathione (GSH) to toxic compounds. During evolution an important catalytic cysteine residue involved in GSH activation was replaced by serine or, more recently, by tyrosine. The utility of these replacements represents an enigma because they yield no improvements in the affinity toward GSH or in its reactivity. Here we show that these changes better protect the cell from nitric oxide (NO) insults. In fact the dinitrosyl·diglutathionyl·iron complex (DNDGIC), which is formed spontaneously when NO enters the cell, is highly toxic when free in solution but completely harmless when bound to GSTs. By examining 42 different GSTs we discovered that only the more recently evolved Tyr-based GSTs display enough affinity for DNDGIC (KD < 10−9 M) to sequester the complex efficiently. Ser-based GSTs and Cys-based GSTs show affinities 102–104 times lower, not sufficient for this purpose. The NO sensitivity of bacteria that express only Cys-based GSTs could be related to the low or null affinity of their GSTs for DNDGIC. GSTs with the highest affinity (Tyr-based GSTs) are also over-represented in the perinuclear region of mammalian cells, possibly for nucleus protection. On the basis of these results we propose that GST evolution in higher organisms could be linked to the defense against NO. DA - 2013/07/03 PY - 2013 PB - The American Society for Biochemistry and Molecular Biology LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 85da13c9-82e5-4f88-944b-ecc04fc044ff ER - TY - JOUR TI - Mapping of quantitative trait Loci underlying cold tolerance in rice seedlings via high-throughput sequencing of pooled extremes DO - 10.1371/journal.pone.0068433 AU - Yang, Zemao AU - Huang, Daiquing AU - Tang, Weiqi AU - Zheng, Yan AU - Liang, Kangjing AU - Cutler, Adrian J. AU - Wu, Weiren T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 7 SP - e68433:1 EP - e68433:7 KW - article; booting stage; bulked segregant analysis; chromosome 1; chromosome 10; chromosome 2; chromosome 5; chromosome 8; cold tolerance; developmental stage; DNA sequence; high throughput sequencing; next generation sequencing; nonhuman; plant breeding; quantitative trait locus mapping; rice; seedling; single nucleotide polymorphism AB - Low temperature is a major limiting factor in rice growth and development. Mapping of quantitative trait loci (QTLs) controlling cold tolerance is important for rice breeding. Recent studies have suggested that bulked segregant analysis (BSA) combined with next-generation sequencing (NGS) can be an efficient and cost-effective way for QTL mapping. In this study, we employed NGS-assisted BSA to map QTLs conferring cold tolerance at the seedling stage in rice. By deep sequencing of a pair of large DNA pools acquired from a very large F3 population (10,800 individuals), we obtained ~450,000 single nucleotide polymorphisms (SNPs) after strict screening. We employed two statistical methods for QTL analysis based on these SNPs, which yielded consistent results. Six QTLs were mapped on chromosomes 1, 2, 5, 8 and 10. The three most significant QTLs on chromosomes 1, 2 and 8 were validated by comparison with previous studies. Two QTLs on chromosomes 2 and 5 were also identified previously, but at the booting stage rather than the seedling stage, suggesting that some QTLs may function at different developmental stages, which would be useful for cold tolerance breeding in rice. Compared with previously reported QTL mapping studies for cold tolerance in rice based on the traditional approaches, the results of this study demonstrated the advantages of NGS-assisted BSA in both efficiency and statistical power. DA - 2013/07/30 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3850677b-ee20-4765-bb7b-e4c6ca24d6c9 ER - TY - JOUR TI - CE with a boron-doped diamond electrode for trace detection of endocrine disruptors in water samples DO - 10.1002/elps.201200480 AU - Browne, Damien J. AU - Zhou, Lin AU - Luong, John H. T. AU - Glennon, Jeremy D. T2 - ELECTROPHORESIS SN - 01730835 VL - 34 IS - 14 SP - 2025 EP - 2032 KW - Boron-doped diamond electrode; Capillary electrophoresis; Endocrine disruptors AB - Off-line SPE and CE coupled with electrochemical detection have been used for the determination of bisphenol A (BPA), bisphenol F, 4-ethylphenol, and bisphenol A diglycidyl ether in bottled drinking water. The use of boron-doped diamond electrode as an electrochemical detector in amperometric mode that provides a favorable analytical performance for detecting these endocrine-disrupting compounds, such as lower noise levels, higher peak resolution with enhanced sensitivity, and improved resistance against electrode passivation. The oxidative electrochemical detection of the endocrine-disrupting compounds was accomplished by boron-doped diamond electrode poised at +1.4 V versus Ag/AgCl without electrode pretreatment. An off-line SPE procedure (Bond Elut® C18 SPE cartridge) was utilized to extract and preconcentrate the compounds prior to separation and detection. The minimum concentration detectable for all four compounds ranged from 0.01 to 0.06 μM, having S/N equal to three. After exposing the plastic bottle water container under sunlight for 7 days, the estimated concentration of BPA in the bottled drinking water was estimated to be 0.03 μM. This proposed approach has great potential for rapid and effective determination of BPA content present in water packaging of plastic bottles that have been exposed to sunlight for an extended period of time. DA - 2013/02/21 PY - 2013 PB - John Wiley & Sons LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a1d824d2-7368-44b0-af15-2904a1e30d5d ER - TY - JOUR TI - Allosteric regulation of the calcium-sensing receptor in obese individuals DO - 10.3892/ijmm.2013.1408 AU - He, Yonghan AU - Perry, Ben AU - Bi, Mingxin AU - Sun, Hui AU - Zhao, Tiantian AU - Li, Ying AU - Sun, Changhao T2 - International Journal of Molecular Medicine SN - 1107-3756 SN - 1791-244X VL - 32 IS - 2 SP - 511 EP - 518 KW - Amino Acids; Calcium; Calcium-Sensing Recepor; Cytokine; Obesity AB - We have previously reported that the calcium-sensing receptor (CaSR) plays an important role in modulating lipid metabolism under low calcium conditions. The aim of this study was to identify possible regulators of CaSR and the mechanisms of action of CaSR in obese individuals. Subcutaneous fat samples were obtained from 10 obese and 10 non-obese males undergoing elective abdominal surgery. Visceral fat pads were obtained from 12 obese and 12 non‑obese male rats. Serum lipid, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) concentrations, as well as the gene and protein expression of CaSR in the white adipose tissue of obese subjects and rats were determined. Serum total calcium, vitamin D, parathyroid hormone (PTH) and amino acid levels in human subjects were measured. Intracellular calcium and cyclic adenosine monophosphate (cAMP) levels in rat adipocytes were measured by laser scanning confocal microscopy and ELISA, respectively. The results revealed that serum triglyceride (TG), total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C), TNF-α, IL-6 and PTH levels were significantly higher in the obese individuals versus the controls. By contrast, serum vitamin D and amino acid concentrations were lower in the obese individuals versus the controls. In addition, intracellular calcium levels were higher, while cAMP levels were lower in the obese rat adipocytes compared with the control group. However, the gene and protein expression of CaSR in white adipose tissue did not differ between the obese groups and the controls. Thus, these results suggest that CaSR functions not through its expression, but rather through allosteric regulation in obese individuals. DA - 2013/06/05 PY - 2013 PB - Spandidos Publications LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8e650958-c188-454e-b5bc-8a23f25f85a4 ER - TY - JOUR TI - Ursolic acid inhibits Adipogenesis in 3T3-L1 Adipocytes through LKB1/AMPK pathway DO - 10.1371/journal.pone.0070135 AU - He, Yonghan AU - Li, Ying AU - Zhao, Tiantian AU - Wang, Yanwen AU - Sun, Changhao T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 7 SP - e70135:1 EP - e70135:12 KW - animal cell; apoptosis; article; cell differentiation; cell proliferation; cell viability; concentration response; controlled study; embryo; lipid storage; lipolysis; mouse; nonhuman; proadipocyte; protein expression; protein phosphorylation AB - Background:Ursolic acid (UA) is a triterpenoid compound with multiple biological functions. This compound has recently been reported to possess an anti-obesity effect; however, the mechanisms are less understood.Objective:As adipogenesis plays a critical role in obesity, the present study was conducted to investigate the effect of UA on adipogenesis and mechanisms of action in 3T3-L1 preadipocytes.Methods and Results:The 3T3-L1 preadipocytes were induced to differentiate in the presence or absence of UA for 6 days. The cells were determined for proliferation, differentiation, fat accumulation as well as the protein expressions of molecular targets that regulate or are involved in fatty acid synthesis and oxidation. The results demonstrated that ursolic acid at concentrations ranging from 2.5 μM to 10 μM dose-dependently attenuated adipogenesis, accompanied by reduced protein expression of CCAAT element binding protein β (C/EBPβ), peroxisome proliferator-activated receptor γ (PPARγ), CCAAT element binding protein α (C/EBPα) and sterol regulatory element binding protein 1c (SREBP-1c), respectively. Ursolic acid increased the phosphorylation of acetyl-CoA carboxylase (ACC) and protein expression of carnitine palmitoyltransferase 1 (CPT1), but decreased protein expression of fatty acid synthase (FAS) and fatty acid-binding protein 4 (FABP4). Ursolic acid increased the phosphorylation of AMP-activated protein kinase (AMPK) and protein expression of (silent mating type information regulation 2, homolog) 1 (Sirt1). Further studies demonstrated that the anti-adipogenic effect of UA was reversed by the AMPK siRNA, but not by the Sirt1 inhibitor nicotinamide. Liver kinase B1 (LKB1), the upstream kinase of AMPK, was upregulated by UA. When LKB1 was silenced with siRNA or the inhibitor radicicol, the effect of UA on AMPK activation was diminished.Conclusions:Ursolic acid inhibited 3T3-L1 preadipocyte differentiation and adipogenesis through the LKB1/AMPK pathway. There is potential to develop UA into a therapeutic agent for the prevention or treatment of obesity. DA - 2013/07/26 PY - 2013 PB - Public Library of Science LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ffd6bf4d-7bb8-45fd-968e-63535ddbcacc ER - TY - JOUR TI - The LuWD40-1 gene encoding WD repeat protein regulates growth and pollen viability in flax (Linum Usitatissimum L.) DO - 10.1371/journal.pone.0069124 AU - Kumar, Santosh AU - Jordan, Mark C. AU - Datla, Raju AU - Cloutier, Sylvie T2 - PLoS ONE SN - 1932-6203 VL - 8 IS - 7 SP - e69124:1 EP - e69124:10 KW - anther; article; cell nucleus; cellular distribution; controlled study; epidermis cell; flowering; intron; Linum; Linum usitatisimmum; LuWD40-1 gene; male plant; male sterility; morphogenesis; nonhuman; nucleotide sequence; ovary development; phenotype; plant growth; pollen; promoter region; protein localization; sequence analysis; shoot; transgenic plant; vegetative stage AB - As a crop, flax holds significant commercial value for its omega-3 rich oilseeds and stem fibres. Canada is the largest producer of linseed but there exists scope for significant yield improvements. Implementation of mechanisms such as male sterility can permit the development of hybrids to assist in achieving this goal. Temperature sensitive male sterility has been reported in flax but the leakiness of this system in field conditions limits the production of quality hybrid seeds. Here, we characterized a 2,588 bp transcript differentially expressed in male sterile lines of flax. The twelve intron gene predicted to encode a 368 amino acid protein has five WD40 repeats which, in silico, form a propeller structure with putative nucleic acid and histone binding capabilities. The LuWD40-1 protein localized to the nucleus and its expression increased during the transition and continued through the vegetative stages (seed, etiolated seedling, stem) while the transcript levels declined during reproductive development (ovary, anthers) and embryonic morphogenesis of male fertile plants. Knockout lines for LuWD40-1 in flax failed to develop shoots while overexpression lines showed delayed growth phenotype and were male sterile. The non-viable flowers failed to open and the pollen grains from these flowers were empty. Three independent transgenic lines overexpressing the LuWD40-1 gene had ~80% non-viable pollen, reduced branching, delayed flowering and maturity compared to male fertile genotypes. The present study provides new insights into a male sterility mechanism present in flax. DA - 2013/07/30 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 950609e5-505d-482f-9b94-ff51d2191f91 ER - TY - JOUR TI - Effects of combined ‘all-fish’ growth hormone transgenics and triploidy on growth and nutrient utilization of Atlantic salmon (Salmo salar L.) fed a practical grower diet of known composition DO - 10.1016/j.aquaculture.2013.05.005 AU - Tibbetts, S. M. AU - Wall, C. L. AU - Barbosa-Solomieu, V. AU - Bryenton, M. D. AU - Plouffe, D. A. AU - Buchanan, J. T. AU - Lall, S. P. T2 - Aquaculture SN - 00448486 VL - 406-407 SP - 141 EP - 152 KW - Atlantic salmon; Energy metabolism; Nutrition; Protein utilization; Transgenics; Triploidy AB - Full-sibling, size-matched ‘all-fish’ growth hormone transgenic (TG; gene construct EO-1α) and non-transgenic (NTG) Atlantic salmon (Salmo salar L.) comprised of conventional diploid (DIP) and reproductively-sterile triploid (TRIP) fish were fed the same experimental grower diet in freshwater until they tripled their weight. The study was conducted to provide baseline data on growth performance, feed efficiency, nutrient digestibility, skeletal disorders, bone ash content and bone mineral composition of NTG/DIP, NTG/TRIP, TG/DIP and TG/TRIP fish and to determine if a practical grower diet for conventional NTG/DIP Atlantic salmon requires modification for TG/TRIP fish. TG fish consumed a significantly higher amount of feed on a daily basis but due to enhanced growth rates, better feed conversion ratios and higher nitrogen retention efficiency they achieved target weight gain in a considerably shorter period (40%) than NTG fish. Total feed required to produce the same fish biomass was reduced by 25%; representative of a significant reduction in overall feed intake. Of TG fish, TRIP had some significant effects on production traits primarily due to lower feed intake relative to DIP fish. Although feed intake was lower in TG/TRIP fish, feed efficiency, digestibility and nutrient retention efficiencies were equal to those of TG/DIP fish and, without exception; TG/TRIP fish out-performed their conventional NTG counterparts, regardless of ploidy. TG/DIP and TG/TRIP fish demonstrated a higher cellular capacity to direct dietary non-protein energy towards satisfying their daily metabolic energy requirements, allowing for a higher proportion of dietary amino acids to be directed towards protein biosynthesis; rather than catabolised as a dietary energy source. Since dietary protein is the largest and most expensive component of salmon feeds and also the major source of nitrogenous pollution from salmon farming, this could represent a highly beneficial alteration of energy metabolism which could result in more economical and ecologically-sustainable Atlantic salmon aquaculture, especially when conducted in closed-containment land-based systems. Although bone ash content of TG fish was slightly lower than NTG fish, no significant differences in key bone mineral composition were observed and the occurrence of skeletal disorders was low (< 4%), regardless of transgenics or ploidy. DA - 2013/05/24 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : af786c6b-2114-4587-bc5f-89cc8107b89b ER - TY - JOUR TI - Wall proximity effects on flow over a simple membrane spacer DO - 10.1016/j.compfluid.2013.08.017 AU - Mahdavifar, A. AU - Pollard, A. AU - Pharoah, J. G. AU - Beale, S. B. T2 - Computers & Fluids SN - 00457930 VL - 88 SP - 180 EP - 188 KW - membranes; DNS; wall proximity AB - Spacer-filled channels are employed in membrane modules in many industrial applications where feedflow spacers (employed to separate membrane sheets and create flow channels) tend to enhance mass transport characteristics (and possibly) mitigate fouling and concentration polarization phenomena. In this work direct numerical simulation was performed for the flow in spacer-filled channels to obtain a better understanding of fluid flow phenomena in these assemblies. Reynolds numbers of 300, 500 and 800 were considered. The effect of spacer location was also studied for three different configurations: spacer at the centre of the channel, off-centre, and attached to the wall. Instantaneous velocity fields and flow structures, such as boundary layer separation on the walls and on the cylinder, eddies on the walls, recirculation regions and vortex shedding were investigated. A Fourier analysis was carried out on the time series velocity data. Using this analysis the Strouhal number was calculated and the development of the flow towards a broader turbulent state at higher Reynolds number was captured. Other statistical characteristics such as time-averaged velocities and wall shear rates are obtained and discussed. The average pressure loss was calculated for the channels and found to be highest for spacer at the centre of the channel and lowest for spacer attached to the wall. DA - 2013/12 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6176792d-055a-43ec-8f36-cf7a0d61823d ER - TY - JOUR TI - Quality assessment of Japanese knotweed (Fallopia japonica) grown on Prince Edward Island as a source of resveratrol DO - 10.1021/jf4019239 AU - Chen, Huaguo AU - Tuck, Tina AU - Ji, Xiuhong AU - Zhou, Xin AU - Kelly, Glen AU - Cuerrier, Alain AU - Zhang, Junzeng T2 - Journal of Agricultural and Food Chemistry SN - 0021-8561 SN - 1520-5118 VL - 61 IS - 26 SP - 6383 EP - 6392 KW - Fallopia japonica; Japanese knotweed; quality assessment; resveratrol; UPLC AB - Japanese knotweed (Fallopia japonica, also known as Polygonum cuspidatum) is a common invasive plant species on Prince Edward Island (PEI), Canada, whereas it has been used in Chinese medicine and more recently as a raw material for extracting resveratrol. This paper reports on the quantification of resveratrol, polydatin, emodin, and physcion in roots, stems, and leaves of Japanese knotweed samples from PEI and British Columbia (BC), Canada, and nine provinces of China, by ultraperformance liquid chromatography (UPLC). The results showed that the root contains a much higher level of resveratrol than the stem and leaf, and it is accumulated in its highest level in October. PEI-grown knotweed contains similar levels of resveratrol and polydatin compared to Chinese samples collected in the month of October, but the contents of the other anthraquinones (emodin and physcion) are different. As such, Japanese knotweed grown in PEI could be a commercially viable source of raw material for resveratrol production; however, caution has to be taken in harvesting the right plant species. DA - 2013/06/06 PY - 2013 PB - ACS Publications LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : fb1bb343-b0ee-4b78-b1a7-b56be3b3643b ER - TY - JOUR TI - Abscisic acid binds to recombinant Arabidopsis thaliana G-protein coupled receptor-type G-protein 1 in Sacaromycese cerevisiae and in vitro DO - 10.1016/j.plaphy.2013.03.025 AU - Kharenko, Olesya A. AU - Choudhary, Pooja AU - Loewen, Michele C. T2 - Plant Physiology and Biochemistry SN - 0981-9428 VL - 68 SP - 32 EP - 36 KW - G-protein couple receptor-type G-Protein KW - Abscisic acid KW - Recombinant expression KW - S. cerevisiae KW - Protein–ligand interaction AB - The G-protein coupled receptor-type G-proteins (GTG) 1 and 2 from Arabidopsis thaliana have been proposed to function in the modulation of abscisic acid (ABA) mediated responses to stress and development. In particular it has been suggested that they function as ABA receptors based on in planta and in vitro analyses. However a recent independent report was inconsistent with this, suggesting that there is no link between the GTGs and ABA in planta. Here we provide an independent assessment of the ability of ABA to bind to recombinant GTG1 in vitro and in vivo in Sacaromycese cerevisiae. Radio-labelled binding assays on enriched lipid-reconstituted recombinant GTG1, demonstrated specific concentration dependent binding of [3H]-ABA with a dissociation constant (KD) of 80 nM, corroborating previous reports. Assessment of the binding of [3H]-ABA to intact GTG1 expressing yeast, showed GTG1-dependent binding in vivo, yielding a physiologically relevant KD of 0.6 μM. Together these results provide independent evidence of a binding-interaction between ABA and GTG1 in vitro and in vivo, in support of the previously proposed possibility of a biologically relevant interaction between GTG1 and ABA. DA - 2013/04/12 PY - 2013 PB - Elsevier Masson SAS LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : dc22fafb-024a-48f8-936e-4bb299a595eb ER - TY - JOUR TI - Bioactive components of the edible strain of red alga, Chondrus crispus, enhance oxidative stress tolerance in Caenorhabditis elegans DO - 10.1016/j.jff.2013.04.001 AU - Sangha, Jatinder, Singh AU - Fan, Di AU - Banskota, Arjun H. AU - Stefanova, Roumiana AU - Khan, Wajahatullah AU - Hafting, Jeff AU - Craigie, James AU - Critchley, Alan T. AU - Prithiviraj, Balakrishnan T2 - Journal of Functional Foods SN - 17564646 VL - 5 IS - 3 SP - 1180 EP - 1190 KW - Caenorhabditis elegans; Chondrus crispus; Cultivated seaweeds; Functional foods; Stress tolerance AB - Seaweeds are rich sources of bioactive compounds with potential health benefits. Anti-stress effects of the cultivated red alga, Chondrus crispus, were investigated in the Caenorhabditis elegans model. Methanolic extracts of C. crispus (CCME) enhanced C. elegans tolerance to juglone-induced oxidative stress and increased life span; however water extracts did not show such effects. CCME treatment reduced reactive oxygen species (ROS) in the worms and increased the transcription of stress response genes; sod3, hsp16.2, daf16 and skn1. The chemical profile of CCME revealed the presence of unsaturated fatty acids, pigments, galactolipids, floridoside, isothionic acid, taurine, phenylalanine and l-citruline. Bioassay guided fractionation revealed that fatty acids, lipids and pigments imparted stress tolerance. Taken together, our results suggest that organic fractions of cultivated C. crispus impart oxidative stress tolerance in C. elegans, possibly by altering the stress response pathways. DA - 2013/05/14 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2d27dd87-375e-496a-bef3-57f66446773f ER - TY - JOUR TI - Radicicol, a heat shock protein 90 inhibitor, inhibits differentiation and adipogenesis in 3T3-L1 preadipocytes DO - 10.1016/j.bbrc.2013.05.068 AU - He, Yonghan AU - Li, Ying AU - Zhang, Shuocheng AU - Perry, Ben AU - Zhao, Tiantian AU - Wang, Yanwen AU - Sun, Changhao T2 - Biochemical and Biophysical Research Communications SN - 0006291X VL - 436 IS - 2 SP - 169 EP - 174 KW - Radicicol; Heat shock protein; Differentiation; Adipocytes AB - Heat shock protein 90 (Hsp90) is involved in various cellular processes, such as cell proliferation, differentiation and apoptosis. As adipocyte differentiation plays a critical role in obesity development, the present study investigated the effect of an Hsp90 inhibitor radicicol on the differentiation of 3T3-L1 preadipocytes and potential mechanisms. The cells were treated with different concentrations of radicicol during the first 8 days of cell differentiation. Adipogenesis, the expression of adipogenic transcriptional factors, differentiation makers and cell cycle were determined. It was found that radicicol dose-dependently decreased intracellular fat accumulation through down-regulating the expression of peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT element binding protein α (C/EBPα), fatty acid synthase (FAS) and fatty acid-binding protein 4 (FABP4). Flow cytometry analysis revealed that radicicol blocked cell cycle at G1-S phase. Radicicol redcued the phosphorylation of Akt while showing no effect on β-catenin expression. Radicicol decreased the phosphorylation of phosphoinositide-dependent kinase 1 (PDK1). The results suggest that radicicol inhibited 3T3-L1 preadipocyte differentiation through affecting the PDK1/Akt pathway and subsequent inhibition of mitotic clonal expansion and the expression/activity of adipogenic transcriptional factors and their downstream adipogenic proteins. DA - 2013/05/28 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e63e9088-3f5e-46ba-91ad-50c882abe7fe ER - TY - JOUR TI - Collagen morphology and texture analysis : from statistics to classification DO - 10.1038/srep02190 AU - Mostaço-Guidolin, Leila B. AU - Ko, Alex C.-T. AU - Wang, Fei AU - Xiang, Bo AU - Hewko, Mark AU - Tian, Ganghong AU - Major, Arkady AU - Shiomi, Masashi AU - Sowa, Michael G. T2 - Scientific Reports SN - 2045-2322 VL - 3 SP - 2190 KW - SHG, collagen, classification, texture, gray level co-occurance matrix, multiphoton microscopy AB - In this study we present an image analysis methodology capable of quantifying morphological changes in tissue collagen fibril organization caused by pathological conditions. Texture analysis based on first-order statistics (FOS) and second-order statistics such as gray level co-occurrence matrix (GLCM) was explored to extract second-harmonic generation (SHG) image features that are associated with the structural and biochemical changes of tissue collagen networks. Based on these extracted quantitative parameters, multi-group classification of SHG images was performed. With combined FOS and GLCM texture values, we achieved reliable classification of SHG collagen images acquired from atherosclerosis arteries with >90% accuracy, sensitivity and specificity. The proposed methodology can be applied to a wide range of conditions involving collagen re-modeling, such as in skin disorders, different types of fibrosis and muscular-skeletal diseases affecting ligaments and cartilage. DA - 2013/07/12 PY - 2013 PB - Nature Publishing Group LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 58e777b9-73a7-484e-918d-49d5e07f0b9b ER - TY - JOUR TI - Preparation of well-dispersed gold/magnetite nanoparticles embedded on cellulose nanocrystals for efficient immobilization of Papain enzyme DO - 10.1021/am4007534 AU - Mahmoud, Khaled A. AU - Lam, Edmond AU - Hrapovic, Sabahudin AU - Luong, John H. T. T2 - ACS Applied Materials & Interfaces SN - 1944-8244 SN - 1944-8252 VL - 5 IS - 11 SP - 4978 EP - 4985 KW - electrochemical detection; enzyme immobilization; gold nanoparticles; magnetite nanoparticles; papain AB - A nanocomposite consisting of magnetite nanoparticles (Fe3O4NPs) and Au nanoparticles (AuNPs) embedded on cellulose nanocrystals (CNCs) was used as a magnetic support for the covalent conjugation of papain and facilitated recovery of this immobilized enzyme. Fe3O4NPs (10–20 nm in diameter) and AuNPs (3–7 nm in diameter) were stable and well-dispersed on the CNC surface. Energy-dispersive spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy were used to evaluate the surface composition and structure of CNC/Fe₃O₄NPs/AuNPs. The nanocomposite was successfully used for the immobilization and separation of papain from the reaction mixture. The optimal enzyme loading was 186 mg protein/g CNC/Fe₃O₄NPs/AuNPs, significantly higher than the value reported in the literature. The activity of immobilized papain was studied by electrochemical detection of its specific binding to the Thc-Fca-Gly-Gly-Tyr-Arg inhibitory sequence bound to an Au electrode. The immobilized enzyme retained 95% of its initial activity after 35 days of storage at 4 °C, compared to 41% for its free form counterpart. DA - 2013/05/15 PY - 2013 PB - ACS Publications LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4b633fe5-11b4-4570-8b2f-f409be7b5436 ER - TY - JOUR TI - Joint photomicrobial process for the degradation of the insensitive munition N-Guanylurea-dinitramide (FOX-12) DO - 10.1021/es4006652 AU - Perreault, Nancy N. AU - Halasz, Annamaria AU - Thiboutot, Sonia AU - Ampleman, Guy AU - Hawari, Jalal T2 - Environmental Science & Technology SN - 0013-936X SN - 1520-5851 VL - 47 IS - 10 SP - 5193 EP - 5198 AB - N-Guanylurea-dinitramide (FOX-12) is a very insensitive energetic material intended to be used in the composition of next-generation insensitive munitions. To help predict the environmental behavior and fate of FOX-12, we conducted a study to determine its photodegradability and biodegradability. When dissolved in water, FOX-12, a guanylurea-dinitramide salt, also named GUDN, dissociated instantly to produce the dinitramide moiety and guanylurea, as demonstrated by high-performance liquid chromatography (HPLC) analysis. When an aqueous solution of FOX-12 was subjected to photolysis using a solar-simulated photoreactor, we found a rapid removal of the dinitramide with concurrent formation of N₂O, NO₂⁻, and NO₃⁻. The second component, guanylurea, was photostable. However, when FOX-12 was incubated aerobically with the soil isolate Variovorax strain VC1 and protected from light, the dinitramide component of FOX-12 was recalcitrant but guanylurea degraded effectively to ammonia, guanidine, and presumably CO₂. When FOX-12 was incubated with strain VC1 in the presence of light, both components of FOX-12 degraded, giving similar products to those described above. We concluded that the new insensitive explosive FOX-12 can be effectively degraded by a joint photomicrobial process and, therefore, should not cause persistent contamination of surface waters. DA - 2013/04/17 PY - 2013 PB - ACS Publications LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c58efae5-5ca4-41c4-b29f-3bf06a802562 ER - TY - JOUR TI - A method for determining regioisomer abundances of polyunsaturated triacylglycerols in omega-3 enriched fish oils using reversed-phase liquid chromatography and triple-stage mass spectrometry DO - 10.1016/j.foodchem.2012.12.059 AU - Cubero Herrera, Lisandra AU - Ramaley, Louis AU - Potvin, Michael A. AU - Melanson, Jeremy E. T2 - Food Chemistry SN - 03088146 VL - 139 IS - 1-4 SP - 655 EP - 662 KW - Triacylglycerols; Omega-3 fatty acids; Eicosapentaenoic acid; Docosahexaenoic acid; Fish oil; Multi-stage mass spectrometry; Regioisomer analysis AB - Reversed-phase high performance liquid chromatography (RP-HPLC), followed by post-column addition of lithium salts and electrospray ionisation triple-stage mass spectrometry (ESI-MS³) of lithiated TAG adducts, is shown to provide a useful method for the positional analysis of triacylglycerols (TAGs) in fish oils containing eicosapentaenoic (EPA, 20:5) and docosahexaenoic acids (DHA, 22:6). One prominent fragmentation pathway in the ESI-MS³ of these adduct ions involves the loss of a fatty acid from the sn-1/3 position in the first step followed by the loss of an α,β-unsaturated fatty acid from the sn-2 position in the second. Regioisomeric TAGs of the type ABA and AAB produced abundant product ions – [ABA + Li − RACOOH − R′BCHCHCOOH]+ and [AAB + Li − RACOOH − R′ACHCHCOOH]+ – the relative intensities of which were dependent on the position of acyl substituents. Standard solutions of TAGs containing different ratios of the regioisomeric pairs MME/MEM, PPE/PEP, PPD/PDP, EEP/EPE and DDP/DPD (M = 14:0, P = 16:0, E = 20:5, D = 22:6) were analysed by ESI-MS3 with a quadrupole linear ion trap instrument. Methodology developed on the standards was applied to quantifying the relative isomeric abundances of EPA and DHA in several fish oil samples. DHA was preferentially located at the sn-2 position in both DHA-containing TAGs studied, while EPA was either observed at near equal levels in all positions, or predominantly at the sn-1 and -3 positions in some cases. The analysis protocol allows for quantification of the designated regioisomers in one simple, rapid chromatographic procedure using a single column and has the advantage of specificity over other methods for the positional analysis of TAGs, since it eliminates interferences associated with co-eluting TAGs of the same molecular weight that yield isobaric diacylglycerol-like product ions. DA - 2013/02/01 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8059b2b7-66cb-4ed2-b039-cdccf88d79aa ER - TY - JOUR TI - Nomoto indices for constant-depth zigzag manoeuvres of an autonomous underwater vehicle DO - 10.5402/2013/219545 AU - Azarsina, Farhood AU - Williams, Christopher D. T2 - ISRN Oceanography SN - 2090-8989 VL - 2013 SP - 219545 SP - 1 EP - 8 AB - A two-dimensional simulation code is used to study the characteristics of constant-depth zigzag manoeuvres of the axisymmetric autonomous underwater vehicle (AUV) MUN Explorer. Sea trials data for several manoeuvres with the AUV have been reported during the past four years; however, to obtain a more complete understanding of the vehicle's hydrodynamics, additional towing tank tests and computer simulation were performed. The present work, based on the towing tank test results and sea-trials data, utilizes computer simulations to predict the performance of the MUN Explorer AUV during horizontal zigzag manoeuvres. Next, the Nomoto indices for this AUV during constant-depth zigzag manoeuvres are estimated using the simulation results, and, then, Nomoto's first-order model for the rate of turn of the vehicle during horizontal zigzag manoeuvres in response to a square-wave input for the rudder deflection angle is analytically solved. The paper investigates the validity of the simplified yaw equation to predict a zigzag manoeuvre. Results of this research are a first step to understand the details of zigzag manoeuvres of an AUV such as duration of the first execute, yaw-checking ability, and duration of the overshoot. DA - 2013/01/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 93669b53-4a97-49fb-9a08-567bb828e05f ER - TY - JOUR TI - Genome-wide identification and characterization of microRNA genes and their targets in flax (Linum usitatissimum) DO - 10.1007/s00425-012-1833-5 AU - Barvkar, Vitthal T. AU - Pardeshi, Varsha C. AU - Kale, Sandip M. AU - Qiu, Shuqing AU - Rollins, Meaghen AU - Datla, Raju AU - Gupta, Vidya S. AU - Kadoo, Narendra Y. T2 - Planta SN - 0032-0935 SN - 1432-2048 VL - 237 IS - 4 SP - 1149 EP - 1161 KW - Linseed KW - MiRNA KW - promoter analysis KW - digital expression analysis KW - gene cluster KW - MiRNA target transcript AB - MicroRNAs (miRNAs) are small (20–24 nucleotide long) endogenous regulatory RNAs that play important roles in plant growth and development. They regulate gene expression at the post-transcriptional level by translational repression or target degradation and gene silencing. In this study, we identified 116 conserved miRNAs belonging to 23 families from the flax (Linumusitatissimum L.) genome using a computational approach. The precursor miRNAs varied in length; while most of the mature miRNAs were 21 nucleotide long, intergenic and showed conserved signatures of RNA polymerase II transcripts in their upstream regions. Promoter region analysis of the flax miRNA genes indicated prevalence of MYB transcription factor binding sites. Four miRNA gene clusters containing members of three phylogenetic groups were identified. Further, 142 target genes were predicted for these miRNAs and most of these represent transcriptional regulators. The miRNA encoding genes were expressed in diverse tissues as determined by digital expression analysis as well as real-time PCR. The expression of fourteen miRNAs and nine target genes was independently validated using the quantitative reverse transcription PCR (qRTPCR). This study suggests that a large number of conserved plant miRNAs are also found in flax and these may play important roles in growth and development of flax. DA - 2013/01/06 PY - 2013 PB - Springer LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 18c2abe4-821d-4649-9eec-19fe01d22738 ER - TY - JOUR TI - Effect of simulated interior lifeboat environments on occupant thermal responses AU - Power, J. T. AU - Simões Ré, A. J. T2 - Journal of Ocean Technology VL - 8 IS - 2 SP - 73 EP - 85 AB - The effects of simulated interior lifeboat environments on the thermoregulatory responses of participants wearing immersion suits were investigated. Two different environmental conditions were investigated: the interior air temperature and relative humidity levels found in a conventional lifeboat that relies on passive ventilation (“Condition 1”); and those proposed to be in a next generation lifeboat that will have an active ventilation system (“Condition 2”). Participants performed three hour tests in both Condition 1 and Condition 2. Condition 1 produced a significantly greater increase (P < 0.05) in the rate of sweat accumulation, rate of mean skin temperature and gastro-intestinal temperature increase, heart rate, and physiological strain index values compared to Condition 2. Condition 1 caused an amount of sweat accumulation sufficient to dampen the underclothing to a level that would cause a significant reduction in predicted survival time. Heart rate, gastro-intestinal temperature and physiological strain index values continued to rise during Condition 1 suggesting that the level of thermal stress was uncompensable by the thermoregulatory systems of the participants which is supported by the air temperature and relative humidity levels being at a critical environmental limit in which heat balance cannot be achieved. It is concluded that the interior environmental conditions of conventional lifeboats that rely on a passive ventilation system will result in a level of thermal stress that cannot be compensated for by people wearing immersion suits which will result in increasing levels of physiological strain. DA - 2013/06/01 PY - 2013 PB - Fisheries and Marine Institute of Memorial University LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 12e09e1b-764a-4070-acfe-443d276a88dd ER - TY - JOUR TI - Comprehensive numerical simulations of a tanker collision with a bergy bit incorporating damage to the vessel AU - Gagnon, R. E. AU - Wang, J. T2 - Ice Research for a Sustainable Environment, the 21st IAHR International Symposium on Ice T2 - IAHR International Symposium on Ice T3 - 21st IAHR International Symposium on Ice (Ice Research for a Sustainable Environment), June 11-15, 2012, Dalian, China SN - 9787894370204 SP - 1094 EP - 1106 AB - Numerical simulations of a collision between a loaded tanker and a bergy bit have been conducted using LS-DynaTM software. The simulation incorporated hydrodynamics, via LSDyna’s ALE formulation, and a validated crushable foam ice model. The major portion of the vessel was treated as a rigid body and a section of the hull, located on the starboard side of the forward bow where the ice contact occurred, was modeled as typical ship grillage that could deform and sustain damage as a result of the collision. Strategies for dealing with the highly varying mesh densities needed for the simulation are discussed as well as load and pressure distribution throughout the course of the collision. Realistic movement of the bergy bit due to the vessel’s bow wave prior to contact with the ice was observed and the damage to the grillage in the initial stage of the collision resembled results from actual grillage damage tests in the lab. The collision eventually ruptured the hull in a ripping fashion resembling documented incidents. DA - 2013/06/15 PY - 2013 PB - Dalian University of Technology Press LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2fd90e88-aebd-405d-8aaf-f528f0c7cf35 ER - TY - JOUR TI - A remote ice detection system suitable for marine and aerospace applications AU - Gagnon, R. E. AU - Groves, J. AU - Pearson, W. T2 - Ice Research for a Sustainable Environment, the 21st IAHR International Symposium on Ice T2 - IAHR International Symposium on Ice T3 - 21st IAHR International Symposium on Ice (Ice Research for a Sustainable Environment), June 11-15, 2012, Dalian, China SP - 685 EP - 698 AB - A new instrument for remote ice detection and thickness measurement is described. It incorporates two optically based technologies that give it capability to measure the thickness of clear or foggy layers of solid or liquid on surfaces. The prototype device, known as RIDE (Remote Ice Detection Equipment), is capable of measurements on moving surfaces such as wind turbines, and aircraft propellers and rotors. The current RIDE prototype is intended for relatively long distance measurements however a small, and much simpler, version of the technology is planned for short distance measurements (within a few meters). In the marine context a miniaturized version of the device could be utilized to regulate power for heating elements intended to deice walkways and stairways on vessels and structures. Similarly it could serve as a warning system to signal the encumbrance of safety and communications equipment. In the aerospace context a miniaturized device could measure and signal the need for mitigating strategies when icing accumulates on components of manned and drone-type aircraft. Details of the RIDE prototype, and miniaturization plans, are presented along with thickness data acquired during two test programs, one study on clear ice layers where measurements were obtained from a distance of ~ 15 m and the other on foggy ice layers at a distance of approximately 13 m. DA - 2013/06/15 PY - 2013 PB - Dalian University of Technology Press LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 45ec8a74-ce98-4ac9-bb77-d61ce9e13e0d ER - TY - JOUR TI - Response of IACS URI ship structures to real-time full-scale operational ice loads AU - Quinton, Bruce W. T. AU - Daley, Claude G. AU - Gagnon, Robert E. T2 - (ICETECH 2012) International Conference and Exhibition on Performance of Ships and Structures in Ice T3 - International Conference and Exhibition on Performance of Ships and Structures in Ice (ICETECH 2012), September 17-20, 2012, Banff, Alberta SP - 89 EP - 95 KW - Polar Sea; polar class; moving load; ice; 4D Pressure Method AB - Moving ice loads can incite significantly different structural responses in a steel grillage structure than can stationary ice loads. This is significant because the accepted standard for the design and analysis of ice-classed ship structures is to assume a stationary ice load (IACS URI I2.3.1). The following work utilizes the 4D Pressure Method ((Quinton, Daley, and Gagnon 2012)) to apply thirty-five of the most significant ice loads recorded during the USCGC Polar Sea trials (1982-86), to fourteen IACS URI PC1-7 classed grillages; using explicit finite element analyses. Two grillage variations for each of the seven PC classes were examined: grillages with "built T" framing and grillages with "flatbar" framing. In short, the following simulations directly employ real-time/real-space measured full-scale ice loads, and thus provide insight into the structural capabilities of the various IACS URI polar classes when subject to actual (moving) ice loads. DA - 2013/04/01 PY - 2013 PB - Curran LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3f43afee-97c5-433d-8d29-06f113e7470b ER - TY - JOUR TI - Tubular daylighting devices. Part I: development of an optical model (1415-RP) DO - 10.1080/10789669.2013.803401 AU - Laouadi, Abdelaziz AU - Galasiu, Anca D. AU - Saber, Hamed H. AU - Arsenault, Chantal T2 - HVAC and R Research VL - 19 IS - 5 SP - 536 EP - 556 KW - Tubular daylighting device; lightpipe; skylight; optical model AB - Tubular daylighting devices are systems that collect and channel daylight from building roofs into deep interior spaces. To meet high standards of building energy efficiency and glare-free indoor environments, tubular daylighting device technologies have been rapidly and continuously evolving over the past two decades. However, this pace has been counteracted by a lack of reliable computer design tools. This article presents the development of analytical models to compute the optical characteristics (transmittance, reflectance, and layer absorptances) of various types of complex tubular daylighting devices New metrics for the optical and lighting performance are developed. The optical models are based on the ray-tracing technique, and account for the spectral (monochromatic) or broad-band optical properties of tubular daylighting device glazing panes. Experimental validation of these models is presented in an accompanying paper. DA - 2013/07/23 PY - 2013 PB - Taylor and Francis LA - eng N1 - DOI not reolving. Sent an error report. C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 249ecd28-a3e4-4f35-9294-2ccbdd121edd ER - TY - JOUR TI - The zero-peak house: full-scale experiments and demonstration DO - 10.1016/j.enbuild.2013.05.004 AU - Newsham, Guy R. AU - Galasiu, Anca D. AU - Armstrong, Marianne M. AU - Beausoleil-Morrison, Ian AU - Szadkowski, Frank AU - Sager, Jeremy M. AU - Pietila, Andrea J. AU - Rowlands, Ian H. T2 - Energy and Buildings SN - 0378-7788 VL - 64 SP - 483 EP - 492 KW - residential; demande response; summer; electricity; peak demand; Canada; house; shading; air conditioning; PV AB - Houses represent a substantial fraction of the summer peak electrical load, and therefore measures to reduce peak demand at the household level may be valuable in stabilizing the grid and lowering peak costs. We conducted studies in geometrically-identical, side-by-side full-scale detached houses. One house was operated in a conventional manner and provided a typical reference case. In the other house we applied a variety of measures designed to reduce or shift load from peak periods. Our results demonstrated that a combination of practical operational modifications (air-conditioner cycling, doing laundry later in the evening) and commercially-available technology (exterior shading, modest PV array, energy-efficient lighting) was able to dramatically reduce (in some cases to zero) the peak electrical demand from the grid on the hottest days of the year. DA - 2013/09/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d07df225-04c0-484a-bf64-2663b9b66d4f ER - TY - JOUR TI - A model of residential energy end-use in Canada: using conditional demand analysis to suggest policy options for community energy planners DO - 10.1016/j.enpol.2013.02.030 AU - Newsham, Guy R. AU - Donnelly, Cara L. T2 - Energy Policy SN - 0301-4215 VL - 59 SP - 133 EP - 142 KW - Residential; design; retrofit; appliances AB - We applied conditional demand analysis (CDA) to estimate the average annual energy use of various electrical and natural gas appliances, and derived energy reductions associated with certain appliance upgrades and behaviours. The raw data came from 9773 Canadian households, and comprised annual electricity and natural gas use, and responses to >600 questions on dwelling and occupant characteristics, appliances, heating and cooling equipment, and associated behaviours. Replacing an old (>10 years) refrigerator with a new one was estimated to save 100 kW h/year; replacing an incandescent lamp with a CFL/LED lamp was estimated to save 20 kW h/year; and upgrading an old central heating system with a new one was estimated to save 2000 kW h/year. This latter effect was similar to that of reducing the number of walls exposed to the outside. Reducing the winter thermostat setpoint during occupied, waking hours was estimated to lower annual energy use by 200 kW h/°C-reduction, and lowering the thermostat setting overnight in winter relative to the setting during waking hours (night-time setback) was estimated to have a similar effect. This information may be used by policy-makers to optimize incentive programs, information campaigns, or other energy use change instruments. DA - 2013/04/10 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 20450f55-93e4-4f30-a675-ec0bfa25d45d ER - TY - JOUR TI - Tubular daylighting devices. Part II: validation of the optical model (1415-RP) DO - 10.1080/10789669.2012.741501 AU - Laouadi, Abdelaziz AU - Arsenault, Chantal AU - Saber, Hamed H. AU - Galasiu, Anca D. T2 - HVAC and R Research SN - 1078-9669 VL - 19 IS - 5 SP - 557 EP - 572 KW - Tubular daylighting; tubular skylight; lightpipe; skylight; light guide; optical model AB - This article presents the development of a methodology to measure the visible transmittance of complex configurations of tubular daylighting devices under direct sunlight, and conducts a comparison study between the measurements and computer simulations using the new optical model developed in the first part of the study. A large integrating box was built and calibrated, and the procedure was benchmarked by comparing the measurement of a transparent glazing sample with the manufacturer data. Two commercially available tubular daylighting devices with prismatic and frosted elements built into the glazing and a custom-made tubular daylighting device with a complex pipe having roof and ceiling elbows were selected for the comparison study. The model predictions were overall in good agreement with the measurement for the tested tubular daylighting device configurations, and the sources of discrepancies were clearly identified. DA - 2013/07/23 PY - 2013 PB - Taylor and Francis LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 13c5a45a-b5b0-42e5-aae5-93c65ceac1dc ER - TY - JOUR TI - Optical model for tubular hollow light guides (1415-RP) DO - 10.1080/10789669.2013.774888 AU - Laouadi, Abdelaziz AU - Saber, Hamed H. AU - Galasiu, Anca D. AU - Arsenault, Chantal T2 - HVAC and R Research VL - 19 IS - 3 SP - 324 EP - 334 KW - Light guide; tubular daylighting device; skylight; lightpipe; optical model AB - Tubular hollow light guides are found in many lighting and daylighting systems to transport collected light into deep spaces of building interiors. Linear straight guides are popularly used due to their high optical efficiency, but non-linear guides with bent sections are sometimes required to fulfill some installation restrictions. The optical performance of such bent guides is, however, unknown. This article presents the development, validation, and application of an optical model to compute the transmittance of light guides with and without bends. The model is based on the ray-tracing technique and can handle segmented guides with connection elbows. Measurement of the light transmittance of a light guide with two connection elbows is conducted using an outdoor large integrating box to benchmark the model. The model predictions are in good agreement with the measurement and public data for vertical light guides without bends. The model predictions for bent light guides installed in a northern mid-latitude location show that orienting the middle pipe section of the guide toward the northern direction results in better control of sunlight and solar heat gains than other orientations. DA - 2013/04/28 PY - 2013 PB - Taylor and Francis LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ea2d36ce-1739-40a4-8a7e-a83da40a23a4 ER - TY - JOUR TI - Tubular daylighting devices: development and validation of a thermal model (1415-RP) DO - 10.1080/10789669.2013.803400 AU - Laouadi, Abdelaziz AU - Saber, Hamed H. AU - Galasiu, Anca D. AU - Arsenault, Chantal T2 - HVAC and R Research VL - 19 IS - 5 SP - 513 EP - 535 KW - Tubular daylighting device; lightpipe; skylight; thermal model AB - This article presents the development and validation of a simplified model to compute the thermal characteristics (solar heat gain coefficient and thermal conductance (U-factor)) and surface temperatures of tubular daylighting devices. The model takes into account the three modes of heat transfer: conduction, convection, and surface-to-surface radiation. A one-dimensional heat conduction model is applied to tubular daylight device glazing layers. The convective heat transfer from tubular daylight device surfaces to their adjacent air spaces uses existing correlations for natural flows in enclosed air cavities and free stream air spaces. A zonal model, in which the pipe air space is divided into a number of thermally stacked zones, is used to predict the vertical average temperature distribution in the air cavity and wall surface of pipe. Thermal radiation exchange among surfaces uses the formulation of the form factor applied to the aforementioned zonal model. An iterative sequential procedure is proposed to solve the temperature distribution in tubular daylight device glazing layers and air cavities. The U-factor predictions of the simplified model are compared with the National Fenestration Rating Council certified product rating measurement data and detailed computational fluid dynamic simulations. Four tubular daylight device products are simulated under the National Fenestration Rating Council standard rating conditions for the residential (insulation at ceiling level) and commercial (insulation at roof level) settings. The temperatures of the tubular daylight device glazing layers and vertical temperature distribution inside the pipe air space are also compared with the computational fluid dynamic simulations. The results show that the U-factor predictions of the simplified model are in good agreement with the measurement data and computational fluid dynamic simulations, within a maximum deviation of 15% for both the residential and commercial rating conditions. DA - 2013/07/23 PY - 2013 PB - Taylor and Francis LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 84c6f686-0188-4586-b77e-e34ea21d8764 ER - TY - JOUR TI - Application of hybrid micro-cogeneration system: thermal and power energy solutions for Canadian residences DO - 10.1016/j.enbuild.2013.02.004 AU - Entchev, E. AU - Yang, L. AU - Szadkowski, F. AU - Armstrong, M. AU - Swinton, M. T2 - Energy and Buildings SN - 0378-7788 VL - 60 SP - 345 EP - 354 KW - Hybrid micro-cogeneration system; Micro CHP; Internal combustion engine; High efficiency furnace; Load profiles; Control strategies AB - This paper presents results from a field trial with a hybrid micro-cogeneration system applied to satisfy both thermal and power needs of a typical Canadian detached house. The hybrid system consists of an internal combustion engine integrated with a high efficiency furnace. It was installed, integrated with the rest of the mechanical systems and demonstrated at the Canadian Center for Housing Technology (CCHT). Cost analysis was performed to examine the economics of such systems in relation to different price structures imposed by the electric utilities. The study revealed that the hybrid micro-cogeneration system performed reliably and generated both heat and power with high efficiency during the heating season and was able to satisfy the heating demand under very cold weather conditions. The power generated by the system was first directed to the house satisfying 50% of the electric load with the other 50% being exported to the grid. The project demonstrated that micro-cogeneration systems when sized to meet the base electric load and design thermal load of the residence are a valuable alternative to the central power generation plants and are able to reliably satisfy the house thermal/power demand even under extreme cold conditions. DA - 2013/05/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e2600b48-ea7d-44d5-bdaf-254d9f55edcc ER - TY - JOUR TI - Do ‘green’ buildings have better indoor environments? New evidence DO - 10.1080/09613218.2013.789951 AU - Newsham, Guy R. AU - Birt, Benjamin J. AU - Arsenault, Chantal AU - Thompson, Alexandra J. L. AU - Veitch, Jennifer A. AU - Mancini, Sandra AU - Galasiu, Anca D. AU - Gover, Bradford (Brad) AU - Macdonald, Iain A. AU - Burns, Gregory J. T2 - Building Research and Information SN - 0961-3218 SN - 1466-4321 VL - 41 IS - 4 SP - 415 EP - 434 KW - Building performance KW - Environmental assessment KW - Green buildings KW - Indoor environment KW - Leadership in Energy and Environmental Design (LEED) KW - Occupant satisfaction KW - Post-occupation evaluation KW - Performances des bâtiments KW - Bilan environnemental KW - Bâtiments verts KW - Environnement intérieur KW - Leadership in Energy and Environmental Design (LEED) KW - Satisfaction des occupants KW - Evaluation après occupation AB - A post-occupancy evaluation (POE) of 12 green and 12 conventional office buildings across Canada and the northern United States was conducted. Occupants (N = 2545) completed an online questionnaire related to environmental satisfaction, job satisfaction and organizational commitment, health and well-being, environmental attitudes, and commuting. In each building on-site physical measurements at a sample of workstations (N= 974) were taken, including: thermal conditions, air quality, acoustics, lighting, workstation size, ceiling height, window access and shading, and surface finishes. Green buildings exhibited superior performance compared with similar conventional buildings. Better outcomes included: environmental satisfaction, satisfaction with thermal conditions, satisfaction with the view to the outside, aesthetic appearance, less disturbance from heating, ventilation and air-conditioning (HVAC) noise, workplace image, night-time sleep quality, mood, physical symptoms, and reduced number of airborne particulates. A variety of physical features led to improved occupant outcomes across all buildings, including: conditions associated with speech privacy, lower background noise levels, higher light levels, greater access to windows, conditions associated with thermal comfort, and fewer airborne particulates. Green building rating systems might benefit from further attention in several areas, including: credits related to acoustic performance, a greater focus on reducing airborne particulates, enhanced support for the interdisciplinary design process and development of POE protocols. AB - Il a été mené une évaluation après occupation (POE) de 12 immeubles de bureaux verts et 12 immeubles de bureaux classiques répartis à travers le Canada et le nord des Etats-Unis. Les occupants (N = 2545) ont rempli un questionnaire en ligne portant sur la satisfaction environnementale, la satisfaction au travail et l'implication organisationnelle, la santé et le bien-être, les attitudes environnementales, et les trajets réguliers. Dans chaque immeuble, des mesures physiques in situ sur un échantillon de postes de travail (N = 974) ont été effectuées, comprenant: les conditions thermiques, la qualité de l'air, l'acoustique, l'éclairage, la taille des postes de travail, la hauteur de plafond, l'accès aux fenêtres et leur occultation, et les finitions de surface. Les bâtiments verts ont affiché des performances supérieures par rapport aux bâtiments classiques similaires. De meilleurs résultats ont été obtenus concernant la satisfaction environnementale, la satisfaction à l'égard des conditions thermiques, la satisfaction à l'égard de la vue sur l'extérieur, l'aspect esthétique, la diminution des perturbations liées aux bruits provenant du chauffage, de la ventilation et de la climatisation (CVC), l'image du lieu de travail, la qualité du sommeil nocturne, l'humeur, les symptômes physiques, et la réduction du nombre de particules en suspension dans l'air. Différentes caractéristiques physiques ont conduit à une amélioration des résultats pour les occupants dans tous les immeubles, concernant notamment les conditions liées à la confidentialité des conversations, les niveaux inférieurs de bruit de fond, les niveaux de luminosité plus élevés, l'accès accru aux fenêtres, les conditions associées au confort thermique, et le nombre moindre de particules en suspension dans l'air. Les systèmes de notation des bâtiments verts pourraient bénéficier d'une plus grande attention apportée à plusieurs domaines, s'agissant en particulier des crédits relatifs aux performances acoustiques, d'un accent accru sur la réduction des particules en suspension dans l'air, d'un soutien renforcé en faveur du processus de conception interdisciplinaire et du développement de protocoles POE. DA - 2013/05/13 PY - 2013 PB - Taylor & Francis Group LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : be8e51e7-9e2b-4a7c-b3a4-f08f5dbadb27 ER - TY - CHAP TI - Failure analysis in energy related materials and coatings - role of nanostructured materials for sustainable solutions AU - Bensebaa, Farid AU - Govil, J. N. T2 - Nanotechnology Vol. 6: Energy and Environment SN - 1626990069 SP - 347 EP - 398 KW - Failure analysis; Nondestructive testing; Corrosion; Nanomaterials; Coating AB - Improving performance and lifetime cost of current base materials and coating solutions requires detailed failure analysis. Materials corrosion has significant financial, environmental and safety impacts in the petrochemical and transportation sectors. Alternative materials have been recently developed to improve performance over cost ratio. Nanomaterials are introduced at even increased pace within components in numerous industrial sectors. In few cases, nanostructured materials and films improve the performance over cost ratio while reducing utilization of raw materials and environmental impact. In most cases, detailed failure analysis is important to quantify advantages and shortcomings of nanomaterials. In particular, detailed and complementary materials science and materials engineering investigation is recommended. This will allow better understanding of the relationship between the composition and structure in one hand and functional properties on the other hand. DA - 2013/07/01 PY - 2013 PB - Studium LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 13ce4bb0-cf58-40df-a625-f9bb624fb369 ER - TY - JOUR TI - Effect of dietary inclusion of Atlantic snow crab, Chionoecetes opilio and Northern pink shrimp, Pandalis borealis processing by-products on nutrient digestibility by juvenile haddock, Melanogrammus aeglefinus L. DO - 10.1016/j.anifeedsci.2013.04.011 AU - Tibbetts, Sean M. AU - Lall, Santosh P. T2 - Animal Feed Science and Technology SN - 03778401 VL - 182 IS - 1-4 SP - 126 EP - 130 KW - Haddock KW - Gadoid KW - crab KW - shrimp KW - nutrient digestibility AB - A study was conducted to evaluate the effect of dietary inclusion of Atlantic snow crab, Chionoecetes opilio (Crab) and Northern pink shrimp, Pandalis borealis (Shrimp) by-product meals on nutrient digestibility in haddock, Melanogrammus aeglefinus. The study provides coefficients of total tract apparent digestibility (CTTADs) essential for diet formulations aimed at further growth performance and nutrient utilization studies with gadoids using these waste streams as potential replacements for high-cost fish meals and poorly digestible wheat by-products. Organic matter (OM) CTTAD was significantly improved (P=0.005) with Shrimp150 (0.82) relative to the Control (0.79), while Shrimp300 was similar (0.79) (P=1.000). No significant difference in OM CTTAD was found between the Control and Crab150 (P=0.110), Shrimp150 (P=0.473) or Shrimp300 (P=0.144) at an average of 0.80. However, OM CTTAD was significantly reduced (P<0.001) for Crab300 (0.76). Inclusion of Shrimp at 150 g/kg significantly improved (P=0.003) gross energy (GE) CTTAD (0.85 on average) relative to the Control (0.83), while Crab150 (P=0.081), Crab300 (P=0.134) and Shrimp300 (P=0.986) were statistically equal to the Control (average, 0.82). Crude protein (CP) CTTAD of Crab150 (P=0.803) and Shrimp150 (P=0.980) were similar to the Control at an average of 0.90 while Crab300 (P<0.001) and Shrimp300 (P=0.005) were significantly reduced (average 0.86). Dietary inclusion of either Atlantic snow crab or Northern pink shrimp processing by-product meal at 150 g/kg, concomitant with a 50% reduction in wheat middlings and 10% reduction in fish meal, resulted in OM, GE and CP CTTADs equal to or exceeding that of the fish meal-based Control diet. DA - 2013/06/12 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a1762d6d-2181-4407-8f12-75783610ac03 ER - TY - JOUR TI - Transcriptome analysis of bitter acid biosynthesis and precursor pathways in hop (Humulus lupulus) DO - 10.1186/1471-2229-13-12 AU - Clark, Shawn M. AU - Vaitheeswaran, Vinidhra AU - Ambrose, Stephen J. AU - Purves, Randy W. AU - Page, Jonathan E. T2 - BMC Plant Biology SN - 1471-2229 VL - 13 SP - 12:1 EP - 12:14 KW - Humulus; Humulus lupulus AB - Background: Bitter acids (e.g. humulone) are prenylated polyketides synthesized in lupulin glands of the hop plant (Humulus lupulus) which are important contributors to the bitter flavour and stability of beer. Bitter acids are formed from acyl-CoA precursors derived from branched-chain amino acid (BCAA) degradation and C5 prenyl diphosphates from the methyl-D-erythritol 4-phosphate (MEP) pathway. We used RNA sequencing (RNA-seq) to obtain the transcriptomes of isolated lupulin glands, cones with glands removed and leaves from high α-acid hop cultivars, and analyzed these datasets for genes involved in bitter acid biosynthesis including the supply of major precursors. We also measured the levels of BCAAs, acyl-CoA intermediates, and bitter acids in glands, cones and leaves.Results: Transcripts encoding all the enzymes of BCAA metabolism were significantly more abundant in lupulin glands, indicating that BCAA biosynthesis and subsequent degradation occurs in these specialized cells. Branched-chain acyl-CoAs and bitter acids were present at higher levels in glands compared with leaves and cones. RNA-seq analysis showed the gland-specific expression of the MEP pathway, enzymes of sucrose degradation and several transcription factors that may regulate bitter acid biosynthesis in glands. Two branched-chain aminotransferase (BCAT) enzymes, HlBCAT1 and HlBCAT2, were abundant, with gene expression quantification by RNA-seq and qRT-PCR indicating that HlBCAT1 was specific to glands while HlBCAT2 was present in glands, cones and leaves. Recombinant HlBCAT1 and HlBCAT2 catalyzed forward (biosynthetic) and reverse (catabolic) reactions with similar kinetic parameters. HlBCAT1 is targeted to mitochondria where it likely plays a role in BCAA catabolism. HlBCAT2 is a plastidial enzyme likely involved in BCAA biosynthesis. Phylogenetic analysis of the hop BCATs and those from other plants showed that they group into distinct biosynthetic (plastidial) and catabolic (mitochondrial) clades.Conclusions: Our analysis of the hop transcriptome significantly expands the genomic resources available for this agriculturally-important crop. This study provides evidence for the lupulin gland-specific biosynthesis of BCAAs and prenyl diphosphates to provide precursors for the production of bitter acids. The biosynthetic pathway leading to BCAAs in lupulin glands involves the plastidial enzyme, HlBCAT2. The mitochondrial enzyme HlBCAT1 degrades BCAAs as the first step in the catabolic pathway leading to branched chain-acyl-CoAs. DA - 2013/01/24 PY - 2013 PB - Biomed Central LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : fbba311a-399b-4c79-868b-69ed3ccf935b ER - TY - JOUR TI - Higher-capacity lithium ion battery chemistries for improved residential energy storage with micro-cogeneration DO - 10.1016/j.apenergy.2013.03.088 AU - Darcovich, K. AU - Henquin, E. R. AU - Kenney, B. AU - Davidson, I. J. AU - Saldanha, N. AU - Beausoleil-Morrison, I. T2 - Applied Energy SN - 0306-2619 VL - 111 SP - 853 EP - 861 KW - Building simulation; Lithium ion battery; High capacity cathode; Battery pack; Residential micro-cogeneration AB - Combined heat and power on a residential scale, also known as micro-cogeneration, is currently gaining traction as an energy savings practice. The configuration of micro-cogeneration systems is highly variable, as local climate, energy supply, energy market and the feasibility of including renewable type components such as wind turbines or photovoltaic panels are all factors. Large-scale lithium ion batteries for electrical storage in this context can provide cost savings, operational flexibility, and reduced stress on the distribution grid as well as a degree of contingency for installations relying upon unsteady renewables. Concurrently, significant advances in component materials used to make lithium ion cells offer performance improvements in terms of power output, energy capacity, robustness and longevity, thereby enhancing their prospective utility in residential micro-cogeneration installations. The present study evaluates annual residential energy use for a typical Canadian home connected to the electrical grid, equipped with a micro-cogeneration system consisting of a Stirling engine for supplying heat and power, coupled with a nominal 2 kW/6 kW h lithium ion battery. Two novel battery cathode chemistries, one a new Li–NCA material, the other a high voltage Ni-doped lithium manganate, are compared in the residential micro-cogeneration context with a system equipped with the presently conventional LiMn2O4 spinel-type battery DA - 2013/06/21 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 41f116b6-7fd3-4b9c-a7b1-9d43693e3a66 ER - TY - JOUR TI - Alteration of microbial community structure affects diesel biodegradation in an Arctic soil DO - 10.1111/1574-6941.12102 AU - Bell, Terrence H. AU - Yergeau, Etienne AU - Juck, Dave F. AU - Whyte, Lyle G. AU - Greer, Charles W. T2 - FEMS Microbiology Ecology SN - 0168-6496 VL - 85 IS - 1 SP - 51 EP - 61 KW - community composition; Arctic; bioremediation; hydrocarbons; Ion Torrent; soil microorganisms AB - A wide range of microbial taxa are active in hydrocarbon-contaminated Arctic soils, and many are capable of hydrocarbon metabolism. The most effective hydrocarbon degraders may not naturally dominate following contamination events, so shifts in microbial abundance could potentially increase hydrocarbon biodegradation. In this study, we contaminated an Arctic soil with diesel and used gentamicin and vancomycin to inhibit distinct portions of the microbial community. We measured diesel loss using gas chromatography, bacterial and fungal abundance with qPCR, and assessed bacterial diversity and community composition through Ion Torrent sequencing of 16S rRNA gene amplicons. The combined addition of both antibiotics increased diesel biodegradation significantly relative to the no-antibiotic treatment, despite reduced bacterial and fungal abundance; however, this effect was not observed when nutrients were also added. All treatments produced unique bacterial communities, and both Xanthomonadaceae and Micrococcineae were dominant in the dual antibiotic treatment. The bacterial communities resulting from dual gentamicin and vancomycin addition were similar both with and without nutrients, although nutrient addition produced a much larger fungal population, which may partly explain the differences in biodegradation between these two treatments. These results suggest that the most efficient hydrocarbon-degrading community may not always be promoted naturally in contaminated soils. DA - 2013/03/20 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c5946a1f-6990-4af7-805d-f97d5b4aa7a0 ER - TY - JOUR TI - Durable sulfonated poly(arylene sulfide sulfone nitrile)s containing naphthalene units for direct methanol fuel cells (DMFCs) DO - 10.1021/ma400154t AU - Shin, Dong Won AU - Lee, So Young AU - Kang, Na Rae AU - Lee, Kang Hyuck AU - Guiver, Michael D. AU - Lee, Young Moo T2 - Macromolecules SN - 0024-9297 SN - 1520-5835 VL - 46 IS - 9 SP - 3452 EP - 3460 KW - direct methanol fuel cell (DMFC); proton exchange membrane (PEM); sulfonated poly(arylene sulfide sulfone nitrile); naphthalene units AB - Sulfonated poly(arylene sulfide sulfone nitrile)s (SN) were synthesized to investigate the effects of naphthalene units in the polymer backbone on membrane properties. The small and planar naphthalene in the main chain induced semi-crystallinity in the polymer, as confirmed by molecular simulations and wide angle X-ray diffraction patters. The semi-crystalline SN polymer membranes exhibited excellent chemical and mechanical properties, better than those of their phenylene counterpart (SP). In particular, the water uptake and swelling ration of the SN membranes were much lower than those of the SP membranes. Furthermore, the SN membranes exhibited a greatly reduced methanol permeability (9-17 x 10(-8) cm(sq) s(-1)) compared to Nafion 212(330 x 10(-8) cm(sq) s(-1)) at 30 degrees Celsius in 10 M methanol. Moreover, sulfide- and naphthalene-based chemical structure and semi-crystalline nature of hte SN membranes enhanced their DMFC single cell performance and long-term stability during fuel cell operation. DA - 2013/04/24 PY - 2013 PB - American Chemical Society LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e60179f7-d893-4823-81bf-ded0a8a782ef ER - TY - JOUR TI - Naphthalene-based poly(arylene ether ketone) anion exchange membranes DO - 10.1039/c3ta10355b AU - Liu, Zhuang AU - Li, Xiaobai AU - Shen, Kunzhi AU - Feng, Pengju AU - Zhang, Yinan AU - Xu, Xu AU - Hu, Wei AU - Jiang, Zhenhua AU - Liu, Baijun AU - Guiver, Michael D. T2 - Journal of Materials Chemistry A SN - 2050-7488 SN - 2050-7496 VL - 1 IS - 21 SP - 6481 EP - 6488 AB - Naphthalene-based poly(arylene ether ketone)s were obtained through a three-step process involving polymerization of methylated polymers, followed by bromination and derivitization with a diquaternary-ammonium group. The ionic conductivities of the anion exchange membranes were above 10(-2) S cm(-1) at room temperature and the membrane with an IEC = 1.46 mequic. g(-1) attained an ion conductivity of 7.4 x 10(-2) S cm(-1) at 100 degrees Celsius, which is higher than many reported results. The membrane series had low water uptake and excellent dimensional stability, even at the highest IEC values. In addition, the membranes were insoluble in organic solvents and concentrated alkaline solutions for many days, even under heating, suggesting their excellent stability. These combined data suggest that the membranes have potential to be used as anion exchange membranes for fuel cell applications. DA - 2013/04/04 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 937d344d-1f2e-4650-9a0d-493ad066f656 ER - TY - JOUR TI - Polyethylene-based radiation grafted anion-exchange membranes for alkaline fuel cells DO - 10.1016/j.memsci.2013.03.053 AU - Sherazi, Tauqir A. AU - Sohn, Joon Yong AU - Lee, Young Moo AU - Guiver, Michael D. T2 - Journal of Membrane Science SN - 0376-7388 VL - 441 SP - 148 EP - 157 KW - Anion exchange membrane; Radiation grafting; Polyethylene; UHMWPE; Vinylbenzylchloride; Trimethylamine AB - Vinyl benzyl chloride was grafted onto ultra-high molecular weight polyethylene powder (UHMWPE) by radiation grafting. The grafted powder was subsequently fabricated into membrane by melt pressing. The effect of absorbed radiation dose on the degree of grafting (DG) is discussed. The melt-flow properties of PVBC grafted PE with low degree of grafting was conducive to forming homogeneous pore-free membranes, which was confirmed by scanning electron microscopic analysis. The grafted polytheylene membranes were post functionalized with trimethylamine, followed by alkalization to obtain anion-exchange membranes (AEMs). The structures of the resulting AEMs were characterized by Fourier transform infrared spectroscopy, which showed that the grafted membranes were successfully functionalized. The properties of the AEMs, including ion exchange capacity, water uptake, in-plane swelling, methanol uptake, methanol permeability, and hydroxide ion conductivity were investigated. The AEMs showed reasonably good chemical stability, as evidenced by the ion exchange capacity being maintained for a ong duration, even in highly alkaline conditions. The membranes exhibited a maximum ionic conductivity of 47.5 mS cm(-1) at 90 degrees Celsius (30 mS cm(-1) at 60 degrees Celsius). Methanol permeability was found to be in the order of 10(-8) cm(sq) s(-1), which is considerably lower than that of Nafion (registered). The membranes have useful properties consistent with anion exchange membranese suitable for alkaline fuel cells. DA - 2013/04/10 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a62e5198-6f45-4ab5-b6d3-bfacba78c401 ER - TY - JOUR TI - A capillary water retention effect to improve medium-temperature fuel cell performance DO - 10.1016/j.elecom.2013.03.018 AU - Lee, So Young AU - Shin, Dong Won AU - Wang, Chenyi AU - Lee, Kang Hyuck AU - Guiver, Michael D. AU - Lee, Young Moo T2 - Electrochemistry Communications SN - 13882481 VL - 31 SP - 120 EP - 124 KW - Fuel cell; Polymer electrolyte membrane; Medium-temperature; Sulfonated poly(arylene ether sulfone); Morphology AB - We demonstrate that small and narrow hydrophilic conducting morphology in sulfonated aromatic membranes leads to much better fuel cell performance at medium temperature and low humidity conditions than those with larger hydrophilic domains. A comparison of three types of sulfonated poly(arylene ether sulfone)s (SPAES) with random, block, and graft architecture indicates that small hydrophilic domain sizes (less than 5 nm) appear to be important in supporting water retention under low relative humidity (RH) conditions intended for medium temperature (less than 100 degrees Celsius) fuel cell applications. The graft copolymer outperformed both a random copolymer and multiblock copolymer at 120 degrees Celsius and 35% RH fuel cell operating conditions due to capillary condensation of water within the 3-5 nm hydrophilic domains. DA - 2013/03/22 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3ac5b5ba-6df7-46d1-99f3-b7f50dfa10ac ER - TY - JOUR TI - Polymer rigidity improves microporous membranes DO - 10.1126/science.1232714 AU - Guiver, Michael D. AU - Lee, Young Moo T2 - Science SN - 0036-8075 SN - 1095-9203 VL - 339 IS - 6117 SP - 284 EP - 285 AB - Microporous membranes with rigid polymer chains have high gas permeability but can separate gas molecules of slightly different sizes. DA - 2013/01/18 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c4f6dc1e-6f0a-41be-acc2-e8f634f6fd60 ER - TY - JOUR TI - The electrochemistry of metallic nickel: oxides, hydroxides, hydrides and alkaline hydrogen evolution DO - 10.1149/2.026303jes AU - Hall, David S. AU - Bock, Christina AU - Macdougall, Barry R. T2 - Journal of the Electrochemical Society T3 - Meeting of the Electro Chemical Society, Oct. 7-12, 2012, Honolulu, Hawaii SN - 0013-4651 SN - 1945-7111 VL - 160 IS - 3 SP - F235 EP - F243 AB - Ni-based catalysts in aqueous alkaline media are low-cost electrode materials for electrolytic hydrogen generation, a renewable method of producing fuel and industrial feedstock. However, Ni cathodes show a significant decrease in their hydrogen evolution reaction (HER) activity after several hours of electrolysis. Further, industrial electrolysers are often subjected to transient anodic currents, the effects of which on Ni-based catalysts are not well-known. We consider the source of electrode deactivation and the effects of temporary anodic currents on smooth metallic Ni electrodes in alkaline solutions by cyclic voltammetry (CV), galvanostatic and potentiostatic polarization, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Polished surfaces are covered by a bilayer composed of α-Ni(OH)2 underlaid by non-stoichiometric NiOx. Below the reversible hydrogen electrode (RHE) potential, the air-formed layer mostly reduces to Ni metal and H atoms incorporate deep into the electrode material. Under industrial conditions, i.e., concentrated NaOH/KOH solutions and large cathodic current densities, α-NiHx and β-NiHx can form at the electrode surface. Above the RHE potential, NiOx, α-Ni(OH)2, β-Ni(OH)2 and β-NiOOH form reversibly and mostly reduce back to Ni on subsequent cathodic polarization. However, repeated oxidation and reduction will introduce strain on a catalyst material, which may lead to its mechanical failure. DA - 2013/01/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3f006742-0870-44ba-b328-0e7dd15cfb1f ER - TY - JOUR TI - Compositional and morphological changes for ordered PtxFey/CO2 electro-reduction catalysts DO - 10.1002/cctc.201200614 AU - Chen, Liang AU - Chan, Mickey C. Y. AU - Nan, Feihong AU - Bock, Christina AU - Botton, Gianluigi A. AU - Mercier, Patrick H. J. AU - Macdougall, Barry R. T2 - ChemCatChem SN - 1867-3880 VL - 5 IS - 6 SP - 1449 EP - 1460 KW - O2 reduction catalysts; Lifetime; PEMFC; HAADF-STEM; EDX spot and line analyses AB - Changes in O2 reduction activity (orr) and structural changes of carbon supported catalysts upon electrochemical stress testing are investigated. Focus is placed on two alloy catalysts of nominal Pt3Fe/C and Pt3Fe2/C compositions. Energy dispersive X-ray Spectroscopy (EDXS) spot and line analyses reveal a dependence of the Fe composition on the particle size particularly for he two as-prepared catalysts. Catalyst particles are shown to exist of a Pt enriched shell and a PtxFey alloy core. Larger (larger ca. 10 nm) particles are shown to have a higher Fe content that approaches the nominal composition suggesting that the smaller (smaller than 6 nm) Pt catalyst particles are more difficult to alloy. HAADF-STEM, XRD, and scanning electron microscope (SEM) with EDXS show that Fe is gradually lost from the catalyst particles as a result of extensive potential (E)-cycling. Changes upon E-cycling are most clearly observed for the small (smaller than 3 nm) particles, for which, Fe is almost entirely depleted. However, the catalytic orr activities remain constant over an extensive cycling period for the PtxFey/C catalysts. In fact, the mass orr activities are seen to decrease proportionally with the Pt surface area (Apt). The histograms before and after cycling are compared to observed changes in APt, and are also discussed in comparison to E-holding experiments. It is concluded that the dissolution of Pt is a strong contributor for the observed drop in APt and mass orr activity for the PtxFey/C catalysts. The continuous transition between Pt-oxide formation and its reduction to Pt metal is suggested to play a major role for the degradation of the PtxFey/C catalysts studied in this work. DA - 2013/03/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6ecb0940-ab05-4ad0-92f5-0d90b8587288 ER - TY - JOUR TI - High-quality reference genes for quantifying the transcriptional responses of Oryza sativa L. (ssp. indica and japonica) to abiotic stress conditions DO - 10.1007/s11434-013-5726-1 AU - Maksup, Sarunyaporn AU - Supaibulwatana, Kanyaratt AU - Selvaraj, Gopalan T2 - Chinese Science Bulletin SN - 1001-6538 SN - 1861-9541 VL - 58 IS - 16 SP - 1919 EP - 1930 KW - KDML105 KW - microarrays KW - quantitative real-time PCR KW - reference gene KW - rice (Oryza sativa L.) KW - stress responsive gene AB - Rice (Oryza sativa L.) is important to food security and is also an excellent model plant for numerous cereal crops. A functional genomics study in rice includes characterization of the expression dynamics of genes by quantitative real-time PCR (qPCR) analysis; this is a significant key for developing rice varieties that perform well in the face of adverse climate change. The qPCR analysis requires the use of appropriate reference genes in order to make any quantitative interpretations meaningful. Here, the new potential reference genes were selected from a huge public database of rice microarray experiments. The expression stability of 14 candidates and 4 conventional reference genes was validated by geNorm PLUS and NormFinder software. Seven candidates are superior to the conventionally used reference genes in qPCR and three genes can be used reliably for quantitating the expression of genes involved in abiotic stress responses. These high-quality references EP (LOC_Os05g08980), HNR (LOC_Os01g71770), and TBC (LOC_Os09g34040) worked very well in three indica genotypes and one japonica genotype. One of indica genotypes including the Jasmine rice, KDML105 developed in Thailand for which no reference genes have been reported until now. DA - 2013/04/03 PY - 2013 PB - Springer-Verlag LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 24c47b36-e930-440b-aaa5-7cc02f193498 ER - TY - JOUR TI - Characterization of carrier states in CuWO4 thin-films at elevated temperatures using conductometric analysis DO - 10.1016/j.jssc.2013.02.002 AU - Gonzalez, Carlos M. AU - Dunford, Jeffrey L. AU - Du, Xiaomei AU - Post, Michael L. T2 - Journal of Solid State Chemistry SN - 0022-4596 VL - 201 SP - 35 EP - 40 KW - Semiconducting metal-oxide; Surface characterization; Electron transport; Conductometric analysis; Activation energy; Oxygen states AB - CuWO4 thin-films were deposited by pulsed laser deposition onto an insulating substrate. The temperature dependence of the electronic conductivity of CuWO4 thin-films was determed over the 100-500 degree Celsius temperature range in a synthetic air atmosphere. Additionally, variations of conductivity at 300 degrees Celsius and 500 degrees Celsius have been measured for oxygen partial pressures (0.1 atm less than p(O2) less than 0.9 atm) in nitrogen. The apparent activation energy (delta)Ea for the electrical conduction has been estimated. The study of the temperature effect on the electron transport properties of CuWO4 thin-films reveals the operation of two temperature-dependent oxygen states. The effect of varying oxygen concentration on the electronic properties is discussed in detail. The electrochemical nature of the operating oxygen states for the 100-500 degree Celsius temperature range is deduced using a physicochemical model that relates electronic conductivity with oxygen partial pressure and temperature. DA - 2013/02/10 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 90b48cb0-8dc6-4ee8-8791-1c1c7ac31811 ER - TY - JOUR TI - Membrane electrode assemblies based on hydrocarbon electrolytes with nitrile groups for direct methanol fuel cells DO - 10.1149/05002.2139ecst AU - Hurter, Stephan AU - Muller, Martin AU - Wippermann, Klaus AU - Guiver, Michael D. AU - Scoles, Ludmilla AU - Stolten, Detlef T2 - ECS Transactions T3 - PRiME 2012: Pacific Rim Meeting on Electronchemical And Solid State Science, October 7-12, 2012, Honolulu, Hawaii SN - 1938-6737 SN - 1938-5862 VL - 50 IS - 2 SP - 2139 EP - 2149 AB - Sulfonated poly(aryl ether ether nitrile)s - sPAEEN are promising materials for reducing the methanol permeation from anode to cathode due to the strong polar interchain interactions caused by the nitrile functional groups. This feature allows the preparation of membranes with high proton conductivities and low crossover of methanol and water. Despite similar specific conductivities and lower thickness of the hydrocarbon membranes compared to Nafion 115, HC-MEAs prepared by a classic hot-pressing step show 40-70 % higher values for the cell resistances compared to Nafion 115 based MEAs. Therefore the MEA preparation procedure was changed to reduce losses due to poor lamination between the Nafion-based GDE and the hydrocarbon membrane. The impact of the type of sPAEEN membrane and the MEA preparation together with the cell performance data will be compared with state-of-the art Nafion-based cells and discussed in terms of consequences for the operating conditions for a DMFC system. DA - 2013/03/15 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c8f77568-1b71-46f8-bbe0-64e9ab3bef11 ER - TY - JOUR TI - Strain fields around dislocation arrays in a Σ9 silicon bicrystal measured by scanning transmission electron microscopy DO - 10.1080/14786435.2013.778428 AU - Couillard, Martin AU - Radtke, Guillaume AU - Botton, Gianluigi A. T2 - Philosophical Magazine SN - 1478-6435 SN - 1478-6443 VL - 93 IS - 10-12 SP - 1250 EP - 1267 AB - Strain fields around grain boundary dislocations are measured by applying geometric phase analysis on atomic resolution images obtained from multiple fast acquisitions in scanning transmission electron microscopy. Maps of lattice distortions in silicon introduced by an array of pure edge dislocations located at a Σ9(122) grain boundary are compared with the predictions from isotropic elastic theory, and the atomic structure of dislocation cores is deduced from images displaying all the atomic columns. For strain measurements, reducing the acquisition time is found to significantly decrease the effects of instabilities on the high-resolution images. Contributions from scanning artefacts are also diminished by summing multiple images following a cross-correlation alignment procedure. Combined with the sub-Ångström resolution obtained with an aberration corrector, and the stable dedicated microscope’s environment, therapid acquisition method provides the measurements of atomic displacements with accuracy below 10 pm. Finally, the advantages of combining strain measurements with the collection of various analytical signals in a scanning transmission electron microscope are discussed. DA - 2013/03/14 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f54913cd-59d3-4b76-90aa-07616df1af4d ER - TY - JOUR TI - Contribution to the crystallography of hydrotalcites: the crystal structures of woodallite and takovite DO - 10.3190/jgeosci.127 AU - Mills, Stuart J. AU - Whitfield, Pamela S. AU - Kampf, Anthony R. AU - Wilson, Siobhan A. AU - Dipple, Gregory M. AU - Raudsepp, Mati AU - Favreau, Georges T2 - Journal of GEOsciences SN - 1803-1943 SN - 1802-6222 VL - 57 IS - 4 SP - 273 EP - 279 KW - Hydrotalcite; Layered double hydroxide; Takovite; Woodallite; Crystal structure; Rietveld refinement AB - The crystal structures of the 3R polytypes of takovite and woodallite are presented. The structure of takovite was solved on a single crystal from the Agoudal mine, Bou Azzer district, Tazenakht, Morocco to R1 = 1.87 % for 94 unique reflections [Fo>4σF] in R-3m, with unit cell parameters a = 3.0290(2) and c = 22.5995(15) Å. The crystal structure of woodallite [space group R-3m, with unit cell parameters a = 3.10124(8) and c = 23.6817(16) Å] was refined utilising the Rietveld method on a sample from the MKD5 orebody at the Mount Keith Nickel Mine, Western Australia. DA - 2013/01/05 PY - 2013 PB - Czech Geological Society LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : dabd616f-3171-49b5-9ecb-cf29f479db0d ER - TY - JOUR TI - The Two-step biosynthesis of cyclic peptides from linear precursors in a member of the plant family Caryophyllaceae involves cyclization by a Serine Protease-like enzyme DO - 10.1074/jbc.M112.437947 AU - Barber, Carla J. S. AU - Pujara, Pareshkumar T. AU - Reed, Darwin W. AU - Chiwocha, Shiela AU - Zhang, Haixia AU - Covello, Patrick S. T2 - Journal of Biological Chemistry SN - 0021-9258 SN - 1083-351X VL - 288 IS - 18 SP - 12500 EP - 12510 KW - Peptidases KW - peptide biosythesis KW - plant biochemsitry KW - plant molecular biology KW - protease KW - Caryophyllaceae KW - Saponaria vaccaria KW - cyclic peptide KW - peptide cyclase KW - orbitide AB - Background: In the Caryophyllaceae, cyclic peptides (CP) are biosynthesized from linear precursors via an unknown pathway. Results: Two protease-like enzymes are involved in precursor processing. Conclusion: A serine protease-like enzyme was recruited for the cyclization step in CP biosynthesis. Significance: This represents a very significant advance in our understanding of the mode and evolution of CP biosynthesis in plants. Caryophyllaceae-type cyclic peptides (CPs) of 5–12 proteinogenic amino acids occur in 10 plant families. In Saponaria vaccaria (Caryophyllaceae), they have been shown to be formed from linear peptide precursors derived from ribosomal translation. There is also evidence for such precursors in other members of the Caryophyllaceae, Rutaceae, and Linaceae families. The biosynthesis of CP in the developing seeds of S. vaccaria was investigated with respect to the enzymes involved in precursor processing. Through biochemical assays with seed extracts and synthetic peptides, an enzyme named oligopeptidase 1 (OLP1) was found that catalyzes the cleavage of intermediates at the N terminus of the incipient CP. A second enzyme, peptide cyclase 1 (PCY1), which was separated chromatographically from OLP1, was found to act on the product of OLP1, giving rise to a cyclic peptide and concomitant removal of a C-terminal flanking sequence. PCY1 was partially purified, and using the methods of proteomics, a full-length cDNA clone encoding an enzyme matching the properties of PCY1 was obtained. The substrate specificity of purified recombinant PCY1, believed to be the first cloned plant enzyme whose function is peptide cyclization, was tested with synthetic peptides. The results are discussed in the light of CP biosynthetic systems of other organisms. DA - 2013/05/03 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : faa9a231-9564-4805-8773-fdee91611fdc ER - TY - JOUR TI - Effect of particle morphology and size distribution on cold-sprayed pure titanium coatings DO - 10.1007/s11666-013-9951-6 AU - Wong, W. AU - Vo, P. AU - Irissou, É. AU - Ryabinin, A. N. AU - Legoux, J.-G. AU - Yue, S. T2 - Journal of Thermal Spray Technology SN - 1059-9630 SN - 1544-1016 KW - cold sprayability; mechanical properties; particle morphology; particle size distribution; particle velocity; titanium AB - The effects of commercially pure titanium particle morphology (spherical, sponge, and irregular) and size distributions (mean particle sizes of 20-49 lm) on the cold spray process and resulting coating properties were investigated. Numerous powder and coating characterizations were performed including: powder oxygen and nitrogen contents, powder flowability, powder compressibility, coating microhardness, coating porosity, LOM/SEM analyses, and XRD. Compared to spherical powders, the sponge and irregular CP-Ti powders had higher oxygen content, poorer powder flowability, higher compression ratio, lower powder packing factor, and higher average particle impact velocities. XRD results showed no new phases present when comparing the various feedstock powders to corresponding coatings. A higher particle temperature was also obtained with larger particle size for all feedstock powder morphologies processed with the same set of spray parameters. A spherical powder with 29 lm mean particle size was found to have the lowest porosity coating and best cold sprayability. The relationships of several as-cold sprayed coating characteristics to the ratio of particle impact and critical velocities were also discussed. DA - 2013/06/15 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c1800c9c-fc62-4bb8-a619-d84dd58c7d16 ER - TY - JOUR TI - Epoxy/clay nanocomposites : preparation and performance improvement DO - 10.2417/spepro.004844 AU - Ngo, Tri-Dung AU - Cole, Kenneth Chesley AU - Ton That, Minh Tan AU - Van Hoa, Suong T2 - Plastics Research Online IS - May SP - 1 EP - 3 DA - 2013/05/28 PY - 2013 PB - Society of Plastics Engineers LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c29ff368-5eba-4bfb-a44a-0770033ef70f ER - TY - JOUR TI - Numerical study of laminar flow and mass transfer for in-line spacer-filled passages DO - 10.1115/1.4007651 AU - Beale, Steven B. AU - Pharoah, Jon G. AU - Kumar, Ashwani T2 - Journal of Heat Transfer SN - 0022-1481 VL - 135 IS - 1 SP - 011004-1 EP - 011004-8 KW - Computational Fluid dynamics; Periodic boundary conditions; Mass transfer; Membrane AB - Performance calculations for laminar fluid flow and mass transfer are presented for a passage containing cylindrical spacers configured in an inline-square arrangement, typical of those employed in the process industries. Numerical calculations are performed for fully-developed flow, based on stream-wise periodic conditions for a unit cell and compared with those obtained for developing regime in a row of ten such units. The method is validated for an empty passage, i.e., a plane duct. Results are presented for the normalized mass transfer coefficient and driving force, as a function of mean flow Reynolds number, and also the wall mass flux, or blowing parameter. Both constant and variable wall velocities were considered, the latter being typical of those found in many practical membrane modules. DA - 2013/01/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 295c5f0a-e202-4177-bfe1-ba0c6d59c88d ER - TY - JOUR TI - The innovative and sustainable approaches to enhance fire resistance of cellulosic fibers for green polymer composites AU - Ngo, T-D. AU - Ton-That, M-T. AU - Hu, W. T2 - SAMPE Journal VL - 49 IS - 3 SP - 31 EP - 37 DA - 2013/05 PY - 2013 UR - http://www.nxtbook.com/nxtbooks/sampe/journal_20130506/index.php?startid=31#/32 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : fa1a9b99-18cd-4259-9d68-dce514285460 ER - TY - JOUR TI - Numerical modeling of preferential and in-line heating of semi-transparent thin polymers in stretch blow molding and thermoforming processes DO - 10.4271/2013-01-1393 AU - Malo, Alain AU - Benrabah, Zohir AU - Thibault, Francis AU - Bardetti, Anna T2 - SAE Technical Papers; no. 2013-01-1393 T3 - SAE 2013 World Congress, 16-18 April 2013, Detroit, Michigan, USA AB - The heating stage is of primary importance in stretch blow molding and thermoforming processes. Computational methods using the finite element technique for modeling the radiation heating stage of thick gauge plastic preforms and thin gauge, roll-fed plastic sheets are presented and discussed. The theoretical approach as well as the experimental validation are also presented. DA - 2013/04/08 PY - 2013 PB - SAE International LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2c1d3733-43a4-47a3-bc18-c03cb721b2ae ER - TY - JOUR TI - Inlet and wall effects on fluid flow in doubly-periodic arrays of spacer-filled passages DO - 10.1115/HT2013-17240 AU - Mojab, S. M. AU - Beale, S. B. AU - Pollard, A. AU - Hanff, E. S. AU - Pharoah, J. G. T2 - Proceedings of the ASME 2013 Summer Heat Transfer Conference collocated with the ASME 2013 7th International Conference on Energy Sustainability and the ASME 2013 11th International Conference on Fuel Cell Science, Engineering and Technology T3 - ASME 2013 Summer Heat Transfer Conference, July 14-19 2013, Minneapolis, Missouri, USA AB - A numerical investigation has been carried out to study the effect of the sidewalls and the number of cells in arrays of spacer-filled channels on the local flow distribution, for Reynolds number, Re = 100, for a spacer-configuration typically employed in process industries. It was found that the channel sidewalls have a significant effect on the velocity profile near the walls. Numerically calculated values of velocity are compared with those measured experimentally, with good agreement being obtained; a maximum deviation of 4.5% was observed. Particle traces emitted from a cell at the channel entrance revealed that, unexpectedly, the flow moves parallel to the spacer filaments within each channel layer and changes 90 degrees direction mostly at the cell adjacent to the channel side walls. The effects of the number of cells and the type of boundary condition imposed on the channel transverse sidewalls on the pressure drop and friction factor are considered. DA - 2013/07/19 PY - 2013 PB - ASME LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 20612314-42c6-469c-af21-19cfb727b2b5 ER - TY - JOUR TI - Self-consistent determination of line-width and probe shape using atomic force microscopy DO - 10.1088/0957-0233/24/8/085401 AU - Eves, B. J. AU - Green, R. G. T2 - Measurement Science and Technology VL - 24 IS - 8 SP - MST/463723/PAP SP - 1 EP - 10 KW - line-width; probe shape; atomic force microscopy; critical dimension AB - A self-consistent method for determining line-width and probe shape using an atomic force microscope (AFM) has been developed. Through acquisition of three images in which one tip images the other, and each tip images the sample a least-squares determination of the shapes of both tips, and the parameters that define the line-width standard can be determined. Application of the self-consistent method produces measurements that can be made traceable to the definition of the metre through appropriate calibration of the AFM. A comparison between the line-width determined by the method and a calibrated line-width standard shows good agreement. Sources of uncertainty specific to the self-consistent method are discussed. DA - 2013/07/02 PY - 2013 PB - IOP Science LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 17d707e2-386b-4b84-8a4b-1763c01cc5b0 ER - TY - JOUR TI - Structure of Pisum sativum Rubisco with bound ribulose 1,5-bisphosphate DO - 10.1107/S1744309112047549 AU - Loewen, Peter C. AU - Didychuk, Allison L. AU - Switala, Jacek AU - Perez-Luque, Rosa AU - Fita, Ignacio AU - Loewen, Michele C. T2 - Acta Crystallographica Section F Structural Biology and Crystallization Communications SN - 1744-3091 VL - 69 IS - 1 SP - 10 EP - 14 KW - molecular replacement; Pisum sativum; ribulose 1,5-bisphosphate; Rubisco AB - The first structure of a ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) from a pulse crop is reported. Rubisco was purified from Pisum sativum (garden pea) and diffraction-quality crystals were obtained by hanging-drop vapour diffusion in the presence of the substrate ribulose 1,5-bisphosphate. X-ray diffraction data were recorded to 2.20 Å resolution from a single crystal at the Canadian Light Source. The overall quaternary structure of non-activated P. sativum Rubisco highlights the conservation of the form I Rubisco hexadecameric complex. The electron density places the substrate in the active site at the interface of the large-subunit dimers. Lys201 in the active site is not carbamylated as expected for this non-activated structure. Some heterogeneity in the small-subunit sequence is noted, as well as possible variations in the conformation and contacts of ribulose 1,5-bisphosphate in the large-subunit active sites. Overall, the active-site conformation most closely correlates with the `closed' conformation observed in other substrate/inhibitor-bound Rubisco structures. DA - 2013/01 PY - 2013 PB - International Union of Crystallography LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c8dc6913-970d-4981-9cfc-661968ce8fac ER - TY - JOUR TI - A generalized sky-LOSA method to quantify soot/black carbon emission rates in atmospheric plumes of gas flares DO - 10.1080/02786826.2013.809401 AU - Johnson, M. R. AU - Devillers, R. W. AU - Thomson, K. A. T2 - Aerosol Science and Technology SN - 0278-6826 VL - 47 IS - 9 SP - AST-MS-2012180.R1 SP - 1017 EP - 1029 AB - A new generalized theory governing sky-LOSA measurements (line-of-sight attenuation measurements of sky-light) of soot mass flux in atmospheric plumes has been developed which enables accurate measurements in the presence of in-scattered light from the sky and sun. The new approach is quantitatively tested using field measurement data collected for a gas flare at a turbocompressor station in Mexico. Although the soot plume of the tested flare was on the threshold of visible to the naked eye, the sensitivity of the current hardware was more than sufficient to resolve the soot mass emission rate of 0.067 g/s, with a quantified 95% confidence interval of 0.050 to 0.090 g/s. Results of a Monte Carlo simulation showed that soot optical property uncertainty was the major contributor to the overall measurement uncertainty. By contrast, correction of in-scattering via the generalized theory was a comparatively minor contributor, and was specifically insensitive to assumptions about the sky polarization state and intensity distribution. Given the prevalence of flaring and its implication as a potentially critical source of black carbon emissions, sky-LOSA is an essential new technology to directly quantify the impact of these globally distributed sources, for which comparable technologies do not exist. DA - 2013/06/24 PY - 2013 PB - Taylor & Francis LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : eb0a29fc-8fd0-4936-a9d3-9f3a25084610 ER - TY - JOUR TI - MicroRNAs and their putative targets in Brassica napus seed maturation DO - 10.1186/1471-2164-14-140 AU - Huang, Daiquing AU - Koh, Chushin AU - Feurtado, J. Allan AU - Tsang, Edward W. T. AU - Cutler, Adrian J. T2 - BMC Genomics SN - 1471-2164 VL - 14 IS - 1 SP - 140:1 EP - 140:25 KW - Seed development KW - embryo KW - next generation sequencing AB - Background : MicroRNAs (miRNAs) are 20–21 nucleotide RNA molecules that suppress the transcription of target genes and may also inhibit translation. Despite the thousands of miRNAs identified and validated in numerous plant species, only small numbers have been identified from the oilseed crop plant Brassica napus (canola) – especially in seeds. Results : Using next-generation sequencing technologies, we performed a comprehensive analysis of miRNAs during seed maturation at 9 time points from 10 days after flowering (DAF) to 50 DAF using whole seeds and included separate analyses of radicle, hypocotyl, cotyledon, embryo, endosperm and seed coat tissues at 4 selected time points. We identified more than 500 conserved miRNA or variant unique sequences with >300 sequence reads and also found 10 novel miRNAs. Only 27 of the conserved miRNA sequences had been previously identified in B. napus (miRBase Release 18). More than 180 MIRNA loci were identified/annotated using the B. rapa genome as a surrogate for the B.napus A genome. Numerous miRNAs were expressed in a stage- or tissue-specific manner suggesting that they have specific functions related to the fine tuning of transcript abundance during seed development. miRNA targets in B. napus were predicted and their expression patterns profiled using microarray analyses. Global correlation analysis of the expression patterns of miRNAs and their targets revealed complex miRNA-target gene regulatory networks during seed development. The miR156 family was the most abundant and the majority of the family members were primarily expressed in the embryo. Conclusions : Large numbers of miRNAs with diverse expression patterns, multiple-targeting and co-targeting of many miRNAs, and complex relationships between expression of miRNAs and targets were identified in this study. Several key miRNA-target expression patterns were identified and new roles of miRNAs in regulating seed development are suggested. miR156, miR159, miR172, miR167, miR158 and miR166 are the major contributors to the network controlling seed development and maturation through their pivotal roles in plant development. miR156 may regulate the developmental transition to germination. DA - 2013/02/28 PY - 2013 PB - BioMed Central LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : af06e482-cfeb-437b-a8bd-1a8b19be56aa ER - TY - JOUR TI - A comparison of rat SPECT images obtained using ⁹⁹mTc derived from ⁹⁹Mo produced by an electron accelerator with that from a reactor DO - 10.1088/0031-9155/58/9/2737 AU - Galea, R. AU - Wells, R. G. AU - Ross, C. K. AU - Lockwood, J. AU - Moore, K. AU - Harvey, J. T. AU - Isensee, G. H. T2 - Physics in Medicine and Biology SN - 0031-9155 SN - 1361-6560 VL - 58 IS - 9 SP - 2737 EP - 2750 AB - Recent shortages of molybdenum-99 (⁹⁹Mo) have led to an examination of alternate production methods that could contribute to a more robust supply. An electron accelerator and the photoneutron reaction were used to produce ⁹⁹Mo from which technetium-99m (⁹⁹mTc) is extracted. SPECT images of rat anatomy obtained using the accelerator-produced ⁹⁹mTc with those obtained using ⁹⁹mTc from a commercial generator were compared. Disks of 100Mo were irradiated with x-rays produced by a 35 MeV electron beam to generate about 1110 MBq (30 mCi) of ⁹⁹Mo per disk. After target dissolution, a NorthStar ARSII unit was used to separate the ⁹⁹mTc, which was subsequently used to tag pharmaceuticals suitable for cardiac and bone imaging. SPECT images were acquired for three rats and compared to images for the same three rats obtained using ⁹⁹mTc from a standard reactor ⁹⁹Mo generator. The efficiency of ⁹⁹Mo–⁹⁹mTc separation was typically greater than 90%. This study demonstrated the delivery of ⁹⁹mTc from the end of beam to the end user of approximately 30 h. Images obtained using the heart and bone scanning agents using reactor and linac-produced ⁹⁹mTc were comparable. High-power electron accelerators are an attractive option for producing ⁹⁹Mo on a national scale. DA - 2013/04/03 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6db87c20-830f-40f8-922b-4e463ead114f ER - TY - GEN TI - Qualifying the calibration uncertainty attributable to thermocouple inhomogeneity AU - Hill, Kenneth D. AU - Gee, Douglas J. T2 - Book of Abstracts - ITS9 Los Angeles 2012 T3 - 9th International Temperature Symposium (ITS9), 19-23 March 2012, Los Angeles, California, USA KW - inhomogeneity, Seebeck, thermocouple AB - Inhomogeneity in the Seebeck coefficient as a function of position along a thermocouple wire frequently dominates the uncertainty budgets of thermocouple calibration and use. The calibration process itself, simply through exposure to elevated temperatures for relatively modest times, generates both reversible and irreversible changes to the thermocouple that are a complex function of time, temperature, alloy composition, sheath structure, etc. We present data acquired using a salt bath at 250C to provide the step-function-like gradient that is our spatial probe if thermoelectric homogeneity. We show how the finite width of the step-function limits our ability to assess the "true" inhomogeneity of the thermocouple, and explore how the inhomogeneity impacts the calibration uncertainty attainable with the various thermal sources used for the calibration of thermocouples (based on their characteristic temperature gradients). DA - 2013/03 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d69da73f-e031-43cb-920b-9eefb48d75bd ER - TY - JOUR TI - Effects of water vapour addition to the air stream on soot volume fraction and flame temperature in a laminar coflow ethylene flame DO - 10.1615/ICHMT.2013.IntSympRadTransf.90 AU - Liu, Fengshan AU - Consalvi, Jean-Louis AU - Fuentes, Andrés AU - Smallwood, Gregory J. T2 - Proceedings of the 7th International Symposium on Radiative Transfer, RAD-13 T3 - 7th International Symposium on Radiative Transfer, RAD-13, 2-8 June 2013, Kusadasi, Turkey SP - RAD-13-CO2 AB - The effects of adding water vapour to the air stream on flame temperature and soot volume fraction were investigated numerically in a laminar coflow ethylene diffusion flame at atmospheric pressure using a detailed C2 reaction mechanism including PAH. Thermal radiation was calculated using the discrete-ordinates method and a statistical narrowband correlated-k based wide band model for the absorption coefficients of CO2 and H2O. Soot formation was modeled using a PAH based inception model and the HACA mechanism for surface growth and oxidation. The added water vapour affects soot formation and flame properties through not only dilution and thermal effects, but also through chemical and radiation effects. Addition of water vapour significantly reduces radiation heat loss. DA - 2013/06/08 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : bd1a93ec-e4c9-49a7-8d53-20ab8c016496 ER - TY - JOUR TI - Monitoring of potential cytotoxic and inhibitory effects of titanium dioxide using on-line and non-invasive cell-based impedance spectroscopy DO - 10.1016/j.aca.2013.03.044 AU - Male, Keith B. AU - Hamzeh, Mahsa AU - Montes, Johnny AU - Leung, Alfred C. W. AU - Luong, John H. T. T2 - Analytica Chimica Acta SN - 00032670 VL - 777 SP - 78 EP - 85 KW - Titanium dioxide KW - cytotoxicity KW - inhibition KW - nanoparticles KW - nano materials KW - impedance biosensing AB - Titanium dioxide (TiO₂) nanoparticles (NPs) with different sizes and structures were probed for plausible cytotoxicity using electric cell-substrate impedance sensing (ECIS), a non-invasive and on-line procedure for continuous monitoring of cytotoxicity. For insect cells (Spodoptera frugiperda Sƒ9), the ECIS₅₀ values, i.e., the concentration required to achieve 50% inhibition of the response, differed depending on the size and shape of the TiO₂ nanostructure. The lowest ECIS₅₀ value (158 ppm) was observed for the needle shaped rutile TiO2 (10 nm × 40 nm, 15.5 nm nominal particle size), followed by 211 ppm for P-25 (34.1 nm, 80% anatase and 20% rutile), 302 ppm for MTI5 (5.9 nm, 99% anatase) and 417 ppm for Hombitan LW-S bulk TiO₂ (169.5 nm, 99% anatase). Exposure of TiO2 NPs to UV light at 254 nm or 365 nm exhibited no significant effect on the ECIS₅₀ value due to the aggregation of TiO₂ NPs with diminishing photocatalytic activities. Chinese hamster lung fibroblast V79 cells, exhibited no significant cytotoxicity/inhibition up to 400 ppm with P25, MTI₅ and bulk TiO₂. However, a noticeable inhibitory effect was observed (ECIS₅₀ value of 251 ppm) with rutile TiO₂ as cell spreading on the electrode surface was prevented. DA - 2013/03/26 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d10f6f1d-7a8f-4964-8d40-2a6b246b4d8d ER - TY - JOUR TI - Novel polylactide/triticale straw biocomposites : processing, formulation, and properties DO - 10.1002/pen.23575 AU - Mihai, Mihaela AU - Ton That, Minh Tan T2 - Polymer Engineering & Science AB - This article aims to the development of polylactide (PLA)/ triticale straw biocomposites with focus on the relationship between triticale straw content, additive presence, processing, and final properties. Prior to melt compounding, the triticale straw used in this study was chopped using the paper process to produce triticale particles that were further pelletized to assure a consistent feed rate into the extrusion line. PLA/triticale straw biocomposites were obtained for different triticale contents from 10 up to 40%vol, without and with maleic anhydride grafted polylactide (PLA-g-MA) as a coupling agent. As a supplementary additive, a PLA-specific branching agentwas used in some selected formulations to minimize the reduction in PLA’s molecular weight. The biocomposites were characterized in terms of rheology, thermal properties, morphology, mechanical properties (tensile, flexural, and impact), and recyclability. The PLAg- MA increased the tensile strength of biocomposites by 10%, whereas boosted the tensile modulus about 2.5 times at 40%vol triticale content. For the same formulation, the flexural strength was raised by 15% and flexural modulus was doubled. However, a combination of PLAg- MA and branching agent proved to be the best approach to enhance PLA/triticale straw mechanical properties. When 20%vol of triticale was used as reinforcement, the presence of branching agent increased the flexural strength about 25%. The results demonstrate that the triticale straw processed in this way could offer a similar reinforcement capability as the cellulosic fibers based on the agricultural and forestry resources and can be easily recycled without losing its mechanical properties. It has a good potential in the biocomposites field with promising applications in construction, common goods, and transportation industries. DA - 2013/05/30 PY - 2013 PB - Wiley LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 1228e659-661d-48c2-8452-cd548ec83dda ER - TY - JOUR TI - Performance analysis and modeling of thermally sprayed resistive heaters DO - 10.1007/s11666-013-9946-3 AU - Lamarre, Jean-Michel AU - Marcoux, Pierre AU - Perrault, Michel AU - Abbott, Richard C. AU - Legoux, Jean-Gabriel T2 - Journal of Thermal Spray Technology SN - 1059-9630 VL - 22 IS - 6 SP - 947 EP - 953 KW - alumina; electrically conductive coatings; finite-element modeling; thermal properties; thermal stress AB - Many processes and systems require hot surfaces. These are usually heated using electrical elements located in their vicinity. However, this solution is subject to intrinsic limitations associated with heating element geometry and physical location. Thermally spraying electrical elements directly on surfaces can overcome these limitations by tailoring the geometry of the heating element to the application. Moreover, the element heat transfer is maximized by minimizing the distance between the heater and the surface to be heated. This article is aimed at modeling and characterizing resistive heaters sprayed on metallic substrates. Heaters were fabricated by using a plasma-sprayed alumina dielectric insulator and a wire flame-sprayed iron-based alloy resistive element. Samples were energized and kept at a constant temperature of 425 °C for up to 4 months. SEM cross-sectional observations revealed the formation of cracks at very specific locations in the alumina layer after thermal use. Finite-element modeling shows that these cracks originate from high local thermal stresses and can be predicted according to the considered geometry. The simulation model was refined using experimental parameters obtained by several techniques such as emissivity and time-dependent temperature profile (infra-red camera), resistivity (four-probe technique), thermal diffusivity (laser flash method), and mechanical properties (micro and nanoindentation). The influence of the alumina thickness and the substrate material on crack formation was evaluated. DA - 2013/06 PY - 2013 PB - Springer LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : dc34fd2e-6e32-4364-9ead-0c712d82c6fa ER - TY - JOUR TI - Strength and wear properties of stainless steel coatings produced by cold spray with various powder sizes AU - Vo, P. AU - Irissou, É. T2 - Thermal Spray 2013 : Proceedings of the International Thermal Spray Conference (ASM International) T3 - ITSC 2013- International Thermal Spray Conference, 13-15 May 2013, Busan City, South Korea SP - 235 EP - 240 AB - Cold spray processing of stainless steel coatings, which represent a cost-effective method for wear and corrosion resistance, has been demonstrated as technically feasible. However, these coatings have a very low tensile strength in the as-sprayed condition, and also may display a marginally higher wear rate. In this study, the cold spray of 316L stainless steel coatings was investigated to characterize the effect of powder size distribution and post-spray heat treatment on strength and wear properties. Coatings on aluminum and steel alloy substrates were produced with a feedstock powder that was obtained in three particle size distributions. The deposition process for all coatings employed nitrogen as the propellant gas and a constant set of spray conditions. A set of screening heat treatments using coupons from coatings produced with one powder size distribution was employed to obtain optimized annealing temperatures. Post-spray annealing at the optimized values was subsequently performed on coatings produced with all three powder size distributions. A comprehensive characterization of the microstructure and mechanical properties, including tensile strength and wear resistance, was performed for coatings produced in the as-sprayed and heat-treated conditions. DA - 2013/05 PY - 2013 PB - ASM International LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 46bea1c2-aa6c-44a9-876b-cc8625f4eb30 ER - TY - JOUR TI - Tribological characterization of plasma sprayed CoNiCrAlY-BN abradable coatings AU - Irissou, É. AU - Dadouche, A. AU - Lima, R. S. T2 - Thermal Spray 2013: Proceedings of the International Thermal Spray Conference (ASM International) T3 - ITSC 2013- International Thermal Spray Conference, May 13-15, 2013, Busan City, South Korea SP - 602 EP - 607 AB - The processing conditions, microstructural and tribological characterizations of plasma sprayed CoNiCrAlY-BN high temperature abradable coatings are reported in this manuscript. Plasma spray torch parameters were varied to produce a set of abradable coatings exhibiting a broad range of porosity levels (34-62%) and superficial Rockwell hardness values (0-78 HR15Y). Abradability tests have been performed using an abradable-seal test rig capable of simulating operational wear at different rotor speeds and seal incursion rates. These tests allowed determining the rubbing forces and quantifying the blade and seal wear characteristics for slow and fast seal incursion rates. Erosion wear performance and ASTM C633 coating adhesion strength test results are also reported. For optimal abradability performance, it is shown that coating hardness needs to be lower than 70 and 50 HR15Y for slow and fast blade incursion rate conditions, respectively. It is shown that the erosion wear performance, as well as, the coating cohesive strength is a function of the coating hardness. The current results allow defining the coating specifications in terms of hardness and porosity for targeted applications. DA - 2013/05 PY - 2013 PB - ASM International LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6168bff8-381c-4564-b0b6-bb32039f693f ER - TY - JOUR TI - Cold spray deposition of mechanically alloyed Cu–Ni–Fe material for application as inert anodes for aluminum production DO - 10.1002/9781118663189.ch216 AU - Goupil, G. AU - Helle, S. AU - Irissou, É. AU - Poirier, D. AU - Legoux, J. G. AU - Guay, D. AU - Roué, L. T2 - Light Metals 2013 T2 - TMS Light Metals T3 - 2013 TMS Annual Meeting and Exhibition, 3-7 March 2013, San Antonio, TX, USA SN - 0147-0809 SN - 9781118605721 SP - 1283 EP - 1287 KW - aluminum electrolysis; inert anode; Cu-Ni-Fe alloys; cold spray deposition; low-temperature electrolyte AB - Cold spray deposition was evaluated for the production of inert anodes for Al electrolysis from mechanically alloyed Cu−Ni−Fe powders. Cu65Ni20Fe15 (in wt. %) alloy was first prepared from elemental Cu, Ni, Fe powders using an attritor. After 40 h of milling, a nanocrystalline and monophasic Cu(Ni,Fe) solid solution was formed. It was shown that the particle size of the milled powder can be controlled with the addition of stearic acid to the initial powder mixture. In a second step, the cold spray parameters (pressure and temperature of the carrier N2 gas) were optimized in order to maximize the impact velocity of the Cu65Ni20Fe15 particles on the substrate. Then, thick (1100 μm), dense (porosity of 1− 2 %) and adherent (adhesion strength of 15 MPa) coatings of Cu65Ni20Fe15 on C63000 substrate (copper aluminium bronze alloy) were produced. No structural change of the Cu65Ni20Fe15 alloy was observed during cold spray processing. DA - 2013/02/23 PY - 2013 PB - Wiley LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : dccb3313-a82c-4cf0-a2a5-ad7d7a1eb269 ER - TY - JOUR TI - Polyamide 12 (PA12) / clay nanocomposites fabricated by conventional extrusion and water-assisted extrusion processes DO - 10.1002/app.39390 AU - Stoeffler, Karen AU - Utracki, Leszek A. AU - Simard, Yves AU - Labonté, Sylvain T2 - Journal of Polymer Science VL - 130 IS - 3 SP - 1959 EP - 1974 KW - composites; clay; extrusion AB - This work aims at comparing the efficiency of three melt compounding methods for preparing polyamide 12 (PA12)/untreated clay composites. Conventional extrusion was compared with two water-assisted extrusion methods previously described in the literature and respectively involving injection of water in the polymer/clay stream or injection of aqueous clay slurry in the polymer stream. The dispersion of the clay in the composites was analyzed at the microscale and at the nanoscale using microscopy (optical and electronic) and wide angle X-ray diffraction (WAXD). The tensile properties of the composites were evaluated. The results showed that injection of aqueous clay slurry in the polymer stream was the most efficient method for preparing PA12/untreated clay composites, although clay particles remained mainly dispersed at the microscale. This method allowed for a drastic size reduction of the microparticles, accompanied by enhancements of ca. +10 % in tensile modulus and tensile strength (compared with equivalent composites obtained by conventional extrusion). The influence of the pH of the aqueous clay slurry was also investigated: neutralization of the clay slurry generated finer dispersions, probably resulting from a better pre-exfoliation of the clay in the water medium. PA12/organophilic clay composites were also prepared as control samples. When an adequate surface treatment was selected, nanoscale dispersion of the clay platelets was easily achieved. In this case, composites prepared by conventional extrusion showed overall similar properties as their equivalents prepared using injection of water in the polymer/clay stream. DA - 2013/05/13 PY - 2013 PB - Wiley LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : bfd6ac87-ec50-4290-a68e-5c848221748f ER - TY - JOUR TI - Controlling the forming of thermoplastics through forming power DO - 10.4271/2013-01-0602 AU - Girard, Patrick AU - Benrabah, Zohir AU - Mir, Hicham T2 - SAE Technical Papers; no. 2013-01-0602 T3 - SAE 2013 World Congress, 16-18 April 2013, Detroit, Michigan, USA AB - Controlling the forming of large thermoplastic parts from a simulation requires very precise predictions of the pressure and volume profile evolution. Present pressure profile based simulations adequately predict the thickness distribution of a part, but the forming pressure and volume profile development lack the precision required for process control. However new simulations based on the amount of power required to form the material can accurately predict these pressure and volume profiles. In addition online monitoring of the forming power on existing machines can be easily implemented by installing a flow rate and pressure meter at the gas entrance, and if necessary, exits of the part. An important additional benefit is that a machine thus equipped can function as an online rheometer that can characterize the viscosity of the material at the operating point by tuning the simulation to the online measurements. This method can characterize materials at the actual, very high strain rates, that are not attainable by conventional characterization methods, and also allows online detection of variations in the rheology of the resin. The rheological model of the material is then updated to fit this point, which would normally lie outside of the characterization range. A basic implementation for a cycle to cycle control system for thermoforming of plastic materials is proposed. The system controls the development of the pressure and volume profile in the part while adjusting to operating conditions, including changes in resin rheology. It ensures that the part is consistently formed cycle after cycle using the same strain rate profiles. A forming power based simulation is run in the background with the rheological model tuned to fit the operating point as shown above. A simple linear sensitivity matrix is then derived from the simulation. Since this linear sensitivity matrix is defined in the vicinity of the actual operating point and provides a much faster response time than the simulation, it can be used as the core of an online forming process control system. The system is applicable to large parts with slow deformation such as gas tanks, and small parts with very high rates of deformation such as angioplasty balloons. DA - 2013/04/08 PY - 2013 PB - SAE International LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 4b6aecf2-92fd-4b21-965e-c5d92c84b31b ER - TY - JOUR TI - Thermo-viscoelastic model for shrinkage and warpage prediction during cooling and solidification of automotive blow molded parts DO - 10.4271/2013-01-1397 AU - Benrabah, Zohir AU - Mir, Hicham AU - Zhang, Yi T2 - SAE International Journal of Materials and Manufacturing T3 - SAE 2013 World Congress, 16-18 April 2013, Detroit, Michigan, USA VL - 6 IS - 2 SP - 2013-01-1397 SP - 349 EP - 364 AB - Blow moulding is one of the most important polymer processing methods for producing complex thermoplastic automotive parts. Contrary to injection molding, little attention has focused on process control and simulation of blow molding processes. Yet, there are still several problems that affect the overall success of forming these parts. Among them are thermally induced stresses, relevant shrinkage and part warpage deformations caused by inappropriate mold design and/or processing conditions. Tolerance issues are critical in automotive applications and therefore part deformation due to solidification needs to be controlled and optimized accordingly. The accurate prediction tool of part deformation due to solidification, under different cooling conditions in automotive formed parts, is important and highly suited for part designers to help achieve an efficient production. DA - 2013/04/08 PY - 2013 PB - SAE International LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ffd2822f-0008-43a3-98ca-f894b4569e5c ER - TY - JOUR TI - Thermodynamic and energetic effects on the diameter and defect density in single-walled carbon nanotube synthesis DO - 10.1021/jp308672a AU - Vinten, Phillip AU - Marshall, Paul AU - Lefebvre, Jacques AU - Finnie, Paul T2 - The Journal of Physical Chemistry C SN - 1932-7447 SN - 1932-7455 VL - 117 IS - 7 SP - 3527 EP - 3536 AB - Single-walled carbon nanotube (SWCNT) ensembles are characterized by their defect density and diameter distribution. Here, SWCNTs are grown using chemical vapor deposition with acetylene as the carbon source and cobalt as the catalyst and analyzed ex situ, without any modification or processing, using Raman spectroscopy. The defect density shows an activated temperature dependence (activation energy ∼0.8 eV or ∼80 kJ/mol) with fewer defects at high growth temperatures for a wide range of experimental parameters. This is consistent with a single activated mechanism, such as the catalytic healing of defects, possibly a single simple defect. Consistent with previous reports, we see that low growth temperatures produce smaller diameter SWCNTs than high growth temperatures. Elementary thermodynamic considerations of the strain energy in the lattice constrain the SWCNT diameter distribution and its temperature dependence and appear consistent with our observations. A “phase diagram” for SWCNT growth is constructed and suggests methods of controlling the diameter distribution. There is a trade-off here between small diameter SWCNTs and SWCNTs with low defect densities. DA - 2013/01/24 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 20076beb-2c24-48ac-a38a-385a2530f2a4 ER - TY - JOUR TI - Magnetic imaging with a Zernike-type phase plate in a transmission electron microscope DO - 10.1063/1.4803908 AU - Pollard, Shawn AU - Malac, Marek AU - Beleggia, Marco AU - Kawasaki, Masahiro AU - Zhu, Yimei T2 - Applied Physics Letters SN - 0003-6951 VL - 102 IS - 19 SP - 192401-1 EP - 192401-4 DA - 2013/05/13 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : cd30af34-0a84-46e7-ab3d-734e08c84a06 ER - TY - JOUR TI - A real-time rocking motion monitoring system AU - Wu, Lixue T2 - Proceedings of the 19th International Congress on Sound and Vibration 2012 T3 - 19th International Congress on Sound and Vibration (ICSV19), 8-12 July 2012, Vilnius, Lithuania SN - 978-1-62276-465-5 VL - 3 SP - 145 SP - 1777 EP - 1784 DA - 2013/02 PY - 2013 PB - Curran LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 583e8173-fc34-4524-9d4f-f9e30bb09dfd ER - TY - JOUR TI - Hybrid fire testing for assessing performance of structures in fire—application DO - 10.1016/j.firesaf.2012.12.003 AU - Mostafaei, Hossein T2 - Fire Safety Journal SN - 0379-7112 VL - 56 SP - 30 EP - 38 KW - Hybrid test; Fire resistance; Performance-based design; Hybrid test; Full-scale test; Test and analysis/simulation; Hybrid fire testing; HFT; Standard fire resistance test AB - This paper presents the results for application and implementation of the hybrid fire testing (HFT) approach, developed previously for performance assessment of the structure in fire. The HFT carried out by means of both computer simulation and experimentation using the National Research Council Canada's (NRC) testing facilities in Ottawa. The test specimen was a full-scale 6-storey building structure with a fire compartment scenario on the main floor of the building. Using the HFT, the column in the designated fire compartment was exposed to the fire in a column furnace and the rest of the building was simulated using a numerical modeling, simultaneously. The methodology of the HFT and its numerical verifications were developed and described in a previous paper. This paper includes application of the HFT and some of results for fire structural performance of the whole 6-storey building. It also includes results of a separate, benchmark, column specimen with identical specifications, tested in fire using the traditional prescriptive fire resistance test method. The HFT was carried out successfully. The results indicated that the hybrid fire testing method would provide more realistic fire endurance evaluation than the prescriptive method due to including the effects from the rest of the building on the column specimen during the test. DA - 2013/01/19 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 56d487a8-a0d1-45a3-ace3-ba6fa820e1f5 ER - TY - JOUR TI - A uniform methodology to establish test parameters for watertightness testing part II: Pareto front analysis on co-occurring rain and wind DO - 10.1016/j.buildenv.2012.12.019 AU - Van Den Bossche, Nathan AU - Lacasse, Michael A. AU - Janssens, Arnold T2 - Building and Environment SN - 0360-1323 VL - 63 SP - 157 EP - 167 KW - Watertightnes; Testing; Wind driven rain; Co-occurrence; Pareto front AB - A critical review on boundary conditions for watertightness testing was presented in a related paper forming Part I of “A uniform methodology to establish test parameters for watertightness testing”. Existing methodologies to establish test conditions only partially consider co-occurrence of rain and wind, which yields large uncertainties when determining return periods for extreme wind-driven rain events. This paper presents a new approach based on a Pareto fronts method for which wind driven rain intensities and wind pressures are derived. Straight lines can be fitted to consecutive fronts, and a generalized Pareto distribution describes the corresponding probabilities of occurrence of wind-driven rain events. Assumptions in the use of the methods are given and constraints to its use provided by means of case-studies. Advantages over existing methods for estimating watertightness test parameters are highlighted. Test conditions can be calculated for various configurations and different averaging periods depending on the failure behavior of specific building envelop components. Subsequently it is shown that the conversion of case-based test conditions to generic test protocols and performance levels requires careful consideration. Finally, the paper provides practical guidelines on defining realistic watertightness performance levels for building envelop components. DA - 2013/05/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3ad7590c-7788-42fc-98f7-2a8ab3a39440 ER - TY - JOUR TI - A uniform methodology to establish test parameters for watertightness testing Part I: A critical review DO - 10.1016/j.buildenv.2012.12.003 AU - Van den bossche, Nathan AU - Lacasse, Michael A. AU - Janssens, Arnold T2 - Building and Environment SN - 0360-1323 VL - 63 SP - 145 EP - 156 KW - Watertightness; Testing; Wind driven rain; Co-occurrence; Pareto front; Review AB - Many of the standards and codes related to watertightness of building components in use today have a long history and in most cases their roots were conceived decades ago. Irrespective of the broad spectrum of research on wind loads, rainfall and wind driven rain (WDR) intensity, little information is available concerning the scientific basis for watertightness test methods or performance criteria. This paper provides an overview of existing methodologies to establish test conditions and a critical review of calculation methods for wind and WDR loads on buildings, from the viewpoint of establishing test parameters for watertightness testing. The operative standard in the field of structural engineering is extended with a gust model to calculate wind loads for varying configurations, return periods and gust lengths, and model implications are discussed. A state-of-the-art on intensity–duration–frequency curves of horizontal rainfall intensity is given, and a new approach to accommodate conflicting models is presented. Furthermore, based on recent advances in WDR research, an adapted semi-empirical model is suggested to calculate extreme WDR intensities on building façades. For two locations boundary conditions for watertightness testing were calculated based on datasets extending over 10 years of 10-min averaged values. Finally, constraints and challenges in extreme value analysis in respect to cut-off values, fitting algorithms, goodness-of-fit (GOF) criteria and co-occurrence of rain and wind are discussed. DA - 2013/05/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ccbfbc59-af58-425c-981a-4f40a94f83d3 ER - TY - CHAP TI - Expressing full-length functional PfEMP1 proteins in the HEK293 expression system DO - 10.1007/978-1-62703-026-7_22 AU - Srivastava, Anand AU - Durocher, Yves AU - Gamain, Benoît T2 - Malaria T2 - Methods in Molecular Biology; 923 SN - 978-1-62703-025-0 SP - 307 EP - 319 AB - Due to the A/T-richness of the genome of Plasmodium falciparum, expressing P. falciparum proteins in heterologous expression systems is challenging. In addition, many P. falciparum proteins have high cysteine content and high molecular weight, which further complicates expression of these proteins in heterologous systems. The high molecular weight Plasmodium falciparum Erythrocyte Membrane Protein 1 (PfEMP1) adhesins expressed on the surface of the infected erythrocytes are among the most difficult proteins to express. Cost reduction in synthetic gene synthesis, as well as improved eukaryotic expression systems, now makes it possible to express such proteins. In this chapter, we describe the construction, production, purification, and functional assessment of the full-length extracellular region of the var2CSA PfEMP1 protein involved in pregnancy-associated malaria (PAM), using a human embryonic kidney (HEK) expression system. DA - 2013 PY - 2013 PB - Springer LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0430c1e2-d9ac-499c-91c7-870908e83625 ER - TY - JOUR TI - Reflections on service to CPA. DO - 10.1037/a0031132 AU - Veitch, Jennifer A. T2 - Canadian Psychology/Psychologie canadienne SN - 1878-7304 SN - 0708-5591 VL - 54 IS - 1 SP - 50 EP - 54 KW - psychology; Canadian Psychological Association; voluntarism; service; scientific discipline; interdisciplinarity AB - The rewards for service to a professional association are many: reputation-building, power, and influence; skill development; networking opportunities; feelings of mastery and belonging. These serve to maintain the behaviours despite occasional dull or routine tasks required in the service role. Voluntary service of this kind is essential to the maintenance of psychological research, practice, and education; arguably it ensures that psychologists can continue to be psychologists. Disciplinary service ensures a strong common core of knowledge, language, and culture to support interdisciplinary and interprofessional endeavours. DA - 2013/01/01 PY - 2013 PB - American Psychological Association LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 88ee1442-417c-4951-9612-4cc057b826c3 ER - TY - JOUR TI - Sustained production of a soluble IGF-I receptor by gutless adenovirus-transduced host cells protects from tumor growth in the liver DO - 10.1038/cgt.2013.10 AU - Wang, N. AU - Lu, Y. AU - Pinard, M. AU - Pilotte, A. AU - Gilbert, R. AU - Massie, B. AU - Brodt, P. T2 - Cancer Gene Therapy SN - 0929-1903 VL - 20 IS - 4 SP - 229 EP - 236 KW - cancer; gutless adenoviral vector; liver metastases; soluble IGF-IR AB - The IGF-I receptor (IGF-IR) has an important role in malignant disease and is the target of several drugs presently in clinical trials. Gene therapy has been explored as cancer treatment, mainly for delivery of genes that induce cell death or enhance the immunological response to cancer. Previously, we have shown that the implantation of autologous bone-marrow stromal cells producing a soluble form of IGF-IR (sIGFIR) inhibited experimental liver metastasis of several tumor types in mice. Here, we evaluated the utility of adenovirus-based gene delivery for generating therapeutically effective plasma levels of this decoy. We constructed a third generation gutless adenovirus expressing sIGFIR and found that HEK-293 cells transduced by this, but not control adenoviruses, secreted soluble receptor protein that blocked IGF-I-induced tumor cell migration, proliferation and survival in vitro. Following virus injection in vivo, viral DNA was detectable by PCR in several host organs, particularly the liver, and this resulted in the production of measurable sIGFIR plasma levels for up to 21 days post injection. In mice producing virus-encoded sIGFIR, experimental liver metastasis was inhibited, indicating that sIGFIR levels were therapeutically effective. The results show that adenovirus-based delivery of inhibitory soluble proteins can provide an effective anticancer strategy. DA - 2013/03/08 PY - 2013 PB - Nature Publishing Group LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e72cfdcd-fea8-4f27-824f-44be702d74de ER - TY - CHAP TI - Papain DO - 10.1016/B978-0-12-382219-2.00418-X AU - Storer, Andrew C. AU - Ménard, Robert T2 - Handbook of Proteolytic Enzymes SN - 978-0-12-407743-0 SN - 9780123822192 VL - 2 SP - 1858 EP - 1861 DA - 2013 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a7c1e230-5fb9-4aa5-b6a0-d32ab57ee8d1 ER - TY - CHAP TI - Cathepsin X DO - 10.1016/B978-0-12-382219-2.00415-4 AU - Nägler, Dorit K. AU - Ménard, Robert AU - Sulea, Traian T2 - Handbook of Proteolytic Enzymes (3rd edition) SN - 978-0-12-382219-2 SP - 1839 EP - 1844 KW - active-site-prob; adhesion; Alzheimer; cancer; carboxypeptidase; immunity; inflammation; inhibitor; integrin; migration; mini-loop; monopeptidyl; specificity; structure; substrate AB - The third edition of the Handbook of Proteolytic Enzymes aims to be a comprehensive reference work for the enzymes that cleave proteins and peptides, and contains over 800 chapters. Each chapter is organized into sections describing the name and history, activity and specificity, structural chemistry, preparation, biological aspects, and distinguishing features for a specific peptidase. The subject of Chapter 415 is Cathepsin X. DA - 2013 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 84aace1b-ba63-44ab-8b4a-d1b094c16d0a ER - TY - JOUR TI - Hybrid fire testing for assessing performance of structures in fire—methodology DO - 10.1016/j.firesaf.2013.02.005 AU - Mostafaei, Hossein T2 - Fire Safety Journal SN - 0379-7112 VL - 58 SP - 170 EP - 179 KW - Fire resistance; Performance-based design; Hybrid test; Full-scale test; Test and analysis/simulation; Hybrid fire testing AB - A new performance-based assessment approach for structures in fire, referred to as hybrid fire testing (HFT) method, is presented in this article. The HFT was developed based on a sub-structuring method, by dividing the whole structure into two substructures, one being tested in a furnace and one being simulated by a computer. This represents a form of “hardware-in-the-loop” simulation. Using HFT, the performance of the whole building can be evaluated at a very reasonable cost, significantly less than the cost of the direct whole building test. More reliable results than the prescriptive method can also be achieved with comparable and even more comprehensive results than that of a direct full-scale test. A 6-storey reinforced concrete building was designed, as a prototype for application of the hybrid fire testing approach. Two fire scenario examples were considered; a 6-storey building with a fire compartment on the first floor, in the center of the building and a 6-storey building with a fire compartment on the third floor. The two substructures for these two HFT scenarios were; one the column in the fire compartment and two the rest of the building. This paper includes the description of the hybrid testing methodology, details of the 6-storey building prototype and the methodology verification. Using the HFT approach, various scenarios could be explored to couple modeling and testing globally. This may also provide the possibility of running one test in a testing facility, e.g. NRC's, and running the analysis remotely at a different location. This would make furnace facilities more accessible to the research communities around the globe. DA - 2013/03/16 PY - 2013 LA - eng N1 - Erratum published in volume 61, page 355, October 2013. DOI: 10.1016/j.firesaf.2013.10.001 C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 8f7954d3-493e-4c3b-a16f-65501374b0ed ER - TY - JOUR TI - Terrestrial ecotoxicity of canola and tallow-biodiesel blended with ulta-low sulphur diesel (PL) AU - Rocheleau, S. AU - Sarrazin, M. AU - Dodard, S. AU - Beaulieu, C. AU - Hawari, J. AU - Hollebone, B. AU - Sunahara, G. AU - Harkness, J. AU - van Aggelen, G. AU - Kennedy, C. J. AU - Jarvis, R. Allen AU - Burridge, L. E. T2 - Proceedings of the 39th Annual Aquatic Toxicity Workshop : September 30-October 3, 2012, Sun Peaks, British Columbia T2 - Canadian Technical Reports of Fisheries and Aquatic Sciences; 3030 T3 - 39th Aquatic Toxicity Workshop (ATW 2012), September 30-October 3, 2012, Sun Peaks, British Columbia SP - 16 AB - Biodiesel is becoming an interesting alternative fuel source considering the continuously diminishing petroleum resources. Biodiesel can be produced from either plant or animal feedstocks, and its storage, transport, and use may pose potential environmental problems to soil and groundwater. Aquatic toxicities of diesel and biodiesel have been extensively studied, but little is still known about their toxicities and environmental fate in soil. The present study evaluates the potential environmental impacts of biodiesel and petroleum ultra-low-sulphur based diesel (ULSD) blended with biodiesel in soil using direct contact toxicity assays. Canola-source biodiesel (B100) and a tallow-source biodiesel (B100) alone and as 20% (volume/volume) blends with ULSD (B20) were compared to neat ULSD. Selected standard terrestrial toxicity tests included ryegrass Lolium perenne seedling emergence and growth, earthworm Eisenia fetida survival, and soil microbial dehydrogenase activity (DHA). Soil loading was quantified using extractable n-alkanes (C10 to C34 hydrocarbons). Results indicate that both B20 biodiesel blends had less deleterious effects to ryegrass growth and earthworm survival than the petroleum ULSD, whereas both B100 biodiesel samples had no deleterious effect on ryegrass growth or earthworm survival at concentrations up to 6310 and 6613 mg n-alkanes·kg⁻¹, respectively. Petroleum ULSD and B20 canola biodiesel inhibited the DHA microbial activity, whereas tallow biodiesel (B20 and B100) and B100 canola biodiesel stimulated the DHA activity. This study provides useful toxicological data for the evaluation of potential adverse impact and risk assessment of biodiesel in the environment. DA - 2013 PY - 2013 UR - http://www.atw.ca/site_pages/Past%20Proceedings/ATW%202012%20Proceedings%20Final.pdf LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3c71d844-61e3-41ac-b4e7-0c013c0d3ad7 ER - TY - JOUR TI - Nutrient remediation rates in municipal wastewater and their effect on biochemical composition of the microalga Scenedesmus sp. AMDD DO - 10.1016/j.algal.2013.01.009 AU - Dickinson, Kathryn E. AU - Whitney, Crystal G. AU - McGinn, Patrick J. T2 - Algal Research VL - 2 IS - 2 SP - 127 EP - 134 KW - Microalgae KW - Chemostat KW - Bioenergy KW - Biofuels KW - Wastewater AB - Microalgae are very efficient at removing nutrients from municipal wastewater and may be a viable tertiary wastewater treatment while additionally improving the economics of microalgal cultivation for biofuel production. The relative quantities and productivities of fatty acids, carbohydrates and proteins were determined in the microalga Scenedesmus sp. AMDD grown in treated municipal wastewater in continuous chemostats under different dilution rates or hydraulic retention times. The dilution rate of the chemostat exerted a strong control over the biochemical composition of the cultivated biomass and clear differences in the patterns of accumulation of cellular constituents were detected. Maximum carbohydrate and protein productivities were estimated to be 130 and 120 mg L⁻¹ d⁻¹, respectively, at dilution rates of 0.5 d⁻¹ and 1.05 d⁻¹, respectively. Fatty acid productivity was fairly constant at about 20 mg L⁻¹ d⁻¹ across all tested dilution rates. Total fatty acid only accumulated when growth rates were very low or when a prolonged nutrient starvation regime was imposed by interrupting the supply of wastewater to the chemostat. Monounsaturated fatty acids increased by 250%, whereas polyunsaturated fatty acids decreased by 60% and saturated fatty acids remained fairly constant, from the highest dilution rate of 1.05 d⁻¹ to nutrient starved cells. The rate of wastewater nutrient remediation therefore strongly controls the composition of the biomass, thereby controlling its commercial applicability. DA - 2013/03/07 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 5f553b97-72f9-4c25-b026-812885664819 ER - TY - JOUR TI - Isolation and characterization of herbaceous lignins for applications in biomaterials DO - 10.1016/j.indcrop.2012.04.049 AU - Monteil-Rivera, Fanny AU - Phuong, Marielle AU - Ye, Mengwei AU - Halasz, Annamaria AU - Hawari, Jalal T2 - Industrial Crops and Products VL - 41 SP - 356 EP - 364 KW - Herbaceous lignin KW - microwave KW - functional groups KW - molecular weight KW - thermal stability KW - biomaterials AB - The imminent industrial production of cellulosic ethanol from annual plants will generate massive amounts of herbaceous lignins that will have to be valorized. However, the chemical and physical properties of herbaceous lignins are much less known than those of wood lignins. In the present study, organosolv lignins were extracted from wheat, triticale, corn, flax, and hemp residues using microwave irradiation under similar conditions. The extracted lignins were extensively analyzed by FT-IR, ³¹P NMR, gel permeation chromatography, thermogravimetric analysis, and elemental and carbohydrate analysis to determine their applicability in polymers. All lignins were of high purity with low sugar, sulfur, and ash content. Corn, hemp, and flax lignins were found to contain high concentrations of non-methoxylated phenolic groups, syringyl phenolic groups, and aliphatic OH groups, respectively, making them promising candidates for production of phenolic resins, stabilization of polyolefins, and polyurethane synthesis, respectively. Triticale or wheat lignins were less specific, with a balanced content of OH groups, which makes them applicable to polyester synthesis. DA - 2013/01/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 037ec80d-beec-4a8d-a705-5342b289d961 ER - TY - JOUR TI - Soot temperature and volume fraction retrieval from spectrally resolved flame emission measurement in laminar axisymmetric coflow diffusion flames : Effect of self-absorption DO - 10.1016/j.combustflame.2013.02.007 AU - Liu, Fengshan AU - Thomson, Kevin A. AU - Smallwood, Gregory J. T2 - Combustion and Flame SN - 0010-2180 VL - 160 IS - 9 SP - 1693 EP - 1705 KW - soot measurement; line-of-sight spectral flame emission; self-absorption; Abel inversion AB - The effects of self-absorption on the inverted soot temperature and volume fraction distributions in coflow laminar diffusion flames were investigated using two correction methods. Self-absorption was found unimportant when the optical thickness of the flame is less than 0.3, but can be very important in flames of large optical thicknesses. Due to the uncertainty in soot absorption function E(m), different assumptions of the variation of E(m) with wavelength were investigated. Decreasing E(m) with wavelength leads to largest errors in the recovered soot temperature and volume fraction when self-absorption correction is not accounted for. The assumption of constant E(m) in general results in smallest errors in the inverted soot volume fraction and the increasing E(m) with wavelength gives rise to smallest errors in the recovered soot temperature. Neglect of self-absorption correction in general leads to underestimate of the inverted soot temperature, while the inverted soot volume fraction can be higher or lower than the true value, depending on how E(m) varies with wavelength. The self-absorption correction method of Snelling et al. [D.R. Snelling, K.A. Thomson, G.J. Smallwood, Ö.L. Gülder, E.J. Weckman, R.A. Fraser, AIAA J. 40(9) (2002) 1789–1795] is effective in recovering accurate soot temperature and volume fraction distributions from noise-free emission data even for flames with optical thickness as large as 5. For inversion of emission data containing noise it is still advantageous to account for self-absorption. Multi-wavelength emission data from a laminar coflow ethylene/air diffusion flame at atmospheric pressure and a methane/air diffusion flame at 40 atm were reanalyzed to demonstrate how self-absorption affects the reconstructed temperature and soot volume fraction distributions. It is preferred to detect flame emissions at longer wavelengths in the visible spectrum to minimize the self-absorption effect. The effect of self-absorption should in general be taken into account in the reconstruction of soot temperature and volume fraction from the line-of-sight spectral flame emission data using the method of Snelling et al. DA - 2013/06 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 9b33fadd-9873-4b00-80a0-0dad5d75f178 ER - TY - JOUR TI - Final report on CCM key comparison CCM.D-K2 : comparison of liquid density standards DO - 10.1088/0026-1394/50/1A/07006 AU - Bettin, Horst AU - Jacques, Claude AU - Zelenka, Zoltan AU - Fujii, Ken-ichi AU - Kuramoto, Naoki AU - Chang, Kyung-Ho AU - Lee, Yong Jae AU - Becerra, Luis Omar AU - Domostroeva, Natalia T2 - Metrologia VL - 50 IS - 1A Technical Supplement SP - 1 EP - 45 AB - The results are presented of the key comparison CCM.D-K2 that covered the density measurements of four liquids: the density of water at 20 °C, of pentadecane at 15 °C, 20 °C, 40 °C and 60°C, of tetrachloroethlyene at 5 °C and 20 °C and of a viscous oil at 20 °C. Seven national metrology institutes measured the densities at atmospheric pressure by hydrostatic weighing of solid density standards in the time interval from 27 April 2004 to 28 June 2004. Since the participants were asked not to include components for a possible drift or inhomogeneity of the liquid in their uncertainty budget, these uncertainty contributions are investigated for the final evaluation of the data. For this purpose, results of stability and homogeneity measurements of the pilot laboratory are used. The participants decided not to include a possible drift of the liquid's density since no significant drift could be detected, and the influence of the drift and its uncertainty are negligible. Similarly, the inhomogeneity of the water and pentadecane samples is not significant and has no influence on the evaluation. Thus, it was neglected. Only the inhomogeneities of tetrachloroethylene and of the viscous oil were significant. Consequently, they were included in the evaluation. With one or two exceptions, the results show good agreement among the participants. Only in the case of water are the results clearly discrepant. The key comparison reference values were calculated by the weighted mean (taking into account a small correlation between two participants) in the case of consistent results. Otherwise the Procedure B of Cox was used. The expanded uncertainties of all reference densities are below 1 × 10−5 in relative terms. This satisfies the needs of all customers who wish to calibrate or check liquid density measuring instruments such as oscillation-type density meters. The comparison fully supports the calibration measurement capabilities table in the BIPM key comparison database. The results can be used to link regional comparisons to this CCM key comparison. DA - 2013 PY - 2013 PB - IOP Science LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0097c54e-c23f-4b6c-a882-356450c2a92e ER - TY - JOUR TI - Evaluation of systematic shifts of the 88Sr+ single-ion optical frequency standard at the 10−17 level DO - 10.1103/PhysRevA.87.023806 AU - Dube, Pierre AU - Madej, Alan A. AU - Zhou, Zichao AU - Bernard, John E. T2 - Physical Review A VL - 87 IS - 2 SP - 023806-1 EP - 023806-18 AB - An ion trap of the end-cap design was built recently at the National Research Council of Canada for improved control of the 88Sr+ single-ion optical frequency standard systematic shifts. The uncertainty on the micromotion-induced shifts is smaller by more than four orders of magnitude when compared to our previous trap system and reaches a fractional frequency uncertainty of 1×10−18. To obtain this low uncertainty level, the micromotion is minimized with trim electrodes and the trap is operated at a special frequency at which there is anticorrelation between the second-order Doppler and Stark shifts. This choice of operating frequency, determined by the differential scalar polarizability of the clock transition, yields a suppression by a factor of ≈28 in the combined micromotion shifts. Like many optical frequency standards, the dominant source of uncertainty in the new trap is the blackbody radiation shift. Its uncertainty has been reduced by an order of magnitude with a recent theoretical evaluation of the differential scalar polarizability of the clock transition. The fractional blackbody shift uncertainty, estimated using a model of the blackbody field at the ion, is 2.2×10−17. The otherwise dominant electric quadrupole shift is reduced to below the 3×10−19 level with a cancellation method based on the average frequency of several pairs of Zeeman components. This method also cancels the tensor Stark shift and simplifies the description of the frequency shifts that are quantization-axis dependent. This paper provides a detailed description of the 88Sr+ optical frequency standard uncertainty evaluation and the methods used to make the standard robust against changes in the trap environment. The total fractional frequency uncertainty of the 88Sr+ ion for our current system is estimated at 2.3×10−17. We also discuss the uncertainty evaluation of a recently reported measurement of the 88Sr+ S-D clock transition made over a 2-month period by comparison with a maser referenced to the SI second. The frequency measured is 444 779 044 095 485.5(9) Hz, with an uncertainty limited by the evaluation of the maser frequency. DA - 2013/02/07 PY - 2013 PB - American Physical Society LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : cf335c08-3cd0-4559-b882-dfa165491d01 ER - TY - JOUR TI - Low-frequency quantum-based AC Power Standard at NRC Canada DO - 10.1109/CPEM.2012.6250924 AU - Djokic, Branislav T2 - 2012 Conference on Precision Electromagnetic Measurements (CPEM 2012) T2 - CPEM Digest T3 - 2012 Conference on Precision Electromagnetic Measurements (CPEM), 1-6 July 2012, Washington, DC, USA SN - 0589-1485 SN - 978-1-4673-0442-9 SP - 306 EP - 307 KW - AC power standard; programmable Josephson Voltage Standard; inductive voltage dividers; current transformers; calibration AB - A low-frequency AC Power Standard based on the Programmable Josephson Voltage Standard (PJVS) has been developed at the National Research Council (NRC) of Canada. At the step voltages, PJVS provides quantum accuracy. Differential digital sampling is used to extend the quantum accuracy to the AC Power Standard output voltage and current, nominally 120 V and 5 A. The paper describes the evaluation of the power standard and its components. DA - 2013/03/07 PY - 2013 PB - IEEE LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : c84a7029-df85-4f43-88c4-7db2321f056e ER - TY - JOUR TI - Discovery of gymnodimine fatty acid ester metabolites in shellfish using liquid chromatography/mass spectrometry DO - 10.1002/rcm.6491 AU - de la Iglesia, P. AU - McCarron, P. AU - Diogene, J. AU - Quilliam, M. A. T2 - Rapid Communications in Mass Spectrometry VL - 27 IS - 5 SP - 643 EP - 653 AB - Gymnodimines (GYMs) are fast-acting toxins that belong to the cyclic imine group, a subclass of lipophilic marine toxins. GYMs are considered to be emerging toxins but have not yet been linked to incidents of human poisoning, Limited knowledge on the metabolism of GYMs means that a proper risk assessment has not been possible and caution must be taken when establishing the relevance of GYMs in terms of food safety of marine products. DA - 2013/02/15 PY - 2013 PB - Wiley LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : fbb78987-9147-4c00-ba17-0178be70b6d3 ER - TY - JOUR TI - 14N overtone NMR spectra under magic angle spinning : experiments and numerically exact simulations DO - 10.1063/1.4775592 AU - O'Dell, Luke A. AU - Brinkmann, Andreas T2 - The Journal of Chemical Physics VL - 138 IS - 6 SP - 064201-1 EP - 064201-10 AB - It was recently shown that high resolution 14N overtone NMR spectra can be obtained directly under magic angle spinning (MAS) conditions [L. A. O’Dell and C. I. Ratcliffe, Chem. Phys. Lett. 514, 168 (2011)]10.1016/j.cplett.2011.08.030. Preliminary experimental results showed narrowed powder pattern widths, a frequency shift that is dependent on the MAS rate, and an apparent absence of spinning sidebands, observations which appeared to be inconsistent with previous theoretical treatments. Herein, we reproduce these effects using numerically exact simulations that take into account the full nuclear spin Hamiltonian. Under sample spinning, the 14N overtone signal is split into five (0, ±1, ±2) overtone sidebands separated by the spinning frequency. For a powder sample spinning at the magic angle, the +2ωr sideband is dominant while the others show significantly lower signal intensities. The resultant MAS powder patterns show characteristic quadrupolar lineshapes from which the 14N quadrupolar parameters and isotropic chemical shift can be determined. Spinning the sample at other angles is shown to alter both the shapes and relative intensities of the five overtone sidebands, with MAS providing the benefit of averaging dipolar couplings and shielding anisotropy. To demonstrate the advantages of this experimental approach, we present the 14N overtone MAS spectrum obtained from L-histidine, in which powder patterns from all three nitrogen sites are clearly resolved. DA - 2013/02/11 PY - 2013 PB - AIP Publishing LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : a417f055-9223-4cbc-83e5-9de05409b249 ER - TY - JOUR TI - Atmospheric plasma sprayed Forsterite (Mg2SiO4) coatings : an investigation of the processing-microstructure-performance relationship DO - 10.1007/s11666-012-9856-9 AU - Cojocaru, C. V. AU - Lamarre, J.-M. AU - Legoux, J.-G. AU - Marple, B. R. T2 - Journal of Thermal Spray Technology VL - 22 IS - 2-3 SP - 145 EP - 151 KW - coefficient of thermal expansion KW - dielectric coatings KW - dielectric strength KW - forsterite KW - plasma-spray AB - Evaluating and understanding the relationship between processing, microstructure and performance of a dielectric coating is essential for its practical usage and reliable application. In this study, the role of the powder feedstock on the properties of atmospheric plasma sprayed forsterite (Mg₂SiO₄) dielectric coatings was investigated by using different forsterite powder granulometries. The microstructural and porosity characteristics of the coatings associated with the spray conditions employed were assessed via scanning electron microscopy (SEM) and image analysis. The phase composition of the coatings was studied via x-ray diffraction and their crystallinity index determined. The electrical insulating characteristics were investigated using the dielectric breakdown test and impedance spectroscopy measurements. The electrical properties obtained were correlated with the microstructural characteristics and a performance comparison between forsterite and other dielectric coatings is presented. DA - 2013/03/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 0b345b47-e97c-4a8e-a32a-3f68163938e9 ER - TY - CHAP TI - Reptation model for the dynamics and rheology of particle reinforced polymer chains DO - 10.1002/9783527644346.ch4 AU - Mittal, Vikas AU - Kabanemi, Kalonji K. AU - Hétu, Jean-François T2 - Modeling and Prediction of Polymer Nanocomposite Properties SN - 9783527331505 SN - 9783527644346 SP - 63 EP - 94 KW - Polymer-particle energetic interaction KW - reptation model KW - mean-square displacement (MSD) KW - Rouse relaxation time KW - polymer dynamics KW - Rouse relaxation DA - 2013/01/17 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d1c3a634-691b-4bca-a636-310b6e8b5d5d ER - TY - JOUR TI - Cold spray forming of Inconel 718 DO - 10.1007/s11666-012-9827-1 AU - Wong, W. AU - Irissou, É. AU - Vo, P. AU - Sone, M. AU - Bernier, F. AU - Legoux, J.-G. AU - Fukanuma, H. AU - Yue, S. T2 - Journal of Thermal Spray Technology VL - 22 IS - 2-3 SP - 413 EP - 421 KW - coatings for engine components KW - cold spray KW - cold gas dynamic spraying KW - Inconel KW - mechanical properties KW - spray forming AB - Inconel 718 was cold spray formed to a 6-mm thickness on an 8-cm diameter aluminum alloy tube using Sulzer Amdry 1718 powder and the Plasma Giken PCS-1000 cold spray system. The effects of spray particle velocity and post-spray heat treatment were studied. Post-spray annealing was performed from 950 to 1250ºC for 1-2 h. The resulting microstructures as well as the corresponding mechanical properties were characterized. As-sprayed coatings exhibited very low ductility. The tensile strength and ductility of the heat-treated coatings were improved to varying levels depending on the heat-treatment and spray conditions. For coatings sprayed at higher particle velocity and heat treated at 1250ºC for 1 h, an elongation of 24% was obtained. SEM micrographs showed a higher fraction of interparticle metallurgical bonds due to some sintering effect. Corresponding fracture surfaces also revealed a higher fraction of dimple features, typically associated with ductile fracture, in the annealed coatings. The results demonstrate that cold spray forming of Inconel 718 is feasible, and with appropriate heat treatment, metallurgical bonding can be increased. The ductility of the spray-formed samples was comparable to that of the bulk material. DA - 2013/03/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : bb38c60f-1b20-445a-9f2d-095c07788298 ER - TY - JOUR TI - A new interface element with progressive damage and osseointegration for modeling of interfaces in hip resurfacing DO - 10.1177/0954411912471494 AU - Caouette, Christiane AU - Bureau, Martin N. AU - Lavigne, Martin AU - Vendittoli, Pascal-André AU - Nuño, Natalia T2 - Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine VL - 227 IS - 3 SP - 209 EP - 220 KW - Bone-implant interface KW - bone-cement interface KW - hip resurfacing prosthesis KW - biomimetic composite material KW - finite element analysis AB - Finite element models of orthopedic implants such as hip resurfacing femoral components usually rely on contact elements to model the load-bearing interfaces that connect bone, cement and implant. However, contact elements cannot simulate progressive degradation of bone–cement interfaces or osseointegration. A new interface element is developed to alleviate these shortcomings. This element is capable of simulating the nonlinear progression of bone–cement interface debonding or bone–implant interface osseointegration, based on mechanical stimuli in normal and tangential directions. The new element is applied to a hip resurfacing femoral component with a stem made of a novel biomimetic composite material. Three load cases are applied sequentially to simulate the 6-month period required for osseointegration of the stem. The effect of interdigitation depth of the bone–cement interface is found to be negligible, with only minor variations of micromotions. Numerical results show that the biomimetic stem progressively osseointegrates (α averages 0.7 on the stem surface, with spot-welds) and that bone–stem micromotions decrease below 10 µm. Osseointegration also changes the load path within the femoral bone: a decrease of 300 µε was observed in the femoral head, and the inferomedial part of the femoral neck showed a slight increase of 165 µε. There was also increased stress in the implant stem (from 7 to 11 MPa after osseointegration), indicating that part of the load is supported through the stem. The use of the new osseointegratable interface element has shown the osseointegration potential of the biomimetic stem. Its ability to model partially osseointegrated interfaces based on the mechanical conditions at the interface means that the new element could be used to study load transfer and osseointegration patterns on other models of uncemented hip resurfacing femoral components. DA - 2013/01/11 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 770d2f4b-3fce-4408-a515-875363a4aa2f ER - TY - JOUR TI - A new osseointegratable and damageable interface element for modeling of bone implant and bone-cement interface AU - Caouette, Christiane AU - Bureau, Martin AU - Vendittoli, Pascal-André AU - Lavigne, Martin AU - Nuño, Natalia T2 - EORS 2012 Amsterdam : European Orthopaedic Research Society 20th Annual Meeting Proceedings T2 - EORS Transactions; 20 T3 - European Orthopaedic Research Society 20th Annual Meeting (EORS 2012), 26-28 September 2012, Amsterdam, Netherlands SP - PB19 AB - We propose a new robust modeling method for the finite element modeling of load-transmitting bone-cement and bone-implant interfaces. This new modeling method allows simulation of osseointegration and progressive debonding. DA - 2013/09/28 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 6b8380bc-46dc-4be5-aa86-b967e9665635 ER - TY - JOUR TI - Engineering HVOF-Sprayed Cr3C2-NiCr coatings : the effect of particle morphology and spraying parameters on the microstructure, properties, and high temperature wear performance DO - 10.1007/s11666-012-9833-3 AU - Poirier, Dominique AU - Legoux, Jean-Gabriel AU - Lima, Rogerio S. T2 - Journal of Thermal Spray Technology VL - 22 IS - 2-3 SP - 280 EP - 289 KW - Chromium carbide KW - high temperature wear KW - HVOF KW - microstructure KW - sliding wear testing KW - spray parameters AB - Chromium carbide-based thermally sprayed coatings are widely used for high temperature wear applications (typical temperature range from 540 to 900ºC). In these extreme environments at those temperatures, several phenomena will degrade, oxidize, and change the microstructure of the coatings, thereby affecting their wear behavior. Although it can be easily conceived that the Cr₃C₂-NiCr coating microstructure evolution after high temperature exposure will depend on the as-sprayed microstructure and spraying parameters, very little has been done in this regard. This study intends to develop a better understanding of the effect of spraying parameters on the resulting chromium carbide coating microstructure after high temperature operation and high temperature sliding wear properties. The microstructures of different coatings produced from two morphologies of Cr₃C₂-NiCr powders and under a window of in-flight particle temperature and velocity values were characterized through x-ray diffraction and scanning electron microscopy. Sliding wear at 800ºC was performed and the wear behavior correlated with the spraying parameters and coating microstructure. Vickers microhardness (300 gf) of the coatings before and after sliding wear was also measured. DA - 2013/03/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 935c0d24-7d9d-44e8-bea3-08673c179bce ER - TY - JOUR TI - Nurses' perceptions and attitudes towards new ADU technology and use DO - 10.3233/THF-2012-120708 AU - Sirois, Pascal AU - Fournier, Helene AU - Lebouthilier, Annette AU - Guerette-Daigle, Lise AU - Robichaud, Suzanne AU - Leblanc-Cormier, Gaetane AU - Molyneaux, Heather AU - O'Donnell, Susan AU - Mather, Lyndsay T2 - Technology and Health Care SN - 0928-7329 VL - 21 IS - 1 SP - 41 EP - 47 KW - new technology; healthcare; medication distribution AB - BACKGROUND: The introduction of a new technology in hospitals – Automated Dispensing Units (ADUs) –aims to contribute to more secure, safe, efficient and cost effective health services. Several studies highlight the beneficial effects of similar technologies as well as their cost-savings potential but there is little literature exploring nurses’ perceptions and attitudes towards technology acceptance and the impact on technology use in a healthcare unit. OBJECTIVE: This research aimed to explore nurses’ perceptions and attitudes towards current technology use on their units and towards the introduction of ADU technology and use with nursing staff in two different hospitals in South-East New-Brunswick, Canada. METHODS: Semi-structured interviews were realized with the collaboration of nursing staff from two hospitals which were in urban and rural settings, prior to the introduction of ADUs in hospital wards. RESULTS: Findings in this study highlight the fact that missing medications (i.e., doses not available in cart) are inherently related to the completion of nursing staff’s medication distribution routine. Missing doses cause delays in medication delivery which may increase the occurrence of medication errors. Participants described current technology use as an intricate part of their routine. The latter is mainly utilized for patient monitoring and information retrieval. Overall, interview data indicated that ADU technology introduction is positively perceived by nursing staff particularly if the technology reduces missing doses events. CONCLUSIONS: Findings in this study underscore important concerns expressed by nursing staff regarding ADU technology integration into the current medication process and its impact on time management. Pre-implementation training and technical support were identified as important factors in facilitating technology acceptance and proper technology use. DA - 2013/01 PY - 2013 PB - IOS LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 96f0827c-5a47-4cc4-a9f4-bbf3e8d1bba2 ER - TY - JOUR TI - The detailed scattering density profile model of PG bilayers as determined by molecular dynamics simulations, and small-angle neutron and x-ray scattering experiments DO - 10.1016/j.bpj.2011.11.2764 AU - Kucerka, Norbert AU - Holland, Bryan AU - Pan, Jianjun AU - Heberle, Frederick A. AU - Gray, Chris G. AU - Tomberli, Bruno AU - Katsaras, John T2 - Biophysical Journal T3 - Biophysical Society 56th Annual Meeting, 25-29 February 2012, San Diego, California, USA SN - 0006-3495 VL - 102 IS - 3 Supplement 1 SP - 504a EP - 505a DA - 2013/01/31 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e566fac4-58ae-4a33-a05e-7ec240a428c2 ER - TY - JOUR TI - Molecular structure of phosphatidylglycerol bilayers : fluid phase lipid areas and bilayer thicknesses as a function of temperature DO - 10.1016/j.bpj.2011.11.2763 AU - Pan, Jianjun AU - Heberle, Frederick AU - Kucerka, Norbert AU - Tristram-Nagle, Stephanie AU - Szymanski, Michelle AU - Koepfinger, Mary AU - Katsaras, John T2 - Biophysical Journal T3 - Biophysical Society 56th Annual Meeting, 25-29 February 2012, San Diego, California, USA SN - 0006-3495 VL - 102 IS - 3 Supplement 1 SP - 504a AB - We have determined bilayer structural parameters of commonly used phosphatidylglycerols (PGs) in the fluid phase, by simultaneously analyzing small-angle neutron and X-ray scattering data. We report the temperature dependence of bilayer parameters obtained using the scattering density profile (SDP) model, including the area per lipid and overall bilayer thickness, as well as various intrabilayer structural parameters (e.g. hydrocarbon region thickness). Lipid areas were found to be larger than their neutral phosphatidylcholine (PC) counterparts, which is likely due to electrostatic repulsion of PG headgroups. In general, PG and PC bilayers show a similar response to changes in temperature and chain length, but a differential effect is observed with regard to chain unsaturation: the inclusion of a double bond in a PG lipid results in a smaller change in bilayer area and thickness than for the corresponding PC lipid. The extrapolated molecular area of saturated PG lipids at infinite chain length is similar to that of PC and PE, indicating the pivotal role of the glycerol-carbonyl backbone in shaping the lipid-water interface. DA - 2013/01/31 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 7bda8bd7-242e-403b-a4f6-2b33cef57359 ER - TY - JOUR TI - Evolution of strain and microstructure during creep of wrought AE42 and ZE10 magnesium alloys DO - 10.1007/s12666-012-0200-3 AU - Fletcher, M. AU - Sebert-Timmer, A. AU - Bichler, L. AU - Sediako, D. T2 - Transactions of the Indian Institute of Metals SN - 0972-2815 VL - 66 IS - 2 SP - 133 EP - 140 AB - Wrought magnesium alloys have been extensively used in the aerospace, electronics and automotive industries, where component weight is of concern and ambient temperatures remain below 100 °C. Undesirable creep relaxation of the wrought alloys above this temperature has been generally attributed to grain boundary sliding and plastic deformation leading to intergranular failure. The objective of this study was to investigate the compressive creep performance and microstructure of two wrought magnesium alloys (AE42 and ZE10) developed for high temperature applications. The total deformation of the AE42 and ZE10 alloys was 2.4 and 0.2 %, respectively, after 24 h creep test at 175 °C and 50 MPa. The poor creep performance of the AE42 alloy was explained via neutron diffraction studies which revealed that the elastic compressive response of (101 ¯ 0),(101 ¯ 1)and(21 ¯ 1 ¯ 0) planes was significantly more anisotropic in the AE42 than in the ZE10 alloy. Further, microstructural analysis revealed ~10 % increase in grain size due to creep, with additional (101 ¯ 2) and (112 ¯ 1) twinning in the AE42 alloy. Precipitation of β-Mg17Al12 phase in the AE42 alloy possibly contributed to grain boundary sliding and high plastic strain during creep testing. DA - 2013/04/01 PY - 2013 PB - Springer LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 98adfb19-b7a1-49be-8a5d-106fc92adf94 ER - TY - JOUR TI - Cognitive modelling of early music reading skill acquisition for piano : a comparison of the Middle-C and Intervallic methods DO - 10.1016/j.cogsys.2012.12.007 AU - Emond, Bruno AU - Comeau, Gilles T2 - Cognitive Systems Research SN - 1389-0417 VL - 24 SP - 26 EP - 34 KW - music reading; Middle-C method; Intervallic method; computer simulation; ACT-R AB - In the classical music tradition, knowing how to read music is an essential skill and is seen as a fundamental component to develop when learning to play the piano. This research’s focus is to study the possible impact of two different teaching approaches to the acquisition of initial reading skills. By using cognitive modeling, we are hoping to observe through computer simulation the problem solving and decision-making tasks involved in decoding a simple musical score. Our model intends to capture a novice initial coordination of music reading and motor operations on a piano keyboard. As such, it does not aim at modelling advanced sight-reading skills. The paper introduces the Middle-C and Intervallic methods followed by a description of an ACT-R cognitive model and simulation results upon learning with each of the reading methods. Inspection of the simulation results reveals differences in terms of declarative memory and cognitive processing demands. In particular, the Intervallic method requires a larger number of declarative knowledge related to notes, and more execution planning than the Middle-C method. DA - 2013/01/12 PY - 2013 PB - Elsevier LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : de2fe345-6493-4162-8990-624df8057c0f ER - TY - CHAP TI - A fuzzy logic-based approach to uncertainty treatment in the rule interchange format: from encoding to extension DO - 10.1007/978-3-642-35975-0_11 AU - Zhao, Jidi AU - Boley, Harold AU - Dong, Jing T2 - Uncertainty Reasoning for the Semantic Web II : International Workshops URSW 2008-2010 Held at ISWC and UniDL 2010 Held at FLoC, Revised Selected Papers T2 - Lecture Notes In Computer Science; 7123 T3 - 4th International Workshop on Uncertainty Reasoning for the Semantic Web (URSW), to be held as part of the 7th International Semantic Web Conference (ISWC), October 26-30, 2008, Karlsruhe, Germany; 5th International Workshop on Uncertainty Reasoning for the Semantic Web (URSW), to be held as part of the 8th International Semantic Web Conference (ISWC), October 25-29, 2009, Washington, D.C. USA; 6th International Workshop on Uncertainty Reasoning for the Semantic Web (URSW-10), to be held as part of the 9th international semantic web conference November 7-11, 2010, Shanghai, China; or presented at the First International Workshop on Uncertainty in Description Logics (UniDL 2010) in July 20‚ 2010, Edinburgh‚ UK. SN - 0302-9743 SN - 978-3-642-35974-3 SN - 978-3-642-35975-0 SP - 197 EP - 216 KW - fuzzy logic; knowledge management; linked data; ontology learning; probability theory AB - The Rule Interchange Format (RIF) is a W3C recommendation that allows rules to be exchanged between rule systems. Uncertainty is an intrinsic feature of real world knowledge, hence it is important to take it into account when building logic rule formalisms. However, the set of truth values in the RIF Basic Logic Dialect (RIF-BLD) currently consists of only two values (t and f), although the RIF Framework for Logic Dialects (RIF-FLD) allows for more. In this paper, we first present two techniques of encoding uncertain knowledge and its fuzzy semantics in RIF-BLD presentation syntax. We then propose an extension leading to an Uncertainty Rule Dialect (RIF-URD) to support a direct representation of uncertain knowledge. In addition, rules in Logic Programs (LP) are often used in combination with the other widely-used knowledge representation formalism of the Semantic Web, namely Description Logics (DL), in many application scenarios of the Semantic Web. To prepare DL as well as LP extensions, we present a fuzzy extension to Description Logic Programs (DLP), called Fuzzy DLP, and discuss its mapping to RIF. Such a formalism not only combines DL with LP, as in DLP, but also supports uncertain knowledge representation. DA - 2013 PY - 2013 PB - Springer Berlin Heidelberg LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d016e61a-7236-421e-8ee1-60d96cc1008d ER - TY - JOUR TI - Iterative classification for multiple target attributes DO - 10.1007/s10844-012-0224-5 AU - Guo, Hongyu AU - Létourneau, Sylvain T2 - Journal of Intelligent Information Systems SN - 0925-9902 VL - 40 IS - 2 SP - 283 EP - 305 KW - multi-target learning ; multitask learning ; iterative classification ; data mining AB - Many real-world applications require the simultaneous prediction of multiple target attributes. The techniques currently available for these problems either employ a global model that simultaneously predicts all target attributes or rely on the aggregation of individual models, each predicting one target. This paper introduces a novel solution. Our approach employs an iterative classification strategy to exploit the relationships among multiple target attributes to achieve higher accuracy. The computation scheme is developed as a wrapper in which many standard single-target classification algorithms can be simply “plugged-in” to simultaneously predict multiple targets. An empirical evaluation using eight data sets shows that the proposed method outperforms 1) an approach that constructs independent classifiers for each target, 2) a multitask neural network method, and 3) ensembles of multi-objective decision trees in terms of simultaneously predicting all target attributes correctly. DA - 2013/04/01 PY - 2013 PB - Springer US LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : ff6b32a6-a0ca-45bf-ad71-ba54d7acd766 ER - TY - JOUR TI - Face recognition using histograms of fuzzy oriented gradients AU - Salhi, Abdel Ilah AU - Kardouchi, Mustapha AU - Belacel, Nabil T2 - Proceedings of International Conference on Computer Applications Technology ICCAT' 2013 T3 - International Conference on Computer Applications Technology ICCAT’ 2013, 20-22 January 2013, Sousse, Tunisia KW - fuzzy sets; HOG; HFOG; face recognition; feature dimension AB - Efficient face descriptors require a careful equilibration between accuracy and feature dimension. In recent years Histogram of Oriented Gradient (HOG) starts to be used in the face recognition task. However the best recognition rate for HOG requires a high dimensional feature. In this paper, we will incorporate fuzzy concept to HOG aiming to achieve a good recognition rate with a low feature vector dimension. The proposed Histogram of Fuzzy Oriented Gradient will be applied to the face recognition task. Experimental results on ORL database show that HFOG outperforms the standard HOG in terms of recognition rate with a lower dimensional vector. DA - 2013/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : f6594e0d-b5cd-4ad8-b034-89b43bde732f ER - TY - JOUR TI - State of the art review of inspection technologies for condition assessment of water pipes DO - 10.1016/j.measurement.2012.05.032 AU - Liu, Zheng AU - Kleiner, Yehuda T2 - Measurement SN - 02632241 VL - 46 IS - 1 SP - 1 EP - 15 KW - Pipe condition assessment; Distress indicator; Deterioration; Non-destructive inspection AB - This paper reviews the state-of-the-art of inspection techniques and technologies towards condition assessment of water distribution and transmission mains. Pipe condition assessment is the determination of its current condition, including structural health, impact on water quality, and hydraulic capacity. The collection and analysis of relevant data and information is the first and a paramount step to detect and monitor critical indicators to prevent or mitigate catastrophic failures. The technologies include conventional non-destructive inspection and advanced sensor techniques for condition monitoring. This paper focuses on the inspection techniques and technologies for structural deterioration of water pipes. Technologies like smart pipe, augmented reality, and intelligent robots are also briefly discussed and summarized. DA - 2013/01/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : cc5c29ab-c163-48db-b879-ef23568426b7 ER - TY - JOUR TI - Practical correlations for the thermal resistance of vertical enclosed airspaces for building applications DO - 10.1016/j.buildenv.2012.09.003 AU - Saber, Hamed H. T2 - Building and Environment VL - 59 SP - 379 EP - 396 KW - Reflective insulation; furred-airspace assembly; low emissivity material; thermal modelling; thermal resistance test method; R-value; heat flow meter; ASTM C-518; ASTM C-1363; airflow; heat transfer by convection; conduction and radiation AB - Many parts of the building envelope contain enclosed airspaces. The thermal resistance (R-value) of an enclosed airspace depends on the emissivity of all surfaces that bound the airspace, the size and orientation of the airspace, the direction of heat transfer through the airspace, and the respective temperatures of all surfaces that define the airspace. The 2009 ASHRAE Handbook of Fundamentals (Chapter 26) provides a table that contains the R-values for an enclosed airspace. The ASHRAE table is extensively used by modelers, architects and building designers in the design of building enclosures. This table provides R-values for enclosed airspaces for different values of the thickness of the airspace, effective emittance, mean airspace temperature, and temperature differences across the airspace. The effect of the airspace aspect ratio (height/thickness of airspace) on the R-value is not included in the ASHRAE table. However, in a recent study on the R-value of reflective insulations using a numerical simulation model, it was shown that the aspect ratio of the airspace can affect the R-value of the enclosed airspace. The numerical simulation model used in this study had been benchmarked against experimental data obtained using two standard test methods: ASTM C-518 and ASTM C-1363. In this paper, a numerical simulation study was conducted, that was based on previous work focused on enclosed airspaces, to investigate the effect of the aspect ratio on the R-value of vertical enclosed airspaces of different thicknesses and having a wide range of values for effective emittance, mean temperature, and temperature differences across the airspace. The R-values predicted from numerical simulation are compared with those provided in the ASHRAE table. Considerations were also given to investigating the potential increase in R-values of enclosed airspaces when a thin sheet is placed vertically in the middle of the airspace and whose surfaces have different values of emissivity. Finally, practical correlations are developed for determining the R-values of an enclosed airspace for future use by modelers, architects and building designers. The simplicity of these correlations suggests that these could be included in the ASHRAE Handbook of Fundamentals. DA - 2013/01/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 47acb711-21f6-416b-a3b9-3b4cd69a71b3 ER - TY - JOUR TI - Convective heat transfer correlations for low-profile spherical cavities with planar bottom surfaces (1415-RP) DO - 10.1080/10789669.2012.730856 AU - Saber, Hamed H. AU - Laouadi, Abdelaziz AU - Galasiu, Anca D. AU - Arsenault, Chantal T2 - HVAC and R Research SN - 1938-5587 SN - 1078-9669 VL - 19 IS - 1 SP - 10 EP - 23 KW - Heat transfer by conduction; convection and radiation; skylight devices; heat transfer correlations; Nusselt number; spherical cavities AB - Domed cavities are found in many building applications, such as conventional skylights and tubular daylighting devices. Heat transfer through domed cavities is thus an important parameter for evaluating the energy performance rating of such skylight systems and in calculating the heating and cooling loads of buildings. Although there have been many studies on the convective heat transfer in related geometries, there is a limited information on natural convective heat transfer in domed cavities with planar inner surfaces. In a previous study, numerical modeling was conducted on natural laminar convective heat transfer in horizontal high-profile domed cavities with planar inner surfaces. In this article, the previous study is extended to investigate the natural convective heat transfer in horizontal low-profile spherical cavities with planar inner surfaces. The bounding surfaces are subject to uniform temperature conditions. The numerical model is based on the finite-element method. The results show that for different boundary temperature conditions, the airflow in the cavities is mono-cellular and reaches steady-state conditions for both cold and hot weather conditions. The numerical results are used to develop practical correlations for the Nusselt number in terms of Rayleigh number. DA - 2013/01/10 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : e4be978e-99a2-4d09-b815-44e250513a24 ER - TY - JOUR TI - Development of a graphite probe calorimeter for absolute clinical dosimetry DO - 10.1118/1.4773870 AU - Renaud, James AU - Marchington, David AU - Seuntjens, Jan AU - Sarfehnia, Arman T2 - Medical Physics VL - 40 IS - 2 SP - 020701-1 EP - 020701-6 KW - graphite calorimetry; reference dosimetry; heat transfer modeling; proof of concept; absolute dosimetry AB - The aim of this work is to present the numerical design optimization, construction, and experimental proof of concept of a graphite probe calorimeter (GPC) conceived for dose measurement in the clinical environment (U.S. provisional patent 61/652,540). A finite element method (FEM) based numerical heat transfer study was conducted using a commercial software package to explore the feasibility of the GPC and to optimize the shape, dimensions, and materials used in its design. A functioning prototype was constructed inhouse and used to perform dose to water measurements under a 6MV photon beam at 400 and 1000 MU/min, in a thermally insulated water phantom. Heat loss correction factors were determined using FEM analysis while the radiation field perturbation and the graphite to water absorbed dose conversion factors were calculated using Monte Carlo simulations. The difference in the average measured dose to water for the 400 and 1000 MU/min runs using the TG-51 protocol and the GPC was 0.2% and 1.2%, respectively. Heat loss correction factors ranged from 1.001 to 1.002, while the product of the perturbation and dose conversion factors was calculated to be 1.130. The combined relative uncertainty was estimated to be 1.4%, with the largest contributors being the specific heat capacity of the graphite (type B, 0.8%) and the reproducibility, defined as the standard deviation of the mean measured dose (type A, 0.6%). By establishing the feasibility of using the GPC as a practical clinical absolute photon dosimeter, this work lays the foundation for further device enhancements, including the development of an isothermal mode of operation and an overall miniaturization, making it potentially suitable for use in small and composite radiation fields. It is anticipated that, through the incorporation of isothermal stabilization provided by temperature controllers, a subpercent overall uncertainty will be achieved. DA - 2013/01/09 PY - 2013 PB - American Association of Physicists in Medicine LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 90c136f3-9a78-4116-b7d1-e379c3882eef ER - TY - JOUR TI - First report of Pn-Li₂MnSiO₄ synthesized by ion exchange AU - Duncan, Hugues AU - Kondamreddy, Abhinay AU - Mercier, Patrick H. J. AU - Le Page, Yvon AU - Abu-Lebdeh, Yaser AU - Couillard, Martin AU - Whitfield, Pamela S. AU - Davidson, Isobel J. T2 - Batteries and Energy Technology (General) - 221st ECS Meeting T2 - ECS Transactions; 45 T2 - ECS Meeting Abstracts; 29 T3 - 221st meeting of the Electrochemical Society, B1 - Batteries and Energy Technology Joint General Session, May 6-11 2012, Seattle, Washington, USA SN - 1938-6737 SN - 1938-5862 SN - 2151-2043 SN - 2151-2041 SN - 9781623320522 DA - 2013/10/22 PY - 2013 PB - Electrochemical Society LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 3840bd5e-73cb-44f3-ac92-21c2bdeb9b75 ER - TY - JOUR TI - Three-dimensional human shape inference from silhouettes: reconstruction and validation DO - 10.1007/s00138-011-0353-9 AU - Boisvert, Jonathan AU - Shu, Chang AU - Wuhrer, Stefanie AU - Xi, Pengcheng T2 - Machine Vision and Applications VL - 24 IS - 1 SP - 145 EP - 157 KW - human models KW - statistical prior KW - shape-from-silhouettes KW - three-dimensional reconstruction AB - Silhouettes are robust image features that provide considerable evidence about the three-dimensional (3D) shape of a human body. The information they provide is, however, incomplete and prior knowledge has to be integrated to reconstruction algorithms in order to obtain realistic body models. This paper presents a method that integrates both geometric and statistical priors to reconstruct the shape of a subject assuming a standardized posture from a frontal and a lateral silhouette. The method is comprised of three successive steps. First, a non-linear function that connects the silhouette appearances and the body shapes is learnt and used to create a first approximation. Then, the body shape is deformed globally along the principal directions of the population (obtained by performing principal component analysis over 359 subjects) to follow the contours of the silhouettes. Finally, the body shape is deformed locally to ensure it fits the input silhouettes as well as possible. Experimental results showed a mean absolute 3D error of 8 mm with ideal silhouettes extraction. Furthermore, experiments on body measurements (circumferences or distances between two points on the body) resulted in a mean error of 11 mm. DA - 2013/06/01 PY - 2013 PB - Springer-Verlag LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : 2997d980-4568-411d-92ac-214d4f062503 ER - TY - JOUR TI - Seasonal freeze resistance of rainbow smelt (Osmerus mordax) is generated by differential expression of glycerol-3 phospahte dehydrogenase, phosoenol pyruvate carboxykinase and antifreeze protein genes DO - 10.1086/499981 AU - Liebscher, Ryan S. AU - Richards, Robert C. AU - Lewis, Johanne M. AU - Short, Connie E. AU - Muise, Denise M. AU - Driedzic, William R. AU - Ewart, K. Vanya T2 - Physiological and Biochemical Zoology VL - 79 IS - 2 SP - 411 EP - 423 KW - antifreeze KW - proteins KW - gene expression regulation KW - genetics KW - glycerolphosphate KW - dehydrogenase KW - osmeriformes KW - osmeriformes metabolism KW - phosphoenolpyruvate KW - GTP KW - carboxykinase KW - seasons AB - In winter, rainbow smelt (Osmerus mordax) accumulate glycerol and produce an antifreeze protein (AFP), which both contribute to freeze resistance. The role of differential gene expression in the seasonal pattern of these adaptations was investigated. First, cDNAs encoding smelt and Atlantic salmon (Salmo salar) phosphoenolpyruvate carboxykinase (PEPCK) and smelt glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were cloned so that all sequences required for expression analysis would be available. Using quantitative PCR, expression of beta actin in rainbow smelt liver was compared with that of GAPDH in order to determine its validity as a reference gene. Then, levels of glycerol-3-phosphate dehydrogenase (GPDH), PEPCK, and AFP relative to beta actin were measured in smelt liver over a fall-winter-spring interval. Levels of GPDH mRNA increased in the fall just before plasma glycerol accumulation, implying a driving role in glycerol synthesis. GPDH mRNA levels then declined during winter, well in advance of serum glycerol, suggesting the possibility of GPDH enzyme or glycerol conservation in smelt during the winter months. PEPCK mRNA levels rose in parallel with serum glycerol in the fall, consistent with an increasing requirement for amino acids as metabolic precursors, remained elevated for much of the winter, and then declined in advance of the decline in plasma glycerol. AFP mRNA was elevated at the onset of fall sampling in October and remained elevated until April, implying separate regulation from GPDH and PEPCK. Thus, winter freezing point depression in smelt appears to result from a seasonal cycle of GPDH gene expression, with an ensuing increase in the expression of PEPCK, and a similar but independent cycle of AFP gene expression. DA - 2013/02/01 PY - 2013 LA - eng C1 - Collection / Collection : NRC Publications Archive / Archives des publications du CNRC C2 - Record identifier / Identificateur de l’enregistrement : d3aeec66-1020-42cf-b7f1-f176c40c4495 ER -