MBE growth of THz quantum cascade lasers - Wasilewski, Z.R. (Molecular Beam Epitaxy, 2013)

Study on the measurement of soot particle size by laser induced incandescence - Li, H.-M.; He, X.; Zheng, L.; Liu, F.-S.; Wang, J.-X. (Kung Cheng Je Wu Li Hsueh Pao/Journal of Engineering Thermophysics, 2013)
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.
Keywords: Coflow diffusion flames; Laser induced incandescence; Laser-based techniques; Particle diameters; Primary particle size; Soot concentration; Soot measurement; Transmission electron microscope; Particle size; Soot; Transmission electron microscopy; Dust

Zero-energy states of graphene triangular quantum dots in a magnetic field - Güçlü, A.D.; Potasz, P.; Hawrylak, P. (Physical Review B - Condensed Matter and Materials Physics, 2013)
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.

Cancer systems biology in the genome sequencing era: Part 2, evolutionary dynamics of tumor clonal networks and drug resistance - Wang, E.; Zou, J.; Zaman, N.; Beitel, L.K.; Trifiro, M.; Paliouras, M. (Seminars in Cancer Biology, 2013)
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.
Keywords: bioinformatics; cancer resistance; carcinogenesis; computer analysis; gene duplication; gene regulatory network; gene sequence; genetic association; genetic heterogeneity; genome analysis; genomics; human; malignant neoplastic disease; molecular cloning; molecular dynamics; molecular model; mutational analysis; nonhuman; review; RNA sequence; signal transduction; systems biology; tumor microenvironment

Atomic weights of the elements 2011 (IUPAC technical report) - Wieser, M.E.; Holden, N.; Coplen, T.B.; Böhlke, J.K.; Berglund, M.; Brand, W.A.; De Bièvre, P.; Gröning, M.; Loss, R.D.; Meija, J.; Hirata, T.; Prohaska, T.; et al. (Pure and Applied Chemistry, 2013)
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.
Keywords: Atomic weights; Atomic-weight intervals; Atomic-weight ranges; Conventional atomic-weight values; Half lives; Iupac inorganic chemistry divisions; Atoms; Bromine; Germanium; Indium; Inorganic compounds; Magnesium; Mercury (metal); Chemical elements

Espectrómetro de transformada de fourier implementado mediante guías de onda en espiral con base de silicio - Velasco, Aitor V.; Cheben, Pavel; Bock, Przemek; Schmid, Jens H.; Lapointe, Jean; Delâge, André; Janz, Siegfried; Calvo, María L.; Xu, Dan-Xia; Florjańczyk, Mirosław (Optica Pura y Aplicada, 2013)
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.

Detection of carbon monoxide and water absorption lines in an exoplanet atmosphere - Konopacky, Q.M.; Barman, T.S.; Macintosh, B.A.; Marois, C. (Science, 2013)
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.
Keywords: carbon dioxide; carbon monoxide; water; absorption; astronomy; atmospheric chemistry; atmospheric structure; carbon monoxide; chemical composition; gravity field; oxygen; planetary atmosphere; planetary evolution; spectral analysis; water; article; astronomy; atmosphere; chemical composition; cloud; energy; gravity; light; light scattering; mass; priority journal; signal noise ratio; temperature; water absorption; Atmosphere; Carbon Monoxide; Evolution, Planetary; Extraterrestrial Environment; Gravitation; Planets; Spectrum Analysis; Water

Electronic temperature in phonon-photon-phonon terahertz quantum cascade devices with high-operating temperature performance - Scamarcio, G.; Patimisco, P.; Santacroce, M. V.; Tempesta, P.; Spagnolo, V.; Vitiello, M. S.; Dupont, E.; Fathololoumi, S.; Laframboise, S. R.; Razavipour, S. G.; Wasilewski, Z.; Ban, D.; et al. (Quantum Sensing and Nanophotonic Devices X, 2013)
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.
Keywords: Band-to-band photoluminescence; Electronic distribution; Electronic temperature; Experimental measurements; Lasing conditions; Quantum-cascade devices; Temperature performance; Terahertz quantum-cascade lasers; Cascade connections; Nanophotonics; Photoluminescence; Photoluminescence spectroscopy; Photons; Semiconductor quantum wells; Phonons

Separation of rare oligodendrocyte progenitor cells from brain using a high-throughput multilayer thermoplastic-based microfluidic device - Didar, T.F.; Li, K.; Veres, T.; Tabrizian, M. (Biomaterials, 2013)
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.
Keywords: Cell sorting; Central nervous systems; Cutting edge technology; Membrane pore size; Micro-fluidic devices; Oligodendrocytes; Regenerative medicine; Separation efficiency; Cell culture; Fluidic devices; Multilayers; Reinforced plastics; Repair; Stem cells; Separation; myelin; animal cell; article; brain tissue; cell culture; cell differentiation; cell population; cell separation; cell size; cell viability; controlled study; flow rate; glia cell; in vitro study; microfluidics; nonhuman; oligodendrocyte progenitor cell; priority journal; rabbit; stem cell; Rattus

High resolution infrared spectra of H2-Xe and D2-Xe van der Waals complexes - McKellar, A.R.W. (Canadian Journal of Physics, 2013)
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.
Keywords: Experimental benchmarks; Fourier transform infrared spectrometer; High spectral resolution; High-resolution infrared spectra; Intermolecular potential energy; Low temperatures; Stretching vibrations; Van der Waals complex; Fourier transform infrared spectroscopy; Hydrogen; Spectral resolution; Stretching; Van der Waals forces

The complex nature of the nuclear star cluster in FCC 277 - Lyubenova, M.; van den Bosch, R.C.E.; Côté, P.; Kuntschner, H.; van de Ven, G.; Ferrarese, L.; Jordán, A.; Infante, L.; Peng, E.W. (Monthly Notices of the Royal Astronomical Society, 2013)
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.

Considerations for the wind tunnel simulation of tractor-trailer combinations: Correlation of full- and half-scale measurements - Leuschen, J. (SAE International Journal of Commercial Vehicles, 2013)
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.
Keywords: Commercial trucks; Drag curves; Flow regimes; Full-scale testing; National Research Council; Test sections; Wind-tunnel simulation; Yaw angles; Automobile testing; Computer simulation; Reynolds number; Tractors (agricultural); Tractors (truck); Truck trailers; Wind tunnels

Methane production from the microalga Scenedesmus sp. AMDD in a continuous anaerobic reactor - Tartakovsky, B.; Matteau-Lebrun, F.; McGinn, P.J.; O'Leary, S.J.B.; Guiot, S.R. (Algal Research, 2013)
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.

High-level semi-synthetic production of the potent antimalarial artemisinin - Paddon, C.J.; Westfall, P.J.; Pitera, D.J.; Benjamin, K.; Fisher, K.; McPhee, D.; Leavell, M.D.; Tai, A.; Main, A.; Eng, D.; Polichuk, D.R.; Teoh, K.H.; et al. (Nature, 2013)
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.
Keywords: artemisinin; singlet oxygen; antimalarial agent; biological production; disease treatment; enzyme activity; malaria; yeast; article; chemical reaction; derivatization; drug potency; esterification; expressed sequence tag; extractive fermentation; fed batch fermentation; fermentation; open reading frame; oxidative stress; photochemistry; priority journal; protein expression; stereochemistry; Antimalarials; Artemisinins; Biosynthetic Pathways; Biotechnology; Fermentation; Genetic Engineering; Malaria, Falciparum; Molecular Sequence Data; Saccharomyces cerevisiae; Singlet Oxygen; Artemisia annua; Artesunate; Plasmodium falciparum; Saccharomyces cerevisiae

Optical fiber interferometer array for scanless Fourier-transform spectroscopy - Velasco, Aitor V.; Cheben, Pavel; Florjańczyk, Mirosław; Schmid, Jens H.; Bock, Przemek J.; Lapointe, Jean; Delâge, André; Janz, Siegfried; Vachon, Martin; Calvo, María L.; Xu, Dan-Xia; Civiš, Svatopluk (Optics Letters, 2013)
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.
Keywords: Fourier transform spectrometers; Fourier transform spectroscopy; Ideal behavior; Optical fiber interferometers; Resolution limits; Scanning elements; Spatial heterodyne; Spectral inversion; Fourier transform infrared spectroscopy; Interferometers; Optical fibers; Optical fiber fabrication

Comparison of metrics to monitor and compensate for piezoceramic debonding in structural health monitoring - Mulligan, K.R.; Quaegebeur, N.; Ostiguy, P.-C.; Masson, P.; Létourneau, S. (Structural Health Monitoring, 2013)
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.
Keywords: Frequency domains; Health monitoring; Lumped parameter models; Mechanical resonance frequency; Piezoceramic; Piezoceramic transducer; Received signals; Resonance frequencies; Adhesives; Damping; Degradation; Electric admittance; Natural frequencies; Piezoelectric ceramics; Piezoelectric transducers; Structural health monitoring

Lipid reassembly in asymmetric Langmuir-Blodgett/Langmuir-Schaeffer bilayers - Yuan, J.; Hao, C.; Chen, M.; Berini, P.; Zou, S. (Langmuir, 2013)
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.
Keywords: 1 ,2-dioleoyl-sn-glycero-3-phosphocholine; AFM; Bi-layer; Binary lipid mixtures; Contrast changes; Domain structure; Dye molecule; Fluid-phase; Force mapping; Gel domains; Gel phase; Glass substrates; Image contrasts; Langmuir-blodgett; Lipid molecules; Multimodal imaging; Novel route; Phase segregations; Reassembly; Rupture forces; Single components; Solid-liquid interfaces; Structure dependent; Ternary mixtures; TIRF imaging; Total internal reflection fluorescence microscopy; Amino acids; Atomic force microscopy; Binary mixtures; Fluorescence; Mica; Molecules; Refractive index; Substrates; Lipid bilayers; aluminum silicate; glass; lipid; mica; article; atomic force microscopy; chemistry; lipid bilayer; Aluminum Silicates; Glass; Lipid Bilayers; Lipids; Microscopy, Atomic Force

Abundant cyanopolyynes as a probe of infall in the Serpens South cluster-forming region - Friesen, R. K.; Medeiros, L.; Schnee, S.; Bourke, T. L.; Di Francesco, J.; Gutermuth, R.; Myers, P. C. (Monthly Notices of the Royal Astronomical Society, 2013)
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.
Keywords: Astrochemistry; Star formation; ISM abundances; ISM radio lines

BigBrain: An ultrahigh-resolution 3D human brain model - Amunts, K.; Lepage, C.; Borgeat, L.; Mohlberg, H.; Dickscheid, T.; Rousseau, M.-É.; Bludau, S.; Bazin, P.-L.; Lewis, L.B.; Oros-Peusquens, A.-M.; Shah, N.J.; Lippert, T.; et al. (Science, 2013)
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.
Keywords: brain; histology; hominid; hypothesis testing; numerical model; article; brain; brain mapping; brain region; human; human tissue; model; neuroanatomy; primary motor cortex; priority journal; simulation; tissue section; ultrahigh resolution three dimensional model; Aged; Brain; Brain Mapping; Cerebral Cortex; Female; Humans; Image Processing, Computer-Assisted; Imaging, Three-Dimensional; Magnetic Resonance Imaging; Microtomy

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 - Ryden, P.; Twine, S.; Shen, H.; Harris, G.; Chen, W.; Sjostedt, A.; Conlan, W. (Molecular Immunology, 2013)
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.
Keywords: cytokine; francisella tularensis vaccine; gamma interferon; live vaccine; monocyte chemotactic protein 1; tumor necrosis factor alpha; unclassified drug; animal cell; animal experiment; animal model; animal tissue; antibody response; article; bacterial immunity; bacterial strain; drug mechanism; female; Francisella tularensis; gene deletion; immune response; immunization; mouse; nonhuman; nucleotide sequence; priority journal; Administration, Cutaneous; Administration, Inhalation; Animals; Bacterial Vaccines; Female; Francisella tularensis; Gene Deletion; Immunity; Immunity, Innate; Mice; Mice, Inbred BALB C; Organisms, Genetically Modified; Tularemia; Vaccination; Virulence; Bacteria (microorganisms); Francisella; Francisella tularensis; Mus

Fully automatic expression-invariant face correspondence - Salazar, A.; Wuhrer, S.; Shu, C.; Prieto, F. (Machine Vision and Applications, 2013)
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.

HTC scientific computing in a distributed cloud environment - Sobie, R.; Agarwal, A.; Gable, I.; Leavett-Brown, C.; Paterson, M.; Taylor, R.; Charbonneau, A.; Impey, R.; Podiama, W. (ScienceCloud 2013 - Proceedings of the 4th ACM Workshop on Scientific Cloud Computing, 2013)
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.
Keywords: Computing capacity; Computing system; Design and implementations; Distributed clouds; High-throughput computing; Scientific applications; Cloud computing; Infrastructure as a service (IaaS); Distributed computer systems

Theoretical and experimental insights into applicability of solid-state 93Nb NMR in catalysis - Papulovskiy, E.; Shubin, A.A.; Terskikh, V.V.; Pickard, C.J.; Lapina, O.B. (Physical Chemistry Chemical Physics, 2013)
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.

Ground-state 12CO emission and a resolved jet at 115GHz (rest frame) in the radio-loud quasar 3C 318 - Heywood, I.; Martínez-Sansigre, A.; Willott, C.J.; Rawlings, S. (Monthly Notices of the Royal Astronomical Society, 2013)
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.

The physico-mechanical stability of C-S-H/polyaniline nanocomposites - Khoshnazar, R.; Alizadeh, R.; Beaudoin, J.J.; Raki, L. (Materials and Structures/Materiaux et Constructions, 2013)
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.

Altruism during predation in an assassin bug - Dejean, A.; Revel, M.; Azémar, F.; UPS, INP; Roux, O. (Naturwissenschaften, 2013)
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.
Keywords: altruism; ant; cannibalism; conspecific; egg; feeding; host plant; hunger; insect; myrmecophyte; predation; prey capture; prey size; shelter; Allomerus decemarticulatus; Drosera; Hexapoda; Hirtella physophora; Reduviidae; Zelus

Transgenic production of omega-3 very long chain polyunsaturated fatty acids in plants: Accomplishment and challenge - Chen, Y.; Meesapyodsuk, D.; Qiu, X. (Biocatalysis and Agricultural Biotechnology, 2013)
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.

Femtosecond laser desorption of thin polymer films from a dielectric surface - Mercadier, L.; Peng, J.; Sultan, Y.; Rayner, D.M.; Corkum, P.B. (CLEO: Science and Innovations, CLEO_SI 2013, 2013)
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.
Keywords: Beam geometry; Dielectric surface; Thin polymer films; Two ways; Atomic force microscopy; Semiconducting films; Ultrashort pulses; Polymer films

Enhancement of amorphous phase formation in alumina-YSZ coatings deposited by suspension plasma spray process - Tarasi, F.; Medraj, M.; Dolatabadi, A.; Oberste-Berghaus, J.; Moreau, C. (Surface and Coatings Technology, 2013)
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.
Keywords: Alumina-YSZ; Amorphous phase; Amorphous phase formation; Ceramic composites; In-flight particle characteristics; Influence of spray parameters; Larger particle sizes; Suspension plasma sprays; Alumina; Coatings; Deposition; Plasma jets; Plasma spraying; Preheating; Amorphous materials

Learning in the presence of large fluctuations : a study of aggregation and correlation - Paquet, Eric; Viktor, Herna Lydia; Guo, Hongyu (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, 2013)
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.
Keywords: Analysis of data; Average values; Central Limit Theorem; Correlation-based Analysis and Covariance; Financial Data Analysis; Relational learning; Set of rules; Stable distributions; Database systems; Oil spills; Gaussian distribution

Metallic transfer films studied in situ and ex situ: The case of cold-sprayed Al-Al2O3 - Michael Shockley, J.; Descartes, S.; Irissou, E.; Legoux, J.-G.; Chromik, R.R. (Tribology and Lubrication Technology, 2013)
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.
Keywords: Cold-sprayed; Ex situ analysis; Metallic transfers; Nano-structured; Nanocrystalline aluminum; Transfer film; Tribological performance; Wear tracks; Composite coatings; Mechanical properties; Aluminum

Dependence of the triple point temperature of neon on isotopic composition and its implications for the ITS-90 - Pavese, F.; Steur, P.P.M.; Hermier, Y.; Hill, K.D.; Kim, J.S.; Lipiński, L.; Nagao, K.; Nakano, T.; Peruzzi, A.; Sparasci, F.; Szmyrka-Grzebyk, A.; Tamura, O.; et al. (TEMPERATURE: ITS MEASUREMENT AND CONTROL IN SCIENCE AND INDUSTRY, VOLUME 8: Proceedings of the Ninth International Temperature Symposium, 2013)
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.

Effect of nucleation and plasticization on the stereocomplex formation between enantiomeric poly(lactic acid)s - Saeidlou, S.; Huneault, M.A.; Li, H.; Park, C.B. (Polymer (United Kingdom), 2013)
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.
Keywords: Crystalline morphologies; Crystallization behavior; Heterogeneous nucleation; High melting point; Isothermal crystallization temperature; Spherulitic morphology; Stereocomplex formation; Stereocomplexes; Blending; Complexation; Crystallization kinetics; Differential scanning calorimetry; Lactic acid; Morphology; Optical data storage; Optical microscopy; Polypropylenes; Nucleation

Centrifugation-induced water-tunable photonic colloidal crystals with narrow diffraction bandwidth and highly sensitive detection of SCN- - Ma, C.; Jiang, Y.; Yang, X.; Wang, C.; Li, H.; Dong, F.; Yang, B.; Yu, K.; Lin, Q. (ACS Applied Materials and Interfaces, 2013)
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.
Keywords: Colloidal crystals; Electromagnetic spectra; Highly sensitive detections; Ion detection; Narrow size distributions; Photonic bandgap (PBG); Polymeric microsphere; Stimuli-responsive; Centrifugation; Diffraction; Hydrogen bonds; Hydrophilicity; Ions; Microspheres; Polymers; Polystyrenes; Self assembly; Spontaneous emission; Hydrogels

Simulation of conjugate heat transfer using the Lattice Boltzmann Method - Tarokh, A.; Mohamad, A.A.; Jiang, L. (Numerical Heat Transfer; Part A: Applications, 2013)
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.
Keywords: Cold streams; Computational domains; Conjugate heat transfer; Energy equation; Extended surfaces; Finite thermal conductivity; Finite thickness; Fluid phasis; Lattice Boltzmann method; Lattice boltzmann methods (LBM); Rate of heat transfer; Two-stream; Heat transfer; Computational fluid dynamics

Polymer peel-off mask for high-resolution surface derivatization, neuron placement and guidance - Martinez, Dolores; Py, Christopher; Denhoff, Mike; Monette, Robert; Comas, Tanya; Krantis, Anthony; Mealing, Geoffrey (Biotechnology and Bioengineering, 2013)
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.
Keywords: chemical patterning; process guidance; dry lift-off; neural network

Rearrangements and addition reactions of biarylazacyclooctynones and the implications to copper-free click chemistry - Chigrinova, M.; McKay, C.S.; Beaulieu, L.-P.B.; Udachin, K.A.; Beauchemin, A.M.; Pezacki, J.P. (Organic and Biomolecular Chemistry, 2013)
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.
Keywords: Bio-conjugation; Copper-free clicks; Highly strained; Living systems; Tetracyclic products; Chemistry; Positive ions; Addition reactions

Effect of duty cycle and applied current frequency on plasma electrolytic oxidation (PEO) coating growth behavior - Dehnavi, V.; Luan, B.L.; Shoesmith, D.W.; Liu, X.Y.; Rohani, S. (Surface and Coatings Technology, 2013)
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 .
Keywords: Alkaline electrolytes; Concentration distributions; Duty cycle; Electrical parameter; Elemental distribution; Frequency; Plasma electrolytic oxidation; Pulsed direct current; Aluminum; Ceramic coatings; Energy dispersive spectroscopy; Oxidation; Plasmas; Scanning electron microscopy; Electrolysis

Comparison of realizations of Re-C fixed points filled and measured at NPL and NRC - Todd, A.D.W.; Lowe, D.H.; Dong, W.; Woods, D.J. (TEMPERATURE: ITS MEASUREMENT AND CONTROL IN SCIENCE AND INDUSTRY, VOLUME 8: Proceedings of the Ninth International Temperature Symposium, 2013)
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.

Isometrically invariant description of deformable objects based on the fractional heat equation - Paquet, Eric; Viktor, Herna Lydia (Computer Analysis of Images and Patterns : 15th International Conference, CAIP 2013, York, UK, August 27-29, 2013, Proceedings, Part II, 2013)
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.
Keywords: Fractional; Heat equation; Isometry; Kernel; Path integral; Geometry; Heat transfer; Image analysis; Random processes; Partial differential equations

Performance of thermally sprayed Si/mullite/BSAS environmental barrier coatings exposed to thermal cycling in water vapor environment - Cojocaru, C.V.; Lévesque, D.; Moreau, C.; Lima, R.S. (Surface and Coatings Technology, 2013)
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; 0<x<1) crack-resistant and water vapor attack resistant top coat. In this study, fully crystalline air plasma sprayed Si/mullite/BSAS-celsian EBCs were engineered under controlled conditions on SiC substrates. The influence of water vapor corrosion on the structural and mechanical properties of a Si/Mullite/BSAS EBC architecture was assessed by furnace thermal cycle testing (i.e.; 50 and 100cycles, 2h/cycles at 1300°C in water vapor atmosphere). The elastic modulus values of the as-sprayed BSAS top coat (~75±6GPa as determined via indentation) did not exhibit major changes after thermal exposure (~78±8GPa). In addition, the BSAS layer exhibited crack healing at high temperatures, the density of cracks decreasing from 15cracks/cm in the as-sprayed state to 2cracks/cm after thermal cycling. These characteristics of the BSAS top coat were related to its glass-ceramic nature, the phase/chemical stabilities of the BSAS-celsian at high temperatures and the engineered deposition conditions at which it was deposited. The overall performance at high-temperature of this functionally graded EBC architecture is discussed and correlated to its microstructural characteristics. © 2012.
Keywords: Air plasma sprayed; Bond coats; BSAS; Controlled conditions; Crack-healing; Crack-resistant; Deposition conditions; Elastic modulus values; Environmental barrier coatings; Functionally graded; High temperature; High temperature structural applications; High-temperature water; Hot zone; Influence of water; Microstructural characteristics; SiC substrates; Silicon-based ceramics; Structural and mechanical properties; Thermal cycle testing; Thermal exposure; Top-coats; Water vapor atmosphere; Aluminosilicates; Ceramic matrix composites; Cracks; Elastic moduli; Gas turbines; High temperature applications; Signal encoding; Silicate minerals; Silicon; Silicon carbide; Thermal barrier coatings; Thermal cycling; Vapors; Sprayed coatings

Photonic wire biosensor microarray chip and instrumentation with application to serotyping of Escherichia coli isolates - Janz, S.; Xu, D.-X.; Vachon, M.; Sabourin, N.; Cheben, P.; McIntosh, H.; Ding, H.; Wang, S.; Schmid, J.H.; Delâge, A.; Lapointe, J.; Densmore, A.; et al. (Optics Express, 2013)
A complete photonic wire molecular biosensor microarray chip architecture and supporting instrumentation is described. Chip layouts with 16 and 128 independent sensors have been fabricated and tested, where each sensor can provide an independent molecular binding curve. Each sensor is 50 μm in diameter, and consists of a millimeter long silicon photonic wire waveguide folded into a spiral ring resonator. An array of 128 sensors occupies a 2 × 2 mm2 area on a 6 × 9 mm2 chip. Microfluidic sample delivery channels are fabricated monolithically on the chip. The size and layout of the sensor array is fully compatible with commercial spotting tools designed to independently functionalize fluorescence based biochips. The sensor chips are interrogated using an instrument that delivers sample fluid to the chip and is capable of acquiring up to 128 optical sensor outputs simultaneously and in real time. Coupling light from the sensor chip is accomplished through arrays of sub-wavelength surface grating couplers, and the signals are collected by a fixed two-dimensional detector array. The chip and instrument are designed so that connection of the fluid delivery system and optical alignment are automated, and can be completed in a few seconds with no active user input. This microarray system is used to demonstrate a multiplexed assay for serotyping E. coli bacteria using serospecific polyclonal antibody probe molecules. © 2013 Optical Society of America.
Keywords: Biosensor microarrays; Chip layout; Coupling light; Delivery channels; E. coli; Fluid delivery; Fully compatible; Independent sensors; Molecular binding; Molecular biosensors; Optical alignments; Photonic wires; Polyclonal antibody; Probe molecules; Real time; Ring resonator; Sensor chips; Serotyping; Silicon photonic wires; Sub-wavelength; Surface grating couplers; Two-dimensional detectors; User input; Bioassay; Biochips; Escherichia coli; Instruments; Two dimensional; Sensors

Unraveling the internal dynamics of the benzene dimer: A combined theoretical and microwave spectroscopy study - Schnell, M.; Erlekam, U.; Bunker, P.R.; Von Helden, G.; Grabow, J.-U.; Meijer, G.; Van Der Avoird, A. (Physical Chemistry Chemical Physics, 2013)
We report a combined theoretical and microwave spectroscopy study of the internal dynamics of the benzene dimer, a benchmark system for dispersion forces. Although the extensive ab initio calculations and experimental work on the equilibrium geometry of this dimer have converged to a tilted T-shaped structure, the rich internal dynamics due to low barriers for internal rotation have remained largely unexplored. We present new microwave spectroscopy data for both the normal (C6H6)2 and partially deuterated (C6D6)(C6H6) dimers. The splitting patterns obtained for both species are unraveled and understood using a reduced-dimensionality theoretical approach. The hindered sixfold rotation of the stem can explain the observed characteristic 1:2:1 tunneling splitting pattern, but only the concerted stem rotation and tilt tunneling motion, accompanied by overall rotation of the dimer, yield the correct magnitude of the splittings and their strong dependence on the dimer angular momentum J that is essential to explain the experimental data. Also the surprising observation that the splittings are reduced by 30% for the mixed (C6D 6)C(C6H6)S dimer in which only the cap (C) in the T-shaped structure is deuterated, while the rotating stem (S) monomer is the same as in the homodimer, is understood using this approach. Stark shift measurements allowed us to determine the dipole moment of the benzene dimer, μ = 0.58 ± 0.051 D. The assumption that this dipole moment is the vector sum of the dipole moments induced in the monomers by the electric field of the quadrupole on the other monomer yields a calculated value of μ = 0.63 D. Furthermore, the observed Stark behavior is typical for a symmetric top, another confirmation of our analysis. © 2013 the Owner Societies.

Graphene-based inkjet printing of flexible bioelectronic circuits and sensors - Sinar, D.; Knopf, G.K.; Nikumb, S. (SPIE - International Society for Optical Engineering. Proceedings, 2013)
Bioelectronics involves interfacing functional biomolecules or living cells with electronic circuitry. Recent advances in electrically conductive inks and inkjet printing technologies have enabled bioelectronic devices to be fabricated on mechanically flexible polymers, paper and silk. In this research, non-conductive graphene-oxide (GO) inks are synthesized from inexpensive graphite powders. Once printed on the flexible substrate the electrical conductivity of the micro-circuitry can be restored through thermal reduction. Laser irradiation is one method being investigated for transforming the high resistance printed GO film into conductive oxygen reduced graphene-oxide (rGO). Direct laser writing is a precision fabrication process that enables the imprinting of conductive and resistive micro-features on the GO film. The mechanically flexible rGO microcircuits can be further biofunctionalized using molecular self-assembly techniques. Opportunities and challenges in exploiting these emerging technologies for developing biosensors and bioelectronic cicruits are briefly discussed. © 2013 Copyright SPIE.
Keywords: Electrical conductivity; Electrically conductive inks; Emerging technologies; Ink-jet printing technologies; Molecular self assembly; Oxygen Reduction; Precision fabrication; Thermal reduction; Biosensors; Composite micromechanics; Electric conductivity; Electrolytic reduction; Flexible electronics; Ink jet printing; Microanalysis; Microfabrication; Micromachining; Technology; Graphene

Inner ensembles : using ensemble methods inside the learning algorithm - Abbasian, Houman; Drummond, Chris; Japkowicz, Nathalie; Matwin, Stan (Machine Learning and Knowledge Discovery in Databases : European Conference, ECML PKDD 2013, Prague, Czech Republic, September 23-27, 2013, Proceedings, Part III, 2013)
Ensemble Methods represent an important research area within machine learning. Here, we argue that the use of such methods can be generalized and applied in many more situations than they have been previously. Instead of using them only to combine the output of an algorithm, we can apply them to the decisions made inside the learning algorithm, itself. We call this approach Inner Ensembles. The main contribution of this work is to demonstrate how broadly this idea can applied. Specifically, we show that the idea can be applied to different classes of learner such as Bayesian networks and K-means clustering. © 2013 Springer-Verlag.
Keywords: Comprehensibility; Different class; Ensemble methods; Inner Ensembles; K-means; K-means clustering; Bayesian networks; Learning systems; Learning algorithms

Expression of human rotavirus chimeric fusion proteins from replicating but non disseminating adenovectors and elicitation of rotavirus-specific immune responses in mice - Girard, A.; Roques, E.; St-Louis, M.-C.; Massie, B.; Archambault, D. (Molecular Biotechnology, 2013)
The aim of this study was to evaluate the usefulness of replicating but non disseminating adenovirus vectors (AdVs) as vaccine vector using human rotavirus (HRV) as a model pathogen. HRV VP7, VP4, or VP4Δ (N-terminal 336 amino acids of VP4) structural proteins as well as the VP4Δ::VP7 chimeric fusion protein were expressed in mammalian cells when delivered with the AdVs. A preliminary experiment demonstrated that VP4Δ was able to induce a HRV-specific IgG response in BALB/c mice inoculated intramuscularly with AdVs expressing the rotaviral protein. Moreover, an AdV-prime/plasmid DNA-boost regimen of vectors resulted in VP4Δ-specific antibody (Ab) titers ~4 times higher than those obtained from mice immunized with AdVs alone. Subsequently, the various HRV protein-encoding AdVs were compared using the AdV-prime/plasmid DNA-boost regimen. Higher IgG and IgA responses to HRV were obtained when VP4Δ::VP7 fusion protein was used as an immunogen as compared to VP7 or VP4 alone or to a mix of both proteins delivered independently by AdVs. A synergetic effect in terms of Ab was obtained with VP4Δ::VP7. In conclusion, this study demonstrated for the first time the suitability of using replicating but non disseminating AdVs as vaccine vector and the VP4Δ::VP7 fusion protein as an immunogen for vaccination against HRV. © 2013 Springer Science+Business Media New York.
Keywords: Immunogenicity; Neutralizing antibodies; Replicating but non disseminating adenovectors; Rotaviruses; VP4; VP7; Amino acids; Antibodies; Vaccines; Vectors; Viruses; Mammals; adenovirus vector; chimeric protein; immunoglobulin A; immunoglobulin G; plasmid DNA; protein VP4; protein VP7; virus fusion protein; animal experiment; article; controlled study; female; human; human cell; Human rotavirus; immune response; immunogenicity; lymphocyte; lymphocyte proliferation; mammal cell; mouse; nonhuman; nucleotide sequence; protein expression; virus expression; Adenoviridae; Analysis of Variance; Animals; Antibodies, Neutralizing; Antigens, Viral; Capsid Proteins; Cell Line, Tumor; Female; Genetic Vectors; Humans; Mice; Mice, Inbred BALB C; Recombinant Fusion Proteins; Rotavirus; Rotavirus Infections; Rotavirus Vaccines; Transfection; Adenoviridae; Human rotavirus A; Mammalia; Mus; Rotavirus

Colonization of gerbils with Helicobacter pylori O-chain-deficient mutant SS1 HP0826:: Kan results in gastritis and is associated with de novo synthesis of extended homopolymers - Chandan, V.; Jeremy, A.H.T.; Dixon, M.F.; Altman, E.; Crabtree, J.E. (Pathogens and Disease, 2013)
The O-chain polysaccharide of Helicobacter pylori is important for colonization and generation of chronic gastritis in mice. There are marked host differences in the development of H. pylori-induced gastric pathology in mice and gerbils. To investigate the role of the O-chain polysaccharide of H. pylori in colonization and gastritis in Mongolian gerbils, inoculation by oral gavage with H. pylori strain SS1 and its corresponding O-chain polysaccharide-deficient mutant SS1 HP0826::Kan was undertaken. Infection with both strains resulted in corpus atrophy, loss of parietal cells, and extensive mucous metaplasia at both 18 and 30 weeks postinfection. Contrary to previous results in splenocyte recipient severe combined immunodeficiency (SCID) mice, no difference was found in the grade of chronic gastritis, polymorphonuclear cell infiltration, atrophy, and mucous metaplasia in gerbils infected with the wild-type SS1 strain or SS1 HP0826::Kan strain. Examination of the effects of gerbil passage on LPS profiles of output SS1 HP0826::Kan isolates by SDS-PAGE, sugar, and methylation analyses revealed significant differences in LPS profiles of SS1 HP0826::Kan cells recovered from infected gerbils as compared to input bacteria. Specifically, the presence of a novel homopolymer of d-galactan, as well as an extended polymer of d-riban, was detected. These data provide evidence for the role of H. pylori LPS in bacterial adaption to promote colonization and pathology. © 2013 Federation of European Microbiological Societies.
Keywords: bacterium lipopolysaccharide; galactan; O antigen; adaptation; animal experiment; animal model; animal tissue; article; bacterial colonization; bacterial strain; bacterium isolation; bacterium mutant; cell infiltration; cell loss; chronic gastritis; controlled study; disease association; gerbil; Helicobacter infection; Helicobacter pylori; histopathology; inoculation; male; metaplasia; methylation; nonhuman; polyacrylamide gel electrophoresis; polymorphonuclear cell; priority journal; stomach atrophy; stomach parietal cell; wild type; Animals; Carbohydrate Sequence; Electrophoresis, Polyacrylamide Gel; Gastric Mucosa; Gastritis; Gerbillinae; Helicobacter Infections; Helicobacter pylori; Male; Mutation; O Antigens; Stomach

Droplet dynamics in controlled InAs nanowire interconnections - Dalacu, D.; Kam, A.; Austing, D.G.; Poole, P.J. (Nano Letters, 2013)
Semiconductor nanowires offer a versatile platform for the fabrication of new nanoelectronic and nanophotonic devices. These devices will require a high level of control of the nanowire position in relation to both other components of the device and to other nanowires. We demonstrate unprecedented control of the position of InAs nanowires using selective-area vapor-liquid-solid epitaxy (VLS) on an InP ridge template. The high level of control allows us to design structures which connect individual nanowires through coalescence of their catalyst particles. The interconnection process acts as a perturbation to the geometry of the nanowire system that can contribute to the understanding of droplet dynamics in VLS growth. Postgrowth imaging reveals a complex sequence of droplet configurations, including predicted geometries that have not previously been observed. © Published 2013 by the American Chemical Society.
Keywords: Catalyst particles; Complex sequences; Design structure; Nanophotonic devices; Selective-area epitaxy; Semiconductor nanowire; Vapor-liquid-solid epitaxies; VLS; Coalescence; Drops; Epitaxial growth; Nanophotonics; Semiconductor devices; Nanowires

New developments with the SEED technology - Côté, P.; Larouche, M.; Chen, X.G. (Diffusion and Defect Data Pt.B: Solid State Phenomena, 2013)
The SEED technology is a commercially available rheocasting process used in the production of high quality semi-solid slurries. The process, which is currently used in the foundry industry, is still actively developed and fully supported by a team of scientists, engineers and technicians. In the later years, works were conducted toward optimizing the process and equipment. At first, the focus was on developing a simplified version of the SEED process to eliminate the so-called "drainage" phase while preserving the prime quality of the slurry produced. Improvement of some system components and integration of new features were also targeted to secure the overall equipment efficiency (OEE) and increase the process reliability. This work, backed with the optimization of process parameters and comprehensive techniques adapted for semi-solid casting, led to the consolidation and even improvement of the properties of the parts produced for common foundry alloys as 356/357 and 319. Furthermore, the non-drained SEED version was applied to the validation of the process capabilities for uncommon cast alloys, with works on AA6061 wrought alloys, high strength 206 cast alloys and Duralcan metal matrix composites. The results confirmed that the SEED process can efficiently be used in non-drained mode and achieve the same quality of slurry as the drained-mode version originally developed. © (2013) Trans Tech Publications, Switzerland.
Keywords: Cast alloys; Foundry alloys; Foundry industries; High quality; High strength; Metal matrix composites; Optimization of process parameters; Overall equipment efficiency; Process capabilities; Process reliability; Rheocasting process; SEED process; Semi solid casting; Semi-solid forming; Semi-solid slurry; System components; Wrought alloys; Agriculture; Foundries; Metallic matrix composites; Optimization; Rheocasting; Slurries; High strength alloys

Electrochemical characterisation of a lithium-ion battery electrolyte based on mixtures of carbonates with a ferrocene-functionalised imidazolium electroactive ionic liquid - Forgie, J.C.; El Khakani, S.; MacNeil, D.D.; Rochefort, D. (Physical Chemistry Chemical Physics, 2013)
Electrolytic solutions of lithium-ion batteries can be modified with additives to improve their stability and safety. Electroactive molecules can be used as such additives to act as an electron (redox) shuttle between the two electrodes to prevent overcharging. The electroactive ionic liquid, 1-ferrocenylmethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide (TFSI), was synthesised and its electrochemical properties were investigated when diluted with ethylene carbonate-diethyl carbonate solvent at various concentrations. Cyclic voltammetry data were gathered to determine the redox potential, diffusion coefficient and heterogeneous rate constants of the electroactive imidazolium TFSI ionic liquid in the carbonate solution. The properties of this molecule as an additive in lithium battery electrolytes were studied in standard coin cells with a metallic Li anode and a Li 4Ti5O12 cathode. © the Owner Societies 2013.

The effects of ground simulation on tractor-trailer combinations - Leuschen, J. (SAE International Journal of Commercial Vehicles, 2013)
The 9-meter wind tunnel of the National Research Council (NRC) of Canada is equipped with a boundary layer suction system, center belt and wheel rollers to simulate ground motion relative to test articles. Although these systems were originally commissioned for testing of full-scale automotive models, they are appropriately sized for ground simulation with half-scale tractor-trailer combinations. The size of the tunnel presents an opportunity to test half-scale commercial vehicles at full-scale Reynolds numbers with a model that occupies 3% of the test section cross-sectional area. This study looks at the effects of ground simulation on the force and pressure data of a half-scale model with rotating tractor wheels. A series of model changes, typical of a drag reduction program, were undertaken and each configuration was tested with both a fixed floor and with full-ground simulation to evaluate the effects of this technology on the total and incremental drag coefficients. The question was whether ground simulation affected predictions of the drag change due to typical model changes. Effects of the ground simulation were further considered by employing wheel rotation or the center belt alone. This was undertaken to determine whether a simplified ground simulation system would suffice for commercial vehicle testing. Copyright © 2013 SAE International.
Keywords: Automotive models; Boundary layer suction; Cross sectional area; Ground motions; National Research Council; Simulation systems; Test sections; Typical model; Automobiles; Commercial vehicles; Reynolds number; Software testing; Tractors (agricultural); Tractors (truck); Truck trailers; Wheels; Wind tunnels; Computer simulation

Indirect dynamics in a highly exoergic substitution reaction - Mikosch, J.; Zhang, J.; Trippel, S.; Eichhorn, C.; Otto, R.; Sun, R.; De Jong, W.A.; Weidemüller, M.; Hase, W.L.; Wester, R. (Journal of the American Chemical Society, 2013)
The highly exoergic nucleophilic substitution reaction F- + CH3I shows reaction dynamics strikingly different from that of substitution reactions of larger halogen anions. Over a wide range of collision energies, a large fraction of indirect scattering via a long-lived hydrogen-bonded complex is found both in crossed-beam imaging experiments and in direct chemical dynamics simulations. Our measured differential scattering cross sections show large-angle scattering and low product velocities for all collision energies, resulting from efficient transfer of the collision energy to internal energy of the CH3F reaction product. Both findings are in strong contrast to the previously studied substitution reaction of Cl - + CH3I [ Science2008, 319, 183-186] at all but the lowest collision energies, a discrepancy that was not captured in a subsequent study at only a low collision energy [ J. Phys. Chem. Lett.2010, 1, 2747-2752]. Our direct chemical dynamics simulations at the DFT/B97-1 level of theory show that the reaction is dominated by three atomic-level mechanisms, an indirect reaction proceeding via an F--HCH2I hydrogen-bonded complex, a direct rebound, and a direct stripping reaction. The indirect mechanism is found to contribute about one-half of the overall substitution reaction rate at both low and high collision energies. This large fraction of indirect scattering at high collision energy is particularly surprising, because the barrier for the F--HCH2I complex to form products is only 0.10 eV. Overall, experiment and simulation agree very favorably in both the scattering angle and the product internal energy distributions. © 2013 American Chemical Society.
Keywords: Atomic-level mechanisms; Differential scattering cross section; Hydrogen-bonded complexes; Imaging experiments; Indirect reactions; Large-angle scattering; Low collision energy; Nucleophilic substitution reactions; Dynamics; Hydrogen bonds; Iodine; Scattering; Substitution reactions; Fluorine; anion; halogen; article; chemical parameters; dynamics; energy conservation; energy transfer; excitation; histogram; hydrogen bond; nucleophilicity; reaction analysis; simulation; substitution reaction; velocity

The coordinated radio and infrared survey for high-mass star formation. II. source catalog - Purcell, C.R.; Hoare, M.G.; Cotton, W.D.; Lumsden, S.L.; Urquhart, J.S.; Chandler, C.; Churchwell, E.B.; Diamond, P.; Dougherty, S.M.; Fender, R.P.; Fuller, G.; Garrington, S.T.; et al. (Astrophysical Journal, Supplement Series, 2013)
The CORNISH project is the highest resolution radio continuum survey of the Galactic plane to date. It is the 5 GHz radio continuum part of a series of multi-wavelength surveys that focus on the northern GLIMPSE region (10° < l < 65°), observed by the Spitzer satellite in the mid-infrared. Observations with the Very Large Array in B and BnA configurations have yielded a 1.″5 resolution Stokes I map with a root mean square noise level better than 0.4 mJy beam-1. Here we describe the data-processing methods and data characteristics, and present a new, uniform catalog of compact radio emission. This includes an implementation of automatic deconvolution that provides much more reliable imaging than standard CLEANing. A rigorous investigation of the noise characteristics and reliability of source detection has been carried out. We show that the survey is optimized to detect emission on size scales up to 14″ and for unresolved sources the catalog is more than 90% complete at a flux density of 3.9 mJy. We have detected 3062 sources above a 7σ detection limit and present their ensemble properties. The catalog is highly reliable away from regions containing poorly sampled extended emission, which comprise less than 2% of the survey area. Imaging problems have been mitigated by down-weighting the shortest spacings and potential artifacts flagged via a rigorous manual inspection with reference to the Spitzer infrared data. We present images of the most common source types found: H II regions, planetary nebulae, and radio galaxies. The CORNISH data and catalog are available online at http://cornish.leeds.ac.uk. © 2013. The American Astronomical Society. All rights reserved.

IGFBP-4 anti-angiogenic and anti-tumorigenic effects are associated with anti-cathepsin B activity - Moreno, M.J.; Ball, M.; Rukhlova, M.; Slinn, J.; L'Abbe, D.; Iqbal, U.; Monette, R.; Hagedorn, M.; O'Connor-McCourt, M.D.; Durocher, Y.; Stanimirovic, D.B. (Neoplasia (United States), 2013)
Insulin-like growth factor-binding protein 4 (IGFBP-4/IBP-4) has potent IGF-independent anti-angiogenic and antitumorigenic effects. In this study, we demonstrated that these activities are located in the IGFBP-4 C-terminal protein fragment (CIBP-4), a region containing a thyroglobulin type 1 (Tg1) domain. Proteins bearing Tg1 domains have been shown to inhibit cathepsins, lysosomal enzymes involved in basement membrane degradation and implicated in tumor invasion and angiogenesis. In our studies, CIBP-4 was shown to internalize and co-localize with lysosomal-like structures in both endothelial cells (ECs) and glioblastoma U87MG cells. CIBP-4 also inhibited both growth factor-induced EC tubulogenesis in Matrigel and the concomitant increases in intracellular cathepsin B (CatB) activity. In vitro assays confirmed CIBP-4 capacity to block recombinant CatB activity. Biodistribution analysis of intravenously injected CIBP-4-Cy5.5 in a glioblastoma tumor xenograft model indicated targeted accumulation of CIBP-4 in tumors. Most importantly, CIBP-4 reduced tumor growth in this animal model by 60%. Pleiotropic anti-angiogenic and anti-tumorigenic activities of CIBP-4 most likely underlie its observed therapeutic potential against glioblastoma. © 2013 Neoplasia Press, Inc.
Keywords: cathepsin B; somatomedin binding protein 1; somatomedin binding protein 4; angiogenesis; animal experiment; animal model; animal tissue; antiangiogenic activity; antineoplastic activity; article; cancer transplantation; cell anchorage; cell growth; cell viability; confocal laser microscopy; controlled study; glioblastoma; human; human cell; male; mouse; nonhuman; priority journal; tissue section; tumor growth

Aircraft Observations of Orographic Cloud and Precipitation Features over Southern Baffin Island, Nunavut, Canada - Fargey, S.; Hanesiak, J.; Stewart, R.; Wolde, M. (Atmosphere - Ocean, 2013)
This study evaluates cloud and precipitation features over the orography of southern Baffin Island in the southeast Canadian Arctic during the Storm Studies in the Arctic (STAR) field project in autumn 2007. Three case studies provide the basis for a comparative analysis of how cloud and precipitation features from upstream ocean regions are modified by the orography, in addition to the variability of these features over diverse synoptic and sea-ice conditions. Using data collected by a research aircraft with an onboard W-band Doppler radar and microphysical instrumentation, multiple factors were found to play roles in enhancing and/or reducing cloud and precipitation over the orography of the region. Gravity waves, terrain shape, atmospheric stability, and atmosphere-ocean exchanges were all associated with precipitation enhancement. In addition, several factors that reduce precipitation were identified, including sublimation, high sea-ice extent, and low-level blocking in the upstream environment. Accretion and aggregation were identified as important particle growth mechanisms over the orography. By increasing particle density and/or mass, the probability of ice particles precipitating to the surface increased. These results indicate that the complexity of these critical features over terrain in high-latitude regions poses considerable challenges for modelling. © 2013 © 2013 Taylor & Francis.

The possible contribution of gravity measurements to the difference between the NIST and NRC watt balance results - Newell, D.B.; Liard, J.O.; Inglis, A.D.; Eckl, M.C.; Winester, D.; Silliker, R.J.; Gagnon, C.G.L. (Metrologia, 2013)
We report on a 2012 comparison of gravity used to determine the Planck constant by the National Institute of Standards and Technology (NIST) and the National Research Council Canada (NRC) watt balances. The results provide verification of the gravity values used in recently published discrepant Planck constant determinations that play a vital role in the redefinition effort of the International System of Units (SI) and set an upper limit of 10 parts in 109 on the relative uncertainty contribution of gravity observations to future Planck constant determinations by the NIST and NRC watt balances. © 2013 BIPM & IOP Publishing Ltd.
Erratum published in volume 50, issue 5, pages 557-8, October 2013. DOI: 10.1088/0026-1394/50/5/557
Keywords: Gravity measurement; National Institute of Standards and Technology; National Research Council; Planck constants; Relative uncertainty; Upper limits; Watt balance; Engineering; Metallurgical engineering; Metric system

Effects of additions of nickel nanoparticles on sintering response of PM hybrid low alloy steels - Tougas, B.; Blais, C.; Chagnon, F.; Pelletier, S. (Powder Metallurgy, 2013)
Addition of pure elements to powder mixes can cause the formation of heterogeneous microstructures in powder metallurgy (PM) parts upon sintering. For instance, it has been shown that additions of nickel particles to an iron powder form nickel rich areas (NRAs), since nickel has low diffusivity in iron at conventional sintering temperature [∼1121°C (2050°F)]. Thus, the present work is aimed at determining if addition of a small quantity of carbon coated nickel nanoparticles to a PM hybrid low alloy steel premix could result in a more homogeneous distribution of nickel in sintered parts. It also characterises the effect of this addition on microstructures and mechanical properties. Grain boundary and volume diffusion coefficients of nickel nanoparticles have been determined using Suzuoka's equation and wavelength dispersive X-ray spectrometry maps. Results show that addition of nanoparticles initiates lattice diffusion at lower temperature and produces less NRA. © 2013 Institute of Materials, Minerals and Mining.
Keywords: Carbon coated nickel nanoparticle; Conventional sintering; Heterogeneous microstructure; Homogeneous distribution; Microstructures and mechanical properties; Nickel nanoparticles; Volume diffusion coefficients; Wavelength dispersive X-rays; Diffusion; Grain boundaries; High strength steel; Iron powder; Mechanical properties; Nanoparticles; Nickel; Powder metallurgy; Sintering; Steel; Nickel powder metallurgy

The herschel and jcmt gould belt surveys: Constraining dust properties in the perseus B1 clump with PACS, SPIRE, and SCUBA-2 - Sadavoy, S.I.; Di Francesco, J.; Johnstone, D.; Currie, M.J.; Drabek, E.; Hatchell, J.; Nutter, D.; André, P.; Arzoumanian, D.; Benedettini, M.; Bernard, J.-P.; Duarte-Cabral, A.; et al. (The Astrophysical Journal, 2013)
We present Herschel observations from the Herschel Gould Belt Survey and SCUBA-2 science verification observations from the JCMT Gould Belt Survey of the B1 clump in the Perseus molecular cloud. We determined the dust emissivity index using four different techniques to combine the Herschel PACS+SPIRE data at 160-500 μm with the SCUBA-2 data at 450 μm and 850 μm. Of our four techniques, we found that the most robust method was filtering out the large-scale emission in the Herschel bands to match the spatial scales recovered by the SCUBA-2 reduction pipeline. Using this method, we find β 2 toward the filament region and moderately dense material and lower β values (β ≳ 1.6) toward the dense protostellar cores, possibly due to dust grain growth. We find that β and temperature are more robust with the inclusion of the SCUBA-2 data, improving estimates from Herschel data alone by factors of 2 for β and by 40% for temperature. Furthermore, we find core mass differences of ≲ 30% compared to Herschel-only estimates with an adopted β = 2, highlighting the necessity of long-wavelength submillimeter data for deriving accurate masses of prestellar and protostellar cores. © 2013. The American Astronomical Society. All rights reserved.

Analysis of couplers between photonic nanowires and subwavelength grating waveguides - Ctyroký, Jirí; Kwiecien, Pavel; Richter, Ivan; Cheben, Pavel (SPIE - International Society for Optical Engineering. Proceedings, 2013)
Subwavelength grating (SWG) waveguides offer the freedom of (effective) refractive index variation in the design of integrated optical components and devices in silicon-on-insulator waveguides without significantly increasing fabrication complexity. An SWG waveguide is formed by a subwavelength (quasi)-periodic structure consisting of short segments of silicon embedded into a lower-index superstrate. As a result, to the first approximation, the SWG waveguide behaves as a channel waveguide with its core refractive index determined by the filling factor of silicon in the superstrate. By changing the filling factor, i.e., the duty-cycle of the SWG structure, its (effective) refractive index can be varied essentially between that of the superstrate and that of silicon. Here we present a numerical analysis of light coupling between a conventional silicon nanowire waveguide and a periodic SWG waveguide by means of a tapered SWG coupler. The coupler function is to facilitate the smooth and low-loss transition from a conventional mode of a photonic nanowire to a Bloch mode of a periodic SWG waveguide, both propagating with different group velocities. To increase the reliability of numerical simulations, two independent 3D numerical codes based on different formulations of a Fourier modal method (FMM) are used for the analysis. Results of modeling of tapered SWG couplers of different lengths confirm excellent optical properties of these couplers, including very low coupling and return losses.
Keywords: Bloch modes; Optical waveguide theory; Photonic nanowires; Silicon-on-insulators; Subwavelength grating waveguides; Tapers; Integrated optics; Modal analysis; Nanowires; Numerical models; Refractive index; Reliability analysis; Silicon; Waveguide couplers; Waveguides

PLA-thermoplastic lignin blends - Li, H.; Legros, N.; Ton-That, M.-T.; Rakotovelo, A. (Plastics Engineering, 2013)
A study was conducted to demonstrate the development and characterization of different polylactic acid (PLA)-lignin blends. The effects of a compatibilizer and chain extender on the blend properties were investigated. PLA/TPL blends were prepared on a Leistritz 34-mm co-rotating twin-screw extruder with an L/D ratio of 42, using a sequence of twin-screw operation. The first half of the extruder was dedicated to lignin plasticization and lignin and sorbitol were fed in a dry powder form and glycerol and water were added to lignin through the plasticizer injection port. The water was used as 'temporary' plasticizer for lignin and was removed by devolatilization in a subsequent extruder portion to provide a water-free TPL. The second part of the extruder was used to mix the TPL with the PLA. The viscosity of the PLA/TPL and effect of a chain extender on the blend's viscosity were also examined with a C.W. Brabender mixer.
Keywords: Blend properties; Brabender mixer; Chain extenders; Devolatilization; Dry powders; Injection ports; Poly lactic acid; Twin screw extruders; Chains; Plasticizers; Reinforced plastics; Screws; Viscosity; Water injection; Lignin

Modeling short-term energy load with continuous conditional random fields - Guo, Hongyu (Machine Learning and Knowledge Discovery in Databases : European Conference, ECML PKDD 2013, Prague, Czech Republic, September 23-27, 2013, Proceedings, Part I, 2013)
Short-term energy load forecasting, such as hourly predictions for the next n (n ≥ 2) hours, will benefit from exploiting the relationships among the n estimated outputs. This paper treats such multi-steps ahead regression task as a sequence labeling (regression) problem, and adopts a Continuous Conditional Random Fields (CCRF) strategy. This discriminative approach intuitively integrates two layers: the first layer aims at the prior knowledge for the multiple outputs, and the second layer employs edge potential features to implicitly model the interplays of the n interconnected outputs. Consequently, the proposed CCRF makes predictions not only basing on observed features, but also considering the estimated values of related outputs, thus improving the overall predictive accuracy. In particular, we boost the CCRF's predictive performance with a multi-target function as its edge feature. These functions convert the relationship of related outputs with continuous values into a set of "sub-relationships", each providing more specific feature constraints for the interplays of the related outputs. We applied the proposed approach to two real-world energy load prediction systems: one for electricity demand and another for gas usage. Our experimental results show that the proposed strategy can meaningfully reduce the predictive error for the two systems, in terms of mean absolute percentage error and root mean square error, when compared with three benchmarking methods. Promisingly, the relative error reduction achieved by our CCRF model was up to 50%. © 2013 Springer-Verlag..
Keywords: Benchmarking methods; Conditional random field; Discriminative approach; Energy demands; Mean absolute percentage error; Predictive accuracy; Predictive performance; Root mean square errors; Electric load forecasting; Forecasting; Learning systems; Mean square error; Random processes

Recent advances in solid-state NMR of alkaline earth elements - Moudrakovski, I.L. (Annual Reports on NMR Spectroscopy, 2013)
Recent developments in the solid-state NMR of 25Mg, 43Ca, 135,137Ba, and 87Sr are discussed in a context of contemporary applications to inorganic, organometallic, and biological materials. While each alkaline earth nucleus presents its own unique combination of NMR challenges, together they are characterized by low intrinsic sensitivity due to their small magnetic moments and low natural abundance. Solid-state NMR advances of the last decade, particularly the increased availability of very high magnetic field beyond 17T, the development and implementation of signal enhancement techniques for quadrupolar nuclei, progress in methods for obtaining wideline and ultra-wideline NMR spectra of solids, together with the widespread use of computational techniques, have all contributed immensely to the accelerated growth of solid-state NMR of alkaline earth nuclei and extension of the method into biology and material science. The specifics and the experimental challenges of each nucleus in solid-state NMR applications are discussed. © 2013.

The study of the core part and non-repeating elements of the O-antigen of Brucella lipopolysaccharide - Kubler-Kielb, J.; Vinogradov, E. (Carbohydrate Research, 2013)
Brucella is an animal and human pathogen that expresses several virulence factors required for host cell invasion and intracellular survival. It produces LPS with unusually low toxicity, which hampers the detection of bacteria by the host immune system and thus provides resistance against intracellular antimicrobial mechanisms of the host. By chemical and spectroscopic methods we determined the structure of the LPS core and of a non-repetitive oligosaccharide fragment at the reducing end of the O-specific polysaccharide. These data should be useful for understanding the biological role of the Brucella LPS. Crown Copyright © 2012 Published by Elsevier Ltd. All rights reserved.
Keywords: Brucella; Core part; Host-cell invasion; Human pathogens; Immune systems; Intracellular survival; Lipopolysaccharides; Low toxicity; LPS; MS; O-Antigen; Reducing ends; Spectroscopic method; Virulence factors; Nuclear magnetic resonance; Organic compounds; Structure (composition); Synthesis (chemical); Spectroscopic analysis; lipopolysaccharide; O antigen; antimicrobial activity; article; Brucella; chemical analysis; immune system; nonhuman; priority journal; spectroscopy; structure analysis; Animalia; Brucella

Process and performance evaluation of ultrasonic, induction and resistance welding of advanced thermoplastic composites - Villegas, I.F.; Moser, L.; Yousefpour, A.; Mitschang, P.; Bersee, H.E.N. (Journal of Thermoplastic Composite Materials, 2013)
The possibility of assembling through welding is one of the major features of thermoplastic composites and it positively contributes to their cost-effectiveness in manufacturing. This article presents a comparative evaluation of ultrasonic, induction and resistance welding of individual carbon fibre-reinforced polyphenylene sulphide (PPS) thermoplastic composite samples that comprises an analysis of the static and dynamic mechanical behaviour of the joints as well as of the main process variables. The induction welding process as used in this research benefitted from the conductive nature of the reinforcing fibres. Hence, no susceptor was placed at the welding interface. Resistance welding used a fine-woven stainless-steel mesh as the heating element and low welding pressures and times were applied to prevent current leakage. Triangular energy directors moulded on a separate tape of PPS resin were used to concentrate ultrasonic heat at the welding interface. The static single-lap shear strength of the joints was found similar for induction and ultrasonic welding. A 15% drop in the static mechanical properties of the resistance welded joints was attributed to incomplete welded overlaps following current leakage prevention. However, the fatigue performance relative to the static one was similar for the three sorts of joints. A comparative analysis of process variables such as welding time, required power and energy was also carried out. © The Author(s) 2012.
Keywords: Comparative analysis; Comparative evaluations; Dynamic mechanical; Fatigue performance; Induction welding; Polyphenylene sulphide; Static mechanical properties; Thermoplastic composite; Carbon fibers; Composite materials; Mechanical properties; Reinforcement; Resistance welding; Stainless steel; Thermoplastics; Ultrasonic welding; Welding

All-thermoplastic nanoplasmonic microfluidic device for transmission SPR biosensing - Malic, L.; Morton, K.; Clime, L.; Veres, T. (Lab on a Chip - Miniaturisation for Chemistry and Biology, 2013)
Early and accurate disease diagnosis still remains a major challenge in clinical settings. Biomarkers could potentially provide useful tools for the detection and monitoring of disease progression, treatment safety and efficacy. Recent years have witnessed prodigious advancement in biosensor development with research directed towards rapid, real-time, label-free and sensitive biomarker detection. Among emerging techniques, nanoplasmonic biosensors pose tremendous potential to accelerate clinical diagnosis with real-time multiplexed analysis, rapid and miniaturized assays, low sample consumption and high sensitivity. In order to translate these technologies from the proof-of-principle concept level to point of care clinical diagnosis, integrated, portable devices having small footprint cartridges that house low-cost disposable consumables are sought. Towards this goal, we developed an all-polymeric nanoplasmonic microfluidic (NMF) transmission surface plasmon resonance (SPR) biosensor. The device was fabricated in thermoplastics using a simple, single step and cost-effective hot embossing technique amenable to mass production. The novel 3D hierarchical mold fabrication process enabled monolithic integration of blazed nanogratings within the detection chambers of a multichannel microfluidic system. Consequently, a single hard thermoplastic bottom substrate comprising plasmonic and fluidic features allowed integration of active fluidic elements, such as pneumatic valves, in the top soft thermoplastic cover, increasing device functionality. A simple and compact transmission-based optical setup was employed with multiplexed end-point or dual-channel kinetic detection capability which did not require stringent angular accuracy. The sensitivity, specificity and reproducibility of the transmission SPR biosensor was demonstrated through label-free immunodetection of soluble cell-surface glycoprotein sCD44 at clinically relevant picomolar to nanomolar concentrations. This journal is © 2013 The Royal Society of Chemistry.
Keywords: Hermes antigen; plastic; polymer; thermoplastic; unclassified drug; accuracy; article; biosensor; cell surface; controlled study; cost effectiveness analysis; kinetics; limit of detection; microfluidics; nanofabrication; nanoplasmonic microfluidic; optics; priority journal; surface plasmon resonance; Antigens, CD44; Biological Markers; Biosensing Techniques; Gold; Humans; Immunoassay; Microfluidic Analytical Techniques; Nanostructures; Polymers; Surface Plasmon Resonance; Surface Properties

Ancient orphan crop joins modern era: Gene-based SNP discovery and mapping in lentil - Sharpe, A.G.; Ramsay, L.; Sanderson, L.-A.; Fedoruk, M.J.; Clarke, W.E.; Li, R.; Kagale, S.; Vijayan, P.; Vandenberg, A.; Bett, K.E. (BMC Genomics, 2013)
Background: The genus Lens comprises a range of closely related species within the galegoid clade of the Papilionoideae family. The clade includes other important crops (e.g. chickpea and pea) as well as a sequenced model legume (Medicago truncatula). Lentil is a global food crop increasing in importance in the Indian sub-continent and elsewhere due to its nutritional value and quick cooking time. Despite this importance there has been a dearth of genetic and genomic resources for the crop and this has limited the application of marker-assisted selection strategies in breeding.Results: We describe here the development of a deep and diverse transcriptome resource for lentil using next generation sequencing technology. The generation of data in multiple cultivated (L. culinaris) and wild (L. ervoides) genotypes together with the utilization of a bioinformatics workflow enabled the identification of a large collection of SNPs and the subsequent development of a genotyping platform that was used to establish the first comprehensive genetic map of the L. culinaris genome. Extensive collinearity with M. truncatula was evident on the basis of sequence homology between mapped markers and the model genome and large translocations and inversions relative to M. truncatula were identified. An estimate for the time divergence of L. culinaris from L. ervoides and of both from M. truncatula was also calculated.Conclusions: The availability of the genomic and derived molecular marker resources presented here will help change lentil breeding strategies and lead to increased genetic gain in the future. © 2013 Sharpe et al.; licensee BioMed Central Ltd.
Keywords: complementary DNA; molecular marker; transcriptome; 3' untranslated region; article; barrel medic; bioinformatics; chromosome inversion; chromosome translocation; computer model; controlled study; crop; cultivated species; gene locus; gene mapping; genetic identification; genetic linkage; genotype; Lens ervoides; lentil; nonhuman; plant genome; sequence analysis; sequence homology; single nucleotide polymorphism; transcriptomics; wild plant; Genetic Linkage; Genomics; Genotype; Lens Plant; Medicago truncatula; Polymorphism, Single Nucleotide; Sequence Analysis, DNA; Cicer arietinum; Lens (angiosperm); Lens culinaris; Lens ervoides; Medicago truncatula; Papilionoideae; Pisum sativum

LuRh2Si2: Sensitivity of the Fermi surface to the Si z-position - Reiss, P.; Rourke, P.M.C.; Zwicknagl, G.; Grosche, F.M.; Friedemann, S. (Physica Status Solidi (B) Basic Research, 2013)
We present band structure calculations of the non-magnetic compound LuRh2Si2 which serves as a reference for YbRh2Si2, a prototypical material for the investigation of quantum critical points. The relative z position of the Si atoms is found to have a strong impact on the band structure and the Fermi surface topology. We find the total energy to be minimized for z=0.381c whereas a comparison of predicted extremal orbits with Shubnikov-de Haas frequencies shows best agreement at the experimental value z=0.379c. We therefore recommend usage of z=0.379c for future electronic structure calculations of LuRh2Si2 and YbRh2Si2. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of internal curing by using superabsorbent polymers (SAP) on autogenous shrinkage and other properties of a high-performance fine-grained concrete: results of a RILEM round-robin test - Mechtcherine, V.; Gorges, M.; Schroefl, C.; Assmann, A.; Brameshuber, W.; Ribeiro, A.B.; Cusson, D.; Custódio, J.; da Silva, E.F.; Ichimiya, K.; Igarashi, S.-i.; Klemm, A.; et al. (Materials and Structures/Materiaux et Constructions, 2013)
The article presents the results of a round-robin test performed by 13 international research groups (representing fifteen institutions) in the framework of the activities of the RILEM Technical Committee 225-SAP "Applications of Superabsorbent Polymers in Concrete Construction". Two commercially available SAP materials were used for internal curing of a high-performance, fine-grained concrete in combination with the addition of extra water. The concrete had the same mix composition in all laboratories involved but was composed of local materials. All found a considerable decrease in autogenous shrinkage attributable to internal curing. Also, with regard to the shrinkage-mitigating effect of both particular SAP materials, the results were consistent. This demonstrates that internal curing using SAP is a robust approach, working independently of some variations in the concretes' raw materials, production process, or measuring technique. Furthermore, the effects of internal curing on other properties of concrete in its fresh and hardened states were investigated. These are consistent as well and expand considerably the existing data basis on properties of concrete materials containing SAP. © 2013 RILEM.

Solution to peptide sequencing challenge - Meija, J. (Analytical and Bioanalytical Chemistry, 2013)
Keywords: cyclotide; cysteine; disulfide; kalata B1; peptide; chemistry; methodology; note; protein conformation; protein tertiary structure; sequence analysis; Cyclotides; Cysteine; Disulfides; Peptides; Protein Conformation; Protein Structure, Tertiary; Sequence Analysis, Protein

Memristive devices for computing - Yang, J.J.; Strukov, D.B.; Stewart, D.R. (Nature Nanotechnology, 2013)
Memristive devices are electrical resistance switches that can retain a state of internal resistance based on the history of applied voltage and current. These devices can store and process information, and offer several key performance characteristics that exceed conventional integrated circuit technology. An important class of memristive devices are two-terminal resistance switches based on ionic motion, which are built from a simple conductor/insulator/conductor thin-film stack. These devices were originally conceived in the late 1960s and recent progress has led to fast, low-energy, high-endurance devices that can be scaled down to less than 10 nm and stacked in three dimensions. However, the underlying device mechanisms remain unclear, which is a significant barrier to their widespread application. Here, we review recent progress in the development and understanding of memristive devices. We also examine the performance requirements for computing with memristive devices and detail how the outstanding challenges could be met. © 2013 Macmillan Publishers Limited. All rights reserved.
Keywords: anion; cation; copper; chemical interaction; electric field; electric potential; electrode; geometry; information processing device; ion transport; mathematical computing; performance; priority journal; review

Phase-shifted fiber bragg grating based humidity sensor - Wang, H.; Guo, H.; Xiao, G.; Mrad, N.; Kazemi, A.; Ban, D. (SPIE - International Society for Optical Engineering. Proceedings, 2013)
A humidity fiber optic sensor based on phase-shifted (PS) fiber Bragg Gratings (FBG) is demonstrated in this paper. The sensor (PS-FBG) is coated with a moisture sensitive polyimide. When this thin coating is exposed to moisture its swells, hence inducing tensile stress on the PS-FBG and affecting its Bragg wavelength. Due to its intrinsic properties, the PS-FBG sensor presents the same trend of wavelength variation as standard fiber Bragg Grating sensor but with higher measurement resolution, and reliable measurements can be obtained in different humidity and temperature environments. This paper assesses the suitability, including sensitivity and response time, of the phaseshifted FBG sensor approach for humidity sensing. By monitoring this change, it is demonstrated that the humidity level of the environment can be accurately monitored. © 2013 SPIE.
Keywords: Bragg wavelength; Humidity and temperatures; Humidity levels; Humidity sensing; Intrinsic property; Measurement resolution; Phase shifted fiber bragg grating (PSFBG); Reliable measurement; Electric sensing devices; Fiber optic sensors; Fibers; Humidity sensors; Moisture; Phase shift; Fiber Bragg gratings

Application of chemical vapor generation in ICP-MS: A review - Gao, Y.; Liu, R.; Yang, L. (Chinese Science Bulletin, 2013)
Chemical vapor generation (CVG) is an important sample introduction technique, and is widely used for atomic spectrometry for its enhanced sensitivity and selectivity. In the past 30 years, inductively coupled plasma mass spectrometry (ICP-MS) has become a widely used and the most sensitive instrument for (ultra-)trace element determination and elemental speciation. A review of applications of this state-of-the-art coupling of CVG and ICP-MS is presented. Discussion is focused on its applications for both element determination and speciation, including hydride generation, cold vapor generation, photochemical vapor generation, alkylation, and electrochemical vapor generation. In addition, recent studies undertaken isotope dilution calibration in CVG-ICP-MS for achieving improved accuracy and precision are summarized, and the future perspectives are discussed. © 2013 The Author(s).

The 10.7 cm solar radio flux (F10.7) - Tapping, K.F. (Space Weather, 2013)

Catalytically active single-atom niobium in graphitic layers - Zhang, X.; Guo, J.; Guan, P.; Liu, C.; Huang, H.; Xue, F.; Dong, X.; Pennycook, S.J.; Chisholm, M.F. (Nature Communications, 2013)
Carbides of groups IV through VI (Ti, V and Cr groups) have long been proposed as substitutes for noble metal-based electrocatalysts in polymer electrolyte fuel cells. However, their catalytic activity has been extremely limited because of the low density and stability of catalytically active sites. Here we report the excellent performance of a niobium-carbon structure for catalysing the cathodic oxygen reduction reaction. A large number of single niobium atoms and ultra small clusters trapped in graphitic layers are directly identified using state-of-the-art aberration-corrected scanning transmission electron microscopy. This structure not only enhances the overall conductivity for accelerating the exchange of ions and electrons, but it suppresses the chemical/thermal coarsening of the active particles. Experimental results coupled with theory calculations reveal that the single niobium atoms incorporated within the graphitic layers produce a redistribution of d-band electrons and become surprisingly active for O2 adsorption and dissociation, and also exhibit high stability. © 2013 Macmillan Publishers Limited. All rights reserved.
Keywords: graphite; niobium; oxygen; adsorption; catalysis; catalyst; electrokinesis; electron; electron microscopy; fuel cell; graphite; mathematical analysis; stabilization; adsorption; article; atom; catalysis; chemical structure; conductance; dissociation; electron; ion exchange; reduction; scanning electron microscopy

Electron-electron interactions and topology in the electronic properties of gated graphene nanoribbon rings in Möbius and cylindrical configurations - Güçlü, A.D.; Grabowski, M.; Hawrylak, P. (Physical Review B - Condensed Matter and Materials Physics, 2013)
We present a theory of the electronic properties of gated graphene nanoribbon rings with zigzag edges in Möbius and cylindrical configurations. The finite width opens a gap and nontrivial topology of the Möbius ring leads to a single edge with edge states with an induced, effective gauge field, in analogy to topological insulators. The single zigzag edge leads to a shell of degenerate states at the Fermi level and a ferromagnetic (FM) ground state at half-filling, i.e., at charge neutrality, due to electron-electron interactions. For fractional fillings, both the magnetic moment and the energy gap are found to oscillate as a function of the shell filling. In cylindrical rings, the two edges lead to AF ground state at half-filling but FM ground state at fractional fillings. ©2013 American Physical Society.

Channel- and angle-resolved above threshold ionization in the molecular frame - Mikosch, J.; Boguslavskiy, A.E.; Wilkinson, I.; Spanner, M.; Patchkovskii, S.; Stolow, A. (Physical Review Letters, 2013)
In strong-field ionization (SFI) of polyatomic molecules, the participation of multiple electronic ionization channels is emerging as a key aspect. In the molecular frame, each channel is expected to show a characteristic dependence of the SFI yield on the polarization direction of the ionizing field. We apply a new angle- and channel-resolved SFI technique to the polyatomic molecule 1,3-butadiene and compare these molecular-frame measurements with two leading theoretical models. © 2013 American Physical Society.
Keywords: 1 ,3-butadiene; Above-threshold ionization; Electronic ionizations; Ionizing fields; Molecular frame; Polarization direction; Polyatomic molecules; Strong field ionization; Theoretical models; Butadiene; Ionization

On ligand binding energies in porphyrinic systems - Schalk, O.; Liang, Y.; Unterreiner, A.-N. (Zeitschrift fur Physikalische Chemie, 2013)
Energy decomposition analysis is a powerful tool to study the bond properties of molecules. Here, we used a recent implementation by P. Su and H. Li (J. Chem. Phys. 131 (2009) 014102) to test the method for investigations of ligand binding to medium sized molecules (30-40 atoms). We studied the properties of the bond between porphyrins or phthalocyanines with central metals without (Mg) or with a closed d shell (Zn and Cd) to ligands binding via various row II and III atoms (nitrogen, oxygen, phosphorus and sulphur) using various methods and basis sets. Several interesting results could be deduced: In the porphyrins, ligands binding via a nitrogen atom were preferred to those binding via oxygen and sixfold coordination was readily available for magnesium as central metal atom as opposed to zinc and cadmium derivatives which also showed a weaker bond strength. In phthalocyanines, a tendency to form fivefold coordination was also seen for magnesium compounds and bonds to nitrogen and oxygen had the same strength. Ligation to row III elements created only weak bonds that were prone to fluctuations. © by Oldenbourg Wissenschaftsverlag, München.

Reinvestigation of the structure of Brucella O-antigens - Kubler-Kielb, J.; Vinogradov, E. (Carbohydrate Research, 2013)
O-Specific polysaccharides of Brucella contain two antigenic determinants, called A and M. Most of the strains express epitope A with a small amount of epitope M, whereas Brucella melitensis strain 16 M expresses longer polymer consisting mostly of M-type epitopes. Proposed explanation was that epitope A is defined by 1-2-linked homopolymer of N-formylperosamine (Rha4NFo), while epitope M is a pentasaccharide with four 2- and one 3-substituted Rha4NFo. We reinvestigated both types of structures by 2D NMR and showed that M-epitope is a tetrasaccharide, missing one of the 2-linked Rha4NFo as compared to the previously proposed structure. Polysaccharide from B. melitensis 16 M contains a fragment of 1-2-linked polymer, capped with M-type polymer. Other strains contain one or two M-type units at the non-reducing end of the 1-2-linked O-chain. Crown Copyright © 2013 Published by Elsevier Ltd.
Keywords: 2-D NMR; Brucella; LPS; MS; O-Chain; O-specific polysaccharides; Pentasaccharides; Tetrasaccharides; Nuclear magnetic resonance; Polymers; Strain; Structure (composition); Epitopes; epitope; O antigen; pentasaccharide; tetrasaccharide; acetylation; antigen structure; article; Brucella melitensis; carbon nuclear magnetic resonance; deacylation; nonhuman; priority journal; proton nuclear magnetic resonance; Brucella; Brucella melitensis; Brucella melitensis 16M

Soil bacteria and archaea found in long-term corn (zea mays L.) agroecosystems in Quebec, Canada - Sheibani, S.; Yanni, S.F.; Wilhelm, R.; Whalen, J.K.; Whyte, L.G.; Greer, C.W.; Madramootoo, C.A. (Canadian Journal of Soil Science, 2013)
The soil microbial community controls all biological processes in soils and is considered a good indicator of general soil health. Assessment of the microbial community in intensively cropped soils that are under reduced tillage management is especially important because the microbes are the primary decomposers of the high residue input in such systems. We investigated the microbial biomass and diversity of bacteria and archaea in a sandy-loam Dystric Gleysol from a long-term (15 yr) corn (Zea mays L.) agroecosystem in Quebec, Canada, under conventional (CT), reduced tillage (RT), and no tillage (NT) and two residue inputs (high level: + R and low level: - R). Analysis included microbial biomass C and N (MBC, MBN), catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH) and 5-(4, 6-dichlorotriazinyl) amino fluorescein hydrochloride (DTAF) cell counts, 16S rRNA polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and an archaeal clone library. The PCR-DGGE analysis identified Proteobacteria, Actinobacteria and Firmicutes as dominant groups in all tillage and residue management treatments. The archaeal group was diverse, with most individuals identified as belonging to the Crenarchaeota phylum. We also detected soil archaea belonging to the newly proposed phylum Thaumarchaeota, the chemolithoautotrophic ammonia-oxidizing archaeota, in a corn agroecosystem in Quebec, Canada. Microbial biomass increased in the +R treatment according to MBC concentration and direct cell counts. Considering results from the CARD-FISH counts (bacterial and archaeal cell counts without fungal cells) and from MBC results (all microbial biomass including fungi) we concluded the likelihood of greater fungal biomass in the NT plots.
Keywords: agricultural ecosystem; assessment method; bacterium; biomass; cell organelle; conservation tillage; fluorescence; maize; phylogeny; polymerase chain reaction; soil microorganism; species diversity; Canada; Quebec [Canada]; Actinobacteria; Archaea; Bacteria (microorganisms); Crenarchaeota; Firmicutes; Fungi; Proteobacteria; Zea mays

Cardiorespiratory fitness and adiposity in metabolically healthy overweight and obese youth - Sénéchal, M.; Wicklow, B.; Wittmeier, K.; Hay, J.; MacIntosh, A.C.; Eskicioglu, P.; Venugopal, N.; McGavock, J.M. (Pediatrics, 2013)
OBJECTIVE: Controversy exists surrounding the contribution of fitness and adiposity as determinants of the Metabolically Healthy Overweight (MHO) phenotype in youth. This study investigated the independent contribution of cardiorespiratory fitness and adiposity to the MHO phenotype among overweight and obese youth. METHODS: This cross-sectional study included 108 overweight and obese youth classified as MHO (no cardiometabolic risk factors) or non-MHO ($1 cardiometabolic risk factor), based on age- and genderspecific cut-points for fasting glucose, triglycerides, high-density lipoprotein cholesterol, systolic and diastolic blood pressure, and hepatic steatosis. RESULTS: Twenty-five percent of overweight and obese youth were classified as MHO. This phenotype was associated with lower BMI z-score (BMI z-score: 1.8 ± 0.3 vs 2.1 ± 0.4, P = .02) and waist circumference (99.7 ± 13.2 vs 106.1 ± 13.7 cm, P = .04) compared with non-MHO youth. When matched for fitness level and stratified by BMI z-score (1.6 ± 0.3 vs 2.4 ± 0.2), the prevalence of MHO was fourfold higher in the low BMI z-score group (27% vs 7%; P = .03). Multiple logistic regression analyses revealed that the best predictor of MHO was the absence of hepatic steatosis even after adjusting for waist circumference (odds ratio 0.57, 95% confidence interval 0.40- 0.80) or BMI z-score (odds ratio 0.59, 95% confidence interval 0.43- 0.80). CONCLUSIONS: The MHO phenotype was present in 25% of overweight and obese youth and is strongly associated with lower levels of adiposity, and the absence of hepatic steatosis, but not with cardiorespiratory fitness. Pediatrics 2013;132:e85-e92. Copyright © 2013 by the American Academy of Pediatrics.
Keywords: glucose; high density lipoprotein cholesterol; triacylglycerol; adolescent; adult; article; body composition; body fat distribution; body mass; cardiometabolic risk; cardiovascular system; cholesterol blood level; controlled study; cross-sectional study; diastolic blood pressure; disease association; fatty liver; female; glucose blood level; health promotion; human; lipid storage; major clinical study; male; obesity; phenotype; prevalence; priority journal; respiratory system; risk factor; scoring system; systolic blood pressure; triacylglycerol blood level; waist circumference

An ultra-compact multimode interference coupler with a subwavelength grating slot - Ortega-Moñux, Alejandro; Alonso-Ramos, Carlos; Maese-Novo, Alejandro; Halir, Robert; Zavargo-Peche, Luis; Pérez-Galacho, Diego; Molina-Fernández, Iñigo; Wangüemert-Pérez, J. Gonzalo; Cheben, Pavel; Schmid, Jens H.; Lapointe, Jean; Xu, Danxia; et al. (Laser and Photonics Reviews, 2013)
Multimode interference couplers (MMIs) are fundamental building blocks in photonic integrated circuits. Here it is experimentally demonstrated, for the first time, a two-fold length reduction in an MMI coupler without any penalty on device performance. The design is based on a slotted 2 × 2 MMI fabricated on a commercial silicon-on-insulator (SOI) substrate. The slot is implemented with a subwavelength grating (SWG) comprising holes fully etched down to the oxide cladding, thereby allowing single etch step fabrication. The device has been designed using an in-house tool based on the Fourier Eigenmode Expansion Method. It has a footprint of only 3.5 μm x 23 μm and it exhibits a measured extinction ratio better than 15 dB within the full C-band (1530 nm-1570 nm). SWG engineered slots thus offer excellent perspectives for the practical realization of MMIs couplers with substantially reduced footprint yet with outstanding performance. Multimode interference couplers (MMIs) are fundamental building blocks in photonic integrated circuits. Here it is experimentally demonstrated, for the first time, a two-fold length reduction in an MMI coupler without any penalty on device performance. The design is based on a slotted 2 × 2 MMI fabricated on a commercial silicon-on-insulator (SOI) substrate. The slot is implemented with a subwavelength grating (SWG) comprising holes fully etched down to the oxide cladding, thereby allowing single etch step fabrication. The device has been designed using an in-house tool based on the Fourier Eigenmode Expansion Method. It has a footprint of only 3.5 μm x 23 μm and it exhibits a measured extinction ratio better than 15 dB within the full C-band (1530 nm-1570 nm). SWG engineered slots thus offer excellent perspectives for the practical realization of MMIs couplers with substantially reduced footprint yet with outstanding performance. © 2013 by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Keywords: Fundamental building blocks; Multimode interference couplers; Photonic integrated circuits; Practical realizations; Silicon-on-insulator substrates; Silicon-on-insulators; Silicon-wire; Subwavelength grating; Fabrication; Light extinction; Photonic devices; Photonic integration technology; Integrated optics

High performance InAs/InP C-Band quantum dot coherence frequency comb lasers - Lu, Z.G.; Liu, J.R.; Poitras, D.; Poole, P.; Barrios, P.; Song, C.Y.; Chang, S.D.; Flueraru, C.; Ding, H.P.; Janz, S. (CLEO: Science and Innovations, CLEO_SI 2013, 2013)
We have experimentally demonstrated several InAs/InP quantum dot C-band coherence frequency comb lasers with the frequency spacing from 10 GHz to 100 GHz with the total output power of up to 50 mW. © 2013 Optical Society of America.
Keywords: 100 GHz; C-band coherence; Frequency spacing; Frequency-comb laser; InAs/InP; InAs/InP quantum dots; Output power; Semiconductor quantum dots

Methanol incorporation in clathrate hydrates and the implications for oil and gas pipeline flow assurance and icy planetary bodies - Shin, K.; Udachin, K.A.; Moudrakovski, I.L.; Leek, D.M.; Alavi, S.; Ratcliffe, C.I.; Ripmeester, J.A. (Proceedings of the National Academy of Sciences of the United States of America, 2013)
One of the best-known uses of methanol is as antifreeze. Methanol is used in large quantities in industrial applications to prevent methane clathrate hydrate blockages from forming in oil and gas pipelines. Methanol is also assigned a major role as antifreeze in giving icy planetary bodies (e.g., Titan) a liquid subsurface ocean and/or an atmosphere containing significant quantities of methane. In this work, we reveal a previously unverified role for methanol as a guest in clathrate hydrate cages. X-ray diffraction (XRD) and NMR experiments showed that at temperatures near 273 K, methanol is incorporated in the hydrate lattice along with other guest molecules. The amount of included methanol depends on the preparative method used. For instance, single-crystal XRD shows that at low temperatures, the methanol molecules are hydrogen-bonded in 4.4% of the small cages of tetrahydrofuran cubic structure II hydrate. At higher temperatures, NMR spectroscopy reveals a number of methanol species incorporated in hydrocarbon hydrate lattices. At temperatures characteristic of icy planetary bodies, vapor deposits of methanol, water, and methane or xenon show that the presence of methanol accelerates hydrate formation on annealing and that there is unusually complex phase behavior as revealed by powder XRD and NMR spectroscopy. The presence of cubic structure I hydrate was confirmed and a unique hydrate phase was postulated to account for the data. Molecular dynamics calculations confirmed the possibility of methanol incorporation into the hydrate lattice and show that methanol can favorably replace a number of methane guests.
Keywords: clathrate hydrate; methane; methanol; oil; tetrahydrofuran; unclassified drug; xenon; article; astronomy; chemical structure; gas pressure gauge; high temperature; hydrogen bond; low temperature; molecular dynamics; nuclear magnetic resonance; nuclear magnetic resonance spectroscopy; oil industry; priority journal; temperature dependence; vapor; X ray diffraction

B1 transmit phase gradient coil for single-axis TRASE RF encoding - Deng, Q.; King, S.B.; Volotovskyy, V.; Tomanek, B.; Sharp, J.C. (Magnetic Resonance Imaging, 2013)
Purpose: TRASE (Transmit Array Spatial Encoding) MRI uses RF transmit phase gradients instead of B0 field gradients for k-space traversal and high-resolution MR image formation. Transmit coil performance is a key determinant of TRASE image quality. The purpose of this work is to design an optimized RF transmit phase gradient array for spatial encoding in a transverse direction (x- or y- axis) for a 0.2T vertical B0 field MRI system, using a single transmitter channel. This requires the generation of two transmit B1 RF fields with uniform amplitude and positive and negative linear phase gradients respectively over the imaging volume. Materials and Methods: A two-element array consisting of a double Maxwell-type coil and a Helmholtz-type coil was designed using 3D field simulations. The phase gradient polarity is set by the relative phase of the RF signals driving the simultaneously energized elements. Results: Field mapping and 1D TRASE imaging experiments confirmed that the constructed coil produced the fields and operated as designed. A substantially larger imaging volume relative to that obtainable from a non-optimized Maxwell-Helmholtz design was achieved. Conclusion: The Maxwell (sine)-Helmholtz (cosine) approach has proven successful for a horizontal phase gradient coil. A similar approach may be useful for other phase-gradient coil designs. © 2013 Elsevier Inc.
Keywords: article; diode; image analysis; image processing; image quality; mathematical analysis; nuclear magnetic resonance imaging; priority journal; process design; process model; process optimization; process technology; signal detection; Transmit Array Spatial Encoding magnetic resonance imaging

Universal IMF versus dark halo response in early-type galaxies: Breaking the degeneracy with the Fundamental Plane - Dutton, A.A.; Macciò, A.V.; Mendel, J.T.; Simard, L. (Monthly Notices of the Royal Astronomical Society, 2013)
We use the relations between aperture stellar velocity dispersion (σap), stellar mass (MSPS) and galaxy size (Re) for a sample of ~150 000 early-type galaxies from Sloan Digital Sky Survey/DR7 to place constraints on the stellar initial mass function (IMF) and dark halo response to galaxy formation.We build λ cold dark matter-based mass models that reproduce, by construction, the relations between galaxy size, light concentration and stellar mass, and use the spherical Jeans equations to predict σap. Given our model assumptions (including those in the stellar population synthesis models), we find that reproducing the median σap versus MSPS relation is not possible with both a universal IMF and a universal dark halo response. Significant departures from a universal IMF and/or dark halo response are required, but there is a degeneracy between these two solutions. We show that this degeneracy can be broken using the strength of the correlation between residuals of the velocity-mass (δlog σap) and size-mass (δlog Re) relations. The slope of this correlation, ∂VR = δlog σap/δ logRe, varies systematically with galaxy mass from ∂VR ≃ -0.45 at MSPS ~ 1010M⊙ to ∂VR ≃ -0.15 at MSPS ~ 1011.6M⊙. The virial Fundamental Plane (FP) has ∂VR = -1/2, and thus we find that the tilt of the observed FP is mass dependent. Reproducing this tilt requires both a nonuniversal IMF and a non-universal halo response. Our best model has mass-follows-light at low masses (MSPS ≲ 1011.2M⊙) and unmodified Navarro, Frenk and White haloes at MSPS ~ 1011.5M⊙. The stellar masses imply a mass-dependent IMF which is 'lighter' than Salpeter at low masses and 'heavier' than Salpeter at high masses. © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.

Low-Temperature approach to highly emissive copper indium sulfide colloidal nanocrystals and their bioimaging applications - Yu, Kui; Ng, Peter; Ouyang, Jianying; Zaman, Md. Badruz; Abulrob, Abedelnasser; Baral, Toya Nath; Fatehi, Dorothy; Jakubek, Zygmunt J.; Kingston, David; Wu, Xiaohua; Liu, Xiangyang; Hebert, Charlie; et al. (ACS Applied Materials and Interfaces, 2013)
We report our newly developed low-temperature synthesis of colloidal photoluminescent (PL) CuInS2 nanocrystals (NCs) and their in vitro and in vivo imaging applications. With diphenylphosphine sulphide (SDPP) as a S precursor made from elemental S and diphenylphosphine, this is a noninjection based approach in 1-dodecanethiol (DDT) with excellent synthetic reproducibility and large-scale capability. For a typical synthesis with copper iodide (CuI) as a Cu source and indium acetate (In(OAc)3) as an In source, the growth temperature was as low as 160 C and the feed molar ratios were 1Cu-to-1In-to-4S. Amazingly, the resulting CuInS2 NCs in toluene exhibit quantum yield (QY) of ∼23% with photoemission peaking at ∼760 nm and full width at half maximum (FWHM) of ∼140 nm. With a mean size of ∼3.4 nm (measured from the vertices to the bases of the pyramids), they are pyramidal in shape with a crystal structure of tetragonal chalcopyrite. In situ 31P NMR (monitored from 30 C to 100 C) and in situ absorption at 80 C suggested that the Cu precursor should be less reactive toward SDPP than the In precursor. For our in vitro and in vivo imaging applications, CuInS 2/ZnS core-shell QDs were synthesized; afterwards, dihydrolipoic acid (DHLA) or 11-mercaptoundecanoic acid (MUA) were used for ligand exchange and then bio-conjugation was performed. Two single-domain antibodies (sdAbs) were used. One was 2A3 for in vitro imaging of BxPC3 pancreatic cancer cells. The other was EG2 for in vivo imaging of a Glioblastoma U87MG brain tumour model. The bioimaging data illustrate that the CuInS2 NCs from our SDPP-based low-temperature noninjection approach are good quality.
Keywords: CuInS2 nanocrystals; quantum dots; diphenylphosphine sulphide; in vitro imaging; in vivo imaging

Lateral spin injection and detection through electrodeposited Fe/GaAs contacts - Majumder, S.; Kardasz, B.; Kirczenow, G.; Thorpe, A.S.; Kavanagh, K.L. (Semiconductor Science and Technology, 2013)
Efforts to achieve efficient injection of spin-polarized electrons into a semiconductor, a key prerequisite for developing electronics that exploit the electron's spin degree of freedom, have so far met with limited success. Here we report experimental studies of lateral spin injection and detection through electrodeposited Fe/GaAs tunnel contacts. We demonstrate spin injection efficiencies two orders of magnitude higher than for state-of-the-art contacts fabricated via ultra-high-vacuum methods, including those with MgO or Al 2O3 tunnel barriers. To account for this enhancement, we propose that an iron oxide layer that forms at the Fe/GaAs interface during electrodeposition, being magnetic acts as a tunnel barrier with a spin-dependent height, presenting quantum spin transport calculations for such systems. This serendipitous discovery of greatly enhanced efficiency of spin injection into GaAs via electrodeposited contacts introduces a promising new direction for the development of practical semiconductor spintronic devices. © 2013 IOP Publishing Ltd.
Keywords: Enhanced efficiency; Experimental studies; GaAs; Iron oxide layers; MgO; Orders of magnitude; Quantum spin transport; Serendipitous discovery; Spin degrees; Spin injection; Spin injection and detections; Spin-injection efficiency; Spin-polarized electrons; Spintronic device; Tunnel barrier; Tunnel contacts; Iron oxides; Semiconductor devices; Electrodeposition

The NRC autocollimator calibration facility - Eves, B.J. (Metrologia, 2013)
An autocollimator calibration facility has been developed based upon both a precision rotary table and a sine-bar. The traceability of the system is through sub-division of the circle and hence to the SI unit of angle, and does not require traceability to the definition of the metre. The rotary encoder that measures the angle of the rotary table is calibrated through circle closure techniques to a combined standard uncertainty of 0.013 arcsec at 5° intervals. The rotation of the sine-bar is measured by two interferometers, and together with the rotary encoder, enables calibration of the scale factor of an autocollimator to a combined standard uncertainty of 1.8 × 10 -5. © 2013 BIPM & IOP Publishing Ltd.
Keywords: Autocollimators; Rotary encoder; Rotary tables; Scale Factor; Standard uncertainty; Plant shutdowns; Calibration

A consensus map of rapeseed (Brassica napus L.) based on diversity array technology markers: Applications in genetic dissection of qualitative and quantitative traits - Raman, H.; Raman, R.; Kilian, A.; Detering, F.; Long, Y.; Edwards, D.; Parkin, I.A.P.; Sharpe, A.G.; Nelson, M.N.; Larkan, N.; Zou, J.; Meng, J.; et al. (BMC Genomics, 2013)
Background: Dense consensus genetic maps based on high-throughput genotyping platforms are valuable for making genetic gains in Brassica napus through quantitative trait locus identification, efficient predictive molecular breeding, and map-based gene cloning. This report describes the construction of the first B. napus consensus map consisting of a 1,359 anchored array based genotyping platform; Diversity Arrays Technology (DArT), and non-DArT markers from six populations originating from Australia, Canada, China and Europe. We aligned the B. napus DArT sequences with genomic scaffolds from Brassica rapa and Brassica oleracea, and identified DArT loci that showed linkage with qualitative and quantitative loci associated with agronomic traits.Results: The integrated consensus map covered a total of 1,987.2 cM and represented all 19 chromosomes of the A and C genomes, with an average map density of one marker per 1.46 cM, corresponding to approximately 0.88 Mbp of the haploid genome. Through in silico physical mapping 2,457 out of 3,072 (80%) DArT clones were assigned to the genomic scaffolds of B. rapa (A genome) and B. oleracea (C genome). These were used to orientate the genetic consensus map with the chromosomal sequences. The DArT markers showed linkage with previously identified non-DArT markers associated with qualitative and quantitative trait loci for plant architecture, phenological components, seed and oil quality attributes, boron efficiency, sucrose transport, male sterility, and race-specific resistance to blackleg disease.Conclusions: The DArT markers provide increased marker density across the B. napus genome. Most of the DArT markers represented on the current array were sequenced and aligned with the B. rapa and B. oleracea genomes, providing insight into the Brassica A and C genomes. This information can be utilised for comparative genomics and genomic evolution studies. In summary, this consensus map can be used to (i) integrate new generation markers such as SNP arrays and next generation sequencing data; (ii) anchor physical maps to facilitate assembly of B. napus genome sequences; and (iii) identify candidate genes underlying natural genetic variation for traits of interest. © 2013 Raman et al.; licensee BioMed Central Ltd.
Keywords: article; chromosome map; consensus sequence; controlled study; diversity array technology; gene locus; gene mapping; genetic linkage; genetic procedures; genetic trait; genetic variability; genotype; microarray analysis; molecular cloning; nonhuman; plant genetics; qualitative analysis; quantitative genetics; quantitative trait locus; quantitative trait locus mapping; rapeseed; sequence homology; single nucleotide polymorphism; Agriculture; Brassica napus; Chromosome Mapping; Consensus; Genetic Linkage; Genetic Variation; Genome, Plant; Genotyping Techniques; Quantitative Trait Loci; Brassica; Brassica napus; Brassica oleracea; Brassica rapa

Dumbbell-Like Fe3O4-Au nanoparticles for ultrabroadband electromagnetic losses by heterogeneous interfacial polarizations - Zhang, X.; Guan, P.; Guo, J. (Particle and Particle Systems Characterization, 2013)
Dumbbell-like Fe3O4-Au superparamagnetic nanoparticles exhibit enhanced electromagnetic losses at gigahertz ascribed to the epitaxial Fe3O4/Au interfaces that induce anisotropic polarizations. This provides insight into the microscopic dielectric polarization of heterogeneous hybrids of noble metal and magnetic oxide and thus has implication for potential applications, such as the development of high electromagnetic loss materials. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Keywords: Au nanoparticle; Dielectric polarization; Dumbbell likes; Electromagnetic loss; Interfacial polarization; Magnetic oxides; Superparamagnetic nanoparticles; Ultra-broadband; Dielectric materials; Electromagnetism; Hybrid materials; Nanoparticles; Polarization; Gold

Optical control of magnetization and spin blockade in graphene quantum dots - Güçlü, A.D.; Hawrylak, P. (Physical Review B - Condensed Matter and Materials Physics, 2013)
We show that the magnetization of triangular graphene quantum dots with zigzag edges can be manipulated optically. When the system is charge neutral, the magnetic moment can be first erased by addition of a single electron spin with a gate, then restored by absorption of a photon. The conversion of a single photon to a magnetic moment results in a many-body effect, optical spin blockade. The effect demonstrated here can potentially lead to efficient spin to photon conversion, quantum memories, and single-photon detectors.

Flagellin in fusion with human rotavirus structural proteins exerts an adjuvant effect when delivered with replicating but non-disseminating adenovectors through the intrarectal route - Girard, A.; Roques, E.; Massie, B.; Archambault, D. (Molecular Biotechnology, 2013)
Human rotavirus (HRV) is the worldwide leading cause of gastroenteritis in young children. Two live attenuated HRV vaccines have been approved since 2006. However, these live vaccines still have potential risks including reversion of virulence. Adenoviruses are suitable vectors for mucosal administration of subunit vaccines. In addition to the adjuvant effect of certain adenovirus components, the use of an adjuvant like flagellin is also another means to increase the immune response to the immunogen. The aim of this study was to determine whether flagellin in fusion with HRV structural proteins stimulates the innate immune response and enhances the HRV-specific immune response when delivered through the intrarectal route with replicating but non-disseminating adenovector (R-AdV). Salmonella typhimurium flagellin B (FljB) in fusion with HRV VP4Δ::VP7 protein induced IL-1β production in J774A.1 macrophages exposed to the R-AdV. Intrarectal administration of R-AdVs expressing either VP4Δ::VP7 or VP4Δ::VP7::FljB in BALB/c mice resulted in HRV-specific mixed Th1/Th2 immune responses. The HRV-specific antibody response elicited with the use of R-AdV expressing VP4Δ::VP7::FljB was higher than that with R-AdV expressing VP4Δ::VP7. The results also show that the replication capability of R-AdVs contributed to enhance the HRV-specific immune response as compared with that obtained with non-replicative AdVs. This work lays the foundation for using the R-AdV system and FljB-adjuvanted formulation to elicit a mucosal immune response specific to HRV. © 2013 Springer Science+Business Media New York.

Impact of tsunami forces on structures the university of Ottawa experience - Palermo, D.; Nistor, I.; Al-Faesly, T.; Cornett, A. (Science of Tsunami Hazards, 2013)
Over the past seven years, a comprehensive interdisciplinary research program has been conducted between researchers at the University of Ottawa and at the Canadian Hydraulics Centre (CHC) of the National Research Council of Canada. The objectives of this on-going research program are to identify and quantify forces that are imposed on near-shoreline structures when exposed to tsunamiinduced hydraulic bores and to investigate mitigation strategies to dampen these forces. The experimental component of this research program involves two structural models (square and circular) that are tested in the High Discharge Flume at CHC. The structural models are instrumented to record base shear force-, base overturning moment-, pressure-, acceleration-, lateral displacement- and bore depth-time histories continually during testing. Impact loading resulting from wood debris of different sizes and located at pre-determined distances from the structural models is also studied. Furthermore, this research program aims to review tsunami-induced forces on structures prescribed by recent design documents.

Understanding genomic alterations in cancer genomes using an integrative network approach - Wang, E. (Cancer Letters, 2013)
In recent years, cancer genome sequencing and other high-throughput studies of cancer genomes have generated many notable discoveries. In this review, novel genomic alteration mechanisms, such as chromothripsis (chromosomal crisis) and kataegis (mutation storms), and their implications for cancer are discussed. Genomic alterations spur cancer genome evolution. Thus, the relationship between cancer clonal evolution and cancer stems cells is commented. The key question in cancer biology concerns how these genomic alterations support cancer development and metastasis in the context of biological functioning. Thus far, efforts such as pathway analysis have improved the understanding of the functional contributions of genetic mutations and DNA copy number variations to cancer development, progression and metastasis. However, the known pathways correspond to a small fraction, plausibly 5-10%, of somatic mutations and genes with an altered copy number. To develop a comprehensive understanding of the function of these genomic alterations in cancer, an integrative network framework is proposed and discussed. Finally, the challenges and the directions of studying cancer omic data using an integrative network approach are commented. © 2012.

Spatial-spectral coupling in coherent anti-Stokes Raman scattering microscopy - Barlow, A.M.; Popov, K.; Andreana, M.; Moffatt, D.J.; Ridsdale, A.; Slepkov, A.D.; Harden, J.L.; Ramunno, L.; Stolow, A. (Optics Express, 2013)
Coherent anti-Stokes Raman scattering (CARS) microscopy is a third-order nonlinear optical technique which permits label-free, molecule-specific hyperspectral imaging. The interference between coherent resonant and non-resonant terms leads to well known distortions in the vibrational spectrum, requiring the use of retrieval algorithms. It also leads to spatial imaging distortions, largely due to the Gouy phase, when objects are smaller than the Rayleigh range. Here we consider that the focal position and spectral contributions to the nonlinear image formation are intrinsically coupled and cannot be corrected by conventional retrieval methods. © 2013 Optical Society of America.
Keywords: Coherent anti-Stokes Raman scattering microscopy; Focal positions; Hyperspectral Imaging; Retrieval algorithms; Retrieval methods; Spatial imaging; Spectral contribution; Third-order nonlinear optical; Raman scattering; Raman spectroscopy; Coherent scattering

Draft genome sequence of chickpea (Cicer arietinum) provides a resource for trait improvement - Varshney, R.K.; Song, C.; Saxena, R.K.; Azam, S.; Yu, S.; Sharpe, A.G.; Cannon, S.; Baek, J.; Rosen, B.D.; Tar'an, B.; Millan, T.; Zhang, X.; et al. (Nature Biotechnology, 2013)
Chickpea (Cicer arietinum) is the second most widely grown legume crop after soybean, accounting for a substantial proportion of human dietary nitrogen intake and playing a crucial role in food security in developing countries. We report the ∼738-Mb draft whole genome shotgun sequence of CDC Frontier, a kabuli chickpea variety, which contains an estimated 28,269 genes. Resequencing and analysis of 90 cultivated and wild genotypes from ten countries identifies targets of both breeding-associated genetic sweeps and breeding-associated balancing selection. Candidate genes for disease resistance and agronomic traits are highlighted, including traits that distinguish the two main market classes of cultivated chickpea - desi and kabuli. These data comprise a resource for chickpea improvement through molecular breeding and provide insights into both genome diversity and domestication. Copyright © 2013 Nature America, Inc.
Keywords: Agronomic traits; Balancing selection; Cicer arietinum; Disease resistance; Genome sequences; Molecular breeding; Trait improvement; Whole-genome shotgun; Developing countries; Food supply; Genes; agronomic trait; article; balancing selection; breeding; chickpea; gene sequence; genotype; nonhuman; nucleotide sequence; plant genome; priority journal; Agriculture; Cicer; Disease Resistance; DNA; Genetic Variation; Genome, Plant; Genotype; Phylogeny; Repetitive Sequences, Nucleic Acid; Sequence Analysis, DNA

Maintaining preference networks that adapt to changing preferences - Lee, Ki Hyang; Buffett, Scott; Fleming, Michael W. (Advances in Artificial Intelligence : 26th Canadian Conference on Artificial Intelligence, Canadian AI 2013, Regina, SK, Canada, May 28-31, 2013. Proceedings, 2013)
Decision making can be more difficult with an enormous amount of information, not only for humans but also for automated decision making processes. Although most user preference elicitation models have been developed based on the assumption that user preferences are stable, user preferences may change in the long term and may evolve with experience, resulting in dynamic preferences. Therefore, in this paper, we describe a model called the dynamic preference network (DPN) that is maintained using an approach that does not require the entire preference graph to be rebuilt when a previously-learned preference is changed, with efficient algorithms to add new preferences and to delete existing preferences. DPNs are shown to outperform existing algorithms for insertion, especially for large numbers of attributes and for dense graphs. They do have some shortcomings in the case of deletion, but only when there is a small number of attributes or when the graph is particularly dense. © 2013 Springer-Verlag.
Keywords: Amount of information; Automated decision making; Dense graphs; Preference elicitation; Preference graph; Transitive reductions; User Modeling; Algorithms; Decision making; Artificial intelligence

Model investgatons on wave disturbance and vessel movements in Dawei Sea Port, Myanmar - Bayram, A.; Carr, C.; Zhang, Y.; Knox, P. (Ports 2013: Success Through Diversification - Proceedings of the 13th Triennial International Conference, 2013)
This paper describes the use of numerical and physical modeling studies for the design of a new port on the southwestern coast of Myanmar. A series of numerical modeling scenarios was carried out to optimize the port layout including entrance channel with respect to wave penetration into the port, and to refine the design wave conditions for the sizing of the primary armor on the breakwaters. Wave conditions inside and outside the port was assessed using a two-dimensional Boussinesq wave model. As a part of design process, three-dimensional physical (scale) modeling studies were undertaken at the Canadian Hydraulic Centre (CHC) in Ottawa, Canada to refine and further optimize wave agitation and disturbance levels within the port basins. This paper focuses on the influence of the length of the main breakwater section on the wave conditions and downtime inside the port, and compares the results from the numerical and physical modeling. © 2013 American Society of Civil Engineers.
Keywords: Design process; Disturbance level; Model study; Numerical and physical modeling; Wave conditions; Wave disturbances; Wave modeling; Wave penetration; Breakwaters; Models; Optimization; Coastal engineering

Bipolar spin blockade and coherent state superpositions in a triple quantum dot - Busl, M.; Granger, G.; Gaudreau, L.; Sánchez, R.; Kam, A.; Pioro-Ladrière, M.; Studenikin, S.A.; Zawadzki, P.; Wasilewski, Z.R.; Sachrajda, A.S.; Platero, G. (Nature Nanotechnology, 2013)
Spin qubits based on interacting spins in double quantum dots have been demonstrated successfully. Readout of the qubit state involves a conversion of spin to charge information, which is universally achieved by taking advantage of a spin blockade phenomenon resulting from Pauli's exclusion principle. The archetypal spin blockade transport signature in double quantum dots takes the form of a rectified current. At present, more complex spin qubit circuits including triple quantum dots are being developed. Here we show, both experimentally and theoretically, that in a linear triple quantum dot circuit the spin blockade becomes bipolar with current strongly suppressed in both bias directions and also that a new quantum coherent mechanism becomes relevant. In this mechanism, charge is transferred non-intuitively via coherent states from one end of the linear triple dot circuit to the other, without involving the centre site. Our results have implications for future complex nanospintronic circuits. Copyright © 2013 Macmillan Publishers Limited. All rights reserved.
Keywords: linear triple quantum dot; quantum dot; unclassified drug; article; bipolar spin blockade; electron transport; magnetic field; priority journal; process design; quantum mechanics

Wavelength independent multimode interference coupler - Maese-Novo, A.; Halir, R.; Romero-García, S.; Pérez-Galacho, D.; Zavargo-Peche, L.; Ortega-Moñux, A.; Molina-Fernández, I.; Wangüemert-Pérez, J.G.; Cheben, P. (Optics Express, 2013)
We propose an ultra-broadband multimode interference (MMI) coupler with a wavelength range exceeding the O, E, S, C, L and U optical communication bands. For the first time, the dispersion property of the MMI section is engineered using a subwavelength grating structure to mitigate wavelength dependence of the device. We present a 2 × 2 MMI design with a bandwidth of 450nm, an almost fivefold enhancement compared to conventional designs, maintaining insertion loss, power imbalance and MMI phase deviation below 1dB, 0.6dB and 3°, respectively. The design is performed using an in-house tool based on the 2D Fourier Eigenmode Expansion Method (F-EEM) and verified with a 3D Finite Difference Time Domain (FDTD) simulator. © 2013 Optical Society of America.
Keywords: 3d finite difference time domains; Conventional design; Dispersion properties; Eigen-mode expansion; Multimode interference couplers; Optical communication bands; Sub-wave length grating; Wavelength dependence; Finite difference time domain method; Integrated optics; Time domain analysis; Design; article; computer aided design; equipment; equipment design; equipment failure; refractometry; surface plasmon resonance; telecommunication; Computer-Aided Design; Equipment Design; Equipment Failure Analysis; Refractometry; Surface Plasmon Resonance; Telecommunications

High-resolution MRI encoding using radiofrequency phase gradients - Sharp, J.C.; King, S.B.; Deng, Q.; Volotovskyy, V.; Tomanek, B. (NMR in Biomedicine, 2013)
Although MRI offers highly diagnostic medical imagery, patient access to this modality worldwide is very limited when compared with X-ray or ultrasound. One reason for this is the expense and complexity of the equipment used to generate the switched magnetic fields necessary for MRI encoding. These field gradients are also responsible for intense acoustic noise and have the potential to induce nerve stimulation. We present results with a new MRI encoding principle which operates entirely without the use of conventional B0 field gradients. This new approach - 'Transmit Array Spatial Encoding' (TRASE) - uses only the resonant radiofrequency (RF) field to produce Fourier spatial encoding equivalent to conventional MRI. k-space traversal (image encoding) is achieved by spin refocusing with phase gradient transmit fields in spin echo trains. A transmit coil array, driven by just a single transmitter channel, was constructed to produce four phase gradient fields, which allows the encoding of two orthogonal spatial axes. High-resolution two-dimensional-encoded in vivo MR images of hand and wrist were obtained at 0.2 T. TRASE exploits RF field phase gradients, and offers the possibility of very low-cost diagnostics and novel experiments exploiting unique capabilities, such as imaging without disturbance of the main B0 magnetic field. Lower field imaging (<1 T) and micro-imaging are favorable application domains as, in both cases, it is technically easier to achieve the short RF pulses desirable for long echo trains, and also to limit RF power deposition. As TRASE is simply an alternative mechanism (and technology) of moving through k space, there are many close analogies between it and conventional B0-encoded techniques. TRASE is compatible with both B0 gradient encoding and parallel imaging, and so hybrid sequences containing all three spatial encoding approaches are possible. © 2013 John Wiley & Sons, Ltd.
Keywords: K-space; Phase gradient; RF; RF arrays; RF coil; Spatial encoding; Acoustic noise; Magnetic fields; Magnetic resonance imaging; Encoding (symbols); article; Fourier analysis; image analysis; imaging system; magnetic field; mathematical model; nuclear magnetic resonance imaging; phantom; priority journal; radiofrequency; Transmit Array Spatial Encoding

Bright single-photon sources based on self-aligned quantum dots in tapered nanowire waveguides - Reimer, M.E.; Bulgarini, G.; Bakkers, E.P.A.M.; Dalacu, D.; Poole, P.J.; Zwiller, V. (SPIE - International Society for Optical Engineering. Proceedings, 2013)
Single quantum dots embedded in tapered nanowire waveguides have emerged as leading candidates for designing high efficiency single-photon and entangled photon sources, with efficiencies exceeding 90%. Here we have developed a bottom-up growth approach that allows for independent control of boththe quantum dot size, and position, as well as the nanowire shape. Importantly, by design, the single quantum dot is always found perfectly on the nanowire axis. By integrating a gold mirror at the base of a tapered nanowire waveguide we obtain a 20-fold enhancement in the single-photon flux in comparison to no waveguide. The 20-fold enhancement is accompanied by a shortening of the exciton lifetime as the quantum emitter couples to the fundamental waveguide mode with an increased rate. Finally, the optical quality of the emitter is drastically improved by removing the nanowire stacking faults in the vicinity of the quantum dot. As a result, we demonstrate very pure single-photon emission with a probability of multi-photon emission below 1%, and an emission line width that is reduced by at least an order of magnitude (<30 μeV) as compared to when stacking faults were present in the nanowire (as high as 10-100 per micron). The demonstrated brightness of our single-photon source (42 % efficiency), combined with the very pure single photon emission and high spectral purity is encouraging in development of future quantum technologies based on nanowires, such as interfacing remote quantum bits or constructing a secure quantum network. © 2013 Copyright SPIE.
Keywords: Entangled photons; Fundamental modes; Self-aligned; single-photon; taper; Efficiency; Elementary particle sources; Optoelectronic devices; Particle beams; Quantum cryptography; Semiconductor quantum dots; Stacking faults; Waveguides; Nanowires

Partial ionization in dense plasmas: Comparisons among average-atom density functional models - Murillo, M.S.; Weisheit, J.; Hansen, S.B.; Dharma-Wardana, M.W.C. (Physical Review E - Statistical, Nonlinear, and Soft Matter Physics, 2013)
Nuclei interacting with electrons in dense plasmas acquire electronic bound states, modify continuum states, generate resonances and hopping electron states, and generate short-range ionic order. The mean ionization state (MIS), i.e, the mean charge Z of an average ion in such plasmas, is a valuable concept: Pseudopotentials, pair-distribution functions, equations of state, transport properties, energy-relaxation rates, opacity, radiative processes, etc., can all be formulated using the MIS of the plasma more concisely than with an all-electron description. However, the MIS does not have a unique definition and is used and defined differently in different statistical models of plasmas. Here, using the MIS formulations of several average-atom models based on density functional theory, we compare numerical results for Be, Al, and Cu plasmas for conditions inclusive of incomplete atomic ionization and partial electron degeneracy. By contrasting modern orbital-based models with orbital-free Thomas-Fermi models, we quantify the effects of shell structure, continuum resonances, the role of exchange and correlation, and the effects of different choices of the fundamental cell and boundary conditions. Finally, the role of the MIS in plasma applications is illustrated in the context of x-ray Thomson scattering in warm dense matter. © 2013 American Physical Society.
Keywords: Average-atom model; Density-functional models; Electron degeneracy; Exchange and correlation; Pair distribution functions; Thomas-Fermi model; Warm dense matters; X ray Thomson scattering; Atoms; Equations of state; Ionization; Plasma applications; Transport properties; Plasmas

The impact of fire on seismic resistance of fibre reinforced polymer strengthened concrete structural systems - Bénichou, N.; Mostafaei, H.; Green, M.F.; Hollingshead, K. (Canadian Journal of Civil Engineering, 2013)
This paper presents the results of a research project to study the seismic resistance of fibre reinforced polymer (FRP) strengthened concrete members after fire exposure. Specifically, the paper presents results of FRP strengthened reinforced concrete columns exposed to a standard fire including temperatures measured during the test and a discussion of the loads applied to the columns. Finally, the paper also presents the impact of lateral loading on structural columns after fire to assess the effectiveness of structural resistance of fire-damaged FRP strengthened building elements in case of an earthquake. Numerical models to simulate the lateral behaviour are presented and the predictions are compared to the test results. Since the FRP strengthened columns were insulated with fire protection, the lateral load resistance of the unstrengthened column was reduced by less than 5% due to fire exposure. © 2013 Published by NRC Research Press.
Keywords: Building element; Concrete members; Fibre reinforced polymers; Reinforced concrete column; Seismic; Seismic resistance; Structural resistance; Structural systems; Columns (structural); Concretes; Earthquakes; Fiber reinforced plastics; Fires; Polymers; Reinforced concrete; Strengthening (metal); Fire resistance; column; concrete structure; fire; loading; numerical model; polymer; reinforcement; seismic response

Evaluation of the sea ice proxy IP25 against observational and diatom proxy data in the SW Labrador Sea - Weckström, K.; Massé, G.; Collins, L.G.; Hanhijärvi, S.; Bouloubassi, I.; Sicre, M.-A.; Seidenkrantz, M.-S.; Schmidt, S.; Andersen, T.J.; Andersen, M.L.; Hill, B.; Kuijpers, A. (Quaternary Science Reviews, 2013)
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.
Keywords: Diatoms; IP25; Labrador Sea; NAO; PIP25; Atmospheric pressure; Ocean currents; Phytoplankton; Sediments; Submarine geology; Sea ice; climate effect; climate modeling; diatom; environmental conditions; ice cover; ice drift; isoprenoid; marine sediment; North Atlantic Oscillation; sea ice; Atlantic Ocean; Canada; Labrador Sea; Newfoundland; Newfoundland and Labrador; Bacillariophyta

Ultrafast photoinduced dynamics of halogenated cyclopentadienes: Observation of geminate charge-transfer complexes in solution - Wolf, T.J.A.; Schalk, O.; Radloff, R.; Wu, G.; Lang, P.; Stolow, A.; Unterreiner, A.-N. (Physical Chemistry Chemical Physics, 2013)
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.
Keywords: cyclopentane derivative; article; chemistry; gas; halogenation; quantum theory; solution and solubility; ultraviolet radiation; X ray photoelectron spectroscopy; Cyclopentanes; Gases; Halogenation; Photoelectron Spectroscopy; Quantum Theory; Solutions; Ultraviolet Rays

Difference in the relative response of the alanine dosimeter to megavoltage x-ray and electron beams - Anton, M.; Kapsch, R.-P.; Krauss, A.; Von Voigts-Rhetz, P.; Zink, K.; McEwen, M. (Physics in Medicine and Biology, 2013)
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.
Keywords: Alanine dosimeters; Calorimetric measurements; Electron detectors; Experimental datum; Measurement and analysis; Monte Carlo simulations; Relative uncertainty; Uncertainty budget; Amino acids; Dosimeters; Dosimetry; Electron beams; Monte Carlo methods; Quality assurance; X rays; Uncertainty analysis; alanine; article; comparative study; electron; methodology; Monte Carlo method; radiometry; X ray; Alanine; Electrons; Monte Carlo Method; Radiometry; X-Rays

An approach to fatigue damage estimation of helicopter rotating components using computational intelligence techniques - Cheung, C.; Rocha, B.; Valdés, J.J.; Stefani, A.; Li, M. (Annual Forum Proceedings - AHS International, 2013)
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.
Keywords: Computational intelligence techniques; Dynamic component; Fatigue damage estimation; Operational flights; Rainflow cycle counting; Real aircraft; Remaining life prediction; Time signals; Artificial intelligence; Military helicopters; Flight control systems

Thermo-active elastomer composite for optical heating in microfluidic systems - Geissler, M.; Voisin, B.; Clime, L.; Le Drogoff, B.; Veres, T. (Small, 2013)
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.
Keywords: As doping; Elastomer composites; IR thermography; Laser lights; Mass fraction; Micro fluidic system; Optical heating; Temperature response; Infrared imaging; Single-walled carbon nanotubes (SWCN); Thermoplastic elastomers; Fluidic devices

High-resolution Fourier-transform spectrometer chip with microphotonic silicon spiral waveguides - Velasco, Aitor V.; Cheben, Pavel; Bock, Przemek J.; Delâge, André; Schmid, Jens H.; Lapointe, Jean; Janz, Siegfried; Calvo, María L.; Xu, Dan-Xia; Florjańczyk, Mirosław; Vachon, Martin (Optics Letters, 2013)
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.
Keywords: Amplitude errors; Compact devices; Fabrication imperfections; Fourier transform spectrometers; Free spectral range; High resolution; Interferograms; Microphotonic waveguides; Optical delay; Optical path delays; Output waveguides; Retrieval algorithms; Si wire waveguide; Spiral waveguides; Transformation matrices; Wavelength resolution; Fourier transform infrared spectroscopy; Linear transformations; Silicon; Spectrometers; Waveguides; silicon; algorithm; article; equipment; Fourier analysis; interferometry; laser; photon; spectroscopy; Algorithms; Fourier Analysis; Interferometry; Lasers; Photons; Silicon; Spectrum Analysis

Failure mechanisms and damage model of ductile cast iron under low-cycle fatigue conditions - Wu, Xijia; Quan, Tony; Sloss, Clayton (SAE Technical Papers, 2013)
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.
Keywords: Fractographic observations; Inelastic deformation; Intergranular embrittlement; Nonlinear interactions; Stress strain behaviours; Synergetic interactions; Temperature conditions; Thermo-mechanical damages; Coalescence; Constitutive models; Embrittlement; Fatigue damage; Plasticity; Strain rate; Surface defects; Textures; Creep

III-V access waveguides using atomic layer deposition - Mnaymneh, K.; Frédérick, S; Dalacu, D.; Lapointe, J; Poole, P.J.; Williams, R.L. (Advanced Fabrication Technologies for Micro/Nano Optics and Photonics VI, 2013)
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.
Keywords: Compound semiconductors; Critical parts; Optically Active; Photonic circuitry; Photonic crystal membranes; Quantum photonics; Selective area epitaxy; Silicon-on-insulators; Atomic layer deposition; Deposition; Quantum chemistry; Refractive index; Technology; Photonics

On the depolarization asymmetry seen in giant radio lobes - Bell, M.B.; Comeau, S.P. (Astrophysics and Space Science, 2013)
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.

Conserved glycolipid termini in capsular polysaccharides synthesized by ATP-binding cassette transporterdependent pathways in Gram-negative pathogens - Willis, L.M.; Stupak, J.; Richards, M.R.; Lowary, T.L.; Li, J.; Whitfield, C. (Proceedings of the National Academy of Sciences of the United States of America, 2013)
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.
Keywords: ABC transporter; glycerophospholipid; glycolipid; glycosaminoglycan polysulfate; polysaccharide; polysialic acid; amino acid sequence; article; bacterial capsule; biosynthesis; Escherichia coli; hydrophobicity; lipid analysis; molecular weight; Neisseria meningitidis; nonhuman; priority journal; proton nuclear magnetic resonance; capsule assembly; polysaccharide export; Adenosine Triphosphate; ATP-Binding Cassette Transporters; Bacterial Capsules; Biological Transport; Escherichia coli; Glycolipids; Gram-Negative Bacteria; Magnetic Resonance Spectroscopy; Mass Spectrometry; Methylation; Mutation; Neisseria meningitidis; Polysaccharides; Virulence Factors

Synthesis of high-purity LiMn2O4 with enhanced electrical properties from electrolytic manganese dioxide treated by sulfuric acid-assisted hydrothermal method - Guo, D.; Chang, Z.; Li, B.; Tang, H.; Yuan, X.-Z.; Wang, H. (Journal of Solid State Electrochemistry, 2013)
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.
Keywords: Cath-ode materials; Electrochemical reactions; Electrolytic manganese dioxides; High-temperature solid-phase; Lithium-ion battery; Lithium-ion battery cathodes; Spinel lithium manganese oxides; Sulfuric acid-assisted hydrothermal; Cathodes; Crystal impurities; Cyclic voltammetry; Diffusion; Electric properties; Electrochemical impedance spectroscopy; Lithium; Lithium alloys; Lithium batteries; Lithium compounds; Oxides; Scanning electron microscopy; Sulfuric acid; X ray diffraction; Manganese oxide

Graphene versus multi-walled carbon nanotubes for electrochemical glucose biosensing - Zheng, D.; Vashist, S.K.; Dykas, M.M.; Saha, S.; Al-Rubeaan, K.; Lam, E.; Luong, J.H.T.; Sheu, F.-S. (Materials, 2013)
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.
Keywords: 3-aminopropyltriethoxysilane; Direct electron transfer; Electrochemical glucose sensors; Glassy carbon electrodes; Glucose oxidases (GOx); Interfering substances; Pathological level; Pathophysiological; Glass membrane electrodes; Glucose; Glucose oxidase; Glucose sensors; Metabolites; Multiwalled carbon nanotubes (MWCN); Graphene

Coherent manipulation of three-spin states in a GaAs/AlGaAs triple dot device - Studenikin, S.; Aers, G.; Granger, G.; Gaudreau, L.; Kam, A.; Zawadzki, P.; Wasilewski, Z.R.; Sachrajda, A. (Physica Status Solidi (C) Current Topics in Solid State Physics, 2013)
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.
Keywords: Charge configuration; Coherent manipulation; Electron spin state; GaAs/AlGaAs; Initialization points; Stability diagram; Three-spin states; Triple quantum; Magnetic moments; Semiconductor quantum dots; Spin dynamics

HVOF Coating case study for power plant process control ball valve application - Vernhes, L.; Lee, D.A.; Poirier, D.; Li, D.; Klemberg-Sapieha, J.E. (Journal of Thermal Spray Technology, 2013)
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.
Keywords: Carbide precipitation; Chromium carbide; Cohesive failures; Failure mechanism; Power plant process; Self-fluxing alloys; Supercritical steam; Temperature variation; Carbides; Chromate coatings; Cracks; Decarburization; Failure (mechanical); High temperature applications; Power plants; HVOF thermal spraying

Stable structures of tantalum at high temperature and high pressure - Yao, Y.; Klug, D.D. (Physical Review B - Condensed Matter and Materials Physics, 2013)
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.

Fluorescence lifetime imaging of alterations to cellular metabolism by domain 2 of the Hepatitis C virus core protein - Mazumder, N.; Lyn, R.K.; Singaravelu, R.; Ridsdale, A.; Moffatt, D.J.; Hu, C.-W.; Tsai, H.-R.; McLauchlan, J.; Stolow, A.; Kao, F.-J.; Pezacki, J.P. (PLoS ONE, 2013)
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.
Keywords: core protein; fat droplet; green fluorescent protein; reduced nicotinamide adenine dinucleotide phosphate; virus RNA; article; cell metabolism; coherent anti Stokes Raman scattering microscopy; correlation analysis; enzyme activity; fluorescence; genetic transfection; glycolysis; hepatitis C; Hepatitis C virus; hepatoma cell; human; human cell; lipogenesis; liver metabolism; metabolic regulation; microscopy; mitochondrial energy transfer; molecular imaging; protein conformation; protein expression; protein function; protein localization; Raman spectrometry

Two mass distributions in the L 1641 molecular clouds: The Herschel connection of dense cores and filaments in Orion A - Polychroni, D.; Schisano, E.; Elia, D.; Roy, A.; Molinari, S.; Martin, P.; André, Ph.; Turrini, D.; Rygl, K.L.J.; Di Francesco, J.; Benedettini, M.; Busquet, G.; et al. (The Astrophysical Journal Letters, 2013)
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.

Chemical structure of the carbohydrate backbone of the lipopolysaccharide from Piscirickettsia salmonis - Vinogradov, E.; Frimmelova, M.; Toman, R. (Carbohydrate Research, 2013)
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.
Keywords: Backbone structures; Chemical degradation; LPS; Methylation analysis; MS; Piscirickettsia salmonis; Pseudaminic acid; Structural information; Alkylation; Chemical analysis; Mass spectrometry; Nuclear magnetic resonance; Structure (composition); Carbohydrates; arabinose derivative; carbohydrate derivative; formic acid derivative; lipid A; lipopolysaccharide; monosaccharide; oligosaccharide; polymer; article; carbohydrate analysis; carbon nuclear magnetic resonance; chemical structure; degradation; mass spectrometry; methylation; nonhuman; Piscirickettsia salmonis; piscirickettsiosis; priority journal; proton nuclear magnetic resonance; Piscirickettsia salmonis; Salmonidae

Morphology and expression status investigations of specific surface markers on B-cell chronic lymphocytic leukemia cells - Niu, S.; Chan, R.; Berini, P.; Wang, C.; Zou, S. (Microscopy Research and Technique, 2013)
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.

Structural analysis of a novel cyclohexylamine oxidase from brevibacterium oxydans IH-35A - Mirza, I.A.; Burk, D.L.; Xiong, B.; Iwaki, H.; Hasegawa, Y.; Grosse, S.; Lau, P.C.K.; Berghuis, A.M. (PLoS ONE, 2013)
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.
Keywords: alicyclic amine; aliphatic amine; cyclohexanone; cyclohexylamine oxidase; flavine adenine nucleotide; oxidoreductase; unclassified drug; unspecific monooxygenase; article; bacterial gene; binding site; Brevibacterium; brevibacterium oxydans; chaA gene; conformational transition; crystal structure; enzyme purification; enzyme specificity; enzyme structure; Escherichia coli; gene expression; hydrophobicity; molecular cloning; molecular dynamics; nonhuman; nucleotide sequence; structure analysis; Bacterial Proteins; Brevibacterium; Oxidoreductases Acting on CH-NH Group Donors; Substrate Specificity; Escherichia coli; Microbacterium oxydans

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 - Mercier, L.G.; Aïch, B.R.; Najari, A.; Beaupré, S.; Berrouard, P.; Pron, A.; Robitaille, A.; Tao, Y.; Leclerc, M. (Polymer Chemistry, 2013)
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.
Keywords: Arylation reactions; Bulk heterojunction solar cells; Cross coupling reactions; Cross-linked materials; Cross-linked polymers; Heteroarylation; Organic solar cell; Polymerization reaction; Crosslinking; Heterojunctions; Monomers; Polymerization; Polymers; Solar cells; Aromatic compounds

Acceptance testing and commissioning of a flight simulator for rotorcraft simulation fidelity research - White, M.D.; Perfect, P.; Padfield, G.D.; Gubbels, A.W.; Berryman, A.C. (Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering, 2013)
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.
Keywords: Certification standards; Fidelity; Flight; Modelling and simulations; Research environment; Rotorcraft; Rotorcraft industry; University of Liverpool; Accident prevention; Environmental impact; Flight simulators; Helicopter rotors; Helicopter services; Research aircraft; Rotors; Simulators; Research

Complex long-range magnetic ordering in the Mn-bearing dugganite Pb 3TeMn3P2O14 - Silverstein, H.J.; Sharma, A.Z.; Cruz-Kan, K.; Zhou, H.D.; Huq, A.; Flacau, R.; Wiebe, C.R. (Journal of Solid State Chemistry, 2013)
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.
Keywords: Antiferromagnetics; Dugganite; Langasites; Long range magnetic order; Magnetic transitions; Magnetization measurements; Magnetoelectric couplings; Neutron scattering measurements; Antiferromagnetic materials; Neutron scattering; Silicon; Lead

A relation between the warm neutral and ionized media observed in the Canadian Galactic plane survey - Foster, T.; Kothes, R.; Brown, J. C. (The Astrophysical Journal Letters, 2013)
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..

Corrosion inhibition of Al-B4C metal matrix composites in a NaCl solution by benzotriazole - Han, Y.-M.; Gallant, D.; Chen, X.-G. (Materials Chemistry and Physics, 2013)
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.
Keywords: Corrosion inhibition; Corrosion inhibition efficiency; Electrochemical impedance; Electrochemical techniques; Freundlich adsorption isotherms; Infrared reflections; Inhibition efficiency; Metal matrix composites; Adsorption; Aluminum; Corrosion; Efficiency; Metallic matrix composites; Corrosion inhibitors

Geometry, chirality, topology and electron-electron interactions in the quadruple quantum dot molecule - Ozfidan, I.; Trojnar, A.H.; Korkusinski, M.; Hawrylak, P. (Solid State Communications, 2013)
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.
Keywords: Electronic transport; Exact diagonalization method; Extended Hubbard model; Fermi statistics; Matrix elements; Number of electrons; Quantum dot molecules; Topological phase; Chirality; Electron-electron interactions; Electronic properties; Geometry; Molecules; Semiconductor quantum dots; Stars; Topology; Stereochemistry

Structurally unique interaction of RBD-like and PH domains is crucial for yeast pheromone signaling - Yerko, V.; Sulea, T.; Ekiel, I.; Harcus, D.; Baardsnes, J.; Cyglera, M.; Whiteway, M.; Wu, C. (Molecular Biology of the Cell, 2013)
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.
Keywords: mitogen activated protein kinase kinase; pheromone; protein Ste11; protein Ste5; scaffold protein; ubiquitin; unclassified drug; amino acid sequence; article; binding site; cell cycle arrest; cellular distribution; crystal structure; mutational analysis; nonhuman; priority journal; protein binding; protein domain; protein expression; protein folding; protein function; protein motif; protein protein interaction; protein structure; Saccharomyces cerevisiae; Schizosaccharomyces pombe; signal transduction; Adaptor Proteins, Signal Transducing; Amino Acid Substitution; Binding Sites; Genes, Mating Type, Fungal; MAP Kinase Kinase Kinases; Models, Molecular; Mutagenesis, Site-Directed; Peptide Mapping; Pheromones; Protein Binding; Protein Interaction Domains and Motifs; Protein Structure, Secondary; Protein Transport; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Signal Transduction

The capsular polysaccharide and lipopolysaccharide structures of two carbapenem resistant Klebsiella pneumoniae outbreak isolates - Kubler-Kielb, J.; Vinogradov, E.; Ng, W.-I.; MacZynska, B.; Junka, A.; Bartoszewicz, M.; Zelazny, A.; Bennett, J.; Schneerson, R. (Carbohydrate Research, 2013)
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.
Keywords: Capsular polysaccharides; CRKP; Klebsiella pneumoniae; KPC; LPS; National Institutes of Health; O-specific polysaccharides; Therapeutic solutions; Organic compounds; Structure (composition); Synthesis (chemical); Bacteria; carbapenem; lipopolysaccharide; polysaccharide; article; bacterium isolate; carbohydrate analysis; Klebsiella pneumoniae; methylation; molecular typing; nonhuman; nuclear magnetic resonance spectroscopy; polyacrylamide gel electrophoresis; priority journal; silver staining; Anti-Bacterial Agents; Carbapenems; Drug Resistance, Bacterial; Klebsiella pneumoniae; Lipopolysaccharides; Polysaccharides, Bacterial; Klebsiella pneumoniae

Determination of total mercury in biological tissue by isotope dilution ICPMS after UV photochemical vapor generation - Liu, R.; Xu, M.; Shi, Z.; Zhang, J.; Gao, Y.; Yang, L. (Talanta, 2013)
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.
Keywords: Biological samples; Certified reference materials; Chemical vapor generation; External calibration; Isotope dilution inductively coupled plasma mass spectrometry; Isotope dilutions; Pneumatic nebulization; Sample preparation procedure; Formic acid; Inductively coupled plasma; Inductively coupled plasma mass spectrometry; Isotopes; Mass spectrometry; Mercury (metal); Vapors; Tissue

Contemporary research on E-business technology and strategy: International Conference, iCETS 2012 Tianjin, China, august 29-31, 2012 revised selected papers - Khachidze, V.; Wang, T.; Siddiqui, S.; Liu, V.; Cappuccio, S.; Lim, A. (Communications in Computer and Information Science, 2013)

Tracing electron beams in the sun's corona with radio dynamic imaging spectroscopy - Chen, B.; Bastian, T.S.; White, S.M.; Gary, D.E.; Perley, R.; Rupen, M.; Carlson, B. (The Astrophysical Journal Letters, 2013)
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.

Structural studies of the cell wall polysaccharides from three strains of Lactobacillus helveticus with different autolytic properties: DPC4571, BROI, and LH1 - Vinogradov, E.; Valence, F.; Maes, E.; Jebava, I.; Chuat, V.; Lortal, S.; Grard, T.; Guerardel, Y.; Sadovskaya, I. (Carbohydrate Research, 2013)
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.
Keywords: 2D-NMR spectroscopy; Autolytic properties; Cell wall polysaccharides; Cell-wall components; Intracellular enzyme; Lactobacillus helveticus; Methylation analysis; Structural studies; Alkylation; Antigen-antibody reactions; Cells; Enzymatic hydrolysis; Nuclear magnetic resonance spectroscopy; Polysaccharides; Strain; Structure (composition); Cytology; autolysin; peptidoglycan; polysaccharide; teichoic acid; article; autolysis; bacterial strain; cell wall; chemical structure; hydrolysis; Lactobacillus helveticus; methylation; nonhuman; nuclear magnetic resonance spectroscopy; priority journal; protein structure; Lactobacillus helveticus

Star clusters in M31. V. Evidence for self-enrichment in old M31 clusters from integrated spectroscopy - Schiavon, R.P.; Caldwell, N.; Conroy, C.; Graves, G.J.; Strader, J.; Macarthur, L.A.; Courteau, S.; Harding, P. (The Astrophysical Journal Letters, 2013)
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.

Synthesis and properties of LiMn2O4 from hydrazine hydrate reduced electrolytic manganese dioxide - Guo, D.; Chang, Z.; Li, B.; Tang, H.; Yuan, X.-Z.; Wang, H. (Solid State Ionics, 2013)
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.
Keywords: Cath-ode materials; Electrochemical impedance; Electrolytic manganese dioxides; Hydrazine hydrate; Lithium-ion battery; Lithium-ion battery cathodes; Manganese dioxide; Spinel lithium manganese oxides; Cathodes; Crystal impurities; Cyclic voltammetry; Diffusion; Electrochemical impedance spectroscopy; Hydrates; Hydration; Hydrazine; Lithium; Lithium batteries; Manganese; Scanning electron microscopy; Synthesis (chemical); X ray diffraction; Lithium alloys

Characterization of AA5754 alloy for identification of Barlat's YLD2000-2D yield criterion - Dion-Martin, O.; Fafard, M.; Ahmed, R.; D'Amours, G. (TMS Annual Meeting, 2013)
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.
Keywords: AA5754; Aluminum plates; Anisotropic behaviors; Bulge; Constitutive law; Material parameter; Work hardening curves; Yld2000-2d; Aluminum alloys; Exhibitions; Strain hardening; Tensile testing; Characterization

Interesting evidence for a low-level oscillation superimposed on the local Hubble flow - Bell, M.B. (Astrophysics and Space Science, 2013)
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.

A study of geological evaluation indicators for the exploitation potential of marine natural gas hydrates: Theory and methodology - Wu, N.; Huang, L.; Su, Z.; Yang, S.; Wang, H.; Liang, J.; Lu, H. (Natural Gas Industry, 2013)
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.
Keywords: Experimental simulations; Exploitation potentials; Geological evaluation; Geological parameters; Index; Marine; Marine hydrate deposits; Reservoir characteristic; Hydration; Natural gas; Natural gas deposits; Production engineering; Reservoirs (water); Gas hydrates

B4-B1 phase transition of GaN under isotropic and uniaxial compression - Yao, Y.; Klug, D.D. (Physical Review B - Condensed Matter and Materials Physics, 2013)
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.

High throughput multilayer microfluidic particle separation platform using embedded thermoplastic-based micropumping - Didar, T.F.; Li, K.; Tabrizian, M.; Veres, T. (Lab on a Chip - Miniaturisation for Chemistry and Biology, 2013)
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.
Keywords: elastomer; polycarbonate; polystyrene; thermoplastic elastomer; unclassified drug; article; cell selection; erythrocyte; fluorescence; in vitro study; microfluidics; osteoblast; particle size; priority journal

Palliser's promise: Brassica carinata, An emerging western Canadian crop for delivery of new bio-industrial oil feedstocks - Marillia, E.-F.; Francis, T.; Falk, K.C.; Smith, M.; Taylor, D.C. (Biocatalysis and Agricultural Biotechnology, 2013)
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.

Crystalline domain size and faulting in the new NIST SRM 1979 zinc oxide - Cline, J.P.; Leoni, M.; Black, D.; Henins, A.; Bonevich, J.E.; Whitfield, P.S.; Scardi, P. (Powder Diffraction, 2013)
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.

Assessment of multidrug resistance on cell coculture patterns using scanning electrochemical microscopy - Kuss, S.; Polcari, D.; Geissler, M.; Brassard, D.; Mauzeroll, J. (Proceedings of the National Academy of Sciences of the United States of America, 2013)
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.
Keywords: ferrocene derivative; ferrocenemethanol; multidrug resistance protein 1; ruthenium complex; unclassified drug; article; cancer cell; cell culture; cell structure; controlled study; electrochemistry; female; HeLa cell; human; human cell; kinetics; multidrug resistance; priority journal; protein localization; quantitative analysis; scanning electrochemical microscopy; target cell; uterine cervix cancer; HeLa cells; microelectrode; MRP1; Cell Culture Techniques; Drug Resistance, Multiple; Female; Ferrous Compounds; HeLa Cells; Humans; Microelectrodes; Microscopy, Fluorescence; Microscopy, Scanning Probe; Multidrug Resistance-Associated Proteins

Inductively coupled plasma mass spectrometry-based immunoassay: A review - Liu, R.; Wu, P.; Yang, L.; Hou, X.; Lv, Y. (Mass Spectrometry Reviews, 2013)
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.

Mechanical and microstructural characterization of cold-sprayed Ti-6Al-4V after heat treatment - Vo, P.; Irissou, E.; Legoux, J.-G.; Yue, S. (Journal of Thermal Spray Technology, 2013)
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.
Keywords: After-heat treatment; As-sprayed conditions; Cold spray; Dense coating; Fracture surfaces; High hardness; Micro-structural characterization; Microstructural changes; Aluminum; Crystal microstructure; Hardness; Heat treatment; Helium; Mechanical properties; Microstructure; Nitrogen; Sprayed coatings; Tensile strength; Tensile testing; Titanium alloys; Aluminum coatings

Resolved debris discs around a stars in the herschel DEBRIS survey - Booth, M.; Kennedy, G.; Sibthorpe, B.; Matthews, B.C.; Wyatt, M.C.; Ducĥene, G.; Kavelaars, J.J.; Rodriguez, D.; Greaves, J.S.; Koning, A.; Vican, L.; Rieke, G.H.; et al. (Monthly Notices of the Royal Astronomical Society, 2013)
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.

Signaling network assessment of mutations and copy number variations predict breast cancer subtype-specific drug targets - Zaman, N.; Li, L.; Jaramillo, M.; Sun, Z.; Tibiche, C.; Banville, M.; Collins, C.; Trifiro, M.; Paliouras, M.; Nantel, A.; O'Connor-McCourt, M.; Wang, E. (Cell Reports, 2013)
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.
Keywords: antineoplastic agent; bms 536924; bosutinib; docetaxel; erlotinib; nutlin 3; protein kinase B inhibitor; rapamycin; rdea 119; tamoxifen; tanespimycin; tcs 2312; tozasertib; unclassified drug; article; breast cancer; cancer cell; cancer classification; cell proliferation; cell survival; copy number variation; drug sensitivity; drug targeting; exome; gene identification; gene mutation; gene sequence; genetic screening; human; human cell; mutation; priority journal; signal transduction; tumor gene

The open cluster NGC 2437 (Messier 46) - Davidge, T.J. (Publications of the Astronomical Society of the Pacific, 2013)
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.

The SCUBA-2 cosmology legacy survey: Blank-Field number counts of 450-μm-selected galaxies and their contribution to the cosmic infrared background - Geach, J.E.; Chapin, E.L.; Coppin, K.E.K.; Dunlop, J.S.; Halpern, M.; Smail, I.; van der Werf, P.; Serjeant, S.; Farrah, D.; Roseboom, I.; Targett, T.; Arumugam, V.; et al. (Monthly Notices of the Royal Astronomical Society, 2013)
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.

A possible divot in the size distribution of the Kuiper Belt's scattering objects - Shankman, C.; Gladman, B. J.; Kaib, N.; Kavelaars, J. J.; Petit, J. M. (The Astrophysical Journal Letters, 2013)
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°.

Fine structure of a biexciton in a single quantum dot with a magnetic impurity - Trojnar, A.H.; Korkusinski, M.; Mendes, U.C.; Goryca, M.; Koperski, M.; Smolenski, T.; Kossacki, P.; Wojnar, P.; Hawrylak, P. (Physical Review B - Condensed Matter and Materials Physics, 2013)
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.

Immobilization of glucose oxidase into a nanoporous TiO2 film layered on metallophthalocyanine modified vertically-aligned carbon nanotubes for efficient direct electron transfer - Cui, H.-F.; Zhang, K.; Zhang, Y.-F.; Sun, Y.-L.; Wang, J.; Zhang, W.-D.; Luong, J.H.T. (Biosensors and Bioelectronics, 2013)
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.
Keywords: Amperometric response; Bioelectrocatalytic; Carbon nanotubes (CNT); Detection sensitivity; Direct electron transfer; Iron phthalocyanines; Metallophthalocyanines; Nano-porous TiO; Carbon nanotubes; Glucose; Glucose oxidase; Glucose sensors; Oxygen; Scanning electron microscopy; Titanium dioxide; Electron transitions; glucose; glucose oxidase; iron phthalocyanine; metallophthalocyanine; multi walled nanotube; nanoparticle; nitrogen; phthalocyanine derivative; titanium dioxide nanoparticle; unclassified drug; amperometry; article; chemical reaction; cyclic potentiometry; direct electron transfer; electric conductivity; enzyme electrode; enzyme immobilization; enzyme stability; limit of detection; nanoanalysis; nanochemistry; oxidation kinetics; porosity; response time; scanning electron microscopy; sensitivity analysis; surface property; Aspergillus niger; Biosensing Techniques; Electrodes; Enzymes, Immobilized; Ferrous Compounds; Glucose; Glucose Oxidase; Indoles; Nanotubes, Carbon; Porosity; Sensitivity and Specificity; Titanium

Phonon lifetime investigation of anharmonicity and thermal conductivity of UO2 by neutron scattering and theory - Pang, J.W.L.; Buyers, W.J.L.; Chernatynskiy, A.; Lumsden, M.D.; Larson, B.C.; Phillpot, S.R. (Physical Review Letters, 2013)
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.
Keywords: Anharmonicities; First-principles simulations; Inelastic neutrons; Longitudinal optics; Phonon lifetimes; Phonon physics; Quantitative correspondence; Phonons; Thermal conductivity

Electronic temperatures of terahertz quantum cascade active regions with phonon scattering assisted injection and extraction scheme - Patimisco, P.; Scamarcio, G.; Santacroce, M.V.; Spagnolo, V.; Vitiello, M.S.; Dupont, E.; Laframboise, S.R.; Fathololoumi, S.; Razavipour, G.S.; Wasilewski, Z. (Optics Express, 2013)
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.
Keywords: Active regions; Electronic temperature; Ground level; Optical phonon scattering; Population ratio; Quantum cascades; Quantum-cascade devices; Resonant phonon; Optical lattices; Quantum well lasers; Phonon scattering; article; equipment; equipment design; equipment failure; light; methodology; radiation scattering; terahertz radiation; thermography; Equipment Design; Equipment Failure Analysis; Light; Scattering, Radiation; Terahertz Radiation; Thermography

Numerical and experimental studies on the new design concept of hydroforming dies for complex tubes - Bihamta, R.; D'Amours, G.; Bui, Q.-H.; Guillot, M.; Rahem, A.; Fafard, M. (Materials and Design, 2013)
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.
Keywords: Axial feeding; Complex geometries; New design; Numerical and experimental study; Numerical results; Numerical verification; Transportation industry; Tube hydroforming; Two parameter; Metal forming; Tubes (components); Dies

Carrier molecules for use in veterinary vaccines - Gerdts, V.; Mutwiri, G.; Richards, J.; Hurk, S.V.D.L.V.D.; Potter, A.A. (Vaccine, 2013)
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.
Keywords: alginic acid; chitosan; CpG oligodeoxynucleotide; DNA vaccine; drug carrier; gamma interferon; glycoconjugate; glycoconjugate vaccine; Haemophilus vaccine; hepatitis B surface antigen; immunoglobulin A; immunoglobulin G1; immunoglobulin G2; immunoglobulin M; immunostimulating agent; influenza vaccine; interleukin 2; interleukin 6; liposome; nanoparticle; peptide vaccine; poly[di(sodium carboxylatoethylphenoxy] phosphazene; poly[di(sodium carboxylatophenoxy)] polyphosphazene; polyglactin; polymer; polysaccharide vaccine; starch; unclassified drug; vaccine; Wart virus vaccine; Actinobacillus pleuropneumoniae; antigen presenting cell; atrophic rhinitis; bacterial load; Bordetella bronchiseptica; bronchopneumonia; CD8+ T lymphocyte; cost effectiveness analysis; cytokine production; cytotoxic T lymphocyte; dendritic cell; Haemophilus influenzae type b; human; Human papillomavirus type 16; immunization; immunogenicity; mucosal immunity; Neisseria meningitidis; nonhuman; Pasteurella multocida infection; priority journal; review; Streptococcus pneumoniae; virus like agent; Animals; Glycoconjugates; Nanoparticles; Vaccination; Vaccines; Vaccines, Conjugate; Vaccines, Subunit; Vaccines, Virus-Like Particle

Neisseria gonorrhoeae-derived heptose elicits an innate immune response and drives HIV-1 expression - Malott, R.J.; Keller, B.O.; Gaudet, R.G.; McCaw, S.E.; Lai, C.C.L.; Dobson-Belaire, W.N.; Hobbs, J.L.; Michael, F.S.; Cox, A.D.; Moraes, T.F.; Gray-Owen, S.D. (Proceedings of the National Academy of Sciences of the United States of America, 2013)
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.
Keywords: heptose; heptose monophosphate; HldA protein; lipid A; toll like receptor 4; toll like receptor 5; unclassified drug; article; CD4+ T lymphocyte; Human immunodeficiency virus 1; innate immunity; mouse; mutagenesis; Neisseria gonorrhoeae; nonhuman; phenotype; priority journal; transposon; coinfection; inflammation; microbial-associated molecular pattern; pathogen-associated molecular pattern; sexually transmitted disease; Bacterial Proteins; CD4-Positive T-Lymphocytes; Coinfection; Female; Gonorrhea; Heptoses; HIV Infections; HIV Long Terminal Repeat; HIV-1; Humans; Jurkat Cells; Male; Neisseria gonorrhoeae; Toll-Like Receptor 5

Design and fabrication of an integrated dual-mode ultrasonic probe - Ono, Y.; Qu, Z.; Wu, K.-T. (Ultrasonics, 2013)
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.
Keywords: Dual modes; Liquid sample; Longitudinal waves; Measurement sensitivity; Mode conversions; Piezoelectric film; Probe design; Pulse echoes; Ultrasonic probe; Viscous liquids; Conversion efficiency; Probes; Shear waves; Silicones; Substrates; Ultrasonic testing; Ultrasonic transducers; Nanocomposites

Towards scalable photonics via quantum storage - Nunn, J.; Langford, N.K.; Kolthammer, W.S.; Champion, T.F.M.; Sprague, M.R.; Michelberger, P.S.; Jin, X.-M.; England, D.G.; Walmsley, I.A. (SPIE - International Society for Optical Engineering. Proceedings, 2013)
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.
Keywords: Experimental demonstrations; Optical quantum-information processing; Quantum Computing; Quantum memory; Quantum-information processing; Single photons; Single-photon source; Time-bandwidth products; Digital storage; Photons; Quantum computers; Quantum optics; Raman scattering; Synchronization; Quantum theory

Graphene-based integrated electronic, photonic and spintronic circuit - Potasz, P.; Güçlü, A.D.; Ozfidan, I.; Korkusinski, M.; Hawrylak, P. (SPIE - International Society for Optical Engineering. Proceedings, 2013)
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.
Keywords: Electric and magnetic fields; Electrical field; Electronic nanodevices; Ferromagnetic orders; Integrated electronics; Semiconductor nanoparticles; Spatial confinement; Spintronic circuits; Absorption spectroscopy; Energy gap; Graphene; Magnetic moments; Magnetic properties; Magnetoelectronics; Nanostructured materials; Nanotechnology; Optical properties; Photons; Semiconductor quantum dots; Sensors; Solids; Photonic integration technology

SWG dispersion engineering for ultra-broadband photonic devices - Halir, Robert; Maese-Novo, Alejandro; Romero-García, Sebastián; Pérez-Galacho, Diego; Zavargo-Peche, Luis; Ortega-Moñux, Alejandro; Molina-Fernández, Íñigo; Wangüemert-Pérez, J. Gonzalo; Cheben, Pavel (SPIE - International Society for Optical Engineering. Proceedings, 2013)
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.
Keywords: Broadband device; Dispersion engineering; Multi-mode interference; Passive waveguides; Silicon on insulator; Sub-wave length grating; Diffraction gratings; Directional couplers; Dispersion (waves); Optical waveguides; Photonics; Refractive index; Silicon on insulator technology; Ultra-wideband (UWB); Dispersions

Spatial-spectral coupling in hyperspectral CARS microscopy image formation - Barlow, A.M.; Popov, K.; Andreana, M.; Moffatt, D.J.; Ridsdale, A.; Slepkov, A.D.; Ramunno, L.; Stolow, A. (Progress in Biomedical Optics and Imaging - Proceedings of SPIE, 2013)
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.
Keywords: Cars microscopies; Coherence imaging; Coherent anti-Stokes Raman scattering microscopy; Kramers-Kronig transformation; Nonlinear microscopy; Numerical calculation; Three dimensional images; Three dimensional space; Coherent scattering; Image acquisition; Three dimensional; Time domain analysis; Raman spectroscopy

Collaborative computing technologies and systems - Yong, J.; Shen, W.; James, A. (Journal of Systems and Software, 2013)

Hidden in plain sight: low-literacy adults in a developed country overcoming social and educational challenges through mobile learning support tools - Munteanu, C.; Molyneaux, H.; Maitland, J.; McDonald, D.; Leung, R.; Fournier, H.; Lumsden, J. (Personal and Ubiquitous Computing, 2013)
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.

Extragalactic number counts at 100 μm, free from cosmic variance - Sibthorpe, B.; Ivison, R.J.; Massey, R.J.; Roseboom, I.G.; van der Werf, P.P.; Matthews, B.C.; Greaves, J.S. (Monthly Notices of the Royal Astronomical Society: Letters, 2013)
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.

Isolation of scFv antibody fragments against HER2 and CEA tumor antigens from combinatorial antibody libraries derived from cancer patients - Ayat, H.; Burrone, O.R.; Sadghizadeh, M.; Jahanzad, E.; Rastgou, N.; Moghadasi, S.; Arbabi, M. (Biologicals, 2013)
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.

Cancer systems biology in the genome sequencing era: Part 1, dissecting and modeling of tumor clones and their networks - Wang, E.; Zou, J.; Zaman, N.; Beitel, L.K.; Trifiro, M.; Paliouras, M. (Seminars in Cancer Biology, 2013)
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.
Keywords: apoptosis; breast cancer; breast carcinogenesis; cancer cell; cancer prognosis; cancer survival; cancer systems biology; cell proliferation; cell subpopulation; cell survival; chromosome breakage; copy number variation; disease marker; gene mutation; human; molecular cloning; oncology; review; RNA sequence; signal transduction; single cell analysis; systems biology

Applications of flexible ultrasonic transducer array for defect detection at 150 °C - Shih, J.-L.; Wu, K.-T.; Jen, C.-K.; Chiu, C.-H.; Tzeng, J.-C.; Liaw, J.-W. (Sensors (Switzerland), 2013)
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.
Keywords: Defect detection; Flexible ultrasonic transducer; Pitch-catch; Pulse-echo mode; PZT; Total focusing method; Antenna phased arrays; Composite films; Defects; Nondestructive examination; Sol-gel process; Sol-gels; Thickness measurement; Transducers; Ultrasonic transducers; Inspection

Subwavelength grating Fourier-transform interferometer array in silicon-on-insulator - Bock, Przemek J.; Cheben, Pavel; Velasco, Aitor V.; Schmid, Jens H.; Delâge, André; Florjańczyk, Mirosław; Lapointe, Jean; Xu, Dan-Xia; Vachon, Martin; Janz, Siegfried; Calvo, María L. (Laser and Photonics Reviews, 2013)
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.
Keywords: Calibration measurements; Fourier transform spectrometers; Free spectral range; Interferometer arrays; Optical path difference; Sub-wave length grating; Sub-wavelength; Subwavelength grating waveguides; Circular waveguides; Diffraction gratings; Errors; Fabrication; Fourier transform infrared spectroscopy; Interferometry; Light extinction; Mach-Zehnder interferometers; Planar waveguides; Silicon on insulator technology; Spectral resolution; Spectrometers; Electric losses

Rate equation analysis of three phonon-photon-phonon terahertz quantum cascade lasers - Razavipour, S. G.; Dupont, E.; Fathololoumi, S.; Wasilewski, Z. R.; Laframboise, S. R.; Liu, H. C.; Ban, D. (CLEO: QELS_Fundamental Science, CLEO:QELS FS 2013, 2013)
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.

Structure of the capsular polysaccharides and lipopolysaccharides from Haemophilus parasuis strains ER-6P (serovar 15) and Nagasaki (serovar 5) - Perry, M.B.; MacLean, L.L.; Gottschalk, M.; Aragon, V.; Vinogradov, E. (Carbohydrate Research, 2013)
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.
Keywords: Capsular polysaccharides; Capsule; Gram-negative bacteria; Haemophilus parasuis; Lipooligosaccharides; Lipopolysaccharides; Upper respiratory tract; Virulent strains; Bacteria; Chains; Mass spectrometry; Nuclear magnetic resonance spectroscopy; Polysaccharides; Strain; bacterial polysaccharide; bacterium lipopolysaccharide; dextro glycero dextro manno heptose; galactosamine; galactose; glucose; glycoprotein; l glycero dextro manno heptose; monosaccharide; n glycoloylneuraminic acid; neuraminic acid; sephadex; unclassified drug; article; bacterial cell; bacterial strain; chemical structure; dephosphorylation; gel chromatography; Haemophilus parasuis; mass spectrometry; molecular mimicry; nonhuman; nuclear magnetic resonance spectroscopy; polyacrylamide gel electrophoresis; priority journal; proton nuclear magnetic resonance; serotype; terminal sequence; Animalia; Bacteria (microorganisms); Haemophilus parasuis; Negibacteria; Pasteurellaceae; Suidae

Virtual endoscopy in neurosurgery: A review - Neubauer, A.; Wolfsberger, S. (Neurosurgery, 2013)
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.
Keywords: anastomosis; angioscopy; clinical feature; endocrine surgery; human; hypophysis; intraoperative period; neuroendoscopy; neurosurgery; nose surgery; paranasal sinus; patient safety; priority journal; review; simulator; virtual endoscopy; Computer Simulation; Humans; Imaging, Three-Dimensional; Neuroendoscopy; Preoperative Care; User-Computer Interface; Ventriculostomy

Comparison of lipopolysaccharide structures of Bordetella pertussis clinical isolates from pre- and post-vaccine era - AlBitar-Nehme, S.; Basheer, S.M.; Njamkepo, E.; Brisson, J.-R.; Guiso, N.; Caroff, M. (Carbohydrate Research, 2013)
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.
Keywords: Bordetella pertussis; Clinical isolates; Evolution; Gram-negative bacteria; Lipopolysaccharides; MALDI-mass spectrometry; Physico-chemical analysis; Vaccine strains; Chemical analysis; Epitopes; Mass spectrometry; Monoclonal antibodies; Polysaccharides; Structure (composition); Vaccines; lipid A; lipopolysaccharide; pertussis vaccine; article; bacterial strain; bacterium isolate; Bordetella pertussis; carbohydrate analysis; mass spectrometry; molecular model; nonhuman; physical chemistry; polyacrylamide gel electrophoresis; priority journal; thin layer chromatography; Bordetella pertussis; Negibacteria

The Next Generation Virgo Cluster Survey. IV. NGC 4216: A bombarded spiral in the virgo cluster - Paudel, S.; Duc, P.-A.; Côté, P.; Cuillandre, J.-C.; Ferrarese, L.; Ferriere, E.; Gwyn, S.D.J.; Mihos, J.C.; Vollmer, B.; Balogh, M.L.; Carlberg, R.G.; Boissier, S.; et al. (The Astrophysical Journal, 2013)
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.

HyDEn: A hybrid steganocryptographic approach for data encryption using randomized error-correcting DNA codes - Tulpan, D.; Regoui, C.; Durand, G.; Belliveau, L.; Léger, S. (BioMed Research International, 2013)
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.
Keywords: article; data analysis; DNA sequence; DNA steganography; error; genetic code; hybrid DNA encryption; process design

A GSP double auction for smart exchange - Ghonaim, W.; Ghenniwa, H.; Shen, W. (Proceedings of the 2013 IEEE 17th International Conference on Computer Supported Cooperative Work in Design, CSCWD 2013, 2013)
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.
Keywords: Bidding languages; Double auction; GSP auction; Preference elicitation; prefernce deduction; Reverse auction; strategic rules; Winner determination; Electronic commerce; Interactive computer systems; Sustainable development; Online systems

Editorial - Marple, B.R; Agarwal, A.; Hyland, M.M.; Lau, Y.-C.; Li, C.-J.; Lima, R.S.; McDonald, A.; Toma, F.-L. (Journal of Thermal Spray Technology, 2013)

Microscopic investigation of platinum deposition in PEMFC cross-sections using AFM and SEM - Helmly, S.; Hiesgen, R.; Morawietz, T.; Yuan, X.-Z.; Wang, H.; Friedrich, K.A. (Journal of the Electrochemical Society, 2013)
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.
Keywords: Conductive AFM; Crystallite growth; Membrane degradation; Platinum depositions; Polymer decomposition; Postmortem analysis; Proton exchange membrane fuel cell (PEMFCs); Pt deposition; Atomic force microscopy; Cathodes; Deposition; Membranes; Platinum; Scanning electron microscopy; Proton exchange membrane fuel cells (PEMFC)

On the discovery of the diffuse interstellar bands - McCall, B.J.; Griffin, R.E. (Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2013)
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).
Keywords: Diffuse interstellar bands; Lick observatory; Long lasting; Mary Lea Heger; Systematic research; Buildings; History; Observatories; Research; Astronomy

Evaluation of novel seat cushions to mitigate helicopter aircrew exposure to vibration - Wickramasinghe, V.; Chen, Y. (Annual Forum Proceedings - AHS International, 2013)
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.
Keywords: Helicopter aircrews; Impedance properties; Long term exposure; Low-cost solution; Polyurethane materials; Research studies; Seat cushions; Vibration level; Air cushioning; Energy absorption; Helicopters; Aircraft seats

Characterization of nickel diffusion and its effect on the microstructure of nickel PM steels - Tougas, B.; Blais, C.; Chagnon, F.; Pelletier, S. (Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science, 2013)
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.
Keywords: Concentration maps; Diffusion mechanisms; Grain-boundary diffusion; Heterogeneous microstructure; Microstructures and properties; Sintered parts; Volume diffusion coefficients; Wavelength dispersive X-rays; Diffusion; Grain boundaries; Microstructure; Nickel powder metallurgy; Powder metallurgy; Steel; Nickel

Human serum activates CIDEB-mediated lipid droplet enlargement in hepatoma cells - Singaravelu, R.; Lyn, R.K.; Srinivasan, P.; Delcorde, J.; Steenbergen, R.H.; Tyrrell, D.L.; Pezacki, J.P. (Biochemical and Biophysical Research Communications, 2013)
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.

Haffner 16: A young moving group in the making - Davidge, T.J.; Carrasco, E.R.; Winge, C.; Pessev, P.; Neichel, B.; Vidal, F.; Rigaut, F. (Publications of the Astronomical Society of the Pacific, 2013)
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.

A method for detecting forward scattering signals on-chip with a photonic-microfluidic integrated device - Watts, B.R.; Zhang, Z.; Xu, C.-Q.; Cao, X.; Lin, M. (Biomedical Optics Express, 2013)
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.
Keywords: Design modifications; False positive rates; Forward scatters; Integrated device; Integrated microfluidic devices; Optimal excitation; Polystyrene beads; Side scatter signal; Geometry; Photoexcitation; Polystyrenes; Signal detection; article; device fabrication; device testing; experimental design; fluorescence imaging; free space detection; laboratory diagnosis; light scattering; limit of detection; microfluidic analysis; optical excitation; optics; scatter detection

Two- and three-electron pauli spin blockade in series-coupled triple quantum dots - Amaha, S.; Izumida, W.; Hatano, T.; Teraoka, S.; Tarucha, S.; Gupta, J.A.; Austing, D.G. (Physical Review Letters, 2013)
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.
Keywords: Sequential tunneling; Spin blockade; Triple quantum; Triplet state; Electrons; Magnetic moments; Semiconductor quantum dots; Spin dynamics; Electrospinning

Efficient optical pumping and high optical depth in a hollow-core photonic-crystal fibre for a broadband quantum memory - Sprague, M.R.; England, D.G.; Abdolvand, A.; Nunn, J.; Jin, X.-M.; Steven Kolthammer, W.; Barbieri, M.; Rigal, B.; Michelberger, P.S.; Champion, T.F.M.; Russell, P.S.J.; Walmsley, I.A. (New Journal of Physics, 2013)
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.
Keywords: Broadband pulse; High-efficiency; Hollow-core photonic-crystal; Light-matter coupling; Multiphoton quantum; Nonlinear optical effects; Quantum memory; Room temperature; Computer simulation; Optical fibers; Optical waveguides; Quantum theory; Optical pumping

The role of the Kramers-Henneberger atom in the higher-order Kerr effect - Richter, Maria; Patchkovskii, Serguei; Morales, Felipe; Smirnova, Olga; Ivanov, Misha (New Journal of Physics, 2013)
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.
Keywords: Driving field; External fields; Generalized models; Intensity-dependent; Kerr response; Non-linear response; Strong field ionization; The standard model; Atomic spectroscopy; Atoms; Optical Kerr effect

Confocal scanner for highly sensitive photonic transduction of nanomechanical resonators - Diao, Zhu; Losby, Joseph E.; Sauer, Vincent T. K.; Westwood, Jocelyn N.; Freeman, Mark R.; Hiebert, Wayne K. (Applied Physics Express, 2013)
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.
Keywords: Confocal laser scanning; Coupling efficiency; Doubly clamped beam; Free-space optical; Nanomechanical resonators; Nanophotonic circuits; Orders of magnitude; Resonant response; Bacteriophages; Nanophotonics; Resonators; Coupled circuits

Substrate integrated waveguide-fed tapered slot antenna with smooth performance characteristics over an ultra-wide bandwidth - Locke, Lisa S.; Bornemann, Jens; Claude, Stéphane (Applied Computational Electromagnetics Society Journal, 2013)
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 Â± 3.2Â° and Â± 2.5Â° 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 Â± 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.
Keywords: Cross-polarization level; Finite integration technique; Gain; Half power beam widths; Linear tapered slot antennas; Performance characteristics; Antipodal tapered slot antennas; Alumina; Antenna feeders; Design; Microwave circuits; Substrate integrated waveguides; Ultra-wideband

Inkjet application, chromatography, and mass spectrometry of sugars on nanostructured thin films - Kirchert, Simone; Wang, Zhen; Taschuk, Michael T.; Jim, Steven R.; Brett, Michael J.; Morlock, Gertrud E. (Analytical and Bioanalytical Chemistry, 2013)
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.
Keywords: Derivatizations; Electrospray ionization mass spectrometry; Glancing Angle Deposition; High performance thin layer chromatography; Miniaturized layers; Quantitation; Ultrathin-layer chromatographies; Vapor-deposition techniques; Deposition; Ink jet printers; Mass spectrometry; Physical vapor deposition; RNA; Sugars; Chromatography; Theobroma cacao

Antiperlecan antibodies are novel accelerators of immune-mediated vascular injury - Cardinal, H.; Dieudé, M.; Brassard, N.; Qi, S.; Patey, N.; Soulez, M.; Beillevaire, D.; Echeverry, F.; Daniel, C.; Durocher, Y.; Madore, F.; Hébert, M. J. (American Journal of Transplantation, 2013)
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.
Keywords: acute rejection; antibody; calcineurin inhibitor; CD4 antigen; immunoglobulin G; perlecan; animal experiment; antibody titer; apoptosis; blood vessel injury; endothelium cell; graft recipient; graft survival; immune mediated injury; immunoglobulin A nephropathy; kidney allograft rejection; kidney transplantation; neointima; protein function

Effect of peptide secondary structure on adsorption and adsorbed film properties - Binazadeh, M.; Zeng, H.; Unsworth, L. D. (Acta Biomaterialia, 2013)
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.
Keywords: Non-specific protein adsorption; Secondary structure; Poly-l-lysine; Circular dichroism; Quartz crystal microbalance with dissipation

Chemical insight into the origin of red and blue photoluminescence arising from freestanding silicon nanocrystals - Dasog, Mita; Yang, Zhenyu; Regli, Sarah; Atkins, Tonya M.; Faramus, Angelique; Singh, Mani P.; Muthuswamy, Elayaraja; Kauzlarich, Susan M.; Tilley, Richard D.; Veinot, Jonathan G. C. (ACS Nano, 2013)
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.
Keywords: silicon nanocrystals; photoluminescence; surface functionalization; nitrogen

Solution-processed zinc phosphide (α-Zn3P2) colloidal semiconducting nanocrystals for thin film photovoltaic applications - Luber, Erik J.; Mobarok, Md Hosnay; Buriak, Jillian M. (ACS Nano, 2013)
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.
Keywords: Core-shell; earth-abundant; Photovoltaics; Semiconductor nanocrystals; Solution-processed; Zinc phosphide; Heterojunctions; Molybdenum oxide; Nanocrystals; Nanoparticles; Photoelectron spectroscopy; Photoelectrons; Quantum confinement; Synthesis (chemical); Thin films; Transmission electron microscopy; X ray diffraction; X ray photoelectron spectroscopy; Zinc

Using nuances of emotion to identify personality - Mohammad, Saif M.; Kiritchenko, Svetlana (Proceedings of the ICWSM Workshop on Computational Personality Recognition, 2013)
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.

NRC-Canada : building the state-of-the-art in sentiment analysis of tweets - Mohammad, Saif M.; Kiritchenko, Svetlana; Zhu, Xiaodan (Proceedings of the Seventh International Workshop on Semantic Evaluation Exercises, 2013)
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.

NMR metabolomics analysis of the effects of 5-lipoxygenase inhibitors on metabolism in glioblastomas - Morin, Pier Jr; Ferguson, Dean; Leblanc, Luc M.; Hébert, Martin J. G.; Paré, Aurélie F.; Jean-François, Jacques; Surette, Marc E.; Touaibia, Mohamed; Cuperlovic-Culf, Miroslava (Journal of Proteome Research, 2013)
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.
Keywords: Drug discovery; NMR Metabolomics; Caffeic acid phenethyl ester; 5-lipoxygenase inhibitors; Glioblastoma multiforme; Antioxidant and antiradical activity