Tabletop imaging of structural evolutions in chemical reactions demonstrated for the acetylene cation - Ibrahim, Heide; Wales, Benji; Beaulieu, Samuel; Schmidt, Bruno E.; Thiré, Nicolas; Fowe, Emmanuel P.; Bisson, Éric.; Hebeisen, Christoph T.; Wanie, Vincent; Giguére, Mathieu; Kieffer, Jean-Claude; Spanner, Michael; et al. (Nature Communications, 2014)
The introduction of femto-chemistry has made it a primary goal to follow the nuclear and electronic evolution of a molecule in time and space as it undergoes a chemical reaction. Using Coulomb Explosion Imaging, we have shot the first high-resolution molecular movie of a to and fro isomerization process in the acetylene cation. So far, this kind of phenomenon could only be observed using vacuum ultraviolet light from a free-electron laser. Here we show that 266 ‰nm ultrashort laser pulses are capable of initiating rich dynamics through multiphoton ionization. With our generally applicable tabletop approach that can be used for other small organic molecules, we have investigated two basic chemical reactions simultaneously: proton migration and C=C bond breaking, triggered by multiphoton ionization. The experimental results are in excellent agreement with the timescales and relaxation pathways predicted by new and quantitative ab initio trajectory simulations.
Keywords: acetylene; cation; proton; acetylene; cation; chemical reaction; molecular analysis; ab initio calculation; absorption; chemical reaction; density functional theory; electric field; electron; imaging; ionization; isomerization; laser; molecule; photon; ultraviolet radiation; vacuum

Laser assisted reduction of printed GO films and traces - Sinar, Dogan; Knopf, George K.; Nikumb, Suwas (14th IEEE International Conference on Nanotechnology, IEEE-NANO 2014, 2014)
Non-conductive graphene oxide (GO) particles (70% carbon, 30% oxygen) synthesized directly from inexpensive graphite powders are hydrophilic and can be dispersed homogeneously in water based solutions. In this study, thin film electrode traces are produced from a GO aqueous suspension using a commercially available inkjet printer. Once deposited on the functionalized substrate the printed film is thermally annealed to remove excess water and harden the material. The electrical conductivity of the high resistance (>10Mω) annealed film is increased through the removal of oxygen molecules using a focused 775nm, 120fs pulsed laser. The electrical properties of select target areas on the thermally reduced graphene oxide (rGO) film can be tuned by adjusting the laser power, material feed rate, and the number of passes that the beam makes over the target surface. Experiments demonstrate that the rGO trace can be modified over a wide range of sheet resistance values (1Mω to 2kω) for a ∼1μm thick film. The proposed fabrication method can also be used to create a variety of resistive and semiconductor components on printed thin films, conductive electrodes and micro-circuit traces.
Keywords: Conductive films; Electrodes; Graphene; Ink jet printers; Printing presses; Semiconductor lasers; Suspensions (fluids); Thick films; Thin films; Aqueous suspensions; Conductive electrodes; Electrical conductivity; Functionalized substrates; Reduced graphene oxides (RGO); Semiconductor components; Thin-film electrode; Water-based solutions; Pulsed lasers

Transition metal chalcogenides for oxygen reduction electrocatalysts in PEM fuel cells - Lee, Kunchan; Alonso-Vante, Nicolas; Zhang, Jiujun (Non-Noble Metal Fuel Cell Catalysts, 2014)
This chapter covers the process of oxygen-reduction reaction (ORR) for fuel-cell systems of nonprecious electrocatalyst centers explored since the 1960s, showing the progress achieved with regard to their catalytic activity and stability. The catalytic centers investigated so far are transition metal chalcogenides and metal-macrocycles; in particular, the chalcogenides and the macrocycles containing cobalt or iron metals. The chapter also displays the progress made via theoretical studies on non-noble metal chalcogenides made in understanding of the ORR mechanism and factors that affect the ORR activity and stability.

Expression of human hepatic lipase negatively impacts apolipoprotein A-I production in primary hepatocytes from Lipc-null mice - Bamji-Mirza, Michelle; Zhang, Wandong; Yao, Zemin (Journal of Biomedical Research, 2014)
This study aimed to examine whether expression of human hepatic lipase (hHL) exerted an intracellular effect on hepatic production of apolipoprotein (apo) A-I. The levels of secreted and cell-associated apoA-I were contrasted between primary hepatocytes isolated from Lipc-null and C57BL/6 mice, and between Lipc-null hepatocytes transfected with either hHL-encoding or control adenovirus. An HSPG-binding deficient hHL protein (hHLmt) was used to determine the impact of cell surface binding on HL action. Accumulation of apoA-I in conditioned media of primary hepatocytes isolated from Lipc-null mice was increased as compared to that from C57BL/6 mice. Metabolic labeling experiments showed that secretion of 35S-apoA-I from Lipc-null cells was significantly higher than that from C57BL/6 cells. Expression of hHL in Lipc-null hepatocytes, through adenovirus-mediated gene transfer, resulted in decreased synthesis and secretion of 35S-apoA-I, but not 35S-apoE, as compared with cells transfected with control adenovirus. Expression of HSPG-binding deficient hHLmt in Lipc-null cells also exerted an inhibitory effect on apoA-I production, even though hHLmt displayed impaired exit from the endoplasmic reticulum as compared with hHL. Subcellular fractionation revealed that expression of hHL or hHLmt led to increased microsome-association of apoA-I relative to non-transfected control. Expression of hHL negatively impacts hepatic production of apoA-I.
Keywords: apolipoprotein A1; apolipoprotein E; liver triacylglycerol lipase; Adenoviridae; animal cell; cell fractionation; cell surface; cellular distribution; controlled study; endoplasmic reticulum; female; gene transfer; genetic transfection; HepG2 cell line; human cell; immunoblotting; liver cell; microsome; mouse; null cell; protein expression; protein secretion; secretory pathway

Theoretical modeling of non-noble metal electrocatalysts for acid and alkaline PEM fuel cells - Dy, Eben; Shi, Zheng (Non-Noble Metal Fuel Cell Catalysts, 2014)
This chapter presents theoretical studies (mainly with first principle methods) of non-noble metal electrocatalysts for oxygen reduction reaction (ORR) in acid and alkaline PEM fuel cells. The focus is on fundamental understanding of effect of structure and properties of these electrocatalysts on oxygen reduction reaction mechanism and electrocatalytic activity. The chapter begins with a brief review of current understanding of oxygen reduction mechanism. The difference between ORR in acidic and alkali media is discussed. Four major types of non-nobel metal electrocatalysts are presented. These include transition metal N-macrocyclic complexes, heat-treated M-Nx/C, functionalized graphitic materials, and conducting polymers. Theoretical investigation of these electrocatalytic systems are presented and discussed; especially, the active site structures and electronic properties of electrocatalysts, adsorption configurations of oxygen and various ORR intermediates on electrocatlysts, energetics of possible reaction pathways, and effect of potentials on activity. These theoretical insights contribute greatly to our knowledge of the electrocatalytic systems and are invaluable for further development in this area.

Residual life assessment of a critical component of a gas turbine-achievements and challenges - Beres, W.; Zhang, Z.; Dudzinski, D.; Chen, W.R.; Wu, X.J. (Proceedings of the ASME Turbo Expo, 2014)
The residual life assessment of a turbine spacer from a gas turbine engine is presented. The spacer has been identified as one of the safety critical components of the engine, therefore the useful life of this component significantly affects economic operation of the fleet. Numerical analyses of fatigue crack propagation at one critical location of the spacer were performed using both three dimensional (3D) finite element based method and the weight function method. These results combined with the material data allowed for basic assessment of the damage tolerance of this component. Experimental validation of the spacer life was performed in a spin rig facility. During this validation, two sets of spacers were tested and the number of cycles to appearance of a detectable crack was recorded. Moreover, a fractographic study was conducted on the fracture surfaces of two spin rig tested spacers using scanning electronic microscopy techniques. It was found that crack nucleation occurred at multiple sites and crack propagation occurred by a mixed mode of striation formation and faceted fracture. Therefore it was concluded that the mixed mode interaction should be considered in predicting the fatigue life of the spacer. Finally, the paper describes the challenges and pitfalls encountered during preparation and execution of the analyses and tests, including availability of engine and operational data and also uncertainties in interpretation of the results. Copyright © 2014 by Her Majesty the Queen in Right of Canada.
Keywords: Crack propagation; Cracks; Damage detection; Engines; Fatigue crack propagation; Fatigue of materials; Finite element method; Fracture; Numerical methods; Uncertainty analysis; Economic operations; Experimental validations; Mixed-mode interactions; Safety critical components; Scanning electronic microscopy; Striation formation; Threedimensional (3-d); Weight function method; Gas turbines

Multi-objective selection of cutting conditions in advanced machining processes via an efficient global optimization approach - Aly, Mohamed; Hamza, Karim; Tauhiduzzaman, Mohammed; Meshreki, Mouhab; Nassef, Ashraf O.; Veldhuis, Stephen; Attia, Helmi (Proceedings of the ASME Design Engineering Technical Conference, 2014)
Optimum selection of cutting conditions in high-speed and ultra-precision machining processes often poses a challenging task due to several reasons; such as the need for costly experimental setup and the limitation on the number of experiments that can be performed before tool degradation starts becoming a source of noise in the readings. Moreover, oftentimes there are several objectives to consider, some of which may be conflicting, while others may be somewhat correlated. Pareto-optimality analysis is needed for conflicting objectives; however the existence of several objectives (highdimension Pareto space) makes the generation and interpretation of Pareto solutions difficult. The approach adopted in this paper is a modified multi-objective efficient global optimization (m-EGO). In m-EGO, sample data points from experiments are used to construct Kriging meta-models, which act as predictors for the performance objectives. Evolutionary multi-objective optimization is then conducted to spread a population of new candidate experiments towards the zones of search space that are predicted by the Kriging models to have favorable performance, as well as zones that are underexplored. New experiments are then used to update the Kriging models, and the process is repeated until termination criteria are met. Handling a large number of objectives is improved via a special selection operator based on principle component analysis (PCA) within the evolutionary optimization. PCA is used to automatically detect correlations among objectives and perform the selection within a reduced space in order to achieve a better distribution of experimental sample points on the Pareto frontier. Case studies show favorable results in ultraprecision diamond turning of Aluminum alloy as well as highspeed drilling of woven composites.
Keywords: Aluminum alloys; Diamond drilling; Global optimization; Interpolation; Machining centers; Optimization; Pareto principle; Principal component analysis; Diamond turning; Efficient global optimization; High speed machining; Kriging; Principle component analysis; Multiobjective optimization

Femtosecond laser induced fiber Bragg gratings for harsh environment sensing applications - Mihailov, S. J.; Grobnic, D.; Walker, R. B.; Lu, P.; Ding, H. (SPIE - International Society for Optical Engineering. Proceedings, 2014)
Fiber Bragg grating sensors have been developed beyond a laboratory curiosity to become a mainstream sensing technology because of their small size, passive nature, immunity to electromagnetic interference, and capability to simultaneously measure multiple physical parameters such as temperature, strain and pressure. Recently, high temperature stable gratings based on regeneration techniques and femtosecond infrared laser processing have shown promise for use in extreme environments such as high temperature, pressure or ionizing radiation. Such gratings are ideally suited for energy production applications where there is a requirement for advanced energy system instrumentation and controls that are operable in harsh environments. This presentation will give a review of some of the more recent developments of femtosecond laser induced fiber Bragg gratings.
Keywords: Bragg gratings; Electromagnetic pulse; Fiber optic sensors; Ionizing radiation; Optical sensors; Ultrashort pulses; Advanced energy systems; Energy productions; Extreme environment; Fiber Bragg Grating Sensors; Instrumentation and control; Nonlinear optical process; Physical parameters; Sensing technology; Fiber Bragg gratings

Measuring transmission and forces from observatory equipment vibration - Thompson, Hugh; MacMartin, Douglas G.; Byrnes, Peter W. G; Tomono, Daigo; Terada, Hiroshi (SPIE - International Society for Optical Engineering. Proceedings, 2014)
We describe measurements of both the vibration forces imparted by various types of observatory equipment, and the transmission of these forces through the soil, foundations and telescope pier. These are key uncertainties both in understanding how to mitigate vibration at existing observatories and for developing a vibration budget in the design of future observatories such as the Thirty Meter Telescope. Typical vibration surveys have measured only the resulting motion (acceleration); however, this depends on both the source and the system being excited (for example, isolating equipment results in less force being transmitted, but greater motion of the equipment itself). Instead, here we (a) apply a known force input to the pier from a shaker and measure the response at different locations, and (b) use isolator properties combined with measured acceleration to infer the forces applied by various equipment directly. The soil foundation and pier transmission can then be combined with a finite element model based vibration transmission analysis to estimate the optical consequences. Estimates of plausible source levels supports the development of a vibration budget for TMT that allocates allowable forces to the sources of vibration; this is described in a companion paper.
Keywords: Airborne telescopes; Equipment; Finite element method; Observatories; Optical telescopes; Extremely Large Telescopes; Soil foundation; Thirty Meter Telescope; TMT; Vibration; Vibration forces; Vibration transmission; Vibration analysis

Gemini planet imager observational calibrations VI: Photometric and spectroscopic calibration for the integral field spectrograph - Maire, JérômeJ.; Ingraham, Patrick J.; De Rosa, Robert J.; Perrin, Marshall D.; Rajan, Abhijith; Savransky, Dmitry; Wang, Jason J.; Ruffio, Jean-Baptiste; Wolff, Schuyler G.; Chilcote, Jeffrey K.; Doyon, René; Graham, James R.; et al. (SPIE - International Society for Optical Engineering. Proceedings, 2014)
The Gemini Planet Imager (GPI) is a new facility instrument for the Gemini Observatory designed to provide direct detection and characterization of planets and debris disks around stars in the solar neighborhood. In addition to its extreme adaptive optics and coronagraphic systems which give access to high angular resolution and high-contrast imaging capabilities, GPI contains an integral field spectrograph providing low resolution spectroscopy across five bands between 0.95 and 2.5 μm. This paper describes the sequence of processing steps required for the spectro-photometric calibration of GPI science data, and the necessary calibration files. Based on calibration observations of the white dwarf HD 8049 B we estimate that the systematic error in spectra extracted from GPI observations is less than 5%. The flux ratio of the occulted star and fiducial satellite spots within coronagraphic GPI observations, required to estimate the magnitude difference between a target and any resolved companions, was measured in the H-band to be μm = 9.23 ± 0.06 in laboratory measurements and μm = 9.39 ± 0.11 using on-sky observations. Laboratory measurements for the Y, J, K1 and K2 filters are also presented. The total throughput of GPI, Gemini South and the atmosphere of the Earth was also measured in each photometric passband, with a typical throughput in H-band of 18% in the non-coronagraphic mode, with some variation observed over the six-month period for which observations were available. We also report ongoing development and improvement of the data cube extraction algorithm.
Keywords: Adaptive optics; Astronomy; Calibration; Earth atmosphere; Photometry; Spectrographs; Spectrophotometry; Stars; Exo-planets; High angular resolutions; High contrast imaging; IFS; Integral field spectrograph; Laboratory measurements; Low resolution spectroscopies; Spectroscopic calibrations; White dwarfs

The integral field spectrograph for the Gemini planet imager - Larkin, James E.; Chilcote, Jeffrey K.; Aliado, Theodore; Bauman, Brian J.; Brims, George; Canfield, John M.; Cardwell, Andrew; Dillon, Daren; Doyon, René; Dunn, Jennifer; Fitzgerald, Michael P.; Graham, James R.; et al. (SPIE - International Society for Optical Engineering. Proceedings, 2014)
The Gemini Planet Imager (GPI) is a complex optical system designed to directly detect the self-emission of young planets within two arcseconds of their host stars. After suppressing the starlight with an advanced AO system and apodized coronagraph, the dominant residual contamination in the focal plane are speckles from the atmosphere and optical surfaces. Since speckles are diffractive in nature their positions in the field are strongly wavelength dependent, while an actual companion planet will remain at fixed separation. By comparing multiple images at different wavelengths taken simultaneously, we can freeze the speckle pattern and extract the planet light adding an order of magnitude of contrast. To achieve a bandpass of 20%, sufficient to perform speckle suppression, and to observe the entire two arcsecond field of view at diffraction limited sampling, we designed and built an integral field spectrograph with extremely low wavefront error and almost no chromatic aberration. The spectrograph is fully cryogenic and operates in the wavelength range 1 to 2.4 microns with five selectable filters. A prism is used to produce a spectral resolution of 45 in the primary detection band and maintain high throughput. Based on the OSIRIS spectrograph at Keck, we selected to use a lenslet-based spectrograph to achieve an rms wavefront error of approximately 25 nm. Over 36,000 spectra are taken simultaneously and reassembled into image cubes that have roughly 192x192 spatial elements and contain between 11 and 20 spectral channels. The primary dispersion prism can be replaced with a Wollaston prism for dual polarization measurements. The spectrograph also has a pupil-viewing mode for alignment and calibration.
Keywords: Aberrations; Adaptive optics; Astronomy; Optical systems; Prisms; Speckle; Spectrographs; Wavefronts; Chromatic aberration; Complex optical systems; Diffraction limited; Dual-polarizations; Integral field spectrograph; RMS wavefront error; Speckle suppression; Wavelength ranges; Extrasolar planets

Heavy-duty vehicle rear-view camera systems - McWha, Tyson (SAE International Journal of Commercial Vehicles, 2014)
Transport Canada, through its ecoTECHNOLOGY for Vehicles program, retained the services of the National Research Council Canada to undertake a test program to examine the operational and human factors considerations concerning the removal of the side mirrors on a Class 8 tractor equipped with a 53 foot dry van semi-trailer. Full scale aerodynamic testing was performed in a 2 m by 3 m wind tunnel on a system component basis to quantify the possible fuel savings associated with the removal of the side mirrors. The mirrors on a Volvo VN780 tractor were removed and replaced with a prototype camera-based indirect vision system consisting of four cameras mounted in the front fender location; two cameras on either side of the vehicle. Four monitors mounted in the vehicle - two mounted on the right A-pillar and two mounted on the left A-pillar - provided indirect vision information to the vehicle operator. Four commercial drivers were asked to perform a series of tests simulating typical driving scenarios on a closed course test track. The tests included an object identification test, a blind spot comparison test, a coupling and uncoupling test, a quasi-static lane change test, a dynamic lane change test and an evasive manoeuvres test. The tests were performed both with the mirrors and with the camera-based indirect vision system. The results of the study provide an analysis of driver performance while using the mirrors in comparison to driver performance while using the camera-based indirect vision system. Driver acceptance of the camera-based indirect vision system was also analyzed through the use of questionnaires.
Keywords: Aerodynamics; Automobile testing; Cameras; Computer vision; Fuel economy; Mirrors; Software testing; Surveys; Tractors (truck); Truck transportation; Wind tunnels; Aerodynamic testing; Commercial drivers; Driver acceptance; Driver performance; Heavy duty vehicles; Object identification; Vehicle operators; Optical testing

Resolved imaging of the HR 8799 debris disk with Herschel - Matthews, Brenda; Kennedy, Grant; Sibthorpe, Bruce; Booth, Mark; Wyatt, Mark; Broekhoven-Fiene, Hannah; Macintosh, Bruce; Marois, Christian (The Astrophysical Journal, 2014)
We present Herschel far-infrared and submillimeter maps of the debris disk associated with the HR 8799 planetary system. We resolve the outer disk emission at 70, 100, 160, and 250 μm and detect the disk at 350 and 500 μm. A smooth model explains the observed disk emission well. We observe no obvious clumps or asymmetries associated with the trapping of planetesimals that is a potential consequence of planetary migration in the system. We estimate that the disk eccentricity must be <0.1. As in previous work by Su et al., we find a disk with three components: a warm inner component and two outer components, a planetesimal belt extending from 100 to 310 AU, with some flexibility (±10 AU) on the inner edge, and the external halo that extends to ∼2000 AU. We measure the disk inclination to be 26° ± 3° from face-on at a position angle of 64° E of N, establishing that the disk is coplanar with the star and planets. The spectral energy distribution of the disk is well fit by blackbody grains whose semi-major axes lie within the planetesimal belt, suggesting an absence of small grains. The wavelength at which the spectrum steepens from blackbody, 47 ± 30 μm, however, is short compared with other A star debris disks, suggesting that there are atypically small grains likely populating the halo. The PACS longer wavelength data yield a lower disk color temperature than do MIPS data (24 and 70 μm), implying two distinct halo dust-grain populations.

Tensile properties of laser additive manufactured Inconel 718 using filler wire - Zhang, Yi-Nan; Cao, Xinjin; Wanjara, Priti; Medraj, Mamoun (Journal of Materials Research, 2014)
A 5 kW continuous wave fiber laser welding system was used to deposit INCONEL® alloy 718 (IN718) on service-exposed IN718 parent metal (PM) substrates using filler wire addition. The microstructure of the deposits was characterized in the fully heat treated condition. The service-exposed IN718 PM and the direct laser deposited (DLD) specimens were then evaluated through room temperature tensile testing. The yield and tensile strengths were well above the minimum values, as defined in the aerospace specifications AMS 5596K and 5663M. However, the ductility at room temperature of the DLD and DLD-PM samples was slightly lower than that specified in AMS 5596K and 5663M. The tensile fracture surfaces of the service-exposed IN718 PM, DLD, and DLD-PM specimens were analyzed using scanning electron microscopy (SEM), and the tensile failure mechanisms are discussed in detail, particularly for the important roles of the secondary particles (MC carbides) and intermetallics (platelet Ni3Nb-δ and Laves phases).
Keywords: Carbides; Fiber lasers; Fillers; Fracture; Intermetallics; Laser beam welding; Scanning electron microscopy; Tensile testing; Wire; Continuous Wave; Heat treated condition; Secondary particles; Tensile failures; Tensile fracture surfaces; Yield and tensile strength; Tensile strength

The Next Generation Virgo Cluster Survey. XV. The photometric redshift estimation for background sources - Raichoor, A.; Mei, S.; Erben, T.; Hildebrandt, H.; Huertas-Company, M.; Ilbert, O.; Licitra, R.; Ball, N. M.; Boissier, S.; Boselli, A.; Chen, Y. -T.; Côté, P.; et al. (The Astrophysical Journal, 2014)
The Next Generation Virgo Cluster Survey (NGVS) is an optical imaging survey covering 104 deg2 centered on the Virgo cluster. Currently, the complete survey area has been observed in the u∗ giz bands and one third in the r band. We present the photometric redshift estimation for the NGVS background sources. After a dedicated data reduction, we perform accurate photometry, with special attention to precise color measurements through pointspread function homogenization. We then estimate the photometric redshifts with the Le Phare and BPZ codes. We add a new prior that extends to iAB = 12.5 mag. When using the u∗griz bands, our photometric redshifts for 15.5mag ≤ i ≲ 23 mag or zphot ≲ 1 galaxies have a bias |Äz| < 0.02, less than 5% outliers, a scatter óoutl.rej., and an individual error on zphot that increases with magnitude (from 0.02 to 0.05 and from 0.03 to 0.10, respectively).When using the u∗giz bands over the same magnitude and redshift range, the lack of the r band increases the uncertainties in the 0.3 ≲ zphot ≲ 0.8 range (-0.05 < Äz < -0.02, óoutl.rej ∼ 0.06, 10%-15% outliers, and zphot.err. ∼ 0.15). We also present a joint analysis of the photometric redshift accuracy as a function of redshift and magnitude. We assess the quality of our photometric redshifts by comparison to spectroscopic samples and by verifying that the angular auto- and cross-correlation function w(θ) of the entire NGVS photometric redshift sample across redshift bins is in agreement with the expectations.

Sulfide oxidations for LC-MS analysis of methionine-containing microcystins in dolichospermum flos-aquae NIVA-CYA 656 - Miles, Christopher O.; Melanson, Jeremy E.; Ballot, Andreas (Environmental Science and Technology, 2014)
Microcystins are cyclic heptapeptides produced by a range of cyanobacteria. More than 150 microcystin analogues have been reported from cultures, algal blooms, or other contaminated samples. Relatively few analytical standards are available, making identification and quantitation of these toxins a challenge, even with LC-MS technology. We developed a two-step oxidative procedure that allows LC-MS identification of microcystins containing methionine and methionine sulfoxide, and reveals the oxidation state of the methionyl sulfur atom. The procedure was used in parallel with mercaptoethanol derivatization and LC-MS2 analysis to demonstrate the presence of [Asp3]MC-MR (12) and MC-MR (17) in a culture of Dolichospermum flos-aquae, together with low levels of [Asp3]MC-M(O)R (5) and MC-M(O)R (7), as well as 20 other microcystins. Fresh culture contained only traces of sulfoxides 5 and 7, but these increased during storage or sample extraction and preparation. This suggests that microcystins containing methionine sulfoxide are primarily postextraction oxidation artifacts, rather than being produced by biosynthesis in cyanobacteria. A simple, rapid extraction under inert gas followed promptly by LC-MS analysis minimized oxidation artifacts for D. flos-aquae.
Keywords: Amino acids; Extraction; Inert gases; Lc-ms analysis; Oxidation state; Rapid extraction; Sample extraction; Sulfide oxidation; mercaptoethanol; methionine; methionine sulfoxide; microcystin; oxidation; oxide; peptide; sulfide; algal bloom; Anabaena; bacterium culture; derivatization; Dolichospermum flos aquae; high performance liquid chromatography; liquid chromatography; mass spectrometry; signal noise ratio; tandem mass spectrometry; ultra performance liquid chromatography; algae; Cyanobacteria; Flos

Signatures of warm carbon monoxide in protoplanetary discs observed with Herschel SPIRE - Van der Wie, M. H. D.; Naylor, D. A.; Kamp, I.; Ménard, F.; Thi, W. -F.; Woitke, P.; Olofsson, G.; Pontoppidan, K. M.; Di Francesco, J.; Glauser, A. M.; Greaves, J. S.; Ivison, R. J. (Monthly Notices of the Royal Astronomical Society, 2014)
Molecular gas constitutes the dominant mass component of protoplanetary discs. To date, these sources have not been studied comprehensively at the longest far-infrared and shortest submillimetre wavelengths. This paper presents Herschel SPIRE FTS spectroscopic observations towards 18 protoplanetary discs, covering the entire 450-1540 GHz (666-195 μm) range at ν/≈ν ≈ 400-1300. The spectra reveal clear detections of the dust continuum and, in six targets, a significant amount of spectral line emission primarily attributable to 12CO rotational lines. Other targets exhibit little to no detectable spectral lines. Low signal-to-noise detections also include signatures from 13CO, [C I] and HCN. For completeness, we present upper limits of non-detected lines in all targets, including low-energy transitions of H2O and CH+ molecules. The 10 12CO lines that fall within the SPIRE FTS bands trace energy levels of 50-500 K. Combined with lower and higher energy lines from the literature, we compare the CO rotational line energy distribution with detailed physical-chemical models, for sources where these are available and published. Our 13CO line detections in the disc around Herbig Be star HD 100546 exceed, by factors of 10-30, the values predicted by a model that matches a wealth of other observational constraints, including the SPIRE 12CO ladder. To explain the observed 12CO/13CO ratio, it may be necessary to consider the combined effects of optical depth and isotope selective (photo)chemical processes. Considering the full sample of 18 objects, we find that the strongest line emission is observed in discs around Herbig Ae/Be stars, although not all show line emission. In addition, two of the six T Tauri objects exhibit detectable 12CO lines in the SPIRE range.

Abscisic acid analogs as chemical probes for dissection of abscisic acid responses in Arabidopsis thaliana - Benson, Chantel L.; Kepka, Michal; Wunschel, Christian; Rajagopalan, Nandhakishore; Nelson, Ken M.; Christmann, Alexander; Abrams, Suzanne R.; Grill, Erwin; Loewen, Michele C. (Phytochemistry, 2014)
Abscisic acid (ABA) is a phytohormone known to mediate numerous plant developmental processes and responses to environmental stress. In Arabidopsis thaliana, ABA acts, through a genetically redundant family of ABA receptors entitled Regulatory Component of ABA Receptor (RCAR)/Pyrabactin Resistant 1 (PYR1)/Pyrabactin Resistant-Like (PYL) receptors comprised of thirteen homologues acting in concert with a seven-member set of phosphatases. The individual contributions of A. thaliana RCARs and their binding partners with respect to specific physiological functions are as yet poorly understood. Towards developing efficacious plant growth regulators selective for specific ABA functions and tools for elucidating ABA perception, a panel of ABA analogs altered specifically on positions around the ABA ring was assembled. These analogs have been used to probe thirteen RCARs and four type 2C protein phosphatases (PP2Cs) and were also screened against representative physiological assays in the model plant Arabidopsis. The 1′-O methyl ether of (S)-ABA was identified as selective in that, at physiologically relevant levels, it regulates stomatal aperture and improves drought tolerance, but does not inhibit germination or root growth. Analogs with the 7′- and 8′-methyl groups of the ABA ring replaced with bulkier groups generally retained the activity and stereoselectivity of (S)- and (R)-ABA, while alteration of the 9′-methyl group afforded an analog that substituted for ABA in inhibiting germination but neither root growth nor stomatal closure. Further in vitro testing indicated differences in binding of analogs to individual RCARs, as well as differences in the enzyme activity resulting from specific PP2Cs bound to RCAR-analog complexes. Ultimately, these findings highlight the potential of a broader chemical genetics approach for dissection of the complex network mediating ABA-perception, signaling and functionality within a given species and modifications in the future design of ABA agonists.

High-efficiency single etch step apodized surface grating coupler using subwavelength structure - Benedikovic, Daniel; Cheben, Pavel; Schmid, Jens H.; Xu, Dan-Xia; Lapointe, Jean; Wang, Shurui; Halir, Robert; Ortega-Moñux, Alejandro; Janz, Siegfried; Dado, Milan (Laser and Photonics Reviews, 2014)
Grating couplers are key elements enabling the coupling of light between planar waveguide circuits and optical fibers. In this work, it is demonstrated using simulations and experiments that a high coupling efficiency can be achieved for an arbitrary buried oxide thickness by judicious adjustment of the grating radiation angle. The coupler strength is engineered by subwavelength structure, allowing straightforward apodization and single etch step fabrication. The design has been implemented using Fourier-eigenmode expansion and finite difference time domain methods. The measured coupling loss of a continuously apodized grating is -2.16 dB with a 3 dB bandwidth of 64 nm, therefore opening promising prospects for low-cost and high-volume fabrication using 193 nm deep-ultraviolet lithography. It is also shown by simulations that a coupling loss as low as -0.42 dB is predicted for a modified coupler structure with bottom mirror.
Keywords: Finite difference time domain method; Integrated optics; Optical fiber fabrication; Optical fibers; Time domain analysis; Buried oxide thickness; Grating couplers; Planar waveguide circuit; Silicon-on- insulators (SOI); Sub-wavelength structures; Subwavelength grating; Surface grating couplers; Ultraviolet lithography; Optical fiber coupling

Transcriptome and methylome profiling reveals relics of genome dominance in the mesopolyploid Brassica oleracea - Parkin, Isobel A. P.; Koh, Chushin; Tang, Haibao; Robinson, Stephen J.; Kagale, Sateesh; Clarke, Wayne E.; Town, Chris D.; Nixon, John; Krishnakumar, Vivek; Bidwell, Shelby L.; Denoeud, France; Belcram, Harry; et al. (Genome Biology, 2014)
Background: Brassica oleracea is a valuable vegetable species that has contributed to human health and nutrition for hundreds of years and comprises multiple distinct cultivar groups with diverse morphological and phytochemical attributes. In addition to this phenotypic wealth, B. oleracea offers unique insights into polyploid evolution, as it results from multiple ancestral polyploidy events and a final Brassiceae-specific triplication event. Further, B. oleracea represents one of the diploid genomes that formed the economically important allopolyploid oilseed, Brassica napus. A deeper understanding of B. oleracea genome architecture provides a foundation for crop improvement strategies throughout the Brassica genus. Results: We generate an assembly representing 75% of the predicted B. oleracea genome using a hybrid Illumina/Roche 454 approach. Two dense genetic maps are generated to anchor almost 92% of the assembled scaffolds to nine pseudo-chromosomes. Over 50,000 genes are annotated and 40% of the genome predicted to be repetitive, thus contributing to the increased genome size of B. oleracea compared to its close relative B. rapa. A snapshot of both the leaf transcriptome and methylome allows comparisons to be made across the triplicated sub-genomes, which resulted from the most recent Brassiceae-specific polyploidy event. Conclusions: Differential expression of the triplicated syntelogs and cytosine methylation levels across the sub-genomes suggest residual marks of the genome dominance that led to the current genome architecture. Although cytosine methylation does not correlate with individual gene dominance, the independent methylation patterns of triplicated copies suggest epigenetic mechanisms play a role in the functional diversification of duplicate genes.
Keywords: Brassica oleracea; Brassica rapa; controlled study; DNA methylation; gene dosage; gene expression; gene mapping; genome size; hexaploidy; plant genome; plant leaf; polyploidy; transcriptomics; Brassica oleracea

The in-situ TEM study of microstructure alteration of MoS2 under carburization - Chen, Jian; Wei, Qiang; Chen, Jinwen (Microscopy and Microanalysis, 2014)

First light of the Gemini Planet Imager - Macintosh, Bruce; Graham, James R.; Ingraham, Patrick; Konopacky, Quinn; Marois, Christian; Perrin, Marshall; Poyneer, Lisa; Bauman, Brian; Barman, Travis; Burrows, Adam S.; Cardwell, Andrew; Chilcote, Jeffrey; et al. (Proceedings of the National Academy of Sciences of the United States of America, 2014)
The Gemini Planet Imager is a dedicated facility for directly imaging and spectroscopically characterizing extrasolar planets. It combines a very high-order adaptive optics system, a diffraction-suppressing coronagraph, and an integral field spectrograph with low spectral resolution but high spatial resolution. Every aspect of the Gemini Planet Imager has been tuned for maximum sensitivity to faint planets near bright stars. During first-light observations, we achieved an estimated H band Strehl ratio of 0.89 and a 5-σ contrast of 106 at 0.75 arcseconds and 105 at 0.35 arcseconds. Observations of Beta Pictoris clearly detect the planet, Beta Pictoris b, in a single 60-s exposure with minimal postprocessing. Beta Pictoris b is observed at a separation of 434 ± 6 milliarcseconds (mas) and position angle 211.8 ± 0.5°. Fitting the Keplerian orbit of Beta Pic b using the new position together with previous astrometry gives a factor of 3 improvement in most parameters over previous solutions. The planet orbits at a semimajor axis of 9:0-0.4+0.8 AU near the 3:2 resonance with the previously known 6-AU asteroidal belt and is aligned with the inner warped disk. The observations give a 4% probability of a transit of the planet in late 2017.
Keywords: brightness; diffraction; Fourier transformation; gemini planet imager; gravity; imaging system; infrared wavefront sensor; interferometer; light; optics; polarimetry; priority journal; satellite imagery; sensor; telescope

Microstructural design for thermal creep and radiation damage resistance of titanium aluminide alloys for high-temperature nuclear structural applications - Zhu, Hanliang; Wei, Tao; Carr, David; Harrison, Robert; Edwards, Lyndon; Seo, Dongyi; Maruyama, Kouichi; Dargusch, Matthew S. (Current Opinion in Solid State and Materials Science, 2014)
Microstructure plays an important role in strengthening of metallic materials. Various microstructures can be developed in titanium aluminide (TiAl) alloys, which can enable different combinations of properties for various extreme environments in advanced nuclear systems. In the present paper the mechanisms for microstructural strengthening and the effects of various microstructural features on thermal creep and radiation damage resistance of TiAl alloys are reviewed and compared. On the basis of the results, the evidence-based optimum microstructure for the best combination of thermal creep and radiation damage resistance of TiAl alloys is proposed. The heat treatment processes for manufacturing the optimal microstructure are also discussed.
Keywords: Alloys; Creep; Creep resistance; High temperature applications; Microstructural evolution; Microstructure; Radiation damage; Radiation effects; Titanium; Titanium compounds; Advanced nuclear system; Extreme environment; Heat treatment process; Microstructural design; Microstructural features; Optimal microstructure; Structural applications; Titanium aluminide alloy; Titanium alloys

Silicon-on-insulator polarization controller with relaxed fabrication tolerances - Sarmiento-Merenguel, J. D.; Alonso-Ramos, C.; Halir, R.; Vivien, L.; Cheben, P.; Ortega-Moñux, A.; Molina-Fernández, I.; Leroux, X.; Marris-Morini, D.; Xu, D. -X.; Schmid, J. H.; Janz, S. (IEEE International Conference on Group IV Photonics GFP, 2014)
Polarization control is essential in applications ranging from optical communications to interferometric sensors. The implementation of integrated polarization controllers is challenging as they require polarization rotating waveguides with stringent fabrication tolerances. Here, we present a fully integrated polarization controller scheme that significantly relaxes the requirements on the rotating waveguides, alleviating fabrication tolerances. We analytically establish a technology-independent, easily measurable tolerance condition for the rotating waveguides. Polarization control in the presence of waveguide width errors of ∼25 % is shown through full vectorial simulation.

Evidence for large grains in the star-forming filament OMC 2/3 - Schnee, Scott; Mason, Brian; Di Francesco, James; Friesen, Rachel; Li, Di; Sadavoy, Sarah; Stanke, Thomas (Monthly Notices of the Royal Astronomical Society, 2014)
We present a new 3.3 mm continuum map of the Orion Molecular Cloud (OMC) 2/3 region. When paired with previously published maps of 1.2 mm continuum and NH3-derived temperature, we derive the emissivity spectral index of dust emission in this region, tracking its changes across the filament and cores. We find that the median value of the emissivity spectral index is 0.9, much shallower than previous estimates in other nearby molecular clouds. We find no significant difference between the emissivity spectral index of dust in the OMC 2/3 filament and the starless or protostellar cores. Furthermore, the temperature and emissivity spectral index, β, are anticorrelated at the 4σ level. The low values of the emissivity spectral index found in OMC 2/3 can be explained by the presence of millimetre-sized dust grains in the dense regions of the filaments to which these maps are most sensitive. Alternatively, a shallow dust emissivity spectral index may indicate non-power-law spectral energy distributions, significant free-free emission, or anomalous microwave emission. We discuss the possible implications of millimetre-sized dust grains compared to the alternatives.

Accurate astronomical atmospheric dispersion models in ZEMAX - Spanò, P. (SPIE - International Society for Optical Engineering. Proceedings, 2014)
ZEMAX provides a standard built-in atmospheric model to simulate atmospheric refraction and dispersion. This model has been compared with other ones to assess its intrinsic accuracy, critical for very demanding application like ADCs for AO-assisted extremely large telescopes. A revised simple model, based on updated published data of the air refractivity, is proposed by using the "Gradient 5" surface of Zemax. At large zenith angles (65 deg), discrepancies up to 100 mas in the differential refraction are expected near the UV atmospheric transmission cutoff. When high-accuracy modeling is required, the latter model should be preferred.
Keywords: Adaptive optics; Refraction; Telescopes; ADC; Atmospheric dispersion; Atmospheric model; Atmospheric refractions; TMT; ZEMAX; Atmospheric movements

Gemini planet imager observational calibrations IX: Least-squares inversion flux extraction - Draper, Zachary H.; Marois, Christian; Wolff, Schuyler; Perrin, Marshall; Ingraham, Patrick J.; Ruffio, Jean-Baptiste; Rantakyrö, Fredrik T.; Hartung, Markus; Goodsell, Stephen J. (SPIE - International Society for Optical Engineering. Proceedings, 2014)
The Gemini Planet Imager (GPI) is an instrument designed to directly image planets and circumstellar disks from 0.9 to 2.5 microns (the YJHK infrared bands) using high contrast adaptive optics with a lenslet-based integral field spectrograph. We develop an extraction algorithm based on a least-squares method to disentangle the spectra and systematic noise contributions simultaneously. We utilize two approaches to adjust for the effect of flexure of the GPI optics which move the position of light incident on the detector. The first method is to iterate the extraction to achieve minimum residual and the second is to cross-correlate the detector image with a model image in iterative extraction steps to determine an offset. Thus far, this process has made clear qualitative improvements to the cube extraction by reducing the Moiré pattern. There are also improvements to the automated routines for finding flexure offsets which are reliable to with ∼ 0.5 pixel accuracy compared to pixel accuracy prior. Further testing and optimization will follow before implementation into the GPI pipeline.
Keywords: Adaptive optics; Astronomy; Iterative methods; Pixels; Exo-planets; flexure; Gemini Planet Imager; GPI; inversion; Least Square; Least squares approximations

On-sky performance during verification and commissioning of the Gemini Planet Imager's adaptive optics system - Poyneer, Lisa A.; De Rosa, Robert J.; MacIntosh, Bruce; Palmer, David W.; Perrin, Marshall D.; Sadakuni, Naru; Savransky, Dmitry; Bauman, Brian; Cardwell, Andrew; Chilcote, Jeffrey K.; Dillon, Daren; Gavel, Donald; et al. (SPIE - International Society for Optical Engineering. Proceedings, 2014)
The Gemini Planet Imager instrument's adaptive optics (AO) subsystem was designed specifically to facilitate high-contrast imaging. It features several new technologies, including computationally efficient wavefront reconstruction with the Fourier transform, modal gain optimization every 8 seconds, and the spatially filtered wavefront sensor. It also uses a Linear-Quadratic-Gaussian (LQG) controller (aka Kalman filter) for both pointing and focus. We present on-sky performance results from verification and commissioning runs from December 2013 through May 2014. The efficient reconstruction and modal gain optimization are working as designed. The LQG controllers effectively notch out vibrations. The spatial filter can remove aliases, but we typically use it oversized by about 60% due to stability problems.
Keywords: Wavefronts; Gemini Planet Imager; LQG control; Modal gain; Wave front reconstruction; Wave front sensors; Adaptive optics

ASTROSAT mission - Singh, Kulinder Pal; Tandon, S. N.; Agrawal, P. C.; Antia, H. M.; Manchanda, R. K.; Yadav, J. S.; Seetha, S.; Ramadevi, M. C.; Rao, A. R.; Bhattacharya, D.; Paul, B.; Sreekumar, P.; et al. (SPIE - International Society for Optical Engineering. Proceedings, 2014)
Is India'€™s first astronomy satellite that will carry an array of instruments capable of simultaneous observations in a broad range of wavelengths: from the visible, near ultraviolet (NUV), far-UV (FUV), soft X-rays to hard X-rays. There will be five principal scientific payloads aboard the satellite: (i) a Soft X-ray Telescope (SXT), (ii) three Large Area Xenon Proportional Counters (LAXPCs), (iii) a Cadmium-Zinc-Telluride Imager (CZTI), (iv) two Ultra-Violet Imaging Telescopes (UVITs) one for visible and near-UV channels and another for far-UV, and (v) three Scanning Sky Monitors (SSMs). It will also carry a charged particle monitor (CPM). Almost all the instruments have qualified and their flight models are currently in different stages of integration into the satellite structure in ISRO Satellite Centre. ASTROSAT is due to be launched by India'€™s Polar Satellite Launch Vehicle (PSLV) in the first half of 2015 in a circular 600 km orbit with inclination of ∼6 degrees, from Sriharikota launching station on the east coast of India. A brief description of the design, construction, capabilities and scientific objectives of all the main scientific payloads is presented here. A few examples of the simulated observations with ASTROSAT and plans to utilize the satellite nationally and internationally are also presented.
Keywords: Astronomy; Cadmium alloys; Cadmium telluride; Charged particles; Orbits; Satellites; Space telescopes; Spacecraft equipment; Sun; Telescopes; X ray optics; Astronomy satellite; ASTROSAT; Cadmium zinc tellurides; Polar satellite launch vehicles; Satellite structure; Simultaneous observation; X ray telescope; Gamma rays

Large scale test apparatus to test external leak detection technologies - Apps, Chris; Ozkan, Istemi; Rizwan, Tania; Derakhshesh, Marzie; Medynski, Scott (Proceedings of the Biennial International Pipeline Conference, IPC, 2014)
When it comes to evaluating traditional computational leak detection technologies pipeline operators have a suite of simulated testing methods available. In the last several years however External Leak Detection Technologies have become more mature and potentially could provide operators with another layer of leak detection with more sensitivity than seen in traditional methods. The challenge with these technologies is in the evaluation of their sensitivity, reliability, and robustness. ENBRIDGE INC (Enbridge) and C-FER Technologies 1999 Inc. (C-FER) begun a comprehensive study to assess the state-of-the-art external, continuously distributed sensors for leak detection in early 2012. Initially, a technology review was undertaken to identify commercial, off-the-shelf technologies with the potential to detect small leaks of oil from buried pipelines. From this literature review, four technologies were identified; Distributed Temperature Sensing (DTS), Distributed Acoustic Sensing (DAS), Vapor Sensing Tubes (VST), and Hydrocarbon Sensing Cables (HSC). All four methods require proprietary materials and technology, which have had limited independent testing efforts to date. To evaluate these four leak detection methods and their vendors in an objective way, Enbridge and C-FER initiated the design and construction of a large-scale External Leak Detection Experimental Research apparatus (ELDER) that can accommodate a full-size segment of pipeline within a trench, at the same scale used in pipeline construction in North America. An instrumented pipe segment is buried in the trench with sensing cables laid alongside. The apparatus generates leaks with controlled variables including rate, pressure and temperature, and at various locations to accurately represent pipeline leaks. This paper summarizes the literature review on the four selected leak detection technologies that were identified as candidates for large-scale evaluation. The discussion will also include features of the ELDER apparatus, and re-engineered pipeline construction techniques that were required to accurately represent a full-scale pipeline trench within a laboratory environment.
Keywords: Cables; Leak detection; Materials testing; Pipeline laying; Temperature sensors; Distributed temperature sensing; Laboratory environment; Leak detection technology; Pipeline construction; Pressure and temperature; Trenching

Evidence of in situ microbial activity and sulphidogenesis in perennially sub-0 °C and hypersaline sediments of a high Arctic permafrost spring - Lamarche-Gagnon, Guillaume; Comery, Raven; Greer, Charles W.; Whyte, Lyle G. (Extremophiles, 2014)
The lost hammer (LH) spring perennially discharges subzero hypersaline reducing brines through thick layers of permafrost and is the only known terrestrial methane seep in frozen settings on Earth. The present study aimed to identify active microbial communities that populate the sediments of the spring outlet, and verify whether such communities vary seasonally and spatially. Microcosm experiments revealed that the biological reduction of sulfur compounds (SR) with hydrogen (e.g., sulfate reduction) was potentially carried out under combined hypersaline and subzero conditions, down to −20 °C, the coldest temperature ever recorded for SR. Pyrosequencing analyses of both 16S rRNA (i.e., cDNA) and 16S rRNA genes (i.e., DNA) of sediments retrieved in late winter and summer indicated fairly stable bacterial and archaeal communities at the phylum level. Potentially active bacterial and archaeal communities were dominated by clades related to the T78 Chloroflexi group and Halobacteria species, respectively. The present study indicated that SR, hydrogenotrophy (possibly coupled to autotrophy), and short-chain alkane degradation (other than methane), most likely represent important, previously unaccounted for, metabolic processes carried out by LH microbial communities. Overall, the obtained findings provided additional evidence that the LH system hosts active communities of anaerobic, halophilic, and cryophilic microorganisms despite the extreme conditions in situ.

Microstructures of nicraly coating applied on CMSX-4 by cathodic arc deposition - Zhao, L. R.; Lupandina, O.; Pankov, V. V.; McKellar, R. C. (Proceedings of the ASME Turbo Expo, 2014)
NiCrAlY overlay coatings were applied on Ni-base single-crystal superalloy CMSX-4 substrates by cathodic arc deposition. The coated specimens were subjected to one- and two-step heat treatments performed under 870°C/20h/AC (AC stands for air cooling) and 1140°C/6h/AC+870°C/20h/AC conditions, respectively. The microstructure of the original NiCrAlY cathodes fabricated by spark plasma sintering and the as-deposited as well as heat-treated coatings were characterized using the scanning electron microscopy, energy-dispersive spectroscopy and X-ray diffraction techniques. It was observed that the cathodes contained multiple phases uniformly distributed across the cathode volume. The as-deposited coatings exhibited a duplex microstructure consisting of splats and inter-splat regions with the latter showing internal porosity and a significantly lower Al concentration compared to that of the cathodes. The post-deposition heat treatments eliminated the porosity but further reduced the Al content, resulting in a coating microstructure dominated by the solid solution γ-Ni phase. The total thickness of the coating including the interdiffusion zone increased significantly during the two-step heat treatment. The oxide scale formed on the coating surface during heat treatment consisted primarily of α-Al2O3, with Y2O3 pegs underpinning the scale to the coating. The oxide scale was continuous on the smooth sections of the coating surface, but became fragmented at the protruding macroparticles present on the coating surface.
Keywords: Aluminum; Cathodes; Deposition; Electrodes; Energy dispersive spectroscopy; Heat treatment; Microstructure; Nickel; Porosity; Scale (deposits); Scanning electron microscopy; Single crystals; Sintering; Spark plasma sintering; X ray diffraction; Cathodic arc deposition; Coating microstructures; Duplex microstructures; Heat-treated coatings; Ni-base single crystal superalloy; Postdeposition heat treatment; Two-step heat treatment; X-ray diffraction techniques; Aluminum coatings

Measuring strain fields surrounding grain-boundary dislocations in silicon using scanning transmission electron microscopy - Couillard, Martin (Microscopy and Microanalysis, 2014)

Parsec-scale magnetic fields in Arp 220 - McBride, James; Robishaw, Timothy; Heiles, Carl; Bower, Geoffrey C.; Sarma, Anuj P. (Monthly Notices of the Royal Astronomical Society, 2014)
We present the first very long baseline interferometry (VLBI) detections of Zeeman splitting in another galaxy. We used Arecibo Observatory, the Green Bank Telescope, and the Very Long Baseline Array to perform dual-polarization observations of OH maser lines in the merging galaxy Arp 220. We measured magnetic fields of ~1-5 mG associated with three roughly parsec-sized clouds in the nuclear regions of Arp 220. Our measured magnetic fields have comparable strengths and the same direction as features at the same velocity identified in previous Zeeman observations with Arecibo alone. The agreement between single dish and VLBI results provides critical validation of previous Zeeman splitting observations of OH megamasers that used a single large dish. The measured magnetic field strengths indicate that magnetic energy densities are comparable to gravitational energy in OH maser clouds. We also compare our total intensity results to previously published VLBI observations of OH megamasers in Arp 220. We find evidence for changes in both structure and amplitude of the OH maser lines that are most easily explained by variability intrinsic to the masing region, rather than variability produced by interstellar scintillation. Our results demonstrate the potential for using high-sensitivity VLBI to study magnetic fields on small spatial scales in extragalactic systems.

Designing speech and language interactions - Munteanu, Cosmin; Aylett, Mathhew; Jones, Matt; Penn, Gerald; Whittaker, Steve; Brewster, Stephen; Oviatt, Sharon; D'Alessandro, Nicolas (Conference on Human Factors in Computing Systems - Proceedings, 2014)
Speech and natural language remain our most natural forms of interaction; yet the HCI community have been very timid about focusing their attention on designing and developing spoken language interaction techniques. While significant efforts are spent and progress made in speech recognition, synthesis, and natural language processing, there is now sufficient evidence that many real-life applications using speech technologies do not require 100% accuracy to be useful. This is particularly true if such systems are designed with complementary modalities that better support their users or enhance the systems' usability. Engaging the CHI community now is timely - many recent commercial applications, especially in the mobile space, are already tapping the increased interest in and need for natural user interfaces (NUIs) by enabling speech interaction in their products. This multidisciplinary, one-day workshop will bring together interaction designers, usability researchers, and general HCI practitioners to analyze the opportunities and directions to take in designing more natural interactions based on spoken language, and to look at how we can leverage recent advances in speech processing in order to gain widespread acceptance of speech and natural language interaction.
Keywords: Human computer interaction; Human engineering; Speech processing; Speech recognition; User interfaces; Automatic speech recognition; Commercial applications; Interaction techniques; Natural interactions; Natural language interaction; NAtural language processing; Natural user interfaces; Real-life applications; Natural language processing systems

Experimental and numerical investigation of corner stall in a highly-loaded compressor cascade - Zhang, Yanfeng; Mahallati, Ali; Benner, Michael (Proceedings of the ASME Turbo Expo, 2014)
Three-dimensional corner stall is one of the most important factors limiting compressor performance. This paper presents a complementary experimental and computational study of corner stall in a highly-loaded compressor cascade subjected to three inlet boundary layer thicknesses, two levels of freestream turbulence intensity and two Reynolds numbers. Experiments included seven-hole pressure probe traverses, airfoil loading and surface oil flow visualization. Measurements were supplemented with the numerical predictions from a commercially available CFD code. It was found that the low momentum boundary layer on the endwall was unable to overcome the large streamwise adverse pressure gradient in this high-lift profile and turned sharply towards the midspan due to the strong cross-passage pressure gradient. The corner stall, with distinct regions of three-dimensional reversed flow, started at 50% chord and occupied a large area of the suction surface as well as the downstream passage. Only a small region of the inlet boundary layer, very close to the endwall seemed to play a role in the corner stall. As such, the flow in the endwall region was found to be nearly independent of the inlet boundary layer thickness, freestream turbulence intensity and Reynolds number. Based on the endwall flow structures, a new topology of corner stall for compressor cascades with high airfoil diffusion factor and high flow turning has also been proposed.
Keywords: Airfoils; Boundary layer flow; Compressors; Computational fluid dynamics; Inlet flow; Pressure gradient; Reynolds number; Turbulence; Wakes; Adverse pressure gradient; Compressor cascade; Compressor performance; Freestream turbulence intensity; Inlet boundary layer; Numerical investigations; Numerical predictions; Atmospheric thermodynamics

The initial mass function and star formation law in the outer disc of NGC 2915 - Bruzzese, S. M.; Meurer, G. R.; Lagos, C. D. P.; Elson, E. C.; Werk, J. K.; Blakeslee, J. P.; Ford, H. (Monthly Notices of the Royal Astronomical Society, 2014)
Using Hubble Space Telescope (HST) Advanced Camera for Surveys/Wide Field Camera data we present the photometry and spatial distribution of resolved stellar populations in the outskirts of NGC 2915, a blue compact dwarf with an extended H I disc. These observations reveal an elliptical distribution of red giant branch stars, and a clumpy distribution of mainsequence stars that correlate with the H I gas distribution. We constrain the upper-end initial mass function (IMF) and determine the star formation law(SFL) in this field, using the observed main-sequence stars and an assumed constant star formation rate. Previously published Hα observations of the field, which show one faint H II region, are used to provide further constraints on the IMF. We find that the main-sequence luminosity function analysis alone results in a best-fitting IMF with a power-law slope α = -2.85 and upper-mass limit Mu = 60M. However, if we assume that all Hα emission is confined to H II regions then the upper-mass limit is restricted to Mu 20M. For the luminosity function fit to be correct, we have to discount the Hα observations implying significant diffuse ionized gas or escaping ionizing photons. Combining the HST photometry with H I imaging, we find the SFL has a power-law index N = 1.53 ± 0.21. Applying these results to the entire outer H I disc indicates that it contributes 11-28 per cent of the total recent star formation in NGC 2915, depending on whether the IMF is constant within the disc or varies from the centre to the outer region.

Measurement of serum immunoglobulin G in dairy cattle using Fourier-transform infrared spectroscopy: A reagent free approach - Elsohaby, Ibrahim; Riley, Christopher B.; Hou, Siyuan; McClure, J. Trenton; Shaw, R. Anthony; Keefe, Gregory P. (Veterinary Journal, 2014)
Simple, rapid and cost-effective methods are sought for measuring immunoglobulin G (IgG) concentrations in bovine serum, which can be applied for diagnosis of failure of transfer of passive immunity (FTPI). The aim of the present study was to investigate the potential use of Fourier-transform infrared (FTIR) spectroscopy, with partial least squares (PLS) regression, to measure IgG concentrations in bovine serum. Serum samples collected from calves and adult cows were tested in parallel by radial immunodiffusion (RID) assay and FTIR spectroscopy. The sample IgG concentrations obtained by the RID method were linked to pre-processed spectra and divided into two sets: a combined set and a test set. The combined set was used for building a calibration model, while the test set was used to assess the predictive ability of the calibration model, resulting in a root mean squared error of prediction (RMSEP) of 307.5-mg/dL.The concordance correlations between the IgG measured by RID and predicted by FTIR spectroscopy were 0.96 and 0.93 for the combined and test data sets, respectively. Analysis of the data using the Bland-Altman method did not show any evidence of systematic bias between FTIR spectroscopy and RID methods for measurement of IgG. The clinical applicability of FTIR spectroscopy for diagnosis of FTPI was evaluated using the entire data set and showed a sensitivity of 0.91 and specificity of 0.96, using RID as the reference standard. The FTIR spectroscopy method, described in the present study, demonstrates potential as a rapid and reagent-free tool for quantification of IgG in bovine serum, as an aid to diagnosis of FTPI in calves.
Keywords: immunoglobulin G; calibration; correlation coefficient; dairy cattle; diagnostic accuracy; diagnostic test accuracy study; diagnostic value; false negative result; false positive result; immunodiffusion; immunoglobulin blood level; infrared spectroscopy; partial least squares regression; passive immunization; placental transfer; quantitative assay; sensitivity and specificity; Bos; Bovinae

A versatile cost-effective and one step process to engineer ZnO superhydrophobic surfaces on Al substrate - Siddaramanna, Ashoka; Saleema, N.; Sarkar, D. K. (Applied Surface Science, 2014)
Multifunctional superhydrophobic surfaces based on photocatalytic material, ZnO have generated significant research interest from both fundamental and potential applications. Superhydrophobic ZnO surfaces are usually made in multi steps by creating rough surface and subsequent hydrophobization by low-surface-energy materials. Herein, a simple and one step chemical bath deposition has been developed to prepare superhydrophobic ZnO surfaces on aluminum substrate. The aluminum surfaces covered with randomly distributed ZnO particles can not only present multiscale surface roughness, but also readily coordinate with fatty acid, leading to special wettability. The contact angle of the resulting superhydrophobic surface reaches up to 165 ± 2° and contact angle hysteresis of 4°. The contact angle and contact angle hysteresis variation as a function of particle size has been discussed systematically based on surface morphology.
Keywords: Aluminum; Aluminum coatings; Contact angle; Hysteresis; Infrared spectroscopy; Surface morphology; Surface properties; Surface roughness; Wetting; X ray diffraction; Zinc oxide; Chemical-bath deposition; Multiscale surface; Photocatalytic materials; Super-hydrophobic surfaces; Superhydrophobicity; ZnO particles; Hydrophobicity

Antiproliferative quillaic acid and gypsogenin saponins from Saponaria officinalis L. roots - Lu, Yuping; Van, Dang; Deibert, Leah; Bishop, Greg; Balsevich, John (Phytochemistry, 2014)
Nine quillaic acid and five gypsogenin bisdesmosides were isolated from roots of Saponaria officinalis L. (Caryophyllaceae). Seven of the quillaic acid saponins possessed a 3-O-β-d-galactopyranosyl-(1 → 2)-[β-d-xylopyranosyl-(1 → 3)]-β-d-glucuronopyranosyl unit, but differed from each other in oligosaccharide units linked to the C-28 ester. The five gypsogenin saponins isolated from the roots all possessed the 3-O-β-d-galactopyranosyl-(1 → 2)-[β-d-xylopyranosyl-(1 → 3)]-β-d-glucuronopyranosyl unit, with their oligosaccharide units linked to the C-28 ester differing. Structures were elucidated by extensive 1D and 2D NMR spectroscopy and mass spectrometry. The saponins were evaluated for growth inhibitory activity in two human cancer cell lines and hemolytic activity in sheep red blood cells.
Keywords: Saponins; Saponaria officinalis L.; Caryophyllaceae; Quillaic acid; Gypsogenin; 2D NMR spectroscopy

An MCAO test bench for NFIRAOS - Turri, Paolo; Andersen, David R.; Véran, Jean-Pierre; Spanò, Paolo; Rosensteiner, Matthias; McVeigh, Eric A. (SPIE - International Society for Optical Engineering. Proceedings, 2014)
At NRC Herzberg - Astronomy we are developing a closed-loop multi-conjugate adaptive optics bench to simulate a scaled-down version of NFIRAOS, the first light MCAO system on the Thirty Meter Telescope. The current bench consists of four laser guide stars, an evenly spaced array of natural guide stars, two magnetic deformable mirrors, a Shack-Hartmann wavefront sensor and a science camera at the focal plane for the evaluation of the performance and the tip-tilt measurements. Three phase screens conjugated at different altitudes simulate the atmospheric perturbation over the telescope. We can recreate the spot elongation on the SHWFS by defocusing the ground DM and at the same time modulating the intensity of the LGS spots in order to simulate the timevarying density profile of the sodium layer. The goals of this experiment are to compare the experimental performance on the bench with the predicted results of NFIRAOS models and to test the robustness of the tomographic reconstruction under conditions including the use of faint guide stars, non-uniform density profiles of the sodium layer and known non-common path aberrations. In this paper we present an update on the status of the bench and some first results.
Keywords: Laser mirrors; Optical telescopes; Sodium; Stars; Telescopes; Atmospheric perturbations; MCAO; Multiconjugate adaptive optics; NFIRAOS; Shack-Hartmann wavefront sensors; Thirty Meter Telescope; TMT; Tomographic reconstruction; Adaptive optics

Current status and future plans for the maunakea spectroscopic explorer (MSE) - Simons, Douglas A.; Crampton, David; Côté, Pat; McConnachie, Alan; Szeto, Kei; Salmon, Derrick; Devost, Daniel; Murowinski, Richard (SPIE - International Society for Optical Engineering. Proceedings, 2014)
The Maunakea Spectroscopic Explorer (MSE; formerly ngCFHT) will be a large format wide field spectroscopic facility that replaces the existing 3.6 m Canada-France-Hawaii Telescope. Capable of recording tens of thousands of spectra on faint targets each night, and sustain that pace for years, MSE will be an ideal complement to emerging space- and ground-based imaging survey facilities. The combination of aperture, spectral resolution, and dedicated access to support large surveys makes MSE distinct from any other facilities under development or being planned. We provide an overview of the MSE technical design, organization of the project office, and the core science goals that will help drive MSE for decades.
Keywords: Airborne telescopes; Fibers; Spectroscopy; Faint target; Imaging surveys; Large surveys; ngCFHT; optical; Wide field; Surveys

Thirty Meter Telescope astrometry error budget - Schöck, Matthias; Do, Tuan; Ellerbroek, Brent L.; Gilles, Luc; Herriot, Glen; Meyer, Leo; Suzuki, Ryuji; Wang, Lianqi; Yelda, Sylvana (SPIE - International Society for Optical Engineering. Proceedings, 2014)
The Thirty Meter Telescope (TMT) with its first-light multi-conjugate adaptive optics system, NFIRAOS, and high-resolution imager, IRIS, is expected to take differential astrometric measurements with an accuracy on the order of tens of micro arcsec. This requires the control, correction, characterization and calibration of a large number of error sources and uncertainties, many of which have magnitudes much in excess of this level of accuracy. In addition to designing the observatory such that very high precision and accuracy astrometric observations are enabled, satisfying the TMT requirements can only be achieved by a careful calibration, observation and data reduction strategy. In this paper, we present descriptions of the individual errors sources, how and when they apply to different astrometry science cases and the mitigation methods required for each of them, as well as example results for individual error terms and the overall error budgets for a variety of different science cases.
Keywords: Calibration; Optical telescopes; Telescopes; Astrometric measurements; Astrometry; Extremely Large Telescopes; High resolution; Mitigation methods; Multi-conjugate adaptive optics systems; Reduction strategy; Thirty Meter Telescope; Adaptive optics

Conceptual design study to determine optimal enclosure vent configuration for the Maunakea Spectroscopic Explorer (MSE) - Szeto, Kei; Vogiatzis, Konstantinos; Hangan, Horia; Jubayer, Chowdhury M.; Breckenridge, Craig; Loewen, Nathan; Bauman, Steven; Salmon, Derrick (SPIE - International Society for Optical Engineering. Proceedings, 2014)
The Maunakea Spectroscopic Explorer (MSE; formerly Next Generation Canada-France-Hawaii Telescope) is a dedicated, 10m aperture, wide-field, fiber-fed multi-object spectroscopic facility proposed as an upgrade to the existing Canada-France-Hawaii Telescope on the summit of Mauna Kea. The enclosure vent configuration design study is the last of three studies to examine the technical feasibility of the proposed MSE baseline concept. The enclosure vent configuration study compares the aero-thermal performance of three enclosure ventilation configurations based on the predicted dome thermal seeing and air flow attenuation over the enclosure aperture opening of a Calotte design derived from computational fluid dynamics simulations. In addition, functional and operation considerations such as access and servicing of the three ventilation configurations is discussed.
Keywords: Airborne telescopes; Computational fluid dynamics; Conceptual design; Domes; Spectrographs; Ventilation; aero-thermal; Baseline concepts; Computational fluid dynamics simulations; Dome seeing; flushing; MSE; Thermal Performance; Vent configurations

Recent results and future DMs for astronomy and for space applications at CILAS - Sinquin, Jean-Christophe; Bastard, Arnaud; Beaufort, Emmanuel; Berkefeld, Thomas; Cadiergues, Laurent; Costes, Vincent; Cousty, Raphaël; Dekhtiar, Charles; Di Gesu, Frédéric; Gilbert, Xavier; Grèzes-Besset, Catherine; Groeninck, Denis; et al. (SPIE - International Society for Optical Engineering. Proceedings, 2014)
We present recent experimental results obtained with CILAS deformable mirrors (DMs) or demonstration prototypes in solar and night-time astronomy (with ground-based telescopes) as well as observation of the Earth (with space telescopes). These important results have been reached thanks to CILAS technology range composed of monomorph and piezostack deformable mirrors, drivers and optical coatings. For instance, the monomorph technology, due to a simple architecture can offer a very good reliability for space applications. It can be used for closed or open loop correction of the primary mirror deformation (thermal and polishing aberrations, absence of gravity). It can also allow a real-time correction of wavefront aberrations introduced by the atmosphere up to relatively high spatial and temporal frequencies for ground-based telescopes. The piezostack technology is useful for very high order correction at high frequency and under relatively low operational temperature (down to -30°C), which is required for future Extremely Large Telescopes (ELTs). This wide range of applications is exposed through recent examples of DMs performances in operation and results obtained with breadboards, allowing promising DMs for future needs.
Keywords: Aberrations; Astronomy; Deformation; Laser pulses; Mirrors; Optical coatings; Space applications; bimorph; Deformable mirrors; Extremely Large Telescopes; Ground-based telescopes; High order corrections; monomorph; Operational temperature; Piezo stack; Adaptive optics

Photometric performance of LGS MCAO with science-based metrics: First results from Gemini/GeMS observations of Galactic globular clusters - Turri, Paolo; McConnachie, Alan W.; Stetson, Peter B.; Fiorentino, Giuliana; Andersen, David R.; Bono, Giuseppe; Véran, Jean-Pierre (SPIE - International Society for Optical Engineering. Proceedings, 2014)
Multi-conjugate adaptive optics can achieve diffraction limited images over a field of arcminutes and is a central technology for the future ELTs: Gemini/GeMS is the first facility-class LGS MCAO system to operate. With it we have taken images in J and Ks bands of the globular cluster NGC 1851 for which we also have HST/ACS observations in the visible. In this paper we present the deepest to date near-infrared photometry of NGC 1851 providing a wide colour baseline CMD that reaches the lower main sequence to have a new insight into the stellar populations of this globular cluster. The use of the GGCs' lower main sequence knee to determine its age is one of the science drivers for the observation of GGCs with MCAO given its visibility in the infrared and because it requires high Strehl ratios to measure the faint stars' photometry. In addition to the stellar population analysis, these data allow to examine the photometric performance of the instrument using a large number of point sources distributed across the field. We analyze the photometric performance of the instrument and the field dependence of the PSF, a central part on the prediction and improvement of the performance of future LGS MCAO systems like NFIRAOS for the Thirty Meter Telescope.
Keywords: Gems; Infrared devices; Optical telescopes; Photometry; Population statistics; Stars; AO Science; Globular clusters; GSAOI; MCAO; Multiconjugate adaptive optics; Near-infrared photometry; Stellar populations; Thirty Meter Telescope; Adaptive optics

Long-term thermal performance of impermeably faced polyiso foam boards: Field and laboratory observations - Mukhopadhyaya, Phalguni; Drouin, Michel; Normandin, Nicole; van Reenen, David; Lackey, John (Journal of Cold Regions Engineering, 2014)
Researchers at the National Research Council (NRC) Canada-Construction Portfolio in association with the Canadian Polyisocyanurate Council conducted collaborative research activities on the long-term thermal resistance (LTTR) of polyisocyanurate (polyiso) foam insulation with impermeable facers. Polyiso boards are commonly used in building envelope constructions (roofs and walls) in cold regions. The primary objective of the research project was to contribute towards the development of a comprehensive test procedure that could be used to measure the LTTR of polyiso foam insulation products with impermeable facers. As a part of that initiative, a project was initiated in 2001 that consisted of accelerated aging tests using thin slices in parallel with a field investigation in which polyiso boards were installed in a purpose-built test hut at the NRC's Ottawa campus. The polyiso boards installed in the field were monitored for a period of 6 years and subsequently removed from the test hut and tested in the laboratory. This paper presents the field thermal performance of the rigid polyiso foam boards with impermeable facers and critically examines its relationship with the laboratory-measured thin slice aging data. It is hoped that these observations will help construction professionals and researchers to develop a better understanding on the LTTR of impermeably faced polyiso foam insulation boards.
Keywords: Testing; Accelerated aging test; Collaborative research activity; Construction professionals; Field performance; Long-term thermal resistance (LTTR); Polyisocyanurate; Thin slicing; Thermal insulation; foam; insulation; performance assessment; plastic

Heterotrophic and mixotrophic cultivation of microalgae for biodiesel production in agricultural wastewaters and associated challenges: a critical review - Lowrey, Joshua; Brooks, Marianne S.; McGinn, Patrick J. (Journal of Applied Phycology, 2014)
Many studies have demonstrated that heterotrophic and mixotrophic growth for various microalgae species yields greater biomass and lipid content as compared to photoautotrophic cultivation. This review explores the possibility of leveraging the natural ability of the microorganisms to metabolize carbon heterotrophically and mixotrophically in agricultural wastewaters. This has the potential advantage of improving the overall economics for the production of biodiesel and value-added biomolecules from microalgae, mitigating an existing waste stream and minimizing water requirements. However, there are a number of challenges and gaps in scientific knowledge that suggest a need for ongoing research in the area. In this review, specific focus is dedicated to the metabolic mechanisms, reported performances, and practical challenges that contribute to the uncertainty of employing agricultural wastewaters for heterotrophic and mixotrophic microalgae cultures.

Characterisation and optimisation of minimum quantity lubrication in milling of Ti-6Al-4V alloy using phase Doppler anemometry (PDA) - Tendolkar, Amit; Damir, Ahmed; Attia, Helmi; Hendrick, Patrick; Diakodimitris, Christophe (International Journal of Mechatronics and Manufacturing Systems, 2014)
The main objective of this work is to understand the effect of the MQL parameters; namely, oil flow rate, air flow rate and nozzle distance from the cutting zone, on the flow characteristics in order to optimise the cooling and lubrication capacities of the jet for machining applications. Flow visualisation experiments were performed for different air and oil flow rates and distances from the nozzle using phase Doppler anemometry (PDA). The visualisation results, such as, the droplet size and velocity vector were used to identify the optimum MQL conditions to achieve the desired flow characteristics for machining applications. It was found that a spray with high air flow rate and high oil flow rate would give an axial, symmetrical, coherent, and undisturbed spray, which is characterised by small droplet size and high velocity. This spray is optimum for machining due to its ability for better penetration and cooling effect in the cutting zone. Milling tests were performed on Ti-6Al-4V alloy to validate the effect of MQL parameters on the machining performance, in terms of cutting forces, surface roughness and tool temperature.
Keywords: Air lubrication; Aluminum; Anemometers; Drops; Flow rate; Flow visualization; Lubrication; Milling (machining); Nozzles; Oil shale; Surface roughness; Visualization; Flow charac-teristics; Flow visualisation; Machining performance; Minimum quantity lubrication; MQL; Phase Doppler anemometry; Tool temperatures; Velocity vectors; Titanium alloys

In situ proteolysis, crystallization and preliminary X-ray diffraction analysis of a VHH that binds listeria internalin B - Huh, Ian; Gene, Robert; Kumaran, Jyothi; MacKenzie, C. Roger; Brooks, Cory L. (Acta Crystallographica Section F:Structural Biology Communications, 2014)
The variable region of camelid heavy-chain antibodies produces the smallest known antibody fragment with antigen-binding capability (a VHH). The VHH R303 binds internalin B (InlB), a virulence factor expressed by the pathogen Listeria monocytogenes. InlB is critical for initiation of Listeria infection, as it binds a receptor (c-Met) on epithelial cells, triggering the entry of bacteria into host cells. InlB is surface-exposed and is required for virulence, hence a VHH targeting InlB has potential applications for pathogen detection or therapeutic intervention. Here, the expression, purification, crystallization and X-ray diffraction of R303 are reported. Crystals of R303 were obtained following in situ proteolysis with trypsin. Gel filtration and SDS-PAGE revealed that trypsin removed the C-terminal tag region of R303, facilitating crystal formation. Crystals of R303 diffracted to 1.3Å resolution and belonged to the monoclinic space group P21, with unit-cell parameters a = 46.4, b = 31.2, c = 74.8Å, β = 93.8°. The crystals exhibited a Matthews coefficient of 1.95Å3Da-1 with two molecules in the asymmetric unit.
Keywords: Camelidae; Listeria; Listeria monocytogenes

Revealing H2D + depletion and compact structure in starless and protostellar cores with alma - Friesen, R. K.; Di Francesco, J.; Bourke, T. L.; Caselli, P.; Jørgensen, J. K.; Pineda, J. E.; Wong, M. (The Astrophysical Journal, 2014)
We present Atacama Large Millimeter/submillimeter Array (ALMA) observations of the submillimeter dust continuum and H2D+ 110-111 emission toward two evolved, potentially protostellar cores within the Ophiuchus molecular cloud, Oph A SM1 and SM1N. The data reveal small-scale condensations within both cores, with mass upper limits of M ≲ 0.02 M ⊙ (20 M Jup). The SM1 condensation is consistent with a nearly symmetric Gaussian source with a width of only 37 AU. The SM1N condensation is elongated and extends 500 AU along its major axis. No evidence for substructure is seen in either source. A Jeans analysis indicates that these sources are unlikely to fragment, suggesting that both will form single stars. H2D+ is only detected toward SM1N, offset from the continuum peak by 150-200 AU. This offset may be due to either heating from an undetected, young, low-luminosity protostellar source or first hydrostatic core, or HD (and consequently H2D+) depletion in the cold center of the condensation. We propose that SM1 is protostellar and that the condensation detected by ALMA is a warm (T 30-50 K) accretion disk. The less concentrated emission of the SM1N condensation suggests that it is still starless, but we cannot rule out the presence of a low-luminosity source, perhaps surrounded by a pseudodisk. These data observationally reveal the earliest stages of the formation of circumstellar accretion regions and agree with theoretical predictions that disk formation can occur very early in the star formation process, coeval with or just after the formation of a first hydrostatic core or protostar.

A study of armour related properties of ceramic - Fakolujo, Olaniyi S.; Merati, Ali; Nganbe, Michel; Bielawski, Mariusz; Bolduc, Manon (Processing and Properties of Advanced Ceramics and Composites VI: Ceramic Transactions, 2014)
Ceramics constitute an integral part of highly effective armours, often coupled together with ductile backing materials such as metals and polymers. The widespread use of armour ceramics is primarily due to their low density, high hardness, strength and elastic modulus. However, none of these properties can individually or collectively be identified as the major controller of armour performance. Rather, the synergistic effects of these properties are considered relevant for the ultimate impact performance. In this study, pressureless sintered alumina with ZrO2 second phase particles as well as monolithic silicon carbide armour ceramics were investigated. They were characterized with respect to armour related properties such as hardness, indentation fracture toughness, porosity and density. The results indicated that the second phase particles and the level of porosity can significantly influence the performance of such armour ceramics.

A hybrid structural health monitoring system for the detection and localization of damage in composite structures - Barazanchy, Darun; Martinez, Marcias; Rocha, Bruno; Yanishevsky, Marko (Journal of Sensors, 2014)
A hybrid structural health monitoring (SHM) system, consisting of a piezoelectric transducer and fiber optic sensors (FOS) for generating and monitoring Lamb waves, was investigated to determine their potential for damage detection and localization in composite aerospace structures. As part of this study, the proposed hybrid SHM system, together with an in-house developed algorithm, was evaluated to detect and localize two types of damage: a through thickness damage (hole of 2 mm in diameter) and a surface damage (2 mm diameter bore hole with a depth of 0.65 mm) located on the backside of the plate. The experiments were performed using an aircraft representative composite plate skin, manufactured from carbon fiber reinforced polymer (CFRP).
Keywords: Carbon fiber reinforced plastics; Composite structures; Damage detection; Fiber optic sensors; Plates (structural components); Surface waves; Carbon fiber reinforced polymer; Composite aerospace structures; Composite plates; Detection and localization; Structural health monitoring (SHM); Structural health monitoring systems; Surface damages; Through-thickness; Structural health monitoring

Data showing the compositional complexity of the mitochondrial proteome of a unicellular eukaryote (Acanthamoeba castellanii, supergroup Amoebozoa) - Gawryluk, Ryan M. R.; Chisholm, Kenneth A.; Pinto, Kenneth M.; Gray, Michael W. (Data in Brief, 2014)
This article describes and directly links to 1033 Acanthamoeba castellanii mitochondrial protein sequences. Of these, 709 are supported by Mass Spectrometry (MS) data (676 nucleus-encoded and 33 mitochondrion-encoded). Two of these entries are previously unannotated mtDNA-encoded proteins, which we identify as highly divergent mitochondrial ribosomal proteins. Our analysis corrects many A. castellanii protein sequences that were incorrectly inferred previously from genomic data deposited in NCBI.

Design of a 70-116 GHz W-band turnstile OMT - Henke, Doug; Claude, Stéphane (European Microwave Week 2014: Connecting the Future, EuMW 2014 - Conference Proceedings; EuMC 2014: 44th European Microwave Conference, 2014)
An orthomode transducer (OMT) is important to separate the incoming signal into two linear polarizations. Using a turnstile junction, good input match, high isolation, and low cross-polarization can be achieved over a wide bandwidth. We report on a design covering 70-116 GHz that is directly machined from aluminum.
Keywords: Millimeter waves; Polarization; Radio astronomy; Transducers; High isolation; Input match; Linear polarization; Low cross polarization; Ortho-mode transducers; Polarization splitters; Turnstile junctions; Wide bandwidth; Millimeter wave devices

An experimental study on grinding fir-tree root forms using vitrified CBN wheels - Shi, Zhongde; Elfizy, Amr; Attia, Helmi (Advanced Materials Research, 2014)
An experimental study was undertaken to explore the conditions and performance on rough and finish grinding fir-tree root forms of turbine blades made of a nickel-based alloy using vitrified CBN wheels and water-based grinding fluid. This work was motivated by switching the grinding of fir-tree root forms from grinding with conventional abrasive wheels to vitrified CBN wheels for reducing overall production cost and enhancing productivity. Grinding experiments were conducted to measure grinding forces, power, surface roughness, and stress near the blade roots under various dressing and grinding conditions. Wheel re-dressing life in terms of the total number of good parts ground between dressing was tested with the condition producing the maximum material removal rate while satisfying preset part quality and process requirements. It was found that the maximum material removal rate achievable in rough grinding was restricted by the stress limit and the wheel re-dressing life was dominated by the radial wheel wear limit. The targeting part quality and process requirements were achieved. It was proved that vitrified CBN grinding process is feasible and very promising to machine fir-tree root forms.
Keywords: Abrasives; Forestry; Grinding wheels; Iron alloys; Nickel; Surface roughness; Turbomachine blades; Wheel dressing; Grinding conditions; Material removal rate; Nickel based alloy; Process requirements; Production cost; Tree root; Vitrified CBN; Vitrified cbn wheels; Grinding (machining); Abrasion; Blades; Grinding; Roots; Wheels

Evaluation of an early stage air cathode for zinc air battery applications - Zhang, Xinge; Qu, Wei; Fahlman, Jason; Tsay, Ken; Yuan, Xiao-Zi (ECS Transactions, 2014)
In this study, we evaluated the performance of the air cathode prepared by our industrial partner in a customized test platform under operating conditions of temperature up to 70°C, potassium hydroxide (KOH) concentration approximately 45wt% and current density of 0.2A/cm2. The temperature and CO2 effect on the performance were also investigated. The air cathode performed for over 1000 hours lifetime with the best degradation rate of approximately 0.15mV/hr.
Keywords: Carbon dioxide; Cathodes; Degradation; Electric batteries; Electrodes; Potassium hydroxide; Air cathode; Operating condition; Test platforms; Zinc-air battery; Primary batteries

Tuning the electrically evaluated electron Landé g factor in GaAs quantum dots and quantum wells of different well widths - Allison, G.; Fujita, T.; Morimoto, K.; Teraoka, S.; Larsson, M.; Kiyama, H.; Oiwa, A.; Haffouz, S.; Austing, D. G.; Ludwig, A.; Wieck, A. D.; Tarucha, S. (Physical Review B - Condensed Matter and Materials Physics, 2014)
We evaluate the Landé g factor of electrons in quantum dots (QDs) fabricated from GaAs quantum well (QW) structures of different well width. We first determine the Landé electron g factor of the QWs through resistive detection of electron spin resonance and compare it to the enhanced electron g factor determined from analysis of the magnetotransport. Next, we form laterally defined quantum dots using these quantum wells and extract the electron g factor from analysis of the cotunneling and Kondo effect within the quantum dots. We conclude that the Landé electron g factor of the quantum dot is primarily governed by the electron g factor of the quantum well suggesting that well width is an ideal design parameter for g-factor engineering QDs.

Use of the zebrafish larvae as a model to study cigarette smoke condensate toxicity - Ellis, Lee D.; Soo, Evelyn C.; Achenbach, John C.; Morash, Michael G.; Soanes, Kelly H. (PLoS ONE, 2014)
The smoking of tobacco continues to be the leading cause of premature death worldwide and is linked to the development of a number of serious illnesses including heart disease, respiratory diseases, stroke and cancer. Currently, cell line based toxicity assays are typically used to gain information on the general toxicity of cigarettes and other tobacco products. However, they provide little information regarding the complex disease-related changes that have been linked to smoking. The ethical concerns and high cost associated with mammalian studies have limited their widespread use for in vivo toxicological studies of tobacco. The zebrafish has emerged as a low-cost, high-throughput, in vivo model in the study of toxicology. In this study, smoke condensates from 2 reference cigarettes and 6 Canadian brands of cigarettes with different design features were assessed for acute, developmental, cardiac, and behavioural toxicity (neurotoxicity) in zebrafish larvae. By making use of this multifaceted approach we have developed an in vivo model with which to compare the toxicity profiles of smoke condensates from cigarettes with different design features. This model system may provide insights into the development of smoking related disease and could provide a cost-effective, high-throughput platform for the future evaluation of tobacco products.
Keywords: cigarette smoke condensate; acute toxicity; animal experiment; animal model; cardiotoxicity; cost effectiveness analysis; developmental toxicity; embryo; high throughput screening; in vivo study; larva; neurotoxicity; smoking; zebra fish; Danio rerio; Mammalia; Nicotiana tabacum

The debris disc of solar analogue Τ Ceti: Herschel observations and dynamical simulations of the proposed multiplanet system - Lawler, S. M.; Di Francesco, J.; Kennedy, G. M.; Sibthorpe, B.; Booth, M.; Vandenbussche, B.; Matthews, B. C.; Holland, W. S.; Greaves, J.; Wilner, D. J.; Tuomi, M.; Blommaert, J. A. D. L.; et al. (Monthly Notices of the Royal Astronomical Society, 2014)
Τ Ceti is a nearby, mature G-type star very similar to our Sun, with a massive Kuiper Belt analogue and possible multiplanet system that has been compared to our Solar system. We present Herschel Space Observatory images of the debris disc, finding the disc is resolved at 70 μm and 160 μm, and marginally resolved at 250 μm. The Herschel images and infrared photometry from the literature are best modelled using a wide dust annulus with an inner edge between 1 and 10 au and an outer edge at~55 au, inclined from face-on by 35° ±10°, and with no significant azimuthal structure. We model the proposed tightly packed planetary system of five super-Earths and find that the innermost dynamically stable disc orbits are consistent with the inner edge found by the observations. The photometric modelling, however, cannot rule out a disc inner edge as close to the star as 1 au, though larger distances produce a better fit to the data. Dynamical modelling shows that the five-planet system is stable with the addition of a Neptune or smaller mass planet on an orbit outside 5 au, where the radial velocity data analysis would not have detected a planet of this mass.

Design of a retrofittable spindle attachment for high frequency vibration-assisted drilling - Panju, J.; Meshreki, M.; Attia, M. H. (ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE), 2014)
1Conventional drilling of modern super alloys and composite material induces high stresses in the vicinity of drilled holes along with high thrust forces which lead to problems in terms of hole quality and accuracy as well as increased tool wear. A recent and promising technique to overcome these challenges is to introduce vibration assistance in the cutting zone by superimposing oscillating vibration in the feed direction of the tool. Two regimes of vibration excitation could be applied for this purpose: low frequency (<500 Hz) high amplitude (>100 μm) and high frequency (<500 Hz) low amplitude (<20 μm). Motivated by the advantages of the HF-VAD and the limited work available in the literature for this regime, a new system is developed by the authors where the rotating tool is excited to high frequency and low amplitude. The new design is based on the use of piezoelectric actuators to generate the motion and a high speed slip ring to ensure the transfer of sufficient power to the actuator. A novel concept was implemented by de-coupling the rotary motion of the spindle from the vibrational motion of the actuator to ensure a higher efficiency of power transmission without damaging either the actuator or the spindle. With this design, a retrofittable HSK 100A toolholder with high frequency excitation spindle attachment was manufactured to incorporate drill sizes up to 1/4 inches. Commissioning tests were performed under no load and spring loaded conditions and it was found that the system has a capability to excite the tool up to 100 μm at 900 Hz (resonance frequency) and up to 5 μm between 500-800 Hz and 1100-2500 Hz. HF-VAD tests were conducted using this new attachment on Aluminum 6061 and it was found that the system was able to successfully obtain the prescribed frequency and amplitude. Up to 50% reduction in.
Keywords: Actuators; Cutting tools; Drilling; Commissioning test; High frequency HF; High frequency vibration; High-frequency excitation; Higher efficiency; Resonance frequencies; Vibration excitation; Vibrational motions; Piezoelectric actuators

MSE spectrograph optical design: A novel pupil slicing technique - Spanò, P. (SPIE - International Society for Optical Engineering. Proceedings, 2014)
The Maunakea Spectroscopic Explorer shall be mainly devoted to perform deep, wide-field, spectroscopic surveys at spectral resolutions from ∼2000 to ∼20000, at visible and near-infrared wavelengths. Simultaneous spectral coverage at low resolution is required, while at high resolution only selected windows can be covered. Moreover, very high multiplexing (3200 objects) must be obtained at low resolution. At higher resolutions a decreased number of objects (∼800) can be observed. To meet such high demanding requirements, a fiber-fed multi-object spectrograph concept has been designed by pupil-slicing the collimated beam, followed by multiple dispersive and camera optics. Different resolution modes are obtained by introducing anamorphic lenslets in front of the fiber arrays. The spectrograph is able to switch between three resolution modes (2000, 6500, 20000) by removing the anamorphic lenses and exchanging gratings. Camera lenses are fixed in place to increase stability. To enhance throughput, VPH first-order gratings has been preferred over echelle gratings. Moreover, throughput is kept high over all wavelength ranges by splitting light into more arms by dichroic beamsplitters and optimizing efficiency for each channel by proper selection of glass materials, coatings, and grating parameters.
Keywords: Astronomy; Cameras; Glass; Infrared devices; Optical design; CFHT; High resolution; MSE; Multiobject spectroscopy; pupil-slicing; VPH gratings; Spectrographs

GRACES: Gemini remote access to CFHT ESPaDOnS spectrograph through the longest astronomical fiber ever made: Experimental phase completed - Chene, André-Nicolas; Padzer, John; Barrick, Gregory; Anthony, Andre; Benedict, Tom; Duncan, David; Gigoux, Pedro; Kleinman, Scot; Malo, Lison; Martioli, Eder; Moutou, Claire; Placco, Vinicius; et al. (SPIE - International Society for Optical Engineering. Proceedings, 2014)
The Gemini Remote Access to CFHT ESPaDONS Spectrograph has achieved first light of its experimental phase in May 2014. It successfully collected light from the Gemini North telescope and sent it through two 270 m optical fibers to the the ESPaDOnS spectrograph at CFHT to deliver high-resolution spectroscopy across the optical region. The fibers gave an average focal ratio degradation of 14% on sky, and a maximum transmittance of 85% at 800nm. GRACES achieved delivering spectra with a resolution power of R = 40,000 and R = 66,000 between 400 and 1,000 nm. It has a ∼8% throughput and is sensitive to target fainter than 21st mag in 1 hour. The average acquisition time of a target is around 10 min. This project is a great example of a productive collaboration between two observatories on Maunakea that was successful due to the reciprocal involvement of the Gemini, CFHT, and NRC Herzberg teams, and all the staff involved closely or indirectly.
Keywords: Fibers; Optical fibers; Spectrographs; Spectroscopic analysis; Spectroscopy; Acquisition time; ESPaDOnS; Focal ratio degradation; High resolution; High-resolution spectroscopy; Optical; Optical regions; Resolution power; Telescopes

New results from the first exoplanet survey in the Canadian High Arctic - Law, Nicholas M.; Carlberg, Raymond; Fors, Octavi; Steinbring, Eric; Ngan, Wayne; Wulfken, Philip; Pedersen, Bjorn; Maire, Jerome; Sivanandam, Suresh (SPIE - International Society for Optical Engineering. Proceedings, 2014)
We present new results from the first search for transiting exoplanets undertaken from the High Arctic: the AWCam (Arctic Wide-field Cameras) survey. The survey, which has been operating for 2.5 years, is based at 80 degrees North on Ellesmere Island in the Canadian High Arctic. The small telescopes monitor 70,000 bright stars in a several-hundred square-degree region around Polaris, with milli-magnitude photometric precision, and are capable of discovering giant planets around 10,000 bright, nearby solar-type stars. We present the first longterm monitoring results from the AWCams, including an assessment of the site characteristics and the systems' long-term performance. The High-Arctic site provided excellent survey efficiency, without diurnal windowing and largely uninterrupted by clouds. Useful data was obtained over the entire survey field 71% of the time; the sky was clear 62% of the time. One pristine clear, dark period in winter 2012/13 persisted for 480 hours. In 2012/13 we recorded a period of 480 hours of continuous photometric conditions, attaining 3-4 millimag photometric stability over the entire period. We report the long-term photometric performance of the AWCam systems and detail the discovery of a bright (V=8) low-amplitude eclipsing binary. Finally, we present a concept for an extremely-wide-field arctic survey based on the Evryscope telescope-array design.
Keywords: Airborne telescopes; Cameras; Extrasolar planets; Photometry; Stars; Turbulent flow; arctic; circumpolar; Exoplanet; Site-testing; transit; Wide field cameras

Gemini planet imager integration to the Gemini South telescope software environment - Rantakyrö, Fredrik T.; Cardwell, Andrew; Chilcote, Jeffrey; Dunn, Jennifer; Goodsell, Stephen; Hibon, Pascale; Macintosh, Bruce; Quiroz, Carlos; Perrin, Marshall D.; Sadakuni, Naru; Saddlemyer, Leslie; Savransky, Dmitry; et al. (SPIE - International Society for Optical Engineering. Proceedings, 2014)
The Gemini Planet Imager is an extreme AO instrument with an integral field spectrograph (IFS) operating in Y, J, H, and K bands. Both the Gemini telescope and the GPI instrument are very complex systems. Our goal is that the combined telescope and instrument system may be run by one observer operating the instrument, and one operator controlling the telescope and the acquisition of light to the instrument. This requires a smooth integration between the two systems and easily operated control interfaces. We discuss the definition of the software and hardware interfaces, their implementation and testing, and the integration of the instrument with the telescope environment.
Keywords: Instrument testing; Observatories; Telescopes; Gemini Planet Imager; Instrument systems; Instrumentation; Integral field spectrograph; Software environments; Integration testing

Gemini planet imager observational calibrations V: Astrometry and distortion - Konopacky, Quinn M.; Thomas, Sandrine J.; MacIntosh, Bruce A.; Dillon, Daren; Sadakuni, Naru; Maire, Jérôme; Fitzgerald, Michael; Hinkley, Sasha; Kalas, Paul; Esposito, Thomas; Marois, Christian; Ingraham, Patrick J.; et al. (SPIE - International Society for Optical Engineering. Proceedings, 2014)
We present the results of both laboratory and on sky astrometric characterization of the Gemini Planet Imager (GPI). This characterization includes measurement of the pixel scale∗ of the integral field spectrograph (IFS), the position of the detector with respect to north, and optical distortion. Two of these three quantities (pixel scale and distortion) were measured in the laboratory using two transparent grids of spots, one with a square pattern and the other with a random pattern. The pixel scale in the laboratory was also estimate using small movements of the artificial star unit (ASU) in the GPI adaptive optics system. On sky, the pixel scale and the north angle are determined using a number of known binary or multiple systems and Solar System objects, a subsample of which had concurrent measurements at Keck Observatory. Our current estimate of the GPI pixel scale is 14.14 ± 0.01 millarcseconds/pixel, and the north angle is -1.00 ± 0.03°. Distortion is shown to be small, with an average positional residual of 0.26 pixels over the field of view, and is corrected using a 5th order polynomial. We also present results from Monte Carlo simulations of the GPI Exoplanet Survey (GPIES) assuming GPI achieves ∼1 milliarcsecond relative astrometric precision. We find that with this precision, we will be able to constrain the eccentricities of all detected planets, and possibly determine the underlying eccentricity distribution of widely separated Jovians.
Keywords: Adaptive optics; Astronomy; Calibration; Distortion (waves); Monte Carlo methods; Spectrographs; astrometry; Gemini Planet Imager; GPI; High contrast imaging; Integral Field Spectroscopy; Pixels

The Infrared Imaging Spectrograph (IRIS) for TMT: Instrument overview - Moore, Anna M.; Larkin, James E.; Wright, Shelley A.; Bauman, Brian; Dunn, Jennifer; Ellerbroek, Brent; Phillips, Andrew C.; Simard, Luc; Suzuki, Ryuji; Zhang, Kai; Aliado, Ted; Brims, George; et al. (SPIE - International Society for Optical Engineering. Proceedings, 2014)
We present an overview of the design of IRIS, an infrared (0.84 - 2.4 micron) integral field spectrograph and imaging camera for the Thirty Meter Telescope (TMT). With extremely low wavefront error (<30 nm) and on-board wavefront sensors, IRIS will take advantage of the high angular resolution of the narrow field infrared adaptive optics system (NFIRAOS) to dissect the sky at the diffraction limit of the 30-meter aperture. With a primary spectral resolution of 4000 and spatial sampling starting at 4 milliarcseconds, the instrument will create an unparalleled ability to explore high redshift galaxies, the Galactic center, star forming regions and virtually any astrophysical object. This paper summarizes the entire design and basic capabilities. Among the design innovations is the combination of lenslet and slicer integral field units, new 4Kx4k detectors, extremely precise atmospheric dispersion correction, infrared wavefront sensors, and a very large vacuum cryogenic system.
Keywords: Astronomy; Atmospheric movements; Diffraction; Infrared imaging; Infrared spectroscopy; Optical telescopes; Spectrographs; Telescopes; Thermography (imaging); Wavefronts; Adaptive optics systems; Astrophysical objects; Atmospheric dispersion; Extremely Large Telescopes; High angular resolutions; High redshift-galaxies; Integral field spectrograph; Thirty Meter Telescope; Adaptive optics

The infrared imaging spectrograph (IRIS) for TMT: Overview of innovative science programs - Wright, Shelley A.; Larkin, James E.; Moore, Anna M.; Do, Tuan; Simard, Luc; Adamkovics, Maté; Armus, Lee; Barth, Aaron J.; Barton, Elizabeth; Boyce, Hope; Cooke, Jeffrey; Cote, Patrick; et al. (SPIE - International Society for Optical Engineering. Proceedings, 2014)
IRIS (InfraRed Imaging Spectrograph) is a first light near-infrared diffraction limited imager and integral field spectrograph being designed for the future Thirty Meter Telescope (TMT). IRIS is optimized to perform astronomical studies across a significant fraction of cosmic time, from our Solar System to distant newly formed galaxies (Barton et al. [1]). We present a selection of the innovative science cases that are unique to IRIS in the era of upcoming space and ground-based telescopes. We focus on integral field spectroscopy of directly imaged exoplanet atmospheres, probing fundamental physics in the Galactic Center, measuring 104 to 1010 M supermassive black hole masses, resolved spectroscopy of young star-forming galaxies (1 < 5) and first light galaxies (6 < 12), and resolved spectroscopy of strong gravitational lensed sources to measure dark matter substructure. For each of these science cases we use the IRIS simulator (Wright et al. [2], Do et al. [3]) to explore IRIS capabilities. To highlight the unique IRIS capabilities, we also update the point and resolved source sensitivities for the integral field spectrograph (IFS) in all five broadband filters (Z, Y, J, H, K) for the finest spatial scale of 0.004" per spaxel. We briefly discuss future development plans for the data reduction pipeline and quicklook software for the IRIS instrument suite.
Keywords: Adaptive optics; Aluminum; Astronomy; Galaxies; Gravitation; Infrared devices; Infrared imaging; Infrared spectroscopy; Light; Optical telescopes; Spectrographs; Stars; Telescopes; Data simulators; Ground-based telescopes; Imaging spectrograph; Integral field spectrograph; Integral Field Spectroscopy; Segmented mirror; Supermassive black holes; Thirty Meter Telescope; Thermography (imaging)

Characterization of resistance-welded thermoplastic composite double-lap joints under static and fatigue loading - Dubé, Martine; Chazerain, Aurélie; Hubert, Pascal; Yousefpour, Ali; Bersee, Harald E. (Journal of Thermoplastic Composite Materials, 2014)
An experimental investigation of resistance welding of thermoplastic composite double lap shear (DLS) joints is presented. DLS specimens consisting of unidirectional carbon fibre/polyetheretherketone (CF/PEEK), carbon fibre/polyetherketoneketone (CF/PEKK), carbon fibre/polyetherimide (CF/PEI) and 8-harness satin weave fabric glass fibre/polyetherimide (GF/PEI) composites were resistance welded using a stainless steel mesh heating element. The welded specimens were tested under static and fatigue loadings, and the quality of the welds was examined using optical and scanning electron microscopy. Weld strengths of 53, 49, 45 and 34 MPa were obtained for CF/PEEK, CF/PEKK, CF/PEI and GF/PEI DLS joints, respectively. Indefinite fatigue lives were obtained between 20 and 30% of the ultimate static failure loads of the joints. Performances of the resistance-welded DLS and single lap shear (SLS) joints were compared. It was shown that the effect of joint geometry, that is, DLS versus SLS, on the mechanical performance of the resistance-welded joints is minimal, indicating a good resistance of welded joints to peel stresses.
Keywords: Carbon; Carbon fibers; Composite materials; Dynamic light scattering; Fatigue of materials; Joints (structural components); Plastics; Reinforced plastics; Resistance welding; Scanning electron microscopy; Stainless steel; Steel fibers; Stresses; Thermoplastics; Double lap joint; Fatigue loadings; Fusion bonding; Mechanical performance; Single lap shears; Stainless steel mesh; Thermoplastic composite; Welding

Halogen bonding from dispersion-corrected density-functional theory: The role of delocalization error - Otero-De-La-Roza, A.; Johnson, Erin R.; DiLabio, Gino A. (Journal of Chemical Theory and Computation, 2014)
Halogen bonds are formed when a Lewis base interacts with a halogen atom in a different molecule, which acts as an electron acceptor. Due to its charge transfer component, halogen bonding is difficult to model using many common density-functional approximations because they spuriously overstabilize halogen-bonded dimers. It has been suggested that dispersion-corrected density functionals are inadequate to describe halogen bonding. In this work, we show that the exchange-hole dipole moment (XDM) dispersion correction coupled with functionals that minimize delocalization error (for instance, BH&HLYP, but also other half-and-half functionals) accurately model halogen-bonded interactions, with average errors similar to other noncovalent dimers with less charge-transfer effects. The performance of XDM is evaluated for three previously proposed benchmarks (XB18 and XB51 by Kozuch and Martin, and the set proposed by Bauzá et al.) spanning a range of binding energies up to ∼50 kcal/mol. The good performance of BH&HLYP-XDM is comparable to M06-2X, and extends to the "extreme" cases in the Bauzá set. This set contains anionic electron donors where charge transfer occurs even at infinite separation, as well as other charge transfer dimers belonging to the pnictogen and chalcogen bonding classes. We also show that functional delocalization error results in an overly delocalized electron density and exact-exchange hole. We propose intermolecular Bader delocalization indices as an indicator of both the donor - acceptor character of an intermolecular interaction and the delocalization error coming from the underlying functional.

12 questions to ... - Cicha, W. (GAIA, 2014)

Effect of ship speed on level ice edge breaking - Sazidy, Mahmud; Daley, Claude; Colbourne, Bruce; Wang, Jungyong (Proceedings of the International Conference on Offshore Mechanics and Arctic Engineering - OMAE, 2014)
This paper presents a numerical model of ship ice-wedge interaction to study the effect of ship speed on level ice edge breaking. The interaction process is modeled using LS-DYNA. The developed model considers ice crushing, ice flexural failure and the water foundation effect. For the ice, two different plasticity-based material models are used to represent ice crushing and ice flexural behaviors. The water foundation effect is modeled using a simple linear elastic material. The analysis is performed for a ship speed range of 0.1 to 5 ms-1 and ice thickness of 0.5 to 1.5 m. The analysis indicates that both ship speed and ice thickness significantly affect the ice breaking process. The model results are in good agreement with a number of analytical and empirical models. The model can be useful in establishing a rational basis for safe speed criteria, improving ship structural standards and tools for ice management capability assessment.
Keywords: Materials properties; Ocean engineering; Ships; Speed; Breaking process; Empirical model; Flexural behavior; Flexural failure; Interaction process; Linear elastic material; Material models; Structural standards; Ice

Electrolysis-enhanced co-digestion of switchgrass and cow manure - Tartakovsky, Boris; Mehta, Punita; Santoyo, Guido; Roy, Caroline; Frigon, Jean-Claude; Guiot, Serge R. (Journal of Chemical Technology and Biotechnology, 2014)
BACKGROUND: Anaerobic digestion of agricultural wastes is a cost effective way for combining resource recovery and methane production. This paper evaluates the co-digestion of cow manure and switchgrass in a completely stirred tank reactor (CSTR) by the electrolysis-enhanced anaerobic digestion (eAD) process. RESULTS: The electrodes for water electrolysis were installed directly in an anaerobic digester and were used to create micro-aerobic conditions. Significant gains in process performance and biogas quality were obtained at current densities of 20-25 mA LR-1 (per digester volume) with a corresponding volumetric energy consumption of 0.07-0.08 Wh LR-1. In particular, the COD removal rate was increased from 0.6 to 0.9 g COD LR-1 d-1, methane production increased by 26%, and H2S content in the biogas declined from 2500-3000 ppm to less than 10 ppm. CONCLUSIONS: The improved performance was achieved due to methane production from hydrolytic H2 and possibly due to the enhanced hydrolysis of organic matter.
Keywords: Co-digestion; Cow manure; Micro aerobics; Switchgrass; Water electrolysis; Anaerobic digestion; Panicum virgatum

Intermetallic phases in Al-Si based cast alloys: New perspective - Samuel, E.; Samuel, A. M.; Doty, H. W.; Valtierra, S.; Samuel, F. H. (International Journal of Cast Metals Research, 2014)
The present work was performed on experimental Al-Si near eutectic cast alloys, with different additives mainly Fe, Mg, Mn, Cr, Sr and P. The alloys were cooled at 0·8°C s-1, very close to equilibrium conditions. Precipitated phases, primarily Fe, Cu, Mg and Sr based intermetallics, were examined. Although the phases reported in the present work were documented previously, the range of chemical composition of each phase was confirmed using an electron probe microanalyser equipped with wavelength dispersive spectroscopy and electron dispersive X-ray spectroscopy facilities.
Keywords: Cast alloys; Chemical compositions; Electron probe microanalyser; Equilibrium conditions; Intermetallic phasis; Q-phase; Sr modification; Aluminum; Intermetallics; Iron alloys; Manganese; Silicon; X ray spectroscopy; Silicon alloys

Domoic acid - La Barre, Stéphane; Bates, Stephen S.; Quilliam, Michael A. (Outstanding Marine Molecules: Chemistry, Biology, Analysis, 2014)
Domoic acid (DA) was of no special scientific interest until a series of case studies revealed its role as the major marine neurotoxin causing amnesic shellfish poisoning (ASP). The analysis, toxicology, synthesis and degradation of the highly polar amino acid DA and its kainoid congeners are discussed in this chapter. Although DA is structurally simple and ubiquitous in contaminated food samples, it was not simple to prove that it was the causative agent of ASP in humans and of DA poisoning in carnivorous birds and mammals. Furthermore, its detection and the prevention of ASP requires regular monitoring of seafood using rapid and accurate analyses. The main producers of DA are certain seasonally blooming diatoms of the genus Pseudo-nitzschia, major components of coastal phytoplankton. Here, details are provided of the species most likely to be involved in food-poisoning episodes, together with a brief account of the molecular mechanisms that underlie DA toxicity, which cause symptoms of acute and chronic neurotoxicity. DA may attain critically toxic levels within two major food chains involving benthic filter-feeders (e.g., mussels) or planktivorous fish (e.g., anchovies). Preventive measures must be complemented by risk assessments of seasonal toxigenic blooms, especially in nutrient-enriched coastal areas. The major chemical and biotic factors that influence diatom bloom formation and toxigenicity are outlined. Genomics of DA production allow the development of novel molecular tools to better understand DA biosynthesis at the gene level, and the evolutionary significance of DA as a metabolite with primary and secondary characteristics.

Determination of bismuth by dielectric barrier discharge atomic absorption spectrometry coupled with hydride generation: method optimization and evaluation of analytical performance - Kratzer, Jan; Boušek, Jaroslav; Sturgeon, Ralph E.; Mester, Zoltán; Dědina, Jiří (Analytical Chemistry, 2014)
Atomization of bismuth hydride in a 17 W planar quartz dielectric barrier discharge (DBD) atomizer was optimized and the performance of this device compared to that of a conventional quartz tube atomizer (QTA) for atomic absorption spectrometry (AAS). Modification of the inner surface of the DBD atomizer using dimethyldichlorsilane (DMDCS) was essential since it improved sensitivity by a factor of 2-4. Argon, at a flow rate of 125 mL min-1, was the best DBD discharge gas. Free Bi atoms were also observed in the DBD with nitrogen, hydrogen, and helium discharge gases but not in air. The detection limit for Bi (1.1 ng mL-1) is worse than with the QTA (0.16 ng mL-1 Bi). A poorer detection limit compared to a QTA is a consequence of the shorter optical path of the DBD. Moreover, the lower atomization efficiency and/or faster decay of free atoms in the DBD has to be considered. The performance of the DBD as an atomizer reflects both effects, i.e., atomization efficiency and free atom decay, was estimated to be 65% of that of the externally heated quartz tube atomizer. Nevertheless, this hydride generation DBD-AAS approach can be used for the routine determination of Bi, providing repeatability and accuracy comparable to that reached with a QTA, as demonstrated by analysis of NIST SRM 1643e (trace elements in water). The potential of in-atomizer preconcentration in a DBD atomizer is outlined.
Keywords: Analytical performance; Dielectric barrier discharges; Hydride generations

Modeling study of cyclic oxidation behavior of NiAl and NiCr alloys - Peng, X. J.; Chen, K. Y.; Liu, R.; Liang, M. (Journal of Materials Engineering and Performance, 2014)
The cyclic oxidation behavior of four high-temperature alloys (two NiAl alloys and two NiCr alloy) is studied utilizing an existing micromechanics-based model, in which Al2O3 and Cr2O3 are formed on the alloys as protective layers. For each alloy, the model parameters are determined based on one ‘complete’ experimental curve of weight change, which is obtained under a high-temperature cyclic oxidation test where the weight change experiences a maximum value and then drops down to a zero point. The model is first tested on two metals which have experimental data available for comparison. It is found that the model parameter, oxide crack density exponent, can be assumed constant within a range of high temperature for each metal, thus with the ‘complete’ experimental curve of weight change, the model can predict the oxidation behavior of the metal at different temperatures. The determination of model parameters, accuracy, and limitations of the model for NiAl and NiCr alloys is analyzed and discussed.
Keywords: Oxidation; Superalloys; Cyclic oxidation behavior; Cyclic oxidation tests; Determination of model parameters; Experimental curves; Micromechanics-based modeling; Model and simulation; Oxidation behaviors; Protective layers; Alloys

An oxalate method for measuring the surface area of nickel electrodes - Hall, David S.; Bock, Christina; MacDougall, Barry R. (Journal of the Electrochemical Society, 2014)
This work establishes a new method to measure the electrochemically active surface area (AECSA) of nickel electrodes, in situ. The addition of 0.08 mol L-1 of an oxalate salt to an alkaline electrolyte solution shifts the half-wave potential of the Ni(II)/Ni(III) redox pair by about -80 mV. Further, these peaks are very narrow. The sharpest peak in this work has a full width at half maximum (FWHM) of just 11 mV. This unusual sharpness is attributed to the layered structure of nickel hydroxides and the adsorption of oxalate from the solution on the (001) surface. This is supported by attenuated total reflectance infrared (ATR-IR) peaks measured at 1265 cm-1, 1655 cm-1, and 1713 cm-1, which correspond to mononuclear bidentate oxalate bonded to nickel. At sufficiently fast potential scan rates (≥150 mV s-1), the adsorbed oxalate limits growth of the surface hydroxide to a single layer. During the reverse scan, the surface NiOOH/Ni(OH)2 reduction peak is well-separated from other electrochemical processes and may be used to accurately and precisely measure the AECSA. The error of this method is estimated at < 10%.
Keywords: Nickel; Oxalic acid; Alkaline electrolytes; Attenuated total reflectance infrared; Electrochemical process; Electrochemically active surface areas; Half-wave potential; Layered Structures; Potential scan rates; Surface hydroxide; Electrodes

High-efficiency subwavelength-engineered surface grating couplers in SOI and DSOI - Benedikovic, Daniel; Cheben, Pavel; Schmid, Jens H.; Xu, Dan-Xia; Wang, Shurui; Janz, Siegfried; Halir, Robert; Ortega-Moñux, Alejandro; Dado, Milan (IEEE International Conference on Group IV Photonics GFP, 2014)
The coupling efficiency of a surface grating coupler is optimized for a an arbitrary buried oxide thickness by adjusting the grating radiation angle. The coupler is apodized using a subwavelength structure, allowing a single etch step fabrication. The measured coupling loss is -2.16dB with 3dB bandwidth of 64nm, for a minimum feature size of 100nm. It is also shown by simulations that by implementing this coupler in a double SOI (DSOI) wafer, an ultra-low coupling loss of -0.42dB is achieved.

A bibliometric analysis of observatory publications for the period 2008-2012 - Crabtree, Dennis R. (SPIE - International Society for Optical Engineering. Proceedings, 2014)
The primary scientific output from an astronomical telescope is the collection of papers published in refereed journals. A telescope's productivity is measured by the number of papers published which are based upon data taken with the telescope. The scientific impact of a paper can be measured quantitatively by the number of citations that the paper receives. In this paper I will examine the productivity and impact of over 20 telescopes, mainly optical/IR, with apertures larger than 3.5-m for the years between 2008 and 2012.
Keywords: Observatories; Productivity; Telescopes; Bibliometrics; Citations; Impact; Metrics

On-sky vibration environment for the Gemini Planet Imager and mitigation effort - Hartung, Markus; Hayward, Tom; Saddlemyer, Les; Poyneer, Lisa; Cardwell, Andrew; Cavedoni, Chas; Cho, Myung; Chilcote, Jeffrey K.; Collins, Paul; Dillon, Darren; Galvez, Ramon; Gausachs, Gaston; et al. (SPIE - International Society for Optical Engineering. Proceedings, 2014)
The Gemini Planet Imager (GPI) entered on-sky commissioning and had its first-light at the Gemini South (GS) telescope in November 2013. GPI is an extreme adaptive optics (XAO), high-contrast imager and integral-field spectrograph dedicated to the direct detection of hot exo-planets down to a Jupiter mass. The performance of the apodized pupil Lyot coronagraph depends critically upon the residual wavefront error (design goal of 60nmRMS with <5 mas RMS tip/tilt), and therefore is most sensitive to vibration (internal or external) of Gemini's instrument suite. Excess vibration can be mitigated by a variety of methods such as passive or active dampening at the instrument or telescope structure or Kalman filtering of specific frequencies with the AO control loop. Understanding the sources, magnitudes and impact of vibration is key to mitigation. This paper gives an overview of related investigations based on instrument data (GPI AO module) as well as external data from accelerometer sensors placed at different locations on the GS telescope structure. We report the status of related mitigation efforts, and present corresponding results.
Keywords: Kalman filters; Telescopes; Extreme adaptive optics; High contrast imaging; Integral field spectrograph; LQG; Specific frequencies; Telescope structures; Vibration absorber; Vibration environment; Adaptive optics

On-sky low order non-common path correction of the GPI calibration unit - Hartung, Markus; MacIntosh, Bruce; Langlois, Paul; Sadakuni, Naru; Gavel, Don; Wallace, J. Kent; Palmer, Dave; Poyneer, Lisa; Savransky, Dmitry; Thomas, Sandrine; Dillon, Darren; Dunn, Jennifer; et al. (SPIE - International Society for Optical Engineering. Proceedings, 2014)
The Gemini Planet Imager (GPI) entered on-sky commissioning phase, and had its First Light at the Gemini South telescope in November 2013. Meanwhile, the fast loops for atmospheric correction of the Extreme Adaptive Optics (XAO) system have been closed on many dozen stars at different magnitudes (I=4-8), elevation angles and a variety of seeing conditions, and a stable loop performance was achieved from the beginning. Ultimate contrast performance requires a very low residual wavefront error (design goal 60 nm RMS), and optimization of the planet finding instrument on different ends has just begun to deepen and widen its dark hole region. Laboratory raw contrast benchmarks are in the order of 10-6 or smaller. In the telescope environment and in standard operations new challenges are faced (changing gravity, temperature, vibrations) that are tackled by a variety of techniques such as Kalman filtering, open-loop models to keep alignment to within 5 mas, speckle nulling, and a calibration unit (CAL). The CAL unit was especially designed by the Jet Propulsion Laboratory to control slowly varying wavefront errors at the focal plane of the apodized Lyot coronagraph by the means of two wavefront sensors: 1) a 7x7 low order Shack-Hartmann SH wavefront sensor (LOWFS), and 2) a special Mach-Zehnder interferometer for mid-order spatial frequencies (HOWFS) - atypical in that the beam is split in the focal plane via a pinhole but recombined in the pupil plane with a beamsplitter. The original design goal aimed for sensing and correcting on a level of a few nm which is extremely challenging in a telescope environment. This paper focuses on non-common path low order wavefront correction as achieved through the CAL unit on sky. We will present the obtained results as well as explain challenges that we are facing.
Keywords: Calibration; Focusing; Telescopes; Wavefronts; Atmospheric corrections; Commissioning phase; Common path; Extreme adaptive optics; High contrast imaging; Jet Propulsion Laboratory; Wave front sensors; Wavefront correction; Adaptive optics

Automated alignment and on-sky performance of the Gemini planet imager coronagraph - Savransky, Dmitry; Thomas, Sandrine J.; Poyneer, Lisa A.; Dunn, Jennifer; MacIntosh, Bruce A.; Sadakuni, Naru; Dillon, Daren; Goodsell, Stephen J.; Hartung, Markus; Hibon, Pascale; Rantakyrö, Fredrik; Cardwell, Andrew; et al. (SPIE - International Society for Optical Engineering. Proceedings, 2014)
The Gemini Planet Imager (GPI) is a next-generation, facility instrument currently being commissioned at the Gemini South observatory. GPI combines an extreme adaptive optics system and integral field spectrograph (IFS) with an apodized-pupil Lyot coronagraph (APLC) producing an unprecedented capability for directly imaging and spectroscopically characterizing extrasolar planets. GPI's operating goal of 10-7 contrast requires very precise alignments between the various elements of the coronagraph (two pupil masks and one focal plane mask) and active control of the beam path throughout the instrument. Here, we describe the techniques used to automatically align GPI and maintain the alignment throughout the course of science observations. We discuss the particular challenges of maintaining precision alignments on a Cassegrain mounted instrument and strategies that we have developed that allow GPI to achieve high contrast even in poor seeing conditions.
Keywords: Adaptive optics; Alignment; Astronomy; Automated operations; Gemini Planet Imager; GPI; High contrast imaging; Extrasolar planets

GPI PSF subtraction with TLOCI: The next evolution in exoplanet/disk high-contrast imaging - Marois, Christian; Correia, Carlos; Galicher, Raphaël.; Ingraham, Patrick; MacIntosh, Bruce; Currie, Thayne; De Rosa, Rob (SPIE - International Society for Optical Engineering. Proceedings, 2014)
To directly image exoplanets and faint circumstellar disks, the noisy stellar halo must be suppressed to a high level. To achieve this feat, the angular differential imaging observing technique and the least-squares Locally Optimized Combination of Images (LOCI) algorithm have now become the standard in single band direct imaging observations and data reduction. With the development and commissioning of new high-order high-contrast adaptive optics equipped with integral field units, the image subtraction algorithm needs to be modified to allow the optimal use of polychromatic images, field-rotated images and archival data. A new algorithm, TLOCI (for Template LOCI), is designed to achieve this task by maximizing a companion signal-to-noise ratio instead of simply minimizing the noise as in the original LOCI algorithm. The TLOCI technique uses an input spectrum and template Point Spread Functions (PSFs, generated from unocculted and unsaturated stellar images) to optimize the reference image least-squares coefficients to minimize the planet self-subtraction, thus maximizing its throughput per wavelength, while simultaneously providing a maximum suppression of the speckle noise. The new algorithm has been developed using on-sky GPI data and has achieved impressive contrast. This paper presents the TLOCI algorithm, on-sky performance, and will discuss the challenges in recovering the planet spectrum with high fidelity.
Keywords: Algorithms; Extrasolar planets; Optical transfer function; Signal to noise ratio; Stars; Circumstellar disks; High contrast imaging; Image subtraction; Integral Field Unit; Optimized combinations; Polychromatic images; Reference image; Rotated images; Adaptive optics

NFIRAOS: First facility AO system for the Thirty Meter Telescope - Herriot, Glen; Andersen, David; Atwood, Jenny; Boyer, Corinne; Byrnes, Peter; Caputa, Kris; Ellerbroek, Brent; Gilles, Luc; Hill, Alexis; Ljusic, Zoran; Pazder, John; Rosensteiner, Matthias; et al. (SPIE - International Society for Optical Engineering. Proceedings, 2014)
NFIRAOS, the Thirty Meter Telescope's first adaptive optics system is an order 60x60 Multi-Conjugate AO system with two deformable mirrors. Although most observing will use 6 laser guide stars, it also has an NGS-only mode. Uniquely, NFIRAOS is cooled to -30 °C to reduce thermal background. NFIRAOS delivers a 2-arcminute beam to three client instruments, and relies on up to three IR WFSs in each instrument. We present recent work including: robust automated acquisition on these IR WFSs; trade-off studies for a common-size of deformable mirror; real-time computing architectures; simplified designs for high-order NGS-mode wavefront sensing; modest upgrade concepts for high-contrast imaging.
Keywords: Deformation; Economic and social effects; Laser pulses; Mirrors; Optical telescopes; Telescopes; Adaptive optics systems; Deformable mirrors; High contrast imaging; Real time computing; Thermal background; Thirty Meter Telescope; TMT; Wave-front sensing; Adaptive optics

Calibrating CHIME: A new radio interferometer to probe dark energy - Newburgh, Laura B.; Addison, Graeme E.; Amiri, Mandana; Bandura, Kevin; Bond, J. Richard; Connor, Liam; Cliche, Jean-Francois; Davis, Greg; Deng, Meiling; Denman, Nolan; Dobbs, Matt; Fandino, Mateus; et al. (SPIE - International Society for Optical Engineering. Proceedings, 2014)
The Canadian Hydrogen Intensity Mapping Experiment (CHIME) is a transit interferometer currently being built at the Dominion Radio Astrophysical Observatory (DRAO) in Penticton, BC, Canada. We will use CHIME to map neutral hydrogen in the frequency range 400 - 800MHz over half of the sky, producing a measurement of baryon acoustic oscillations (BAO) at redshifts between 0.8 - 2.5 to probe dark energy. We have deployed a pathfinder version of CHIME that will yield constraints on the BAO power spectrum and provide a test-bed for our calibration scheme. I will discuss the CHIME calibration requirements and describe instrumentation we are developing to meet these requirements.
Keywords: Airborne telescopes; Calibration; Cosmology; Hydrogen; Interferometers; Probes; 21cm; Acoustic oscillation; Astrophysical observatory; Calibration schemes; Dark energy; Frequency ranges; Intensity mapping; Radio interferometers; Astrophysics

Interaction of 2-, 3- and 4-nitrobenzoic acid with the structure of calcium–silicate–hydrate - Khoshnazar, Rahil; Beaudoin, James J.; Raki, Laila; Alizadeh, Rouhollah (Materials and Structures/Materiaux et Constructions, 2014)
Interaction of nitrobenzoic acid (NBA) with the structure of calcium–silicate–hydrate (C–S–H) was investigated. Phase pure C–S–H and C–S–H with 2-, 3- or 4NBA (0.01 and 0.02 mol/mol of Ca) were synthesized, and characterized by the X-ray diffraction, thermal analysis, Fourier transform infrared spectroscopy and scanning electron microscope techniques. Nitrogen adsorption measurements were also performed to estimate the surface area of the samples. It is suggested that all NBA isomers with the concentration of 0.01 mol/mol of Ca were able to fill the defects on the surface of the C–S–H layers, block access to the space between the stacked C–S–H layers, and possibly partially intercalate the layered structure. The C–S–H-based samples prepared with different types of NBA compounds, however, had different characteristics. The interaction of organic and inorganic phases was limited in the samples incorporating higher concentration of NBA. Traces of unreacted NBA were detected in a few samples with 0.02 mol of NBA/mol of Ca.
Keywords: Calcium; Carboxylic acids; Fourier transform infrared spectroscopy; Gas adsorption; Hydrates; Intercalation; Isomers; Nanocomposites; Scanning electron microscopy; Silicates; Surface defects; Thermoanalysis; X ray diffraction; 4-Nitrobenzoic acids; Inorganic phasis; Layered Structures; Nitrobenzoic acids; Nitrogen adsorption measurements; Surface adsorption; Surface area; Calcium silicate

Bioactive glass-ceramic scaffolds with high-strength for orthopedic applications - Aguilar-Reyes, E.; León-Patiño, C.; Villicaña-Molina, E.; Lefebvre, L. -P. (Biomaterials Science: Processing, Properties and Applications IV: Ceramic Transactions, 2014)
This study aims to produce 45S5 bioactive glass scaffolds (45% Si02-24.5% CaO-24.5% Na20-6 % P2O5) through a novel process of powder technology and polymer foaming, patented by the IMI (Industrial Materials Institute, NRC). Initially, various foaming agent/binder/bioglass powder ratios were proved and the optimal ratio was 0.5/54.5/45.0 in wt. %, respectively. The mixing of the powders was carried out in a shaker-mixer and it was compacted in alumina molds. The samples obtained were submitted to a heat treatment in two stages, the first one, foaming, and the second one, pyrolysis and sintering in the same thermal profile, with the goal of obtaining scaffolds with mechanical properties and a bioactive response by immersion in SBF appropriated for orthopedic applications. The sintering temperature of scaffolds was 975°C. Then, the scaffolds were machined to obtain uniform cylindrical samples for mechanical testing and cut into tablets of 3 mm in thickness that were immersed in SBF for bioactivity tests for 0, 1, 3, 7, 14, 21 and 28 days. The characterization of scaffolds before immersion in SBF was performed by scanning electron microscopy (SEM) and microtomography (μCT), also they were tested for compression, and measurement of density and porosity. After immersion the samples were observed with SEM and analyzed by EDS, X-ray diffraction (XRD) and infrared spectroscopy (FT-IR), also the mass variation was estimated. The scaffolds obtained by the experimental method described above, showed a 55 to 65% interconnected porosity and an average compressive strength of 13.78 ± 2.43 MPa, and showed the formation of hydroxyapatite layer after 7 days of immersion in SBF, fulfilling the requirements to be used as a regenerative scaffold. The proposed method of powder technology and polymer foaming, allows controlling the porosity, pore size and compression strength of the scaffolds by vailing the ratio foaming agent/binder/bioglass powder and sintering temperature.

Benchmarking hardware architecture candidates for the NFIRAOS real-time controller - Smith, Malcolm; Kerley, Dan; Herriot, Glen; Véran, Jean-Pierre (SPIE - International Society for Optical Engineering. Proceedings, 2014)
As a part of the trade study for the Narrow Field Infrared Adaptive Optics System, the adaptive optics system for the Thirty Meter Telescope, we investigated the feasibility of performing real-time control computation using a Linux operating system and Intel Xeon E5 CPUs. We also investigated a Xeon Phi based architecture which allows higher levels of parallelism. This paper summarizes both the CPU based real-time controller architecture and the Xeon Phi based RTC. The Intel Xeon E5 CPU solution meets the requirements and performs the computation for one AO cycle in an average of 767 microseconds. The Xeon Phi solution did not meet the 1200 microsecond time requirement and also suffered from unpredictable execution times. More detailed benchmark results are reported for both architectures.
Keywords: Adaptive control systems; Benchmarking; Computer operating systems; Controllers; Optical telescopes; Program processors; Real time control; NFIRAOS; Phi; Real time controllers; RTC; Xeon; Adaptive optics

Canadian hydrogen intensity mapping experiment (CHIME) pathfinder - Bandura, Kevin; Addison, Graeme E.; Amiri, Mandana; Bond, J. Richard; Campbell-Wilson, Duncan; Connor, Liam; Cliche, Jean-FrançoisJ.-F.; Davis, Greg; Deng, Meiling; Denman, Nolan; Dobbs, Matt; Fandino, Mateus; et al. (SPIE - International Society for Optical Engineering. Proceedings, 2014)
A pathfinder version of CHIME (the Canadian Hydrogen Intensity Mapping Experiment) is currently being commissioned at the Dominion Radio Astrophysical Observatory (DRAO) in Penticton, BC. The instrument is a hybrid cylindrical interferometer designed to measure the large scale neutral hydrogen power spectrum across the redshift range 0.8 to 2.5. The power spectrum will be used to measure the baryon acoustic oscillation (BAO) scale across this poorly probed redshift range where dark energy becomes a significant contributor to the evolution of the Universe. The instrument revives the cylinder design in radio astronomy with a wide field survey as a primary goal. Modern low-noise amplifiers and digital processing remove the necessity for the analog beam forming that characterized previous designs. The Pathfinder consists of two cylinders 37m long by 20m wide oriented north-south for a total collecting area of 1,500 square meters. The cylinders are stationary with no moving parts, and form a transit instrument with an instantaneous field of view of ∼100 degrees by 1-2 degrees. Each CHIME Pathfinder cylinder has a feedline with 64 dual polarization feeds placed every ∼30 cm which Nyquist sample the north-south sky over much of the frequency band. The signals from each dual-polarization feed are independently amplified, filtered to 400-800 MHz, and directly sampled at 800 MSps using 8 bits. The correlator is an FX design, where the Fourier transform channelization is performed in FPGAs, which are interfaced to a set of GPUs that compute the correlation matrix. The CHIME Pathfinder is a 1/10th scale prototype version of CHIME and is designed to detect the BAO feature and constrain the distance-redshift relation. The lessons learned from its implementation will be used to inform and improve the final CHIME design.
Keywords: Airborne telescopes; Astrophysics; Cosmology; Frequency bands; Hydrogen; Low noise amplifiers; Mapping; Polarization; Power spectrum; Program processors; Radio astronomy; Acoustic oscillation; Astrophysical observatory; BAO; CHIME; Correlation matrix; Intensity mapping; Wide-field surveys

Gemini planet imager observational calibrations VIII: Characterization and role of satellite spots - Wang, Jason J.; Rajan, Abhijith; Graham, James R.; Savransky, Dmitry; Ingraham, Patrick J.; Ward-Duong, Kimberly; Patience, Jennifer; De Rosa, Robert J.; Bulger, Joanna; Sivaramakrishnan, Anand; Perrin, Marshall D.; Thomas, Sandrine J.; et al. (SPIE - International Society for Optical Engineering. Proceedings, 2014)
The Gemini Planet Imager (GPI) combines extreme adaptive optics, an integral field spectrograph, and a high performance coronagraph to directly image extrasolar planets in the near-infrared. Because the coronagraph blocks most of the light from the star, it prevents the properties of the host star from being measured directly. Instead, satellite spots, which are created by diffraction from a square grid in the pupil plane, can be used to locate the star and extract its spectrum. We describe the techniques implemented into the GPI Data Reduction Pipeline to measure the properties of the satellite spots and discuss the precision of the reconstructed astrometry and spectrophotometry of the occulted star. We find the astrometric precision of the satellite spots in an H-band datacube to be 0.05 pixels and is best when individual satellite spots have a signal to noise ratio (SNR) of > 20. In regards to satellite spot spectrophotometry, we find that the total flux from the satellite spots is stable to ∼7% and scales linearly with central star brightness and that the shape of the satellite spot spectrum varies on the 2% level.
Keywords: Adaptive optics; Astronomy; Extrasolar planets; Infrared devices; Signal to noise ratio; Spectrophotometry; Stars; astrometry; Exo-planets; Gemini Planet Imager; GPI; High contrast imaging; Satellites

MAPLE: Reflected light from exoplanets with a 50-cm diameter stratospheric balloon telescope - Marois, Christian; Bradley, Colin; Pazder, John; Nash, Reston; Metchev, Stanimir; Grandmont, Frédéric; Maire, Anne-Lise; Belikov, Ruslan; Macintosh, Bruce; Currie, Thayne; Galicher, Raphaël; Marchis, Franck; et al. (SPIE - International Society for Optical Engineering. Proceedings, 2014)
Detecting light reflected from exoplanets by direct imaging is the next major milestone in the search for, and characterization of, an Earth twin. Due to the high-risk and cost associated with satellites and limitations imposed by the atmosphere for ground-based instruments, we propose a bottom-up approach to reach that ultimate goal with an endeavor named MAPLE. MAPLE first project is a stratospheric balloon experiment called MAPLE-50. MAPLE-50 consists of a 50 cm diameter off-axis telescope working in the near-UV. The advantages of the near-UV are a small inner working angle and an improved contrast for blue planets. Along with the sophisticated tracking system to mitigate balloon pointing errors, MAPLE-50 will have a deformable mirror, a vortex coronograph, and a self-coherent camera as a focal plane wavefront-sensor which employs an Electron Multiplying CCD (EMCCD) as the science detector. The EMCCD will allow photon counting at kHz rates, thereby closely tracking telescope and instrument-bench-induced aberrations as they evolve with time. In addition, the EMCCD will acquire the science data with almost no read noise penalty. To mitigate risk and lower costs, MAPLE-50 will at first have a single optical channel with a minimum of moving parts. The goal is to reach a few times 109 contrast in 25 h worth of flying time, allowing direct detection of Jovians around the nearest stars. Once the 50 cm infrastructure has been validated, the telescope diameter will then be increased to a 1.5 m diameter (MAPLE-150) to reach 1010 contrast and have the capability to image another Earth.
Keywords: Adaptive optics; Astronomy; Extrasolar planets; Meteorological balloons; Millimeter waves; Space telescopes; Wavefronts; Coronagraph; Exo-planets; High contrast imaging; Planetary system; Space observatories; Wave front control; Balloons

Multi-granularity resource virtualization and sharing strategies in cloud manufacturing - Liu, Ning; Li, Xiaoping; Shen, Weiming (Journal of Network and Computer Applications, 2014)
Cloud Manufacturing is a new and promising manufacturing paradigm. Resource virtualization is critical for Cloud Manufacturing. It encapsulates physical resources into cloud services and determines the robustness of the cloud platform. This paper proposes novel multi-granularity resource virtualization and sharing strategies for bridging the gap between complex manufacturing tasks and underlying resources. The proposed approach considers three factors, including workflow, activity, and resource that significantly influence stepwise decompositions of a complex manufacturing task. Resource aggregation functions are constructed to classify resources over different granularities. Resource clustering algorithms are presented for mapping physical resources to virtualized resources. Cloud service specifications are designed to describe virtualized resources and are implemented through a prototype. A case study is illustrated to validate the proposed approach.
Keywords: Cloud Manufacturing; Multi-granularity; Resource Virtualization; Sharing strategies; Task decomposition; Virtualizations; Cloud computing

Observation of strongly entangled photon pairs from a nanowire quantum dot - Versteegh, Marijn A. M.; Reimer, Michael E.; Jöns, Klaus D.; Dalacu, Dan; Poole, Philip J.; Gulinatti, Angelo; Giudice, Andrea; Zwiller, Val (Nature Communications, 2014)
A bright photon source that combines high-fidelity entanglement, on-demand generation, high extraction efficiency, directional and coherent emission, as well as position control at the nanoscale is required for implementing ambitious schemes in quantum information processing, such as that of a quantum repeater. Still, all of these properties have not yet been achieved in a single device. Semiconductor quantum dots embedded in nanowire waveguides potentially satisfy all of these requirements; however, although theoretically predicted, entanglement has not yet been demonstrated for a nanowire quantum dot. Here, we demonstrate a bright and coherent source of strongly entangled photon pairs from a position-controlled nanowire quantum dot with a fidelity as high as 0.859±0.006 and concurrence of 0.80±0.02. The two-photon quantum state is modified via the nanowire shape. Our new nanoscale entangled photon source can be integrated at desired positions in a quantum photonic circuit, single-electron devices and light-emitting diodes.
Keywords: nanowire; quantum dot; electron; nanotechnology; quantum mechanics; theoretical study; birefringence; observational study; photon; polarization

Characterizing SL2S galaxy groups using the Einstein radius - Verdugo, T.; Motta, V.; Foëx, G.; Forero-Romero, J. E.; Munõz, R. P.; Pello, R.; Limousin, M.; More, A.; Cabanac, R.; Soucail, G.; Blakeslee, J. P.; Mejiá-Narvaéz, A. J.; et al. (Astronomy and Astrophysics, 2014)
Aims. We aim to study the reliability of RA (the distance from the arcs to the center of the lens) as a measure of the Einstein radius in galaxy groups. In addition, we want to analyze the possibility of using RA as a proxy to characterize some properties of galaxy groups, such as luminosity (L) and richness (N). Methods. We analyzed the Einstein radius, θE, in our sample of Strong Lensing Legacy Survey (SL2S) galaxy groups, and compared it with RA, using three different approaches: 1) the velocity dispersion obtained from weak lensing assuming a singular isothermal sphere profile (θE,I); 2) a strong lensing analytical method (θE,II) combined with a velocity dispersion-concentration relation derived from numerical simulations designed to mimic our group sample; and 3) strong lensing modeling (θE,III) of eleven groups (with four new models presented in this work) using Hubble Space Telescope (HST) and Canada-France-Hawaii Telescope (CFHT) images. Finally, RA was analyzed as a function of redshift z to investigate possible correlations with L, N, and the richness-to-luminosity ratio (N/L). Results. We found a correlation between θE and RA, but with large scatter. We estimate θE,I = (2.2 ± 0.9) + (0.7 ± 0.2)RA, θE,II = (0.4 ± 1.5) + (1.1 ± 0.4)RA, and θE,III = (0.4 ± 1.5) + (0.9 ± 0.3)RA for each method respectively. We found weak evidence of anti-correlation between RA and z, with Log RA = (0.58 ± 0.06)-(0.04 ± 0.1)z, suggesting a possible evolution of the Einstein radius with z, as reported previously by other authors. Our results also show that RA is correlated with L and N (more luminous and richer groups have greater RA), and a possible correlation between RA and the N/L ratio. Conclusions. Our analysis indicates that RA is correlated with θE in our sample, making RA useful for characterizing properties like L and N (and possibly N/L) in galaxy groups. Additionally, we present evidence suggesting that the Einstein radius evolves with z.
Keywords: Dispersions; Luminance; Numerical methods; Analytical method; Einstein radius; Galaxies: groups: generals; Gravitational lensing: strong; Hubble space telescopes; Isothermal spheres; Velocity dispersion; Weak lensing; Galaxies

The development and assessment of high-throughput mass spectrometry-based methods for the quantification of a nanoparticle drug delivery agent in cellular lysate - Buse, Joshua; Purves, Randy W.; Verrall, Ronald E.; Badea, Ildiko; Zhang, Haixia; Mulligan, Christopher C.; Peru, Kerry M.; Bailey, Jonathan; Headley, John V.; El-Aneed, Anas (Journal of Mass Spectrometry, 2014)
The safe use of lipid-based drug delivery agents requires fast and sensitive qualitative and quantitative assessment of their cellular interactions. Many mass spectrometry (MS) based analytical platforms can achieve such task with varying capabilities. Therefore, four novel high-throughput MS-based quantitative methods were evaluated for the analysis of a small organic gene delivery agent: N,N-bis(dimethylhexadecyl)-1,3-propane-diammonium dibromide (G16-3). Analysis utilized MS instruments that detect analytes using low-resolution tandem MS (MS/MS) analysis (i.e. QTRAP or linear ion trap in this work) or high-resolution MS analysis (i.e. time of flight (ToF) or Orbitrap). Our results indicate that the validated fast chromatography (FC)-QTRAP-MS/MS, FC- LTQ-Orbitrap-MS, desorption electrospray ionization-collision-induced dissociation (CID)-MS/MS and matrix assisted laser desorption ionization-ToF/ToF-MS MS methods were superior in the area of method development and sample analysis time to a previously developed liquid chromatography (LC)-CID-MS/MS. To our knowledge, this is the first evaluation of the abilities of five MS-based quantitative methods that target a single pharmaceutical analyte. Our findings indicate that, in comparison to conventional LC-CID-MS/MS, the new MS-based methods resulted in a (1) substantial reduction in the analysis time, (2) reduction in the time required for method development and (3) production of either superior or comparable quantitative data. The four new high-throughput MS methods, therefore, were faster, more efficient and less expensive than a conventional LC-CID-MS/MS for the quantification of the G16-3 analyte within tissue culture. When applied to cellular lysate, no significant change in the concentration of G16-3 gemini surfactant within PAM212 cells was observed between 5 and 53 h, suggesting the absence of any metabolism/excretion from PAM212 cells.
Keywords: Chromatography; Desorption; Gene transfer; Ionization; Ionization of liquids; Liquids; Matrix algebra; Spectrometry; Surface active agents; Throughput; Tissue culture; Desorption electrospray ionization; Fast chromatography; Gemini surfactant; Matrix assisted laser desorption ionization; Electrospray ionization; lipid; n,n bis(dimethylhexadecyl) 1,3 propane diammonium; nanoparticle; surfactant; cell extract; analytic method; cell interaction; cell lysate; collisionally activated dissociation; controlled study; intermethod comparison; mass spectrometry; matrix assisted laser desorption ionization time of flight mass spectrometry; qualitative analysis; quantitative analysis; tandem mass spectrometry; tissue culture; cell line; drug delivery system; genetic transfection; high throughput screening; liquid chromatography; metabolism; reproducibility; sensitivity and specificity; statistical model; Linear Models; Pharmaceutical Preparations

Parameter estimation of a microbial fuel cell process control-oriented model - Recio-Garrido, Dídac; Perrier, Michel; Tartakovsky, Boris (2014 22nd Mediterranean Conference on Control and Automation, MED 2014, 2014)
Microbial fuel cells (MFCs) are novel devices capable of producing electricity while cleaning wastewater. Developing dynamic control-oriented models for such systems represents a crucial tool for the future design of software sensors and model-based control strategies. To this end, this work presents a MFC process control-oriented model obtained by combining fundamental equations based on mass and electron balances with equations describing an equivalent electrical circuit. Such model accounts for the double layer capacitance effect and complex nonlinear dynamics observed during pulse-width modulated operation of the external resistance and therefore, it is able to describe the observed biological or long-term dynamics as well as the electrical or short-term dynamics. The parameter estimation for a simulation and a prediction MFC process control-oriented model is here described.
Keywords: Electrochemical electrodes; Fuel cells; Microbial fuel cells; Parameter estimation; Complex nonlinear dynamics; Control oriented models; Double-layer capacitance; Equivalent electrical circuits; External resistance; Fundamental equations; Microbial fuel cells (MFCs); Modulated operations; Process control

Poly(lactic acid) stereocomplex formation: Application to PLA rheological property modification - Saeidlou, Sajjad; Huneault, Michel A.; Li, Hongbo; Park, Chul B. (Journal of Applied Polymer Science, 2014)
Poly(lactic acid) (PLA) stereocomplex formation in isothermal conditions in the absence and presence of a nucleating agent was studied from a rheological point of view due to sensitivity of viscoelastic properties to structural changes during this process. PDLA was melt blended in low concentrations with PLLA to produce a stereocomplex. Amorphous samples were prepared and crystallization was carried out in a rheometer at high temperatures to simulate melt processing conditions. Stereocomplexation was explored over time by measuring rheological parameters in small deformation oscillatory shear mode at a low frequency using parallel plate geometry. Kinetic data obtained by this means was compared to data from calorimetric studies, showing a different trend depending on the characterization method. Moreover, after the completion of crystallization, final crystalline structure was probed over a wide range of frequencies to investigate the rheological modification role of PDLA on PLLA major component. Differences in rheological characteristics of asymmetric PLLA/PDLA blends as compared to neat PLLA were associated to the structural changes happening because of the formation of the stereocomplex.

High performance zinc oxide thin film transistors through improved material processing and device design - Adl, Ahmad Hossein; Farsinezhad, Samira; Ma, Alex; Barlage, Douglas W.; Shankar, Karthik (ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE), 2014)
Solution processing (SP) is a cheap, simple and highthroughput method for the fabrication of ZnO thin film transistors (TFTs). Lack of enhancement mode operation, poor crystallinity, traps, and poor control of the carrier concentration are some of the disadvantages of this method. The high intrinsic electron concentration of SP-ZnO makes saturation of TFTs non-trivial. We report on Schottky barrier thin film transistors (SB-TFT). By biasing the source Schottky contact in reverse bias, a depletion region is formed around the source contact hence depleting the region from the free charge carriers which produces the saturation of the device. The effect of the Schottky contact is illustrated by comparing the operation of SB-TFTs with that of conventional TFTs.
Keywords: Carrier concentration; Schottky barrier diodes; Thin films; Zinc oxide; Electron concentration; Free charge carriers; High-throughput method; Material processing; Poor crystallinity; Schottky barrier thin-film transistors; Solution-processing; Zinc oxide thin films; Thin film transistors

Effects of temperature on the hardness and wear resistance of high-tungsten stellite alloys - Liu, Rong; Wu, X. J.; Kapoor, Samit; Yao, M. X.; Collier, Rachel (Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science, 2014)
In this research, two new Stellite alloys containing high tungsten are developed for wear resistance application owing to the distinct beneficial effects of tungsten in Stellite alloys. The microstructures of these alloys are analyzed using a scanning electron microscope (SEM) with an EDAX energy dispersive X-ray (EDX) spectroscopy system and X-ray diffraction spectrum. The micro-hardness and wear resistance of the alloys at room temperature and at elevated temperatures are investigated utilizing a Microhardness Tester Unit, with a Hot Stage, and a Hot Pin-on-Disk Tribometer, respectively. The wear test results of these alloys are compared with those of commercial wear-resistant Stellite 3 and Stellite 12. The worn surfaces of the specimens are analyzed using SEM/EDX to explore the wear mechanisms of these alloys with temperature change. The variations of hardness and wear resistance of these alloys with temperature are studied and discussed.
Keywords: Alloys; Scanning electron microscopy; Stellite; Temperature; Tribology; Tungsten; X ray diffraction; Effects of temperature; Elevated temperature; Energy dispersive x-ray; Microhardness tester; Pin-on-disk tribometers; X-ray diffraction spectrum

N-3 polyunsaturated fatty acids inhibit IFN-γ-induced IL-18 binding protein production by prostate cancer cells - Wang, Xiaofeng; Breeze, Andrew; Kulka, Marianna (Cancer Immunology, Immunotherapy, 2014)
Prostate cancer cells can produce IL-18 binding protein (IL-18BP) in response to interferon-γ (IFN-γ), which may function to neutralize IL-18, an anti-tumor factor formerly known as IFN-γ inducing factor. The consumption of n-3 polyunsaturated fatty acids (PUFAs) has been associated with a lower risk of certain types of cancer including prostate cancer, although the precise mechanisms of this effect are poorly understood. We hypothesized that n-3 PUFAs could modify IL-18BP production by prostate cancer cells by altering IFN-γ receptor-mediated signal transduction. Here, we demonstrate that n-3 PUFA treatment significantly reduced IFN-γ-induced IL-18BP production by DU-145 and PC-3 prostate cancer cells by inhibiting IL-18BP mRNA expression and was associated with a reduction in IFN-γ receptor expression. Furthermore, IFN-γ-induced phosphorylation of Janus kinase 1 (JAK1), signal transducers and activators of transcription 1 (STAT1), extracellular signal-regulated kinases 1/2 (ERK1/2), and P38 were suppressed by n-3 PUFA treatment. By contrast, n-6 PUFA had no effect on IFN-γ receptor expression, but decreased IFN-γ-induced IL-18BP production and IFN-γ stimulation of JAK1, STAT1, ERK1/2, and JNK phosphorylation. These data indicate that both n-3 and n-6 PUFAs may be beneficial in prostate cancer by altering IFN-γ signaling, thus inhibiting IL-18BP production and thereby rendering prostate cancer cells more sensitive to IL-18-mediated immune responses.
Keywords: gamma interferon; gamma interferon receptor; interleukin 18 binding protein; Janus kinase 1; messenger RNA; mitogen activated protein kinase 1; omega 3 fatty acid; STAT1 protein; synaptophysin; gamma interferon; gamma interferon receptor; interferon receptor; interleukin-18 binding protein; messenger RNA; signal peptide; cancer cell; cytokine production; immune response; prostate cancer; protein binding; protein expression; protein phosphorylation; signal transduction; biosynthesis; drug effects; gene expression regulation; genetics; metabolism; prostate tumor; tumor cell line; Gene Expression Regulation, Neoplastic; Intercellular Signaling Peptides and Proteins; Prostatic Neoplasms

Identification of candidate genes, regions and markers for pre-harvest sprouting resistance in wheat (Triticum aestivum L.) - Cabral, Adrian L.; Jordan, Mark C.; McCartney, Curt A.; You, Frank M.; Humphreys, D. Gavin; MacLachlan, Ron; Pozniak, Curtis J. (BMC Plant Biology, 2014)
Background: Pre-harvest sprouting (PHS) of wheat grain leads to a reduction in grain yield and quality. The availability of markers for marker-assisted selection (MAS) of PHS resistance will serve to enhance breeding selection and advancement of lines for cultivar development. The aim of this study was to identify candidate regions and develop molecular markers for PHS resistance in wheat. This was achieved via high density mapping of single nucleotide polymorphism (SNP) markers from an Illumina 90 K Infinium Custom Beadchip in a doubled haploid (DH) population derived from a RL4452/'AC Domain' cross and subsequent detection of quantitative trait loci (QTL) for PHS related traits (falling number [FN], germination index [GI] and sprouting index [SI]). SNP marker sequences flanking QTL were used to locate colinear regions in Brachypodium and rice, and identify genic markers associated with PHS resistance that can be utilized for MAS in wheat. Results: A linkage map spanning 2569.4 cM was constructed with a total of 12,201 SNP, simple sequence repeat (SSR), diversity arrays technology (DArT) and expressed sequence tag (EST) markers. QTL analyses using Multiple Interval Mapping (MIM) identified four QTL for PHS resistance traits on chromosomes 3B, 4A, 7B and 7D. Sequences of SNPs flanking these QTL were subject to a BLASTN search on the International Wheat Genome Sequencing Consortium (IWGSC) database (http://wheat-urgi.versailles.inra.fr/Seq-Repository). Best survey sequence hits were subject to a BLASTN search on Gramene (www.gramene.org) against both Brachypodium and rice databases, and candidate genes and regions for PHS resistance were identified. A total of 18 SNP flanking sequences on chromosomes 3B, 4A, 7B and 7D were converted to KASP markers and validated with matching genotype calls of Infinium SNP data. Conclusions: Our study identified candidate genes involved in abscissic acid (ABA) and gibberellin (GA) metabolism, and flowering time in four genomic regions of Brachypodium and rice respectively, in addition to 18 KASP markers for PHS resistance in wheat. These markers can be deployed in future genetic studies of PHS resistance and might also be useful in the evaluation of PHS in germplasm and breeding material.
Keywords: Brachypodium; Triticum aestivum

The ambient and high temperature deformation behavior of Al-Si-Cu-Mg alloy with minor Ti, Zr, Ni additions - Hernandez-Sandoval, J.; Garza-Elizondo, G. H.; Samuel, A. M.; Valtiierra, S.; Samuel, F. H. (Materials and Design, 2014)
The principal aim of the present work was to investigate the effects of minor additions of nickel and zirconium on the strength of cast aluminum alloy 354 at ambient and high temperatures. Tensile properties of the as-cast and heat-treated alloys were determined at room temperature and at high temperatures (190. °C, 250. °C, 350. °C). The results show that Zr reacts only with Ti, Si and Al. From the quality index charts constructed for these alloys, the quality index attains minimum and maximum values of 259. MPa and 459. MPa, in the as-cast and solution-treated conditions; also, maximum and minimum values of yield strength are observed at 345. MPa and 80. MPa, respectively, within the series of aging treatments applied. A decrease in tensile properties of ~10% with the addition of 0.4. wt.% nickel is attributed to a nickel-copper reaction. The reduction in mechanical properties due to addition of different elements is attributed principally to the increase in the percentage of intermetallic phase particles formed during solidification; such particles act as stress concentrators, decreasing the alloy ductility. Tensile test results at ambient temperatures show a slight increase (~10%) in alloys with Zr and Zr/Ni additions, particularly at aging temperatures above 240. °C. Additions of Zr and Zr. +. Ni increase the high temperature tensile properties, in particular for the alloy containing 0.2. wt.% Zr. +. 0.2. wt.% Ni, which exhibits an increase of more than 30% in the tensile properties at 300. °C compared with the base 354 alloy.
Keywords: Aluminum; Aluminum alloys; Copper alloys; High temperature effects; Intermetallics; Mechanical properties; Nickel; Quality assurance; Silicon; Stress concentration; Tensile testing; Zirconium; Al-si-cu-mg alloys; Cast aluminum alloy; High temperature deformation behavior; High temperature tensile properties; Intermetallic phase; Quality indices; Solution-treated conditions; Stress concentrators; Titanium alloys

Advances in radical-trapping antioxidant chemistry in the 21st century: A kinetics and mechanisms perspective - Ingold, Keith U.; Pratt, Derek A. (Chemical Reviews, 2014)
Antioxidants were divided in two parts radical-trapping antioxidants (RTAs) and preventive antioxidants. By the final quarter of the 20th century, the commercial importance of antioxidants was overshadowed by their putative role in human health, as the implication of radical-mediated oxidation in virtually all types of degenerative diseases, including cancer and aging, emerged. From a commercial perspective, there continues to be significant interest in the development of RTA technology. Much of the industrial research effort has been on optimization of the structures of existing RTAs to provide appropriate physical properties and identification of combinations of existing RTAs that achieve optimal performance via the synergistic interactions.
Keywords: Industrial research; Structural optimization; 20th century; Anti-oxidant chemistry; Commercial perspectives; Degenerative disease; Kinetics and mechanism; Optimal performance; Radical trapping; Synergistic interaction; Antioxidants

Formation of inter-diffusion layer between NiCrAlY coating and Nb substrate during vacuum heat-treatment - Saito, Shigeru; Takashima, Toshiyuki; Miyama, Katsumi; Narita, Toshio; Zhao, Linruo (Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals, 2014)
The formation of the inter-diffusion zone (IDZ) between NiCrAlY coating and Nb substrate during vacuum heat treatment was investigated. A NiCrAlY coating was applied on Nb substrate by cathode arc deposition. Vacuum heat treatments were carried out at 800°C, 900°Cand 1000°C for 2 h. SEM, EPMA, EDS and XRD were performed to analyze the microstructure of the IDZ and the results were interpreted using the 1002°C isothermal ternary Nb-Ni-Cr phase diagram. It was found that at 800°C the IDZ has a single NbNi3layer; at 900°C the IDZ consists of an outer NbNi3layer, a thin intermediate NbCr2(HT) layer and an inner Nb7Ni6 layer; at 1000°C the IDZ has three well-developed layers: an outer NbNi3layer, an intermediate NbCr2(HT) layer and an inner Nb7Ni6 layer. A small amount of Cr exists in both NbNi3and Nb7Ni6phases as solid solution, and a large amount of Ni in NbCr2(HT) phase as solid solution.
Keywords: Cathodes; Deposition; Diffusion; Diffusion coatings; Nickel; Solid solutions; Arc deposition; NbCr2(HT) phase; NbNi3 phase; Nickel chromium; Vacuum heat treatment; Heat treatment

Batch-to-batch variation of polymeric photovoltaic materials: Its origin and impacts on charge carrier transport and device performances - Lee, Harrison Ka Hin; Li, Zhao; Constantinou, Iordania; So, Franky; Tsang, Sai Wing; So, Shu Kong (Advanced Energy Materials, 2014)
A detailed investigation of the impact of molecular weight distribution of a photoactive polymer, poly[N-9′-heptadecanyl-2,7-carbazole-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)] (PCDTBT), on photovoltaic device performance and carrier transport properties is reported. It is found that different batches of as-received polymers have substantial differences in their molecular weight distribution. As revealed by gel permeation chromatography (GPC), two peaks can generally be observed. One of the peaks corresponds to a high molecular weight component and the other peak corresponds to a low molecular weight component. Photovoltaic devices fabricated with a higher proportion of low molecular weight component have power conversion efficiencies (PCEs) reduced from 5.7% to 2.5%. The corresponding charge carrier mobility at the short-circuit region is also significantly reduced from 2.7 × 10-5 to 1.6 × 10-8 cm2 V-1 s-1. The carrier transport properties of the polymers at various temperatures are further analyzed by the Gaussian disorder model (GDM). All polymers have similar energetic disorders. However, they appear to have significant differences in carrier hopping distances. This result provides insight into the origin of the molecular weight effect on carrier transport in polymeric semiconducting materials. Batch-to-batch variation of the photovoltaic performance of devices based on commercial samples of the polymer poly[N-9′-heptadecanyl-2,7-carbazole-alt-5,5- (4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)] (PCDTBT) is reported, with efficiency ranging from 5.7% to 2.5%. As revealed by gel permeation chromatography, bimodal distributions are observed in the molecular weight. Charge transport data suggest that low molecular weight components increase the average hopping distance, resulting in lower mobility and poorer photovoltaic performance. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Keywords: Carrier mobility; Carrier transport; Charge carriers; Charge transfer; Chromatography; Gel permeation chromatography; Molecular weight; Molecular weight distribution; Polycyclic aromatic hydrocarbons; Transport properties; Batch-to-batch variations; Gaussian disorder models; Gel permeation chromatography (GPC); Hopping distances; Photovoltaic devices; Photovoltaic performance; Power conversion efficiencies; Semiconducting materials; Polymers

Evaluation of electron beam welded AISI 415 stainless steel - Sarafan, Sheida; Wanjara, Priti; Champliaud, Henri; Thibault, Denis; Mathieu, Louis (ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE), 2014)
Sustainable manufacturing for assembly of turbines used in hydro power generation systems is driving the development of advanced technologies targeted to reduce life-cycle costs whilst assuring high performance over the prolonged product life-span. The turbine runner, a critical component in hydro power generation systems, requires weld assembly between the crown, band and blade sub-components. With due consideration of the thick-gauge sections involved, design and fabrication of a turbine runner that would integrate a high energy density technology for assembly, such as vacuum electron beam welding (EBW), has marked potential to achieve deep penetration with a low heat input, thereby rendering a weldment with narrow heataffected zones (HAZ) and low distortion. In this study, the weldability of thick-gauge section AISI 415 martensitic stainless steels that are widely utilized in hydro turbine manufacturing was investigated by EBW. Particularly, bead-on-plate (BOP) welding of 88 mm-thick AISI 415 plate was carried out using a 42 kW high vacuum EBW system. The characteristics of the weldments, such as fusion zone (FZ) and HAZ microstructures and hardness were evaluated. The microstructural constituents across the weldment for process conditions that rendered nearcomplete penetration were studied and related to the microhardness evolution.
Keywords: Electron beam welding; Electron beams; Gages; Heat affected zone; Hydroelectric power; Martensitic stainless steel; Microhardness; Turbines; Turbomachine blades; Welding; High energy densities; Hydro-power generation; Microhardness evolutions; Sustainable manufacturing; Thick gauge section; Vacuum electron beam welding; Stainless steel

Investigation of changes in tetracycline repressor binding upon mutations in the tetracycline operator - Bolintineanu, Dan S.; Volzing, Katherine; Vivcharuk, Victor; Sayyed-Ahmad, Abdallah; Srivastava, Poonam; Kaznessis, Yiannis N. (Journal of Chemical and Engineering Data, 2014)
The tetracycline operon is an important gene network component, commonly used in synthetic biology applications because of its switch-like character. At the heart of this system is the highly specific interaction of the tet repressor protein (TetR) with its cognate DNA sequence (tetO). TetR binding on tetO practically stops expression of genes downstream of tetO by excluding RNA polymerase from binding the promoter and initiating transcription. Mutating the tetO sequence alters the strength of TetR-tetO binding and thus provides a tool to synthetic biologists to manipulate gene expression levels. We employ molecular dynamics (MD) simulations coupled with the free energy perturbation method to investigate the binding affinity of TetR to different tetO mutants. We also carry out in vivo tests in Escherichia coli for a series of promoters based on these mutants. We obtain reasonable agreement between experimental green fluorescent protein (GFP) repression levels and binding free energy differences computed from molecular simulations. In all cases, the wild-type tetO sequence yields the strongest TetR binding, which is observed both experimentally, in terms of GFP levels, and in simulation, in terms of free energy changes. Two of the four tetO mutants we tested yield relatively strong binding, whereas the other two mutants tend to be significantly weaker. The clustering and relative ranking of this subset of tetO mutants is generally consistent between our own experimental data, previous experiments with different systems and the free energy changes computed from our simulations. Overall, this work offers insights into an important synthetic biological system and demonstrates the potential, as well as limitations of molecular simulations to quantitatively explain biologically relevant behavior.

The UVIT telescopes on board the ISRO Astrosat Observatory - Hutchings, J. B. (SPIE - International Society for Optical Engineering. Proceedings, 2014)
UVIT consists of two co-aligned 38cm telescopes that provide ∼1 arsec resolution imaging over 28 arcmin fields, in FUV, NUV, and Visible bands simultaneously. Each channel has a choice of filters, and, for the UV channels, gratings. UVIT is also co-aligned with three X-ray telescopes on the observatory, and all operate together. This paper gives details of the operation and performance of the instrument.
Keywords: Image reconstruction; Imaging techniques; Observatories; Space telescopes; Multi-wavelengths; Resolution imaging; space; Ultraviolet; Visible band; X ray telescope; Gamma rays

Optical turbulence profiling with SloDAR in the Canadian High Arctic - Maire, Jérôme; Mieda, Etsuko; Steinbring, Eric; Murowinski, Richard; Graham, James R.; Carlberg, Raymond; Wright, Shelley A.; Law, Nicholas M.; Sivanandam, Suresh (SPIE - International Society for Optical Engineering. Proceedings, 2014)
The Earth's polar regions offer unique advantages for ground-based astronomical observations with its cold and dry climate, long periods of darkness, and the potential for exquisite image quality. We present preliminary results from a site-testing campaign during nighttime from October to November 2012 at the Polar Environment Atmospheric Research Laboratory (PEARL), on a 610-m high ridge near the Eureka weatherstation on Ellesmere Island, Canada. A Shack-Hartmann wavefront sensor was employed, using the Slope Detection and Ranging (SloDAR) method. This instrument (Mieda et al, this conference) was designed to measure the altitude, strength and variability of atmospheric turbulence, in particular for operation under Arctic conditions. First SloDAR optical turbulence profiles above PEARL show roughly half of the optical turbulence confined to the boundary layer, below about 1 km, with the majority of the remainder in one or two thin layers between 2 km and 5 km, or above. The median seeing during this campaign was measured to be 0.65 arcsec.
Keywords: Airborne telescopes; Atmospheric thermodynamics; Atmospheric turbulence; Boundary layers; Earth (planet); Research laboratories; Space optics; Wavefronts; Astronomical instrument; Astronomical observation; Atmospheric characterization; Atmospheric research; Canadian high arctic; Polar environments; Shack-Hartmann wavefront sensors; Wave front sensors; Adaptive optics

SPIRou: The near-infrared spectropolarimeter/high-precision velocimeter for the Canada-France-Hawaii telescope - Artigau, Étienne; Kouach, Driss; Donati, Jean-FrançoisJ.-F.; Doyon, René; Delfosse, Xavier; Baratchart, Sébastien; Lacombe, Marielle; Moutou, Claire; Rabou, Patrick; Parès, Laurent P.; Micheau, Yoan; Thibault, Simon; et al. (SPIE - International Society for Optical Engineering. Proceedings, 2014)
SPIRou is a near-IR echelle spectropolarimeter and high-precision velocimeter under construction as a next- generation instrument for the Canada-France-Hawaii-Telescope. It is designed to cover a very wide simultaneous near-IR spectral range (0.98-2.35 μm) at a resolving power of 73.5K, providing unpolarized and polarized spectra of low-mass stars at a radial velocity (RV) precision of 1m/s. The main science goals of SPIRou are the detection of habitable super-Earths around low-mass stars and the study of stellar magnetism of star at the early stages of their formation. Following a successful final design review in Spring 2014, SPIRou is now under construction and is scheduled to see first light in late 2017. We present an overview of key aspects of SPIRou's optical and mechanical design.
Keywords: Astronomy; Data handling; Data processing; Giant stars; Infrared devices; Infrared radiation; Planets; Stars; Telescopes; Velocity measurement; Design review; High-precision; Low-mass stars; Near Infrared; Optical and mechanical designs; Polarized spectra; Radial velocity; Spectropolarimeters; Velocimeters

Volume stability of calcium-silicate-hydrate/polyaniline nanocomposites in aqueous salt solutions - Khoshnazar, Rahil; Beaudoin, James J.; Raki, Laila; Alizadeh, Rouhollah (ACI Materials Journal, 2014)
The volume stability of phase pure calcium-silicate-hydrates (C-S-H) and C-S-H/polyaniline nanocomposites prepared with two CaO-SiO2 molar ratio (C/S) variations (0.8 and 1.2) was assessed in MgSO4, MgCl2, LiCl, and NaCl aqueous solutions. The change in the crystalline structure of the samples with the time of immersion was also explored using X-ray diffraction, scanning electron microscopy, and thermal gravimetric analysis techniques. It was observed that the modification of the C-S-H samples with polyaniline significantly enhanced their volume stability and durability in all the salt solutions. The beneficial effect of the polyaniline modification was more pronounced in the C-S-H host with higher C/S (C/S = 1.2). The longitudinal expansion of the C-S-H/polyaniline nanocomposites with C/S = 1.2 in the salt solutions was about 30% of that of the phase pure C-S-H with a similar C/S ratio. In addition, the polyaniline modification of C-S-H samples reduced the rate of formation of gypsum, brucite, and other reaction products in the samples.
Keywords: Additives; Calcium; Durability; Gravimetric analysis; Hydration; Nanocomposites; Phase stability; Polyaniline; Scanning electron microscopy; Silicate minerals; Thermogravimetric analysis; X ray diffraction; Aqueous salt solution; Calcium silicate hydrate; Crystalline structure; Longitudinal expansions; NaCl aqueous solution; Thermal gravimetric analysis; Volume stability

Study on relationships between climate-related covariates and pipe bursts using evolutionary-based modelling - Laucelli, Daniele; Rajani, Balvant; Kleiner, Yehuda; Giustolisi, Orazio (Journal of Hydroinformatics, 2014)
Researchers extensively studied external loads since they are widely recognized as significant contributors to water pipe failures. Physical phenomena that affect pipe bursts, such as pipeenvironment interactions, are very complex and only partially understood. This paper analyses the possible link between pipe bursts and climate-related factors. Many water utilities observed consistent occurrence of peaks in pipe bursts in some periods of the year, during winter or summer. The paper investigates the relationships between climate data (i.e., temperature and precipitationrelated covariates) and pipe bursts recorded during a 24-year period in Scarborough (Ontario, Canada). The Evolutionary Polynomial Regression modelling paradigm is used here. This approach is broader than statistical modelling, implementing a multi-modelling approach, where a multiobjective genetic algorithm is used to get optimal models in terms of parsimony of mathematical expressions vs. fitting to data. The analyses yielded interesting results, in particular for cold seasons, where the discerned models show good accuracy and the most influential explanatory variables are clearly identified. The models discerned for warm seasons show lower accuracy, possibly implying that the overall phenomena that underlay the generation of pipe bursts during warm seasons cannot be thoroughly explained by the available climate-related covariates.

Compositional complexity of the mitochondrial proteome of a unicellular eukaryote (Acanthamoeba castellanii, supergroup Amoebozoa) rivals that of animals, fungi, and plants - Gawryluk, Ryan M. R.; Chisholm, Kenneth A.; Pinto, Devanand M.; Gray, Michael W. (Journal of Proteomics, 2014)
We present a combined proteomic and bioinformatic investigation of mitochondrial proteins from the amoeboid protist Acanthamoeba castellanii, the first such comprehensive investigation in a free-living member of the supergroup Amoebozoa. This protist was chosen both for its phylogenetic position (as a sister to animals and fungi) and its ecological ubiquity and physiological flexibility. We report 1033 A. castellanii mitochondrial protein sequences, 709 supported by mass spectrometry data (676 nucleus-encoded and 33 mitochondrion-encoded), including two previously unannotated mtDNA-encoded proteins, which we identify as highly divergent mitochondrial ribosomal proteins. Other notable findings include duplicate proteins for all of the enzymes of the tricarboxylic acid (TCA) cycle-which, along with the identification of a mitochondrial malate synthase-isocitrate lyase fusion protein, suggests the interesting possibility that the glyoxylate cycle operates in A. castellanii mitochondria. Additionally, the A. castellanii genome encodes an unusually high number (at least 29) of mitochondrion-targeted pentatricopeptide repeat (PPR) proteins, organellar RNA metabolism factors in other organisms. We discuss several key mitochondrial pathways, including DNA replication, transcription and translation, protein degradation, protein import and Fe-S cluster biosynthesis, highlighting similarities and differences in these pathways in other eukaryotes. In compositional and functional complexity, the mitochondrial proteome of A. castellanii rivals that of multicellular eukaryotes. Biological significance: Comprehensive proteomic surveys of mitochondria have been undertaken in a limited number of predominantly multicellular eukaryotes. This phylogenetically narrow perspective constrains and biases our insights into mitochondrial function and evolution, as it neglects protists, which account for most of the evolutionary and functional diversity within eukaryotes. We report here the first comprehensive investigation of the mitochondrial proteome in a member (A. castellanii) of the eukaryotic supergroup Amoebozoa. Through a combination of tandem mass spectrometry (MS/MS) and in silico data mining, we have retrieved 1033 candidate mitochondrial protein sequences, 709 having MS support. These data were used to reconstruct the metabolic pathways and protein complexes of A. castellanii mitochondria, and were integrated with data from other characterized mitochondrial proteomes to augment our understanding of mitochondrial proteome evolution. Our results demonstrate the power of combining direct proteomic and bioinformatic approaches in the discovery of novel mitochondrial proteins, both nucleus-encoded and mitochondrion-encoded, and highlight the compositional complexity of the A. castellanii mitochondrial proteome, which rivals that of animals, fungi and plants.
Keywords: glyoxylic acid; hybrid protein; iron; isocitrate lyase; malate synthase; mitochondrial protein; pyruvic acid; sulfur; tricarboxylic acid; ferrous sulfide; isocitrate lyase; malate synthase; mitochondrial DNA; proteome; ribosome protein; amino acid metabolism; amino acid sequence; bioinformatics; biosynthesis; cell nucleus; cell respiration; chemical composition; computer model; data mining; DNA metabolism; DNA replication; DNA transcription; mass spectrometry; mitochondrial targeting signal; molecular evolution; phylogeny; protein analysis; protein degradation; protein domain; protein metabolism; protein targeting; protein transport; RNA metabolism; citric acid cycle; nucleotide metabolism; protist; tandem mass spectrometry; Acanthamoeba castellanii; Amoebozoa; Fungi

Short-time dynamics at a conical intersection in high-harmonic spectroscopy - Patchkovskii, Serguei; Schuurman, Michael S. (The Journal of Physical Chemistry A, 2014)
High-harmonic spectroscopy probes molecular dynamics using electrons liberated from the same molecule earlier in the laser cycle. It affords sub-A˚ngstrom spatial and subfemtosecond temporal resolution. Nuclear dynamics in the intermediate cation influence the spectrum of the emitted high-harmonic photons through an autocorrelation function. Here, we develop an analytical approach for computing short-time nuclear autocorrelation functions in the vicinity of conical intersections, including laser-induced and nonadiabatic coupling between the surfaces. We apply the technique to two molecules of current experimental interest, C6H6 and C6H5F. In both molecules, high-harmonics generated within the same electronic channel are not sensitive to nonadiabatic dynamics, even in the presence of substantial population transfer. Calculated autocorrelation functions exhibit significant deviations from the expected Gaussian decay and may undergo revivals at short (∼1.5 fs) times. The associated phase of the nuclear wavepacket provides a possible experimental signature.
Keywords: Harmonic analysis; Molecular dynamics; Molecules; Optical systems; Analytical approach; Autocorrelation functions; Conical intersection; Electronic channels; Non-adiabatic coupling; Non-adiabatic dynamics; Population transfer; Short-time dynamics; Autocorrelation

Planar patch clamp for neuronal networks - Considerations and future perspectives - Bosca, Alessandro; Martina, Marzia; Py, Christophe (Methods in Molecular Biology, 2014)
The patch-clamp technique is generally accepted as the gold standard for studying ion channel activity allowing investigators to either "clamp" membrane voltage and directly measure transmembrane currents through ion channels, or to passively monitor spontaneously occurring intracellular voltage oscillations. However, this resulting high information content comes at a price. The technique is labor-intensive and requires highly trained personnel and expensive equipment. This seriously limits its application as an interrogation tool for drug development. Patch-clamp chips have been developed in the last decade to overcome the tedious manipulations associated with the use of glass pipettes in conventional patch-clamp experiments. In this chapter, we describe some of the main materials and fabrication protocols that have been developed to date for the production of patch-clamp chips. We also present the concept of a patch-clamp chip array providing high resolution patch-clamp recordings from individual cells at multiple sites in a network of communicating neurons. On this chip, the neurons are aligned with the aperture-probes using chemical patterning. In the discussion we review the potential use of this technology for pharmaceutical assays, neuronal physiology and synaptic plasticity studies.
Keywords: silicon dioxide; silicon nitride; cell adhesion; cell aggregation; immunofluorescence microscopy; microelectromechanical system; microfluidics; microtechnology; nerve cell culture; nerve cell network; nerve cell plasticity; planar patch clamp; scanning electron microscopy

Capture of CO2 and storage in depleted gas reservoirs in Alberta as gas hydrate - Sun, Duo; Daraboina, Nagu; Ripmeester, John; Englezos, Peter (Gas Injection for Disposal and Enhanced Recovery, 2014)
Storage of CO2 in depleted natural gas reservoirs is considered an attractive option to mitigate climate change concerns arising from the emissions of CO2 from sources such as thermal power plants. A number of depleted gas reservoirs located in Northern Alberta with the pressure and temperature conditions of 2-5 MPa and 1-10°C, respectively, are identified as potential sites for CO2 storage in gas hydrate form. CO2 hydrate is ice-like crystalline compound consisting of hydrogen-bonded water molecules and CO2 molecules. The water molecules build a network with hydrogen bonds to stabilize CO2 molecules in it. Equilibrium pressures of CO2 hydrate corresponding to 1 and 10°C are 1.41 and 4.29 MPa, respectively. Therefore, the pressure and temperature conditions of depleted gas reservoirs in Northern Alberta are within CO2 hydrate formation region. There are several computer simulations that have demonstrated the possibility of storing CO2 as solid hydrate in these depleted natural gas pools. However, there has not any laboratory demonstration of CO2 injection and storage in a simulated depleted gas reservoir. We are investigating the injection of CO2 in a bed of silica sand partially saturated with water (wet sand) at pressure and temperature conditions similar to those in a typical depleted gas reservoir in Northern Alberta. Through the pressure drop measurements, the CO2 gas consumption is determined and also the amount of water converted to hydate is calculated. The results indicate that most CO2 gas is consumed in a Semi-batch gas injection experiment, and 35-40%,40-45%, and 45-50% of water formed hydrate in Batch, Series-batch, and Semibatch gas injection experiments, respectively.

A measurement of the systematic astrometric error in GeMS and the short-term astrometric precision in ShaneAO - Ammons, S. Mark; Neichel, Benoit; Lu, Jessica; Gavel, Donald T.; Srinath, Srikar; McGurk, Rosalie; Rudy, Alex; Rockosi, Connie; Marois, Christian; MacIntosh, Bruce; Savransky, Dmitry; Galicher, Raphael; et al. (SPIE - International Society for Optical Engineering. Proceedings, 2014)
We measure the long-term systematic component of the astrometric error in the GeMS MCAO system as a function of field radius and Ks magnitude. The experiment uses two epochs of observations of NGC 1851 separated by one month. The systematic component is estimated for each of three field of view cases (15'' radius, 30'' radius, and full field) and each of three distortion correction schemes: 8 DOF/chip + local distortion correction (LDC), 8 DOF/chip with no LDC, and 4 DOF/chip with no LDC. For bright, unsaturated stars with 13 < Ks < 16, the systematic component is < 0.2, 0.3, and 0.4 mas, respectively, for the 15'' radius, 30'' radius, and full field cases, provided that an 8 DOF/chip distortion correction with LDC (for the full-field case) is used to correct distortions. An 8 DOF/chip distortion-correction model always outperforms a 4 DOF/chip model, at all field positions and magnitudes and for all field-of-view cases, indicating the presence of high-order distortion changes. Given the order of the models needed to correct these distortions (∼8 DOF/chip or 32 degrees of freedom total), it is expected that at least 25 stars per square arcminute would be needed to keep systematic errors at less than 0.3 milliarcseconds for multi-year programs. We also estimate the short-term astrometric precision of the newly upgraded Shane AO system with undithered M92 observations. Using a 6-parameter linear transformation to register images, the system delivers ∼0.3 mas astrometric error over short-term observations of 2-3 minutes.
Keywords: Degrees of freedom (mechanics); Linear transformations; Mathematical transformations; Stars; Systematic errors; Tomography; astrometry; Brown dwarfs; M92; multi-conjugate; NGC 1851; Adaptive optics

Near-infrared detection and characterization of the exoplanet HD 95086 b with the Gemini Planet Imager - Galicher, R.; Rameau, J.; Bonnefoy, M.; Baudino, J. -L.; Currie, T.; Boccaletti, A.; Chauvin, G.; Lagrange, A. -M.; Marois, C. (Astronomy and Astrophysics, 2014)
HD 95086 is an intermediate-mass debris-disk-bearing star. VLT/NaCo 3.8 μm observations revealed it hosts a 5 ± 2 MJup companion (HD 95086 b) at â‰ 56 AU. Follow-up observations at 1.66 and 2.18 μm yielded a null detection, suggesting extremely red colors for the planet and the need for deeper direct-imaging data. In this Letter, we report H-(1.7 μm) and K1-(2.05 μm) band detections of HD 95086 b from Gemini Planet Imager (GPI) commissioning observations taken by the GPI team. The planet position in both spectral channels is consistent with the NaCo measurements and we confirm it to be comoving. Our photometry yields colors of H-L′ = 3.6 ± 1.0 mag and K1-L′ = 2.4 ± 0.7 mag, consistent with previously reported 5-σ upper limits in H and Ks. The photometry of HD 95086 b best matches that of 2M 1207 b and HR 8799 cde. Comparing its spectral energy distribution with the BT-SETTL and LESIA planet atmospheric models yields Teff ~ 600-1500 K and log g ~ 2.1-4.5. Hot-start evolutionary models yield M = 5 ± 2 MJup. Warm-start models reproduce the combined absolute fluxes of the object for M = 4-14 M Jup for a wide range of plausible initial conditions (S init = 8-13 kB/baryon). The color-magnitude diagram location of HD 95086 b and its estimated Teff and log g suggest that the planet is a peculiar L-T transition object with an enhanced amount of photospheric dust.
Keywords: Color; Photometry; Planets; Stars; Color magnitude diagrams; Evolutionary models; Initial conditions; Instrumentation: adaptive optics; Planets and satellites: atmospheres; Planets and satellites: detections; Spectral energy distribution; Stars: individual; Satellites

Residual stress mapping along the cylinder bores of Al alloy engine blocks subjected to production solution heat treatment schedule - Lombardi, Anthony; Sediako, Dimitry; Ravindran, C.(Ravi); Mackay, Robert (SAE International Journal of Materials and Manufacturing, 2014)
The development of an optimized heat treatment schedule, with the aim of maximizing strength and relieving tensile residual stress, is important to prevent in-service cylinder distortion in Al alloy engine blocks containing cast-in gray iron liners. However, to effectively optimize the engine block heat treatment schedule, the current solutionizing parameters must be analyzed and compared to the as-cast condition to establish a baseline for residual stress relief. In this study, neutron diffraction was carried out to measure the residual stress along the aluminum cylinder bridge following solution heat treatment. The stresses were measured in the hoop, radial and axial orientations and compared to a previous measured as-cast (TSR) engine block. The results suggest that solution heat treatment using the current production parameters partially relieved tensile residual stress in the Al cylinder bridge, with stress relief being more effective near the bottom of the cylinder.
Keywords: Aluminum cylinders; Axial orientations; Current production; Cylinder bore; Engine blocks; Heat treatment schedule; Solution heat treatment; Tensile residual stress; Aluminum; Cast iron; Engines; Heat treatment; Neutron diffraction; Residual stresses; Cylinder blocks

Carbohydrate functionalization of silver nanoparticles modulates cytotoxicity and cellular uptake - Kennedy, David C.; Orts-Gil, Guillermo; Lai, Chian-Hui; Müller, Larissa; Haase, Andrea; Luch, Andreas; Seeberger, Peter H. (Journal of Nanobiotechnology, 2014)
Background: Increasing use of silver nanoparticles (Ag-NPs) in various products is resulting in a greater likelihood of human exposure to these materials. Nevertheless, little is still known about the influence of carbohydrates on the toxicity and cellular uptake of nanoparticles. Methods: Ag-NPs functionalized with three different monosaccharides and ethylene glycol were synthesized and characterised. Oxidative stress and toxicity was evaluated by protein carbonylation and MTT assay, respectively. Cellular uptake was evaluated by confocal microscopy and ICP-MS. Results: Ag-NPs coated with galactose and mannose were considerably less toxic to neuronal-like cells and hepatocytes compared to particles functionalized by glucose, ethylene glycol or citrate. Toxicity correlated to oxidative stress but not to cellular uptake. Conclusions: Carbohydrate coating on silver nanoparticles modulates both oxidative stress and cellular uptake, but mainly the first has an impact on toxicity. These findings provide new perspectives on modulating the bioactivity of Ag-NPs by using carbohydrates.
Keywords: Carbonylation; Ethylene; Nanoparticles; Polyols; Toxicity; Biointerfaces; Carbohydrate coatings; Functionalizations; Nanotoxicology; Silver; carbohydrate; ethylene glycol; galactose; glucose; mannose; monosaccharide; reactive oxygen metabolite; silver nanoparticle; sugar; carbohydrate analysis; cell culture; cell surface; cellular parameters; cellular uptake; confocal microscopy; cytotoxicity; liver cell; MTT assay; oxidative stress; particle size; polyacrylamide gel electrophoresis; protein carbonylation; roentgen spectroscopy; synthesis; transmission electron microscopy; zeta potential

Paralytic shellfish toxins, including deoxydecarbamoyl-STX, in wild-caught Tasmanian abalone (Haliotis rubra) - Harwood, D. Tim; Selwood, Andrew I.; van Ginkel, Roel; Waugh, Craig; McNabb, Paul S.; Munday, Rex; Hay, Brenda; Thomas, Krista; Quilliam, Michael A.; Malhi, Navreet; Dowsett, Natalie; McLeod, Catherine (Toxicon, 2014)
For the first time wild-caught Tasmanian abalone, Haliotis rubra, have been reported to contain paralytic shellfish toxins (PSTs). This observation followed blooms of the toxic dinoflagellate Gymnodinium catenatum. No illnesses were reported, but harvesting restrictions were enforced in commercial areas. Abalone were assayed using HPLC-FLD methodology based on AOAC official method 2005.06. An uncommon congener, deoxydecarbamoyl-STX (doSTX), was observed in addition to regulated PSTs as unassigned chromatographic peaks. A quantitative reference material was prepared from contaminated Tasmanian abalone viscera and ampouled at 54.2 μmol/L. The LD50 of doSTX via intraperitoneal injection was 1069 nmol/kg (95% confidence limits 983-1100 nmol/kg), indicating it is nearly 40 times less toxic than STX. A toxicity equivalence factor of 0.042 was generated using the mouse bioassay. Levels of PSTs varied among individuals from the same site, although the toxin profile remained relatively consistent. In the foot tissue, STX, decarbamoyl-STX and doSTX were identified. On a molar basis doSTX was the dominant congener in both foot and viscera samples. The viscera toxin profile was more complex, with other less toxic PST congeners observed and was similar to mussels from the same site. This finding implicates localised dinoflagellate blooms as the PST source in Tasmanian abalone.
Keywords: marine toxin; animal; Australia; gastropod; isolation and purification; liquid chromatography; metabolism; standard; tandem mass spectrometry; Animals; Chromatography, Liquid; Gastropoda; Marine Toxins; Reference Standards; Tandem Mass Spectrometry; Tasmania

Field comparison study of indoor environment quality in office buildings with underfloor and overhead ventilation systems - Ouazia, Boualem; Tardif, Michel; Thompson, Alexandra; Booth, Daniel (ASHRAE Transactions, 2014)
The use of UFAD (Underfloor Air Distribution) systems is increasing rapidly and reported advantages of UFAD include energy savings and improved indoor air quality. At present few publications documenting measurements of ventilation effectiveness and indoor environment quality in occupied buildings with UFAD have been identified. In this field comparison study we measured several aspects of the thermal environment in two buildings with different ventilation systems (underfloor air distribution and mixing) located in Montreal (Quebec). The results are presented in terms of thermal stratification, predicted thermal comfort indices (VATD , limit to air speed and PMV/ PPD), and IAQ index (CO2 level and stratification). The aim of the study was to determine whether UFAD in practice results in improved ventilation effectiveness compared to typical overhead air distribution without affecting the thermal comfort. The study found that there was little stratification for UFAD under operating conditions and it performed as a mixing system, thus no improvement in ventilation effectiveness was identified in the occupied zone, in comparison to the reference mixing system. In addition the predicted thermal comfort in term of VATD, air speed and PMV/PPD was similar to those obtained for mixing ventilation and was within the acceptable limits set by ASHRAE 55-2010.
Keywords: UFAD; mixing ventilation; office building; IAQ; predicted thermal comfort

Metabolomic shifts in Brassica napus lines with enhanced BnPLC2 activity impact their response to low temperature stress and plant pathogens - Nokhrina, Kateryna; Ray, Heather; Bock, Cheryl; Georges, Fawzy (GM Crops and Food, 2014)
Phosphatidylinositol-specific phospholipase C2 (PLC2) is a signaling enzyme with hydrolytic activity against membrane-bound phosphoinositides. It catalyzes the cleavage of phosphatidylinositol(4,5)bisphosphate (PtdIns(4,5)P2) into two initial second messengers, myo-inositol-1,4,5-trisphosphate (InsP3) and diacylglycerol (DAG). The former, as well as its fully phosphorylated derivative, myo-inositol-1,2,3,4,5,6-hexakisphosphate (InsP6), play a major role in calcium signaling events within the cell, while DAG may be used in the regeneration of phospholipids or as a precursor for phosphatidic acid (PA) biosynthesis, an important signaling molecule involved in both biotic and abiotic types of stress tolerance. Overexpression of the gene for Brassica napus phospholipase C2 (BnPLC2) in Brassica napus has been shown to enhance drought tolerance, modulate multiple genes involved in different processes and favorably affect hormonal levels in different tissues. We, therefore, undertook the current study with a view to examining, at the metabolome level, its effect on both abiotic (low temperature) and biotic (stem white rot disease) types of stress in canola. Thus, while transgenic plants exhibited a significant rise in maltose levels and a concomitant elevation in some unsaturated free fatty acids (FFAs), glycerol, and glycerol 3-phosphate under subzero temperatures, they accumulated high levels of raffinose, stachyose and other sugars as well as some flavonoids under acclimatization conditions. Collectively, overexpression of BnPLC2 appears to have triggered different metabolite patterns consistent with its abiotic and, to a limited extent, biotic stress tolerance phenotypes.
Keywords: abiotic stress, biotic stress; canola; cold; metabolomics; phospholipase C; sclerotinia; signal transduction

Genome-wide analysis of drought induced gene expression changes in flax (Linum usitatissimum) - Dash, Prasanta K.; Cao, Yongguo; Jailani, Abdul K.; Gupta, Payal; Venglat, Prakesh; Xiang, Daoquan; Rai, Rhitu; Sharma, Rinku; Thirunavukkarasu, Nepolean; Abdin, Malik Z.; Yadava, Devenedra K.; Singh, Nagendra K.; et al. (GM Crops and Food, 2014)
A robust phenotypic plasticity to ward off adverse environmental conditions determines performance and productivity in crop plants. Flax (linseed), is an important cash crop produced for natural textile fiber (linen) or oilseed with many health promoting products. This crop is prone to drought stress and yield losses in many parts of the world. Despite recent advances in drought research in a number of important crops, related progress in flax is very limited. Since, response of this plant to drought stress has not been addressed at the molecular level; we conducted microarray analysis to capture transcriptome associated with induced drought in flax. This study identified 183 differentially expressed genes (DEGs) associated with diverse cellular, biophysical and metabolic programs in flax. The analysis also revealed especially the altered regulation of cellular and metabolic pathways governing photosynthesis. Additionally, comparative transcriptome analysis identified a plethora of genes that displayed differential regulation both spatially and temporally. These results revealed co-regulated expression of 26 genes in both shoot and root tissues with implications for drought stress response. Furthermore, the data also showed that more genes are upregulated in roots compared to shoots, suggesting that roots may play important and additional roles in response to drought in flax. With prolonged drought treatment, the number of DEGs increased in both tissue types. Differential expression of selected genes was confirmed by qRT-PCR, thus supporting the suggested functional association of these intrinsic genes in maintaining growth and homeostasis in response to imminent drought stress in flax. Together the present study has developed foundational and new transcriptome data sets for drought stress in flax.
Keywords: flax/linseed; drought; abiotic stress; microarray; gene expression profiling; transcriptomics

UBC13, an E2 enzyme for Lys63-linked ubiquitination, functions in root development by affecting auxin signaling and Aux/IAA protein stability - Wen, Rui; Wang, Sheng; Xiang, Daoquan; Venglat, Prakash; Shi, Xianzong; Zang, Yuepeng; Datla, Raju; Xiao, Wei; Wang, Hong (The Plant Journal, 2014)
Unlike conventional lysine (K) 48–linked polyubiquitination, K63-linked polyubiquitination plays signaling roles in yeast and animals. Thus far, UBC13 is the only known ubiquitin-conjugating enzyme (E2) specialized in K63-linked polyubiquitination. Previous identification of Arabidopsis genes encoding UBC13 as well as its interacting partner UEV1 indicates that the UBC13-mediated ubiquitination pathway is conserved in plants; however, little is known about functions and signaling mediated through K63-linked polyubiquitination in plants. To address the functions of UBC13-mediated ubiquitination in plants, we created Arabidopsis ubc13 null mutant lines in which the two UBC13 genes were disrupted. The double mutant displayed altered root development, including shorter primary root, fewer lateral roots and only a few short root hairs in comparison with the wild type and single mutant plants, indicating that UBC13 activity is critical for all major aspects of root development. The double mutant plants were insensitive to auxin treatments, suggesting that the strong root phenotypes do not simply result from a reduced level of auxin. Instead, the ubc13 mutant had a reduced auxin response, as indicated by the expression of an auxin-responsive DR5 promoter-GFP. Furthermore, both the enzymatic activity and protein level of an AXR3/IAA17-GUS reporter were greatly increased in the ubc13 mutant, whereas the induction of many auxin-responsive genes was suppressed. Collectively, these results suggest that Aux/IAA proteins accumulate in the ubc13 mutant, resulting in a reduced auxin response and defective root development. Hence, this study provides possible mechanistic links between UBC13-mediated protein ubiquitination, root development and auxin signaling.
Keywords: Arabidopsis; UBC13; Lys63-linked; protein ubiquitination; root development; auxin signaling

From blind spot into the spotlight: introduction to the special issue 'Light, lighting, and human behaviour' - de Kort, Yvonne A. W.; Veitch, Jennifer A. (Journal of Environmental Psychology, 2014)
Light stimulates vision, and a growing body of knowledge shows that the environment thus revealed affects mood, health, and cognition. Recent neurological and biological discoveries of non-visual processes stimulated by light have spurred a wealth of research in those areas, but these processes are as behavioural, and therefore psychological, as they are physiological. Lighting research is an interdisciplinary activity, one that we think should attract greater attention from environmental psychologists. This editorial outlines the underlying processes through which light and lighting influence behaviour, and describes the diverse articles in the special issue. Collectively, the papers in this special issue convey the message that light and lighting deserve more attention from psychologists; rather than being a fringe topic, it should be near the heart of the domain of environmental psychology.

Instrumentation for monitoring pavement performance in cold regions - Maadani, Omran; Halim, A. O. Abd El; Mostafa, Nofal (Journal of cold region engineering, 2014)
The Mechanistic-Empirical(ME) design guide developed under the National Cooperative Highway Research Program represents a true change in the approach to engineering road structures. Changes in material properties with seasonal variations in moisture and temperature condition, which influence the mechanical response of the materials and hence the structural response of road layers, forced reliance on empirical measures to predict performance. These empirical functions will require calibration to ensure the prediction model is responsive to local conditions including adopted construction practice. The performance of pavements in cold regions clearly reveal the need to properly measure the distribution of stresses, strains, moisture, and thermal regimes, within road layers over a period of time. This paper presents the design, implementation, and use of a practical road instrumentation monitoring system capable of capturing all structural and environmental data for roadways. This proposed road installation scheme is simple yet effective in generating data that be used to calibrate a host of design M-E and visco-elastic models including the new AASHTO design guide. Details include selection of sensors, data acquisition systems, data processing techniques and some actual data.
Keywords: pavement performance; cold region

Reliability-based life cycle design of resilient highway bridge - Lounis, Zoubir (Transportation 2014: Past, Present, Future - 2014 Conference and Exhibition of the Transportation Association of Canada, 2014)
Highway bridges are critical links in Canada’s transportation network, which enable personal mobility and transport of goods that support trade and economic development of neighbouring communities. Highway bridges should be designed and maintained to last at least 75 years with minimum maintenance. The average service life of bridge structures vary from 30 years to 100 years, which are continually extended by using different maintenance and rehabilitation strategies. Different technologies are used for bridge life extensions, including different combinations of protective systems, repair, strengthening, rehabilitation, and replacement actions of decks, superstructures, substructures and entire bridges. The growing concerns with aging bridges, increased load and reduced strength, environmental protection and vulnerability to extreme events require the development of resilient transportation infrastructure that minimizes traffic disruption and ensures social, economic and environmental sustainability and resilience over the entire life cycle of the bridge. Given the considerable uncertainty that is associated with the key parameters and physical models that affect the life cycle performance of highway bridges, there is a need to develop robust mechanistic and stochastic models to predict the service life of bridges. This paper presents a practical reliability-based approach for the life cycle design of resilient concrete bridges that enables to achieve long life bridges with an acceptable probability of failure, which minimizes traffic disruption and reduces the life cycle costs to the bridge owners and users. An example illustrates the benefits of implementing a life cycle-based design approach through the construction of high performance concrete highway bridge structures that yield lower risk of failure when compared to conventional normal concrete construction, in terms of lower traffic disruption, life cycle costs to the bridge owners and users; lower CO2 emissions and volume of construction waste materials; and reduced accident costs.
Keywords: Highway bridge

Building application and thermal performance of vacuum insulation panels (VIPs) in Canadian subarctic climate - Mukhopadhyaya, P.; MacLean, D.; Korn, J.; van Reenen, D.; Molleti, S. (Energy and buildings, 2014)
Vacuum insulation panels (VIPs) have thermal resistance values, at the center of the panel, up to 10 times or more than those of conventional thermal insulation materials. In Canada, known for its predominantly extreme cold climate, the potential to apply VIPs in the building construction industry is estimated to be enormous, particularly with the introduction of the new 2011 National Energy Code of Canada for Buildings (NECB 2011). VIPs can play a major role in Canadian buildings to meet energy requirements of the NECB 2011. However, the lack of long-term performance credentials and various constructability issues are among the major barriers for mass application of VIPs in the Canadian construction industry. This paper presents the design strategy, construction details, instrumentation and thermal performance monitoring observations of a VIP retrofitted wall system in Yukon, located in Northern Canada. Experience gained from the construction process and available thermal performance data over a period of three years provide encouraging indicators for the constructability and long-term thermal performance of VIPs in Canadian subarctic weather.
Keywords: Vacuum insulation panel (VIP); Subarctic climate; Retrofit; Long-term performance

Predictive genomics: a cancer hallmark network framework for predicting tumor clinical phenotypes using genome sequencing data - Wang, Edwin; Zaman, Naif; Mcgee, Shauna; Milanese, Jean-Sébastien; Masoudi-Nejad, Ali; O'Connor-McCourt, Maureen (Seminars in Cancer Biology, 2014)
Tumor genome sequencing leads to documenting thousands of DNA mutations and other genomic alterations. At present, these data cannot be analyzed adequately to aid in the understanding of tumorigenesis and its evolution. Moreover, we have little insight into how to use these data to predict clinical phenotypes and tumor progression to better design patient treatment. To meet these challenges, we discuss a cancer hallmark network framework for modeling genome sequencing data to predict cancer clonal evolution and associated clinical phenotypes. The framework includes: (1) cancer hallmarks that can be represented by a few molecular/signaling networks. ‘Network operational signatures’ which represent gene regulatory logics/strengths enable to quantify state transitions and measures of hallmark traits. Thus, sets of genomic alterations which are associated with network operational signatures could be linked to the state/measure of hallmark traits. The network operational signature transforms genotypic data (i.e., genomic alterations) to regulatory phenotypic profiles (i.e., regulatory logics/strengths), to cellular phenotypic profiles (i.e., hallmark traits) which lead to clinical phenotypic profiles (i.e., a collection of hallmark traits). Furthermore, the framework considers regulatory logics of the hallmark networks under tumor evolutionary dynamics and therefore also includes: (2) a self-promoting positive feedback loop that is dominated by a genomic instability network and a cell survival/proliferation network is the main driver of tumor clonal evolution. Surrounding tumor stroma and its host immune systems shape the evolutionary paths; (3) cell motility initiating metastasis is a byproduct of the above self-promoting loop activity during tumorigenesis; (4) an emerging hallmark network which triggers genome duplication dominates a feed-forward loop which in turn could act as a rate-limiting step for tumor formation; (5) mutations and other genomic alterations have specific patterns and tissue-specificity, which are driven by aging and other cancer-inducing agents. This framework represents the logics of complex cancer biology as a myriad of phenotypic complexities governed by a limited set of underlying organizing principles. It therefore adds to our understanding of tumor evolution and tumorigenesis, and moreover, potential usefulness of predicting tumors’ evolutionary paths and clinical phenotypes. Strategies of using this framework in conjunction with genome sequencing data in an attempt to predict personalized drug targets, drug resistance, and metastasis for cancer patients, as well as cancer risks for healthy individuals are discussed. Accurate prediction of cancer clonal evolution and clinical phenotypes will have substantial impact on timely diagnosis, personalized treatment and personalized prevention of cancer.
Keywords: Tumor genome sequencing; Cancer systems biology; Network; Cancer hallmark network framework; Cancer hallmark; Gene regulatory profile; Regulatory Phenotype; Clinical phenotype; Network operational signature; Drug resistance; Personalized medicine

Progress towards the development of a glycoconjugate vaccine against Helicobacter pylori - Altman, Eleonora (2014)
Helicobacter pylori infection is particularly common in developing countries as well as Indigenous populations of North America and has been associated with chronic gastritis and increased risk of ulcers and gastric cancer in adults. Our group has been interested in the development of a conjugate vaccine based on lipopolysaccharide (LPS), a major cell surface component of H. pylori. We have identified a common antigenic LPS core epitope, Î±-1,6-glucan, and have recently demonstrated that synthetic glycoconjugates based on a truncated H. pylori LPS devoid of Lewis antigens and presenting an Î±-1,6-glucan epitope in the outer core region induced broadly cross-reactive bactericidal antibodies in immunized animals and conferred partial protection against H. pylori challenge in a mouse model. To investigate the candidacy of Î±-1,6-glucan as an alternative vaccine strategy we prepared glycoconjugates based on dextrans produced by lactic acid bacteria Leuconostoc mesenteroides B512F. The conjugates were immunogenic in both rabbits and mice and induced specific IgG responses against Î±-1,6-glucan-expressing H. pylori LPS. Future studies will focus on further development of H. pylori vaccine formulations, including the choice of carrier proteins and adjuvants.

A binary integer programming model for global optimization of learning path discovery - Belacel, Nabil; Durand, Guillaume; Laplante, François (EDM 2014 Extended Proceedings, 2014)
This paper introduces a method based on graph theory and operations research techniques to optimize learning path discovery. In this method, learning objects are considered as nodes and competencies as vertices of a learning graph. A first step consists in reducing the solution space by obtaining an induced subgraph H. In a second step, the search of an optimal learning path in H is considered as a binary integer programming problem which we propose to solve using an exact method based on the well-known branch-and-bound algorithm. The method detailed in the paper takes into account the prerequisite and gained competencies as constraints of the optimization problem by minimizing the total competencies needed to reach the learning objective.

Challenges to research in MOOCs - Fournier, Helene; Kop, Rita; Durand, Guillaume (MERLOT Journal of Online Learning and Teaching, 2014)
Over the past five years, the emergence of interactive social media has influenced the development of learning environments.Learning management systems have come to maturity, but because they are controlled by educational institutions and are subsequently used to support institutional learning, have been seen by learning technologists as not capturing the spirit and possibilities that new media have to offer for learning. Academics and researchers are currently investigating a different learning environment, more open and networked, while the underpinning learning theory is moving from social constructivism towards connectivism. Research in open learning environments is only in its infancy and researchers have only started to become interested in massive open online courses (MOOCs) as a topic of investigation. Recent research and development efforts have focused on generating technologies that might facilitate learning within a self-directed information and communication stream. In this paper, the authors report on an exploratory case study of PLENK, a connectivist-style MOOC, and highlight some of the challenges in the research and analysis process, especially as significant amounts of both quantitative and qualitative data were involved. Important findings related to activity levels and important dimensions of self-directed learning in an open learning environment are presented.
Keywords: massive open online courses; MOOCs; connectivist massive open online course; cMOOC; connectivism; activity level; learner motivation

Salmonella enterica serovar typhimurium productively infects human primary trophoblast cells and induces inflammatory cell death - Nguyen, Tina; Perry, Ian; Murphy, Shawn; Gruslin, Andree; Krishnan, Lakshmi (Placenta, 2014)
Salmonella enterica species are intracellular pathogens causative agents of gastroenteritis and typhoid fever in humans worldwide. Pregnancy poses an increased risk of severe Salmonellosis in many mammalian species contributing to miscarriage and maternal illness. Previous studies have indicated that Salmonella enterica Typhimurium (S. Tm) rapidly replicates within murine placenta leading to placental inflammation and death. Furthermore, IL-10 production by human choriocarcinoma trophoblast cells was shown to delay phagosomal maturation facilitating intracellular pathogen replication. The objective of this study was to evaluate the potential vulnerability of human primary trophoblast cells (TBCs) to S. Tm infection and elucidate the mechanism of cell death and inflammation.

Placental infection by Salmonella enterica typhimurium in a murine model : mechanisms of pathogenesis and role of inflammatory cell death - Wachholz, Kristina; Agbayani, Gerard; Nguyen, Tina; Gurnani, Komal; Krishnan, Lakshmi (Placenta, 2014)
Pregnancy confers increased susceptibility to intracellular infections such as Salmonella enterica serovar Typhimurium (S. Tm). S. Tm infection during pregnancy in normally resistant mice (129X1/SvJ with a fully functional Nramp gene) leads to rapid severe placental inflammation followed by fetal and maternal death. However, the immune mechanism of feto-maternal interface inflammation has not been fully elucidated. The objective of this study was to test the hypothesis that the mechanism of trophoblast (TBC) cell death following infection, contributes to feto-maternal inflammation and adverse effects on the mother and fetus.

Microarray analysis identifies pathways in progression of early stage lung adenocarcinoma: the importance of focal adhesion and ECM-receptor interactions - Douglas, Susan E.; Bethune, Drew C.; Xu, Zhaolin (Pulmonary Research and Respiratory Medicine, 2014)
Recurrence after lung cancer surgery is high, even among Non-Small Cell Lung Cancer (NSCLC) adenocarcinoma patients diagnosed early as Stage I, where there has been no spread to lymph nodes. Understanding the biological underpinnings of aggressivity and recurrence in this subset of tumours may enable the identification of patients who would benefit from adjuvant therapy. The purpose of this study was to identify differentially expressed molecular biomarkers that might underlie recurrence of Stage I tumours by comparing gene expression in later-stage tumours with those expressed in early-stage tumours. Gene expression in tissue biopsy samples from five Stage I and five Stage II/III NSCLC adenocarcinoma patients was analysed using an oligonucleotide microarray containing 17,000 probes printed in duplicate. Analyses were performed on total RNA isolated from tumour tissue of each patient using universal human RNA as a reference. Compared to normal tissues, the transcriptome of Stage I NSCLC adenocarcinomas showed enrichment in general pathways in cancer, whereas in Stage II/III more specific cancer pathways such as focal adhesion and ECM-receptor interaction pathways were enriched and components of the PPAR signalling pathway were depleted. Relative to early-stage NSCLC, Stage II/III adenocarcinomas showed up-regulation of genes of the basic transcriptional and translational machinery, particularly the “cancer testis antigen” PASD1 transcription factor. The actin cytoskeleton re-organisation and interleukin-6 pathways were also up-regulated whereas there was a generalized down-regulation of immune effectors and genes involved in immune system development. This small-scale transcriptome study provides important information about the pathways and molecules likely to be involved in the more metastatic propensity of those Stage I NSCLC adenocarcinomas that recur.
Keywords: Adenocarcinoma; Biomarkers; Microarray; Non-small cell lung cancer; Recurrence; Transcriptome

Field performance of low-shrinkage high-performance concrete deck at Canal Bridge in Cornwall, Ontario - Cusson, Daniel; Margeson, Jim; Hewus, Glenn (Proceedings of 9th International Conference on Short and Medium Span Bridges, 2014)

Staged failure mechanism of aged RC beam-columns subjected to corrosion loads using simplified nonlinear finite element model - Nohanned, A.M.; Almansour, H. (Structures Congress 2014, 2014)
An analysis approach to simulate the staged failure mechanism of corrosion-affected beam-column subjected to ultimate or seismic load using a simplified, non-linear, finite element model is proposed. The instantaneous axial and flexural rigidities at the sectional level are transferred to the element level, establishing the instantaneous structure stiffness at each load step. The approach efficiency and accuracy are verified through comparison with available experimental and analytical results. The proposed approach is numerically stable in all studied cases. It is found that the staged failure mechanism of the columns subjected to quasi-static load and cyclic load up to failure can be simulated with high accuracy. It is also found that corrosion-induced damage results in a large drop of the column load and displacement capacities, and a large shrinkage in the hysteretic relationship, which indicates similar drop in the energy absorption capacities of the beam-columns.
Keywords: ultimate capacity; seismic; corrosion; finite element method; nonlinear analysis; residual capacity

The intrinsic cysteine and histidine residues of the anti-Salmonella antibody Se155-4: a model for the introduction of new functions into antibody-binding sites - Young, N. Martin; Watson, David C.; Cunningham, Anna M.; Mackenzie, C. Roger (Protein Engineering Design and Selection, 2014)
New functions can be incorporated into anti-hapten or anti-protein antibodies by mutating selected residues in the binding-site region either to Cys, to allow alkylation with reagents bearing the desired functional groups, or to His, to create metal-binding sites or to make antigen binding pH-sensitive. However, choosing suitable sites for these mutations has been hampered by the lack of antibodies with these features, to serve as models. Remarkably, the anti-carbohydrate antibody Se155-4, specific for the Salmonella group B lipopolysaccharide, already has a Cys and two pairs of His residues close to the antigen-binding pocket in its structure, and shows pH-dependent antigen binding. We therefore investigated modification of its Cys94L in an scFv version of the antibody with the aims of creating a ‘reagentless’ fluorescent sensor and attaching a metal-binding group that might confer lyase activity. These groups were successfully introduced, as judged by mass spectrometry, and had only slightly reduced antigen binding in enzyme-linked immunosorbent assay. The fluorescent product was sensitive to addition of antigen in a solution format, unlike a modification of a more distant Cys introduced into the VH CDR4 loop. Two other routes to modulate antigen binding were also explored, metal binding by the His pair alongside the antigen-binding pocket and insertions into CDR4 to extend the antigen-contact area. His residues adjacent to the antigen-binding pocket bound copper, causing a 5-fold decrease in antigen binding. In CDR4 of the VH domain, the preferred insert length was four residues, which gave stable antigen-binding products but did not improve overall antigen affinity.
Keywords: binding-site modification; CDR4 loops; histidine and cysteine residues; metal affinity

Comparison of S-nitrosoglutathione- and staurosporine-induced apoptosis in human neural cells - Sodja, Caroline; Ribecco-Lutkiewicz, Maria; Haukenfrers, Julie; Merchant, Fahar; Costain, Willard J.; Bani-Yaghoub, Mahmud (Canadian Journal of Physiology and Pharmacology, 2014)
S-nitrosoglutathione (GSNO) is an endogenously produced S-nitrosylating compound that controls the function of various proteins. While a number of rodent cell lines have been used to study GSNO-induced apoptosis, the mechanisms of action remain to be evaluated in human cells and in parallel with other common apoptosis-inducing agents. In this study, we compared the pro-apoptotic effects of GSNO and staurosporine (STS) on human neural progenitors (NT2, hNP1) and neuroblasts (SH-SY5Y). We show that these cells exhibit comparable levels of susceptibility to GSNO- and STS-induced apoptotic cell death, as demonstrated by condensed nuclei and CASP3 activation. Mechanistic differences in apoptotic responses were observed as differential patterns of DNA fragmentation and levels of BAX, BCL-XL, CASP8, and p-ERK in response to GSNO and STS treatment. Mitochondrial membrane potential analysis revealed that NT2 and hNP1 cells, but not SH-SY5Y cells, undergo mitochondrial hyperpolarization in response to short-term exposure to STS prior to undergoing subsequent depolarization. This is the first study to report differences in apoptotic responses to GSNO and STS in 3 complementary human neural cell lines. Furthermore, these cells represent useful tools in cell pharmacological paradigms in which susceptibility to apoptosis-inducing agents needs to be assessed at different stages of neural cell fate commitment and differentiation.
Keywords: neural progenitors; caspase 3; caspase 8; BAX; BCL-XL; mitochondria; NT2; hNP1; SH-SY5Y

Small-molecule inhibitors of the pseudaminic acid biosynthetic pathway : targeting motility as a key bacterial virulence factor - Menard, Robert; Schoenhofen, Ian C.; Tao, Limei; Aubry, Annie; Bouchard, Patrice; Reid, Christopher W.; Lachance, Paul; Twine, Susan M.; Fulton, Kelly M.; Cui, Qizhi; Hogues, Hervé; Purisima, Enrico O.; et al. (Antimicrobial Agents and Chemotherapy, 2014)
Helicobacter pylori is motile by means of polar flagella, and this motility has been shown to play a critical role in pathogenicity. The major structural flagellin proteins have been shown to be glycosylated with the nonulosonate sugar, pseudaminic acid (Pse). This glycan is unique to microorganisms, and the process of flagellin glycosylation is required for H. pylori flagellar assembly and consequent motility. As such, the Pse biosynthetic pathway offers considerable potential as an antivirulence drug target, especially since motility is required for H. pylori colonization and persistence in the host. This report describes screening the five Pse biosynthetic enzymes for small-molecule inhibitors using both high-throughput screening (HTS) and in silico (virtual screening [VS]) approaches. Using a 100,000-compound library, 1,773 hits that exhibited a 40% threshold inhibition at a 10 μM concentration were identified by HTS. In addition, VS efforts using a 1.6-million compound library directed at two pathway enzymes identified 80 hits, 4 of which exhibited reasonable inhibition at a 10 μM concentration in vitro. Further secondary screening which identified 320 unique molecular structures or validated hits was performed. Following kinetic studies and structure-activity relationship (SAR) analysis of selected inhibitors from our refined list of 320 compounds, we demonstrated that three inhibitors with 50% inhibitory concentrations (IC50s) of approximately 14 μM, which belonged to a distinct chemical cluster, were able to penetrate the Gram-negative cell membrane and prevent formation of flagella.

High affinity anti-Internalin B VHH antibody fragments isolated from naturally and artificially immunized repertoires - Gene, Robert W.; Kumaran, Jyothi; Aroche, Cristina; van Faassen, Henk; Hall, J. Christopher; Mackenzie, C. Roger; Arbabi-Ghahroudi, Mehdi (Journal of Immunological Methods, 2014)
The need for rapid and easy technologies for the detection of food-borne and environmental pathogens is essential for safeguarding the health of populations. Furthermore, distribution of tainted food and water can have consequences which can affect whole economies. Antibodies and antibody fragments have been historically used in detection platforms due to their antigen specificity and robust physicochemical properties. In this study, we report the isolation and characterization of antibody fragments from the heavy chain antibody repertoire (VHH) of Camelidae which bind with specificity and high affinity to the Listeria monocytogenes invasin, Internalin B (InlB). To the best of our knowledge, this is the first report of anti-InlB VHHs from camelids. These anti-InlB VHHs were not cross-reactive to the structurally related Listeria invasin Internalin A (InlA) and are potential reagents to be used in the development of detection and medical technologies.
Keywords: Listeria; Camelid; Single-domain antibody; Phage display; ELISA; Surface plasmon resonance

The structure of the Morganella morganii lipopolysaccharide core region and identification of its genomic loci - Vinogradov, Evgeny; Nash, John H. E.; Foote, Simon; Young, N. Martin (Carbohydrate Research, 2014)
The core region of the lipopolysaccharide of Morganella morganii serotype O:1ab was obtained by hydrolysis of the LPS and studied by 2D NMR, ESI MS, and chemical methods. Its structure was highly homologous to those from the two major members of the same Proteeae tribe, Proteus mirabilis and Providencia alcalifaciens, and analysis of the M. morganii genome disclosed that the loci for its outer core, lipid A and Ara4N moieties are similarly conserved.
Keywords: Morganella morganii; LPS; Core; Carbohydrate gene loci

Particle quantification of influenza viruses by high performance liquid chromatography - Transfiguracion, Julia; Manceur, Aziza P.; Petiot, Emma; Thompson, Christine M.; Kamen, Amine A. (Vaccine, 2014)
The influenza virus continuously undergoes antigenic evolution requiring manufacturing, validation and release of new seasonal vaccine lots to match new circulating strains. Although current production processes are well established for manufacturing seasonal inactivated influenza vaccines, significant limitations have been underlined in the case of pandemic outbreaks. The World Health Organization called for a global pandemic influenza vaccine action plan including the development of new technologies. A rapid and reliable method for the quantification of influenza total particles is crucially needed to support the development, improvement and validation of novel influenza vaccine manufacturing platforms. This work presents the development of an ion exchange-high performance liquid chromatography method for the quantification of influenza virus particles. The method was developed using sucrose cushion purified influenza viruses A and B produced in HEK 293 suspension cell cultures. The virus was eluted in 1.5 M NaCl salt with 20 mM Tris–HCl and 0.01% Zwittergent at pH 8.0. It was detected by native fluorescence and the total analysis time was 13.5 min. A linear response range was established between 1 × 10^9 and 1 × 10^11 virus particle per ml (VP/ml) with a correlation coefficient greater than 0.99. The limit of detection was between 2.07 × 10^8 and 4.35 × 10^9 whereas the limit of quantification was between 6.90 × 10^8 and 1.45 × 10^10 VP/ml, respectively. The coefficient of variation of the intra- and inter-day precision of the method was less than 5% and 10%. HPLC data compared well with results obtained by electron microscopy, HA assay and with a virus counter, and was used to monitor virus concentrations in the supernatant obtained directly from the cell culture production vessels. The HPLC influenza virus analytical method can potentially be suitable as an in-process monitoring tool to accelerate the development of processes for the manufacturing of influenza vaccines.
Keywords: Influenza; HPLC; Quantification; Vaccine; Particle; Pandemic

Protective effects of glucose-6-phosphate dehydrogenase on neurotoxicity of aluminium applied into the CA1 sector of rat hippocampus - Jovanovic, Marina D.; Jelenkovic, Ankica; Stevanovic, Ivana D.; Bokonjic, Dubravko; Colic, Miodrag; Petronijevic, Natasa; Stanimirovic, Danica B. (Indian Journal of Medical Research, 2014)
Background & objectives: Aluminum (Al) toxicity is closely linked to the pathogenesis of Alzheimer's disease (AD). This experimental study was aimed to investigate the active avoidance behaviour of rats after intrahippocampal injection of Al, and biochemical and immunohistochemical changes in three bilateral brain structures namely, forebrain cortex (FBCx), hippocampus and basal forebrain (BF). Methods: Seven days after intra-hippocampal (CA1 sector) injection of AlCl 3 into adult male Wistar rats they were subjected to two-way active avoidance (AA) tests over five consecutive days. Control rats were treated with 0.9% w/v saline. The animals were decapitated on the day 12 post-injection. The activities of acetylcholinesterase (AChE) and glucose-6-phosphate dehydrogenase (G6PDH) were measured in the FBCx, hippocampus and BF. Immunohistochemical staining was performed for transferrin receptors, amyloid β and tau protein. Results: The activities of both AChE and G6PDH were found to be decreased bilaterally in the FBCx, hippocampus and basal forebrain compared to those of control rats. The number of correct AA responses was reduced by AlCl 3 treatment. G6PDH administered prior to AlCl 3 resulted in a reversal of the effects of AlCl 3 on both biochemical and behavioural parameters. Strong immunohistochemical staining of transferrin receptors was found bilaterally in the FBCx and the hippocampus in all three study groups. In addition, very strong amyloid β staining was detected bilaterally in all structures in AlCl 3 -treated rats but was moderate in G6PDH/AlCl 3 -treated rats. Strong tau staining was noted bilaterally in AlCl 3 -treated rats. In contrast, tau staining was only moderate in G6PDH/AlCl 3 -treated rats. Interpretation & conclusions: Our findings indicated that the G6PDH alleviated the signs of behavioural and biochemical effects of AlCl 3 -treatment suggesting its involvement in the pathogenesis of Al neurotoxicity and its potential therapeutic benefit. The present model could serve as a useful tool in AD investigations.
Keywords: active avoidance; aluminium; Alzheimer′s disease; brain; glucose-6-phosphate dehydrogenase; neurotoxicity

A novel platform for engineering blood-brain barrier-crossing bispecific biologics - Farrington, Graham K.; Caram-Salas, Nadia; Haqqani, Arsalan S.; Brunette, Eric; Eldredge, John; Pepinsky, Blake; Antognetti, Giovanna; Baumann, Ewa; Ding, Wen; Garber, Ellen; Jiang, Susan; Delaney, Christie; et al. (The FASEB Journal, 2014)
The blood-brain barrier (BBB) prevents the access of therapeutic antibodies to central nervous system (CNS) targets. The engineering of bispecific antibodies in which a therapeutic “arm” is combined with a BBB-transcytosing arm can significantly enhance their brain delivery. The BBB-permeable single-domain antibody FC5 was previously isolated by phenotypic panning of a naive llama single-domain antibody phage display library. In this study, FC5 was engineered as a mono- and bivalent fusion with the human Fc domain to optimize it as a modular brain delivery platform. In vitro studies demonstrated that the bivalent fusion of FC5 with Fc increased the rate of transcytosis (Papp) across brain endothelial monolayer by 25% compared with monovalent fusion. Up to a 30-fold enhanced apparent brain exposure (derived from serum and cerebrospinal fluid pharmacokinetic profiles) of FC5- compared with control domain antibody-Fc fusions after systemic dosing in rats was observed. Systemic pharmacological potency was evaluated in the Hargreaves model of inflammatory pain using the BBB-impermeable neuropeptides dalargin and neuropeptide Y chemically conjugated with FC5-Fc fusion proteins. Improved serum pharmacokinetics of Fc-fused FC5 contributed to a 60-fold increase in pharmacological potency compared with the single-domain version of FC5; bivalent and monovalent FC5 fusions with Fc exhibited similar systemic pharmacological potency. The study demonstrates that modular incorporation of FC5 as the BBB-carrier arm in bispecific antibodies or antibody-drug conjugates offers an avenue to develop pharmacologically active biotherapeutics for CNS indications.
Keywords: single-domain antibody; neuropeptides; drug delivery; blood-brain barrier

Blood–brain barrier models : in vitro to in vivo translation in preclinical development of CNS-targeting biotherapeutics - Stanimirovic, Danica B.; Bani-Yaghoub, Mahmud; Perkins, Martin; Haqqani, Arsalan S. (Expert Opinion on Drug Discovery, 2014)
The majority of therapeutics, small molecule or biologics, developed for the CNS do not penetrate the blood–brain barrier (BBB) sufficiently to induce pharmacologically meaningful effects on CNS targets. To improve the efficiency of CNS drug discovery, several in vitro models of the BBB have been used to aid early selection of molecules with CNS exposure potential. However, correlative studies suggest relatively poor predictability of in vitro BBB models underscoring the need to combine in vitro and in vivo BBB penetration assessment into an integrated preclinical workflow.
Keywords: biomarkers; blood–brain barrier; in vitro blood–brain barrier models; stem cells

Experimental determination of megavoltage electron beam k'R50 factors using water calorimetry - Renaud, J.; Sarfehnia, A.; Marchant, K.; McEwen, M.; Ross, C.; Seuntjens, J. (Radiotherapy and Oncology, 2014)
In this work, electron quality conversion factors, K'R50, for both a cylindrical ion chamber and a parallel plate ion chamber are measured for electron beam energies of 6, 9, 12, 16, and 20 MeV, using a water calorimeter. The photon-electron conversion factor, k ecal, for the cylindrical chamber is derived from calorimetry measurements in 60 Co. The purpose of this work is to experimentally verify the accuracy of values included in current dosimetry protocols.

Assessment of the metallicity of single-wall carbon nanotube ensembles at high purities - Finnie, Paul; Ding, Jianfu; Li, Zhao; Kingston, Christopher T. (The Journal of physical chemistry C, 2014)
The purity of single-wall carbon nanotube (SWCNT) ensembles is critical, but assessing the purity in terms of metal vs semiconductor content is challenging at high purities. We describe possible bulk Raman spectroscopy based procedures to assess this metallicity and compare it to absorption procedures. A simple metric for metallicity is the G+ band peak intensity ratio at two appropriate wavelengths. Related metallic G– band area derived metrics extend to higher purities. The G band signal scales linearly over orders of magnitude in concentration. However, the ratio-derived metrics may still be nonlinear because of resonance. Therefore, they break down if the tube diameter distributions differ greatly between samples, and other complications are possible. Additionally, the absolute Raman cross sections for each type of SWCNT can be estimated, and the abundance of semiconductors and metals can be tracked independently. Raman-derived metallicity figures of merit can meaningfully evaluate samples of purities which are not otherwise easily accessible, but there are important limitations to this simple approach to metallicity assessment.
Keywords: single-wall carbon nanotube (SWCNT); Raman spectroscopy; metallic G– band; higher purities

Further analysis of dynamic measurement function of electrical energy meter for type approval tests - Lu, Zuliang; So, Eddy; Li, Min; Wang, Lei; Huang, Hongtao; Liu, Lijuan (IEEE conference digest CPEM 2014, 2014)
The dynamic function of electrical energy meters is further analyzed and presented. It can be verified through a type approval. Test. The corresponding measurements and guidelines are discussed. Harmonic standards, and the sine modulated waveform can be used to verify the function.
Keywords: dynamic function; electrical energy meter; type approval; verification; uncertainty

The establishment of DC power meter calibration system at China Electric Power Research Institute - Bai, Jingfen; Liu, Fantao; Lu, Da; Song, Xiaohui; Zhao, Sha; Yu, Haibo; So, Eddy (2014 Conference on Precision Electromagnetic Measurements (CPEM 2014), 2014)
The establishment of a DC power meter calibration system using a DC current comparator and a synchronous sampling technique at China Electric Power Research Institute (CEPRI) is described. Measurements can be made at DC voltages ranging from lOmV to IOOOV, and DC currents from lOrnA to SOOA. The system features a synchronous voltage/current sampling system and a multi-ratio DC current comparator. The uncertainty of the DC power meter calibration system is estimated to be not more than 120 JJ.WIW. Furthermore, a comparison of DC power meter calibration systems between CEPRI and National Institute of Metrology China (NIMC) is discussed and presented.
Keywords: DC power; calibration system; DC current comparator; synchronous sampling

Speciation of organometals using a synchronizing GC-EIMS and GC-ICPMS system for simultaneous detection - D'Ulivo, Lucia; Yang, Lu; Feng, Yong-Lai; Murimboh, John; Mester, Zoltan (Journal of Analytical Atomic Spectrometry, 2014)
In analytical chemistry, improvement in instrument performances is always important for achieving better analytical results and obtaining more information on the target analytes. Gas chromatography-inductively coupled plasma mass spectrometry (GC-ICPMS), which combines powerful separation ability and high sensitivity, has found broad applications in sensitive speciation of organometals such as methylmercury (MeHg), butyltin (BuSn), and seleniomethionine (SeMet). Unfortunately, GC-ICPMS is unable to provide molecular information of the analytes such as molecular fragmentations or isotopic patterns, which are very important for identifying target analytes. A method is reported for the simultaneous determination of organometals including MeHg, dibutyltin (DBT), tributyltin (TBT) and SeMet using a unique interface with gas chromatography-electron ionization mass spectrometry (GC-EIMS) and GC-ICPMS systems synchronously. The method was validated with measurements of MeHg, DBT, TBT and SeMet in the certified reference materials (CRMs) including dogfish liver (DOLT-4), marine sediments (PACS-2) and selenium-enriched yeast (SELM-1). Compared with EIMS, ICPMS achieved a remarkable gain in sensitivity for MeHg, DBT and SeMet (19-, 130- and 2850-fold S/N gain, respectively). The concentrations of MeHg (1.335 ± 0.033 μg g−1), DBT (1.171 ± 0.005 μg g−1) and TBT (0.834 ± 0.003 μg g−1) obtained with isotope dilution are in agreement with the certified values of the corresponding CRMs. With the proposed method, the ICPMS system can provide higher precision and sensitivity, and the EIMS system can provide information on the molecular structure, which is essential for identification of target analytes.
Keywords: Synchronizing GC-MS/ICPMS system; Isotope dilution; Organometals; Sensitive speciation

Alberta fire code 2014 - National Research Council Canada. Construction (2014)
The Alberta Fire Code 2014 (AFC) sets out the technical provisions regulating: •activities related to the construction, use or demolition of buildings and facilities •the condition of specific elements of buildings and facilities •the design or construction of specific elements of facilities related to certain hazards •protection measures for the current or intended use of buildings.
Keywords: buidling; construction; code; fire

Alberta building code 2014 - National Research Council Canada. Construction (2014)
The Alberta Building Code 2014 (ABC) sets out technical provisions for the design and construction of new buildings. It also applies to the alteration, change of use and demolition of existing buildings. The ABC complements the Alberta Fire Code 2014, and both are indispensable for building officials, educators and professionals in the construction industry.
Keywords: buidling; construction; code

Sensitive determination of domoic acid in mussel tissue using dansyl chloride derivatization and liquid chromatography-mass spectrometry - Beach, Daniel G.; Liu, Hechun; Quilliam, Michael A. (Analytical methods, 2014)
This paper describes a new method for sensitive determination of domoic acid (DA), the causative toxin of amnesic shellfish poisoning (ASP), in shellfish. The method involves extraction of tissue homogenates with 50% methanol followed by a highly selective strong anion exchange solid phase extraction and a derivatization with dansyl chloride (DNS-Cl) to form the dansyl derivative of domoic acid (DNS-DA). Reaction times were very rapid and proceeded under ambient conditions to yield stable derivatives. A study of the collision-induced dissociation of ESI-produced protonated DNS-DA was carried out to identify the most sensitive transitions to use in development of a selected reaction monitoring detection method. Compared with un-derivatized DA, DNS-DA showed a 5-fold increase in sensitivity of MS/MS detection and improved retention on a reversed phase LC stationary phase. Resolution of DNS-DA and its isomers was achieved using isocratic elution in 15 min.

Bright photoluminescence from ordered arrays of SiGe nanowires grown on Si(111) - Lockwood, D.J.; Rowell, N.L.; Benkouider, A.; Ronda, A.; Favre, L.; Berbezier, I. (Beilstein journal of nanotechnology, 2014)
We report on the optical properties of SiGe nanowires (NWs) grown by molecular beam epitaxy (MBE) in ordered arrays on SiO2/ Si(111) substrates. The production method employs Au catalysts with self-limited sizes deposited in SiO2-free sites opened-up in the substrate by focused ion beam patterning for the preferential nucleation and growth of these well-organized NWs. The NWs thus produced have a diameter of 200 nm, a length of 200 nm, and a Ge concentration x = 0.15. Their photoluminescence (PL) spectra were measured at low temperatures (from 6 to 25 K) with excitation at 405 and 458 nm. There are four major features in the energy range of interest (980–1120 meV) at energies of 1040.7, 1082.8, 1092.5, and 1098.5 meV, which are assigned to the NW-transverse optic (TO) Si–Si mode, NW-transverse acoustic (TA), Si–substrate–TO and NW-no-phonon (NP) lines, respectively. From these results the NW TA and TO phonon energies are found to be 15.7 and 57.8 meV, respectively, which agree very well with the values expected for bulk Si1−xGex with x = 0.15, while the measured NW NP energy of 1099 meV would indicate a bulklike Ge concentration of x = 0.14. Both of these concentrations values, as determined from PL, are in agreement with the target value. The NWs are too large in diameter for a quantum confinement induced energy shift in the band gap. Nevertheless, NW PL is readily observed, indicating that efficient carrier recombination is occurring within the NWs.
Keywords: bandgap; germanium; nanowires; near field; silicon; photoluminescence

The inverse-square gamma-irradiation anomaly of the nuclear enterprise 2575 large-volume ionisation chamber - Bielajew, Alex F.; Tessier, Frederic; Gamal, Islam El (Radiation protection dosimetry, 2014)
The Nuclear Enterprises (Model 2575) 600 cc ionisation chamber is examined to discover the cause of its anomalous behaviour in inverse-square stability measurements. Measurements and Monte Carlo calculations are employed to isolate the cause of the discrepancy. It is found that most of the effect is due to the long photon attenuation pathlengths in the long side wall of the instrument. A phenomenological procedure, based on measurements, is proposed to correct for the anomaly. The procedure results in inverse-square stability to within 0.5% over a range of 1-7 meters.

Direct determination of Si isotope ratios in natural waters and commercial Si standards by ion exclusion chromatography multi-collector inductively coupled plasma mass spectrometry - Yang, Lu; Zhou, Lian; Hu, Zhaochu; Gao, Shan (Analytical chemistry, 2014)
Silicon isotope ratios in natural waters and several commercial Si standards were determined by on-line ion exclusion chromatography (IEC) multicollector inductively couple plasma mass spectrometry (MC-ICPMS). As recent studies have shown that mass-independent fractionation (MIF) also exists in MC-ICPMS itself, e.g., Nd, Ce, W, Sr, Ge, Hg and Pb isotopes, the nature of mass bias for Si isotopes was thus investigated. MIF was observed for Si isotopes on both Neptune and Neptune plus MC-ICPMS instruments in this study. Therefore, a standard-sample-standard bracketing (SSB) mass bias correction model which is capable of correcting both mass-dependent and mass-independent bias was employed to obtain accurate Si isotope ratio results in all samples by using NBS28 Si standard as the bracketing standard. Medium resolution was used for all measurements in order to resolve polyatomic interferences on Si isotopes. NBS28 Si standard solutions prepared in nutrient-free seawater and 0.1% NaOH matrix, respectively, were used for the method validation and subjected to the on-line IEC-MC-ICPMS determination ofSi isotope ratios. Values of -0.01±0.06 and 0.00±0.06 %o (lSD, n=IO); and -0.01±0.03 and 0.01±0.06 %o (lSD, n=IO) for J29128 Si and J30128 Si, respectively, were obtained, confirming accurate results can be obtained using the proposed method for natural waters.
Keywords: Si isotope ratio; multi-collector inductively coupled plasma mass spectrometry; Ion exclusion chromatography; mass bias; mass-independent fractionation; mass-dependent fractionation

Characterization of a 10V Programmable Josephson Voltage Standard and Comparison with a Hysteretic Josephson Standard - Granger, G.; Gertsvolf, M.; Wood, B.M. (CPEM 2014 special issue of IEEE Transactions on Instrumentation and Measurement, 2014)
A 10 V programmable Josephson voltage standard system has been installed at the National Research Council Canada. The current margins for the first Josephson step at either current polarity are greater than 1 mA. Measurements are made to establish the frequency offset and leakage resistance components of the uncertainty budget. Measurements are made to establish the frequency offset and leakage resistance components of the uncertainty budget...
Keywords: DC voltage; DC voltage calibration; Josephson junctions; programmable Josephson voltage standard; hysteretic Josephson voltage standard; Josephson system comparison; volt age measurements

A dual-channel calibration system for AC currents and small AC voltages - Djokic, Branislav (Instrumentation and Measurement, IEEE Transactions on, 2014)
A new current-comparator-based dual-channel calibration system for AC currents and AC voltages in the millivolt range has been developed. The range of generated currents is 1 rnA - 5 A, and the range of generated voltages is 1 mV- 500 mV. The calibration system in-phase and quadrature expanded measurement uncertainties (k=2) are within 25·10"6 Although the system has been developed primarily for operation at power frequencies, it is also capable of operating at frequencies up to 1000 Hz with slightly increased uncertainties. The traceability to SI units is established through the calibration of AC voltage by means of AC/DC transfer and DC voltage reference, standard resistor, capacitor, and current comparator ratios.
Keywords: Terms-AC voltage measurement; AC current measurement; current comparator; digital sampling; calibration; measurement uncertainty

An improved sampling approach to overcome transient effect in staircase waveform and its application - Lu, Zuliang; Yang, Yan; Huang, Lu; Wang, Lei; So, Eddy (2014 Conference on Precision Electromagnetic Measurements (CPEM 2014), 2014)
The advantage of the new sampling approach to overcome transient effect in staircase waveform is described. Based on this sampling approach, a general form is developed in this paper. In this form, more samples are used for calculations in the measurement. It provides a better basis to achieve a lower uncertainty as reduced noise impact and more information. A sine-wave experiment shows the advantage of the multi-point approach. When the more frequency components of the measured signal are asked, it faces a matter of unequal-interval sampling. It is found that the aliasing effect of sampling is solvable under the discussed condition. A novel method is developed to perform Fourier transform to extend application of Nyquist Theorem, in which the matrixes to solve the relative equation set are given out in the forms of digital and formula. Experiments for a non-sinusoidal wave validates that the higher frequency components can be analyzed, in which a differential sampling scheme is proposed.
Keywords: Terms-Differential measurement; digital-analog conversion; Transient effect; discrete Fourier transform; non-sinusoidal wave; Nyquist Theorem; sampling; staircase waveform; transient effect

Isolation, structural elucidation, relative LC-MS response, and in vitro toxicity of novel azaspiracids from azadinium spinosum - Kilcoyne, Jane; Nulty, Ciara; Jauffrais, Thierry; McCarron, Pearse; Herve, Fabienne; Foley, Barry; Rise, Frode; Crain, Sheila; Wilkins, Alistair L.; Twiner, Michael J.; Hess, Philipp; Miles, Christopher O. (Journal of natural products, 2014)
We identified three new azaspiracids (AZAs) with molecular weights of 715, 815, and 829 (AZA33 (3), AZA34 (4), and AZA35, respectively) in mussels, seawater, and Azadinium spinosum culture. Approximately 700 μg of 3 and 250 μg of 4 were isolated from a bulk culture of A. spinosum, and their structures determined by MS and NMR spectroscopy. These compounds differ significantly at the carboxyl end of the molecule from known AZA analogues and therefore provide valuable information on structure–activity relationships. Initial toxicological assessment was performed using an in vitro model system based on Jurkat T lymphocyte cytotoxicity, and the potencies of 3 and 4 were found to be 0.22- and 5.5-fold that of AZA1 (1), respectively. Thus, major changes in the carboxyl end of 1 resulted in significant changes in toxicity. In mussel extracts, 3 was detected at low levels, whereas 4 and AZA35 were detected only at extremely low levels or not at all. The structures of 3 and 4 are consistent with AZAs being biosynthetically assembled from the amino end.

Space charge evolution in polypropylene loaded with synthetic and natural nanoclay aged at 50 °C temperature - Abou-Dakka, Mahmoud; AtefGhunem, Refat; Mcintyre, Douglas (Electrical Insulation and Dielectric Phenomena (CEIDP), 2014 IEEE Conference on, 2014)
The evolution of space charges in Polypropylene (PP) filled with synthetic and natural nanoclay after aging with -25 kV/mm DC field under 50 °C were investigated. Following certain periods of aging, the space charge was measured by the PEA technique. The PP materials, bases for the two types of Polymer nanocomposites, i.e. PP were loaded with synthetic and natural nanoclay. The unfilled PP contains grafted maleic anhydride as compatibilizers. It was observed that the percentage amount of compatibilizers affects the charge distribution in the PP materials. The results indicated that aging with 50 °C temperature of the PNC with 2 and 4-wt% synthetic clay stocks high quantity of charges compared to the other filled materials. These two concentrations could not be optimal for aging under 50 °C. Insignificant accumulation of space charge and independent from aging time was observed for the PP loaded with 2-wt% of natural clay. This could be due to the smaller aspect ratio of natural nanoclay platelets compared to the synthetic nanoclay platelets. The clay platelets limit the molecular motion in the amorphous phase due to the interaction between the platelets and PP matrix. But, more work is required to investigate the effect of the percentage of compatibilizers on the charge accumulation property. Highly doped PNCs like the PP1-S8% and PP2-N6% can enhance overlapping of the diffuse double layer charge clouds around nanoparticles and promote movement of space charges, thereby leading to a sharp increase of the conductivity of PNCs.

A current-comparator-based high voltage R-L-C bridge - So, Eddy; Bennett, David (2014 Conference on Precision Electromagnetic Measurements (CPEM 2014), 2014)
The development of a current-comparator-based high-voltage impedance bridge at the National Research Council of Canada (NRC) for the accurate measurements of high-voltage resistive (R), Inductive (L), and capacitive (C) impedances is described. The bridge has ratio uncertainties of les than 10 x 10-6 in both magnitude and phase.
Keywords: terms-accurate measurements; current-comparator-based bridge; high voltage; impedance; resistive; uncertainty

Analysis of β-N-methylamino-L-alanine (BMAA) in spirulina-containing supplements by liquid chromatography-tandem mass spectrometry - McCarron, Pearse; Loganb, Alan C.; Giddings, Sabrina; Quilliama, Michael A. (Aquatic biosystems, 2014)
Over the last decade the amino acid P-N-methylamino-L-alanine (BMAA) has come under intense scrutiny. International laboratory and epidemiological research continues to support the hypothesis that environmental exposure to BMAA (e.g., through dietary practices, water supply) can promote the risk of various neurodegenenitive diseases. A wide variety of cyanobacteria spp. have previously been reported to produce BMAA, with production levels dependent upon species, strain and environmental conditions. Since spirulina (Arthrospira spp.) is a member of the cyanobacteria phylum frequently consumed via dietary supplements, the presence ofBMAA in such products may have public health implications. In the current work, we have analyzed ten spirulina-containing samples for the presence ofBMAA; six pure spirulina samples from two separate raw materials suppliers, and four commercially-available multi-ingredient products containing 1.45 grams of spirulina per serving. Because·of controversy surrounding the measurement of BMAA, we have used two complementary liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods: one based on reversed phase LC (RPLC) with derivatization and the other based on hydrophilic interaction LC (HILIC). Potential matrix effects were corrected for by internal standardization using a stable isotope labeled BMAA standard. BMAA was not detected at low limits of detection (80 ng/g dry weight) in any of these the product samples. Although these results are reassuring, BMAA analyses should be conducted on a wider sample selection and, perhaps, as part of ongoing spirulina production quality control testing and specifications.

A reference system for on-site calibration of high-voltage revenue metering systems - Rietveld, Gert; Fransen, Martin; Blanc, Nicolas; Houtzager, Ernest; So, Eddy (2014 Conference on Electromagnetic Measurements (CPEM 2014), 2014)
A reference setup for on-site calibration and validation of revenue metering systems is realized. The system consists of a three-phase power meter and high-accuracy current and voltage transformers (CTs and VTs). Measurements can be made up to 150 kV (system voltage) and line currents up to 5000 A. The power meter, the CTs, and the VTs were all calibrated. Based on the excellent results of the calibration of these components it is possible to predict the full system performance with an accuracy of 35 J.lWNA. This estimation was verified with a full system validation, showing that the system is much more accurate than required and that detrimental effects to the accuracy are well understood.
Keywords: power, revenue metering, billing, traceability, substation, high voltage (HV), high current, current transformer, voltage transformer, power meter, precision measurements

Experimental determination of the differential scalar polarizability of the 88Sr+ clock transition - Dube, Pierre; Madej, Alan A.; Tibbot, Maria; Bernard, John E. (2014 IEEE International Frequency Control Symposium proceedings, 2014)
We present preliminary results on a method used to determine the differential scalar polarizability Aao of the clock transition of the 88Sr+ ion optical frequency standard. The method is based on the relation that exists between Aao and the trap frequency 00 at which the micromotion shifts cancel. Aa0 is important not only for cancellation of the micromotion shifts but also for the evaluation of the blackbody radiation shift. The decrease in the uncertainty of Aa0 obtained reduces the evaluated blackbody radiation shift uncertainty of the NRC 88Sr+ ion to the 1x 10-11 level.
Keywords: scalar polarizability; clock transition

Traceability of impulse test for diagnostic measurements of power apparatus - Hanique, Ernst; So, Eddy (2014 Conference on Precision Electromagnetic Measurements (CPEM 2014), 2014)
This paper describes the diagnostic measurements involved while performing impulse tests. For most applications during impulse tests, the impulse voltage and impulse current are measured. Because of the nature of impulse test it is very common that Electro Magnetic Interference signals (EMI) are generated. This EMI will influence the measurement. Therefore these tests are done in well-shielded high voltage laboratories. Also the relevant sensors e.g. voltage dividers, current shunts and other components used for the measurements, including traceability issues, will be discussed in this paper.
Keywords: divider; electro mechanical compatibility; impulse; measurement; shunt and uncertainty

Tailoring biomass-derived carbon nanoarchitectures for high-performance supercapacitors - Wang, Huanlei; Li, Zhi; Mitlin, David (ChemElectroChem, 2014)
Supercapacitors are attracting intense scientific attention as they can bridge the energy-power gap between commercial batteries and electrolytic capacitors. High-surface area activated carbon remains the electrode material of choice for commercial systems due to the inherently lower cost relative to the more exotic alternatives such as graphene, carbon nanotubes, or their hybrids. However, activated carbon possesses an inferior electrochemical performance relative to these more open and electrically conductive structures. This limits its feasibility as electrodes for future high-performance devices. In this concept paper we summarized two case studies of creating unique biomass-derived carbons by preserving the precursors’ intrinsic structure or transforming the precursor structure into graphene-like materials that actually demonstrate electrochemical performance on par with, or even better than, their much costlier alternatives.
Keywords: biomass; carbon; electrochemistry; energy storage; supercapacitors

Unlocking the potential energy savings from shorter time delay occupancy sensors - Dikel, Erhan E.; Newsham, G. R. (LD+A Magazine, 2014)
Linking occupancy sensors to switches or dimmers is a well-established strategy yielding substantial lighting energy savings. Indeed the technology is considered proven enough that it is now mandated for many space types in most commercial buildings via all major energy codes. Current codes typically require a maximum 30-minute timeout or delay following the last detected occupancy before switching lights off. New codes may reduce this timeout to 20 minutes, promising more savings. It has been long recognized that reducing timeouts further, to 5 minutes or less, will deliver even greater savings [1, 2]. So, why aren’t energy codes more aggressive in mandating shorter timeouts? There are two principal answers to this: (1) prevailing sensor technology is not reliable enough to detect occupancy at such short timescales; (2) even if the sensors were reliable, shorter timeouts would mean more frequent switching, potentially reducing the lifetime of fluorescent lamps to an uneconomical degree. In this article we re-evaluate the potential energy savings of shorter timeout periods with two datasets, and discuss how such timeouts might be viable with LED technology.
Keywords: lighting; occupancy sensors; energy savings

Supplement to the NECB 2011 : Intent Statements - Canadian Commission on Building and Fire Codes, National Research Council of Canada and Natural Resources Canada (2014)
Keywords: Codes and guides

User’s Guide: National Energy Code of Canada for Buildings 2011 - Canadian Commission on Building and Fire Codes, National Research Council Canada (National Research Council Canada, 2014)
This first edition of the User’s Guide to the National Energy Code of Canada for Buildings 2011 (NECB) is designed to complement the National Energy Code of Canada for Buildings 2011 (NECB) by providing additional background information as well as detailed examples and calculations. It describes the various compliance approaches in the NECB and presents examples of trade-off path calculations. The User’s Guide is an ideal training tool for educators and trainers and features checklists at the end of each Part to help designers verify that provisions in the NECB have been considered in their design. Code users familiar with the useful explanatory material in the appendices of the Model National Energy Code of Canada for Buildings 1997 (MNECB) will note that much of this material has been updated in the new User’s Guide and augmented with additional examples and information. This material includes calculation examples for thermal properties of building assemblies.
Keywords: Codes and guides

Guide illustré de l’utilisateur - CNB 2010 maisons et petits bâtiments (partie 9) - Commission canadienne des codes du bâtiment et de prévention des incendies, Conseil national de recherches Canada (Code national du bâtiment; nº partie 9, 2014)
Ce Guide de l’utilisateur combine deux publications antérieures, soit le Code national de construction de maisons et Guide illustré – Canada 1998 et le Guide de l'utilisateur – CNB 1995, Maisons et petits bâtiments (Partie 9), en un document complet qui décrit diverses méthodes de conformité, y compris des exemples et des formules à l’appui. Afin de faciliter la navigation, on a réorganisé le Guide de l’utilisateur afin que sa présentation corresponde à celle utilisée dans la partie 9 du Code national du bâtiment (CNB). Ce Guide illustré de l’utilisateur présente de nouvelles informations sur les exigences relatives à l’efficacité énergétique des maisons et des petits bâtiments et comprend des mises à jour visant à assurer l’uniformité avec les dispositions qui ont été modifiées ou introduites dans les éditions 2005 et 2010 du CNB. Le Guide de l’utilisateur illustre les principes essentiels des pratiques minimales reconnues et explique les motifs et le contexte scientifique des exigences de la partie 9. Bien que ce guide ne soit pas un guide pratique sur la construction des maisons, des renseignements pertinents tirés des codes y sont incorporés par renvoi et des sources statistiques y sont fournies.
Keywords: efficacité énergétique; maison; bâtiment

Illustrated user’s guide - NBC 2010 part 9 housing and small buildings - Canadian Commission on Building and Fire Codes, National Research Council Canada (National Building Code of Canada; no. part 9, 2014)
This User’s Guide combines two earlier publications, the National Housing Code of Canada 1998 and Illustrated Guide and the User’s Guide – NBC 1995 Housing and Small Buildings (Part 9), into one comprehensive document that describes various compliance approaches, including examples and supporting formulas. To facilitate navigation, the User’s Guide has been reorganized to match the format used in Part 9 of the National Building Code of Canada (NBC). This illustrated User's Guide features new material on energy efficiency requirements for housing and small buildings and includes updates to match the provisions that were changed or introduced in the 2005 and 2010 editions of the NBC. The User’s Guide illustrates important principles of minimum accepted practice and explains the reasons and scientific background behind the Part 9 requirements. This is not a how-to guide on home construction; however, relevant code information is cross-referenced and statistical sources are provided.
Keywords: energy efficiency; building; construction

NRCC experiments for ASTM E57 medium-range measurement error standards development - MacKinnon, David Kenneth; Cournoyer, Luc (Journal of the CMSC, 2014)
Adoption of 3D imaging systems is on the rise with the global market expected to exceed $450 million by 2016. An increasing number of users are expected to invest in high-accuracy/high-speed non-contact systems as their claimed performance approaches the claimed performance of tactile probing systems, particularly as the cost of non-contact systems has decreased significantly. To address the lack of published standards for 3D imaging systems, the National Research Council of Canada (NRCC) has been working closely with NIST on the ASTM E57 committee to develop two standards to evaluate the performance of medium-range (2 to 150 m) LiDAR systems. We present an overview of work completed to date by the WK12373 (Relative Range Error) and WK431218 (Volumetric Error) working groups and, in particular, present the results of experiments conducted at the NRCC in support of this work.

A methodology for creating large scale reference models with known uncertainty for evaluating imaging solution - Drouin, Marc-Antoine; Beraldin, Jean-Angelo; Cournoyer, Luc; MacKinnon, David; Borgeat, Louis; Godin, Guy; Fournier, Jonathan (2014 2nd International Conference on 3D Vision, 2014)
We propose a methodology for acquiring reference models with known uncertainty of complex building-sized objects. Those can be used to quantitatively evaluate the performance of passive 3D reconstruction when working at large scale. The proposed methodology combines the use of a time-of-flight scanner, a laser tracker, spherical artifacts and contrast targets. To demonstrate the soundness of the proposed approach, we built a reference model composed of a 3D model of exterior walls and courtyards of a 130m X 55m X 20m Building. The expanded uncertainty of the 3D reference model and the spatial resolution were calculated.

Uptake and depuration of gold nanoparticles in Daphnia magna - Skjolding, L. M.; Kern, K.; Hjorth, R.; Hartmann, N.; Overgaard, S.; Ma, G.; Veinot, J. G. C.; Baun, A. (Ecotoxicology, 2014)
This study presents a series of short-term studies (total duration 48 h) of uptake and depuration of engineered nanoparticles (ENP) in neonate Daphnia magna. Gold nanoparticles (Au NP) were used to study the influence of size, stabilizing agent and feeding on uptake and depuration kinetics and animal body burdens. 10 and 30 nm Au NP with different stabilizing agents [citrate (CIT) and mercaptoundecanoic acid (MUDA)] were tested in concentrations around 0.5 mg Au/L. Fast initial uptake was observed for all studied Au NP, with CIT stabilized Au NP showing similar rates independent of size and MUDA showing increased uptake for the smaller Au NP (MUDA 10 nm > CIT 10 nm, 30 nm > MUDA 30 nm). However, upon transfer to clean media no clear trend on depuration rates was found in terms of stabilizing agent or size. Independent of stabilizing agent, 10 nm Au NP resulted in higher residual whole-animal body burdens after 24 h depuration than 30 nm Au NP with residual body burdens about one order of magnitude higher of animals exposed to 10 nm Au NP. The presence of food (P. subcapitata) did not significantly affect the body burden after 24 h of exposure, but depuration was increased. While food addition is not necessary to ensure D. magna survival in the presented short-term test design, the influence of food on uptake and depuration kinetics is essential to consider in long term studies of ENP where food addition is necessary. This study demonstrates the feasibility of a short-term test design to assess the uptake and depuration of ENP in D. magna. The findings underlines that the assumptions behind the traditional way of quantifying bioconcentration are not fulfilled when ENPs are studied.
Keywords: Kinetics; Feeding; Size; Test design; Au

Enhanced image processing and archiving capabilities of magneto-optical imaging for non-destructive evaluation - Genest, Marc; Mandache, Catalin (International Journal of Applied Electromagnetics and Mechanics, 2014)
In its current state, the wide acceptance of the Magneto-Optical Imaging (MOI) technique is hindered due to noise, lack of recordable results, and impossibility of data post-processing. This paper presents some add-ons made to a commercial MOI system to ease the image interpretation, archiving and reporting of the results. In addition, a few image processing techniques are also employed in an attempt to perform automatic flaw detection. The recording capability of the MOI instrument output images was addressed by digitizing the video signal in video or image files. To help with the identification of the damage location and distance between images, a rotary quadrature encoder was mounted onto the MOI scan head. The use of the encoder allowed the identification of the inspection location with respect to a reference position, such as the beginning of the scan. Moreover, it allowed saving images at fixed intervals, which were then stitched into a single image, thus simplifying the post inspection analysis process. Both live and post-inspection image processing capabilities were made available. Implemented image processing included background subtraction, de-noising, contrast adjustment and morphological operation, among others. Contrast stretching transform and background subtractions were found to be among the most powerful techniques that could be used in simplifying the image interpretation.
Keywords: Magneto-optical imaging; Non destructive evaluation; Image processing

Quantification of residual strain associated with reduction of hot tears by grain refinement in B206 aluminium alloy - D'Elia, F.; Ravindran, C.; Sediako, D. (Canadian Metallurgical Quarterly, 2014)
Hot tearing continues to limit the industrial use of many aluminium casting alloys. The hot tearing susceptibility of an alloy is influenced by microstructure, solidification rate and the stress/strain conditions it experiences during solidification. In this study, a novel technique was used to quantify the residual strain associated with hot tearing in B206 aluminium alloy. Neutron diffraction strain mapping was carried out on three B206 castings with varying levels of titanium (i.e. unrefined, 0·02 and 0·05 wt-%). Titanium additions were effective in causing grain refinement of the alloy and eliminating hot tears. Neutron diffraction strain mapping was successfully used to demonstrate more uniform distribution of strain in the casting, resulting from grain refinement with consequent higher resistance to hot tearing.
Keywords: Grain refinement; Neutron diffraction; Hot tearing; B206 aluminium alloy; Residual strain

The morphological transformation of red sequence galaxies in the distant cluster XMMU J1229+0151 - Cerulo, P.; Couch, W. J.; Lidman, C.; Delaye, L.; Demarco, R.; Huertas-Company, M.; Mei, S.; Sánchez-Janssen, R. (Monthly Notices of the Royal Astronomical Society, 2014)
We present the results of a detailed analysis of galaxy properties along the red sequence in XMMU J1229+0151, an X-ray selected cluster at z = 0.98 drawn from the High AcuityWide field K-band Imager Cluster Survey. Taking advantage of the broad photometric coverage and the availability of 77 spectra in the cluster field, we fit synthetic spectral energy distributions, and estimate stellar masses and photometric redshifts, which we use to determine the cluster membership. We investigate morphological and structural properties of red sequence galaxies and find that elliptical galaxies populate the bright end, while S0 galaxies represent the predominant population at intermediate luminosities, with their fraction decreasing at fainter magnitudes. A comparison with the low-redshift sample of the Wide Field Nearby Galaxyclusters Survey cluster survey reveals that at z̃1 the bright end of the red sequence ofXMMU J1229+0151 is richer in S0 galaxies. The faint end of the red sequence inXMMUJ1229+0151 appears rich in disc-dominated galaxies, which are rarer in the low-redshift comparison sample at the same luminosities. Despite these differences between the morphological composition of the red sequence in XMMU J1229+0151 and in low-redshift samples, we find that to within the uncertainties, no such difference exists in the ratio of luminous to faint galaxies along the red sequence.
Keywords: galaxies: clusters: individual: XMMU J1229+0151; galaxies: elliptical and lenticular, cD; galaxies: evolution; galaxies: high redshift; galaxies: spiral

Inductive and solid-state sensing of pulsed eddy current : a comparative study - Mandache, Catalin (International Journal of Applied Electromagnetics and Mechanics, 2014)
In recent years, solid-state devices made their way in the development of electromagnetic non-destructive evaluation (NDE) probes. This fact was evidenced especially for pulsed eddy current, where magneto-resistive and Hall effect devices are used as sensing elements. Their low frequency range and small surface area are suitable to improve the detection of buried and small discontinuities. Although their properties are expected to enhance detectability over simple induction coils, this was still to be proven or demonstrated in a comparative study. This work compares the sensing capabilities of an induction coil to those of two solid-state devices: giant-magneto-resistive (GMR) and Hall effect sensors. All of them are used as detectors in pulsed eddy current probes that have the same excitation mechanism, a ring-type copper coil driven by a constant amplitude square waveform. While the excitation part of the probe is fixed, the sensing components are inter-changeable. Although both induction coils and solid-state sensors output a voltage value as an indication of the magnetic field they are detecting, the voltage for pick-up coils is directly proportional to the rate of change of the magnetic flux. For solid-state sensors the output is in direct relation to the detected magnetic field. Under this study, all three sensing elements are used to detect the driving coil's magnetic output (magnetic field or flux) in air, on planes perpendicular and parallel to the face of the driver coil. The results obtained by all three sensors are quantitatively compared. Then the sensing devices are inserted in the inner space of the driving coil and, subsequently, used for detection of artificially made defects. Finally, the results are compared in terms of magnetic field sensitivity and inspection performance.
Keywords: Comparative studies; Magnetic sensing; Non destructive evaluation; Pulsed eddy current

The origin of ionized filaments within the Orion-Eridanus superbubble - Pon, Andy; Johnstone, Doug; Bally, John; Heiles, Carl (Monthly Notices of the Royal Astronomical Society, 2014)
The Orion-Eridanus superbubble, formed by the nearby Orion high-mass star-forming region, contains multiple bright Ha filaments on the Eridanus side of the superbubble. We examine the implications of the Hα brightnesses and sizes of these filaments, the Eridanus filaments. We find that either the filaments must be highly elongated along the line of sight or they cannot be equilibrium structures illuminated solely by the Orion star-forming region. The Eridanus filaments may, instead, have formed when the Orion-Eridanus superbubble encountered and compressed a pre-existing, ionized gas cloud, such that the filaments are nowout of equilibrium and slowly recombining.
Keywords: ISM: bubble; ISM: cloud; ISM: individual objects: Eridanus filments; ISM: individual objects: Orion-Eridanus superbubble; ISM: structu

An analytical model for vortex core pinning in a micromagnetic disk - Burgess, J. A. J.; Losby, J. E.; Freeman, M. R. (Journal of Magnetism and Magnetic Materials, 2014)
A two-parameter analytical model is constructed to describe a thin, magnetically soft, circular disk in the vortex state. The model is capable of describing the change in evolution of net magnetization and of vortex core position when the core interacts with a magnetic pinning site. The basis of the two-parameter model is formed by a piecewise, physically continuous, magnetization distribution constructed with two regions described by different one-parameter models. Benchmarking against numerical simulations of ideal disks with and without pinning sites shows that the model provides accurate predictions of magnetization, hysteretic transitions, and 2-D displacement of the vortex core in the presence of pinning sites. The demonstrated accuracy of the model supports its use as an empirical tool to extract quantitative maps of vortex pinning energies from measurements of magnetization.
Keywords: Magnetic vortex; Micromagnetic modeling; Pinning

Effect of miss-alignment on residual stress in carbon steel socket welded joint - Hayashi, Makoto; Root, John H. (Zairyo/Journal of the Society of Materials Science, Japan, 2014)
Residual stress remarkably affects the fatigue strength of welded socket joint. In carbon and austenitic stainless steel the fatigue strength of socket welded joint is about half of base metal. This is caused by the high tensile residual stress at the root of socked weld. In this study the variation of residual stress distribution near the weld start and end points, effects of miss-alignment on the residual stress distribution and the principal strain and stress were examined using the neutron diffraction method. As a result, the effects of miss-alignment are negligibly small and the residual stress at the weld root is almost the same with that of normally welded joint. The deviations of principal axes from the specimen directions are not so much large and the principal stresses almost agree with those of specimen axes.
Keywords: Neutron diffraction; Residual stress; Socket weld; Carbon steel

Magnolol causes alterations in the cell cycle in androgen insensitive human prostate cancer cells in vitro by affecting expression of key cell cycle regulatory proteins - McKeown, Brendan T.; McDougall, Luke; Catalli, Adriana; Hurta, Robert A. R. (Nutrition and Cancer, 2014)
Prostate cancer, one of the most common cancers in the Western world, affects many men worldwide. This study investigated the effects of magnolol, a compound found in the roots and bark of the magnolia tree Magnolia officinalis, on the behavior of 2 androgen insensitive human prostate cancer cell lines, DU145 and PC3, in vitro. Magnolol, in a 24-h exposure at 40 and 80 M, was found to be cytotoxic to cells. Magnolol also affected cell cycle progression of DU145 and PC3 cells, resulting in alterations to the cell cycle and subsequently decreasing the proportion of cells entering the G2/M-phase of the cell cycle. Magnolol inhibited the expression of cell cycle regulatory proteins including cyclins A, B1, D1, and E, as well as CDK2 and CDK4. Protein expression levels of pRBp107 decreased and pRBp130 protein expression levels increased in response to magnolol exposure, whereas p16INK4a, p21, and p27 protein expression levels were apparently unchanged post 24-h exposure. Magnolol exposure at 6 h did increase p27 protein expression levels. This study has demonstrated that magnolol can alter the behavior of androgen insensitive human prostate cancer cells in vitro and suggests that magnolol may have potential as a novel anti-prostate cancer agent.

A Chandra-Swift view of point sources in Hickson compact groups : high agn fraction but a dearth of strong AGNs - Tzanavaris, P.; Gallagher, S. C.; Hornschemeier, A. E.; Fedotov, K.; Eracleous, M.; Brandt, W. N.; Desjardins, T. D.; Charlton, J. C.; Gronwall, C. (Astrophysical Journal, Supplement Series, 2014)
We present Chandra X-ray point source catalogs for 9 Hickson Compact Groups (HCGs, 37 galaxies) at distances of 34-89 Mpc. We perform detailed X-ray point source detection and photometry and interpret the point source population by means of simulated hardness ratios. We thus estimate X-ray luminosities (Lx ) for all sources, most of which are too weak for reliable spectral fitting. For all sources, we provide catalogs with counts, count rates, power-law indices (Γ), hardness ratios, and Lx , in the full (0.5-8.0 keV), soft (0.5-2.0 keV), and hard (2.0-8.0 keV) bands. We use optical emission-line ratios from the literature to re-classify 24 galaxies as star-forming, accreting onto a supermassive black hole (AGNs), transition objects, or low-ionization nuclear emission regions. Two-thirds of our galaxies have nuclear X-ray sources with Swift/UVOT counterparts. Two nuclei have L x, 0.5-8.0 keV >10^42 erg s-1, are strong multi-wavelength active galactic nuclei (AGNs), and follow the known αOX-νL ν (nearUV) correlation for strong AGNs. Otherwise, most nuclei are X-ray faint, consistent with either a low-luminosity AGN or a nuclear X-ray binary population, and fall in the "non-AGN locus" in αOX-νL ν (nearUV) space, which also hosts other normal galaxies. Our results suggest that HCG X-ray nuclei in high specific star formation rate spiral galaxies are likely dominated by star formation, while those with low specific star formation rates in earlier types likely harbor a weak AGN. The AGN fraction in HCG galaxies with MR ≤ -20 and L x, 0.5-8.0 keV ≥10^41 erg s-1 is 0.08 +0.035/-0.01, somewhat higher than the 5% fraction in galaxy clusters.
Keywords: catalogs; galaxies: active; galaxies: nuclei; ultraviolet: galaxies; X-rays: galaxies

A dynamical model of the local cosmic expansion - Peñarrubia, Jorge; Ma, Yin-Zhe; Walker, Matthew G.; McConnachie, Alan (Monthly Notices of the Royal Astronomical Society, 2014)
We combine the equations of motion that govern the dynamics of galaxies in the local volume with Bayesian techniques in order to fit orbits to published distances and velocities of galaxies within 3 Mpc. We find a Local Group (LG) mass 2.3 ± 0.7 × 10^12 M⊙ that is consistent with the combined dynamical masses of M31 and the Milky Way, and a mass ratio 0.54+0.23 -0.17 that rules out models where our Galaxy is more massive than M31 with ~95 per cent confidence. The MilkyWay's circular velocity at the solar radius is relatively high, 245±23 km s-1, which helps to reconcile the mass derived from the local Hubble flow with the larger value suggested by the 'timing argument'. Adopting Planck's bounds on ΩΛ yields a (local) Hubble constant H0 = 67 ± 5 kms-1 Mpc-1 which is consistent with the value found on cosmological scales. Restricted N-body experiments show that substructures tend to fall on to the LG along the Milky Way-M31 axis, where the quadrupole attraction is maximum. Tests against mock data indicate that neglecting this effect slightly overestimates the LG mass without biasing the rest of model parameters.We also show that both the time dependence of the LG potential and the cosmological constant have little impact on the observed local Hubble flow.
Keywords: Galaxy: fundamental parameters; Galaxy: kinematics and dynamics; Local Group; cosmological parameters; dark energy; dark matter

Optical and near-infrared UBVRIJHK photometry for the RR Lyrae stars in the nearby globular cluster M4 (NGC 6121) - Stetson, P. B.; Braga, V. F.; Dall'Ora, M.; Bono, G.; Buonanno, R.; Ferraro, I.; Iannicola, G.; Marengo, M.; Neeley, J. (Publications of the Astronomical Society of the Pacific, 2014)
We present optical and near-infrared UBVRIJHK photometry of stars in the Galactic globular cluster M4 (NGC 6121) based upon a large corpus of observations obtained mainly from public astronomical archives. We concentrate on the RR Lyrae variable stars in the cluster, and make a particular effort to accurately reidentify the previously discovered variables. We have also discovered two new probable RR Lyrae variables in the M4 field: one of them by its position on the sky and its photometric properties is a probable member of the cluster, and the second is a probable background (bulge?) object. We provide accurate equatorial coordinates for all 47 stars identified as RR Lyraes, new photometric measurements for 46 of them, and new period estimates for 45.We have also derived accurate positions and mean photometry for 34 more stars previously identified as variable stars of other types, and for an additional five non-RR Lyrae variable stars identified for the first time here. We present optical and near-infrared color-magnitude diagrams for the cluster and show the locations of the variable stars in them. We present the Bailey (period-amplitude) diagrams and the period-frequency histogram for the RR Lyrae stars in M4 and compare them to the corresponding diagrams for M5 (NGC 5904). We conclude that the RR Lyrae populations in the two clusters are quite similar in all the relevant properties that we have considered. The mean periods, pulsation-mode ratios, and Bailey diagrams of these two clusters show support for the recently proposed "Oosterhoff-neutral" classification.

In situ magnetic resonance imaging of plant roots - Gruwel, Marco L. H. (Vadose Zone Journal, 2014)
Visualization of the root system architecture of plants is possible using a combination of magnetic resonance imaging of water mobility and trac-tography. Diffusion tensor imaging (DTI), a magnetic resonance application, was used to provide a three-dimensional map of water mobility inside a pot containing soil and roots. Tractography generates channels that constitute pathways of facilitated water movement, representing the roots, calculated from water diffusion properties obtained from DTI experiments. Examples of pea (Pisum sativum L.) and corn [Zea mays L. var. indentata (Sturtev.) L.H. Bailey] root growth are provided.
Keywords: Diffusion tensor imaging; Plants (botany); Tensors; Pisum sativum; Root growth; Root system; Three-dimensional maps; Tractography; Water diffusion; Water mobility; Water movements; Magnetic resonance imaging; diffusion; maize; movement; plant; research; root architecture; root system; visualization; water

Dissipative and dispersive optomechanics in a nanocavity torque sensor - Wu, Marcelo; Hryciw, Aaron C.; Healey, Chris; Lake, David P.; Jayakumar, Harishankar; Freeman, Mark R.; Davis, John P.; Barclay, Paul E. (Physical Review X, 2014)
Dissipative and dispersive optomechanical couplings are experimentally observed in a photonic crystal split-beam nanocavity optimized for detecting nanoscale sources of torque. Dissipative coupling of up to approximately 500 MHz/nm and dispersive coupling of 2 GHz/nm enable measurements of sub-pg torsional and cantileverlike mechanical resonances with a thermally limited torque detection sensitivity of 1.2 × 10-20 Nm/√Hz in ambient conditions and 1.3 × 10-21 Nm=/√Hz in low vacuum. Interference between optomechanical coupling mechanisms is observed to enhance detection sensitivity and generate a mechanical-mode-dependent optomechanical wavelength response.
Keywords: Physics; Ambient conditions; Coupling mechanism; Detection sensitivity; Dissipative coupling; Limited torques; Measurements of; Mechanical resonance; Wavelength response; Dispersion (waves)

Binarity in carbon-enhanced metal-poor stars - Starkenburg, Else; Shetrone, Matthew D.; McConnachie, Alan W.; Venn, Kim A. (Monthly Notices of the Royal Astronomical Society, 2014)
A substantial fraction of the lowest metallicity stars show very high enhancements in carbon. It is debated whether these enhancements reflect the stars' birth composition, or if their atmospheres were subsequently polluted, most likely by accretion from an asymptotic giant branch binary companion. Here we investigate and compare the binary properties of three carbon-enhanced subclasses: The metal-poor CEMP-s stars that are additionally enhanced in barium; the higher metallicity (sg)CH-and Ba II stars also enhanced in barium; and the metal-poor CEMP-no stars, not enhanced in barium. Through comparison with simulations, we demonstrate that all barium-enhanced populations are best represented by a ̃100 per cent binary fraction with a shorter period distribution of at maximum ̃20 000 d. This result greatly strengthens the hypothesis that a similar binary mass transfer origin is responsible for their chemical patterns. For the CEMP-no group we present new radial velocity data from the Hobby-Eberly Telescope for 15 stars to supplement the scarce literature data. Two of these stars show indisputable signatures of binarity. The complete CEMP-no data set is clearly inconsistent with the binary properties of the CEMP-s class, thereby strongly indicating a different physical origin of their carbon enhancements. The CEMP-no binary fraction is still poorly constrained, but the population resembles more the binary properties in the solar neighbourhood.
Keywords: keywordA; stars: abundance; stars: AGB and post-AGB; stars: chemically peculiar; Galaxy: halo; alaxies: formation

Results of fire experiments to quantify residential design fires - Bwalya, Alex; Kashef, Ahmed; Lougheed, Gary (ASHRAE Transactions, 2014)
Fire data on temporal combustion characteristics that define design fires, such as heat release rates, temperatures, radiant heat flux, smoke and composition of fire gases for different fire scenarios are indispensible in carrying out fire safety engineering analysis and design of buildings. This paper presents results from a project that was conducted at the National Research Council of Canada (NRC) in order to characterize fires in multi-family residential dwellings and develop information on design fires. Such information is currently lacking for dwellings containing modern furniture.

Fiber laser cladding of Spherotene spherical fused WC/Inconel 625 metal matrix composite (MMC) coatings - Chen, Jianyin; Xue, Lijue (Processes, Applications, and Performance of Materials in Additive Manufacturing, 2014)
Many industrial tools/equipment require superior surface properties such as high abrasive wear and corrosion resistances as compared to their bulk materials in order to meet harsh operating environments in automotive tooling manufacturing, mining and mineral processing. One strategy is to deposit a layer of hardfacing metal-matrix-composite (MMC) coating onto the working surface of the tool/equipment. This study is to coat Spherotene® spherical fused tungsten carbides (WC) premixed with nickel-based Inconel 625 alloy powders as a binder onto the surface of low carbon steel substrate using a 500W fibre laser which possesses better beam quality, high efficiency, affordable cost, and can easily scale-up, as compared with Nd:YAG and CO2 lasers; the produced coatings free of cracks and pores are expected to offer high surface resistances to abrasive wear as well as corrosion. In this paper, fibre laser cladability, cracking susceptibility, phases and microstructures of spherical fused WC/Inconel 625 coatings are investigated using optical microscopy (OM), scanning electronic microscopy equipped with energy dispersive spectrometry (SEM/EDS) and X-ray diffraction (XRD) method.
On CD-only volume
Keywords: Fiber laser cladding; composite coating; tungsten carbides; wear resistance; corrosion resistance

Simultaneous remediation of nutrients from liquid anaerobic digestate and municipal wastewater by the microalga Scenedesmus sp. AMDD grown in continuous chemostats - Dickinson, K.E.; Bjornsson, W.J.; Garrison, L.L.; Whitney, C.G.; Park, K.C.; Banskota, A.H.; McGinn, P.J. (Journal of Applied Microbiology, 2014)
The primary aim of this study was to investigate the capacity of a microalga, Scenedesmus sp. AMDD, to remediate nutrients from municipal wastewater, either as the sole nutrient source or after blending with wastewater obtained from the anaerobic digestion of swine manure. A complimentary aim was to study and define the effects of these wastewaters on microalgal growth, biomass productivity and composition which have important implications for a commercial biofuels production system.
Keywords: anaerobic digestate; biochemical composition; chemostat; microalgae; wastewater

Biochemical characterization of microalgal biomass from freshwater species isolated in Alberta, Canada for animal feed applications - Tibbetts, Sean M.; Whitney, Crystal G.; MacPherson, Margaret J.; Bhatti, Shabana; Banskota, Arjun H.; Stefanova, Roumiana; McGinn, Patrick J. (Algal Research, 2014)
Biochemical composition of freshwater microalgae isolates from Alberta, Canada was determined. Growth rate (0.98 ± 0.07 d− 1), biomass production (0.35 ± 0.03 g DW L− 1) and daily productivity (0.14 ± 0.01 g DW L− 1 d− 1) were the same for Chlorella vulgaris (AB02-C-U-BBM), Nannochloris bacillaris (AB03-C-F-PLM), Tetracystis sp. (AB04-C-F-PLM02) and Micractinium reisseri (AB05-C-U-BBM02). Whole algal biomass (WAB) contained low ash (~ 2 g 100 g DW− 1) and protein (13–15 g 100 g DW− 1), high esterifiable lipid (32–36 g 100 g DW− 1), carbohydrate (27–30 g 100 g DW− 1) and energy (26–28 MJ kg DW− 1). Oil fractionation was relatively ineffective for C. vulgaris and M. reisseri while oil was effectively extracted from N. bacillaris and Tetracystis sp. Accordingly, lipid-extracted biomass (LEB) from N. bacillaris and Tetracystis sp. contained higher protein (22 g 100 g DW− 1) and carbohydrate (43–44 g 100 g DW− 1) and lower residual esterifiable lipid (6–9 g 100 g DW− 1) than C. vulgaris and M. reisseri at 17–18 g 100 g DW− 1 (protein), 34–36 g 100 g− 1 DW (carbohydrate) and 28–32 g 100 g DW− 1 (residual esterifiable lipid). Biomass had favorable essential amino acid (EAA) profiles with high EAA indices (0.9–1.1); rich in first-limiting EAA lysine (0.9–1.5 g 100 g DW− 1). Fatty acids (% of total) were predominantly monounsaturated fatty acids (MUFA; 40–53%), high in polyunsaturated fatty acids (PUFA; 27–40%) and low in saturated fatty acids (14–24%). N. bacillaris and Tetracystis sp. were particularly rich (9–12%) in α-linolenic acid (18:3n − 3), had attractive n − 3:n − 6 ratios (0.5–0.7:1), were rich in iron (800–1616 mg kg DW− 1), had attractively low Ca:P ratios (0.6–0.9:1) and were virtually absent of contaminating heavy metals.
Keywords: Microalgae; Composition; Amino acids; Fatty acids; Minerals; Carotenoids; Animal feed

Deciphering the roles of Arabidopsis LPCAT and PAH in phosphatidylcholine homeostasis and pathway coordination for chloroplast lipid synthesis - Wang, Liping; Kazachkov, Michael; Shen, Wenyun; Bai, Mei; Wu, Hong; Zou, Jitao (The Plant Journal, 2014)
Phosphatidylcholine (PC) is a key intermediate in the metabolic network of glycerolipid biosynthesis. Lysophosphatidylcholine acyltransferase (LPCAT) and phosphatidic acid phosphatase (PAH) are two key enzymes of PC homeostasis. We report that LPCAT activity is markedly induced in the Arabidopsis pah mutant. The quadruple pah lpcat mutant, with dual defects in PAH and LPCAT, had a level of lysophosphatidylcholine (LPC) that was much higher than that in the lpcat mutants and a PC content that was higher than that in the pah mutant. Comparative molecular profile analysis of monogalactosyldiacylglycerol and digalactosyldiacylglycerol revealed that both the pah and pah lpcat mutants had increased proportions of 34:6 from the prokaryotic pathway despite differing levels of LPCAT activity. We show that a decreased representation of the C16:0C18:2 diacylglycerol moiety in PC was a shared feature of pah and pah lpcat, and that this change in PC metabolic profile correlated with the increased prokaryotic contribution to chloroplast lipid synthesis. We detected increased PC deacylation in the pah lpcat mutant that was attributable at least in part to the induced phospholipases. Increased LPC generation was also evident in the pah mutant, but the phospholipases were not induced, raising the possibility that PC deacylation is mediated by the reverse reaction of LPCAT. We discuss possible roles of LPCAT and PAH in PC turnover that impacts lipid pathway coordination for chloroplast lipid synthesis.
Keywords: acyl editing; Arabidopsis thaliana; chloroplast lipid synthesis; LPCAT activity; PC deacylation; reverse reaction

Development of a fast extraction method and optimization of liquid chromatography–mass spectrometry for the analysis of phenolic compounds in lentil seed coats - Mirali, Mahla; Ambrose, Stephen J.; Wood, Stephen A.; Vandenberg, Albert; Purves, Randy W. (Journal of Chromatography B, 2014)
A systematic set of optimization experiments was conducted to design an efficient extraction and analysis protocol for screening six different sub-classes of phenolic compounds in the seed coat of various lentil (Lens culinaris Medik.) genotypes. Different compounds from anthocyanidins, flavan-3-ols, proanthocyanidins, flavanones, flavones, and flavonols sub-classes were first optimized for use as standards for liquid chromatography mass spectrometry (LC-MS) with UV detection. The effect of maceration duration, reconstitution solvent, and extraction solvent were investigated using lentil genotype CDC Maxim. Chromatographic conditions were optimized by examining column separation efficiencies, organic composition, and solvent gradient. The results showed that a 1. h maceration step was sufficient and that non-acidified solvents were more appropriate; a 70:30 acetone: water (v/v) solvent was ultimately selected. Using a Kinetex PFP column, the organic concentration, gradient, and flow rate were optimized to maximize the resolution of phenolic compounds in a short 30-min analysis time. The optimized method was applied to three lentil genotypes with different phenolic compound profiles to provide information of value to breeding programs.
Keywords: Acetone; Chromatography; Extraction; Flavonoids; High performance liquid chromatography; Mass spectrometry; Phenols; Solvents; Chromatographic conditions; Condition optimizations; Core-shell columns; Lens culinaris; Liquid chromatography - mass spectrometries; Liquid chromatography-Mass spectrometry; Organic compositions; Polyphenols; Drug isolation; Drug screening; Flow rate; Genotype; Lentil; Nonhuman; Plant breeding; Priority journal; Seed husk; Ultraviolet radiation

Label-free hyperspectral nonlinear optical microscopy of the biofuel micro-algae Haematococcus Pluvialis - Barlow, Aaron M.; Slepkov, Aaron D.; Ridsdale, Andrew; Mcginn, Patrick J.; Stolow, Albert (Biomedical Optics Express, 2014)
We consider multi-modal four-wave mixing microscopies to be ideal tools for the in vivo study of carotenoid distributions within the important biofuel microalgae Haematococcus pluvialis. We show that hyperspectral coherent anti-Stokes Raman scattering (CARS) microscopy generates non-invasive, quantitative real-time concentrations maps of intracellular carotenoid distributions in live algae.
Keywords: Haematococcus pluvialis; HyperSpectral; Label free; Micro-algae; Nonlinear optical microscopy

Carbon materials as catalyst supports and catalysts in the transformation of biomass to fuels and chemicals - Lam, Edmond; Luong, John H. T. (ACS Catalysis, 2014)
Carbon plays a dual role as a catalyst or a catalyst support for chemical and enzymatic biomass transformation reactions due to its large specific surface area, high porosity, excellent electron conductivity, and relative chemical inertness. Advantageously, carbon materials can be prepared from residual biomass, an attractive property for decreasing the so-called "carbon-footprint" of a biomass transformation process. Carbon can be chemically functionalized and/or decorated with metallic nanoparticles and enzymes to impart or improve novel catalytic activity. Sulfonated porous carbon materials exhibit high reactivity in diversified catalytic reactions compared to their nonporous counterparts. However, the SO3H groups prevent the incorporation of hydrophobic molecules into the bulk, thereby causing hydrophobic acid-catalyzed reactions to proceed only on the surface. Metal and enzymatic catalysts on carbon supports have significant advantages over other oxide materials for different types of reactions. The future success of biorefinery will require the design of a new generation of multifunctional catalysts, possibly derived from emerging carbon materials such as graphene, carbon nanotubes, and carbon monoliths, for the selective processing of carbohydrates and lignin. The most achievable and economical way is to convert lignocellulosic biomass directly, rather than pure cellulose, hemicellulose, or lignin using multifunctional catalysts.
Keywords: biocatalysis; biomass; carbon; catalysis; catalyst; graphene; monolith; nanotube