HVOF coating case study for power plant process control ball valve application - Vernhes, Luc; Lee, David A.; Poirier, Dominique; Sapieha, Jolanta; Li, Duanjie; Lima, R. S.; Agarwal, A.; Hyland, M. M.; Lau, Y.-C.; Li, C.-J.; McDonald, A.; Toma, F.-L. (Thermal Spray 2012 : Proceedings from the International Spray Conference, 2012)
This case study is the result of an investigation on HVOF Cr3C2-NiCr coating failure of on-off metal seated ball valve (MSBV) used in supercritical steam lines in a power plant and solution. HVOF Cr3C2-NiCr coating is used to protect thousands of MSBVs without incident. However, in this case the valves are challenged with exposure to rapid high pressure and temperature variation resulting in a unique situation where the coating experiences cracking and cohesive failure. A detailed investigation was undertaken by Velan, Kennametal Stellite, the National Research Council of Canada and the Ecole Polytechnique to determine possible failure cause and develop solutions in which highlights are presented.

Cold spray forming Inconel 718 - Wong, W.; Irissou, É.; Legoux, J.-G.; Bernier, F.; Vo, P.; Yue, S.; Michiyoshi, S.; Fukanuma, H. (Thermal Spray 2012: Proceedings from the International Spray Conference and Exposition, 2012)
In this investigation, Inconel 718, a material known to cause nozzle clogging upon cold spraying, was cold spray formed to 6 mm-thick using the Plasma Giken cold spray system PCS- 1000. This was made possible due to the novel non-clogging nozzle material combined with a nozzle water cooling system. Coatings were as-spray formed using both nitrogen and helium as the propelling gasses. The resulting microstructures as well as the corresponding mechanical properties were studied. In addition, the effect of post-heat treatments was also investigated. It was found that for a given propelling gas used, the coating porosity level remained relatively similar (about 2.4% for nitrogen and 3.6% for helium) regardless of the coating treatment (as-sprayed or heat treated). Visual inspection from SEM micrographs showed a higher fraction of inter-particle metallurgical bonds for nitrogen gas sprayed coatings heat treated at 1250°C for 1 hour due to some sintering effect. This significantly affected its tensile properties with an average resulting ductility of 24.7%.

SPAEK-based binary blends and ternary composites as proton exchange membranes for DMFCs - Zhu, Ming; Song, Yang; Hu, Wei; Li, Xuefeng; Jiang, Zhenhua; Guiver, Michael D.; Liu, Baijun (Journal of Membrane Science, 2012)
Naphthalene-containing blendmembranes, comprising sulfonated polyaryletherketone (SPAEK) as the primary matrix, and basic component polyazomethine (PAM), which has a chemical structure partially similar with SPAEK, were investigated as protonexchangemembranes (PEMs). Further, a ternary-compositemembrane was successfully prepared by introducing acid-functionalized polysilsesquioxane (POSS–SO3H) into SPAEK/PAM composite using a sol–gel process. The relevant properties of the PEMs, such as proton conductivity, methanol permeability, water uptake, and morphology were determined, and it was shown that the ternary-compositemembrane, SPAEK/PAM/POSS–SO3H, showed a superior combination of properties for proton conductivity and methanol resistance. Its selectivity was 7.5 times higher than Nafion.
Keywords: Poly(aryl ether ketone); Protonexchangemembranes; Composites; Sol–gel, Fuel cells

Modeling DME addition effects to fuel on PAH and soot in laminar coflow ethylene/air diffusion flames using two PAH mechanisms - Liu, F; Dworkin, S. B.; Thomson, M. J.; Smallwood, G. J. (Combustion Science and Technology, 2012)
Effects of dimethyl ether (DME) addition to fuel on polycyclic aromatic hydrocarbons (PAH) and soot formation in laminar coflow ethylene/air diffusion flames were revisited numerically. Calculations were conducted using two gas-phase reaction mechanisms with PAH formation and growth: one is the C2 chemistry of the Appel, Bockhorn, and Frenklach (ABF) mechanism with PAH growth up to A4 (pyrene); the other is also a C2 chemistrymechanism newly developed at the German Space Center (DLR) with PAH growth up to A5 (corannulene). Soot was modeled based on the assumptions that soot inception is due to the collision of two pyrene molecules, and soot surface growth and oxidation follow a hydrogen abstraction carbon addition (HACA) sequence. The DLR mechanism predicted much higher concentrations of pyrene than the ABF mechanism. A much smaller value of α in the surface growth model associated with the DLR mechanism must be used to predict the correct peak soot volume fraction. Both reaction mechanisms are capable of predicting the synergistic effect of DME addition to fuel on PAH formation. The locations of high PAH concentrations predicted by the DLR mechanism are in much better agreement with available experimental observations. A weak synergistic effect of DME addition on soot formation was predicted by the ABF mechanism. The DLR mechanism failed to predict the synergistic effect on soot. The likely causes for such a failure and the implications for future research on soot inception and surface growth were discussed.
Keywords: bimethyl ether addition; laminar diffusion flame; Soot and PAH formation; synergistic effect

Copper tungstate thin-films for nitric oxide sensing - Gonzalez, C. M.; Du, X.; Dunford, J. L.; Post, M. L. (Sensors and Actuators B: Chemical, 2012)
CuWO4 thin-films prepared by the pulsed laser deposition technique were studied for monitoring nitric oxide (NO) in the concentration range of 10 < [NO] < 400 ppm under synthetic air. The thin-film films were characterized by X-ray diffraction (XRD), depth-profilometry and electron transport measurements. The CuWO4 thin-film response to O2 confirmed an n-type conductivity. Monitoring the thin-film conductometric response to NO at both 300 and 500 °C revealed the operation of a temperature-dependent mechanism for detection. At 300 °C, increasing [NO] produced a consistent increment in thin-film resistance, while at 500 °C the thin-film resistance decreased with [NO]. At 500 °C, a transient response was systematically observed. The chemical origin of the transient is discussed. The estimation of response factors to NO exposure in the presence of high [O2] indicates a significantly higher selectivity to NO. Extensive conductometric measurements show that the thin-films feature good electronic and thermal stability over time.
Keywords: Electrochemical sensors; Conductometric sensors; Gas sensors; NOx sensors; Gas-phase pollutants; Environment monitoring technologies; Thin-films; Semiconducting metal-oxides

Polysulfones with phenylalanine derivatives as chiral selectors – membranes for chiral separation - Isezaki, Jun; Yoshikawa, Masakazu; Li, Nanwen; Robertson, Gilles P.; Guiver, Michael D. (Journal of Membrane and Separation Technology, 2012)
Polysulfone with a derivative of phenylalanyl residue as a chiral selector (PSf-Ac-D-Phe or PSf-Ac-L-Phe) were prepared by polymer reaction of benzylamine-modified polysulfones with N-a-acetyl-D-phenylalanine or N-a-acetyl-L-phenylalanine. Both polysulfones having a chiral selector gave durable self-standing membranes. The specific rotations of those polymers revealed that the chiral selectors were successfully introduced into the polysulfone. PSf-Ac-D-Phe membrane incorporated L-Glu in preference to D-Glu and vice versa. The chiral separation ability was studied by applying a concentration gradient as a driving force for membrane transport. Permselectivities for those two types of membrane reflected their adsorption selectivities. PSf-Ac-D-Phe membrane selectively transported L-Glu and vice versa. Predicted permselectivities by adopting membrane resistance coincided with the observed ones.
Keywords: Chiral separation, membrane, optical resolution, permselectivity, polysulfone

Prétraitement des résidus de la collecte à 3 voies pour améliorer leur biométhanisation - Frigon, J.-C.; Guiot, S. R.; Barnabé, S.; Adjallé, K. D.; Moreau, A.; Camirand, É. (Vecteur environnement, 2012)

Sorption of 2,4-dinitroanisole (DNAN) on lignin - Saad, Rabih; Radovic-Hrapovic, Zorana; Ahvazi, Behzad; Thiboutot, Sonia; Ampleman, Guy; Hawari, Jalal (Journal of Environmental Sciences, 2012)
The present study describes the use of two commercially available lignins, namely, alkali and organosolv lignin, for the removal of 2,4-dinitroanisole (DNAN), a chemical widely used by the military and the dye industry, from water. Sorption of DNAN on both lignins reached equilibrium within 10 hr and followed pseudo second-order kinetics with sorption being faster with alkali than with organosolv lignin, i.e. k2 10.3 and 0.3 g/(mg·hr), respectively. In a separate study we investigated sorption of DNAN between 10 and 40C and found that the removal of DNAN by organosolv lignin increased from 0.8 to 7.5 mg/g but reduced slightly from 8.5 to 7.6 mg/g in the case of alkali lignin. Sorption isotherms for either alkali or organosolv lignin best fitted Freundlich equation with enthalpy of formation, ΔH0 equaled to 14 or 80 kJ/mol. To help understand DNANsorption mechanisms we characterized the twolignins by elemental analysis, BET nitrogen adsorption-desorption and 31P NMR. Variations in elemental compositions between the twolignins indicated that alkali lignin should have more sites (O- and S-containing functionalities) for H-bonding. The BET surface area and calculated total pore volume of alkali lignin were almost 10 times greater than that of organosolv lignin suggesting that alkali lignin should provide more sites for sorption. 31P NMR showed that organosolv lignin contains more phenolic -OH groups than alkali lignin, i.e., 70% and 45%, respectively. The variations in the type of OH groups between the twolignins might have affected the strength of H-bonding between DNAN and the type of lignin used.
Keywords: sorption; DNAN; lignin; kinetics; isotherms

Sub-inhibitory concentrations of different pharmaceutical products affect the meta-transcriptome of river biofilm communities cultivated in rotating annular reactors - Yergeau, Étienne; Sanschagrin, Sylvie; Waiser, Marley J.; Lawrence, John R; Greer, Charles W. (Environmental Microbiology Reports, 2012)
Surface waters worldwide are contaminated by pharmaceutical products that are released into the environment from wastewater treatment plants. Here, we hypothesize that pharmaceutical products have effects on organisms as well as genes related to nutrient cycling in complex microbial communities. To test this hypothesis, biofilms were grown in reactors and subjected low concentrations of three antibiotics [erythromycin, ER, sulfamethoxazole, SL and sulfamethazine, SN) and a lipid regulator (gemfibrozil, GM). Total community RNA was extracted and sequenced together with PCR amplicons of the 16S rRNA gene using 454 pyrosequencing. Exposure to pharmaceutical products resulted in very little change in bacterial community composition at the phylum level based on 16S rRNA gene amplicons, even though some genera were significantly affected. In contrast, large shifts were observed in the active community composition based on taxonomic affiliations of mRNA sequences. Consequently, expression of gene categories related to N, P and C cycling were strongly affected by the presence of pharmaceutical products, with each treatment having specific effects. These results indicate that low pharmaceutical product concentrations rapidly provoke a variety of functional shifts in river bacterial communities. In the longer term these shifts in gene expression and microbial activity could lead to a disruption of important ecosystem processes like nutrient cycling.

The performance of a thermophilic microbial fuel cell fed with synthesis gas - Hussain, A.; Mehta, P.; Raghavan, V.; Wang, H.; Guiot, S. R.; Tartakovsky, B. (Enzyme and Microbial Technology, 2012)
This study demonstrated electricity generation in a thermophilic microbial fuel cell (MFC) operated on synthesis gas (syngas) as the sole electron donor. At 50 °C, a volumetric power output of View the MathML source and a syngas conversion efficiency of 87–98% was achieved. The observed pathway of syngas conversion to electricity primarily consisted of a two-step process, where the carbon monoxide and hydrogen were first converted to acetate, which was then consumed by the anodophilic bacteria to produce electricity. A denaturing gradient gel electrophoresis (DGGE) analysis of the 16S rDNA revealed the presence of Geobacter species, Acetobacter, methanogens and several uncultured bacteria and archaea in the anodic chamber.
Keywords: MFC; Synthesis gas; Carbon monoxide; Thermophilic conditions

Microbial fuel cell operation with intermittent connection of the electrical load - Grondin, F.; Perrier, M.; Tartakovsky, B. (Journal of Power Sources, 2012)
Laboratory-scale microbialfuelcells are often operated with a constant electricalload. Meanwhile, variations in influent strength and quality, as well as the processes of biofilm growth and decay lead to significant changes of the MFC internal resistance over time. This inevitably results in a mismatch between the internal and the external resistances therefore decreasing MFC power output. This study presents the concept of MFC operation with intermittentconnection of the electricalload (external resistance). The efficiency of the proposed method is demonstrated by MFC operation with external resistances significantly below the MFC internal resistance and comparing power outputs obtained using either constant or intermittently connected resistances.
Keywords: MFC; External resistance; Intermittentconnection; Duty cycle

Evolution of space charges and conductivity with DC aging of polyethylene-synthetic and natural clay-composites - Abou-Dakka, Mahmoud (Journal of Nanomaterials, 2012)
To develop new materials with better dielectric properties for electric equipment, such as power capacitors, two types of polypropylene (PP)-based nanocomposites (PNC) were manufactured. The PNCs were composed of PP with different concentrations of synthetic and natural organoclays. The evolution of the space charge density and dc conductivity with dc poling of these composites were investigated. It was observed that the optimal concentration of nanofillers for space charge mitigation with aging time was 2-wt% for PP-natural clay composite and between 2 and 4 wt% for the PP-synthetic clay. Above these percentages, charge transport through overlapping of nanoparticles can occur. This fact is due to the interaction zone of double layers formed at the nanoparticle/host material interfaces. Under dc field the overlapping increases the conductivity of polymer nanocomposite (PNC), which could reduce the benefit of incorporating nanofillers into PP. The total charge stored in unfilled PP increased continuously with time, reaching a maximum around 5000 h before decreasing. However, the total charges in all filled specimens only changed slightly. The effect of platelet size on space charge mitigation reported by other authors is confirmed here, i.e. nanofillers with smaller platelets such as natural clay can mitigate space charge more efficiently than nanofillers with larger platelets such as synthetic clay. The conductivity with -25 kV/mm dc field of the specimens containing 6-wt% of natural clay and 8-wt% of synthetic clay reached ≈ 6 times the level for unfilled PP. This observation could be related to crossing the percolation threshold of these composites. At least 1000 h of aging with -25 kV/mm dc field is required before correctly evaluating the impact of filling the PP with nano-particles.
Keywords: polypropylene nano-composites (PNC); dc field conductivity; space charge evolution; PEA technique; natural and synthetic organoclay

Characterization of Zn-containing metal–organic frameworks by solid-state 67Zn NMR spectroscopy and computational modeling - Sutrisno, Andre; Terskikh, Victor V.; Shi, Qi; Song, Zhengwei; Dong, Jinxiang; Ding, San Yuan; Wang, Wei; Provost, Bianca R.; Daff, Thomas D.; Woo, Tom K.; Huang, Yining (Chemistry : a European Journal, 2012)
Metal–organic frameworks (MOFs) are an extremely important class of porous materials with many applications. The metal centers in many important MOFs are zinc cations. However, their Zn environments have not been characterized directly by 67Zn solid-state NMR (SSNMR) spectroscopy. This is because 67Zn (I=5/2) is unreceptive with many unfavorable NMR characteristics, leading to very low sensitivity. In this work, we report, for the first time, a 67Zn natural abundance SSNMR spectroscopic study of several representative zeolitic imidazolate frameworks (ZIFs) and MOFs at an ultrahigh magnetic field of 21.1 T. Our work demonstrates that 67Zn magicangle spinning (MAS) NMR spectra are highly sensitive to the local Zn environment and can differentiate nonequivalent Zn sites. The 67Zn NMR parameters can be predicted by theoretical calculations. Through the study of MOF-5 desolvation, we show that with the aid of computational modeling, 67Zn NMR spectroscopy can provide valuable structural information on the MOF systems with structures that are not well described. Using ZIF-8 as an example, we further demonstrate that 67Zn NMR spectroscopy is highly sensitive to the guest molecules present inside the cavities. Our work also shows that a combination of 67Zn NMR data and molecular dynamics simulation can reveal detailed information on the distribution and the dynamics of the guest species. The present work establishes 67Zn SSNMR spectroscopy as a new tool complementary to X-ray diffraction for solving outstanding structural problems and for determining the structures of many new MOFs yet to come.
Keywords: desolvation; host–guest systems; metal–organic frameworks; NMR spectroscopy; solid-state structures; zinc

Solid-state (73) Ge NMR spectroscopy of simple organogermanes - Hanson, Margaret A.; Sutrisno, Andre; Terskikh, Victor V.; Baines, Kim M.; Huang, Yining (Chemistry : a European Journal, 2012)
Germanium-73 is an extremely challenging nucleus to examine by NMR spectroscopy due to its unfavorable NMR properties. Through the use of an ultrahigh (21.1 T) magnetic field, a systematic study of a series of simple organogermanes was carried out. In those cases for which X-ray structural data were available, correlations were drawn between the NMR parameters and structural metrics. These data were combined with DFT calculations to obtain insight into the structures of several compounds with unknown crystal structures.
Keywords: density functional calculations; germanium; NMR spectroscopy

Identification of volatile iron species generated by UV photolysis - Grinberg, Patricia; Sturgeon, Ralph E.; Gardner, Graeme (Microchemical Journal, 2012)
The volatile products of photochemical generation (PVG) of iron from solutions of formic and acetic acids were examined by GC-MS. Iron pentacarbonyl was the sole analytical species detected in both cases, as confirmed by comparison of the results with a NIST reference spectrum. Silylation of the interior surfaces of the quartz tubing comprising the photochemical reactor essentially eliminated memory effects such that signal duration was determined simply by the residence time of the sample solution.
Keywords: volatile metal species; vapor generation; iron; iron pentacarbonyl; GC-MS; silylation

Systematic shift evaluation of the NRC 88Sr+ single-ion optical frequency standard to a few parts in 10^-17 - Dubé, P.; Madej, A. A.; Bernard, J. E.; Zhou, Z. (2012 IEEE International Frequency Control Symposium, 2012)
A new strontium ion trap of the endcap design was built recently at the National Research Council of Canada for better control of the micromotion shifts. The uncertainty caused by these shifts has been reduced by more than four orders of magnitude compared to the original NRC trap, down to a level of ≈ 10-18. In this paper we discuss the evaluation of micromotion shifts and of several other sources of importance to optical frequency standards based on single ions. The total fractional frequency uncertainty of the new strontium ion trap system is estimated to be ≈ 2 × 10-17, limited by the blackbody radiation shift. A preliminary measurement of the clock transition frequency with a fractional uncertainty of 2×10-15, limited by the accuracy of the maser reference, is also presented.

Peptide sequencing challenge - Meija, Juris (Analytical and Bioanalytical Chemistry, 2012)

An improved current-comparator-based power standard with an uncertainty of 2.5 uW/VA (k=1) - So, Eddy; Arseneau, Rejean; Angelo, Dave (IEEE Transactions on Instrumentation and Measurement - Special Issue, 2012)
An improved standard derived from a current power bridge for calibrating active/reactive power and energy meters under sinusoidal conditions is described. Measurements can be made at any power factor from zero lag through unity to zero lead, positive or negative power, at 120 V,5 A, and 50 or 60 Hz. The improved power standard has an estimated uncertainty of not more than 2.5 uW/VA at k=1. Special high accuracy current and voltage range extenders have been incorporated to extend the current and voltage ranges up to 200 A and 1200 V, respectively.
Keywords: current-comparator; power bridge; power standard; uncertainty

Determination of amino acids in selenium-enriched yeast by gas chromatography–mass spectrometry after microwave assisted hydrolysis - Zhang, Xu; Yang, Lu; Mester, Zoltan (Analytica Chimica Acta, 2012)
A simple, rapid microwave digestion procedure for protein hydrolysis preceding the determination of amino acids in yeast using gas chromatography–mass spectrometry (GC–MS) is described. Protein hydrolysis was performed in a focused microwave using 4 M methanesulfonic acid (MAS). Amino acids were derivatized with methyl chlorofomate (MCF) and extracted into chloroform prior to GC–MS analysis. The microwave parameters, including power, temperature and heating time, were optimized. It was found that temperature and heating time were the most influential factors. A total of 17 amino acids were determined in selenium-enriched yeast with use of standard addition calibration. Limits of detection and quantitation (LODs/LOQs) of the amino acids measured were in the sub-nmol range, suitable for monitoring of amino acids in yeast and other food products.
Keywords: amino acids; microwave-irradiation hydrolysis; gas chromatography–mass spectrometry; selenium enriched yeast

Ontology fusion in high-level-architecture-based collaborative engineering environments - Sun, Hongbo; Fan, Wenhui; Shen, Weiming; Xiao, Tianyuan (IEEE Transactions on Systems, Man, and Cybernetics, Part A: Systems And Humans, 2012)
In high-level-architecture (HLA)-based distributed heterogeneous collaborative engineering environments (CEEs), the construction of federation object model files is time consuming. This paper presents an ontology fusion approach aiming at establishing a common understanding in such collaborative environments. The proposed approach has three steps: ontology mapping, ontology alignment, and ontology merging. Ontology mapping employs a top-down approach to explore all bridge relations between two terms from different ontologies based on bridge axioms and deduction rules. Ontology alignment adopts a bottom-up approach to discover implicit bridge relations between two terms from different domain ontologies based on equivalent inference. Ontology merging generates a new collaboration ontology from discovered equivalent bridge relations. It adopts an axiom-based ontology fusion strategy and takes heavy-weighted ontologies into consideration. It can find all the explicit and derived interontology relations. In a typical CEE, the proposed approach has a great potential to improve the efficiency of preparation for HLA-based collaborative engineering processes, reduce the work load for adaptive adjustment of existing platforms, and enhance the reusability and flexibility of CEEs. A case study has been conducted to validate the feasibility of the proposed approach.
Keywords: collaborative engineering environments (CEEs), high-level architecture (HLA), ontology, product development

Frame-based ontological view for semantic integration - Xue, Yunjiao; Ghenniwa, Hamada H.; Shen, Weiming (Journal of Network and Computer Applications, 2012)
Semantic integration is crucial for successful collaboration between heterogeneous information systems. Traditional ontology-driven approaches rely on the availability of explicit ontologies. However, in most application domains, this prerequisite cannot be met. In order to address this issue, this paper investigates the theoretical foundation of ontologies and extends the traditional ontology concept to an ontologicalview concept. To explicitly and formally specify the ontologicalviews, a Frame-basedOntologicalview Specification Language (FOSL) is proposed. This language is based on the frame knowledge representation paradigm and uses XML as the encoding. The ontologicalview driven semanticintegration can be achieved based on the specifications. A proof-of-concept prototype environment has been implemented to achieve semanticintegrationbased on ontologicalviews specified with FOSL.
Keywords: semantic integration; ontology; ontologicalview; frame; specification language

Ontology-based interoperation model of collaborative product development - Sun, Hongbo; Fan, Wenhui; Shen, Weiming; Xiao, Tianyuan (Journal of Network and Computer Applications, 2012)
The reuse of existing systems is an important objective of HLA (High Level Architecture)-based collaborative product development systems. However, in order to reuse an existing system, its interoperation interface has to be modified to comply with the objective and interaction representations defined in a corresponding FOM (Federation Object Model). Such modifications imply added time and effort, which diminishes the efficiency of system reuse in collaborative product development. This paper presents a heavy-weighted ontology-based construction method for interoperation models to support the reuse of subsystems in various collaborative contexts. In this method ontologies are used to specify the semantics of object classes and interaction classes in subsystems in a formal and computer readable fashion. In doing so, a FCA (Formal Concept Analysis) -like construction method is introduced to establish the original interoperation ontology from scratch. An automatic transforming method from a SOM (Simulation Object Model) into interoperation ontology is also described to make it easy for existing HLA-based systems to adopt this approach. Then a consistency verification method is introduced to guarantee the consistency of the interoperation ontologies. A case study is used to demonstrate the feasibility of the proposed method. As a human- friendly modeling method, compared with existing interoperation modeling methods, the proposed method is more flexible, efficient and reliable.
Keywords: collaborative product development; HLA - high level architecture; ontology

Exchange bias in a nanocrystalline hematite/permalloy thin film investigated with polarized neutron reflectometry - Cortie, D. L.; Lin, K.-W.; Shueh, C.; Hsu, H.-F.; Wang, X. L.; James, M.; Fritzsche, H.; Bruck, S.; Klose, F. (Physical Review B: condensed matter and materials physics, 2012)
We investigated a hematite α-Fe2O3/permalloy Ni80Fe20 bilayer film where the antiferromagnetic layer consisted of small hematite grains in the 2 to 16 nm range. A pronounced exchange bias effect occurred below the blocking temperature of 40 K. The magnitude of exchange bias was enhanced relative to reports for identical compounds in large grain, epitaxial films. However, the blocking temperature was dramatically reduced. As the Néel temperature of bulk α-Fe2O3 is known to be very high (860 K), we attribute the low-temperature onset of exchange bias to the well-known finite-size effect which suppresses the Morin transition for nanostructured hematite. Polarized neutron reflectometry was used to place an upper limit on the concentration and length scale of a layer of uncompensated moments at the antiferromagnetic interface. The data were found to be consistent with an induced magnetic region at the antiferromagnetic interface of 0.5–1.0 μB per Fe atom within a depth of 1–2 nm. The field dependence of the neutron spin-flip signal and spin asymmetry was analyzed in the biased state, and the first and second magnetic reversal were found to occur by asymmetric mechanisms. For the fully trained permalloy loop, reversal occurred symmetrically at both coercive fields by an in-plane spin rotation of ferromagnetic domains.

Performance of Cu-coated vanadium cans for in situ neutron powder diffraction experiments on hydrogen storage materials - Flacau, Roxana; Bolduc, Jim; Bibienne, Thomas; Huot, Jacques; Fritzsche, Helmut (Journal of Applied Crystallography, 2012)
In situ neutron powder diffraction (NPD) measurements of hydrogenation processes taking place at high temperatures pose difficulties related to the choice of sample can material. This article describes a simple design for a copper-coated vanadium can and its connection to the gas-handling system, tested up to 523 K. High-quality NPD patterns of TiV1.2Mn0.8 body-centred cubic alloy, as-cast and partially hydrogenated, were collected at 373 K and deuterium pressures up to 2 bar (200 kPa).

Efficient image recognition using local feature and fuzzy triangular number based similarity measures - Belacel, Nabil; Kardouchi, Mustapha; Liu, Zikuan (International Journal of Engineering and Industries, 2012)
Image local scale invariant features are of great importance for object recognition. Among various local scale invariant feature descriptors, Scale Invariant Feature Transform (SIFT) descriptor has been shown to be the most descriptive one and thus widely applied to image retrieval, object recognition and computer vision. By SIFT descriptor, an image may be described by hundreds of key points with each point depicted by a 128-element feature vector; this representation makes the subsequent feature matching very computationally demanding. In this paper, we propose to incorporate the fuzzy set concepts into SIFT features and define fuzzy similarity between images. The proposed approach is applied to image recognition. Experimental results with the coil-100 image database are provided to show the superiority of the proposed approach.

PSOA2TPTP: a reference translator for interoperating PSOA RuleML with TPTP reasoners - Zou, Gen; Peter-Paul, Reuben; Boley, Harold; Riazanov, Alexandre (Rules on the Web: Research and Applications - Proceedings of the 6th International Symposium on Rules, RuleML 2012, 2012)
PSOA RuleML is a recently specified rule language combining relational and object-oriented modeling. In order to provide reasoning services for PSOA RuleML, we have implemented a reference translator, PSOA2TPTP, to map knowledge bases and queries in the PSOA RuleML presentation syntax (PSOA/PS) to the popular TPTP format, supported by many first-order logic reasoners. In particular, PSOA RuleML reasoning has become available using the open-source VampirePrime reasoner, enabling query answering and entailment as well as consistency checking. The translator, currently composed of a lexer, a parser, and tree walkers, is generated by the ANTLR v3 parser generator tool from the grammars we developed. We discuss how to rewrite the original PSOA/PS grammar into an LL(1) grammar, thus demonstrating that PSOA/PS can be parsed efficiently. We also present a semantics-preserving mapping from PSOA RuleML to TPTP through a normalization and a translation phase. We wrap the translation and querying code into RESTful Web services for convenient remote access and provide a demo Web site.

A heterogeneous sensors integration platform for independent living spaces - Zheng, Cheng; Shen, Weiming; Xue, Henry; Hao, Qi (Proceedings of the 2012 IEEE 16th International Conference on Computer Supported Cooperative Work in Design (CSCWD 2012), 2012)
Continual advances in modern technologies make it feasible to build intelligent independent living spaces for the elderly and disabled. In the past few years, various sensors and medical devices have been commercially available for home healthcare applications, but still there is a lack of effort on integrating heterogeneous commercial off-the-shelf (COTS) sensors from various vendors to collect data and provide more flexibility in product selection for customers. In order to address this issue, this paper presents a heterogeneous sensors integration platform for independent living spaces. The proposed platform, which is based on Apache Thrift, can accomplish the tasks of data collection, organization, and storage through cross-language services. A prototype system has been implemented and integrated into an independent living space monitoring system to validate the proposed approach.
Keywords: independent living spaces; cross-language services; Apache Thrift; sensors integration; COTS sensors and devices; data collection

Security and privacy considerations for wireless sensor networks in smart home environments - Islam, Kamrul; Shen, Weiming; Wang, Xianbin (Proceedings of the 2012 IEEE 16th International Conference on Computer Supported Cooperative Work in Design (CSCWD 2012), 2012)
Wireless Sensor Network (WSN) has emerged as a dependable technology to improve the quality of life in smart homes through offering various automated, interactive and comfortable services. Sensors integrated at different places in homes, offices, and even in clothes, equipment, and utilities are used to sense and monitor occupants' positions, movements, vital signs, utility usage, temperature and humidity levels of rooms, etc. Along with sensing and monitoring capabilities, sensors cooperate and communicate with themselves to deliver, share and process sensed information and assist real-time decisionmaking procedures through triggering appropriate alerts and actions. However, ensuring privacy and providing adequate security in these crucial services provided by WSNs is a major issue in smart home environments. In this paper, we examine the privacy and security challenges of WSNs and survey its practicality for smart home environments. We discuss the unique characteristics that distinguish a smart environment from the rest, elaborate on security and privacy issues and their respective solution measures. A number of challenges and interesting research issues emerging from this study have been reported for further investigation.
Keywords: wireless sensor networks; smart home; privacy; security; cryptography

PSOA RuleML API : a tool for processing abstract and concrete syntaxes - Al Manir, Mohammad Sadnan; Riazanov, Alexandre; Boley, Harold; Baker, Christopher J. O. (Rules on the Web: Research and Applications the 6th International Symposium, RuleML 2012 Proceedings, 2012)
PSOA RuleML is a rule language which introduces positionalslotted, object-applicative terms in generalized rules, permitting relation applications with optional object identifiers and positional or slotted arguments. This paper describes an open-source PSOA RuleML API, whose functionality facilitates factory-based syntactic object creation and manipulation. The API parses an XML-based concrete syntax of PSOA RuleML, creates abstract syntax objects, and uses these objects for translation into a RIF-like presentation syntax. The availability of such an API will benefit PSOA rule-based research and applications.

Transcending the display size: the case for speech interaction in educational applications - Munteanu, Cosmin (CHI 2012: ACM SIGCHI Conference on Human Factors in Computing Systems, 2012)
Speech is the most natural form of communication that humans employ, and is one of the main modalities through which we acquire and share knowledge. Moreover, speech is used not only to deliver knowledge, but as a modality that supports learning, such as student-teacher interactions around printed materials. During the past decade, we have witnessed significant advances mainly in preserving spoken educational materials, from informal how-to videos to full academic lectures being stored and available through a variety of online channels. Unfortunately, there is proportionately less research on enabling access to such multimedia knowledge repositories (e.g. searching, indexing) or on facilitating spoken, natural interaction between learners and digital interactive media (such as automated tutors or interactive learning resources). By enabling speech as a modality, learners become less constrained by the physical properties of the educational materials and can interact more naturally with the educational software, be it in the form of a mobile language assistant, a desktop-based online lecture browsing system, or a mixed-reality serious gaming system. In this paper I present examples of such recent research on improving the way we interact with educational resources through speech and natural language, and make the case for the need to conduct further research in this area.
Keywords: Educational interfaces; automatic speech recognition; interface design; multimodal interaction

Towards conservative helicopter loads prediction using computational intelligence techniques - Valdes, Julio J.; Cheung, Catherine; Li, Matthew (Proceedings of the IEEE 2012 World Congress on Computational Intelligence, IEEE 2012 International Joint Conference on Neural Networks, 2012)
Airframe structural integrity assessment is a major activity for all helicopter operators. The accurate estimation of component loads is an important element in life cycle management and life extension efforts. This paper explores continued efforts to utilize a wide variety of computational intelligence techniques to estimate some of these helicopter dynamic loads. Estimates for two main rotor sensors (main rotor normal bending and pushrod axial load) on the Australian Black Hawk helicopter were generated from an input set that consisted of thirty standard flight state and control system parameters. These estimates were produced for two flight conditions: full speed forward level flight and left rolling pullout at 1.5g. Two sampling schemes were attempted, specifically k-leaders sampling and a biased sampling scheme. Ensembles were constructed from the top performing models that used conjugate gradient, Levenberg-Marquardt (LM), extreme learning machines, and particle swarm optimization (PSO) as the learning method. Hybrid and memetic approaches combining the deterministic optimization and evolutionary computation techniques were also explored. The results of this work show that using a biased sampling scheme significantly improved the predictions, particularly at the peak values of the target signal. Hybrid models using PSO and LM learning provided accurate and correlated predictions for the main rotor loads in both flight conditions.

Use of evolutionary computation techniques for exploration and prediction of helicopter loads - Cheung, Catherine; Valdes, Julio J.; Li, Matthew (IEEE 2012 World Congress on Computational Intelligence, IEEE 2012 Congress on Evolutionary Computation, 2012)
The development of accurate load spectra for helicopters is necessary for life cycle management and life extension efforts. This paper explores continued efforts to utilize evolutionary computation (EC) methods and machine learning techniques to estimate several helicopter dynamic loads. Estimates for the main rotor normal bending (MRNBX) on the Australian Black Hawk helicopter were generated from an input set that included thirty standard flight state and control system parameters under several flight conditions (full speed forward level flight, rolling left pullout at 1:5g, and steady 45◦ left turn at full speed). Multiobjective genetic algorithms (MOGA) used in combination with the Gamma test found reduced subsets of predictor variables with modeling potential. These subsets were used to estimate MRNBX using Cartesian genetic programming and neural network models trained by deterministic and evolutionary computation techniques, including particle swarm optimization (PSO), differential evolution (DE), and MOGA. PSO and DE were used alone or in combination with deterministic methods. Different error measures were explored including a fuzzy-based asymmetric error function. EC techniques played an important role in both the exploratory and modeling phase of the investigation. The results of this work show that the addition of EC techniques in the modeling stage generated more accurate and correlated models than could be obtained using only deterministic optimization.

#Emotional Tweets - Mohammad, Saif M (Proceedings of First Joint Conference on Lexical and Computational Semantics (*Sem), 2012)
Detecting emotions in microblogs and social media posts has applications for industry, health, and security. However, there exists no microblog corpus with instances labeled for emotions for developing supervised systems. In this paper, we describe how we created such a corpus from Twitter posts using emotionword hashtags. We conduct experiments to show that the self-labeled hashtag annotations are consistent and match with the annotations of trained judges. We also show how the Twitter emotion corpus can be used to improve emotion classification accuracy in a different domain. Finally, we extract a word–emotion association lexicon from this Twitter corpus, and show that it leads to significantly better results than the manually crafted WordNet Affect lexicon in an emotion classification task.

Expression, purification and analysis of an Arabidopsis recombinant CBL-interacting protein kinase3 (CIPK3) and its constitutively active form - Gao, Peng; Kolenovsky, Allan; Cui, Yuhai; Cutler, Adrian J.; Tsang, Edward W. T. (Protein Expression and Purification, 2012)
CIPK3 is a member of CBL (calcineurin B-like)-interacting serine–threonine protein kinases which play an important role in many developmental and adaptation processes in Arabidopsis. Studies conducted on members of this family such as SOS2, PKS8 and PKS11 have provided insight into how these kinases interact with their target substrates in the signal-response process. Since SOS2, PKS8 and PKS11 have low enzymatic activities in vitro and their amino acid sequences are homologous to that of CIPK3, it was assumed that CIPK3 would have a low enzymatic activity. To enhance CIPK3 enzyme activity, a constitutively active form, CIPK3T183D, was generated by a Thr¹⁸³ to Asp¹⁸³ substitution in the activation loop. To obtain proteins for analysis, glutathione S-transferase (GST) fusion protein system was used. Although both CIPK3 and CIPK3T183D were successfully expressed, they were found in inclusion bodies with three truncated proteins. Since the truncated proteins had a similar afﬁnity to the GST-Bind Resin as the target protein, the one-step afﬁnity puriﬁcation could no longer be used. As an alternative, His fusion protein expression system was employed for protein production. Although both His-CIPK3 and His-CIPK3T183D also accumulated in inclusion bodies, they were expressed as a single protein species. A method involving Sarkosyl was developed for isolating and purifying the His fusion proteins. His-CIPK3 and HisCIPK3T183D produced were highly puriﬁed and enzymatically active. In addition, a 9-fold increase in kinase activity in His-CIPK3T183D was observed, indicating that Thr¹⁸³ to Asp¹⁸³ substitution in the activation loop of CIPK3 had succeeded in enhancing the kinase activity.
Keywords: CIPK3; Site-directed mutagenesis; Inclusion bodies; Sarkosyl; Enzymatically active; Affinity purification; Protein kinase; Peptide phosphorylation

Chemical inhibition of potato ABA8'-hydroxylase activity alters in vitro and in vivo ABA metabolism and endogenous ABA levels but does not affect potato microtuber dormancy duration - Suttle, Jeffrey C.; Abrams, Suzanne R.; De Stefano-Beltran, Luis; Huckle, Linda L. (Journal of Experimental Botany, 2012)
The effects of azole-type P450 inhibitors and two metabolism-resistant abscisic acid (ABA) analogues on in vitro ABA-8'-hydroxylase activity, in planta ABA metabolism, endogenous ABA content, and tuber meristem dormancy duration were examined in potato (Solanum tuberosum L. cv. Russet Burbank). When functionally expressed in yeast, three potato CYP707A genes were demonstrated to encode enzymatically active ABA-8'-hydroxylases with micromolar affinities for (+)-ABA. The in vitro activity of the three enzymes was inhibited by the P450 azole-type inhibitors ancymidol, paclobutrazol, diniconazole, and tetcyclasis, and by the 8'-acetylene- and 8'-methylene-ABA analogues, with diniconazole and tetcyclasis being the most potent inhibitors. The in planta metabolism of [3H](±)-ABA to phaseic acid and dihydrophaseic acid in tuber meristems was inhibited by diniconazole, tetcyclasis, and to a lesser extent by 8'-acetylene- and 8'-methylene-ABA. Continuous exposure of in vitro generated microtubers to diniconazole resulted in a 2-fold increase in endogenous ABA content and a decline in dihydrophaseic acid content after 9 weeks of development. Similar treatment with 8'-acetylene-ABA had no effects on the endogenous contents of ABA or phaseic acid but reduced the content of dihydrophaseic acid. Tuber meristem dormancy progression was determined ex vitro in control, diniconazole-, and 8'-acetylene-ABA-treated microtubers following harvest. Continuous exposure to diniconazole during microtuber development had no effects on subsequent sprouting at any time point. Continuous exposure to 8'-acetylene-ABA significantly increased the rate of microtuber sprouting. The results indicate that, although a decrease in ABA content is a hallmark of tuber dormancy progression, the decline in ABA levels is not a prerequisite for dormancy exit and the onset of tuber sprouting.
Keywords: ABA; ABA-8'-hydroxylase; abscisic acid; dormancy; microtuber; mixed-function oxidase; P450; potato; Solanum tubersum L.

Disaggregating categories of electrical energy end-use from whole-house hourly data - Birt, Benjamin J.; Newsham, Guy R.; Beausoleil-Morrison, Ian; Armstrong, Marianne M.; Saldanha, Neil; Rowlands, Ian H. (Energy and Buildings, 2012)
The residential sector uses nearly 30% of all electricity in Canada, and, it is important to know how this energy is being used, so that savings may be identified and realised. We propose a method that can be applied to hourly whole-house electrical energy data to partially disaggregate total household electricity use into five load categories/parameters (base load, activity load, heating season gradient, cooling season gradient and lowest external temperature at which air-conditioning is used). This paper develops the proposed method, and verifies it using high-resolution end-use data from twelve households with known characteristics. We then apply the method to hourly whole-house (smart meter) data from 327 households in Ontario. The roll-out of smart (advanced) metering infrastructure in many countries will make hourly whole-house data abundant, and we propose that this method could be widely applied by utilities to target their demand-side management programs towards households more likely to provide benefits, thus increasing the cost-effectiveness of such programs.
Keywords: load disaggregation; residential; electricity; smart meter; Canada

Identity verification based on haptic handwritten signatures: genetic programming with unbalanced data - Alsulaiman, Fawaz A.; Valdes, Julio J.; El Saddik, Alsulaiman ((CISDA 2012): Proceedings of the IEEE Symposium on Computational Intelligence for Security and Defence Applications, 2012)
In this paper, haptic-based handwritten signature verification using Genetic Programming (GP) classification is presented. The relevance of different haptic data types (e.g., force, position, torque, and orientation) in user identity verification is investigated. In particular, several fitness functions are used and their comparative performance is investigated. They take into account the unbalance dataset problem (large disparities within the class distribution), which is present in identity verification scenarios. GP classifiers using such fitness functions compare favorably with classical methods. In addition, they lead to simple equations using a much smaller number of attributes. It was found that collectively, haptic features were approximately as equally important as visual features from the point of view of their contribution to the identity verification process.
Keywords: Haptics; Biometrics; Genetic Programming; user verification; classification

Spotting keywords and sensing topic changes in speech - Zhu, Xiaodan (CISDA 2012: Proceedings of the IEEE Symposium on Computational Intelligence for Security and Defence Applications, 2012)
Security concerns involved in dealing with sensitive information conveyed in human languages must be able to handle speech, which is the most basic, natural form of human communication and a huge amount of data are being generated daily. Dealing with such data is naturally associated with typical big-data problems in terms of both computational complexity and storage space. Unfortunately, compared with written texts, speech is inherently more difficult to browse, if no technical support is provided. In this paper we are interested in spotting keywords, which could reflect a security agent's information needs, and study its usefulness in helping automatically disclose topic changes (boundaries) in speech data under concern. Our results show that keyword spotting can help identify topics with a competitive performance.
Keywords: keyword spotting; topic segmentation; speech understanding

Simulating social commerce applied to buyer group pricing, recommendation incentives, and bundling - Spencer, Bruce; Buffett, Scott (ICEC 2012: International Conference on Electronic Commerce, 2012)
Currently social networks are used by buyers to become more aware of sellers and their goods. Increasingly, they are used with three other market mechanisms: Buyers use social networks to form buyer groups that leverage purchasing power. Sellers incentivize buyers to post recommendations on social media. Sellers or buyers compose compatible items into bundles with increased value and reduced price. In this paper we study the potential e ects of social networks on these mechanisms. For comprehensive and consistent coverage, we simulate combinations of these mechanisms, using published metrics for authenticity. Our results show seller pro tability increases with the use of social networks applied to all possible combinations.

Filtering and routing multilingual documents for translation - Carpuat, Marine; Goutte, Cyril; Isabelle, Pierre (2012 IEEE Symposium on Computational Intelligence for Security and Defence Applications (CISDA 2012), 2012)
Translation is a key capability to access relevant information expressed in various languages on social media. Unfortunately, systematically translating all content far exceeds the capacity of most organizations. Computer-aided translation (CAT) tools can significantly increase the productivity of translators, but can not ultimately cope with the overwhelming amount of content to translate. In this contribution, we describe and experiment with an approach where we use the structure in a corpus to adequately route the content to the proper workflow, including translators, CAT tools or purely automatic approaches. We show that linguistically motivated structure such as document genre can help decide on the proper translation workflow. However, automatically discovered structure has an effect that is at least as important and allows us to define groups of documents that may be translated automatically with reasonable output quality. This suggests that computational intelligence models that can efficiently organize document collection will provide increased capability to access textual content from various target languages.

The trouble with SMT consistency - Carpuat, Marine; Simard, Michel (Proceedings of the 7th Workshop on Statistical Machine Translation, 2012)
SMT typically models translation at the sentence level, ignoring wider document context. Does this hurt the consistency of translated documents? Using a phrase-based SMT system in various data conditions, we show that SMT translates documents remarkably consistently, even without document knowledge. Nevertheless, translation inconsistencies often indicate translation errors. However, unlike in human translation, these errors are rarely due to terminology inconsistency. They are more often symptoms of deeper issues with SMT models instead.

Liuwei Dihuang (LWDH), a traditional Chinese medicinal formula, protects against β-amyloid toxicity in transgenic caenorhabditis elegans - Sangha, Jatinder S.; Sun, Xiaoli; Wally, Owen S. D.; Zhang, Kaibin; Ji, Xiuhong; Wang, Zhimin; Wang, Yanwen; Zidichouski, Jeffrey; Prithiviraj, Balakrishnan; Zhang, Junzeng (PLos ONE, 2012)
Liuwei Dihuang (LWDH), a classic Chinese medicinal formula, has been used to improve or restore declined functions related to aging and geriatric diseases, such as impaired mobility, vision, hearing, cognition and memory. Here, we report on the effect and possible mechanisms of LWDH mediated protection of b-amyloid (Ab) induced paralysis in Caenorhabditis elegans using ethanol extract (LWDH-EE) and water extract (LWDH-WE). Chemical profiling and quantitative analysis revealed the presence of different levels of bioactive components in these extracts. LWDH-WE was rich in polar components such as monosaccharide dimers and trimers, whereas LWDH-EE was enriched in terms of phenolic compounds such as gallic acid and paeonol. In vitro studies revealed higher DPPH radical scavenging activity for LWDH-EE as compared to that found for LWDH-WE. Neither LWDH-EE nor LWDH-WE were effective in inhibiting aggregation of Ab in vitro. By contrast, LWDH-EE effectively delayed Ab induced paralysis in the transgenic C. elegans (CL4176) model which expresses human Ab1–42. Western blot revealed no treatment induced reduction in Ab accumulation in CL4176 although a significant reduction was observed at an early stage with respect to b-amyloid deposition in C. elegans strain CL2006 which constitutively expresses human Ab1–42. In addition, LWDH-EE reduced in vivo reactive oxygen species (ROS) in C. elegans (CL4176) that correlated with increased survival of LWDH-EE treated N2 worms under juglone-induced oxidative stress. Analysis with GFP reporter strain TJ375 revealed increased expression of hsp16.2::GFP after thermal stress whereas a minute induction was observed for sod3::GFP. Quantitative gene expression analysis revealed that LWDH-EE repressed the expression of amy1 in CL4176 while up-regulating hsp16.2 induced by elevating temperature. Taken together, these results suggest that LWDH extracts, particularly LWDH-EE, alleviated b-amyloid induced toxicity, in part, through up-regulation of heat shock protein, antioxidant activity and reduced ROS in C. elegans.
Keywords: Liuwei Dihuang; LWDH; beta-amyloid

Are emissions of black carbon from gasoline vehicles underestimated? Insights from near and on-road measurements - Liggio, John; Gordon, Mark; Smallwood, Gregory; Li, Shao-Meng; Stroud, Craig; Staebler, Ralf; Lu, Gang; Lee, Patrick; Taylor, Brett; Brook, Jeffrey R. (Environmental Science and Technology, 2012)
Measurements of black carbon (BC) with a high-sensitivity laser-induced incandescence (HS-LII) instrument and a single particle soot photometer (SP2) were conducted upwind, downwind, and while driving on a highway dominated by gasoline vehicles. The results are used with concurrent CO2 measurements to derive fuel-based BC emission factors for real-world average fleet and heavy-duty diesel vehicles separately. The derived emission factors from both instruments are compared, and a low SP2 bias (relative to the HS-LII) is found to be caused by a BC mass mode diameter less than 75 nm, that is most prominent with the gasoline fleet but is not present in the heavy-duty diesel vehicle exhaust on the highway. Results from both the LII and the SP2 demonstrate that the BC emission factors from gasoline vehicles are at least a factor of 2 higher than previous North American measurements, and a factor of 9 higher than currently used emission inventories in Canada, derived with the MOBILE 6.2C model. Conversely, the measured BC emission factor for heavy-duty diesel vehicles is in reasonable agreement with previous measurements. The results suggest that greater attention must be paid to black carbon from gasoline engines to obtain a full understanding of the impact of black carbon on air quality and climate and to devise appropriate mitigation strategies.

Raman and infrared spectroscopy of α and β phases of thin nickel hydroxide films electrochemically formed on nickel - Hall, David Scott; Lockwood, David J; Poirier, Shawn; Bock, Christina; MacDougall, Barry R (The Journal of Physical Chemistry A, 2012)
The present work utilizes Raman and infrared (IR) spectroscopy, supported by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) to re-examine the fine structural details of Ni(OH)2, which is a key material in many energy-related applications. This work also unifies the large body of literature on the topic. Samples were prepared by the galvanostatic basification of nickel salts and by aging the deposits in hot KOH solutions. A simplified model is presented consisting of two fundamental phases (α and β) of Ni(OH)2 and a range of possible structural disorder arising from factors such as impurities, hydration, and crystal defects. For the first time, all of the lattice modes of β-Ni(OH)2 have been identified and assigned using factor group analysis. Ni(OH)2 films can be rapidly identified in pure and mixed samples using Raman or IR spectroscopy by measuring their strong O–H stretching modes, which act as fingerprints. Thus, this work establishes methods to measure the phase, or phases, and disorder at a Ni(OH)2 sample surface and to correlate desired chemical properties to their structural origins.

Electrospun nanofiber membranes from polysulfones with chiral selector aimed for optical resolution - Mizushima, Hiroaki; Yoshikawa, Masakazu; Li, Nanwen; Robertson, Gilles P.; Guiver, Michael D. (European Polymer Journal, 2012)
Polysulfones with three types of alanyl residue, such as N-α-acetylalanine (Ac-Ala-OH), N-α-benzoylalanine (Bzo-Ala-OH), and N-α-benzyloxycarbonylalanine (Z-Ala-OH), as chiralselectors were prepared by polymer reaction. The resulting modified polysulfones showed chiroptical properties, indicating that the chiralselector residues were successfully introduced into the polysulfone. Nanofibermembranes prepared from the polymeric materials showed adsorption selectivity toward mixtures of racemic Glu, which were adopted as model racemates. Flux values for the nanofibermembranes were enhanced two to three orders of magnitude in comparison with the corresponding typical membranes, but without reduction in permselectivity. In the present study, it is shown that nanofiber is a suitable membrane form not only for molecularly imprinted membranes, but it exhibits enhanced throughput in comparison with typical dense membranes without concurrent reduction in permselectivity.
Keywords: chiral separation; electrospray deposition; membrane; nanofiber fabric; optical resolution; permselectivity; polysulfone

Roles for endothelin receptor B and BCL2A1 in spontaneous CNS metastasis of melanoma - Cruz-Munoz, William; Jaramillo, Maria L.; Man, Shan; Xu, Ping; Banville, Myriam; Collins, Catherine; Nantel, Andre; Morgan, Sherif S.; Cranmer, Lee D.; O'Connor-McCourt, Maureen D.; Kerbel, Robert S. (Cancer Research, 2012)
Metastatic spread of melanoma to CNS is a common and devastating manifestation of disease progression, which, despite its clinical importance, remains poorly understood with respect to undelying molecular mechanisms. Using a recently developed preclinical model of spontaneous melanoma CNS metastasis, we have identified alterations in expression of endothelin receptor B (ednrb) as a potential factor that influences brain metastatic potential. Induced overexpression of this gene mediated enhanced overall metastatic disease, and resulted in an increased incidence of spontaneous CNS metastases. In contrast, the overexpression of other highlighted genes, such as bcl2a1, did not affect the incidence of CNS metastases but nevertheless appears to facilitate intracranial tumor growth. The pro-metastatic effect in the CNS associated with EDNRB appears to be mediated by the interaction with its ligands resulting in enhanced tumor cell proliferation and thus intracranial melanoma growth. That EDRNB contributes to melanoma metastasis is underscored by the fact that its therapeutic inhibition by the EDNRB-specific inhibitor, A192621, translated into improved outcomes when treating mice with either visceral metastases or intracranial tumors. The identification of an influential role of EDNRB in CNS melanoma spontaneous metastasis may provide both a target for therapeutic intervention as well as a potential prognostic marker for patients having an increased predisposition for incidence of CNS melanoma metastases.

Polymers of intrinsic microporosity (PIMs) substituted with methyl tetrazole - Du, Naiying; Robertson, Gilles P.; Dal-Cin, Mauro M.; Scoles, Ludmila; Guiver, Michael D. (Polymer, 2012)
A polymer of intrinsic microporosity (PIM-1) containing nitrile groups was reacted by [2 + 3] cycloaddition reaction to give a polymer substituted with tetrazole groups (TZ-PIM), and then was further methylated to give a new PIM substituted with methyl tetrazole groups (MTZ-PIM). In contrast to TZ-PIMs, the MTZ-PIMs had distinctly improved solubility characteristics, enabling a more detailed investigation of the degree of conversion for the cycloaddition reaction and the structures of TZ-PIMs, which showed the presence of two kinds of tetrazole rings. Compared with PIM-1, the MTZ-PIM showed higher gas permselectivity with a corresponding decrease in gas permeability for pure gas pairs such as O₂/N₂ and CO₂/N₂, and for mixed gases, such as CO₂/N₂. Data for selectivity coupled with high gas permeability is close to the Robeson 2008 upper-bound performance limit for the O₂/N₂ and CO2/N2 pure gas pairs, and exceeds the upper-bound for the CO₂/N₂ mixed gas pair.
Keywords: Microporosity; Membrane; Tetrazole

Application of the Hough transform for the automatic determination of soot aggregate morphology - Grishin, Igor; Thomson, Keven; Migliorini, Francesca; Sloan, James J. (Applied Optics, 2012)
We report a new method for automated identification and measurement of primary particles within soot aggregates as well as the sizes of the aggregates and discuss its application to high-resolution transmission electron microscope (TEM) images of the aggregates. The image processing algorithm is based on an optimized Hough transform, applied to the external border of the aggregate. This achieves a significant data reduction by decomposing the particle border into fragments, which are assumed to be spheres in the present application, consistent with the known morphology of soot aggregates. Unlike traditional techniques, which are ultimately reliant on manual (human) measurement of a small sample of primary particles from a subset of aggregates, this method gives a direct measurement of the sizes of the aggregates and the size distributions of the primary particles of which they are composed. The current version of the algorithm allows processing of high-resolution TEM images by a conventional laptop computer at a rate of 1–2 ms per aggregate. The results were validated by comparison with manual image processing, and excellent agreement was found.

Metal supported tubular solid oxide fuel cells fabricated by suspension plasma spray and suspension high velocity oxy-fuel spray - Yoo, Yeong; Wang, Youliang; Deng, Xiaohua; Singh, Devinder; Legoux, Jean-Gabriel (Journal of Power Sources, 2012)
Low temperature (LT) metalsupportedsolidoxidefuelcells (SOFCs) have many advantages in comparison to conventional electrode or electrolyte supported type SOFCs. NRC has demonstrated high performance LT metalsupported planar SOFCs fabricated by either wet colloidal spray/sintering or suspension thermal spray. The combination of tubular configuration and metalsupported SOFCs may produce more unique and very attractive advantages such as easy and inexpensive sealing method and materials, high specific and volumetric power density, cost-effective fabrication, enhanced robustness, rapid start up, red-ox cycle tolerance and potential use for a pressurized integrated system. In this paper, thin film solid electrolyte of Sm₀.₂Ce₀.₈O₁.₉₀ (SDC) and NiO-SDC composite anode on sintered porous tubularmetal supports were deposited by suspension HVOF spray and suspensionplasmaspray, respectively on sintered porous tubularmetal support. La₀.₆Sr₀.₄Co₀.₂Fe₀.₈O₃₋δ (LSCF) cathode on the SDC electrolyte was formed by wet colloidal spray and subsequent sintering process as the final fabrication step. The detailed investigation of suspension and process-related parameters for suspension thermal spray was performed in order to produce thin and crack-free SDC thin film coatings. The electrochemical performance of single cells was demonstrated.
Keywords: Metal supported; Tubular; Suspension plasma spray; Suspension HVOF spray; Low temperature solid oxide fuel cell

Selective inhibition of USP7 - Menard, Robert; Sulea, Traian (Chemistry & Biology, 2012)
The deubiquitinating enzyme USP7 is an emerging oncology and antiviral target. Reverdy et al., in this issue of Chemistry & Biology, disclose the first small-molecule inhibitor selective for USP7, which recapitulates its knockdown in cancer cells and hence demonstrates the therapeutic feasibility of USP7 inhibitors.

Lateral resolution challenges for triangulation-based three-dimensional imaging systems - MacKinnon, David; Beraldin, Jean-Angelo; Cournoyer, Luc; Picard, Michel; Blais, Francois (Optical Engineering, 2012)
Lateral spatial resolution is a particularly challenging concept to quantify in triangulation-based 3D imaging systems. In this paper, we present these challenges, then describe an artifact-based methodology for evaluating the lateral resolution of a triangulation-based 3D imaging system that uses laser spots or laser lines. In particular, the response of a 3D imaging system to a spatial discontinuity (step edge) has traditionally been modelled as a first-order linear system. We model the response of a triangulation-based laser imaging system to a spatial step edge from first principles and demonstrate that the response should be modelled as a non-linear system. This model is then used as a basis for evaluating the lateral (structural) resolution of a triangulation-based laser imaging system.
Keywords: lateral resolution; modeling; system response; 3D imaging system; triangulation-based 3D imaging system; laser imaging system

Enlarging paraphrase collections through generalization and instantiation - Fujita, Atsushi; Isabelle, Pierre; Kuhn, Roland (Proceedings of the Joint Conference on Empirical Methods on Natural Language Processing and Computational Natural Language Learning, 2012)
This paper presents a paraphrase acquisition method that uncovers and exploits generalities underlying paraphrases: paraphrase patterns are first induced and then used to collect novel instances. Unlike existing methods, ours uses both bilingual parallel and monolingual corpora. While the former are regarded as a source of high-quality seed paraphrases, the latter are searched for paraphrases that match patterns learned from the seed paraphrases. We show how one can use monolingual corpora, which are far more numerous and larger than bilingual corpora, to obtain paraphrases that rival in quality those derived directly from bilingual corpora. In our experiments, the number of paraphrase pairs obtained in this way from monolingual corpora was a large multiple of the number of seed paraphrases. Human evaluation through a paraphrase substitution test demonstrated that the newly acquired paraphrase pairs are of reasonable quality. Remaining noise can be further reduced by filtering seed paraphrases.

Domain and function: a dual-space model of semantic relations and compositions - Turney, Peter D. (Journal of Artificial Intelligence Research (JAIR), 2012)
Given appropriate representations of the semantic relations between carpenter and wood and between mason and stone (for example, vectors in a vector space model), a suitable algorithm should be able to recognize that these relations are highly similar (carpenter is to wood as mason is to stone; the relations are analogous). Likewise, with representations of dog, house, and kennel, an algorithm should be able to recognize that the semantic composition of dog and house, dog house, is highly similar to kennel (dog house and kennel are synonymous). It seems that these two tasks, recognizing relations and compositions, are closely connected. However, up to now, the best models for relations are significantly different from the best models for compositions. In this paper, we introduce a dual-space model that unifies these two tasks. This model matches the performance of the best previous models for relations and compositions. The dual-space model consists of a space for measuring domain similarity and a space for measuring function similarity. Carpenter and wood share the same domain, the domain of carpentry. Mason and stone share the same domain, the domain of masonry. Carpenter and mason share the same function, the function of artisans. Wood and stone share the same function, the function of materials. In the composition dog house, kennel has some domain overlap with both dog and house (the domains of pets and buildings). The function of kennel is similar to the function of house (the function of shelters). By combining domain and function similarities in various ways, we can model relations, compositions, and other aspects of semantics.

White versus gray matter : fMRI hemodynamic responses show similar characteristics, but differ in peak amplitude - Fraser, Leanne M.; Stevens, M. Tynan; Beyea, Steven D.; D'Arcy, Ryan C. N. (BMC Neuroscience, 2012)
BACKGROUND: There is growing evidence for the idea of fMRI activation in white matter. In the current study, we compared hemodynamic response functions (HRF) in white matter and gray matter using 4 T fMRI. White matter fMRI activation was elicited in the isthmus of the corpus callosum at both the group and individual levels (using an established interhemispheric transfer task). Callosal HRFs were compared to HRFs from cingulate and parietal activation. RESULTS: Examination of the raw HRF revealed similar overall response characteristics. Finite impulse response modeling confirmed that the WM HRF characteristics were comparable to those of the GM HRF, but had significantly decreased peak response amplitudes. CONCLUSIONS: Overall, the results matched a priori expectations of smaller HRF responses in white matter due to the relative drop in cerebral blood flow (CBF) and cerebral blood volume (CBV). Importantly, the findings demonstrate that despite lower CBF and CBV, white matter fMRI activation remained within detectable ranges at 4 T.
Keywords: white matter; functional connectivity; BOLD response; hemodynamic response function; event-related

Searching for poor quality machine translated text : learning the difference between human writing and machine translations - Carter, Dave; Inkpen, Diana (Advances in Artificial Intelligence, 2012)
As machine translation (MT) tools have become mainstream, machine translated text has increasingly appeared on multilingual websites. Trustworthy multilingual websites are used as training corpora for statistical machine translation tools; large amounts of MT text in training data may make such products less effective. We performed three experiments to determine whether a support vector machine (SVM) could distinguish machine translated text from human written text (both original text and human translations). Machine translated versions of the Canadian Hansard were detected with an F-measure of 0.999. Machine translated versions of six Government of Canada web sites were detected with an F-measure of 0.98.We validated these results with a decision tree classifier. An experiment to find MT text on Government of Ontario web sites using Government of Canada training data was unfruitful, with a high rate of false positives. Machine translated text appears to be learnable and detectable when using a similar training corpus.

Machine learning for resource management in smart environments - Fabbricatore, Christian; Boley, Harold; Karduck, Achim P. (2012 6th IEEE International Conference on Digital Ecosystem Technologies (DEST), 2012)
Efficient resource and energy management is a key research and business area in todays IT markets. Cyber-physical ecosystems, like smart homes (SHs) and smart Environments (SEs) get interconnected, the efficient allocation of resources will become essential. Machine Learning and Semantic Web techniques for improving resource allocation and management are the focus of our research. They allow machines to process information on all levels, inferring expressive knowledge from raw data, in particular resource predictions from usage patterns. Our aim is to devise a novel approach for a machine learning (ML) and resource Management (RM) framework in SEs. It combines ML and SemanticWeb techniques and integrates user interaction. The main objective is to enable the creation of platforms that decrease the overall resource consumption by learning and predicting various usage patterns, and furthermore making decisions based on user-feedback. For this purpose, we evaluate recent research and applications, elicit framework requirements, and present a framework architecture. The approach and components are assessed and a prototype implementation is described.
Keywords: machine learning; resource management; energy savings; ambient assisted living; smart environment; semantic web

Posture-invariant statistical shape analysis using Laplace operator - Wuhrer, Stefanie; Shu, Chang; Xi, Pengcheng (Computers & Graphics, 2012)
Statistical shape analysis is a tool that allows to quantify the shape variability of a population of shapes. Traditional tools to perform statistical shape analysis compute variations that reflect both shape and posture changes simultaneously. In many applications, such as ergonomic design applications, we are only interested in shape variations. With traditional tools, it is not straightforward to separate shape and posture variations. To overcome this problem, we propose an approach to perform statistical shape analysis in a posture-invariant way. The approach is based on a local representation that is obtained using the Laplace operator.
Keywords: statistical shape analysis; posture-invariant shape processing; Laplace operator

SemEval-2012 Task 2 : measuring degrees of relational similarity - Jurgens, David A.; Mohammad, Saif M.; Turney, Peter D.; Holyoak, Keith J. (The First Joint Conference on Lexical and Computational Semantics. Volume 2: Proceedings of the 6th International Workshop on Semantic Evaluation (SemEval 2012), pages 356–364, 2012)
Up to now, work on semantic relations has focused on relation classification: recognizing whether a given instance (a word pair such as virus:flu) belongs to a specific relation class (such as CAUSE:EFFECT). However, instances of a single relation class may still have significant variability in how characteristic they are of that class. We present a new SemEval task based on identifying the degree of prototypicality for instances within a given class. As a part of the task, we have assembled the first dataset of graded relational similarity ratings across 79 relation categories. Three teams submitted six systems, which were evaluated using two methods.

WSReasoner : a prototype hybrid reasoner for ALCHOI ontology classification using a weakening and strengthening approach - Song, Weihong; Spencer, Bruce; Du, Weichang (Proceedings of the 1st International Workshop on OWL Reasoner Evaluation Workshop (ORE 2012) in conjunction with 6th International Joint Conference on Automated Reasoning (IJCAR 2012), 2012)
In the ontology classification task, consequence-based reasoners are typically significantly faster while tableau-based reasoners can process more expressive DL languages. However, both of them have difficulty to classify some available large and complex ALCHOI ontologies with complete results in acceptable time. We present a prototype hybrid reasoning system WSReasoner, which is built upon and takes advantages of both types of reasoners to provide efficient classification service. In our proposed approach, we approximate the target ontology O by a weakened version Owk and a strengthened version Ostr , both are in a less expressive DL ALCH and classified by a consequence-based main reasoner. Classification of Owk produces a subset of subsumptions of ontology O and the target of the classification of Ostr is to produce a superset of subsumptions of O. Additional subsumptions derived from Ostr may be unsound, so they are further verified by a tableau-based assistant reasoner. For the ALCHOI ontologies in our experiment, except for one for which WSReasoner has not obtained the result, the number of subsumptions derived from WSReasoner is no fewer than from the reasoners that could finish the classification. Moreover, WSReasoner takes less time than tableau-based reasoners when the ALCHOI ontologies are large.

Mixing multiple translation models in statistical machine translation - Razmara, Majid; Foster, George; Sankaran, Baskaran; Sarkar, Anoop (Proceedings of the 50th Annual Meeting of the Association for Computational Linguistics, 2012)
Statistical machine translation is often faced with the problem of combining training data from many diverse sources into a single translation model which then has to translate sentences in a new domain. We propose a novel approach, ensemble decoding, which combines a number of translation systems dynamically at the decoding step. In this paper, we evaluate performance on a domain adaptation setting where we translate sentences from the medical domain. Our experimental results show that ensemble decoding outperforms various strong baselines including mixture models, the current state-of-the-art for domain adaptation in machine translation.

Transductive relational classification in the co-training paradigm - Ceci, Michelangelo; Appice, Annalisa; Viktor, Herna L.; Malerba, Donato; Paquet, Eric; Guo, Hongyu (Machine Learning and Data Mining in Pattern Recognition : 8th International Conference, MLDM 2012, Berlin, Germany, July 13-20, 2012. Proceedings, 2012)
Consider a multi-relational database, to be used for classification, that contains a large number of unlabeled data. It follows that the cost of labeling such data is prohibitive. Transductive learning, which learns from labeled as well as from unlabeled data already known at learning time, is highly suited to address this scenario. In this paper, we construct multi-views from a relational database, by considering different subsets of the tables as contained in a multi-relational database. These views are used to boost the classification of examples in a co-training schema. The automatically generated views allow us to overcome the independence problem that negatively affect the performance of co-training methods. Our experimental evaluation empirically shows that co-training is beneficial in the transductive learning setting when mining multi-relational data and that our approach works well with only a small amount of labeled data.
Keywords: transductive learning; co-training; multi-relational classification

Androgenesis-inducing stress treatments change phytohormone levels in anthers of three legume species (Fabaceae) - Lulsdorf, Monika; Yuan, Hai Ying; Slater, Susan; Vandenberg, Albert; Han, Xiumei; Zaharia, L. Irina (Plant Cell Reports, 2012)
Legumes are recalcitrant to androgenesis and induction protocols were only recently developed for pea (Pisum sativum L.) and chickpea (Cicer arietinum L.), albeit with low regeneration frequencies. Androgenesis is thought to be mediated through abscisic acid (ABA) but other phytohormones, such as auxins, cytokinins, and gibberellins, have also been implicated. In view of improving induction protocols, the hormone content of pea, chickpea, and lentil anthers was measured after exposure to cold, centrifugation, electroporation, sonication, osmotic shock, or various combinations thereof using an analytical mass spectrometer. Indole-3-acetic acid (IAA) had a key function during the induction process. In pea, high concentrations of IAA-asparagine (IAA-Asp), a putative IAA metabolite, accumulated during the application of the different stresses. In chickpea, the IAA-Asp concentration increased 30-fold compared to pea but only during the osmotic shock treatment and likely as a result of the presence of exogenous IAA in the medium. In contrast, no treatment in lentil (Lens culinaris) invoked such an increase in IAA-Asp content. Of the various cytokinins monitored, only cis zeatin riboside increased after centrifugation and electroporation in pea and possibly chickpea. No bioactive gibberellins were detected in any species investigated, indicating that this hormone group is likely not linked to androgenesis in legumes. In contrast to the other stresses, osmotic shock treatment caused a reduction in the levels of all hormones analyzed, with the exception of IAA-Asp in chickpea. A short period of low hormone content might be a necessary transition phase for androgenesis induction of legumes.
Keywords: Abscisic acid; auxin, cytokinin; gibberellin; centrifugation; electroporation; sonication; osmotic shock

Properties of polysaccharides in several seaweeds from Atlantic Canada and their potential anti-influenza viral activities - Jiao, Guangling; Yu, Guangli; Wang, Wei; Xhao, Xiaoliang; Zhang, Junzeng; Ewart, Stephen H. (Journal of Ocean University of China, 2012)
To explore the polysaccharides from selected seaweeds of Atlantic Canada and to evaluate their potential anti-influenza virus activities, polysaccharides were isolated from several Atlantic Canadian seaweeds, including three red algae (Polysiphonia lanosa, Furcellaria lumbricalis, and Palmaria palmata), two brown algae (Ascophyllum nodosum and Fucus vesiculosus), and one green alga (Ulva lactuca) by sequential extraction with cold water, hot water, and alkali solutions. These polysaccharides were analyzed for monosaccharide composition and other general chemical properties, and they were evaluated for anti-influenza virus activities. Total sugar contents in these polysaccharides ranged from 15.4% (in U. lactuca) to 91.4% (in F. lumbricalis); sulfation level was as high as 17.6% in a polysaccharide from U. lactuca, whereas it could not be detected in an alikali-extract from P. palmaria. For polysaccharides from red seaweeds, the main sugar units were sulfated galactans (agar or carrageenan) for P. lanosa, F. lumbricalis, and xylans for P. palmata. In brown seaweeds, the polysaccharides largely contained sulfated fucans, whereas the polysaccharides in green seaweed were mainly composed of heteroglycuronans. Screening for antiviral activity against influenza A/PR/8/34 (H1N1) virus revealed that brown algal polysaccharides were particularly effective. Seaweeds from Atlantic Canada are a good source of marine polysaccharides with potential antiviral properties.
Keywords: anti-influenza viral activity; H1N1; monosaccharide composition; polysaccharides

Biodegradation of RDX nitroso products MNX and TNX by cytochrome P450 XpIA - Halasz, Annamaria; Manno, Dominic; Perreault, Nancy N.; Sabbadin, Federico; Bruce, Neil C.; Al-Hawari, Jalal (Environmental Science & Technology, 2012)
Anaerobic transformation of the explosive RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) by microorganisms involves sequential reduction of N-NO2 to the corresponding N-NO groups resulting in the initial formation of MNX (hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine). MNX is further reduced to the dinitroso (DNX) and trinitroso (TNX) derivatives. In this paper, we describe the degradation of MNX and TNX by the unusual cytochrome P450 XplA that mediates metabolism of RDX in Rhodococcus rhodochrous strain 11Y. XplA is known to degrade RDX under aerobic and anaerobic conditions, and, in the present study, was found able to degrade MNX to give similar products distribution including NO2-, NO3-, N2O, and HCHO but with varying stoichiometric ratio, that is, 2.06, 0.33, 0.33, 1.18, and 1.52, 0.15, 1.04, 2.06, respectively. In addition, the ring cleavage product 4-nitro-2,4,-diazabutanal (NDAB) and a trace amount of another intermediate with a [M-H]- at 102 Da, identified as ONNHCH2NHCHO (NO-NDAB), were detected mostly under aerobic conditions. Interestingly, degradation of TNX was observed only under anaerobic conditions in the presence of RDX and/or MNX. When we incubated RDX and its nitroso derivatives with XplA, we found that successive replacement of N-NO2 by N-NO slowed the removal rate of the chemicals with degradation rates in the order RDX > MNX > DNX, suggesting that denitration was mainly responsible for initiating cyclic nitroamines degradation by XplA. This study revealed that XplA preferentially cleaved the N-NO2 over the N-NO linkages, but could nevertheless degrade all three nitroso derivatives, demonstrating the potential for complete RDX removal in explosives-contaminated sites.

Comparison of four models to rank failure likelihood of individual pipes - Kleiner, Y.; Rajani, B. B. (Journal of Hydroinformatics, 2012)
This paper describes alternative models developed into operational tools that can assist network owners and planners to identify individual mains for renewal in their water distribution networks. Four models were developed and compared: a heuristic model, naïve Bayesian classification model, a model based on logistic regression and finally a probabilistic model based on the Non Homogeneous Poisson Process (NHPP). These models rank individual water mains in terms of their anticipated breakage frequency, while considering both static (e.g., pipe material, diameter, vintage, surrounding soil, etc.) and dynamic (e.g., climate, operations, cathodic protection, etc.) effects influencing pipe deterioration rates.
Keywords: Pipes and pipelines; Conduites

Some effects on natural ventilation system for subway tunnel fires - Kashef, A.; Yuan, Z.; Lei, B. (2012)
A series of experiments, using a 1:15 model tunnel, were designed in accordance with the Froude conservation approach to investigate the influential parameters on temperature distributions in tunnel fires with natural ventilation. The effect of parameters such as fire size, shaft length and height were investigated. A natural ventilation system was achieved by introducing four vertical shafts spaced at 4 m in the ceiling of the tunnel. In the study reported in this paper, propane gas, located on the floor of the tunnel, was used to simulate the fire source which produced heat release rates in the range of 3.61kW to 12.2 kW. The smoke temperature distributions along the tunnel ceiling and in the vertical direction along the tunnel length were measured using K-type thermocouples trees. Based on the fire plume theory, a dimensionless temperature was defined and it was found that the fire size did not have a major effect on the dimensionless temperature. Despite the fact that the shaft sizes did not significantly affect the distribution of the temperature in the near-field of the fire, they did influence the temperature values with the temperatures dropping with the increase of shaft size. Based on the one-dimensional theory and rational assumptions, two formulas were developed to predict the ceiling longitudinal temperature distribution in tunnel fires with natural ventilation.
Keywords: Tunnels, fires, emergency ventilation, fire and smoke control and visibility; Tunnels; Tunnels

Effect of structural changes on acoustic performance of wood frame walls - Schoenwald, Stefan; Wenzke, Erik; King, Frances; Zeitler, Berndt (Proceedings - European Conference on Noise Control, 2012)
Sometimes in wood frame construction wall assemblies are required that have a higher axial loadbearing capacity than conventional loadbearing wall designs. To increase the axial load bearingcapacity to carry higher vertical loads, i.e. dead load or traffic load of upper building storeys, theframing has to be stronger, which can be achieved by either decreasing the spacing of the studs orby using stronger studs at a wider spacing. These significant structural measures increase the wallstiffness and thus can also affect the airborne sound insulation of the wall assemblies. The effectof wall stiffness on airborne sound insulation was investigated, by analysing bendingwavenumbers measured along the primary axis on the gypsum board leaf of a common staggeredstud wood frame wall and of assemblies with smaller than typical stud spacing (i.e. <400 mm),with multi-stud columns at a wider spacing, and with shear membranes in various configurations.A correlation in the change of bending wavenumber results and the change of airborne soundinsulation was found in frequency ranges where the wall stiffness was influenced by the designchanges. The results are promising and a first step towards a method for the estimation ofairborne sound insulation changes from the mechanical properties of the wall.
Keywords: Office acoustics; Acoustique des bureaux

Fire protection performance of Novec1230 in electronic facilities - Kim, A. K. (Fire and Safety, 2012)
Keywords: Fire; Incendie; Suppression; Extinction

Household materials as emission sources of naphthalene in Canadian homes and their contribution to indoor air - Kang, Dong Hwa; Choi, Dong Hee; Won, Doyun; Yang, Wenping; Schleibinger, Hans; David, Jacinthe (Atmospheric Environment, 2012)
The objective of this study was to identify household materials that may contribute to the indoor naphthalene concentration in Canadian homes. Ninety-nine household materials including building materials, furnishings, and consumer products were tested. These materials included well-known naphthalene-containing products such as mothballs as well as building and consumer products where naphthalene could have been either added as part of a liquid formulation or used as a chemical intermediate in the manufacture of solid materials and product components. A fast screening method was used to determine the naphthalene concentration in a micro-scale test chamber. The tested materials were ranked based on the naphthalene emission strength combined with the amount of products typically used in homes. As expected, the results showed that mothballs, which had the highest emission factor, are one of the predominant sources. Interestingly, vinyl and wooden furniture with high emission factors and painted walls and ceiling with large surface areas were found to be important sources with the source strength even larger than those of mothballs when maximum emission factors were assumed for these building materials and furnishings. This suggests that some building materials and furnishings could be significant contributors to indoor naphthalene concentrations. This study shows that selecting materials with lower naphthalene emission factors could be one of many ways to reduce the indoor naphthalene concentration.
Keywords: Naphthalene; household materials; emission source; Canadian homes; exposure; micro-scale chamber; Indoor air; Air intérieur

State of the art review of technologies for pipe structural health monitoring - Liu, Z.; Kleiner, Y. (IEEE Sensors Journal, 2012)
This paper presents a state of the review of sensor technologies used for monitoring indicators pointing to pipe structural deterioration. The potential for multi-sensor system and sensor data fusion for condition-based maintenance are also discussed.
Keywords: pipe condition assessment, sensor, structural health monitoring, sensor data fusion; Pipes and pipelines; Conduites

Improved laser scan for pitting corrosion measurement by using super resolution technique - Liu, Z.; Krys, D. (Automation in Construction, 2012)
In this paper, a single-frame super resolution method is proposed to infer a high-resolution laser scan from the low-resolution input. The relation between the low resolution input and high-resolution result is modeled with a Markov random field (MRF) with the aid of a training set built in advance. A belief propagation algorithm is implemented to infer the super-resolved result. The experiments demonstrate a good performance of the proposed method in comparison with the traditional interpolation methods.
Keywords: Ductile iron pipe, performance assessment, pitting corrosion, image super resolution, Markov random field; Pipes and pipelines; Conduites

Condensation risk assessment on box windows : the effect of the window-wall interface - Maref, W.; Van Den Bossche, N.; Armstrong, M.; Lacasse, M. A.; Elmahdy, H.; Glazer, R. (Journal of Building Physics, 2012)
Windows generally have the lowest temperature index in current building types, and will consequently be the primary location for interior surface condensation. Surface temperatures can easily be calculated using thermal finite-element-models, but these generally omit the effect of convection in the windows and the window-wall interface. Hence, there is a need to determine if specific interface details provide potential for condensation on the window components in which air leakage paths may be prominent. The paper reports on a laboratory evaluation of condensation risk assessment in a hotbox, with varying pressure differences and the introduction of deficiencies. It was concluded that the effect of the type of insulation in the window-wall interface was very low for isobaric boundary conditions, whereas it has a significant effect when pressure differences are applied.
Keywords: condensation; window-wall interface; box window; pressure difference; deficiency; temperature index; laboratory experiment; guarded hot box; full-scale; Wall/Window interface; l'Interface fenêtre-mur

Comparison of proposed methods to include lightweight framed structures in EN 12354 prediction model - Schoenwald, Stefan (Proceedings - European Conference on Noise Control, 2012)
In this paper proposed methods are compared through prediction of flanking sound transmission across a wood frame wall-wall junction. Data measured in the NRC-IRC flanking sound transmission facility is used as input data as well as for the validation of the methods.
Keywords: Building acoustics, flanking sound transmission, precition method; Office acoustics; Acoustique des bureaux

Exploration of the relationship between water main breaks and temperature covariates - Rajani, B. B.; Kleiner, Y.; Sink, J-E. (Urban Water Journal, 2012)
This paper examines the impact of temperature changes on observed pipe breakage rate for three pipe materials, namely, cast iron, ductile iron and galvanized steel. Several water and air temperature-based covariates were tested in conjunction with a non-homogeneous Poisson pipe break model to assess their impact on water main breaks, using data sets from three different water utilities in the USA and Canada. Temperature-based covariates, such as average mean air temperature, maximum air temperature increase and decrease, and how fast the air temperature increase and decrease over a specific period of days, were found to be consistently significant. While the availability of water temperature data (which most utilities do not have) can enhanced the prediction of water main breaks, it appears that air temperature data alone (which most utilities can access) are usually sufficient.
Keywords: ductile iron pipes, corrosion pit, pipe sampling, condition assessment; Water mains; Conduites d'eau

Hybrid fire testing of building structures - Mostafaei, H. (2012)
A performance-based fire resistance evaluation method, called hybrid fire testing (HFT), was developed and carried out at the Fire Research Program of the National Research Council of Canada (NRC). HFT offers a more cost-effective approach to the assessment of the full structures performance in fire than that of a full-scale test and provides more reliable results than prescriptive single component testing. In the HFT method, the whole building is divided into two substructures; 1) the test specimen and 2) the model component. Then, fire performance of the whole structure is evaluated based on coupling the performance of the two substructures and by including their interactions in real time during the simulation. In this study, the HFT was applied for a 6-storey reinforced concrete building structure with a fire compartment scenario on the first floor. The test specimen was a worst-case scenario column in the compartment of fire origin in the building. The specimen was physically tested in a full-scale furnace, and the remaining of the building structure was modeled using numerical analysis software. In the HFT, the real time interactions between the two substructures are based not only on including the experimental results obtained from the test specimen into the numerical model component but most importantly also including feeding the output of the model component back into the test specimen environment (e.g. vertical and lateral loading changes). In other words, both equilibrium and compatibility conditions are satisfied between the test specimen and the model component. The results of this study show that the HFT is achievable and can be performed successfully for fire performance evaluation of a building structure.
Keywords: Hybrid test, performance-based assessment, fire resistance, numerical analysis, fire test building in fire; Design fires/Fire modeling; Conception d'incendies-types

Investigation of thermal performance of reflective insulations for different applications - Saber, H. H. (Journal of Building and Environment, 2012)
In this study, the test data was obtained from a different test method based on the heat flow meter in accordance of ASTM C-518 in the case of horizontal sample stacks with reflective insulations. Results showed that the predicted heat fluxes on the same area and same location of Heat Flux Transducers (HFTs) on the top and bottom surfaces of the sample stacks are in good agreement with the measured heat fluxes (within ±1%). The derived R-values using these heat fluxes are also in good agreements. Due to the combined effect of heat transfer by convection and radiation in the airspace (facing the reflective surface), these predicted and measured heat fluxes are greater than the area-weighted average heat flux of whole sample stack, which is needed to determine the effective R-value of the sample. As such, the derived R-value from the test data resulted in underestimation of the effective R-value of the sample stack. After gaining confidence in the present model, it was used to conduct parametric study in order to quantify the contribution of reflective insulations to the effective R-value for a sample stack with different inclination angles, different directions of heat flow (upward and downward) and for a wide range of foil emissivity. Furthermore, the present model was used to compare the predicted R-values with the listed R-values in the 2009 ASHRAE Handbook [22] for enclosed air cavity (20 mm thick) of different effective emittance, inclinations and directions of heat flow.
Keywords: Reflective insulation, furred-airspace assembly, low emissivity material, thermal modelling, thermal resistance test method, R-value, heat flow meter, ASTM C-518, ASTM C-1363, airflow, heat transfer by convection, conduction and radiation; Walls; Murs

Fire suppression performance of manually applied CAF and other water based systems - Kim, A. K.; Crampton, G. P. (2012)
Keywords: Fire; Incendie; Suppression; Extinction

Multi-objective and probabilistic decision-making approaches to sustainable design and management of highway bridge decks - Lounis, Z.; Daigle, L. (Structure and Infrastructure Engineering (Special Issue on Asset Management), 2012)
In this paper, a simplified approach to sustainable design and management of highway bridge decks is proposed in which relevant data on some key social, economic and environmental performance measures are provided to support effective decision-making. The socioeconomic performance measures include physical condition of the deck, life cycle costs to owners and users, including accident costs, traffic delay costs and vehicle operating costs. The environmental performance measures include C02 emissions and construction waste. The proposed life cycle-based design and management approach is based on probabilistic mechanistic models that predict the time varying probabilities of chloride contamination, reinforcement corrosion, and corrosion -induced damage of the deck. The proposed approach is illustrated on the life cycle design and management of highway bridge decks using normal and high performance concrete. It is shown that high performance concrete decks outperform normal concrete decks in terms of longer service life, lower life cycle costs, and higher reductions in C02 emissions and waste materials.
Keywords: Highway bridge decks; life cycle design; mechanistic service life models; social-economic-environmental performance; sustainable management; uncertainty modelling.; Concrete; Béton

Evaluation of the fire suppression effectiveness of manually applied compressed-air-foam (CAF) system - Kim, A. K.; Crampton, G. P. (Fire Technology, 2012)
Keywords: Fire; Incendie; Suppression; Extinction

Design fires for road tunnels safety design - Kashef, A.; Viegas, J.; Mos, A.; Harvey, N. (ASHRAE Transactions, 2012)
Design fires are an intrinsic part in designing tunnels for fires. They provide, quantitatively, the fire characteristics that are used to establish the sizing of equipment in tunnels and the scenarios to consider when developing emergency response plans. They are also used, indirectly, when considering the impact of fires on the structure. As such, design fires form the base input for emergency ventilation, evacuation, and structural design analyses. A design fire is generally defined in terms of heat release rate, and species output as functions of time. This paper summarizes efforts to develop a set of design fire curves as a useful tool for road tunnel fire risk assessment.
Keywords: Design fires/Fire modeling; Conception d'incendies-types

Federal investigation of the evacuation of the World Trade Centre on September 11, 2001 - Averill, Jason D.; Mileti, D.; Peacock, R.; Kuligowski, E.; Groner, N.; Proulx, G.; Reneke, P.; Nelson, H. (Fire and Materials, 2012)
Keywords: evacuation; human behaviour; world trade center; Comportement humain; World Trade Centre

Decarboxylation-induced cross-linking of polymers of intrinsic microporosity (PIMs) for membrane gas separation - Du, Naiying; Dal-Cin, Mauro M.; Robertson, Gilles P.; Guiver, Michael D. (Macromolecules, 2012)
Keywords: cross-linked membranes; gas separation; C-PIMs; decarboxylation; carboxylated PIMs; polymers of intrinsic microporosity; fourier transform infrared spectroscopy; FTIR

Mining biological information from 3D gene expression data : the OPTricluster algorithm - Tchagang, Alain B.; Phan, Sieu; Famili, Fazel; Shearer, Heather; Fobert, Pierre; Huang, Yi; Zou, Jitao; Huang, Daiqing; Cutler, Adrian; Liu, Ziying; Pan, Youlian (BMC Bioinformatics 2012, 2012)
Background: Nowadays, it is possible to collect expression levels of a set of genes from a set of biological samples during a series of time points. Such data have three dimensions: gene-sample-time (GST). Thus they are called 3D microarray gene expression data. To take advantage of the 3D data collected, and to fully understand the biological knowledge hidden in the GST data, novel subspace clustering algorithms have to be developed to effectively address the biological problem in the corresponding space.

Ecological validity and the evaluation of speech summarization quality - McCallum, Anthony; Munteanu, Cosmin; Penn, Gerald; Zhu, Xiaodan (Proceeding of the Workshop on Evaluation Metrics and System Comparison for Automatic Summarization, 2012)
There is little evidence of widespread adoption of speech summarization systems. This may be due in part to the fact that the natural language heuristics used to generate summaries are often optimized with respect to a class of evaluation measures that, while computationally and experimentally inexpensive, rely on subjectively selected gold standards against which automatically generated summaries are scored. This evaluation protocol does not take into account the usefulness of a summary in assisting the listener in achieving his or her goal. In this paper we study how current measures and methods for evaluating summarization systems compare to human-centric evaluation criteria. For this, we have designed and conducted an ecologically valid evaluation that determines the value of a summary when embedded in a task, rather than how closely a summary resembles a gold standard. The results of our evaluation demonstrate that in the domain of lecture summarization, the wellknown baseline of maximal marginal relevance (Carbonell and Goldstein, 1998) is statistically significantly worse than human-generated extractive summaries, and even worse than having no summary at all in a simple quiz-taking task. Priming seems to have no statistically significant effect on the usefulness of the human summaries. In addition, ROUGE scores and, in particular, the contextfree annotations that are often supplied to ROUGE as references, may not always be reliable as inexpensive proxies for ecologically valid evaluations. In fact, under some conditions, relying exclusively on ROUGE may even lead to scoring human-generated summaries that are inconsistent in their usefulness relative to using no summaries very favourably.

On hierarchical re-ordering and permutation parsing for phrase-based decoding - Cherry, Colin; Moore, Robert C.; Quirk, Chris (Proceedings of the 7th Workshop on Statistical Machine Translation (WMT 2012), 2012)
The addition of a deterministic permutation parser can provide valuable hierarchical information to a phrase-based statistical machine translation (PBSMT) system. Permutation parsers have been used to implement hierarchical re-ordering models (Galley and Manning, 2008) and to enforce inversion transduction grammar (ITG) constraints (Feng et al., 2010). We present a number of theoretical results regarding the use of permutation parsers in PBSMT. In particular, we show that an existing ITG constraint (Zens et al., 2004) does not prevent all non-ITG permutations, and we demonstrate that the hierarchical reordering model can produce analyses during decoding that are inconsistent with analyses made during training. Experimentally, we verify the utility of hierarchical re-ordering, and compare several theoretically-motivated variants in terms of both translation quality and the syntactic complexity of their output.

Binary classifiers and latent sequence models for emotion detection in suicide notes - Cherry, Colin; Mohammad, Saif M.; de Bruijn, Berry (Biomedical Informatics Insights, 2012)
This paper describes the National Research Council of Canada’s submission to the 2011 i2b2 NLP challenge on the detection of emotions in suicide notes. In this task, each sentence of a suicide note is annotated with zero or more emotions, making it a multi-label sentence classification task. We employ two distinct large-margin models capable of handling multiple labels. The first uses one classifier per emotion, and is built to simplify label balance issues and to allow extremely fast development. This approach is very effective, scoring an F-measure of 55.22 and placing fourth in the competition, making it the best system that does not use web-derived statistics or re-annotated training data. Second, we present a latent sequence model, which learns to segment the sentence into a number of emotion regions. This model is intended to gracefully handle sentences that convey multiple thoughts and emotions. Preliminary work with the latent sequence model shows promise, resulting in comparable performance using fewer features.

Cybersickness induced by desktop virtual reality - Vinson, Norman G.; Lapointe, Jean-Francois; Parush, Avi; Roberts, Shelley (Proceedings Graphics Interface 2012, 2012)
Cybersickness, a syndrome resulting from exposure to virtual reality displays, raises ethical and liability issues. We have found that, contrary to the majority of previous reports in the literature, cybersickness can be induced by desktop virtual real-ity. Moreover, our findings suggest that some individuals susceptible to cybersickness can be screened out on the basis of their self-reported susceptibility to motion sickness.
Keywords: Cybersickness; simulator sickness; screening; desktop; liability; ethics

Portable features for classifying emotional text - Mohammad, Saif (Proceedings of The 2012 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies (NAACL:HLT-2012), Montreal, QC, June 3-8, 2012, 2012)
Are word-level affect lexicons useful in detecting emotions at sentence level? Some prior research finds no gain over and above what is obtained with ngram features-arguably the most widely used features in text classification. Here, we experiment with two very different emotion lexicons and show that even in supervised settings, an affect lexicon can provide significant gains. We further show that while ngram features tend to be accurate, they are often unsuitable for use in new domains. On the other hand, affect lexicon features tend to generalize and produce better results than ngrams when applied to a new domain.

Batch tuning strategies for statistical machine translation - Cherry, Colin; Foster, George (Proceedings of the 2012 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies - (HLT-NAACL 2012), 2012)
There has been a proliferation of recent work on SMT tuning algorithms capable of handling larger feature sets than the traditional MERT approach. We analyze a number of these algorithms in terms of their sentence-level loss functions, which motivates several new approaches, including a Structured SVM. We perform empirical comparisons of eight different tuning strategies, including MERT, in a variety of settings. Among other results, we find that a simple and efficient batch version of MIRA performs at least as well as training online, and consistently outperforms other options.

A methodology for composing behaviour models for military simulations - Unrau, David P.; Emond, Bruno (21st Annual Conference on Behavior Representation in Modeling and Simulation (BRiMS 2012), 2012)
Keywords: Decision-making; Ontology; Military Simulation; Standardization

Fractal geometry and multimedia retrieval: a theoretical framework - Paquet, Eric; Viktor, Herna L. (3D Image Processing (3DIP) and Applications 2012 Conference Proceedings, 2012)
This paper presents a theoretical analysis of the occurrence of fractal geometry within index spaces and discusses the impact for multimedia retrieval. Firstly, we explain how to detect the presence of such a fractal geometry. Then, with the fractal hypothesis in hand, we analyze the impact of this geometry when calculating the distance between indexes and searching for similar multimedia objects. We demonstrate that it is possible to define probability distributions in fractal index space and we present an approach to calculate them. Practical consequences are discussed, with particular emphasis to multimedia retrieval methods based on Bayesian analysis.
Keywords: Bayesian; distance; distribution; fractal; geometry; indexing; Lagrangian; multimedia; object; probability; retrieval

Cognitive modelling of early music reading skill acquisition for piano - Emond, Bruno; Comeau, Gilles (Proceedings of the 11th International Conference on Cognitive Modeling (ICCM 2012), 2012)
In the classical music tradition, knowing how to read music is an essential skill and is seen as a fundamental component to develop when learning to play the piano. This research's focus is to study the possible impact of the different teaching approach on the acquisition of initial reading skills. By using cognitive modeling, we are hoping to observe through computer simulation the problem solving and decisionmaking tasks involved in decoding a simple musical score. The paper introduces the Middle-C and Intervallic methods followed by a description of an ACT-R cognitive model and simulation results upon learning with each of the piano methods.
Keywords: Music reading; piano methods; ACT-R

A tale of two studies: challenges in field research with low-literacy adult learners in a developed country - Munteanu, Cosmin; Molyneaux, Heather; Maitland, Julie; McDonald, Daniel; Leung, Rock (CHI 2012: Proceedings of the 2012 ACM annual conference extended abstracts on Human Factors in Computing Systems, 2012)
Efforts to address the problems of literacy are often focused on developing countries. However, functional illiteracy is a challenge encountered by up to 50 percent of adults in developed countries. In this paper we reflect on the challenges we faced in trying to design and study the use of a mobile application to support adult literacy with two user groups: adults enrolled in literacy classes and carpenters without a high school education enrolled in an essential skills program. We also elaborate on aspects of the evaluations that are specific to a marginalized, functionally illiterate, group in a developed country – aspects that are less frequently present in similar studies of mobile literacy support technologies in developing countries. We conclude with presenting the lessons learnt from our evaluations and the impact of the studies' specific challenges on the outcome and uptake of such mobile assistive technologies in providing practical support to low-literacy adults in conjunction with literacy and essential skills training.
Keywords: User studies; evaluation methodology; mobile computing; interface design; educational interfaces; mobile learning; assistive technology

Cost-sensitive self-training - Guo, Yuanyuan; Zhang, Harry; Spencer, Bruce (Advances in Artificial Intelligence : 25th Canadian Conference on Artificial Intelligence, Canadian AI 2012, Toronto, ON, Canada, May 28-30, 2012. Proceedings, 2012)
In some real-world applications, it is time-consuming or expensive to collect much labeled data, while unlabeled data is easier to obtain. Many semi-supervised learning methods have been proposed to deal with this problem by utilizing the unlabeled data. On the other hand, on some datasets, misclassifying different classes causes different costs, which challenges the common assumption in classification that classes have the same misclassification cost. For example, misclassifying a fraud as a legitimate transaction could be more serious than misclassifying a legitimate transaction as fraudulent. In this paper, we propose a cost-sensitive self-training method (CS-ST) to improve the performance of Naive Bayes when labeled instances are scarce and different misclassification errors are associated with different costs. CS-ST incorporates the misclassification costs into the learning process of self-training, and approximately estimates the misclassification error to help select unlabeled instances. Experiments on 13 UCI datasets and three text datasets show that, in terms of the total misclassification cost and the number of correctly classified instances with higher costs, CS-ST has better performance than the self-training method and the base classifier learned from the original labeled data only.
Keywords: self-training; cost-sensitive; Naive Bayes

An ecologically valid evaluation of speech summarization - McCallum, Anthony; Munteanu, Cosmin; Penn, Gerald; Zhu, Xiaodan (CHI 2012: Proceedings of the 2012 ACM annual conference extended abstracts on Human Factors in Computing Systems, 2012)
The past decade has witnessed an explosion in the size and availability of online audio-visual repositories, such as entertainment, news, or lectures. Summarization systems have the potential to provide significant assistance with navigating such repositories. Unfortunately, automatically-generated summaries often fall short of delivering the information needed by users. This is due, in no small part, to the fact that the natural language heuristics used to generate summaries are often optimized with respect to currently-used evaluation metrics. Such metrics simply score automaticallygenerated summaries against subjectively-classified gold standards without taking into account the usefulness of a summary in assisting a user achieve a certain goal or even overall summary coherence. We have previously shown that an immediate consequence of this problem is that even the most linguistically-complex summarization systems perform no better than basic heuristics, such as picking the longest sentences from a general-topic, spontaneous dialog, or the first few sentences from a news recording. Our hypothesis is that complex systems are in fact better, if measured properly. What is thus needed instead are evaluation metrics (and consequently, automatic summarizers) that incorporate features such as user preferences and task-orientation. For this, we propose an ecologically valid evaluation metric that determines the value of a summary when embedded in a task, rather than how closely a summary matches a gold standard.
Keywords: Speech summarization; user study; extrinsic evaluation

Improving AMBER, an MT Evaluation Metric - Chen, Boxing; Kuhn, Roland; Foster, George (NAACL 2012 Workshop on Statistical Machine Translation: (WMT-2012), 2012)
A recent paper described a new machine translation evaluation metric, AMBER. This paper describes two changes to AMBER. The first one is incorporation of a new ordering penalty; the second one is the use of the downhill simplex algorithm to tune the weights for the components of AMBER. We tested the impact of the two changes, using data from the WMT metrics task. Each of the changes by itself improved the performance of AMBER, and the two together yielded even greater improvement, which in some cases was more than additive. The new version of AMBER clearly outperforms BLEU in terms of correlation with human judgment.

Near-infrared fluorescence imaging of mouse myocardial microvascular endothelium using Cy5.5-lectin conjugate - Nguyen, Cecilia; Bascaramurty, Saro; Kuzio, Bozena; Gregorash, Lori; Kupriyanov, Valery; Jilkina, Olga (Journal of Biophotonics, 2012)
Cy5.5-lectin, a non-toxic conjugate, combines the benefits of near-infrared (NIR) imaging, such as significant reduction of background fluorescence and increased tissue depth penetration, with its affinity for vascular endothelial cells. When compared to endothelial staining methods using FITC-lectin and ICAM2 antibodies, Cy5.5-lectin was confirmed to specifically bind endothelial cells and produce a fluorescence signal both in real-time and post-infusion. Ex-vivo experiments with isolated hearts demonstrated that binding was limited to perfused areas of the myocardium. With mouse in-vivo tail-vein injections, other organs such as the liver, spleen, and kidney were also stained and yielded similar quality images of the heart.
Keywords: Cy5.5; Lycopersicon esculentum lectin; mouse; fluorescence microscopy; cardiac imaging techniques; endothelial cells

One test microbial diagnostic microarray for identification of Mycoplasma mycoides subsp. mycoides and other Mycoplasma species - Tonelli, A.; Sacchini, F.; Krasteva, I.; Zilli, K.; Scacchia, M.; Beaurepaire, C.; Nantel, A.; Pini, A. (Molecular Biotechnology, 2012)
The present study describes the use of microarray technology for rapid identification and differentiation of Mycoplasma mycoides subsp. mycoides from other mycoplasmas that may be pathogenic to ruminants, including those of the Mycoplasma mycoides cluster, genetically and antigenically strictly correlated with Mycoplasma mycoides subsp. mycoides. A microarray containing genetic sequences of 55 different bacterial species from Acholeplasma, Mycoplasma, Spiroplasma and Ureaplasma genera was constructed. Sequences to genes of interest were collected in FASTA format from NCBI. The collected sequences were processed with OligoPicker software. Oligonucleotides were then checked for their selectivity with BLAST searches in GenBank. The microarray was tested with ATCC/NCTC strains of Mycoplasma spp. of veterinary importance in ruminants including Mycoplasma belonging to the mycoides cluster as well as Mycoplasma mycoides subsp. mycoides and Mycoplasma mycoides subsp. capri field strains. The results showed that but one ATCC/NCTC reference strains hybridized with their species-specific sequences showed a profile/signature different and distinct from each other. The heat-map of the hybridization results for the nine genes interrogated for Mycoplasma mycoides subsp. mycoides demonstrated that the reference strain Mycoplasma mycoides subsp mycoides PG1 was positive for all of the gene sequences spotted on the microarray. CBPP field, vaccine and reference strains were all typed to be M. mycoides subsp. mycoides, and seven of the nine strains gave positive hybridization results for all of the nine genes. Two Italian strains were negative for some of the genes. Comparison with non-Mycoplasma mycoides subsp. mycoides reference strains showed some positive signals or considerable homology to Mycoplasma mycoides subsp. mycoides genes. As expected, some correlations were observed between the strictly genetically and antigenically correlated Mycoplasma mycoides subsp. mycoides and Mycoplasma mycoides subsp. capri strains. Specifically, we observed that some Italian Mycoplasma mycoides subsp. mycoides strains were positive for two out of the three Mycoplasma mycoides subsp. capri genes, differently from what has been observed for other European or African Mycoplasma mycoides subsp. mycoides strains. This study highlighted the use of microarray technology as a simple and effective method for a single-step identification and differentiation of Mycoplasma mycoides subsp. mycoides from other mycoplasmas that may be pathogenic to ruminants, including those of the Mycoplasma mycoides cluster, genetically and antigenically strictly correlated with Mycoplasma mycoides subsp. mycoides. The opportunity to discriminate several mycoplasmas in a single analysis enhances diagnostic rapidity and may represent a useful tool to screen occasionally mycoplasmas affecting animal farming in territories where diagnostic laboratory support is limited. The heat-map of the hybridization results of the comparative genomic hybridizations DNA-designed chip clearly indicates that the microarray performs well for the identification of the tested Mycoplasma mycoides subsp. mycoides reference and field strains, discriminating them from other mycoplasmas.
Keywords: Diagnosis; Microarray; Mycoplasma: Contagious bovine pleuropneumonia; Mycoplasma mycoides subsp. Mycoides; Cluster analysis

Cloning, Baeyer-Villiger biooxidations, and structures of the camphor pathway 2-Oxo-Δ3-4,5,5-Trimethylcyclopentenylacetyl-Coenzyme A monooxygenase of Pseudomonas putida ATCC 17453 - Leisch, Hannes; Shi, Rong; Grosse, Stephan; Morley, Krista; Bergeron, Hélène; Cygler, Miroslaw; Iwaki, Hiroaki; Hasegawa, Yoshie; Lau, Peter C. K. (Applied and Environmental Microbiology, 2012)
A dimeric Baeyer-Villiger monooxygenase (BVMO) catalyzing the lactonization of 2-oxo-Δ3-4,5,5-trimethylcyclopentenylacetyl-CoA, a key intermediate in the metabolism of camphor by Pseudomonas putida ATCC 17453 had been initially characterized in 1983 by Trudgill and co-workers (H.J. Ougham, D.G. Taylor, and P.W. Trudgill, J. Bacteriol. 153:140-152, 1983). Here we have cloned and overexpressed the 2-oxo-Δ3-4,5,5-trimethylcyclopentenylacetyl-CoA monooxygenase (OTEMO) in Escherichia coli, and determined its three-dimensional structure with bound FAD at 1.95 Å resolution as well as with bound FAD and NADP+ at 2.0 Å resolution. OTEMO represents the first homodimeric type 1 BVMO structure bound to FAD/NADP+. Comparison of several crystal forms of OTEMO bound to FAD and NADP+ revealed conformational plasticity of several loop regions, some of which have been implicated as contributing to the substrate specificity profile of structurally-related BVMOs. Substrate specificity studies confirmed that the 2-oxo-Δ3-4,5,5-trimethylcyclopentenylacetic acid coenzyme A ester is preferred over the free acid. However, the catalytic efficiency (kcat/Km) favors 2-n-hexyl cyclopentanone (4.3 × 105 M−1s−1) as a substrate, although its affinity (Km = 32 μM) was lower than that of the CoA-activated substrate (18 μM). In whole cell biotransformation experiments, OTEMO showed a unique enantiocomplementarity to the action of the prototypical cyclohexanone monooxygenase (CHMO), and appeared to be particularly useful for the oxidation of 4-substituted cyclohexanones. Overall, this work expands our understanding of the molecular structure and mechanistic complexity of the type 1 family of BVMOs as well as expanding the catalytic repertoire of one of its original members.

Polymers in membrane electrode assemblies - Kim, D. S.; Welch, C.; Hjelm, R. P.; Kim, Y. S.; Guiver, M. D. (Polymers for a Sustainable Environment and Green Energy, 2012)
This chapter is devoted to polymer electrolytes for use in membrane electrode assemblies of proton exchange membrane fuel cells. This chapter starts with a discussion of structure–property relationships of polymer electrolytes used as proton exchange membranes, in terms of water uptake, conductivity, and methanol permeability. The second part discusses polymer electrolytes used as electrode ionomers, specifically the structural effects of ionomer composition, ion exchange capacity, hydrophobicity, and dispersing solvent on fuel cell performance. The issue of interfacial compatibility between membrane and electrode is also discussed.
Keywords: Dispersion; Electrode; Ion exchange capacity (IEC); Ionomer; Hydrophilicity; Hydrophobicity; Interface; Membrane electrode assembly (MEA); Methanol permeability; Perfluorosulfonic acid (PFSA); Polarization curve; Proton conductivity; Proton exchange membrane (PEM); Water uptake

Photoinduced band gap shift and deep levels in luminescent carbon nanotubes - Finnie, Paul; Lefebvre, Jacques (ACS Nano, 2012)
Individual air-suspended single-walled carbon nanotubes are imaged both spatially and spectrally in photoluminescence. At low excitation power, photoluminescence is bright and stable with high quantum efficiency; however, higher power initially causes a gradual red shift and then more severe changes. Blinking, the loss of quantum efficiency, and the appearance of new deep levels are all seen and can be explained by the introduction of defects. We propose that optical excitation induces molecular deposition onto the nanotube by optically induced van der Waals interactions, leading to physisorption and ultimately chemisorption which severely degrades the luminescence.
Keywords: single-walled carbon nanotube; photoluminescence; exciton; quantum efficiency; band gap shift; van der Waals interaction

Engineering and therapeutic application of single-chain bivalent TGF-β family traps - Zwaagstra, John C.; Sulea, Traian; Baardsnes, Jason; Lenferink, Anne E. G.; Collins, Cathy; Cantin, Christiane; Paul-Roc, Béatrice; Grothe, Suzanne; Hossain, Sazzad; Richer, Louis-Philippe; L'Abbé, Denis; Tom, Roseanne; et al. (Molecular Cancer therapeutics, 2012)
Deregulation of TGF-β superfamily signaling is a causative factor in many diseases. Here we describe a protein engineering strategy for the generation of single-chain bivalent receptor traps for TGF-β superfamily ligands. Traps were assembled using the intrinsically disordered regions flanking the structured binding domain of each receptor as "native linkers" between two binding domains. This yields traps that are approximately threefold smaller than antibodies and consists entirely of native receptor sequences. Two TGF-β type II receptor-based, single-chain traps were designed, termed (TβRII)2 and (TβRIIb)2, that have native linker lengths of 35 and 60 amino acids, respectively. Both single-chain traps exhibit a 100 to 1,000 fold higher in vitro ligand binding and neutralization activity compared with the monovalent ectodomain (TβRII-ED), and a similar or slightly better potency than pan–TGF-β–neutralizing antibody 1D11 or an Fc-fused receptor trap (TβRII-Fc). Despite its short in vivo half-life (<1 hour), which is primarily due to kidney clearance, daily injections of the (TβRII)2 trap reduced the growth of 4T1 tumors in BALB/c mice by 50 percent, an efficacy that is comparable with 1D11 (dosed thrice weekly). In addition, (TβRII)2 treatment of mice with established 4T1 tumors (100 mm3) significantly inhibited further tumor growth, whereas the 1D11 antibody did not. Overall, our results indicate that our rationally designed bivalent, single-chain traps have promising therapeutic potential.
Keywords: TGF-β family receptors: molecular design; traps; therapy; cancer

PalI domain protiens of Saccharomyces cerevisiae and Candida albicans - Yan, Lan; Côte, Pierre; Li, Xing-Xing; Jiang, Yuan-Ying; Whiteway, Malcolm (Microbiological Research, 2012)
The Rim9/PalI groups of proteins are members of the Sur7 family, all of which contain a signal sequence and a block of three potential trans-membrane helices. Multi-protein sequence comparisons among fungi suggest that there are two classes of Rim9/PalI proteins; longer proteins like PalI that contain a Sur7 domain and a C-terminal extension, and shorter proteins like Rim9 that contain essentially only the Sur7 domain. We have examined possible roles of the longer, PalI-like proteins of both Saccharomyces cerevisiae (Yol019w) and Candida albicans (Orf19.1510/Srd1), two species that also contain short Rim9 proteins required for alkaline-associated stress responses. Deletions of the long form genes did not create any significant stress response phenotype in either S. cerevisiae or C. albicans, nor did the deletions enhance any of the rim9 deletion effects when combined in a double mutant. Furthermore, challenges in C. albicans show RIM9 but not SRD1 is important for proper response and hyphal formation. It appears that in fungal species such as Aspergillus nidulans containing only a long-form PalI-like protein, this element functions in the process of stress response, while in fungi with both versions the response to stress function is limited to the short-form protein.
Keywords: PalI domain; Candida albicans; Saccharomyces cerevisiae; Environmental stress response

Molecular imaging of breast tumors using a near-infrared fluorescently labeled clusterin binding peptide - Filfil, Rana; Paul-Roc, Béatrice; Cantin, Christiane; Iqbal, Umar; Tolkatchev, Dmitri; Vinogradova, Anna; Xu, Ping; Ni, Feng; O'Connor-McCourt, Maureen D.; Lenferink, Anne E. G. (International Journal of Cancer, 2012)
Several reports have shown that secreted clusterin (sCLU) plays multiple roles in tumor development and metastasis. Here, we report on a 12-mer sCLU binding peptide (designated P3378) that was identified by screening a phage-display peptide library against purified human sCLU. Differential resonance perturbation nuclear magnetic resonance using P3378 and a scrambled control peptide (designated P3378R) confirmed the P3378-sCLU interaction and demonstrated that it was sequence specific. P3378 and P3378R peptides were conjugated to an Alexa680 near infrared fluorophore (NIRF) and assessed for their tumor homing abilities in in vivo time-domain fluorescence optical imaging experiments using living 4T1 tumor bearing BALB/c mice. When injected in separate animals, both peptides accumulated at the tumor site, however the NIRF-labeled P3378 peptide was retained for a significant longer period of time than the P3378R peptide. Similar observations were made after simultaneously injecting the same tumor-bearing animal with a peptide mixture of P3378 DyLight (DL)680 and the P3378R-DL800. Coinjection of P3378-DL680 with excess unlabeled P3378 blocked tumor accumulation of fluorescent signal while excess P3378R control peptide did not confirming the sequence specificity of the tumor accumulation. Finally, ex vivo fluorescence microscopy of these tumors confirmed the presence of P3378-DL680 in the tumor and its colocalization with CLU. These results confirm the tumor targeting specificity of the P3378 CLU-binding peptide and suggest its usefulness for the in vivo monitoring of solid tumors secreting detectable levels of CLU.
Keywords: secreted clusterin; 4T1; time-domain near-infrared fluorescence imaging; binding peptide; breast cancer

Chiral modulations and reorientation effects in MnSi thin films - Karhu, E. A.; Roßler, U. K.; Bogdanov, A. N.; Kahwaji, S.; Kirby, B. J.; Fritzsche, H.; Robertson, M. D.; Majkrzak, C. F.; Monchesky, T. L. (Physical Review B : Condensed Matter and Materials Physics, 2012)
We present an experimental and theoretical investigation of the influence of a uniaxial magnetocrystalline anisotropy on the magnetic textures that are formed in a chiral magnetic system. We show that the epitaxially induced tensile stress in MnSi thin films grown on Si(111) creates an easy-plane uniaxial anisotropy. The magnetoelastic shear stress coefficient is derived from SQUID magnetometry measurements in combination with transmission electron microscopy and x-ray diffraction data. Density functional calculations of the magnetoelastic coefficient support the conclusion that the uniaxial anisotropy originates from the magnetoelastic coupling. Theoretical calculations based on a Dzyaloshinskii model that includes an easy-plane anisotropy predict a variety of modulations to the magnetic order that are not observed in bulk MnSi crystals. Evidence for these states is found in the magnetic hysteresis and polarized neutron reflectometry measurements.

Probing the room temperature deuterium absorption kinetics in nanoscale magnesium based hydrogen storage multilayers using neutron reflectometry, X-ray diffraction, and atomic force microscopy - Kalisvaart, W. P.; Luber, E. J.; Poirier, E.; Harrower, C. T.; Teichert, A.; Wallacher, D.; Grimm, N.; Steitz, R.; Fritzsche, H.; Mitlin, D. (The Journal of Physical Chemistry C, 2012)

Neutron reflectometry : a unique tool to determine the hydrogen profile in thin films - Fritzsche, H.; Haagsma, J.; Ophus, C.; Luber, E.; Harrower, T.; Mitlin, D. (Role of nuclear based technique in development and characterization of materials for hydrogen storage and fuel cells, 2012)

Optimizing energy productivity of microbial electrochemical cells - Pinto, R. P.; Tartakovsky, B.; Srinivasan, B. (Journal of Process Control, 2012)
Microbial electrochemical cells, such as microbial fuel cells (MFCs) and microbial electrolysis cells (MECs) are bioreactors that produce energy from organic matter, e.g. wastewater. The goal of this work is to optimize their product generation, either electricity or hydrogen, by selecting optimum operating current, with the influent flow (organic load) being adjusted to guarantee a given treatment capacity. Analysis of a multi-population model of a microbial electrochemical cell reveals that the ratio between different microbial populations in the anodic biofilm is determined by the current. Furthermore, the optimal operating current varies considerably with the internal resistance.

The role of intermetallics on creep behaviour of extruded magnesium alloys - Fletcher, Michelle; Bichler, Lukas; Sediako, Dimitry (Proceedings of a symposium sponsored by the Magnesium Committee of the Light Metals Division of The Minerals, Metals and Materials Society (TMS), 2012)
This research examined in-situ creep behavior of three extruded high performance magnesium alloys (AE42, AJ32 and ZE10). Neutron diffraction was used to measure compressive creep behavior at 175°C in the extrusion direction. The AE42 and AJ32 alloys exhibited higher creep strains than the ZE10 alloy. The highest strain was recorded for AE42 (2.4 percent), while ZE10 exhibited greatest creep resistance (0.2 percent strain). Microstructure analysis has shown that the distribution and composition of secondary phases was critical for creep resistance. The aluminum containing alloys had acicular and globular intermetallics, whereas the ZE10 alloy contained fine and irregular intermetallics dispersed along grain boundaries, effectively contributing to pinning of grains under high temperature loads. Significant grain re-crystallization was also observed in the aluminum containing alloys, but was absent in ZE10.
Keywords: Magnesium; Neutron Diffraction; Creep; Microstructure

Effect of uniaxial strain on the structural and magnetic phase transitions in BaFe2As2 - Dhital, Chetan; Yamani, Z.; Tian, Wei; Zeretsky, J.; Sefat, A. S.; Wang, Ziqiang; Birgeneau, R. J.; Wilson, Stephen D. (Physical Review Letters, 2012)
We report neutron scattering experiments probing the influence of uniaxial strain on both the magnetic and structural order parameters in the parent iron pnictide compound, BaFe₂As₂. Our data show that modest strain fields along the in-plane orthorhombic b axis can affect significant changes in phase behavior simultaneous to the removal of structural twinning effects. As a result, we demonstrate in BaFe₂As₂ samples detwinned via uniaxial strain that the in-plane C₄ symmetry is broken by both the structural lattice distortion and long-range spin ordering at temperatures far above the nominal (strain-free) phase transition temperatures. Surprising changes in the magnetic order parameter of this system under relatively small strain fields also suggest the inherent presence of magnetic domains fluctuating above the strain-free ordering temperature in this material.

Phonon density of states and the search for a resonance mode in LaFeAsO0.85F0.15 (Tc = 26 K) - Yamani, Z.; Ryan, D. H.; Cadogan, J. M.; Canepa, F.; Palenzona, A.; Orecchini, Andrea (Journal of Physics: Conference Series, 2012)
While the high transition temperatures suggest that the conventional BCS phononmediated mechanism may not provide the main pairing mechanism in the recently discovered RFeAsO1−xFx (1111-type) superconductors, there is, as yet, no consensus, despite extensive experimental and theoretical study. We report here the results of an inelastic neutron scattering investigation of an overdoped polycrystalline sample of LaFeAsO1−xFx with x = 0.15 (Tc = 26 K). Four excitation peaks were observed at 13.6±1.5, 24.2±0.8, 32.2±0.5, and 41.4±1.0 meV. They were identified as phonon modes based on their wavevector and temperature dependence. The peak positions agree well with first-principles calculations of phonon density of states as well as experimental data on both the insulating parent and optimally doped LaFeAsO1−xFx compounds. No evidence for the presence of a resonance mode was found. We found that the phonon density of states of the x = 0.15 sample remains unchanged below Tc and is similar to samples with other fluorine concentrations. This suggests that a standard electron-phonon pairing mechanism cannot explain the high transition temperatures observed in these materials.

Competing ferri- and antiferromagnetic phases in geometrically frustrated LuFe2O4 - de Groot, J.; Marty, K.; Lumsden, M. D.; Christianson, A. D.; Nagler, S. E.; Adiga, S.; Borghols, W. J. H.; Schmalzl, K.; Yamani, Z.; Bland, S. R.; de Souza, R.; Staub, U.; et al. (Physical Review Letters, 2012)
We present a detailed study of magnetism in LuFe₂O₄, combining magnetization measurements with neutron and soft x-ray diffraction. The magnetic phase diagram in the vicinity of TN involves a metamagnetic transition separating an antiferro- and a ferrimagnetic phase. For both phases the spin structure is refined by neutron diffraction. Observed diffuse magnetic scattering far above TN is explained in terms of near degeneracy of the magnetic phases.

Coexistence and competition of the short-range incommensurate antiferromagnetic order with superconducting state of BaFe2-xNixAs2 - Luo, Huiqian; Zhang, Rui; Laver, Mark; Yamani, Zahra; Wang, Meng; Lu, Xingye; Wang, Miaoyin; Chen, Yanchao; Li, Shiliang; Chang, Sung; Lynn, Jeffrey W.; Dai, Pengcheng (Physical Review Letters, 2012)
Superconductivity in the iron pnictides develops near antiferromagnetism, and the antiferromagnetic (AF) phase appears to overlap with the superconducting phase in some materials such as BaFe2-xTxAs2 (where T=Co or Ni). Here we use neutron scattering to demonstrate that genuine long-range AF order and superconductivity do not coexist in BaFe2-xNixAs2 near optimal superconductivity. In addition, we find a first-order-like AF-to-superconductivity phase transition with no evidence for a magnetic quantum critical point. Instead, the data reveal that incommensurate short-range AF order coexists and competes with superconductivity, where the AF spin correlation length is comparable to the superconducting coherence length.

The effect of the B-site cation and oxygen stoichiometry on the local and average crystal and magnetic structures of Sr2Fe1.9M0.1O5+y (M = Mn, Cr, Co; y = 0, 0.5) - Ramezanipour, Farshid; Greedan, John E.; Cranswick, Lachlan M. D.; Garlea, V. Ovidiu; Siewenie, Joan; King, Graham; Llobet, Anna; Donaberger, Ronald L. (Journal of Materials Chemistry, 2012)
Six compounds with formula Sr₂Fe₁.₉M₀.₁O₅+y (M = Mn, Cr, Co; y = 0, 0.5) were synthesized in air and argon, exhibiting surprisingly different properties depending on the B-cation type in spite of the low (5%) doping level. All argon synthesized phases, y 0, have long range brownmillerite ordering of oxygen vacancies with Icmm symmetry as shown by neutron diffraction (ND). All show long-range G-type antiferromagnetic order with Néel temperatures, TN, from variable temperature ND of 649(3)K, 636(2)K and 668(5)K for Cr, Mn and Co-compounds, respectively, compared with Sr₂Fe₂O₅, TN = 693 K. Competing ferromagnetic interactions may be responsible for the anomalously low value in the M = Mn case. The air synthesized phases with y ~ 0.5 show surprising variation with M as investigated by X-ray, TOF and constant wavelength neutron diffractions. The M = Co compound is isostructural with Sr₄Fe₄O₁₁ (Sr₂Fe₂O₅.₅), Cmmm, while the M = Cr phase is cubic, Pm-3m, and that for M = Mn appears to be cubic but the reflections are systematically broadened in a manner which suggests a local Cmmm structure. NPDF studies show that the local structure of the Cr phase is better described in terms of a Cmmm ordering of oxygen vacancies with Fe–O coordination numbers of five and six. The M = Co material shows C-type antiferromagnetic long-range magnetic order at 4 K as found for Sr₄Fe₄O₁₁. TN 230 K is inferred from a ZFC-FC magnetic susceptibility divergence compared with TN = 232 K for un-doped Sr4Fe4O11. The M = Cr and Mn compounds show no long-range magnetic ordering down to 4 K, but the divergence of ZFC and FC susceptibility data indicative of spin glass-like transitions occur at ~60 K and ~45 K for Cr and Mn, respectively. ND shows both diffuse and sharp Bragg magnetic reflections at positions consistent with a Cmmm cell for the M = Mn phase. For the M = Cr material, a very weak magnetic Bragg peak indexed as (1/2 1/2 1/2), consistent with a G-type AF order, is found at 4 K. These results rule out a spin glass-like ground state for both materials.

Zn-induced spin dynamics in overdoped La2−xSrxCu1−yZnyO4 - Wilson, Stephen D.; Yamani, Z.; Dhital, Chetan; Freelon, B.; Freeman, P. G.; Fernandez-Baca, J. A.; Yamada, K.; Wakimoto, S.; Buyers, W. J. L.; Birgeneau, R. J. (Physical Review B, 2012)
Spin fluctuations and the local spin susceptibility in isovalently Zn-substituted La2−xSrxCu1−yZnyO4 (x=0.25, y≈0.01) are measured via inelastic neutron-scattering techniques. As Zn2+ is substituted onto the Cu2+-sites, an anomalous enhancement of the local spin susceptibility χ′′(ω) appears due to the emergence of a commensurate antiferromagnetic excitation centered at wave vector Q =(π,π,0) that coexists with the known incommensurate spin-density wave excitations at QHK=(π±δ,π),(π,π±δ). Our results support a picture of Zn-induced antiferromagnetic (AF) fluctuations appearing through a local staggered polarization of Cu2+ spins, and the simultaneous suppression of Tc as AF fluctuations are slowed in proximity to Zn impurities suggests the continued importance of high-energy AF fluctuations at the far overdoped edge of superconductivity in the cuprates.

Neutron scattering from the static and dynamic lattice of SrCu2(BO3)2 in its Shastry-Sutherland - Haravifard, S.; Gaulin, B. D.; Yamani, Z.; Dunsiger, S. R.; Dabkowska, H. A. (Physical Review B, 2012)
Elastic and inelastic neutron scattering results show that SrCu₂(BO₃)₂ enters its low-temperature singlet ground state below 10 K without an obvious accompanying structural phase transition, despite suggestions emanating from earlier heat capacity measurements. However, evidence for significant spin-phonon coupling is found in the energy widths, and the corresponding lifetimes, of transverse acoustic phonons propagating in the (H00) direction of the Shastry-Sutherland, tetragonal basal plane. Transverse acoustic phonons with energies comparable to and higher than the onset of the two-triplet continuum show substantially increased lifetimes on entering the singlet ground state below ∼10 K. This is qualitatively consistent with the removal of a decay channel for the phonons due to the gapping of the spin excitation spectrum in SrCu₂(BO₃)₂ at low temperatures.

Co-existence of gel and fluid lipid domains in single-component phospholipid membranes - Armstrong, C. L.; Barrett, M. A.; Toppozini, L.; Kucerka, N.; Yamani, Z.; Katsaras, J.; Fragneto, G.; Rheinstädter, M. C. (Soft Matter, 2012)
Lateral nanostructures in membranes, so-called rafts, are believed to strongly influence membrane properties and functions. The experimental observation of rafts has proven difficult as they are thought to be dynamic structures that likely fluctuate on nano- to microsecond time scales. Using neutron diffraction we present direct experimental evidence for the co-existence of gel and fluid lipid domains in a single-component phospholipid membrane made of DPPC as it undergoes its main phase transition. The coherence length of the neutron beam sets a lower limit for the size of structures that can be observed. Neutron coherence lengths between 30 and 242 Å used in this study were obtained by varying the incident neutron energy and the resolution of the neutron spectrometer. We observe Bragg peaks corresponding to co-existing nanometer sized structures, both in out-of-plane and in-plane scans, by tuning the neutron coherence length. During the main phase transition, instead of a continuous transition that shows a pseudo-critical behavior, we observe the co-existence of gel and fluid domains.

Global ice impact forces on the CCGS Amundsen, Beaufort Sea - Johnston, Michelle (Technical Report, 2012)
The global ship impact forces on the CCGS Amundsen are quantified here for 44 impacts with multi-year ice floes in the Beaufort Sea. Global impact forces were derived from an inertial measurement system called MOTAN. In general, global forces of up to 9.0 MN were measured for maximum impact speed from 3.1 to 10.2 kt. Most of the impacts were conducted with two floes of known thickness and strength. Only two floes were sampled during the two-week program, but they characterized a wide spectrum of multi-year ice. Floe B1S1 was the thinner of the two floes (7.2 m), quite warm, saline and relatively weak (the depth-averaged borehole strength of the two test holes was 7.3 MPa and 4.5 MPa). Floe B1S2 was thicker (8.0 m), colder, less saline and stronger (the depth-averaged borehole strength of the uppermost 7 m of ice was 22.0 MPa). As anticipated, global impact forces and ship accelerations were higher during collisions with the thicker, stronger floe than the weaker floe, for comparable ship speeds. The highest surge acceleration (1.03 m/s²) occurred during the final ram with Floe B1S2 which was conducted at a maximum impact speed of 6.7 kt. That collision generated the highest global impact force of the program: 9.0 MN. The highest heave acceleration (0.84 m/s²) and sway acceleration (0.46 m/s²) occurred during rams with Floe B1S1, while transiting to a natural harbour within the floe. Global forces from 18 impacts with isolated multi-year floes floating in open pack ice were comparable to many of the rams with Floe B1S1, for a given impact speed. Comparison of the Commanding Officer’s expected ice severity for the 18 impacts indicated that even experienced personnel can have difficulty ascertaining the competency of multi-year ice. Impact forces and accelerations measured by MOTAN on the CCGS Amundsen were comparable to MOTAN-derived measurements on the CCGS Terry Fox from oblique impacts with bergy bits. The maximum heave, surge and sway accelerations on the CCGS Terry Fox were respectively 0.57 m/s², 0.56 m/s² and 1.24 m/s² during the Bergy Bit Trials, with measured global impact forces of up to 10.6 MN. Global impact forces and accelerations on the CCGS Amundsen during this study were not nearly as high as the impact forces measured by other instrumentation systems on ships operating more aggressively in Beaufort Sea multi-year ice.
Keywords: Ice Impact; CCGS Amundsen; Beaufort Sea

Monitoring global ice impact forces on the CCGS Louis S. St-Laurent : interim report - Johnston, Michelle (Technical Report, 2012)
The global ship impact forces on the CCGS Amundsen are quantified here for 44 impacts with multi-year ice floes in the Beaufort Sea. Global impact forces were derived from an inertial measurement system called MOTAN. In general, global forces of up to 9.0 MN were measured for maximum impact speed from 3.1 to 10.2 kt. Most of the impacts were conducted with two floes of known thickness and strength. Only two floes were sampled during the two-week program, but they characterized a wide spectrum of multi-year ice. Floe B1S1 was the thinner of the two floes (7.2 m), quite warm, saline and relatively weak (the depth-averaged borehole strength of the two test holes was 7.3 MPa and 4.5 MPa). Floe B1S2 was thicker (8.0 m), colder, less saline and stronger (the depth-averaged borehole strength of the uppermost 7 m of ice was 22.0 MPa). As anticipated, global impact forces and ship accelerations were higher during collisions with the thicker, stronger floe than the weaker floe, for comparable ship speeds. The highest surge acceleration (1.03 m/s²) occurred during the final ram with Floe B1S2 which was conducted at a maximum impact speed of 6.7 kt. That collision generated the highest global impact force of the program: 9.0 MN. The highest heave acceleration (0.84 m/s²) and sway acceleration (0.46 m/s²) occurred during rams with Floe B1S1, while transiting to a natural harbour within the floe. Global forces from 18 impacts with isolated multi-year floes floating in open pack ice were comparable to many of the rams with Floe B1S1, for a given impact speed. Comparison of the Commanding Officer’s expected ice severity for the 18 impacts indicated that even experienced personnel can have difficulty ascertaining the competency of multi-year ice. Impact forces and accelerations measured by MOTAN on the CCGS Amundsen were comparable to MOTAN-derived measurements on the CCGS Terry Fox from oblique impacts with bergy bits. The maximum heave, surge and sway accelerations on the CCGS Terry Fox were respectively 0.57 m/s², 0.56 m/s² and 1.24 m/s² during the Bergy Bit Trials, with measured global impact forces of up to 10.6 MN. Global impact forces and accelerations on the CCGS Amundsen during this study were not nearly as high as the impact forces measured by other instrumentation systems on ships operating more aggressively in Beaufort Sea multi-year ice.
Keywords: Interim Report; Monitoring; Ice Impact Forces

Modelling the impact of variations in electrode manufacturing on lithium-ion battery modules - Kenney, Ben; Darcovich, Ken; MacNeil, Dean D.; Davidson, Isobel J. (Journal of Power Sources, 2012)
The performance of a lithium-ion battery is closely related to its manufacturing and can be impacted by variability in the electrodes. Typically, manufacturers must set aside cells which are deemed to be of insufﬁcient quality, thus contributing to the cost of manufacturing high quality cells. The performance of a lithium-ion battery module, that is, a string of cells conﬁgured in series, depends on the performance of the weakest cell. In this work, the single particle model was adapted to simulate the coupled behaviour of an arbitrary number of cells conﬁgured in series. The impact of slight variations in the manufacturing of electrodes was then investigated with a goal of linking electrode properties such as variations in thickness, electrode density and active material weight fraction with the performance of battery modules made from these cells. Results indicate that the initial capacity, the rate of capacity fade and other important aspects such as the distribution of state-of-charge from one cell to another depends on the extent of variability in the manufacturing of the electrodes. In this work, the variation in the performance of the module has been quantiﬁed as a function of manufacturing variation at the electrode level.
Keywords: Lithium-ion battery; Electrode variability; Degradation; Battery modules; Battery packs

Identification and characterization of antifungal compounds using a Saccharomyces cerevisiae reporter bioassay - Tebbets, Brad; Stewart, Douglas; Lawry, Stephanie; Nett, Jeniel; Nantel, Andre; Andes, David; Klein, Bruce S. (PLoS ONE, 2012)
New antifungal drugs are urgently needed due to the currently limited selection, the emergence of drug resistance, and the toxicity of several commonly used drugs. To identify drug leads, we screened small molecules using a Saccharomyces cerevisiae reporter bioassay in which S. cerevisiae heterologously expresses Hik1, a group III hybrid histidine kinase (HHK) from Magnaporthe grisea. Group III HHKs are integral in fungal cell physiology, and highly conserved throughout this kingdom; they are absent in mammals, making them an attractive drug target. Our screen identified compounds 13 and 33, which showed robust activity against numerous fungal genera including Candida spp., Cryptococcus spp. and molds such as Aspergillus fumigatus and Rhizopus oryzae. Drug-resistant Candida albicans from patients were also highly susceptible to compounds 13 and 33. While the compounds do not act directly on HHKs, microarray analysis showed that compound 13 induced transcripts associated with oxidative stress, and compound 33, transcripts linked with heavy metal stress. Both compounds were highly active against C. albicans biofilm, in vitro and in vivo, and exerted synergy with fluconazole, which was inactive alone. Thus, we identified potent, broad-spectrum antifungal drug leads from a small molecule screen using a high-throughput, S. cerevisiae reporter bioassay.
Keywords: amphotericin B; antifungal agent; cortisone; fluconazole; fludioxonil; antifungal agent; protein histidine kinase; protein kinase; antifungal activity; Aspergillus fumigatus; bioassay; biofilm; Candida albicans; candidiasis; colony forming unit; Cryptococcus; disk diffusion; down regulation; drug potency; drug screening; drug structure; drug targeting; fungal strain; fungus growth; genetic transcription; high throughput screening; Magnaporthe grisea; microarray analysis; minimum inhibitory concentration; oxidative stress; protein expression; rat; Rhizopus oryzae; Saccharomyces cerevisiae; single drug dose; upregulation; antifungal resistance; DNA damage; DNA microarray; DNA repair; drug effect; drug potentiation; reporter gene; Candida; Mammalia; Biological Assay; Drug Evaluation, Preclinical; Drug Resistance, Fungal; Drug Synergism; Microbial Sensitivity Tests; Oligonucleotide Array Sequence Analysis

Driver mutations in histone H3.3 and chromatin - Schwartzentruber, Jeremy; Korshunov, Andrey; Liu, Xiao-Yang; Jones, David T. W.; Pfaff, Elke; Jacob, Karine; Sturm, Dominik; Fontebasso, Adam M.; Khuong Quang, Dong-Anh; Tönjes, Martje; Hovestadt, Volker; Albrecht, Steffen; et al. (Nature, 2012)
Glioblastoma multiforme (GBM) is a lethal brain tumour in adults and children. However, DNA copy number and gene expression signatures indicate differences between adult and paediatric cases. To explore the genetic events underlying this distinction, we sequenced the exomes of 48 paediatric GBM samples. Somatic mutations in the H3.3-ATRX-DAXX chromatin remodelling pathway were identified in 44% of tumours (21/48). Recurrent mutations in H3F3A, which encodes the replication-independent histone 3 variant H3.3, were observed in 31% of tumours, and led to amino acid substitutions at two critical positions within the histone tail (K27M, G34R/G34V) involved in key regulatory post-translational modifications. Mutations in ATRX (α-thalassaemia/mental retardation syndrome X-linked) and DAXX (death-domain associated protein), encoding two subunits of a chromatin remodelling complex required for H3.3 incorporation at pericentric heterochromatin and telomeres, were identified in 31% of samples overall, and in 100% of tumours harbouring a G34R or G34V H3.3 mutation. Somatic TP53 mutations were identified in 54% of all cases, and in 86% of samples with H3F3A and/or ATRX mutations. Screening of a large cohort of gliomas of various grades and histologies (n = 784) showed H3F3A mutations to be specific to GBM and highly prevalent in children and young adults. Furthermore, the presence of H3F3A/ATRX-DAXX/TP53 mutations was strongly associated with alternative lengthening of telomeres and specific gene expression profiles. This is, to our knowledge, the first report to highlight recurrent mutations in a regulatory histone in humans, and our data suggest that defects of the chromatin architecture underlie paediatric and young adult GBM pathogenesis.

The functions of Mediator in Candida albicans support a role in shaping species-specific gene expression - Uwamahoro, Nathalie; Qu, Yue; Jelicic, Branka; Lo, Tricia L.; Beaurepaire, Cecile; Quenault, Tara; Boag, Peter R.; Ramm, Georg; Callaghan, Judy; Beilharz, Traude H.; Nantel, André; Peleg, Anton Y.; et al. (PLoS Genetics, 2012)

Pho85, Pcl1, and Hms1 signaling governs Candida albicans morphogenesis induced by high temperature or Hsp90 compromise - Shapiro, Rebecca S.; Sellam, Adnane; Tebbji, Faiza; Whiteway, Malcolm; Nantel, Andre; Cowen, Leah E. (Current Biology, 2012)
Background Temperature exerts powerful control over development and virulence of diverse pathogens. In the leading human fungal pathogen, Candida albicans, temperature governs morphogenesis, a key virulence trait. Many cues that induce the yeast to filament transition are contingent on a minimum of 37°C, whereas further elevation to 39°C serves as an independent inducer. The molecular chaperone Hsp90 is a key regulator of C. albicans temperature-dependent morphogenesis. Compromise of Hsp90 function genetically, pharmacologically, or by elevated temperature induces filamentation in a manner that depends on protein kinase A signaling but is independent of the terminal transcription factor, Efg1. Results Here, we establish that despite morphological and regulatory differences, inhibition of Hsp90 induces a transcriptional profile similar to that induced by other filamentation cues and does so independently of Efg1. Further, we identify Hms1 as a transcriptional regulator required for morphogenesis induced by elevated temperature or Hsp90 compromise. Hms1 functions downstream of the cyclin Pcl1 and the cyclin-dependent kinase Pho85, both of which are required for temperature-dependent filamentation. Upon Hsp90 inhibition, Hms1 binds to DNA elements involved in filamentous growth, including UME6 and RBT5, and regulates their expression, providing a mechanism through which Pho85, Pcl1, and Hms1 govern morphogenesis. Consistent with the importance of morphogenetic flexibility for virulence, deletion of C. albicans HMS1 attenuates virulence in a metazoan model of infection. Conclusions Thus, we establish a new mechanism through which Hsp90 orchestrates C. albicans morphogenesis, and define novel regulatory circuitry governing a temperature-dependent developmental program, with broad implications for temperature sensing and virulence of microbial pathogens.

Alternaria alternata as a new fungal enzyme system for the release of phenolic acids from wheat and triticale brans - Xiao, Zhizhuang; Bergeron, Hélène; Lau, Peter C. K. (Antonie van Leeuwenhoek, 2012)
This study describes the release of antioxidant ferulic acid from wheat and triticale brans by mixtures of extracellular enzymes produced in culture by a strain FC007 of Alternaria alternata, a dark mold originally isolated from Canadian wood log. The genus of the mold was confirmed as Alternaria by 18S ribosomal DNA characterization. Enzyme activities for feruloyl esterase (FAE) and polysaccharide hydrolyzing enzymes were measured, and conditions for release of ferulic acid and reducing sugars from the mentioned brans were evaluated. The highest level of FAE activity (89 ± 7 mU ml -1 fermentation culture) was obtained on the fifth day of fermentation on wheat bran as growth substrate. Depending on biomass and processing condition, up to 91.2 or 72.3% of the ferulic acid was released from wheat bran and triticale bran, respectively, indicating the proficiency of A. alternata extracellular enzymes in plant cell wall deconstruction. The apparent high extraction of ferulic acid from wheat and triticale brans represents a potential advantage of using a whole fungal cell enzyme complement over yields reported previously through an artificial assembly of cloned FAE with a particular xylanase in a cocktail format.

Applications of functionalized and nanoparticle-modified nanocrystalline cellulose - Lam, Edmond; Male, Keith B.; Chong, Jonathan H.; Leung, Alfred C. W.; Luong, John H. T. (Trends in Biotechnology, 2012)
Nanocrystalline cellulose (NCC), a rod-shaped nanoscale material with exceptional strength and physicochemical properties, can be prepared from inexpensive renewable biomass. Besides its potential use as a reinforcing agent for industrial biocomposites, pristine NCC exhibits low toxicity and poses no serious environmental concerns, providing impetus for its use in bioapplications. Here, we review recent developments in the use of modified NCC for emerging bioapplications, specifically enzyme immobilization, antimicrobial and medical materials, green catalysis, biosensing and controlled drug delivery. We focus on the modification of NCC with chemical functionalities and inorganic nanoparticles, reviewing practical considerations such as reusability, toxicity and scale-up capability. © 2012.

Life at the wedge: the activity and diversity of Arctic ice wedge microbial communities - Wilhelm, Roland C.; Radtke, Kristin J.; Mykytczuk, Nadia C. S.; Greer, Charles W.; Whyte, Lyle G. (Astrobiology, 2012)
The discovery of polygonal terrain on Mars underlain by ice heightens interest in the possibility that this water-bearing habitat may be, or may have been, a suitable habitat for extant life. The possibility is supported by the recurring detection of terrestrial microorganisms in subsurface ice environments, such as ice wedges found beneath tundra polygon features. A characterization of the microbial community of ice wedges from the high Arctic was performed to determine whether this ice environment can sustain actively respiring microorganisms and to assess the ecology of this extreme niche. We found that ice wedge samples contained a relatively abundant number of culturable cells compared to other ice habitats (?10 5 CFU•mL -1). Respiration assays in which radio-labeled acetate and in situ measurement of CO 2 flux were used suggested low levels of microbial activity, though more sensitive techniques are required to confirm these findings. Based on 16S rRNA gene pyrosequencing, bacterial and archaeal ice wedge communities appeared to reflect surrounding soil communities. Two Pseudomonas sp. were the most abundant taxa in the ice wedge bacterial library (?50%), while taxa related to ammonia-oxidizing Thaumarchaeota occupied 90% of the archaeal library. The tolerance of a variety of isolates to salinity and temperature revealed characteristics of a psychrotolerant, halotolerant community. Our findings support the hypothesis that ice wedges are capable of sustaining a diverse, plausibly active microbial community. As such, ice wedges, compared to other forms of less habitable ground ice, could serve as a reservoir for life on permanently cold, water-scarce, ice-rich extraterrestrial bodies and are therefore of interest to astrobiologists and ecologists alike. © Copyright 2012, Mary Ann Liebert, Inc.

Microbial diversity and activity in hypersaline high Arctic spring channels - Lay, Chih-Ying; Mykytczuk, Nadia C. S.; Niederberger, Thomas D.; Martineau, Christine; Greer, Charles W.; Whyte, Lyle G. (Extremophiles, 2012)
Lost Hammer (LH) spring is a unique hypersaline, subzero, perennial high Arctic spring arising through thick permafrost. In the present study, the microbial and geochemical characteristics of the LH outflow channels, which remain unfrozen at ≥-18°C and are more aerobic/less reducing than the spring source were examined and compared to the previously characterized spring source environment. LH channel sediments contained greater microbial biomass (~100-fold) and greater microbial diversity reflected by the 16S rRNA clone libraries. Phylotypes related to methanogenesis, methanotrophy, sulfur reduction and oxidation were detected in the bacterial clone libraries while the archaeal community was dominated by phylotypes most closely related to THE ammonia-oxidizing Thaumarchaeota. The cumulative percent recovery of ¹⁴C-acetate mineralization in channel sediment microcosms exceeded ~30% and ~10% at 5 and -5°C, respectively, but sharply decreased at -10°C (≤1%). Most bacterial isolates (Marinobacter, Planococcus, and Nesterenkonia spp.) were psychrotrophic, halotolerant, and capable of growth at -5°C. Overall, the hypersaline, subzero LH spring channel has higher microbial diversity and activity than the source, and supports a variety of niches reflecting the more dynamic and heterogeneous channel environment.
Keywords: Cryomicrobiology; Arctic spring; Methane seep; Polar microbial ecology; Thaumarchaeota; Hypersaline

Characterization of welded joints produced by FSW in AA1100-B4C metal matrix composites - Guo, J. F.; Gougeon, P.; Chen, X.-G. (Science and technology of Welding & Joining, 2012)
The feasibility of friction stir welding for joining AA 1100 based metal matrix composites reinforced with B4C particulate is studied for 16 and 30%B4C volume concentrations. For both composites, friction stir welding has a significant influence on the particle size distribution and the matrix grain size. For the 16% composite, the average particle size decreases after welding by ,20% and the grain size from 15 to 5 mm as measured in the weld nugget. Tensile testing of welded joints showed up to 100% joint efficiency for both annealed AA 1100–16%B4C and AA 1100–30%B4C composite materials. However, if the ultimate tensile strength values of all the studied composites are similar at ,130 MPa, then the weld ductility is higher for the annealed materials. Furthermore, it was observed that varying the welding speed between 100 and 275 mm min21 does not influence the tensile properties and the particle size distribution in the nugget.
Keywords: Friction Stir Welding, Al-B4C Metal Matrix Composite; Microstructure; Mechanical Properties; Ductility; Joint Efficiency; Grain Structure; Fractography

SPH model approach used to predict skin inclusions into semisolid metal castings - Pineau, Frédéric; D'Amours, Guillaume (CFD Modeling and Simulation in Materials Processing, 2012)
Semisolid metal processing of metallic alloys takes advantage of the thixotropic behavior of material with non-dendritic microstructure to produce near-net-shape components with improved mechanical properties. The much higher apparent viscosity of the semisolid billet limits the risk of oxide formed on the free surfaces to become incorporated into the easting during the process. But, the external-skin on the periphery of the billet, which is often partially solidified and contaminated with lubricants, should not be included into the casting as this can be a cause of reject for most structural parts. In this paper, a preliminary model is set-up using the LS-DYNA SPH formulation to follow the paths of the skin. Calculations carried out show that this approach appears to be very promising to predict the paths of contaminated skins into semisolid castings. It can then be utilized to design suitable molds and gating systems.
Keywords: modelling; Smooth Particle Hydrodynamic; semisolid casting

Three dimensional numerical study of the mixing behavior of twin-screw elements - Ilinca, F.; Hétu, J.-F. (International Polymer Processing, 2012)
In this work the numerical modeling of the flow inside co-rotating twin-screw extruders is performed and solutions are analyzed to determine the mixing behavior of two screw elements: conveying and mixing elements. The flow around intermeshing screws is computed using an immersed boundary finite element method capable of dealing with complex moving solid boundaries. The flow is considered isothermal and the material behaves as a generalized non-Newtonian fluid. Because the viscosity depends on the shear rate, solutions will be shown for various rotation velocities of the screw. The 3D solutions are then analyzed in order to determine various parameters characterizing the flow mixing such as the residence time and the linear stretch. Residence time distribution inside the twin-screw extruder is first computed by using a particle tracking algorithm based on a fourth order Runge-Kutta method. A large number of particles are tracked inside the extruder and the resulting particle data is used to determine the distribution of the residence time and of the linear stretch. The spatial distribution of the residence time is also computed by solving a transport equation tracking the injection time of the polymer melt. The methodology shows important differences in the mixing behavior of the screw elements considered.

Simultaneous analysis of cardiolipin and lipid A from Helicobacter pylori by matrix-assited laser desorption/ionization time-of-flight mass spectrometry - Zhou, Ping; Hu, Rui; Chandan, Vandana; KuoLee, Rhonda; Liu, Xin; Chen, Wangxue; Liu, Bifeng; Altman, Eleonora; Li, Jianjun (Molecular BioSystems, 2012)
Cardiolipin (CL) is an anionic tetraacylphospholipid found in mammalian tissues, inner membrane of mitochondria and in the cytoplasmic membrane of Gram-positive and -negative bacteria. Lipid A is the principal structural component responsible for the range of biological activities of lipopolysaccharides. Here we report a MALDI-MS-based method for the sensitive simultaneous analysis of CL and lipid A from Helicobacter pylori cells. The sensitivity was demonstrated by the analysis of CL and lipid A from a single bacterial colony of in vitro grown H. pylori strain NCTC 11637 (ATCC 43504). We then characterized the CL and lipid A structures in H. pylori cells grown under three different conditions, on agar-horse blood plates, in liquid culture and ex vivo. The results revealed the presence of high amounts of myristic (C14:0) and 19-carbon cyclopropane (C19:0cyc) fatty acids. Alterations in CL structure were observed in H. pylori cells cultivated on plates as compared with the bacteria grown in broth culture. Furthermore, significant changes in lipid A acylation pattern were detected in H. pylori cells during formation of coccoids. In contrast, structural analysis of CL from ex vivo H. pylori cells recovered from the stomachs of infected Mongolian gerbils demonstrated only minor changes in acyl chain combination. This is the first report of simultaneous analysis of CL and lipid A from ex vivo cells of H. pylori.

Colloidal clay gelation: relevance to current oil sands operations - Mercier, P.H.J.; Ng, S.; Moran, K.; Sparks, B.D.; Kingston, D.; Kotlyar, L.S.; Kung, J.; Woods, J.; Patarachao, B.; McCracken, T. (Petroleum Science and Technology, 2012)
Ultrafines are predominantly delaminated colloidal clays with dimensions <0.9um that exist naturally in oil sands and are released during conditioning of surface-mined ores. Critical concentrations of these ultrafines and the cations present in process water are capable of forming flocculated structures with a very high water holding capacity. During primary separation of bitumen these ultrafines are detrimental to recovery as a result of increased slurry viscosity as well as through slime coating of released bitumen. Disposition into tailings ponds eventually produces mature fine tailings (MFT) as a result of thixotropic gel formation that entraps coarser solids. The ultrafines concentration of ~3 wt% observed in MFT coincides with the critical gelation concentration determined for suspensions of ultrafines in salt solutions with cationic concentration representative of that in pond water. This observation accounts for 100% of the water holding capacity of MFT and also explains why virtually no water is released once an MFT gel state has been formed. Here, we review earlier research in this area and identify the harmful effects of ultrafines in some current problematic ores.
Keywords: bitumen recovery; gelation; oil sands; slime coatings; sludging; tailings; ultrafines

Rapid identification of triacylglycerol-estolides in plant and fungal oils - Zhang, Haixia; Olson, Douglas J. H.; Van, Dang; Purves, Randy W.; Smith, Mark A. (Industrial Crops and Products, 2012)
Triacylglycerol-estolides are components of the storage oil of certain plant and fungal species and are generally associated with the presence of fatty acids containing hydroxyl groups. These unusual acyl-glycerols can easily go undetected when oils are analysed by techniques such as gas chromatography of fatty acid methyl esters, or thin layer chromatography. We describe the detection of TAG-estolides in intact seeds of Lesquerella lyrata and whole sclerotia of the ergot fungus Claviceps purpurea using 1H MAS-NMR for non destructive analysis. We also conducted analysis of small amounts of oil by MALDI-TOF MS to clearly show the presence of TAG-estolides and to rapidly characterize their acyl composition. The matrix used in this work was 2,4,6-trihydroxyacetophenone (THAP) made up in sodium chloride-saturated solvent. We were able to confirm the presence of TAG-estolides with no free hydroxyl groups in the fungal oil, and TAG-estolides with free hydroxyl groups in the oil of Lesquerella lyrata. The development of a technique for the rapid identification of TAG-estolides in oil samples will simplify the detection of these novel lipids in plant and fungal species.
Keywords: estolide; Lesquerella fendleri; Lesquerella lyrata; ergot (Claviceps purpurea); seed oil; hydroxy fatty acids

The hexanoyl-CoA precursor for cannabinoid biosynthesis is formed by an acyl-activating enzyme in Cannabis sativa trichomes - Stout, Jake M.; Boubakir, Zakia; Ambrose, Stephen J.; Purves, Randy W.; Page, Jonathan E. (The Plant Journal, 2012)
The psychoactive and analgesic cannabinoids (e.g. Δ9-tetrahydrocannabinol, THC) in Cannabis sativa are formed from the short-chain fatty acyl-CoA precursor hexanoyl-CoA. Cannabinoids are synthesized in glandular trichomes present mainly on female flowers. We quantified hexanoyl-CoA using LC-MS/MS and found levels of 15.5 pmol g−1 fresh weight in female hemp flowers with lower amounts in leaves, stems and roots. This pattern parallels the accumulation of the end-product cannabinoid, cannabidiolic acid (CBDA). To search for the acyl-activating enzyme (AAE) that synthesizes hexanoyl-CoA from hexanoate, we analyzed the transcriptome of isolated glandular trichomes. We identified 11 unigenes encoding putative AAEs, including CsAAE1 which shows high-transcript abundance in glandular trichomes. In vitro assays show that recombinant CsAAE1 activates hexanoate and other short- and medium-chain fatty acids. This activity and the trichome-specific expression of CsAAE1 suggests that it is the hexanoyl-CoA synthetase that supplies the cannabinoid pathway. CsAAE3 encodes a peroxisomal enzyme that activates a variety of fatty acid substrates including hexanoate. Although phylogenetic analysis shows that CsAAE1 groups with peroxisomal AAEs, it lacks a peroxisome targeting sequence 1 (PTS1) and localizes to the cytoplasm. We suggest that CsAAE1 may have been recruited to the cannabinoid pathway through the loss of its PTS1, thereby redirecting it to the cytoplasm. To probe the origin of hexanoate, we analyzed the trichome EST dataset for enzymes of fatty acid metabolism. The high abundance of transcripts encoding desaturases and a lipoxygenase suggests that hexanoate may be formed through a pathway involving the oxygenation and breakdown of unsaturated fatty acids.
Keywords: Cannabis sativa; marijuana; cannabinoid; acyl-CoA; acyl-activating enzyme; hexanoate

Triacylglycerol synthesis by PDAT1 in the absence of DGAT1 activity is dependent on re-acylation of LPC by LPCAT2 - Xu, Jingyu; Carlsson, Anders S.; Francis, Tammy; Zhjang, Meng; Hoffmann, Travis; Giblin, Michael E.; Taylor, David C. (BMC Plant Biology, 2012)
Background: The Arabidopsis thaliana dgat1 mutant, AS11, has an oil content which is decreased by 30%, and a strongly increased ratio of 18:3/20:1, compared to wild type. Despite lacking a functional DGAT1, AS11 still manages to make 70% of WT seed oil levels. Recently, it was demonstrated that in the absence of DGAT1, PDAT1 was essential for normal seed development, and is a dominant determinant in Arabidopsis TAG biosynthesis. Methods: Biochemical, metabolic and gene expression studies combined with genetic crossing of selected Arabidopsis mutants have been carried out to demonstrate the contribution of Arabidopsis PDAT1 and LPCAT2 in the absence of DGAT1 activity. Results: Through microarray and RT-PCR gene expression analyses of AS11 vs. WT mid-developing siliques, we observed consistent trends between the two methods. FAD2 and FAD3 were up-regulated and FAE1 down-regulated, consistent with the AS11 acyl phenotype. PDAT1 expression was up-regulated by ca 65% while PDAT2 expression was up-regulated only 15%, reinforcing the dominant role of PDAT1 in AS11 TAG biosynthesis. The expression of LPCAT2 was up-regulated by 50-75%, while LPCAT1 expression was not significantly affected. In vitro LPCAT activity was enhanced by 75-125% in microsomal protein preparations from mid-developing AS11 seed vs WT. Co-incident homozygous knockout lines of dgat1/lpcat2 exhibited severe penalties on TAG biosynthesis, delayed plant development and seed set, even with a functional PDAT1; the double mutant dgat1/lpcat1 showed only marginally lower oil content than AS11. Conclusions: Collectively, the data strongly support that in AS11 it is LPCAT2 up-regulation which is primarily responsible for assisting in PDAT1-catalyzed TAG biosynthesis, maintaining a supply of PC as co-substrate to transfer sn-2 moieties to the sn-3 position of the enlarged AS11 DAG pool.
Keywords: dgat1 mutant AS11; LPCAT1; LPCAT2; PDAT1; oil biosynthesis

Overexpression of Nelumbo nucifera metallothioneins 2a and 3 enhances seed germination vigor in Arabidopsis - Zhou, Yuliang; Chu, Pu; Chen, Huhui; Li, Yin; Liu, Jun; Ding, Yu; Tsang, Edward W. T.; Jiang, Liwen; Wu, Keqiang; Huang, Shangzhi (Planta, 2012)
Metallothioneins (MTs) are small, cysteine-rich and metal-binding proteins which are involved in metal homeostasis and scavenging of reactive oxygen species. Although plant MTs have been intensively studied, their roles in seeds remain to be clearly established. Here, we report the isolation and characterization of NnMT2a, NnMT2b and NnMT3 from sacred lotus (Nelumbo nucifera Gaertn.) and their roles in seed germination vigor. The transcripts of NnMT2a, NnMT2b and NnMT3 were highly expressed in developing and germinating sacred lotus seeds, and were dramatically up-regulated in response to high salinity, oxidative stresses and heavy metals. Analysis of transformed Arabidopsis protoplasts showed that NnMT2a-YFP and NnMT3-YFP were localized in cytoplasm and nucleoplasm. Transgenic Arabidopsis seeds overexpressing NnMT2a and NnMT3 displayed improved resistance to accelerated aging (AA) treatment, indicating their significant roles in seed germination vigor. These transgenic seeds also exhibited higher superoxide dismutase activity compared to wild-type seeds after AA treatment. In addition, we showed that NnMT2a and NnMT3 conferred improved germination ability to NaCl and methyl viologen on transgenic Arabidopsis seeds. Taken together, these data demonstrate that overexpression of NnMT2a and NnMT3 in Arabidopsis significantly enhances seed germination vigor after AA treatment and under abiotic stresses.
Keywords: Arabidopsis; Metallothionein; Oxidative stresses; Sacred lotus; Salt stress; Seed germination vigor

Photoluminescence fatigue in three-dimensional silicon/silicon-germanium nanostructures - Modi, N.; Tsybeskov, L.; Baribeau, J.-M.; Wu, X.; Lockwood, D. J. (Journal of Applied Physics, 2012)
We find fatigue of low temperature photoluminescence (PL) in Si/SiGe three-dimensional island morphology nanostructures under continuous excitation. Initially, the PL intensity slowly decreases by less than 15%, and after ~10 min it decreases rapidly by more than 80%. After the PL intensity stabilizes, a complete recovery requires heating the sample to nearly room temperature. We propose that accumulation of charge within SiGe islands is responsible for the enhancement of Auger recombination and hence the observed PL fatigue.

Chiral separation with molecularly imprinted polysulfone-aldehyde derivatized nanofiber membranes - Sueyoshi, Yuuki; Utsunomiya, Akira; Yoshikawa, Masakazu; Robertson, Gilles P.; Guiver, Michael D. (Journal of Membrane Science, 2012)
Molecularly imprinted membranes (MIPMs) and molecularly imprinted nanofiber membranes (MINFMs) were prepared from polysulfone with aldehyde (PSf-CHO-05 or PSf-CHO-10) and N- -benzyloxycarbonyl-D-gultamic acid (Z-D-Glu) or N-a-benzyloxycarbonyl-L-glutamic acid (Z-L-Glu) as a print molecule. Those two types of molecularly imprinted membrane, such as MIPMs and MINFMs, incorporated the enantiomer, of which absolute configuration was same as that of the print molecule, in preference to the corresponding antipode. In other words, the membranes imprinted by the D-isomer preferentially adsorbed the D-isomer and vice-versa. Those two types of membrane showed chiral separation ability by membrane transport. Against expectation, transport of the enantiomer less adsorbed in the membrane was selectively transported. The fluxes through the molecularly imprinted nanofiber membranes gave one to two orders of magnitude higher than those of usual molecularly imprinted membranes without depression of permselectivity. The present study demonstrated that molecularly imprinted nanofiber membrane gave high flux without depression of permselectivity. A breakthrough in membrane separation would be realized by adopting molecularly imprinted nanofiber membranes.
Keywords: Electrospray deposition; Chiral separation; Membrane; Molecular imprinting; Molecularly imprinted nanofiber membrane; Nanofiber fabric; Optical resolution

Phenyltrimethylammonium Functionalized Polysulfone Anion Exchange Membranes - Li, Nanwen; Zhang, Qiang; Wang, Chenyi; Lee, Young Moo; Guiver, Michael D. (Macromolecules, 2012)
Anion exchange membrane (AEM) materials were prepared from commercial polysulfone (PSf) by functionalization with tertiary amines via lithiation chemistry. By optimizing the reaction conditions, a degree of substitution (DS) of 0.81 could be achieved without evident polymer decomposition or cross-linking. The PSf containing pendent bis-(phenyldimethylamine) substituents were then quaternized with CH3I and ion exchange reaction to provide bis(phenylthrimethylammonium) (PTMA) polymer with hydroxide-conductive properties. Flexible and tough membranes with various ion exchange capacities (IEC)s could be prepared by casting the polymers from DMAc solutions. The ionomeric membranes showed considerably lower water uptake (less than 20%), and thus dimensional swelling in water, compared with many reported AEMs. The hydroxide conductivities of the membranes were above 10 mSécm at room temperature. The unusually low water uptake and good hydroxide conductivity may be attributed to the "side-chain-type" structures of pendent functional groups, which facilitate ion transport. Although the PTMA substituents on the AEM were found to have insufficient long-term stability for alkaline fuel cell application, the investigation gives some insight and directions for polymeric designs by postfunctionalization.

Development of a low-noise wide-band phased-array feed - Veidt, Bruce; Burgess, Tom; Messing, Rob; Hovey, Gary J.; Smegal, Rick J. (General Assembly and Scientific Symposium, 2011 XXXth URSI (URSI GASS, 2011), 2012)
Low-noise phased-array feeds are a new way to expand the field of view of radio telescopes at centimetre wavelengths. First generation engineering demonstrators of this technology have been constructed and tested by several institutes worldwide. The development of second-generation phased-array feeds is now underway. We describe one effort to design and build an astronomy-capable phased-array feed using techniques to reduce front-end noise and increase system bandwidth.
Keywords: Arrays; Bandwidth; Feeds; Radio astronomy; Receivers

Elucidation of matrix effects and performance of solid-phase extraction for LC-MS/MS analysis of β-N-methylamino-l-alanine (BMAA) and 2,4-diaminobutyric acid (DAB) neurotoxins in cyanobacteria - Li, Aifeng; Fan, Hua; Ma, Feifei; McCarron, Pearse; Thomas, Krista; Tang, Xianghai; Quilliam, Michael A. (Analyst, 2012)
A liquid chromatography-mass spectrometry (LC-MS/MS) method using hydrophilic interaction liquid chromatography (HILIC) was developed for the analysis of neurotoxins β-N-methylamino-l-alanine (BMAA) and 2,4-diaminobutyric acid (DAB), using multiple reaction monitoring (MRM) scan mode. Oasis-MCX and Strata-X-C polymeric cation-exchange cartridges were used to clean extracts of cyanobacterial cultures, including two strains of Microcystis aeruginosa and one strain of Nostoc sp. The performance of the solid-phase extraction (SPE) cartridges for BMAA and DAB were evaluated using mixed standards and spiked cyanobacterial extracts, which demonstrated recoveries of BMAA and DAB ranging from 66% to 91%. Matrix effects in LC-MS/MS were evaluated, and while there was no effect on BMAA quantitation, suppression of DAB was found. Full scan (Q1) and enhanced product ion (EPI) monitoring showed that the DAB suppression may be due to closely eluting compounds, including lysine, histidine, arginine and three other compounds with [M + H] +m/z of 88, 164 and 191. The procedures developed allow the sensitive and effective analysis of trace BMAA and DAB levels in cyanobacteria. While DAB was confirmed to be present, no BMAA was found in the cyanobacterial samples tested in the present study.

Changes in enzymatic activity during early development of bay scallops Argopecten irradians and sea scallops Placopecten magellanicus - Milke, Lisa M.; Bricelj, V. Monica; Ross, Neil W. (Aquatic Biology, 2012)
Poor growth and survival of scallops is often reported during early developmental stages. Stage- and species-specific dietary requirements have been identified, but the mechanisms responsible for these differences remain largely unknown. Dietary success depends on food biochemical properties, digestive and/or assimilative capacity, as well as the animal's specific nutritional demands, which can vary over development and between species. The present study examines developmental changes in the activities of key digestive enzymes in larval and postlarval bay scallops Argopecten irradians and sea scallops Placopecten magellanicus raised on a mixed algal diet until ~4 to 5 mm in shell height (SH) and sampled at intervals encompassing major transitions in feeding organ development. Colorimetric assays measured general protease, lipase (esterase) and carbohydrase (α-amylase, cellulase and laminarinase) activities. The most pronounced changes in enzymatic activity occurred prior to scallops attaining ~1.2 mm SH in both scallop species. The esterase:protease ratio exhibited similar ontogenetic patterns in both scallop species, decreasing sharply between larval and immediate postlarval stages before increasing to an intermediate level and stabilizing around 1.2 mm SH. In contrast, mean carbohydrase activities measured over the experimental duration differed between species, with bay scallops exhibiting higher specific activities of α-amylase and cellulase but much lower activities of laminarinase than sea scallops. These findings have implications for understanding scallop utilization of the food supply in nature, as well as developing targeted diets that could enhance their growth and survival in culture.
Keywords: digestive enzyme activity; scallops; Placopecten magellanicus; Argopecten irradians; development

Image formation in CARS and SRS : effect of an inhomogeneous nonresonant background medium - Popov, K. I.; Pegoraro, A. F.; Stolow, A.; Ramunno, L. (Optics Letters, 2012)
We investigate the role of a spatially inhomogenous nonresonant background medium on several Raman-based imaging modalities. In particular, we consider a small resonant bead submerged in a spatially heterogeneous nonresonant χ(3) background. Using detailed 3D electrodynamic simulations, we compare coherent anti-Stokes Raman scattering (CARS), frequency-modulated CARS, amplitude-modulated stimulated Raman scattering (SRS), and frequency-modulated SRS. We find that only FM-SRS is background-free.

Antiproliferative activity of Saponaria vaccaria constituents and related compounds - Balsevich, J. John; Ramirez-Erosa, Irving; Hickie, Robert A.; Dunlop, Donna M.; Bishop, Greg G.; Deibert, Leah K. (Fitoterapia, 2012)
Total methanolic extracts of Saponaria vaccaria seed derived from several varieties, as well as various purified components obtained through successive chromatographic separations of total extracts were evaluated for their growth inhibitory activity in WiDr (colon), MDA-MB-231 (breast), NCI-417 (lung) and PC-3 (prostate) human cancer cells as well as the non-tumorigenic fibroblast BJ (CRL-2522) cell line using MTT colorimetric assay. Purified bisdesmosidic saponins segetoside H and I were further examined using microscopy and apoptosis assays. Bisdesmosidic saponins exhibited dose-dependent growth inhibitory and selective apoptosis-inducing activity. Growth inhibitory effects were particularly strong in a breast (MDA-MB-231) and a prostate (PC-3) cancer cell line. Total extracts exhibited a different preference being most active against a colon cancer cell line (WiDr). In a comparison of varieties, all of the total seed extracts exhibited similar dose-dependent activities, but with some variation in potency. Monodesmosidic saponins vaccarosides A and B, phenolic vaccarin, and cyclopeptide segetalin A, co-occurring seed substituents, did not exhibit activity. The non-tumorigenic fibroblast cell line BJ (CRL 2522) was growth inhibited but did not undergo apoptosis when treated with bisdesmosidic saponins at low micromolar concentrations. Saponin-rich extracts from Kochia scoparia seed and Chenopodium quinoa were also evaluated alongside Saponaria saponins but did not exhibit activity. Closely related Quillaja saponins exhibited activity but were less potent.
Keywords: Saponaria vaccaria; saponins; growth inhibition; apoptosis; cancer; MDA-MB-231; PC-3.

Analysis of Phytohormone profiles during male and female cone initiation and early differentiation in long-shoot buds of Lodgepole pine - Kong, Lisheng; von Aderkas, Patrick; Zaharia, Irina; Abrams, Suzanne R.; Lee, Tim; Woods, Jack (Journal of Plant Growth Regulation, 2012)
In lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm), cone initiation and gender differentiation are site-specific in long-shoot buds with female cones in the distal portion and male cones in the proximal portion. By using high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) in multiple reaction monitoring (MRM) mode, cytokinins, indole-3-acetic acid (IAA), gibberellins (GAs), abscisic acid (ABA) and their selected metabolites, were investigated in developing long-shoot buds from multiple genotypes. Spatially, higher concentrations of trans-zeatin riboside (t-ZR) and dihydrozeatin (dhZR) existed in the distal parts of long-shoot buds, whereas concentrations of isopentenyl adenosine (iPA), IAA, GA24, ABA, ABA glucose ester (ABA-GE) and phaseic acid (PA) were higher in the proximal parts in all investigated genotypes. In long-shoot buds of genotypes with a history of high female cone yield, concentrations of t-ZR and the ratio of zeatin-type to isopentenyl-type cytokinins were higher in the entire buds, whereas dhZR or IAA was higher either in the distal or in the proximal part respectively. In low female cone yielding genotypes, concentrations of c-ZR, iPA, ABA-GE and PA were higher in both of the parts, whereas ABA was higher mainly in the distal part with higher GA24 in the proximal part. Temporally, concentrations of several hormone-related compounds showed obvious changes in late June and late July, prior to male and female cone bud differentiation. This study reveals that the local hormonal status in a long-shoot bud at specific developmental stages may play an important role in gender determination and cone yield.
Keywords: cone gender; Lodgepole pine; long-shoot bud; genotype; metabolite; phytohormone

Molecular structure of phospholipase D and regulatory mechanisms of its activity in plant and animal cells - Kolesnikov, Y. S.; Nokhrina, K. P.; Kretynin, S. V.; Volotovski, I. D.; Martinec, J.; Romanov, G. A.; Kravets, V. S. (Biochemistry (Moscow), 2012)
Phospholipase D (PLD) catalyzes hydrolysis of phospholipids with production of phosphatidic acids, which often act as secondary messengers on transmission of intracellular signals. This review summarizes data of various leading laboratories on specific features of organization and regulation of PLD activity in plant and animal cells. The main structural domains of PLD (C2, PX, PH), the active site, and other functionally important parts of the enzyme are considered. Regulatory mechanisms of PLD activity are characterized in detail. Studies associated with molecular design, analysis, and synthesis of new nontoxic substances capable of inhibiting different PLD isoenzymes in vivo are shown to be promising for biotechnology and medicine.
Keywords: phospholipase D; domains; calcium; lipids; G-proteins; protein kinases; protein–protein interactions

Halogen and hydrogen host-guest bonding in cathrate hydrates - Udachin, Konstantin; Ripmeester, John (Proceedings of the 7th International Conference on Gas Hydrates (ICGH 2011), 2012)
Clathrate hydrates with low melting points (often below –20°C) are difficult subjects for single crystal data collection. A high level of guest molecule disorder inside the high symmetry cages causes difficulty for structure determination of such crystals as well. Recent advances in single crystal X-ray diffraction have allowed this technique to be used as a valuable tool for the analysis of hydrate structure and composition. With detailed analysis of guest and water molecules disorder, not only the guest positions are clearly defined, but also it becomes possible to find interactions between guest and water molecules. For the first time, single crystal x-ray crystallography is used to detect the presence of guest host hydrogen and halogen bonding in structure I, II and structure H clathrate hydrates. Clathrates studied are the tert- butylamine (tBA) sII clathrate with H2S and Xe help gases, the pinacolone + H2S binary sH clathrate, 1,3-Dioxolane hydrate, chlorine, bromine, and mixed chlorine with bromine hydrates. X-ray structural analysis shows that the tBA nitrogen atom has a distance of 2.64 Å from the closest large cage oxygen atom. This water molecule is pulled inwards toward the tBA guest (cage center) and the structure of the large cage is substantially distorted in comparison to the ideal cage structure. The pinacolone oxygen atom is determined to have a distance of 2.96 Å from the closest large cage oxygen atom.
Keywords: clathrate hydrates, crystal structure, chlorine, bromine, pinacolone, tert-butylamine.

Ship manoeuvring-in-ice modeling software OSIS-IHI - Lau, Michael (21st International Conference on Port and Ocean Engineering under Arctic Condition 2011 (Proceedings), 2012)
Software to model a ship manoeuvring in ice has been developed which will simulate the ice forces on a ship passing through a field of level ice and the resulting motions. OSIS-IHI (Ocean Structure Interaction Simulator – Ice-Hull Interaction) is an integration of two separatelydeveloped components. The first component is a static force solver that uses discrete-time motion data to calculate the resultant ice forces at a given point in time. The second component is an ordinary differential equation solver that produces dynamic motion data given a set of steering methods, such as propeller revolution and rudder angle deflection. It has been verified extensively and used for client consulting work with success. The development and integration of both components is discussed, accompanied by preliminary verifications.
Keywords: OSIS-IHI; manoeuvring; ice load; software; ship motions

Numerical assessment for stationary structure (Kulluk) in moving broken ice - Wang, J.; Derradji-Aouat, A. (21st International Conference on Port and Ocean Engineering under Arctic Condition 2011 (Proceedings), 2012)
Keywords: LS-DYNA; structure ice interaction; managed ice; Arbitrary Lagrangian Eulerian method

Performance measurements of the effect of simulator training on novice operators in simulated ice conditions - Power MacDonald, Stephanie; MacKinnon, Scott; Simões Ré, Antonio; Power, Jonathan (21st International Conference on Port and Ocean Engineering under Arctic Condition 2011 (Proceedings), 2012)
Shipping and offshore sectors are moving operations into the ice-covered waters of the Arctic. As these exploration endeavours evolve, more guidance is needed for equipment, procedures, and training to operate in cold, harsh environments. At present, limited training exists for lifeboat coxswains charged with navigating lifeboats in ice-covered water during emergency evacuation situations. This research study examines the effectiveness of simulator training in comparison with traditional Standard Training, Certification and Watchkeeping (STCW) training for navigating lifeboats in ice fields. These findings will inform manufacturers, trainers and regulators regarding the operational demands and training requirements needed to safely and efficiently perform these tasks.
Keywords: simulation training; EER (Escape, Evacuation, and Rescue); STCW; arctic environment

Microstructural effects on the mechanical properties of ATI 718Plus® Alloy - Kearsey, R. M.; Tsang, J.; Oppenheimer, S.; McDevitt, E. (Journal of the Minerals, Metals and Materials Society, 2012)
Four microstructural variants of ATI 718Plus® alloy (718Plus) have been investigated to elucidate the effects of grain size, precipitate size, morphology, and phase fraction (δ and γ′) on mechanical properties such as low cycle fatigue (LCF) life, fatigue crack growth rate (FCGR) properties, and dwell FCGR behavior at both 649°C and 704°C under 100 s dwell and nondwell conditions. Similar tests have also been performed on Waspaloy in two comparative microstructural conditions. LCF test results demonstrate that all four microstructural conditions of 718Plus have superior life compared with Waspaloy under all investigated test conditions. FCGR results show that, at both test temperatures, all microstructural conditions of 718Plus and Waspaloy exhibit identical behavior in the steady-state regime, except that 718Plus exhibits a much higher threshold stress intensity (ΔK TH). However, the dwell FCGR results show that Waspaloy displays better steady-state crack growth resistance under dwell conditions. However, with a thermal exposed precipitate microstructure, 718Plus shows considerable improvement in this response.
Keywords: Superalloys; damage tolerance; FCGR; dwell fatigue; ATI 718Plus Alloy; Waspaloy

Static strength of a composite butt joint configuration with different attachments - Li, Gang; Chen, Ji Hua; Yanishevsky, Marko; Bellinger, Nicholas C. (Composite Structures, 2012)
The static failure behaviour of a composite single-strap joint configuration using three different attachments was studied experimentally. The attachments used were: adhesive bonding; mechanical bolting; and bonded-bolted joining. The dimensions of the composite butt joint used were determined based on actual joint configurations in aircraft structures, such that the test results would be beneficial to both the academic exploration and practical engineering application for advanced composite joint design and analysis. A damage evolution process was presented for the bonded-bolted butt joints based on the observed stress versus displacement curves and associated failure modes from all the related butt joints with the three attachments. An approach was then proposed for estimating the ultimate tensile strength in the bonded-bolted joints.
Keywords: Bonded-bolted composite joints; Damage; Failure mode; Ultimate strength

How language enables abstraction : a study in computational cultural psychology - Neuman, Yair; Turney, Peter; Cohen, Yohai (Integrative Psychological and Behavioral Science, 2012)
The idea that language mediates our thoughts and enables abstract cognition has been a key idea in socio-cultural psychology. However, it is not clear what mechanisms support this process of abstraction. Peirce argued that one mechanism by which language enables abstract thought is hypostatic abstraction, the process through which a predicate (e.g., dark) turns into an object (e.g., darkness). By using novel computational tools we tested Peirce’s idea. Analysis of the data provides empirical support for Peirce's mechanism and evidence of the way the use of signs enables abstraction. These conclusions are supported by the in-depth analysis of two case studies concerning the abstraction of sweet and dark. The paper concludes by discussing the findings from a broad and integrative theoretical perspective and by pointing to computational cultural psychology as a promising perspective for addressing long-lasting questions of the field.
Keywords: thought and language; abstraction; hypostatic abstraction; computational cultural psychology

Enhanced photonic crystal cavity-waveguide coupling using local slow-light engineering - Mnaymneh, K.; Frederick, S.; Dalacu, D.; Lapointe, J.; Poole, P. J.; Williams, R. L. (OPTICS LETTERS, 2012)
This Letter introduces an enhanced cavity-waveguide coupling architecture based upon slow-light engineering in a two-port photonic crystal system. After analyzing the system transmittance using coupled-mode theory, the system is probed experimentally and shown to have increased transmittance due to the enhanced cavity-waveguide coupling. Such a coupling architecture may facilitate next-generation planar lightwave circuitry such as onchip quantum information processing or high precision light-matter sensing applications.

Ultrawide-bandwidth, superluminescent light-emitting diodes using InAs quantum dots of tuned height - Haffouz, S.; Barrios, P. J.; Normandin, R.; Poitras, D.; Lu, Z. (OPTICS LETTERS, 2012)
An ultrawide-bandwidth, superluminescent light-emitting diode (SLED) utilizing multiple layers of dots of tuned height is reported. Due to thermal effect, the superluminescent phenomenon is observed only under pulse-mode operation. The device exhibits a 3 dB bandwidth of 190 nm with central wavelength of 1020 nm under continuouswave (cw) conditions. The maximum corresponding output power achieved in this device under cw and pulsed operation conditions are 0.54 mW and 17 mW, respectively.

Lipid sensing apolipoprotein A-I for novel high -throughput lipidation assays - Niedziela-Majka, Anita; Lad, Latesh; Chishom, Jeffrey W.; Lagpacan, Leanna; Schwartz, Karen; Hung, Magdeleine; Jin, Debi; Fung, Wanchi; Brendza, Katherine M.; Liu, Xioahong; Pagratis, Nikos; Sakowicz, Roman (Biophysical Journal, 2012)
Apolipoprotein A-I (ApoA-I) is the primary protein component of high density lipoproteins (HDL). ApoA-I plays an important role in cholesterol metabolism by mediating the formation of nascent HDL and the efflux of cellular cholesterol from macrophage foam cells in arterial walls. Lipidation of ApoA-I is mediated by the ATP-binding cassette A1 (ABCA1). Insufficient ABCA1 activity my lead to reduced HDL formation, reduced cholesterol efflux and the development of arteriosclerosis. The standard radioactive assay for measuring cholesterol transport to lipid-free ApoA-I has low through-put, poor dynamic range and fails to measure phospholipid transferred with cholesterol. We describe the development of two sensitive, non-radioactive high-throughput assays that report on the lipidation state of ApoA-I and may have applications for studying ABCA1 function and HDL metabolism: a homogenous assay based on the Time Resolved FRET (TR-FRET) and a discontinuous assay that uses the Epic. The TR-FRET assay employs a fluorescent ApoA-I where Cysteine is labeled with the FRET acceptor HiLyte-Fluor-647 and an N-terminal Biotin-AviTag is bound to the streptavidin-Terbium conjugate. When this ApoA-I was incorporated into recombinant HDL, TR-FRET decreased proportionally to the increase in the ratio of lipid to ApoA-I in agreement with the expansion of the surface area of lipids concomitant with the increase in separation of N-terminal and central regions of the protein and demonstrated that the HTRF assay was sensitive to the amount of lipid associated with ApoA-I. The Epic is a label-free platform that allows for the observation of direct biomolecular interactions via a resonant wavelength shift which is proportional to the mass bound to the surface. In the Epic assay, biotinylated ApoA-I was captured on streptavidin-coated sensor. The response was proportional to the amount of lipids associated with ApoA-I indicating that the assay could sense lipidation of ApoA-I.
Keywords: high-throughput; lipid sensing; apolipoprotein

Synthesis of 4-acetamidohexoses in bacteria: structural insights from the bacillosamine and nonulosonic acid pathways - Matte, Allan; Schoenhofen, Ian C.; Sulea, Traian; Cygler, Miroslaw; Young, N. Martin (Bacterial Glycomics: Current Research, Technology and Applications, 2012)
Many hexose sugars in bacteria undergo a variety of modifications, including oxidation/reduction, amination and acetylation, as part of biosynthesis into their final biologically-active forms. Enzymes that catalyze these reactions normally utilize nucleotide-linked sugar substrates, utilizing the nucleotide as an 'ancient handle' to bind and orient the sugar within the enzymes' active site. We and others have focused efforts on elucidating structure-function relationships for a subset of such biosynthetic enzymes, those associated with the synthesis of trideoxy-diacetamidohexoses, and the nonulsonate sugars subsequently derived from them. With structural information combined with site-directed mutagenesis, enzymatic analysis and molecular modeling, these studies have been essential to understanding the chemistry of how these enzymes bind their substrates and effect catalysis. Enzymes having different folds, such as N-acetyltransferases, can utilize different scaffolds to attain the same 4-acetamido-sugar product. In the case of dehydratases/epimerases and aminotransferases, the enzymes have a conserved structure, but utilize subtle differences within their active site to confer substrate binding and the nature of the final product. These studies depict the structural relationships between these enzymes, while at the same time high-lighting important differences that are beginning to reveal their function at the molecular level.

Increased EID1 nuclear translocation impairs synaptic plasticity and memory function associated with pathogenesis of Alzheimer's disease - Liu, Rugao; Lei, Joy X.; Luo, Chun; Lan, Xun; Chi, Liying; Deng, Panyue; Lei, Saobo; Ghribi, Othman; Liu, Qing Yan (Neurobiology of Disease, 2012)
Though loss of function in CBP/p300, a family of CREB-binding proteins, has been causally associated with a variety of human neurological disorders, such as Rubinstein–Taybi syndrome, Huntington's disease and drug addiction, the role of EP300 interacting inhibitor of differentiation 1 (EID1), a CBP/p300 inhibitory protein, in modulating neurological functions remains completely unknown. Through the examination of EID1 expression and cellular distribution, we discovered that there is a significant increase of EID1 nuclear translocation in the cortical neurons of Alzheimer's disease (AD) patient brains compared to that of control brains. To study the potential effects of EID1 on neurological functions associated with learning and memory, we generated a transgenic mouse model with a neuron-specific expression of human EID1 gene in the brain. Overexpression of EID1 led to an increase in its nuclear localization in neurons mimicking that seen in human AD brains. The transgenic mice had a disrupted neurofilament organization and increase of astrogliosis in the cortex and hippocampus. Furthermore, we demonstrated that overexpression of EID1 reduced hippocampal long-term potentiation and impaired spatial learning and memory function in the transgenic mice. Our results indicated that the negative effects of extra nuclear EID1 in transgenic mouse brains are likely due to its inhibitory function on CBP/p300 mediated histone and p53 acetylation, thus affecting the expression of downstream genes involved in the maintenance of neuronal structure and function. Together, our data raise the possibility that alteration of EID1 expression, particularly the increase of EID1 nuclear localization that inhibits CBP/p300 activity in neuronal cells, may play an important role in AD pathogenesis.
Keywords: EP300 interacting inhibitor of differentiation 1; CBP/p300; histone; acetylation; Alzheimer's disease

Application of bacterial glycosyltransferases in the synthesis of bioactive glycans - Wakarchuk, Warren (Bacterial Glycomics : Current Research, Technology and Applications, 2012)

Conical intersection dynamics in NO2 probed by homodyne high-harmonic spectroscopy - Worner, H. J.; Bertrand, J. B.; Fabre, B.; Higuet, J.; Ruf, H.; Dubrouil, A.; Patchkovskii, S.; Spanner, M.; Mairesse, Y.; Blanchet, V.; Mevel, E.; Constant, E.; et al. (Science, 2012)
Conical intersections play a crucial role in the chemistry of most polyatomic molecules, ranging from the simplest bimolecular reactions to the photostability of DNA. The real-time study of the associated electronic dynamics poses a major challenge to the latest techniques of ultrafast measurement. We show that high-harmonic spectroscopy reveals oscillations in the electronic character that occur in nitrogen dioxide when a photoexcited wave packet crosses a conical intersection. At longer delays, we observe the onset of statistical dissociation dynamics. The present results demonstrate that high-harmonic spectroscopy could become a powerful tool to highlight electronic dynamics occurring along nonadiabatic chemical reaction pathways.

Effects of bending and torsion rigidity on deformation and breakage of flexible fibers : a direct simulation study - Kabanemi, Kalonji K.; Hétu, Jean-François (Journal of Chemical Physics, 2012)

Fire resistance cellulosic fibers for green polymer composites - Ton That, Minh Tan; Ngo, Tri-Dung; Hu, Wei (2012)

Simulation of gas-substrate heat exchange during cold-gas dynamic spraying - Ryabinin, A. N.; Irissou, E.; McDonald, A.; Legoux, J.-G. (International Journal of Thermal Sciences, 2012)
Keywords: biot number; cold spraying; jet impingement; temperature distribution number

Metagenomic analysis of the bioremediation of diesel-contaminated Canadian high arctic soils - Yergeau, Etienne; Sanschagrin, Sylvie; Beaumier, Danielle; Greer, Charles W. (PLoS ONE, 2012)
As human activity in the Arctic increases, so does the risk of hydrocarbon pollution events. On site bioremediation of contaminated soil is the only feasible clean up solution in these remote areas, but degradation rates vary widely between bioremediation treatments. Most previous studies have focused on the feasibility of on site clean-up and very little attention has been given to the microbial and functional communities involved and their ecology. Here, we ask the question: which microorganisms and functional genes are abundant and active during hydrocarbon degradation at cold temperature? To answer this question, we sequenced the soil metagenome of an ongoing bioremediation project in Alert, Canada through a time course. We also used reverse-transcriptase real-time PCR (RT-qPCR) to quantify the expression of several hydrocarbon-degrading genes. Pseudomonas species appeared as the most abundant organisms in Alert soils right after contamination with diesel and excavation (t = 0) and one month after the start of the bioremediation treatment (t = 1m), when degradation rates were at their highest, but decreased after one year (t = 1y), when residual soil hydrocarbons were almost depleted. This trend was also reflected in hydrocarbon degrading genes, which were mainly affiliated with Gammaproteobacteria at t = 0 and t = 1m and with Alphaproteobacteria and Actinobacteria at t = 1y. RT-qPCR assays confirmed that Pseudomonas and Rhodococcus species actively expressed hydrocarbon degradation genes in Arctic biopile soils. Taken together, these results indicated that biopile treatment leads to major shifts in soil microbial communities, favoring aerobic bacteria that can degrade hydrocarbons.

Involvement of cytochrome c CymA in the anaerobic metabolism of RDX by Shewanella oneidensis MR-1 - Perreault, Nancy N.; Crocker, Fiona H.; Indest, Karl J.; Hawari, Jalal (Canadian Journal of Microbiology, 2012)
Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is a cyclic nitramine explosive commonly used for military applications that is responsible for severe soil and groundwater contamination. In this study, Shewanella oneidensis MR-1 was shown to efficiently degrade RDX anaerobically (3.5 ?mol·h -1·(g protein) -1) via two initial routes: (1) sequential N-NO2 reductions to the corresponding nitroso (N-NO) derivatives (94% of initial RDX degradation) and (2) denitration followed by ring cleavage. To identify genes involved in the anaerobic metabolism of RDX, a library of ~2500 mutants of MR-1 was constructed by random transposon mutagenesis and screened for mutants with a reduced ability to degrade RDX compared with the wild type. An RDX-defective mutant (C9) was isolated that had the transposon inserted in the c-type cytochrome gene cymA. C9 transformed RDX at ~10% of the wild-type rate, with degradation occurring mostly via early ring cleavage caused by initial denitration leading to the formation of methylenedinitramine, 4-nitro-2,4-diazabutanal, formaldehyde, nitrous oxide, and ammonia. Genetic complementation of mutant C9 restored the wild-type phenotype, providing evidence that electron transport components have a role in the anaerobic reduction of RDX by MR-1.
Keywords: RDX; explosive; nitramine; biotransformation; Shewanella

A review of electrochemical desulfurization technologies for fossil fuels - Lam, Vincent; Li, Guangchun; Song, Chaojie; Chen, Jinwen; Fairbridge, Craig; Hui, Rob; Zhang, Jiujun (Fuel Processing Technology, 2012)
Desulfurization is an important process for crude oil upgrading. Electrochemical desulfurization technologies have advantages over conventional hydrodesulfurization technologies in terms of lowtemperature and pressure operation with high product selectivity and therefore less energy consumption. In this paper the authors reviewed the research done in the past decades on electrochemical desulfurization for fossil fuels. The principles, electrochemical methods, electrochemical reactors, catalysts and electrolytes employed in the electrochemical desulfurization process were discussed; and future research work is recommended.
Keywords: electrochemical desulfurization; fossil fuel; heavy crude oil; coal; catalysts

Proton conductivity of aromatic polymers - Liu, Baijun; Guiver, Michael D. (Solid State Proton Conductors : Properties and Applications in Fuel Cells, 2012)

Terahertz quantum cascade lasers operating up to ~ 200 K with optimized oscillator strength and improved injection tunneling - Fathololoumi, S.; Dupont, E.; Chang, C. W. I.; Wasilewski, Z. R.; Laframboise, S. R.; Ban, D.; Matyas, A.; Jirauschek, C.; Hu, Q.; Liu, H. C. (Optics Express, 2012)
A new temperature performance record of 199.5 K for terahertz quantum cascade lasers is achieved by optimizing the lasing transition oscillator strength of the resonant phonon based three-well design. The optimum oscillator strength of 0.58 was found to be larger than that of the previous record (0.41) by Kumar et al. [Appl. Phys. Lett. 94, 131105 (2009)]. The choice of tunneling barrier thicknesses was determined with a simplified density matrix model, which converged towards higher tunneling coupling strengths than previously explored and nearly perfect alignment of the states across the injection and extraction barriers at the design electric field. At 8 K, the device showed a threshold current density of 1 kA/cm2, with a peak output power of ∼ 38 mW, and lasing frequency blue-shifting from 2.6 THz to 2.85 THz with increasing bias. The wavelength blue-shifted to 3.22 THz closer to the maximum operating temperature of 199.5 K, which corresponds to ∼ 1.28¯hω/κB. The voltage dependence of laser frequency is related to the Stark effect of two intersubband transitions and is compared with the simulated gain spectra obtained by a Monte Carlo approach.

Fabrication and performance of a photonic-microfluidic integrated device - Watts, Benjamin R.; Kowpak, Thomas; Zhang, Zhiyi; Xu, Chang-Qing; Zhu, Shiping; Cao, Xudong; Lin, Min (Micromachines, 2012)
Fabrication and performance of a functional photonic-microfluidic flow cytometer is demonstrated. The devices are fabricated on a Pyrex substrate by photolithographically patterning the microchannels and optics in a SU-8 layer that is sealed via a poly(dimethylsiloxane) (PDMS) layer through a unique chemical bonding method. The resulting devices eliminate the free-space excitation optics through integration of microlenses onto the chip to mimic conventional cytometry excitation. Devices with beam waists of 6 μm and 12 μm in fluorescent detection and counting tests using 2.5 and 6 μm beads-show CVs of 9%–13% and 23% for the two devices, respectively. These results are within the expectations for a conventional cytometer (5%–15%) and demonstrate the ability to integrate the photonic components for excitation onto the chip and the ability to maintain the level of reliable detection.
Keywords: SU-8; PDMS; microfludics; optical waveguide; integration; devices

Effects of small specimen tilt and probe convergence angle on ADF-STEM image contrast of Si0.8Ge0.2 epitaxial strained layers on (100) Si - Wu, X.; Robertson, M. D.; Kawasaki, M.; Baribeau, J.-M. (Ultramicroscopy, 2012)
The effects of specimen tilt and probe convergence angle on annular darkfield(ADF) image contrast of Si0.8Ge0.2 heteroepitaxial strained layers on(100) Si were investigated in a 200kV scanning transmission electron microscope (STEM) for a TEM specimen thickness of 195nm. With 0.5 degrees of specimen tilt away from the exact <011S> zone-axis orientation, the signal-to-noise level of atomic columns was significantly reduced for both Si0.8Ge0.2 and Si in high resolution ADF-STEM lattice images. When the specimen was tilted 0.5 degrees around the <011S> axis, or the STEM probe convergence semi angle was reduced from 14.3 to 3.6 mrad, the ADF-STEM image intensity profiles across the Si0.8Ge0.2 and Si layers changed significantly as compared to those obtained at the exact <011S> zone axis orientation, and no longer reflected the composition changes occurring across the layer structure. Multislice image simulation results revealed that the misfit strain between the Si0.8Ge0.2 and Silayers, and strain relaxation near the surface of the TEM specimen, were responsible for the observed changes in image intensity.
Keywords: annular dark field scanning transmission electron microscopy; semiconductor heteroepitaxial strained layers

Ultracompact polarization converter with a dual subwavelength trench built in a silicon-on-insulator waveguide - Velasco, Aitor, V.; Calvo, Maria L.; Cheben, Pavel; Ortega-Monux, Alejandro; Schmid, Jens H.; Ramos, Carlos Alonso; Fernandez, Inigo Molina; Lapointe, Jean; Vachon, Martin; Janz, Siegfried; Xu, Dan-Xia (OPTICS LETTERS, 2012)
The design and fabrication of an ultracompact silicon-on-insulator polarization converter is reported. The polarization conversion with an extinction ratio of 16 dB is achieved for a conversion length of only 10 m. Polarization rotation is achieved by inducing a vertical asymmetry by forming in the waveguide core two subwavelength trenches of different depths. By taking advantage of the calibrated reactive ion etch lag, the two depths are implemented using a single mask and etching process. The measured converter loss is 0.7 dB and the 3 dB bandwidth is 26 nm.

Resonance-hybrid states in a triple quantum dot - Amaha, S.; Hatano, T.; Tamura, H.; Teraoka, S.; Kubo, T.; Tokura, Y.; Austing, D. G.; Tarucha, S. (Physical Review B, 2012)
Delocalization by resonance between contributing structures explains the enhanced stability of resonancehybrid molecules. Here we report the realization of resonance-hybrid states in a few-electron triple quantum dot (TQD) obseved by excitation spectroscopy. The stabilization of the resonance-hybrid state and the bond between contributing states are achieved through access to the intermediate states with double occupancy of the dots. This explains why the energy of the hybridized singlet state is significantly lower than that of the triplet state. The properties of the three-electron doublet states can also be understood with the resonance-hybrid picture and geometrical phase. As well as for fundamental TQD physics, our results are useful for the investigation of materials such as quantum dot arrays, quantum information processors, and chemical reaction and quantum simulators.

Free-carrier absorption in quantum cascade structures - Carosell, F.; Ndebeka-Bandou, C.; Ferreira, R.; Dupont, E.; Unterrainer, K.; Strasser, G.; Wacker, A.; Bastard, G. (Physical Review B, 2012)
We show that the free-carrier absorption in quantum cascade lasers (QCLs) is very small and radically different from the classical Drude result due to the orthogonality between the direction of the carrier free motion and the electric field of the laser emission. A quantum mechanical calculation of the free-carrier absorption and intersubband oblique absorption induced by interface defects, Coulombic impurities, and optical phonon absorption/emission is presented for QCLs with a double-quantum-well design. The interaction between the electrons and the optical phonons dominates at room temperature.

Highly ordered LiFePO4 cathode material for Li-ion batteries templated by surfactant-modified polystyrene colloidal crystals - Yim, Chae-Ho; Baranova, Elena A.; Abu-Lebdeh, Yaser; Davidson, Isobel (Journal of Power Sources, 2012)
An organic template assisted synthesis was developed to obtain highly ordered porous LiFePO4 cathode material. The developed synthesis enabled the use of polystyrene (PS) as template by modifying its surface with a surfactant (Brij 78) to render it hydrophilic. The material was synthesized in high yield and purity as confirmed by X-ray powder diffraction. The TEM and SEM images clearly confirmed the presence of a highly ordered porous structure and the latter showed that the structure has an average pore diameter of 400 nm and a wall thickness and depth of ~100 nm. Thermal scans and elemental analysis showed that the material contains a high amount of carbon reaching 23-28% by weight. The surface area was calculated using the BET method and found to be 7.71m(to the power of 2)g(to the power of-1). Li/LiFePO4 half cells were tested and gave satisfactory discharge capacities; an initial capacity [158mAhg(to the power of -1)] close to the theoretical value and recoverable capacities at high C-rates (2-5 C).
Keywords: LiFePO4; Li-ion battery; cathode material; three-dimensionally ordered macroporous structure; organic template assisted synthesis

Optimization of synthesis conditions for LiFePO4/C nanocomposites by dimethyl sulfoxide assisted solution-phase method - Chang, Zhaorong; Tang, Hongwei; Liu, Yao; Yuan, Xiao Zi; Wang, Haijiang; Gao, Shuyan (Journal of the Electrochemical Society, 2012)
Olivine-type LiFePO4 is synthesized by a solution-phase method, using dimethyl sulfoxide (DMSO) as a boiling point raiser and crystal growth inhibitor under ambient pressure and low temperature for a short time. The crystalline structure and morphology of the composites are characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. By analyzing the ratio of solvent to water, reactant concentration, reaction time, sintering time, and temperature we determine the optimal conditions for synthesizing LiFePO4/C nanocomposites, which are as follows: DMSO:water = 1:1, reactant concentration 1 M, reaction time 2 h, mixed with a certain amount of glucose and sintered at 600◦C under a 5% H2–95% N2 atmosphere for 3 h. The LiFePO4/C thus prepared has a well developed olivine-type structure, small crystals, and a narrow size distribution. Electrochemical performance tests show that the special capacity of LiFePO4/C at discharge rates of 0.2 C and 1 C is 157.7 mAh g−1 and 142.5 mAh g−1, respectively. A special capacity of 126 mAh g−1 at 5 C and 104 mAh g−1 at 10 C is even achievable, with no significant capacity fading after 200 cycles, and thematerial delivers a good high-rate discharge property and excellent cycling performance.
Keywords: olivine-type LiFePO4; dimethyl sulfoxide (DMSO); X-ray diffraction (XRD); nanocomposites

Effect of open circuit voltage on degradation of a short proton exchange membrane fuel cell stack with bilayer membrane configurations - Zhang, Shengsheng; Yuan, Xiao-Zi; Hiesgen, Renate; Friedrich, K. Andreas; Wang, Haijiang; Schulze, Mathias; Haug, Andrea; Li, Hui (Journal of Power Sources, 2012)
In the present work, membrane electrode assembly degradation of a 4-cell stack with specially designed twin catalyst coated membranes (twin-CCMs) was carried out for 1600 h under open circuit voltage (OCV) conditions. Four types of membrane with various thicknesses were employed in the experiment. Each twin-CCM was composed of two membranes of the same type with a catalyst layer coated only on one side. The purpose of this special configuration was to facilitate postmortem analysis of the membrane after degradation due to the detachable membrane structure. By means of several in situ electrochemical measurements, the performance of the individual cells was analysed every 200 h during the degradation process. Postmortem analyses such as scanning electron microscopy, atomic force microscopy, and infrared imaging were also conducted to identify the membrane degradation mechanisms after exposure to OCV. The results indicate that membrane degradation, which correlates with electrode degradation, is the most direct reason for the failure of the whole cell/stack during OCV operation, especially for cells with thinner membranes.
Keywords: PEM fuel cell; twin-CCM; degradation; membrane; open circuit voltage

Degradation of a PEM fuel cell stack with Nafion® membranes of different thicknesses. Part II : Ex situ diagnosis - Yuan, Xiao-Zi; Zhang, Shengsheng; Ban, Shuai; Huang, Cheng; Wang, Haijiang; Singara, Vengatesan; Fowler, Michael; Schulze, Mathias; Haug, Andrea; Friedrich, K. Andreas; Hiesgen, Renate (Journal of Power Sources, 2012)
Part I of this study carried out membrane electrode assembly degradation of a four-cell stack with Nafion membranes of different thicknesses, including N117, N115, NR212, and NR211, for 1000 h under idle conditions. Through on-line electrochemical measurements it was found that as degradation advanced, cells with thinner membranes experienced much more rapid performance degradation than those with thicker membranes, especially after 800 h of operation, due to a dramatic increase in hydrogen crossover. In the present work we investigate the degradation mechanisms of this four-cell stack using several ex situ diagnostic tools, including scanning electron microscopy (SEM), infrared (IR) imaging, ion chromatography (IC), gas permeability measurement, contact angle measurement, and simulation. The results indicate that the drastic increase in hydrogen crossover is due to membrane thickness loss and pinhole formation.
Keywords: proton exchange membrane fuel cell; stack; ex situ; durability; idle conditions; degradation

A review on performance degradation of proton exchange membrane fuel cells during startup and shutdown processes : causes, consequences, and mitigation strategies - Yu, Yi; Li, Hui; Wang, Haijiang; Yuan, Xiao-Zi; Wang, Guangjin; Pan, Mu (Journal of Power Sources, 2012)
Performance degradation during startup and shutdown is considered an important issue affecting the durability and lifetime of proton exchange membrane fuel cells (PEMFCs). Due to the high potentials experienced by the cathode during startup and shutdown, the conventional carbon support for the cathode catalyst is prone to oxidation by reacting with oxygen or water. This paper presents an overview of the causes and consequences of performance degradation after frequent startup shutdown cycles. Mitigation strategies are also summarized, including the use of novel catalyst supports and the application of system strategies to prevent performance degradation in PEMFCs. It is found from the literature review that improvements in catalyst supports to prevent oxidation come at the expense of high cost, and the novel supports developed to date are not sufficient to completely prevent carbon oxidation in fuel cell engines. System strategies, including potential control and reaction gas control, have been developed and applied in fuel cell engines to alleviate or even avoid performance decay. This review aims to provide a clear understanding of the mechanisms related to degradation behaviors during the startup and shutdown processes, thereby helping fuel cell material or system developers in their efforts to prevent performance degradation and prolong the lifetime of PEMFCs.
Keywords: proton exchange membrane fuel cell; startup and shutdown process; hydrogen/air interface; reverse current; system strategies

Appetite regulation and weight control : the role of gut hormones - Perry, B.; Wang, Y. (Nutrition and Diabetes, 2012)
The overwhelming increase in the prevalence of overweight and obesity in recent years represents one of the greatest threats to the health of the developed world. Among current treatments, however, gastrointestinal (GI) surgery remains the only approach capable of achieving significant weight loss results with long-term sustainability. As the obesity prevalence approaches epidemic proportions, the necessity to unravel the mechanisms regulating appetite control has garnered significant attention. It is well known that physical activity and food intake regulation are the two most important factors involved in body weight control. To regulate food intake, the brain must alter appetite. With this realization has come increased efforts to understand the intricate interplay between gut hormones and the central nervous system, and the role of these peptides in food intake regulation through appetite modulation. This review discusses the central mechanisms involved in body weight regulation and explores a suite of well characterized and intensely investigated anorexigenic and orexigenic gut hormones. Their appetite-regulating capabilities, post-GI surgery physiology and emerging potential as anti-obesity therapeutics are then reviewed.
Keywords: obesity; appetite; hypothalamus; gut hormones

Accelerated conditioning for a proton exchange membrane fuel cell - Yuan, Xiao-Zi; Sun, Jian Colin; Wang, Haijiang; Li, Hui (Journal of Power Sources, 2012)
A conditioning process is usually needed for a newly fabricated proton exchange membrane (PEM) fuel cell to be activated. Depending on the membrane electrode assemblies, this process can take hours and even days to complete. To provide for accelerated conditioning techniques that can complete the process in a short time, this paper compares various reported methods to condition a PEM single cell. The major objectives are to identify accelerated conditioning approaches that can significantly reduce the conditioning duration for the existing conditioning regime in an operationally easy manner, and to understand the fundamental principles that govern accelerated conditioning. Various effects investigated include temperature, cycling steps, and cycling frequencies. Other techniques, such as short circuiting, hydrogen pumping, and hot water circulation, are also discussed. For each technique, measurements are taken using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and linear sweep voltammetry (LSV).
Keywords: conditioning; pre-conditioning; activating; commissioning; break-in

Aerobic and anaerobic operation of an active membraneless direct methanol fuel cell - Lam, Alfred; Dara, Mohammad S.; Wilkinson, David P.; Fatih, Khalid (Electrochemistry Communications, 2012)
In this paper the operational and architectural flexibilities of a membraneless direct liquid fuel cell were demonstrated under aerobic and anaerobic configurations at 60 C and 1 atm. The aerobic membraneless direct methanol fuel cell (DMFC) was fed an anolyte solution of 1 MCH3OH/0.5 MH2SO4 and an air oxidant. The anaerobic membraneless direct methanol redox fuel cell (DMRFC) was fed an anolyte solution of 1 M CH3OH/0.1 M HClO4 and a catholyte solution of 2 M Fe(ClO4)3 and 0.22 M Fe(ClO4)2 oxidant. For both cases the membraneless architecture performed significantly better than for the conventional PEM architecture with Nafion 117. The maximum power density for the membraneless and Nafion 117 based DMFC was 52 mW cm 2 and 41 mW cm 2 respectively. The maximum power density for the membraneless and Nafion 117 based DMRFC was 46mW cm 2 and 34mW cm 2 respectively. In addition, anaerobic operation using a Fe2 /Fe3 catholyte gave similar performance to that for air as an oxidant. Both membraneless and anaerobic operation can result in significant cost reduction with improved operational flexibility.
Keywords: Membraneless; Direct methanol fuel cell; Direct methanol redox fuel cell; Aerobic; Anaerobic

Non-contact detection of ultrasound applied to biomedical photoacoustic tomography and ultrasonography - Rousseau, Guy; Blouin, Alain; Monchalin, Jean-Pierre (Proceedings of SPIE--the international society for optical engineering, 2012)

Swept-source OCT using programmable laser - Lamouche, Guy; Vergnole, Sébastien; Kim, Youngjae; Burgoyne, Bryan; Villeneuve, Alain (SPIE Proceedings: Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XVI, 2012)

PW12B-BO103-22 real-time control of angioplasty balloon inflation based on feedback from intravascular optical coherence tomography - Azarnoush, Hamed; Vergnole, Sébastien; Lamouche, Guy (Photonics West 2012, 2012)

Non-contact photoacoustic tomography and ultrasonography for biomedical imaging - Rousseau, Guy; Levesque, Daniel; Blouin, Alain; Monchalin, Jean-Pierre; Oraevsky, Alexander A.; Wang, Lihong V. (Photons plus ultrasound : imaging and sensing 2012, 2012)
Keywords: biomedical imaging; photoacoustic tomography; ultrasonography; laser ultrasonics; laser safety limits; tissue imaging; chicken breast

Non-contact photoacoustic tomography and ultrasonography for brain imaging - Rousseau, Guy; Blouin, Alain; Monchalin, Jean-Pierre (Photonic Therapeutics and Diagnostics VIII, 2012)
Keywords: biomedical imaging; photoacoustic tomography; ultrasonography; non-contact detection; neurosurgery; brain; blood oxygenation; ischemia

CO optical sensing properties of nanocrystalline ZnO-Au films: Effect of doping with transition metal ions - Della Gaspera, E.; Guglielmi, M.; Perotto, G.; Agnoli, S.; Granozzi, G.; Post, M. L.; Martucci, A. (Sensors and actuators B: Chemical, 2012)
Zinc oxide nanocrystals, pure and doped with transition metal ions, have been synthesized using colloidal techniques; after purification and concentration protocols, the ZnO solutions are mixed with monodisperse Au colloidal suspensions and used for thin film depositions. The effect of the dopant ions on the structural, morphological and optical properties of the as-synthesized colloids as well as the nanocomposite thin films has been analyzed and discussed. The dopant presence has been found to affect the CO optical sensing properties of the nanocomposite ZnO–Au films: compared to pure ZnO, an increase in sensitivity up to 80 percent and 55 percent has been detected for Co-doped and Mn-doped ZnO respectively, while Ni-doped ZnO films show only minor improvements. This observation has been ascribed to the multiple oxidation states of cobalt and manganese ions that can facilitate electron transfer between the target gas and semiconductive oxide matrix, and also to the lower surface concentration of Ni ions inside ZnO crystals, as compared to Co and Mn. A fast and reversible response after repeated CO exposures has been detected for all tested samples, and a linear response intensity with the order of magnitude of CO concentration has been observed in the 10–10,000 ppm range, with a lower detection limit of 1–2 ppm.
Keywords: Nanoparticles; Nanocomposite; Thin films; Sensors

Investigation of CrSi2 and MoSi2 as anode materials for lithium-ion batteries - Courtel, Fabrice M.; Duguay, Dominique; Abu-Lebdeh, Yaser; Davidson, Isobel J. (Journal of Power Sources, 2012)
We report on the suitability of the two metal silicides MoSi 2 and CrSi 2 as anode materials for Li-ion batteries. The two materials were synthesized by high energy ball milling of the corresponding metals and X-ray diffraction was used to follow the evolution/formation of the crystalline phases. The in-house prepared powders have shown better battery performance than commercial powders (as-received or ball-milled). We observed that 20 h were necessary for the formation of MoSi 2 whereas 100 h were needed for the formation of the CrSi 2 powder. The best battery performance was obtained with the synthesized CrSi 2 powder that has a theoretical capacity value of 469 mAh g-¹. This powder provided capacities of 340, 262, 167, 110, and 58 mAh g-¹ at C/12, C/6, C/2, C, and 2C, respectively. Cycling at 60 °C showed higher capacity values, but with a faster fade of these values.
Keywords: CrSi2; MoSi2; Silicide; Li-ion batteries; Anode material

The classical-map hyper-netted-chain (chnc) method and associated novel density-functional techniques for warm dense matter - Dharma-Wardana, M. W. C. (International Journal of Quantum Chemistry, 2012)
The advent of short-pulse lasers, nanotechnology, as well as shock-wave techniques have created new states of matter (e.g., warm dense matter) that call for new theoretical tools. Ion correlations, electron correlations, as well as bound states, continuum states, partial degeneracies and quasi-equilibrium systems need to be addressed. Bogoliubov’s ideas of timescales can be used to discuss the quasi-thermodynamics of nonequilibrium systems. A rigorous approach to the associated many-body problem turns out to be the computation of the underlying pair-distribution functions gee, gei, and gii, that directly yield nonlocal exchange-correlation potentials, free energies etc., valid within the timescales of each evolving system. An accurate classical map of the strongly-quantum uniform electron-gas problem given by Dharma-wardana and Perrot is reviewed. This replaces the quantum electrons at T = 0 by an equivalent classical fluid at a finite temperature Tq, and having the same correlation energy. The classical map is used with classical molecular dynamics (CMMD) or hyper-netted-chain integral equations (CHNC) to determine the pair-distribution functions (PDFs), and hence their thermodynamic and linear transport properties. The CHNC is very efficient for calculating the PDFs of uniform systems, while CMMD is more adapted to nonuniform systems. Applications to 2D and 3D quantum fluids, Si metal-oxide-field-effect transistors, Al plasmas, shock-compressed deuterium, two-temperature plasmas, pseudopotentials, as well as calculations for parabolic quantum dots are reviewed.
Keywords: density functional therapy; warm dense matter; CHNC-pair distributions; fermi liquids; Hugoniot

In situ measurement and modelling of austenite grain growth in a Ti/Nb microalloyed steel - Maalekian, M.; Radis, R.; Militzer, M.; Moreau, A.; Poole, W. J. (Acta Materialia, 2012)
Using a novel laser ultrasonics technique in situ measurements of austenite grain growth were conducted during continuous heating (10 °C s−1) and subsequent isothermal holding at various temperatures in the range 950–1250 °C in a microalloyed linepipe steel. Based on the experimental results, a grain growth model was developed, which includes the pinning effect of precipitates present in the steel. Analyzing the grain growth behaviour and using the advanced thermo-kinetic software MatCalc, an approach was developed to estimate the initial distribution of precipitates in the as-received material and their dissolution kinetics. The evolution of the volume fractions and mean particle sizes of NbC and TiN leads to a time-dependent pinning pressure that is coupled with the proposed grain growth model to successfully describe the observed kinetics of austenite grain growth. The predictive capabilities of the model are illustrated by its application to independent grain growth data for rapid heat treatment cycles that are typical of the weld heat affected zone.
Keywords: Austenite grain growth; Laser ultrasonics; Microalloyed steel; Precipitation kinetics; Grain growth modelling

Mechanical properties of thermomechanically-processed metastable beta Ti-Nb-Zr alloys for biomedical applications - Braïlovski, Vladimir; Gauthier, Maxime; Prokoshkin, Sergei; Inaekyan, Karine; Dubinskiy, Sergei; Zhukova, Yulia (Materials science forum, 2012)
Metastable beta-titanium alloys combine exceptionally low Young's modulus and high biocompatibility, thus attracting special interest in the prospect of their application as biomedical implant material. In this work, Ti-21.8Nb-6Zr (at. percent) ingots were manufactured by vacuum argon melting followed by hot isothermal pressing. The obtained ingots were thermomechanically processed using the following TMP sequence: a) cold rolling (CR) from e=0.37 to 2 of the logarithmic thickness reduction; and b) post-deformation annealing (PDA) of between 450 and 700oC (10’…5 h for 600oC and 1 h for other temperatures). The influence of the TMP on the alloy’s mechanical properties under static and cyclic loading was studied.
Keywords: shape memory alloys; titanium alloys; thermomechanical processing (TMP); biomedical applications

Characterization of polypropylene composites reinforced with flax fibers treated by mechanical and alkali method - Hu, Wei; Ton-That, Minh-Tan; Denault, Johanne; Belanger, Christian (Science and Engineering of Composite Materials, 2012)
Flax is a type of natural fiber widely used as reinforcing materials for polymer composites. The commercially available flax fibers in Canada consist of a significant amount of shive and other impurities, which could act as stress concentration regions to negatively affect the mechanical property of composites. In this study, the shive was manually removed from the commercial flax fibers by screening and combing to obtain different shive contents from 0 to 30 wt percentage. By contrast, the obtained flax fibers were further treated with alkaline solution. The fibers obtained from mechanical and alkali treatment were compared on their thermal and mechanical properties. As expected, it was found that the thermal stability and mechanical properties of the flax reinforced polypropylene composites increased significantly with the removal of the shive content. However, the alkali treatment on flax fiber did not further improve the composites properties. The possible reason was that the proper mechanical treatment (screening and combing) prior to alkaline treatment effectively loosened the fiber bundles for better single fiber separation in matrix and significantly removed the impurities, thus the effect of alkaline treatment did not become obvious.
Keywords: alkaline treatment; flax; mechanical treatment; polypropylene composites; shive

Mechanical properties of porous metastable beta Ti-Nb-Zr alloys for biomedical applications - Braïlovski, V.; Prokoshkin, S.; Gauthier, M.; Inaekyan, K.; Dubinskiy, S. (Journal of alloys and compounds, 2012)
For this study, Ti–(20–22)Nb–(5–6)Zr (at percent) ingots were manufactured by vacuum and argon arc melting. The obtained ingots were divided into two batches: the first subjected to cold rolling (CR) from 30 to 85 percent of thickness reduction, and subsequent annealing in the 450–600 °C temperature range (1 h). Regardless of the CR intensity, Ti–Nb–Zr samples subjected to 600 °C annealing showed the highest fatigue resistance during room-temperature cumulative cycling due to the stress-induced martensitic transformation occurring in the polygonized dislocation substructure (average subgrain size ∼ 100 nm). The second batch was atomized to produce 100-μm-size powders in order to manufacture open-cell porous material (cell size vary from 136 to 561 μm) of 46 percent porosity by means of powder metallurgy using a polymer-based foaming process. Tensile, compression and bending testing were performed at RT on foam samples annealed at 450–600 °C (1 h). Results indicated that Young's modulus of Ti–Nb–Zr foams significantly decreases as compared to the as-sintered material: when annealing temperature increases from 450 to 600 °C, Young's modulus decreases from 10 ± 2 GPa to 6 ± 1 GPa. Under the same testing conditions, Ti-CP foams produced by the same technology and having similar porosity remain fairly insensible to post-sintering annealing.
Keywords: Metals and alloys; Powder metallurgy; Sintering; Mechanical properties; Shape memory

Molecular Mechanisms of Neuroinflammation in Alzheimer's Disease - Vukic, Vanja; Callaghan, Debbie; Liu, Hong; Zhang, Wandong; Gemma, Carmelina (Neuroinflammation : Pathogenesis, Mechanisms and Management, 2012)

Culturing and electrophysiology of cells on NRCC patch-clamp chips - Py, Christophe; Martina, Marzia; Monette, Robert; Comas, Tanya; Denhoff, Mike W.; Luk, Collin; Syed, Naweed I.; Mealing, Geoff (Journal of visualized experiments, 2012)
Due to its exquisite sensitivity and the ability to monitor and control individual cells at the level of ion channels, patch-clamping is the gold standard of electrophysiology applied to disease models and pharmaceutical screens alike 1. The method traditionally involves gently contacting a cell with a glass pipette filled by a physiological solution in order to isolate a patch of the membrane under its apex 2. An electrode inserted in the pipette captures ion-channel activity within the membrane patch or, when ruptured, for the whole cell. In the last decade, patch-clamp chips have been proposed as an alternative 3, 4: a suspended film separates the physiological medium from the culture medium, and an aperture microfabricated in the film replaces the apex of the pipette. Patch-clamp chips have been integrated in automated systems and commercialized for high-throughput screening 5. To increase throughput, they include the fluidic delivery of cells from suspension, their positioning on the aperture by suction, and automated routines to detect cell-to-probe seals and enter into whole cell mode. We have reported on the fabrication of a silicon patch-clamp chip with optimized impedance and orifice shape that permits the high-quality recording of action potentials in cultured snail neurons 6; recently, we have also reported progress towards interrogating mammalian neurons 7. Our patch-clamp chips are fabricated at the Canadian Photonics Fabrication Centre 8, a commercial foundry, and are available in large series. We are eager to engage in collaborations with electrophysiologists to validate the use of the NRCC technology in different models. The chips are used according to the general scheme represented in Figure 1: the silicon chip is at the bottom of a Plexiglas culture vial and the back of the aperture is connected to a subterranean channel fitted with tubes at either end of the package. Cells are cultured in the vial and the cell on top of the probe is monitored by a measuring electrode inserted in the channel.The two outside fluidic ports facilitate solution exchange with minimal disturbance to the cell; this is an advantage compared to glass pipettes for intracellular perfusion.
Keywords: Neuroscience; Issue 60; disease models; pharmaceutical screens; electrophysiological recordings; patch-clamp; silicon planar patch-clamp chip; cultured neurons

Multifunctional nanoprobes for pathogen-selection capture and detection - Paquet, Chantal; Ryan, Shannon; Zou, Shan; Kell, Arnold; Tanha, Jamshid; Hulse, John; Tay, Li-Lin; Simard, Benoit (Chemical communications, 2012)
The synthesis of magnetic and ﬂuorescent particles is described. The particles are biofunctionalized by binding pathogen-speciﬁc proteins to the particles via interactions between His-tags of proteins and zinc of the quantum dots. Detection of Salmonella and Staphylococcus aureus (S. aureus) by these particles is demonstrated.

Comparison between dew-retted and enzyme-retted flax fibers as reinforcing material for composites - Hu, Wei; Ton-That, Minh-Tan; Denault, Johanne; Rho, Denis; Yang, Jianzhong; Lau, Peter C.K. (Polymer Engineering and Science, 2012)
Two kinds of retted Canadian linseed flax fibers, dew-retted (F1) and enzyme-retted flax fibers (F2) were characterized in detail for their applications in composites, such as retting degree, thermal stability, tensile strength, and interfacial behavior in polypropylene (PP) matrix. It's clear from Scanning Electron Micrograph that the aspect ratio of F2 was much higher than that of F1 in the light of their separated elementary fibers in most cases. Instead, the elementary fibers of F1 remained tightly bundled into technical fiber wrapping with more non-cellulose portions. This reflected its lower retting degree and resulted in its lower thermal stability. Single fiber tensile test and single fiber pull-out test were used to evaluate the fiber tensile properties and fiber/PP interfacial shear strength, respectively. Better retting degree and fewer damages on F2 endowed F2 better tensile property. Consequently, higher aspect ratio, retting degree, and tensile strength proved F2 to be a kind of better reinforcing material than F1 for composites.

The role of sialic acid in the formation of protective conformational bacterial polysaccharide epitopes - Jennings, Harold J.; Kosma, Paul; Müller-Loennies, Sven (Anticarbohydrate Antibodies : From Molecular Basis to Clinical Application, 2012)

Who are our clients: consumer segmentation through explorative data mining - Viktor, Herna L.; Peña, Isis; Paquet, Eric (International Journal of Data Mining, Modelling and Management, 2012)
The apparel industry aims to produce comfortable and aesthetically pleasing garments that fit populations well. However, repeated studies of apparel customers' levels of satisfaction indicate that their needs are often not being met. In order to produce better fitting clothes, it is crucial to understand the body profiles of typical consumers. Exploring the demographic profiles of correctly identified customer segments holds obvious benefit for production, marketing and ensuring return on investments. To this end, we explore a database, containing anthropometric measurements, demographic profiles and 3-D body scans, of samples of the North American, Italian and Dutch populations. Through the use of objective interestingness measures-based feature selection and feature extraction, we accurately discover the relevant subsets of body measurements that require special care when designing clothes. Furthermore, we apply association analysis to the demographic data, in order to target customers and thus potentially defining new market opportunities. Copyright © 2012 Inderscience Enterprises Ltd.
Keywords: Utility-based data mining; anthropometry; interestingness measures; consumer segmentation; marketing