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Three certified sugar reference materials for carbon isotope delta measurements
No full textFor isotope delta analysis, it is preferable to have at least two matrix\u2010matched reference materials whose isotope delta values encompass those of the samples to be analyzed. The National Research Council Canada (NRC) has developed three sugar Certified Reference Materials (CRMs), BEET\u20101 (beet sugar), GALT\u20101 (galactose), and FRUT\u20101 (fructose), to be collectively used for carbon isotope delta measurements in sugars, and other organic materials.Peer reviewed: YesNRC publication: Ye
Construction of high-density linkage maps for mapping quantitative trait loci for multiple traits in field pea (Pisum sativum L.)
No full textBackground: The objective of this research was to map quantitative trait loci (QTLs) of multiple traits of breeding importance in pea (Pisum sativum L.). Three recombinant inbred line (RIL) populations, PR-02 (Orb x CDC Striker), PR-07 (Carerra x CDC Striker) and PR-15 (1\u20132347-144 x CDC Meadow) were phenotyped for agronomic and seed quality traits under field conditions over multiple environments in Saskatchewan, Canada. The mapping populations were genotyped using genotyping-by-sequencing (GBS) method for simultaneous single nucleotide polymorphism (SNP) discovery and construction of high-density linkage maps. Results: After filtering for read depth, segregation distortion, and missing values, 2234, 3389 and 3541 single nucleotide polymorphism (SNP) markers identified by GBS in PR-02, PR-07 and PR-15, respectively, were used for construction of genetic linkage maps. Genetic linkage groups were assigned by anchoring to SNP markers previously positioned on these linkage maps. PR-02, PR-07 and PR-15 genetic maps represented 527, 675 and 609 non-redundant loci, and cover map distances of 951.9, 1008.8 and 914.2 cM, respectively. Based on phenotyping of the three mapping populations in multiple environments, 375 QTLs were identified for important traits including days to flowering, days to maturity, lodging resistance, Mycosphaerella blight resistance, seed weight, grain yield, acid and neutral detergent fiber concentration, seed starch concentration, seed shape, seed dimpling, and concentration of seed iron, selenium and zinc. Of all the QTLs identified, the most significant in terms of explained percentage of maximum phenotypic variance (PVmax) and occurrence in multiple environments were the QTLs for days to flowering (PVmax =\u200947.9%), plant height (PVmax =\u200965.1%), lodging resistance (PVmax =\u200935.3%), grain yield (PVmax =\u200954.2%), seed iron concentration (PVmax =\u200927.4%), and seed zinc concentration (PVmax =\u200943.2%). Conclusion: We have identified highly significant and reproducible QTLs for several agronomic and seed quality traits of breeding importance in pea. The QTLs identified will be the basis for fine mapping candidate genes, while some of the markers linked to the highly significant QTLs are useful for immediate breeding applications.Peer reviewed: YesNRC publication: Ye
Exponential family restricted boltzmann machines and annealed importance sampling
No full textIn this paper, we investigate restricted Boltzmann machines (RBMs) from the exponential family perspective, en-abling the visible units to follow any suitable distributions from the exponential family. We derive a unified view to compute the free energy function for exponential family RBMs (exp-RBMs). Based on that, annealed important sampling (AIS) is generalized to the entire exponential family, allowing for estimating the log-partition function and log-likelihood. Our experiments on a document processing task demonstrate that the generalized free energy functions and AIS estimation perform well in helping capture useful knowledge from the data; the estimated log-partition functions are stable. The appropriate instances of exp-RBMs can generate novel and meaningful samples and can be applied to classification tasks.Peer reviewed: YesNRC publication: Ye
A lavender ABC transporter confers resistance to monoterpene toxicity in yeast
No full textThe interest in functionalized cellulose nanocrystals (CNCs) for multiple biomedical application has been increasing in recent years. CNCs are suitable to functionalization with an array of polymers, generating chemically related nanomaterials with different morphologies, surface charges that can affect bioreactivity, including immune response. In this study, we sought to understand the mechanistic differences regarding immunological responses evoked by functionalized CNCs and whether surface charges play a role in this effect. We investigated the effect of a cationic, CNCs-poly(APMA), and an anionic, CNCs-poly(NIPAAm) derivatives on the secretion of inflammatory cytokines, mitochondria-derived ROS and mitochondrial function and antioxidant response as well as on endoplasmic reticulum (ER) stress, in human and murine inflammatory cells. The cationic CNCs-poly(APMA) evoked a more robust immunological response in murine cell line, while the anionic CNCs-poly(NIPAAm) showed a significant NLRP3 inflammasome-dependent and independent immunological response in human monocytes. Moreover, CNCs-poly(NIPAAm) induced greater formation of acidic vesicular organelles, mitochondrial ROS in non-stimulated cells while CNCs-poly(APMA) mainly affected mitochondrial function by decreasing the intracellular ATP. The differences on the biological responses may be related to the surface charges of CNCs, and their likely interactions with intra and extracellular biomolecules.Peer reviewed: YesNRC publication: Ye
IC 4499 revised: spectro-photometric evidence of small light-element variations
No full textIt has been suggested that IC 4499 is one of the very few old globulars to not host multiple populations with light-element variations. To follow-up on this very interesting result, here we have made use of accurate HST photometry and FLAMES at VLT high-resolution spectroscopy to investigate in more detail the stellar population properties of this system. We find that the red giant branch of the cluster is clearly bimodal in near-UV-optical colour-magnitude diagrams, thus suggesting that IC 4499 is actually composed by two sub-populations of stars with different nitrogen abundances. This represents the first detection of multiple populations in IC 4499. Consistently, we also find that one star out of six is Na-rich to some extent, while we do not detect any evidence of intrinsic spread in both Mg and O. The number ratio between stars with normal and enriched nitrogen is in good agreement with the number ratio \u2013 mass trend observed in Galactic globular clusters. Also, as typically found in other systems, nitrogen rich stars are more centrally concentrated than normal stars, although this result cannot be considered conclusive because of the limited field of view covered by our observations ( 3c1rh). On the contrary, we observe that both the RGB UV colour spread, which is a proxy of N variations, and Na abundance variations, are significantly smaller than those observed in Milky Way globular clusters with mass and metallicity comparable to IC 4499. The modest N and Na spreads observed in this system can be tentatively connected to the fact that IC 4499 likely formed in a disrupted dwarf galaxy orbiting the Milky Way, as previously proposed based on its orbit.Peer reviewed: YesNRC publication: Ye
Linear and nonlinear stability of Soret-Dufour Lapwood convection near double codimension-2 points
No full textIn this study, the Dufour and Soret effects on natural double\u2010diffusion convection in a horizontal porous layer was studied numerically using FORTRAN 90 programming and analytically near various convection onset thresholds. The porous layer was subject to a uniform heat and mass fluxes on the horizontal walls while the vertical walls were impermeable and adiabatic. The Darcy model along with the Boussinesq approximation was assumed in the problem formulation. The governing parameters of the problem are the thermal Rayleigh number, RT, the buoyancy ratio, N, the Lewis number, Le, the aspect ratio of the cavity, A, and the Dufour, Du, and Soret, Sr, numbers. For a shallow enclosure, the analytical solution was derived assuming zero convection wave number, which is valid near and above criticality. The onset of subcritical, supercritical and oscillatory convection was investigated. Two linear and nonlinear codimension\u20102 points were found to exist. Whether the system was subject to constant fluxes and heat and solute, regardless of the aspect ratio of the layer, the subcritical convection behavior remained the same with similarity in the thresholds expressions for subcritical bifurcation.Peer reviewed: YesNRC publication: Ye
Low-dimensional spaces for relating sensor signals with internal data structure in a propulsion system
No full textAdvances in technology have enabled the installation of an increasing number of sensors in various mechanical systems allowing for more detailed equipment health monitoring capabilities. It is hoped the sensor data will enable development of predictive tools to prevent system failures. This work describes continued analysis of sensor data surrounding a seizure of a turbocharger within a propulsion system. The objective of the analysis was to characterize and distinguish healthy and failed states of the turbocharger. The analysis approach included mapping of multi-dimensional sensor data to a low-dimensional space using various linear and nonlinear techniques in order to highlight and visualize the underlying structure of the information. To provide some physical insight into the structure of the low-dimensional representation, the transformation plots were analyzed from the perspective of several engine signals. By overlaying operating ranges of individual sensor signals, certain regions of the mappings could be associated with distinct operational states of the engine, and several anomalies could be related to various points in the turbocharger seizure. Although the failed points did not map to an obvious outlier location in the transformations, incorporating expert domain knowledge with the data mining tools significantly enhanced the insight derived from the sensor data.Peer reviewed: YesNRC publication: Ye
Perceptual assessment of environmental stability modulates postural sway
No full textWe actively maintain postural equilibrium in everyday life, and, although we are unaware of the underlying processing, there is increasing evidence for cortical involvement in this postural control. Converging evidence shows that we make appropriate use of \u2018postural anchors\u2019, for example static objects in the environment, to stabilise our posture. Visually evoked postural responses (VEPR) that are caused when we counteract the illusory perception of self-motion in space (vection) are modulated in the presence of postural anchors and therefore provide a convenient behavioural measure. The aim of this study is to evaluate the factors influencing visual appraisal of the suitability of postural anchors. We are specifically interested in the effect of perceived \u2018reality\u2019 in VR the expected \u2018stability\u2019 of visual anchors. To explore the effect of \u2018reality\u2019 we introduced an accommodation-vergence conflict. We show that VEPR are appropriately modulated only when virtual visual \u2018anchors\u2019 are rendered such that vergence and accommodation cues are consistent. In a second experiment we directly test whether cognitive assessment of the likely stability of real perceptual anchors (we contrast a \u2018teapot on a stand\u2019 and a \u2018helium balloon\u2019) affects VEPR. We show that the perceived positional stability of environmental anchors modulate postural responses. Our results confirm previous findings showing that postural sway is modulated by the configuration of the environment and further show that an assessment of the stability and reality of the environment plays an important role in this process. On this basis we propose design guidelines for VR systems, in particular we argue that accommodation-vergence conflicts should be minimised and that high quality motion tracking and rendering are essential for high fidelity VR.Peer reviewed: YesNRC publication: Ye
Printed sensors for building management
No full textA high density wireless environmental sensor network has great potential to provide enhanced control options to building automation systems to reduce energy consumption and thus GHG emissions. In this work, we have developed light sensors and temperature sensors with solar energy harvesting and wireless communication capability for the application. The hybrid sensors are built by integrating printed sensing elements with EnOcean's technology that provides solar energy harvesting and wireless transmission functions. The light sensing and temperature sensing elements were printed on flexible PET films using organic photosensitive materials and particle-filled polymer inks developed by our team. The resulting hybrid sensors were tested and shown to meet design specifications. The light sensors have been installed in a full-scale office test bed for demonstrating efficient light control.Peer reviewed: YesNRC publication: Ye
SKA telescope manager: a status update
No full textThe international Square Kilometre Array (SKA) project to build two radio interferometers is approaching the end of its design phase, and gearing up for the beginning of formal construction. A key part of this distributed Observatory is the overall software control system: the Telescope Manager (TM). The two telescopes, a Low frequency dipole array to be located in Western Australia (SKA-Low) and a Mid-frequency dish array to be located in South Africa (SKA-Mid) will be operated as a single Observatory, with its global headquarters (GHQ) based in the United Kingdom at Jodrell Bank. When complete it will be the most powerful radio observatory in the world. The TM software must combine the observatory operations based at the GHQ with the monitor and control operations of each telescope, covering the range of domains from proposal submission to the coordination and monitoring of the subsystems that make up each telescope. It must also monitor itself and provide a reliable operating platform. This paper will provide an update on the design status of TM, covering the make-up of the consortium delivering the design, a brief description of the key challenges and the top level architecture, and its software development plans for tackling the construction phase of the project. It will also briefly describe the consortium\u2019s response to the SKA Project\u2019s decision in the second half of 2016 to adopt the processes set out by the Software Engineering Institute (SEI) for system architecture design and documentation, including a re-evaluation of its deliverables, documentation and approach to internal reviews.Peer reviewed: YesNRC publication: Ye