1,051 research outputs found

    Comparative studies of the nucleotide sequences of pea seed storage protein genes

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    Nucleotide sequence data from several pea (Piswn sativum L.) seed storage protein genes was obtained. Of two legumin genes sequenced, one was shown to be a pseudogene, apparently once coding for a polypeptide belonging to the 'major' legumin class, whilst the other was shown to be a functional gene coding for a polypeptide of the 'minor' legumin class. Sequence data was also obtained for two vicilin genes. Complete sequencing of one revealed it to be truncated by sequence of unknown origin at its 3' end, whilst partial sequence for the other suggested the presence of a stop codon in the coding region. These findings implied that both vicilin genes are no longer functional. Additionally, various comparisons of nucleic acid and amino acid sequence data were made between these genes and also with other legume seed storage protein genes. Results showed these genes conform with the major structural features of eukaryotic genes, and also revealed the presence of potential tissue -specific regulatory elements in the 5' flanking regions of the genes. Dendrograms for legume 11S and 7S classes of globulin seed storage protein genes clearly supported the model theory of each class having arisen by successive duplications from a common ancestral gene

    Polaron relaxation in ferroelectric thin films

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    We report a dielectric relaxation in ferroelectric thin films of the ABO3 family. We have compared films of different compositions with several growth modes: sputtering (with and without magnetron) and sol-gel. The relaxation was observed at cryogenic temperature (T<100K) for frequencies from 100Hz up to 10MHz. This relaxation activation energy is always lower than 200meV. It is very similar to the polaron relaxation that we reported in the parent bulk perovskites. Being independent of the materials size, morphology and texture, this relaxation can be a useful probe of defects in actual integrated capacitors with no need for specific shapin

    Benchmark calculations for elastic fermion-dimer scattering

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    We present continuum and lattice calculations for elastic scattering between a fermion and a bound dimer in the shallow binding limit. For the continuum calculation we use the Skorniakov-Ter-Martirosian (STM) integral equation to determine the scattering length and effective range parameter to high precision. For the lattice calculation we use the finite-volume method of L\"uscher. We take into account topological finite-volume corrections to the dimer binding energy which depend on the momentum of the dimer. After subtracting these effects, we find from the lattice calculation kappa a_fd = 1.174(9) and kappa r_fd = -0.029(13). These results agree well with the continuum values kappa a_fd = 1.17907(1) and kappa r_fd = -0.0383(3) obtained from the STM equation. We discuss applications to cold atomic Fermi gases, deuteron-neutron scattering in the spin-quartet channel, and lattice calculations of scattering for nuclei and hadronic molecules at finite volume.Comment: 16 pages, 5 figure

    Strategies for Reliable Exploitation of Evolutionary Concepts in High Throughput Biology

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    The recent availability of the complete genome sequences of a large number of model organisms, together with the immense amount of data being produced by the new high-throughput technologies, means that we can now begin comparative analyses to understand the mechanisms involved in the evolution of the genome and their consequences in the study of biological systems. Phylogenetic approaches provide a unique conceptual framework for performing comparative analyses of all this data, for propagating information between different systems and for predicting or inferring new knowledge. As a result, phylogeny-based inference systems are now playing an increasingly important role in most areas of high throughput genomics, including studies of promoters (phylogenetic footprinting), interactomes (based on the presence and degree of conservation of interacting proteins), and in comparisons of transcriptomes or proteomes (phylogenetic proximity and co-regulation/co-expression). Here we review the recent developments aimed at making automatic, reliable phylogeny-based inference feasible in large-scale projects. We also discuss how evolutionary concepts and phylogeny-based inference strategies are now being exploited in order to understand the evolution and function of biological systems. Such advances will be fundamental for the success of the emerging disciplines of systems biology and synthetic biology, and will have wide-reaching effects in applied fields such as biotechnology, medicine and pharmacology

    The distribution of methylated sulfur compounds, DMS and DMSP, in Canadian subarctic and Arctic marine waters during summer 2015

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    © The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Biogeosciences 15 (2018): 2449–2465, doi:10.5194/bg-15-2449-2018.We present seawater concentrations of dimethyl sulfide (DMS) and dimethylsulfoniopropionate (DMSP) measured across a transect from the Labrador Sea to the Canadian Arctic Archipelago during summer 2015. Using an automated ship-board gas chromatography system and a membrane-inlet mass spectrometer, we measured a wide range of DMS (∼ 1 to 18 nM) and DMSP (∼ 1 to 150 nM) concentrations. The highest DMS and DMSP concentrations occurred in a localized region of Baffin Bay, where surface waters were characterized by high chlorophyll a (chl a) fluorescence, indicative of elevated phytoplankton biomass. Across the full sampling transect, there were only weak relationships between DMS(P), chl a fluorescence and other measured variables, including positive relationships between DMSP : chl a ratios and several taxonomic marker pigments, and elevated DMS(P) concentrations in partially ice-covered areas. Our high spatial resolution measurements allowed us to examine DMS variability over small scales (< 1 km), documenting strong DMS concentration gradients across surface hydrographic frontal features. Our new observations fill in an important observational gap in the Arctic Ocean and provide additional information on sea–air DMS fluxes from this ocean region. In addition, this study constitutes a significant contribution to the existing Arctic DMS(P) dataset and provides a baseline for future measurements in the region.This work was supported by grants from the Natural Sciences and Engineering Research Council of Canada (NSERC) through the Climate Change and Atmospheric Research program (Arctic-GEOTRACES)

    Detection of lensing substructure using ALMA observations of the dusty galaxy SDP.81

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    We study the abundance of substructure in the matter density near galaxies using ALMA Science Verification observations of the strong lensing system SDP.81. We present a method to measure the abundance of subhalos around galaxies using interferometric observations of gravitational lenses. Using simulated ALMA observations, we explore the effects of various systematics, including antenna phase errors and source priors, and show how such errors may be measured or marginalized. We apply our formalism to ALMA observations of SDP.81. We find evidence for the presence of a M=108.96±0.12MM=10^{8.96\pm 0.12} M_{\odot} subhalo near one of the images, with a significance of 6.9σ6.9\sigma in a joint fit to data from bands 6 and 7; the effect of the subhalo is also detected in both bands individually. We also derive constraints on the abundance of dark matter subhalos down to M2×107MM\sim 2\times 10^7 M_{\odot}, pushing down to the mass regime of the smallest detected satellites in the Local Group, where there are significant discrepancies between the observed population of luminous galaxies and predicted dark matter subhalos. We find hints of additional substructure, warranting further study using the full SDP.81 dataset (including, for example, the spectroscopic imaging of the lensed carbon monoxide emission). We compare the results of this search to the predictions of Λ\LambdaCDM halos, and find that given current uncertainties in the host halo properties of SDP.81, our measurements of substructure are consistent with theoretical expectations. Observations of larger samples of gravitational lenses with ALMA should be able to improve the constraints on the abundance of galactic substructure.Comment: 18 pages, 13 figures, Comments are welcom

    Public, Private, and Non-profit Sector Employees: Voting Behaviour and Ideology in the 2011-2012 Provincial Elections

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    This paper focuses attention on the political orientation and civic behaviour of people working in the non-profit, private, and public sectors. While considerable research has been completed to understand how variables such as age and gender influence voting patterns, one variable that remains understudied is employment by sector. To develop hypothesis statements for this research, this paper begins with the Bureau Voting Model which is rooted in rational choice theory. The hypothesis statements are tested using data from the SSHRC-funded Canadian Provincial Election Project (CPEP) Survey, conducted post-provincial election in 2011-2012 in eight provinces. The paper concludes that while there were diverging orientations amongst employees in the three sectors, there were also some areas of convergence to suggest that there may be substantial diversity within each sector

    Large-scale Perturbations from the Waterfall Field in Hybrid Inflation

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    We estimate large-scale curvature perturbations from isocurvature fluctuations in the waterfall field during hybrid inflation, in addition to the usual inflaton field perturbations. The tachyonic instability at the end of inflation leads to an explosive growth of super-Hubble scale perturbations, but they retain the steep blue spectrum characteristic of vacuum fluctuations in a massive field during inflation. The power spectrum thus peaks around the Hubble-horizon scale at the end of inflation. We extend the usual delta-N formalism to include the essential role of these small fluctuations when estimating the large-scale curvature perturbation. The resulting curvature perturbation due to fluctuations in the waterfall field is second-order and the spectrum is expected to be of order 10^{-54} on cosmological scales.Comment: 10 pages, 4 figures; v2 comments added on application of delta-N formalism including Hubble scale fluctuation
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