928 research outputs found

    Multilocus sequence analysis of phylogroup 1 and 2 oral treponeme strains

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    More than 75 ‘species-level' phylotypes of spirochete bacteria belonging to the genus Treponema reside within the human oral cavity. The majority of these oral treponeme phylotypes correspond to as-yet uncultivated taxa, or strains of uncertain standing in taxonomy. Here, we analyze phylogenetic and taxonomic relationships between oral treponeme strains using a multilocus sequence analysis (MLSA) scheme based on the highly-conserved 16S rRNA, pyrH, recA and flaA genes. We utilize this MLSA scheme to analyze genetic data from a curated collection of oral treponeme strains (n=71) of diverse geographical origins. This comprises phylogroup 1 (n=23) and phylogroup 2 (n=48) treponeme strains; including all relevant ATCC reference strains. The taxonomy of all strains was confirmed or inferred via the analysis of ca. 1,450 bp 16S rRNA gene sequences using a combination of bioinformatic and phylogenetic approaches. Taxonomic and phylogenetic relationships between the respective treponeme strains were further investigated by analyzing individual and concatenated flaA (1,074 nt), recA (1,377 nt) and pyrH (696 nt) gene sequence datasets. Our data confirmed the species differentiation between Treponema denticola (n=41) and Treponema putidum (n=7) strains. Notably, our results clearly supported the differentiation of the 23 phylogroup 1 treponeme strains into 5 distinct ‘species-level' phylotypes. These respectively corresponded to ‘Treponema vincentii' (n=11), Treponema medium (n=1); ‘Treponema sinensis' (T. sp. IA; n=4); Treponema sp. IB (n=3); and Treponema sp. IC (n=4). In conclusion, our MLSA-based approach can be used to effectively discriminate oral treponeme taxa, confirm taxonomic assignment, and enable the delineation of species boundaries with high confidence.published_or_final_versio

    Verified Compilation of CakeML to Multiple Machine-Code Targets

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    This paper describes how the latest CakeML compiler supports verified compilation down to multiple realistically modelled target architectures. In particular, we describe how the compiler definition, the various language semantics, and the correctness proofs were organised to minimize target-specific overhead. With our setup we have incorporated compilation to four 64-bit architectures, ARMv8, x86-64, MIPS-64, RISC-V, and one 32-bit architecture, ARMv6. Our correctness theorem allows interference from the environment: the top-level correctness statement takes into account execution of foreign code and per-instruction interference from external processes, such as interrupt handlers in operating systems. The entire CakeML development is formalised in the HOL4 theorem prover.Engineering and Physical Sciences Research Council (EPSRC); Swedish Research Counci

    Verified Compilation of CakeML to Multiple Machine-Code Targets

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    This paper describes how the latest CakeML compiler supports verified compilation down to multiple realistically modelled target architectures. In particular, we describe how the compiler definition, the various language semantics, and the correctness proofs were organised to minimize target-specific overhead. With our setup we have incorporated compilation to four 64-bit architectures, ARMv8, x86-64, MIPS-64, RISC-V, and one 32-bit architecture, ARMv6. Our correctness theorem allows interference from the environment: the top-level correctness statement takes into account execution of foreign code and per-instruction interference from external processes, such as interrupt handlers in operating systems. The entire CakeML development is formalised in the HOL4 theorem prover.Engineering and Physical Sciences Research Council (EPSRC); Swedish Research Counci

    Superconductivity below 20 K in heavily electron-doped surface layer of FeSe bulk crystal

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    A superconducting transition temperature (T-c) as high as 100 K was recently discovered in one monolayer FeSe grown on SrTiO3. The discovery ignited efforts to identify the mechanism for the markedly enhanced T-c from its bulk value of 8 K. There are two main views about the origin of the T-c enhancement: interfacial effects and/or excess electrons with strong electron correlation. Here, we report the observation of superconductivity below 20 K in surface electron-doped bulk FeSe. The doped surface layer possesses all the key spectroscopic aspects of the monolayer FeSe on SrTiO3. Without interfacial effects, the surface layer state has a moderate T-c of 20 K with a smaller gap opening of 4.2 meV. Our results show that excess electrons with strong correlation cannot induce the maximum T-c, which in turn reveals the need for interfacial effects to achieve the highest T-c in one monolayer FeSe on SrTiO3.1116Ysciescopu

    Species-specified VOC emissions derived from a gridded study in the Pearl River Delta, China

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    This study provides a top-down approach to establish an emission inventory of volatile organic compounds (VOC) based on ambient measurements, by combining the box model and positive matrix factorization (PMF) model. Species-specified VOC emissions, source contributions, and spatial distributions are determined based on regional-scale gridded measurements between September 2008 to December 2009 in the Pearl River Delta (PRD), China. The most prevalent anthropogenic species in the PRD was toluene estimated by the box model to be annual emissions of 167.8 ± 100.5 Gg, followed by m,p-xylene (68.0 ± 45.0 Gg), i-pentane (49.2 ± 40.0 Gg), ethene (47.6 ± 27.6 Gg), n-butane (47.5 ± 40.7 Gg), and benzene (46.8 ± 29.0 Gg). Alkanes such as propane, i-butane, and n-pentane were 2–8 times higher in box model than emission inventories (EI). Species with fewer emissions were highly variable between EI and box model results. Hotspots of VOC emissions were identified in southwestern PRD and port areas, which were not reflected by bottom-up EI. This suggests more research is needed for VOC emissions in the EI, especially for fuel evaporation, industrial operations and marine vessels. The species-specified top-down method can help improve the quality of these emission inventories

    Optimal Resource Allocation over Networks via Lottery-Based Mechanisms

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    We show that, in a resource allocation problem, the ex ante aggregate utility of players with cumulative-prospect-theoretic preferences can be increased over deterministic allocations by implementing lotteries. We formulate an optimization problem, called the system problem, to find the optimal lottery allocation. The system problem exhibits a two-layer structure comprised of a permutation profile and optimal allocations given the permutation profile. For any fixed permutation profile, we provide a market-based mechanism to find the optimal allocations and prove the existence of equilibrium prices. We show that the system problem has a duality gap, in general, and that the primal problem is NP-hard. We then consider a relaxation of the system problem and derive some qualitative features of the optimal lottery structure

    Renin, endothelial no synthase and endothelin gene expression in the 2Kidney-1clip goldblatt model of long-term renovascular hypertension

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    <p>Abstract</p> <p>Objective</p> <p>Numerous reports have shown the influence of renin, nitric oxide (NO) and the endothelin (ET) systems for regulation of blood pressure and renal function. Furthermore, interactions between these peptides have been reported. Aim of our study was to investigate the relative contribution of these compounds in long-term renovascular hypertension/renal ischemia.</p> <p>Methods</p> <p>Hypertension/left-sided renal ischemia was induced using the 2K1C-Goldblatt rat model. Renal renin, ET-1, ET-3 and endothelial NO synthase (eNOS) gene expression was measured by means of RNAse protection assay at different timepoints up to 10 weeks after induction of renal artery stenosis.</p> <p>Results</p> <p>Plasma renin activity and renal renin gene expression in the left kidney were increased in the clipped animals while eNOS expression was unchanged. Furthermore, an increase in ET-1 expression and a decrease of ET-3 expression was detected in early stenosis.</p> <p>Conclusions</p> <p>While renin is obviously involved in regulation of blood pressure and renal function in unilateral renal artery stenosis, ET-1, ET-3 and endothelium derived NO do not appear to play an important role in renal adaptation processes in long-term renal artery stenosis, although ET-1 and ET-3 might be involved in short-term adaptation processes.</p

    Morbidity and related factors among elderly people in South Korea: results from the Ansan Geriatric (AGE) cohort study

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    BACKGROUND: A thorough examination of the morbidity and comorbidity profiles among the elderly and an evaluation of the related factors are required to improve the delivery of health care to the elderly and to estimate the cost of that care. In South Korea where the aged population is rapidly increasing, however, to date only one study using a limited sample (84 subjects) has provided information on morbidity and related factors among the elderly. Using a large, stratified, random sample (2,767 subjects) from the population-based Ansan Geriatric study, the present study sought to assess the morbidity and comorbidity, and to determine the relationships of these variables with sociodemographic and health characteristics in elderly people in South Korea. METHODS: A total of 2,767 subjects (1,215 men and 1,552 women) aged 60–84 years were randomly selected from September 2002 to August 2003 in Ansan, South Korea. Data on sociodemographic and health characteristics, and clinical diagnosis were collected using questionnaires. When available, the medical records and medications taken by the subjects were also cross-checked. RESULTS: Of the total subjects, 78.0% reported diagnosed disease, 11.0% had been cured, and 46.8% had been diagnosed with more than two diseases. The mean number of morbidities per person among elderly Koreans was 1.62 ± 1.35 (mean ± standard deviation), and women had a greater number of diseases per person than did men. The most common morbidities were chronic diseases such as hypertension, arthritis, and diabetes mellitus. In women, osteoporosis and arthritis were the second and third most prevalent diseases, respectively. Morbidity was significantly associated with gender, employment, household income, alcohol intake, self-assessed health status, and worries about health. CONCLUSION: These data will enhance understanding of the patterns of health problems among elderly Koreans and will contribute to the application of appropriate intervention strategies

    Observation of a ppb mass threshoud enhancement in \psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) decay

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    The decay channel ψπ+πJ/ψ(J/ψγppˉ)\psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) is studied using a sample of 1.06×1081.06\times 10^8 ψ\psi^\prime events collected by the BESIII experiment at BEPCII. A strong enhancement at threshold is observed in the ppˉp\bar{p} invariant mass spectrum. The enhancement can be fit with an SS-wave Breit-Wigner resonance function with a resulting peak mass of M=186113+6(stat)26+7(syst)MeV/c2M=1861^{+6}_{-13} {\rm (stat)}^{+7}_{-26} {\rm (syst)} {\rm MeV/}c^2 and a narrow width that is Γ<38MeV/c2\Gamma<38 {\rm MeV/}c^2 at the 90% confidence level. These results are consistent with published BESII results. These mass and width values do not match with those of any known meson resonance.Comment: 5 pages, 3 figures, submitted to Chinese Physics
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