1,203,407 research outputs found

    Alterations in serum amino acid concentrations in dogs with protein-losing enteropathy

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    BackgroundCertain amino acids are decreased in humans with inflammatory bowel disease (IBD) and supplementation with the same amino acids has shown beneficial effects in animal models of IBD. Currently, the amino acid status of dogs with protein-losing enteropathy (PLE) is unknown.Hypothesis/objectiveTo determine if serum amino acid concentrations are abnormal in dogs with PLE and correlated with clinical and laboratory variables and outcome.AnimalsThirty client-owned dogs diagnosed with PLE and 12 apparently healthy dogs seen at Bristol Veterinary School.MethodsRetrospective study using stored residual serum from fasted dogs with PLE, collected at the time of diagnostic investigation and from apparently healthy dogs. Serum was analyzed for 30 amino acids using an automated high-performance liquid chromatography amino acid analyzer.ResultsSerum tryptophan concentrations were significantly decreased in dogs with PLE (median, 22 nmol/mL; range, 1-80 nmol/mL) compared with apparently healthy control dogs (median, 77.5 nmol/mL; range, 42-135 nmol/mL, P < .001). There were no significant differences in the remaining 29 serum amino acids between dogs with PLE and apparently healthy. Serum tryptophan concentrations were also significantly correlated with serum albumin concentrations in dogs with PLE (P = .001, R2 = 0.506).Conclusions and clinical importanceDecreased serum tryptophan concentration might play a role in the pathogenesis of canine PLE or be a consequence of the disease

    Towards an institutional PLE

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    PLEs in their broader sense (the ad-hoc, serendipitous and potentially chaotic set of tools that learners bring to their learning) are increasingly important for learners in the context of formal study. In this paper we outline the approach that we are taking at the University of Southampton in redesigning our teaching and learning infrastructure into an Institutional PLE. We do not see this term as an oxymoron. We define an Institutional PLE as an environment that provides a personalised interface to University data and services and at the same time exposes that data and services to a student’s personal tools. Our goal is to provide a digital platform that can cope with an evolving learning and teaching environment, as well as support the social and community aspects of the institution

    Anti-phage islands force their target phage to directly mediate island excision and spread.

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    Vibrio cholerae, the causative agent of the diarrheal disease cholera, is antagonized by the lytic phage ICP1 in the aquatic environment and in human hosts. Mobile genetic elements called PLEs (phage-inducible chromosomal island-like elements) protect V. cholerae from ICP1 infection and initiate their anti-phage response by excising from the chromosome. Here, we show that PLE 1 encodes a large serine recombinase, Int, that exploits an ICP1-specific protein as a recombination directionality factor (RDF) to excise PLE 1 in response to phage infection. We show that this phage-encoded protein is sufficient to direct Int-mediated recombination in vitro and that it is highly conserved in all sequenced ICP1 genomes. Our results uncover an aspect of the molecular specificity underlying the conflict between a single predatory phage and V. cholerae PLE and contribute to our understanding of long-term evolution between phage and their bacterial hosts

    Cosmic Star Formation: Constraints on the Galaxy Formation Models

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    We study the evolution of the cosmic star formation by computing the luminosity density (LD) in the UV, B, J, and K bands, and the stellar mass density (MD) of galaxies in two reference models of galaxy evolution: the pure luminosity evolution (PLE) model developed by Calura & Matteucci (2003) and the semi-analytical model (SAM) of hierarchical galaxy formation by Menci et al. (2002). The former includes a detailed description of the chemical evolution of galaxies of different morphological types with no density evolution; the latter includes the merging histories of the galactic DM haloes, as predicted by the hierarchical clustering scenario, but it does not contain morphological classification nor chemical evolution. We find that at z< 1.5 both models are consistent with the available data on the LD of galaxies in all the considered bands. At high z, the LDs predicted in the PLE model show a peak due to the formation of ellipticals, whereas the SAM predicts a gradual decrease of the star formation and of the LD for z> 2.5. At such redshifts the PLE predictions tend to overestimate the present data in the B band whereas the SAM tends to underestimate the observed UV LD. As for the stellar MD, the PLE picture predicts that nearly 50% and 85% of the present stellar mass are in place at z=4 and z=1, respectively. According to the SAM, 50% and 60% of the present stellar mass are in place at z=1.2 and z=1, respectively. Both predictions fit the observed MD up to z=1. At z>1, the PLE model and the SAM tend to overestimate and underestimate the observed values, respectively. We discuss the origin of the above model results, and the role of observational uncertainties (such as dust extinction) in comparing models with observations.Comment: 14 pages, accepted for publication in MNRA

    Exciton Binding Energy of Monolayer WS2

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    The optical properties of monolayer transition metal dichalcogenides (TMDC) feature prominent excitonic natures. Here we report an experimental approach toward measuring the exciton binding energy of monolayer WS2 with linear differential transmission spectroscopy and two-photon photoluminescence excitation spectroscopy (TP-PLE). TP-PLE measurements show the exciton binding energy of 0.71eV around K valley in the Brillouin zone. The trion binding energy of 34meV, two-photon absorption cross section 4X10^{4}cm^{2}W^{-2}S^{-1} at 780nm and exciton-exciton annihilation rate around 0.5cm^{2}/s are experimentally obtained.Comment: 5page,3 figure

    Cloud services within a ROLE-enabled Personal Learning Environment

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    The ROLE project (Responsive Open Learning Environments) is focused on the next generation of Personal Learning Environments (PLE). In this paper, we first describe the engineering process used to create either a new widget bundle, a group of applications or service widgets. The widgets integrated in a ROLE PLE consist of two cloud-based services, a social networking and a mind-mapping tool, where learners can perform and collaborate on learning activities. We also modified other widgets to create a complete learning experience. The whole platform is running on a cloudcomputing infrastructure and one of the services is using a cloud-based database. Additionally, we describe the initial experiences from using this cloud education environment in Galileo University, Guatemala, in a web-based course with students from three different Latin-American countries. We measured emotional aspects, motivation, usability and attitudes towards the environment. The results demonstrated the readiness of cloud-based education solutions, and how ROLE can bring together such an environment from a PLE perspective
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