770 research outputs found

    Surface abundances of light elements for a large sample of early B-type stars - IV. The magnesium abundance in 52 stars - a test of metallicity

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    From high-resolution spectra a non-LTE analysis of the MgII 4481.2 A feature is implemented for 52 early and medium local B stars on the main sequence (MS). The influence of the neighbouring line AlIII 4479.9 A is considered. The magnesium abundance is determined; it is found that log e(Mg) = 7.67 +- 0.21 on average. It is shown that uncertainties in the microturbulent parameter Vt are the main source of errors in log e(Mg). When using 36 stars with the most reliable Vt values derived from OII and NII lines, we obtain the mean abundance log e(Mg) = 7.59 +- 0.15. The latter value is precisely confirmed for several hot B stars from an analysis of the MgII 7877 A weak line. The derived abundance log e(Mg) = 7.59 +- 0.15 is in excellent agreement with the solar magnesium abundance log e_sun(Mg) = 7.55 +- 0.02, as well as with the proto-Sun abundance log e_ps(Mg) = 7.62 +- 0.02. Thus, it is confirmed that the Sun and the B-type MS stars in our neighbourhood have the same metallicity.Comment: 9 pages, 6 figures. Has been accepted for publication at MNRA

    Lipidomic profiling of adipose tissue reveals an inflammatory signature in cancer-related and primary Lymphedema

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    © 2016 Sedger et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Cancer-related and primary lymphedema (LE) are associated with the production of adipose tissue (AT). Nothing is known, however, about the lipid-based molecules that comprise LE AT. We therefore analyzed lipid molecules in lipoaspirates and serum obtained from LE patients, and compared them to lipoaspirates from cosmetic surgery patients and healthy control cohort serum. LE patient serum analysis demonstrated that triglycerides, HDL- and LDL-cholesterol and lipid transport molecules remained within the normal range, with no alterations in individual fatty acids. The lipidomic analysis also identified 275 lipid-based molecules, including triacylglycerides, diacylglycerides, fatty acids and phospholipids in AT oil and fat. Although the majority of lipid molecules were present in a similar abundance in LE and non-LE samples, there were several small changes: increased C20:5-containing triacylglycerides, reduced C10:0 caprinic and C24:1 nervonic acids. LE AT oil also contained a signature of increased cyclopropane-type fatty acids and inflammatory mediators arachidonic acid and ceramides. Interestingly C20:5 and C22:6 omega-3-type lipids are increased in LE AT, correlating with LE years. Hence, LE AT has a normal lipid profile containing a signature of inflammation and omega-3-lipids. It remains unclear, however, whether these differences reflect a small-scale global metabolic disturbance or effects within localised inflammatory foci

    Mus musculus deficient for secretory antibodies show delayed growth with an altered urinary metabolome

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    © 2019 The Author(s). Background: The polymeric immunoglobulin receptor (pIgR) maintains the integrity of epithelial barriers by transporting polymeric antibodies and antigens through the epithelial mucosa into the lumen. In this study, we examined the role of pIgR in maintaining gut barrier integrity, which is important for the normal development in mice. Methods: Cohorts of pIgR -/- mice and their wildtype controls were housed under Specific Pathogen Free (SPF) conditions and monitored for weight gain as an indicator of development over time. The general physiology of the gastrointestinal tract was analysed using immunohistochemistry in young (8-12 weeks of age) and aged mice (up to 18 months of age), and the observed immunopathology in pIgR -/- mice was further characterised using flow cytometry. Urinary metabolites were analysed using gas chromatography-mass spectrometry (GC-MS), which revealed changes in metabolites that correlated with age-related increase in gut permeability in pIgR -/- mice. Results: We observed that pIgR -/- mice exhibited delayed growth, and this phenomenon is associated with low-grade gut inflammation that increased with ageing. The gross intraepithelial lymphocytic (IEL) infiltration characteristic of pIgR -/- mice was redefined as CD8α+αβ+ T cells, the majority of which expressed high levels of CD103 and CD69 consistent with tissue resident memory T cells (TRM). Comparison of the urinary metabolome between pIgR -/- and wild-type mice revealed key changes in urinary biomarkers fucose, glycine and Vitamin B5, suggestive of altered mucosal permeability. A significant increase in gut permeability was confirmed by analysing the site-specific uptake of sugar probes in different parts of the intestine. Conclusion: Our data show that loss of the secretory antibody system in mice results in enhanced accumulation of inflammatory IELs in the gut, which likely reflects ongoing inflammation in reaction to gut microbiota or food antigens, leading to delayed growth in pIgR -/- mice. We demonstrate that this leads to the presence of a unique urinary metabolome profile, which may provide a biomarker for altered gut permeability

    MASTR-MS: A web-based collaborative laboratory information management system (LIMS) for metabolomics

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    Background An increasing number of research laboratories and core analytical facilities around the world are developing high throughput metabolomic analytical and data processing pipelines that are capable of handling hundreds to thousands of individual samples per year, often over multiple projects, collaborations and sample types. At present, there are no Laboratory Information Management Systems (LIMS) that are specifically tailored for metabolomics laboratories that are capable of tracking samples and associated metadata from the beginning to the end of an experiment, including data processing and archiving, and which are also suitable for use in large institutional core facilities or multi-laboratory consortia as well as single laboratory environments. Results Here we present MASTR-MS, a downloadable and installable LIMS solution that can be deployed either within a single laboratory or used to link workflows across a multisite network. It comprises a Node Management System that can be used to link and manage projects across one or multiple collaborating laboratories; a User Management System which defines different user groups and privileges of users; a Quote Management System where client quotes are managed; a Project Management System in which metadata is stored and all aspects of project management, including experimental setup, sample tracking and instrument analysis, are defined, and a Data Management System that allows the automatic capture and storage of raw and processed data from the analytical instruments to the LIMS. Conclusion MASTR-MS is a comprehensive LIMS solution specifically designed for metabolomics. It captures the entire lifecycle of a sample starting from project and experiment design to sample analysis, data capture and storage. It acts as an electronic notebook, facilitating project management within a single laboratory or a multi-node collaborative environment. This software is being developed in close consultation with members of the metabolomics research community

    Coherent control using adaptive learning algorithms

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    We have constructed an automated learning apparatus to control quantum systems. By directing intense shaped ultrafast laser pulses into a variety of samples and using a measurement of the system as a feedback signal, we are able to reshape the laser pulses to direct the system into a desired state. The feedback signal is the input to an adaptive learning algorithm. This algorithm programs a computer-controlled, acousto-optic modulator pulse shaper. The learning algorithm generates new shaped laser pulses based on the success of previous pulses in achieving a predetermined goal.Comment: 19 pages (including 14 figures), REVTeX 3.1, updated conten

    Conformity Motives For Alcohol Use Are Associated With Risky Sexual Behavior Among Alcohol-Dependent Patients In Residential Substance Abuse Treatment

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    Alcohol misuse is associated with a variety of negative outcomes, including risky sexual behavior (RSB). In an attempt to better identify the subset of individuals at greatest risk for these negative outcomes, a growing body of research has begun to examine the role of alcohol use motives in risk for alcohol use-related negative outcomes. Although the majority of research in this area has focused on coping motives, conformity motives may be particularly relevant to outcomes such as RSB. Specifically, conformity motives may operate as a proxy risk factor for RSB, reflecting the tendency to engage in interpersonally-oriented risk behaviors in order to avoid rejection, interpersonal conflict, or social ostracism. Therefore, the current study examined the relation between conformity motives for alcohol use and RSB in a sample of 94 patients in a residential substance abuse treatment center. Results indicated that conformity motives were associated with RSB above and beyond other motives for alcohol use, as well as relevant covariates. Findings support the notion that conformity motives may operate as a proxy risk factor that could assist in identifying individuals at elevated risk for engaging in RSB
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