414 research outputs found
Ampicillin-Improved Glucose Tolerance in Diet-Induced Obese C57BL/6NTac Mice Is Age Dependent
Ampicillin has been shown to improve glucose tolerance in mice. We hypothesized that this effect is present only if treatment is initiated prior to weaning and that it disappears when treatment is terminated. High-fat fed C57BL/6NTac mice were divided into groups that received Ampicillin at different ages or not at all. We found that both diet and Ampicillin significantly changed the gut microbiota composition in the animals. Furthermore, there was a significant improvement in glucose tolerance in Ampicillin-treated, five-week-old mice compared to nontreated mice in the control group. At study termination, expressions of mRNA coding for tumor necrosis factor, serum amyloid A, and lactase were upregulated, while the expression of tumor necrosis factor (ligand) superfamily member 15 was downregulated in the ileum of Ampicillin-treated mice. Higher dendritic cell percentages were found systemically in high-fat diet mice, and a lower tolerogenic dendritic cell percentage was found both in relation to high-fat diet and late Ampicillin treatment. The results support our hypothesis that a “window” exists early in life in which an alteration of the gut microbiota affects glucose tolerance as well as development of gut immunity and that this window may disappear after weaning
A dual thromboxane inhibitor and thromboxane receptor antagonist prevents pig myocardial infarction induced by coronary thrombosis
peer reviewe
Background Light in Potential Sites for the ANTARES Undersea Neutrino Telescope
The ANTARES collaboration has performed a series of {\em in situ}
measurements to study the background light for a planned undersea neutrino
telescope. Such background can be caused by K decays or by biological
activity. We report on measurements at two sites in the Mediterranean Sea at
depths of 2400~m and 2700~m, respectively. Three photomultiplier tubes were
used to measure single counting rates and coincidence rates for pairs of tubes
at various distances. The background rate is seen to consist of three
components: a constant rate due to K decays, a continuum rate that
varies on a time scale of several hours simultaneously over distances up to at
least 40~m, and random bursts a few seconds long that are only correlated in
time over distances of the order of a meter. A trigger requiring coincidences
between nearby photomultiplier tubes should reduce the trigger rate for a
neutrino telescope to a manageable level with only a small loss in efficiency.Comment: 18 pages, 8 figures, accepted for publication in Astroparticle
Physic
Epistemic Dependence and Collective Scientific Knowledge
I argue that scientific knowledge is collective knowledge, in a sense to be specified and defended. I first consider some existing proposals for construing collective knowledge and argue that they are unsatisfactory, at least for scientific knowledge as we encounter it in actual scientific practice. Then I introduce an alternative conception of collective knowledge, on which knowledge is collective if there is a strong form of mutual epistemic dependence among scientists, which makes it so that satisfaction of the justification condition on knowledge ineliminably requires a collective. Next, I show how features of contemporary science support the conclusion that scientific knowledge is collective knowledge in this sense. Finally, I consider implications of my proposal and defend it against objections. © 2013 Springer Science+Business Media Dordrecht
The ANTARES Optical Beacon System
ANTARES is a neutrino telescope being deployed in the Mediterranean Sea. It
consists of a three dimensional array of photomultiplier tubes that can detect
the Cherenkov light induced by charged particles produced in the interactions
of neutrinos with the surrounding medium. High angular resolution can be
achieved, in particular when a muon is produced, provided that the Cherenkov
photons are detected with sufficient timing precision. Considerations of the
intrinsic time uncertainties stemming from the transit time spread in the
photomultiplier tubes and the mechanism of transmission of light in sea water
lead to the conclusion that a relative time accuracy of the order of 0.5 ns is
desirable. Accordingly, different time calibration systems have been developed
for the ANTARES telescope. In this article, a system based on Optical Beacons,
a set of external and well-controlled pulsed light sources located throughout
the detector, is described. This calibration system takes into account the
optical properties of sea water, which is used as the detection volume of the
ANTARES telescope. The design, tests, construction and first results of the two
types of beacons, LED and laser-based, are presented.Comment: 21 pages, 18 figures, submitted to Nucl. Instr. and Meth. Phys. Res.
Explicating ways of consensus-making in science and society: distinguishing the academic, the interface and the meta-consensus
In this chapter, we shed new light on the epistemic struggle between establishing consensus and acknowledging plurality, by explicating different ways of consensus-making in science and society and examining the impact hereof on their field of intersection, i.e. consensus conferences (in particular those organized by the National Institute of Health). We draw a distinction between, what we call, academic and interface consensus, to capture the wide appeal to consensus in existing literature. We investigate such accounts - i.e. from Miriam Solomon, John Beatty and Alfred Moore, and Boaz Miller - as to put forth a new understanding of consensus-making, focusing on the meta-consensus. We further defend how (NIH) consensus conferences enable epistemic work, through demands of epistemic adequacy and contestability, contrary to the claim that consensus conferences miss a window for epistemic opportunity (Solomon M, The social epistemology of NIH consensus conferences. In: Kincaid H, McKitrick J (ed) Establishing medical reality: methodological and metaphysical issues in philosophy of medicine. Springer, Dordrecht, 2007). Paying attention to the dynamics surrounding consensus, moreover, allows us to illustrate how the public understanding of science and the public use of the ideal of consensus could be well modified
A DEMETER-like DNA demethylase protein governs tomato fruit ripening
In plants, genomic DNA methylation which contributes to development and stress responses can be actively removed by DEMETER-like DNA demethylases (DML). Indeed, in Arabidopsis DMLs are important for maternal imprinting and endosperm demethylation, but only few studies demonstrate the developmental roles of active DNA demethylation conclusively in this plant. Here we show a direct cause and effect relationship between active DNA demethylation mainly mediated by the tomato DML, SlDML2, and fruit ripening; an important developmental process unique to plants. RNAi SlDML2 knock-down results in ripening inhibition via hypermethylation and repression of the expression of genes encoding ripening transcription factors and rate-limiting enzymes of key biochemical processes such as carotenoid synthesis. Our data demonstrate that active DNA demethylation is central to the control of ripening in tomat
Glucagon-Like Peptide-1 Protects Human Islets against Cytokine-Mediated β-Cell Dysfunction and Death: A Proteomic Study of the Pathways Involved
Glucagon-like peptide-1 (GLP-1) has been shown to protect pancreatic β-cells against cytokine-induced dysfunction and destruction. The mechanisms through which GLP-1 exerts its effects are complex and still poorly understood. The aim of this study was to analyze the protein expression profiles of human islets of Langerhans treated with cytokines (IL-1β and IFN-γ) in the presence or absence of GLP-1 by 2D difference gel electrophoresis and subsequent protein interaction network analysis to understand the molecular pathways involved in GLP-1-mediated β-cell protection. Co-incubation of cytokine-treated human islets with GLP-1 resulted in a marked protection of β-cells against cytokine-induced apoptosis and significantly attenuated cytokine-mediated inhibition of glucose-stimulated insulin secretion. The cytoprotective effects of GLP-1 coincided with substantial alterations in the protein expression profile of cytokine-treated human islets, illustrating a counteracting effect on proteins from different functional classes such as actin cytoskeleton, chaperones, metabolic proteins, and islet regenerating proteins. In summary, GLP-1 alters in an integrated manner protein networks in cytokine-exposed human islets while protecting them against cytokine-mediated cell death and dysfunction. These data illustrate the beneficial effects of GLP-1 on human islets under immune attack, leading to a better understanding of the underlying mechanisms involved, a prerequisite for improving therapies for diabetic patients.status: publishe
The future of metabolomics in ELIXIR.
Metabolomics, the youngest of the major omics technologies, is supported by an active community of researchers and infrastructure developers across Europe. To coordinate and focus efforts around infrastructure building for metabolomics within Europe, a workshop on the "Future of metabolomics in ELIXIR" was organised at Frankfurt Airport in Germany. This one-day strategic workshop involved representatives of ELIXIR Nodes, members of the PhenoMeNal consortium developing an e-infrastructure that supports workflow-based metabolomics analysis pipelines, and experts from the international metabolomics community. The workshop established metabolite identification as the critical area, where a maximal impact of computational metabolomics and data management on other fields could be achieved. In particular, the existing four ELIXIR Use Cases, where the metabolomics community - both industry and academia - would benefit most, and which could be exhaustively mapped onto the current five ELIXIR Platforms were discussed. This opinion article is a call for support for a new ELIXIR metabolomics Use Case, which aligns with and complements the existing and planned ELIXIR Platforms and Use Cases
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