37 research outputs found

    Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set

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    We report a measurement of the bottom-strange meson mixing phase \beta_s using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity. We report confidence regions in the two-dimensional space of \beta_s and the B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2, -1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +- 0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +- 0.009 (syst) ps, which are consistent and competitive with determinations by other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012

    Nothing Lasts Forever: Environmental Discourses on the Collapse of Past Societies

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    The study of the collapse of past societies raises many questions for the theory and practice of archaeology. Interest in collapse extends as well into the natural sciences and environmental and sustainability policy. Despite a range of approaches to collapse, the predominant paradigm is environmental collapse, which I argue obscures recognition of the dynamic role of social processes that lie at the heart of human communities. These environmental discourses, together with confusion over terminology and the concepts of collapse, have created widespread aporia about collapse and resulted in the creation of mixed messages about complex historical and social processes

    Genomic epidemiology of global Klebsiella pneumoniae carbapenemase (KPC)-producing Escherichia coli

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    The dissemination of carbapenem resistance in Escherichia coli has major implications for the management of common infections. blaKPC, encoding a transmissible carbapenemase (KPC), has historically largely been associated with Klebsiella pneumoniae, a predominant plasmid (pKpQIL), and a specific transposable element (Tn4401, ~10kb). Here we characterize the genetic features of blaKPC emergence in global E. coli, 2008-2013, using both long- and short-read whole-genome sequencing. Amongst 43/45 successfully sequenced blaKPC-E. coli strains, we identified substantial strain diversity (n=21 sequence types, 18% of annotated genes in the core genome); substantial plasmid diversity (≥9 replicon types); and substantial blaKPC-associated, mobile genetic element (MGE) diversity (50% not within complete Tn4401 elements). We also found evidence of inter-species, regional and international plasmid spread. In several cases blaKPC was found on high copy number, small Col-like plasmids, previously associated with horizontal transmission of resistance genes in the absence of antimicrobial selection pressures. E. coli is a common human pathogen, but also a commensal in multiple environmental and animal reservoirs, and easily transmissible. The association of blaKPC with a range of MGEs previously linked to the successful spread of widely endemic resistance mechanisms (e.g. blaTEM, blaCTX-M) suggests that it may become similarly prevalent.</p

    Genomic epidemiology of global Klebsiella pneumoniae carbapenemase (KPC)-producing Escherichia coli

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    The dissemination of carbapenem resistance in Escherichia coli has major implications for the management of common infections. blaKPC, encoding a transmissible carbapenemase (KPC), has historically largely been associated with Klebsiella pneumoniae, a predominant plasmid (pKpQIL), and a specific transposable element (Tn4401, ~10kb). Here we characterize the genetic features of blaKPC emergence in global E. coli, 2008-2013, using both long- and short-read whole-genome sequencing. Amongst 43/45 successfully sequenced blaKPC-E. coli strains, we identified substantial strain diversity (n=21 sequence types, 18% of annotated genes in the core genome); substantial plasmid diversity (≥9 replicon types); and substantial blaKPC-associated, mobile genetic element (MGE) diversity (50% not within complete Tn4401 elements). We also found evidence of inter-species, regional and international plasmid spread. In several cases blaKPC was found on high copy number, small Col-like plasmids, previously associated with horizontal transmission of resistance genes in the absence of antimicrobial selection pressures. E. coli is a common human pathogen, but also a commensal in multiple environmental and animal reservoirs, and easily transmissible. The association of blaKPC with a range of MGEs previously linked to the successful spread of widely endemic resistance mechanisms (e.g. blaTEM, blaCTX-M) suggests that it may become similarly prevalent.</p

    Effect of calcitriol on bone turnover and osteocalcin in recent-onset type 1 diabetes

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    Contains fulltext : 125353.pdf (publisher's version ) (Open Access)BACKGROUND: Vitamin D supplementation in childhood improves the achievement of peak bone mass. We investigated the effect of supplementation with calcitriol on bone turnover in recent-onset type 1 diabetes (T1D). Moreover, the association between osteocalcin and parameters of beta-cell function and metabolic control was examined. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a post-hoc analysis of a double-blind, placebo-controlled study of calcitriol supplementation to preserve beta-cell function. 27 recent-onset T1D subjects, mean age 22 years, were randomized to 0.25 microg calcitriol per day or placebo (1:1) and followed up for one year. Changes in bone formation (osteoclacin) and resorption (beta-CrossLaps) markers, and differences between placebo and calcitriol-treated group were evaluated. At baseline, osteocalcin levels were significantly lower in female than in male patients (P<0.01) while no other metabolic parameters as HbA1c and C-peptide differed between gender. No significant correlations were found in relation to HbA1c, insulin requirement and C-peptide. At 1 year follow-up, no significant differences were observed between calcitriol and placebo groups for osteocalcin and beta-CrossLaps. In the placebo group osteocalcin levels were unrelated with parameters of metabolic control, such as C-peptide, insulin requirement or HbA1c. Changes of C-peptide, insulin requirement and HbA1c were not related to osteocalcin levels. CONCLUSIONS: Supplementation with 0.25 microg calcitriol per day to patients with new-onset T1D does not affect circulating markers of bone turnover. OC levels were unrelated to beta-cell function and other metabolic parameters suggesting that OC is ineffective to control pancreatic function in presence of aggressive autoimmune destruction
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