6,503 research outputs found

    Detoxification enzyme activities (CYP1A1 and GST) in the skin of humpback whales as a function of organochlorine burdens and migration status

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    The activities of glutathione-s-transferase (GST) and cytochrome P-450 1A1 (CYP1A1) enzymes were measured in freshly extracted epidermis of live-biopsied, migrating, southern hemisphere humpback whales (Megaptera novaeangliae). The two quantified enzyme activities did not correlate strongly with each other. Similarly, neither correlated strongly with any of the organochlorine compound groups previously measured in the superficial blubber of the sample biopsy core, likely reflecting the anticipated low levels of typical aryl-hydrocarbon receptor ligands. GST activity did not differ significantly between genders or between northward (early migration) or southward (late migration) migrating cohorts. Indeed, the inter-individual variability in GST measurements was relatively low. This observation raises the possibility that measured activities were basal activities and that GST function was inherently impacted by the fasting state of the sampled animals, as seen in other species. These results do not support the implementation of CYP1A1 or GST as effective biomarkers of organochlorine contaminant burdens in southern hemisphere populations of humpback whales as advocated for other cetacean species. Further investigation of GST activity in feeding versus fasting cohorts may, however, provide some insight into the fasting metabolism of these behaviourally adapted populations. © 2014

    Implications of Hadron Collider Observables on Parton Distribution Function Uncertainties

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    Standard parton distribution function sets do not have rigorously quantified uncertainties. In recent years it has become apparent that these uncertainties play an important role in the interpretation of hadron collider data. In this paper, using the framework of statistical inference, we illustrate a technique that can be used to efficiently propagate the uncertainties to new observables, assess the compatibility of new data with an initial fit, and, in case the compatibility is good, include the new data in the fit.Comment: 22 pages, 5 figure

    Copper(II)-bis(thiosemicarbazonato) complexes as anti-chlamydial agents

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    Lipophilic copper (Cu)-containing complexes have shown promising antibacterial activity against a range of bacterial pathogens. To examine the susceptibility of the intracellular human pathogen Chlamydia trachomatis to copper complexes containing bis(thiosemicarbazone) ligands [Cu(btsc)], we tested the in vitro effect of CuII-diacetyl- and CuII-glyoxal-bis[N(4)-methylthiosemicarbazonato] (Cu(atsm) and Cu(gtsm), respectively) on C. trachomatis. Cu(atsm) and to a greater extent, Cu(gtsm), prevented the formation of infectious chlamydial progeny. Impacts on host cell viability and respiration were also observed in addition to the Chlamydia impacts. This work suggests that copper-based complexes may represent a new lead approach for future development of new therapeutics against chlamydial infections, although host cell impacts need to be fully explored

    Outcome of all-inside second-generation meniscal repair: Minimum five-year follow-up

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    BACKGROUND: Meniscal repair and preservation are the goal, when possible, of the treatment of meniscal injury. Current research on second-generation all-inside repair systems has been limited to a maximum of three years of follow-up. The purpose of this study was to evaluate the mid-term clinical success (at more than five years) of meniscal repair performed with a second-generation all-inside repair device, both as an isolated procedure and with a concomitant anterior cruciate ligament (ACL) reconstruction. METHODS: This is a retrospective review of patients who underwent meniscal repair with use of the all-inside FAST-FIX Meniscal Repair System (Smith & Nephew Arthroscopy, Andover, Massachusetts) from December 1999 to January 2007. Eighty-three meniscal repairs (in eighty-one patients) were identified, and follow-up data were obtained for seventy-five (90%). Twenty-six (35%) of the meniscal repairs were performed as isolated procedures. Clinical failure was defined as repeat surgical intervention involving resection or revision repair. Clinical outcomes were also assessed with the Knee injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee (IKDC) score, and the Marx activity score. RESULTS: The minimum duration of follow-up was five years (average, seven years). Twelve patients (16%) had failure of the meniscal repair, at an average of forty-seven months (range, fifteen to ninety-five months). The data did not offer enough statistical evidence, at alpha = 0.05, to establish a difference in average patient age, patient sex, or number of sutures utilized between successful repairs and failures. There was no difference in the failure rate between isolated repairs (12%; 95% confidence interval [CI]: −0.76% to 23.76%) and those performed with concurrent ACL reconstruction (18%; 95% CI: 7.47% to 29.13%), and the average time to failure was similar between these two groups (48.1 months versus 46.6 months, p = 0.939). Postoperative KOOS and IKDC outcome scores were also similar between the groups. CONCLUSIONS: This report of mid-term follow-up results of primary second-generation all-inside meniscal repair demonstrates its effectiveness both as an isolated procedure and when it is performed with concurrent ACL reconstruction. After a minimum of five years of follow-up, 84% of the patients continued to demonstrate successful repair. Treatment success was further supported by favorable results on patient-based outcome measures. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence

    Phylogenetic analysis of human Chlamydia pneumoniae strains reveals a distinct Australian indigenous clade that predates European exploration of the continent

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    © 2015 Roulis et al. Background: The obligate intracellular bacterium Chlamydia pneumoniae is a common respiratory pathogen, which has been found in a range of hosts including humans, marsupials and amphibians. Whole genome comparisons of human C. pneumoniae have previously highlighted a highly conserved nucleotide sequence, with minor but key polymorphisms and additional coding capacity when human and animal strains are compared. Results: In this study, we sequenced three Australian human C. pneumoniae strains, two of which were isolated from patients in remote indigenous communities, and compared them to all available C. pneumoniae genomes. Our study demonstrated a phylogenetically distinct human C. pneumoniae clade containing the two indigenous Australian strains, with estimates that the most recent common ancestor of these strains predates the arrival of European settlers to Australia. We describe several polymorphisms characteristic to these strains, some of which are similar in sequence to animal C. pneumoniae strains, as well as evidence to suggest that several recombination events have shaped these distinct strains. Conclusions: Our study reveals a greater sequence diversity amongst both human and animal C. pneumoniae strains, and suggests that a wider range of strains may be circulating in the human population than current sampling indicates

    kt Effects in Direct-Photon Production

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    We discuss the phenomenology of initial-state parton-kt broadening in direct-photon production and related processes in hadron collisions. After a brief summary of the theoretical basis for a Gaussian-smearing approach, we present a systematic study of recent results on fixed-target and collider direct-photon production, using complementary data on diphoton and pion production to provide empirical guidance on the required amount of kt broadening. This approach provides a consistent description of the observed pattern of deviation of next-to-leading order QCD calculations relative to the direct-photon data, and accounts for the shape and normalization difference between fixed-order perturbative calculations and the data. We also discuss the uncertainties in this phenomenological approach, the implications of these results on the extraction of the gluon distribution of the nucleon, and the comparison of our findings to recent related work.Comment: LaTeX, uses revtex and epsf, 37 pages, 15 figure

    Generic User Process Interface for Event Generators

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    Generic Fortran common blocks are presented for use by High Energy Physics event generators for the transfer of event configurations from parton level generators to showering and hadronization event generators.Comment: Physics at TeV Colliders II Workshop, Les Houches, France, May 2001 14 pages, 6 figure

    Tevatron-for-LHC Report of the QCD Working Group

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    The experiments at Run 2 of the Tevatron have each accumulated over 1 inverse femtobarn of high-transverse momentum data. Such a dataset allows for the first precision (i.e. comparisons between theory and experiment at the few percent level) tests of QCD at a hadron collider. While the Large Hadron Collider has been designed as a discovery machine, basic QCD analyses will still need to be performed to understand the working environment. The Tevatron-for-LHC workshop was conceived as a communication link to pass on the expertise of the Tevatron and to test new analysis ideas coming from the LHC community. The TeV4LHC QCD Working Group focussed on important aspects of QCD at hadron colliders: jet definitions, extraction and use of Parton Distribution Functions, the underlying event, Monte Carlo tunes, and diffractive physics. This report summarizes some of the results achieved during this workshop.Comment: 156 pages, Tevatron-for-LHC Conference Report of the QCD Working Grou

    Leptoquark Contribution to the Higgs Boson Production at the LHC Collider

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    In this report we study how a light-scalar leptoquark could affect the Higgs boson production cross-section at the LHC collider. We construct the most general renormalizable and gauge invariant effective Lagrangian involving the standard model particles and a scalar, isoscalar leptoquark, \eta. The total cross-section for pp -> H+X is then calculated for different values of the unknown parameters \lambda_eta, m_eta and m_H.(Here \lambda_eta is the coupling associated with the Higgs-leptoquark interaction.) We find that if \lambda_eta is moderately large and m_eta is around a few hundred GeV, then the cross-section is significantly larger than the standard model value.Comment: 9 pages, 4 postscript figure
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