332 research outputs found

    Initial State Interactions for K−K^--Proton Radiative Capture

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    The effects of the initial state interactions on the K−−pK^--p radiative capture branching ratios are examined and found to be quite sizable. A general coupled-channel formalism for both strong and electromagnetic channels using a particle basis is presented, and applied to all the low energy K−−pK^--p data with the exception of the {\it 1s} atomic level shift. Satisfactory fits are obtained using vertex coupling constants for the electromagnetic channels that are close to their expected SU(3) values.Comment: 16 pages, uses revte

    Monitoring Soil Quality to Assess the Sustainability of Harvesting Corn Stover

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    Harvesting feedstock for biofuel production must not degrade soil, water, or air resources. Our objective is to provide an overview of field research being conducted to quantify effects of harvesting corn (Zea mays L.) stover as a bioenergy feedstock. Coordinated field studies are being conducted near Ames, IA; St. Paul and Morris, MN; Mead, NE; University Park, PA; Florence, SC; and Brookings, SD., as part of the USDA-ARS Renewable Energy Assessment Project (REAP). A baseline soil quality assessment was made using the Soil Management Assessment Framework (SMAF). Corn grain and residue yield for two different stover harvest rates (∌50% and ∌90%) are being measured. Available soil data remains quite limited but sufficient for an initial SMAF analysis that confirms total organic carbon (TOC) is a soil quality indicator that needs to be closely monitored closely to quantify crop residue removal effects. Overall, grain yields averaged 9.7 and 11.7 Mg ha−1 (155 and 186 bu acre−1) in 2008 and 2009, values that are consistent with national averages for both years. The average amount of stover collected for the 50% treatment was 2.6 and 4.2 Mg ha−1 for 2008 and 2009, while the 90% treatment resulted in an average removal of 5.4 and 7.4 Mg ha−1, respectively. Based on a recent literature review, both stover harvest scenarios could result in a gradual decline in TOC. However, the literature value has a large standard error, so continuation of this long-term multi-location study for several years is warranted

    The Gribov-Zwanziger action in the presence of the gauge invariant, nonlocal mass operator Tr∫d4xFΌΜ(D2)−1FΌΜTr \int d^4x F_{\mu\nu} (D^2)^{-1} F_{\mu\nu} in the Landau gauge

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    We prove that the nonlocal gauge invariant mass dimension two operator FΌΜ(D2)−1FΌΜF_{\mu\nu} (D^2)^{-1} F_{\mu\nu} can be consistently added to the Gribov-Zwanziger action, which implements the restriction of the path integral's domain of integration to the first Gribov region when the Landau gauge is considered. We identify a local polynomial action and prove the renormalizability to all orders of perturbation theory by employing the algebraic renormalization formalism. Furthermore, we also pay attention to the breaking of the BRST invariance, and to the consequences that this has for the Slavnov-Taylor identity.Comment: 30 page

    On the Behavior of the Effective QCD Coupling alpha_tau(s) at Low Scales

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    The hadronic decays of the tau lepton can be used to determine the effective charge alpha_tau(m^2_tau') for a hypothetical tau-lepton with mass in the range 0 < m_tau' < m_tau. This definition provides a fundamental definition of the QCD coupling at low mass scales. We study the behavior of alpha_tau at low mass scales directly from first principles and without any renormalization-scheme dependence by looking at the experimental data from the OPAL Collaboration. The results are consistent with the freezing of the physical coupling at mass scales s = m^2_tau' of order 1 GeV^2 with a magnitude alpha_tau ~ 0.9 +/- 0.1.Comment: 15 pages, 4 figures, submitted to Physical Review D, added references, some text added, no results nor figures change

    Hadronic Mass Spectrum Analysis of D+ into K- pi+ mu+ nu Decay and Measurement of the K*(892)^0 Mass and Width

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    We present a Kpi mass spectrum analysis of the four-body semileptonic charm decay D+ into K- pi+ mu+ nu in the range of 0.65 GeV < mKpi < 1.5 GeV. We observe a non-resonant contribution of 5.30 +- 0.74 +0.99 -0.51 % with respect to the total D+ into K- pi+ mu+ nu decay. For the K*(892)^0 resonance, we obtain a mass of 895.41 +- 0.32 +0.35 -0.36 MeV, a width of 47.79 +- 0.86 +1.3 -1.1 MeV, and a Blatt-Weisskopf damping factor parameter of 3.96 +- 0.54 +0.72 -0.90 GeV^(-1). We also report 90 % CL upper limits of 4 % and 0.64 % for the branching ratios of D+ into K*(1680)^0 mu+ nu with respect to D+ into K- pi+ mu+ nu and D+ into K*(1430)^0 mu+ nu with respect to D+ into K- pi+ mu+ nu, respectively.Comment: 14 page

    'Education, education, education' : legal, moral and clinical

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    This article brings together Professor Donald Nicolson's intellectual interest in professional legal ethics and his long-standing involvement with law clinics both as an advisor at the University of Cape Town and Director of the University of Bristol Law Clinic and the University of Strathclyde Law Clinic. In this article he looks at how legal education may help start this process of character development, arguing that the best means is through student involvement in voluntary law clinics. And here he builds upon his recent article which argues for voluntary, community service oriented law clinics over those which emphasise the education of students

    Study of the Cabibbo-suppressed decay modes D0-->Pi-pi+ and D0-->K-K+

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    Using data from the FOCUS (E831) experiment at Fermilab, we present a new measurement for the branching ratios of the Cabibbo-suppressed decay modes D0-->Pi-Pi+ and D0-->K-K+. We measured: Gamma(D0-->K-K+)/Gamma(D0-->Pi-Pi+) = 2.81 +/- 0.10(stat) +/- 0.06(syst), Gamma(D0-->K-K+)/Gamma(D0-->K-Pi+) = 0.0993 +/- 0.0014(stat) +/- 0.0014(syst), and Gamma(D0-->Pi-Pi+)/Gamma(D0-->K-Pi+) = 0.0353 +/- 0.0012 (stat) +/- 0.0006(syst). These values have been combined with other experimental data to extract the ratios of isospin amplitudes and the phase shifts for the D-->KK and D-->PiPi decay channels.Comment: 12 pages, 1 Figure, accepted for publication in Phys.Lett.

    Context, Complexity and Contestation: Birmingham's Agreed Syllabuses for Religious Education since the 1970s

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    publication-status: AcceptedThis is an Author's Original Manuscript of an article whose final and definitive form, the Version of Record, has been published in the Journal of Beliefs and Values, September 2011. Available online at: http://www.tandfonline.com/ or DOI: 10.1080/13617672.2011.600823The present article offers an historical perspective on the 1975, 1995 and 2007 Birmingham Agreed Syllabuses for Religious Education. It draws upon historical evidence uncovered as part of ‘The hidden history of curriculum change in religious education in English schools, 1969–1979’ project, and curriculum history theories, especially David Labaree’s observations about the distance between the ‘rhetorical’ and ‘received’ curricula. We argue that, contrary to the existing historiography, curriculum change in religious education (RE) has been evolutionary not revolutionary. Multiple reasons are posited to explain this, not least among which is the capacity and agency of teachers. Furthermore, we argue that ongoing debates about the nature and purpose of RE, as exemplified in the Birmingham context, reflect the multiple expectations that religious educators and other stakeholders had, and continue to have, of the curriculum subject. These debates contribute to the inertia evident in the implementation of RE curriculum reforms. A consciousness of the history of RE enables curriculum contestations to be contextualised and understood, and, thereby, provides important insights which can be applied to ongoing and future debates and developments

    Mitochondrial Mutations in Subjects with Psychiatric Disorders

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    A considerable body of evidence supports the role of mitochondrial dysfunction in psychiatric disorders and mitochondrial DNA (mtDNA) mutations are known to alter brain energy metabolism, neurotransmission, and cause neurodegenerative disorders. Genetic studies focusing on common nuclear genome variants associated with these disorders have produced genome wide significant results but those studies have not directly studied mtDNA variants. The purpose of this study is to investigate, using next generation sequencing, the involvement of mtDNA variation in bipolar disorder, schizophrenia, major depressive disorder, and methamphetamine use. MtDNA extracted from multiple brain regions and blood were sequenced (121 mtDNA samples with an average of 8,800x coverage) and compared to an electronic database containing 26,850 mtDNA genomes. We confirmed novel and rare variants, and confirmed next generation sequencing error hotspots by traditional sequencing and genotyping methods. We observed a significant increase of non-synonymous mutations found in individuals with schizophrenia. Novel and rare non-synonymous mutations were found in psychiatric cases in mtDNA genes: ND6, ATP6, CYTB, and ND2. We also observed mtDNA heteroplasmy in brain at a locus previously associated with schizophrenia (T16519C). Large differences in heteroplasmy levels across brain regions within subjects suggest that somatic mutations accumulate differentially in brain regions. Finally, multiplasmy, a heteroplasmic measure of repeat length, was observed in brain from selective cases at a higher frequency than controls. These results offer support for increased rates of mtDNA substitutions in schizophrenia shown in our prior results. The variable levels of heteroplasmic/multiplasmic somatic mutations that occur in brain may be indicators of genetic instability in mtDNA
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