1,068 research outputs found

    Two-Pion Decay Widths of Excited Charm Mesons

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    The widths for ππ\pi\pi decay of the L=1 charm mesons are calculated by describing the pion coupling to light constituents quarks by the lowest order chiral interaction. The wavefunctions of the charm mesons are obtained as solutions to the covariant Blankenbecler-Sugar equation. These solutions correspond to an interaction Hamiltonian modeled as the sum of a linear scalar confining and a screened one-gluon exchange (OGE) interaction. This interaction induces a two-quark contribution to the amplitude for two-pion decay, which is found to interfere destructively with the single quark amplitude. For the currently known L=1 DD mesons, the total ππ\pi\pi decay widths are found to be ∌1\sim 1 MeV for the D1(2420)D_1(2420) and ∌3\sim 3 MeV for the D2∗(2460)D^*_2(2460) if the axial coupling of the constituent quark is taken to be gAq=1g_A^q=1. The as yet undiscovered spin singlet D1∗D_1^* state is predicted to have a larger width of 7 - 10 MeV for ππ\pi\pi decay.Comment: 20 pages, uses Feynmf Submitted to Nuclear Physics A, published versio

    A model structure for coloured operads in symmetric spectra

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    We describe a model structure for coloured operads with values in the category of symmetric spectra (with the positive model structure), in which fibrations and weak equivalences are defined at the level of the underlying collections. This allows us to treat R-module spectra (where R is a cofibrant ring spectrum) as algebras over a cofibrant spectrum-valued operad with R as its first term. Using this model structure, we give suficient conditions for homotopical localizations in the category of symmetric spectra to preserve module structures.Comment: 16 page

    Press protest and publics: the agency of publics in newspaper campaigns

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    Campaign advocacy is a common but rarely researched practice in British tabloid journalism. Newspaper campaigns give an account of ‘public opinion’ to politicians, make explicit claims to speak for ‘the public’ and authentically represent them, and also address readers in an unconventional way in order to recruit their support. This article therefore examines the effect to which agency is attributed to readers and other publics in two such campaigns, and argues that publics were portrayed as active only in relation to the newspaper’s activity, and as primarily as reacting emotionally to the problem. The campaigning press promote themselves commercially and politically as quasi-representatives who challenge distant and ‘out of touch’ political representatives with the populist impulses of ‘public’ demands, but without enhancing the democratic process, or publics’ position within it

    An endogenous inhibitor of angiogenesis downregulated by hypoxia in human aortic valve stenosis promotes disease pathogenesis

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    Acknowledgements The authors would like to acknowledge the NHS Grampian Biorepository for their support and assistance with all immunohistochemistry. Sources of funding This work was generously funded by the British Heart Foundation, UK (FS/17/28/32807) and Grampian NHS Endowments.Peer reviewedPublisher PD

    Pseudo Goldstone Bosons Phenomenology in Minimal Walking Technicolor

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    We construct the non-linear realized Lagrangian for the Goldstone Bosons associated to the breaking pattern of SU(4) to SO(4). This pattern is expected to occur in any Technicolor extension of the standard model featuring two Dirac fermions transforming according to real representations of the underlying gauge group. We concentrate on the Minimal Walking Technicolor quantum number assignments with respect to the standard model symmetries. We demonstrate that for, any choice of the quantum numbers, consistent with gauge and Witten anomalies the spectrum of the pseudo Goldstone Bosons contains electrically doubly charged states which can be discovered at the Large Hadron Collider.Comment: 25 pages, 5 figure

    The Oxytocin Product Correlates with Total Oxytocin Received during Labor: A Research Methods Study

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    Objective Total dose of oxytocin received during labor is an important variable in studies of human labor but is difficult to calculate. We sought to identify a surrogate measure for total dose of oxytocin received. Study Design For each subject receiving oxytocin during labor, the oxytocin total dose received in labor was calculated as the area under the curve. Maximal oxytocin infusion rate, total duration of oxytocin infusion, and the product of both, defined as the oxytocin product, were then each correlated with the total dose of oxytocin received using the Pearson's correlation coefficient. Results Oxytocin dosing data were available from 402 women at Duke and 6,907 women from Pithagore6. The two variables alone, or combined as the oxytocin product, demonstrated a high correlation with the oxytocin total dose (r > 0.7), with the oxytocin product demonstrating the highest (r > 0.9). This was true whether labor was induced or augmented and whether delivery was vaginal or cesarean. Conclusion The oxytocin product, composed of two easily obtained variables, demonstrated a very high correlation with total oxytocin dose received in labor and represents a simple and accurate surrogate for total dose of oxytocin received during labor. The oxytocin product can be used in clinical studies in which oxytocin dose is an important variable

    Study of B→D∗∗πB\to D^{**} \pi decays

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    We investigate the production of the novel PP-wave mesons D0∗D^{*}_{0} and D1â€Č(D1)D^{\prime}_{1} (D_{1}), identified as JP=0+J^{P}=0^+ and 1+1^+, in heavy BB meson decays, respectively. With the heavy quark limit, we give our modelling wave functions for the scalar meson D0∗D^{*}_{0}. Based on the assumptions of color transparency and factorization theorem, we estimate the branching ratios of B→D0∗πB\to D^{*}_{0} \pi decays in terms of the obtained wave functions. Some remarks on D1(â€Č)D^{(\prime)}_{1} productions are also presented.Comment: 16 pages, 2 figures, Revtex4, to be published in Phys. Rev.

    Unification of multi-species vertebrate anatomy ontologies for comparative biology in Uberon.

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    BACKGROUND: Elucidating disease and developmental dysfunction requires understanding variation in phenotype. Single-species model organism anatomy ontologies (ssAOs) have been established to represent this variation. Multi-species anatomy ontologies (msAOs; vertebrate skeletal, vertebrate homologous, teleost, amphibian AOs) have been developed to represent 'natural' phenotypic variation across species. Our aim has been to integrate ssAOs and msAOs for various purposes, including establishing links between phenotypic variation and candidate genes. RESULTS: Previously, msAOs contained a mixture of unique and overlapping content. This hampered integration and coordination due to the need to maintain cross-references or inter-ontology equivalence axioms to the ssAOs, or to perform large-scale obsolescence and modular import. Here we present the unification of anatomy ontologies into Uberon, a single ontology resource that enables interoperability among disparate data and research groups. As a consequence, independent development of TAO, VSAO, AAO, and vHOG has been discontinued. CONCLUSIONS: The newly broadened Uberon ontology is a unified cross-taxon resource for metazoans (animals) that has been substantially expanded to include a broad diversity of vertebrate anatomical structures, permitting reasoning across anatomical variation in extinct and extant taxa. Uberon is a core resource that supports single- and cross-species queries for candidate genes using annotations for phenotypes from the systematics, biodiversity, medical, and model organism communities, while also providing entities for logical definitions in the Cell and Gene Ontologies. THE ONTOLOGY RELEASE FILES ASSOCIATED WITH THE ONTOLOGY MERGE DESCRIBED IN THIS MANUSCRIPT ARE AVAILABLE AT: http://purl.obolibrary.org/obo/uberon/releases/2013-02-21/ CURRENT ONTOLOGY RELEASE FILES ARE AVAILABLE ALWAYS AVAILABLE AT: http://purl.obolibrary.org/obo/uberon/releases
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