1,514 research outputs found

    Taking the C out of CVMFS

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    The Cern Virtual Machine File System is most well known as a distribution mechanism for the WLCG VOs@@ experiment software; as a result, almost all the existing expertise is in installing clients mount the central Cern repositories. We report the results of an initial experiment in using the cvmfs server packages to provide Glasgow-based repository aimed at software provisioning for small UK-local VOs. In general, although the documentation is sparse, server configuration is reasonably easy, with some experimentation. We discuss the advantages of local CVMFS repositories for sites, with some examples from our test VOs, vo.optics.ac.uk and neiss.org.uk

    Canonical Generations and the British Left: The Narrative Construction of the Miners’ Strike 1984–85

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    ‘Generations’ have been invoked to describe a variety of social and cultural relationships, and to understand the development of self-conscious group identity. Equally, the term can be an applied label and politically useful construct; generations can be retrospectively produced. Drawing on the concept of ‘canonical generations’ – those whose experiences come to epitomise an event of historic and symbolic importance – this article examines the narrative creation and functions of ‘generations’ as collective memory shapes and re-shapes the desire for social change. Building a case study of the canonical role of the miners’ strike of 1984–85 in the narrative history of the British left, it examines the selective appropriation and transmission of the past in the development of political consciousness. It foregrounds the autobiographical narratives of activists who, in examining and legitimising their own actions and prospects, (re)produce a ‘generation’ in order to create a relatable and useful historical understanding

    Why Pad\'e Approximants reduce the Renormalization-Scale dependence in QFT?

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    We prove that in the limit where the beta function is dominated by the 1-loop contribution (``large beta_0 limit'') diagonal Pad\'e Approximants (PA's) of perturbative series become exactly renormalization scale (RS) independent. This symmetry suggest that diagonal PA's are resumming correctly contributions from higher order diagrams that are responsible for the renormalization of the coupling-constant. Non-diagonal PA's are not exactly invariant, but generally reduce the RS dependence as compared to partial-sums. In physical cases, higher-order corrections in the beta function break the symmetry softly, introducing a small scale and scheme dependence. We also compare the Pad\'e resummation with the BLM method. We find that in the large-N_f limit using the BLM scale is identical to resumming the series by a x[0/n]x[0/n] non-diagonal PA.Comment: 25 pages, LateX. Replaced so that the figures would fit into the page siz

    Pade Approximants, Optimal Renormalization Scales, and Momentum Flow in Feynman Diagrams

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    We show that the Pade Approximant (PA) approach for resummation of perturbative series in QCD provides a systematic method for approximating the flow of momentum in Feynman diagrams. In the large-β0\beta_0 limit, diagonal PA's generalize the Brodsky-Lepage-Mackenzie (BLM) scale-setting method to higher orders in a renormalization scale- and scheme-invariant manner, using multiple scales that represent Neubert's concept of the distribution of momentum flow through a virtual gluon. If the distribution is non-negative, the PA's have only real roots, and approximate the distribution function by a sum of delta-functions, whose locations and weights are identical to the optimal choice provided by the Gaussian quadrature method for numerical integration. We show how the first few coefficients in a perturbative series can set rigorous bounds on the all-order momentum distribution function, if it is positive. We illustrate the method with the vacuum polarization function and the Bjorken sum rule computed in the large-β0\beta_0 limit.Comment: 28 pages, LaTeX, including 6 figures requires epsfig.st

    Optimizing Illumina next-generation sequencing library preparation for extremely AT-biased genomes.

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    BAckground: Massively parallel sequencing technology is revolutionizing approaches to genomic and genetic research. Since its advent, the scale and efficiency of Next-Generation Sequencing (NGS) has rapidly improved. In spite of this success, sequencing genomes or genomic regions with extremely biased base composition is still a great challenge to the currently available NGS platforms. The genomes of some important pathogenic organisms like Plasmodium falciparum (high AT content) and Mycobacterium tuberculosis (high GC content) display extremes of base composition. The standard library preparation procedures that employ PCR amplification have been shown to cause uneven read coverage particularly across AT and GC rich regions, leading to problems in genome assembly and variation analyses. Alternative library-preparation approaches that omit PCR amplification require large quantities of starting material and hence are not suitable for small amounts of DNA/RNA such as those from clinical isolates. We have developed and optimized library-preparation procedures suitable for low quantity starting material and tolerant to extremely high AT content sequences. Results: We have used our optimized conditions in parallel with standard methods to prepare Illumina sequencing libraries from a non-clinical and a clinical isolate (containing ~53% host contamination). By analyzing and comparing the quality of sequence data generated, we show that our optimized conditions that involve a PCR additive (TMAC), produces amplified libraries with improved coverage of extremely AT-rich regions and reduced bias toward GC neutral templates. Conclusion: We have developed a robust and optimized Next-Generation Sequencing library amplification method suitable for extremely AT-rich genomes. The new amplification conditions significantly reduce bias and retain the complexity of either extremes of base composition. This development will greatly benefit sequencing clinical samples that often require amplification due to low mass of DNA starting material

    Comparison of the Pade Approximation Method to Perturbative QCD Calculations

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    We present a method of estimating perturbative coefficients in Quantum Field Theory using Pade Approximants. We test this method on various known QCD results, and find that the method works very well.Comment: 14 pages (phyzzx macropackage) + 1 postscript figure encoded through uufiles, appended at the end of the tex file. Additional relevant references adde

    Provider perspectives on patient-provider communication for adjuvant endocrine therapy symptom management

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    Providers’ communication skills play a key role in encouraging breast cancer survivors to report symptoms and adhere to long-term treatments such as adjuvant endocrine therapy (AET). The purpose of this study was to examine provider perspectives on patient-provider communication regarding AET symptom management and to explore whether provider perspectives vary across the multi-disciplinary team of providers involved in survivorship care

    The relation between age, weight and fat production in dairy cows

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    Cover title.Includes bibliographical references

    The Journal of the Friends' Historical Society vol. 4 No. 3

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    1. Notices. 2. Notes and Queries. 3. Visits of American Ministers to Europe. 4. A Prophecy of Toleration. 5. Presentations of Quakers in Episcopal Visitations, 1662-1679. 6. Editors' Notes. 7. Episodes in the Life of May Drummond II. 8. Review of Hancock's "Peculium". 9. The Wilkinson and Story Controversy in Bristol. 10. Service in Sackcloth. 11. Present State of the Nonconformists. 12. A Vision seen by George Fox. 13. Friends in Current Literature. 14. George Fox and the Durham College
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