33 research outputs found

    Moments of Nucleon Light Cone Quark Distributions Calculated in Full Lattice QCD

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    Moments of the quark density, helicity, and transversity distributions are calculated in unquenched lattice QCD. Calculations of proton matrix elements of operators corresponding to these moments through the operator product expansion have been performed on 163×3216^3 \times 32 lattices for Wilson fermions at ÎČ=5.6\beta = 5.6 using configurations from the SESAM collaboration and at ÎČ=5.5\beta = 5.5 using configurations from SCRI. One-loop perturbative renormalization corrections are included. At quark masses accessible in present calculations, there is no statistically significant difference between quenched and full QCD results, indicating that the contributions of quark-antiquark excitations from the Dirac Sea are small. Close agreement between calculations with cooled configurations containing essentially only instantons and the full gluon configurations indicates that quark zero modes associated with instantons play a dominant role. Naive linear extrapolation of the full QCD calculation to the physical pion mass yields results inconsistent with experiment. Extrapolation to the chiral limit including the physics of the pion cloud can resolve this discrepancy and the requirements for a definitive chiral extrapolation are described.Comment: 53 Pages Revtex, 26 Figures, 9 Tables. Added additional reference and updated referenced data in Table I

    Software quality management improvement through mentoring: an exploratory study from GSD projects

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    Proceeding of: OTM 2011 Workshops: Confederated InternationalWorkshops and Posters: EI2N+NSF ICE, ICSP+INBAST, ISDE, ORM, OTMA, SWWS+MONET+SeDeS, and VADER 2011, Hersonissos, Crete, Greece, October 17-21, 2011Software Quality Management (SQM) is a set of processes and procedures designed to assure the quality of software artifacts along with their development process. In an environment in which software development is evolving to a globalization, SQM is seen as one of its challenges. Global Software Development is a way to develop software across nations, continents, cultures and time zones. The aim of this paper is to detect if mentoring, one of the lead personnel development tools, can improve SQM of projects developed under GSD. The results obtained in the study reveal that the influence of mentoring on SQM is just temperate

    Burden and risk factors for Pseudomonas aeruginosa community-acquired pneumonia:a Multinational Point Prevalence Study of Hospitalised Patients

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    Pseudornonas aeruginosa is a challenging bacterium to treat due to its intrinsic resistance to the antibiotics used most frequently in patients with community-acquired pneumonia (CAP). Data about the global burden and risk factors associated with P. aeruginosa-CAP are limited. We assessed the multinational burden and specific risk factors associated with P. aeruginosa-CAP. We enrolled 3193 patients in 54 countries with confirmed diagnosis of CAP who underwent microbiological testing at admission. Prevalence was calculated according to the identification of P. aeruginosa. Logistic regression analysis was used to identify risk factors for antibiotic-susceptible and antibiotic-resistant P. aeruginosa-CAP. The prevalence of P. aeruginosa and antibiotic-resistant P. aeruginosa-CAP was 4.2% and 2.0%, respectively. The rate of P. aeruginosa CAP in patients with prior infection/colonisation due to P. aeruginosa and at least one of the three independently associated chronic lung diseases (i.e. tracheostomy, bronchiectasis and/or very severe chronic obstructive pulmonary disease) was 67%. In contrast, the rate of P. aeruginosa-CAP was 2% in patients without prior P. aeruginosa infection/colonisation and none of the selected chronic lung diseases. The multinational prevalence of P. aeruginosa-CAP is low. The risk factors identified in this study may guide healthcare professionals in deciding empirical antibiotic coverage for CAP patients

    A pooled analysis of mortality in patients with COPD receiving dual bronchodilation with and without additional inhaled corticosteroid

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    Acknowledgements Support for this project was provided by Boehringer Ingelheim International GmbH (BI). The authors did not receive payment related to the development of the manuscript. Medical writing assistance, in the form of the preparation and revision of the manuscript, was supported financially by BI and provided by Vicki Cronin of MediTech Media, under the authors’ conceptual direction and based on feedback from the authors. BI was given the opportunity to review the manuscript for medical and scientific accuracy as well as intellectual property considerations. The authors would like to thank Wenqiong Xue for her contributions to the statistical analysis.Peer reviewedPublisher PD

    Reflections on 40 Years of Drug Abuse Research: Changes in the Epidemiology of Drug Abuse

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    The discipline of epidemiology utilizes the constructs of agent, host, vector, and environment to study the incidence and prevalence (i.e., the nature, extent, distribution, correlates) and the contexts, and consequences of drug abuse in the United States. This paper provides a selected review of the results of 40 years of epidemiological study of drug abuse using surveillance systems, general population surveys, ethnography and qualitative research approaches. It then addresses the challenges in conducting research on drug abuse epidemiology. The paper concludes with some missed opportunities and lessons learned in four decades of a large portfolio of research studies conducted by an impressive array of distinguished scientists
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