11 research outputs found

    Transversity distributions in the nucleon in the large-N_c limit

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    We compute the quark and antiquark transversity distributions in the nucleon at a low normalization point of 600 MeV in the large-NcN_c limit, where the nucleon can be described as a soliton of an effective chiral theory (chiral quark-soliton model). The flavor-nonsinglet distributions, δu(x)δd(x)\delta u(x) - \delta d(x) and δuˉ(x)δdˉ(x)\delta\bar u(x) - \delta\bar d(x), appear in leading order of the 1/Nc1/N_c-expansion, while the flavor-singlet distributions, δu(x)+δd(x)\delta u(x) + \delta d(x) and δuˉ(x)+δdˉ(x)\delta\bar u(x) + \delta\bar d(x), are non-zero only in next-to-leading order. The transversity quark and antiquark distributions are found to be significantly different from the longitudinally polarized distributions Δu(x)±Δd(x)\Delta u (x) \pm \Delta d (x) and Δuˉ(x)±Δdˉ(x)\Delta\bar u (x) \pm \Delta\bar d (x), respectively, in contrast to the prediction of the naive non-relativistic quark model. We show that this affects the predictions for the spin asymmetries in Drell-Yan pair production in transversely polarized pp and ppbar collisions.Comment: 45 pages, 16 figure

    Ochratoxin A-producing Aspergilli in Vietnamese green coffee beans

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    The definitive version is available at www.blackwell-synergy.comAims: To determine the incidence and severity of infection by ochratoxin A (OA)-producing fungi in Vietnamese green coffee beans. Methods and Results: Aspergillus carbonarius, A. niger and yellow Aspergilli (A. ochraceus and related species in section Circumdati) were isolated by direct plating of surface-disinfected Robusta (65 samples) and Arabica (11 samples) coffee beans from southern and central Vietnam. Significantly, more Robusta than Arabica beans were infected by fungi. Aspergillus niger infected 89% of Robusta beans, whereas A. carbonarius and yellow Aspergilli each infected 12–14% of beans. OA was not produced by A. niger (98 isolates) or A. ochraceus (77 isolates), but was detected in 110 of 113 isolates of A. carbonarius, 10 isolates of A. westerdijkiae and one isolate of A. steynii. The maximum OA observed in samples severely infected with toxigenic species was 1·8 μg kg−1; however, no relationship between extent of infection and OA contamination was observed. Conclusions: Aspergillus niger is the dominant species infecting Vietnamese coffee beans, yet A. carbonarius is the likely source of OA contamination. Significance and Impact of Study: Vietnamese green coffee beans were more severely infected with fungi than the levels reported for beans from other parts of the world, yet OA contamination appears to be infrequent.S.L. Leong, L.T. Hien, T.V. An, N.T. Trang, A.D. Hocking, E.S. Scot

    O desenvolvimento dos "Diagnosis Related Groups"- DRGs. Metodologia de classificação de pacientes hospitalares The development of "Diagnosis Related Groups" - DRGs, a methodology for classifying hospital patients

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    É descrito o processo de desenvolvimento do sistema de classificação de pacientes internados em hospitais que atendem casos agudos, denominada Diagnosis Relatd Group - DRGs, desenvolvido e difundido por pesquisadores da Universidade de Yale, USA. Esse sistema vem a ser um instrumento que permite a mensuração do produto hospitalar, principalmente sob o ponto de vista gerencial. São apresentadas considerações acerca do que é entendido como produto hospitalar, seguindo nos meandros do desenvolvimento dos primeiros DRGs, até a mais recente revisão do sistema. É descrita sua utilização em alguns países e diversos usos potenciais desse sistema, que abrangem desde o uso para pagamento a instrumento de controle de qualidade.<br>The history of Diagnosis Related Groups (DRG's), a system for classifying patients in acute care hospitals, developed by researchers at Yale University, USA, is reviewed. DRGs are an instrument for measuring the hospital product, primarily from a management viewpoint. Starting with a review of the definitions of hospital product, the article follows the course from the first DRGs through the most recent revision, providing a summary of potential and current applications of the system in several countries, which range from payment mechanism to uses in quality control

    Lessons from the "Euro-Lupus Cohort"

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    The "Euro-Lupus Cohort" is composed by 1,000 patients with systemic lupus erythematosus (SLE) that have been followed prospectively since 1991. These patients have been gathered by a European consortium - the "Euro-Lupus Project Group". This consortium was originated as part of the network promoted by the "European Working Party on SLE", a working group created in 1990 in order to promote research in Europe on the different problems related to this disease. The "Euro-Lupus Cohort" provides an updated information on the SLE morbidity and mortality characteristics in the present decade as well as defines several clinical and immunological prognostic factors
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