Measurement of D-s(+) and D-s(*+) production in B meson decays and from continuum e(+)e(-) annihilation at √s=10.6 GeV

This is the pre-print version of the Article. The official published version can be accessed from the links below. Copyright @ 2002 APSNew measurements of Ds+ and Ds*+ meson production rates from B decays and from qq̅ continuum events near the Υ(4S) resonance are presented. Using 20.8 fb-1 of data on the Υ(4S) resonance and 2.6 fb-1 off-resonance, we find the inclusive branching fractions B(B⃗Ds+X)=(10.93±0.19±0.58±2.73)% and B(B⃗Ds*+X)=(7.9±0.8±0.7±2.0)%, where the first error is statistical, the second is systematic, and the third is due to the Ds+→φπ+ branching fraction uncertainty. The production cross sections σ(e+e-→Ds+X)×B(Ds+→φπ+)=7.55±0.20±0.34pb and σ(e+e-→Ds*±X)×B(Ds+→φπ+)=5.8±0.7±0.5pb are measured at center-of-mass energies about 40 MeV below the Υ(4S) mass. The branching fractions ΣB(B⃗Ds(*)+D(*))=(5.07±0.14±0.30±1.27)% and ΣB(B⃗Ds*+D(*))=(4.1±0.2±0.4±1.0)% are determined from the Ds(*)+ momentum spectra. The mass difference m(Ds+)-m(D+)=98.4±0.1±0.3MeV/c2 is also measured.This work was supported by DOE and NSF (USA), NSERC (Canada), IHEP (China), CEA and CNRS-IN2P3 (France), BMBF (Germany), INFN (Italy), NFR (Norway), MIST (Russia), and PPARC (United Kingdom). Individuals have received support from the Swiss NSF, A. P. Sloan Foundation, Research Corporation, and Alexander von Humboldt Foundation

Measurement of the branching fraction and CP content for the decay B(0) -> D(*+)D(*-)

This is the pre-print version of the Article. The official published version can be accessed from the links below. Copyright @ 2002 APS.We report a measurement of the branching fraction of the decay B0→D*+D*- and of the CP-odd component of its final state using the BABAR detector. With data corresponding to an integrated luminosity of 20.4  fb-1 collected at the Υ(4S) resonance during 1999–2000, we have reconstructed 38 candidate signal events in the mode B0→D*+D*- with an estimated background of 6.2±0.5 events. From these events, we determine the branching fraction to be B(B0→D*+D*-)=[8.3±1.6(stat)±1.2(syst)]×10-4. The measured CP-odd fraction of the final state is 0.22±0.18(stat)±0.03(syst).This work is supported by DOE and NSF (USA), NSERC (Canada), IHEP (China), CEA and CNRS-IN2P3 (France), BMBF (Germany), INFN (Italy), NFR (Norway), MIST (Russia), and PPARC (United Kingdom). Individuals have received support from the A.P. Sloan Foundation, Research Corporation, and Alexander von Humboldt Foundation

Replication and Recombination Factors Contributing to Recombination-Dependent Bypass of DNA Lesions by Template Switch

Damage tolerance mechanisms mediating damage-bypass and gap-filling are crucial for genome integrity. A major damage tolerance pathway involves recombination and is referred to as template switch. Template switch intermediates were visualized by 2D gel electrophoresis in the proximity of replication forks as X-shaped structures involving sister chromatid junctions. The homologous recombination factor Rad51 is required for the formation/stabilization of these intermediates, but its mode of action remains to be investigated. By using a combination of genetic and physical approaches, we show that the homologous recombination factors Rad55 and Rad57, but not Rad59, are required for the formation of template switch intermediates. The replication-proficient but recombination-defective rfa1-t11 mutant is normal in triggering a checkpoint response following DNA damage but is impaired in X-structure formation. The Exo1 nuclease also has stimulatory roles in this process. The checkpoint kinase, Rad53, is required for X-molecule formation and phosphorylates Rad55 robustly in response to DNA damage. Although Rad55 phosphorylation is thought to activate recombinational repair under conditions of genotoxic stress, we find that Rad55 phosphomutants do not affect the efficiency of X-molecule formation. We also examined the DNA polymerase implicated in the DNA synthesis step of template switch. Deficiencies in translesion synthesis polymerases do not affect X-molecule formation, whereas DNA polymerase δ, required also for bulk DNA synthesis, plays an important role. Our data indicate that a subset of homologous recombination factors, together with DNA polymerase δ, promote the formation of template switch intermediates that are then preferentially dissolved by the action of the Sgs1 helicase in association with the Top3 topoisomerase rather than resolved by Holliday Junction nucleases. Our results allow us to propose the choreography through which different players contribute to template switch in response to DNA damage and to distinguish this process from other recombination-mediated processes promoting DNA repair

Measurement of the Ratio of b Quark Production Cross Sections in Antiproton-Proton Collisions at 630 GeV and 1800 GeV

We report a measurement of the ratio of the bottom quark production cross section in antiproton-proton collisions at 630 GeV to 1800 GeV using bottom quarks with transverse momenta greater than 10.75 GeV identified through their semileptonic decays and long lifetimes. The measured ratio sigma(630)/sigma(1800) = 0.171 +/- .024 +/- .012 is in good agreement with next-to-leading order (NLO) quantum chromodynamics (QCD)

Assistência a crianças desnutridas: análise de dados do Sistema de Informação Hospitalar do Sistema Único de Saúde do Brasil Care for malnourished children: an analysis of Brazilian National Health Service Hospital Information System data

OBJETIVOS: caracterizar aspectos da assistência aos desnutridos menores de cinco anos, internados durante o ano de 2004 em hospitais conveniados ao Sistema Único de Saúde (SUS). MÉTODOS: foram analisadas as informações geográficas, demográficas, de diagnóstico e resultado da assistência, das internações hospitalares disponíveis no Sistema de Informação Hospitalar do Sistema Único de Saúde. RESULTADOS: a taxa mais alta de internação por desnutrição foi encontrada na região Nordeste. Do total de internações por desnutrição no Brasil, 36,2% foram registradas como não especificadas. A taxa de mortalidade hospitalar por desnutrição para o Brasil apresentou-se baixa, porém, mostrou-se moderada para crianças menores de seis meses e alta quando desnutrição grave foi registrada no campo de diagnóstico secundário. Para 102 municípios brasileiros a taxa de mortalidade hospitalar por desnutrição também foi alta. Merece atenção o fato de que 11,4% das crianças faleceram nas primeiras 24 horas de hospitalização, e a complementação do tratamento ambulatorial foi indicada em 3,7% das Autorizações de Internação Hospitalar. CONCLUSÕES: mostram-se necessárias a valorização pelos profissionais de saúde da avaliação do estado nutricional e seu correto registro como causa de internação, bem como, a integração e a hierarquização dos diferentes níveis de atenção à criança desnutrida.<br>OBJECTIVES: to characterize features of care provided for malnourished children aged under five years admitted to hospitals affiliated to the Brazilian National Health Service in 2004. METHODS: geographical, demographic data and information relating to diagnosis, results of care and admission to hospital available on the Brazilian National Health Service's Hospital Information System were analyzed. RESULTS: the highest rate for admission to hospital for malnutrition was found in the Northeast region. Of all admissions to hospital for malnutrition in Brazil as a whole, 36.2% were registered as non-specific. The hospital mortality rate for malnutrition in Brazil was low, but moderate for children aged under six months and high when severe malnutrition was registered in the secondary diagnosis field. The hospital mortality rate for malnutrition was also high in 102 Brazilian municipalities. It is worth noting that 11.4% of children died within the first 24 hours following admission to hospital and the complementary outpatient treatment was recommended in 3.7% of Hospital Admissions Authorizations. CONCLUSIONS: the study revealed the importance of health workers recognizing the value of the nutritional status evaluation and correctly registering this as the cause of admission to hospital, and also integrating and ordering the various levels of care for malnourished children