321 research outputs found

    Potential impacts of climate variability on Dengue Hemorrhagic Fever in Honduras, 2010

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    Climate change and variability are affecting human health and disease direct or indirectly through many mechanisms. Dengue is one of those diseases that is strongly influenced by climate variability; however its study in Central America has been poorly approached. In this study, we assessed potential associations between macroclimatic and microclimatic variation and dengue hemorrhagic fever (DHF) cases in the main hospital of Honduras during 2010. In this year, 3,353 cases of DHF were reported in the Hospital Escuela, Tegucigalpa. Climatic periods marked a difference of 158% in the mean incidence of cases, from El Niño weeks (-99% of cases below the mean incidence) to La Niña months (+59% of cases above it) (p<0.01). Linear regression showed significantly higher dengue incidence with lower values of Oceanic Niño Index (p=0.0097), higher rain probability (p=0.0149), accumulated rain (p=0.0443) and higher relative humidity (p=0.0292). At a multiple linear regression model using those variables, ONI values shown to be the most important and significant factor found to be associated with the monthly occurrence of DHF cases (r2=0.649; ÎČstandardized=–0.836; p=0.01). As has been shown herein, climate variability is an important element influencing the dengue epidemiology in Honduras. However, it is necessary to extend these studies in this and other countries in the Central America region, because these models can be applied for surveillance as well as for prediction of dengue

    ParĂĄmetros de calidad en sueros controles utilizados en Laboratorios ClĂ­nicos del estado Zulia, Venezuela |Quality parameters in control sera used in Clinical Laboratories of Zulia state, Venezuela

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    El aseguramiento de la calidad constituye un aspecto esencial que garantiza resultados fiables en los anĂĄlisis clĂ­nicos. Por tal motivo, este estudio, descriptivo y transversal, tiene como propĂłsito evaluar los parĂĄmetros de calidad en materiales de control empleados en laboratorios clĂ­nicos del estado Zulia, Venezuela. Se valoraron sueros controles de cinco casas comerciales, a los cuales se les determinaron variables fisicoquĂ­micas, calidad bacteriolĂłgica e inmunolĂłgica. Para Ă©sta Ășltima se evaluĂł la presencia de anticuerpos contra HIV, Hepatitis B y C. Finalmente, se estableciĂł asociaciĂłn entre los datos bioquĂ­micos obtenidos y los aportados por el fabricante. Siguiendo los lineamientos de la ConfederaciĂłn Latinoamericana de BioquĂ­mica ClĂ­nica; al considerar aspectos fisicoquĂ­micos, todos los resultados mostraron ser satisfactorios para tiempo de reconstituciĂłn. En cuanto a turbidez, un nivel de suero control (7,14%) reflejĂł valores elevados y tres presentaron un pH inferior al intervalo establecido (21,42%). La totalidad de los materiales de control mostraron ser negativos desde el punto de vista bacteriolĂłgico e inmunolĂłgico. Al asociar las medias aportadas por el fabricante y las obtenidas en esta investigaciĂłn, se empleĂł el Porcentaje de DesviaciĂłn o DesvĂ­o Relativo Porcentual (DRP); resultando que 35,7% de los lotes superan el lĂ­mite de aceptabilidad del 10%, lo cual sugiere al fabricante la realizaciĂłn de estudios que consideren la reasignaciĂłn de los lĂ­mites permisibles de error. Estos resultados constituyen un punto de partida para futuras investigaciones que permitan verificar que los materiales de control en los laboratorios clĂ­nicos cumplan con los estĂĄndares de calidad para asĂ­ asegurar la confiabilidad de los anĂĄlisis clĂ­nicos. Palabras clave: QuĂ­mica clĂ­nica. ABSTRACT The quality assurance is an essential aspect that ensures reliable results in the clinical analysis. For this reason, this study, descriptive and transverse, is aimed at evaluating the quality parameters in control materials employed in clinical laboratories of Zulia State, Venezuela. Control sera of five commercial houses were evaluated, through physico chemical variables and bacteriological and immunological quality. The latter involved the determination of antibodies for HIV, Hepatitis B and C. Finally, an association was established between the biochemical data obtained with those provided by the manufacturer. Following the guidelines of the Latin American Confederation of Clinical Biochemistry; when considering physical and chemical aspects, all the results were satisfactory for reconstitution time. With regard to turbidity, one level of control sera (7,14%) reflected high values and three (21,4%) presented a pH lower than the set range. All control materials were negative from bacteriological and immunological point of view By associating the means provided by the manufacturer and those obtained in this research, we use the percentage of deviation or Percentage Relative Deviation, resulting that 35.7% of the lots exceed the limit of acceptability of 10%, which suggests that the manufacturer should study the reallocation of the permissible limits of error. These results are a starting point for future research that enable the verification that the control materials in clinical laboratories comply with quality standards to ensure the reliability of the clinical analysis. Key words: Clinical chemistry

    Standalone vertex ïŹnding in the ATLAS muon spectrometer

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    A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011

    Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

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    Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H →γ Îł, H → Z Z∗ →4l and H →W W∗ →lÎœlÎœ. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV, corresponding to an integrated luminosity of about 25 fb−1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined ïŹts probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson

    Measurement of the top quark-pair production cross section with ATLAS in pp collisions at \sqrt{s}=7\TeV

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    A measurement of the production cross-section for top quark pairs(\ttbar) in pppp collisions at \sqrt{s}=7 \TeV is presented using data recorded with the ATLAS detector at the Large Hadron Collider. Events are selected in two different topologies: single lepton (electron ee or muon Ό\mu) with large missing transverse energy and at least four jets, and dilepton (eeee, ΌΌ\mu\mu or eΌe\mu) with large missing transverse energy and at least two jets. In a data sample of 2.9 pb-1, 37 candidate events are observed in the single-lepton topology and 9 events in the dilepton topology. The corresponding expected backgrounds from non-\ttbar Standard Model processes are estimated using data-driven methods and determined to be 12.2±3.912.2 \pm 3.9 events and 2.5±0.62.5 \pm 0.6 events, respectively. The kinematic properties of the selected events are consistent with SM \ttbar production. The inclusive top quark pair production cross-section is measured to be \sigmattbar=145 \pm 31 ^{+42}_{-27} pb where the first uncertainty is statistical and the second systematic. The measurement agrees with perturbative QCD calculations.Comment: 30 pages plus author list (50 pages total), 9 figures, 11 tables, CERN-PH number and final journal adde

    Measurement of the top quark pair cross section with ATLAS in pp collisions at √s=7 TeV using final states with an electron or a muon and a hadronically decaying τ lepton

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    A measurement of the cross section of top quark pair production in proton-proton collisions recorded with the ATLAS detector at the Large Hadron Collider at a centre-of-mass energy of 7 TeV is reported. The data sample used corresponds to an integrated luminosity of 2.05 fb -1. Events with an isolated electron or muon and a τ lepton decaying hadronically are used. In addition, a large missing transverse momentum and two or more energetic jets are required. At least one of the jets must be identified as originating from a b quark. The measured cross section, σtt-=186±13(stat.)±20(syst.)±7(lumi.) pb, is in good agreement with the Standard Model prediction

    Hunt for new phenomena using large jet multiplicities and missing transverse momentum with ATLAS in 4.7 fb−1 of √s=7 TeV proton-proton collisions

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    Results are presented of a search for new particles decaying to large numbers of jets in association with missing transverse momentum, using 4.7 fb−1 of pp collision data at s√=7TeV collected by the ATLAS experiment at the Large Hadron Collider in 2011. The event selection requires missing transverse momentum, no isolated electrons or muons, and from ≄6 to ≄9 jets. No evidence is found for physics beyond the Standard Model. The results are interpreted in the context of a MSUGRA/CMSSM supersymmetric model, where, for large universal scalar mass m 0, gluino masses smaller than 840 GeV are excluded at the 95% confidence level, extending previously published limits. Within a simplified model containing only a gluino octet and a neutralino, gluino masses smaller than 870 GeV are similarly excluded for neutralino masses below 100 GeV

    Measurement of the inclusive isolated prompt photon cross-section in pp collisions at sqrt(s)= 7 TeV using 35 pb-1 of ATLAS data

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    A measurement of the differential cross-section for the inclusive production of isolated prompt photons in pp collisions at a center-of-mass energy sqrt(s) = 7 TeV is presented. The measurement covers the pseudorapidity ranges |eta|<1.37 and 1.52<=|eta|<2.37 in the transverse energy range 45<=E_T<400GeV. The results are based on an integrated luminosity of 35 pb-1, collected with the ATLAS detector at the LHC. The yields of the signal photons are measured using a data-driven technique, based on the observed distribution of the hadronic energy in a narrow cone around the photon candidate and the photon selection criteria. The results are compared with next-to-leading order perturbative QCD calculations and found to be in good agreement over four orders of magnitude in cross-section.Comment: 7 pages plus author list (18 pages total), 2 figures, 4 tables, final version published in Physics Letters

    Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

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    This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio
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