1,176 research outputs found

    DiarrĂ©ia associada a astrovĂ­rus em crianças de ambulatĂłrio em Hospital PĂșblico de CĂłrdoba, Argentina

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    Human astroviruses have been increasingly identified as important agents of diarrheal disease in children. However, the disease burden of astrovirus infection is still incompletely assessed. This paper reports results on the epidemiological and clinical characteristics of astrovirus-associated diarrhea, as well as the impact of astrovirus infection on the ambulatory setting at a Public Hospital in CĂłrdoba city, Argentina. From February 2001 through January 2002, 97 randomly selected outpatient visits for diarrhea among children ; 0.05). According to our estimation about one out of seventy-four children in this cohort would be assisted annually for an astroviral-diarrheal episode in the Public Hospital and one out of eight diarrheal cases could be attributed to astrovirus infection. Astrovirus is a common symptomatic infection in pediatric outpatient visits in the public hospital in the study area, contributing 12.37% of the overall morbidity from diarrhea.Os astrovĂ­rus humanos tĂȘm sido identificados como importantes agentes de diarrĂ©ias em crianças embora o impacto da sua infecção nĂŁo tenha sido esclarecido. Este estudo nĂŁo sĂł mostra os resultados das caracterĂ­sticas epidemiolĂłgicas e clĂ­nicas, mas tambĂ©m o impacto da infecção por astrovĂ­rus em pacientes ambulatoriais de um Hospital PĂșblico da cidade de CĂłrdoba na Argentina. Escolheram-se randomicamente 97 pacientes ambulatoriais com menos de 36 meses, entre fevereiro de 2001 e janeiro de 2002, que consultaram por diarrĂ©ia. Pesquisou-se antĂ­geno de astrovĂ­rus por ensaio imuno-enzimĂĄtico em uma Ășnica amostra de fezes por paciente estudado. Determinou-se a presença de astrovĂ­rus em 12,37% dos casos de diarrĂ©ia. Todos os casos positivos foram em crianças de 4 a 18 meses, mas o Ă­ndice mais elevado se apresentou em crianças de 4 a 6 meses (23,80%). Os sintomas de diarrĂ©ia associada a astrovĂ­rus foram febre 41,66%; vĂŽmitos 25,00% e desidratação 8,33%; ou seja, 16,66% dos pacientes precisaram hospitalização. A presença de astrovĂ­rus foi anual sem se observar comportamento sazonal, semestre frio 15,21% versus semestre quente 9,80% p >; 0,05. Em nossa pesquisa, uma de cada 74 crianças seria atendida anualmente por apresentar um episĂłdio de diarrĂ©ia associada a astrovĂ­rus no hospital pĂșblico e um de cada 8 casos de diarrĂ©ia poderia atribuir-se Ă  infecção por astrovĂ­rus. AstrovĂ­rus Ă© uma infecção sintomĂĄtica em pacientes pediĂĄtricos ambulatoriais, representando 12,37% da morbidade por diarrĂ©ia

    Epidemiologia da gastrenterite viral aguda em crianças hospitalizadas na cidade de Córdoba, Argentina: uma percepção ao impacto da doença

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    Information concerning the disease burden of viral gastroenteritis has important implications for the use and monitoring the impact of public health policies. The present study, carried out in CĂłrdoba city, Argentina, documents the epidemiology of severe viral diarrhea as well as the burden of viral gastrointestinal disease in the hospital children admission. A total of 133 stools were collected from hospitalized children (Town Childhood Hospital) suffering from acute diarrhea and studied for the presence of Group A rotavirus, astrovirus and adenovirus 40/41 by enzyme-immuno assay, between November 1997 and October 1998. Enteric viruses accounted for 42.1% of the total diarrheal cases analyzed. Group A rotaviruses, astroviruses, adenoviruses 40/41 and mixed infections were found in 35.3, 4.5, 1.5, and 0.8% studied specimens respectively. We estimated that 1 in 27 children in the 0-35 month-old cohort/range would be annually hospitalized for a viral gastroenteritis illness. The major impact on viral diarrhea lies on rotaviral infection, accouting for 84.0% of the viral diarrheal cases analyzed and for approximately one third of severe diarrheas requiring hospital admission in CĂłrdoba City, Argentina.Dados a respeito do impacto das gastrenterites virais tĂȘm implicaçÔes importantes para o monitoraramento do impacto das polĂ­ticas de saĂșde pĂșblica. O presente estudo, feito na cidade de CĂłrdoba, Argentina, documenta a epidemiologia da diarrĂ©ia viral severa como tambĂ©m o impacto que a mesma representa na admissĂŁo hospitalar de crianças. Pesquisou-se a presença de RotavĂ­rus grupo A, AstrovĂ­rus e AdenovĂ­rus 40/41 por ensaio imuno-enzimĂĄtico em 133 amostras de fezes obtidas durante o perĂ­odo de novembro de 1997 a outubro de 1998, de crianças hospitalizadas por diarrĂ©ia aguda. Os virus entĂ©ricos constituĂ­ram 42,1% do total de casos de diarrĂ©ia analisados. Encontraram-se RotavĂ­rus Grupo A, AstrovĂ­rus, AdenovĂ­rus 40/41 e infecçÔes mistas em 35,3; 4,5; 1,5 e 0,8% das amostrras estudadas, respectivamente. Observamos que uma de cada 27 crianças entre 0-35 meses de idade seria hospitalizada por ano devido a uma gastrenterite viral. O principal impacto da diarrĂ©ia viral Ă© representado pela infecção por RotavĂ­rus, correspondendo a 84,0% dos casos analisados e cerca de um terço das diarrĂ©ias graves que precisam hospitalização em CĂłrdoba, Argentina

    Impacts of the Tropical Pacific/Indian Oceans on the Seasonal Cycle of the West African Monsoon

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    The current consensus is that drought has developed in the Sahel during the second half of the twentieth century as a result of remote effects of oceanic anomalies amplified by local land–atmosphere interactions. This paper focuses on the impacts of oceanic anomalies upon West African climate and specifically aims to identify those from SST anomalies in the Pacific/Indian Oceans during spring and summer seasons, when they were significant. Idealized sensitivity experiments are performed with four atmospheric general circulation models (AGCMs). The prescribed SST patterns used in the AGCMs are based on the leading mode of covariability between SST anomalies over the Pacific/Indian Oceans and summer rainfall over West Africa. The results show that such oceanic anomalies in the Pacific/Indian Ocean lead to a northward shift of an anomalous dry belt from the Gulf of Guinea to the Sahel as the season advances. In the Sahel, the magnitude of rainfall anomalies is comparable to that obtained by other authors using SST anomalies confined to the proximity of the Atlantic Ocean. The mechanism connecting the Pacific/Indian SST anomalies with West African rainfall has a strong seasonal cycle. In spring (May and June), anomalous subsidence develops over both the Maritime Continent and the equatorial Atlantic in response to the enhanced equatorial heating. Precipitation increases over continental West Africa in association with stronger zonal convergence of moisture. In addition, precipitation decreases over the Gulf of Guinea. During the monsoon peak (July and August), the SST anomalies move westward over the equatorial Pacific and the two regions where subsidence occurred earlier in the seasons merge over West Africa. The monsoon weakens and rainfall decreases over the Sahel, especially in August.Peer reviewe

    An embedding technique to determine ττ backgrounds in proton-proton collision data

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    An embedding technique is presented to estimate standard model tau tau backgrounds from data with minimal simulation input. In the data, the muons are removed from reconstructed mu mu events and replaced with simulated tau leptons with the same kinematic properties. In this way, a set of hybrid events is obtained that does not rely on simulation except for the decay of the tau leptons. The challenges in describing the underlying event or the production of associated jets in the simulation are avoided. The technique described in this paper was developed for CMS. Its validation and the inherent uncertainties are also discussed. The demonstration of the performance of the technique is based on a sample of proton-proton collisions collected by CMS in 2017 at root s = 13 TeV corresponding to an integrated luminosity of 41.5 fb(-1).Peer reviewe

    Search for anomalous production of events with three or more leptons in pp collisions at √s = 8TeV

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    Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published articles title, journal citation, and DOI.A search for physics beyond the standard model in events with at least three leptons is presented. The data sample, corresponding to an integrated luminosity of 19.5fb-1 of proton-proton collisions with center-of-mass energy s=8TeV, was collected by the CMS experiment at the LHC during 2012. The data are divided into exclusive categories based on the number of leptons and their flavor, the presence or absence of an opposite-sign, same-flavor lepton pair (OSSF), the invariant mass of the OSSF pair, the presence or absence of a tagged bottom-quark jet, the number of identified hadronically decaying τ leptons, and the magnitude of the missing transverse energy and of the scalar sum of jet transverse momenta. The numbers of observed events are found to be consistent with the expected numbers from standard model processes, and limits are placed on new-physics scenarios that yield multilepton final states. In particular, scenarios that predict Higgs boson production in the context of supersymmetric decay chains are examined. We also place a 95% confidence level upper limit of 1.3% on the branching fraction for the decay of a top quark to a charm quark and a Higgs boson (t→cH), which translates to a bound on the left- and right-handed top-charm flavor-violating Higgs Yukawa couplings, λtcH and λctH, respectively, of |λtcH|2+|λctH|2<0.21

    Measurement of the Splitting Function in &ITpp &ITand Pb-Pb Collisions at root&ITsNN&IT=5.02 TeV

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    Data from heavy ion collisions suggest that the evolution of a parton shower is modified by interactions with the color charges in the dense partonic medium created in these collisions, but it is not known where in the shower evolution the modifications occur. The momentum ratio of the two leading partons, resolved as subjets, provides information about the parton shower evolution. This substructure observable, known as the splitting function, reflects the process of a parton splitting into two other partons and has been measured for jets with transverse momentum between 140 and 500 GeV, in pp and PbPb collisions at a center-of-mass energy of 5.02 TeV per nucleon pair. In central PbPb collisions, the splitting function indicates a more unbalanced momentum ratio, compared to peripheral PbPb and pp collisions.. The measurements are compared to various predictions from event generators and analytical calculations.Peer reviewe

    Combined searches for the production of supersymmetric top quark partners in proton-proton collisions at root s=13 TeV

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    A combination of searches for top squark pair production using proton-proton collision data at a center-of-mass energy of 13 TeV at the CERN LHC, corresponding to an integrated luminosity of 137 fb(-1) collected by the CMS experiment, is presented. Signatures with at least 2 jets and large missing transverse momentum are categorized into events with 0, 1, or 2 leptons. New results for regions of parameter space where the kinematical properties of top squark pair production and top quark pair production are very similar are presented. Depending on themodel, the combined result excludes a top squarkmass up to 1325 GeV for amassless neutralino, and a neutralinomass up to 700 GeV for a top squarkmass of 1150 GeV. Top squarks with masses from 145 to 295 GeV, for neutralino masses from 0 to 100 GeV, with a mass difference between the top squark and the neutralino in a window of 30 GeV around the mass of the top quark, are excluded for the first time with CMS data. The results of theses searches are also interpreted in an alternative signal model of dark matter production via a spin-0 mediator in association with a top quark pair. Upper limits are set on the cross section for mediator particle masses of up to 420 GeV

    Search for Physics beyond the Standard Model in Events with Overlapping Photons and Jets

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    Results are reported from a search for new particles that decay into a photon and two gluons, in events with jets. Novel jet substructure techniques are developed that allow photons to be identified in an environment densely populated with hadrons. The analyzed proton-proton collision data were collected by the CMS experiment at the LHC, in 2016 at root s = 13 TeV, and correspond to an integrated luminosity of 35.9 fb(-1). The spectra of total transverse hadronic energy of candidate events are examined for deviations from the standard model predictions. No statistically significant excess is observed over the expected background. The first cross section limits on new physics processes resulting in such events are set. The results are interpreted as upper limits on the rate of gluino pair production, utilizing a simplified stealth supersymmetry model. The excluded gluino masses extend up to 1.7 TeV, for a neutralino mass of 200 GeV and exceed previous mass constraints set by analyses targeting events with isolated photons.Peer reviewe

    Measurement of b jet shapes in proton-proton collisions at root s=5.02 TeV

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    We present the first study of charged-hadron production associated with jets originating from b quarks in proton-proton collisions at a center-of-mass energy of 5.02 TeV. The data sample used in this study was collected with the CMS detector at the CERN LHC and corresponds to an integrated luminosity of 27.4 pb(-1). To characterize the jet substructure, the differential jet shapes, defined as the normalized transverse momentum distribution of charged hadrons as a function of angular distance from the jet axis, are measured for b jets. In addition to the jet shapes, the per-jet yields of charged particles associated with b jets are also quantified, again as a function of the angular distance with respect to the jet axis. Extracted jet shape and particle yield distributions for b jets are compared with results for inclusive jets, as well as with the predictions from the pythia and herwig++ event generators.Peer reviewe
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