862 research outputs found

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at s√=8 TeV with the ATLAS detector

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    The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1fb−1 of proton–proton collision data at √s = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t˜→tχ˜01 or t˜→ bχ˜±1 →bW(∗)χ˜01 , where χ˜01 (χ˜±1 ) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of t˜ → tχ˜01 . For a branching fraction of 100%, top squark masses in the range 270–645 GeV are excluded for χ˜01 masses below 30 GeV. For a branching fraction of 50% to either t˜ → tχ˜01 or t˜ → bχ˜±1 , and assuming the χ˜±1 mass to be twice the χ˜01 mass, top squark masses in the range 250–550 GeV are excluded for χ˜01 masses below 60 GeV

    Observation of associated near-side and away-side long-range correlations in √sNN=5.02  TeV proton-lead collisions with the ATLAS detector

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    Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁡2Δϕ modulation for all ΣETPb ranges and particle pT

    The view of teachers on bullying and implications for nursing

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    Objetivo: Compreender o bullying escolar, na perspectiva dos professores, e refletir sobre as possíveis ações da área da saúde em seu enfrentamento. Para tanto, tomaram- se por base as diretrizes do Programa Saúde na Escola, dos Ministérios da Saúde e da Educação. Método: Estudo de caso qualitativo, realizado com professores de uma escola pública de Minas Gerais. Foram utilizados grupos focais na coleta de dados e o material empírico foi decodificado a partir de técnica de análise temática de conteúdo, resultando em uma categoria analítica: concepções e experiências de professores diante do bullying. Resultados: Foram identificadas percepções pontuais sobre o fenômeno e utilização de recursos de intervenção pouco eficazes. No plano interpretativo, problematizaram-se as contribuições da saúde e da enfermagem no redimensionamento das intervenções e no processo de formação continuada dos professores. Conclusão: Os resultados apontam para a construção de práticas intersetoriais para o enfrentamento do bullying.To understand school bullying from the perspective of teachers and reflect about the possible actions of the health area when coping with it. The guidelines of the School Health Program of the Ministries of Health and Education were used to reach that purpose. Method: A qualitative study carried out with teachers of a public school in Minas Gerais. Focus groups were used to collect data and the empirical material was decoded from thematic analysis of content, resulting in an analytical category: conceptions and experiences of teachers on bullying. Results: Specific perceptions about the phenomenon and the use of ineffective intervention resources were identified. In the interpretive plan were problematized the health and nursing contributions with resizing the interventions and the continuing training process of teachers. Conclusion: The results point to the construction of intersectoral practices forcoping with bullying.Objetivo: Comprender el bullying escolar desde la perspectiva de los profesores, y reflexionar sobre las posibles acciones del área de salud en su enfrentamiento. Tomando como base los lineamientos del Programa de Salud Escolar, de los Ministerios de Salud y de Educación. Método: Estudio de caso cualitativo realizado con los profesores de una escuela pública en Minas Gerais. Para la recolección de datos se utilizaron grupos focales y el material empírico fue decodificado a partir de la técnica de análisis temático de contenido, dando lugar a una categoría analítica: concepciones y experiencias de los profesores sobre el acoso escolar. Resultados: Se identificaron percepciones específicas sobre el fenómeno y la utilización de recursos ineficaces de intervención. En el plano interpretativo, se problematizaron las contribuciones de la salud y de la enfermería en el redimensionamiento de las intervenciones y en el proceso de formación continua de los profesores. Conclusión: Los resultados apuntan a la construcción de prácticas intersectoriales para el enfrentamiento del bullying.CIEC - Centro de Investigação em Estudos da Criança, UM (UI 317 da FCT

    Search for R-parity-violating supersymmetry in events with four or more leptons in sqrt(s) =7 TeV pp collisions with the ATLAS detector

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    A search for new phenomena in final states with four or more leptons (electrons or muons) is presented. The analysis is based on 4.7 fb−1 of s=7  TeV \sqrt{s}=7\;\mathrm{TeV} proton-proton collisions delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in two signal regions: one that requires moderate values of missing transverse momentum and another that requires large effective mass. The results are interpreted in a simplified model of R-parity-violating supersymmetry in which a 95% CL exclusion region is set for charged wino masses up to 540 GeV. In an R-parity-violating MSUGRA/CMSSM model, values of m 1/2 up to 820 GeV are excluded for 10 < tan β < 40

    Measurement of the cross-section of high transverse momentum vector bosons reconstructed as single jets and studies of jet substructure in pp collisions at √s = 7 TeV with the ATLAS detector

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    This paper presents a measurement of the cross-section for high transverse momentum W and Z bosons produced in pp collisions and decaying to all-hadronic final states. The data used in the analysis were recorded by the ATLAS detector at the CERN Large Hadron Collider at a centre-of-mass energy of √s = 7 TeV;{\rm Te}{\rm V}andcorrespondtoanintegratedluminosityof and correspond to an integrated luminosity of 4.6\;{\rm f}{{{\rm b}}^{-1}}.ThemeasurementisperformedbyreconstructingtheboostedWorZbosonsinsinglejets.ThereconstructedjetmassisusedtoidentifytheWandZbosons,andajetsubstructuremethodbasedonenergyclusterinformationinthejetcentreofmassframeisusedtosuppressthelargemultijetbackground.ThecrosssectionforeventswithahadronicallydecayingWorZboson,withtransversemomentum. The measurement is performed by reconstructing the boosted W or Z bosons in single jets. The reconstructed jet mass is used to identify the W and Z bosons, and a jet substructure method based on energy cluster information in the jet centre-of-mass frame is used to suppress the large multi-jet background. The cross-section for events with a hadronically decaying W or Z boson, with transverse momentum {{p}_{{\rm T}}}\gt 320\;{\rm Ge}{\rm V}andpseudorapidity and pseudorapidity |\eta |\lt 1.9,ismeasuredtobe, is measured to be {{\sigma }_{W+Z}}=8.5\pm 1.7$ pb and is compared to next-to-leading-order calculations. The selected events are further used to study jet grooming techniques

    The Idealized Brazilian Health System versus the real one: contributions from the nursing field

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    OBJECTIVE: to identify the perceptions of professionals working in a facility connected with the Brazilian Unified Health System - SUS in regard to what they know, think and talk about public health policy.METHOD: this exploratory-descriptive study with a qualitative nature was conducted with 28 professionals working in a facility connected with the SUS. Data were collected through interviews with guiding questions and analyzed through the thematic content analysis technique.RESULTS: coded and interpreted data resulted in three thematic axes: The SUS - perfect web that does not work in practice; The recurrent habit of complaining about the SUS; The need to rethink the way of thinking about, acting in and managing the SUS.CONCLUSION: the professionals working for the SUS are aware of the principles and guidelines that govern the Brazilian health system, however, they reproduce a dichotomous and linear model of conception and practice strongly linked to the thinking of society in general

    Cuidado de enfermagem para enfermeiros docentes na perspectiva da complexidade

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    O cuidado de enfermagem complexo é condição essencial para a compreensão do ser humano como singular e multidimensional. Assim, objetivou-se conhecer o significado do cuidado de enfermagem para enfermeiros docentes, na perspectiva da complexidade. Trata-se de uma pesquisa qualitativa, realizada com sete enfermeiros docentes deum curso de enfermagem de nível superior da região central do Rio Grande do Sul, Brasil. Os dados foram coletados no mês de novembro de 2011, por meio do grupo focal, a partir de três encontros, sistematizados com temáticas que contemplassem o objetivo deste estudo. Para a análise de dados, foi utilizada a análise textual discursiva. Os resultados evidenciaram o cuidado de enfermagem como construção singular que vai além de um cuidado técnico-prescritivo, pontual e linear. Conclui-se que o cuidado de enfermagem não pode ser concebido como açãoreducionista, mas como construção singular, que envolve interações, reflexões e autoconhecimento

    Regulation of microRNA biogenesis and turnover by animals and their viruses

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    Item does not contain fulltextMicroRNAs (miRNAs) are a ubiquitous component of gene regulatory networks that modulate the precise amounts of proteins expressed in a cell. Despite their small size, miRNA genes contain various recognition elements that enable specificity in when, where and to what extent they are expressed. The importance of precise control of miRNA expression is underscored by functional studies in model organisms and by the association between miRNA mis-expression and disease. In the last decade, identification of the pathways by which miRNAs are produced, matured and turned-over has revealed many aspects of their biogenesis that are subject to regulation. Studies in viral systems have revealed a range of mechanisms by which viruses target these pathways through viral proteins or non-coding RNAs in order to regulate cellular gene expression. In parallel, a field of study has evolved around the activation and suppression of antiviral RNA interference (RNAi) by viruses. Virus encoded suppressors of RNAi can impact miRNA biogenesis in cases where miRNA and small interfering RNA pathways converge. Here we review the literature on the mechanisms by which miRNA biogenesis and turnover are regulated in animals and the diverse strategies that viruses use to subvert or inhibit these processes
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