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

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

O estresse entre enfermeiros que atuam em Unidade de Terapia Intensiva El estrés entre enfermeros que actúan en las Unidades de Terapia Intensiva Stress among nurses who work at the intensive care unit

A presença de estresse tem sido verificada em diferentes profissionais e também entre enfermeiros de UTI, pelo fato de ser grande sua proximidade com os pacientes em sofrimento e com risco de morte. Esse fato se agrava devido à necessidade de cuidados diretos e intensivos. Este estudo, seguindo uma metodologia quantitativa, objetivou caracterizar os enfermeiros que desenvolvem suas atividades em UTI e verificar a presença de estresse entre eles. Para isso, vinte e um enfermeiros de UTIs de cinco hospitais do interior do estado de São Paulo responderam a um roteiro de perguntas direcionadas a sua caracterização e ao Inventário do Estresse em Enfermeiros. Os resultados mostraram que 57,1% dos enfermeiros estudados consideraram a UTI um local estressante e 23,8% deles apresentaram um escore elevado, indicando a presença de estresse. Tal fato demonstra que o estresse, mesmo sendo discutido desde longa data, ainda acomete esses profissionais, e as instituições ainda não oferecem atenção especial aos enfermeiros no sentido de promover sua saúde integral.<br>La presencia de estrés ha sido verificada en diferentes profesionales y también entre enfermeros de UTIs, debido al hecho de su gran proximidad con los pacientes en sufrimiento y con riesgo de muerte. Ese hecho se agrava debido a la necesidad de prestar cuidados directos e intensivos. Este estudio, siguiendo una metodología cuantitativa, objetivó caracterizar los enfermeros que desarrollan sus actividades en la UTI y verificar la presencia de estrés entre ellos. Para esto, veintiún enfermeros de UTIs de cinco hospitales del interior del estado de São Paulo respondieron un cuestionario de preguntas dirigidas a su caracterización y al Inventario del Estrés en Enfermeros. Los resultados mostraron que 57,1% de los enfermeros estudiados consideraron la UTI un local causador de estrés y 23,8% de ellos presentaron un puntaje elevado, indicando la presencia de estrés. Este hecho demuestra que el estrés, inclusive siendo discutido desde hace mucho tiempo, todavía acomete a esos profesionales, y las instituciones todavía no ofrecen atención especial a los enfermeros en el sentido de promover su salud integral.<br>Stress has been observed among various professionals, including intensive care unit (ICU) nurses, due to their close contact with patients in distress and at the risk of death. This situation becomes worse due to the need for direct and intensive care. This study was performed to characterize nurses working at ICU and verify the presence of stress among them. A total of 21 ICU nurses from five hospitals located in the state of São Paulo answered a series of questions about the ICU and completed the Nurse Stress Inventory. Study results showed that 57.1% of nurses consider the ICU a stressful place, and 23.8% achieved a high score, indicating the presence of stress. Stress continues to affect these professionals, and institutions do not offer any special care for nurses in the sense of promoting comprehensive health care

Measurement of the inclusive isolated prompt photon cross section in pp collisions at √s=7 TeV with the ATLAS detector

A measurement of the 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 |etaγ|<1.37 and 1.52≤|etaγ|<1.81 in the transverse energy range 15≤ETγ<100  GeV. The results are based on an integrated luminosity of 880  nb-1, collected with the ATLAS detector at the Large Hadron Collider. Photon candidates are identified by combining information from the calorimeters and from the inner tracker. Residual background in the selected sample is estimated from data based on the observed distribution of the transverse isolation energy in a narrow cone around the photon candidate. The results are compared to predictions from next-to-leading-order perturbative QCD calculations.United States. Dept. of EnergyNational Science Foundation (U.S.