562 research outputs found

    Andes Basin Focal Project

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    The CPWF Basin Focal Project for the Andes system of basins worked with a range of local stakeholders to develop a better understanding of the mechanisms for improving the productivity of water in the Andes. We considered productivity in broad terms as the productivity of energy (HEP), food and fiber (agriculture) and livelihoods (industry, transport and benefit sharing such as Payments for Environmental Services schemes (PES)). In addition to the compiled data bases and analyses on poverty and institutions, one of the key deliverables of the project was the development and deployment of the AguAAndes policy support system (PSS). This integrates analyses of water availability and productivity within the local environmental and policy context. It is a web-based policy support system combining an extensive spatial database with process-based models for hydrology, crop production and socio-economic processes. It is intended to allow analysts and decision makers to test the potential onsite and offsite impacts of land and water management decisions in terms of their ability to sustain environmental services and human wellbeing. Interventions and recommendations for future actions on water and food in the region are presented

    Epidemiología del tabaquismo en los estudiantes de ciencias de la salud

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    The characteristics of tobacco use by students of the Division of Health Sciences of the University of Barcelona have been studied. During the 1988-1989 school year, 382 students were individually interviewed about their use of tobacco by means of a questionnaire routinely used by the Department of Health and Social Security of the Generalitat of Catalonia (Spain), with pertinent modifications for this specific group. These interviews were performed by appropriately trained personnel. Information was also gathered on the influence of university-level studies on smoking habits, the effect of advertising and the efficacy of antitobacco programs and campaigns carried out by the government. The study sample was drawn from lists supplied by the registrars' offices, by means of a random sampling by school (Medicine, Pharmacy, Psychology, Odontology and Nursing). The prevalence of tobacco use was 40.8% (29.8% daily smokers and 11% occasional smokers). These results are similar to those described in the literature, although these values are somewhat higher than those in more developed countries with a longer tradition of resistance to the use of tobacco. It is important to note that studying health sciences does not appera to be a major influence on the student's habits, but that the social and cultural environment is the factor which weighs the most in this respect. In conclusion, to reduce the prevalence of tobacco use in this important group, educational programs must be begun at the pre-university level (secundary school) and changes should be made in the curricula of the health professional so that areas related to tobacco use are more motivational for students.Las características del hábito tabáquico en los estudiantes de la División de Ciencias de la Salud de la Universidad de Barcelona han sido estudiadas en este trabajo. Durante el Curso Académico 1988-89, 382 alumnos han sido entrevistados individualmente en relación al tabaquismo, mediante el cuestionario utilizado habitualmente por el Departamento de Sanidad y Segundad Social de la Generalidad de Cataluña (España), con las modificaciones más oportunas para este colectivo específico. Asimismo se ha recogido información relacionada con la influencia de los estudios universitarios en el hábito de fumar, la autorización de la publicidad y la eficacia de los programas y campañas de lucha antitabaco desarrollados por las Administraciones públicas. La prevalencia de tabaquismo ha sido del 40,8% (29,8% de fumadores habituales y 11% de fumadores ocasionales). Hay que remarcar que los estudios relacionados con la salud no parecen influir de forma destacada en el hábito de los estudiantes, siendo el entorno cultural y social los factores que tienen un papel más determinante en este sentido. Como conclusión final señalar que, para disminuir la prevalencia de tabaquismo en este importante colectivo, hay que instaurar programas educativos a nivel de la escolarización pre-universitaria (bachillerato unificado polivalente y curso de orientación universitaria), e introducir modificaciones en los futuros planes de estudio de las profesiones sanitarias, de manera que los contenidos relacionados con el tabaco sean más motivadores para los alumnos.Foram estudadas as características do habito de fumar nos estudantes de ciências da saúde da Universidade de Barcelona. Durante o ano letivo 1988-89 foram entrevistados 382 alunos em relação ao uso do fumo, por meio de questionário rotinamente utilizado por um Departamento daquela Universidade, no qual foram efetuadas modificações pertinentes ao grupo estudado. Foram obtidas informações relacionadas com a influência dos estudos universitários no hábito de fumar, com os efeitos da publicidade e com a eficácia dos programas e das campanhas da luta anti-fumo desenvolvidos pelas administrações públicas. A amostra foi obtida a partir das listagens fornecidas pelas diferentes secretarias administrativas, por meio de uma amostragem aleatória estratificada por Faculdades (Medicina, Farmácia, Psicologia, Odontologia e Enfermagem). A prevalência do tabagismo foi de 40,8% (29,8% de fumantes habituais e 11% ocasionais). Os estudos relacionados com a saúde não parecem influir, de um forma destacada, no hábito dos estudantes, sendo o meio cultural e social o fator que exerce papel mais determinante nesse sentido. Assinala-se que, para poder diminuir a prevalência do fumo nesse importante grupo, devem-se iniciar programas educativos ao nível de escolarização pré-universitária (bacharelato unificado polivalente e curso de orientação universitária) e introduzir modificações nos futuros planos de estudo das profissões sanitárias, de forma a que os conteúdos relacionados com o fumo sejam canais motivadores para os alunos

    Measurements of long-range near-side angular correlations in sNN=5\sqrt{s_{\text{NN}}}=5TeV proton-lead collisions in the forward region

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    Two-particle angular correlations are studied in proton-lead collisions at a nucleon-nucleon centre-of-mass energy of sNN=5\sqrt{s_{\text{NN}}}=5TeV, collected with the LHCb detector at the LHC. The analysis is based on data recorded in two beam configurations, in which either the direction of the proton or that of the lead ion is analysed. The correlations are measured in the laboratory system as a function of relative pseudorapidity, Δη\Delta\eta, and relative azimuthal angle, Δϕ\Delta\phi, for events in different classes of event activity and for different bins of particle transverse momentum. In high-activity events a long-range correlation on the near side, Δϕ0\Delta\phi \approx 0, is observed in the pseudorapidity range 2.0<η<4.92.0<\eta<4.9. This measurement of long-range correlations on the near side in proton-lead collisions extends previous observations into the forward region up to η=4.9\eta=4.9. The correlation increases with growing event activity and is found to be more pronounced in the direction of the lead beam. However, the correlation in the direction of the lead and proton beams are found to be compatible when comparing events with similar absolute activity in the direction analysed.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-040.htm

    Study of the production of Λb0\Lambda_b^0 and B0\overline{B}^0 hadrons in pppp collisions and first measurement of the Λb0J/ψpK\Lambda_b^0\rightarrow J/\psi pK^- branching fraction

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    The product of the Λb0\Lambda_b^0 (B0\overline{B}^0) differential production cross-section and the branching fraction of the decay Λb0J/ψpK\Lambda_b^0\rightarrow J/\psi pK^- (B0J/ψK(892)0\overline{B}^0\rightarrow J/\psi\overline{K}^*(892)^0) is measured as a function of the beauty hadron transverse momentum, pTp_{\rm T}, and rapidity, yy. The kinematic region of the measurements is pT<20 GeV/cp_{\rm T}<20~{\rm GeV}/c and 2.0<y<4.52.0<y<4.5. The measurements use a data sample corresponding to an integrated luminosity of 3 fb13~{\rm fb}^{-1} collected by the LHCb detector in pppp collisions at centre-of-mass energies s=7 TeV\sqrt{s}=7~{\rm TeV} in 2011 and s=8 TeV\sqrt{s}=8~{\rm TeV} in 2012. Based on previous LHCb results of the fragmentation fraction ratio, fΛB0/fdf_{\Lambda_B^0}/f_d, the branching fraction of the decay Λb0J/ψpK\Lambda_b^0\rightarrow J/\psi pK^- is measured to be \begin{equation*} \mathcal{B}(\Lambda_b^0\rightarrow J/\psi pK^-)= (3.17\pm0.04\pm0.07\pm0.34^{+0.45}_{-0.28})\times10^{-4}, \end{equation*} where the first uncertainty is statistical, the second is systematic, the third is due to the uncertainty on the branching fraction of the decay B0J/ψK(892)0\overline{B}^0\rightarrow J/\psi\overline{K}^*(892)^0, and the fourth is due to the knowledge of fΛb0/fdf_{\Lambda_b^0}/f_d. The sum of the asymmetries in the production and decay between Λb0\Lambda_b^0 and Λb0\overline{\Lambda}_b^0 is also measured as a function of pTp_{\rm T} and yy. The previously published branching fraction of Λb0J/ψpπ\Lambda_b^0\rightarrow J/\psi p\pi^-, relative to that of Λb0J/ψpK\Lambda_b^0\rightarrow J/\psi pK^-, is updated. The branching fractions of Λb0Pc+(J/ψp)K\Lambda_b^0\rightarrow P_c^+(\rightarrow J/\psi p)K^- are determined.Comment: 29 pages, 19figures. All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-032.htm

    Evidence for the strangeness-changing weak decay ΞbΛb0π\Xi_b^-\to\Lambda_b^0\pi^-

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    Using a pppp collision data sample corresponding to an integrated luminosity of 3.0~fb1^{-1}, collected by the LHCb detector, we present the first search for the strangeness-changing weak decay ΞbΛb0π\Xi_b^-\to\Lambda_b^0\pi^-. No bb hadron decay of this type has been seen before. A signal for this decay, corresponding to a significance of 3.2 standard deviations, is reported. The relative rate is measured to be fΞbfΛb0B(ΞbΛb0π)=(5.7±1.80.9+0.8)×104{{f_{\Xi_b^-}}\over{f_{\Lambda_b^0}}}{\cal{B}}(\Xi_b^-\to\Lambda_b^0\pi^-) = (5.7\pm1.8^{+0.8}_{-0.9})\times10^{-4}, where fΞbf_{\Xi_b^-} and fΛb0f_{\Lambda_b^0} are the bΞbb\to\Xi_b^- and bΛb0b\to\Lambda_b^0 fragmentation fractions, and B(ΞbΛb0π){\cal{B}}(\Xi_b^-\to\Lambda_b^0\pi^-) is the branching fraction. Assuming fΞb/fΛb0f_{\Xi_b^-}/f_{\Lambda_b^0} is bounded between 0.1 and 0.3, the branching fraction B(ΞbΛb0π){\cal{B}}(\Xi_b^-\to\Lambda_b^0\pi^-) would lie in the range from (0.57±0.21)%(0.57\pm0.21)\% to (0.19±0.07)%(0.19\pm0.07)\%.Comment: 7 pages, 2 figures, All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-047.htm

    BB flavour tagging using charm decays at the LHCb experiment

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    An algorithm is described for tagging the flavour content at production of neutral BB mesons in the LHCb experiment. The algorithm exploits the correlation of the flavour of a BB meson with the charge of a reconstructed secondary charm hadron from the decay of the other bb hadron produced in the proton-proton collision. Charm hadron candidates are identified in a number of fully or partially reconstructed Cabibbo-favoured decay modes. The algorithm is calibrated on the self-tagged decay modes B+J/ψK+B^+ \to J/\psi \, K^+ and B0J/ψK0B^0 \to J/\psi \, K^{*0} using 3.0fb13.0\mathrm{\,fb}^{-1} of data collected by the LHCb experiment at pppp centre-of-mass energies of 7TeV7\mathrm{\,TeV} and 8TeV8\mathrm{\,TeV}. Its tagging power on these samples of BJ/ψXB \to J/\psi \, X decays is (0.30±0.01±0.01)%(0.30 \pm 0.01 \pm 0.01) \%.Comment: All figures and tables, along with any supplementary material and additional information, are available at http://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-027.htm

    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

    Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS

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    The chi_b(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4 fb^-1, these states are reconstructed through their radiative decays to Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes. This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table, corrected author list, matches final version in Physical Review Letter

    Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

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    We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters

    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
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