10,098 research outputs found

    Study of psi' and chi_c decays as feed-down sources of J/psi hadro-production

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    The interpretation of the J/psi suppression patterns observed in nuclear collisions, at CERN and RHIC, as a signature of the formation of a deconfined phase of QCD matter, requires knowing which fractions of the measured J/psi yields, in pp collisions, are due to decays of heavier charmonium states. From a detailed analysis of the available mid-rapidity charmonium hadro-production cross sections, or their ratios, we determine that the J/psi feed-down contributions from psi' and chi_c decays are, respectively, (8.1 +/- 0.3) % and (25 +/- 5) %. These proton-proton values are derived from global averages of the proton-nucleus measurements, assuming that the charmonium states are exponentially absorbed with the length of matter they traverse in the nuclear targets.Comment: 12 pages, 4 figures, 3 table

    Cartilha - palestra sobre ferrugem asiática da soja.

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    Esta palestra trata de aspectos da ferrugem asiática da soja: uma doença recente no Brasil e com alto potencial de dano.bitstream/item/56144/1/ID-26146.pd

    Caracterização das explorações de ovinos Serra da Estrela

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    A raça ovina serra da estrela tem o seu solar ao largo da nascente da bacia hidrográfica do rio Mondego. Com um efectivo actual de cerca de 90000 cabeças e encabeçamento de 35,8, esta raça autóctone de vocação predominantemente leiteira, apresenta na rusticidade, uma característica fundamental para a sua adaptação ao sistema semi-extensivo em que é explorada. A alimentação é feita à base de pastagens naturais e melhoradas, forragens e concentrados apenas durante o alavão. Nos ovis predominam as construções próprias para o efeito, utilizando tanto o sistema de camas de mato ou palha, como o ripado. As condições higiosanitárias da maioria das explorações são ainda muito deficitárias quer ao nível da qualidade das estruturas quer ao nível do maneio dos animais. Aquando da selecção das explorações foram tomados em conta, entre outros, critérios como a dimensão do efectivo, a indemnidade em relação à Brucelose, o tipo de maneio, bem como a existência de suspeita clínica O sobredimensionamento das explorações, a não existência de maternidades e parques de recria, comedouros e bebedouros mal dimensionados, a ausência de instalações para isolamento de animais doentes ou suspeitos, foram também identificados como factores predisponentes ao aparecimento e manutenção nas explorações de doenças com características epidemiológicas semelhantes à paratuberculose. O exame clínico de alguns animais destas explorações revelou a existência de animais com acentuadas quebras de produção, emagrecimento progressivo, diarreia terminal e edema intermandibular, compatíveis com um quadro sintomático de Paratuberculose ovina.Agradecimentos: Ao Projecto Agro 786, Medida 8. Desenvolvimento Tecnológico e Demonstração. Acção 8.1-Desenvolvimento Experimental e Demonstração, bem como a todas as entidades nele interveniente

    Heavy-ion Physics at a Fixed-Target Experiment Using the LHC Proton and Lead Beams (AFTER@LHC): Feasibility Studies for Quarkonium and Drell-Yan Production

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    We outline the case for heavy-ion-physics studies using the multi-TeV lead LHC beams in the fixed-target mode. After a brief contextual reminder, we detail the possible contributions of AFTER@LHC to heavy-ion physics with a specific emphasis on quarkonia. We then present performance simulations for a selection of observables. These show that Υ(nS)\Upsilon(nS), J/ψJ/\psi and ψ(2S)\psi(2S) production in heavy-ion collisions can be studied in new energy and rapidity domains with the LHCb and ALICE detectors. We also discuss the relevance to analyse the Drell-Yan pair production in asymmetric nucleus-nucleus collisions to study the factorisation of the nuclear modification of partonic densities and of further quarkonia to restore their status of golden probes of the quark-gluon plasma formation.Comment: 18 pages, 7 figure

    First report of a linezolid-resistant MRSA (methicillin resistant Staphylococcus aureus) isolated from a dog with a severe bilateral otitis in Portugal

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    The widespread use of antimicrobials has lead to the emergence of resistant bacteria to one or more antibiotic, including new drugs like linezolid. This antimicrobial is the first of the oxazolidinone group and soon after its approval in 2000, linezolid-resistant MRSA and linezolid vancomycin-resistant enterococci have emerged. Several outbreaks of linezolid-resistant MRSA have been reported worldwide but, to our knowledge, this is the first report of a linezolid-resistant MRSA isolated from a dog in Portugal. The animal arrived at the Teaching Hospital of the Faculty of Veterinary Medicine, Technical University of Lisboa with a severe bilateral otitis that was refractory to antibiotic therapy. Bacteriology showed that the infection was caused by a multiresistant Staphylococcus aureus strain that also phenotipically expressed other virulence factors. Besides the challenge to practitioners, the isolation of this strain is of pub­lic health concern due to its antimicrobial resistant profile.

    A Expressão Global da Doença de Chagas – Oportunidades Emergentes e Impacto em Portugal

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    Chagas disease, caused by the protozoan Trypanosoma cruzi is endemic in the countries of Central and South America. Despite vector control programs and other measures taken in the blood banks and maternity hospitals, it is estimated that there are about eight million people infected worldwide. Although traditionally associated with rural life and poverty, the current migration flows transform it into a global public health problem. In Portugal, this problem is poorly known, with an estimated underdiagnosis index that exceeds 99%. In European countries, besides imported cases, autochthonous infections arise through vertical transmission and blood/organ donation.The conventional serological tests for diagnosing Chagas disease and verifying its cure are indirect hemagglutination (IHA), indirect immunofluorescence (IFAT), and enzyme-linked immunoabsorbent assay (ELISA).The hypothesis of autoimmunity as a basic mechanism of this disease and the absence of early markers of cure are the causes of controversy regarding the specific treatment of this disease. The currently available drugs have adverse effects on a large number of patients and parasitological efficacy in chronic disease is suboptimal.The authors reinforce the need of a high level of suspicion in patients with suggestive epidemiology and the need of populational screening of specific high risk groups
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