762 research outputs found

    Les principes de la cynégétique en forêt.

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    La cynégétique a pour objet d'améliorer les méthodes de gestion des espèces animales terrestres exploitées et de leurs habitats. Les principes de base indispensables à la réalisation des objectifs sont résumés en insistant sur les méthodes de suivi des populations : cynégétique démographique et dynamique des populations; stratégies biodémographiques; éthologie notamment comportement social. La cynégétique de demain devra contribuer à la conservation de la biodiversité et des équilibres biologiques

    La place de la chasse dans les espaces méditerranéens du IIIe millénaire (résumé).

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    La région méditerranéenne : espace "naturel" producteur de faune sauvage

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    A l'occasion de la publication du n°100 de la revue Forêt Méditerranéenne, il a été demandé aux grandes institutions nationales qu'elles nous présentent leur vision des espaces forestiers méditerranéens "depuis Paris". Cet article nous donne le regard porté par les chasseurs (Institut méditerranéen du patrimoine cynégétique et faunistique) sur la forêt méditerranéenne

    Levantamento fitossociológico de plantas daninhas em cafezal orgânico.

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    A adequação de um cafezal para o sistema orgânico causa grande mudança no sistema de manejo de plantas daninhas, mas as informações sobre o comportamento da comunidade infestante em áreas de cultivo de café orgânico são escassas no Brasil. Objetivou-se com este trabalho realizar um levantamento fitossociológico da comunidade infestante em três cafezais (variedades Mundo Novo, Bourbon Vermelho e Obatã) desenvolvidos em sistema orgânico, no município de Garça (SP). Nas três áreas estudadas foram arremessados ao acaso cem quadrados metálicos com área vazada de 0,25 m2, nas entrelinhas da cultura. As espécies contidas no interior dos quadros foram identificadas segundo a espécie botânica, nome popular e família. A partir dos resultados, determinaram-se os parâmetros fitossociológicos: frequência, densidade, abundância, frequência relativa, densidade relativa, abundância relativa, índice de valor de importância e similaridade florísticas pelos métodos de Simple Matching de Sneath & Sokal e similaridade de Sorensen. As famílias que mais se destacaram, com maior número de espécies nas três áreas foram Poaceae e Asteraceae. Houve alta similaridade em todos os contrastes testados, já que pelo menos metade das espécies identificadas foi comum às duas áreas contrastadas

    Observation of Scaling Violations in Scaled Momentum Distributions at HERA

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    Charged particle production has been measured in deep inelastic scattering (DIS) events over a large range of xx and Q2Q^2 using the ZEUS detector. The evolution of the scaled momentum, xpx_p, with Q2,Q^2, in the range 10 to 1280 GeV2GeV^2, has been investigated in the current fragmentation region of the Breit frame. The results show clear evidence, in a single experiment, for scaling violations in scaled momenta as a function of Q2Q^2.Comment: 21 pages including 4 figures, to be published in Physics Letters B. Two references adde

    A First Search for coincident Gravitational Waves and High Energy Neutrinos using LIGO, Virgo and ANTARES data from 2007

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    We present the results of the first search for gravitational wave bursts associated with high energy neutrinos. Together, these messengers could reveal new, hidden sources that are not observed by conventional photon astronomy, particularly at high energy. Our search uses neutrinos detected by the underwater neutrino telescope ANTARES in its 5 line configuration during the period January - September 2007, which coincided with the fifth and first science runs of LIGO and Virgo, respectively. The LIGO-Virgo data were analysed for candidate gravitational-wave signals coincident in time and direction with the neutrino events. No significant coincident events were observed. We place limits on the density of joint high energy neutrino - gravitational wave emission events in the local universe, and compare them with densities of merger and core-collapse events.Comment: 19 pages, 8 figures, science summary page at http://www.ligo.org/science/Publication-S5LV_ANTARES/index.php. Public access area to figures, tables at https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=p120000

    Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

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    This paper presents measurements of the W+μ+νW^+ \rightarrow \mu^+\nu and WμνW^- \rightarrow \mu^-\nu cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

    The gravitational wave detector VIRGO

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    The Virgo data acquisition system

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