103 research outputs found

    Wild birds as pets in Campina Grande, Paraíba State, Brazil: An Ethnozoological Approach

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    Birds are one of the animals most widely used by humans and are highly valued as pets. The present work reports the use of wild birds as pets in the city of Campina Grande, Paraíba State (PB), Brazil. The owners' choice and perceptions of the species ecology was assessed as well. The methodology employed included unstructured and semi-structured interviews, guided tours and direct observations. A total of 26 bird species distributed among ten families and four orders were identified. The most frequently encountered order was Passeriformes (76.9%), with a predominance of the family Emberizidae (34.6%). The specimens kept as pets were principally obtained in public markets or between the breeders themselves. The popularity of birds as pets, compounded by the inefficiency of official controls over the commerce of wild animals has stimulated the illegal capture and breeding of wild birds in Campina Grande

    Ecological Guild Evolution and the Discovery of the World's Smallest Vertebrate

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    Living vertebrates vary drastically in body size, yet few taxa reach the extremely minute size of some frogs and teleost fish. Here we describe two new species of diminutive terrestrial frogs from the megadiverse hotspot island of New Guinea, one of which represents the smallest known vertebrate species, attaining an average body size of only 7.7 mm. Both new species are members of the recently described genus Paedophryne, the four species of which are all among the ten smallest known frog species, making Paedophryne the most diminutive genus of anurans. This discovery highlights intriguing ecological similarities among the numerous independent origins of diminutive anurans, suggesting that minute frogs are not mere oddities, but represent a previously unrecognized ecological guild

    Avaliação funcional do sistema vestibular de cobaias intoxicadas agudamente por organofosforado por meio da prova calórica

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    OBJETIVO:avaliar o funcionamento do sistema vestibular de cobaias expostas ao organofosforado clorpirifós, de forma aguda, por meio da prova calórica da eletronistagmografia.MÉTODOS:a pesquisa do tipo experimental realizou a eletronistagmografia de cobaias expostas a organofosforado durante 10 dias consecutivos, nas doses 0,5mg/kg/dia e 1,0mg/kg/dia por via intraperitoneal e comparadas com grupo controle que recebeu administração de água destilada. Foi realizada prova calórica gelada (10ºC) e comparadas as variáveis frequência de aparecimento de nistagmos em 10 segundos (u/s) e velocidade angular da componente lenta (º/s).RESULTADOS:os resultados não demonstraram diferença estatisticamente significante na comparação das variáveis entre os grupos.CONCLUSÃO:conclui-se que nas doses testadas o agrotóxico organofosforado clorpirifós não causou danos funcionais detectáveis na prova calórica

    Measurement of the associated production of a Higgs boson decaying into b-quarks with a vector boson at high transverse momentum in pp collisions at s=13\sqrt{s}=13 TeV with the ATLAS detector

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    The associated production of a Higgs boson with a W or Z boson decaying into leptons and where the Higgs boson decays to a pair is measured in the high vector-boson transverse momentum regime, above 250 GeV, with the ATLAS detector. The analysed data, corresponding to an integrated luminosity of , were collected in proton–proton collisions at the Large Hadron Collider between 2015 and 2018 at a centre-of-mass energy of . The measured signal strength, defined as the ratio of the measured signal yield to that predicted by the Standard Model, is corresponding to an observed (expected) significance of 2.1 (2.7) standard deviations. Cross-sections of associated production of a Higgs boson decaying into b quark pairs with a W or Z gauge boson, decaying into leptons, are measured in two exclusive vector boson transverse momentum regions, 250–400 GeV and above 400 GeV, and interpreted as constraints on anomalous couplings in the framework of a Standard Model effective field theory

    Medium-Induced Modification of Z-Tagged Charged Particle Yields in Pb+Pb Collisions at 5.02 TeV with the ATLAS Detector

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    The yield of charged particles opposite to a Z boson with large transverse momentum ( p T ) is measured in 260     pb − 1 of p p and 1.7     nb − 1 of Pb + Pb collision data at 5.02 TeV per nucleon pair recorded with the ATLAS detector at the Large Hadron Collider. The Z boson tag is used to select hard-scattered partons with specific kinematics, and to observe how their showers are modified as they propagate through the quark-gluon plasma created in Pb + Pb collisions. Compared with p p collisions, charged-particle yields in Pb + Pb collisions show significant modifications as a function of charged-particle p T in a way that depends on event centrality and Z boson p T . The data are compared with a variety of theoretical calculations and provide new information about the medium-induced energy loss of partons in a p T regime difficult to measure through other channels

    Measurements of differential cross-sections in top-quark pair events with a high transverse momentum top quark and limits on beyond the Standard Model contributions to top-quark pair production with the ATLAS detector at √s = 13 TeV

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    Cross-section measurements of top-quark pair production where the hadronically decaying top quark has transverse momentum greater than 355 GeV and the other top quark decays into ℓνb are presented using 139 fb−1 of data collected by the ATLAS experiment during proton-proton collisions at the LHC. The fiducial cross-section at s = 13 TeV is measured to be σ = 1.267 ± 0.005 ± 0.053 pb, where the uncertainties reflect the limited number of data events and the systematic uncertainties, giving a total uncertainty of 4.2%. The cross-section is measured differentially as a function of variables characterising the tt¯ system and additional radiation in the events. The results are compared with various Monte Carlo generators, including comparisons where the generators are reweighted to match a parton-level calculation at next-to-next-to-leading order. The reweighting improves the agreement between data and theory. The measured distribution of the top-quark transverse momentum is used to search for new physics in the context of the effective field theory framework. No significant deviation from the Standard Model is observed and limits are set on the Wilson coefficients of the dimension-six operators OtG and Otq(8), where the limits on the latter are the most stringent to date. [Figure not available: see fulltext.]

    Measurements of Higgs bosons decaying to bottom quarks from vector boson fusion production with the ATLAS experiment at √=13TeV

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    The paper presents a measurement of the Standard Model Higgs Boson decaying to b-quark pairs in the vector boson fusion (VBF) production mode. A sample corresponding to 126 fb−1 of s√=13TeV proton–proton collision data, collected with the ATLAS experiment at the Large Hadron Collider, is analyzed utilizing an adversarial neural network for event classification. The signal strength, defined as the ratio of the measured signal yield to that predicted by the Standard Model for VBF Higgs production, is measured to be 0.95+0.38−0.36 , corresponding to an observed (expected) significance of 2.6 (2.8) standard deviations from the background only hypothesis. The results are additionally combined with an analysis of Higgs bosons decaying to b-quarks, produced via VBF in association with a photon
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