146 research outputs found

    Perfil hematológico, bioquímico sérico, proteína C reativa e cortisol de ararajubas (Guaroba guarouba) mantidas em cativeiro

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    Objetivou-se determinar os valores hematolĂłgicos, bioquĂ­micos sĂ©ricos, proteĂ­na C reativa e cortisol de 14 ararajubas (Guaroba guarouba) clinicamente saudĂĄveis mantidas em cativeiro no zoolĂłgico do Parque Estadual de Dois IrmĂŁos Recife/PE. Amostras de sangue foram obtidas da veia jugular com volume mĂ©dio de 0,8ml, fracionando em duas porçÔes, a primeira depositada em tubo MiniCollectÂźCE contendo EDTA e a outra tubo com gel separador, para a separação do soro sanguĂ­neo. Os indicadores bioquĂ­micos e PCR foram determinados atravĂ©s do analisador ARCHITECT c8000. O cortisol foi analisado no Cobas E411 da Roche. Para a determinação dos nĂșmeros de eritrĂłcitos e leucĂłcitos, foi utilizada a metodologia da contagem em cĂąmara de Neubauer. O hematĂłcrito foi avaliado pelo mĂ©todo do microhematĂłcrito e a hemoglobina pelo mĂ©todo da cianometahemoglobulina. Para a contagem diferencial de leucĂłcitos, foi utilizada a tĂ©cnica de Shilling. Os Ă­ndices hematimĂ©tricos (VCM, HCM E CHCM) foram determinados com os valores encontrados na sĂ©rie eritrocĂ­tica. Os dados foram caracterizados por dispersĂŁo de freqĂŒĂȘncias, utilizando-se as seguintes medidas de tendĂȘncia central: MĂ©dia, desvio-padrĂŁo, mediana e percentil de 25 e percentil 75. A determinação de alguns parĂąmetros como ferro, triglicerĂ­deos, PCR e cortisol foram identificados como sendo pioneiramente referenciados nesta espĂ©cie de ave. Os dados sĂŁo apresentados como sendo de referĂȘncia para a ararajuba (Guaroba guarouba) criada em cativeiro em condiçÔes similares de manejo e higidez e ainda pode contribuir para os trabalhos de conservação ex situ desta espĂ©cie

    Memory retrieval improvement by Heteropterys aphrodisiaca in aging rats

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    Few data exists about the pharmacological properties of Heteropterys aphrodisiaca O. Mach. (Malpighiaceae), which is native to the scrubland regions of Brazil. The present study investigated the effects of oral treatment with H. aphrodisiaca extract (BST0298) on the learning and memory of young (3-6 months) and aged (21-23 months) rats, and compared the in vitro antioxidant activity of three lots collected in different years. An improvement in the number of sessions to learn the task was observed in the left/right discrimination test in aged rats treated for 45 days with 25 mg/kg (7.0 ± 0.5; p=0.005) or 50 mg/kg (7.6 ± 0.6; p=0.012) compared with control old rats (11.0 ± 1.6). On the other hand, pre-treatment did not improve the performance of scopolamine-treated mice in the passive avoidance test. The in vitro malondialdehyde test showed that all three different extracts presented similar antioxidant activity. The flavonoids astilbin, isoastilbin and neoastilbin were isolated from the extract and may contribute to the biological activity. These results suggest that repeated treatment with H. aphrodisiaca improves learning and memory, probably by a non-muscarinic mechanism.Existem poucos dados disponĂ­veis sobre as propriedades farmacolĂłgicas da Heteropterys aphrodisiaca O. Mach. (Malpighiaceae), nativa da regiĂŁo do pantanal brasileiro. O presente estudo investigou o efeito do tratamento oral com um extrato de H. aphrodisiaca (BST0298) sobre a memĂłria e aprendizagem de ratos jovens (3-6 meses) e idosos (21-23 meses) e comparou a atividade antioxidante in vitro de trĂȘs lotes, coletados em diferentes anos. Melhora quanto ao nĂșmero de sessĂ”es necessĂĄrias para aprender a tarefa foi observada no teste de discriminação direita/esquerda em ratos idosos tratados por 45 dias com doses de 25 mg/kg (7,0 ± 0,5; p=0,005) e 50 mg/kg (7,6 ± 0,6; p=0,012) comparados com ratos idosos controle (11,0 ± 1,6). Por outro lado, o prĂ©-tratamento com o extrato nĂŁo melhorou o desempenho de camundongos tratados com escopolamina no teste da esquiva passiva. Em relação Ă  avaliação da atividade antioxidante in vitro pelo teste do malonodialdeĂ­do, os trĂȘs lotes analisados apresentaram atividade antioxidante semelhante. Os flavonĂłides astilbina, isoastilbina e neoastilbina foram isolados do extrato e podem contribuir para a atividade biolĂłgica. Estes resultados sugerem que a administração repetida de H. aphrodisiaca melhora a memĂłria e aprendizagem provavelmente por um mecanismo nĂŁo muscarĂ­nico

    ϒ production in p–Pb collisions at √sNN=8.16 TeV

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    ϒ production in p–Pb interactions is studied at the centre-of-mass energy per nucleon–nucleon collision √sNN = 8.16 TeV with the ALICE detector at the CERN LHC. The measurement is performed reconstructing bottomonium resonances via their dimuon decay channel, in the centre-of-mass rapidity intervals 2.03 < ycms < 3.53 and −4.46 < ycms < −2.96, down to zero transverse momentum. In this work, results on the ϒ(1S) production cross section as a function of rapidity and transverse momentum are presented. The corresponding nuclear modification factor shows a suppression of the ϒ(1S) yields with respect to pp collisions, both at forward and backward rapidity. This suppression is stronger in the low transverse momentum region and shows no significant dependence on the centrality of the interactions. Furthermore, the ϒ(2S) nuclear modification factor is evaluated, suggesting a suppression similar to that of the ϒ(1S). A first measurement of the ϒ(3S) has also been performed. Finally, results are compared with previous ALICE measurements in p–Pb collisions at √sNN = 5.02 TeV and with theoretical calculations.publishedVersio

    Observation of quantum entanglement with top quarks at the ATLAS detector

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    Entanglement is a key feature of quantum mechanics with applications in fields such as metrology, cryptography, quantum information and quantum computation. It has been observed in a wide variety of systems and length scales, ranging from the microscopic to the macroscopic. However, entanglement remains largely unexplored at the highest accessible energy scales. Here we report the highest-energy observation of entanglement, in top–antitop quark events produced at the Large Hadron Collider, using a proton–proton collision dataset with a centre-of-mass energy of √s = 13 TeV and an integrated luminosity of 140 inverse femtobarns (fb)−1 recorded with the ATLAS experiment. Spin entanglement is detected from the measurement of a single observable D, inferred from the angle between the charged leptons in their parent top- and antitop-quark rest frames. The observable is measured in a narrow interval around the top–antitop quark production threshold, at which the entanglement detection is expected to be significant. It is reported in a fiducial phase space defined with stable particles to minimize the uncertainties that stem from the limitations of the Monte Carlo event generators and the parton shower model in modelling top-quark pair production. The entanglement marker is measured to be D = −0.537 ± 0.002 (stat.) ± 0.019 (syst.) for 340 GeV < mtt < 380 GeV. The observed result is more than five standard deviations from a scenario without entanglement and hence constitutes the first observation of entanglement in a pair of quarks and the highest-energy observation of entanglement so far

    Measurements of the production cross-section for a Z boson in association with b- or c-jets in proton–proton collisions at √s = 13 TeV with the ATLAS detector

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    This paper presents a measurement of the production cross-section of a Z boson in association with bor c-jets, in proton–proton collisions at √s = 13 TeV with the ATLAS experiment at the Large Hadron Collider using data corresponding to an integrated luminosity of 140 fb−1. Inclusive and differential cross-sections are measured for events containing a Z boson decaying into electrons or muons and produced in association with at least one b-jet, at least one c-jet, or at least two b-jets with transverse momentum pT > 20 GeV and rapidity |y| < 2.5. Predictions from several Monte Carlo generators based on next-to-leading-order matrix elements interfaced with a parton-shower simulation, with different choices of flavour schemes for initial-state partons, are compared with the measured cross-sections. The results are also compared with novel predictions, based on infrared and collinear safe jet flavour dressing algorithms. Selected Z+ ≄ 1 c-jet observables, optimized for sensitivity to intrinsic-charm, are compared with benchmark models with different intrinsic-charm fractions

    Constraints on simplified dark matter models involving an s-channel mediator with the ATLAS detector in pp collisions at s = 13 TeV

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    The ATLAS trigger system for LHC Run 3 and trigger performance in 2022

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    The ATLAS trigger system is a crucial component of the ATLAS experiment at the LHC. It is responsible for selecting events in line with the ATLAS physics programme. This paper presents an overview of the changes to the trigger and data acquisition system during the second long shutdown of the LHC, and shows the performance of the trigger system and its components in the proton-proton collisions during the 2022 commissioning period as well as its expected performance in proton-proton and heavy-ion collisions for the remainder of the third LHC data-taking period (2022–2025)

    Combination of searches for heavy spin-1 resonances using 139 fb−1 of proton-proton collision data at √s = 13 TeV with the ATLAS detector

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    A combination of searches for new heavy spin-1 resonances decaying into diferent pairings of W, Z, or Higgs bosons, as well as directly into leptons or quarks, is presented. The data sample used corresponds to 139 fb−1 of proton-proton collisions at √s = 13 TeV collected during 2015–2018 with the ATLAS detector at the CERN Large Hadron Collider. Analyses selecting quark pairs (qq, bb, ttÂŻ, and tb) or third-generation leptons (Ï„Îœ and τ τ ) are included in this kind of combination for the frst time. A simplifed model predicting a spin-1 heavy vector-boson triplet is used. Cross-section limits are set at the 95% confdence level and are compared with predictions for the benchmark model. These limits are also expressed in terms of constraints on couplings of the heavy vector-boson triplet to quarks, leptons, and the Higgs boson. The complementarity of the various analyses increases the sensitivity to new physics, and the resulting constraints are stronger than those from any individual analysis considered. The data exclude a heavy vector-boson triplet with mass below 5.8 TeV in a weakly coupled scenario, below 4.4 TeV in a strongly coupled scenario, and up to 1.5 TeV in the case of production via vector-boson fusion

    Measurement of diferential cross-sections in tt¯ and tt¯+jets production in the lepton+jets fnal state in pp collisions at √s = 13 TeV using 140 fb−1 of ATLAS data

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    Diferential cross-sections for top-quark pair production, inclusively and in association with jets, are measured in pp collisions at a centre-of-mass energy of 13 TeV with the ATLAS detector at the LHC using an integrated luminosity of 140 fb−1. The events are selected with one charged lepton (electron or muon) and at least four jets. The differential cross-sections are presented at particle level as functions of several jet observables, including angular correlations, jet transverse momenta and invariant masses of the jets in the final state, which characterise the kinematics and dynamics of the top-antitop system and the hard QCD radiation in the system with associated jets. The typical precision is 5%–15% for the absolute differential cross-sections and 2%–4% for the normalised differential cross-sections. Next-to-leading-order and next-to-next-to-leading-order QCD predictions are found to provide an adequate description of the rate and shape of the jet-angular observables. The description of the transverse momentum and invariant mass observables is improved when next-to-next-to-leading-order QCD corrections are included
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