174 research outputs found

    Intensidade e duração dos esforços físicos em aulas de Educação Física

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    OBJETIVO: Avaliar a intensidade e a duração dos esforços fĂ­sicos em aulas de Educação FĂ­sica no ensino fundamental e mĂ©dio. MÉTODOS: Estudo transversal de base escolar por meio de observação de 218 aulas de Educação FĂ­sica, incluindo um total de 272 estudantes (avaliados trĂȘs vezes cada um). O estudo foi realizado em Pelotas, RS, de agosto a setembro de 2009. Para a intensidade dos esforços, foram utilizados acelerĂŽmetros e adotados os pontos de corte (em counts por minuto): atividades sedentĂĄrias (0 a 100), leves (101 a 2.000), moderadas (2.001 a 4.999), vigorosas (5.000 a 7.999) e muito vigorosas (&gt; 8.000). RESULTADOS: O tempo mĂ©dio de duração das aulas foi de 35,6 minutos (dp 6,0). A proporção mĂ©dia de tempo das aulas em atividades fĂ­sicas de intensidade moderada a vigorosa foi de 32,7% (dp 25,2). Os meninos (44,1%) envolveram-se significativamente mais em atividades fĂ­sicas moderadas a vigorosas do que as meninas (21,0%; p < 0,01). Estudantes que se envolvem em atividade fĂ­sica fora das aulas tiveram maior participação em atividades fĂ­sicas moderadas a vigorosas nas aulas de Educação FĂ­sica. CONCLUSÕES: AlĂ©m de o tempo da aula de Educação FĂ­sica ser reduzido, os estudantes praticam atividades fĂ­sicas de intensidade moderada a vigorosa um terço da aula, com pouca contribuição significativa para o nĂ­vel de atividade fĂ­sica dos estudantes.OBJECTIVE: To evaluate the intensity and duration of physical efforts in Physical Education classes in primary and secondary school. METHODS: School-based cross-sectional study carried out by means of the observation of 218 Physical Education classes, including a total of 272 students (each one of the students was evaluated three times). The study was carried out in the city of Pelotas (Southern Brazil), between August and December 2009. In order to evaluate the intensity of the efforts, accelerometers were used and the following cut-off points were adopted (in counts per minute): sedentary activities (0-100), light activities (101-2,000), moderate (2,001-4,999), vigorous (5,000-7,999), and very vigorous activities (&gt;8000). RESULTS: The mean duration of the classes was 35.6 minutes (SD 6.0). The mean proportion of time spent in moderate to vigorous physical activity was 32.7% (SD 25.2). Boys (44.1%) were involved significantly more in moderate to vigorous physical activity as compared to girls (21.0%; pOBJETIVO: Evaluar la intensidad y la duraciĂłn de los esfuerzos fĂ­sicos en clases de EducaciĂłn FĂ­sica en la enseñanza bĂĄsica y media. MÉTODOS: Estudio transversal de base escolar por medio de observaciĂłn de 218 clases de EducaciĂłn FĂ­sica, incluyendo un total de 272 estudiantes (evaluados tres veces cada uno). El estudio fue realizado en Pelotas, Sur de Brasil, de agosto a septiembre del año 2009. Para la intensidad de los esfuerzos, se utilizaron acelerĂłmetros y se adoptaron los puntos de corte (en counts por minuto): actividades sedentarias (0 a 100), leves (101 a 2.000), moderadas (2.001 a 4.999), vigorosas (5.000 a 7.999) y muy vigorosas (&gt; 8.000). RESULTADOS: El tiempo promedio de duraciĂłn de las clases fue de 35,6 minutos (de 6,0). La proporciĂłn promedio de tiempo de las clases en actividades fĂ­sicas de intensidad moderada a vigorosa fue de 32,7% (desviaciĂłn estĂĄndar 25,2). Los niños varones (44,1%) se involucraron significativamente en actividades fĂ­sicas moderadas a vigorosas con relaciĂłn a las niñas (21,0%;

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

    Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

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    The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≄20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≀pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≀{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration

    Variability of coastal and ocean water temperature in the upper 700 m along the western Iberian Peninsula from 1975 to 2006

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    Temperature is observed to have different trends at coastal and ocean locations along the western Iberian Peninsula from 1975 to 2006, which corresponds to the last warming period in the area under study. The analysis was carried out by means of the Simple Ocean Data Assimilation (SODA). Reanalysis data are available at monthly scale with a horizontal resolution of 0.5° × 0.5° and a vertical resolution of 40 levels, which allows obtaining information beneath the sea surface. Only the first 21 vertical levels (from 5.0 m to 729.35 m) were considered here, since the most important changes in heat content observed for the world ocean during the last decades, correspond to the upper 700 m. Warming was observed to be considerably higher at ocean locations than at coastal ones. Ocean warming ranged from values on the order of 0.3 °C dec(-1) near surface to less than 0.1 °C dec(-1) at 500 m, while coastal warming showed values close to 0.2 °C dec(-1) near surface, decreasing rapidly below 0.1 °C dec(-1) for depths on the order of 50 m. The heat content anomaly for the upper 700 m, showed a sharp increase from coast (0.46 Wm(-2)) to ocean (1.59 Wm(-2)). The difference between coastal and ocean values was related to the presence of coastal upwelling, which partially inhibits the warming from surface of near shore water.publishe

    The influence of the landscape structure within buffer zones, catchment land use and instream environmental variables on mollusc communities in a medium-sized lowland river

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    The world’s freshwater molluscan fauna is facing unprecedented threats from habitat loss and degradation. Declines in native populations are mostly attributed to the human impact, which results in reduced water quality. The objectives of our survey were to analyse the structure of the mollusc communities in a medium-sized lowland river and to determine the most important environmental variables at different spatial scales, including landscape structure, catchment land use and instream environmental factors that influence their structure. Our survey showed that a medium-sized river, that flows through areas included in the European Ecological Natura 2000 Network Programme of protected sites, provides diverse instream habitats and niches that support 47 mollusc species including Unio crassus, a bivalve of Community interest, whose conservation requires the designation of a special conservation area under the Habitats Directive Natura 2000. This survey showed that mollusc communities are impacted by several environmental variables that act together at multiple scales. The landscape structure within buffer zones, catchment land use and instream environmental variables were all important and influenced the structure of mollusc communities. Therefore, they should all be taken into consideration in the future restoration of the river, future management projects and programmes for the conservation of biodiversity in running waters. The results of this study may be directly applicable for the rehabilitation of river ecosystems and are recommended to stakeholders in their future decision concerning landscape planning, monitoring species and their habitats, conservation plans and management in accordance with the requirements of sustainable development

    Illuminating the life of GPCRs

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    The investigation of biological systems highly depends on the possibilities that allow scientists to visualize and quantify biomolecules and their related activities in real-time and non-invasively. G-protein coupled receptors represent a family of very dynamic and highly regulated transmembrane proteins that are involved in various important physiological processes. Since their localization is not confined to the cell surface they have been a very attractive "moving target" and the understanding of their intracellular pathways as well as the identified protein-protein-interactions has had implications for therapeutic interventions. Recent and ongoing advances in both the establishment of a variety of labeling methods and the improvement of measuring and analyzing instrumentation, have made fluorescence techniques to an indispensable tool for GPCR imaging. The illumination of their complex life cycle, which includes receptor biosynthesis, membrane targeting, ligand binding, signaling, internalization, recycling and degradation, will provide new insights into the relationship between spatial receptor distribution and function. This review covers the existing technologies to track GPCRs in living cells. Fluorescent ligands, antibodies, auto-fluorescent proteins as well as the evolving technologies for chemical labeling with peptide- and protein-tags are described and their major applications concerning the GPCR life cycle are presented

    Action to protect the independence and integrity of global health research

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    Storeng KT, Abimbola S, Balabanova D, et al. Action to protect the independence and integrity of global health research. BMJ GLOBAL HEALTH. 2019;4(3): e001746
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