2,711 research outputs found

    Photosynthetic quantum efficiency in south‐eastern Amazonian trees may be already affected by climate change

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    Tropical forests are experiencing unprecedented high‐temperature conditions due to climate change that could limit their photosynthetic functions. We studied the high‐temperature sensitivity of photosynthesis in a rainforest site in southern Amazonia, where some of the highest temperatures and most rapid warming in the Tropics have been recorded. The quantum yield (F v /F m ) of photosystem II was measured in seven dominant tree species using leaf discs exposed to varying levels of heat stress. T 50 was calculated as the temperature at which F v /F m was half the maximum value. T 5 is defined as the breakpoint temperature, at which F v /F m decline was initiated. Leaf thermotolerance in the rapidly warming southern Amazonia was the highest recorded for forest tree species globally. T 50 and T 5 varied between species, with one mid‐storey species, Amaioua guianensis , exhibiting particularly high T 50 and T 5 values. While the T 50 values of the species sampled were several degrees above the maximum air temperatures experienced in southern Amazonia, the T 5 values of several species are now exceeded under present‐day maximum air temperatures

    Produção orgùnica de rabanete em plantio direto sobre cobertura morta e viva.

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    O objetivo deste trabalho foi avaliar o uso de plantas espontùneas e cobertura viva de amendoim forrageiro(Arachis pintoi), associado à aplicação de composto orgùnico na produção orgùnica do rabanete em plantio direto. O experimento foi instalado na Universidade Federal do Acre, em Rio Branco-AC, de 15/06 a 14/07/2007. O delineamento experimental utilizado foi em blocos casualizados com parcelas subdivididas 4x3, em quatro repetiçÔes. As parcelas corresponderam ao sistema de plantio direto com cobertura viva de amendoim forrageiro, cobertura viva de planta espontùnea, cobertura morta de planta espontùnea e sistema de plantio em canteiro com solo descoberto. As subparcelas foram compostas pelas doses de composto orgùnico de 5, 10 e 15 t ha-1 (base seca). O plantio direto na palha de plantas espontùneas teve desempenho semelhante ao preparo convencional do solo, ambos superiores ao plantio sobre as coberturas vivas. A produtividade do rabanete cv. Cometo, não foi afetada pelas doses crescentes de composto orgùnico, podendo aplicar-se apenas 5 t ha-1, enquanto em preparo convencional do solo, o aumento da produtividade ultrapassa o plantio direto na palha apenas na dose maior de composto (15 t ha-1)

    Waiting time to radiotherapy as a prognostic factor for glioblastoma patients in a scenario of medical disparities

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    Objective To evaluate the effect of waiting time (WT) to radiotherapy (RT) on overall survival (OS) of glioblastoma (GBM) patients as a reliable prognostic variable in Brazil, a scenario of medical disparities. Method Retrospective study of 115 GBM patients from two different health-care institutions (one public and one private) in Brazil who underwent post-operative RT. Results Median WT to RT was 6 weeks (range, 1.3-17.6). The median OS for WT ≀ 6 weeks was 13.5 months (95%CI , 9.1-17.9) and for WT > 6 weeks was 14.2 months (95%CI, 11.2-17.2) (HR 1.165, 95%CI 0.770-1.762; p = 0.470). In the multivariate analysis, the variables associated with survival were KPS (p 6 semanas foi de 14,2 meses (IC95%, 11,2-17,2) (HR 1,165, 0,770-1,762; p = 0,470). Na anĂĄlise multivariada, as variĂĄveis associadas Ă  sobrevida foram perfomance status (p < 0,001), extensĂŁo da ressecção (p = 0,009) e tratamento adjuvante (p = 0,001). ConclusĂŁo NĂŁo se observou impacto prognĂłstico para TE atĂ© a radioterapia na sobrevida. Diante de outros fatores prognĂłsticos, Ă© possĂ­vel assegurar de que o espaço de tempo atĂ© a radioterapia nĂŁo parece influenciar o controle da doença.Hospital Israelita Albert EinsteinUniversidade Federal de SĂŁo Paulo (UNIFESP) Escola Paulista de MedicinaHospital do Coração Departamento de OncologiaUniversidade de SĂŁo Paulo Faculdade de MedicinaUNIFESP, EPMSciEL

    Nursing diagnosis sedentary lifestyle in individuals with hypertension: an analysis of accuracy

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    Objective Assessing the accuracy of the defining characteristics (DC) of the nursing diagnosis Sedentary Lifestyle (SL) in people with hypertension. Method A cross-sectional study carried out in a referral center in the outpatient care of people with hypertension and diabetes, with a sample of 285 individuals. The form used in the study was designed from operational definitions constructed for each DC of the diagnosis. Four nurses with training to carry out diagnostic inferences did the clinical assessment for the presence of SL. Results The prevalence of SL was 55.8%. Regarding measures of accuracy, the main DC for SL was chooses a daily routine lacking physical exercise, with sensitivity of 100% and specificity of 84.13%. Two DC stood out in the logistic regression, namely: reports preference for activities low in physical activity and poor performance in instrumental activities of daily living (IADL). Conclusion The results allowed identifying the best clinical indicators for SL in hypertensive adults

    TRY plant trait database - enhanced coverage and open access

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    Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

    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+→Ό+ÎœW^+ \rightarrow \mu^+\nu and W−→Ό−ΜW^- \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

    Expected Performance of the ATLAS Experiment - Detector, Trigger and Physics

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    A detailed study is presented of the expected performance of the ATLAS detector. The reconstruction of tracks, leptons, photons, missing energy and jets is investigated, together with the performance of b-tagging and the trigger. The physics potential for a variety of interesting physics processes, within the Standard Model and beyond, is examined. The study comprises a series of notes based on simulations of the detector and physics processes, with particular emphasis given to the data expected from the first years of operation of the LHC at CERN

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente
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