30 research outputs found

    Space Telescope and Optical Reverberation Mapping Project. VII. Understanding the Ultraviolet Anomaly in NGC 5548 with X-Ray Spectroscopy

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    During the Space Telescope and Optical Reverberation Mapping Project observations of NGC 5548, the continuum and emission-line variability became decorrelated during the second half of the six-month-long observing campaign. Here we present Swift and Chandra X-ray spectra of NGC 5548 obtained as part of the campaign. The Swift spectra show that excess flux (relative to a power-law continuum) in the soft X-ray band appears before the start of the anomalous emission-line behavior, peaks during the period of the anomaly, and then declines. This is a model-independent result suggesting that the soft excess is related to the anomaly. We divide the Swift data into on- and off-anomaly spectra to characterize the soft excess via spectral fitting. The cause of the spectral differences is likely due to a change in the intrinsic spectrum rather than to variable obscuration or partial covering. The Chandra spectra have lower signal-to-noise ratios, but are consistent with the Swift data. Our preferred model of the soft excess is emission from an optically thick, warm Comptonizing corona, the effective optical depth of which increases during the anomaly. This model simultaneously explains all three observations: the UV emission-line flux decrease, the soft-excess increase, and the emission-line anomaly

    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

    Avaliação das características do líquido ruminal, hemogasometria, atividade pedométrica e diagnóstico de laminite subclínica em vacas leiteiras

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    Este estudo objetivou avaliar as caracterĂ­sticas do lĂ­quido ruminal, hemogasometria, atividade pedomĂ©trica e ocorrĂȘncia laminite subclĂ­nica, por meio da presença de enfermidades podais secundĂĄrias, em vacas leiteiras de alta produção, provenientes de um rebanho comercial. Foram avaliadas 200 vacas holandesas, oriundas da mesma propriedade, localizada na regiĂŁo de Araçatuba, SP, divididas em quatro grupos, sendo estes estabelecidos a partir da produtividade diĂĄria. Inicialmente procedeu-se o exame clĂ­nico dos animais, seguido da colheita de amostras do lĂ­quido ruminal, por meio de sondagem esofĂĄgica, sendo este avaliado quanto ao pH, cor, odor, consistĂȘncia, sedimentação, flutuação e prova de redução pelo azul de metileno. TambĂ©m foram colhidas amostras de sangue venoso para hemogasometria, alĂ©m da coleta dos dados da pedometria (nĂșmero de passos) e produção de leite diĂĄria das vacas. Os dados obtidos foram tabulados e submetidos Ă  anĂĄlise de correlação. Nenhum animal avaliado apresentou alteraçÔes no pH ruminal, bem como nĂŁo foram encontrados distĂșrbios do desequilĂ­brio ĂĄcido bĂĄsico, pois os valores de pH sanguĂ­neo, PCO2, TCO2, HCO3- e EB estavam dentro da normalidade, durante a anĂĄlise hemogasomĂ©trica. A pedometria foi efetiva como mĂ©todo de triagem para as vacas acometidas de afecçÔes podais, pois se observou a redução no nĂșmero de passos devido Ă  dor, correlacionada a menor produção leiteira. Contudo, a identificação destas afecçÔes, somente foi possĂ­vel mediante exame clĂ­nico especĂ­fico dos dĂ­gitos. A ocorrĂȘncia das afecçÔes podais em 49,5% do rebanho deveu-se aos fatores de riscos presentes na propriedade, como o concreto abrasivo e instalaçÔes inadequadas, associados tambĂ©m a possĂ­vel ocorrĂȘncia de acidose ruminal subaguda, nĂŁo diagnosticada pela metodologia utilizada. A correlação entre os valores do pH ruminal, pedometria e hemogasometria se mostrou eficiente para o diagnĂłstico precoce das afecçÔes podais e tambĂ©m no estabelecimento da etiologia destas enfermidades. A laminite subclĂ­nica acometeu primariamente as vacas do rebanho, considerando a etiologia multifatorial desta afecção, ocorrĂȘncia e distribuição das enfermidades podais diagnosticadas

    Licófitas e monilófitas das Unidades de Conservação da Usina Hidroelétrica - UHE de Tucuruí, Parå, Brasil

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    Feedback in the ERP value-chain: what influence has thoughts about competitive advantage

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    Different opinions about whether an organization gains a competitive advantage (CA) from an enterprise resource planning (ERP) system exist. However, this paper describes another angle of the much reported competitive advantage discussion. The basic question in the paper concerns how thoughts about receiving competitive advantage from customizing ERPs influences feedback in ERP development. ERP development is described as having three stakeholders: an ERP vendor, an ERP partner or re-seller, and the ERP end-user or client. The question asked is: What influence has thoughts about receiving competitive advantage on the feedback related to requirements in ERP development? From a set of theoretical propositions eight scenarios are proposed. These scenarios are then illustrated from interviews with stakeholders in ERP development. From an initial research, evidence for six of these eight scenarios was uncovered. The main conclusion is that thoughts about competitive advantage seem to influence the feedback, but not really in the way that was initial assumed. Instead of, as was assumed, having a restrict view of providing feedback stakeholders seems to be more interested in having a working feedback loop in the ERP value-chain making the parties in a specific value-chain more interested in competing with other parties in other ERP valuechains
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