222 research outputs found

    Improvement of Odin/SMR water vapour and temperature measurements and validation of the obtained data sets

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    Its long photochemical lifetime makes H2O a good tracer for mesospheric dynamics. Temperature observations are also critical to study middle atmospheric dynamics. In this study, we present the reprocessing of 18 years of mesospheric H2O and temperature measurements from the Sub-Millimetre Radiometer (SMR) aboard the Odin satellite, resulting in a part of the SMR version 3.0 level 2 data set. The previous version of the data set showed poor accordance with measurements from other instruments, which suggested that the retrieved concentrations and temperature were subject to instrumental artefacts. Different hypotheses have been explored, and the idea of an underestimation of the singlesideband leakage turned out to be the most reasonable one. The value of the lowest transmission achievable has therefore been raised to account for greater sideband leakage, and new retrievals have been performed with the new settings. The retrieved profiles extend between 40-100 km altitude and cover the whole globe to reach 85\ub0 latitudes. A validation study has been carried out, revealing an overall better accordance with the compared instruments. In particular, relative differences in H2O mixing ratio are always in the \ub120% range between 40 and 70 km and diverge at higher altitudes, while temperature absolute differences are within \ub15K between 40-80 km and also diverge at higher altitudes

    Effectiveness of Statins as Primary Prevention in People With Different Cardiovascular Risk: A Population-Based Cohort Study

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    The purpose was to analyze statin effectiveness in a general population with differing levels of coronary heart disease (CHD) risk. Patients (35-74 years) without previous cardiovascular disease were included and stratified according to 10-year CHD risk ( < 5%, 5-7.4%, 7.5-9.9%, and 10-19.9%). New users were categorized according to their medical possession ratio (MPR). The main outcome was atherosclerotic cardiovascular disease (ASCVD) (myocardial infarction and ischemic stroke). In adherent patients (MPR 70%), statin treatment decreased ASCVD risk across the range of coronary risk (from 16-30%). The 5-year number needed to treat (NNT) was 470 and 204 in the risk categories < 5% and 5-7.4%, respectively, and 75 and 62 in the 7.5-9.9% category than in the 10-19.9% category, respectively. Statin therapy should remain a priority in patients at high 10-year CHD risk (10-19.9%). Most patients with intermediate risk could benefit from statin treatment, but the treatment decision should focus on the net benefit, safety, and patient preference, given the higher NNT

    PaCTS 1.0: A Crowdsourced Reporting Standard for Paleoclimate Data

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    The progress of science is tied to the standardization of measurements, instruments, and data. This is especially true in the Big Data age, where analyzing large data volumes critically hinges on the data being standardized. Accordingly, the lack of community-sanctioned data standards in paleoclimatology has largely precluded the benefits of Big Data advances in the field. Building upon recent efforts to standardize the format and terminology of paleoclimate data, this article describes the Paleoclimate Community reporTing Standard (PaCTS), a crowdsourced reporting standard for such data. PaCTS captures which information should be included when reporting paleoclimate data, with the goal of maximizing the reuse value of paleoclimate data sets, particularly for synthesis work and comparison to climate model simulations. Initiated by the LinkedEarth project, the process to elicit a reporting standard involved an international workshop in 2016, various forms of digital community engagement over the next few years, and grassroots working groups. Participants in this process identified important properties across paleoclimate archives, in addition to the reporting of uncertainties and chronologies; they also identified archive-specific properties and distinguished reporting standards for new versus legacy data sets. This work shows that at least 135 respondents overwhelmingly support a drastic increase in the amount of metadata accompanying paleoclimate data sets. Since such goals are at odds with present practices, we discuss a transparent path toward implementing or revising these recommendations in the near future, using both bottom-up and top-down approaches

    Manejo del neonato con coartación de aorta e hipoplasia de arco

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    ResumenIntroducciónLa coartación aórtica del neonato puede asociar en un porcentaje importante hipoplasia del arco aórtico, llegando en algunas series al 60%.Cuando existe hipoplasia del arco aórtico distal el tratamiento estándar consiste en la resección de la zona de coartación y anastomosis termino-terminal extendida.En casos de hipoplasia severa del arco aórtico distal y arco distal largo, podría no ser suficiente con la resección y anastomosis termino-terminal extendida, por lo que sería razonable realizar alguna técnica adicional para ampliar el arco aórtico distal, evitando así un abordaje anterior, el uso de parada circulatoria con o sin perfusión cerebral selectiva y el aumento de la morbimortalidad perioperatoria.MétodosPresentamos los resultados de 4 neonatos, a los que se les realizó una ampliación del arco aórtico distal, según técnica de Amato (anastomosis latero-lateral entre las arterias carótida y subclavia izquierdas), para posteriormente resecar la zona de coartación y anastomosar la aorta descendente al arco aórtico previamente ampliado.ResultadosEn todos los casos el ecocardiograma postoperatorio mostró arco reconstruido con flujo laminar. No se ha presentado ningún caso de recoartación durante un período de seguimiento medio de 12 meses.ConclusiónConsideramos que la técnica de elección en la coartación con hipoplasia de arco distal es la resección y anastomosis termino-terminal extendida.En casos seleccionados, con arco aórtico distal muy largo y severamente hipoplásico, la técnica de Amato es una alternativa atractiva, con el objeto de evitar un abordaje anterior y el uso de CEC. Además, puede realizarse en un primer tiempo, manteniendo perfusión sistémica ductus-dependiente.AbstractIntroductionNeonatal aortic coarctation can be combined with a significant percentage of aortic arch hypoplasia, reaching 60% in some series.When there is hypoplasia of the distal aortic arch, the standard treatment consists of resection of the coarctation zone and extended end-to-end anastomosis.In cases of severe distal aortic arch hypoplasia and a long distal arch, resection and extended end-to-end anastomosis would not be sufficient, making it reasonable to perform an additional technique to widen the distal aortic arch, thus avoiding an anterior approach and interrupting the blood circulation with or without selective cerebral infusion, with the resulting risk of an increase in perioperative morbidity and mortality.MethodsThe results are presented on 4 neonates on whom a widening of the distal aortic arch was performed using the Amato technique (side-to-side anastomosis between the left carotid and subclavian arteries), in order to subsequently resect the coarctation zone and perform an anastomosis of the descending aorta to the previously widened aortic arch.ResultsThe post-operative echocardiogram showed a reconstructed arch with laminar flow in all cases. There has been no recurrence of coarctation in any of the cases during a mean follow-up of 12 months.ConclusionWe believe that resection with extended end-to-end anastomosis is the technique of choice in coarctation with distal arch hypoplasia.The Amato technique is an attractive alternative in selected cases with a very long and severely hypoplastic distal arch, with the aim of avoiding an anterior approach and the use of extracorporeal circulation. This could also be performed initially, maintaining ductal-dependent systemic perfusion

    GGPS1 Mutation and Atypical Femoral Fractures with Bisphosphonates

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    Atypical femoral fractures have been associated with long-term bisphosphonate treatment.1,2 However, the underlying mechanisms remain obscure. We studied three sisters who had atypical femoral fractures after receiving various oral bisphosphonates for 6 years. Two of the sisters had a single fracture (at the ages of 64 and 73 years), and one had bilateral fractures (one at the age of 60 years and the other at the age of 61 years). Given the low incidence of atypical femoral fractures in the general population (5.9 per 10,000 person-years),3 we hypothesized that these sisters might have an underlying genetic background that contributed to these fractures

    Four lectures on secant varieties

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    This paper is based on the first author's lectures at the 2012 University of Regina Workshop "Connections Between Algebra and Geometry". Its aim is to provide an introduction to the theory of higher secant varieties and their applications. Several references and solved exercises are also included.Comment: Lectures notes to appear in PROMS (Springer Proceedings in Mathematics & Statistics), Springer/Birkhause
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