297 research outputs found

    Making SPIFFI SPIFFIER: Upgrade of the SPIFFI instrument for use in ERIS and performance analysis from re-commissioning

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    SPIFFI is an AO-fed integral field spectrograph operating as part of SINFONI on the VLT, which will be upgraded and reused as SPIFFIER in the new VLT instrument ERIS. In January 2016, we used new technology developments to perform an early upgrade to optical subsystems in the SPIFFI instrument so ongoing scientific programs can make use of enhanced performance before ERIS arrives in 2020. We report on the upgraded components and the performance of SPIFFI after the upgrade, including gains in throughput and spatial and spectral resolution. We show results from re-commissioning, highlighting the potential for scientific programs to use the capabilities of the upgraded SPIFFI. Finally, we discuss the additional upgrades for SPIFFIER which will be implemented before it is integrated into ERIS.Comment: 20 pages, 12 figures. Proceedings from SPIE Astronomical Telescopes and Instrumentation 201

    The Anatomy of Changing Male Earnings Inequality: An Empirical Exploration of Determinants

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    The source of the increased inequality in the distribution of male earnings has been the focus of much economic analysis. In this working paper, Robert H. Haveman and Lawrence Buron attempt to find the source of the increased inequality in the distribution of male earnings since the 1970s. Specifically, they seek to find: (1) the relative contributions of changes in wage rates and hours worked to the observed increase in male earnings inequality; (2) whether the relative contributions of changes in relative wage rates and work times to earnings inequality alters if the population examined is all males versus all male workers; (3) the changes over time in wage rate and work time variability within the standard categories of male work patterns; and (4) what the effect of changes in the structure of male work patterns—for example, FTYR work versus part–time or part–year work—has been on the pattern of earnings inequality.

    Toma de decisiones individuales y colectivas para sistemas multi-agente en entornos distribuidos

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    Esta línea de investigación se enfoca en mejorar las capacidades para la toma de decisiones individuales y colectivas de agentes en sistemas multi-agente. Dentro de este enfoque, se planea estudiar y desarrollar como mejorar en los agentes los siguientes aspectos: la capacidad de representación de conocimiento individual y colectivo, la capacidad de realizar inferencias, la capacidad de interacción e intercambio de información, y la capacidad de integrar esos elementos para tomar decisiones tanto individuales como colectivas. El aporte de esta investigación está orientado al desarrollo de formalismos y mecanismos para la toma de decisiones, por parte de agentes inteligentes deliberativos, en el contexto de un sistema multi-agente.Eje: Agentes y Sistemas Inteligentes.Red de Universidades con Carreras en Informática (RedUNCI

    Pancreatic Allograft Thrombosis: Implementation of the CPAT-Grading System in a Retrospective Series of Simultaneous Pancreas-Kidney Transplantation

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    Pancreatic graft thrombosis (PAT) is a major surgical complication, potentially leading to graft loss. The recently proposed Cambridge Pancreas Allograft Thrombosis (CPAT) grading system provides diagnostic, prognostic and therapeutic recommendations. The aim of the present study was to retrospectively assess computed tomography angiography (CTA) examinations performed routinely in simultaneous pancreas-kidney (SPK) recipients to implement the CPAT grading system and to study its association with the recipients' outcomes. We retrospectively studied 319 SPK transplant recipients, who underwent a routine CTA within the first 7 postoperative days. Analysis of the CTA scans revealed PAT in 215 patients (106 grade 1, 85 grade 2, 24 grade 3), while 104 showed no signs. Demographic data of the patients with and without PAT (thrombosis and non-thrombosis group) were not significantly different, except for the higher number of male donors in the thrombosis group. Pancreatic graft survival was significantly shorter in the thrombosis group. Graft loss due to PAT was significantly associated with grade 2 and 3 thrombosis, while it did not differ for recipients with grade 0 or grade 1 thrombosis. In conclusion, the CPAT grading system was successfully implemented in a large series of SPK transplant recipients and proved applicable in clinical practice

    Risk of incident atrial fibrillation in patients presenting with retinal artery or vein occlusion:a nationwide cohort study

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    Abstract Background The inter-relationships of atrial fibrillation (AF) to retinal vascular occlusions (whether retinal artery occlusion (RAO) or retinal venous occlusion (RVO)) remain unclear. It is unknown if a presentation of retinal artery or venous occlusions may indicate a new onset cardiac arrhythmia. To shed light on this association, we investigated the risk of new onset AF in patients with known RAO and RVO. Methods Patients with retinal occlusions from 1997 to 2011 were identified through Danish nationwide registries and matched 1:5 according to sex and age. Cumulative incidence and unadjusted rates of AF according to retinal vascular occlusions (i.e. RAO or RVO) were determined. Hazard ratios (HR) of AF according to retinal vascular occlusion were adjusted for hypertension, diabetes, vascular disease and prior stroke/systemic thromboembolism/transient ischemic attack. Results One thousand three hundred sixty-eight cases with retinal vascular occlusions were identified (median age 71.4 (inter quartile range (IQR); 61.2–79.8), 47.3% male). RAO constituted 706 cases (51.6%) and RVO 529 (38.7%). The rate of incident AF amongst all cases with retinal vascular occlusion was 1.74 per 100 person-years (95% confidence interval (CI), 1.47–2.06) compared to 1.22 (95% CI, 1.12–1.33) in the matched control group. The rate of AF in RAO was 2.01 (95% CI, 1.6–2.52) and 1.52 (1.15–2.01) in RVO. HRs of incident AF adjusted for cardiovascular comorbidities were 1.26 (95% CI; 1.04–1.53, p = 0.019) for any retinal vascular occlusion, 1.45 (95% CI; 1.10–1.89, p = 0.015) for RAO, and 1.02 (95% CI; 0.74–1.39, p = 0.920) for RVO. Conclusions A new diagnosis of retinal vascular occlusion in patients without prior AF was associated with increased risk of incident AF, particularly amongst patients with RAO. Awareness of AF in patients with retinal vascular occlusions is advised

    UNA MIRADA GLOBAL DEL ESTADO DE LAACUMULACIÓN POR METALES PESADOS POR HELMINTOS CON UNA NOTA EN EL USO DE CULTIVO IN VITRO DE ACANTOCÉFALOS ADULTOS PARA ESTUDIAR LOS MECANISMOS DE BIOACUMULACIÓN

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    Bioaccumulation of metals by helminths is a well acknowledged phenomenon that has triggered increasing research interest in the past two decades and found applications in environmental studies. The ecological literature is fairly abundant but still shows gaps with some taxa not having been studied. Variations in the ability of helminths to sequester various metals are recognized and a synthetic overview of the literature is provided herein. Adult acanthocephalans are known to be particularly efficient as bioaccumulators of heavy metals. We optimized an in vitro culture technique of the acanthocephalan Moniliformis moniliformis and initiated in vitro exposure to cadmium and lead. We propose to use this technique to study the mechanisms of uptake and sequestration of heavy metals, which are yet to be understood.La bioacumulación por metales por helmintos es un fenómeno bien reconocido que ha provocado un incremento de interés en investigación en las dos décadas pasadas y ha encontrado aplicaciones en estudios ambientales. La literatura ecológica es bastante abundante pero aun muestra lagunas con algunos taxas que no han sido estudiados. Variaciones en la habilidad de los helmintos para secuestrar varios metales son reconocidos y una sintética mirada global de la literatura es proporcionada aquí. Los acantocéfalos adultos son conocidos por ser particularmente eficientes como bioacumuladores de metales pesados. Optimizamos una técnica de cultivo in vitro del acantocéfalo Moniliformis moniliformise iniciamos una exposición in vitroa cadmio y plomo. Proponemos el uso de esta técnica para estudiar el mecanismo de captación y secuestro de metales, los cuales aun deben ser entendidos

    Mortality Prediction after the First Year of Kidney Transplantation: An Observational Study on Two European Cohorts.

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    After the first year post transplantation, prognostic mortality scores in kidney transplant recipients can be useful for personalizing medical management. We developed a new prognostic score based on 5 parameters and computable at 1-year post transplantation. The outcome was the time between the first anniversary of the transplantation and the patient's death with a functioning graft. Afterwards, we appraised the prognostic capacities of this score by estimating time-dependent Receiver Operating Characteristic (ROC) curves from two prospective and multicentric European cohorts: the DIVAT (Données Informatisées et VAlidées en Transplantation) cohort composed of patients transplanted between 2000 and 2012 in 6 French centers; and the STCS (Swiss Transplant Cohort Study) cohort composed of patients transplanted between 2008 and 2012 in 6 Swiss centers. We also compared the results with those of two existing scoring systems: one from Spain (Hernandez et al.) and one from the United States (the Recipient Risk Score, RRS, Baskin-Bey et al.). From the DIVAT validation cohort and for a prognostic time at 10 years, the new prognostic score (AUC = 0.78, 95%CI = [0.69, 0.85]) seemed to present significantly higher prognostic capacities than the scoring system proposed by Hernandez et al. (p = 0.04) and tended to perform better than the initial RRS (p = 0.10). By using the Swiss cohort, the RRS and the the new prognostic score had comparable prognostic capacities at 4 years (AUC = 0.77 and 0.76 respectively, p = 0.31). In addition to the current available scores related to the risk to return in dialysis, we recommend to further study the use of the score we propose or the RRS for a more efficient personalized follow-up of kidney transplant recipients

    First direct detection of an exoplanet by optical interferometry; Astrometry and K-band spectroscopy of HR8799 e

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    To date, infrared interferometry at best achieved contrast ratios of a few times 10410^{-4} on bright targets. GRAVITY, with its dual-field mode, is now capable of high contrast observations, enabling the direct observation of exoplanets. We demonstrate the technique on HR8799, a young planetary system composed of four known giant exoplanets. We used the GRAVITY fringe tracker to lock the fringes on the central star, and integrated off-axis on the HR8799e planet situated at 390 mas from the star. Data reduction included post-processing to remove the flux leaking from the central star and to extract the coherent flux of the planet. The inferred K band spectrum of the planet has a spectral resolution of 500. We also derive the astrometric position of the planet relative to the star with a precision on the order of 100μ\,\muas. The GRAVITY astrometric measurement disfavors perfectly coplanar stable orbital solutions. A small adjustment of a few degrees to the orbital inclination of HR 8799 e can resolve the tension, implying that the orbits are close to, but not strictly coplanar. The spectrum, with a signal-to-noise ratio of 5\approx 5 per spectral channel, is compatible with a late-type L brown dwarf. Using Exo-REM synthetic spectra, we derive a temperature of 1150±501150\pm50\,K and a surface gravity of 104.3±0.310^{4.3\pm0.3}\,cm/s2^{2}. This corresponds to a radius of 1.170.11+0.13RJup1.17^{+0.13}_{-0.11}\,R_{\rm Jup} and a mass of 104+7MJup10^{+7}_{-4}\,M_{\rm Jup}, which is an independent confirmation of mass estimates from evolutionary models. Our results demonstrate the power of interferometry for the direct detection and spectroscopic study of exoplanets at close angular separations from their stars.Comment: published in A&
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