3,571 research outputs found

    Extreme distributions of ground winds /3 to 150 meters/ at Cape Kennedy, Florida

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    Statistical analysis of wind distribution probabilities at Cape Kenned

    Association of inferior vena cava filter placement for venous thromboembolic disease and a contraindication to anticoagulation with 30-day mortality

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    Importance: Despite the absence of data from randomized clinical trials, professional societies recommend inferior vena cava (IVC) filters for patients with venous thromboembolic disease (VTE) and a contraindication to anticoagulation therapy. Prior observational studies of IVC filters have suggested a mortality benefit associated with IVC filter insertion but have often failed to adjust for immortal time bias, which is the time before IVC filter insertion, during which death can only occur in the control group. Objective: To determine the association of IVC filter placement with 30-day mortality after adjustment for immortal time bias. Design, Setting, and Participants: This comparative effectiveness, retrospective cohort study used a population-based sample of hospitalized patients with VTE and a contraindication to anticoagulation using the State Inpatient Database and the State Emergency Department Database, part of the Healthcare Cost and Utilization Project of the Agency for Healthcare Research and Quality, from hospitals in California (January 1, 2005, to December 31, 2011), Florida (January 1, 2005, to December 31, 2013), and New York (January 1, 2005, to December 31, 2012). Data analysis was conducted from September 15, 2015, to March 14, 2018. Exposure: Inferior vena cava filter placement. Main Outcomes and Measures: Multivariable Cox proportional hazard models were constructed with IVC filters as a time-dependent variable that adjusts for immortal time bias. The Cox model was further adjusted using the propensity score as an adjustment variable. Results: Of 126 030 patients with VTE, 61 281 (48.6%) were male and the mean (SD) age was 66.9 (16.6) years. In this cohort, 45 771 (36.3%) were treated with an IVC filter, whereas 80 259 (63.7%) did not receive a filter. In the Cox model with IVC filter status analyzed as a time-dependent variable to account for immortal time bias, IVC filter placement was associated with a significantly increased hazard ratio of 30-day mortality (1.18; 95% CI, 1.13-1.22; P \u3c .001). When the propensity score was included in the Cox model, IVC filter placement remained associated with an increased hazard ratio of 30-day mortality (1.18; 95% CI, 1.13-1.22; P \u3c .001). Conclusions and Relevance: After adjustment for immortal time bias, IVC filter placement was associated with increased 30-day mortality in patients with VTE and a contraindication to anticoagulation. Randomized clinical trials are needed to determine the efficacy of IVC filter placement in patients with VTE and a contraindication to anticoagulation

    Screening for mood disorders after stroke: a systematic review of psychometric properties and clinical utility

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    BackgroundRoutine mood screening is recommended after stroke. However, clinicians report difficulty selecting appropriate tools from the wide range available. We aimed to systematically review the psychometric properties and clinical utility of mood screening tools for stroke survivors.MethodElectronic databases (AMED, EMBASE, CINAHL, Medline and PsycINFO) were searched to identify studies assessing the sensitivity and specificity of mood screening tools. Tools that demonstrated at least 80% sensitivity and 60% specificity with stroke survivors with identifiable cut-off scores indicating major and/or any mood disorder in at least one study were selected and clinical utility was assessed. Those with high clinical utility (against predefined criteria) were selected for recommendation.ResultsThirty papers examining 27 screening tools were identified and 16 tools met the psychometric and clinical utility criteria: 10 were verbal self-report tools, four were observational and two incorporated visual prompts for those with communication problems. Only the Stroke Aphasic Depression Questionnaire –Hospital version (SADQ-H) met all the psychometric and utility criteria. The nine-item Patient Health Questionnaire (PHQ-9) can detect major depression and the 15-item Geriatric Depression Scale (GDS-15) can identify milder symptoms; both are feasible to use in clinical practice. The Hospital Anxiety and Depression Scale (HADS) was the only tool able to identify anxiety accurately, but clinical utility was mixed.ConclusionsValid and clinically feasible mood screening tools for stroke have been identified but methodological inconsistency prevented recommendations about the optimal cut-off scores.</jats:sec

    Milking the Cache Cow With Fairness in Mind

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    Guiding chemical pulses through geometry: Y-junctions

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    We study computationally and experimentally the propagation of chemical pulses in complex geometries.The reaction of interest, CO oxidation, takes place on single crystal Pt(110) surfaces that are microlithographically patterned; they are also addressable through a focused laser beam, manipulated through galvanometer mirrors, capable of locally altering the crystal temperature and thus affecting pulse propagation. We focus on sudden changes in the domain shape (corners in a Y-junction geometry) that can affect the pulse dynamics; we also show how brief, localized temperature perturbations can be used to control reactive pulse propagation.The computational results are corroborated through experimental studies in which the pulses are visualized using Reflection Anisotropy Microscopy.Comment: submitted to Phys. Rev.

    The Size Distribution of Trans-Neptunian Bodies

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    [Condensed] We search 0.02 deg^2 for trans-Neptunian objects (TNOs) with m<=29.2 (diameter ~15 km) using the ACS on HST. Three new objects are discovered, roughly 25 times fewer than expected from extrapolation of the differential sky density Sigma(m) of brighter objects. The ACS and other recent TNO surveys show departures from a power law size distribution. Division of the TNO sample into ``classical Kuiper belt'' (CKB) and ``Excited'' samples reveals that Sigma(m) differs for the two populations at 96% confidence. A double power law adequately fits all data. Implications include: The total mass of the CKB is ~0.010 M_Earth, only a few times Pluto's mass, and is predominately in the form of ~100 km bodies. The mass of Excited objects is perhaps a few times larger. The Excited class has a shallower bright-end size distribution; the largest objects, including Pluto, comprise tens of percent of the total mass whereas the largest CKBOs are only ~2% of its mass. The predicted mass of the largest Excited body is close to the Pluto mass; the largest CKBO is ~60 times less massive. The deficit of small TNOs occurs for sizes subject to disruption by present-day collisions, suggesting extensive depletion by collisions. Both accretion and erosion appearing to have proceeded to more advanced stages in the Excited class than the CKB. The absence of distant TNOs implies that any distant (60 AU) population must have less than the CKB mass in the form of objects 40 km or larger. The CKB population is sparser than theoretical estimates of the required precursor population for short period comets, but the Excited population could be a viable precursor population.Comment: Revised version accepted to the Astronomical Journal. Numerical results are very slightly revised. Implications for the origins of short-period comets are substantially revised, and tedious material on statistical tests has been collected into a new Appendi

    SCANDEX: Service centric networking for challenged decentralised networks

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    Do-It-Yourself (DIY) networks are decentralised networks built by an (often) amateur community. As DIY networks do not rely on the need for backhaul Internet connectivity, these networks are mostly a mix of both offine and online networks. Although DIY networks have their own home- grown services, the current Internet-based cloud services are often useful, and access to some services could be beneficial to the community. Considering that most DIY networks have challenged Internet connectivity, migrating current ser- vice virtualisation instances could face great challenges. Ser- vice Centric Networking (SCN) has been recently proposed as a potential solution to managing services more efficiently using Information Centric Networking (ICN) principles. In this position paper, we present our arguments for the need for a resilient SCN architecture, propose a strawman SCN architecture that combines multiple transmission technolo- gies for providing resilient SCN in challenged DIY networks and, finally, identify key challenges that need to be explored further to realise the full potential of our architecture.The work has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No. 645124.This is the accepted manuscript of a paper published in the Proceedings of the 2015 Workshop on Do-it-yourself Networking (Sathiaseelan A, Wang L, Aucinas A, Tyson G, Crowcroft J, Proceedings of the 2015 Workshop on Do-it-yourself Networking: an Interdisciplinary Approach, 2015, 15-20, doi:10.1145/2753488.2753490). The final version is available at http://dx.doi.org/10.1145/2753488.275349
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