3,186 research outputs found

    Non-invasive Optical End-to-End Test of a Large TMA Telescope (JWST) from the Intermediate Focus

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    The James Webb Space Telescope (JWST) requires testing of the full optical system in a cryogenic vacuum environment before launch. Challenges with the telescope architecture and the test environment lead to placing removable optical test sources at the Cassegrain intermediate focus of the Telescope. The Science Instrument suite will be used to align the telescope and to verify the wavefront error. The Science Instruments capture test images that are analyzed using focus diverse phase retrieval. The wavefront sensing algorithms have the large dynamic range required to measure the relatively small wavefronts of interest in the presence of the large aberrations resulting from the off-axis source locations at the intermediate focus. These inherent aberrations of the off-axis design are removed analytically from the measured data. The test design and in-situ wavefront sensing process enables a number of tests to verify the alignment and optical quality of the system

    PSY50 PHYSICIANS' INTENTIONS TO MEASURE BODY MASS INDEX IN CHILDREN AND ADOLESCENTS:ATHEORY OF REASONED ACTION MODEL

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    Oral rivaroxaban versus standard therapy for the treatment of symptomatic venous thromboembolism : a pooled analysis of the EINSTEIN-DVT and PE randomized studies

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    Background: Standard treatment for venous thromboembolism (VTE) consists of a heparin combined with vitamin K antagonists. Direct oral anticoagulants have been investigated for acute and extended treatment of symptomatic VTE; their use could avoid parenteral treatment and/or laboratory monitoring of anticoagulant effects. Methods: A prespecified pooled analysis of the EINSTEIN-DVT and EINSTEIN-PE studies compared the efficacy and safety of rivaroxaban (15 mg twice-daily for 21 days, followed by 20 mg once-daily) with standard-therapy (enoxaparin 1.0 mg/kg twice-daily and warfarin or acenocoumarol). Patients were treated for 3, 6, or 12 months and followed for suspected recurrent VTE and bleeding. The prespecified noninferiority margin was 1.75. Results: 8282 patients were enrolled. 4151 received rivaroxaban and 4131 received standard-therapy. The primary efficacy outcome occurred in 86 rivaroxaban-treated patients (2.1%) compared with 95 (2.3%) standard-therapy-treated patients (hazard ratio, 0.89; 95% confidence interval [CI], 0.66-1.19; pnoninferiority<0.001). Major bleeding was observed in 40 (1.0%) and 72 (1.7%) patients in the rivaroxaban and standard-therapy groups, respectively (hazard ratio, 0.54; 95% CI, 0.37-0.79; p=0.002). In key subgroups, including fragile patients, cancer patients, patients presenting with large clots and those with a history of recurrent VTE, the efficacy and safety of rivaroxaban was similar compared with standard-therapy. Conclusion: The single-drug approach with rivaroxaban resulted in similar efficacy to standard-therapy and was associated with a significantly lower rate of major bleeding. Efficacy and safety results were consistent among key patient subgroups

    A multicentre trial of voltaren in the treatment of rheumatoid arthritis

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    Voltaren, a compound with analgesic, anti-inflammatory and antipyretic properties, has been compared at two dose levels-25 mg t.d.s. and 50 mg t.d.s. with indomethacin 25 mg t.d.s. and acetylsalicylic acid 1 500 mg t.d.s. Ninety-one patients with definite or classical rheumatoid arthritis took part in this study. The trial was a doubleblind cross-over study, with each  medication being given for one week. Patients were washed out for one week prior to the first active treatment. Each patient received only two of the four possible treatments. Voltaren in a dose of 25 mg t.d.s. was found to improve the symptoms of rheumatoid arthritis to a greater degree than indomethacin or acetylsalicylic acid. Voltaren 50 mg t.d.s. evoked a greater response than acetylsalicylic acid and was at least as efficacious as indomethacin. Voltaren was better tolerated than either indomethacin or acetylsalicylic acid. The incidence of gastro-intestinal side-effects was similar with Voltaren and indomethacin, and half that produced by acetylsalicylic acid. Some evidence of possible drug interaction was found.S. Afr. Med. J., 48, 2013 (1974)

    Simulation-based reachability analysis for nonlinear systems using componentwise contraction properties

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    A shortcoming of existing reachability approaches for nonlinear systems is the poor scalability with the number of continuous state variables. To mitigate this problem we present a simulation-based approach where we first sample a number of trajectories of the system and next establish bounds on the convergence or divergence between the samples and neighboring trajectories. We compute these bounds using contraction theory and reduce the conservatism by partitioning the state vector into several components and analyzing contraction properties separately in each direction. Among other benefits this allows us to analyze the effect of constant but uncertain parameters by treating them as state variables and partitioning them into a separate direction. We next present a numerical procedure to search for weighted norms that yield a prescribed contraction rate, which can be incorporated in the reachability algorithm to adjust the weights to minimize the growth of the reachable set

    Parameterized tests of the strong-field dynamics of general relativity using gravitational wave signals from coalescing binary black holes: Fast likelihood calculations and sensitivity of the method

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    Thanks to the recent discoveries of gravitational wave signals from binary black hole mergers by Advanced Laser Interferometer Gravitational Wave Observatory and Advanced Virgo, the genuinely strong-field dynamics of spacetime can now be probed, allowing for stringent tests of general relativity (GR). One set of tests consists of allowing for parametrized deformations away from GR in the template waveform models and then constraining the size of the deviations, as was done for the detected signals in previous work. In this paper, we construct reduced-order quadratures so as to speed up likelihood calculations for parameter estimation on future events. Next, we explicitly demonstrate the robustness of the parametrized tests by showing that they will correctly indicate consistency with GR if the theory is valid. We also check to what extent deviations from GR can be constrained as information from an increasing number of detections is combined. Finally, we evaluate the sensitivity of the method to possible violations of GR.Comment: 19 pages, many figures. Matches PRD versio

    Genetic diversity, demographic history and neo-sex chromosomes in the Critically Endangered Raso lark

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    Small effective population sizes could expose island species to inbreeding and loss of genetic variation. Here, we investigate factors shaping genetic diversity in the Raso lark, which has been restricted to a single islet for approximately 500 years, with a population size of a few hundred. We assembled a reference genome for the related Eurasian skylark and then assessed diversity and demographic history using RAD-seq data (75 samples from Raso larks and two related mainland species). We first identify broad tracts of suppressed recombination in females, indicating enlarged neo-sex chromosomes. We then show that genetic diversity across autosomes in the Raso lark is lower than in its mainland relatives, but inconsistent with long-term persistence at its current population size. Finally, we find that genetic signatures of the recent population contraction are overshadowed by an ancient expansion and persistence of a very large population until the human settlement of Cape Verde. Our findings show how genome-wide approaches to study endangered species can help avoid confounding effects of genome architecture on diversity estimates, and how present-day diversity can be shaped by ancient demographic events
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