2,575 research outputs found

    Coherent Waveform Consistency Test for LIGO Burst Candidates

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    The burst search in LIGO relies on the coincident detection of transient signals in multiple interferometers. As only minimal assumptions are made about the event waveform or duration, the analysis pipeline requires loose coincidence in time, frequency and amplitude. Confidence in the resulting events and their waveform consistency is established through a time-domain coherent analysis: the r-statistic test. This paper presents a performance study of the r-statistic test for triple coincidence events in the second LIGO Science Run (S2), with emphasis on its ability to suppress the background false rate and its efficiency at detecting simulated bursts of different waveforms close to the S2 sensitivity curve.Comment: 11 pages, 9 figures. Submitted to the Proceedings of the 8th Gravitational Wave Data Analysis Workshop, in Classic and Quantum Gravit

    A First Comparison of SLOPE and Other LIGO Burst Event Trigger Generators

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    A number of different methods have been proposed to identify unanticipated burst sources of gravitational waves in data arising from LIGO and other gravitational wave detectors. When confronted with such a wide variety of methods one is moved to ask if they are all necessary, i.e. given detector data that is assumed to have no gravitational wave signals present, do they generally identify the same events with the same efficiency, or do they each 'see' different things in the detector? Here we consider three different methods, which have been used within the LIGO Scientific Collaboration as part of its search for unanticipated gravitational wave bursts. We find that each of these three different methods developed for identifying candidate gravitational wave burst sources are, in fact, attuned to significantly different features in detector data, suggesting that they may provide largely independent lists of candidate gravitational wave burst events.Comment: 10 Pages, 5 Figures, Presented at the 10th Gravitational Wave Data Analysis Workshop (GWDAW-10), 14-17 December 2005 at the University of Texas, Brownsvill

    Direct observation of large temperature fluctuations during DNA thermal denaturation

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    In this paper we report direct measurement of large low frequency temperature fluctuations in double stranded (ds) DNA when it undergoes thermal denaturation transition. The fluctuation, which occurs only in the temperature range where the denaturation occurs, is several orders more than the expected equilibrium fluctuation. It is absent in single stranded (ss) DNA of the same sequence. The fluctuation at a given temperature also depends on the wait time and vanishes in a scale of few hours. It is suggested that the large fluctuation occurs due to coexisting denaturated and closed base pairs that are in dynamic equilibrium due to transition through a potential barrier in the scale of 25-30k_{B}T_{0}(T_{0}=300K).Comment: 4 pages, 5 figures, Replaced with revised versio

    Local structure of ReO3_3 at ambient pressure from neutron total scattering study

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    A hypothesis that the local rotations of ReO6_6 octahedra persist in the crystallographically untilted ambient phase of ReO3_3 is examined by the high-resolution neutron time-of-flight total scattering based atomic pair distribution function analysis. Three candidate models were tested, Pm3ˉ\bar{3}m, P4/mbm, and Im3ˉ\bar{3}, for the local structure of ReO3_3 at ambient pressure and 12 K, and both quantitative and qualitative assessment of the data were performed. No evidence for large local octahedral rotations was found, suggesting that the local and the average structure are the same (Pm3ˉ\bar{3}m) as normally assumed.Comment: Submitte

    The glycemic elemental profile of trichosanthes dioica: a LIBS-based study

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    The scientific evaluation of the antidiabetic efficacy of aqueous extract of Trichosanthes dioica fruits on streptozotocin-induced diabetic rats is being presented. The graded doses of the extract, viz., 500, 750, 1,000, and 1,250 mg/kg body weight (bw), were administered orally, and it was observed that the blood glucose concentration decreased in a dose-dependent manner. The dose of 1,000 mg/kg bw showed the maximum fall of 23.8% and 19.1% in blood glucose level (BGL) during fasting BGL and glucose tolerance test (GTT) studies, respectively, of nondiabetic rats. Whereas in the case of subdiabetic and mild diabetic models, the same dose showed reduction in BGL of 22.0% and 31.4% during GTT. The study also involves the first use of laser-induced breakdown spectroscopy as a sensitive analytical tool to detect the elemental profile responsible for the antidiabetic activity of aqueous extract of T. dioica fruits that exhibits the antidiabetic activity. High intensities of Ca, Mg, and Fe indicate large concentrations of these elements in the extract, since according to Boltzmann’s distribution law, intensities are directly proportional to concentrations. The higher concentrations of these glycemic elements, viz. Ca, Mg, and Fe, are responsible for the antidiabetic potential of T. dioica as well as other plant already reported by our research group

    Comments on the Martingale Convergence Theorem Technical Report No. 21

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    Proofs of generality of martingale convergence theore

    Risk factors for incidence and persistence of disability in chronic major depression and alcohol use disorders: longitudinal analyses of a population-based study

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    BackgroundMajor depression and alcohol use disorders are risk factors for incidence of disability. However, it is still unclear whether a chronic course of these health conditions is also prospectively associated with incidence of disability. The aim of the present study was, first, to confirm whether chronic major depression (MD) and alcohol use disorders (AUD) are, respectively, risk factors for persistence and incidence of disability in the general population; and then to analyze the role of help-seeking behavior in the course of disability among respondents with chronic MD and chronic AUD. MethodData from two assessments in the National Epidemiologic Survey on Alcohol and Related Conditions were analyzed. Disability was measured by eight domains of the Short Form 12 Health Survey version 2 (SF-12). Generalized estimating equations and logistic regression models were run to estimate risk factors for persistence and incidence of disability, respectively. ResultsAnalyses conducted on data from the US general population showed that chronic MD was the strongest risk factor for incidence and persistence of disability in the social functioning, emotional role and mental health domains. Chronic AUD were risk factors for incidence and persistence of disability in the vitality, social functioning, and emotional role domains. Within the group of chronic MD, physical comorbidity and help-seeking were associated with persistent disability in most of the SF-12 domains. Help-seeking behavior was also associated with incidence of problems in the mental health domain for the depression group. Regarding the AUD group, comorbidity with physical health problems was a strong risk factor for persistence of disability in all SF-12 domains. Help-seeking behavior was not related to either persistence or incidence of disability in the chronic alcohol group. ConclusionsChronic MD and chronic AUD are independent risk factors for persistence and incidence of disability in the US general population. People with chronic MD seek help for their problems when they experience persistent disability, whereas people with chronic AUD might not seek any help even if they are suffering from persistent disability.<br/
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