2,536 research outputs found

    Development and test of advanced composite components. Center Directors discretionary fund program

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    This report describes the design, analysis, fabrication, and test of a complex bathtub fitting. Graphite fibers in an epoxy matrix were utilized in manufacturing of 11 components representing four different design and layup concepts. Design allowables were developed for use in the final stress analysis. Strain gage measurements were taken throughout the static load test and correlation of test and analysis data were performed, yielding good understanding of the material behavior and instrumentation requirements for future applications

    Is State Law Looking for Trouble: The Federal Arbitration Act Flexes Its Preemptive Muscle

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    This article begins with an overview of the preemption concept as it affects the American legal system. The source of preemption power is revealed and the most common forms of preemption are introduced. Next, the article discusses preemption and its interaction with the Federal Arbitration Act (FAA). The discussion begins with a chronological view of the cases that have defined the effects the FAA has on arbitration agreements via its preemption power and ends with a summary of the current state of the law

    \u27Scared Straight\u27 and Other Juvenile Awareness Programs for Preventing Juvenile Delinquency

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    Background: \u27Scared Straight\u27 and other similar programs involve organized visits to prison by juvenile delinquents or children at risk for criminal behavior. Programs are designed to deter participants from future offending through firsthand observation of prison life and interaction with adult inmates. These programs remain in use despite research questioning their effectiveness. This is an update of a 2002 review. Objectives: To assess the effects of programs comprising organized visits to prisons by juvenile delinquents (officially adjudicated, that is, convicted by a juvenile court) or pre-delinquents (children in trouble but not officially adjudicated as delinquents), aimed at deterring them from delinquency. Search methods: To update this review, we searched 22 electronic databases, including CENTRAL, MEDLINE, PsycINFO, and Criminal Justice Abstracts, in December 2011. In addition, we searched clinical trials registries, consulted experts, conducted Google Scholar searches, and followed up on all relevant citations. Selection criteria: We included studies that tested programs involving the organized visits of delinquents or children at risk for delinquency to penal institutions such as prisons or reformatives. Studies that had overlapping samples of juvenile and young adults (for example, ages 14 to 20 years) were included. We only considered studies that assigned participants to conditions randomly or quasi-randomly (that is, by odd/even assignment to conditions). Each study had to have a no-treatment control condition and at least one outcome measure of \u27post-visit\u27 criminal behavior. Data collection and analysis: The search methods for the original review generated 487 citations, most of which had abstracts. The lead review author screened these citations, determining that 30 were evaluation reports. Two review authors independently examined these citations and agreed that 11 were potential randomized trials. All reports were obtained. Upon inspection of the full-text reports, two review authors independently agreed to exclude two studies, resulting in nine randomized trials. The lead review author extracted data from each of the nine study reports using a specially designed instrument. In cases in which outcome information was missing from the original reports, we made attempts via correspondence to retrieve the data for the analysis from the original investigators. Outcome data were independently checked by a second review author (CTP). In this review, we report the results of each of the nine trials narratively. We conducted two meta-analyses of seven studies that provided postintervention offending rates using official data. Information from other sources (for example, self-report) was either missing from some studies or critical information was omitted (for example, standard deviations). We examined the immediate post-treatment effects (that is, \u27first-effects\u27) by computing odds ratios (OR) for data on proportions of each group reoffending, and assumed both fixed-effect and random-effects models in our analyses. Main results: We have included nine studies in this review. All were part of the original systematic review; no new trials meeting eligibility criteria were identified through our updated searches. The studies were conducted in eight different states of the USA, during the years 1967 to 1992. Nearly 1000 (946) juveniles or young adults of different races participated, almost all males. The average age of the participants in each study ranged from 15 to 17 years. Meta-analyses of seven studies show the intervention to be more harmful than doing nothing. The OR (fixed-effect) for effects on first post-treatment effect on officially measured criminal behavior indicated a negative program effect (OR 1.68, 95% confidence interval (CI) 1.20 to 2.36) and nearly identical regardless of themeta-analytic strategy (random-effects OR 1.72, 95% CI 1.13 to 2.62). Sensitivity analyses (random-effects) showed the findings were robust even when removing one study with an inadequate randomization strategy (OR 1.47, 95% CI 1.03 to 2.11), or when removing one study with high attrition (OR 1.96, 95% CI 1.25 to 3.08), or both (OR 1.68, 95% CI 1.10 to 2.58). Authors\u27 conclusions: We conclude that programs such as \u27Scared Straight\u27 increase delinquency relative to doing nothing at all to similar youths. Given these results, we cannot recommend this program as a crime prevention strategy. Agencies that permit such programs, therefore, must rigorously evaluate them, to ensure that they do not cause more harm than good to the very citizens they pledge to protect

    Vertex Reconstruction Using a Single Layer Silicon Detector

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    Typical vertex finding algorithms use reconstructed tracks, registered in a multi-layer detector, which directly point to the common point of origin. A detector with a single layer of silicon sensors registers the passage of primary particles only in one place. Nevertheless, the information available from these hits can also be used to estimate the vertex position, when the geometrical properties of silicon sensors and the measured ionization energy losses of the particles are fully exploited. In this paper the algorithm used for this purpose in the PHOBOS experiment is described. The vertex reconstruction performance is studied using simulations and compared with results obtained from real data. The very large acceptance of a single-layered multiplicity detector permits vertex reconstruction for low multiplicity events where other methods, using small acceptance subdetectors, fail because of insufficient number of registered primary tracks.Comment: accepted for publication in Nucl. Instr. Meth.

    Observational Results of a Multi-Telescope Campaign in Search of Interstellar Urea [(NH2_2)2_2CO]

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    In this paper, we present the results of an observational search for gas phase urea [(NH2_2)2_2CO] observed towards the Sgr B2(N-LMH) region. We show data covering urea transitions from \sim100 GHz to 250 GHz from five different observational facilities: BIMA, CARMA, the NRAO 12 m telescope, the IRAM 30 m telescope, and SEST. The results show that the features ascribed to urea can be reproduced across the entire observed bandwidth and all facilities by best fit column density, temperature, and source size parameters which vary by less than a factor of 2 between observations merely by adjusting for telescope-specific parameters. Interferometric observations show that the emission arising from these transitions is cospatial and compact, consistent with the derived source sizes and emission from a single species. Despite this evidence, the spectral complexity, both of (NH2_2)2_2CO and of Sgr B2(N), makes the definitive identification of this molecule challenging. We present observational spectra, laboratory data, and models, and discuss our results in the context of a possible molecular detection of urea.Comment: 38 pages, 9 Figures, accepted in the Astrophysical Journa

    R Aquarii: The Large-Scale Optical Nebula and the Mira Variable Position

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    The R Aquarii symbiotic star system is surrounded by a large-scale optical nebula. We present observations of the nebular [O III] structure and discuss its morphological significance in context with previously observed small-scale radio-continuum features, which may be related. We suggest that a precessing accretion disk may explain the global features of both the large-scale optical emission and the small-scale radio emission. Moreover, we have determined an accurate position of the system\u27s Mira, which suggests that a recent theoretical model, yielding an egg-shaped central H II region for symbiotic systems with certain physical parameters, may apply to R Aquarii. The optical position of the 387d period Mira variable is consistent with our previous findings in the radio, that SiO maser emission is far removed from the Mira photosphere

    The [N II] Kinematics of R Aquarii

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    We report a kinematic study of the symbiotic star system R Aqr derived from [N H]lambda 6584 emission observations with a Fabry-Perot imaging spectrometer. The [N II] spatial structure of the R Aqr jet, first observed circa 1977, and surrounding hourglass-shaped nebulosity, due to an explosion approximately 660 years ago, are derived from 41 velocity planes spaced at approximately 12 km/s intervals. Fabry-Perot imagery shows the elliptical nebulosity comprising the waist of the hourglass shell is consistent with a circular ring expanding radially at 55 km/s as seen at an inclination angle, i approximately 70 deg. Fabry-Perot imagery shows the two-sided R Aqr jet is collimated flow in opposite directions. The intensity-velocity structure of the strong NE jet component is shown in contrast to the amorphous SW jet component. We offer a idealized schematic model for the R Aqr jet motion which results in a small-scale helical structure forming around a larger-scale helical path. The implications of such a jet model are discussed. We present a movie showing a side-by-side comparison of the spatial structure of the model and the data as a function of the 41 velocity planes

    Evaluating Digital Health Interventions: Key Questions and Approaches

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    Digital health interventions have enormous potential as scalable tools to improve health and healthcare delivery by improving effectiveness, efficiency, accessibility, safety, and personalization. Achieving these improvements requires a cumulative knowledge base to inform development and deployment of digital health interventions. However, evaluations of digital health interventions present special challenges. This paper aims to examine these challenges and outline an evaluation strategy in terms of the research questions needed to appraise such interventions. As they are at the intersection of biomedical, behavioral, computing, and engineering research, methods drawn from all of these disciplines are required. Relevant research questions include defining the problem and the likely benefit of the digital health intervention, which in turn requires establishing the likely reach and uptake of the intervention, the causal model describing how the intervention will achieve its intended benefit, key components, and how they interact with one another, and estimating overall benefit in terms of effectiveness, cost effectiveness, and harms. Although RCTs are important for evaluation of effectiveness and cost effectiveness, they are best undertaken only when: (1) the intervention and its delivery package are stable; (2) these can be implemented with high fidelity; and (3) there is a reasonable likelihood that the overall benefits will be clinically meaningful (improved outcomes or equivalent outcomes at lower cost). Broadening the portfolio of research questions and evaluation methods will help with developing the necessary knowledge base to inform decisions on policy, practice, and research

    Potential associations between fecal shedding of Salmonella in feedlot cattle treated for apparent respiratory disease and subsequent adverse health outcomes

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    A prospective cohort study was used to assess whether Salmonella fecal shedding in commercial feedlot cattle treated with antimicrobials for respiratory disease was associated with subsequent adverse health outcomes. Feces were collected per rectum from cattle that were examined for apparent respiratory disease, had a rectal temperature ≥40 °C, and subsequently received antimicrobial treatment. Salmonella were recovered from 918 (73.7%) of 1 245 fecal samples and weekly prevalence estimates ranged from 49 to 100% over the 3-month study. Genotypic and phenotypic characteristics of Salmonella strains in the population were determined. Serogroup E Salmonella were most common (73.3%), followed by C1 (11.0%), C3 (8.6%), and B (1.1%). Predominant serotypes were Orion (46.5%), Anatum (19.8%), Kentucky (8.7%), Montevideo (7.5%), and Senftenberg (4.9%). Few isolates (36/918) were positive for antimicrobial resistance-associated integron gene intI1. Phenotypic susceptibility was associated with isolate intI1 status. Crude re-pull, re-treatment and case fatality risks were higher for cattle that were Salmonella-positive versus -negative at initial treatment, but not statistically different on multivariable analysis. However, case fatality risk was higher for cattle shedding Group B Salmonella than for cattle shedding other serogroups. Lots (groups) with a higher Salmonella prevalence at first treatment had a higher proportion of mortalities occur in a hospital pen, higher overall re-treatment risks, and were more likely to be sampled later in the study. Results indicate a high prevalence of Salmonella in this population of cattle treated for apparent respiratory disease, but that effects associated with clinical outcomes may depend on the Salmonella strain
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