331 research outputs found

    Self-Efficacy Belief and the Influential Coach: An Examination of Collegiate Athletes

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    Self-efficacy beliefs related to the performance of a task have been identified as strong predictors of performance success. Research has hypothesized that the most influential contextual factor in athlete self-efficacy development is the athlete-coach relationship, yet there is little research on this relationship. The purpose of this study was to examine collegiate athletes’ perceptions of the prevalence of transformative and destructive coaches, the teaching methods athletes perceive to be transformative (strengthening self-efficacy belief), and the influence of coaching methods on sport self-efficacy belief. Just over two-thirds of the athletes expressed having transformative coaches while over one-third experienced coaches they defined as destructive, with many of these coaches utilizing overtly abusive tactics. This positive and negative exposure was significantly related to athlete self-efficacy belief. Transformative coaching methods were highlighted which add to the body of sport management research by highlighting how coaches influence performance beliefs of their athletes

    Network Governance in the E-Lance Economy

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    Investigation of Hypersonic Laminar Heating Augmentation in the Stagnation Region

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    Laminar stagnation region heating augmentation is investigated in the AEDC Tunnel 9 at Mach 10 by performing high frequency surface pressure and heat transfer measurements on the Orion CEV capsule at zero degree angle-of-attack for unit Reynolds numbers between 0.5 and 15 million per foot. Heating augmentation increases with Reynolds number, but is also model size dependent as it is absent on a 1.25-inch diameter model at Reynolds numbers where it reaches up to 15% on a 7-inch model. Heat transfer space-time correlations on the 7-inch model show that disturbances convect at the boundary layer edge velocity and that the streamwise integral scale increases with distance. Therefore, vorticity amplification due to stretching and piling-up in the stagnation region appears to be responsible for the stagnation point heating augmentation on the larger model. This assumption is reinforced by the f(exp -11/3) dependence of the surface pressure spectrum compared to the f(exp -1) dependence in the free stream. Vorticity amplification does not occur on the 1.25- inch model because the disturbances are too large. Improved free stream fluctuation measurements will be required to determine if significant vorticity is present upstream or mostly generated behind the bow shock

    Understanding determinants of acute stroke thrombolysis using the tailored implementation for chronic diseases framework: a qualitative study

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    Abstract Background The Tailored Implementation in Chronic Disease (TICD) framework is a comprehensive framework describing the determinants of implementation success that has been used extensively in primary care settings. We explored the utility of the TICD to identify determinants of practice in an acute setting, namely guideline concordant acute stroke thrombolysis in a low-resourced, predominately minority serving, large, Emergency Department (ED). Methods Through workshops and expert review, we developed an interview guide informed by the TICD framework. We then conducted semi-structured interviews with data collected through written transcripts, audio transcripts or interviewer notes based on participant availability. Three independent coders then performed a content analysis using template analysis, but open to new determinants that arose from the data, into the TICD framework. Results We performed a total of 15 semi-structured interviews with ED acute stroke providers including medical technicians, nurses, and physicians. We found that guideline factors, individual health professional factors, and patient factors domains were barriers to guideline concordant acute stroke thrombolysis. The domain professional interactions was a facilitator to treatment. We identified three determinants, healthcare professional burnout, health care professional turnover and surrogate decision making, that are not part of the TICD framework. Conclusions Most determinants of acute stroke thrombolysis are included within the TICD framework. Inclusion of healthcare professional burnout, healthcare professional turnover and surrogate decision making may assist in expanding the TICD to time-sensitive ED conditions. Further work is needed to confirm this finding and to establish whether the TICD is applicable for use in non-time sensitive ED conditions. Interventions that address guideline, individual health professional and patient factors may improve guideline concordant acute stroke thrombolysis.https://deepblue.lib.umich.edu/bitstream/2027.42/148315/1/12913_2019_Article_4012.pd

    Dissection, Culture, and Analysis of Xenopus laevis Embryonic Retinal Tissue

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    The process by which the anterior region of the neural plate gives rise to the vertebrate retina continues to be a major focus of both clinical and basic research. In addition to the obvious medical relevance for understanding and treating retinal disease, the development of the vertebrate retina continues to serve as an important and elegant model system for understanding neuronal cell type determination and differentiation(1-16). The neural retina consists of six discrete cell types (ganglion, amacrine, horizontal, photoreceptors, bipolar cells, and Muller glial cells) arranged in stereotypical layers, a pattern that is largely conserved among all vertebrates (12,14-18). While studying the retina in the intact developing embryo is clearly required for understanding how this complex organ develops from a protrusion of the forebrain into a layered structure, there are many questions that benefit from employing approaches using primary cell culture of presumptive retinal cells (7,19-23). For example, analyzing cells from tissues removed and dissociated at different stages allows one to discern the state of specification of individual cells at different developmental stages, that is, the fate of the cells in the absence of interactions with neighboring tissues (8,19-22,24-33). Primary cell culture also allows the investigator to treat the culture with specific reagents and analyze the results on a single cell level (5,8,21,24,27-30,33-39). Xenopus laevis, a classic model system for the study of early neural development (19,27,29,31-32,40-42), serves as a particularly suitable system for retinal primary cell culture (10,38,43-45). Presumptive retinal tissue is accessible from the earliest stages of development, immediately following neural induction (25,38,43). In addition, given that each cell in the embryo contains a supply of yolk, retinal cells can be cultured in a very simple defined media consisting of a buffered salt solution, thus removing the confounding effects of incubation or other sera-based products (10,24,44-45). However, the isolation of the retinal tissue from surrounding tissues and the subsequent processing is challenging. Here, we present a method for the dissection and dissociation of retinal cells in Xenopus laevis that will be used to prepare primary cell cultures that will, in turn, be analyzed for calcium activity and gene expression at the resolution of single cells. While the topic presented in this paper is the analysis of spontaneous calcium transients, the technique is broadly applicable to a wide array of research questions and approaches (Figure 1)

    Degeneration of the osteocyte network in the C57BL/6 mouse model of aging

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    Age-related bone loss and associated fracture risk are major problems in musculoskeletal health. Osteocytes have emerged as key regulators of bone mass and as a therapeutic target for preventing bone loss. As aging is associated with changes in the osteocyte lacunocanalicular system, we focused on the responsible cellular mechanisms in osteocytes. Bone phenotypic analysis was performed in young-(5mo) and aged-(22mo) C57BL/6 mice and changes in bone structure/geometry correlated with alterations in osteocyte parameters determined using novel multiplexed-3D-confocal imaging techniques. Age-related bone changes analogous to those in humans were observed, including increased cortical diameter, decreased cortical thickness, reduced trabecular BV/TV and cortical porosities. This was associated with a dramatic reduction in osteocyte dendrite number and cell density, particularly in females, where osteocyte dendricity decreased linearly from 5, 12, 18 to 22mo and correlated significantly with cortical bone parameters. Reduced dendricity preceded decreased osteocyte number, suggesting dendrite loss may trigger loss of viability. Age-related degeneration of osteocyte networks may impair bone anabolic responses to loading and gender differences in osteocyte cell body and lacunar fluid volumes we observed in aged mice may lead to gender-related differences in mechanosensitivity. Therapies to preserve osteocyte dendricity and viability may be beneficial for bone health in aging

    The global burden of non-typhoidal salmonella invasive disease: a systematic analysis for the Global Burden of Disease Study 2017

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    Background Non-typhoidal salmonella invasive disease is a major cause of global morbidity and mortality. Malnourished children, those with recent malaria or sickle-cell anaemia, and adults with HIV infection are at particularly high risk of disease. We sought to estimate the burden of disease attributable to non-typhoidal salmonella invasive disease for the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017. Methods We did a systematic review of scientific databases and grey literature, and estimated non-typhoidal salmonella invasive disease incidence and mortality for the years 1990 to 2017, by age, sex, and geographical location using DisMod-MR, a Bayesian meta-regression tool. We estimated case fatality by age, HIV status, and sociodemographic development. We also calculated the HIV-attributable fraction and estimated health gap metrics, including disability-adjusted life-years (DALYs). Findings We estimated that 535 000 (95% uncertainty interval 409 000-705 000) cases of non-typhoidal salmonella invasive disease occurred in 2017, with the highest incidence in sub-Saharan Africa (34.5 [26.6-45.0] cases per 100 000 person-years) and in children younger than 5 years (34.3 [23.2-54.7] cases per 100 000 person-years). 77 500 (46 400-123 000) deaths were estimated in 2017, of which 18 400 (12 000-27 700) were attributable to HIV. The remaining 59 100 (33 300-98 100) deaths not attributable to HIV accounted for 4.26 million (2.38-7.38) DALYs in 2017. Mean all-age case fatality was 14.5% (9.2-21.1), with higher estimates among children younger than 5 years (13.5% [8.4-19.8]) and elderly people (51.2% [30.2-72.9] among those aged >= 70 years), people with HIV infection (41.8% [30.0-54.0]), and in areas of low sociodemographic development (eg, 15.8% [10.0-22.9] in sub-Saharan Africa). Interpretation We present the first global estimates of non-typhoidal salmonella invasive disease that have been produced as part of GBD 2017. Given the high disease burden, particularly in children, elderly people, and people with HIV infection, investigating the sources and transmission pathways of non-typhoidal salmonella invasive disease is crucial to implement effective preventive and control measures. Funding Bill & Melinda Gates Foundation. Copyright (c) 2019 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Keywords: 195 COUNTRIES; CLINICAL PRESENTATION; TERRITORIES; RESISTANCE; EPIDEMIOLOGY; INFECTIONS; DISABILITY; INJURIES; OUTCOME

    THE OAK ORCHARD SOIL WATER ASSESSMENT TOOL A decision support system for watershed management Part 1: Calibration and Validation

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    A hydrologic model (SWAT) was developed and calibrated for the Oak Orchard watershed to evaluate sources and sinks of sediment and nutrients. The model included the most important anthropogenic features that impacted water flow and nonpoint source pollution in the watershed. These features included reservoirs at the Iroquois National Wildlife Refuge, Waterport and Medina; point sources such as the Erie Canal, US Gypsum, Allen Canning, wastewater treatment plants at Medina, Oakfield and Elba, and tiledrains at the mucklands, an intensely farmed area that was drained to combat malaria in the 19th century. The model included point sources for every subbasin so that the effects of future point sources can be evaluated. The model was calibrated for waterflow and sediment using observed loading data collected by Makarewicz and Lewis (2000, 2009). To achieve the proper water balance observed at the watershed, seasonal inputs of water had to be added from the Erie Canal and the Onondaga escarpment. This water came from outside of the watershed. The resulting calibration had a Nash-Sutcliffe (NS) prediction efficiency of 0.81 for the calibration period (1997-1999). The total cumulative sediment loading was within 2%, of observed and the monthly sediment loads fell within the uncertainty of the observed data (NS=0.31). Cumulative total phosphorous loads were within 2% of observed and the NS prediction efficiency was 0.91. The model validated very poorly in the 2008 time period primarily because of inaccurate precipitation data and incorrect groundwater fluxes from the escarpment. Further research needs to evaluate the timing and amount of groundwater flow from the escarpment because it has a significant impact on monthly flows in this watershed. It is likely that other watersheds that are nestled against the Onondaga escarpment are impacted by spring flows from this geologic feature

    Clinical pattern of tolvaptan-associated liver injury in trial participants with autosomal dominant polycystic kidney disease (ADPKD): An analysis of pivotal clinical trials

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    RATIONALE & OBJECTIVE: Tolvaptan is associated with risk of drug-induced liver injury when used to treat autosomal dominant polycystic kidney disease (ADPKD). After this risk was described based on the clinical trials TEMPO 3:4 and TEMPO 4:4, additional data from the REPRISE trial and a long-term extension of TEMPO 4:4, REPRISE, and other tolvaptan trials in ADPKD have become available. To further characterize the hepatic safety profile of tolvaptan, an analysis of the expanded dataset was conducted. STUDY DESIGN: Analysis of safety data from prospective clinical trials of tolvaptan. SETTING & PARTICIPANTS: Multicenter clinical trials including more than 2,900 tolvaptan-treated participants, more than 2,300 with at least 18 months of drug exposure. INTERVENTION: Tolvaptan administered twice daily in split-dose regimens. OUTCOMES: Frequency of liver enzyme level increases detected by regular laboratory monitoring. RESULTS: In the placebo-controlled REPRISE trial, more tolvaptan- than placebo-treated participants (38 of 681 [5.6%] vs 8 of 685 [1.2%]) experienced alanine aminotransferase level increases to \u3e3× the upper limit of normal (ULN), similar to TEMPO 3:4 (40 of 957 [4.4%] vs 5 of 484 [1.0%]). No participant in REPRISE or the long-term extension experienced concurrent alanine aminotransferase level increases to \u3e3× ULN and total bilirubin increases to \u3e2× ULN ( Hy\u27s Law laboratory criteria). Based on the expanded dataset, liver enzyme increases most often occurred within 18 months after tolvaptan initiation and were less frequent thereafter. Increased levels returned to normal or near normal after treatment interruption or discontinuation. Thirty-eight patients were rechallenged with tolvaptan after the initial drug-induced liver injury episode, with return of liver enzyme level increases in 30; 1 additional participant showed a clinical adaptation after the initial episode, with resolution of the enzyme level increases despite continuation of tolvaptan. LIMITATIONS: Retrospective analysis. CONCLUSIONS: The absence of Hy\u27s Law cases in REPRISE and the long-term extension trial support monthly liver enzyme monitoring during the first 18 months of tolvaptan exposure and every 3 months thereafter to detect and manage enzyme level increases, as is recommended on the drug label. FUNDING: Otsuka Pharmaceutical Development & Commercialization, Inc. TRIAL REGISTRATION: Trials included in the dataset were registered at ClinicalTrials.gov with study numbers NCT00428948 (TEMPO 3:4), NCT01214421 (TEMPO 4:4), NCT02160145 (REPRISE), and NCT02251275 (long-term extension)
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