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This research was motivated by our goal to design an efficient clinical trial to compare two doses of docosahexaenoic acid supplementation for reducing the rate of earliest preterm births (ePTB) and/or preterm births (PTB). Dichotomizing continuous gestational age (GA) data using a classic binomial distribution will result in a loss of information and reduced power. A distributional approach is an improved strategy to retain statistical power from the continuous distribution. However, appropriate distributions that fit the data properly, particularly in the tails, must be chosen, especially when the data are skewed. A recent study proposed a skew-normal method. We propose a three-component normal mixture model and introduce separate treatment effects at different components of GA. We evaluate operating characteristics of mixture model, beta-binomial model, and skew-normal model through simulation. We also apply these three methods to data from two completed clinical trials from the USA and Australia. Finite mixture models are shown to have favorable properties in PTB analysis but minimal benefit for ePTB analysis. Normal models on log-transformed data have the largest bias. Therefore we recommend finite mixture model for PTB study. Either finite mixture model or beta-binomial model is acceptable for ePTB study.  相似文献   
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The study purpose was to develop and pilot an undue influence screening tool for California’s Adult Protective Services (APS) personnel based on the definition of undue influence enacted into California law January 1, 2014. Methods included four focus groups with APS providers (n = 33), piloting the preliminary tool by APS personnel (n = 15), and interviews with four elder abuse experts and two APS administrators. Social service literature—including existing undue influence models—was reviewed, as were existing screening and assessment tools. Using the information from these various sources, the California Undue Influence Screening Tool (CUIST) was developed. It can be applied to APS cases and potentially adapted for use by other professionals and for use in other states. Implementation of the tool into APS practice, policy, procedures, and training of personnel will depend on the initiative of APS management. Future work will need to address the reliability and validity of CUIST.  相似文献   
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This study extends Flores et al.'s ( 2006 ) 36‐year analysis of racial/ethnic minority (REM) career research to identify recent trends in choice of topics and leading individual and institutional contributors. The authors identified 166 articles on REM career research published from 2005 to 2015 in the Journal of Vocational Behavior, The Career Development Quarterly, the Journal of Career Assessment, and the Journal of Career Development. Of these studies, 92% were empirical, with more than three quarters of these using quantitative rather than qualitative methodology. Most frequently, the empirical studies (n = 153) were based on samples of high school (30.7%) or undergraduate (34.6%) students. The authors discuss the implications of their findings and suggest ways to expand REM career research in the future.  相似文献   
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Despite the central role of women drug users in escalating AIDS statistics, there is still a limited number of studies that examine the roles of gender and drug use type in HIV seroprevalence. This lacuna in the research literature has led to significant gaps in researchers' understanding of how and to what extent women may differ in their drug-using and HIV risk behaviors compared to their better-studied male counterparts. This study, derived from a sample of 3,555 out-of-treatment drug users residing in three South Florida urban and rural communities, attempts to compare the drug usage and needle and sexual risk behaviors of male and female drug users that put them at risk for HIV infection. The overall seropositivity rate for women drug users was 26.5% compared to 19.5% for their male counterparts. Results of multivariate analyses indicate that females compared to males were 1.4 times more likely to be HIV seropositive. Risk behaviors associated with this elevated seropositivity include living arrangements, homeless status, drug use, sexual trading behaviors, and history of STDs. Furthermore, there was a strong linear relationship between drug use type and HIV seroprevalence among women drug users. Compared to those who were neither crack smokers nor injectors of illicit drugs, those who were crack smokers only were 2 times more likely to be HIV seropositive, while those who were both crack smokers and injectors were 5 times more likely to be HIV seropositive, and those who were injectors only were 6 times more likely to be HIV seropositive. These findings indicate that among women, drug abuse and its associated risk behaviors, increase the vulnerability of this population for HIV and thus render them an extremely important priority population on which to focus HIV prevention and public health efforts and programs.  相似文献   
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Conflict and Creativity in Groups   总被引:1,自引:0,他引:1  
Consultants and researchers have long recognized the debilitating effects that conflict between group members can have on both group and individual outcomes . Yet less attention has been paid to the important role that conflict may play in helping generate innovative solutions to ill-structured problems . Furthermore , conflict (properly managed) is critical to the avoidance of groupthink (i . e ., the tendency to sacrifice quality decision making and problem solving for the sake of consensus and conflict avoidance) . What strategies can group members use to incorporate conflict , or more specifically , dissent in group problem solving? We argue that the delivery of dissenting opinions (negative evaluations) affects the extent to which dissent fosters creativity . We report the results of an experiment in which the target of negative evaluations was varied (e . g ., source of an idea vs . idea itself ) and compared to a condition in which no negative evaluations were incorporated . The results show that (1) creativity is higher in the conditions involving idea-targeted negative evaluations than source-targeted or no negative evaluations; (2) negative evaluations from others increase in conditions in which there are source-targeted negative evaluations and idea-targeted negative evaluations , compared to no negative evaluations; and (3) group members report higher levels of satisfaction when working under conditions involving idea-targeted negative evaluations , compared to source-targeted or no negative evaluations . We discuss the implications of this research for organizational settings , with particular attention to how they might inform the design of group decision support systems .  相似文献   
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