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791.
We use data from the National Longitudinal Survey of Adolescent Health to estimate effects of adolescent girls' overweight on their propensity to engage in risky sexual behavior. We estimate single equation, two‐stage, and sibling fixed‐effects models. We consider both absolute weight and weight relative to other girls in the individual's school. We focus on vaginal intercourse without a condom, any type of sexual activity while under the influence of alcohol, and anal intercourse. Our findings confirm previous research indicating that overweight or obese girls are less likely than their recommended‐weight counterparts to be sexually active. As a result, they are less likely to have vaginal intercourse without a condom. However, overweight or obese girls are not less likely to have sex under the influence of alcohol, and once they have had vaginal intercourse, their consistency of condom use is no different from that of their recommended‐weight peers. The most striking finding is that overweight or obese girls are at least 15% more likely than their recommended‐weight peers to have ever had anal intercourse regardless of whether they have ever had vaginal sexual intercourse. The results from this study underscore the importance of using multifaceted and contemporary measures of risky sexual behavior and have implications for the health and well‐being of adolescent girls. (JEL I12, J13)  相似文献   
792.
Semi‐structured one‐on‐one interviews with 102 gay and bisexual men were conducted to examine the reasoning processes men use to exempt themselves from practicing safe sex. Qualitative analysis of the interviews revealed the following recurring themes: (a) Many men who were in couple relationships avoided condom use for reasons involving intimacy or trust, or because both partners were HIV‐negative; (b) unsafe sex sometimes occurred inadvertently or involuntarily; (c) negative moods and self‐images were associated with unsafe sex; (d) by “intuiting” that their partner was HIV‐negative, participants exempted themselves from the need for safe sex; and (e) when the boundary between safe and unsafe was unclear, participants used a combination of unofficial and official guidelines to determine what is safe.  相似文献   
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A class of goodness-of-fit estimators is found to provide a useful alternative in certain situations to the standard maximum likelihood method which has some undesirable estimation characteristics for estimation from the three-parameter lognormal distribution. The class of goodness-of-fit tests considered include the Shapiro-Wilk and Filliben tests which reduce to a weighted linear combination of the order statistics that can be maximized in estimation problems. The weighted order statistic estimators are compared to the standard procedures in Monte Carlo simulations. Robustness of the procedures are examined and example data sets analyzed.  相似文献   
796.
Much leadership literature neglects its historical-contextual antecedents and as a result over-emphasizes zeitgeist, or tenor of the time's social forces. This neglect impedes leadership research by encouraging academic amnesia and promoting a strong feeling of research déjà vu among many researchers and practitioners. In this article, we develop a leadership historical-contextual superstructure consisting of evolutionary antecedents, paradigmatic antecedents, purpose and definitional antecedents, stakeholder antecedents, levels of analysis and temporal antecedents, and research dissemination antecedents. We use this superstructure to analyze current work in the increasingly important relational leadership research stream to illustrate how the superstructure's use can aid leadership researchers and practitioners in avoiding leadership déjà vu and academic amnesia and help build a more cumulative field.  相似文献   
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The study is based on a sample of 965 children living in Oulu region (Finland), who were monitored for acute middle ear infections from birth to the age of two years. We introduce a nonparametrically defined intensity model for ear infections, which involves both fixed and time dependent covariates, such as calendar time, current age, length of breast-feeding time until present, or current type of day care. Unmeasured heterogeneity, which manifests itself in frequent infections in some children and rare in others and which cannot be explained in terms of the known covariates, is modelled by using individual frailty parameters. A Bayesian approach is proposed to solve the inferential problem. The numerical work is carried out by Monte Carlo integration (Metropolis-Hastings algorithm).  相似文献   
800.
Direct scribing is a technique that transforms oral discourse into written text, basically by typing oral material verbatim . It was developed in practice with youth in child welfare care and adapted for research data collection. The technique flattens the power imbalance in the interview situation and between oral speech and written text, supports self-reflection, democratizes the ownership of written material, is potentially empowering, and is an efficient means to produce high-quality text. The origins in practice are reviewed and a research application is discussed in detail. Thirty youths aged 18/19 from child welfare constructed self-narratives about how they conceptualized and managed the adolescent transition, and collaborated with the researcher in analysing the narrative as a story. Each interview was direct scribed and printed copy given to the participant. Participants were introduced to direct scribing by completing a questionnaire presented on a note-book computer, and some took part in a gender-specific group discussion as a final data-collection event, which was audio-taped and transcribed. The value of direct scribing and self-narrative in this research project and possibilities for other applications are discussed.  相似文献   
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