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981.
Walters SJ 《Pharmaceutical statistics》2009,8(2):163-169
Pre‐study sample size calculations for clinical trial research protocols are now mandatory. When an investigator is designing a study to compare the outcomes of an intervention, an essential step is the calculation of sample sizes that will allow a reasonable chance (power) of detecting a pre‐determined difference (effect size) in the outcome variable, at a given level of statistical significance. Frequently studies will recruit fewer patients than the initial pre‐study sample size calculation suggested. Investigators are faced with the fact that their study may be inadequately powered to detect the pre‐specified treatment effect and the statistical analysis of the collected outcome data may or may not report a statistically significant result. If the data produces a “non‐statistically significant result” then investigators are frequently tempted to ask the question “Given the actual final study size, what is the power of the study, now, to detect a treatment effect or difference?” The aim of this article is to debate whether or not it is desirable to answer this question and to undertake a power calculation, after the data have been collected and analysed. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
982.
Kevin J. A. Thomas 《Demography》2009,46(3):513-534
In this study, I examine disparities in schooling progress among children born to immigrant and U.S.-born blacks. I find that
in one- and two-parent families, children born to black immigrants are less likely to fall behind in school than those born
to U.S.-born blacks. In two-parent immigrant families, children born to two immigrant parents have a significant schooling
advantage over children born to one immigrant parent. While children born to two immigrant parents in the wealthiest black
immigrant families do better in the second generation than in the first, the reverse is observed among children in less wealthy
families. These findings contribute in two ways to our understanding of the assimilation processes of children born to black
immigrant parents. First, they show that there is a positive association between the number of immigrant parents in a family
and children’s schooling performance. Second, they suggest that disparities in the assimilation patterns of the children of
black immigrants are a likely product of the interaction between their parental characteristics and the socioeconomic circumstances
of their families. 相似文献
983.
Research has examined various elements of Twitter; however, no scholarship has explored how sociologists currently use the platform. This empirically driven paper explores how individuals that self-identify as sociologists on Twitter use the popular micro-blogging social media site. A total of 152,977 tweets from Twitter profiles of 130 sociologists were collected and examined using qualitative media analysis. The potential use of Twitter allows the sociologist to become both the generator and interlocutor of dialogue with publics. We frame our data analysis and discussion around the core theme of expertise - namely, the role that expertise plays in the use of Twitter by sociologists. Our findings indicate that when sociologists used Twitter as sociologists (i.e., drawing upon their stated research expertise) little direct engagement with publics occurred. Thus, while sociologists appear to be using Twitter as a space for public sociology, the use of this interactive platform is mostly limited to the generation of content, a finding consistent with Burawoy’s traditional form of public sociology. Suggestions for future research are noted. 相似文献
984.
Fathers' roles in family life have changed dramatically over the past 50 years. In addition to ongoing breadwinning responsibilities, many fathers are now involved in direct caregiving and engagement with children. Yet there is considerable variation in what fathers do, especially depending on whether they live with or away from their child. In this article, the authors use data from the Fragile Families and Child Wellbeing Study (N = 3,869) to describe how fathers' economic capacities (money) and direct involvement with children (time) are associated over child ages 1 to 9 for resident versus nonresident fathers, net of confounding factors. They found suggestive evidence that money and time investments operate differently across residential contexts: Resident fathers experience a trade‐off between market work and time involved with children. In contrast, nonresident fathers' higher economic capacities are associated with more time involvement, underscoring the greater challenge for such fathers to remain actively involved. 相似文献
985.
Using data from the Fragile Families and Child Wellbeing survey linked to respondents' medical records (N = 2,870), this study examines the association between grandparents' education and birth outcomes and explores potential pathways underlying this relationship. Results show that having a grandfather with less than a high school education was associated with a 93 gram reduction in birth weight, a 59% increase in the odds of low birth weight, and a 136% increase in the odds of a neonatal health condition when compared with having a grandfather with a high school education or more. These associations were partially accounted for by mother's educational attainment and marital status as well as by prenatal history of depression, hypertension, and prenatal health behaviors, depending on the specific outcome. The findings from this study call for heightened attention to the multigenerational influences of educational attainment for infant health. 相似文献
986.
Scott W. Semenyna Doug P. VanderLaan Lanna J. Petterson Paul L. Vasey 《Journal of sex research》2017,54(8):1077-1084
Previous research established that male androphilia (i.e., sexual arousal and attraction to adult males) clusters in families. Some studies find that male androphilia clusters in both the paternal and maternal lines, while others find that it clusters only in the latter. Most of the research investigating the familial nature of male androphilia has taken place in Western cultural contexts that are problematic for such research because they are characterized by low fertility. To address this, our previous work has examined familial patterning of male androphilia in Samoa, a high-fertility population in which androphilic males are readily identified due to their public status as fa’afafine (a third gender category). Building on this work, the present study replicated the familial nature of male androphilia in Samoa using a sample size that was ~122% larger than the one we previously employed (N = 382, M ±SD age: 29.72 years ±10.16). Samoan fa’afafine had significantly more fa’afafine relatives in their maternal and paternal lines compared to Samoan gynephilic males (p < .001). The prevalence of male androphilia was equivalent across both the paternal and maternal lines (all p > .15). The revised prevalence estimate of male androphilia in Samoa falls between 0.61% and 3.51%. 相似文献
987.
Paul J. Fleming Clare Barrington Lisa D. Pearce Leonel Lerebours Yeycy Donastorg Maximo O. Brito 《Journal of sex research》2017,54(1):42-54
Ethnographic studies from numerous societies have documented the central role of male circumcision in conferring masculinity and preparing boys for adult male sexuality. Despite this link between masculinity, sexuality, and circumcision, there has been little research on these dynamics among men who have been circumcised for HIV prevention. We employed a mixed methods approach with data collected from recently circumcised men in the Dominican Republic (DR) to explore this link. We analyzed survey data collected six to 12 months post-circumcision (N = 293) as well as in-depth interviews conducted with a subsample of those men (n = 30). We found that 42% of men felt more masculine post-circumcision. In multivariate analysis, feeling more masculine was associated with greater concern about being perceived as masculine (OR = 1.70, 95% CI: 1.25–2.32), feeling more potent erections post-circumcision (OR = 2.25, 95% CI: 1.26–4.03), and reporting increased ability to satisfy their partners post-circumcision (OR = 2.30, 95% CI: 1.11–4.77). In qualitative interviews, these factors were all related to masculine norms of sexually satisfying one’s partner, and men’s experiences of circumcision were shaped by social norms of masculinity. This study highlights that circumcision is not simply a biomedical intervention and that circumcision programs need to incorporate considerations of masculine norms and male sexuality into their programming. 相似文献
988.
Previous research suggests that an increasing age at first marriage has contributed to the prevalence of sexual hookups on U.S. college campuses. In this article, we use life course and marital horizons theories to analyze the influence of ideal age at first marriage on hooking up among unmarried heterosexual college students. Analyses of the Online College Social Life Survey (N = 17,981) show a positive association between ideal age at first marriage and hookups for most students, but not for students whose mothers have no post‐secondary education, Asian men, Asian women, and Latina women. Variation in ideal marriage timing does not account for gender, racial/ethnic, and class gaps in hookup participation. Results are discussed with reference to the role of sexuality in processes of stratification throughout young adulthood. 相似文献
989.
We examine the ways Mormon leaders establish “what it means to be a man” for their followers. Based on content analysis of over 40 years of archival material, we analyze how Mormon leaders represent manhood as the ability to signify control over self and others as well as an inability to be controlled. Specifically, we demonstrate how these representations stress controlling the self, emotional and sexual expression, and others while emphasizing the development of self-reliance and independence from others’ control. We draw out implications for understanding (1) how religious leaders create ideal notions of manhood, (2) what the religious interpretations of secular constructions of manhood are, and (3) how these relate to the reproduction of gender inequalities. 相似文献
990.
Developing a lobbying model of repeated agency, we explain previously unexplained features of the real‐world lobbying industry. Lobbying is divided between direct representation by special interests to policymakers, and indirect representation where special interests employ professional intermediaries called commercial lobbyists to lobby policymakers on their behalf. Our analytical structure allows us to explain several trends in lobbying. For example, using the observation that in the United States over the last 20 years, policymakers have spent an increasing amount of their time fundraising as opposed to legislating, we are able to explain why the share of commercial lobbyist activity in total lobbying has risen dramatically and now constitutes over 60% of the total. The key scarce resource in our analysis is policymakers' time. Policymakers allocate this resource via implicit repeated agency contracts that are used to incent special interests and commercial lobbyists to provide a mix of financial contributions and information on policy proposals. These implicit agency contracts solve both an information problem in the presence of unverifiable policy information and a contracting problem in the absence of legal enforcement. These repeated relationships, that are often described using the pejorative term “cronyism” in the popular press, may in certain circumstances be welfare improving. (JEL D72, D82, H1, P16) 相似文献