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21.
Cancho Vicente G. Macera Márcia A. C. Suzuki Adriano K. Louzada Francisco Zavaleta Katherine E. C. 《Lifetime data analysis》2020,26(2):221-244
Lifetime Data Analysis - Frailty models are generally used to model heterogeneity between the individuals. The distribution of the frailty variable is often assumed to be continuous. However, there... 相似文献
22.
AbstractThe economic mobility of individuals and households is of fundamental interest. While many measures of economic mobility exist, reliance on transition matrices remains pervasive due to simplicity and ease of interpretation. However, estimation of transition matrices is complicated by the well-acknowledged problem of measurement error in self-reported and even administrative data. Existing methods of addressing measurement error are complex, rely on numerous strong assumptions, and often require data from more than two periods. In this article, we investigate what can be learned about economic mobility as measured via transition matrices while formally accounting for measurement error in a reasonably transparent manner. To do so, we develop a nonparametric partial identification approach to bound transition probabilities under various assumptions on the measurement error and mobility processes. This approach is applied to panel data from the United States to explore short-run mobility before and after the Great Recession. 相似文献
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Objectives: In the United States, HIV continues to disproportionately affect men who have sex with men. One promising area of research that may inform the development of behavioral interventions among male–male couples is within the realm of sexual agreements. Methods: The purpose of our analysis was to determine whether respondents who report having an open agreement or an agreement breakage also report a higher incidence of recent (within the previous 12 months) intimate-partner violence (IPV) compared to respondents who report having a monogamous agreement or no agreement breakage after controlling for demographic variables. Results: Results showed that men who have an open agreement are less likely to report recent physical IPV. Conclusions: The results highlight the need to develop dyadic behavior interventions that address sexual agreements and stress management. 相似文献
26.
Prior research suggests that nonprofits are flexible and possess multiple identities, although we know less about how transformative changes, such as mergers, shape nonprofit identity. This qualitative study draws upon in‐depth interviews from 13 nonprofit merger cases to explore factors that influence postmerger identity and integration. In particular, we focus on the roles of organizational similarity and relationships, program and personnel retention, and rebranding. Ultimately, we derive a typology of postmerger integration in nonprofits and suggest that postmerger identity may be classified in terms of absorption, preservation, or creation. Implications for nonprofit leaders are discussed. 相似文献
27.
In studies with recurrent event endpoints, misspecified assumptions of event rates or dispersion can lead to underpowered trials or overexposure of patients. Specification of overdispersion is often a particular problem as it is usually not reported in clinical trial publications. Changing event rates over the years have been described for some diseases, adding to the uncertainty in planning. To mitigate the risks of inadequate sample sizes, internal pilot study designs have been proposed with a preference for blinded sample size reestimation procedures, as they generally do not affect the type I error rate and maintain trial integrity. Blinded sample size reestimation procedures are available for trials with recurrent events as endpoints. However, the variance in the reestimated sample size can be considerable in particular with early sample size reviews. Motivated by a randomized controlled trial in paediatric multiple sclerosis, a rare neurological condition in children, we apply the concept of blinded continuous monitoring of information, which is known to reduce the variance in the resulting sample size. Assuming negative binomial distributions for the counts of recurrent relapses, we derive information criteria and propose blinded continuous monitoring procedures. The operating characteristics of these are assessed in Monte Carlo trial simulations demonstrating favourable properties with regard to type I error rate, power, and stopping time, ie, sample size. 相似文献
28.
Alex B. Anderson 《Journal of sex research》2015,52(3):317-326
Distraction from erotic cues during sexual encounters is a major contributor to sexual difficulties in men and women. Being able to assess distraction in studies of sexual arousal will help clarify underlying contributions to sexual problems. The current study aimed to identify the most accurate assessment of distraction from erotic cues in healthy men (n = 29) and women (n = 38). Participants were assigned to a no distraction, low distraction, or high distraction condition. Distraction was induced using an auditory distraction task presented during the viewing of an erotic video. Attention to erotic cues was assessed using three methods: a written quiz, a visual quiz, and a self-reported distraction measure. Genital and psychological sexual responses were also measured. Self-reported distraction and written quiz scores most accurately represented the level of distraction present, while self-reported distraction also corresponded with a decrease in genital arousal. Findings support the usefulness of self-report measures in conjunction with a brief quiz on the erotic material as the most accurate and sensitive ways to simply measure experimentally-induced distraction. Insight into distraction assessment techniques will enable evaluation of naturally occurring distraction in patients suffering from sexual problems. 相似文献
29.
When Working Hard Is Not Enough for Female and Racial/Ethnic Minority Apprentices in the Highway Trades
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Maura Kelly Lindsey Wilkinson Maura Pisciotta Larry S. Williams 《Sociological Forum》2015,30(2):415-438
Drawing on employment records, qualitative interviews, and a survey, we explore the experiences of apprentices in the highway trades in Oregon. We demonstrate that female and racial/ethnic minority apprentices have lower rates of recruitment and retention and disproportionately face challenges with interpersonal interactions, hiring practices, and supervisory practices. Yet, we find a pervasive narrative that attributes apprentices' success to “hard work,” which contributes to the legitimacy of these inequalities. Consistent with the conceptualization of work organizations as inequality regimes, we argue that the apprenticeship system has policies, practices, and ideologies that are on the surface gender and race/ethnicity neutral, yet lead to the perpetuation of inequalities. 相似文献
30.
Social media is pervasive in the lives of young people, and this paper critically analyses how politically engaged young people integrate social media use into their existing organisations and political communications. This qualitative research project studied how young people from a broad range of existing political and civic groups use social media for sharing information, mobilisation and, increasingly, as a means to redefine political action and political spaces. Twelve in-person focus groups were conducted in Australia, the USA and the UK with matched affinity groups based on university campuses. The groups were of four types: party political group, issue-based group, identity-based group and social group. Our focus group findings suggest that this in-depth approach to understanding young people's political engagement reveals important group-based differences emerging in young people's citizenship norms: between the dutiful allegiance to formal politics and a more personalised, self-actualising preference for online, discursive forms of political engagement and organising. The ways in which political information is broadcast, shared and talked about on social media by engaged young people demonstrate the importance of communicative forms of action for the future of political engagement and connective action. 相似文献