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41.
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The probability of first marriage for men who graduated from Wisconsin high schools in 1957 was analyzed with respect to their Social Security earnings records, Wisconsin income tax reports for parents, and other variables. The findings provide no support for Easterlin's hypothesis that marriage will occur earlier when young men judge their economic prospects favorably with respect to their parents' income. However, young men's earnings and time spent in schooling to increase them were found to be important influences on marriage timing. Additional schooling had little effect net of the time it absorbed.  相似文献   
43.
Anecdotal reports have suggested that the use and abuse of methamphetamine is increasing in the United States. To date, however, few scholarly works have explored the prevalence and correlates of methamphetamine use in the United States. To address this limitation, a secondary analysis was undertaken with data collected through the Arrestee Drug Abuse Monitoring (ADAM) Program. An examination of methamphetamine-positive rates among ADAM arrestees interviewed between 1991 and 2001 identified that its use is concentrated within the Western part of the United States. Supplementary analyses of Sacramento arrestees indicated that 71% were diagnosed as needing some form of alcohol or other drug treatment. Compared to those arrestees who were detected methamphetamine-negative, methamphetamine-positive arrestees in Sacramento were three times as likely to be white and to have been diagnosed in need of drug treatment. Implications for drug control policy are discussed.  相似文献   
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Simple, closed form saddlepoint approximations for the distribution and density of the singly and doubly noncentral F distributions are presented. Their overwhelming accuracy is demonstrated numerically using a variety of parameter values. The approximations are shown to be uniform in the right tail and the associated limitating relative error is derived. Difficulties associated with some algorithms used for exact computation of the singly noncentral F are noted.  相似文献   
46.
In the current study, we used a qualitative approach to investigate relevant beliefs and norms associated with codeine and promethazine hydrochloride cough syrup (CPHCS) consumption, initiation, and perceived addiction among 48 alternative school students who identified themselves as current CPHCS users. In general, both boys and girls believed that CPHCS addiction started during an individual's initial consumption. A majority of both groups reported that their second CPHCS event was initiated during the same or next day after their first event. Our findings suggest that friends and an innovative form of hip-hop music called "screw" are strong reinforcers of CPHCS use.  相似文献   
47.
The fusion of male- and female-derived gametes initiates the phenomenal process of producing a highly complex mammalian organism. Successful reproduction is so important that mammals invoke a battery of protective mechanisms for the germ cell lineages that function to maximize genetic integrity while still allowing genetic diversity and adaptation. Protective mechanisms likely include, but are not limited to, robust DNA repair to safeguard genetic integrity and apoptosis to remove cells with intolerable levels of DNA damage. Analyses of spontaneous mutant frequencies are generally consistent with germline DNA being stringently maintained relative to somatic tissues. Despite the rigorous protection afforded germ cells, genetic integrity is observed to decline with increased maternal and paternal age. It is not yet clear whether cells in the germ line truly age or whether other processes decline or become dysfunctional with age. For example, in a younger animal, the differentiation and/or utilization of germ cells with lower genetic integrity might be disallowed, whereas in an older animal, such cells might slip past these quality-control mechanisms.  相似文献   
48.
Relationships between parenting styles, academic performance, and the mediating effects of motivation, goal orientation, and self-efficacy were examined. One hundred forty-eight high school students participated, including 58 males and 90 females. The Parenting Style/Parental Involvement Questionnaire was used to measure students' perceptions of their parents' parenting styles. The Intrinsic-Extrinsic Orientation Scale measured students' motivation. The Patterns of Adapted Learning Survey measured participants' goal orientation and academic self-efficacy. Adolescents who reported their parents as having a more authoritative parenting style were found to demonstrate more intrinsic motivation in their academic pursuits. Future implications for intervention and research are discussed.  相似文献   
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This paper reports on the relationship between dimensions of control (skill discretion and decision authority) and burnout (emotional exhaustion, depersonalization, and reduced personal accomplishment) among 164 human service workers. It examines the differential influence of job demands, control (skill discretion and decision authority) and social support (supervisor, co-workers, others) on each burnout dimension. Then it examines the moderating effects of higher skill discretion, higher decision authority, and higher social support on burnout. Low skill discretion was found to be associated with high emotional exhaustion and depersonalization and low personal accomplishment. The effects of decision authority were not statistically significant. High job demands were associated with high emotional exhaustion only. Social support (supervisor, co-worker, and others) was not associated with burnout when demographic variables and job characteristics were controlled for. Neither dimension of control moderated the impact of high job demands on burnout. Social support did not moderate the impact of high demands, low skill discretion, or low decision authority on any burnout dimension. The full model explained 44% of the variance in emotional exhaustion, 25% in depersonalization, and 42% in personal accomplishment. Despite its limitations, the study suggests that the Job Demand-Control model may provide a useful theoretical foundation for the study of burnout, but that the control dimensions need to be evaluated independently since they appear to be differentially related to the burnout dimensions.  相似文献   
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