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This article examines the changing patterns of poverty in Singapore. As Singapore's population ages, the poor increasingly includes the elderly. It appears that ascribed factors, such as gender and race, have significant influence on financial security at old age. As the population ages, the adequacy of existing anti-poverty policy is challenged. 相似文献
113.
Logistic Regression in Rare Events Data 总被引:27,自引:1,他引:26
We study rare events data, binary dependent variables with dozensto thousands of times fewer ones (events, such as wars, vetoes,cases of political activism, or epidemiological infections)than zeros ("nonevents"). In many literatures, these variableshave proven difficult to explain and predict, a problem thatseems to have at least two sources. First, popular statisticalprocedures, such as logistic regression, can sharply underestimatethe probability of rare events. We recommend corrections thatoutperform existing methods and change the estimates of absoluteand relative risks by as much as some estimated effects reportedin the literature. Second, commonly used data collection strategiesare grossly inefficient for rare events data. The fear of collectingdata with too few events has led to data collections with hugenumbers of observations but relatively few, and poorly measured,explanatory variables, such as in international conflict datawith more than a quarter-million dyads, only a few of whichare at war. As it turns out, more efficient sampling designsexist for making valid inferences, such as sampling all availableevents (e.g., wars) and a tiny fraction of nonevents (peace).This enables scholars to save as much as 99% of their (nonfixed)data collection costs or to collect much more meaningful explanatoryvariables. We provide methods that link these two results, enablingboth types of corrections to work simultaneously, and softwarethat implements the methods developed. 相似文献
114.
This Article analyzes the issues involved in converting nonprofit Blue Cross organizations to for-profit status. These issues have arisen in the context of litigation regarding the "reorganization" of Blue Cross and Blue Shield of Missouri ("BCBSMo"). BCBSMo had reorganized by creating and transferring a majority of its business to a new for-profit subsidiary. Missouri consumer groups and state regulators characterized the "reorganization" as a conversion requiring BCBSMo to transfer its assets to a foundation dedicated to charitable health purposes. BCBSMo, however, denied that it had any obligation to leave behind its assets in the nonprofit sector. The BCBSMo litigation raises issues common to most conversions of nonprofit healthcare organizations, particularly conversions of nonprofit Blue Cross plans. This Article provides a road map for state regulators and the public to follow in ensuring that the public interest is fully protected in such conversions. 相似文献
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Darling Nancy Dowdy Bonnie B. Van Horn M. Lee Caldwell Linda L. 《Journal of youth and adolescence》1999,28(4):461-480
This study examines the association of self-perceptions with sixth to eighth graders' exposure to mixed-sex and dating contexts. It contrasts two hypotheses: the stress hypothesis, which suggests that the transition to romantic relationships will be associated with declines in self-esteem, especially for girls, and the leisure hypothesis, which suggests that movement into a desired role in an emotionally positive social context will be associated with positive emotions and higher self-esteem. Results indicate that adolescents experience mixed-sex settings positively, and that comfort with the other sex (for girls) and more time spent with the other sex (for boys) are predictive of more positive self-perceptions. Activity diary data suggest that these differences are due to differences in the emotional climate of same- and mixed-sex settings, rather than to the activities adolescents engage in with same- and mixed-sex groups. Dating boys who are less interested in dating experience lower self-esteem. Results are discussed in light of the transitional nature of mixed-sex relationships in early adolescence and the preparatory role played by same-sex friendships. 相似文献
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A validation study for the extraction and analysis of DNA from human nail material and its application to forensic casework. 总被引:5,自引:0,他引:5
T D Anderson J P Ross R K Roby D A Lee M M Holland 《Journal of forensic sciences》1999,44(5):1053-1056
A validation study was conducted to demonstrate that deoxyribonucleic acid (DNA) could be successfully extracted from human nail material and analyzed using short tandem repeat (STR) profiling and/or mitochondrial DNA (mtDNA) sequencing. This study involved the development of a DNA extraction protocol that includes a cleaning procedure designed to remove external contaminants (e.g., biological, chemical). This protocol was used to test human nail material that had been soaked in whole blood from a second donor and coated with gold-palladium to simulate scanning electron microscopic analysis. The results showed no indication of a mixture and were consistent with that of the nail donor. Fresh human nail material usually yielded both STR profiles and mtDNA sequence information; however, aged human nail material (approximately eight years old) yielded only mtDNA sequence information. Upon completion of the validation study, the extraction protocol was used for the analysis of a torn fingernail fragment recovered from the scene of a violent homicide in 1983. A partial STR profile and mtDNA sequence information indicated that the fingernail fragment was excluded as originating from the suspect and was, in fact, consistent with originating from one of the victims. 相似文献
120.
Felecia A. Lee Rhonda K. Lewis Chris M. Kirk 《Journal of prevention & intervention in the community》2013,41(4):277-288
The purpose of this article is to examine the self-reported sexual attitudes and behaviors of adolescents living in the Midwest. A survey was administered to 463 African American youths ages 11–19. The results indicate that intent to have sexual intercourse, reported likelihood toward having sexual intercourse, and whether participants felt that they would have sex in the next 3 months were predictors of whether they had sexual intercourse at the 3-month follow-up. The results also revealed that the opinions of referent others did not predict sexual intercourse at 3 months. Negative attitudes toward condoms did predict condom use at 3 months and the opinions of referent others also predicted condom use at 3 months. Limitations as well as future research are also discussed. 相似文献