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971.
Elective single mothers are adult, unmarried women who intentionally become mothers. This study utilized longitudinal data about 17 Caucasian, elective single mothers and their children to identify fathers' roles in these families, and to understand children's views of their fathers. These single mothers and their children resided for the first six years of the children's lives in father-absent households. By age six, most of the children had ghost fathers, whom they had never met or knew little about. The data suggest that the father often becomes a family secret, and that children may blame themselves for their fathers' absence.  相似文献   
972.
973.
974.
Between 1987 and 1990, the Robert Wood Johnson Foundation funded six service credit banking demonstration programs among the elderly in which participants delivered services in return for credits, entitling them to later service. This evaluation of the demonstrations found that these six sites successfully attracted elders for the delivery of household support services to a relatively old, frail population with potentially limited social networks. Evidence on the significance of the "credit" in attracting volunteers was mixed, but the programs have attracted new volunteers, and have not substituted for other volunteer activities. Program development has entailed considerable staff investment in volunteer support; programs are better understood as community membership organizations than as mechanical exchanges.  相似文献   
975.
A paradox currently exists regarding legal sports gambling in North America: various forms are flourishing in Nevada, Oregon, and several Canadian provinces, while at the same time the United States Congress is conducting hearings on two bills that would prohibit any new state-sponsored sports gambling initiatives. This study examines the issue of why some jurisdictions are enthusiastic about legal sports gambling while others strongly resist the concept. In reviewing these divergent viewpoints, a case study of the newfledged Canadian Sport Select gambling format is presented. This example is used to highly the perils and payoffs of a typical state-sponsored sports gambling scheme, with a view toward broadening our understanding of how they work and how they might be fairer to the public.  相似文献   
976.
977.
Principal curves revisited   总被引:15,自引:0,他引:15  
A principal curve (Hastie and Stuetzle, 1989) is a smooth curve passing through the middle of a distribution or data cloud, and is a generalization of linear principal components. We give an alternative definition of a principal curve, based on a mixture model. Estimation is carried out through an EM algorithm. Some comparisons are made to the Hastie-Stuetzle definition.  相似文献   
978.
Jane Carmichael's views on Managing Inputs provide a further interesting contribution on a topic, strategic control, that we have covered on several occasions in this column. Carmichael's approach is to dig back behind the results being achieved to the 'inputs' on which they depend. But, while this may unearth causes of performance that can often be missed by a bottom-line orientation, results must ultimately remain vital; a business that is on track with all its input measures, but is missing its output goal is still in trouble. We continue to be interested in hearing from readers with views on strategic control processes, particularly those who have found productive ways of setting input and output targets.  相似文献   
979.
Nearly six years after the National Practitioner Data Bank was authorized by Congress in the Health Care Quality Improvement Act of 1986, and more than a year after its actual creation, the device is still only partially operational. What is more, the success of even those limited efforts is being questioned, and the timetable for future developments remains to be firmed up. Also, the costs are much higher than estimated.  相似文献   
980.
The day-to-day management of medical practice is so heavily influenced by tactical imperatives that few physicians have the time to think strategically. Traditionally, the difference between tactics and strategy is not a major concern of most physician executives. The realm of tactics is the short run, when managers must make do with the fixed resources at hand. Strategy addresses the long run, when all resources and markets are variable. A tactical focus is understandable, maybe even acceptable, in industries where nothing challenges traditional approaches to production of an established product or service. However, medical care in the 1990s is changing so fast that a physician executive must devote an incredible amount of time and effort just to stay confused about what is going on.  相似文献   
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