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961.
We present a method for estimating transmission matrices that describe the mixing and the probability of infection between age groups. Transmission matrices can be used to estimate age-dependent forces of infection in age-structured, compartmental models for the study of infectious diseases. We analyze the social network generated by the synthetic population of Portland and extract mixing patterns. Our results show that the mixing within the population consists of two groups, children and adults. Children interact most frequently with other children close to their own age, while adults interact with a wider range of age groups and the durations of typical adult contacts are shorter than typical contacts between children. Furthermore, the transmission matrix shows that children are more likely to acquire infection than adults.  相似文献   
962.
Summary.  We examine the claim that the well-known Petersen estimator which is used in population size estimation was not in fact used by the scientist after whom it is named. We show how, in the early years of the last century, the modern use of the Petersen estimator grew from that of the fishing coefficient. Contending with the somewhat conflicting claims that were made at the time, and what by modern standards is poor referencing of sources, we investigate where the credit lies for these concepts, and the principles and protocols which support them. We assess also how far attributions of credit were affected by practical considerations, and the history of the estimator by the nature of the problems being pursued. We identify scientists whose early work on marking and estimating fish populations deserves more credit than it has received.  相似文献   
963.
As part of a larger study on the health and safety of shiftworkers in the mining population by the US Bureau of Mines, the association between meal frequency, meal regularity, eating satisfaction and a self-reported health index was examined. Although the link between shiftwork and some health complaints, such as gastrointestinal disorders, has been established, the research needed to understand why this occurs has not been fully undertaken. Specifically, academic nutritional research has substantially ignored the question of how working irregular hours affects the eating behavior of industrial workers such as miners. In this study the eating habits of 101 surface mine workers were studied. It was found that working the day, afternoon/evening, and night-shifts was related to the number of meals eaten on those shifts and to the consistency of timing of those meals. The lowest eating satisfaction levels were reported by those who ate at different times on all shifts and who changed the number of meals eaten per day on each shift. Lowest self-reported health ratings were reported by those who changed the number of meals taken on each shift, rather than by those who ate one, two or three meals per day. These results are discussed in relation to the possible mechanisms contributing to gastrointestinal disorders and to coping mechanisms that could be adopted by shiftworkers.  相似文献   
964.
965.
The article provides evidence that there is a relationship between government debt and interest rates via the demand for money. This relationship is examined through the wealth effect of government debt on money demand, and the robustness of the results is tested by the use of extreme bound analysis in addition to standard econometric techniques. We find that OLS regression shows government debt fnfecting the demand for money positively, implying that Federal government debt is net wealth. In addition, the extreme bound analysis shows that the estimates of the government debt coefficient are robust under alternative specifications of the Goldfeld model.  相似文献   
966.
This paper suggests that the concept of the muse in relation to the creative process is more than a myth or cultural artifact. It is argued that the muse is a psychic recollection of our memories of the female who presided over our first experiences of consciousness as we traversed the borders of inner and outer reality—that is, the mother. The shift of consciousness required in creative activity triggers recall of this figure. Object relations theory, recent findings from infant research, and the intuitive observations of several authors are used to support this thesis. Clinical examples illustrate the application of this concept in treatment.  相似文献   
967.
A cohort of twenty British national voluntary agencies serving handicapped people was studied in 1976 and again in 1989 after a decade of major shifts in public policy. Changes and continuities were identified in income, structure, governance, management, programme, interorganisation relations and advocacy. A consistent pattern of growth, bureaucratisation and professionalisation was found, with relatively little change in the dominant mode of financing, statutory or philanthropic. A three-stage model is proposed to describe the development of British voluntary agencies since the 1970s, and some of the organisational implications of current policies for the 1990s are noted.This research is part of a Fulbright, Western European Regional Research Grant for 1989 and also received support from the University of California, Institute for International Studies and the Committee for Research at Berkeley. I wish to thank Marilyn Taylor and Stuart Etherington in London, and my colleagues Neil Gilbert, Bart Grossman and Paul Terrell for their helpful comments on an earlier draft. The assistance of David Billis, Director, and the staff of the Centre for Voluntary Organisation, London School of Economics, is also gratefully acknowledged.  相似文献   
968.
This article reports on a preliminary study of the impact of parent-led prevention groups on youthful drug and alcohol use. In addition, the study assessed the extent to which families involved with parent-led prevention programs reported improved family relations and increased parental control of children's social activities--two major mechanisms by which parent-group advocates claim their activities alter youth substance use patterns. Consistent with the claims of parent-group advocates, the study results suggest that the parent groups did have some impact on family relations and on parental control of children's social activities. The evidence for an impact on drug and alcohol use was, however, weak. A somewhat unexpected finding was that parents who become involved in parent-led prevention activities may not be those parents whose children are at highest risk.  相似文献   
969.
Grounded theory research: Procedures,canons, and evaluative criteria   总被引:35,自引:0,他引:35  
Using grounded theory as an example, this paper examines three methodological questions that are generally applicable to all qualitative methods. How should the usual scientific canons be reinterpreted for qualitative research? How should researchers report the procedures and canons used in their research? What evaluative criteria should be used in judging the research products? We propose that the criteria should be adapted to fit the procedures of the method. We demonstrate how this can be done for grounded theory and suggest criteria for evaluating studies following this approach. We argue that other qualitative researchers might be similarly specific about their procedures and evaluative criteria.  相似文献   
970.
Analysis reported here examined youth in residential group home placements in order to better understand how sexual behaviors, drug use, and environmental experiences differ by race and gender subgroups. Data were collected from 336 youth aged 14–21 residing in one of 41 group homes in Maryland. Chi square and logistic regression analyses were done to determine differences on study variables among the race-gender groupings. Results demonstrate not only significant health concerns overall but notable differences were also found between race-gender subgroups. Findings suggest that found race-gender subgroup differences might be informative for tailoring programming for youth of residential group home settings.  相似文献   
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