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161.
The completely random character of radioactive disintegration provides the basis of a strong justification for a Poisson linear model for single-photon emission computed tomography data, which can be used to produce reconstructions of isotope densities, whether by maximum likelihood or Bayesian methods. However, such a model requires the construction of a matrix of weights, which represent the mean rates of arrival at each detector of photons originating from each point within the body space. Two methods of constructing these weights are discussed, and reconstructions resulting from phantom and real data are presented.  相似文献   
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A nationally representative sample of respondents estimated their fatality risks from four types of natural disasters, and indicated whether they favored governmental disaster relief. For all hazards, including auto accident risks, most respondents assessed their risks as being below average, with one-third assessing them as average. Individuals from high-risk states, or with experience with disasters, estimate risks higher, though by less than reasonable calculations require. Four-fifths of our respondents favor government relief for disaster victims, but only one-third do for victims in high-risk areas. Individuals who perceive themselves at higher risk are more supportive of government assistance.  相似文献   
166.
This study examined the unique and interactive roles of mother and teacher depressive symptoms in child adjustment in 277 African American single mother‐headed families, as well as whether the associations differed depending on the age and gender of the child. Findings revealed a significant association between maternal depressive symptoms and child depressive symptoms in girls, but not boys. Moreover, the combination of higher levels of both mother and teacher depressive symptoms was associated with the highest level of child depressive symptoms and, for younger children, externalizing symptoms. The importance of considering the multiple social contexts in which children interact is discussed.  相似文献   
167.
The aim of the study was to explore the degree (and type) of burnout and trauma symptoms, personal histories and coping strategies retrospectively reported by those who work with maltreated children and their families. A self‐selected sample of workers (N = 44) completed a self‐report questionnaire assessing childhood maltreatment, family background characteristics, current adjustment, coping strategies and burnout. Workers reported high levels of emotional exhaustion and depersonalization, and a low to moderate sense of personal accomplishment. Family background characteristics predicted the occurrence of maltreatment and current adjustment, and a personal history of maltreatment predicted current trauma symptoms, but not burnout. Workers most frequently used problem‐focused coping strategies and sought social support; however, coping strategies were not associated with the level of either trauma symptoms or burnout. Despite employing positive coping strategies, their efficacy may be affected by other interpersonal, intra‐individual and job resource issues. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   
168.
This study challenges the prevailing view that marital companionship promotes marital satisfaction. By following a cohort of married couples for over a decade and by incorporating several methodological improvements—such as refining the measurement of marital satisfaction, determining how much spouses enjoy doing the leisure activities they pursue together and apart, and using diary data to portray marital leisure patterns—we found that the association between companionship and satisfaction is less robust than previously believed, and that it depends on how often spouses pursue activities that reflect their own and their partner's leisure preferences. Over time, involvement in leisure liked by husbands but disliked by wives, whether as a couple or by husbands alone, is both a cause and a consequence of wives' dissatisfaction.  相似文献   
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This article addresses the process of initiation into the Catholic Church by analyzing in‐depth interviews with parish‐based professional initiation coordinators. The formal title given to this process of initiation by the Church since Vatican II is the Rite of Christian Initiation of Adults (RCIA). Since the RCIA's promulgation, the Church has hired a host of lay and religious professionals to coordinate its implementation at the parish level. Our analysis focuses on the temporal sequencing and the problem of duration of initiation. The data show that both city and suburban coordinators adapted the Church's mandated length of time for initiation in different ways as they negotiated covenantal and contractual social relations among RCIA participants.  相似文献   
170.
Rainfall interception by Santa Monica's municipal urban forest   总被引:4,自引:2,他引:2  
Effects of urban forests on rainfall interception and runoff reduction have been conceptualized, but not well quantified. In this study rainfall interception by street and park trees in Santa Monica, California is simulated. A mass and energy balance rainfall interception model is used to simulate rainfall interception processes (e.g., gross precipitation, free throughfall, canopy drip, stemflow, and evaporation). Annual rainfall interception by the 29,299 street and park trees was 193,168 m3 (6.6 m3/tree), or 1.6% of total precipitation. The annual value of avoided stormwater treatment and flood control costs associated with reduced runoff was $110,890 ($3.60/tree). Interception rate varied with tree species and sizes. Rainfall interception ranged from 15.3% (0.8 m3/tree) for a small Jacaranda mimosifolia (3.5 cm diameter at breast height) to 66.5% (20.8 m3/tree) for a mature Tristania conferta (38.1 cm). In a 25-year storm, interception by all street and park trees was 12,139.5 m3 (0.4%), each tree yielding $0.60 (0.4 m3/tree) in avoided flood control costs. Rainfall interception varied seasonally, averaging 14.8% during a 21.7 mm winter storm and 79.5% during a 20.3 mm summer storm for a large, deciduous Platanus acerifolia tree. Effects of differences in temporal precipitation patterns, tree population traits, and pruning practices on interception in Santa Monica, Modesto, and Sacramento, California are described.  相似文献   
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