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51.
Asthma patients' health status may be especially sensitive to some types of air pollution, but the evidence on this is mixed. We explore the effects of ground-level ozone on asthma patient's activities, breaking apart the usual aggregated category of leisure into indoor and outdoor activities, and differentiating those by whether the activities were active or inactive. Applying the semiparametric censored estimation method we demonstrate that even though the period over which activities were observed was relatively low in ozone levels, there is a significant impact of ozone on a few activities. The (non-ozone) economic and demographic variables in the model play significant roles in explaining the allocation of time among seven activities, suggesting the suitability of the approach for other household decision-making contexts.  相似文献   
52.
Abstract An examination of big‐city newspaper coverage of violent crimes in small towns during a recent five‐year period reveals a remarkable degree of uniformity in the language reporters use to characterize life in these places. The cliches signal an underlying set of stereotypes of small‐town life: They are safe, close‐knit communities where bad things are “not supposed to happen.” Yet the point of the stories is that bad things do happen. Drawing upon culturological and sociological approaches to the study of news production, this paper argues that the small towns described in the news are symbolic landscapes that reflect a pastoral orientation among journalists and in the culture at large.  相似文献   
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The goal of Louisiana's 1990–1991 comparative risk project, also called the Louisiana Environmental Action Plan (LEAP), was to incorporate risk assessment into state environmental planning and policymaking. Scientists, government officials, and citizens were brought together to estimate the relative risk to human health, natural resources, and quality of life posed by 33 selected environmental issues. The issues were then ranked according to their relative estimated risks. It was hoped that this ranking of "comparative risks" would enable state policymakers to target the most important environmental problems and allocate scarce public resources more rationally and efficiently. As a result of the project, the governor issued an Executive Order forming a permanent Public Advisory Committee to continue this type of comparative risk assessment in Louisiana.  相似文献   
55.
Native American drinking: a neglected subject of study and research   总被引:1,自引:0,他引:1  
Although Native Americans are plagued by high rates of alcoholism, violence, suicide and early death, these social and clinical problems are usually given little more than cursory treatment in textbooks. A content analysis of twenty-six textbooks on alcoholism and substance misuse revealed that only four provided a detailed discussion of Native American drinking. Greater attention needs to be given to the cultural, psychological, and biological issues of drinking and drunkenness among this special population.  相似文献   
56.
The EM algorithm is a popular method for maximizing a likelihood in the presence of incomplete data. When the likelihood has multiple local maxima, the parameter space can be partitioned into domains of convergence, one for each local maximum. In this paper we investigate these domains for the location family generated by the t-distribution. We show that, perhaps somewhat surprisingly, these domains need not be connected sets. As an extreme case we give an example of a domain which consists of an infinite union of disjoint open intervals. Thus the convergence behaviour of the EM algorithm can be quite sensitive to the starting point.  相似文献   
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Preface     
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58.
The present study was conducted to assess differences in the behavioral and demographic characteristics of snuff (dip) users as compared to users of chewing tobacco. High School football players (1116) were surveyed concerning their use and perceptions of smokeless tobacco. Adolescent athletes who tried smokeless tobacco were more likely to be white, to use cigarettes, alcohol, and cigars and to have family users than those who never tried. Initial use was highest before the age of fourteen years and was influenced by friends, curiosity and family. Dippers tended to initiate use because of friends, while chewers started because of family users. Users of both dip and chew started primarily because of curiosity. Users of both were more likely to consume greater amounts to alcohol and cigarettes and to smoke cigars and pipes. It appears that the longer smokeless tobacco is consumed, the more likely both dip and chew will be used. Users of smokeless tobacco for more than two years tended to consume more of the product each week, used it for more hours/day, initiated use at an earlier age, and used it more often at school and work than those using it for less than two years. Use of cigars/pipes, consumption of alcohol, and quantity of cigarette consumption increased significantly with longer duration of smokeless tobacco use. Intervention and prevention programs would be helped by understanding differences between users of various smokeless tobacco products and differences related to the duration of use. In addition, further analyses of smokeless tobacco users should study chewers, dippers, and users of both separately.  相似文献   
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Prior corporate reputation, one responsibility of a public relations department, affects public perceptions toward corporate philanthropic messages and ultimately affects public attitudes toward the company. Using an experiment that emulates the sort of news consumption individuals normally undertake, participants inferred corporate charitable giving as a mutually beneficial activity when a company had a good reputation (H1a). Participants inferred corporate charitable giving as a self-interested activity when the company had a bad reputation (H1b). Also, public inference (suspicion) successfully mediated corporate prior reputation on public attitude toward the company (H2). Participants showed positive attitude toward the company when they inferred the company had an altruistic motive for charitable giving (H3a). However, participants showed negative attitude toward the company when they inferred the company had a self-interested motive for charitable giving (H3b).  相似文献   
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