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921.
922.
ABSTRACT

The purpose of this qualitative study was to explore the social networks of Appalachian adolescents to understand socialization strategies and goals. A total of 46 interviews were conducted with five families (mothers, fathers, and adolescents) and 11 socialization agents the families identified as exerting significant influence in the lives of the adolescents. Interviews were transcribed and then analyzed using principles of grounded theory. Five themes developed from the interviews: the importance of community to the socialization process, adult involvement and support, adolescent monitoring, teaching respect and responsibility, and adolescent autonomy. Results suggest the need for in-depth investigation of adolescent development within a variety of cultural and social contexts to more fully understand these processes.  相似文献   
923.
In this paper, we consider noninformative priors for the ratio of variances in two normal populations. We develop first and second order matching priors. We find that the second order matching prior matches alternative coverage probabilities up to the second order and is also a HPD matching prior. It turns out that among the reference priors, only one-at-a-time reference prior satisfies a second order matching criterion. Our simulation study indicates that the one-at-a-time reference prior performs better than other reference priors in terms of matching the target coverage probabilities in a frequentist sense. This work is supported by Korea Research Foundation Grant (KRF-2004-002-C00041).  相似文献   
924.
925.
The concept of exposure is central to chemical risk assessment and plays an important role in communicating to the public about the potential health risks of chemicals. Research on chemical risk perception has found some indication that the model lay people use to judge chemical exposure differs from that of toxicologists, thereby leading to different conclusions about chemical safety. This paper presents the results of a series of studies directed toward developing a model for understanding how lay people interpret the concept of chemical exposure. The results indicate that people's beliefs about chemical exposure (and its risks) are based on two broad categories of inferences. One category of inferences relates to the nature in which contact with a chemical has taken place, including the amount of a chemical involved and its potential health consequences. A second category of inferences about chemical exposure relates to the pragmatics of language interpretation, leading to beliefs about the motives and purposes behind chemical risk communication. Risk communicators are encouraged to consider how alternative models of exposure and language interpretation can lead to conflicting conclusions on the part of the public about chemical safety.  相似文献   
926.
This study examined the antecedents of job strain (emotional exhaustion, health complaints) and withdrawal behaviour (e.g. lowered organizational commitment) among a cross-sectional sample of 131 academic staff members of the law department of a large Dutch university. Conservation of resources theory (Hobfoll, 1989) provided the theoretical background for this study. Strains and withdrawal behaviours were expected to be most prominent among those who reported having few resources and/or who reported high job demands. Structural equation modelling revealed that this was indeed the case. As predicted, differential patterns of effects emerged for job demands and job resources. Analysis of the effects of four job-specific stressors revealed that especially the structural aspects of a staff member's teaching task (e.g. the number of students in their classes) contributed strongly to perceived job demands. Theoretical and practical implications of the study are discussed.  相似文献   
927.
The rationale for policy interest in career development services and the way in which this rationale is being strengthened by the current transformations in work and career are discussed. The potential roles of public policy in relation to career development services are explored, along with ways in which such services can influence the policy‐making process. A range of policy issues related to making career development services available to all throughout life are identified. Stronger structures and processes are needed to bring together career development practitioners with policy makers and other stakeholder interests in order to address tasks of common concern.  相似文献   
928.
Confidence intervals for parameters that can be arbitrarily close to being unidentified are unbounded with positive probability [e.g. Dufour, J.-M., 1997. Some impossibility theorems in econometrics with applications to instrumental variables and dynamic models. Econometrica 65, 1365–1388; Pfanzagl, J. 1998. The nonexistence of confidence sets for discontinuous functionals. Journal of Statistical Planning and Inference 75, 9–20], and the asymptotic risks of their estimators are unbounded [Pötscher, B.M., 2002. Lower risk bounds and properties of confidence sets for ill-posed estimation problems with applications to spectral density and persistence estimation, unit roots, and estimation of long memory parameters. Econometrica 70, 1035–1065]. We extend these “impossibility results” and show that all tests of size α concerning parameters that can be arbitrarily close to being unidentified have power that can be as small as α for any sample size even if the null and the alternative hypotheses are not adjacent. The results are proved for a very general framework that contains commonly used models.  相似文献   
929.
Formative research is often required for program planning, and for reducing uncertainty about generalizability of program effects. This article describes and justifies methods of formative research conducted for the REACT study (Rapid Early Action for Coronary Treatment), a multi-center collaborative randomized community trial aimed at reducing patient delay in seeking care for acute myocardial infarction (AMI). Formative research cast light on patient and community members’ decision-making process in seeking help for AMI, as well as barriers and facilitators of this process. Investigators at all five REACT Field Centers participated in the formative research. The process consisted of: (1) developing a common theoretical framework for the study intervention; (2) conducting a literature review and qualitative research to identify and address gaps in knowledge; and (3) developing a common protocol for the REACT study that accommodated the diversity of the target communities in terms of services, resources, history, and ethnicity. Analysis employed triangulation, defined as an explicit search for heterogeneous data sources to reduce uncertainty about forces at work and opportunities for intervention across settings and populations. Because the collection and interpretation of data went in stages, staff of several REACT Field Centers had independent input to the overall synthesis, then shared and revised the results. Advantages and limitations of this approach are discussed.  相似文献   
930.
Objective . This article examines individual level black-white differences in adult homicide mortality. Homicide is a major social problem and a central cause of preventable death in the United States. A homicide not only claims one life prematurely but can also devastate a family, friends, and a neighboring community. Methods . We link eight consecutive years of the National Health Interview Survey (1987–94) to the Multiple Cause of Death file through the National Death Index (1987–97), and use Cox proportional hazard models to examine the role of social factors in black-white homicide mortality in the United States. Results . We find that individual level sociodemographic characteristics—age, sex, marital status, education, employment status, and geographic factors—explain almost 35 percent of the racial differences in homicide mortality. Conclusions . These results demonstrate the contributions that National Center for Health Statistics data can make to criminological literature and reveal the mechanisms through which blacks experience higher homicide mortality than whites. Such illumination may lead to a reduction in the fourth leading preventable cause of death in the United States.  相似文献   
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