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231.
Summary. Possible health hazards from mobile phones arise from the use of the phones themselves and via the base stations that relay signals. Except for an increase in traffic accidents induced by the use of mobile phones in cars the evidence for a health hazard is at most indirect, but it cannot be entirely dismissed; the phones have not been widely used for sufficiently long for direct epidemiological studies to have high sensitivity for detecting any induced incidence of cancer, for example. The background and evidence are briefly reviewed and the steps taken in the UK to make information widely available described.  相似文献   
232.
The Alchian and Allen theorem predicts that it will be harder to find "good" apples in the State of Washington, a prime apple-growing region, than in, say, New York City, where the addition of shipping charges makes "bad" apples comparatively more expensive. We recast the theorem as a testable proposition by explicitly taking the supply side into account and identifying plausible scenarios in which a fixed cost either has no effect on the relative prices of high and low quality grades of the same good in distant markets or, indeed, causes more of the bad apples to be shipped out.  相似文献   
233.
The moderating role of maternal characteristics and maternal sensitivity on the concordance between maternal reports and laboratory observations of negative emotionality was examined. Participants were 90 primiparous mothers and their infants. Mothers completed questionnaires about remembered care from their own parents and their depressive symptoms prenatally, infant temperament (distress to novelty and distress to limitations), and depressive symptoms postnatally. Mothers and infants participated in a laboratory assessment of infant temperament (distress to novelty and limitations) and maternal sensitivity at 6 months postpartum. Several factors that moderate the degree of concordance between maternal reports and behavioral observations were identified, as predicted. Novelty concordance was higher when mothers reported having their emotional needs met in childhood and low prenatal depressive symptoms. Limitations concordance was higher when mothers were less sensitive during the observational tasks. Methodological and theoretical implications are discussed.  相似文献   
234.
235.
This paper is concerned with joint tests of non-nested models and simultaneous departures from homoskedasticity, serial independence and normality of the disturbance terms. Locally equivalent alternative models are used to construct joint tests since they provide a convenient way to incorporate more than one type of departure from the classical conditions. The joint tests represent a simple asymptotic solution to the “pre-testing” problem in the context of non-nested linear regression models. Our simulation results indicate that the proposed tests have good finite sample properties.  相似文献   
236.
Fertility and Employment   总被引:3,自引:0,他引:3  
  相似文献   
237.
1. Research shows that many emergency workers are affected physically and emotionally by critical incident stress. 2. Debriefings conducted by trained team members are an effective method to mitigate the impact of critical incident stress. A debriefing is a structured, time-limited group intervention. 3. Cooperation among community agencies is essential for the development and effective functioning of a critical incident stress debriefing team. 4. Several teams in Illinois have organized to form a Critical Incident Stress Debriefing Network. The Illinois network is part of an international organization composed of critical incident stress debriefing providers.  相似文献   
238.
Research on gambling has the double mandate of public service and the advancement of science. This paper is meant to carry forward that mandate. Latent in research on the causes of problem gambling is the policy insight that these causes represent different types of phenomena and are unequally mutable to practitioners' efforts to prevent and/or treat problem gambling. By making the issue of mutability manifest in research, findings from research would have more policy relevance and practical import. Data from a 1989 Iowa survey on lottery play and problem gambling are analyzed to illustrate this point. 1,226 respondents were contacted by phone and phone interviews were completed with 1,011 of these 1,226 eligible respondents. With multiple regression, we assessed the contributions of mutable and immutable variables to the explained variance in problem gambling. The results show mutable correlates explain enough variance in problem gambling to recommend their consideration in treatment/prevention. The results also suggest a social as well as a psychological etiology to problem gambling. Future research should, however, do a more complete comparison of social and psychological causes of problem gambling.This research was partially supported by the Iowa Department of Human Services and the National Institute of Mental Health (1 R01 MH50369-01A1). The authors wish to thank Willis Goudy, anonymous readers and the editor of this journal for helpful comments.  相似文献   
239.
This study examines the relationships among personal coping resources, social support, external coping resources, job stressors and job strains in a sample of 110 American Telephone and Telegraph employees undergoing a major organizational restructuring. The study expanded on a model suggested by Ashford (1988) by defining another category of coping resources that employees may draw upon to deal with the stressors and strains which occur during major organizational changes. External coping resources were defined as those which provided employees with a sense of 'vicarious control' in stressful situations. Results indicated that personal coping resources, social support and external coping resources had a direct effect upon job stressor and strain levels. No 'buffering' effect of these coplng resources was found. Hierarchical regression analyses indicated that external coping resources added to the prediction of job stressors and strains even when pertonal coping resources and social support were entered first into the prediction questions.  相似文献   
240.
We tested a mathematical model of psychological well-being (PWB) with data from a paradigm that included a negative mood induction followed by a positive induction. The propositions from the model encompass the hypothesis that the relative mood prior to either induction has implications for the magnitude of subsequent induction effects, such that relative mood is defined by current mood as a ratio of the prevailing mood that is predicted by the model. The findings confirm the hypothesis that the relative mood at baseline predicts mood change in a nonoverlapping time period, even after control for potentially mediating variables.  相似文献   
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