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391.
To develop a quantitative exposure‐response relationship between concentrations and durations of inhaled diesel engine exhaust (DEE) and increases in lung cancer risks, we examined the role of temporal factors in modifying the estimated effects of exposure to DEE on lung cancer mortality and characterized risk by mine type in the Diesel Exhaust in Miners Study (DEMS) cohort, which followed 12,315 workers through December 1997. We analyzed the data using parametric functions based on concepts of multistage carcinogenesis to directly estimate the hazard functions associated with estimated exposure to a surrogate marker of DEE, respirable elemental carbon (REC). The REC‐associated risk of lung cancer mortality in DEMS is driven by increased risk in only one of four mine types (limestone), with statistically significant heterogeneity by mine type and no significant exposure‐response relationship after removal of the limestone mine workers. Temporal factors, such as duration of exposure, play an important role in determining the risk of lung cancer mortality following exposure to REC, and the relative risk declines after exposure to REC stops. There is evidence of effect modification of risk by attained age. The modifying impact of temporal factors and effect modification by age should be addressed in any quantitative risk assessment (QRA) of DEE. Until there is a better understanding of why the risk appears to be confined to a single mine type, data from DEMS cannot reliably be used for QRA.  相似文献   
392.
In this paper, we examine individuals’ career migration across international borders. It is widely recognized that globalization has fundamental implications for the careers of people across geographical and cultural boundaries. However, our understanding of the interplay of migration, career development and national/cultural identities remains undeveloped within the extant literature. In this paper, we seek to offer insights into this relationship. Focusing on Indian scientists, an occupational group whose careers have long been associated with movement around the world, in this paper we examine these issues. Empirically, we examine three themes: why Indian scientists see international mobility as important in the development of their careers; continued links with India; and the interplay of national/cultural affiliation and respondents’ career experiences. In light of our findings, in the discussion section we argue that considering Indian scientists as a career diaspora highlights three important features that in the main have received only limited attention in the extant literature: career as a social form and process; the notion of the scientific career as a cultural product; and the interrelationship of career and national/cultural affiliation as ongoing facets of individuals’ identities as they develop diasporic careers.  相似文献   
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In this article, we consider some nonparametric goodness-of-fit tests for right censored samples, viz., the modified Kolmogorov, Cramer–von Mises–Smirnov, Anderson–Darling, and Nikulin–Rao–Robson χ2 tests. We also consider an approach based on a transformation of the original censored sample to a complete one and the subsequent application of classical goodness-of-fit tests to the pseudo-complete sample. We then compare these tests in terms of power in the case of Type II censored data along with the power of the Neyman–Pearson test, and draw some conclusions. Finally, we present an illustrative example.  相似文献   
396.
Two symmetrical fractional factorial designs are said to be combinatorially equivalent if one design can be obtained from another by reordering the runs, relabeling the factors and relabeling the levels of one or more factors. This article presents concepts of ordered distance frequency matrix, distance frequency vector, and reduced distance frequency vector for a design. Necessary conditions for two designs to be combinatorial equivalent based on these concepts are presented. A new algorithm based on the results obtained is proposed to check combinatorial non-equivalence of two factorial designs and several illustrating examples are provided.  相似文献   
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In this article, we examine the situation of disabled people in England and Wales with regard to one specific aspect of social exclusion—experience of justiciable problems, and the potential effects such problems can have on their lives. Having defined 'disability', we examine how this fits within the wider dialogue on social exclusion issues. By analysing the results of the Legal Services Research Centre's (LSRC) periodic survey of justiciable problems, we find that disabled respondents were not only more likely to experience a problem, they also experienced more problems. Increased likelihood of a problem was observed in the majority of problem categories and particularly those relating to issues of social exclusion, such as housing and welfare benefits. This propensity to experience multiple problems can lead to a negative impact on the lives of long-term ill and disabled people.  相似文献   
399.
Faced with the problems of access, distance and low population density, the provision of quality services to rural areas is inherently difficult. Although the role of market towns in alleviating problems in the provision of rural services has been given little consideration within the academic literature, they are currently being targeted by UK government policy. Using a case of the hinterland of Alnwick, a market town in the North East of England, this paper explores the current and future role of market towns in servicing their hinterlands. The results suggest a mutual dependence between market town services and hinterland residents and that the continuation of this relationship depends on market towns taking advantage of demographic trends in rural areas. Faced with changing demographics and the wider use of the Internet, potential is identified for ‘clawing-back’ trade from larger urban areas and creating an enhanced role for market towns. Extending the sense of belonging beyond the boundaries of the town itself will also be important in increasing patronage of town services.  相似文献   
400.
This article reviews the extant published and unpublished studies that estimate the prevalence of adolescent gambling problems in North America. The nine nonduplicative studies identified by our literature search included data collected from more than 7700 adolescents from five different regions of the United States and Canada. In addition to comparing the conceptual and methodological differences that exist among these studies, this article employed a meta-analytic strategy to synthesize prevalence estimates from the existing studies. This analysis revealed that within a 95 percent confidence interval, between 9.9% and 14.2% of adolescents are at risk of developing or returning to serious gambling problems. Similarly, between 4.4% and 7.4% of adolescents exhibit seriously adverse compulsive or pathological patterns of gambling activity. Finally, the discussion proposes a generic multi-level classification scheme to reconcile the divergent classification methods and data reporting strategies. This new multi-level approach to reporting gambling prevalence will facilitate interstudy comparisons among existing estimates of gambling prevalence and help to provide a general data reporting system for future research.  相似文献   
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