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21.
This study evaluates the dose-response relationship for inhalation exposure to hexavalent chromium [Cr(VI)] and lung cancer mortality for workers of a chromate production facility, and provides estimates of the carcinogenic potency. The data were analyzed using relative risk and additive risk dose-response models implemented with both Poisson and Cox regression. Potential confounding by birth cohort and smoking prevalence were also assessed. Lifetime cumulative exposure and highest monthly exposure were the dose metrics evaluated. The estimated lifetime additional risk of lung cancer mortality associated with 45 years of occupational exposure to 1 microg/m3 Cr(VI) (occupational exposure unit risk) was 0.00205 (90%CI: 0.00134, 0.00291) for the relative risk model and 0.00216 (90%CI: 0.00143, 0.00302) for the additive risk model assuming a linear dose response for cumulative exposure with a five-year lag. Extrapolating these findings to a continuous (e.g., environmental) exposure scenario yielded an environmental unit risk of 0.00978 (90%CI: 0.00640, 0.0138) for the relative risk model [e.g., a cancer slope factor of 34 (mg/kg-day)-1] and 0.0125 (90%CI: 0.00833, 0.0175) for the additive risk model. The relative risk model is preferred because it is more consistent with the expected trend for lung cancer risk with age. Based on statistical tests for exposure-related trend, there was no statistically significant increased lung cancer risk below lifetime cumulative occupational exposures of 1.0 mg-yr/m3, and no excess risk for workers whose highest average monthly exposure did not exceed the current Permissible Exposure Limit (52 microg/m3). It is acknowledged that this study had limited power to detect increases at these low exposure levels. These cancer potency estimates are comparable to those developed by U.S. regulatory agencies and should be useful for assessing the potential cancer hazard associated with inhaled Cr(VI).  相似文献   
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This study concerned the immunological correlates of stress and work. Self reported stress, emotional state, ego-strength, and defensiveness were examined in relation to measures of cellular immunity (T-cell response to Con A and number of T4 and T8 cells) and humoral immunity (concentrations of immunoglobulins and complement components in plasma) in a group of 96 Norwegian female bank employees. The analyses showed that workload, the stress factor with the highest group mean, was associated with number of T-cells, while strain due to body posture during work was related to concentrations of IgM and C3. Further, depression was significantly correlated with IgM concentration and T-cell number, and anxiety with C3 concentration. T-cell activity was the immunological parameter most consistently associated with psychological well-being, showing positive correlations with defensiveness and ego-strength and negative correlations with anxiety and depression. In conclusion, T-cell number and concentrations of IgM and C3 were sensitive to both work-related stress experience and emotional distress. Coping abilities, indicated by the MMPI Ego-strength scale and emotional distress, were reflected in T-cell activity; insufficient coping was associated with low T-cell activity.  相似文献   
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Abstract Routes to economic development attract considerable attention in community and rural sociology. Social scientists draw increasingly on studies of social capital and environmental surroundings as they examine the factors that facilitate and inhibit economic development. However, few empirical analyses exist that analyze the impact of the combination of social infrastructure and natural capital on different forms of economic development such as on industrial recruitment and self‐development. Using data collected from six communities in Washington State, the interaction of a community's social infrastructure and natural capital on industrial recruitment and self‐development efforts is examined. Results suggest that while natural capital positively impacts a community's successful recruitment of outside industries, it is not significant for a community's level of self‐development. However, a community's social infrastructure, measured by the existence of active civic organizations, local businesses that support local community projects, community‐wide fund‐raising capacity, and extra‐local linkages to nearby communities, state, and national agencies, positively affects both industrial recruitment and self‐development. These findings illustrate the need for communities and local activists to carefully weigh their advantages and potential shortcomings when deciding on an economic development strategy.  相似文献   
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Abstract Accounts of poverty generally fall into either “individualist” or “structuralist” camps. Often these are seen as irreconcilable and incompatible competing perspectives. This paper integrates individualist and structuralist accounts of poverty by examining the relationship between “person poverty” and “place poverty” in nonmetropolitan and metropolitan labor markets, using a multilevel framework. I fashion a general model of poverty production and allocation, drawing on the labor market ecology perspective. After a discussion of this perspective, I develop a multilevel framework for analyzing data from the 1990 Census PUMS‐L sample, STF‐3c, and other sources to show how compositional and contextual factors affect households' likelihoods of being in poverty. These multilevel models also allow us to estimate the degree to which labor market conditions influence the magnitude of household labor supply characteristics. Results suggest that both compositional and contextual factors contribute to the metro‐nonmetro difference in poverty rates, and that the effects of employment vary in accordance with labor market characteristics.  相似文献   
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A general form for characterizing inverse Gaussian and Wald distributions, based on their respective length-biased distributions, is introduced. Further results for characterizations of the gamma distribution, the negative binomial distribution and some mixtures of them by using their lengthbiased distributions are establised.  相似文献   
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The authors examine the effect of premarital cohabitation on the division of household labor in 22 countries. First, women do more routine housework than men in all countries. Second, married couples that cohabited before marriage have a more equal division of housework. Third, national cohabitation rates have equalizing effects on couples regardless of their own cohabitation experience. However, the influence of cohabitation rates is only observed in countries with higher levels of overall gender equality. The authors conclude that the trend toward increasing cohabitation may be part of a broader social trend toward a more egalitarian division of housework.  相似文献   
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This essay illustrates the value of time in understanding baby boomers' experiences of rock ‘n’ roll. In a distinctively interactionist style, I use time as a sensitizing concept in my research on this phenomenon. The orientation that guides this research is methodological tourism, by which the researcher treats something as common and taken‐for‐granted as rock ‘n’ roll music in everyday life as strange if not exotic. Structurally, songs about time constitute the most visible temporal structures in the world of rock ‘n’ roll. Interactionally, I will argue that the concept of the cohort is more useful than that of the decade for an interpretive analysis of musical nostalgia, a key feature of the phenomenon in question. Illustrations of the reflexive relationship between rock ‘n’ roll and time in middle age include using awareness of recent deaths of rock ‘n’ roll performers to interpret the existential significance of aging; using rock ‘n’ roll songs as benchmarks for significant events such as birthdays and anniversaries, as well as gift giving for these events; and using rock ‘n’ roll music to pass the time.  相似文献   
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