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261.

Acknowledgments

Acknowledgement to editorial collaborators  相似文献   
262.
Biomonitoring programs for urinary chromium (Cr) typically attempt to evaluate occupational exposure via the inhalation route. This study investigated whether Cr can be detected in the urine of people following the ingestion of soils that contain relatively high concentrations of chromium in chromite ore processing residue (COPR). To evaluate the reasonableness of using urinary monitoring to assess environmental exposure, six volunteers ingested 400 mg of soil/day (low-dose group), two others ingested 2.0 g of soil/day (high-dose group) for 3 consecutive days, and one person ingested a placebo on each of 3 days. The soil and COPR mixture contained concentrations of total chromium (Cr) and hexavalent chromium [Cr(VI)] of 103 ± 20 and 9.3 ± 3.8 mg/kg, respectively. Therefore, the low-dose group ingested 41 μg Cr/day [including 3.7 μg Cr(VI)] and the high-dose group ingested 206 μg Cr/day [including 18.6 μg Cr(VI)] on each of 3 consecutive days. All urine samples were collected and analyzed individually for total Cr on the day prior to dosing, during the 3 days of dosing, and up to the first void 48 h after the last dose. No significant increases in urinary Cr excretion were found when background excretion data were compared with data following each of the 3 days of dosing or in daily mean urine concentrations of the high- vs the low-dose groups. It appears that Cr present in a soil and COPR mixture at Cr doses up to 200 μg/day is not sufficiently bioavailable for biomonitoring of urine to be informative. These results are consistent with previously published findings suggesting that incidental exposure to dusts and soils containing comparable levels of Cr will not result in increased concentrations of Cr in urine.  相似文献   
263.
We examine the phenomenon of shifting production bottlenecks from an analytic perspective. We quantify the propensity of a work center to be a bottleneck, defined as maximal queue length, using a simple Jackson production network model. Comparison of the analytic model against an empirical simulation-based model shows that the two are in good agreement. A scalar measure of bottleneck shiftiness is proposed and used to investigate several policies for mitigating shiftiness. Simulation experiments show that several commonly observed managerial policies for coping with shifting bottlenecks actually increase shiftiness, but that shiftiness declines when the capacity of nonbottleneck resources is increased.  相似文献   
264.
The present study examined the career advancement prospects of MIS and non-MIS employees, as well as the relationships of career advancement prospects with job performance evaluations, job satisfaction, career satisfaction, and organizational commitment for MIS and non-MIS professionals and managers. Participants included 134 MIS professionals and managers and 397 non-MIS professionals and managers of a large communications company. The results provided no evidence that MIS employees experience more restricted career advancement prospects than non-MIS employees. In addition, job performance evaluations generally had positive effects on career advancement prospects; career advancement prospects had a number of positive effects on job satisfaction, career satisfaction, and organizational commitment; and job satisfaction and career satisfaction had positive effects on organizational commitment. These findings are related to prior research, suggestions for future research are offered, and implications for the management of MIS employees are identified.  相似文献   
265.
Kee H. Chung 《决策科学》1993,24(6):1215-1221
This paper presents a contingent-claims approach to project valuation when capital expenditures are made sequentially over time. It focuses on an important facet of sequential investment projects that the firm can undertake—or pass up projects—as more information becomes available. The contingent-claims approach takes account of this important feature of firms' investment decision process, whereas the traditional capital budgeting procedure does not. Since the traditional method does not reflect the options nature of investment opportunities, it underestimates the value of sequential investment projects. As a result, a naive implementation of the traditional capital budgeting procedure could result in rejecting profitable projects. The extent of undervaluation associated with the traditional capital budgeting procedure is greater when the correlation between the random component of the future asset value and that of the required capital expenditure is smaller and/or when the growth rate of the required capital expenditure is higher.  相似文献   
266.
Abstract

China is home to approximately 245 million rural-to-urban migrant workers. The influx of migrants into urban areas has posed various challenges for local social service systems. Recently, increasing number of community services have been developed to meet the growing service demands from the migrant population. However, whether increase in community service use results in improved wellbeing among migrant workers remains critically unexplored. As such, this study examines the role of community service use in migrant workers’ life satisfaction and the potential mediating effect of identity integration in Shenzhen, China. Bootstrapped models were adopted to examine relationship among variables. Drawing from a sample of 1,087 rural-to-urban migrant workers, we found that community service use is positively correlated with both identity integration and migrant workers’ life satisfaction. Moreover, identity integration served as a partial mediator between community service use and life satisfaction. The mediating effect of identity integration was found to increase with age. This study highlights that diverse services should be implemented to address divergent needs of migrants in different age groups. Community service can also serve as a vehicle to foster integration among migrant workers in host communities, especially for older age groups. Future studies may further investigate the relationships between community social capital, community social support, quality of community-based organization and frequency of service use so as to optimize the life satisfaction of migrant workers.  相似文献   
267.
This review examines the current published and “grey” literature relating to the experiences of homelessness by people seeking asylum within Australia. While many people seeking asylum have experienced homelessness during their flight, inadequate and unaffordable housing are a feature of the settlement experience for a large number of new arrivals to Australia, putting at risk their successful settlement. This study aims to explore the factors influencing access to stable housing. A systematic review of the academic literature and a search of the grey literature identified 11 articles and 20 documents related to homelessness and people seeking asylum in Australia. The academic literature included a variety of methods and approaches to the investigation of the experience of homelessness in Australia. The grey literature was more practice based, including evaluation and research reports, submissions, and newsletters. Findings suggest that experiences of homelessness are multifaceted and have a range of influences, including policy, financial stress, lack of access to education and employment, and a lack of affordable and suitable housing. Any solutions to address homelessness need to be similarly diverse. Discrimination from real estate agents and employers was also identified as a barrier to housing for many people seeking asylum, an issue that will need to be addressed at a systematic level. The lack of research published in the academic literature means that although there may be some programmes or solutions operating in the community, as demonstrated in the grey literature, this information is not being shared beyond organisation websites or subscriber lists, resulting in a lack of coherency or sharing of solutions. This review highlights the need for further attention to the factors influencing homelessness in asylum seekers, the experience of homelessness, and how these can be addressed by government and non-government led strategies and policy development.  相似文献   
268.
This article uses ethnographic methods to explore how peer support and community involvement influence the mental health and well-being of transgender (or, trans) people in the southeastern United States. The study builds on existing research that suggests that trans community involvement and peer support among trans people enhance mental health experiences and moderate the effects of stigma and discrimination on health outcomes. Through qualitative analysis of 158 hours of participant observation and 33 in-depth interviews with members of a trans community organization in the U.S. Southeast, this paper identifies three key processes through which peer support and community involvement enhance the mental health and well-being of trans people: (1) the normalization of trans identities and experiences; (2) the creation of a social support network; and (3) the empowerment of trans people.  相似文献   
269.
Urban Ecosystems - Residential yardscapes are at the forefront of human interaction with nature for those living in urban areas across Europe and North America. In recent years a significant amount...  相似文献   
270.
Urban Ecosystems - Critical resources for birds nesting in cities can support populations in spite of the challenges imposed by urbanization, and the identification of such resources can shed light...  相似文献   
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