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41.
Mehta NK  Elo IT 《Demography》2012,49(2):425-447
Few prior studies have investigated the health of U.S. immigrants from the former Soviet Union (FSU). Utilizing data from the 2000 U.S. census and the 2000–2007 National Health Interview Survey (NIHS), we compare levels of disability of FSU immigrants with U.S.-born whites (ages 50–84). Our findings suggest an “epidemiologic paradox” in that FSU immigrants possess higher levels of education compared with U.S.-born whites, but report considerably higher disability with and without adjustment for education. Nonetheless, FSU immigrants report lower levels of smoking and heavy alcohol use compared with U.S.-born whites. We further investigate disability by period of arrival among FSU immigrants. Changes in Soviet emigration policies conceivably altered the level of health selectivity among émigrés. We find evidence that FSU immigrants who emigrated during a period when a permission to emigrate was hard to obtain (1970–1986) displayed less disability compared with those who emigrated when these restrictions were less stringent (1987–2000). Finally, we compare disability among Russian-born U.S. immigrants with that of those residing in Russia as a direct test of health selectivity. We find that Russian immigrants report lower levels of disability compared with Russians in Russia, suggesting that they are positively selected for health despite their poor health relative to U.S.-born whites.  相似文献   
42.
In many environmental sampling situations, the variable of interest is either not easily observable or is too expensive to observe. Under such circumstances, the need arises to observe another variable, related to the variable of interest, so as to estimate the population parameters of interest. We study the performance of two different sampling procedures, i.e. ranked set sampling and stratified simple random sampling, when both stratification and ranking are accomplished on the basis of such a concomitant variable. The relative precision of the two methods is obtained and expressed as a function of population variance, between-stratum and between-rank variation, and the correlation coefficient between the variable of interest and the concomitant variable. The relative precision is computed for several important families of distributions that occur frequently in environmental and ecological work. Under equal allocation of sampling units, stratified simple random sampling is found to perform better than ranked set sampling, when the costs incurred to obtain sample measurements are ignored. When optimum allocation is considered for both methods, ranked set sampling performs better than stratified simple random sampling, when the concomitant variable is not highly correlated with the variable of interest. Furthermore, when the costs of sampling and the costs of measurement are incorporated into the assessment of the relative precision, the ranked set sampling is seen to be more efficient than stratified simple random sampling, particularly when the cost of stratification is high compared with that of ranking. This is generally the case in practice.  相似文献   
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Systematic and appropriate statistical analysis is needed to examine the relative performance of anthropometrical indices, viz. body mass index (BMI), waist circumference (WC), waist hip ratio (WHR) and waist stature ratio (WSR) for predicting type 2 diabetes. Using information on socio-demographic, anthropometric and biochemical variables from 2148 males, we examined collinearity and non-linearity among the predictors before studying the association between anthropometric indices and type 2 diabetes. The variable involving in collinearity was removed from further analysis, and the relative importance of BMI, WC and WHR was examined by logistic regression analysis. To avoid non-interpretable odds ratios (ORs), cut point theory is used. Optimal cut points are derived and tested for significance. Multivariable fractional polynomial (MFP) algorithm is applied to reconcile non-linearity. As expected, WSR and WC were collinear with WHR and BMI. Since WSR was jointly as well as independently collinear, it was dropped from further analysis. The OR for WHR could not be interpreted meaningfully. Cut point theory was adopted. Deciles emerged as the optimal cut point. MFP recognized non-linearity effects on the outcome. Multicollinearity among the anthropometric indices was examined. Optimal cut points were identified and used to study the relative ORs. On the basis of the results of analysis, MFP is recommended to accommodate non-linearity among the predictors. WHR is relatively more important and significant than WC and BMI.  相似文献   
45.
Given a graph \(G=(V,E)\) and a non-negative integer \(c_u\) for each \(u\in V\), partial degree bounded edge packing problem is to find a subgraph \(G^{\prime }=(V,E^{\prime })\) with maximum \(|E^{\prime }|\) such that for each edge \((u,v)\in E^{\prime }\), either \(deg_{G^{\prime }}(u)\le c_u\) or \(deg_{G^{\prime }}(v)\le c_v\). The problem has been shown to be NP-hard even for uniform degree constraint (i.e., all \(c_u\) being equal). In this work we study the general degree constraint case (arbitrary degree constraint for each vertex) and present two combinatorial approximation algorithms with approximation factors \(4\) and \(2\). Then we give a \(\log _2 n\) approximation algorithm for edge-weighted version of the problem and an efficient exact algorithm for edge-weighted trees with time complexity \(O(n\log n)\). We also consider a generalization of this problem to \(k\)-uniform hypergraphs and present a constant factor approximation algorithm based on linear programming using Lagrangian relaxation.  相似文献   
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Fifty two foster parents participated in one of seven offerings of a two-and-a-half hour training on the issue of children caught in a loyalty conflict. Prior to the training foster parents completed a measure of their demographics, receptivity to learning about the issue, and their knowledge about the issue. Following the training the participants completed a measure of their perception that the training was helpful, their intent to change based on the training, and their knowledge about loyalty conflicts. They also participated in a focused discussion about loyalty conflicts. In this sample foster parents were found to have high levels of receptivity to training, high rates of perceived helpfulness of the training, and high levels of intent to change after the training as well as an increase in knowledge regarding loyalty conflict from before to after the training. Despite limitations in sampling strategy and sample size, the data support the belief that foster parents want to learn about this issue and can benefit from a single training on it.  相似文献   
48.
We identify managerial challenges and opportunities faced by business process outsourcing (BPO) firms in India by interviewing 28 executives in lower (n = 10), middle (n = 11), and upper management (n = 7) in 15 BPO firms. Content analysis of the responses revealed human resources and organizationrelated challenges as the most critical issues. SWOT (Strengths, Weaknesses, Opportu-nities, Threats) analysis uncovered future opportunities, e.g., Knowledge Process Outsourcing. Secondary data, from four global research agencies and a national trade association, supported our findings. Organizational changes to address challenges and to exploit opportunities are explored.  相似文献   
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Aboriginal foster parents were surveyed about their physical needs. Each was asked ‘What do you need physically to be a good foster parent?’ A total of 39 unique responses were made. They were grouped together by participants and the grouping data were analysed using multidimensional scaling and cluster analysis. Five concepts resulted from the analysis. The concepts included physical, financial and emotional resources, supplies and equipment, community, fitness and wellness. Results were compared and contrasted with the fostering literature.  相似文献   
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