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991.
We consider the case of a multicenter trial in which the center specific sample sizes are potentially small. Under homogeneity, the conventional procedure is to pool information using a weighted estimator where the weights used are inverse estimated center-specific variances. Whereas this procedure is efficient for conventional asymptotics (e. g. center-specific sample sizes become large, number of center fixed), it is commonly believed that the efficiency of this estimator holds true also for meta-analytic asymptotics (e.g. center-specific sample size bounded, potentially small, and number of centers large). In this contribution we demonstrate that this estimator fails to be efficient. In fact, it shows a persistent bias with increasing number of centers showing that it isnot meta-consistent. In addition, we show that the Cochran and Mantel-Haenszel weighted estimators are meta-consistent and, in more generality, provide conditions on the weights such that the associated weighted estimator is meta-consistent.  相似文献   
992.
Clinical gait and stepping performance measures in older adults   总被引:1,自引:1,他引:0  
Problems with ambulation and mobility are frequent problems in older adults. Each year, about one in 100 older adults develops new severe mobility disability. Assessment of abnormal gait constitutes a major component of clinical practice and may lead to fall reduction. Clinicians can benefit from simple gait and mobility assessment tools to be used in busy clinical settings. This review focuses on gait and stepping performance measures that can be used by the busy clinician to assess gait, mobility performance, balance, and falls risk in the older adult.  相似文献   
993.
Understanding Life-Threatening Risks   总被引:2,自引:0,他引:2  
Modern science and medicine, and increasing prosperity, have brought many benefits to our society, but not without costs. One cost is that some of the technological innovations and new activities bring with them different and perhaps greater risks that threaten our lives. Any problem involving life-threatening risks is complex, so it is difficult to think through all the implications of the alternatives proposed to address it. This paper presents a number of "facts" to guide constructive thinking about decisions concerning life-threatening risks. The intent is to help us appraise alternatives, design public policy and laws, and communicate about specific risk problems.  相似文献   
994.
Abstract In this paper we examine differences in upper secondary school attendance among subgroups of the population in Thailand. We ascertain where inequalities continue to exist and where they have been mediated. We analyze data from samples of the 1990 and 2000 Thai censuses. We find that the gender gap favoring boys has closed at the national level and that girls now transition to upper secondary school more often than do boys. Inequalities still exist according to socioeconomic background of families. Rural‐urban differences have narrowed considerably since 1990, but they continue to be observed, particularly in certain parts of the country. Similarly, differences between Muslims and others appear to have lessened over the last decade, but Muslims continue to be disadvantaged compared to others, particularly in the South.  相似文献   
995.
科尔沁土语被认为是蒙古语方言中发展、变化较快的土语。研究科尔沁土语基本词汇对现代蒙 古语词汇学、蒙古语方言学,以及蒙古语的发展和规范研究具有重要的学术价值和实际意义。科尔沁土语基 本词汇具有农业词汇丰富、内部差异性和变异性等特点。  相似文献   
996.
We summarize and comment on the policy sections of the articles in this issue concerned with the health effects of residential environments. We review the implications in the context of public policies implemented over at least the last century to improve the least, as well as most, expensive housing. We make the argument that public policy can reduce but not eliminate the contribution of housing to the differences in health between the wealthy and poor. We conclude that the applied value of work such as that presented in this issue arises from its contribution to sustaining the improvements in health enjoyed over the last century, not from whether it helps eliminate the gap in health between the poor and wealthy .  相似文献   
997.
998.
Arising from interest concerning the possibility of causal relationships among the three components of the Maslach Burnout Inventory, several process models have been proposed for the development of burnout. The present paper first reviews the evidence in favour of the three most influential of these (Leiter and Maslach's model (1988); Golembiewski, Boudreau, Munzenrider, & Luo's (1996) phase model; and Lee and Ashforth's model (1993)). These three models, and our own model (which integrates of two of them, and includes feedback effects of depersonalization on emotional exhaustion) are then compared with each other using structural equation modelling, drawing on longitudinal data from two Dutch samples (total N=1185). The review revealed that none of the seven previous studies on this issue provided any convincing support for any particular causal order proposed so far. In contrast, our own study showed that high levels of exhaustion were associated with high levels of depersonalization over time across both samples. Further, higher levels of depersonalization led to higher levels of emotional exhaustion and lower levels of personal accomplishment. To our knowledge, the present research is the first to provide reliable longitudinal evidence for the conceptualization of burnout as a developmental process, although the effects are not large enough to be of practical use in the recognition of burnout.  相似文献   
999.
Using the 1994–1998 waves of the Current Population Survey—Child Support Supplement (N =5,387), the aims of this study are to document child support obligation rates of nonresident fathers, to examine the effect of the obligation rate on child support compliance, and to calculate the trade‐off between fathers’ financial responsibility and children's well‐being, paying particular attention to low‐income fathers. The results indicate that low‐income fathers have high child support obligation rates, which significantly reduce their child support compliance. Although lowering the obligation rate for these fathers may improve their compliance, it does not fully offset the lowered obligation amounts and leads to a 30% net payment loss for welfare mothers and a 43% loss for nonwelfare mothers. Policy implications are discussed.  相似文献   
1000.
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