A Weighting Approach for GEE Analysis with Missing Data

We propose a new weighting (WT) method to handle missing categorical outcomes in longitudinal data analysis using generalized estimating equations (GEE). The proposed WT provides a valid GEE estimator when the data are missing at random (MAR), and has more stable weights and shows advantage in efficiency compared to the inverse probability weighing method in the presence of small observation probabilities. The WT estimator is similar to the stabilized weighting (SWT) estimator under mild conditions, but it is more stable and efficient than SWT when the associations of the outcome with the observation probabilities and the covariate are strong.     

Marginal homogeneity,symmetry, and independence

A contingency table of the mc form provides a convenient summary of data when c individuals in a matched set9 each belonging to a different one of c classifications, are identified as belonging to one of m categories, A study in which matched sets (c=3) of 1 case, 1 hospital control, and 1 neighborhood control are classified into one of m=4 occupational categories would be an example, Independence in the cxm tables for each of the matched sets implies symmetry in the summary mc table with consequent marginal homogeneity. Adaptation of the Mantel-Haenszel procedure for testing independence to the case of many cxm tables so as to yield a chi square with (cl)(ml) degrees of freedom (DF) provides a test of marginal homogeneity in the summary mc table. This can be viewed as a test of symmetry directed against alternatives which would make for marginal inhomogeneity and can differ     

海明威文学小说的悲剧特色和死亡意识

从古希腊悲剧开始,不管哪个时期的悲剧文本,虽然有各自的形式,有诸多差异,但最终殊途同归,都有着相同的结局。悲剧意识几乎成为了文学作品的共同特征,值得一提的是,悲剧特色往往会与死亡意识相结合,让文学作品散发出较强的生命意识。海明威的文学小说作品凝聚了悲剧性和死亡性两大要素,让小说本身充满了对于生命和人性的拷问。     

The shifting landscape of LGBT organizational research

Over the past generation, sexual minorities—particularly lesbian, gay, bisexual, and transgender (LGBT) persons—have gained increased visibility in the public arena. Yet organizational research has lagged behind in recognizing and studying this category of organizational members. This article offers a critical review of this growing body of research. More specifically, we identify and discuss four dominant scholarly frames that have informed LGBT organizational research from the late nineteenth century to date. The frames include a “medical abnormality,” “deviant social role,” “collective identity,” and “social distinctiveness” view of sexual minorities. We argue that these frames have profoundly shaped the scope and range of organizational scholarship devoted to sexual minorities by showing that scholars using such contrasted frames have been drawn to very different research questions with respect to sexual minorities. We document and discuss the main and contrasted questions asked within each of these frames and show how they have both enabled and constrained LGBT organizational research. We conclude by calling for more attention to the frames organizational scholars adopt when studying sexual minorities, but also for more research on both minority and majority sexual orientations in organizations.     

A Tiered Framework for Risk‐Relevant Characterization and Ranking of Chemical Exposures: Applications to the National Children's Study (NCS)

A challenge for large‐scale environmental health investigations such as the National Children's Study (NCS), is characterizing exposures to multiple, co‐occurring chemical agents with varying spatiotemporal concentrations and consequences modulated by biochemical, physiological, behavioral, socioeconomic, and environmental factors. Such investigations can benefit from systematic retrieval, analysis, and integration of diverse extant information on both contaminant patterns and exposure‐relevant factors. This requires development, evaluation, and deployment of informatics methods that support flexible access and analysis of multiattribute data across multiple spatiotemporal scales. A new “Tiered Exposure Ranking” (TiER) framework, developed to support various aspects of risk‐relevant exposure characterization, is described here, with examples demonstrating its application to the NCS. TiER utilizes advances in informatics computational methods, extant database content and availability, and integrative environmental/exposure/biological modeling to support both “discovery‐driven” and “hypothesis‐driven” analyses. “Tier 1” applications focus on “exposomic” pattern recognition for extracting information from multidimensional data sets, whereas second and higher tier applications utilize mechanistic models to develop risk‐relevant exposure metrics for populations and individuals. In this article, “tier 1” applications of TiER explore identification of potentially causative associations among risk factors, for prioritizing further studies, by considering publicly available demographic/socioeconomic, behavioral, and environmental data in relation to two health endpoints (preterm birth and low birth weight). A “tier 2” application develops estimates of pollutant mixture inhalation exposure indices for NCS counties, formulated to support risk characterization for these endpoints. Applications of TiER demonstrate the feasibility of developing risk‐relevant exposure characterizations for pollutants using extant environmental and demographic/socioeconomic data.     

民族社会学视野下的回族女性研究

回族女性研究是中国妇女研究的重要组成部分,20世纪90年代以来,中国回族女性研究取得了长足的进步和发展。本文着力于回顾既往回族女性研究中所涉及的诸多问题展开历史追溯与反思,就回族女性研究的内涵、研究的对象与范围、研究的意义与作用、研究的方法、理论构建、学术素养等学术界较为关注的几个问题进行了论述,在追溯中反思我们今后研究的拓展方向,力求为未来回族女性的发展提供一定参考。     

近十年来土族研究综述

本文从历史、语言文字、文学艺术、宗教文化、婚姻家庭、经济发展等方面 ,对土族近十年来的研究状况作了总结 ,可资参考     

北亚突厥百年研究(1900-2000年)

突厥是生活在我国北方的一个游牧民族。其在公元六世纪中叶,兴起于今新疆东北部,势力扩大到漠北、漠南及中亚一带,衰于八世纪中叶。本文综述阿尔泰以东的突厥即传统上所说的东突厥的范围近百余年的研究。包括族源、族属、社会性质、社会经济、语言、文字、习俗、宗教、碑文、官号、与周边各族各国间的关系和其他方面的内容。通过这些研究,可以发现我国学者在百年来对突厥巨大成就,使国际学术同行了解我国学者在这一领域取得的成果,促进此方面的进一步研究。该文可能对方家一些著述有遗漏,或者评述失当之处,请予指教。     

Intergenerational class mobility in contemporary Britain: political concerns and empirical findings

In Britain in recent years social mobility has become a topic of central political concern, primarily as a result of the effort made by New Labour to make equality of opportunity rather than equality of condition a focus of policy. Questions of the level, pattern and trend of mobility thus bear directly on the relevance of New Labour's policy analysis, and in turn are likely be crucial to the evaluation of its performance in government. However, politically motivated discussion of social mobility often reveals an inadequate grasp of both empirical and analytical issues. We provide new evidence relevant to the assessment of social mobility - in particular, intergenerational class mobility - in contemporary Britain through cross-cohort analyses based on the NCDS and BCS datasets which we can relate to earlier cross-sectional analyses based on the GHS. We find that, contrary to what seems now widely supposed, there is no evidence that absolute mobility rates are falling; but, for men, the balance of upward and downward movement is becoming less favourable. This is overwhelmingly the result of class structural change. Relative mobility rates, for both men and women, remain essentially constant, although there are possible indications of a declining propensity for long-range mobility. We conclude that under present day structural conditions there can be no return to the generally rising rates of upward mobility that characterized the middle decades of the twentieth century - unless this is achieved through changing relative rates in the direction of greater equality or, that is, of greater fluidity. But this would then produce rising rates of downward mobility to exactly the same extent - an outcome apparently unappreciated by, and unlikely to be congenial to, politicians preoccupied with winning the electoral 'middle ground'.