Scheduling Updates of Probabilistic Risk Assessments: The Arkansas Nuclear One-Unit 1 Experience

This paper presents the results of a study that identified how often a probabilistic risk assessment (PRA)should be updated to accommodate the changes that take place at nuclear power plants. Based on a 7-year analysis of design and procedural changes at one plant, we consider 5 years to be the maximum interval for updating PRAs. This conclusion is preliminary because it is based on the review of changes that occurred at a single plant, and it addresses only PRAs that involve a Level 1 analysis (i.e., a PRA including calculation of core damage frequency only). Nevertheless, this conclusion indicates that maintaining a useful PRA requires periodic updating efforts. However, the need for this periodic update stems only partly from the number of changes that can be expected to take place at nuclear power plants–changes that individually have only a moderate to minor impact on the PRA, but whose combined impact is substantial and necessitates a PRA update. Additionally, a comparison of two generations of PRAs performed about 5 years apart indicates that PRAs must be periodically updated to reflect the evolution of PRA methods. The most desirable updating interval depends on these two technical considerations as well as the cost of updating the PRA. (Cost considerations, however, were beyond the scope of this study.)     

Political theater and student organizations in the 1989 Chinese movement: A multivariate analysis of Tiananmen

Social movement research has often been divided between organizational and cultural analyses of collective action. Organizationally oriented theorists have viewed indigenous organizational structure as the critical variable in the emergence of collective action. Political culture and cultural frame theorists have focused instead on the cultural frames that resonate with audiences, mobilizing them to action. But social movements cannot be the result of one or the other of these factors. An analysis of the 1989 Chinese movement illuminates the multivariate aspects of this social movement. This movement was a two-tiered movement with an organized student leadership tier and a mass audience. Enmeshed in university organizations and student networks, the student leaders relied on an organizational structure that had been emerging since the mid-1980s. This organized leadership tier employed cultural symbols and acts to mobilize mass audiences that were beyond the scope of the students' organizational linkages. The political theater of the organized student leaders was complemented by institutional changes that had been occurring over the decade of reform in China and a political opportunity that allowed wide coverage of the students' activities.     

Premium will continue to be on performance. Interview by Wesley Curry.

With a new name for its professional organization (the American College of Physician Executives) and a new certifying organization (the American Board of Medical Management), the profession of medical management is in the throes of significant and far-reaching change. At the College's National Conference in Washington, D.C. in May, we talked to two leaders of the profession, Michael B. Guthrie, MD, MBA, FACPE, and Robert H. Hodge, Jr., MD, FACPE about what the future holds for physician executives and what physician executives can do to position themselves for success. Dr. Guthrie, the Immediate Past President of the College is Vice President for Business Development, Penrose/St. Francis Healthcare System, Colorado Springs, Colo. Dr. Hodge, the new President of the College, is a Program Director, W.K. Kellogg Foundation, Battle Creek, Mich.     

Challenging the Rhetoric of Choice in Maternal Labour‐Force Participation: Preferred Versus Contracted Work Hours

The notion of choice in maternal labour‐force participation (LFP) is a contentious one, with assertions that LFP is a direct result of either personal inclinations, such as employment commitment or external factors, such as historically available opportunities. This article suggests an alternative framework for understanding and testing choice in LFP using preferred versus contracted work hours. It explores these constructs quantitatively in a group of working mothers (N = 275) with dependent children and investigates qualitatively the underlying reasons for discrepant preferred versus contracted work hours in a sub‐sample of these women with under‐school‐aged children (N = 20). The results show that nearly two‐thirds of women working full time would prefer to work part time and the major reasons for not acting on their preferences is because of the nature of the job and the lack of career opportunities available for part‐time employees.     

Overcoming biases and misconceptions in ecological studies

The aggregate data study design provides an alternative group level analysis to ecological studies in the estimation of individual level health risks. An aggregate model is derived by aggregating a plausible individual level relative rate model within groups, such that population-based disease rates are modelled as functions of individual level covariate data. We apply an aggregate data method to a series of fictitious examples from a review paper by Greenland and Robins which illustrated the problems that can arise when using the results of ecological studies to make inference about individual health risks. We use simulated data based on their examples to demonstrate that the aggregate data approach can address many of the sources of bias that are inherent in typical ecological analyses, even though the limited between-region covariate variation in these examples reduces the efficiency of the aggregate study. The aggregate method has the potential to estimate exposure effects of interest in the presence of non-linearity, confounding at individual and group levels, effect modification, classical measurement error in the exposure and non-differential misclassification in the confounder.     

Understanding China's Transition to Capitalism: The Contributions of Victor Nee and Andrew Walder

Sociological Forum -     

Age Changes in Prosocial Responding and Moral Reasoning in Adolescence and Early Adulthood

Age changes' measures of prosocial responding and reasoning were examined. Participants' reports of helping, empathy‐related responding, and prosocial moral reasoning were obtained in adolescence (from age 15–16 years) and into adulthood (to age 25–26 years). Perspective taking and approval/interpersonal oriented/stereotypic prosocial moral reasoning increased from adolescence into adulthood, whereas personal distress declined. Helping declined and then increased (a cubic trend). Prosocial moral judgment composite scores (and self‐reflective empathic reasoning) generally increased from late adolescence into the early 20s (age 17–18 to 21–22) but either leveled off or declined slightly thereafter (i.e., showed linear and cubic trends); rudimentary needs‐oriented reasoning showed the reverse pattern of change. The increase in self‐reflective empathic moral reasoning was for females only. Thus, perspective taking and some aspects of prosocial moral reasoning—capacities with a strong sociocognitive basis—showed the clearest increases with age, whereas simple prosocial proclivities (i.e., helping, sympathy) did not increase with age.