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.)     

Clinical supervision: Its role in “Containing” countertransference responses to a filicidal patient

This paper illustrates the role of supervision in processing countertransference responses with might have disrupted the therapist's empathy with a patient who had killed her child. The clinical material demonstrates how the therapist's responses of initial denial and subsequent disgust and fear were dealt with in supervision. As a result, the treatment process led to genuine, albeit limited, therapeutic change in a patient with severe character pathology.This paper is developed from a presentation of the case of Mrs. Jay at Department of Psychiatry Grand Rounds, University of Cincinnati College of Medicine, on May 2, 1989.     

An Examination of How Supervisors Influence Their Subordinates to Engage in Environmental Behaviors

Employee engagement in environmental behaviors is an important topic in operations management. Drawing upon stakeholder, commitment, and organizational support theories, this study creates and tests an empirical model of how store managers (i.e., supervisors) influence their direct reports (i.e., subordinates) to become engaged in environmental behaviors. Based on a dataset derived from supervisors and their subordinates who are employed at the same grocery store location across a large retail grocery chain, we test our study's nomological model and find support for the linkages proposed. Key research and managerial implications are discussed.     

The Residential Mobility of Seniors Among Different Residential Forms: Analysis of Metropolitan and Rural Issues for Six Contrasted Regions in Québec,Canada

The purpose of this research is to describe and analyze the residential mobility of senior citizens, between 2006 and 2011, among different residential forms in rural and metropolitan areas in the province of Quebec (Canada). A systematic analysis of residential form variability in territories that include both metropolitan and rural areas is performed. First, a typology of residential forms is proposed using a principal component analysis and a hierarchical cluster analysis on environment-related and housing variables. Second, the residential mobility of seniors among these different residential forms is analyzed. The results reveal a certain amount of residential stability among seniors, except where specific conditions are met, such as the death of a spouse or the onset of health problems limiting day-to-day activities. For those who moved, high-rise habitat areas and mixed areas with older rental apartments held the greatest attraction. However, suburban areas attracted the largest number of seniors because these areas account for a sizeable portion of the real estate market.     

Estimation and diagnostic for skew-normal partially linear models

Partially linear models (PLMs) are an important tool in modelling economic and biometric data and are considered as a flexible generalization of the linear model by including a nonparametric component of some covariate into the linear predictor. Usually, the error component is assumed to follow a normal distribution. However, the theory and application (through simulation or experimentation) often generate a great amount of data sets that are skewed. The objective of this paper is to extend the PLMs allowing the errors to follow a skew-normal distribution [A. Azzalini, A class of distributions which includes the normal ones, Scand. J. Statist. 12 (1985), pp. 171–178], increasing the flexibility of the model. In particular, we develop the expectation-maximization (EM) algorithm for linear regression models and diagnostic analysis via local influence as well as generalized leverage, following [H. Zhu and S. Lee, Local influence for incomplete-data models, J. R. Stat. Soc. Ser. B 63 (2001), pp. 111–126]. A simulation study is also conducted to evaluate the efficiency of the EM algorithm. Finally, a suitable transformation is applied in a data set on ragweed pollen concentration in order to fit PLMs under asymmetric distributions. An illustrative comparison is performed between normal and skew-normal errors.     

Asymmetrically fair rules for an indivisible good problem with a budget constraint

We study a particular restitution problem where there is an indivisible good (land or property) over which two agents have rights: the dispossessed agent and the owner. A third party, possibly the government, seeks to resolve the situation by assigning rights to one and compensate the other. There is also a maximum amount of money available for the compensation. We characterize a family of asymmetrically fair rules that are immune to strategic behavior, guarantee minimal welfare levels for the agents, and satisfy the budget constraint.     

The incidence of metabolic risk factors in an inpatient psychiatric setting

Our study examines risk factors for metabolic syndrome on admission to an acute psychiatric facility and the incidence of medical referrals at discharge. Data on demographics, risk factors for metabolic syndrome, other health risk factors, medications, related diagnoses, and primary care providers and referrals were collected from 125 psychiatric patient charts. Comparison analysis was done for two groups: those with two or more risk factors for metabolic syndrome and those with less than two risk factors. Differences between groups were statistically significant for age, waist circumference, body mass index, high-density lipoprotein, triglycerides, and fasting glucose levels. Few patients were referred to their primary care provider for follow-up care. This study has clinical implications for improving assessment of psychiatric patients at risk for developing metabolic syndrome, for designing interventions to help patients adopt lifestyle changes to mitigate these risks, and for working toward fuller integration of psychiatric and primary care.