Improving Weight of Evidence Approaches to Chemical Evaluations

Federal and other regulatory agencies often use or claim to use a weight of evidence (WoE) approach in chemical evaluation. Their approaches to the use of WoE, however, differ significantly, rely heavily on subjective professional judgment, and merit improvement. We review uses of WoE approaches in key articles in the peer‐reviewed scientific literature, and find significant variations. We find that a hypothesis‐based WoE approach, developed by Lorenz Rhomberg et al., can provide a stronger scientific basis for chemical assessment while improving transparency and preserving the appropriate scope of professional judgment. Their approach, while still evolving, relies on the explicit specification of the hypothesized basis for using the information at hand to infer the ability of an agent to cause human health impacts or, more broadly, affect other endpoints of concern. We describe and endorse such a hypothesis‐based WoE approach to chemical evaluation.     

Production functions and population theory

The persistence of the population problem in many developing countries' especially in Asia, must mean that the relation between population trends and productivity has to be kept continually under review. In recent years the economists' interest in this relation has shifted away from the Keynesian stagnation analysis, with its emphasis on the influence of population trends on the level and composition of consumption and investment, to a reconsideration of their influence on production. It is a striking testimony to the influence of Malthus that his theory is still under active consideration and that it frequently serves as starting point, as it does for Professor Belshaw, for an analysis of the economics of population. Divorced from its particular context, in which value judgements particularly distasteful to many commentators abound, and reformulated in terms of modern production theory, it clarifies the main issues, by showing what facts are required and what logic demands in order to provide a useful answer to practical problems of policy. Readers of the first two chapters of Professor Buquet's book will find ample confirmation of the sterility of much of the debate regarding optimum populations which developed largely from differences of opinion about definitions of “good” and “bad” economic criteria for policy than from faults in logic. The debate continues and the posthumous career of Parson Malthus still occasions even personal abuse! It would be difficult, however, to accuse Professor Belshaw of taking sides in the Malthusian debate. He takes the Malthusian analysis for what it is worth, shows where it fits the facts and where it does not, provides convincing evidence of a Malthusian problem in Asia by a skilful round-up of well presented statistics, and then, instead of committing himself to a forecast of what is likely to happen in Asia, he illustrates through the modern theory of production what are the pre-conditions for a removal of the population problem. This is surely a sensible procedure and contrasts favourably with the sibylline utterances of a number of distinguished amateur social scientists.     

The Eating Disorders NOS Diagnostic Profile Among College Women

Abstract

The authors examined a proposed profile of eating-related behaviors, associated features, developmental issues, and help-seeking behavior among college women, using an eating disorder response program. The most common symptom scenario was a pattern of regular binge eating, together with daily exercise and occasional purging. The most common associated features were distressing or dysfunctional overconcern about body image and self-esteem, usually with day-to-day stress and intermittent depression. The women who fit this pattern also presented developmental issues of perfectionism, conflictual relationships with parents, and struggles for independence; and they tended to be ambivalent about seeking services. Implications for practice, including the need to develop a framework for eating disorder responses on campus that includes preventive programs and developmental interventions to target emerging and moderate concerns are discussed; limitations and the preliminary nature of the findings are explicated.     

Complex Thinking and Computing Organization Facing Contingent Problems

Public Organization Review - Facing the reflexive modernity, social wealth production is systematically correlated with the production of social and technical problems. Due to the complexity...     

Exploring Parameter Relations for Multi‐Stage Models in Stage‐Wise Constant and Time Dependent Hazard Rates

Single cohort stage‐frequency data are considered when assessing the stage reached by individuals through destructive sampling. For this type of data, when all hazard rates are assumed constant and equal, Laplace transform methods have been applied in the past to estimate the parameters in each stage‐duration distribution and the overall hazard rates. If hazard rates are not all equal, estimating stage‐duration parameters using Laplace transform methods becomes complex. In this paper, two new models are proposed to estimate stage‐dependent maturation parameters using Laplace transform methods where non‐trivial hazard rates apply. The first model encompasses hazard rates that are constant within each stage but vary between stages. The second model encompasses time‐dependent hazard rates within stages. Moreover, this paper introduces a method for estimating the hazard rate in each stage for the stage‐wise constant hazard rates model. This work presents methods that could be used in specific types of laboratory studies, but the main motivation is to explore the relationships between stage maturation parameters that, in future work, could be exploited in applying Bayesian approaches. The application of the methodology in each model is evaluated using simulated data in order to illustrate the structure of these models.     

A Seemingly Unrelated Nonparametric Additive Model with Autoregressive Errors

This article considers a nonparametric additive seemingly unrelated regression model with autoregressive errors, and develops estimation and inference procedures for this model. Our proposed method first estimates the unknown functions by combining polynomial spline series approximations with least squares, and then uses the fitted residuals together with the smoothly clipped absolute deviation (SCAD) penalty to identify the error structure and estimate the unknown autoregressive coefficients. Based on the polynomial spline series estimator and the fitted error structure, a two-stage local polynomial improved estimator for the unknown functions of the mean is further developed. Our procedure applies a prewhitening transformation of the dependent variable, and also takes into account the contemporaneous correlations across equations. We show that the resulting estimator possesses an oracle property, and is asymptotically more efficient than estimators that neglect the autocorrelation and/or contemporaneous correlations of errors. We investigate the small sample properties of the proposed procedure in a simulation study.     

The changing practice of eating: evidence from UK time diaries, 1975 and 2000

This paper examines some central themes about change in consumption behaviour through an empirical investigation of the practice of eating. It analyses patterns of food consumption in the UK using time diary data from 1975 and 2000. The practice of eating is decomposed into four component activities which are used to explore systematically the inter-relationships between social processes - such as commodification and temporal fragmentation - and ways of providing and consuming food. It charts the expansion of eating out, the degree to which it substitutes for other eating activities, and the implications of its development for social relations and the temporal organization of daily life. Analysis reveals that food consumption continues to be differentiated along established lines of social division, although the content of those divisions has changed and varies across components of the practice. Increasing commodification of the food chain is documented, but without appearing to have a corrosive impact on household organization or social relationships. While tendencies indicative of temporal fragmentation are revealed, counter-tendencies exist which suggest that the practice of eating is resilient to many forms of external pressure. Finally, the application of a practice-based analytical approach permits critical evaluation of theories of social transformation.     

A family systems-based model of organizational intervention

Employee assistance professionals are expected to be proficient at intervening in organizations and creating meaningful behavioral change in interpersonal functioning. Because of their training in family systems theories and concepts, marriage and family therapists (MFTs) are well suited to serve organizations as "systems consultants." Unfortunately, the authors were unable to identify any family systems-based models for organizational intervention that have been empirically tested and supported. In this article, the authors present a family systems-based model of intervention that they developed while working in an employee assistance program (EAP). They also present research that was used to refine the model and to provide initial support for its effectiveness.