Uncertainties in Pharmacokinetic Modeling for Perchloroethylene: II. Comparison of Model Predictions with Data for a Variety of Different Parameters

In this paper we compare expectations derived from 10 different human physiologically based pharmacokinetic models for perchloroethylene with data on absorption via inhalation, and concentrations in alveolar air and venous blood. Our most interesting finding is that essentially all of the models show a time pattern of departures of predictions of air and blood levels relative to experimental data that might be corrected by more sophisticated model structures incorporating either (a) heterogeneity of the fat compartment (with respect to either perfusion or partition coefficients or both) or (b) intertissue diffusion of perchloroethylene between the fat and muscle/VRG groups. Similar types of corrections have recently been proposed to reduce analogous anomalies in the fits of pharmacokinetic models to the data for several volatile anesthetics.^(17-20) A second finding is that models incorporating resting values for alveolar ventilation in the region of 5.4 L/min seemed to be most compatible with the most reliable set of perchloroethylene uptake data.     

New contracts: The key to change

Successfully managing change in an organization is very difficult. Paul Strebel sets out a new way of doing this, based on contract theory which states that stakeholders have both an explicit and implicit individual contract with their companies. These contracts must be modified if corporate change is to proceed.The author develops five propositions about the role of contracts in change management. Change can only succeed if these five propositions are satisfied and the operational implications fully understood and implemented.     

The UK National Telephone Gambling Helpline-Results on the First Year of Operation

This study outlines the results of the UK's national gambling helpline run by GamCare. The results outlined here cover the period of the first 12 months of operation (November 1997 to October 1998). The helpline received a total of 1729 calls. Of these, 51% were from problem gamblers themselves (90% male; 10% female) and a further 26% of calls were from relatives of problem gamblers. The remaining calls came from other professionals handling problem gambling cases (13%), attempted calls, e.g., people calling and then putting the phone down due to being scared of talking (4%), information requests (3%) and the media (3%). Fruit machine gambling appeared to be most problematic for the callers as a whole and for particular sub-groups such as adolescents (82%) and women (52%).     

A Reply to Gambino's "An Epidemiologic Note on Verification Bias: Implications for Estimation of Rates"

While two-stage designs in problem gambling research are expensive and relatively difficult to execute, they have the potential to yield more accurate prevalence estimates as well as valuable additional information about gambling and problem gambling in the community. However, gains in precision are heavily dependent on the accuracy of the screening methods used and the sample sizes involved. Sound practice requires reliable information about the variances and confidence levels associated with different screens. In the spirit of contributing to the ongoing dialog about ways to improve the measurement of problem gambling, we examine several reasons to question whether the revised estimates offered by Gambino are in fact an improvement.     

Supplier involvement in product development in the electronics industry: A case study

The movement of activities earlier in the product development process requires a re-examination of the total supply network. The objective of this paper is to determine the degree of early supplier involvement (ESI) that exists between a multinational electronics company and its key suppliers, in terms of depth of integration, information exchange and buyer–supplier relationships. The paper provides insights into the strategic factors that affect the dynamics of the ESI process. The research indicates that there are considerable impediments for those participants responsible for establishing and managing the implementation of ESI. A number of strategic insights are identified that explain the existence of the impediments to the ESI process. Finally, based upon the findings a number of lessons are highlighted for organisations considering the adoption of the ESI process.     

Role Performance and Person Perception: Toward an Interactions Approach*

This paper examines and critiques the manner in which one strand of attribution theory has addressed the relationship between role performances and person perception. An interactionist approach is formulated as an alternative, and an experiment is designed to test its viability. The experiment supports our hypothesis that the informational value of “in-role” performances is similar to the informational value of “out-of-role” performances, and that neither type of performance is consistently more informative than the other. Further, it is suggested that the informational value of role performances is not adequately explained by the in-role/out-of-role dichotomy. The interactionist conception of role, combined with a notion of informal role types, provides a more accurate understanding of role performance and person perception.