Cardiac Sensitization Thresholds of Halon Replacement Chemicals Predicted in Humans by Physiologically-Based Pharmacokinetic Modeling

Human exposure to halons and halon replacement chemicals is often regulated on the basis of cardiac sensitization potential. The dose-response data obtained from animal testing are used to determine the no observable adverse effect level (NOAEL) and lowest observable adverse effect level (LOAEL) values. This approach alone does not provide the information necessary to evaluate the cardiac sensitization potential for the chemical of interest under a variety of exposure concentrations and durations. In order to provide a tool for decision-makers and regulators tasked with setting exposure guidelines for halon replacement chemicals, a quantitative approach was established which allowed exposures to be assessed in terms of the chemical concentrations in blood during the exposure. A physiologically-based pharmacokinetic (PBPK) model was used to simulate blood concentrations of Halon 1301 (bromotrifluoromethane, CF₃Br), HFC-125 (pentafluoroethane, CHF₂CF₃), HFC-227ea (heptafluoropropane, CF₃CHFCF₃), HCFC-123 (dichlorotrifluoroethane, CHCl₂CF₃), and CF₃I (trifluoroiodomethane) during inhalation exposures. This work demonstrates a quantitative approach for use in linking chemical inhalation exposures to the levels of chemical in blood achieved during the exposure.     

Protective Responses to Household Risk: A Case Study of Radon Mitigation

This study analyzes the effectiveness of a mass-media radon information and testing campaign conducted in the Washington, D.C. area in the winter of 1988. Although an impressive number of test kits (approximately 100,000) were sold, the ultimate mitigation rates resulting from the campaign were extremely low. Analyses show that low mitigation rates cannot be explained by postulating that people's responses to radon are insensitive to the level of objective risk. They may instead be due to characteristics of the protective response required to reduce radon risk. Radon may be thought of as one of a family of household risks which have risk response profiles that make them particularly difficult for people to manage and remediate. Traditional information campaigns for such risks are likely to be ineffective; instead, they may require regulatory strategies or programs which provide active guidance and assistance.     

Factors influencing perceived learning transfer of an outdoor management development programme in Malaysia

This study investigated if components of outdoor management programme, participant characteristics and work environment characteristics influence perceived transferable skills. The study used 148 executive and management participants who attended a 3-day outdoor management programme using experiential learning at a secondary rainforest in Malaysia. Motivation to learn was the predictor of perceived transferable skills. Macro-dynamic activities, continuous learning culture and self-efficacy were found to significantly influence perceived transferable skills, but micro-dynamic activities, instructor's skills and perceived content validity were not. The outdoor management development programme was not effective in achieving its main objectives and return on investment to the relevant stakeholders. A well-designed instructional programme should be developed for accountability purposes.     

Testing a “Push–Pull” theory of work commitment among organizational professionals

Writers have suggested that the current trend toward decreased job security requires employees to commit more strongly to newly “professionalized” occupations to compensate for social and resource support no longer received from their employers. And it has sometimes been implied that such a shift toward increased professional commitment will arise naturally as organizational commitment is whittled away by perceived job insecurity. We propose that job insecurity does not automatically push the employee toward professional commitment, but rather that such commitment stems from the pull of perceived occupational professionalization. We construct a nonrecursive model proposing relationships between job insecurity, perceived professionalization, and both organizational and professional commitment. This model is supported (using structural equation modeling) in a study of 622 employees in 3 occupations: corporate law, human resource management, and computer programming, all of which can be considered professions or semiprofessions. Finally, we suggest how occupations can be fashioned better to support employees when faced with job insecurity and job loss.     

Visibility,Immobility and Stigma: Young People's Use of Sexual Health Services in Rural Areas†

Teenage pregnancy has become a major policy issue, for which young people are often publicly held solely responsible. However, a combination of factors substantially increases the risks of conception faced by young people engaging in early sexual activity. This article reports the main findings of a study of teenage pregnancy in linked seaside and rural areas, focusing on the experiences and perceptions of young people living in rural localities. They identify the issues of immobility, visibility and attitudes of stigma as affecting their ability to access sexual health services. The young people highlighted issues for service and policy development and the behaviour of professionals, both within schools and from sexual health services. Education, social and health services and the voluntary sector have important roles to play in responding to their needs.     

Review Essay: Community and Religion in a Post‐Modern Global World: A Review Essay on Anabaptist Religious Groups

The Amish on the Iowa Prairie: 1840 to 1910, by Steven D. Reschly. Mennonites in the Global Village, by Leo Driedger. On the Backroad to Heaven: Old Order Hutterites, Mennonites, Amish, and Brethren, by Donald B. Kraybill and Carl F. Bowman.     

For Richer or for Poorer? Evidence from Indonesia, South Africa, Spain, and Venezuela

We analyze household income dynamics using longitudinal data from Indonesia, South Africa (KwaZulu-Natal), Spain and Venezuela. In all four countries, households with the lowest reported base-year income experienced the largest absolute income gains. This result is robust to reasonable amounts of measurement error in two of the countries. In three of the four countries, households with the lowest predicted base-year income experienced gains at least as large as their wealthier counterparts. Thus, with one exception, the empirical importance of cumulative advantage, poverty traps, and skill-biased technical change was no greater than structural or macroeconomic changes that favored initially poor households in these four countries.