Biological and social determinants of body size across the life span

The accuracy of demographic models designed to project future trends of population-level health and disease can be improved by incorporating biological data. One barrier to this process are quantitative characteristics of the data themselves. Biological data are characteristically time-dependent phenomena that behave in a nonlinear fashion. To develop accurate projections of the morbidity, disability, and mortality experience among future cohorts in late life, research needs to focus on development of models that create the opportunity to distinguish all-or-none, boundaries, and latency aspects of biological factors driving demographic phenomena, development of methods to identify time-dependent effects, and development of genetically informative samples. This presentation focuses on the biology of adult body size, its behavior as a variable in statistical analyses, and strategies for the incorporation of this variable into demographic models of population aging in the United States. First, several examples of generally observed quantitative characteristics of biological variables are reviewed. To illustrate the nonlinear character of biological data, three general patterns of change with aging are presented. Next, issues concerning the measurement of body size are discussed. Scenarios describing body size over the adult life span are described. By the end of this process, recommendations for starting a dialogue between researchers interested in biological endpoints (individual weight change, disease risk) and those interested in demographic outcomes (population-level disease and disability issues) using body size will be presented.     

Victimization, Psychological Distress and Subsequent Offending Among Youth

The current study examined the relationship between the victimization of youth, psychological distress and subsequent offending. It examined whether direct and vicarious victimization by exposure to violence in the family, among peers, and in the neighborhood, significantly predicted psychological distress among study participants and whether psychological distress significantly predicted subsequent offending over time. In addition, it examined the extent (if any) to which psychological distress mediated the relationship between victimization and subsequent offending. Method: study data are from wave 1 and wave 2 of the Buffalo Longitudinal Study of Young Men (BLSYM), a population based sample (n = 625) of young men, ages 16-19 years old in a metropolitan area of Buffalo, New York. A path analytic approach was used for the main analyses. Findings: personal, vicarious victimization by exposure to violence among peers, and perception of neighborhood safety were significant predictors of offending at wave 1. Personal and property victimization was significant predictors of psychological distress. Psychological distress did not have a significant relationship with offending at wave 1 yet, it did at wave 2. Vicarious victimization by exposure to violence among peers and offending at wave 1 were all significant predictors of offending at wave 2. The results highlight the need to respond to both direct and vicarious victimization among young males to reduce psychological distress and subsequent offending.     

Labour Market Policies in Times of Crisis: A Reaction Function Approach for the Period 1985–2010

This article examines the reaction function of labour market expenditure to unemployment in 24 OECD countries, over the period 1985–2010, using the OECD panel data. The level of public debt is also introduced as a factor that is likely to influence these expenditures. Using a fixed‐effect model with interaction terms, this research focuses on two periods of crisis (1992–93 and 2007–09). The results confirm the counter‐cyclical variation of labour market policy expenditures. Nevertheless, the sensitivity of labour market expenditure to the economic cycle has in general decreased and the policy mix has changed. This could result from the important labour market reforms undertaken in the last 20 years.     

Feeling at Risk Matters: Water Managers and the Decision to Use Forecasts

Experts contend that weather and climate forecasts could have an important role in risk management strategies for community water systems. Yet, most water managers make minimal use of these forecasts. This research explores the determinants of the use of weather and climate forecasts by surveying managers of community water systems in two eastern American states (South Carolina and the Susquehanna River Basin of Pennsylvania). Assessments of the reliability of weather and climate forecasts are not driving their use as water managers who find forecasts reliable are no more likely to use them than are managers who find them unreliable. Although larger systems and those depending on surface water are more likely to use forecasts for some (but not all) purposes, the strongest determinant of forecast use is risk perceptions. Water managers who expect to face problems from weather events in the next decade are much more likely to use forecasts than are water managers who expect few problems. Their expectations of future problems are closely linked with past experience: water managers who have had problems with specific types of weather events (e.g., flood emergencies) in the last 5 years are likely to expect to experience problems in the next decade. Feeling at risk, regardless of the specific source of that weather-related risk, stimulates a decision to use weather and climate forecasts.     

Task design as an influence on dialogue and learning: primary school group work with object flotation

Previous studies suggest that group work would yield conceptual gains in physics if tasks specifically promoted dialogue about the factors which determine observed outcomes. This might be done by constraining task items to present critical tests of the effects of individual factors; and, additionally, by requiring participants to generate or select explicit rules about those effects. In order to test this hypothesis, groups of primary school children were asked to work on one of four versions of a task concerning object flotation: Random (i.e. a control in which there were no task constraints), Critical Tests, Rule Generation, and Rule Selection. Learning was assessed via change between a pre-test and two post-tests. Although the effect was delayed, children from the Random and Rule Generation conditions showed an increased awareness of relevant factors which was strongly related to prior group activity. This gain was absent in the Critical Tests and Rule Selection conditions. The results indicate that group dialogue can be productively shaped by task design, but also that its effects may take time to appear, and are negated by overmuch external direction of attention.     

A Risk Assessment for Occupational Acrylonitrile Exposure Using Epidemiology Data

The extensive data from the Blair et al.((1)) epidemiology study of occupational acrylonitrile exposure among 25460 workers in eight plants in the United States provide an excellent opportunity to update quantitative risk assessments for this widely used commodity chemical. We employ the semiparametric Cox relative risk (RR) regression model with a cumulative exposure metric to model cause-specific mortality from lung cancer and all other causes. The separately estimated cause-specific cumulative hazards are then combined to provide an overall estimate of age-specific mortality risk. Age-specific estimates of the additional risk of lung cancer mortality associated with several plausible occupational exposure scenarios are obtained. For age 70, these estimates are all markedly lower than those generated with the cancer potency estimate provided in the USEPA acrylonitrile risk assessment.((2)) This result is consistent with the failure of recent occupational studies to confirm elevated lung cancer mortality among acrylonitrile-exposed workers as was originally reported by O'Berg,((3)) and it calls attention to the importance of using high-quality epidemiology data in the risk assessment process.     

Female-headed households in nonmetropolitan areas: Housing and demographic characteristics

This article describes selected demographic and housing characteristics of nonmetropolitan female-headed households. It compares nonmetropolitan female householders with the average U.S. household, including regional differences. Female heads are older and more likely to have members in poor health than U.S. households on average. Female heads are also more likely to be in poverty and to experience housing poverty. Although the female householders do not suffer from space and quality problems, housing affordability is a problem. Most female heads live in owned, single-family dwellings and are more likely to live in mobile homes than the average U.S. household. This research was funded under the auspices of the U.S. Department of Agriculture, Cooperative State Research Service, and the experiment stations in Idaho, Indiana (Purdue University), Iowa, Minnesota, Missouri, Nebraska, and New York (Cornell University). Also supporting the research were East Carolina University, Illinois State University, Kansas State University, and Western Michigan University. The authors thank Mary Ann Horvath and Roxanne Miller for their assistance in preparing the figures and document. She received her Ph.D. from Oklahoma State University. Her work includes research in housing and the economic well-being of women. She received her Ph.D. from The Ohio State University. Her research interests include housing and neighborhood assessment and women and public policy issues.