Estimating rates of population change for a neotropical parrot with ratio,mark-recapture and matrix methods

Robust methods for estimating rates of population change ( u ) are necessary for applied and theoretical goals in conservation and evolutionary biology. Traditionally, u has been calculated from either ratios of population counts (observed u or u obs ), or population models based on projection matrices (asymptotic u or u asy ,). New mark-recapture methods permit calculation of u from mark-resighting information alone (realized u or u rea ), but empirical comparisons with other methods are rare. In this paper, rates of population change were calculated for a population of green-rumped parrotlets ( Forpus passerinus ) that have been studied for more than a decade in central Venezuela. First, a ratio method based on counts of detected birds was used to calculate u obs. Next, a temporal symmetry method based on mark-recapture data (i.e. the u -parameterization introduced by Pradel, 1996) was used to calculate u rea . Finally, a stage-structured matrix model based on state-specific estimates of fecundity, immigration, local survival, and transition rates was used to calculate u asy . Analyses were conducted separately for females and males. Overall values of u from the three methods were consistent and all indicated that the finite rate of population change was not significantly different from 1. Annual values of u from the three methods were also in general agreement for a majority of years. However, u rea from the temporal symmetry method had the greatest precision, and apparently better accuracy than u asy . Unrealistic annual values of u asy could have been due to poor estimates of the transitional probability of becoming a breeder ( é ) or to a mismatch between the actual and the asymptotic stable stage distribution. In this study, the trade-off between biological realism and accuracy was better met by the temporal symmetry than the matrix method. Our results suggest that the temporal symmetry models can be applied with confidence to populations where less information may be available.     

Implementing the family preservation program: Feedback from focus groups with consumers and providers of services

There is a growing understanding that preventative child welfare efforts can be both more cost effective and are more desirable philosophically than strictly remedial programs. The Family Preservation Act provides funds to assist communities in strengthening and preserving at-risk families. In order to implement this program effectively, local communities must design new programs and procedures which will be both attractive to consumers and effective in meeting their needs. This study it identifies problems with contemporary child and family services and suggests solutions to those problems. This study uses a focus group format and presents ideas generated by those individuals who will be most directly affected by this legislation; front line service providers and service consumers. Several areas of weakness in the current service delivery system are identified, including bureaucratic barriers, limited resources, problematic consumer/provider relations and a range of collaborative issues, both within and between agencies and the communities they serve.     

The emergent ‘coaching industry’: a wake-up call for HRD professionals

Recent years have seen the rapid growth of an emergent ‘coaching industry’ in many countries with some scholars calling for the development of a ‘coaching profession’ replete with its own clear identity, clear boundaries and unique body of knowledge. Yet, at the same time, coaching has also been conceived as a necessary area of expertise and skill set among contemporary HRD professionals. Therefore, this article reports the results of a comparative study of the different conceptualizations and definitions of ‘coaching’ and contemporary HRD as reported in the literature. Results suggest that the intended purposes and processes associated with both fields of practice are virtually the same. The challenge and dilemma posed by these results are described from both a coaching and HRD perspective, and are discussed in terms of seeing the findings of this comparative study as a wake-up call for HRD professionals.     

Leukemia Risk Associated with Benzene Exposure in the Pliofilm Cohort. II. Risk Estimates

The detailed work histories of the individual workers composing the Pliofilm cohort represent a unique resource for estimating the dose-respoonse for leukemia that may follow occupational exposure to benzene. In this paper, we report the results of analyzing the updated Pliofilm cohort using the proportional hazards model, a more sophisticated technique that uses more of the available exposure data than the conditional logistic model used by Rinsky et al. The more rigorously defined exposure estimates derived by Paustenbach et al. are consistent with those of Crump and Allen in giving estimates of the slope of the leukemogenic dose-response that are not as steep as the slope resulting from the exposure estimates of Rinsky et al. We consider estimates of 0.3-0.5 additional leukemia deaths per thousand workers with 45 ppm-years of cumulative benzene exposure to be the best estimates currently available of leukemia risk from occupational exposure to benzene. These risks were estimated in the proportional hazards model when the exposure estimates of Crump and Allen or of Paustenbach et al. were used to derive a cumulative concentration-by-time metric.     

Social norms theory-based interventions: testing the feasibility of a purported mechanism of action

Social norms-based interventions targeting college student drinking behaviors have become increasingly popular. Such interventions purportedly modify student misperceptions of fellow student drinking behaviors, which leads to changes in individual drinking behavior. Despite claims of successful interventions, research demonstrating that social norms-based interventions modify student perceptions is lacking. OBJECTIVE: The authors conducted a laboratory experiment examining the feasibility of this mechanism of action and aimed to determine the validity of the campus-specific drinking norms hypothesis. PARTICIPANTS AND METHODS: The authors randomly assigned 60 students to 1 of 3 research conditions: Alcohol 101 (national drinking norms), a didactic presentation of campus specific drinking norms, or a control condition. RESULTS: Both intervention groups modified student misperceptions regarding peer alcohol use, and these changes were sustained 1 week later. CONCLUSIONS: Social norms-based interventions can contribute to more accurate drinking perceptions among college students.     

Pension systems and prospects in Asia and the Pacific

There is a diversity of pension systems in the Asia and Pacific region. A growing number of countries have social insurance pension schemes, but many others which have provident funds have not set up any mandatory pension system at all. Demographic, social and economic changes mean the need for a regular income in old age will increase enormously. Existing schemes should be extended to all employees, benefits should meet certain minimum standards, administrative arrangements must adapt to structural change, and the budgeting both of governments and of households must be adjusted to take account of changing age dependency ratios.