Evaluation of NASA space grant consortia programs

The meaningful evaluation of the NASA Space Grant Consortium and Fellowship Programs must overcome unusual difficulties: (1) the program, in its infancy, is undergoing dynamic change; (2) the several state consortia and universities have widely divergent parochial goals that defy a uniform evaluative process; and (3) the pilot-sized consortium programs require that the evaluative process be economical in human costs less the process of evaluation comprise the effectiveness of the programs they are meant to assess. This paper represents an attempt to assess the context in which evaluation is to be conducted, the goals and limitations inherent to the evaluation, and to recommend appropriate guidelines for evaluation

Determining Structurally Identifiable Parameter Combinations Using Subset Profiling

Identifiability is a necessary condition for successful parameter estimation of dynamic system models. A major component of identifiability analysis is determining the identifiable parameter combinations, the functional forms for the dependencies between unidentifiable parameters. Identifiable combinations can help in model reparameterization and also in determining which parameters may be experimentally measured to recover model identifiability. Several numerical approaches to determining identifiability of differential equation models have been developed, however the question of determining identifiable combinations remains incompletely addressed. In this paper, we present a new approach which uses parameter subset selection methods based on the Fisher Information Matrix, together with the profile likelihood, to effectively estimate identifiable combinations. We demonstrate this approach on several example models in pharmacokinetics, cellular biology, and physiology

Obesogenic Environmental Influences on Young Adults: Evidence From Randomized Dormitory Assignment

This study utilizes a natural experiment—conditionally random dormitory assignments of first-year US college students—to investigate the influence of obesogenic environmental factors in explaining changes in weight and exercise behavior during the 2009–2010 academic year. The design addresses potential selection biases resulting from the likelihood that individuals sort into built environments that match their preferences for exercise and healthy eating. We find some evidence that the food environment, specifically access to campus dining, significantly affected the weight of female students in our study. Females assigned to dormitories where the nearest campus dining hall was closed on the weekends gained about 1 lb less over the course of the year than females assigned to dormitories near dining halls that were open 7 days a week. We also find some evidence that female who lived in close proximity to a grocery store gained less weight over the course of the year. Finally, females who lived closer to campus gym reported more frequent exercise over the course of the year. We do not find significant effects of the built environment on weight changes of males in our sample, but we are cautious to draw strong conclusions from this because the male weight change in our sample was quite small