Populations of Drosophila melanogaster kept at high population density (K-selected) for 125 generations have higher larval viability than populations kept at low densities (r-selected) when both are raised under crowded conditions. In addition K-selected adults that emerge from crowded cultures are larger than their r-selected counterparts. These d...
A total of 1151 children from indigenous Quechua-speaking families residing in squatter settlements of the city and in two remote rural environments in Peru was given a battery of 16 tests of academic achievement and cognitive abilities. The former tests assessed reading and mathematics achievement and the latter tapped a broad range of cognitive f...
The authors examined the relationship among psychosocial vulnerability (stress) and resilience (adaptive potential) factors and three outcome measures, self-reported physical symptoms, positive and negative affect, and natural killer cell activity in 39 male and female older adults residing in a retirement community (mean age = 73.5). Although life...
To determine local access to medical care among Latinos, we conducted telephone interviews with residents of Orange County, California. The survey replicated on a local level the national access surveys sponsored by the Robert Wood Johnson Foundation. We compared access among Latino citizens of the United States (including permanent legal residents...
Twenty-eight chronic alcoholics and 36 age- and sex-matched non-alcoholic controls were examined with magnetic resonance imaging and brain morphometric analyses. Results confirmed large increases in subarachnoid cerebrospinal fluid (CSF) volume and mild ventricular enlargement in the alcoholics and revealed associated volume reductions of localized...
Naltrexone significantly attenuated self-injurious behavior in a 20-year-old mildly retarded autistic male patient. The patient was videotaped daily and behavior was evaluated with a time-sampling procedure. Behavioral ratings of SIB frequency, SIB severity, and activity were collected automatically with a computerized system. Learning and memory w...
Theories of density-dependent natural selection predict that evolution should favor those genotypes with the highest per capita rates of population growth under the current density conditions. These theories are silent about the mechanisms that may give rise to these increases in density-dependent growth rates. We have observed the evolution of six...
Demographic change and behavioral shifts in employment and household arrangements have caused scholars and social critics to question the nature of individuals’ involvement with work and family. Interpreting the cultural meaning of those behavioral changes requires the study of individual commitment per se. This chapter reviews research on commitme...
The relationship between olfactory identification ability and MRI volumetric indices of specific cortical and subcortical brain regions was investigated in 36 recently detoxified male alcoholics. The results of correlational analyses between MRI indices and score on the University of Pennsylvania Smell Identification Test (UPSIT) revealed that impa...
Spatial relationships between predators and prey have important implications for landscape processes and patterns. Highly mobile oceanic birds and their patchily distributed prey constitute an accessible model system for studying these relationships. High-frequency echosounders can be used together with simultaneous direct visual observations to qu...
