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Abstract: The social and behavioral sciences are at a crossroads in public health. In this paper, we attempt to describe a path toward the further integration of the natural and behavioral sciences with respect to the study of behavior and health. Three innovations are proposed. First, we extend and modify the “stream of causation” metaphor along two axes: time, and levels of nested systems of social and biological organization. Second, we address the question of whether ‘upstream’ features of social context are causes of disease, fundamental or otherwise. Finally, we propose the concept of a risk regulator to advance the study of behavior and health in populations. To illustrate the potential of these innovations, we develop a multilevel framework for the study of health behaviors and obesity in social and biological context. [Copyright &y& Elsevier]

Background: Elevated cortisol indicates stress and may be a risk factor for cognitive decline in aging. Genetic factors may influence individual vulnerability to the adverse effects of stress on cognitive function in aging. Method: The authors investigated whether the gene-environment interaction between the genotype for the apolipoprotein E gene (APOE) and cortisol predicted cognitive performance in older urban adults. Cross-sectional data were analyzed from a population-based sample of 50-70-year-old men and women. Cognitive performance, salivary cortisol levels, and APOE genotype were assessed in 962 subjects. Scores on 20 standard cognitive tests were combined into seven domain scores (language, processing speed, eyehand coordination, executive functioning, verbal memory and learning, visual memory and learning, visuoconstruction). Results: In adjusted models, while a higher cortisol level was associated with worse cognitive scores, the slopes of the adverse relations were steeper in persons with at least one APOE-e4 allele. Effect sizes were large: for example, the effect of having one ϵ4 allele plus a cortisol area under the curve greater than the 75th percentile was equivalent to a decrease in language score expected from an age increase of 8.0 years (95% confidence interval=1.7-14.4), while having two ϵ4 alleles and a cortisol area under the curve greater than the 75th percentile was equivalent to an age increase of 33.4 years (95% Cl=14.8-52.0). Conclusions: These data suggest that APOE genotype modifies cortisol's relations with cognitive functioning and that the ϵ4 allele increases vulnerability of the aging brain to adverse effects of stress. [ABSTRACT FROM AUTHOR]

This report presents results from a study on the bacterial diversity of cigarette brands collected from military personnel during the U.S. Army’s investigation of a series of cases of acute eosinophilic pneumonitis in military personnel deployed in Operation Iraqi Freedom. Eight species of Bacillus, including five new species, and one new species of Kurthia were isolated from the cigarettes. Some of these species have been identified elsewhere as causes of hypersensitivity pneumonitis and other respiratory syndromes. All of the isolates were facultative anaerobes, and many displayed mucoid growth under anaerobic conditions. In addition, many isolates also displayed the ability to form surface biofilms under liquid culture. Although biofilm formation and mucoid growth were not correlated, the former was found to be much more pronounced under anaerobic conditions as opposed to aerobic ones. The implications of these findings are discussed. [ABSTRACT FROM AUTHOR]