The Basic Behavioral and Social Sciences Research Opportunity Network (OppNet) of the National Institutes of Health (NIH) issued a funding opportunity announcement (RFA-HD-12-204) for Research Project Grant (R21) applications that propose to investigate the reciprocal interactions of the processes of sleep and circadian regulation and function with behavioral and social environment processes. The grant offers a unique opportunity to link social environment factors that shape sleep behaviors with the direct neurobehavioral and circadian biology effects of sleep processes on individuals in the context of their social milieu. Applicants are encouraged to develop theoretical models that capture social and behavioral interactions associated with sleep disturbance in social environments, including residential, employment, and school settings, while simultaneously incorporating biobehavioral markers of high and low susceptibility to sleep debt.  The application due date is Sept. 30, 2011.