2006 Annual Report 4a.List the single most significant research accomplishment during FY 2006. None 4b.List other significant research accomplishment(s), if any. None 4c.List significant activities that support special target populations. None 4d.Progress report. This report serves to document research conducted under an interagency reimbursable agreement between ARS and National Cancer Institute of the National Institutes of Health. Additional details of research can be found in the report for the parent project 5450-51000-036-00D. This collaboration planned and implemented the first clinical intervention trial using nutritional doses of selenium, the "LoDoSe trial", which was initiated in FY2006 and will continue through FY2008. This trial will provide the fundamental information to allow the projection of daily dietary selenium needs from plasma selenium levels found to be thresholds for such health effects as minimalization of cancer risks in healthy Americans, which prospect has direct implications to the US food industry which can produce foods capable of providing 50-100 mcg selenium per day through geographic sourcing, or selenium-fortification. This year, more than 300 adult men and women volunteers were recruited and screened, and a total of 213 subjects were enrolled in the study. This comprises 89% of our enrollment target of 240 total subjects. In addition, a new methodology was developed for assessing the degree cellular resistance to oxidative stress-induced programmed cell death (apoptosis), using high-volume flow cytometric analysis of whole blood samples. This method may have special utility for both nutritional and toxicological evaluations using minimally invasive techniques.