DAYTON, Ohio (Dec. 2, 2020) Lt. Dan Xu, right, a biochemist and full-time Duty Under Instruction (DUINS) Fellow provides a research initiative update to Dr. Karen Mumy, Director of Environmental Health Effects Laboratory (EHEL), at Naval Medical Research Unit Dayton (NAMRU-Dayton). Xu is looking to characterize toxicity and identify biomarkers of diesel exhaust. (U.S. Navy photo by Megan Mudersbach)