The document is a research update that provides a semi-annual overview of select research activities conducted by DLH. It outlines the essential role of research in enhancing understanding, uncovering insights, and promoting improved outcomes across various sectors. The document presents the core capabilities of DLH, which include Science, Research, & Development; Digital Transformation & Cybersecurity; and Systems Engineering & Integration. Specific research topics include an increase in HIV preexposure prophylaxis (PrEP) usage among U.S. veterans between 2014 and 2022, a study on the association between life events and the diagnosis of systemic autoimmune rheumatic diseases, and an analysis of tuberculosis-related stigma in Ugandan communities. Additionally, the update details the neurological symptoms associated with fine particulate matter exposure among workers involved in the Deepwater Horizon oil spill cleanup. Further areas of research cover blood styrene concentrations and their impact on neurobehavioral function, as well as indoor allergen exposure and its relationship with sleep health.