The OPUS program seeks to provide opportunities for mid- to later-career investigators to develop new understanding of science in the fields supported by the Division of Environmental Biology (DEB) through two tracks of synthesis activities. 1) OPUS: Mid-Career Synthesis: This track provides an opportunity for a mid-career researcher, defined as a candidate at the associate professor rank (or equivalent) to enable a new synthesis of their ongoing research. Synthesis is achieved by developing new research capabilities through collaboration with a mentor to enable new understanding of their research system and questions of interest. This track aims to provide mid-career scientists with new capabilities to enhance their productivity, improve their retention as scientists, and ensure a diverse scientific workforce that remains engaged in active research (including more women and minorities at high academic ranks). 2) OPUS: Core Research Synthesis: This track provides an opportunity for an individual or a group of investigators to revisit and synthesize a significant body of their prior research in a way that will enable new understanding of their research system and questions of interest. This track would also be appropriate early enough in a career to produce unique, integrated insight useful both to the scientific community and to the development of the investigator’s future career. Full proposal deadlines: November 19, 2018 and August 5, 2019.