Emmi Mueller is a fifth-year Ph.D. candidate in Professor Jay Lennon's lab where she studies patterns of biodiversity in various ecosystems, including mammalian guts and lakes. Her dissertation aims to answer questions about how residence time (e.g., the time microorganisms spend in a lake) and habitat structure (e.g., intestinal villi arrangement) shape microbial communities. For mammalian gut-related research, Emmi designs 3D-printed gut segments with varying levels of residence time and habitat structure. For lake microbial community research, she uses bioreactors to impose a gradient of residence times on the system. The Hoover Fellowship will support her as she completes experiments using her 3D-printed gut segments this summer.