After a few years away from UNC Charlotte, I get to join back in the Carolinas Topology Seminar, virtually at least. Slides from my talk are available at https://docs.google.com/presentation/d/1rTAEq6-wte7GjHa1YvT9mYiTlqFfDZMaGex0Dun9fQo/edit?usp=sharing.