My final Penn State course (Spring 2017) was about K-theory and operator algebras – the connection between these two has been central to my mathematical life. I wrote up lecture notes for this course, as has become usual for me. I’m pleased to report that these have now appeared on the AMS *Open Math Notes* page.

The American Mathematical Society hosts *AMS Open Math Notes*, which is “a repository of freely downloadable mathematical works in progress hosted by the AMS as a service to researchers, teachers and students.”

The Open Math Notes homepage continues “These draft works include course notes, textbooks, and research expositions in progress. They have not been published elsewhere, and, as works in progress, are subject to significant revision. Visitors are encouraged to download and use these materials as teaching and research aids, and to send constructive comments and suggestions to the authors.”