After leaving Columbia, Sezen went on to receive another Ph.D. in molecular biology at Germany’s Heidelberg University.I have, however, been unable to locate any reference in the German National Library of a dissertation accepted at Heidelberg by someone of this name, and all doctorates granted in Germany must be listed here. The blog linked to above has collected many interesting links on the topic.
Update: A correspondent writes:
According to this list http://www.zmbh.uni-heidelberg.de/schiebel/alumni-alt.html Sezen graduated on 18 August 2009, which also corresponds to this calendar entry for her doctoral exam. http://www.zmbh.uni-heidelberg.de/WebCalendar/view_entry.php?id=1938