I held a Visiting Fellow position at the Isaac Newton Institute for Mathematical Sciences in Cambridge during March — April and June 2012, where I participated in the workshop on Logical Approaches to Barriers in Complexity II, March 26-30, 2012, a part of the program Semantics and Syntax: A Legacy of Alan Turing.
This visit was extremely productive mathematically for me, and it was at the Isaac Newton Institute that I proved the main part of my theorems on embeddings of countable models of set theory.