1. Minneapolis VA Health Care System; Minneapolis MN USA
2. University of Minnesota; Minneapolis MN USA
3. VA Connecticut Health Care System; West Haven CT USA
4. Yale School of Medicine; New Haven CT USA
5. Washington D.C. VA Medical Center; Washington, DC USA
6. George Washington University; Washington, DC USA
7. James J. Peters VA Medical Center; Bronx NY USA
8. Atlanta VA Medical Center; Atlanta GA USA
9. Emory University; Atlanta GA USA
10. Michael E. DeBakey VA Medical Center; Houston TX USA
11. Baylor College of Medicine; Houston TX USA
12. University of Washington; Seattle WA USA