1. Virginia Commonwealth University and Central Virginia Veterans Healthcare System, Richmond, Virginia, USA;
2. Mayo Clinic College of Medicine and Science, Rochester, Minnesota, USA;
3. University of Pennsylvania, Philadelphia, Pennsylvania, USA;
4. Baylor University Medical Center, Dallas, Texas, USA;
5. Mayo Clinic College of Medicine and Science, Jacksonville, Florida, USA;
6. University of Alberta, Edmonton, Alberta, Canada;
7. University of Pittsburgh, Pittsburgh, Pennsylvania, USA;
8. Northwestern University, Chicago, Illinois, USA;
9. Duke University, Durham, North Carolina, USA;
10. Columbia University Medical Center, New York, New York, USA;
11. University of Washington, Seattle, Washington, USA;
12. Mayo Clinic College of Medicine and Science, Phoenix, Arizona, USA;
13. University of Toronto, Toronto, Ontario, Canada;
14. Mercy Medical Center & University of Maryland School of Medicine, Baltimore, Maryland, USA.