1. Department of NeurologyUniversity of Pittsburgh Pittsburgh Pennsylvania USA
2. Graduate School of Public HealthUniversity of Pittsburgh Pittsburgh Pennsylvania USA
3. Georgetown University Washington DC USA
4. Department of NeurologyDuke University Durham North Carolina USA
5. Tuck School of BusinessDartmouth College Dartmouth New Hampshire USA
6. SSRS Glen Mills Pennsylvania USA
7. The Michael J. Fox Foundation for Parkinson's Research New York New York USA
8. Department of NeurologyUniversity of Toronto Ontario Canada