1. University of Colorado Boulder, Boulder, Colorado 80309, United States
2. University of California San Diego, La Jolla, California 92093, United States
3. University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
4. Worcester Polytechnic Institute, Worcester, Massachusettes 01609, United States
5. Virginia Commonwealth University, Richmond, Virginia 23284, United States
6. University of Utah, Salt Lake City, Utah 84112, United States
7. NORC at the University of Chicago Bethesda, Chicago, Illinois 60637, United States