1. Department of Mechanical Engineering; University of Colorado Boulder; Boulder Colorado USA
2. Now at Civil, Architectural, and Environmental Engineering Department; Drexel University; Philadelphia Pennsylvania USA
3. Department of Civil and Environmental Engineering; Syracuse University; Syracuse New York USA
4. Department of Biology; Boston University; Boston Massachusetts USA
5. Sonoma Technology Inc.; Petaluma California USA
6. Harvard Forest; Harvard University; Petersham Massachusetts USA