1. Department of Biomedical Engineering, Michigan Technological University, 1400 Townsend, Houghton, MI 49931, USA
2. School of Forestry and Natural Resources and Department of Genetics, The University of Georgia, 111 Riverbend Road, Athens, GA 30602, USA
3. Department of Mechanical Engineering, Colorado State University, 1602 Campus Delivery, Fort Collins, CO 80523, USA