1. Department of Biology, Tufts University, Medford, MA 02155, USA
2. Department of Biology, Emmanuel College, Boston, MA 02115, USA
3. Department of Kinesiology, University of Maryland, College Park, MD 20742, USA
4. Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
5. Department of Electrical and Electronics Engineering, Middle East Technical University, Ankara, Turkey