1. Rensselaer Polytechnic Institute, Department of Biomedical Engineering, 110 8th Street, Troy, New York 12180
2. University of Georgia, Department of Physics and Astronomy, Athens, Georgia 30602
3. GE Global Research Center, 1 Research Circle, Niskayuna, New York 12309
4. Purdue University, Department of Mathematics, 150N University Street, West Lafayette, Indiana 47907