1. Department of Biomedical Engineering, University of Alberta, Edmonton, AB T6G 2V2, Canada
2. Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
3. Department of Physics, University of Alberta, Edmonton, AB T6G 2E9, Canada
4. Dipartimento di Ingegneria Meccanica e Aerospaziale (DIMEAS), Politecnico di Torino, I-10129 Turin, Italy