1. Department of Molecular and Cellular Biology, Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138
2. Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Cuernavaca 62210, México
3. Department of Biomedical Engineering, University of California, Davis, CA 95616
4. Institute for Medical Engineering & Science, Massachusetts Institute of Technology, Cambridge, MA 02139
5. Biofisika Institutua (CSIC, UPV/EHU), University of the Basque Country UPV/EHU, Bilbao, 48080 Spain
6. Ikerbasque, 48013 Bilbao, Spain