1. Division of Applied Mathematics, Brown University, Providence, RI, USA
2. Beetham Eye Institute, Joslin Diabetes Center, Department of Medicine and Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
3. McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, USA
4. School of Engineering, Brown University, Providence, RI, USA
5. Division of Applied Mathematics and School of Engineering, Brown University, Providence, RI, USA