1. Department of Information Sciences and Technology, George Mason University, Fairfax, Virginia, USA
2. Department of Biomedical Informatics, Harvard Medical School, Boston, Massachusetts, USA
3. Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
4. Division of Mathematics, Computing, and Statistics, Simmons University, Boston, Massachusetts, USA
5. Department of Medicine, Medical College of South Carolina, Charleston, South Carolina, USA