1. Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
2. Department of Mathematics, Lehigh University, Bethlehem, Pennsylvania, USA
3. Department of Mathematical Sciences, University of Texas—El Paso, El Paso, Texas, USA
4. Department of Mathematics, New Mexico State University, Las Cruces, New Mexico, USA
5. Institute for Modeling Collaboration and Innovation, University of Idaho, Moscow, Idaho, USA
6. Department of Mathematics, Harbin Institute of Technology—Weihai, Weihai, Shandong, China
7. Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA