1. Department of Mathematics, Florida State University, 208 Love Building, Tallahassee, Fl 32306
2. Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, USA, Centre for Dermatology Research, University of Manchester, and NIHR Biomedical Research Centre, Manchester, UK
3. School of Mathematical and Natural Sciences, Arizona State University - West Campus, Glendale, AZ 85306, USA, and Department of Mathematics, North Carolina State University, Raleigh, NC 27695, USA