1. Facultad de Ciencias, Universidad de Oviedo, Federico García Lorca, 18, 33007-Oviedo, Spain.
2. School of Mathematics, Monash University, Melbourne, Victoria 3800, Australia; World-Class Research Center “Digital Biodesign and Personalized Healthcare”, Sechenov First Moscow State Medical University, Moscow, Russia; and Universidad Adventista de Chile, Chillán, Chile.