1. Sección de Matemática, Sede de Occidente, Universidad de Costa Rica, San Ramón, Alajuela, Costa Rica.
2. Department of Mathematics, Division of Mechanics, University of Oslo, Oslo, Norway; and Simula Research Laboratory, 1325 Lysaker, Norway.
3. School of Mathematics, Monash University, 9 Rainforest Walk, Melbourne 3800 VIC, Australia; and World-Class Research Center “Digital biodesign and personalized healthcare,” Sechenov First Moscow State Medical University, Moscow, Russia; and Universidad Adventista de Chile, Casilla 7-D, Chillán, Chile.
4. Department for Numerical Analysis and Scientific Computing, Simula Research Laboratory, Lysaker, Norway.