1. Centre for Research in Mathematics A.C., Jalisco S/N, Col. Valenciana, Guanajuato 36000, Mexico
2. CONACYT-Centre for Research in Mathematics A.C., Jalisco S/N, Col. Valenciana, Guanajuato 36000, Mexico
3. High Speciality Medical Unit (UMAE), Specialities Hospital No. 1, Mexican Social Security Institute (IMSS), Leon 37320, Mexico
4. Department of Health Sciences, Universidad Tecnológica de México (UNITEC) Campus León, Leon 37200, Mexico