This article has been published by the scientific journal Dyna, and therefore it was requested to be removed from this public space, so it could be considered as an original publication. A link to the article can be found here: http://www.revistadyna.com/Articulos/Ficha.aspx?Cod=7177&CodArt=BA2AC136-6E50-4E1285CD-472C06BBFAEA