First Author:   Marcelo de C. Griebeler Federal University of Santa Catarina griebeler.marcelo@gmail.com   UFSC - Campus Reitor João David Ferreira Lima, CNM, sala 102 Florianópolis, 88040-900, Brasil   55 48 37212745(Phone) 55 48 37212745(Fax) www.cnm.ufsc.br Second Author: Ronald Otto Hillbrecht Federal University of Rio Grande do Sul ottohill@ufrgs.br