The authors would like to thank the Fundação de Amparo à
Pesquisa do Estado de Minas Gerais (FAPEMIG) and the Coordenação
de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) for their
financial support. We would also like to thank Dr. Raimundo Alberto
Gomes da Silva (in memoriam) for his assistance during this study.