Mailing Address: Claudia Maria Vilas Freire •
Universidade Federal de Minas Gerais – UFMG. Rua Ivai 96, Serra. Postal
Code 30210-520, Belo Horizonte, MG – Brazil
E-mail: claudiavilasfreire@gmail.com
Manuscript received March 30, 2015; revised manuscript October 26, 2015;
accepted November 06, 2015