First Author:   Valdir Domeneghetti University of São Paulo domeneghetti@usp.br   1882 Cav.Torquato Rizzi St,101 apartament Ribeirão Preto, 14021-676, Brazil   +5516997220443(Phone) +5516997220443(Fax) Second Author: Fabiano Guasti Lima University of Sao Paulo fgl@usp.br   Ribeirão Preto, 14040-900, Brazil   +551633150432(Phone)