First Author:   Thiernaud T. D. Behanzin GASTON BERGER UNIVERSITY behanzinthiernaud@gmail.com   behanzinthiernaud@gmail.com Dakar, Senegal   00221770902133(Phone) 00221770902133(Fax) Second Author: Mamadou A. Konte GASTON BERGER UNIVERSITY mamadou-abdoulaye.konte@ugb.edu.sn   ST LOUIS, SENEGAL   00221776221350(Phone)