1. ON THE EXISTENCE OF POSITIVE SOLUTIONS OF A CLASS OF PARABOLIC REACTION DIFFUSION SYSTEMS. Authors: MOUNIR REDJOUH, SALIM MESBAHI.2. GENERALIZED RESULT ON THE GLOBAL EXISTENCE OF POSITIVE SOLUTIONS FOR A PARABOLIC REACTION DIFFUSION MODEL WITH A FULL DIFFUSION MATRIX. Authors: NABILA BARROUK, SALIM MESBAHI.