“…, x), v(t, x)) of (21) and at least a positive solution (u s , v s ) of (22). Moreover, a positive solution (u s , v s ) of (22) u(t, x), v(t, x)) of (21) and at least a positive solution (u s , v s ) of (22). If m = 2 there exists a unique global positive solution (u(t, x), v(t, x)) of (21) and not bounded.…”