Permanence, oscillation and attractivity of the discrete hematopoiesis model with variable coefficients

In this paper, we consider the nonlinear delay difference equation with periodic coefficients Pn+l - P-n = -delta(n)p(n) + beta(n)/1 + (p(n-omega)) and demonstrate that solutions are permanent. The existence of a positive periodic solution is proven and sufficient conditions for the attractivity of this solution are obtained. Oscillation and nonoscillation about the positive periodic solution is considered. (C) 2006 Elsevier Ltd. All rights reserved.