Oscillation and Global Attractivity in a Nonlinear Delay Periodic Model of Respiratory Dynamics

In this paper we shall consider the nonlinear delay differential equationwhere and are positive integers, () and λ() are positive periodic functions of period . In the nondelay case we shall show that (*) has a unique positive periodic solution , and provide sufficient conditions for the global attractivity of . In the delay case we shall present sufficient conditions for the oscillation of all positive solutions of (*) about , and establish sufficient conditions for the global attractivity of