A generalization of the nonautonomous Mackey–Glass equation for the regulation of the hematopoiesis with several non-constant delays is studied. Using topological degree methods we prove, under appropriate conditions, the ...

This paper proposes an omega-periodic version of the Ellermeyer model of delayed chemostat. We obtain a sufficient condition ensuring the existence of a positive omega-periodic solution. Our proof is based on the application ...

The Wheldon model (1975) of a chronic myelogenous leukemia (CML) dynamics is modified and enriched by introduction of a time-varying microenvironment and time-dependent drug efficacies. The resulting model is a special ...

To enrich the dynamics of mathematical models of angiogenesis, all mechanisms involved are time-dependent. We also assume that the tumor cells enter the mechanisms of angiogenic stimulation and inhibition with some delays. ...

We give sufficient and necessary conditions for the existence of at least one positive T -periodic solution for a generalized Nicholson’s blowflies model with a nonlinear harvesting term. Our results extend those of the ...

In this paper we establish a method to obtain the stability of periodic travelling-wave solutions for equations of Korteweg-de Vries-type u(t) + u(p)u(x) - Mu(x) = 0, with M being a general pseudodifferential operator and ...

This paper introduces a new consideration in the well known chemostat model of a one-species with a periodic input of single nutrient with period omega, which is described by a system of differential delay equations. The ...

In this work we consider a class of systems of two vector fields on the 3-torus associated to a closed smooth complex 1-form c = a + ib with b exact. Necessary conditions and sufficient conditions for this system to be ...

A generalized non-linear nonautonomous model for the haematopoiesis (cell production) with several delays and an oscillating circulation loss rate is studied. We prove a fixed point theorem in abstract cones, from which ...