An age-structured model of cannibalism.
An asymptotic test for quantitative gene detection
An asymptotic test for Quantitative Trait Locus detection in presence of missing genotypes
We consider the likelihood ratio test (LRT) process related to the test of the absence of QTL (a QTL denotes a quantitative trait locus, i.e. a gene with quantitative effect on a trait) on the interval representing a chromosome. The originality is in the fact that some genotypes are missing. We give the asymptotic distribution of this LRT process under the null hypothesis that there is no QTL on and under local alternatives with a QTL at on . We show that the LRT process is asymptotically...
An efficient linear numerical scheme for the Stefan problem, the porous medium equation and nonlinear cross-diffusion systems
This paper deals with nonlinear diffusion problems which include the Stefan problem, the porous medium equation and cross-diffusion systems. We provide a linear scheme for these nonlinear diffusion problems. The proposed numerical scheme has many advantages. Namely, the implementation is very easy and the ensuing linear algebraic systems are symmetric, which show low computational cost. Moreover, this scheme has the accuracy comparable to that of the wellstudied nonlinear schemes and make it possible...
An epidemic model with a time delay in transmission
We study a mathematical model which was originally suggested by Greenhalgh and Das and takes into account the delay in the recruitment of infected persons. The stability of the equilibria are also discussed. In addition, we show that the introduction of a time delay in the transmission term can destabilize the system and periodic solutions can arise by Hopf bifurcation.
An epidemic model with density dependent parameters and vaccination.
An Epidemic Model With Post-Contact Prophylaxis of Distributed Length II. Stability and Oscillations if Treatment is Fully Effective
A possible control strategy against the spread of an infectious disease is the treatment with antimicrobials that are given prophylactically to those that had contact with an infective person. The treatment continues until recovery or until it becomes obvious that there was no infection in the first place. The model considers susceptible, treated uninfected exposed, treated infected, (untreated) infectious, and recovered individuals. The overly optimistic assumptions are made that treated uninfected...
An existence theorem for Volterra integrodifferential equations with infinite delay.
An impulsive two-prey one-predator system with seasonal effects.
An Initial-Boundary-Value Problem for a Certain Density-Dependent Diffusion System.
An Intracellular Delay-Differential Equation Model of the HIV Infection and Immune Control
Previous work has shown that intracellular delay needs to be taken into account to accurately determine the half-life of free virus from drug perturbation experiments [1]. The delay also effects the estimated value for the infected T-cell loss rate when we assume that the drug is not completely effective [19]. Models of virus infection that include intracellular delay are more accurate representations of the biological data. We analyze a non-linear model of the human immunodeficiency virus (HIV)...
An LPV fractional model for canal control.
An Optimal Control Problem for a Predator-Prey Reaction-Diffusion System
An optimal control problem is studied for a predator-prey system of PDE, with a logistic growth rate of the prey and a general functional response of the predator. The control function has two components. The purpose is to maximize a mean density of the two species in their habitat. The existence of the optimal solution is analyzed and some necessary optimality conditions are established. The form of the optimal control is found in some particular...
An SIRS epidemic model of Japanese encephalitis.
An unconditionally positive and global stability preserving NSFD scheme for an epidemic model with vaccination
In this paper, a NonStandard Finite Difference (NSFD) scheme is constructed, which can be used to determine numerical solutions for an epidemic model with vaccination. Here the NSFD method is employed to derive a set of difference equations for the epidemic model with vaccination. We show that difference equations have the same dynamics as the original differential system, such as the positivity of the solutions and the stability of the equilibria, without being restricted by the time step. Our...
An unconditionally stable nonstandard finite difference method applied to a mathematical model of HIV infection
We formulate and analyze an unconditionally stable nonstandard finite difference method for a mathematical model of HIV transmission dynamics. The dynamics of this model are studied using the qualitative theory of dynamical systems. These qualitative features of the continuous model are preserved by the numerical method that we propose in this paper. This method also preserves the positivity of the solution, which is one of the essential requirements when modeling epidemic diseases. Robust numerical...
Analysis and numerical solution of a nonlinear cross-diffusion system arising in population dynamics.
En este trabajo se estudia de modo analítico y numérico un problema en ecuaciones diferenciales en derivadas parciales que modela la dinámica de dos poblaciones afectadas por la presión poblacional inter e intraespecíficas y por un potencial medioambiental. Debido a los términos de difusión cruzada, el problema es fuertemente no lineal por lo que el principio del máximo y los métodos relacionados con el mismo no pueden ser aplicados. En primer lugar demostramos la existencia de soluciones débiles...
Analysis of a delayed SIR model with nonlinear incidence rate.
Analysis of a Model with Multiple Infectious Stages and Arbitrarily Distributed Stage Durations
Infectious diseases may have multiple infectious stages with very different epidemiological attributes, including infectivity and disease progression. These stages are often assumed to have exponentially distributed durations in epidemiological models. However, models that use the exponential distribution assumption (EDA) may generate biased and even misleading results in some cases. This discrepancy is particularly damaging if the models are employed to assist policy-makers in disease control...
Analysis of a nonautonomous delayed predator-prey system with a stage structure for the predator in a polluted environment.