Toshikazu Kuniya

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In this paper, we investigate the dynamics of a five-dimensional virus model with immune responses and an intracellular delay which describes the interactions of the HIV virus, CD4 cells and CTLs within host, which is an improvement of some existing models by incorporating (i) two distributed kernels reflecting the variance of time for virus to invade into(More)
We present a measurement of the standard model CP violation parameter sin2 phi(1) based on a 29.1 fb(-1) data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. One neutral B meson is fully reconstructed as a J/psi K(S), psi(2S)K(S), chi(c1)K(S), eta(c)K(S), J/psi K(L), or J/psi K(*0) decay(More)
In this paper, we study the long-time behavior of a nonautonomous SEIRS epidemic model. We obtain new su cient conditions for the permanence (uniform persistence) and extinction of infectious population of the model. By numerical examples we show that there are cases such that our results improve the previous results obtained in [T. Zhang and Z. Teng, On a(More)
Despite the fact that density effects and individual differences in life history are considered to be important for evolution, these factors lead to several difficulties in understanding the evolution of life history, especially when population sizes reach the carrying capacity. r/K selection theory explains what types of life strategies evolve in the(More)
In this paper, we are concerned with an age-structured SIR epidemic model with time periodic coefficients. We obtain the basic reproduction number R0 as the spectral radius of the next generation operator, and show that it plays the role of a threshold value for the existence of a nontrivial periodic solution, that is, the model has a nontrivial periodic(More)
A recent paper [F. Brauer, Z. Shuai and P. van den Driessche, Dynamics of an age-of-infection cholera model, Math. Biosci. Eng., 10, 2013, 1335--1349.] presented a model for the dynamics of cholera transmission. The model is incorporated with both the infection age of infectious individuals and biological age of pathogen in the environment. The basic(More)
In this paper, an Susceptible-Vaccines-Exposed-Infectious-Recovered model with continuous age-structure in the exposed and infectious classes is investigated. These two ages are assumed to have arbitrary distributions that are represented by age-specific rates leaving the exposed and the infectious classes. We investigate the global dynamics of this model(More)
Herpes Simplex Virus Type 2 (HSV-2) is one of the most common sexually transmitted diseases. Although there is still no licensed vaccine for HSV-2, a theoretical investigation of the potential effects of a vaccine is considered important and has recently been conducted by several researchers. Although compartmental mathematical models were considered for(More)
In this article, we study a continuous age-structured HIV infection model. For the case of the saturation infection rate, the basic reproduction number <0 is shown to be a sharp threshold value for the global dynamics; that is, the infection-free equilibrium is globally stable if <0 < 1, while a unique infection equilibrium is so if <0 > 1. For the proof,(More)