Biomedical subjects

Shinji Nakaoka

Publications and source records attributed to Shinji Nakaoka.

2 recordsLinked to original sources

PubMed2006

Competition in chemostat-type equations with two habitats.

Competition on a model with nutrient recycling is considered. The model is based on a chemostat-type equation which is used to study population dynamics of microorganisms. The model consists of four organisms competing for a limiting nutrient. Nutrient is supplied both from the in-flow of medium and a recycling with delay, the latter is generated from dead organisms by bacterial decomposition. This paper shows that the model undergoes a Hopf bifurcation through a critical value of time delay when the in-flow is small. Coexistence of four organisms competing for one limiting nutrient is indicated by numerical simulation results.

Bacteria↗

PubMed2006

Prey-predator system with parental care for predators.

A stage structure is incorporated into a prey-predator model in which predators are split into immature predators and mature predators. It is assumed that immature predators are raised by their parents in the sense that they cannot catch the prey and their foods are provided by parents. Further, it is assumed that the maturation rate of immature predators is a function of the food availability for one immature individual. It is found that the model admits periodic solutions which are produced from the stage structure. Further, it is shown that two stability switches of positive equilibria may occur due to the transition rate incorporating the influence of nutrient, and that the enrichment of adult predators may lead to the catastrophe of the ecological system.

Animals↗