Scientific research is supported by infrastructure, and e-infrastructure is one part of this. Repositories of data are a part of the e-infrastructure and have their own particular needs arising from the requirement for permanence of their data holdings. There are many threats to permanence, and there is a growing awareness of these threats and how they may be countered. Current Research Informa...

This paper is concerned with a cyclic predator-prey system with Sigmoidal type functional response. By using the differential inequality theory, some sufficient conditions are derived for the permanence of the system. By constructing a suitable Liapunov function, we obtain that the system has a unique asymptotically periodic solution which is globally asymptotically stable. Some numerical simul...

We consider ecological difference equations of the form X i t+1 = X i t Ai(Xt) where X i t is a vector of densities corresponding to the subpopulations of species i (e.g. subpopulations of different ages or living in different patches), Xt = (X 1 t , X 2 t ,. .. , X m t) is state of the entire community, and Ai(Xt) are matrices determining the update rule for species i. These equations are perm...

In this paper, a biologically inspired computational model is proposed and implemented on a robot to study one of the most fundamental and controversial issues in cognitive science – “Object Permanence.” Because of the world-knowledgefree design and the developmental learning ability of this model, we are able to analyze the robot’s behavior based on its perceptual development through different...

We investigate a delayed stage-structured Ivlev’s functional response predator-prey model with impulsive stocking on prey and continuous harvesting on predator. Sufficient conditions of the global attractivity of predator-extinction periodic solution and the permanence of the system are obtained. These results show that the behavior of impulsive stocking on prey plays an important role for the ...

w . m w . w . where f : 0, ` a 0, ` and the initial values x , . . . , x g 0, ` . 0 1ym Ž . In studying the global behavior of the solutions of Eq. 1 , we often need Ž . to establish that 1 is permanent, i.e., it has the property that every one of its solutions is eventually confined within a fixed compact interval regardless of the initial values chosen. Permanence is needed directly or indire...

This paper is concerned with a n-species cooperation system with distributed delays and feedback controls on time scales. For general nonautonomous case, by using differential inequality theory and constructing a suitable Lyapunov functional, sufficient conditions which guarantee the permanence and the global attractivity of the system are obtained. For the almost periodic case, by using the Ra...

In this paper, we prove that a stochastic logistic population under regime switching controlled by a Markov chain is either stochastically permanent or extinctive, and we obtain the sufficient and necessary conditions for stochastic permanence and extinction under some assumptions. In the case of stochastic permanence we estimate the limit of the average in time of the sample path of the soluti...

1. Activity and microhabitat use are important factors determining species performance in habitats that differ in permanence and species composition of top predators. This study examined the relationship between the distribution across a gradient of habitat permanence and an associated transition in the composition of top predators and the behaviour of species of larval dragonflies. It also ass...