the food chain refers to a natural system by which energy is transmitted from one organism to another. in fact, a food chain consists of producers, consumers and decomposition. presence of complex food web increase the stability of the ecosystem. classical food chain theory arises from lotka-volterra model. in the present paper, the dynamics behavior of three level food chain is studied. a syst...

Research on post-traumatic stress disorder (PTSD) is faced with the challenge of understanding how a traumatic experience produces long-lasting detrimental effects on behavior and brain functioning, and more globally, how stress exacerbates somatic disorders, including cardiovascular disease. Moreover, the design of translational research needs to link animal models of PTSD to clinically releva...

This paper consists of design of digital FIR high pass filter using predator prey optimization and hybrid predator prey optimization (HPPO) technique. HPPO is a combination of predator prey optimization (PPO) and exploratory search where Predator prey optimization is a global search method and exploratory move is a local search method. Local stagnation is possible in PSO but there is no local s...

We study a tritrophic food chain model which is based on Schnakenberg type kinetics. This model is realistic in a predator-prey context if cooperation of predators is prevalent in the system. The system also serves as a model for a sequence of irreversible autocatalytic reactions in a container which is in contact with a well-stirred reservoir. It is an extension of the Schnakenberg model sugge...

Predator-prey interactions play an important role for species composition and community dynamics at local scales, but their importance in shaping large-scale gradients of species richness remains unexplored. Here, we use global range maps, structural equation models (SEM), and comprehensive databases of dietary preferences and body masses of all terrestrial, non-volant mammals worldwide, to tes...

Changes in predator diversity via extinction and invasion are increasingly widespread and can have important ecological and socio-economic consequences. Anticipating and managing these consequences requires understanding how predators shape ecological communities. Previous predator biodiversity research has focused on post-colonization processes. However, predators can also shape communities by...

The strength of interference between foraging individuals can influence per capita consumption rates, with important consequences for predator and prey populations and system stability. Here we demonstrate how the replacement of a previously established invader, the predatory crab Carcinus maenas, by the recently invading predatory crab Hemigrapsus sanguineus shifts predation from a species tha...

This experimental study tests new theory for multiple predator effects on communities by using warming to alter predator habitat use and hence direct and indirect interactions in a grassland food web containing two dominant spider predator species, a dominant grasshopper herbivore and grass and herb plants. Experimental warming further offers insight into how climate change might alter direct a...

1. Top-down control can be an important determinant of ecosystem structure and function, but in oceanic ecosystems, where cascading effects of predator depletions, recoveries, and invasions could be significant, such effects had rarely been demonstrated until recently. 2. Here we synthesize the evidence for oceanic top-down control that has emerged over the last decade, focusing on large, high ...

We examined conspicuous signalling displays in the context of predator-prey interactions. To determine in which context Puerto Rican crested anoles, Anolis cristatellusperform conspicuous signals, we exposed wild lizards to a model of a natural snake predator. The lizards gave six behavioural responses to the model: immobility, predator inspection, flight, lateral face-off, dewlapping and push-...