local site conditions have a strong effect on ground response during earthquakes. two important soil parameters that control the amplification effects of seismic motions by a soil column are the soil hysteretic damping ratio and shear wave velocity. this paper presents the results of in situ damping ratio measurements performed using continuous surface wave attenuation data at a site in semnan ...

A predator’s per capita feeding rate on prey, or its functional response, provides a foundation for predator–prey theory. Since 1959, Holling’s prey-dependent Type II functional response, a model that is a function of prey abundance only, has served as the basis for a large literature on predator–prey theory. We present statistical evidence from 19 predator–prey systems that three predator-depe...

We study a diffusive predator-prey system with a ratio-dependent functional response when a prey population is infected under homogeneous Neumann boundary condition. All non-negative and positive equilibria are investigated, and the conditions that give rise to asymptotic behavior of these equilibria are examined. In particular, we present a biological interpretation of disease-free and total e...

The distribution of weak and strong non-linear feeding interactions (i.e., functional responses) across the links of complex food webs is critically important for their stability. While empirical advances have unravelled constraints on single-prey functional responses, their validity in the context of complex food webs where most predators have multiple prey remain uncertain. In this study, we ...

In the paper, we investigate a three-species food chain model with diffusion and ratio-dependent predation functional response. We mainly focus on the coexistence of the three species. For this coupled reaction-diffusion system, we study the persistent property of the solution, the stability of the constant positive steady state solution, and the existence and nonexistence of nonconstant positi...

The present studyinvestigated the impact of selection for body weight (BW) on productive performance, predicted BW and genetic improvement of related traits in Japanese quail. Base population, selected parent and F1 progeny were tested. Pens and cages were used for rearing and breeding. A total of 240 birds in two successive generations, 27 sires and 54 dams (as selected parents) were used. Bod...

In the paper, we investigate a three-species food chain model with diffusion and ratio-dependent predation functional response. We mainly focus on the co-existence of the three species. For this coupled reaction-diffusion system, we study the persistent property of the solution, the stability of the constant positive steady state solution, and the existence and non-existence of non-constant pos...

T he objective of this study is using the Markov Switching Vector Autoregressive method and regime dependent impulse response functions to measure the pass-through of world food prices to consumer price index in Iran from 1990 to 2013. With respect to information criteria and the log-likelihood ratio statistic, MSIA(2)-VAR(1) model has a better fit to data than other models. The magn...

In this paper, by incorporating the general delay to reaction term in memory-based diffusive system, we propose a system with memory and (e.g., digestion, gestation, hunting, migration maturation delays, etc.). We first derive an algorithm for calculating normal form of Hopf bifurcation proposed system. The developed can be used investigate direction stability bifurcation. As real application, ...