In this work, our aim is to investigate the impact of a non-Kolmogorov predator-prey-subsidy model incorporating nonlinear prey refuge and the effect of fear with Holling type II functional response. The model arises from the study of a biological system involving arctic foxes, lemmings, and seal carcasses. The positivity and asymptotically uniform boundedness of the solutions of the system have been derived. Analytically, we have studied the criteria for the feasibility and stability of different equilibrium points. In addition, we have (...) derived sufficient conditions for the existence of local bifurcations of codimension 1. It is also observed that there is some time lag between the time of perceiving predator signals through vocal cues and the reduction of prey’s birth rate. So, we have analyzed the dynamical behaviour of the delayed predator-prey-subsidy model. Numerical computations have been performed using MATLAB to validate all the analytical findings. Numerically, it has been observed that the predator, prey, and subsidy can always exist at a nonzero subsidy input rate. But, at a high subsidy input rate, the prey population cannot persist and the predator population has a huge growth due to the availability of food sources. (shrink)

The Greek polis has been arousing interest as a subject for study for a long time, but recent approaches have shown that it is a subject on which there are still important questions to be asked and worthwhile issues to be explored. This book contains a selection of essays which embody the results of the latest research. Beyond the historical development of the Greek polis , the contributors ask questions about the civic institutions of ancient Greece as a whole and (...) their relationships to each other. Questions of power or the significance of a written code of law are discussed as well as the nature of Greek overseas settlements. Development of the Greek Polis presents up-to-date research and asks up-to-date questions on various aspects of an important topic. (shrink)

It is widely accepted that stressful conditions can facilitate evolutionary change. The mechanisms elucidated thus far accomplish this with a generic increase in heritable variation that facilitates more rapid adaptive evolution, often via plastic modifications of existing characters. Through scrutiny of different meanings of stress in biological research, and an explicit recognition that stressors must be characterized relative to their effect on capacities for maintaining functional integrity, we distinguish between: (1) previously identified stress-responsive mechanisms that facilitate evolution by maintaining an (...) adaptive fit with the environment, and (2) the co-option of stress-responsive mechanisms that are specific to stressors leading to the origin of novelties via compensation. Unlike standard accounts of gene co-option that identify component sources of evolutionary change, our model documents the cost-benefit trade-offs and thereby explains how one mechanism—an immediate response to acute stress—is transformed evolutionarily into another—routine protection from recurring stressors. We illustrate our argument with examples from cell type origination as well as processes and structures at higher levels of organization. These examples suggest a general principle of evolutionary origination based on the capacity to switch between regulatory states related to reproduction and proliferation versus survival and differentiation. (shrink)

History, Prophecy, and the Stars: The Christian Astrology of Pierre d'Ailly. By Laura Ackerman Smoller (Princeton: Princeton University Press, 1994), xii + 233 pp., $35.00 cloth. The Jewish Alchemists: A History and Sourcebook. By Raphael Patai (Princeton: Princeton University Press, 1994), xv + 617 pp., $35.00/£29.95 cloth. Access to Western Esotericism. By Antoine Faivre (Albany: State University of New York Press, 1994), x + 369 pp., $19.95 cloth.

Organic crosstalk or intercommunication among different organs is an interesting medical concept based on the biosemiotic perspective which considers the organism as a process maintained by the vital information flow between structural plane and biosemiotic plane, both with their different layers of biological complexity. From this point of view the organ is not merely the structure which produces crosstalk but just as much its product. The crosstalk perspective seeks two main goals: to investigate the characteristic serum biosemiotic patterns of pathogenic (...) organic crosstalk in order to achieve early diseases diagnosis, and to learn how to correct it. These achievements could allow physicians to evolve from a medical practice that focuses on misbiosemiotic effects, diagnosing and treating damaged organs, to a medical practice that focuses on misbiosemiotic processes, in this way diagnosing and treating pathogenic organ crosstalk before it culminates in organ damage. (shrink)

These essays are primarily concerned with the character of ethological research in the context of conflicts between animal and human interests. Specifically, to what extent is the projection into animals of human feelings a useful means to understand animal behavior? Annotation copyright Book News,.