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1.
Namiot VA 《Biofizika》2001,46(5):856-858
At present there is no generally accepted theory of the effect of macroscopic fluctuations. It the article, an attempt is made to relate this effect to some basic properties of quantum systems, in particular, to the formal absence of dynamic chaos in these systems. Based on this approach, it was shown why the level of the effect must be of the same order of magnitude as the level of noise and cannot exceed this level as the number of experiments increases. It was shown qualitatively what is the cause of the similarity of histograms observed in different experiments.  相似文献   

2.
展望数学生态学与生态模型的未来   总被引:11,自引:0,他引:11  
李典谟  马祖飞 《生态学报》2000,20(6):1083-1089
首先简要回顾了20世纪数学生态学发展的历史,特别是半2个世纪以来在中国的发展。然后指出了生物学的进步为数学生态学的发展提供了机遇。作者列出了当前数学生态学和生态模型研究的几个热点:⑴非线性动力学;⑵种群的时空动态:包括异质种群动态,源-汇理论以及种群对时、空变化的响应等;⑶多样性和稳定性的关系;⑷行为的动态模型;⑸基于个体的模型。最后指出,生态学中混沌现象,可能表明多年来理论生态学家寻找的种群动态  相似文献   

3.
混沌理论及其在建立神经网络模型中的应用   总被引:3,自引:0,他引:3  
随着许多学科的相互紧密交叉以及混沌理论的日益深入的研究,人们从生物现象中提出了许多与混沌有关的神经网络模型,本文对混沌理论的基本原理做了简要概述,并着重介绍了四种有代表性的混沌神经网络模型及其应用.同时指出这一研究方向无论在理论还是在应用方面都具有十分诱人的前景.  相似文献   

4.
The apparent synchronisation of spatially discrete populations is a well documented phenomenon. However, it is not clear what the governing mechanisms are for this synchrony, and whether they are robust over a range of environmental conditions and patch specific population dynamic behaviours. In this paper, we explore two (possibly interacting) modes of coupling, and investigate their theoretically discernible, and perhaps even experimentally measurable, signatures. To aid us in this investigation we employ a planktonic example system, with direct application to plankton patchiness. Furthermore, we address the role of chaos in complex spatio-temporal dynamics; we find that chaos associated with funnel attractors can play a distinguished role, over dynamics less sensitive to small variations, in being more susceptible to generalised synchronisation (such as phase synchronisation) in the presence of small local parameter variation. This is in contrast to the case for coupled systems with identical dynamics, and suggests that non-identically coupled systems are more vulnerable to global extinction events when exhibiting funnel-type chaotic dynamics.  相似文献   

5.
Khrennikov A 《Bio Systems》2006,84(3):225-241
We present a contextualist statistical realistic model for quantum-like representations in physics, cognitive science, and psychology. We apply this model to describe cognitive experiments to check quantum-like structures of mental processes. The crucial role is played by interference of probabilities for mental observables. Recently one such experiment based on recognition of images was performed. This experiment confirmed our prediction on the quantum-like behavior of mind. In our approach "quantumness of mind" has no direct relation to the fact that the brain (as any physical body) is composed of quantum particles. We invented a new terminology "quantum-like (QL) mind." Cognitive QL-behavior is characterized by a nonzero coefficient of interference lambda. This coefficient can be found on the basis of statistical data. There are predicted not only cos theta-interference of probabilities, but also hyperbolic cosh theta-interference. This interference was never observed for physical systems, but we could not exclude this possibility for cognitive systems. We propose a model of brain functioning as a QL-computer (there is a discussion on the difference between quantum and QL computers).  相似文献   

6.
Alkon DL 《Biophysical journal》2001,80(5):2056-2061
In quantum theory, nothing that is observable, be it physical, chemical, or biological, is separable from the observer. Furthermore, ". all possible knowledge concerning that object is given by its wave function" (Wigner, E. 1967. Symmetries and Reflections. Indiana University Press, Bloomington, IN), which can only describe probabilities of future events. In physical systems, quantum mechanical probabilistic events that are microscopic must, in turn, account for macroscopic events that are associated with a greater degree of certainty. In biological systems, probabilistic statistical mechanical events, such as secretion of microscopic synaptic vesicles, must account for macroscopic postsynaptic potentials; probabilistic single-channel events sum to produce a macroscopic ionic current across a cell membrane; and bleaching of rhodopsin molecules (responsible for quantal potential "bumps") produces a photoreceptor generator potential. Among physical systems, a paradigmatic example of how quantum theory applies to the observation of events concerns the interactions of particles (e.g., photons, electrons) with the two-slit apparatus to generate an interference pattern from a single common light source. For two-slit systems that use two independent laser sources with brief (<1 ms) intervals of mutual coherence (Paul, H. 1986. Rev. Modern Phys. 58:209-231), each photon has been considered to arise from both beams and has a probability amplitude to pass through each of the two slits. Here, a single laser source two-slit interference system was constructed so that each photon has a probability amplitude to pass through only one or the other, but not both slits. Furthermore, all photons passing through one slit could be distinguished from all photons passing through the other slit before their passage. This "either-or" system produced a stable interference pattern indistinguishable from the interference produced when both slits were accessible to each photon. Because this system excludes the interaction of one photon with both slits, phase correlation of photon movements derives from the "entanglement" of all photon wave functions due to their dependence on a common laser source. Because a laser source (as well as Young's original point source) will have stable time-averaged spatial coherence even at low intensities, the "either-or" two-slit interference can result from distinct individual photons passing one at a time through one or the other slit-rather than wave-like behavior of individual photons. In this manner, single, successive photons passing through separate slits will assemble over time in phase-correlated wave distributions that converge in regions of low and high probability.  相似文献   

7.
Labos E 《Biophysical chemistry》1994,50(1-2):217-223
Formal neural networks (FNN) can display dynamical behaviours, more or less different from each other depending on their units, the functions attributed to these units, interconnections, parameters, state spaces and initial states, etc. Whatever is 'chaos' - of which several practical and more exact definitions exist -, it used to be emerging at special conditions. Its prediction most often requires an individual analysis of the dynamical system (DS) in question. A study of such conditions is usually necessary in order to reach suitable control, which now seems to become a new trend in chaos theory. In chaos control tasks quick commands and at least short-term foresight of trends are required. It is a primary question also to define in advance what is regarded to be a controlled case of chaos. Possible importance of these general considerations at molecular scale is also discussed, avoiding not well-founded speculations.  相似文献   

8.
系统生物学是研究一个生物系统中所有组成成分(基因、mRNA、蛋白质等)的构成与组分之间相互关系的学科,近年来,系统生物学作为后基因组学时代研究的一个重要内容,已广泛深入到生命科学和医药学的各个领域。而作为中国传统医学而言,似乎与之相去甚远,然而当我们对这两个新老学科基础理论进行比较时,我们发现:传统中国医药与现代系统生物学研究理论的殊途同归。有鉴于此,本文论述了系统生物学和中医学的思想起源、相互联系,基于系统生物学的发展、研究思路和方法,阐述了生物学由还原论的研究方法过渡到系统论的研究方法,强调对生命现象从系统和整体的层次进行研究和把握,对传统中医学研究方法的变革起到了推动作用,最后对系统生物学在中医药学未来发展进行了评价。  相似文献   

9.
害虫灾害研究的复杂性理论框架   总被引:1,自引:0,他引:1  
害虫灾害是高度复杂的大系统 ,表现出不均匀性、差异性、多样性、突发性、随机性、可预测性和周期性等复杂性特征 ,使得经典的理论和方法已不适用于害虫灾害的研究。依据复杂性科学和分形、神经网络、混沌及小波等非线性科学的发展及其近期在害虫灾害中的部分研究成果 ,该文从复杂大系统出发 ,构建了害虫灾害研究的复杂性理论框架 ,为深入研究害虫灾害的成因、机制与预测提供理论依据。  相似文献   

10.
Skott Brill 《Bioethics》2019,33(2):287-293
Some critics of Don Marquis's ‘future‐like‐ours’ anti‐abortion argument launch what has been called the Identity Objection. The upshot of this objection is that under a psychological theory of personal identity, a non‐sentient fetus lacks precisely what Marquis believes gives it a right to life – a future like ours. However, Eric Vogelstein, in a recent article, has argued that under this theory of personal identity a non‐sentient fetus, in fact, has a future like ours, which he believes dissolves the Identity Objection. But Vogelstein is mistaken. Even if he is correct that there is a sense in which a non‐sentient fetus has a future of value under a psychological theory of personal identity, the sense in which it has one is importantly different from the sense in which we have one, meaning that, under such a theory, a non‐sentient fetus does not have a future like ours.  相似文献   

11.
Ulanowicz  Robert E. 《Hydrobiologia》2004,514(1-3):3-12
According to conventional wisdom, the brackish water ecology of the Baltic, like all ecology, is a secondary science. That is, the phenomena it considers can be decomposed into series of more elementary events acting under a sequence of laws that culminates either in the netherworld of quantum physics or in the realm of the cosmological. Ecology, however, is not a derivative science; it is fundamental in its own right. The Baltic ecosystem, for example, is a complex system of many-components. Using combinatorics one may argue that most of the whole-system configurations which ecologists encounter comprise unique and original events that elude treatment via the conventional Baconian approach. Chaos does not reign, however, because there exist among the populations of the ecosystem self-reinforcing mutualistic loops that exert a form of selection upon their constituent members quite different from the `natural selection' of evolutionary theory. This feedback gives rise to what Karl Popper described as `propensities' that serve in contingent systems in lieu of conventional forces to maintain the coherence of the ecosystem. The ensuing autonomous `ecodynamics' can be quantified using information theory, resulting in measures that can be used to compare the status of the Baltic ecosystem with those of similar bodies of water, such as Chesapeake Bay.  相似文献   

12.
Hiett PJ 《Bio Systems》1999,49(2):127-142
This paper aims to provide a deeper understanding of the 'edge of chaos' phenomenon. This is an important concept in some strands of work on complex systems, but exactly what it means remains unclear. Broadly, it may be seen as a region between rigid order and chaos. In cellular automata which show the edge of chaos phenomenon, this is indicated by the occurrence of smooth transitions in certain variables, such as the average Shannonian entropy, where generally one finds sudden jumps. The abrupt jump is between an ordered realm and a chaotic one, so the smoothness of a transition holds out the promise of the existence of a realm between order and chaos. Since living systems may also be described as lying between order and chaos, then the edge of chaos may be the key to understanding the form of organization which characterizes life. The smooth transitions in 2-D cellular automata were therefore investigated in detail to see whether it is possible to characterize the cellular automata rules which give rise to them. It was found that the transitions were smoother the less that there was a marked jump in the number of rule table entries applied. But, the bare fact of this correspondence does not reveal the cause of the smoothness. Further work was therefore carried out to try to understand more about what led to the smooth behaviour. However in two further studies in which 'smooth rules' were slightly altered and in which the dominant parts of a 'smooth rule' were imposed on other rules, it was found that the rules which led to a smooth transition were very sensitive to small changes. A change of less than 0.05% of the rule table entries of a 'smooth rule' was more than likely to lead to an abrupt rather than smooth transition. This suggests that it may prove difficult to understand what it is about the rules which leads to the edge of chaos.  相似文献   

13.
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15.
Throughout the nineteenth century, physicians assumed the major task of analyzing and warning against quackery and unorthodoxy. The nature of this criticism is described, with key reliance on Worthington Hooker's Lessons from the History of Medical Delusions (1850). Most physicians viewed prospects for suppressing quackery more hopefully than Hooker did. Even he, however, would be shocked that delusion could persist so stubbornly despite advancing medical science, expanding education, and increasing regulation. Many factors help explain today's continuing-even burgeoning-quackery. These include a less cheerful view of both human nature and of the future, widespread skepticism about the fruits for science, impatience with governmental regulation, the vogue for self-help in health, increasing promotional sophistication on the part of unorthodox health vendors, and cooperation among various wings of unorthodoxy to maximize political pressure. Examples are given. Champions of alternative therapies predict their triumph over orthodox medical science in the contest being waged for the allegiance of the public.  相似文献   

16.
The review of applications of chaos theory in physiology shows, that this theory makes possible to get quantitative measure of degree of the order for such processes as neuronal activity, heart rate, electroencephalogram etc. The basic concepts of chaos theory--fractal dimension. Liapunov exponents, entropy, some algorithms for obtaining of quantitative characteristics of degree of the order for different processes--have been considered in this paper. The main areas for application chaos theory in physiology and medicine have been revealed and some examples of practical and theoretical achievements in this new region of investigation are given, as well as existing limitations and problems with results interpretation. Entirely new possibilities for understanding of the order in physiological processes are shown when estimation is made from the point of view of the functional system theory.  相似文献   

17.
In metabolomics, time-resolved, dynamic or temporal data is more and more collected. The number of methods to analyze such data, however, is very limited and in most cases the dynamic nature of the data is not even taken into account. This paper reviews current methods in use for analyzing dynamic metabolomic data. Moreover, some methods from other fields of science that may be of use to analyze such dynamic metabolomics data are described in some detail. The methods are put in a general framework after providing a formal definition on what constitutes a ‘dynamic’ method. Some of the methods are illustrated with real-life metabolomics examples.  相似文献   

18.
Of late, laboratories around the world are considering building X-ray free electron lasers based on high energy electron accelerators (with energies exceeding 10 GeV) to produce bright coherent X rays with wavelengths on the order of 1 Å. Because of the extremely small wavelength and high brilliance of these coherent X rays, there is an unprecedented opportunity to explore new applications of what is sometimes called the fourth generation of light sources. Here, we point out that in addition to the anticipated applications to material science and biology, a number of applications to fundamental physics may become possible in the fields of extreme high-energy accelerating gradients, ultrahot matter creation, coherent γ-ray generation, violent acceleration and “horizon physics,” and nonlinear field theory (quantum electrodynamics). Intensive development in technical areas, particularly that of X-ray optics, will be needed, however, in order to achieve ultrahigh intensity X-rays that can allow these applications.  相似文献   

19.
This paper analyzes the remarkable popularity of William Paley's argument from design among contemporary naturalists in biology and the philosophy of science. In philosophy of science Elliott Sober has argued that creationism should be excluded from the schools not because it is not science but because it is 'less likely' than evolution according to fairly standard confirmation theory. Creationism is said to have been a plausible scientific option as presented by Paley but no longer to be acceptable according to the same standards that once approved it. In biology C. G. Williams and Richard Dawkins have seen in Paley a proto-adaptationist. This paper shows that the historical assumptions of Sober's arguments are wrong and that the philosophical arguments themselves take alternatives to science to be alternatives in science and conflate the null hypothesis, chance, with a competing explanatory hypothesis. It is also shown that the similarity of Paley's adaptationism to that of contemporary biology is not what it is made out to be.  相似文献   

20.
Exploring biomolecule behavior, such as proteins and nucleic acids, using quantum mechanical theory can identify many life science phenomena from first principles. Fragment molecular orbital (FMO) calculations of whole single particles of biomolecules can determine the electronic state of the interior and surface of molecules and explore molecular recognition mechanisms based on intermolecular and intramolecular interactions. In this review, we summarized the current state of FMO calculations in drug discovery, virology, and structural biology, as well as recent developments from data science.  相似文献   

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