The cortico-thalamic theory for generalised spike-wave discharges

The origin of generalized absence epilepsy is still not known. In the last century, four theories have dominated the debate about the origin of the bilateral synchronous generalized spike-wave discharges associated with absence seizures: the "centrencephalic" theory [Penfield and Jasper], the "cortical" [Bancaud, Niedermeyer, Luders], the "cortico-reticular" theory [Gloor, Kostop[oulos, Avoli] and the "thalamic clock" theory [Buzsaki]. There is now some evidence that absence epilepsy, as studied in the WAG/Rij model, is a corticothalamic type of epilepsy. A new hypothesis is proposed which suggests that a cortical focus in the somatosensory cortex is driving the widespread corticothalamic networks during spontaneous absence seizures. This modern theory was given the name "hot spot' theory" [Meeren et al., 2002]. According to the present view three brain structures are critically involved and their integrity seems a minimal and sufficient condition for the occurrence of spike-wave discharges. Firstly, the reticular thalamic nucleus is involved and most likely its rostral pole. Secondly, the thalamocortical relay cells in the ventrobasal complex play a role and, thirdly and most importantly, the cerebral cortex with its epileptic zone. The zone in which the epileptic focus seems to be localised is located on the somato-sensory cortex, and more precisely in the area on which the peri-oral region including the upper lip, projects.     

Three Facets of Meaning

Vygotsky and Luria's "cultural-historical theory of psychology" is little known to broad circles of the Soviet public. Nor is this theory yet very familiar in the world of pedagogy, since the leaders in this area of psychology do not yet have a completed system of views. The "cultural-historical theory of psychology" is just in the process of being formed, but even so has managed to do much damage to psychology's theoretical front, deftly concealing its pseudoscientific aspects alien to Marxism with quotations from the works of the founders of Marxism. This theory is being aggressively introduced into pedagogical practice in higher education; its authors are forcefully publicizing it in the pages of journals and books, textbooks, and encyclopedias; and it makes claims to being the closest to Marxism of all the psychological currents existing in the USSR.     

Punctualism, non-adaptationism, neutralism and evolution

In its further development the theory of evolution will incorporate molecular biology, synergetics and the theory of information. Using a simple model it is shown that speciation can be similar to phase transition. This is a thermodynamical statement which does not say anything concerning the sharpness and kinetic features of transition. Hence there is no contradiction between punctuated equilibrium and phyletic gradualism. The notion of punctualism can be used in the sense of phase transition. Evolution is directional because of constraints of natural selection due to the structure of organisms already existing and to the possible pathways of development. Correspondingly many characters are non-adaptative. Not only are the structures of proteins important for speciation but also the exact answers to the questions: "how much", "where" and "when"? These answers can be obtained as the results of regulation of genes, particularly of homeiotic regulation. The basis features of the structure of proteins are considered and the sense of the neutral theory is discussed in connection with degeneracy of correlation between the primary structure of a protein, its spatial structure and biological function. Informational aspects of evolution are discussed. Punctualism, non-adaptationism and neutralism form the triad of internally connected features of evolution. The Darwinian theory preserves its fundamental significance.     

Neo-rationalism versus neo-Darwinism: Integrating development and evolution

An increasing number of biologists are expressing discontent with the prevailing theory of neo-Darwinism. In particular, the tendency of neo-Darwinians to adopt genetic determinism and atomistic notions of both genes and organisms is seen as grossly unfair to the body of developmental theory. One faction of dissenteers, the Process Structuralists, take their inspiration from the rational morphologists who preceded Darwin. These neo-rationalists argue that a mature biology must possess universal laws and that these generative laws should be sought within organismal development. Such a rational biology will only be possible once the neo-Darwinian paradigm, with its reliance on inherently stochastic processes, is overthrown.To facilitate this revolution, process structuralism launches a broad attack on the theoritical adequacy of its opponent. It is charged that neo-Darwinism is untestable and therefore its hypotheses are nothing more than adaptive stories. Further, the lamentable tendencies toward genetic determinism and atomism by modern biologists is seen as the inescapable consequences of adopting the neo-Darwinian outlook.I allow that neo-Darwinism is untestable but argue that this does not pose a major difficulty for the theory. Further, it is not clear to what extent genetic determinism and atomism result from sloppy methodology as opposed to fundamental theoritical commitments. But the process structuralist critique does reveal some deep-seated problems with orthodox evolutionary theory and some of its suggestions may be employed to good effect.     

From a pump handle to oral rehydration therapy: a model of translational research

Few afflictions have attracted as much attention and impacted on as many societal and biomedical areas as cholera. Dr. John Snow's studies launched the field of epidemiology, were early applications of medical cartography, and promoted the use of statistical methods in medicine. The finding that cholera was due to the ingestion of contaminated water lent to the demise of the prevalent "miasmatic theory of contagion," set the platform for the "germ theory of disease," and promoted the growth of public health concerns for water purification and sanitation. More recent attention to this disease led to the notion of "secretory diarrhea" and the translation of basic principles to the development of oral rehydration therapy and its "spin-offs" (Gatorade and Pedilyte).     

Towards a general theory of neural computation based on prediction by single neurons

Although there has been tremendous progress in understanding the mechanics of the nervous system, there has not been a general theory of its computational function. Here I present a theory that relates the established biophysical properties of single generic neurons to principles of Bayesian probability theory, reinforcement learning and efficient coding. I suggest that this theory addresses the general computational problem facing the nervous system. Each neuron is proposed to mirror the function of the whole system in learning to predict aspects of the world related to future reward. According to the model, a typical neuron receives current information about the state of the world from a subset of its excitatory synaptic inputs, and prior information from its other inputs. Prior information would be contributed by synaptic inputs representing distinct regions of space, and by different types of non-synaptic, voltage-regulated channels representing distinct periods of the past. The neuron's membrane voltage is proposed to signal the difference between current and prior information ("prediction error" or "surprise"). A neuron would apply a Hebbian plasticity rule to select those excitatory inputs that are the most closely correlated with reward but are the least predictable, since unpredictable inputs provide the neuron with the most "new" information about future reward. To minimize the error in its predictions and to respond only when excitation is "new and surprising," the neuron selects amongst its prior information sources through an anti-Hebbian rule. The unique inputs of a mature neuron would therefore result from learning about spatial and temporal patterns in its local environment, and by extension, the external world. Thus the theory describes how the structure of the mature nervous system could reflect the structure of the external world, and how the complexity and intelligence of the system might develop from a population of undifferentiated neurons, each implementing similar learning algorithms.     

Gibbard's evolutionary theory of rationality and its ethical implications

Gibbard's theory of rationality is evolutionary in terms of its result as well as its underpinning argument. The result is that judgments about what is rational are analyzed as being similar to judgments of morality — in view of what Darwin suggests concerning the latter. According to the Darwinian theory, moral judgments are based on sentiments which evolve to promote the survival and welfare of human societies. On Gibbard's theory, rationality judgments should be similarly regarded as expressing emotional attachments to behavioral norms which originate and function to coordinate social interaction. Consequently, Gibbard's theory of rationality might be used to illuminate Darwin's theory of morality, and vice versa. Additionally, as argued in the present essay, both can be further elaborated, and defended, by developing related themes in philosophical ethics: viz., connected with Hume and 20th-century emotivists. The main problem is that this general Darwinian approach faces widespread opposition nowadays, not only in ethics but in philosophy of science. The purpose of this essay is to analyze Gibbard's theory, critically and constructively, with emphasis on the pertinent commonalities in Darwin, Hume and the emotivists, while also critically addressing their common enemies. The pervasive methodological orientation is to relate this analysis to (philosophy of) science in general, and biological science in particular.     

Deconstructing Darwin: Evolutionary theory in context

The topic of this paper is external versus internal explanations, first, of the genesis of evolutionary theory and, second, its reception. Victorian England was highly competitive and individualistic. So was the view of society promulgated by Malthus and the theory of evolution set out by Charles Darwin and A.R. Wallace. The fact that Darwin and Wallace independently produced a theory of evolution that was just as competitive and individualistic as the society in which they lived is taken as evidence for the impact that society has on science. The same conclusion is reached with respect to the reception of evolutionary theory. Because Darwins contemporaries lived in such a competitive and individualistic society, they were prone to accept a theory that exhibited these same characteristics. The trouble is that Darwin and Wallace did not live in anything like the same society and did not formulate the same theory. Although the character of Victorian society may have influenced the acceptance of evolutionary theory, it was not the competitive, individualistic theory that Darwin and Wallace set out but a warmer, more comforting theory.     

Preference versus performance: body temperature of the intertidal snail Chlorostoma funebralis

Evolutionary theory predicts that, in variable environments, it is advantageous for ectothermic organisms to prefer a body temperature slightly below the physiological optimum. This theory works well for many terrestrial organisms but has not been tested for animals inhabiting the hypervariable physical environment of intertidal shores. In laboratory experiments, we allowed the intertidal snail Chlorostoma funebralis to position itself on a temperature gradient, then measured its thermal preference and determined an index of how its performance varied with temperature. Snails performed a biased random walk along the temperature gradient, which, contrary to expectations, caused them to aggregate where body temperature was 15 to 17 °C below their temperature of optimum performance and near the species' lower thermal limit. This "cold-biased" behavioral response may guide snails to refuges in shaded cracks and crevices, but potentially precludes C. funebralis from taking full advantage of its physiological capabilities.     

面向生态文明的超循环经济:理论、模型与实例

在全球气候变化背景下,研究适应生态文明要求的新的经济运行模式——超循环经济的基本原理、结构模型、运行机理和实际应用。首先,运用系统结构分析方法梳理不同时期经济运行模式的演进过程:由"从摇篮到产品"的粗放经济,到"从摇篮到坟墓"的末端治理经济,再到"从摇篮到摇篮"的循环经济。延续这一绿色发展趋势,根据文明演化的共生理论和艾根创立的超循环理论,提出超循环经济的理论构想,并描绘"从孕育到孕育"的超循环经济的概念结构。其次,将超循环经济思想应用于林纸拓展系统(EFPS)。在分析中国造纸工业的发展现状和瓶颈及其与林业和生态环境相互关系的基础上,按照资源链、生态链和价值链(简称"三链",或3C)逐层拓展的逻辑顺序,研究EFPS超循环经济的系列结构模型。具体来说,依次建立起各层次的超循环结构模型——制浆造纸系统的资源链核心层模型、供应链系统的资源链拓展层模型、生态环境系统的生态链拓展层模型,以及社会经济系统的价值链拓展层模型。然后将各层次的结构模型综合起来,形成EFPS超循环经济的多重拓展-嵌套整体模型。该模型既能展示EFPS超循环经济系统的全貌,又包含其各层次的系统结构。因此既能为各级政府在制定国家和地区的循环经济总体发展规划时提供参考,又能为制造企业、营林组织、供应链、行业协会等各类经济主体的绿色经营决策提供支撑。最后,在上述实证研究的基础上进行理论提升。一方面提出超循环经济的5R原则:减量化、再循环、再利用、再分配和再培育。另一方面基于5R原则和3C循环链,构建5R-3C理论模型,并研究其5R-3C共生运行机理。研究表明,在超循环经济模式下,产业与生态系统可以实现互利共生的良性循环。以上研究成果的主要创新之处在于:在原理上,揭示了面向生态文明的超循环经济的概念结构、本质属性和5R原则;在机理上,创立了超循环经济的5R-3C模型及其共生运行机理;在实施上,以林纸拓展系统为例,为超循环经济理论的"落地生根"和推广应用构建了具体的多重拓展-嵌套模型。     

Deducing implications of fitness maximization when a trade-off exists among alternative currencies

While the theory of natural selection posits that those behaviorsmaximizing reproductive success ("fitness") tend to survive,behavioral ecologists more frequently explain observed behaviorsas maximizing some "currency" on which fitness depends. In thecase of optimal foraging theory, for example, the currency isthe long-term rate of energy intake. This currency approachis adopted because little is known about the form of the fitnessfunction itself. A weakness of the approach is that reproductivesuccess often depends on more than one currency and behaviorswhich augment one currency may reduce another. We explain howto deduce from the hypothesis of fitness maximization testablequalitative and quantitative predictions about behavior whensuch trade-offs exist among currencies and little is known aboutthe fitness function. The methodology we describe is centralto microeconomic theory, and its usefulness explains the centralrole accorded "efficiency conditions" in that theory. We expoundthe approach entirely in terms of two biological examples: apreliminary example involving flower replacement by a perennialand a more elaborate one involving over-winter hoarding by afemale mammal.     

Two neo-Darwinisms

There are two extant theories of evolution, each of which deserves the honourific "neo-Darwinism": Modern Synthesis Replicator theory and a theory I shall call Developmental Darwinism. The principal difference concerns the canonical unit of biological organization. Modern Synthesis replicator theory explains the process of evolution by appeal to the activities of genes or replicators. Developmental Darwinism explains the process of evolution by appeal to the capacities of organisms. In particular, it is the plasticity of organisms, manifested most distinctly during development, that causes adaptive evolution. Despite the fact that each, in its own way, traces its origin to the theory outlined by Darwin, they are radically different. The objectives of this essay are twofold: to underscore the differences between these theories, and to argue that Developmental Darwinism, though nascent, is a viable alternative to Modern Synthesis replicator theory.     

Mapping of statistical physics to information theory with application to biological systems

The problem of achieving a mapping of formalisms in statistical physics and theoretical biology to information theory is discussed using an example for canonical ensembles. We extend the meaning of the Handscomb Monte-Carlo method to a general recipe for the transformation from a "configuration" space to a "sentence" space. The ensemble of "sentences" and its corresponding source uncertainty function are introduced. A possible mapping procedure based on a generalization of the Handscomb representation is described. For a biological illustration, we present a way to introduce a pathway representation to describe metabolic processes in living systems.     

Thermodynamics and the conceptual structure of evolutionary theory

Thermodynamics and evolutionary theory have spent most of their shared history in adversarial relationship to one another. The point of this paper is to consider some qualitative ways in which thermodynamics can enrich both the theory and epistemology of evolution. The "autonomy of biology" posture in evolutionary theory hangs on the supposed uniqueness of why-questions in biology. With this posture, and with the general obstruction of constructive dialogue between evolution and the physical sciences it fosters, come the perennial accusations that Darwinism deals in adaptational teleology but not mechanisms. Thermodynamics provides for a two-tiered hierarchy of causation in nature in which the why-question is rendered not only legitimate materialistically, but essential to understanding the evolutionary process in its totality--from the emergence of life to the branching of lineages in speciation.     

Networks in ecology

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Recently, ecology has shown a strong interest in network theory. The question, as with any other emerging field, is to what extent we are making real progress in understanding ecological and evolutionary processes or just telling the same stories with fancy new words. I first present a biased overview of the development of network theory, focusing on its search for common patterns across seemingly different systems. I then proceed by discussing some applications of network theory in ecology, namely, species interactions, spatial ecology, epidemiology, and evolution in social groups . Finally, I suggest important contributions of the network approach such as identifying the consequences of heterogeneity for population and community dynamics, potential pitfalls, and future directions.     

Hypothesis testing in ecology: psychological aspects and the importance of theory maturation

Proper hypothesis testing is the subject of much debate in ecology. According to studies in cognitive psychology, confirmation bias (a tendency to seek confirming evidence) and theory tenacity (persistent belief in a theory in spite of contrary evidence) pervasively influence actual problem solving and hypothesis testing, often interfering with effective testing of alternative hypotheses. On the other hand, these psychological factors play a positive role in the process of theory maturation by helping to protect and nurture a new idea until it is suitable for critical evaluation. As a theory matures it increases in empirical content and its predictions become more distinct. Efficient hypothesis testing is often not possible when theories are in an immature state, as is the case in much of ecology. Problem areas in ecology are examined in light of these considerations, including failure to publish negative results, misuses of mathematical models, confusion resulting from ambiguous terms (such as "diversity" and "niche"), and biases against new ideas.     

论“风邪犯肺”的肺微生态失调与中医药干预

肺为"娇脏",易受风邪侵袭而出现咳嗽喘息等症状。研究发现,微生态的平衡对人体健康的保持意义重大。在本文中我们解释了中医病机"风邪犯肺",并从微生态失衡的角度来思考"风邪犯肺"的科学内涵,探讨风邪犯肺与微生态失衡的联系。认为中医药主要通过直接作用于微生物、改变机体内部环境以及肺—肠轴这三种途径来调整风邪犯肺导致的微生态失衡。旨在将现代研究理论与中医理论相结合,挖掘中医药在调整微生态失衡方面的可能作用机制和潜力,深入探讨中医认识疾病、治疗疾病的本质和优势,以期为微生态学的研究和中医药的现代化开拓思路。     

The philosophical "mind-body problem" and its relevance for the relationship between psychiatry and the neurosciences

Parallel to psychiatry, "philosophy of mind" investigates the relationship between mind (mental domain) and body/brain (physical domain). Unlike older forms of philosophy of mind, contemporary analytical philosophy is not exclusively based on introspection and conceptual analysis, but also draws upon the empirical methods and findings of the sciences. This article outlines the conceptual framework of the "mind-body problem" as formulated in contemporary analytical philosophy and argues that this philosophical debate has potentially far-reaching implications for psychiatry as a clinical-scientific discipline, especially for its own autonomy and its relationship to neurology/neuroscience. This point is illustrated by a conceptual analysis of the five principles formulated in Kandel's 1998 article "A New Intellectual Framework for Psychiatry." Kandel's position in the philosophical mind-body debate is ambiguous, ranging from reductive physicalism (psychophysical identity theory) to non-reductive physicalism (in which the mental "supervenes" on the physical) to epiphenomenalist dualism or even emergent dualism. We illustrate how these diverging interpretations result in radically different views on the identity of psychiatry and its relationship with the rapidly expanding domain of neurology/neuroscience.