As a follow-up to that article, Monitor readers may be interested to know that, at that time, a group of eight physicists at the University of Alberta produced a scientific assessment of the Bomarc's capability, with particular reference to the claims that the nuclear-tipped Bomarc was capable of "cooking" nuclear bombs, a process aimed at rendering a bomb inactive, before it could be released over a target, during presumed intercontinental bomber attacks by the Soviet Union; the conclusion of the Alberta eight was that the proposed nuclear war-heads " would be worse than useless for the protection of Canada." We raise this history of the Bomarc episode at this time, and recall some of our experiences with it, because of its relevance to the not too dissimilar situation which confronts the present Canadian Government in its consideration of possible participation in the latest version of the United State's NMD. (National Missile Defence) proposal. What is common to the two situations (Bomarc and NMD), is scientific input negating the prospects for success in both instances. In the Bomarc case, political "realities" overrode scientific considerations in a matter relating to the national security of Canada; there is no information yet on the outcome of the NMD proposal for Canada, but there are political implications. For the Bomarc, the Alberta Eight Report (which we will refer to as RUA8, for convenience) pointed out that the Bomarc could not possibly accomplish its mission in the manner being proposed, and that it was highly probable that a thermo-nuclear weapon would be detonated at the point of interception by the Bomarc of the incoming bomber (given the Bomarc's operational range, this would be within 400 miles, of North Bay, Ontario, or LaMacaza, Quebec). This interpretation was tacitly recognized by Robert McNamara, U.S. Secretary of State at the time, who stated before a U.S. Congressional Committee that the U.S. was down-playing the protective role of the Bomarcs, in favour of deterrence strategies. For the NMD proposal, the body questioning the wisdom of deploying this much larger missile system, has been the American Physical Society (A.P.S.), the prestigious organization representing the community of physicists in the United States. An A.P.S. committee found that the Boost-phase Intercept Systems of NMD ("the bullet to hit a bullet") being promoted by the current U.S. administration, would, in their words, "... not be feasible against potential threats"; their report is available at http://www.aps.org.

Interpretations of quantum measurement theory have been plagued by two questions, one concerning the role of observer consciousness and the other the entanglement phenomenon arising from the superposition of quantum states. We emphasize here the remarkable role of quantum statistics in describing the entanglement problem correctly and discuss the relationship to issues arising from current discussions of intelligent observers in entangled, decohering quantum worlds.

A multi-modular neural network model, which is different from BP network for mapping y=f(x), is proposed. The architecture and parallel dynamics equations of the network are given, and the stability of dynamics is also proven. Through establishing learning algorithm, It^s been proven that the network can perform mapping or input vector pair(x,y)to associative output vector z. It is the most inportant that both the pattern series varing with time and statics patterns can be stored sitmutaneously, thus the economic principle of memory is proposed. In addition, a dynamics learning algorithm is given and have proven its convergence, computer simulation confirms fully theoretical results. Finally, Some possible applications are discussed.

The analysis of bifurcating solutions in the Totafurno and Trainor [23] model of supernumerary limb production in salamanders is re-examined using the symmetry analysis developed by Totafurno [22]. In particular, we show analytically that the appearance of field solutions possessing 2 and 4 singularities (the 2- and 4-centered solutions, respectively) also correspond to true bifurcations with reduced symmetries, just as had been previously found for a solution to the field equations not possessing such singularities (the twist solution). While the results have significance primarily for the biological problem, this work serves as an instructive example of the application of symmetry groups to the bifurcation analysis of nonlinear field equations arising from a variational principle. The relationship between the solutions of the nonlinear equations and the corresponding linear equations is discussed.

Previous articleNext article No AccessNew Biological BooksFrom Chemical to Biological Organization. Based on a Meeting Held at the Max-Planck-Institut in Dortmund, March 16-19, 1987. M. Markus , S. C. Müller , G. Nicolis , Hermann Haken L. E. H. TrainorL. E. H. Trainor Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The Quarterly Review of Biology Volume 64, Number 2Jun., 1989 Published in association with Stony Brook University Article DOIhttps://doi.org/10.1086/416247 Copyright 1989 The Stony Brook Foundation, Inc.PDF download Crossref reports no articles citing this article.

A neural circuit model is presented that consists of a hierarchy of nested clusters of neuron-like elements. Each hierarchical level of cluster organisation encodes a different level of distributed memory. Associate memory properties within and between levels are investigated numerically in simple versions of the model. The results may provide insight into mechanisms of memory storage, recall and loss in real neural circuits, such as those found in the cerebral cortex.

A robust model of neocortical circuitry based on hierarchical synaptic organization is described. The parallel distributed and hierarchical properties of the model can be used as an associative memory capable of simulating multi-level responses and selective memory loss in real neural circuits.

Many biomedical systems possess features of multi-level or hierarchical organization. To investigate how structure and behaviour are related in such systems, a simple two level time dependent model is proposed and studied using the methods of non-equilibrium statistical mechanics. Analytic expressions are derived which characterize the model in terms of the intra-level and interlevel couplings, environl1lental conditions, and time scales of interest. The model is shown to possess a continuum of global behaviours, ranging from those of a control hierarchy, wherein one level slaves another, to a hierarchy whcrein each structural level is associated with an essentially autonomous behaviour.

We construct a "codon space" in which a given DNA sequence can be plotted as a function of its base composition in each of the three codon positions. We demonstrate that the base composition is very highly nonrandom, with sequences from more primitive organisms having the least random compositions. By using cluster analysis on the points plotted in codon space we show that there is a strong correlation between base composition and type of organism, with the most primitive organisms having the highest A or T content in the second and third codon positions. A smooth transition toward lower A + T and higher G + C content is observed in the second and third codon positions as the evolutionary complexity of the organism increases. Besides this general trend, more detailed structure can be observed in the clustering that will become clearer as the data base is increased.

It is well-known in quantum field theory and statistical physics that the effective action (i.e., the Legendre transform of the free energy) is the generating function for one particle irreducible diagrams. We present an explicit diagrammatic proof of this result which permits a clear statement concerning its validity in the context of self-consistent approximation schemes. In particular, we find a necessary and sufficient condition on the approximate set of Green's functions for the Legendre transform theorem to hold. This condition is exactly what one expects on physical grounds. Our proof also lends itself to an examination of more extended diagrammatic schemes, such as those involving composite operators in renormalization theory.

The modern theory of generalized Hamiltonian systems is used to construct a unified canonical description of the linear Lagrangian biodynamics introduced by Kerner.