Showing papers by "University of Sussex published in 1982"
Book•
01 Dec 1982TL;DR: A modification of the theory of games, a branch of mathematics first formulated by Von Neumann and Morgenstern in 1944 for the analysis of human conflicts, was proposed in this paper.
Abstract: I want in this article to trace the history of an idea. It is beginning to become clear that a range of problems in evolution theory can most appropriately be attacked by a modification of the theory of games, a branch of mathematics first formulated by Von Neumann and Morgenstern in 1944 for the analysis of human conflicts. The problems are diverse and include not only the behaviour of animals in contest situations but also some problems in the evolution of genetic mechanisms and in the evolution of ecosystems. It is not, however, sufficient to take over the theory as it has been developed in sociology and apply it to evolution. In sociology, and in economics, it is supposed that each contestant works out by reasoning the best strategy to adopt, assuming that his opponents are equally guided by reason. This leads to the concept of a ‘minimax’ strategy, in which a contestant behaves in such a way as to minimise his losses on the assumption that his opponent behaves so as to maximise them. Clearly, this would not be a valid approach to animal conflicts. A new concept has to be introduced, the concept of an ‘evolutionary stable strategy’.
8,276 citations
TL;DR: In this article, the authors propose a model to account for both continuous changes and discontinuities in technological innovation, and define the process of selection of new technological paradigms among a greater set of notionally possible ones.
5,460 citations
Book•
01 Jan 1982TL;DR: The emergence of an economics of technical advance has been studied by Schumpeterian hypotheses and game theory as discussed by the authors, and the game theoretic approach has been used for market structure and innovation.
Abstract: Preface 1. The emergence of an economics of technical advance 2. Schumpeterian hypotheses 3. empirical studies of the Schumpeterian hypotheses 4. Modern theories of market structure and innovation: the decision theoretic approach 5. Modern theories of market structure and innovation: the game theoretic approach 6. Summary and prospectus References Author index Subject index.
1,412 citations
Posted Content•
TL;DR: In this paper, the authors surveyed and synthesised a body of research on the performance of the market economy in the allocation of resources to technical advance, and the consequent body of literature is surveyed.
Abstract: Technical advance requires resources and is motivated by the quest for profits; therefore, the rate and direction of advance is determined by the economic system. Recognition of this fact has focused attention on the performance of the market economy in the allocation of resources to technical advance, and the consequent body of research is surveyed and synthesised in this book. The theories of market structure and innovation proposed by Schumpeter, Galbraith, Arrow, Schmookler, Scherer, Mansfield, Phillips, Barzel, Kamien and Schwartz, Loury, Nelson and Winter, Grabowski, Dasgupta and Stiglitz, and others are presented in an integrated form. These theories deal with the nature of competition, the incentives to innovate and the pace of innovative activity under different market structures, and the existence of a market structure that yields the most rapid rate of innovation. In addition, the findings of seventy empirical studies dealing with various facets of the microeconomics of technical innovation are presented. The book is designed to be accessible to economists working in a variety of situations - in universities, business and government - and who are concerned with questions of technical innovation. It is also suitable for senior-level undergraduates and first year graduate students approaching the subject in a comprehensive way for the first time.
930 citations
TL;DR: The neo-Darwinian synthesis that resulted from the integration of Mendelian genetics into evolutionary theory has dominated evolutionary biology for the last 30 to 40 years, due largely to its agreement with a huge body of experimental and observational data.
Abstract: The neo-Darwinian synthesis that resulted from the integration of Mendelian genetics into evolutionary theory has dominated evolutionary biology for the last 30 to 40 years, due largely to its agreement with a huge body of experimental and observational data. The classic works representative of this school of thought come from the fields of genetics (Fisher, 1930; Wright, 1931; Haldane, 1932; Dobzhansky, 1937; Muller, 1940), development (de Beer, 1940), zoology, (Huxley, 1942; Mayr, 1942; Rensch, 1959), botany (Stebbins, 1950), and paleontology (Simpson, 1944, 1953). These authors broadly agree with Darwin's view that most important evolutionary changes at the level of the visible phenotype, as revealed by paleontological and systematic studies, have resulted from natural selection acting on variation within populations. This variation is ultimately due to mutations that arise at random with respect to the direction of selection. A role for evolutionary forces other than selection and mutation, such as random genetic drift, is of course recognized by neo-Darwinists, but selection is regarded as the main guiding force of phenotypic evolution. Within this general framework, there has been plenty of room for vigorous disagreements about the relative importance of different processes, such as the Wright-Fisher debate on the significance of random genetic drift. Recently, however, certain elements of neo-Darwinism have been sharply challenged by advocates of the "punctuated equilibria" theory of evolution (Eldredge and Gould, 1972; Gould, 1977, 1980; Stanley, 1975, 1979; Gould and Eldredge, 1977). Indeed, Gould (1980) states:
559 citations
TL;DR: In this article, the authors describe how some irrigation engineers raise vast amounts of illicit revenue from the distribution of water and contracts, and redistribute part to superior officers and politicians, and argue that the corruption system, which is centred on control of personnel transfers, is an important supply side reason for poor performance of canal-irrigated agriculture.
Abstract: The paper describes how some irrigation engineers raise vast amounts of illicit revenue from the distribution of water and contracts, and redistribute part to superior officers and politicians. It argues that the corruption ‘system’, which is centred on control of personnel transfers, is an important supply‐side reason for poor performance of canal‐irrigated agriculture. Insofar as the same system operates in other government departments, it may be more important for understanding Indian politics and the political influences on economic development than has previously been realised.
516 citations
TL;DR: It is concluded that the cdc 2 and cdc 28 genes perform homologous cell cycle control functions in the two organisms.
Abstract: The cdc 2 (previously called wee 2) cell cycle start gene of Schizosaccharomyces pombe, which is required for start and the control of mitosis, has been isolated from an S. pombe gene bank by complementation of a cdc 2 mutation. A functionally homologous sequence which complements the cdc 2 mutation has also been isolated from a Saccharomyces cerevisiae gene bank and this sequence has been shown to contain the cdc 28 cell cycle start gene of S. cerevisiae. It is concluded that the cdc 2 and cdc 28 genes perform homologous cell cycle control functions in the two organisms.
443 citations
TL;DR: Relationships between home-range size, metabolic needs of the animals occupying the homerange, and ecology are examined across species in the order Carnivora, finding Carnivores with a large proportion of flesh in their diets have particularly large home-ranges.
Abstract: Relationships between home-range size, metabolic needs of the animals occupying the homerange, and ecology are examined across species in the order Carnivora. Home-range size increases with metabolic needs, irrespective of taxonomic affinity. When the effects of metabolic needs are removed, among ecological variables (including activity pattern, habitat, diet and zonation) only diet shows a significant influence on home-range size. Carnivores with a large proportion of flesh in their diets have particularly large home-ranges. Intraspecific variation in feeding patterns as a determinant of variation in home-range size is emphasized.
443 citations
TL;DR: Two small low-copy-number plasmid vectors were constructed by in vitro and in vivo recombinant DNA techniques, and carry genes conferring resistance to tetracycline and kanamycin, and should be useful for cloning many genes coding for membrane and regulatory proteins which cannot be cloned into high-copy number plasmids.
366 citations
TL;DR: Experiments are described which support the hypothesis that ADP-ribosylation activates DNA ligase activity and suggest that ADPRT has a general function in the control of the breaking and rejoining of DNA.
Abstract: Nuclear ADP-ribosyl transferase (ADPRT)1,2 catalyses the transfer of ADP-ribose from NAD+ to chromatin proteins to form mono-, oligo- and poly (ADP-ribose)-modified chromatin proteins3–7. The enzyme is entirely dependent on DNA for activity8 and is activated by nicks in the DNA9–11. Both radiation and alkylating agents deplete cells of NAD which is used to make (ADP-ribose)n (refs 1, 2, 12, 15–17), and this depletion is prevented by inhibitors of ADPRT13,15,18–25. ADPRT inhibitors also retard DNA strand-rejoining after damage1,2,26,27, and potentiate the lethality of DNA-damaging agents1,2,28. N-methyl-N′-nitro-N-nitrosoguanidine, an alkylating agent, transiently increases intracellular (ADP-ribose)n over 100-fold17. These data suggest that (ADP-ribose)n biosynthesis is necessary for effective repair of some types of DNA damage1. The question remains of which step in DNA repair requires ADPRT activity. The enzyme inhibitors do not prevent incision events1,2,27 nor do they inhibit repair replication29–31. Here we describe experiments which support the hypothesis that ADP-ribosylation activates DNA ligase activity. We suggest that ADPRT has a general function in the control of the breaking and rejoining of DNA.
349 citations
TL;DR: Two experiments investigated the mental representation of spatial descriptions and showed that, although the semantic implications of a determinate description are better remembered than are those of an indeterminate description, the verbatim details of an Indeterminate Description are easier to recall than are Those of a determined description.
Abstract: Two experiments investigated the mental representation of spatial descriptions. In Experiment 1, the subjects classified a series of diagrams, each presented after a spatial description, as either consistent or inconsistent with the description. They were then given an unexpected recognition test of their memory for the descriptions. The subjects remembered the meanings of determinate descriptions very much better than those of grossly indeterminate descriptions; their memory for a description was not reliably affected by whether or not the diagram had been consistent with it. Experiment 2 extended these findings and showed that, although the semantic implications of a determinate description are better remembered than are those of an indeterminate description, the verbatim details of an indeterminate description are easier to recall than are those of a determinate description. The results are taken to imply the existence of two different sorts of encoding: propositional representations that are relatively hard to remember but correspond closely to the sentences in the description, and mental models that are relatively easy to remember but are analogous to spatial arrays and accordingly poor in linguistic detail.
TL;DR: An obligatory involvement of ADPRT activity in the differentiation of muscle cells is reported and the appearance during cytodifferentiation of single-strand DNA breaks is described which is not due to a general deficiency in DNA repair.
Abstract: The nuclear enzyme ADP-ribosyl transferase (ADPRT) catalyses the formation of poly(ADP-ribose)-modified chromatin proteins from NAD+ (refs 1–5) and is entirely dependent on DNA6 containing nicks7–11. Nuclear ADPRT activity is required for efficient DNA excision repair12,13, probably because it regulates DNA ligase activity14. Indirect evidence has suggested that ADPRT activity may also be involved in control of gene expression and cell differentiation15–21. We report here an obligatory involvement of ADPRT activity in the differentiation of muscle cells. Inhibitors of ADPRT activity reversibly inhibit both fusion of myoblasts to form multi-nucleate muscle fibres and the differentiation-specific increase in creatine phos-phokinase (CPK) activity. These two markers of differentiation can also be reversibly inhibited by depriving the cells of nicotinamide and thus lowering their cellular NAD content. Specific gene expression sometimes requires gene rearrangements or DNA transposition; this implies that DNA strand-breaking and rejoining might be involved in gene expression. We also describe the appearance during cytodifferentiation of single-strand DNA breaks which are not due to a general deficiency in DNA repair.
TL;DR: The vertical disparities of a few non-meridional image points are shown to account quantitatively for Ogle's induced effect—the marked distortion of a scene by a vertically magnifying lens placed in front of one eye.
Abstract: We point out that the horizontal disparities between a pair of retinal images are inadequate for computing the three-dimensional structure of a scene unless supplemented by independent information about the distance and direction of the fixation point. We suggest that this supplementary information is derived not from non-visual sources, but from the vertical disparities of a few non-meridional image points. This hypothesis is shown to account quantitatively for Ogle's induced effect—the marked distortion of a scene by a vertically magnifying lens placed in front of one eye.
01 Jan 1982
TL;DR: Transformational grammars for natural languages, as currently envisaged, deploy a large number of devices: complex symbols, base rules, rule schemata, lexical insertion rules, Lexical redundancy rules, movement rules, coindexing procedures, binding conventions, local and nonlocal filters, case marking conventions, feature percolation, constraints on movement, and so on.
Abstract: Transformational grammars for natural languages, as currently envisaged, deploy a large number of devices: complex symbols, base rules, rule schemata, lexical insertion rules, lexical redundancy rules, movement rules, coindexing procedures, binding conventions, local and nonlocal filters, case marking conventions, feature percolation, constraints on movement, and so on The mathematical properties of the resulting baroque systems are almost entirely unknown: we are ignorant, for example, as to whether ungrammaticality with respect to such grammars is decidable, ie given an arbitrary string on the terminal vocabulary, no way is known of proving that that string is not generated by the grammar In this situation, claims by grammarians to the effect that such and such a string of words cannot be generated by their grammar merely reflect their intuitions about the apparatus they are using These intuitions cannot be verified at present and may indeed by unverifiable in principle (ie if the class of grammars permitted under universal grammar generate nonrecursive sets)
TL;DR: In this paper, the Mixmaster universe is studied as a dynamical system in a appropriate phase space, a Poincare return mapping is constructed for the system and a smooth invariant measure is calculated.
TL;DR: Bees trained to forage at a place specified by landmarks do not construct a cartesian map of the arrangement of landmarks and food source, but store something like a two-dimensional snapshot of their surroundings taken from the food source.
Abstract: Bees trained to forage at a place specified by landmarks do not construct a cartesian map of the arrangement of landmarks and food source. Instead they store something like a two-dimensional snapshot of their surroundings taken from the food source. To return there, bees move so as to reduce discrepancies between the snapshot and their current retinal image. A computational model embodying these principles mimics the bees' behaviour.
TL;DR: For instance, the authors found that subjects try to integrate each incoming sentence into a single coherent mental model, and that those sentences which cannot be immediately integrated are represented in a propositional form.
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TL;DR: The class S(λ;) is strictly smaller than the class of F for which the distribution function ∫x0eλλdF(y)∫∞ 0 eλλDF(Y)<∞ as discussed by the authors.
TL;DR: In this paper, the Coulomb effect, the finite mass and the size of the nucleon are all taken into account analytically, and the 19 terms entering the lifetime of the neutron within the V, A framework are quantitatively evaluated.
TL;DR: In this article, the authors show that patent statistics underestimate innovative activities in large firms, and that the degree to which patents measure an increment of technical improvement depends on the degree of specialisation and formalisation of innovative activities.
TL;DR: E. coli dam mutants are also sensitive to the DNA methylating agent N-methyl-N′-nitro-N-nitrosoguanidine (MNNG), which introduces O6-methylguanine (m6G) into the DNA, but it appears that mismatch correction at m6G residues in DNA does not lead to reduced induction of mutation by MNNG.
Abstract: Escherichia coli has a correction system which removes mismatched bases from DNA1. Mutants (dam) which lack the major DNA adenine methylase2 are hypersensitive to the effects of base analogue mutagens such as 2-aminopurine3 and appear to be defective in mismatch correction. Phenotypic revertants of dam mutants to base analogue resistance include second site mutations in mutL or mutS genes4, which are also part of the correction system. We report here that E. coli dam mutants are also sensitive to the DNA methylating agent N-methyl-N′-nitro-N-nitrosoguanidine (MNNG), which introduces O6-methylguanine (m6G) into the DNA. This sensitivity, however, was not observed using methylating agents which generate only low amounts of this alkylated base. Furthermore, the introduction of either a mutL or a mutS mutation into dam strains abolished the sensitivity to MNNG. These results suggest that mismatch correction occurs at m6G residues in DNA. These lesions miscode in DNA polymerase I-mediated DNA synthesis in vitro5 and are known to be mutagenic in vivo6. Nevertheless, it appears that mismatch correction at m6G residues in DNA does not lead to reduced induction of mutation by MNNG.
TL;DR: The question of when the human languages purely as sets of strings of words (henceforth stringsets) fall within the class called context-free languages (CFL’s) is taken up, and it is shown that it is still open.
Abstract: In his 1956 paper ‘Three Models for the Description of Language’ Noam Chomsky posed an interesting open question: when we consider the human languages purely as sets of strings of words (henceforth stringsets), do they always fall within the class called context-free languages (CFL’s)? Chomsky declared that he did not know the answer to this question, and turned to a very different set of questions concerning relative elegance and economy of different types of description. Since 1956 various authors (Chomsky included) have attempted to provide answers in the negative, and the negative answer is now the standardly accepted one. We take up the question again in this paper, and show that it is still open, as all the arguments for the negative answer that have been provided in the literature are either empirically or formally incorrect.
TL;DR: A simple theory is proposed of how a listener may infer the rhythm of such a sequence by comparing the note lengths, and it is assumed that the listener forms an idea of the rhythm as the sequence unfolds, constructing and eliminating metrical hypotheses in the light of what he hears.
Abstract: There are many musical sequences in which the rhythm is evident from the mere durations of the notes. A simple theory is proposed of how a listener may infer the rhythm of such a sequence by comparing the note lengths. It is assumed that the listener forms an idea of the rhythm as the sequence unfolds, constructing and eliminating metrical hypotheses in the light of what he hears. The theory, which differs in some important respects from earlier proposals, has been implemented as a computer program. The program has been tested on a wide variety of musical examples, and its successes and failures are discussed in detail.
TL;DR: The question raised in this paper is whether small-scale producers in developing countries can expand or whether they are up against external constraints which stunt their growth, while most of the literature has been optimistic on this score; while internal constraints (e.g. lack of managerial ability) or external constraints such as discrimination from government) are identified, expansion is seen as an open-ended process.
TL;DR: Radionuclide tracer studies showed that the discontinuous distribution of sodium (from leaf to leaf) is constitutive, and cannot be explained by time of exposure or differential leaf growth rates, and that significant quantities of sodium were not subsequently retranslocated, either within the plant or to the root medium.
Abstract: Oryza sativa L. (rice) is a salt-sensitive crop species which is relatively ineffective in controlling the influx of sodium and chloride ions to the shoot. Nonetheless, there is considerable varietal and individual variability in salinity resistance, much of which must derive, therefore, from differences in the fates and subsequent effects of saline ions after they have entered the plant. The destination of sodium ions within the plant has been investigated, in saline conditions, by examining the time-course of sodium ion concentrations in different leaves of four varieties and breeding lines of rice of differing salinity resistance. Radionuclide tracers were employed to study short term effects and the degree of retranslocation of these sodium ions. Sodium was not distributed uniformly but accumulated in the older leaves before the younger ones. At least some leaves were maintained at sub-lethal salt concentrations in at least the more salt resistant varieties. Radionuclide tracer studies showed that the discontinuous distribution of sodium (from leaf to leaf) is constitutive, and cannot be explained by time of exposure or differential leaf growth rates, and that significant quantities of sodium were not subsequently retranslocated, either within the plant or to the root medium.
TL;DR: In this article, a gene bank of partial Sau3A restriction fragments of S. pombe DNA has been constructed in the plasmid vector, pDB248', which is capable of high frequency transformation.
Abstract: A gene bank of partial Sau3A restriction fragments of S. pombe DNA has been constructed in the plasmid vector, pDB248', which is capable of high frequency transformation of S. pombe. Procedures are described which enable plasmids to be recovered from S. pombe by their reintroduction into E. coli. These methods have been used to detect the S. pombe genes lys 1+, ade 6+ and his 2+ in the gene bank by complementation of mutant gene functions, and to physically isolate the lys 1+ gene.