Showing papers by "Brunel University London published in 1981"
TL;DR: An alternative multiple-level, multiple-process model of evolution is presented which posits that the primary process that operates via selection upon the genes cannot account for certain kinds of biological phenomena, especially complex, learned, social behaviours.
Abstract: The fundamental tenet of contemporary sociobiology, namely the assumption of a single process of evolution involving the selection of genes, is critically examined. An alternative multiple-level, multiple-process model of evolution is presented which posits that the primary process that operates via selection upon the genes cannot account for certain kinds of biological phenomena, especially complex, learned, social behaviours. The primary process has evolved subsidiary evolutionary levels and processes that act to bridge the gap between genes and these complex behaviours. The subsidiary levels are development, individual animal learning, and socioculture itself. It is argued that individual learning is pivotal to the derivation and biological analysis of culture. The differences between cultural and noncultural societies are stressed. It is concluded that such a multiple-level model of evolution can form the basis for reconciling opposing sides in the sociobiology debate.
289 citations
TL;DR: Comparison with other data suggest that other free radicals are also likely to react with these compounds; in the case of the hydroxyl radical and DABCO k = 1.25 × 109 M−1s−1 has been determined.
171 citations
TL;DR: In a survey of adult ticks infesting livestock in Ethiopia, 33 species and subspecies were identified and the distribution and abundance of each are discussed in relation to ecology (altitude, climate and vegetation).
Abstract: In a survey of adult ticks infesting livestock in Ethiopia, 33 species and subspecies were identified. The distribution and abundance of each are discussed in relation to ecology (altitude, climate and vegetation). Amblyomma variegatum (F.) is the most widespread and abundant tick parasitising cattle. A. cohaerens Don. is common on cattle in wetter western habitats but is replaced by A. gemma Don. in drier eastern areas. A. lepidum Don. occupies intermediate habitats. The distribution of Boophilus decoloratus (Koch) is similar to that of A. variegatum. Hyalomma truncatum Koch and H. marginatum rufipes Koch are both common except in extremely arid and humid zones. H. anatolicum anatolicum Koch, H. anatolicum excavatum Koch, H. dromedarii Koch, H. erythraeum Tonelli-Rondelli, and H. impeltatum Schulze & Schlottke are usually associated with camels in semi-arid areas of eastern Ethiopia. Rhipicephalus evertsi evertsi Neum., R. sanguineus (Latr.) group and R. simus Koch do not display marked ecological preferences. East of the Rift Valley in semi-arid areas below 2000 m, R. pulchellus (Gerst.) is abundant on cattle and camels. R. longicoxatus Neum. and R. pravus Don. inhabit drier localities, but R. lunulatus Neum. occurs only in wetter western areas. Species taken infrequently were A. nuttalli Don., A. sparsum Neum., B. annulatus (Say), Haemaphysalis aciculifer Warb., H. leachii (Aud.), H. parmata Neum., H. spinulosa Neum., Hyalomma marginatum marginatum Koch, H. marginatum turanicum Pom., H. punt Hoogst., Kaiser & Pedersen, Ornithodoros savignyi (Aud.), R. longus Neum., R. muhsamae Morel & Vassiliades, and R. senegalensis Koch. The seasonal dynamics of the common species and observations on their relationships to tick-borne diseases of man and domestic animals are discussed.
98 citations
01 Jan 1981
TL;DR: In this paper, the authors argue that a fruitful understanding of the nature of scientific inquiry must eschew many of the features of both philosophical and sociological perspectives on knowledge production, and make an attempt to explicate the central assumption of the analytic perspectiveL that of isomorphism between presentational context ad scientific concepts.
Abstract: The work of this paper is part of a more general exploration of the viability of an ethnomethodological approach to understanding science. I have argued elsewhere that ethnomethodologically inclined approaches to the study of science should provide useful insights into the nature of the activities which constitute scientific practice. In particular, an examination of some of the standard objections to ethnomethodology shows them to be misguided, in that they are based on an overly narrow conception of the range of phenomena with which ethnomethodology can deal and on an intractable definition of the legitimate substance of sociological inquiry (2). However, a full assessment of the value of ethnomethodology for understanding science can only be made in relation to the fruits of empirical inquiry (3). The argument of this aper is divided into two parts. In the first part, an analytic perspective informed by ethnomethodology thinking is located in relation to the debate between rationalist philosophy and the strong programme in the sociology of knowledge. This debate is taken as the basis of an examination and clarification of the position that a fruitful understanding of the nature of scientific inquiry must eschew many of the features of both philosophical and sociological perspectives on knowledge production. An attempt is also made to explicate the central assumption of the analytic perspectiveL that of isomorphism between presentational context ad scientific concepts. The second part of this paper offers a tentative analysis of one aspect of the practical activity of scientific investigation: the accomplishment of a discovery as related in a scientific text.
87 citations
TL;DR: The present results are consistent with lipid peroxidation being a major contributory factor to the decrease in glucose-6-phosphatase activity observed in CCl4-induced liver injury.
65 citations
TL;DR: In this article, the mean velocities in turbulent flows in a flat channel, one of whose walls can move relative to the other, so that the role of the stress gradient within the wall layers can be varied widely and in a controlled manner.
Abstract: This paper complements an earlier study of the mean velocities in turbulent flows in a flat channel, one of whose walls can move relative to the other, so that the role of the stress gradient within the wall layers can be varied widely and in a controlled manner.Measurements of longitudinal, normal and lateral velocity fluctuation intensities (u′,v′,w′) and of shear stresses have been made in essentially fully developed flows established by various combinations of pressure gradient and wall velocity The channel aspect ratio (breadth/height) has been varied between 12 and 28 and the development ratio (development length/height) between 20 and 45. The introduction of a turbulence-generating grid at the entrance to the duct increases the effective development length.The study has considered twenty-six flows that are two-dimensional in the mean, which have been established by blowing and relative motion either in the same direction or directly opposed. Empirical descriptions, based on similarity laws incorporating either the wall stress or the local stress, are developed for the turbulence near the walls and in the core. The profiles of u′, v′ and w′ coalesce, to a reasonable approximation, when normalized with appropriate length and velocity scales. Extensive ‘plateau’ regions are identified, in which the scaled intensities are sensibly constant.A number of quantities characteristic of the structure of the turbulence are considered, in order to elucidate the effect of the stress gradient on the wall layer, and stages in the erosion of the constant-stress layer are identified.
56 citations
TL;DR: In this paper, two explicit representations of a C1 quintic interpolant over triangles are derived by generalization of Coons' methods and Bernstein-Bezier methods, respectively.
Abstract: Two explicit representation of a C1 quintic interpolant over triangles are given. These representations are derived by generalization of Coons' methods and Bernstein-Bezier methods, respectively.
55 citations
TL;DR: Two spectral components have been identified: a minor component attributed to the neutral tryptophanyl radical which can react with ascorbate and intramolecularly with tyrosine residues and a major component which does not undergo either of these reactions and is probably a radical adduct.
Abstract: SummaryThe trichloromethyl peroxy radical Cl3COO. reacts with tryptophan, tryptophanyl-tyrosine and with lysozyme to form products whose overall absorption spectrum is different from those observed following the reaction of hydroxyl, bromide, thiocyanate or azide radicals. Two spectral components have been identified: a minor component attributed to the neutral tryptophanyl radical which can react with ascorbate and intramolecularly with tyrosine residues and a major component which does not undergo either of these reactions and is probably a radical adduct.
48 citations
45 citations
TL;DR: In this paper, it was shown that weakly coordinated water and ammonia molecules in these gels, whose removal either through hydrolysis and bridging with increasing pH or heat treatment leads to the variations in xerogel porosity observed in these materials.
36 citations
TL;DR: Many of the commentaries cohere around two major points of criticism as discussed by the authors, namely, the lack of discussion of the mechanisms that are assumed to operate at levels 2, 3, and 4 and the fact that organisms change the environment by their activities.
Abstract: Many of the commentaries cohere around two major points of criticism. The first is that we have omitted discussion of the mechanisms that are assumed to operate at levels 2, 3, and 4. Campbell, Cloak, Dewsbury, Eckberg, Mundinger, Pulliam, Richerson & Boyd, Slobodkin, Simon, Williams, and Wahlsten all make comments that bear on this point. The second point is that we have omitted discussion of the fact that "organisms change the environment by their activities" (Lewontin) and thereby modify the selection pressures that act on them. Apart from Lewontin, this point has been raised in different forms by Barkow, Chase, Hull, Perzigian, Ruyle, and less directly by Slobodkin. Stemming from these two basic omissions there is a third general criticism. Numerous commentators have pointed out that we have failed to discuss sufficiently either the extent or nature of the constraints that may or may not be operating on supraordinate evolutionary processes as a function of their nested relationships to subordinate evolutionary processes within our scheme (Barkow, Campbell, Cloak, Chase, Lenington, Lewontin, Perzigian, Peterson, Pulliam, Richerson & Boyd, Simon, Slobodkin, and Williams). We start by acknowledging these three basic omissions. We agree that they exist and that they are serious.
TL;DR: In this paper, a model of solid-solution hardening based on an assumed random dispersion of solute atoms account inadequately for the observed temperature and concentration dependence of the cross of relatively dilute alloys.
TL;DR: In this paper, a cubic spline method is described for the numerical solution of a two-point boundary value problem involving a fourth order linear differential equation, which is closely related to a known fourth order finite difference scheme.
TL;DR: The nitro group in 2- and 4-nitronaphthalic-1,8-anhydrides can be substituted by amines in certain cases with retention of the anhydride grouping as discussed by the authors.
TL;DR: In this article, the authors consider the use of spline functions of various degrees for the approximation of the source density in the neighborhood of each corner, where a boundary singularity occurs, and modify the spline approximation and blend the singular functions with the splines, which approximate the remainder of the boundary, so that the global approximating function has continuity of appropriate order at the transition points between the two types of approximation.
Abstract: We consider the integral equation method of Symm for the conformal mapping of simply-connected domains. For the numerical solution, we examine the use of spline functions of various degrees for the approximation of the source density ?. In particular, we consider ways for overcoming the difficulties associated with corner singularities. For this we modify the spline approximation and in the neighborhood of each corner, where a boundary singularity occurs, we approximate ? by a function which reflects the main singular behaviour of the source density. The singular functions are then blended with the splines, which approximate ? on the remainder of the boundary, so that the global approximating function has continuity of appropriate order at the transition points between the two types of approximation. We show, by means of numerical examples, that such approximations overcome the difficulties associated with corner singularities and lead to numerical results of high accuracy.
TL;DR: In this paper, two numerical methods are considered for the conformai mapping of a bounded simply-connected domain onto the unit disc, namely the Bergman kernel method and the Ritz method.
TL;DR: The wear properties of sintered iron powders were improved by steam treatment and by the addition of copper in amounts up to 8 wt.%. However, steam treatment had adverse effects on wear resistance as discussed by the authors.
TL;DR: The relationship between activity of the extracts measured on the ileum and their haemolytic activity was studied, providing a second assay method based on the latter property, and it is proposed that for future work on the extract a new AU should be used.
Abstract: 1. Column chromatography with Agarose A50m followed by Sephadex G100 was used to separate a fraction (extract II) in the molecular weight range 12,000 to 14,000 daltons from saline extracts of the sea anemone, Tealia felina. 2. Extract II inhibited histamine-induced contractions of the guinea-pig ileum and produced haemolysis of human blood, effects on which bioassays were based. 3. The potency of extracts was assayed. A standard unit of activity (= AU) was defined such that 100 AU produced 90% inhibition of histamine-induced contractions of the guinea-pig ileum after 30 to 35 min exposure. 4. The relationship between activity of the extracts measured on the ileum and their haemolytic activity was studied, providing a second assay method based on the latter property. 5 Based on values from both methods of assay, the calculated yield in AU at the end of the separation procedure was 0.53 AU for each AU present in the original extract. In crude extract there were 5.0 AU/mg dry weight and 36.7 AU/mg protein, and after separation (extract II) there were 11.2 AU/mg dry weight and 312.2 AU/mg protein. 6 The acute LD50 values determined in mice (i.v.) were: for crude extract 124 mg/kg for extract I, 76 mg/kg and for extract II, 69 mg/kg. 7 Extract II (0.18 to 0.72 AU/ml) produced a slowly developing contraction of guinea-pig ileum. Indomethacin (2.8 x 10(-5) M) substantially reduced this response. 8 Extract II (0.03 AU/ml) reduced the contractile response of the guinea-pig ileum to acetylcholine by 39 +/- 8%, n = 6, and the response to histamine by 26 +/- 6.6%, n = 6. The response to 5-hydroxytryptamine (5-HT) was not reduced by 0.08 AU/ml of extract II, a concentration that actually increased the contractile response to KC1 by 32 +/- 11.2% n = 7. 9 It is proposed that for future work on the extract a new AU should be used. This AU is defined such that 50 AU produce 50% inhibition of histamine-induced contractions of the guinea-pig ileum after 30 to 35 min exposure.
TL;DR: Activities of various components of microsomal suspensions obtained from a considerable number of rat tissues have been studied, and the very low rate of lipid peroxidation in extrahepatic microsomes is discussed in terms of the fatty acid contents of the suspensions, and of antioxidant status.
TL;DR: In this article, a strain of T. congolense has been cloned, passaged through the tsetse fly, and subsequently recloned, and relapsing infections have been induced in two rats by syringe passage of the cloned trypanosomes.
TL;DR: In this article, the authors discuss the use made of the 'Austrian' concept of entrepreneurship in the present British government's policy discussions, and, using an Austrian method of argument, demonstrates that there is a deep-seated inconsistency in its policies which suggests that it, along with the administrations of a number of other western democracies including the United States, has not fully understood the implications of the doctrines to which it appears to have committed itself.
Abstract: This article discusses the use made of the 'Austrian' concept of entrepreneurship in the present British government's policy discussions, and, using an 'Austrian' method of argument, demonstrates that there is a deep-seated inconsistency in its policies which suggests that it, along with the administrations of a number of other western democracies including the United States, has not fully understood the implications of the doctrines to which it appears to have committed itself. This inconsistency relates to its continued support for the existing structure of subsidies in the UK housing market which, it is argued, have made private home-buying so profitable an activity for entrepreneurial individuals as to substantially reduce the attractiveness of the option of setting up new businesses. Whether or not the government is right to believe that, in an economic environment with greater incentives, there would be a great expansion in individual entrepreneurial effort in 'productive' activities, this is not likely to happen whilst, amongst other things, the structure of housing subsidies remains substantially unchanged. We suggest, in the light of comparative international evidence, that a better alternative is available. i. The government and the Austrian view of the economy I am able to approach my task this afternoon on this one, crucially important piece of common ground: that the poor performance of the British economy in recent years has not been due to a shortage of demand. We are suffering from a growing series of failures on the supply side of the economy. It is our belief that many of these failures are themselves the result of * We would like to thank friends and ex-colleagues at Stirling University for a number of helpful discussions of these ideas, and especially Keith Glaister for constructive criticism of an earlier version of the paper. Donald Winch, Ray Robinson and Pete Saunders of Sussex University and Barry Smith of Manchester University have also helped us improve the argument, as have two anonymous referees for this journal. Errors and omissions remain our own responsibility. This content downloaded from 157.55.39.4 on Fri, 09 Sep 2016 04:21:36 UTC All use subject to http://about.jstor.org/terms 308 Mary K. Farmer and Ray Barrell actions and interventions by Government themselves laws that stand in the way of change and stifle enterprise; and, as important as anything, a structure of taxation that might have been designed to discourage innovation and punish success... We need to strengthen incentives, by allowing people to keep more of what they earn, so that hard work, talent and ability are properly rewarded. (Sir Geoffrey Howe, Budget Speech, I!2 June
TL;DR: In this article, the microstructure and texture of injection-moulded plaques of an acetal copolymer were determined by polarized light microscopy and X-ray pole-figure analysis, respectively.
Abstract: Processing conditions, microstructure and mechanical property correlations have been explored in injection-moulded plaques of an acetal copolymer. Barrel temperature was varied systematically between 453 and 503 K, with a constant mould temperature of 343 K. The microstructure and texture were determined by polarized light microscopy and X-ray pole-figure analysis, respectively. The overall structure of the mouldings was layered through the thickness and symetrical about the moulding centre line. At all barrel temperatures five layers were present: the outer three layers possessed significant preferred chain-axis orientation in the crystalline phase, while the two layers at the centre of the moulding were equiaxed. The texture and morphology of each layer is described and related to a model of mould filling. Increases in the barrel temperature reduced the extent of the outer oriented layers while increasing the extent of the equiaxed layers. Tensile tests were conducted on samples taken at 0° and 90° to the injection direction. Increases in barrel temperature had no influence on modulus but decreased both (α=0 and 90°) engineering yield stresses. The yield stress could be correlated with the extent of the oriented layers within mouldings. At all barrel temperatures the yield stress was greater when α=90°; this behaviour is explained in terms of a composite model.
TL;DR: In this article, the authors analyzed the causes of the emergence and the stability of monopolies of representation of industrial unions in competition with sectional interest associations of specific occupational groups in the railway industries of Great Britain and West Germany.
Abstract: This article analyses some of the causes of the emergence and the stability of monopolies of representation of industrial unions in competition with sectional interest associations of specific occupational groups. As its empirical point of reference, the article takes the trade union systems in the railway industries of Great Britain and West Germany. In both countries, there are three railway unions whose areas of jurisdiction largely correspond to each other cross-nationally: one industrial union, one union of loco motive engine drivers, and one union for administrative staff. However, while in West Germany the proportion of the industrial union (GdED) in the total number of unionized railway workers increases at the expense of the sectional competitors, in Great Britain it has for a long time been declining. This divergent development of two otherwise similar trade union systems — a development which in Great Britain has led to the establishment of three sectional monopolies of representation, while in...
TL;DR: In this article, a finite difference solution of a system of first-order partial differential equations, using a central difference scheme, is presented, which describes the linear elastic behaviour of a thick rectangular plate resting on an elastic foundation and carrying an arbitrary transverse load.
Abstract: A finite difference solution of a system of first-order partial differential equations, using a central difference scheme, is presented. The equations describe the linear elastic behaviour of a thick rectangular plate resting on an elastic foundation and carrying an arbitrary transverse load. The lateral edges of the plate are unstressed. The main deflections and stresses predicted by the method for a particular case are given, together for purposes of comparison, with results from a finite element analysis.
TL;DR: In this paper, a family of one-step multiderivative methods based on Pade approximants to the exponential function is developed for use in PECE mode and compared with well-known linear multi-step combinations and combinations using high accuracy Newton-Cotes quadrature formulas as correctors.
Abstract: A family of one-step multiderivative methods based on Pade approximants to the exponential function is developed. The methods are extrapolated and analysed for use inPECE mode. Error constants, stability intervals and stability regions are given in two associated Technical Reports. Comparisons are made with well-known linear multi-step combinations and combinations using high accuracy Newton-Cotes quadrature formulas as correctors.
TL;DR: Lysosomal participation is most clearly established for the degradation of long half-life proteins in situations in which turnover is accelerated because of nutritional or hormonal deficiencies.
Abstract: Considerable evidence from studies with group-specific proteinase inhibitors, in particular pepstatin, the aspartic proteinase inhibitor, implicates lysosomes in turnover of endogenous cellular proteins. Recent experiments using a new group-specific inhibitor of thiol (cysteine) proteinases, Z-Phe-Ala-diazomethyl ketone, are described. Lysosomal participation is most clearly established for the degradation of long half-life proteins in situations in which turnover is accelerated because of nutritional or hormonal deficiencies. Some evidence indicating their involvement in 'basal' proteolysis is also discussed. Whether lysosomal proteolysis is selective remains to be established, and possible approaches to this question are outlined.