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Showing papers by "University of Sussex published in 1979"


Journal ArticleDOI
01 Feb 1979-Futures
TL;DR: The authors of as discussed by the authors suggest that a wide range of services which were once produced in the money economy are increasingly provided informally on a self-service basis. But they do not consider the role of the state in the provision of these services.

1,023 citations


Journal ArticleDOI
TL;DR: Data from two experiments examined the nature of access, storage, and comprehension of idiomatic phrases and support a Lexical Representation Hypothesis for the processing of idioms.

608 citations


Journal ArticleDOI
TL;DR: Migrations which were unlikely to be due to the avoidance of inbreeding were made by males with above average reproductive activity into troops with more oestrous females than the prior troop, and females showed a preference for transferred males over natal males, and for males who could not have been their father over males whocould have been.

580 citations


Journal ArticleDOI
26 Apr 1979-Nature
TL;DR: The experimental results reported here show that after adaptation to a particular grating the sensitivity of a single neurone to that grating may be reduced more than its sensitivity to other gratings.
Abstract: PROLONGED viewing of a grating pattern produces striking ‘after-effects’, involving changes in the detectability, apparent size, orientation and contrast of subsequently viewed gratings1–3. Studies of perceptual after-effects have been used to infer properties of neurones in the human visual cortex2,4,5 similar to those pattern-selective neurones whose sensitivities have been directly measured in the visual cortex of cats and monkeys6,7. Such inferences are based on two assumptions: first, that perceptual changes result from changes in the distribution of activity within the responding population of neurones; second, that the effect of adaptation on each neurone of the population is to reduce its sensitivity uniformly to all stimuli. The experimental results reported here support the first but challenge the second assumption, as they show that after adaptation to a particular grating the sensitivity of a single neurone to that grating may be reduced more than its sensitivity to other gratings.

461 citations


Journal ArticleDOI
TL;DR: How far can game theory account for the evolution of contest behaviour in animals?
Abstract: How far can game theory account for the evolution of contest behaviour in animals? The first qualitative prediction of the theory was that symmetric contests in which escalation is expensive should lead to mixed strategies. As yet it is hard to say how far this is borne out, because of the difficulty of distinguishing a 'mixed evolutionarily stable strategy' maintained by frequency-dependent selection from a 'pure conditional strategy'; the distinction is discussed in relation to several field studies. The second prediction was that if a contest is asymmetric (e.g. in ownership) then the asymmetry will be used as a conventional cue to settle it. This prediction has been well supported by observation. A third important issue is whether or not information about intentions is exchanged during contests. The significance of 'assessment' strategies is discussed.

336 citations


Journal ArticleDOI
TL;DR: In this article, the class of subexponential distribution functions with Levy measure v was studied and the following assertions were proved: 1) For F infinitely divisible on [0, ∞] with Levy measures v, the following results on ∞ are established.
Abstract: Let ℒ denote the class of subexponential distribution functions. For F infinitely divisible on [0, ∞) with Levy measure v, the following assertions are proved to be equivalent: In the proof of this theorem, some new results on ∞ are established.

330 citations


Journal ArticleDOI
TL;DR: In this article, the positions of quantized vortex lines in rotating superfluid helium have been recorded using a photographic technique, and the observed patterns are in good agreement with theoretical predictions.
Abstract: The positions of quantized vortex lines in rotating superfluid helium have been recorded using a photographic technique. The photographs show stationary arrays of vortices. The observed patterns are in good agreement with theoretical predictions.

315 citations


Journal ArticleDOI
TL;DR: The dominance relations of the sexually mature males residing in three troops of Papio anubis at Gombe National Park, Tanzania are examined and three tactics which males employed to increase temporarily their dominance against other males are discussed.

313 citations


Journal ArticleDOI
TL;DR: In this paper, the authors surveyed common methods of estimating the Weibull modulus and their respective adjustment factors, for a range of experimentally feasible sample sizes, are given.
Abstract: Common methods of estimating the Weibull modulus are surveyed. Computer simulation is used to obtain the statistical properties of different estimators. Most estimators are shown to be biased and their respective adjustment factors, for a range of experimentally feasible sample sizes, are given.

308 citations


Journal ArticleDOI
TL;DR: It is concluded that it may prove feasible to develop a questionnaire that would predict the degree to which people's rhythms would adjust to shift work, and that flexibility of sleeping habits and the ability to overcome drowsiness should be components of such a questionnaire.
Abstract: A questionnaire was developed to distinguish between people who differed in the degree to which their circadian rhythms adjusted to night work. This was administered to 48 ‘ permanent ’ night nurses taking part in a large shift work study. Factor analyses indicated that there were three main factors. These were (I) rigidity/flexibility of sleeping habits, (ii) ability/inability to overcome drowsiness, and (iii) morningness/eveningness. Correlations were computed between the nurses'scores on each of these factors and a range of measures of adjustment of circadian rhythm. A number of significant correlations were found with both psychological and physiological measures, thus indicating that the factors had at least concurrent validity. It is concluded that it may prove feasible to develop a questionnaire that would predict the degree to which people's rhythms would adjust to shift work, and that flexibility of sleeping habits and the ability to overcome drowsiness should be components of such a questionnaire.

299 citations


Journal ArticleDOI
TL;DR: The decrease in cellular NAD level produced by y-radiation and by N-methyl-N-nitrosourea is proposed to be caused by an increased flux through poly(ADP-ribose) mediated by anincreased activity of poly( ADP- ribose) polymerase, which consequently lowers the cellular NADlevel.
Abstract: Both N-methylN-nitrosourea and γ-radiation lower cellular NAD in mouse leukaemia cells (L-1210) in a dose-dependent way. The minimum NAD level is reached 2 h after a brief exposure to N-methyl-N-nitrosourea, but within 15 min of y-irradiation. The cells remain metabolically active; they are able to recover their control NAD levels and are impermeable to trypan blue. Several inhibitors of poly(ADP-ribose) polymerase inhibit the drop in cellular NAD caused by these two agents: 2 mM 5-methylnicotinamide, 1 mM theophylline or 1 mM theobromine inhibit the effect of N-methyl-N-nitrosourea on cellular NAD level; 200 uM thymidine, 500 uM 5-methyl-nicotinamide, 500 αM theophylline and 500 αM theobromine prevent the lowering of cellular NAD by y-irradiation. The extent to which the drop in cellular NAD is inhibited is dependent on both the concentration of cytotoxic agent and of polymerase inhibitor. Caffeine will inhibit the drop in NAD but only at 10 mM, while nicotonic acid is ineffective even at this dose. The activity of poly(ADP-ribose) polymerase in permeabilized cells immediately after y-radiation increases with dose up to 12 krad, giving a maximal 3.4-fold stimulation of the enzyme activity, whereas the degradation of NAD under conditions optimal for NAD glycohydrolase does not change. The activity of the polymerase shows a close temporal correlation with the NAD drop following both γ-radiation and N-methyl-N-nitrosourea. The enzyme activity is maximal when the NAD content is decreasing at the highest rate and has returned to normal levels when it ceases falling. In permeabilized cells we can distinguish poly(ADP-ribose) polymerase and NAD glycohydrolase activity by their differential response to inhibitors. The polymerase is sensitive to 5-methylnicotin-amide, theophylline, theobromine and thymidine; the NAD glycohydrolase is sensitive to 5-methyl-nicotinamide and theophylline, but not to theobromine and thymidine. We propose that the decrease in cellular NAD level produced by y-radiation and by N-methyl-N-nitrosourea is caused by an increased flux through poly(ADP-ribose) mediated by an increased activity of poly(ADP-ribose) polymerase. This consequently lowers the cellular NAD level. This hypothesis implies an involvement of (ADP-ribose)n in the cellular response to cytotoxic drugs.

Journal ArticleDOI
TL;DR: It is argued that adaptation should be defined by its effects rather than by its causes as any difference between two phenotypic traits (or trait complexes) which increases the inclusive fitness of its carrier.
Abstract: It has sometimes been suggested that the term adaptation should be reserved for differences with a known genetic basis. We argue that adaptation should be defined by its effects rather than by its causes as any difference between two phenotypic traits (or trait complexes) which increases the inclusive fitness of its carrier. This definition implies that some adaptations may arise by means other than natural selection. It is particularly important to bear this in mind when behavioural traits are considered. Critics of the 'adaptationist programme' have suggested that an important objection to many adaptive explanations is that they rely on ad-hoc arguments concerning the function of previously observed differences. We suggest that this is a less important problem (because evolutionary explanations generally claim some sort of generality and are therefore testable) than the difficulties arising from confounding variables. These are more widespread and more subtle than is generally appreciated. Not all differences between organisms are directly adapted to ecological variation. The form of particular traits usually constrains the form of value that other traits can take, presenting several obstacles to attempts to relate variation in morphological or behavioural characteristics directly to environmental differences. We describe some of the repercussions of differences in body size among vertebrates and ways in which these can be allowed for. In addition, a variety of evolutionary processes can produce non-adaptive differences between organisms. One way of distinguishing between these and adaptations is to investigate adaptive trends in phylogenetically different groups of species.

Journal ArticleDOI
09 Aug 1979-Nature
TL;DR: The central problem discussed in a series of papers by Manfred Eigen and Peter Schuster proposing the ‘hypercycle’ as a necessary intermediate stage is that one cannot have accurate replication without a length of RNA, say, 2000 or more base pairs, and one cannotHave that much RNA without accurate replication.
Abstract: Perhaps the most difficult step to explain in the origin of life is that from the replication of molecules (RNA for example) in the absence of specific proteins, to the appearance of polymerases and other proteins involved in the replication of RNA and themselves coded for by that RNA. Suppose we start with a population of replicating RNA molecules. Without specific enzymes the accuracy of replication is low and hence the length of RNA which could be precisely replicated small. Before replication can be reasonably accurate, there must as a minimum be a specific polymerase, as well as synthetases and tRNAs, which in turn implies an RNA genome of considerable length. Thus, even if one supposes an initially very limited set of codons, one cannot have accurate replication without a length of RNA, say, 2000 or more base pairs, and one cannot have that much RNA without accurate replication. This is the central problem discussed in a series of papers by Manfred Eigen and Peter Schuster proposing the ‘hypercycle’ as a necessary intermediate stage.

Journal ArticleDOI
01 Jun 1979-Futures
TL;DR: The influence of the market may vary greatly, with cyclic changes (birth, growth, and decline) and discontinuities in industry, and chance plays a far greater role in competitive survival and growth than it is comfortable to admit.

Journal ArticleDOI
TL;DR: The recent increase in the incidence of shiftwork has been accompanied by a change in the type of task typically performed by the shift worker as discussed by the authors. But the technological advances which have produced both shifts and shifts have not yet been considered.
Abstract: The recent increase in the incidence of shiftwork has been accompanied by a change in the type of task typically performed by the shiftworker. The technological advances which have produced both th...

Journal ArticleDOI
TL;DR: Analysis of the ability of multimeric forms of other pMB8::Tn3 deletion derivatives to be stably propagated in a recA- strain, has allowed the localization of the Tn3 sequences necessary for the recombination event.
Abstract: Deletions of transposons Tn1 and Tn3 that extend into a region of the transposon that specifies a 19,000 molecular weight protein, are unable to resolve presumptive transposition intermediates in recA strains of Escherichia coli. For example, when transposition of such mutant transposons occurs from replicon A to replicon B, cointegrate molecules containing A and B separated by directly repeated copies of the transposons are efficiently produced. Such cointegrates are stable in a recA strain, but are resolved within a recA+ host into replicons A and B each containing a copy of the transposon. One mutant gives cointegrates that can be complemented to resolve when a wild type Tn3 is present in the same recA cell, whereas another gives cointegrates that cannot be resolved by complementation in trans. We suggest that the first such mutant still carries the sequences necessary for the recombination event whereas the latter has lost them.

Journal ArticleDOI
G Barton1
TL;DR: In this paper, the authors disencumber the proper heuristic functions of the model from such misconceptions, avoidable in the light of the classic papers by Block (1933), Jensen (1937) and Samoilovich (1945).
Abstract: This review aims mainly to disencumber the proper heuristic functions of the model from such misconceptions, avoidable in the light of the classic papers by Block (1933), Jensen (1937) and Samoilovich (1945). The boundary conditions and linearised differential equations are established without cutoff; they determine the normal modes and orthogonality relations. The model is quantised through its normal modes, and the equal-time commutation rules are discussed. The equations in Fourier space are found; it is argued that a cutoff, if required, should be imposed on the Hamiltonian in this representation and before diagonalisation, and the consequences are explored. With such a cutoff, surface though not bulk modes become dispersive even when beta =0. The formalism is applied briefly to image potentials, and in more detail to the attraction between two half-spaces; the role of bulk modes (when beta >0) is stressed; the asymptotics are discussed at long and short distances.

Journal ArticleDOI
01 Nov 1979-Nature
TL;DR: In this article, the authors reported hybridisation between restriction fragments of plasmid DNA from R. leguminosarum and DNA encoding part of the structural genes for Klebsiella pneumoniae nitrogenase.
Abstract: The distinguishing characteristic of bacteria that belong to the genus Rhizobium is their ability to induce nodules and fix nitrogen in the roots of leguminous plants—hence their importance in agriculture. The demonstration of nitrogen-fixation by rhizobia in the absence of host plant material showed that the genes for nitrogenase synthesis and function reside in the bacterium1–3. The presence of large plasmids (molecular weight (MW) 90–350 × 106) in many Rhizobium strains is now well established4–6 and earlier genetic evidence suggested that at least some of the genes required for symbiosis were plasmid-linked7,8. More recently, Johnston et al.9 found evidence that genes required for nodulation were carried on a plasmid in Rhizobium leguminosarum. We now report hybridisation between restriction fragments of plasmid DNA from R. leguminosarum and DNA encoding part of the structural genes for Klebsiella pneumoniae nitrogenase. Our results provide evidence that at least some of the Rhizobium nif genes are carried on plasmids indigenous to the strains examined.

Journal ArticleDOI
TL;DR: All of the nif genes were assigned to endonculease restriction fragments of DNA using the Southern blotting technique (Southern, 1975) with total DNA of nif insertion mutants and radioactive plasmid DNA which contained cloned nif DNA sequences.
Abstract: A HindIII (17.0 kb) and an EcoRl restriction fragment (6.9 kb) of Klebsiella pneumoniae nif DNA were cloned on two small amplifiable plasmids, pCM1 and pSA30 respectively. These plasmids between them carry 14 of the 15 known Klebsiella nif genes. The operon for the three structural genes for nitrogenase, nifpHDK, is carried on pSA30: four and five of the remaining six operons are on pCRA37 and pCM1 respectively. All of the nif genes were assigned to endonculease restriction fragments of DNA using the Southern blotting technique (Southern, 1975) with total DNA of nif insertion mutants and radioactive plasmid DNA which contained cloned nif DNA sequences. Their locations were consistent with the genetic map of nif genes. The estimated size of the nif gene cluster was 24 kb.

Journal ArticleDOI
Luc Soete1
TL;DR: In this paper, the authors analyzed the relationship between firm size and inventive activity in the United States for the late seventies and found that the inventive activity seems to increase more than proportionately with firm size.

Journal ArticleDOI
TL;DR: The central generation of burst activity was investigated in the buccal ganglia of Lymnaea by generating eight different patterns of burst Activity generated by one or two consecutive phases of compound synaptic potentials resulting from activity of neurones.
Abstract: The central generation of burst activity was investigated in the buccal ganglia of Lymnaea. Eight different patterns of burst activity were generated by one or two consecutive phases of compound synaptic potentials resulting from activity of neurones. These inputs acted upon the different endogenous properties of buccal neurones such as post-inhibitory rebound and spike adaptation. Effects of synaptic inputs were reinforced by by electrotonic coupling of some buccal neurones of the same type.

Journal ArticleDOI
TL;DR: In this paper, the authors described experiments on the coating of germanium targets on a water-cooled electrode in a butane r.f. plasma (13.56 MHz) with the electrode capacitively coupled to the supply to provide a negative bias to enhance ion impact.

Journal ArticleDOI
TL;DR: Populations with no absolute barrier to selfing, and with intermediate levels of self-fertilization, appear to be the most likely starting state for the evolution of outbreeding mechanisms, and some evidence for inbreeding depression is suggested.
Abstract: Population genetic studies of the evolution of breeding systems in flowering plants are reviewed. The selective advantage of a gene's increasing the selfing rate is stressed. In the evolution of outbreeding mechanisms, some strong disadvantage to selfing must therefore be acting; it is suggested that this disadvantage is inbreeding depression. Populations with no absolute barrier to selfing, and with intermediate levels of self-fertilization, appear to be the most likely starting state for the evolution of outbreeding mechanisms. There is some evidence for inbreeding depression in such populations. The evolution of distyly and dioecy are considered in some detail. An explanation for the existence of supergenes controlling these systems is proposed. The breakdown of distyly and tristyly are also considered. The evolution of recombination rates in selfing and outcrossing species is examined briefly.

Journal ArticleDOI
01 Mar 1979-Nature
TL;DR: UV-A: Biological Effects of Ultraviolet Radiation, with Emphasis on Human Responses to Longwave Ultraviolet, with emphasis on human responses to longwave Ult ultraviolet, is published.
Abstract: UV-A: Biological Effects of Ultraviolet Radiation, with Emphasis on Human Responses to Longwave Ultraviolet. By J. A. Parrish, R. A. Anderson, F. Urbach and D. Pitts. Pp.262. (Plenum: New York and London, 1978.) £15.75.

Journal ArticleDOI
TL;DR: Cells from a xeroderma pigmentosum patient XP2BI who has reached 17 years of age with no keratoses or skin tumours constitute a new, 7th complementation group G, which exhibits a low residual level of excision repair, an impairment of post-replication repair characteristic of excison-defective XPs and is sensitive to the lethal effects of UV.
Abstract: Cells from a xeroderma pigmentosum patient XP2BI who has reached 17 years of age with no keratoses or skin tumours constitute a new, 7th complementation group G. These cells exhibit a low residual level of excision repair, 2% of normal after a UV dose of 5 J/m2 and an impairment of post-replication repair characteristic of excision-defective XPs. They are also sensitive to the lethal effects of UV and defective in host-cell reactivation of UV-irradiated SV40 DNA.

Book Chapter
01 Jan 1979

Journal ArticleDOI
TL;DR: In this paper, the authors consider the problem of the loss of an additive from the surface of its solution in a polyethylene or polypropylene polypropylene solution and apply it to a discussion of the relative importance of the three parameters under various conditions occurring or expected in practical application of additives as oxidation stabilizers.
Abstract: The rate at which an additive is lost from the surface of its solution in a polymer is considered to depend upon three factors—the solubility of the additive, the rate at which it volatilizes from the polymer surface, and its diffusion coefficient within the bulk of the polymer. By adapting the mathematics of heat flow in a solid, the loss of additive from a polymer is mathematically modeled in terms of these three variables for bulk polymer and for film and fiber samples. Two cases are considered—loss of additive by volatilization or dissolution from the polymer surface and loss by precipitation on the surface from a supersaturated solution of the additive. The results are applied to a discussion of the relative importance of the three parameters under various conditions occurring or expected in practical application of additives as oxidation stabilizers for polyethylene and polypropylene.

Journal ArticleDOI
TL;DR: Electromyographic recordings from the buccal muscles of Lymnaea during feeding has shown that there are 4 component phases in the feeding cycle, and the combination of physiological and anatomical approaches has led to the suggestion that the single and double input cells described by Benjamin & Rose (1979) are involved with the control of buccAL and oesophageal activity respectively.
Abstract: Electromyographic recordings from the buccal muscles of Lymnaea during feeding has shown that there are 4 component phases in the feeding cycle. Cinephotography of feeding cycles has confirmed that these correspond to protraction, 2 phases of retraction, and an inactive phase. The 4 phases of muscle activity can also be related to the cycle of neural activity described previously (Benjamin & Rose, 1979). Thus types 6, 4 group, and type 8 cells are motoneurones involved in protraction and the two retraction phases, while the type 5 cell fires in the inactive period. The combination of physiological and anatomical approaches has led to the suggestion that the single and double input cells described by Benjamin & Rose (1979) are involved with the control of buccal and oesophageal activity respectively.


Journal ArticleDOI
TL;DR: In this article, the authors argue for the need to take much more explicit account of noneconomic costs (and benefits) in this field, and link the discussion to questions that have preoccupied those concerned with general issues of development in recent years.