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Showing papers by "University of Stirling published in 1998"


Journal ArticleDOI
TL;DR: Assessment of the GOS using a standard format with a written protocol is practical and reliable and a set of guidelines are outlined that are directed at the main problems encountered in applying the G OS.
Abstract: The Glasgow Outcome Scale (GOS) is the most widely used outcome measure after traumatic brain injury, but it is increasingly recognized to have important limitations. It is proposed that shortcomings of the GOS can be addressed by adopting a standard format for the interview used to assign outcome. A set of guidelines are outlined that are directed at the main problems encountered in applying the GOS. The guidelines cover the general principles underlying the use of the GOS and common practical problems of applying the scale. Structured interview schedules are described for both the five-point GOS and an extended eight-point GOS (GOSE). An interrater reliability study of the structured interviews for the GOS and GOSE yielded weighted kappa values of 0.89 and 0.85, respectively. It is concluded that assessment of the GOS using a standard format with a written protocol is practical and reliable.

1,821 citations


Journal ArticleDOI
TL;DR: In this paper, the authors outline the choice experiment approach to environmental valuation, which has its roots in Lancaster's characteristics theory of value, in random utility theory and in experimental design, and illustrate the use of choice experiments with reference to a recent UK study on public preferences for alternative forest landscapes.
Abstract: This paper we outline the “choice experiment” approach to environmental valuation. This approach has its roots in Lancaster's characteristics theory of value, in random utility theory and in experimental design. We show how marginal values for the attributes of environmental assets, such as forests and rivers, can be estimated from pair-wise choices, as well as the value of the environmental asset as a whole. These choice pairs are designed so as to allow efficient statistical estimation of the underlying utility function, and to minimise required sample size. Choice experiments have important advantages over other environmental valuation methods, such as contingent valuation and travel cost-type models, although many design issues remain unresolved. Applications to environmental issues have so far been relatively limited. We illustrate the use of choice experiments with reference to a recent UK study on public preferences for alternative forest landscapes. This study allows us to perform a convergent validity test on the choice experiment estimates of willingness to pay.

1,140 citations


Journal ArticleDOI
18 Dec 1998-Science
TL;DR: Treatment of the grouse population prevented population crashes, demonstrating that parasites were the cause of the cyclic fluctuations.
Abstract: The regular cyclic fluctuations in vertebrate numbers have intrigued scientists for more than 70 years, and yet the cause of such cycles has not been clearly demonstrated. Red grouse populations in Britain exhibit cyclic fluctuations in abundance, with periodic crashes. The hypothesis that these fluctuations are caused by the impact of a nematode parasite on host fecundity was tested by experimentally reducing parasite burdens in grouse. Treatment of the grouse population prevented population crashes, demonstrating that parasites were the cause of the cyclic fluctuations.

844 citations


Journal ArticleDOI
TL;DR: The scale of family company activity in the United Kingdom was measured with regard to several family firm definitions as mentioned in this paper, which confirmed that family companies are a numerically important group of companies.
Abstract: The scale of family company activity in the United Kingdom was measured with regard to several family firm definitions. This study confirms that family companies are a numerically important group o...

634 citations


Journal ArticleDOI
13 Aug 1998-Nature
TL;DR: A nonlinear time-series model shows that part of the required environmental synchronicity can be accounted for by large-scale weather variations and underline the importance of understanding the interaction between intrinsic and extrinsic influences on population dynamics.
Abstract: A major debate in ecology concerns the relative importance of intrinsic factors and extrinsic environmental variations in determining population size fluctuations1,2,3,4,5,6. Spatial correlation of fluctuations in different populations caused by synchronous environmental shocks2,7,8 is a powerful tool for quantifying the impact of environmental variations on population dynamics8,9. However, interpretation of synchrony is often complicated by migration between populations8,10. Here we address this issue by using time series from sheep populations on two islands in the St Kilda archipelago11,12,13. Fluctuations in the sizes of the two populations are remarkably synchronized over a 40-year period. A nonlinear time-series model shows that a high and frequent degree of environmental correlation is required to achieve this level of synchrony. The model indicates that if there were less environmental correlation, population dynamics would be much less synchronous than is observed. This is because of a threshold effect that is dependent on population size; the threshold magnifies random differences between populations. A refined model showsthat part of the required environmental synchronicity can be accounted for by large-scale weather variations. These results underline the importance of understanding the interaction between intrinsic and extrinsic influences on population dynamics14.

532 citations


Journal ArticleDOI
30 Oct 1998-Science
TL;DR: Although many fisheries stocks have declined precipitously throughout the world, fish farming--and especially shrimp and salmon farming--has boomed and increasingly large scale of these enterprises is now having unforeseen ecological consequences on ocean resources through habitat destruction, effluent discharge, exotic species introductions, and heightened fish catch for feed use.
Abstract: Although many fisheries stocks have declined precipitously throughout the world, fish farming--and especially shrimp and salmon farming--has boomed. The increasingly large scale of these enterprises is now having unforeseen ecological consequences on ocean resources through habitat destruction, effluent discharge, exotic species introductions, and heightened fish catch for feed use. Ending unsustainable production practices will require reorienting regulatory policies and fiscal incentives in shrimp- and salmon-producing counties, and enhancing restrictions on environmentally unsound practices.

438 citations


Journal ArticleDOI
TL;DR: Bermudez as mentioned in this paper argues that any explanation of fully fledged self-consciousness that answers these two questions requires attention to primitive forms of selfconsciousness, such as prelinguistic and preconceptual self-reference.
Abstract: In this book, Jose Luis Bermudez addesses two fundamental problems in the philosophy and psychology of self-consciousness: (1) Can we provide a noncircular account of fully fledged self-conscious thought and language in terms of more fundamental capacities? (2) Can we explain how fully fledged self-conscious thought and language can arise in the normal course of human development? Bermudez argues that a paradox (the paradox of self-consciousness) arises from the apparent strict interdependence between self-conscious thought and linguistic self-reference. The paradox renders circular all theories that define self-consciousness in terms of linguistic mastery of the first-person pronoun. It seems to follow from the paradox of self-consciousness that no such account or explanation can be given. Drawing on recent work in empirical psychology and philosophy, the author argues that any explanation of fully fledged self-consciousness that answers these two questions requires attention to primitive forms of self-consciousness that are prelinguistic and preconceptual. Such primitive forms of self-consciousness are to be found in somatic proprioception, the structure of exteroceptive perception, and prelinguistic forms of social interaction. The author uses these primitive forms of self-consciousness to dissolve the paradox of self-consciousness and to show how the two questions can be given an affirmative answer.

426 citations


Book
03 Dec 1998
TL;DR: In the brain of the beholder: the neuroscience of face perception as discussed by the authors, the face is an organ of communication and the mating game of attractiveness and the sociobiology of faces.
Abstract: 1 The face: organ of communication 2 Light, colour, and shape: the science of vision 3 Physical differences between faces: age, sex and race 4 The mating game: attractiveness and the sociobiology of faces 5 Whose face is it? How individual faces are recognized 6 Messages from the face: lip-reading, gaze, and expression 7 In the brain of the beholder: the neuroscience of face perception

416 citations


Journal ArticleDOI
TL;DR: A zinc binding template in protein crystal structures is derived from observing the sequence pattern of the zinc ligands and residues that provide elecs, and identifying conserved hydrophobic residues in the endopeptidases that also appear to contribute to stabilizing the catalytic zinc site.
Abstract: The geometrical properties of zinc binding sites in a dataset of high quality protein crystal structures deposited in the Protein Data Bank have been examined to identify important differences between zinc sites that are directly involved in catalysis and those that play a structural role. Coordination angles in the zinc primary coordination sphere are compared with ideal values for each coordination geometry, and zinc coordination distances are compared with those in small zinc complexes from the Cambridge Structural Database as a guide of expected trends. We find that distances and angles in the primary coordination sphere are in general close to the expected (or ideal) values. Deviations occur primarily for oxygen coordinating atoms and are found to be mainly due to H-bonding of the oxygen coordinating ligand to protein residues, bidentate binding arrangements, and multi-zinc sites. We find that H-bonding of oxygen containing residues (or water) to zinc bound histidines is almost universal in our dataset and defines the elec-His-Zn motif. Analysis of the stereochemistry shows that carboxyl elec-His-Zn motifs are geometrically rigid, while water elec-His-Zn motifs show the most geometrical variation. As catalytic motifs have a higher proportion of carboxyl elec atoms than structural motifs, they provide a more rigid framework for zinc binding. This is understood biologically, as a small distortion in the zinc position in an enzyme can have serious consequences on the enzymatic reaction. We also analyze the sequence pattern of the zinc ligands and residues that provide elecs, and identify conserved hydrophobic residues in the endopeptidases that also appear to contribute to stabilizing the catalytic zinc site. A zinc binding template in protein crystal structures is derived from these observations.

406 citations


Journal ArticleDOI
TL;DR: It is suggested that the membrane phospholipid hypothesis can provide such a biochemical basis and that the neurodevelopmental phospholIPid concept offers a powerful paradigm to guide future research.

389 citations


Journal ArticleDOI
01 Mar 1998-Genetics
TL;DR: A genetic map for a tilapia, Oreochromis niloticus, using DNA markers is constructed, a starting point for the mapping of single loci and quantitative traits in cichlid fishes.
Abstract: We have constructed a genetic map for a tilapia, Oreochromis niloticus, using DNA markers. The segregation of 62 microsatellite and 112 anonymous fragment length polymorphisms (AFLPs) was studied in 41 haploid embryos derived from a single female. We have identified linkages among 162 (93.1%) of these markers. 95% of the microsatellites and 92% of the AFLPs were linked in the final map. The map spans 704 Kosambi cM in 30 linkage groups covering the 22 chromosomes of this species. Twenty-four of these linkage groups contain at least one microsatellite polymorphism. From the number of markers 15 or fewer cM apart, we estimate a total map length of z1000-1200 cM. High levels of interference are observed, consistent with measurements in other fish species. This map is a starting point for the mapping of single loci and quantitative traits in cichlid fishes.


Journal ArticleDOI
TL;DR: The changes in the behaviour of multihost, pathogen models can be revealed through bifurcation analysis, and it is shown that when these transmission coefficients are high then complexities can arise, with multiple equilibria present.
Abstract: The changes in the behaviour of multihost, pathogen models can be revealed through bifurcation analysis. This analysis identifies bifurcation points that define surfaces that separate different types of model behaviour, such as stability or instability. As an example, consider the case of a shared microparasite between two host species that we can describe with the basic susceptible–infectious model. The two figures illustrate the bifurcation surfaces in the cross section of parameter space; defined by the reciprocals of the reproductive numbers (the number of new cases arising from a primary case introduced into a population of susceptibles) of the pathogen in each host species i (R0i). The reciprocal is used so that single host infections persist close to the origin. The shaded areas are the regions where the infected coexistence equilibria are relevant (i.e. positive) and the numbers represent p,q, where there are p relevant equilibria of which q are stable. In (a), where between-species transmission-coefficients are low, infected coexistence occurs for sufficiently high values of R0i, but host exclusion is not possible. In (b), where between-species transmission-coefficients are high, then stable infected coexistence is not possible for high R0i, in which case host exclusion takes place. Figure (b) also shows that when these transmission coefficients are high then complexities can arise, with multiple equilibria present.Fig. 3Fig. 3Fig. 3View Large Image | Download PowerPoint Slide

Journal ArticleDOI
TL;DR: The nitrogen, phosphorus and solids budget have been constructed for water exchange systems and alternative culture systems such as lined ponds, low salinity rearing and recirculation farms are described in relation to their potential for remediating problems within the shrimp culture industry.

Journal ArticleDOI
TL;DR: Recent progress in the ethology and ecology of sleep in diurnal monkeys and apes is reviewed, with emphasis on safety from predators at sleeping sites, physical comfort, social behavior, and psychophysiology of sleep.
Abstract: Since primates spend about half of their life at sleeping sites, knowledge of behavior in the vicinity of sleeping sites and analysis of factors influencing their use is important for understanding the diversity of primates' adaptations to their environment. The present paper reviews recent progress in the ethology and ecology of sleep in diurnal monkeys and apes. Emphasis is given to the following topics: safety from predators at sleeping sites, physical comfort, social behavior, and psychophysiology of sleep. In all cases, study at the group level and at the individual level can provide insights into behavioral adaptations. As well as increasing understanding of behavior in the wild, knowledge of sleep-related behavior can be applied with a view to improving the environment for captive primates.

Journal ArticleDOI
TL;DR: It is demonstrated that melanized S. exempta larvae were more resistant than non–melanized forms, independent of rearing density, and that the melanized cuticles characteristic of the high–density form may be indicative of a more active immune system.
Abstract: Parasite resistance mechanisms can be costly to maintain. We would therefore predict that organisms should invest in resistance only when it is likely to be required. Insects that show density-dependent phase polyphenism, developing different phenotypes at high and low population densities, have the opportunity to match their levels of investment in resistance with the likelihood of exposure to pathogens. As high population densities often precipitate disease epidemics, the high-density form should be selected to invest relatively more in resistance. We tested this prediction in larvae of the noctuid Spodoptera exempta. Larvae reared at a high density were found to be considerably more resistant to a nuclear polyhedrosis virus than those reared in isolation. A conspicuous feature of the high-density phase of S. exempta and other phase-polyphenic Lepidoptera is cuticular melanization. As melanization is controlled by the phenoloxidase enzyme system, which is also involved in the immune response, this suggests a possible mechanism for increased resistance at high population densities. We demonstrated that melanized S. exempta larvae were more resistant than non-melanized forms, independent of rearing density. We also found that haemolymph phenoloxidase activity was correlated with cuticular melanization, providing further evidence for a link between melanization and immunity. These results suggest that pathogen resistance in S. exempta is phenotypically plastic, and that the melanized cuticles characteristic of the high-density form may be indicative of a more active immune system.

Journal ArticleDOI
TL;DR: The results indicate that cultivated mussels were suitable for marketing from May to December, particularly in Loch Etive, where they remained in good condition during summer and autumn.

Journal ArticleDOI
TL;DR: In this paper, the authors explore some key antionomies which have emerged in relation to children and childhood in late modernity: tensions between autonomy and protection and between perceptions of children as ''at risk'' and as potentially threatening.
Abstract: In this paper we explore some key antionomies which have emerged in relation to children and childhood in late modernity: tensions between autonomy and protection and between perceptions of children as `at risk' and as potentially threatening. A particular focus here is on the sexualisation of risk, the degree of public concern expressed whenever the sexual `innocence' of children is thought to be endangered. We argue that the concept of risk anxiety provides a useful means of analysing contemporary fears about children and childhood and may thus be understood as contributing to the ongoing social construction of childhood. Here risk anxiety must be located within the context of gendered and generational power relations, in which children's lives are bounded by adult surveillance. Furthermore, risk anxiety may have material consequences for children's daily lives and for everyday adult-child negotiations around safety and danger, protection and autonomy.

Journal ArticleDOI
TL;DR: The results suggest that at least two dimensions of facial information contribute to a face's apparent distinctiveness, but that these sources of information are differentially affected by turning the face upside-down.
Abstract: Distinctiveness contributes strongly to the recognition and rejection of faces in memory tasks. In four experiments we examine the role played by local and relational information in the distinctiveness of upright and inverted faces. In all experiments subjects saw one of three versions of a face: original faces, which had been rated as average in distinctiveness in a previous study (Hancock, Burton, & Bruce, 1996), a more distinctive version in which local features had been changed (D-local), and a more distinctive version in which relational features had been changed (D-rel). An increase in distinctiveness was found for D-local and D-rel faces in Experiment 1 (complete faces) and 3 and 4 (face internals only) when the faces had to be rated in upright presentation, but the distinctiveness of the D-rel faces was reduced much more than that of the D-local versions when the ratings were given to the faces presented upside-down (Experiments 1 and 3). Recognition performance showed a similar pattern: presented...

Journal ArticleDOI
TL;DR: The inferred mannan/cellulose sandwich structure may underlie the densification processes which can accompany mannan-containing secondary cell wall formation and promote network formation from galactomannan solutions under conditions where this would not normally occur.

Journal ArticleDOI
TL;DR: Natural selection will favour those individuals that use early larval density to predict the optimal level of resources to allocate to pathogen resistance later in life, which may explain the results of several recent studies of moth caterpillars and their baculoviruses.
Abstract: Insects from a range of taxa use early larval density as a cue to the future deterioration of their current habitat (Dingle, 1996). Their response to this cue is often to redirect resources away from activities favouring immediate reproduction at the natal site (e.g. egg maturation) towards those that favour reproduction in a different location or at a different time (e.g. the development of wings and flight muscles or the deposition of lipid reserves). As well as predicting a decline in the quality or quantity of the larval food resource, early larval density may also predict the risk of exposure to pathogens, which often increases in a predictable manner with population density. Under such circumstances, natural selection will favour those individuals that use early larval density to predict the optimal level of resources to allocate to pathogen resistance later in life. Such an adaptive prophylactic response to larval density may explain the results of several recent studies of moth caterpillars and their baculoviruses. Kunimi & Yamada (1990) reared caterpillars of the Oriental armyworm moth ( Mythimna separata ) at densities ranging between one and twenty larvae per container. They then orally inoculated newly emerged fourth-instar caterpillars with various concentrations of nuclear polyhedrosis virus (NPV) and recorded the number of deaths. They found that NPV-induced mortality declined gradually from 95% for insects reared solitarily to 37% for those reared at a density of twenty larvae per container. The LC 50 value for caterpillars reared at the highest density was about tenfold that for individuals reared solitarily. In a second experiment, Kunimi & Yamada (1990) allowed second-instar caterpillars to feed for 2 days on artificial diet contaminated with a granulosis virus (GV) before rearing them for a further 36 days under either solitary or crowded conditions. They found that larvae reared at high densities (twenty per container) were about fourfold more resistant to GV than those reared singly. Thus, in this species at least,

Journal ArticleDOI
TL;DR: The theory of social representations is by now nearly 40 years old as discussed by the authors, and it has its critics, some of them argue that the theory is too loose; others, that it is too cognitive; still others would like to marry the theory either to discourse analysis or to social constructivism(s) and constructionism-or to both of them at the same time.
Abstract: Serge Moscovici's theoretical system of social representations is by now nearly 40 years old; yet, today, various social psychological activities surrounding this field seem to flourish more than ever; much research into social representations is being carried out all over Europe and on other continents; there is a European PhD programme on social representations and communication; there is an association and a network on social representations; and a journal on social representations is in the pipeline. At the same time the theory has its critics; some of them argue that the theory is too loose; others, that it is too cognitive; that it is not clear how the concept of social representation differs from other concepts, say, from attitudes, social cognition, beliefs, stereotypes, and so on; still others would like to marry the theory either to discourse analysis or to social constructivism(s) and constructionism-or to both of them at the same time. Readers of French, in addition, are familiar with Moscovic...


Journal ArticleDOI
TL;DR: Within the Artemia-fed population, DHA and EPA levels were slightly, but significantly, raised in the eye PC fractions of normally pigmented fish compared to malpigmented ones, however, there was no significant difference in DHA:EPA ratios between normal and malPigmented fish fed Artemia.

Journal ArticleDOI
TL;DR: In this paper, the processes and strategies associated with the growth of business clusters by habitual entrepreneurs were investigated, and the authors were able to gain insights into the process and strategies used by these individuals.
Abstract: Previous studies on habitual entrepreneurs have not researched in any depth the processes and strategies associated with the growth of business clusters by habitual entrepreneurs. To gain insights ...

Journal ArticleDOI
TL;DR: In this paper, the authors explored the perceived benefits of a science park location in the UK for independent technology-based firms and compared the property needs of independent science parks firms with a control group of similar firms located off-park.
Abstract: This study explores the perceived benefits of a science park location in the UK for independent technology-based firms. Property needs of independent science parks firms were compared with the property needs of a 'control' group of similar firms located off-park. Factors which influenced owner-managers to locate their ventures on a science park or an off-park location were ascertained. Further, the perceived benefits of selected locations were explored. Conclusions and implications for policy-makers and practitioners are detailed.

Journal ArticleDOI
TL;DR: Fish are relatively rich in polyunsaturated fatty acids and thus GSTA mediated conjugation may be an important mechanism for detoxifying peroxidised lipid breakdown products.

Journal ArticleDOI
TL;DR: The dominance of diatoms in the ice-algae assemblages in the Marginal Ice Zone and their high nutritional value as a source of 20:5(n-3) for higher trophic levels are emphasised.
Abstract: Samples of ice algae from the Marginal Ice Zone in the Barents Sea could be divided into two categories: one dominated by assemblages of Melosira arctica, and the other dominated by Nitzschia frigida and associated diatoms. Total lipid from the Melosira assemblages consisted of approximately equal amounts of polar lipids and triacylglycerols. Total lipid from the Nitzschia assemblages contained more triacylglycerols than polar lipids. Total lipid from the Melosira assemblages had higher percentages of C16 PUFA, especially 16:4(n-1) and 20:5(n-3), than that from the Nitzschia assemblages, this reflecting the higher percentages of both C16 PUFA and 20:5(n-3) in polar lipids than in triacylglycerols. Phytoplankton from the pelagic zone were␣richer in flagellates and contained less C16 PUFA and 20:5(n-3) but more C18 PUFA and 22:6(n-3). The dominance of diatoms in the ice-algae assemblages in the Marginal Ice Zone and their high nutritional value as a source of 20:5(n-3) for higher trophic levels are emphasised.

Journal ArticleDOI
TL;DR: Findings indicate the importance of food ration in laboratory-based toxicity tests as well as the difficulty in predicting the environmental fate and effect of contaminants using such tests.
Abstract: Freshwater algae, as with all suspended particulate matter in the water column, exhibit a net negative charge resulting in an affinity for positively charged species, such as toxic metal cations, which will readily adsorb to algal cell surfaces. In this study, the adsorption of a representative toxic metal cadmium cation (Cd{sup 2+}) to a freshwater algal species, Chlorella vulgaris, was investigated using environmentally realistic concentrations of both. A further study of the effects of this particulate adsorption of Cd{sup 2+} on lethal toxicity and feeding in Daphnia magna was conducted. Two apparently contrasting effects were observed. For the D. magna feeding study, cell ingestion was inhibited, leading to reduced growth and reproduction. Experiments comparing the effect of algal-bound cadmium and dissolved forms of cadmium demonstrate that this inhibition is almost entirely due to the surface-bound fraction of ions. However, at concentrations of dissolved cadmium that are lethal to Daphnia, algal cells were found to reduce toxicity. Such findings indicate the importance of food ration in laboratory-based toxicity tests as well as the difficulty in predicting the environmental fate and effect of contaminants using such tests.

Journal ArticleDOI
TL;DR: The authors determine the genetic and environmental components of variability in acute responses among four Daphnia magna clones exposed to both essential and non-essential metals in waters with varying water hardness, and show that Zn–Cd were consistent, but Cu–U inconsistent, with the essentiality hypothesis.