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Showing papers by "University of Bath published in 2006"


Journal ArticleDOI
TL;DR: The data indicate that ethylene and H(2)O( 2) signalling in guard cells are mediated by ETR1 via EIN2 and ARR2-dependent pathway(s), and identify AtrbohF as a key mediator of stomatal responses to ethylene.
Abstract: Ethylene is a plant hormone that regulates many aspects of growth and development. Despite the well-known association between ethylene and stress signalling, its effects on stomatal movements are largely unexplored. Here, genetic and physiological data are provided that position ethylene into the Arabidopsis guard cell signalling network, and demonstrate a functional link between ethylene and hydrogen peroxide (H(2)O(2)). In wild-type leaves, ethylene induces stomatal closure that is dependent on H(2)O(2) production in guard cells, generated by the nicotinamide adenine dinucleotide phosphate hydrogen (NADPH) oxidase AtrbohF. Ethylene-induced closure is inhibited by the ethylene antagonists 1-MCP and silver. The ethylene receptor mutants etr1-1 and etr1-3 are insensitive to ethylene in terms of stomatal closure and H(2)O(2) production. Stomata of the ethylene signalling ein2-1 and arr2 mutants do not close in response to either ethylene or H(2)O(2) but do generate H(2)O(2) following ethylene challenge. Thus, the data indicate that ethylene and H(2)O(2) signalling in guard cells are mediated by ETR1 via EIN2 and ARR2-dependent pathway(s), and identify AtrbohF as a key mediator of stomatal responses to ethylene.

990 citations


Journal ArticleDOI
TL;DR: While considerable chemical development of enzyme electrodes has occurred, relatively little progress has been made towards the engineering development of biofuel cells.

940 citations


Journal ArticleDOI
TL;DR: In this article, the authors estimate a model of corporate reputation, derived from the assessments of managers and market analysts, to be determined by a firm's social performance, financial performance, market risk, the extent of long-term institutional ownership, and the nature of its business activities.
Abstract: Utilizing data on a sample of large firms, we estimate a model of corporate reputation. We find reputation, derived from the assessments of managers and market analysts, to be determined by a firm's social performance, financial performance, market risk, the extent of long-term institutional ownership, and the nature of its business activities. Furthermore, the reputational effect of social performance is found to vary both across sectors, and within sectors across the various types of social performance. Specifically, our results demonstrate the need to achieve a ‘fit’ among the types of corporate social performance undertaken and the firm's stakeholder environment. For example, a strong record of environmental performance may enhance or damage reputation depending on whether the firm's activities ‘fit’ with environmental concerns in the eyes of stakeholders.

884 citations


Journal ArticleDOI
TL;DR: It is shown that TRIZ, the Russian system of problem solving, can be adapted to illuminate and manipulate this process of transfer of ideas and analogues from biology to technology.
Abstract: Biomimetics, a name coined by Otto Schmitt in the 1950s for the transfer of ideas and analogues from biology to technology, has produced some significant and successful devices and concepts in the past 50 years, but is still empirical. We show that TRIZ, the Russian system of problem solving, can be adapted to illuminate and manipulate this process of transfer. Analysis using TRIZ shows that there is only 12% similarity between biology and technology in the principles which solutions to problems illustrate, and while technology solves problems largely by manipulating usage of energy, biology uses information and structure, two factors largely ignored by technology.

866 citations


Journal ArticleDOI
TL;DR: New evidence indicates that even some synonymous mutations are subject to constraint, often because they affect splicing and/or mRNA stability, which has implications for understanding disease, optimizing transgene design, detecting positive selection and estimating the mutation rate.
Abstract: Although the assumption of the neutral theory of molecular evolution - that some classes of mutation have too small an effect on fitness to be affected by natural selection - seems intuitively reasonable, over the past few decades the theory has been in retreat. At least in species with large populations, even synonymous mutations in exons are not neutral. By contrast, in mammals, neutrality of these mutations is still commonly assumed. However, new evidence indicates that even some synonymous mutations are subject to constraint, often because they affect splicing and/or mRNA stability. This has implications for understanding disease, optimizing transgene design, detecting positive selection and estimating the mutation rate.

819 citations


Journal ArticleDOI
TL;DR: This Letter shows how the dispersion relation of surface plasmon polaritons propagating along a perfectly conducting wire can be tailored by corrugating its surface with a periodic array of radial grooves, opening the way to important applications such as energy concentration on cylindrical wires and superfocusing using conical structures.
Abstract: In this Letter, we show how the dispersion relation of surface plasmon polaritons (SPPs) propagating along a perfectly conducting wire can be tailored by corrugating its surface with a periodic array of radial grooves. In this way, highly localized SPPs can be sustained in the terahertz region of the electromagnetic spectrum. Importantly, the propagation characteristics of these spoof SPPs can be controlled by the surface geometry, opening the way to important applications such as energy concentration on cylindrical wires and superfocusing using conical structures.

729 citations


Journal ArticleDOI
TL;DR: This article examined the relation between corporate social performance and stock returns in the UK and found that the poor financial reward offered by such firms is attributable to their good social performance on the environment and, to a lesser extent, the community aspects.
Abstract: This study examines the relation between corporate social performance and stock returns in the UK. We closely evaluate the interactions between social and financial performance with a set of disaggregated social performance indicators for environment, employment, and community activities instead of using an aggregate measure. While scores on a composite social performance indicator are negatively related to stock returns, we find the poor financial reward offered by such firms is attributable to their good social performance on the environment and, to a lesser extent, the community aspects. Considerable abnormal returns are available from holding a portfolio of the socially least desirable stocks. These relationships between social and financial performance can be rationalized by multi-factor models for explaining the cross-sectional variation in returns, but not by industry effects.

685 citations


Journal ArticleDOI
TL;DR: The finding of seven missense mutations in 15 individuals, of whom four had familial ALS and 11 apparently 'sporadic' ALS, provides further evidence that variations in hypoxia-inducible genes have an important role in motor neuron degeneration.
Abstract: We recently identified angiogenin (ANG) as a candidate susceptibility gene for amyotrophic lateral sclerosis (ALS), a neurodegenerative disorder characterized by adult-onset loss of motor neurons. We now report the finding of seven missense mutations in 15 individuals, of whom four had familial ALS and 11 apparently 'sporadic' ALS. Our findings provide further evidence that variations in hypoxia-inducible genes have an important role in motor neuron degeneration.

653 citations


Journal ArticleDOI
TL;DR: In this article, the authors present the results of the European project, RUROS, primarily concerned with the environmental and comfort conditions of open spaces in cities, and confirm a strong relationship between microclimatic and comfort condition, with air temperature and solar radiation being important determinants of comfort, although one parameter alone is not sufficient for the assessment of thermal comfort conditions.

564 citations


Journal ArticleDOI
TL;DR: Technical challenges in the formulation of antibody-based materials to maintain sufficient stability in a variety of configurations and sometimes at particularly high concentrations are reviewed.

540 citations


Journal ArticleDOI
TL;DR: The status of a much-needed coherent view that integrates studies on protein evolution with biochemistry and functional and structural genomics is discussed.
Abstract: Why do proteins evolve at different rates? Advances in systems biology and genomics have facilitated a move from studying individual proteins to characterizing global cellular factors. Systematic surveys indicate that protein evolution is not determined exclusively by selection on protein structure and function, but is also affected by the genomic position of the encoding genes, their expression patterns, their position in biological networks and possibly their robustness to mistranslation. Recent work has allowed insights into the relative importance of these factors. We discuss the status of a much-needed coherent view that integrates studies on protein evolution with biochemistry and functional and structural genomics.

Journal ArticleDOI
02 Nov 2006-Nature
TL;DR: The results indicate that ‘silver-bullet’ conservation strategies alone will not deliver efficient conservation solutions, and priority areas for biodiversity conservation must be based on high-resolution data from multiple taxa.
Abstract: 'Silver bullet' conservation strategies assume that the distribution of extinction-prone species in one well studied taxonomic group will predict the distribution of comparable species in other groups. This has been hard to test, but the availability of new databases on the global distribution of birds, mammals and amphibians means that a test is now possible. The three groups show similar patterns in terms of overall species richness, but the distribution of threatened and rare species is different in each group. Silver bullet strategies alone, it seems, miss the target. Instead, priority areas for biodiversity conservation must be based on high-resolution data from multiple taxa. 'Silver-bullet' approaches to conservation assume that conservation strategy can be based on the distribution of species in one or two well known taxonomic groups, as there is high cross-taxon congruence in large-scale patterns of biodiversity. Although birds, mammals and amphibians show similar patterns in terms of overall species richness, the distribution of threatened and rare species is found to be different in each group. Global conservation strategies commonly assume that different taxonomic groups show congruent geographical patterns of diversity, and that the distribution of extinction-prone species in one group can therefore act as a surrogate for vulnerable species in other groups when conservation decisions are being made1,2,3,4. The validity of these assumptions remains unclear, however, because previous tests have been limited in both geographical and taxonomic extent5,6,7,8,9,10,11,12. Here we use a database on the global distribution of 19,349 living bird, mammal and amphibian species to show that, although the distribution of overall species richness is very similar among these groups, congruence in the distribution of rare and threatened species is markedly lower. Congruence is especially low among the very rarest species. Cross-taxon congruence is also highly scale dependent, being particularly low at the finer spatial resolutions relevant to real protected areas. ‘Hotspots’ of rarity and threat are therefore largely non-overlapping across groups, as are areas chosen to maximize species complementarity. Overall, our results indicate that ‘silver-bullet’ conservation strategies alone will not deliver efficient conservation solutions. Instead, priority areas for biodiversity conservation must be based on high-resolution data from multiple taxa.

Journal ArticleDOI
Simon N. Wood1
TL;DR: The smooths offer several advantages: they have one wiggliness penalty per covariate and are hence invariant to linear rescaling of covariates, making them useful when there is no “natural” way to scale covariates relative to each other.
Abstract: Summary A general method for constructing low-rank tensor product smooths for use as components of generalized additive models or generalized additive mixed models is presented. A penalized regression approach is adopted in which tensor product smooths of several variables are constructed from smooths of each variable separately, these “marginal” smooths being represented using a low-rank basis with an associated quadratic wiggliness penalty. The smooths offer several advantages: (i) they have one wiggliness penalty per covariate and are hence invariant to linear rescaling of covariates, making them useful when there is no “natural” way to scale covariates relative to each other; (ii) they have a useful tuneable range of smoothness, unlike single-penalty tensor product smooths that are scale invariant; (iii) the relatively low rank of the smooths means that they are computationally efficient; (iv) the penalties on the smooths are easily interpretable in terms of function shape; (v) the smooths can be generated completely automatically from any marginal smoothing bases and associated quadratic penalties, giving the modeler considerable flexibility to choose the basis penalty combination most appropriate to each modeling task; and (vi) the smooths can easily be written as components of a standard linear or generalized linear mixed model, allowing them to be used as components of the rich family of such models implemented in standard software, and to take advantage of the efficient and stable computational methods that have been developed for such models. A small simulation study shows that the methods can compare favorably with recently developed smoothing spline ANOVA methods.

Journal ArticleDOI
TL;DR: In this article, the attractions and shortcomings of the positive neohumanisitic turn in organizational theorizing and how positivity might be developed are examined, and suggestions on how positive scholarship could be reconfigured in light of the present critique and against the emancipatory ideas of critical organizational theory.
Abstract: In this article I examine the attractions and shortcomings of the “positive” neohumanisitic turn in organizational theorizing and how positivity might be developed. I evaluate positivity's moral and cultural underpinnings and claims to separate positive from negative emotions, and I explore the deployment of positiveness in HRM programs of empowerment, emotional intelligence, and fun at work. I conclude with suggestions on how positive scholarship could be reconfigured in light of the present critique and against the emancipatory ideas of critical organizational theory.

Journal ArticleDOI
TL;DR: In this paper, the authors define collective identities as the totality of such narratives and draw attention to their complex, and often fragmented and heterogeneous nature, and propose a conceptual model for theorizing and researching collective identities.
Abstract: From a narrative perspective, organizations' identities are discursive (linguistic) constructs constituted by the multiple identity-relevant narratives that their participants author about them, and which feature, for example, in documents, conversations and electronic media. By defining collective identities as the totality of such narratives I draw attention to their complex, and often fragmented and heterogeneous nature. My approach contrasts with much of the theorizing in this field which has tended to homogenize collective identities by emphasizing what is common or shared, failed to capture the interplay between different communities within organizations, and produced bland, undifferentiated empirical research. In particular, the theoretical framework that I outline focuses attention on the importance of reflexivity, voice, plurivocity, temporality, and fictionality to an understanding of collective identities as locales for competing hegemonic claims. In combination, these notions form a unique conceptual model for theorizing and researching collective identities. This said, a narrative approach also has its limitations, and is proposed as an additional, not exclusive, interpretive lens.

Journal ArticleDOI
TL;DR: The past 25 years has seen a phenomenal growth of interest in judgemental approaches to forecasting and a significant change of attitude on the part of researchers to the role of judgement as discussed by the authors.

Journal ArticleDOI
TL;DR: In this paper, a large scale survey of UK manufacturing firms was conducted to explore different explanations for why firms develop process innovations, and they found that the presence of formal research and development, and the use of suppliers as a source of knowledge all increase the chances that a firm will be a process innovator.
Abstract: Although it retains a central position in the main theories of innovation, there are few studies that examine the factors that provide inducements for process innovation at the firm level. Using a large scale survey of UK manufacturing firms, we explore different explanations for why firms develop process innovations. Contrasting the sources of incremental and radical process innovation, our study indicates that there may be complementarities between them. We also find that firm size, the presence of formal research and development, and the use of suppliers as a source of knowledge all increase the chances that a firm will be a process innovator. This article discusses the implications of these results for future theoretical and empirical studies of the innovation process.

Journal ArticleDOI
TL;DR: A biological, process-based framework for vector-borne zoonoses is developed, using Borrelia burgdorferi sensu lato (s.l.), the causative agent of Lyme borreliosis in humans, as an example, and explores the fundamental biological processes that operate in this zoonosis.
Abstract: The evolutionary ecology of many emerging infectious diseases, particularly vector-borne zoonoses, is poorly understood. Here, we aim to develop a biological, process-based framework for vector-borne zoonoses, using Borrelia burgdorferi sensu lato (s.l.), the causative agent of Lyme borreliosis in humans, as an example. We explore the fundamental biological processes that operate in this zoonosis and put forward hypotheses on how extrinsic cues and intrinsic dynamics shape B. burgdorferi s.l. populations. Additionally, we highlight possible epidemiological parallels between B. burgdorferi s.l. and other vector-borne zoonotic pathogens, including West Nile virus.

Journal ArticleDOI
Peter Reason1
TL;DR: Action research is characteristically full of choices, and the argument is made that quality in inquiry comes from awareness of and transparency about the choices available at each stage of the inquiry as discussed by the authors.
Abstract: This article explores the nature of quality in action research practice. The origins and purposes of action research and its relation to social science methodology are reviewed. Action research is described in terms of four characteristic dimensions—worthwhile practical purposes, democracy and participation, many ways of knowing, and emergent developmental form—that present a broad range of criteria beyond those of the empirical research paradigm against which quality research might be judged. Recent debates concerning validity and quality in qualitative research are explored. It is argued that action research is characteristically full of choices, and the argument is made that quality in inquiry comes from awareness of and transparency about the choices available at each stage of the inquiry.

Journal ArticleDOI
TL;DR: The model showed that students who perceived an autonomy supportive environment experienced greater levels of autonomy, competence, and relatedness and had higher scores on an index of self-determination.
Abstract: In the present study, we used a model of motivation grounded in self-determination theory (Deci & Ryan, 1985, 1991; Ryan & Deci, 2000a, 2000b, 2002) to examine the relationship between physical education (PE) students' motivational processes and ratings of their effort and persistence as provided by their PE teacher. Data were obtained from 394 British secondary school students (204 boys, 189 girls, 1 gender not specified; M age = 11.97 years; SD = .89; range = 11-14 years) who responded to a multisection inventory (tapping autonomy-support, autonomy, competence, relatedness, and self-determined motivation). The students' respective PE teachers subsequently provided ratings reflecting the effort and persistence each student exhibited in their PE classes. The hypothesized relationships among the study variables were examined via structural equation modeling analysis using latent factors. Results of maximum likelihood analysis using the bootstrapping method revealed the proposed model demonstrated a good fi...


Journal ArticleDOI
TL;DR: It is demonstrated that a simple time lag model provides a general, parsimonious explanation of the extensive variation in the dN/dS ratio seen when comparing closely related bacterial genomes, and a role for hitch-hiking in the accumulation of non-synonymous mutations is suggested.

Journal ArticleDOI
TL;DR: In this paper, the techniques of neutron diffraction and x-ray diffraction, as applied to structural studies of liquids and glasses, are reviewed, with an emphasis on the explanation and discussion of the experimental techniques and data analysis methods, as illustrated by the results of representative experiments.
Abstract: The techniques of neutron diffraction and x-ray diffraction, as applied to structural studies of liquids and glasses, are reviewed. Emphasis is placed on the explanation and discussion of the experimental techniques and data analysis methods, as illustrated by the results of representative experiments. The disordered, isotropic nature of the structure of liquids and glasses leads to special considerations and certain difficulties when neutron and x-ray diffraction techniques are applied, especially when used in combination on the same system. Recent progress in experimental technique, as well as in data analysis and computer simulation, has motivated the writing of this review.

Journal ArticleDOI
TL;DR: The findings confirmed that treatment of microglia with anti-inflammatory cytokines such as IL-4 and IL-13 induces a gene profile typical of alternative activation similar to that previously observed in peripheral macrophages and suggest that innate immune cells in AD may exhibit a hybrid activation state that includes characteristics of classical and alternative activation.
Abstract: Microglia are associated with neuritic plaques in Alzheimer disease (AD) and serve as a primary component of the innate immune response in the brain. Neuritic plaques are fibrous deposits composed of the amyloid beta-peptide fragments (Abeta) of the amyloid precursor protein (APP). Numerous studies have shown that the immune cells in the vicinity of amyloid deposits in AD express mRNA and proteins for pro-inflammatory cytokines, leading to the hypothesis that microglia demonstrate classical (Th-1) immune activation in AD. Nonetheless, the complex role of microglial activation has yet to be fully explored since recent studies show that peripheral macrophages enter an "alternative" activation state. To study alternative activation of microglia, we used quantitative RT-PCR to identify genes associated with alternative activation in microglia, including arginase I (AGI), mannose receptor (MRC1), found in inflammatory zone 1 (FIZZ1), and chitinase 3-like 3 (YM1). Our findings confirmed that treatment of microglia with anti-inflammatory cytokines such as IL-4 and IL-13 induces a gene profile typical of alternative activation similar to that previously observed in peripheral macrophages. We then used this gene expression profile to examine two mouse models of AD, the APPsw (Tg-2576) and Tg-SwDI, models for amyloid deposition and for cerebral amyloid angiopathy (CAA) respectively. AGI, MRC1 and YM1 mRNA levels were significantly increased in the Tg-2576 mouse brains compared to age-matched controls while TNFα and NOS2 mRNA levels, genes commonly associated with classical activation, increased or did not change, respectively. Only TNFα mRNA increased in the Tg-SwDI mouse brain. Alternative activation genes were also identified in brain samples from individuals with AD and were compared to age-matched control individuals. In AD brain, mRNAs for TNFα, AGI, MRC1 and the chitinase-3 like 1 and 2 genes (CHI3L1; CHI3L2) were significantly increased while NOS2 and IL-1β mRNAs were unchanged. Immune cells within the brain display gene profiles that suggest heterogeneous, functional phenotypes that range from a pro-inflammatory, classical activation state to an alternative activation state involved in repair and extracellular matrix remodeling. Our data suggest that innate immune cells in AD may exhibit a hybrid activation state that includes characteristics of classical and alternative activation.

Journal ArticleDOI
TL;DR: In this article, the authors compare four alternative strategies to reducing end-of-life waste within the context of extended producer responsibility: repairing, reconditioning, remanufacturing or recycling.
Abstract: Between 1980 and 1997, municipal waste in OECD countries increased by around 40%. This paper outlines the very real negative effects of this increase and then introduces the two main European Union policies that have been established to address this problem: a landfill directive and legislation on extended producer responsibility (EPR). The paper then describes and compares the four alternative strategies to reducing end-of-life waste within the context of extended producer responsibility: namely repairing, reconditioning, remanufacturing or recycling. It also introduces a more robust definition of remanufacturing, validated by earlier research, which differentiates it from repair and reconditioning. From a consideration of the different factors involved, it concludes that remanufacturing may well be the best strategy. This is because it enables the embodied energy of virgin production to be maintained, preserves the intrinsic added value of the product for the manufacturer and enables the resultant products to be sold as new with updated features if necessary.

Journal ArticleDOI
TL;DR: In vivo time-lapse confocal microscopy is used to show that zebrafish OPCs continuously extend and retract numerous filopodium-like processes as they migrate and settle into their final positions, facilitating uniform spacing of oligodendrocytes and complete myelination.
Abstract: Myelinating oligodendrocytes arise from migratory and proliferative oligodendrocyte progenitor cells (OPCs). Complete myelination requires that oligodendrocytes be uniformly distributed and form numerous, periodically spaced membrane sheaths along the entire length of target axons. Mechanisms that determine spacing of oligodendrocytes and their myelinating processes are not known. Using in vivo time-lapse confocal microscopy, we show that zebrafish OPCs continuously extend and retract numerous filopodium-like processes as they migrate and settle into their final positions. Process remodeling and migration paths are highly variable and seem to be influenced by contact with neighboring OPCs. After laser ablation of oligodendrocyte-lineage cells, nearby OPCs divide more frequently, orient processes toward the ablated cells and migrate to fill the unoccupied space. Thus, process activity before axon wrapping might serve as a surveillance mechanism by which OPCs determine the presence or absence of nearby oligodendrocyte-lineage cells, facilitating uniform spacing of oligodendrocytes and complete myelination.

Journal ArticleDOI
TL;DR: The known expression patterns of the GluCl explain most of the observed biological effects of treatment with the macrocyclic lactones, though the reason for the long-lasting inhibition of larval production in filarial species is still poorly understood.
Abstract: The macrocyclic lactones are the biggest selling and arguably most effective anthelmintics currently available. They are good substrates for the P-glycoproteins, which might explain their selective toxicity for parasites over their vertebrate hosts. Changes in the expression of these pumps have been implicated in resistance to the macrocyclic lactones, but it is clear that they exert their anthelmintic effects by binding to glutamate-gated chloride channels expressed on nematode neurones and pharyngeal muscle cells. This effect is quite distinct from the channel opening induced by glutamate, the endogenous transmitter acting at these receptors, which produces rapidly opening and desensitising channels. Ivermectin-activated channels open very slowly but essentially irreversibly, leading to a very long-lasting hyperpolarisation or depolarisation of the neurone or muscle cell and therefore blocking further function. Molecular and genetic studies have shown that there are multiple GluCl isoforms in both free-living and parasitic nematodes: the exact genetic make-up and functions of the GluCl may vary between species. The known expression patterns of the GluCl explain most of the observed biological effects of treatment with the macrocyclic lactones, though the reason for the long-lasting inhibition of larval production in filarial species is still poorly understood.

Journal ArticleDOI
TL;DR: It is shown that plasmonic cavities with nanometric dielectric gaps indeed allow for physical as well as effective mode volumes well below the diffraction limit in the gap material, despite significant energy penetration into the metal.
Abstract: The controlled creation of nanometric electromagnetic field confinement via surface plasmon polariton excitations in metal/insulator/metal heterostructures is described via the concept of an effective electromagnetic mode volume Veff. Extensively used for the description of dielectric microcavities, its extension to plasmonics provides a convenient figure of merit and allows comparisons with dielectric counterparts. Using a one-dimensional analytical model and three-dimensional finite-difference time-domain simulations, it is shown that plasmonic cavities with nanometric dielectric gaps indeed allow for physical as well as effective mode volumes well below the diffraction limit in the gap material, despite significant energy penetration into the metal. In this picture, matter-plasmon interactions can be quantified in terms of quality factor Q and Veff, enabling a resonant cavity description of surface enhanced Raman scattering.

Journal ArticleDOI
Geof Wood1, Ian Gough1
TL;DR: In this article, a comparative typology of regimes (welfare state, informal security, insecurity) is proposed, which captures the essential relationships between social and cultural conditions, institutional performance, welfare outcomes, and path dependence.

Journal ArticleDOI
TL;DR: In this paper, the unstructured kinetics and the structured kinetics models were described in batch processes but the continuous kinetic model is insufficiently cared, and the problem of limited oxygen transfer suggests that a new bioreactor design is required.