Showing papers by "University of Warwick published in 2003"
Book•
01 Jan 2003TL;DR: Archer as discussed by the authors identifies three distinctive forms of internal conversation, i.e., internal dialogue, internal conversation is seen as being the missing link between society and the individual, structure and agency.
Abstract: The central problem of social theory is 'structure and agency'. How do the objective features of society influence human agents? Determinism is not the answer, nor is conditioning as currently conceptualised. It accentuates the way structure and culture shape the social context in which individuals operate, but it neglects our personal capacity to define what we care about most and to establish a modus vivendi expressive of our concerns. Through inner dialogue, 'the internal conversation', individuals reflect upon their social situation in the light of current concerns and projects. On the basis of a series of unique, in-depth interviews, Archer identifies three distinctive forms of internal conversation. These govern agents' responses to social conditioning, their individual patterns of social mobility and whether or not they contribute to social stability or change. Thus the internal conversation is seen as being the missing link between society and the individual, structure and agency.
1,843 citations
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TL;DR: An overview of the nutritional requirements of different plants for Ca is provided, and how this impacts on natural flora and the Ca content of crops is reviewed.
1,831 citations
TL;DR: An efficient procedure for creating precise gene replacements in the cosmid clones by using PCR targeting and λ-Red-mediated recombination is described, which is used successfully by >20 researchers to mutate around 100 Streptomyces genes.
Abstract: Streptomycetes are high G+C Gram-positive, antibiotic-producing, mycelial soil bacteria. The 8.7-Mb Streptomyces coelicolor genome was previously sequenced by using an ordered library of Supercos-1 clones. Here, we describe an efficient procedure for creating precise gene replacements in the cosmid clones by using PCR targeting and λ-Red-mediated recombination. The cloned Streptomyces genes are replaced with a cassette containing a selectable antibiotic resistance and oriTRK2 for efficient transfer to Streptomyces by RP4-mediated intergeneric conjugation. Supercos-1 does not replicate in Streptomyces, but the clones readily undergo double-crossover recombination, thus creating gene replacements. The antibiotic resistance cassettes are flanked by yeast FLP recombinase target sequences for removal of the antibiotic resistance and oriTRK2 to generate unmarked, nonpolar mutations. The technique has been used successfully by >20 researchers to mutate around 100 Streptomyces genes. As an example, we describe its application to the discovery of a gene involved in the production of geosmin, the ubiquitous odor of soil. The gene, Sco6073 (cyc2), codes for a protein with two sesquiterpene synthase domains, only one of which is required for geosmin biosynthesis, probably via a germacra-1 (10) E,5E-dien-11-ol intermediate generated by the sesquiterpene synthase from farnesyl pyrophosphate.
1,411 citations
TL;DR: Cells are packed with large molecules and the ramifications of this 'crowding' for a wide range of intracellular processes are only now becoming more generally understood.
Abstract: Cells are packed with large molecules. The ramifications of this 'crowding' for a wide range of intracellular processes are only now becoming more generally understood.
788 citations
TL;DR: The authors argue that cynicism is a process through which employees disidentify with cultural prescriptions, yet often still perform them, and they label this the ''ideology interpretation'' because in disidentifying with power, it is inadvertently reproduced at work.
Abstract: Subjectivity and power are important concepts for understanding corporate culture engineering in critical organization studies. Although recent research indicates that many workers do identify with the organization as a result of these management strategies, they have also shown that some workers resist through dis-identification, in particular cynicism. Managerialist literature views cynicism as a psychological defect that needs to be `corrected', while a radical humanist approach constructs cynicism as a defence mechanism, a way of blocking the colonization of a pre-given self. We highlight a third and increasingly dominant perspective that suggests cynicism is a process through which employees dis-identify with cultural prescriptions, yet often still perform them. Cynical employees have the impression that they are autonomous, but they still practice the corporate rituals nonetheless. We label this the `ideology' interpretation because in dis-identifying with power, it is inadvertently reproduced at th...
713 citations
TL;DR: The effects of interventions designed to reduce the incidence of falls in elderly people (living in the community, or in institutional or hospital care) are assessed to assess their effectiveness.
658 citations
TL;DR: This paper proposed an exchange rate model that can explain both the observed volatility and the persistence of real and nominal exchange rate movements and thus in some measure resolves Rogoff's (1996) purchasing power parity puzzle.
648 citations
TL;DR: It is concluded that the production by Streptomyces species of two or more secondary metabolites that act synergistically or contingently against biological competitors may be far more common than has previously been recognized.
Abstract: In this article we briefly review theories about the ecological roles of microbial secondary metabolites and discuss the prevalence of multiple secondary metabolite production by strains of Streptomyces, highlighting results from analysis of the recently sequenced Streptomyces coelicolor and Streptomyces avermitilis genomes. We address this question: Why is multiple secondary metabolite production in Streptomyces species so commonplace? We argue that synergy or contingency in the action of individual metabolites against biological competitors may, in some cases, be a powerful driving force for the evolution of multiple secondary metabolite production. This argument is illustrated with examples of the coproduction of synergistically acting antibiotics and contingently acting siderophores: two well-known classes of secondary metabolite. We focus, in particular, on the coproduction of β-lactam antibiotics and β-lactamase inhibitors, the coproduction of type A and type B streptogramins, and the coregulated production and independent uptake of structurally distinct siderophores by species of Streptomyces. Possible mechanisms for the evolution of multiple synergistic and contingent metabolite production in Streptomyces species are discussed. It is concluded that the production by Streptomyces species of two or more secondary metabolites that act synergistically or contingently against biological competitors may be far more common than has previously been recognized, and that synergy and contingency may be common driving forces for the evolution of multiple secondary metabolite production by these sessile saprophytes.
592 citations
TL;DR: This article examined the relationship between teacher leadership and distributed leadership, focusing particularly upon the idea of activity theory. But they also discussed the possible sources of resistance to the notion of teachers as leaders in schools and explored how distributing leadership to teachers may contribute to building professional learning communities within and between schools.
Abstract: This article focuses on the issue of teacher leadership and explores various interpretations and definitions within the literature. It examines the relationship between teacher leadership and distributed leadership, focusing particularly upon the idea of activity theory. The article suggests that there are some important connections and overlaps between distributed leadership and teacher leadership. The article also discusses the possible sources of resistance to the idea of teachers as leaders in schools and explores how distributing leadership to teachers may contribute to building professional learning communities within and between schools.
584 citations
569 citations
TL;DR: In this paper, the importance of social aspects of knowledge retention and transfer has been emphasised in the literature on managing knowledge, with the recognition that knowledge is often tacit and situated and embedded within particular social groups and situations.
Posted Content•
TL;DR: In this article, the authors focus on education as a private decision to invest in "human capital" and the estimation of the rate of return to that private investment, and show that there is an unambiguously positive effect on the earnings of an individual from participation in education.
Abstract: In this paper we focus on education as a private decision to invest in "human capital" and the estimation of the rate of return to that private investment. While the literature is replete with studies that estimate the rate of return using regression methods where the estimated return is obtained as the coefficient on a years of education variable in a log wage equation that contains controls for work experience and other individual characteristics, the issue is surrounded with difficulties. We outline the theoretical arguments underpinning the empirical developments and show that the evidence on private returns to the individual is compelling. Despite some of these issues surrounding the estimation of the return to schooling, our evidence, based on estimates from a variety of datasets and specifications, is that there is an unambiguously positive effect on the earnings of an individual from participation in education. Moreover, the size of the effect seems large relative to the returns on other investments.
TL;DR: In this article, the authors explore Castells' proposition that the innovation process is being progressively intensified by developments in technological and organizational forms, that knowledge is being applied to the generation of knowledge, and that the constraints posed by the social embeddedness of knowledge as having a crucial effect.
Abstract: This paper aims to explore Castells’ proposition that the innovation process is being progressively intensified by developments in technological and organizational forms – that knowledge is being applied to the generation of knowledge. The paper focuses on the emergence and implementation of knowledge management (KM), and its particular application in Ebank. A global approach to KM focussing on intranet technology proved unsuccessful. In explaining this outcome, the paper focuses on the constraints posed by the social embeddedness of knowledge as having a crucial effect. In this case, such embeddedness seemed to be linked to the lack of extensive intra‐organizational networks and the disparate identities developed by the different business units of the firm. These findings highlight several implications for KM's role in the innovation process.
TL;DR: The genome of P. marinus SS120 is one of the two smallest genomes of a photosynthetic organism known to date and lacks many genes that are involved in photosynthesis, DNA repair, solute uptake, intermediary metabolism, motility, phototaxis, and other functions that are conserved among other cyanobacteria.
Abstract: Prochlorococcus marinus, the dominant photosynthetic organism in the ocean, is found in two main ecological forms: high-light-adapted genotypes in the upper part of the water column and low-light-adapted genotypes at the bottom of the illuminated layer. P. marinus SS120, the complete genome sequence reported here, is an extremely low-light-adapted form. The genome of P. marinus SS120 is composed of a single circular chromosome of 1,751,080 bp with an average G+C content of 36.4%. It contains 1,884 predicted protein-coding genes with an average size of 825 bp, a single rRNA operon, and 40 tRNA genes. Together with the 1.66-Mbp genome of P. marinus MED4, the genome of P. marinus SS120 is one of the two smallest genomes of a photosynthetic organism known to date. It lacks many genes that are involved in photosynthesis, DNA repair, solute uptake, intermediary metabolism, motility, phototaxis, and other functions that are conserved among other cyanobacteria. Systems of signal transduction and environmental stress response show a particularly drastic reduction in the number of components, even taking into account the small size of the SS120 genome. In contrast, housekeeping genes, which encode enzymes of amino acid, nucleotide, cofactor, and cell wall biosynthesis, are all present. Because of its remarkable compactness, the genome of P. marinus SS120 might approximate the minimal gene complement of a photosynthetic organism.
TL;DR: In this article, the authors consider the impact of taxation when investors face a discrete choice between two or more mutually exclusive projects; in particular, they consider the location choice of multinationals and propose a precise measure of this rate, which is shown to be equal to a weighted average of an effective marginal tax rate and an adjusted statutory tax rate.
Abstract: We consider the impact of taxation when investors face a discrete choice between two or more mutually exclusive projects; in particular we consider the location choice of multinationals. Such choices depend on an effective average tax rate. We propose a precise measure of this rate, which is shown to be equal to a weighted average of an effective marginal tax rate and an adjusted statutory tax rate, where the weights depend on the profitability of the investment. Estimates of the distribution of this measure are presented and compared for domestic and international investment in the USA, France, Germany and the UK. We analyse the impact of harmonising corporate tax rates in Europe on incentives to locate in France, Germany and the UK.
TL;DR: Evidence that universal school mental health promotion programmes can be effective is provided and suggests that long‐term interventions promoting the positive mental health of all pupils and involving changes to the school climate are likely to be more successful than brief class‐based mental illness prevention programmes.
Abstract: Reviews previous studies of the universal approach to mental health promotion, and disease prevention programmes or interventions in schools. Over 8,000 publications were identified initially and 425 studies obtained for further review. The inclusion criteria were met by 17 (mostly US) studies investigating 16 interventions. Positive evidence of effectiveness was obtained for programmes that adopted a whole‐school approach, were implemented continuously for more than a year, and were aimed at the promotion of mental health as opposed to the prevention of mental illness. Provides evidence that universal school mental health promotion programmes can be effective and suggests that long‐term interventions promoting the positive mental health of all pupils and involving changes to the school climate are likely to be more successful than brief class‐based mental illness prevention programmes.
TL;DR: A reactive strategy, ‘predictive’ vaccination, is explored, which can reduce markedly the long tail that characterizes many FMD epidemics and have broader implications for the control of human and livestock infectious diseases in heterogeneous spatial landscapes.
Abstract: Vaccination has proved a powerful defence against a range of infectious diseases of humans and animals. However, its potential to control major epidemics of foot-and-mouth disease (FMD) in livestock is contentious. Using an individual farm-based model, we consider either national prophylactic vaccination campaigns in advance of an outbreak, or combinations of reactive vaccination and culling strategies during an epidemic. Consistent with standard epidemiological theory, mass prophylactic vaccination could reduce greatly the potential for a major epidemic, while the targeting of high-risk farms increases efficiency. Given sufficient resources and preparation, a combination of reactive vaccination and culling might control ongoing epidemics. We also explore a reactive strategy, ‘predictive’ vaccination, which targets key spatial transmission loci and can reduce markedly the long tail that characterizes many FMD epidemics. These analyses have broader implications for the control of human and livestock infectious diseases in heterogeneous spatial landscapes.
TL;DR: This article explored the possible benefits of teacher leadership, as well as the possible barriers to and opportunities for making teacher leadership work in practice, and concluded that teacher leadership could have beneficial effects on school improvement, school and teacher effectiveness and teacher motivation and retention, but that the right conditions need to be in place in order for teacher leadership to flourish.
Abstract: As the limitations of the `charismatic head' theories of leadership in schools have become ever more apparent, there has been a move towards teacher leadership, characterized by a form of collective leadership in which teachers develop expertise by working collaboratively. In this article, the possible benefits of teacher leadership are explored, as well as the possible barriers to and opportunities for making teacher leadership work in practice. It is concluded that teacher leadership could have beneficial effects on school improvement, school and teacher effectiveness and teacher motivation and retention, but that the right conditions need to be in place in order for teacher leadership to flourish. The lack of research on teacher leadership in the UK is noted.
TL;DR: One hundred and eleven individuals completed the NEO Five Factor Inventory along with three measures of subjective well-being, the Oxford Happiness Inventory, the Depression-Happiness Scale, and the Satisfaction With Life Scale as mentioned in this paper.
TL;DR: The findings are that multimethod research within the information system (IS) discipline is relatively scarce, and where it occurs involves only a small set of traditional methods.
Abstract: . It has commonly been argued that the use of different research methods within the information system (IS) discipline and within individual pieces of research will produce richer and more reliable results. This paper reports on a survey of the IS literature to discover the extent of multimethod research. The findings are that such work is relatively scarce, and where it occurs involves only a small set of traditional methods. Possible reasons for this are discussed.
TL;DR: In this article, the authors focus on education as a private decision to invest in "human capital" and the estimation of the rate of return to that private investment, and show that there is an unambiguously positive effect on the earnings of an individual from participation in education.
Abstract: In this paper we focus on education as a private decision to invest in “human capital” and the estimation of the rate of return to that private investment. While the literature is replete with studies that estimate the rate of return using regression methods where the estimated return is obtained as the coefficient on a years of education variable in a log wage equation that contains controls for work experience and other individual characteristics, the issue is surrounded with difficulties. We outline the theoretical arguments underpinning the empirical developments and show that the evidence on private returns to the individual is compelling. Despite some of these issues surrounding the estimation of the return to schooling, our evidence, based on estimates from a variety of datasets and specifications, is that there is an unambiguously positive effect on the earnings of an individual from participation in education. Moreover, the size of the effect seems large relative to the returns on other investments.
TL;DR: The aim was to generate and prove the concept of “smart” plants to monitor plant phosphorus (P) status in Arabidopsis, and to allow precision management of P fertilization, thereby maintaining yields while reducing costs, conserving natural resources, and preventing pollution.
Abstract: Our aim was to generate and prove the concept of "smart" plants to monitor plant phosphorus (P) status in Arabidopsis. Smart plants can be genetically engineered by transformation with a construct containing the promoter of a gene up-regulated specifically by P starvation in an accessible tissue upstream of a marker gene such as beta-glucuronidase (GUS). First, using microarrays, we identified genes whose expression changed more than 2.5-fold in shoots of plants growing hydroponically when P, but not N or K, was withheld from the nutrient solution. The transient changes in gene expression occurring immediately (4 h) after P withdrawal were highly variable, and many nonspecific, shock-induced genes were up-regulated during this period. However, two common putative cis-regulatory elements (a PHO-like element and a TATA box-like element) were present significantly more often in the promoters of genes whose expression increased 4 h after the withdrawal of P compared with their general occurrence in the promoters of all genes represented on the microarray. Surprisingly, the expression of only four genes differed between shoots of P-starved and -replete plants 28 h after P was withdrawn. This lull in differential gene expression preceded the differential expression of a new group of 61 genes 100 h after withdrawing P. A literature survey indicated that the expression of many of these "late" genes responded specifically to P starvation. Shoots had reduced P after 100 h, but growth was unaffected. The expression of SQD1, a gene involved in the synthesis of sulfolipids, responded specifically to P starvation and was increased 100 h after withdrawing P. Leaves of Arabidopsis bearing a SQD1::GUS construct showed increased GUS activity after P withdrawal, which was detectable before P starvation limited growth. Hence, smart plants can monitor plant P status. Transferring this technology to crops would allow precision management of P fertilization, thereby maintaining yields while reducing costs, conserving natural resources, and preventing pollution.
TL;DR: It is confirmed that G-quartet formation is essential for biological activity of GROs and show that, in some cases, quadruplex structures formed in the presence of potassium ions are significantly more active than those formed inThe presence of sodium ions.
Abstract: Single-stranded guanosine-rich oligodeoxyribonucleotides (GROs) have a propensity to form quadruplex structures that are stabilized by G-quartets. In addition to intense speculation about the role of G-quartet formation in vivo, there is considerable interest in the therapeutic potential of quadruplex oligonucleotides as aptamers or non-antisense antiproliferative agents. We previously have described several GROs that inhibit proliferation and induce apoptosis in cancer cell lines. The activity of these GROs was related to their ability to bind to a specific cellular protein (GRO-binding protein, which has been tentatively identified as nucleolin). In this report, we describe the physical properties and biological activity of a group of 12 quadruplex oligonucleotides whose structures have been characterized previously. This group includes the thrombin-binding aptamer, an anti-HIV oligonucleotide, and several quadruplexes derived from telomere sequences. Thermal denaturation and circular dichroism (CD) spectropolarimetry were utilized to investigate the stability, reversibility and ion dependence of G-quartet formation. The ability of each oligonucleotide to inhibit the proliferation of cancer cells and to compete for binding to the GRO-binding protein was also examined. Our results confirm that G-quartet formation is essential for biological activity of GROs and show that, in some cases, quadruplex structures formed in the presence of potassium ions are significantly more active than those formed in the presence of sodium ions. However, not all quadruplex structures exhibit antiproliferative effects, and the most accurate factor in predicting biological activity was the ability to bind to the GRO-binding protein. Our data also indicate that the CD spectra of quadruplex oligonucleotides may be more complex than previously thought.
TL;DR: In this paper, the authors examined the implications for the SME financing market of application costs that vary between firms, and of imperfect screening of applicants by banks, and showed that discouragement is at a maximum where there is some, but not perfect, information.
Abstract: This paper examines the implications for the SME financing market of Application costs that vary between firms, and of imperfect screening of applicants by Banks. Under these conditions 'Discouraged Borrowers' can exist. These are good borrowers who do not apply for a bank loan because they feel they will be rejected. The paper shows that, under a range of assumptions, the scale of discouragement in an economy depends upon the screening error of the banks, the scale of Application costs and the extent to which the bank interest rate differs from that charged by the moneylender. Discouragement is shown to be at a maximum where there is some, but not perfect, information.
12 May 2003
TL;DR: Results indicate that local and global grid workflow management can coordinate with each other to optimise workflow execution time and solve conflicts of interest in a cross-domain and highly dynamic grid environment.
Abstract: Grid computing is becoming a mainstream technology for large-scale distributed resource sharing and system integration. Workflow management is emerging as one of the most important grid services. In this work, a workflow management system for grid computing, called GridFlow, is presented, including a user portal and services of both global grid workflow management and local grid sub-workflow scheduling. Simulation, execution and monitoring functionalities are provided at the global grid level, which work on top of an existing agent-based grid resource management system. At each local grid, sub-workflow scheduling and conflict management are processed on top of an existing performance prediction based task scheduling system. A fuzzy timing technique is applied to address new challenges of workflow management in a cross-domain and highly dynamic grid environment. A case study is given and corresponding results indicate that local and global grid workflow management can coordinate with each other to optimise workflow execution time and solve conflicts of interest.
TL;DR: A simple relationship is found between the efficiency of contact tracing necessary for eradication and the basic reproductive ratio of the disease, and this holds for a wide variety of realistic situations including heterogeneous networks containing core–groups or super–spreaders, and asymptomatic individuals.
Abstract: Contact tracing, followed by treatment or isolation, is a key control measure in the battle against infectious diseases. It is an extreme form of locally targeted control, and as such has the potential to be highly efficient when dealing with low numbers of cases. For this reason it is frequently used to combat sexually transmitted diseases and new invading pathogens. Accurate modelling of contact tracing requires explicit information about the disease-transmission pathways from each individual, and hence the network of contacts. Here, pairwise-approximation methods and full stochastic simulations are used to investigate the utility of contact tracing. A simple relationship is found between the efficiency of contact tracing necessary for eradication and the basic reproductive ratio of the disease. This holds for a wide variety of realistic situations including heterogeneous networks containing core-groups or super-spreaders, and asymptomatic individuals. Clustering (transitivity) within the transmission network is found to destroy the relationship, requiring lower efficiency than predicted.
TL;DR: A bacteriophage may protect itself and its host against a deadly effect of bright sunlight as mentioned in this paper, but it is not known how to protect itself from exposure to bright sunlight.
Abstract: A bacteriophage may protect itself and its host against a deadly effect of bright sunlight.
TL;DR: Research exploring the idea that simplicity drives a wide range of cognitive processes is reviewed, outlining mathematical theory, computational results and empirical data that underpin this viewpoint.
TL;DR: This work reviews the use of models in smallpox planning within the broader epidemiological context set by recent outbreaks of both novel and re-emerging pathogens.
Abstract: Mathematical models of viral transmission and control are important tools for assessing the threat posed by deliberate release of the smallpox virus and the best means of containing an outbreak. Models must balance biological realism against limitations of knowledge, and uncertainties need to be accurately communicated to policy-makers. Smallpox poses the particular challenge that key biological, social and spatial factors affecting disease spread in contemporary populations must be elucidated largely from historical studies undertaken before disease eradication in 1979. We review the use of models in smallpox planning within the broader epidemiological context set by recent outbreaks of both novel and re-emerging pathogens.