Showing papers by "University of Reading published in 2005"

The ERA‐40 re‐analysis

Abstract: ERA-40 is a re-analysis of meteorological observations from September 1957 to August 2002 produced by the European Centre for Medium-Range Weather Forecasts (ECMWF) in collaboration with many institutions. The observing system changed considerably over this re-analysis period, with assimilable data provided by a succession of satellite-borne instruments from the 1970s onwards, supplemented by increasing numbers of observations from aircraft, ocean-buoys and other surface platforms, but with a declining number of radiosonde ascents since the late 1980s. The observations used in ERA-40 were accumulated from many sources. The first part of this paper describes the data acquisition and the principal changes in data type and coverage over the period. It also describes the data assimilation system used for ERA-40. This benefited from many of the changes introduced into operational forecasting since the mid-1990s, when the systems used for the 15-year ECMWF re-analysis (ERA-15) and the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) re-analysis were implemented. Several of the improvements are discussed. General aspects of the production of the analyses are also summarized. A number of results indicative of the overall performance of the data assimilation system, and implicitly of the observing system, are presented and discussed. The comparison of background (short-range) forecasts and analyses with observations, the consistency of the global mass budget, the magnitude of differences between analysis and background fields and the accuracy of medium-range forecasts run from the ERA-40 analyses are illustrated. Several results demonstrate the marked improvement that was made to the observing system for the southern hemisphere in the 1970s, particularly towards the end of the decade. In contrast, the synoptic quality of the analysis for the northern hemisphere is sufficient to provide forecasts that remain skilful well into the medium range for all years. Two particular problems are also examined: excessive precipitation over tropical oceans and a too strong Brewer-Dobson circulation, both of which are pronounced in later years. Several other aspects of the quality of the re-analyses revealed by monitoring and validation studies are summarized. Expectations that the ‘second-generation’ ERA-40 re-analysis would provide products that are better than those from the firstgeneration ERA-15 and NCEP/NCAR re-analyses are found to have been met in most cases. © Royal Meteorological Society, 2005. The contributions of N. A. Rayner and R. W. Saunders are Crown copyright.

Uncertainty in predictions of the climate response to rising levels of greenhouse gases.

Abstract: In the climateprediction.net project, thousands of individuals have volunteered spare computing capacity on their PCs to help quantify uncertainty in the way our climate responds to increasing levels of greenhouse gases. By running a state-of-the-art climate model thousands of times, it is possible to find out how the model responds to slight changes in the approximations of physical processes that cannot be calculated explicitly. The first batch of results has now been analysed, and surface temperature changes in simulations that capture the climate realistically are ranging from below 2 °C to more than 11 °C. These represent the possible long-term change, averaged over the whole planet, as a result of doubling the levels of atmospheric carbon dioxide in the model. This is the first time that complex models have been found with such a wide range of responses. Their existence will help in quantifying the risks associated with climate change on a regional level. The range of possibilities for future climate evolution1,2,3 needs to be taken into account when planning climate change mitigation and adaptation strategies. This requires ensembles of multi-decadal simulations to assess both chaotic climate variability and model response uncertainty4,5,6,7,8,9. Statistical estimates of model response uncertainty, based on observations of recent climate change10,11,12,13, admit climate sensitivities—defined as the equilibrium response of global mean temperature to doubling levels of atmospheric carbon dioxide—substantially greater than 5 K. But such strong responses are not used in ranges for future climate change14 because they have not been seen in general circulation models. Here we present results from the ‘climateprediction.net’ experiment, the first multi-thousand-member grand ensemble of simulations using a general circulation model and thereby explicitly resolving regional details15,16,17,18,19,20,21. We find model versions as realistic as other state-of-the-art climate models but with climate sensitivities ranging from less than 2 K to more than 11 K. Models with such extreme sensitivities are critical for the study of the full range of possible responses of the climate system to rising greenhouse gas levels, and for assessing the risks associated with specific targets for stabilizing these levels.

Interaction of Flavonoids with Bovine Serum Albumin: A Fluorescence Quenching Study

Abstract: The interaction between four flavonoids (catechin, epicatechin, rutin, and quercetin) and bovine serum albumin (BSA) was investigated using tryptophan fluorescence quenching. Quenching constants were determined using the Stern-Volmer equation to provide a measure of the binding affinity between the flavonoids and BSA. The binding affinity was strongest for quercetin and ranked in the order quercetin > rutin > epicatechin = catechin. The pH in the range of 5-7.4 does not affect significantly (p < 0.05) the association of rutin, epicatechin, and catechin with BSA, but quercetin exhibited a stronger affinity at pH 7.4 than at lower pH (p < 0.05). Quercetin has a total quenching effect on BSA tryptophan fluorescence at a molar ratio of 10:1 and rutin at approximately 25:1. However, epicatechin and catechin did not fully quench tryptophan fluorescence over the concentration range studied. Furthermore, the data suggested that the association between flavonoids and BSA did not change molecular conformation of BSA and that hydrogen bonding, ionic, and hydrophobic interaction are equally important driving forces for protein-flavonoid association.

Probing theoretically into Central and Eastern Europe: transactions, resources, and institutions

Abstract: Since the 1990s, Central and Eastern Europe (CEE) has provided unique societal quasi-experiments, which represent opportunities to test the applicability of existing theories in international business and management studies and to develop new ones. Specifically, three lines of theorising have been advanced: (1) organisational economics theories; (2) resource-based theories; and (3) institutional theories. For each of these theories, we discuss how they contribute to the understanding of key issues, such as entry strategies of foreign investors, restructuring strategies of local incumbents, and entry and growth strategies of entrepreneurs. On this basis, we assess how CEE research has influenced the overall trajectories of theory development. CEE research has in particular highlighted the importance of contextual influences such as institutions. Thus, scholars have aimed at incorporating institutions into theories (such as organisational economics theories and resource based theories) and advancing an institution-based view of business strategy as a complementary perspective. We outline how future research in CEE and other emerging economies may advance this research agenda further.

Corporate Social Performance and Stock Returns: UK Evidence from Disaggregate Measures

Abstract: This study examines the relationship between corporate social performance and stock returns in the UK. Using a set of disaggregated social performance indicators for environment, employment and community activities, we are able to more closely evaluate the interactions between social and financial performance than would be the case for an aggregate measure. While scores on a composite social performance indicator are significantly negatively related to stock returns, we find that the poor financial reward offered by such firms is attributable to their good social performance on the employment and to a lesser extent the environmental aspects. Interestingly, we find that considerable abnormal returns are available from holding a portfolio of the socially least desirable stocks. These relationships between social and financial performance cannot be rationalised by multi-factor models for explaining the cross-sectional variation in returns or by industry effects.

Differences between the gut microflora of children with autistic spectrum disorders and that of healthy children

Abstract: Children with autistic spectrum disorders (ASDs) tend to suffer from severe gastrointestinal problems. Such symptoms may be due to a disruption of the indigenous gut flora promoting the overgrowth of potentially pathogenic micro-organisms. The faecal flora of patients with ASDs was studied and compared with those of two control groups (healthy siblings and unrelated healthy children). Faecal bacterial populations were assessed through the use of a culture-independent technique, fluorescence in situ hybridization, using oligonucleotide probes targeting predominant components of the gut flora. The faecal flora of ASD patients contained a higher incidence of the Clostridium histolyticum group (Clostridium clusters I and II) of bacteria than that of healthy children. However, the non-autistic sibling group had an intermediate level of the C. histolyticum group, which was not significantly different from either of the other subject groups. Members of the C. histolyticum group are recognized toxin-producers and may contribute towards gut dysfunction, with their metabolic products also exerting systemic effects. Strategies to reduce clostridial population levels harboured by ASD patients or to improve their gut microflora profile through dietary modulation may help to alleviate gut disorders common in such patients.

Species divergence and trait convergence in experimental plant community assembly

Abstract: Despite decades of research, it remains controversial whether ecological communities converge towards a common structure determined by environmental conditions irrespective of assembly history. Here, we show experimentally that the answer depends on the level of community organization considered. In a 9-year grassland experiment, we manipulated initial plant composition on abandoned arable land and subsequently allowed natural colonization. Initial compositional variation caused plant communities to remain divergent in species identities, even though these same communities converged strongly in species traits. This contrast between species divergence and trait convergence could not be explained by dispersal limitation or community neutrality alone. Our results show that the simultaneous operation of trait-based assembly rules and species-level priority effects drives community assembly, making it both deterministic and historically contingent, but at different levels of community organization.

Alternatives to the global warming potential for comparing climate impacts of emissions of greenhouse gases

Abstract: The Global Warming Potential (GWP) is used within the Kyoto Protocol to the United Nations Framework Convention on Climate Change as a metric for weighting the climatic impact of emissions of different greenhouse gases. The GWP has been subjected to many criticisms because of its formulation, but nevertheless it has retained some favour because of the simplicity of its design and application, and its transparency compared to proposed alternatives. Here, two new metrics are proposed, which are based on a simple analytical climate model. The first metric is called the Global Temperature Change Potential and represents the temperature change at a given time due to a pulse emission of a gas (GTPP); the second is similar but represents the effect of a sustainedemission change (hence GTPS). Both GTPP and GTPS are presented as relative to the temperature change due to a similar emission change of a reference gas, here taken to be carbon dioxide. Both metrics are compared against an upwelling-diffusion energy balance model that resolves land and ocean and the hemispheres. The GTPP does not perform well, compared to the energy balance model, except for long-lived gases. By contrast, the GTPS is shown to perform well relative to the energy balance model, for gases with a wide variety of lifetimes. It is also shown that for time horizons in excess of about 100 years, the GTPS and GWP produce very similar results, indicating an alternative interpretation for the GWP. The GTPS retains the advantage of the GWP in terms of transparency, and the relatively small number of input parameters required for calculation. However, it has an enhanced relevance, as it is further down the cause–effect chain of the impacts of greenhouse gases emissions and has an unambiguous interpretation. It appears to be robust to key uncertainties and simplifications in its derivation and may be an attractive alternative to the GWP.

A model intercomparison of changes in the Atlantic thermohaline circulation in response to increasing atmospheric CO2 concentration

Abstract: [ 1] As part of the Coupled Model Intercomparison Project, integrations with a common design have been undertaken with eleven different climate models to compare the response of the Atlantic thermohaline circulation ( THC) to time-dependent climate change caused by increasing atmospheric CO2 concentration. Over 140 years, during which the CO2 concentration quadruples, the circulation strength declines gradually in all models, by between 10 and 50%. No model shows a rapid or complete collapse, despite the fairly rapid increase and high final concentration of CO2. The models having the strongest overturning in the control climate tend to show the largest THC reductions. In all models, the THC weakening is caused more by changes in surface heat flux than by changes in surface water flux. No model shows a cooling anywhere, because the greenhouse warming is dominant.

Collective Learning and Relational Capital in Local Innovation Processes

Abstract: Capello R. and Faggian A. (2005) Collective learning and relational capital in local innovation processes, Regional Studies39, 75-87. Innovative capacity of firms has traditionally been explained through intra-firm characteristics. In the more recent literature, much emphasis has been put on determinants that are external to the firm. These external factors, called knowledge spillovers, refer to the positive externalities that firms receive in terms of knowledge from the environment in which they operate. Geographers and industrial economists underline the importance of knowledge spillovers. As the paper underlines, an important difference exists between the approach of knowledge spillover and that of socialized processes of local knowledge creation developed by regional economists; while in the former, the mere probability of contacts explains local knowledge transfer, in the latter, the channels through which knowledge spills over a local area are clearly identified in the relational capital of the area...

The prevalence of and risk factors for, loneliness in later life: a survey of older people in Great Britain

Abstract: This study examines the prevalence of loneliness amongst older people in Great Britain, and makes comparisons with the findings of studies undertaken during the last five decades. In addition, the risk factors for loneliness are examined using a conceptual model of vulnerability and protective factors derived from a model of depression. Loneliness was measured using a self-rating scale, and measures of socio-demographic status and health/social resources were included. Interviews were undertaken with 999 people aged 65 or more years living in their own homes, and the sample was broadly representative of the population in 2001. Among them the prevalence of 'severe loneliness' was seven per cent, indicating little change over five decades. Six independent vulnerabiliy factors for loneliness were identified: marital status, increases in loneliness over the previous decade, increases in time alone over the previous decade; elevated mental morbidity; poor current health; and poorer health in old age than expected. Advanced age and possession of post-basic education were independently protective of loneliness. From this evidence we propose that there are three loneliness pathways in later life: continuation of a long-established attribute, late-onset loneliness, and decreasing loneliness. Confirmation of the different trajectories suggests that policies and interventions should reflect the variability of loneliness in later life, for undifferentiated responses may be neither appropriate nor effective.

Land plants and DNA barcodes: short-term and long-term goals.

Abstract: Land plants have had the reputation of being problematic for DNA barcoding for two general reasons: (i) the standard DNA regions used in algae, animals and fungi have exceedingly low levels of variability and (ii) the typically used land plant plastid phylogenetic markers (e.g. rbcL, trnL-F, etc.) appear to have too little variation. However, no one has assessed how well current phylogenetic resources might work in the context of identification (versus phylogeny reconstruction). In this paper, we make such an assessment, particularly with two of the markers commonly sequenced in land plant phylogenetic studies, plastid rbcL and internal transcribed spacers of the large subunits of nuclear ribosomal DNA (ITS), and find that both of these DNA regions perform well even though the data currently available in GenBank/EBI were not produced to be used as barcodes and BLAST searches are not an ideal tool for this purpose. These results bode well for the use of even more variable regions of plastid DNA (such as, for example, psbA-trnH) as barcodes, once they have been widely sequenced. In the short term, efforts to bring land plant barcoding up to the standards being used now in other organisms should make swift progress. There are two categories of DNA barcode users, scientists in fields other than taxonomy and taxonomists. For the former, the use of mitochondrial and plastid DNA, the two most easily assessed genomes, is at least in the short term a useful tool that permits them to get on with their studies, which depend on knowing roughly which species or species groups they are dealing with, but these same DNA regions have important drawbacks for use in taxonomic studies (i.e. studies designed to elucidate species limits). For these purposes, DNA markers from uniparentally (usually maternally) inherited genomes can only provide half of the story required to improve taxonomic standards being used in DNA barcoding. In the long term, we will need to develop more sophisticated barcoding tools, which would be multiple, low-copy nuclear markers with sufficient genetic variability and PCR-reliability; these would permit the detection of hybrids and permit researchers to identify the ‘genetic gaps’ that are useful in assessing species limits.

Constructing design weather data for future climates

Abstract: We develop a method, here called ‘morphing’, to produce design weather data for building thermal simulations that accounts for future changes to climate. Morphing combines present-day observed weather data with results from climate models. The procedure yields weather time series that encapsulate the average weather conditions of future climate scenarios, whilst preserving realistic weather sequences. In this sense the method ‘downscales’ coarse resolution climate model predictions to the fine spatial and temporal resolutions required for building thermal simulations. The morphing procedure is illustrated by application to CIBSE design weather years and climate change scenarios for the UK. Heating degree days calculated from the weather series morphed to future climates show a marked reduction compared to present day, by an amount that agrees well with results calculated directly from the climate model. This agreement gives confidence that the morphing technique faithfully transforms the weather sequences...

Role of nesting resources in organising diverse bee communities in a Mediterranean landscape

Abstract: 1. The habitat components determining the structure of bee communities are well known when considering foraging resources; however, there is little data with respect to the role of nesting resources. 2. As a model system this study uses 21 diverse bee communities in a Mediterranean landscape comprising a variety of habitats regenerating after fire. The findings clearly demonstrate that a variety of nesting substrates and nest building materials have key roles in organising the composition of bee communities. 3. The availability of bare ground and potential nesting cavities were the two primary factors influencing the structure of the entire bee community, the composition of guilds, and also the relative abundance of the dominant species. Other nesting resources shown to be important include availability of steep and sloping ground, abundance of plant species providing pithy stems, and the occurrence of pre-existing burrows. 4. Nesting resource availability and guild structure varied markedly across habitats in different stages of post-fire regeneration; however, in all cases, nest sites and nesting resources were important determinants of bee community structure.

Adaptation and speciation: what can F(st) tell us?

Abstract: A useful way of summarizing genetic variability among different populations is through estimates of the inbreeding coefficient, Fst. Several recent studies have tried to use the distribution of estimates of Fst from individual genetic loci to detect the effects of natural selection. However, the promise of this approach has yet to be fully realized owing to the pervasive dogma that this distribution is highly dependent on demographic history. Here, I review recent theoretical results that indicate that the distribution of estimates of Fst is generally expected to be robust to the vagaries of demographic history. I suggest that analyses based on it provide a useful first step for identifying candidate genes that might be under selection, and explore the ways in which this information can be used in ecological and evolutionary studies.

The Social Construction of Entrepreneurship: Narrative and Dramatic Processes in the Coproduction of Organizations and Identities

Abstract: A social dimension to business development and inertia is currently acknowledged in several accounts of learning, business models, vision building, and innovation, and through more general concepts of networking, social capital, and embeddedness. Here a constructionist perspective is developed to improve our understanding of the interactions between entrepreneurs and stakeholders in all of these areas. This identifies narrative and dramatic processes that describe how notions of individual and collective identity and organization are coproduced over time. A framework is created to show how selective and emotional processes that produce storylines, emplotment, and narrative structure support sense making and action making.

Entrepreneurship and the theory of the firm

Abstract: A missing component of several leading theories of the firm, entrepreneurship is key to the growth and survival of firms in a volatile environment, because entrepreneurial judgement is necessary for success in making complex decisions under uncertainty The addition of entrepreneurship is not a minor refinement of the theory of the firm, but represents a radical change The paper summarises the principle changes It suggests that the introduction of entrepreneurship can facilitate the development of an integrated synthetic theory of the firm

FOLSOMIA CANDIDA (COLLEMBOLA): A “Standard” Soil Arthropod*

Abstract: Folsomia candida Willem 1902, a member of the order Collembola (colloquially called springtails), is a common and widespread arthropod that occurs in soils throughout the world. The species is parthenogenetic and is easy to maintain in the laboratory on a diet of granulated dry yeast. F. candida has been used as a "standard" test organism for more than 40 years for estimating the effects of pesticides and environmental pollutants on nontarget soil arthropods. However, it has also been employed as a model for the investigation of numerous other phenomena such as cold tolerance, quality as a prey item, and effects of microarthropod grazing on pathogenic fungi and mycorrhizae of plant roots. In this comprehensive review, aspects of the life history, ecology, and ecotoxicology of F. candida are covered. We focus on the recent literature, especially studies that have examined the effects of soil pollutants on reproduction in F. candida using the protocol published by the International Standards Organization in 1999.

Pollinator diversity and crop pollination services are at risk.

Abstract: In a recent opinion article in TREE, Ghazoul [1] questionsthe existence of a global pollinator crisis and, in doing so,raises some important points about the uncertainty ofhuman dependence upon pollination services. We agreewith Ghazoul [1] that much uncertainty remains regard-ing pollinator–pollination declines. However, we thinkthat his assessment draws biased conclusions for polli-nator declines from existing studies, misrepresents theextent of agricultural reliance on animal pollination, andunderestimates the extent of pollination reduction inintensive monocultures.In his article [1], Ghazoul suggests that a pollinatorcrisisisdrivenmainlybyreporteddeclinesofhoneybeesinNorth America, and bumblebees and butterflies inEurope. However, local and regional declines of solitarywild bees, bumblebees and honeybees owing to habitatloss, agricultural intensification and pesticide use havebeen reported in both Europe and America [2–5], and theimpact of habitat loss, measured by species–area relation-ships, is much stronger for native bees than for otherinsect groups [6]. For genetic reasons alone, bees are moreextinction prone than are other taxa, because single-locussex determination makes them particularly sensitive tothe effects of small population size through the productionof sterile diploid males [7].Pollinators,otherthanhoneybees and bumblebees, have many Red Data Bookentries (e.g. for 11 European countries, an average of27.4% of the national bee fauna is listed

On the Regulation of Populations of Mammals, Birds, Fish, and Insects

Abstract: A key unresolved question in population ecology concerns the relationship between a population's size and its growth rate. We estimated this relationship for 1780 time series of mammals, birds, fish, and insects. We found that rates of population growth are high at low population densities but, contrary to previous predictions, decline rapidly with increasing population size and then flatten out, for all four taxa. This produces a strongly concave relationship between a population's growth rate and its size. These findings have fundamental implications for our understanding of animals' lives, suggesting in particular that many animals in these taxa will be found living at densities above the carrying capacity of their environments.

All changes great and small: exploring approaches to change and its leadership

Abstract: Although the growing need for change in organizations it is widely acknowledged it is asserted that up to 70% of change initiatives fail. While there have been attempts to understand the reasons for failure these have been seen as inconclusive, and a need for further empirical work has been identified. Within the growing literature on change leadership there are assertions that the root cause of many change problems is leadership behaviour. This article begins by exploring the change literature and, in particular the broadening of this literature with the inclusion of complexity and evolutionary theories. From the literature the authors propose a typology of change approach is proposed. In examining change the authors also examine emerging thoughts from the change leadership literature. Combining these different streams of literature leads to three core research questions, which are: (1) What approach to change management is likely to be most effective in today's business environment? (2) What leadership behaviours tend to be associated with effective change management? And (3) Are leadership behaviours related to the underlying assumptions within different approaches to change? These questions are explored using a case study methodology. The study involved seven organizations and 40 informants who provided 70 change stories. The data was initially analysed as qualitative data and subsequently (following participant lines of inquiry) quantitatively. Both qualitative and quantitative data indicated that change approaches that were based on assumptions of linearity, were unsuccessful, whereas those built on assumptions of complexity were more successful. Approaches classified as emergent change were found to be the most successful. In examining leadership behaviours three broad categories emerged: (1) shaping behaviour; (2) framing change; and (3) creating capacity. Analyses of the data indicated that leader-centric behaviours (shaping behaviour) impaired change implementation. The implications of the findings are discussed together with suggestions for further research.

Visualization: A Metacognitive Skill in Science and Science Education

Abstract: The range of terminology used in the field of ‘visualization’ is reviewed and, in the light of evidence that it plays a central role in the conduct of science, it is argued that it should play a correspondingly important role in science education. As all visualization is of, and produces, models, an epistemology and ontology for models as a class of entities is presented. Models can be placed in the public arena by means of a series of ‘modes and sub-modes of representation’. Visualization is central to learning, especially in the sciences, for students have to learn to navigate within and between the modes of representation. It is therefore argued that students -science students’ especially - must become metacognitive in respect of visualization, that they must show what I term ‘metavisual capability’. Without a metavisual capability, students find great difficulty in being able to undertake these demanding tasks. The development of metavisual capability is discussed in both theory and practice. Finally, some approaches to identifying students’ metavisual status are outlined and evaluated. It is concluded that much more research and development is needed in respect of visualization in science education if its importance is to be recognised and its potential realised.

A new perspective on southern hemisphere storm tracks

Abstract: A detailed view of Southern Hemisphere storm tracks is obtained based on the application of filtered variance and modern feature-tracking techniques to a wide range of 45-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40) data. It has been checked that the conclusions drawn in this study are valid even if data from only the satellite era are used. The emphasis of the paper is on the winter season, but results for the four seasons are also discussed. Both upper- and lower-tropospheric fields are used. The tracking analysis focuses on systems that last longer than 2 days and are mobile (move more than 1000 km). Many of the results support previous ideas about the storm tracks, but some new insights are also obtained. In the summer there is a rather circular, strong, deep high-latitude storm track. In winter the high-latitude storm track is more asymmetric with a spiral from the Atlantic and Indian Oceans in toward Antarctica and a subtropical jet–related lower-latitu...

New Perspectives on the Structure of Graphitic Carbons

Abstract: Graphitic forms of carbon are important in a wide variety of applications, ranging from pollution control to composite materials, yet the structure of these carbons at the molecular level is poorly understood. The discovery of fullerenes and fullerene-related structures such as carbon nanotubes has given a new perspective on the structure of solid carbon. This review aims to show how the new knowledge gained as a result of research on fullerene-related carbons can be applied to well-known forms of carbon such as microporous carbon, glassy carbon, carbon fibers, and carbon black.

Global climate change and soil carbon stocks; predictions from two contrasting models for the turnover of organic carbon in soil

Abstract: Enhanced release of CO2 to the atmosphere from soil organic carbon as a result of increased temperatures may lead to a positive feedback between climate change and the carbon cycle, resulting in much higher CO2 levels and accelerated global warming. However, the magnitude of this effect is uncertain and critically dependent on how the decomposition of soil organic C (heterotrophic respiration) responds to changes in climate. Previous studies with the Hadley Centre’s coupled climate–carbon cycle general circulation model (GCM) (HadCM3LC) used a simple, single-pool soil carbon model to simulate the response. Here we present results from numerical simulations that use the more sophisticated ‘RothC’ multipool soil carbon model, driven with the same climate data. The results show strong similarities in the behaviour of the two models, although RothC tends to simulate slightly smaller changes in global soil carbon stocks for the same forcing. RothC simulates global soil carbon stocks decreasing by 54GtC by 2100 in a climate change simulation compared with an 80GtC decrease in HadCM3LC. The multipool carbon dynamics of RothC cause it to exhibit a slower magnitude of transient response to both increased organic carbon inputs and changes in climate. We conclude that the projection of a positive feedback between climate and carbon cycle is robust, but the magnitude of the feedback is dependent on the structure of the soil carbon model.

The Genetic Basis of Resistance to Anticoagulants in Rodents

Abstract: Anticoagulant compounds, i.e., derivatives of either 4-hydroxycoumarin (e.g., warfarin, bromadiolone) or indane-1,3-dione (e.g., diphacinone, chlorophacinone), have been in worldwide use as rodenticides for >50 years. These compounds inhibit blood coagulation by repression of the vitamin K reductase reaction (VKOR). Anticoagulant-resistant rodent populations have been reported from many countries and pose a considerable problem for pest control. Resistance is transmitted as an autosomal dominant trait although, until recently, the basic genetic mutation was unknown. Here, we report on the identification of eight different mutations in the VKORC1 gene in resistant laboratory strains of brown rats and house mice and in wild-caught brown rats from various locations in Europe with five of these mutations affecting only two amino acids (Tyr139Cys, Tyr139Ser, Tyr139Phe and Leu128Gln, Leu128Ser). By recombinant expression of VKORC1 constructs in HEK293 cells we demonstrate that mutations at Tyr139 confer resistance to warfarin at variable degrees while the other mutations, in addition, dramatically reduce VKOR activity. Our data strongly argue for at least seven independent mutation events in brown rats and two in mice. They suggest that mutations in VKORC1 are the genetic basis of anticoagulant resistance in wild populations of rodents, although the mutations alone do not explain all aspects of resistance that have been reported. We hypothesize that these mutations, apart from generating structural changes in the VKORC1 protein, may induce compensatory mechanisms to maintain blood clotting. Our findings provide the basis for a DNA-based field monitoring of anticoagulant resistance in rodents.

Recent Location of Foreign-owned Research and Development Activities by Large Multinational Corporations in the European Regions: The Role of Spillovers and Externalities

Abstract: Cantwell J. and Piscitello L. (2005) Recent location of foreign-owned research and development activities by large multinational corporations in the European regions: the role of spillovers and externalities, Regional Studies39, 1-16. This paper examines the role of spillovers and externalities in influencing the recent siting of foreign-owned research and development activities in European regions. In accordance with the literature on knowledge creation in multinational corporations, the location of foreign-owned research tends to agglomerate depending upon the potential for the following different sources of spillovers and externalities: (1) intra- industry spillovers or specialization externalities associated with the presence of a wide-ranging collection of firms active in the same sector; (2) inter-industry spillovers or diversity externalities associated with the co-presence of firms working in different fields; and (3) science-technology spillovers and externalities stemming from the presence of a ...