Showing papers by "University of East Anglia published in 2004"

Genetic consequences of climatic oscillations in the Quaternary.

Abstract: An appreciation of the scale and frequency of climatic oscillations in the past few million years is modifying our views on how evolution proceeds. Such major events caused extinction and repeated changes in the ranges of those taxa that survived. Their spatial effects depend on latitude and topography, with extensive extinction and recolonization in higher latitudes and altitudinal shifts and complex refugia nearer the tropics. The associated population dynamics varied with life history and geography, and the present genetic constitution of the populations and species carry attenuated signals of these past dynamics. Phylogeographic studies with DNA have burgeoned recently and studies are reviewed from the arctic, temperate and tropical regions, seeking commonalities of cause in the resulting genetic patterns. Arctic species show distinct shallow genetic clades with common geographical boundaries. Thus Beringia is distinct phylogeographically, but its role as a refugial source is complex. Arctic taxa do not show the common genetic pattern of southern richness and northern purity in north-temperate species. Temperate refugial regions in Europe and North America show relatively deep DNA divergence for many taxa, indicating their presence over several Ice Ages, and suggesting a mode of speciation by repeated allopatry. DNA evidence indicates temperate species in Europe had different patterns of postglacial colonization across the same area and different ones in previous oscillations, whereas the northwest region of North America was colonized from the north, east and south. Tropical montane regions contain deeply diverged lineages, often in a relatively small geographical area, suggesting their survival there from the Pliocene. Our poor understanding of refugial biodiversity would benefit from further combined fossil and genetic studies.

Effects of climate change on global food production under SRES emissions and socio-economic scenarios

Abstract: This paper analyses the global consequences to crop yields, production, and risk of hunger of linked socio-economic and climate scenarios. Potential impacts of climate change are estimated for climate change scenarios developed from the HadCM3 global climate model under the Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios (SRES) A1FI, A2, B1, and B2. Projected changes in yield are calculated using transfer functions derived from crop model simulations with observed climate data and projected climate change scenarios. The basic linked system (BLS) is used to evaluate consequent changes in global cereal production, cereal prices and the number of people at risk from hunger. The crop yield results elucidate the complex regional patterns of projected climate variables, CO 2 effects, and agricultural systems that contribute to aggregations of global crop production. The A1FI scenario, as expected with its large increase in global temperatures, exhibits the greatest decreases both regionally and globally in yields, especially by the 2080s. The contrast between the yield change in developed and developing countries is largest under the A2a–c scenarios. Under the B1 and B2 scenarios, developed and developing countries exhibit less contrast in crop yield changes, with the B2 future crop yield changes being slightly more favourable than those of the B1 scenario. When crop yield results are introduced to the BLS world food trade system model, the combined model and scenario experiments demonstrate that the world, for the most part, appears to be able to continue to feed itself under the SRES scenarios during the rest of this century. However, this outcome is achieved through production in the developed countries (which mostly benefit from climate change) compensating for declines projected, for the most part, for developing nations. While global production appears stable, regional differences in crop production are likely to grow stronger through time, leading to a significant polarisation of effects, with substantial increases in prices and risk of hunger amongst the poorer nations, especially under scenarios of greater inequality (A1FI and A2). The use of the SRES scenarios highlights several non-linearities in the world food supply system, both in the biophysical sense, where the levels of atmospheric CO 2 tested reach new levels, and the socio-economic sense, where changes in population dynamics and economic and political structures complicate the translation of biophysical climate change impacts into social indices, such as the number of people at risk of hunger.

The need for evidence-based conservation

Abstract: Much of current conservation practice is based upon anecdote and myth rather than upon the systematic appraisal of the evidence, including experience of others who have tackled the same problem. We suggest that this is a major problem for conservationists and requires a rethinking of the manner in which conservation operates. There is an urgent need for mechanisms that review available information and make recommendations to practitioners. We suggest a format for web-based databases that could provide the required information in accessible form.

Values, Environmental Concern, and Environmental Behavior A Study into Household Energy Use

Abstract: In this study, the role of values in the field of household energy use is investigated by using the concept of quality of life (QOL). Importance judgments on 22 QOL aspects could be summarized into seven clearly interpretable value dimensions. The seven value dimensions and general and specific environmental concern contributed significantly to the explanation of policy support for government regulation and for market strategies aimed at managing environmental problems as well as to the explanation of the acceptability of specific home and transport energy-saving measures. In line with earlier research, home and transport energy use were especially related to sociodemographic variables like income and household size. These results show that it is relevant to distinguish between different measures of environmental impact and different types of environmental intent. Moreover, the results suggest that using only attitudinal variables, such as values, may be too limited to explain all types of environmental behavior.

Climate over past millennia

Abstract: [1] We review evidence for climate change over the past several millennia from instrumental and high-resolution climate “proxy” data sources and climate modeling studies. We focus on changes over the past 1 to 2 millennia. We assess reconstructions and modeling studies analyzing a number of different climate fields, including atmospheric circulation diagnostics, precipitation, and drought. We devote particular attention to proxy-based reconstructions of temperature patterns in past centuries, which place recent large-scale warming in an appropriate longer-term context. Our assessment affirms the conclusion that late 20th century warmth is unprecedented at hemispheric and, likely, global scales. There is more tentative evidence that particular modes of climate variability, such as the El Nino/Southern Oscillation and the North Atlantic Oscillation, may have exhibited late 20th century behavior that is anomalous in a long-term context. Regional conclusions, particularly for the Southern Hemisphere and parts of the tropics where high-resolution proxy data are sparse, are more circumspect. The dramatic differences between regional and hemispheric/global past trends, and the distinction between changes in surface temperature and precipitation/drought fields, underscore the limited utility in the use of terms such as the “Little Ice Age” and “Medieval Warm Period” for describing past climate epochs during the last millennium. Comparison of empirical evidence with proxy-based reconstructions demonstrates that natural factors appear to explain relatively well the major surface temperature changes of the past millennium through the 19th century (including hemispheric means and some spatial patterns). Only anthropogenic forcing of climate, however, can explain the recent anomalous warming in the late 20th century.

Creating agile supply chains in the fashion industry

Abstract: Fashion markets are synonymous with rapid change and, as a result, commercial success or failure is largely determined by the organisation's flexibility and responsiveness. Responsiveness is characterised by short time‐to‐market, the ability to scale up (or down) quickly and the rapid incorporation of consumer preferences into the design process. In this paper it is argued that conventional organisational structures and forecast‐driven supply chains are not adequate to meet the challenges of volatile and turbulent demand which typify fashion markets. Instead, the requirement is for the creation of an agile organisation embedded within an agile supply chain.

Genre and Second Language Writing

Abstract: The last 20 years have seen increasing interest in the idea of genre and how it can be applied in second language writing classrooms. Because genres represent how writers typically use language to respond to recurring situations, they are a key resource for L2 writers unfamiliar with the conventions other members of the community recognize and find convincing. In the classroom, teachers are asked to identify the genres students will have to write and then make the typical structures and key features of these genres explicit to students so they can communicate effectively. In this entry I provide a brief overview of different views of genre and what they mean for teachers of L2 writing.

Transforming careers:from linear to multidirectional career paths

Abstract: Within the dynamic nature of labour markets, career systems have witnessed major changes in recent decades. This paper presents several career perspectives, to manifest a trend in career systems and their meaning and implications for individuals, organizations and society. This trend may be portrayed as a transition from what may be labelled “linear career system” into a “multidirectional career system”. Possible explanations to the phenomenon are presented, with suggested ideas for analysing and learning from the trend. The last section of the paper presents the academic career model as a prospective role model for future career systems, suggested as an intriguing idea and food for thought. Such a mental exercise of examining alternative career models, different from the traditional concept of careers, may be useful for both theory development and managerial practice.

The economic burden of illness for households in developing countries: a review of studies focusing on malaria, tuberculosis, and human immunodeficiency virus/acquired immunodeficiency syndrome.

Abstract: Ill-health contributes to impoverishment, a process brought into sharper focus by the impact of the human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) epidemic. This paper reviews studies that have measured the economic costs and consequences of illness for households, focusing on malaria, tuberculosis (TB), and HIV/AIDS. It finds that in resource-poor settings illness imposed high and regressive cost burdens on patients and their families. Direct and indirect costs of illness for malaria were less than 10% of the household income, but still significant when combined with the costs of other illnesses. The costs of TB and HIV/AIDS were catastrophic for households (more than 10% of the income). Health service weaknesses in many countries, including low coverage, user charges, and poor quality of care, contributed to high costs. Poor households in developing countries with a member with TB or HIV/AIDS struggled to cope, highlighting the urgent need for a substantial increase in health sector investment to expand access to preventive and curative health services. Government and non-governmental interventions should also be broadened to encompass measures that reduce the substantial indirect costs associated with diseases such as malaria, TB, and HIV/AIDS.

North Atlantic oscillation influence on precipitation, river flow and water resources in the Iberian Peninsula

Abstract: The Iberian Peninsula precipitation and river flow regimes are characterized by large values of inter-annual variability, with large disparities between wet and dry years, especially in southern Iberia. This situation is a major problem for water resources management in general, and for the production of hydroelectricity in particular. Hydroelectric production represents, in an average year of precipitation, 20% of the total Spanish electricity production (and 35% for Portuguese production). Its absolute value, however, can vary by a factor of three between wet and dry years. We have assessed the impact of the North Atlantic oscillation (NAO) on winter precipitation and river flow regimes for the three main international Iberian river basins, namely the Douro (north), the Tejo (centre) and the Guadiana (south). Results show that the large inter-annual variability in the flows of these three rivers is largely modulated by the NAO phenomenon. Throughout most of the 20th century, the January-to-March river flow is better correlated with the December to February (DJF) NAO index than is the simultaneous (DJF) river flow. Correlation values for the period 1973-98 are highly significant (-0.76 for Douro, -0.77 for Tejo and -0.79 for Guadiana), being consistently of higher magnitude than those obtained over previous decades. This impact of the NAO on winter river flow was quantified in terms of total Spanish potential hydroelectricity production. The important control exerted by the NAO and the recent positive trend in the NAO index contribute to a significant decrease in the available flow. This reduction represents an important hazard for the two Iberian economies because of its negative impact on water-dependent resources, such as intensive agriculture and hydroelectric power production.

Rural Livelihoods and Poverty Reduction Strategies in Four African Countries

Abstract: This paper compares and contrasts rural livelihoods in Uganda, Kenya, Tanzania and Malawi, with a view to informing rural poverty reduction policies within Poverty Reduction Strategy Plans (PRSPs). Low household incomes in rural areas of all countries are associated with low land and livestock holdings, high reliance on food crop agriculture, and low monetisation of the rural economy. These adverse factors are in some instances made more difficult by land sub-division at inheritance, declining civil security in rural areas, deteriorating access to proper agronomic advice and inputs, and predatory taxation by decentralised district councils. Better off households are distinguished by virtuous spirals of accumulation typically involving diverse livestock ownership, engagement in non-farm self-employment, and diversity of on-farm and non-farm income sources. Lessons for PRSPs centre on the creation of a facilitating, rather than blocking, public sector environment for the multiplication of non-farm enterprises; seeking creative solutions to the spread of technical advice to farmers; and examining critically the necessity for, and impact of, tax revenue collection by district councils on rural incomes and enterprise.

COPSE: a new model of biogeochemical cycling over Phanerozoic time

Abstract: We present a new model of biogeochemical cycling over Phanerozoic time. This work couples a feedback-based model of atmospheric O2 and ocean nutrients (Lenton and Watson, 2000a, 2000b) with a geochemical carbon cycle model (Berner, 1991, 1994), a simple sulfur cycle, and additional components. The resulting COPSE model (Carbon-Oxygen-Phosphorus-Sulfur-Evolution) represents the co-evolution of biotic and abiotic components of the Earth system, in that it couples interactive and evolving terrestrial and marine biota to geochemical and tectonic processes. The model is forced with geological and evolutionary forcings and time-dependent solar insolation. The baseline model succeeds in giving simultaneous predictions of atmospheric O2, CO2, global temperature, ocean composition, δ13C and δ34S that are in reasonable agreement with available data and suggested constraints. The behavior of the coupled model is qualitatively different to single cycle models. While atmospheric pCO2 (CO2 partial pressure) predictions are mostly determined by the model forcings and the response of silicate weathering rate to pCO2 and temperature, multiple negative feedback processes and coupling of the C, O, P and S cycles are necessary for regulating pO2 while allowing δ13C changes of sufficient amplitude to match the record. The results support a pO2 dependency of oxidative weathering of reduced carbon and sulfur, which raises early Paleozoic pO2 above the estimated requirement of Cambrian fauna and prevents unrealistically large δ34S variation. They do not support a strong anoxia dependency of the C:P burial ratio of marine organic matter (Van Cappellen and Ingall, 1994, 1996) because this dependency raises early Paleozoic δ13C and organic carbon burial rates too high. The dependency of terrestrial primary productivity on pO2 also contributes to oxygen regulation. An intermediate strength oxygen fire feedback on terrestrial biomass, which gives a pO2 upper limit of ∼1.6PAL (present atmospheric level) or 30 volume percent, provides the best combined pO2 and δ13C predictions. Sulfur cycle coupling contributes critically to lowering the Permo-Carboniferous pCO2 and temperature minimum. The results support an inverse dependency of pyrite sulfur burial on pO2 (for example, Berner and Canfield, 1989), which contributes to the shuttling of oxygen back and forth between carbonate carbon and gypsum sulfur. A pO2 dependency of photosynthetic carbon isotope fractionation (Berner and others, 2000; Beerling and others, 2002) is important for producing sufficient magnitude of δ13C variation. However, our results do not support an oxygen dependency of sulfur isotope fractionation in pyrite formation (Berner and others, 2000) because it generates unrealistically small variations in δ34S. In the Early Paleozoic, COPSE predicts pO2=0.2–0.6PAL and pCO2>10PAL, with high oceanic [PO43-] and low [SO4=]. Land plant evolution caused a ‘phase change’ in the Earth system by increasing weathering rates and shifting some organic burial to land. This change resulted in a major drop in pCO2 to 3 to 4PAL and a rise in pO2 to ∼1.5PAL in the Permo-Carboniferous, with temperatures below present, ocean variables nearer present concentrations, and PO4:NO3 regulated closer to Redfield ratio. A second O2 peak of similar or slightly greater magnitude appears in the mid-Cretaceous, before a descent towards PAL. Mesozoic CO2 is in the range 3 to 7PAL, descending toward PAL in the Cretaceous and Cenozoic.

Expression profiling of metalloproteinases and their inhibitors in cartilage.

Abstract: Objective To profile the expression of all known members of the matrix metalloproteinase (MMP), ADAMTS, and tissue inhibitor of metalloproteinases (TIMP) gene families in normal cartilage and cartilage from patients with osteoarthritis (OA). Methods Human cartilage was obtained from femoral heads at joint replacement for OA or following fracture to the femoral neck. Total RNA was purified, and gene expression was assayed using quantitative real-time polymerase chain reaction. Results Several members of the above gene families were regulated in OA. Genes that showed increased expression in OA were MMP13, MMP28, and ADAMTS16 (all at P < 0.001), MMP9, MMP16, ADAMTS2, and ADAMTS14 (all at P < 0.01), and MMP2, TIMP3, and ADAMTS12 (all at P < 0.05). Genes with decreased expression in OA were MMP1, MMP3, and ADAMTS1 (all at P < 0.001), MMP10, TIMP1, and ADAMTS9 (all at P < 0.01), and TIMP4, ADAMTS5, and ADAMTS15 (all at P < 0.05). Correlation analysis revealed that groups of genes across the gene families were coexpressed in cartilage. Conclusion This is the first comprehensive expression profile of all known MMP, ADAMTS, and TIMP genes in cartilage. Elucidation of patterns of expression provides a foundation with which to understand mechanisms of gene regulation in OA and potentially to refine the specificity of antiproteolytic therapies.

Defining and experiencing dangerous climate change: An editorial esssay

Abstract: Understanding what constitutes dangerous climate change is of critical importance for future concerted action (Schneider, 2001, 2002). To date separate scientific and policy discourses have proceeded with competing and somewhat arbitrary definitions of danger based on a variety of assumptions and assessments generally undertaken by 'experts'. We argue that it is not possible to make progress on defining dangerous climate change, or in developing sustainable responses to this global problem, without recognising the central role played by social or individual perceptions of danger. There are therefore at least two contrasting perspectives on dangerous climate change, what we term 'external' and 'internal' definitions of risk. External definitions are usually based on scientific risk analysis, performed by experts, of system characteristics of the physical or social world. Internal definitions of danger recognise that to be real, danger has to be either experienced or perceived - it is the individual or collective experience or perception of insecurity or lack of safety that constitutes the danger. A robust policy response must appreciate both external and internal definitions of danger.

Changing Governance Patterns in the Trade in Fresh Vegetables between Africa and the United Kingdom

Abstract: Over the past twenty years the marketing of African fresh vegetables in the United Kingdom has become dominated by large retailers that have adopted competitive strategies based on quality, year-round supply, and product differentiation. This has led to a dramatic change in marketing channels, from wholesale markets to tightly knit supply chains. Global value chain analysis is used to explain why the various stages of production and marketing have become much more closely integrated and to consider the likely outcome of a further round of restructuring occurring at the present time. Although the current trends may lead to a changing role for importers, the tendency towards the concentration of production and processing in Africa in the hands of a few large firms is likely to continue.

The recent Sahel drought is real

Abstract: Using station rainfall data extracted from two comprehensive data sets, we show that large decreasing rainfall trends were widespread in the Sahel (10–20 °N and 18 °W–20 °E) from the late 1950s to the late 1980s. Thereafter, Sahel rainfall has recovered somewhat through 2003, although the drought conditions have not ended in the region. These results confirm the findings of many previous studies. We also found that large multi-year oscillations appear to be more frequent and extreme after the late 1980s than previously. Analyses of Sahel regional rainfall time series derived from a fixed subset of stations and from all available stations show that the decreasing trend in Sahel rainfall is not an artifact of changing station networks. The rainfall model used by Chappell and Agnew (2004 International Journal of Climatology 24: 547–554) is incorrect and their modelled rainfall time series is totally unrepresentative of Sahel average rainfall. Their conclusion about the Sahel rainfall trends being an artifact of changing station locations is emphatically wrong and their speculative statements about the implications of their results for other studies and other regions of the world are completely unfounded. Copyright  2004 Royal Meteorological Society.

The application of two-dimensional polyacrylamide gel electrophoresis and downstream analyses to a mixed community of prokaryotic microorganisms.

Abstract: In the post-genomic era, the focus of numerous researchers has moved to studying the functional products of gene expression. In microbiology, these 'omic' approaches have largely been limited to pure cultures of microorganisms. Consequently, they do not provide information on gene expression in a complex mixture of microorganisms as found in the environment. Our method enabled the successful extraction and purification of the entire proteome from a laboratory-scale activated sludge system optimized for enhanced biological phosphorus removal, its separation by two-dimensional polyacrylamide gel electrophoresis and the mapping of this metaproteome. Highly expressed protein spots were excised and identified using quadrupole time-of-flight mass spectrometry with de novo peptide sequencing. The proteins isolated were putatively identified as an outer membrane protein (porin), an acetyl coenzyme A acetyltransferase and a protein component of an ABC-type branched-chain amino acid transport system. These proteins possibly stem from the dominant and uncultured Rhodocyclus-type polyphosphate-accumulating organism in the activated sludge. We propose the term 'metaproteomics' for the large-scale characterization of the entire protein complement of environmental microbiota at a given point in time.

Large-scale temperature inferences from tree rings: a review

Abstract: This paper is concerned with dendroclimatic research aimed at representing the history of very large-scale temperature changes. It describes recent analyses of the data from a widespread network of tree-ring chronologies, made up of ring width and densitometric measurement data spanning three to six centuries. The network was built over many years from trees selected to maximise their sensitivity to changing temperature. This strategy was adopted so that temperature reconstructions might be achieved at both regional and very large spatial scales. The focus here is on the use of one growth parameter: maximum latewood density (MXD). The detailed nature of the temperature sensitivity of MXD across the whole network has been explored and the dominant common influence of mean April–September temperature on MXD variability is demonstrated. Different approaches to reconstructing past temperature for this season include the production of detailed year-by-year gridded maps and wider regional integrations in the form of subcontinental and quasi-hemispheric-scale histories of temperature variability spanning some six centuries. These ‘hemispheric’ summer series can be compared with other reconstructions of temperature changes for the Northern Hemisphere over the last millennium. The tree-ring-based temperature reconstructions show the clear cooling effect of large explosive volcanic eruptions. They also exhibit greater century-timescale variability than is apparent in the other hemispheric series and suggest that the late 15th and the 16th centuries were cooler than indicated by some other data. However, in many tree-ring chronologies, we do not observe the expected rate of ring density increases that would be compatible with observed late 20th century warming. This changing climate sensitivity may be the result of other environmental factors that have, since the 1950s, increasingly acted to reduce tree-ring density below the level expected on the basis of summer temperature changes. This prevents us from claiming unprecedented hemispheric warming during recent decades on the basis of these tree-ring density data alone. Here we show very preliminary results of an investigation of the links between recent changes in MXD and ozone (the latter assumed to be associated with the incidence of UV radiation at the ground). D 2003 Elsevier B.V. All rights reserved.

Comparison of trends and low-frequency variability in CRU, ERA-40, and NCEP//NCAR analyses of surface air temperature

Abstract: [1] Anomalies in monthly mean surface air temperature from the 45-Year European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40) and the first National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis are compared with corresponding values from the Climatic Research Unit (CRU) CRUTEM2v data set derived directly from monthly station data. There is mostly very similar short-term variability, especially between ERA-40 and CRUTEM2v. Linear trends are significantly lower for the two reanalyses when computed over the full period studied, 1958–2001, but ERA-40 trends are within 10% of CRUTEM2v values for the Northern Hemisphere when computed from 1979 onward. Gaps in the availability of synoptic surface data contribute to relatively poor performance of ERA-40 prior to 1967. A few highly suspect values in each of the data sets have also been identified. ERA-40's use of screen-level observations contributes to the agreement between the ERA-40 and CRUTEM2v analyses, but the quality of the overall observing system and general character of the ERA-40 data assimilation system are also contributing factors. Temperatures from ERA-40 vary coherently throughout the boundary layer from the late 1970s onward, in general, and earlier for some regions. There is a cold bias in early years at 500 hPa over the data-sparse southern extratropics and at the surface over Antarctica. One indicator of this comes from comparing the ERA-40 analyses with results from a simulation of the atmosphere for the ERA-40 period produced using the same model and same distributions of sea surface temperature and sea ice as used in the ERA-40 data assimilation. The simulation itself reproduces quite well the warming trend over land seen in CRUTEM2v and captures some of the low-frequency variability.

The interminable issue of effectiveness: substantive purposes, outcomes and research challenges in the advancement of environmental impact assessment theory

Abstract: An analysis of studies of the outcomes of environmental impact assessment (EIA) indicates that its role in consent and design decisions is limited, due primarily to passive integration with the decision processes it is intended to inform. How much EIA helps sustainable development is largely unknown, but it is hypothesised that it is more than is typically assumed, through a plethora of causes, including emancipation of stakeholders and incremental change in the bureaucracy, companies and scientific institutions. To enhance the effectiveness of EIA, research should focus more on theory about the nature and operation of diverse causal processes, even though the concepts, methods and analytical challenges would be substantial.

Intrinsic Images by Entropy Minimization

Abstract: A method was recently devised for the recovery of an invariant image from a 3-band colour image. The invariant image, originally 1D greyscale but here derived as a 2D chromaticity, is independent of lighting, and also has shading removed: it forms an intrinsic image that may be used as a guide in recovering colour images that are independent of illumination conditions. Invariance to illuminant colour and intensity means that such images are free of shadows, as well, to a good degree. The method devised finds an intrinsic reflectivity image based on assumptions of Lambertian reflectance, approximately Planckian lighting, and fairly narrowband camera sensors. Nevertheless, the method works well when these assumptions do not hold. A crucial piece of information is the angle for an “invariant direction” in a log-chromaticity space. To date, we have gleaned this information via a preliminary calibration routine, using the camera involved to capture images of a colour target under different lights. In this paper, we show that we can in fact dispense with the calibration step, by recognizing a simple but important fact: the correct projection is that which minimizes entropy in the resulting invariant image. To show that this must be the case we first consider synthetic images, and then apply the method to real images. We show that not only does a correct shadow-free image emerge, but also that the angle found agrees with that recovered from a calibration. As a result, we can find shadow-free images for images with unknown camera, and the method is applied successfully to remove shadows from unsourced imagery.

The Driver-car

Abstract: The car has become ubiquitous in late modern society and has become the leading object in the ordinary social relations of mobility. Despite its centrality to the culture and material form of modern societies, the relationship between the car and human beings has remained largely unexplored by sociology. This article argues that cars are combined with their drivers into an assemblage, the ‘driver-car’, which has become a form of social being that brings about distinctive social actions in modern society – driving, transporting, parking, consuming, polluting, killing, communicating and so on. To understand the nature of this assemblage a number of theoretical perspectives that describe the interaction and collaboration between human beings and complex objects are explored; the process of driving, ‘affordance’, actor-network theory, and the embodied relationship between driver and car. This theoretical account of the driver-car is intended as a preliminary to the empirical investigation of the place of the driver-car in modern societies.

The Social Support and Family Health Study: a randomised controlled trial and economic evaluation of two alternative forms of postnatal support for mothers living in disadvantaged inner-city areas

Abstract: Objectives: To determine whether increased postnatal support could influence maternal and child health outcomes. Design: This was a randomised controlled trial comparing maternal and child health outcomes for women offered either of the support interventions with those for control women receiving standard services only. Outcome data were collected through questionnaires distributed 12 and 18 months postrandomisation. Process data were also collected. There was also an integral economic evaluation. Setting and participants: Women living in deprived enumeration districts in selected London boroughs were eligible for the trial if they gave birth between 1 January and 30 September 1999. Results: The 731 participants were found to be well matched in terms of socio-economic characteristics and health and support variables (14% of the participants were non- English speaking). Response rates at the two follow-up points were 90% and 82%. At both points there were no differences that could not be attributed to chance on the primary outcomes of maternal depression, child injury or maternal smoking. At the first follow-up, there was reduced use of general practitioners by support health visitor (SHV) children, but increased use of NHS health visitors and social workers by mothers. At the second follow-up, both community group support (CGS) and SHV mothers had less use of midwifery services ( fewer were pregnant), and SHV mothers were less worried about their child's health and development. Uptake of the CGS intervention was low: 19%, compared with 94% for the SHV intervention. Satisfaction with the intervention among women in the SHV group was high. Based on the assumptions and conditions of the costing methods, the economic evaluation found no net economic cost or benefit of choosing either of the two interventions. Conclusions: There was no evidence of impact on the primary outcomes of either intervention. The SHV intervention was popular with women, and was associated with improvement in some of the secondary outcomes. This suggests that greater emphasis on the social support role of health visitors could improve some measures of family well-being. Possible areas for future research include a systematic review of social support and its effect on health; developing and testing other postnatal models of support that match more closely the age of the baby and the changing patterns of mothers' needs; evaluating other strategies for mobilising 'non-professional' support; developing and testing more culturally specific support interventions; developing more culturally appropriate standardised measures of health outcomes; providing longer term follow-up of social support interventions; and exploring the role of social support on the delay in subsequent pregnancy.

RAR1 Positively Controls Steady State Levels of Barley MLA Resistance Proteins and Enables Sufficient MLA6 Accumulation for Effective Resistance

Abstract: The polymorphic barley (Hordeum vulgare) Mla locus harbors allelic race-specific resistance (R) genes to the powdery mildew fungus Blumeria graminis f sp hordei. The highly sequence-related MLA proteins contain an N-terminal coiled-coil structure, a central nucleotide binding (NB) site, a Leu-rich repeat (LRR) region, and a C-terminal non-LRR region. Using transgenic barley lines expressing epitope-tagged MLA1 and MLA6 derivatives driven by native regulatory sequences, we show a reversible and salt concentration-dependent distribution of the intracellular MLA proteins in soluble and membrane-associated pools. A posttranscriptional process directs fourfold greater accumulation of MLA1 over MLA6. Unexpectedly, in rar1 mutant plants that are compromised for MLA6 but not MLA1 resistance, the steady state level of both MLA isoforms is reduced. Furthermore, differential steady state levels of MLA1/MLA6 hybrid proteins correlate with their requirement for RAR1; the RAR1-independent hybrid protein accumulates to higher levels and the RAR1-dependent one to lower levels. Interestingly, yeast two-hybrid studies reveal that the LRR domains of RAR1-independent but not RAR1-dependent MLA isoforms interact with SGT1, a RAR1 interacting protein required for the function of many NB-LRR type R proteins. Our findings implicate the existence of a conserved mechanism to reach minimal NB-LRR R protein thresholds that are needed to trigger effective resistance responses.