225 research outputs found

    IDENTIFICATION OF INSTANTS OF TOUCHDOWN AND TAKE-OFF IN SPRINT RUNNING USING AN AUTOMATIC MOTION ANALYSIS SYSTEM

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    The identification of the instants of touchdown and take-off are important in determining step characteristics during the biomechanical analysis of sprinting. Six athletes performed 20 sprint trials each in which a single foot contact was made with a force plate, and kinematic data were gathered with five toe markers. Criterion event times taken from the force plate were compared to event times calculated using vertical displacement thresholds from standing trials and peak vertical acceleration values. The lowest RMS differences between the criterion value and the standing trial thresholds were between 0.003 and 0.005 s, whilst the lowest RMS differences for vertical acceleration ranged between 0.005 and 0.007 s. These results revealed that accurate touchdown and take-off events in sprinting could be determined using an automatic motion analysis system

    BIOMECHANICAL VARIABILITY IN THE SPRINT START

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    Research into the acceleration phase of sprint running has encompassed a spectrum of biomechanical variables (e.g. Mero et al., 1983), but little has been reported on intra-subject variability. This study reports preliminary data from ongoing research into variability in sprinting performance

    Communities, Commodities and Crazy Ideas: Changing Livestock Policies in Africa

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    In the late 1990s a review of aid-assisted livestock projects included an assessment of sustained impact on poorer producers (Ashley et al. 1998). The review looked back over 35 years and analysed documents from more than 800 livestock projects funded by major donors, including the Department for International Development (UK), theWorld Bank, the US Agency for International Development, the European Commission, DANIDA, the Netherlands Development Cooperation and the Swiss Development Cooperation. The majority of these projects were based on a technical transfer paradigm in which constraints facing poor livestock keepers were to be addressed by the development and uptake of technologies, including new methods to control animal diseases, improve livestock breeds or raise production through a variety of other means. However, the lack of sustained impact on the poor was dramatic. In many cases, technologies were developed which livestock keepers either did not want or could not access due to weak delivery systems.European Research Council (ERC

    Understanding Gender Equality Policy and Practice Gaps Through the Lens of Organisational Justice: Development of an Employee Alignment Model

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    Policies and actions to address gender inequalities are widespread across a range of institutional and organisational contexts. Concerns have been raised about the efficacy and impacts of such measures in the absence of sustained evaluation of these activities. It has been proposed that important contextual factors may propel or inhibit measures to promote gender equality, including a critical mass of women, role models, diverse leaders and inclusive organisational cultures. This paper explores relationships between organisational justice and equality interventions to better understand gaps between equality policies and practices using a comparative case study approach in a male-dominated sector. A combination of questionnaire and interview data analysis with employees in three case organisations in the construction sector are used to outline links between perceptions of gender equality initiatives and organisational justice, and the mechanisms used to reinforce in-group dominance. The findings culminate in the development of an Employee Alignment Model and a discussion of how this relates to the organisational climate for gender equality work. The findings suggest that the development of interactional organisational justice is an important precursor for successful gender equality interventions in organisations. These findings have implications for those looking to minimize unintentional harm of policies or interventions to improve gender equality

    ECOSSE: Estimating Carbon in Organic Soils - Sequestration and Emissions: Final Report

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    Background Climate change, caused by greenhouse gas ( GHG) emissions, is one of the most serious threats facing our planet, and is of concern at both UK and devolved administration levels. Accurate predictions for the effects of changes in climate and land use on GHG emissions are vital for informing land use policy. Models which are currently used to predict differences in soil carbon (C) and nitrogen (N) caused by these changes, have been derived from those based on mineral soils or deep peat. None of these models is entirely satisfactory for describing what happens to organic soils following land-use change. Reports of Scottish GHG emissions have revealed that approximately 15% of Scotland's total emissions come from land use changes on Scotland's high carbon soils; the figure is much lower for Wales. It is therefore important to reduce the major uncertainty in assessing the carbon store and flux from land use change on organic soils, especially those which are too shallow to be deep peats but still contain a large reserve of C. In order to predict the response of organic soils to external change we need to develop a model that reflects more accurately the conditions of these soils. The development of a model for organic soils will help to provide more accurate values of net change to soil C and N in response to changes in land use and climate and may be used to inform reporting to UKGHG inventories. Whilst a few models have been developed to describe deep peat formation and turnover, none have so far been developed suitable for examining the impacts of land-use and climate change on the types of organic soils often subject to land-use change in Scotland and Wales. Organic soils subject to land-use change are often (but not exclusively) characterised by a shallower organic horizon than deep peats (e.g. organo-mineral soils such as peaty podzols and peaty gleys). The main aim of the model developed in this project was to simulate the impacts of land-use and climate change in these types of soils. The model is, a) be driven by commonly available meteorological data and soil descriptions, b) able to simulate and predict C and N turnover in organic soils, c) able to predict the impacts of land-use change and climate change on C and N stores in organic soils in Scotland and Wales. In addition to developing the model, we have undertaken a number of other modelling exercises, literature searches, desk studies, data base exercises, and experimentation to answer a range of other questions associated with the responses of organic soils in Scotland and Wales to climate and land-use change. Aims of the ECOSSE project The aims of the study were: To develop a new model of C and N dynamics that reflects conditions in organic soils in Scotland and Wales and predicts their likely responses to external factors To identify the extent of soils that can be considered organic in Scotland and Wales and provide an estimate of the carbon contained within them To predict the contribution of CO 2, nitrous oxide and methane emissions from organic soils in Scotland and Wales, and provide advice on how changes in land use and climate will affect the C and N balance In order to fulfil these aims, the project was broken down into modules based on these objectives and the report uses that structure. The first aim is covered by module 2, the second aim by module 1, and the third aim by modules 3 to 8. Many of the modules are inter-linked. Objectives of the ECOSSE project The main objectives of the project were to: Describe the distribution of organic soils in Scotland and Wales and provide an estimate of the C contained in them Develop a model to simulate C and N cycling in organic soils and provide predictions as to how they will respond to land-use, management and climate change using elements of existing peat, mineral and forest soil models Provide predictive statements on the effects of land-use and climate change on organic soils and the relationships to GHG emissions, including CO 2, nitrous oxide and methane. Provide predictions on the effects of land use change and climate change on the release of Dissolved Organic Matter from organic soils Provide estimates of C loss from scenarios of accelerated erosion of organic soils Suggest best options for mitigating C and N loss from organic soils Provide guidelines on the likely effects of changing land-use from grazing or semi-natural vegetation to forestry on C and N in organic soils Use the land-use change data derived from the Countryside Surveys of Scotland and Wales to provide predictive estimates for changes to C and N balance in organic soils over time

    Sub‐nanometer thick gold nanosheets as highly efficient catalysts

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    2D metal nanomaterials offer exciting prospects in terms of their properties and functions. However, the ambient aqueous synthesis of atomically‐thin, 2D metallic nanomaterials represents a significant challenge. Herein, freestanding and atomically‐thin gold nanosheets with a thickness of only 0.47 nm (two atomic layers thick) are synthesized via a one‐step aqueous approach at 20 °C, using methyl orange as a confining agent. Owing to the high surface‐area‐to‐volume ratio, abundance of unsaturated atoms exposed on the surface and large interfacial areas arising from their ultrathin 2D nature, the as‐prepared Au nanosheets demonstrate excellent catalysis performance in the model reaction of 4‐nitrophenol reduction, and remarkable peroxidase‐mimicking activity, which enables a highly sensitive colorimetric sensing of H2O2 with a detection limit of 0.11 × 10−6 m. This work represents the first fabrication of freestanding 2D gold with a sub‐nanometer thickness, opens up an innovative pathway toward atomically‐thin metal nanomaterials that can serve as model systems for inspiring fundamental advances in materials science, and holds potential across a wide region of applications

    Sub‐nanometer thick gold nanosheets: sub‐nanometer thick gold nanosheets as highly efficient catalysts (Adv. Sci. 21/2019)

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    In article number 1900911, Stephen D. Evans and co‐workers develop an ambient aqueous synthesis for preparing atomically‐thin gold nanosheets (termed gold nanoseaweed, AuNSW, because of its morphology, color and aqueous growth). These AuNSWs represent the first free‐standing 2D gold with a sub‐nanometer thickness (0.47 nm, e.g., two atomic layers thick), and exhibit excellent catalysis performance in the model reaction of 4‐nitrophenol reduction, as well as remarkable peroxidase‐mimicking activity

    Sub‐nanometer thick gold nanosheets: sub‐nanometer thick gold nanosheets as highly efficient catalysts (Adv. Sci. 21/2019)

    Get PDF
    In article number 1900911, Stephen D. Evans and co‐workers develop an ambient aqueous synthesis for preparing atomically‐thin gold nanosheets (termed gold nanoseaweed, AuNSW, because of its morphology, color and aqueous growth). These AuNSWs represent the first free‐standing 2D gold with a sub‐nanometer thickness (0.47 nm, e.g., two atomic layers thick), and exhibit excellent catalysis performance in the model reaction of 4‐nitrophenol reduction, as well as remarkable peroxidase‐mimicking activity

    The microaerophilic microbiota of de-novo paediatric inflammatory bowel disease: the BISCUIT study

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    <p>Introduction: Children presenting for the first time with inflammatory bowel disease (IBD) offer a unique opportunity to study aetiological agents before the confounders of treatment. Microaerophilic bacteria can exploit the ecological niche of the intestinal epithelium; Helicobacter and Campylobacter are previously implicated in IBD pathogenesis. We set out to study these and other microaerophilic bacteria in de-novo paediatric IBD.</p> <p>Patients and Methods: 100 children undergoing colonoscopy were recruited including 44 treatment naïve de-novo IBD patients and 42 with normal colons. Colonic biopsies were subjected to microaerophilic culture with Gram-negative isolates then identified by sequencing. Biopsies were also PCR screened for the specific microaerophilic bacterial groups: Helicobacteraceae, Campylobacteraceae and Sutterella wadsworthensis.</p> <p>Results: 129 Gram-negative microaerophilic bacterial isolates were identified from 10 genera. The most frequently cultured was S. wadsworthensis (32 distinct isolates). Unusual Campylobacter were isolated from 8 subjects (including 3 C. concisus, 1 C. curvus, 1 C. lari, 1 C. rectus, 3 C. showae). No Helicobacter were cultured. When comparing IBD vs. normal colon control by PCR the prevalence figures were not significantly different (Helicobacter 11% vs. 12%, p = 1.00; Campylobacter 75% vs. 76%, p = 1.00; S. wadsworthensis 82% vs. 71%, p = 0.312).</p> <p>Conclusions: This study offers a comprehensive overview of the microaerophilic microbiota of the paediatric colon including at IBD onset. Campylobacter appear to be surprisingly common, are not more strongly associated with IBD and can be isolated from around 8% of paediatric colonic biopsies. S. wadsworthensis appears to be a common commensal. Helicobacter species are relatively rare in the paediatric colon.</p&gt

    Ebullition of methane from peatlands: Does peat act as a signal shredder?

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    Bubbling (ebullition) of greenhouse gases, particularly methane, from peatlands has been attributed to environmental forcings, such as changes in atmospheric pressure. However, observations from peat soils suggest that ebullition and environmental forcing may not always be correlated and that interactions between bubbles and the peat structure may be the cause of such decoupling. To investigate this possibility, we used a simple computer model (Model of Ebullition and Gas storAge) to simulate methane ebullition from a model peat. We found that lower porosity peat can store methane bubbles for lengthy periods of time, effectively buffering or moderating ebullition so that it no longer reflects bubble production signals. Our results suggest that peat structure may act as a “signal shredder” and needs to be taken into account when measuring and modeling ebullition
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