4,787 research outputs found

    Managing the risk of iatrogenic transmission of Creutzfeldt-Jakob disease in the UK.

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    BACKGROUND: With the emergence of bovine spongiform encephalopathy (BSE) and variant Creutzfeldt-Jakob disease (CJD) in the UK, there is concern about iatrogenic transmission, and the approach to managing this risk is unique. AIM: To describe and review CJD incident management and the notification of individuals 'at increased risk' as a strategy for reducing iatrogenic transmission. METHODS: A description of iatrogenic CJD transmission, the CJD Incidents Panel's role, the number and nature of CJD incidents reported and the individuals considered 'at increased risk' by mid-2012. FINDINGS: Seventy-seven UK cases of CJD are likely to have resulted from iatrogenic transmission, among recipients of human-derived growth hormone (64 cases), dura mater grafts (eight cases), blood transfusions (four cases) and plasma products (one case). To limit transmission, the Panel reviewed 490 incidents and advised on look-backs, recalls of blood and plasma products, and quarantining and disposing of surgical instruments. Additionally, on Panel advice, around 6000 asymptomatic individuals have been informed they are at increased risk of CJD and have been asked to follow public health precautions. CONCLUSION: The strategy to reduce iatrogenic transmission of CJD has been developed in a context of scientific uncertainty. The rarity of transmission events could indicate that incident-related exposures present negligible transmission risks, or--given the prolonged incubation and subclinical phenotypes of CJD--infections could be yet to occur or have been undetected. Scientific developments, including better estimates of infection prevalence, a screening test, or improvements in decontaminating surgical instruments, may change future risk management

    Tidal energy machines: A comparative life cycle assessment

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    Marine energy in the UK is currently undergoing a period of exponential growth in terms of development and implementation. The current installed tidal energy capacity of around 4MW is expected to rise to provide up to 20% of the UK’s electricity demand by 2050 [5]. With this in mind, there is a huge range of energy devices, all seemingly promoted by their developers as the best method of extracting power from the ocean. Embodied energy is an important aspect of any power producing device or process, and is used to describe the amount of energy required to begin and maintain the process of energy generation. Until a device or process has generated this amount of energy it cannot be said to be a net contributor of energy. This work used Life Cycle Assessment to study four tidal energy devices, representing a cross section of the existing designs, and compares their embodied energy and carbon dioxide emissions. In order to ensure a fair comparison, a hypothetical installation site is used, with conditions typical of those found at potential array installation sites in the UK. The designs studied include a multi-blade turbine, two three blade horizontal axis turbine machines, and an Archimedes’ screw device. These machines were chosen to represent a cross section of device, foundation, installation and operation designs. They have all been developed to prototype stage, meaning that actual manufacturing data is available. Embodied energy is considered over the entire lifetime of each device, beginning with extraction of raw materials. Energy use from fabrication, transport, installation, lifetime maintenance, end-of-life decommissioning and recycling are all calculated, and compared to the energy generation from each device at the test site. Finally, the embodied energy; CO2 intensity; and energy payback periods are compared to those of conventional power generating systems as well as other renewable energy sources. A range of data sources are used. Embodied energy of steel has been provided by the World Steel Association. Of the four devices studied, all were found to achieve CO2 and energy payback within the first 12 years of their lifetime, and exhibited CO2 intensity of between 18 and 35 gCO2/kWh. This compares favourably to many current energy sources, and is likely to fall as technology improves, array size increases and industry experience progresses

    Overcoming the risk of inaction from emissions uncertainty in smallholder agriculture

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    The potential for improving productivity and increasing the resilience of smallholder agriculture, while also contributing to climate change mitigation, has recently received considerable political attention (Beddington et al 2012). Financial support for improving smallholder agriculture could come from performance-based funding including sale of carbon credits or certified commodities, payments for ecosystem services, and nationally appropriate mitigation action (NAMA) budgets, as well as more traditional sources of development and environment finance. Monitoring the greenhouse gas fluxes associated with changes to agricultural practice is needed for performance-based mitigation funding, and efforts are underway to develop tools to quantify mitigation achieved and assess trade-offs and synergies between mitigation and other livelihood and environmental priorities (Olander 2012)

    Aerodynamics of aero-engine installation

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    This paper describes current progress in the development of methods to assess aero-engine airframe installation effects. The aerodynamic characteristics of isolated intakes, a typical transonic transport aircraft as well as a combination of a through-flow nacelle and aircraft configuration have been evaluated. The validation task for an isolated engine nacelle is carried out with concern for the accuracy in the assessment of intake performance descriptors such as mass flow capture ratio and drag rise Mach number. The necessary mesh and modelling requirements to simulate the nacelle aerodynamics are determined. Furthermore, the validation of the numerical model for the aircraft is performed as an extension of work that has been carried out under previous drag prediction research programmes. The validation of the aircraft model has been extended to include the geometry with through flow nacelles. Finally, the assessment of the mutual impact of the through flow nacelle and aircraft aerodynamics was performed. The drag and lift coefficient breakdown has been presented in order to identify the component sources of the drag associated with the engine installation. The paper concludes with an assessment of installation drag for through-flow nacelles and the determination of aerodynamic interference between the nacelle and the aircraft

    Seasonal variation of carbon monoxide in northern Japan: Fourier transform IR measurements and source-labeled model calculations

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    Tropospheric carbon monoxide (CO) was measured throughout 2001 using groundbased Fourier transform IR (FTIR) spectrometers at Moshiri 44.4N and Rikubetsu 43.5N) observatories in northern Japan, which are separated by 150 km. Seasonal and day-to-day variations of CO are studied using these data, and contributions from various CO sources are evaluated using three-dimensional global chemistry transport model (GEOS-CHEM) calculations. Seasonal maximum and minimum FTIR-derived tropospheric CO amounts occurred in April and September, respectively. The ratio of partial column amounts between the 0–4 and 0–12 km altitude ranges is found to be slightly greater in early spring. The GEOS-CHEM model calculations generally reproduce these observed features. Source-labeled CO model calculations suggest that the observed seasonal variation is caused by seasonal contributions from various sources, in addition to a seasonal change in chemical CO loss by OH. Changes in meteorological fields largely control the relative importance of various source contributions. The contributions from fossil fuel (FF) combustion in Asia and photochemical CO production have the greatest yearly averaged contribution at 1 km among the CO sources (31% each). The Asian FF contribution increases from winter to summer, because weak southwesterly wind in summer brings more Asian pollutants to the observation sites. The seasonal variation from photochemical CO production is small (±17% at 1 km), likely because of concurrent increases (decreases) of photochemical production and loss rates in summer (winter), with the largest contribution between August and December. The contribution from intercontinental transport of European FF combustion CO is found to be comparable to that of Asian FF sources in winter. Northwesterly wind around the Siberian high in this season brings pollutants from Europe directly to Japan, in addition to southward transport of accumulated pollution from higher latitudes. The influences are generally greater at lower altitudes, resulting in a vertical gradient in the CO profile during winter. The model underestimates total CO by 12–14% between March and June. Satellite-derived fire-count data and the relationship between FTIR-derived HCN and CO amounts are generally consistent with biomass burning influences, which could have been underestimated by the model calculations

    A review of climate change and the implementation of marine biodiversity legislation in the United Kingdom

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    1. Marine legislation, the key means by which the conservation of marine biodiversity is achieved, has been developing since the 1960s. In recent decades, an increasing focus on ‘holistic’ policy development is evident, compared with earlier ‘piecemeal’ sectoral approaches. Important marine legislative tools being used in the United Kingdom, and internationally, include the designation of marine protected areas and the Marine Strategy Framework Directive (MSFD) with its aim of meeting ‘Good Environmental Status’ (GES) for European seas by 2020. 2. There is growing evidence of climate change impacts on marine biodiversity, which may compromise the effectiveness of any legislation intended to promote sustainable marine resource management. 3. A review of key marine biodiversity legislation relevant to the UK shows climate change was not considered in the drafting of much early legislation. Despite the huge increase in knowledge of climate change impacts in recent decades, legislation is still limited in how it takes these impacts into account. There is scope, however, to account for climate change in implementing much of the legislation through (a) existing references to environmental variability; (b) review cycles; and (c) secondary legislation and complementary policy development. 4. For legislation relating to marine protected areas (e.g. the EC Habitats and Birds Directives), climate change has generally not been considered in the site-designation process, or for ongoing management, with the exception of the Marine (Scotland) Act. Given that changing environmental conditions (e.g. rising temperatures and ocean acidification) directly affect the habitats and species that sites are designated for, how this legislation is used to protect marine biodiversity in a changing climate requires further consideration. 5. Accounting for climate change impacts on marine biodiversity in the development and implementation of legislation is vital to enable timely, adaptive management responses. Marine modelling can play an important role in informing management decisions

    Problematising parent–professional partnerships in education

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    The value of, and need for, parent–professional partnerships is an unchallenged mantra within policy relating to ‘special educational needs’. In spite of this, partnerships continue to be experienced as problematic by both parents and professionals. This paper brings together the different perspectives of two disability researchers: one a parent of a disabled child while the other was a teacher for 20 years of children with the label autism. The paper deconstructs the concept of partnership and then, drawing on the expertise of parents, suggests how enabling and empowering parent–professional relationships might be achieved

    Problematising parent–professional partnerships in education

    Get PDF
    The value of, and need for, parent–professional partnerships is an unchallenged mantra within policy relating to ‘special educational needs’. In spite of this, partnerships continue to be experienced as problematic by both parents and professionals. This paper brings together the different perspectives of two disability researchers: one a parent of a disabled child while the other was a teacher for 20 years of children with the label autism. The paper deconstructs the concept of partnership and then, drawing on the expertise of parents, suggests how enabling and empowering parent–professional relationships might be achieved
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