908 research outputs found

    What is the potential for reducing national greenhouse gas emissions from crop and livestock production systems?

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    Agriculture has a devolved commitment to reduce national emissions of greenhouse gases (GHG). Using a systems model-based life-cycle analysis we explored the potential for reducing GHG in systems used to produce twelve crop and seven livestock commodities. With a functional unit of kg of product, differences in GHG between crops reflect differences in yield. Metabolisable energy (ME) or crude protein (CP) could be used, but deriving an economic value of GB£8.6/GJ ME and GB£0.62/kg CP, leads to a relatively consistent 2.6 kg CO2e/£ nutrient value. Potential GHG reductions ranged from 2% (sugar beet) to 15% (cereals) with agronomic changes, and 4–12% with increased crop yields. The best alternative livestock systems reduced GHG ranging between 7% (beef from the dairy herd) and 21% (extensive sheep meat). Half of the options reduced national production and hence increased imports. Overall, improvements in productivity and use of resources are the best options for reducing GH

    The synthesis of an analogue of the locust CRF-like diuretic peptide, and the biological activities of this and some C-terminal fragments.

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    The synthesis is described of an analogue of the locust CRF-like diuretic peptide in which methionine in positions 1,3, and 13 is replaced by isosteric methyl-homoserine residues. This analogue has been tested for biological activity on Malpighian tubules in vitro, and feeding behavior in vivo. It is highly active in stimulating fluid secretion and accumulation of cAMP in tubules, and on increasing the latency to feed and reducing meal duration. A 15 residue fragment from the C-terminus of the CRF-like peptide, Locmi-DP32–46, is fully active in the feeding assay, but has only weak ability to stimulate the accumulation of cAMP in tubules. Two smaller fragments, Locmi-DP32–37 and Locmi-DP41–46, were tested but neither had consistent biological activity in any of the assays used here. None of the peptides tested have any substantive activity in increasing cGMP in tubules

    Citizen schools offer a chance to rebuild our democracy fromthe bottom up

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    The Conservative Party’s ‘Big Society’ was supposed to bring about a new age of public involvement and active citizen participation in public affairs. But as that agenda crumbles, Jamie Audsley, the co-author of a new IPPR report, argues that to achieve those ends, we must place the citizenship agenda at the heart of every school

    Socio-economic Scenarios of Agricultural Land Use Change in Central and Eastern European Countries

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    The study presented in this paper is part of the ACCELERATES (Assessing Climate Change Effects on Land Use and Ecosystems from Regional Analysis to The European Scale) project whose main goal is the construction of integrated predictions of future land use in Europe. The scenarios constructed in the project include estimates not only due to changes in the climate baseline, but also estimates due to possible future changes in socio-economics. The overall aim of the ACCELERATES was to assess the vulnerability of European agroecosystems based on economic and environmental considerations in term of both their sensitivity and capacity to adapt changes. The historical background, the type of economy, the policy aim and governance and importance of agriculture in the overall national economy have created large differences between Western and Central and Eastern European countries (CEECs). This paper focuses on vulnerability of the farm sector and rural economy of CEECs.ACCELERATES, climate change, agricultural land use, scenario, Land Economics/Use, Q24,

    Unraveling Lessons from Mary Oliver

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    A young poet describes the ways Oliver’s commitment to the craft inspired her

    Traces as a Solution to Pessimism and Modeling Costs in WCET Analysis

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    WCET analysis models for superscalar out-of-order CPUs generally need to be pessimistic in order to account for a wide range of possible dynamic behavior. CPU hardware modifications could be used to constrain operations to known execution paths called traces, permitting exploitation of instruction level parallelism with guaranteed timing. Previous implementations of traces have used microcode to constrain operations, but other possibilities exist. A new implementation strategy (virtual traces) is introduced here. In this paper the benefits and costs of traces are discussed. Advantages of traces include a reduction in pessimism in WCET analysis, with the need to accurately model CPU internals removed. Disadvantages of traces include a reduction of peak throughput of the CPU, a need for deterministic memory and a potential increase in the complexity of WCET models

    Improving efficiency of persistent storage access in embedded Linux

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    Real-time embedded systems increasingly need to process and store large volumes of persistent data, requiring fast, timely and predictable storage. Traditional methods of accessing storage using general-purpose operating system-based file systems do not provide the performance and timing predictability needed. This paper firstly examines the speed and consistency of SSD operations in an embedded Linux system, identifying areas where inefficiencies in the storage stack cause issues for performance and predictability. Secondly, the CharIO storage device driver is proposed to bypass Linux file systems and the kernel block layer, in order to increase performance, and provide improved timing predictability
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