31,836 research outputs found

    National-scale modelling of N leaching in organic and conventional horticultural crop rotations - policy implications

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    A method is presented to model N leaching in crop rotations on a national scale. Representative crop rotations for different regions and soil types are used in the cross-disciplinary, plant, soil, environment & economics model EU-Rotate_N. By comparing contrasting farming systems (organic and conventional) in the UK, their strengths and weaknesses in delivering environmental and economic sustainability can be assessed. Modelling results show that the annual leaching in different horticultural rotations and UK regions, using median weather, is within the range of 13-88 kg N/ha/year for organic and 54-130 kg N /ha/year for conventional. The weighted annual average figures are 39 kg N/ha/year for organic and 81 kg N/ha/year for conventional, respectively. It is concluded that organic horticultural rotations, with a current share of 6.1% already contribute to lower overall N losses from agriculture. However, on a UK national scale, only a large share of organic land use (e.g. >50%) has a large effect on reducing N losses. Similar reductions are also predicted by substantial cuts in conventional N inputs, giving a policy choice if pollution from agriculture steps up further on the political agenda

    SimFusion: A Unified Similarity Measurement Algorithm for Multi-Type Interrelated Web Objects

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    In this paper, we use a Unified Relationship Matrix (URM) to represent a set of heterogeneous web objects (e.g., web pages, queries) and their interrelationships (e.g., hyperlink, user click-through relationships). We claim that iterative computations over the URM can help overcome the data sparseness problem (a common situation in the Web) and detect latent relationships among heterogeneous web objects, thus, can improve the quality of various information applications that require the combination of information from heterogeneous sources. To support our claim, we further propose a unified similarity-calculating algorithm, the SimFusion algorithm. By iteratively computing over the URM, the SimFusion algorithm can effectively integrate relationships from heterogeneous sources when measuring the similarity of two web objects. Experiments based on a real search engine query log and a large real web page collection demonstrate that the SimFusion algorithm can significantly improve similarity measurement of web objects over both traditional content based similarity-calculating algorithms and the cutting edge SimRank algorithm

    Splicing-dependent NMD does not require the EJC in Schizosaccharomyces pombe

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    Nonsense-mediated mRNA decay (NMD) is a translation-linked process that destroys mRNAs with premature translation termination codons (PTCs). In mammalian cells, NMD is also linked to pre-mRNA splicing, usually PTCs trigger strong NMD only when positioned upstream of at least one intron. The exon junction complex (EJC) is believed to mediate the link between splicing and NMD in these systems. Here, we report that in Schizosaccharomyces pombe splicing also enhances NMD, but against the EJC model prediction, an intron stimulated NMD regardless of whether it is positioned upstream or downstream of the PTC and EJC components are not required. Still the effect of splicing seems to be direct—we have found that the important NMD determinant is the proximity of an intron to the PTC, not just the occurrence of splicing. On the basis of these results, we propose a new model to explain how splicing could affect NMD

    Survivability of probiotics in symbiotic low fat buffalo milk yogurt

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    In present study, symbiotic low fat buffalo milk yogurt prototypes (plain and blueberry) were developed using a commercial starter containing probiotics. Samples were analyzed for physicochemical and microbiological properties, and the survivability of probiotics during 10 weeks of storage. Gross composition results were: total solids 11.60 ± 0.58 and 17.12 ± 0.36%, ash 0.82 ± 0.06 and 0.78 ± 0.02%, protein 4.49 ± 0.31 and 4.16 ± 0.11%, fat 0.68 ± 0.03 and 0.55 ± 0.05%, carbohydrates 5.68 ± 0.18 and 11.38 ± 0.18% for plain and blueberry flavored samples, respectively. Mineral contents (mg/g) were: Calcium 1.97 ± 0.20 and 1.72 ± 0.06, magnesium 1.63 ± 0.02 and 1.69 ± 0.01, zinc 0.07 ± 0.01 and 0.07 ± 0.00, sodium 0.87 ± 0.15 and 0.94 ± 0.12 for the plain and blueberry flavored yogurt respectively. The values of pH, titratable acidity and viscosity ranged from 4.34 to 4.01 and 4.42 to 3.70, 0.96 to 1.13% and 0.94 to 1.30%, 1.40 to 1.67 and 2.15 to 1.56 Pa.s for the plain and blueberry flavored yogurts respectively. The initial population of Bifidobacterium spp. and Lactobacillus casei were above 108 CFU/g for both the plain and blueberry flavored yogurts. Lactobacillus acidophilus was viable only for the first two weeks; however, Bifidobacterium spp and L. casei remained viable (>106 CFU/g) during the storage. The results indicate that the low fat buffalo milk yogurt is a good vehicle for developing symbiotic yogurt.Key words: Buffalo milk, symbiotic yogurt, refrigerated storage, probiotic survivability, physicochemical properties

    Rapid changes of precipitation pH in Qinghai Province, the northeastern Tibetan Plateau

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    Rainfall monitoring programs were conducted in two industrial cities of China's Qinghai Province, Xining and Germu, in some periods of the 1980s and 1990s. The results show that the natural precipitation in this area is originally alkaline. Compared with the late 1980s records, pH values declined significantly from approximately 8 in the 1980s to below 7 in mid-1990s. Such rapid and drastic changes were attributed to fast industrial development that released a large amount of pollutants. Subsequent tough control on pollutant emission partly restored pH values back to above 7 in the late 1990s. The pH and rainfall chemical analyses indicate that alkaline rain in this continental arid region is caused by airborne dusts which originate from local alkaline soils. With decrease of pH value, the total ionic concentration of rainwater is increased because acids were added to the rainwater. © 2002 Elsevier Science B.V. All rights reserved.postprin

    Environmental and economic modelling of organic, stockless, horticultural crop rotations

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    Selected results from the ongoing “EU-Rotate_N” research project are presented. This EU 5th-framework project is developing a model-based decision support system to optimise nitrogen use in horticultural crop rotations across Europe. This paper introduces the economic and the fertility-building crops sub-models, and shows data from model validation and first model runs on an organic farm in central England. Preliminary results show that the model has the potential to be a powerful support tool for farmers and advisors, making decisions on rotational plan-ning. The economic, agronomic and environmental consequences of different rotational designs can be projected and assessed in detail

    D-SPACE4Cloud: A Design Tool for Big Data Applications

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    The last years have seen a steep rise in data generation worldwide, with the development and widespread adoption of several software projects targeting the Big Data paradigm. Many companies currently engage in Big Data analytics as part of their core business activities, nonetheless there are no tools and techniques to support the design of the underlying hardware configuration backing such systems. In particular, the focus in this report is set on Cloud deployed clusters, which represent a cost-effective alternative to on premises installations. We propose a novel tool implementing a battery of optimization and prediction techniques integrated so as to efficiently assess several alternative resource configurations, in order to determine the minimum cost cluster deployment satisfying QoS constraints. Further, the experimental campaign conducted on real systems shows the validity and relevance of the proposed method
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