1,061 research outputs found

    Objectives of public participation: Which actors should be involved in the decision making for river restorations?

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    River restoration as a measure to improve both flood protection and ecological quality has become a common practice in river management. This new practice, however, has also become a source of conflicts arising from a neglect of the social aspects in river restoration projects. Therefore appropriate public involvement strategies have been recommended in recent years as a way of coping with these conflicts. However, an open question remains: Which stakeholders should be involved in the decision-making process? This, in turn, raises the question of the appropriate objectives of public participation. This study aims to answer these questions drawing on two case studies of Swiss river restoration projects and a related representative nationwide survey. Our findings suggest that public involvement should not be restricted to a small circle of influential stakeholder groups. As restoration projects have been found to have a substantial impact on the quality of life of the local population, avoiding conflicts is only one of several objectives of the involvement process. Including the wider public provides a special opportunity to promote social objectives, such as trust building and identification of people with their local environment

    MetaCrop 2.0: managing and exploring information about crop plant metabolism

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    MetaCrop is a manually curated repository of high-quality data about plant metabolism, providing different levels of detail from overview maps of primary metabolism to kinetic data of enzymes. It contains information about seven major crop plants with high agronomical importance and two model plants. MetaCrop is intended to support research aimed at the improvement of crops for both nutrition and industrial use. It can be accessed via web, web services and an add-on to the Vanted software. Here, we present several novel developments of the MetaCrop system and the extended database content. MetaCrop is now available in version 2.0 at http://metacrop.ipk-gatersleben.de

    Influence of tunneling on electron screening in low energy nuclear reactions in laboratories

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    Using a semiclassical mean field theory, we show that the screening potential exhibits a characteristic radial variation in the tunneling region in sharp contrast to the assumption of the constant shift in all previous works. Also, we show that the explicit treatment of the tunneling region gives a larger screening energy than that in the conventional approach, which studies the time evolution only in the classical region and estimates the screening energy from the screening potential at the external classical turning point. This modification becomes important if the electronic state is not a single adiabatic state at the external turning point either by pre-tunneling transitions of the electronic state or by the symmetry of the system even if there is no essential change with the electronic state in the tunneling region.Comment: 3 figure

    Meta-All: a system for managing metabolic pathway information

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    BACKGROUND: Many attempts are being made to understand biological subjects at a systems level. A major resource for these approaches are biological databases, storing manifold information about DNA, RNA and protein sequences including their functional and structural motifs, molecular markers, mRNA expression levels, metabolite concentrations, protein-protein interactions, phenotypic traits or taxonomic relationships. The use of these databases is often hampered by the fact that they are designed for special application areas and thus lack universality. Databases on metabolic pathways, which provide an increasingly important foundation for many analyses of biochemical processes at a systems level, are no exception from the rule. Data stored in central databases such as KEGG, BRENDA or SABIO-RK is often limited to read-only access. If experimentalists want to store their own data, possibly still under investigation, there are two possibilities. They can either develop their own information system for managing that own data, which is very time-consuming and costly, or they can try to store their data in existing systems, which is often restricted. Hence, an out-of-the-box information system for managing metabolic pathway data is needed. RESULTS: We have designed META-ALL, an information system that allows the management of metabolic pathways, including reaction kinetics, detailed locations, environmental factors and taxonomic information. Data can be stored together with quality tags and in different parallel versions. META-ALL uses Oracle DBMS and Oracle Application Express. We provide the META-ALL information system for download and use. In this paper, we describe the database structure and give information about the tools for submitting and accessing the data. As a first application of META-ALL, we show how the information contained in a detailed kinetic model can be stored and accessed. CONCLUSION: META-ALL is a system for managing information about metabolic pathways. It facilitates the handling of pathway-related data and is designed to help biochemists and molecular biologists in their daily research. It is available on the Web at and can be downloaded free of charge and installed locally

    Upside-Down Preference Reversal: How to Override Ceteris-Paribus Preferences?

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    Specific preference statements may reverse general prefer-ence statements, thus constituting a change of attitude in par-ticular situations. We define a semantics of preference rever-sal by relaxing the popular ceteris-paribus principle. We char-acterize preference reversal as default reasoning and we link it to prioritized Pareto-optimization, which permits a natu-ral computation of preferred solutions. The resulting method simplifies elicitation, representation, and utilization of com-plex preference relations and may thus enable a more realistic preference handling in personalized decision support systems and in preference-based intelligent systems

    Atomic effects in astrophysical nuclear reactions

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    Two models are presented for the description of the electron screening effects that appear in laboratory nuclear reactions at astrophysical energies. The two-electron screening energy of the first model agrees very well with the recent LUNA experimental result for the break-up reaction He3(He3,2p)He4% He3(He3,2p)He^{4}, which so far defies all available theoretical models. Moreover, multi-electron effects that enhance laboratory reactions of the CNO cycle and other advanced nuclear burning stages, are also studied by means of the Thomas-Fermi model, deriving analytical formulae that establish a lower and upper limit for the associated screening energy. The results of the second model, which show a very satisfactory compatibility with the adiabatic approximation ones, are expected to be particularly useful in future experiments for a more accurate determination of the CNO astrophysical factors.Comment: 14 RevTex pages + 2 ps (revised) figures. Phys.Rev.C (in production

    Fusion rate enhancement due to energy spread of colliding nuclei

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    Experimental results for sub-barrier nuclear fusion reactions show cross section enhancements with respect to bare nuclei which are generally larger than those expected according to electron screening calculations. We point out that energy spread of target or projectile nuclei is a mechanism which generally provides fusion enhancement. We present a general formula for calculating the enhancement factor and we provide quantitative estimate for effects due to thermal motion, vibrations inside atomic, molecular or crystal system, and due to finite beam energy width. All these effects are marginal at the energies which are presently measurable, however they have to be considered in future experiments at still lower energies. This study allows to exclude several effects as possible explanation of the observed anomalous fusion enhancements, which remain a mistery.Comment: 17 pages with 3 ps figure included. Revtex styl

    Spin-orbit coupling and intrinsic spin mixing in quantum dots

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    Spin-orbit coupling effects are studied in quantum dots in InSb, a narrow-gap material. Competition between different Rashba and Dresselhaus terms is shown to produce wholesale changes in the spectrum. The large (and negative) gg-factor and the Rashba field produce states where spin is no longer a good quantum number and intrinsic flips occur at moderate magnetic fields. For dots with two electrons, a singlet-triplet mixing occurs in the ground state, with observable signatures in intraband FIR absorption, and possible importance in quantum computation.Comment: REVTEX4 text with 3 figures (high resolution figs available by request). Submitted to PR

    The North Atlantic Oscillation controls air pollution transport to the Arctic

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    This paper studies the interannual variability of pollution pathways from northern hemisphere (NH) continents into the Arctic. Using a 15-year model simulation of the dispersion of passive tracers representative of anthropogenic emissions from NH continents, we show that the North Atlantic Oscillation (NAO) exerts a strong control on the pollution transport into the Arctic, particularly in winter and spring. For tracer lifetimes of 5 (30) days, surface concentrations in the Arctic winter are enhanced by about 70% (30%) during high phases of the NAO (in the following referred to as NAO<sup>+</sup>) compared to its low phases (NAO<sup>-</sup>). This is mainly due to great differences in the pathways of European pollution during NAO<sup>+</sup> and NAO<sup>-</sup> phases, respectively, but reinforced by North American pollution, which is also enhanced in the Arctic during NAO<sup>+ </sup>phases. In contrast, Asian pollution in the Arctic does not significantly depend on the NAO phase. The model results are confirmed using remotely-sensed NO<sub>2</sub> vertical atmospheric columns obtained from seven years of satellite measurements, which show enhanced northward NO<sub>2</sub> transport and reduced NO<sub>2</sub> outflow into the North Atlantic from Central Europe during NAO<sup>+</sup> phases. Surface measurements of carbon monoxide (CO) and black carbon at high-latitude stations further corroborate the overall picture of enhanced Arctic pollution levels during NAO<sup>+</sup> phase
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