456 research outputs found

    Environmental performance of industrial companies, sites, installations and production processes

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    A set of 10 environmental impact indicators is proposed for the evaluation the environmental impact of industrial installations and processes or industrial companies and sites: global warming, destruction of the ozone layer (ozone depletion), acidification, photochemical ozone creation, human toxicity, ecotoxicity, eutrophication, resource consumption (abiotic depletion), water consumption and waste production. These are »weighed« indicators: the individual emissions or discharges of components contributing to a certain theme are multiplied with a weighing factor and aggregated. Eco-efficiency indicators are calculated by dividing the »weighed« indicators by a value related to production. These relative indicators make it possible to quantify the evolution of the environmental performance for a process, company or industrial site and to evaluate which component(s) contribute(s) most to a given theme, thus allowing to set priorities for lowering the environmental impact. Examples illustrate the proposed method. Attention is also given to the emission of persistent organic pollutants (POPs) during the incineration of waste, trying to answer the question: are waste incinerators sinks or sources of POPs? It is shown that for non-carcinogenic effects of POPs, according to the incineration scenario, the weighed input/output ranges from 0.3 to 20,500 when considering the POPs in flue gases and solid residues

    Finite size effects on transport coefficients for models of atomic wires coupled to phonons

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    We consider models of quasi-1-d, planar atomic wires consisting of several, laterally coupled rows of atoms, with mutually non-interacting electrons. This electronic wire system is coupled to phonons, corresponding, e.g., to some substrate. We aim at computing diffusion coefficients in dependence on the wire widths and the lateral coupling. To this end we firstly construct a numerically manageable linear collision term for the dynamics of the electronic occupation numbers by following a certain projection operator approach. By means of this collision term we set up a linear Boltzmann equation. A formula for extracting diffusion coefficients from such Boltzmann equations is given. We find in the regime of a few atomic rows and intermediate lateral coupling a significant and non-trivial dependence of the diffusion coefficient on both, the width and the lateral coupling. These results, in principle, suggest the possible applicability of such atomic wires as electronic devices, such as, e.g., switches.Comment: 9 pages, 5 figures, accepted for publication in Eur. Phys. J.

    The role of oligosaccharides in seed vigour revisited using the legume model Medicago truncatula

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    The role of oligosaccharides in seed vigour revisited using the legume model Medicago truncatula

    RÎle des oligosaccharides de la famille du raffinose (RFO) dans la vigueur des semences de Medicago truncatula

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    RĂŽle des oligosaccharides de la famille du raffinose (RFO) dans la vigueur des semences de Medicago truncatula

    ENOBIO - First Tests of a Dry Electrophysiology Electrode Using Carbon Nanotubes

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    We describe the development and first tests of ENOBIO, a dry electrode sensor concept for biopotential applications. In the proposed electrodes the tip of the electrode is covered with a forest of multi-walled Carbon Nanotubes (CNTs) that can be coated with Ag/AgCl to provide ionic–electronic transduction. The CNT brushlike structure is to penetrate the outer layers of the skin improving electrical contact as well as increase the contact surface area. In this paper we report the results of the first tests of this concept—immersion on saline solution and pig skin signal detection. These indicate performance on a par with state of the art researchoriented wet electrodes.</p

    Phosphodiesterase type 4 anchoring regulates cAMP signaling to Popeye domain-containing proteins.

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    Cyclic AMP is a ubiquitous second messenger used to transduce intracellular signals from a variety of Gs-coupled receptors. Compartmentalisation of protein intermediates within the cAMP signaling pathway underpins receptor-specific responses. The cAMP effector proteins protein-kinase A and EPAC are found in complexes that also contain phosphodiesterases whose presence ensures a coordinated cellular response to receptor activation events. Popeye domain containing (POPDC) proteins are the most recent class of cAMP effectors to be identified and have crucial roles in cardiac pacemaking and conduction. We report the first observation that POPDC proteins exist in complexes with members of the PDE4 family in cardiac myocytes. We show that POPDC1 preferentially binds the PDE4A sub-family via a specificity motif in the PDE4 UCR1 region and that PDE4s bind to the Popeye domain of POPDC1 in a region known to be susceptible to a mutation that causes human disease. Using a cell-permeable disruptor peptide that displaces the POPDC1-PDE4 complex we show that PDE4 activity localized to POPDC1 modulates cycle length of spontaneous Ca2+ transients firing in intact mouse sinoatrial nodes

    Characterization of a dual-affinity nitrate transporter MtNRT1.3 in the model legume Medicago truncatula

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    Primary root growth in the absence or presence of exogenous NO(3)(-) was studied by a quantitative genetic approach in a recombinant inbred line (RIL) population of Medicago truncatula. A quantitative trait locus (QTL) on chromosome 5 appeared to be particularly relevant because it was seen in both N-free medium (LOD score 5.7; R(2)=13.7) and medium supplied with NO(3)(-) (LOD score, 9.5; R(2)=21.1) which indicates that it would be independent of the general nutritional status. Due to its localization exactly at the peak of this QTL, the putative NRT1-NO(3)(-) transporter (Medtr5g093170.1), closely related to Arabidopsis AtNRT1.3, a putative low-affinity nitrate transporter, appeared to be a significant candidate involved in the control of primary root growth and NO(3)(-) sensing. Functional characterization in Xenopus oocytes using both electrophysiological and (15)NO(3)(-) uptake approaches showed that Medtr5g093170.1, named MtNRT1.3, encodes a dual-affinity NO(3)(-) transporter similar to the AtNRT1.1 \u27transceptor\u27 in Arabidopsis. MtNRT1.3 expression is developmentally regulated in roots, with increasing expression after completion of germination in N-free medium. In contrast to members of the NRT1 superfamily characterized so far, MtNRT1.3 is environmentally up-regulated by the absence of NO(3)(-) and down-regulated by the addition of the ion to the roots. Split-root experiments showed that the increased expression stimulated by the absence of NO(3)(-) was not the result of a systemic signalling of plant N status. The results suggest that MtNRT1.3 is involved in the response to N limitation, which increases the ability of the plant to acquire NO(3)(-) under N-limiting conditions
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