886 research outputs found

    Electronic structure investigation of the cubic inverse perovskite Sc3AlN

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    The electronic structure and chemical bonding of the recently discovered inverse perovskite Sc3AlN, in comparison to ScN and Sc metal have been investigated by bulk-sensitive soft x-ray emission spectroscopy. The measured Sc L, N K, Al L1, and Al L2,3 emission spectra are compared with calculated spectra using first principle density-functional theory including dipole transition matrix elements. The main Sc 3d - N 2p and Sc 3d - Al 3p chemical bond regions are identified at -4 eV and -1.4 eV below the Fermi level, respectively. A strongly modified spectral shape of 3s states in the Al L2,3 emission from Sc3AlN in comparison to pure Al metal is found, which reflects the Sc 3d - Al 3p hybridization observed in the Al L1 emission. The differences between the electronic structure of Sc3AlN, ScN, and Sc metal are discussed in relation to the change of the conductivity and elastic properties.Comment: 11 pages, 5 picture

    Global emissions of fluorinated greenhouse gases until 2050: technical mitigation potentials and cost

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    The anthropogenic fluorinated (F-gases) greenhouse gas emissions have increased significantly in recent years and are estimated to rise further in response to increased demand for cooling services and the phase out of ozonedepleting substances (ODS) under the Montreal Protocol. F-gases (HFCs, PFCs and SF6) are potent greenhouse gases, with a global warming effect up to 22,800 times greater than carbon dioxide (CO2). This study presents estimates of current and future global emissions of F-gases, their technical mitigation potential and associated costs for the period 2005 to 2050. The analysis uses the GAINS model framework to estimate emissions, mitigation potentials and costs for all major sources of anthropogenic F-gases for 162 countries/regions, which are aggregated to produce global estimates. For each region, 18 emission source sectors with mitigation potentials and costs were identified. Global F-gas emissions are estimated at 0.7 Gt CO2eq in 2005 with an expected increase to about 3.6 Gt CO2eq in 2050. There are extensive opportunities to reduce emissions by over 95 percent primarily through replacement with existing low GWP substances. The initial results indicate that at least half of the mitigation potential is attainable at a cost of less than 20C per t CO2eq, while almost 90 percent reduction is attainable at less than 100C per t CO2eq. Currently, several policy proposals have been presented to amend the Montreal Protocol to substantially curb global HFC use. We analyze the technical potentials and costs associated with the HFC mitigation required under the different proposed Montreal Protocol amendments

    Carbon in global waste and wastewater flows – its potential as energy source under alternative future waste management regimes

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    This study provides a quantification of the maximum energy that can be generated from global waste and wastewater sectors in the timeframe to 2050, as well as of the potential limitations introduced by different future waste and wastewater management regimes. Results show that considerable amounts of carbon are currently stored in waste materials without being recovered for recycling or made available for energy generation. Future levels of energy recovery when maintaining current states of waste and wastewater management systems are contrasted with those that can be attained under a circular system identified here as a system with successful implementation of food and plastic waste reduction policies, maximum recycling rates of all different types of waste streams, and once the recycling capacity is exhausted, incineration of remaining materials to produce energy. Moreover, biogas is assumed to be produced from anaerobic codigestion of food and garden wastes, animal manure, and anaerobically treated wastewater. Finally, we explore the limits for energy generation from waste and wastewater sources should the efficiency of energy recovery be pushed further through development of existing technology. We find that global implementation of such an ideal system could increase the relative contribution of waste and wastewater sources to global energy demand from 2% to 9% by 2040, corresponding to a maximum energy potential of 64 EJ per year. This would however require widespread adoption of policies and infrastructure that stimulate and allow for large-scale waste prevention and separation, as well as highly advanced treatment processes. Giving priority to such efforts would enable circularity of the waste-energy system

    Non-CO2 greenhouse gas emissions in the EU-28 from 2005 to 2050: GAINS model methodology

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    This report presents the GAINS model methodology for the 2016 Reference scenario for emissions of non-CO2 greenhouse gases (GHGs), mitigation potentials and costs in the EU-28 with projections to 2050. The non-CO2 emission scenarios form part of the work under the EUCLIMIT2 project1. The project aims at producing projections for all emissions of GHGs in the EU-28 consistent with the macroeconomic and population projections presented in EC/DG ECFIN (2015). Four modelling groups were involved in the work: PRIMES (National Technical University of Athens), CAPRI (Bonn University), GLOBIOM (IIASA-ESM program) and GAINS (IIASA-MAG program). This report focuses on describing the methodology of the GAINS model for the estimation of the non-CO2 GHGs, i.e., methane (CH4), nitrous oxide (N2O) and three groups of fluorinated gases (F-gases) viz. hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphur hexafluoride (SF6). The report is structured as follows. Section 2 presents the general GAINS methodology for estimating draft non-CO2 greenhouse gas emissions for EU-28. Sections 3, 4 and 5 describe in detail the methodology applied for estimation of emissions by source for CH4, N2O and Fgases, respectively. Finally, Section 6 provides a comparison between emissions reported by member states to the UNFCCC for years 2005 and 2010 and the emissions estimated by the GAINS model for the same years

    Cytotoxic T Lymphocyte–associated Antigen 4 (CTLA-4) Regulates the Unfolding of Autoimmune Diabetes

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    Evidence has been accumulating that shows that insulin-dependent diabetes is subject to immunoregulation. To determine whether cytotoxic T lymphocyte–associated antigen 4 (CTLA-4) is involved, we injected anti–CTLA-4 mAb into a TCR transgenic model of diabetes at different stages of disease. When injected into young mice, months before they would normally become diabetic, anti–CTLA-4 induced diabetes rapidly and essentially universally; this was not the result of a global activation of T lymphocytes, but did reflect a much more aggressive T cell infiltrate in the pancreatic islets. These effects were only observed if anti–CTLA-4 was injected during a narrow time window, before the initiation of insulitis. Thus, engagement of CTLA-4 at the time when potentially diabetogenic T cells are first activated is a pivotal event; if engagement is permitted, invasion of the islets occurs, but remains quite innocuous for months, if not, insulitis is much more aggressive, and diabetes quickly ensues

    Convolutional LSTM Networks for Subcellular Localization of Proteins

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    Machine learning is widely used to analyze biological sequence data. Non-sequential models such as SVMs or feed-forward neural networks are often used although they have no natural way of handling sequences of varying length. Recurrent neural networks such as the long short term memory (LSTM) model on the other hand are designed to handle sequences. In this study we demonstrate that LSTM networks predict the subcellular location of proteins given only the protein sequence with high accuracy (0.902) outperforming current state of the art algorithms. We further improve the performance by introducing convolutional filters and experiment with an attention mechanism which lets the LSTM focus on specific parts of the protein. Lastly we introduce new visualizations of both the convolutional filters and the attention mechanisms and show how they can be used to extract biological relevant knowledge from the LSTM networks

    Some Restrictions Abroad Affecting Corporations

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    A neutron detector concept based on solid layers of boron carbide enriched in 1 B has been in development for the last few years as an alternative for He-3 by collaboration between the ILL, ESS and Linkoping University. This Multi-Grid detector uses layers of aluminum substrates coated with (B4C)-B-10 on both sides that are traversed by the incoming neutrons. Detection is achieved using a gas counter readout principle. By segmenting the substrate and using multiple anode wires, the detector is made inherently position sensitive. This development is aimed primarily at neutron scattering instruments with large detector areas, such as time-of-flight chopper spectrometers. The most recent prototype has been built to be interchangeable with the He-3 detectors of IN6 at ILL. The 1 B detector has an active area of 32 x 48 cm(2). It was installed at the IN6 instrument and operated for several weeks, collecting data in parallel with the regularly scheduled experiments, thus providing the first side-by-side comparison with the conventional He-3 detectors. Results include an efficiency comparison, assessment of the in-detector scattering contribution, sensitivity to gamma-rays and the signal-to-noise ratio in time-of-flight spectra. The good expected performance has been confirmed with the exception of an unexpected background count rate. This has been identified as natural alpha activity in aluminum. New convertor substrates are under study to eliminate this source of background

    CREBBP and WDR 24 Identified as Candidate Genes for Quantitative Variation in Red-Brown Plumage Colouration in the Chicken

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    Plumage colouration in birds is important for a plethora of reasons, ranging from camouflage, sexual signalling, and species recognition. The genes underlying colour variation have been vital in understanding how genes can affect a phenotype. Multiple genes have been identified that affect plumage variation, but research has principally focused on major-effect genes (such as those causing albinism, barring, and the like), rather than the smaller effect modifier loci that more subtly influence colour. By utilising a domestic × wild advanced intercross with a combination of classical QTL mapping of red colouration as a quantitative trait and a targeted genetical genomics approach, we have identified five separate candidate genes (CREBBP, WDR24, ARL8A, PHLDA3, LAD1) that putatively influence quantitative variation in red-brown colouration in chickens. By treating colour as a quantitative rather than qualitative trait, we have identified both QTL and genes of small effect. Such small effect loci are potentially far more prevalent in wild populations, and can therefore potentially be highly relevant to colour evolution.Funding agencies:  Carl Tryggers Stiftelse; Swedish Research CouncilSwedish Research Council; Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (FORMAS)Swedish Research Council Formas; European Research CouncilEuropean Research Council (ER</p
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