1,304 research outputs found

    Local protection against mountain hazards ? state of the art and future needs

    No full text
    International audienceDuring the last decades, settlement activities increased in European mountain regions. Due to the scarceness of areas suitable for development, residential estates were extended into areas endangered by natural hazards such as mass movements. These settlements generally show a considerable vulnerability to tangible assets. Integral risk management strategies to reduce the vulnerability to tangible assets are presented for the assessment of such endangered areas. Conventional mitigation and local structural measures are discussed with respect to the necessary delimitation of endangered areas, the preparedness of people and possible financial prevention. According to different natural hazard processes (flash floods with and without bedload transport, debris flows, land slides, rock falls and avalanches) and various structural elements of buildings, a catalogue of local structural measures is presented with respect to occurring process impacts and protection objectives. Thereby, different local structural measures are classified and recommended according to a possible implementation for newly-erected buildings and for upgrading existing buildings, respectively. Based on these recommendations, future needs for a sustainable and comprehensive reduction of risk in settlement areas endangered by mass movements are outlined. Above all, this includes a prescription of building codes and the re-introduction of an obligatory final inspection of buildings

    Impact of Different Active-Speech-Ratios on PESQ’s Predictions in Simulated VoIP Environment

    Get PDF
    In this work, we experimentally study how behaviour of the PESQ predictions varies with reference signal characteristic. In particular we investigate the impact of different Active-Speech-Ratios on speech quality prediction in simulated VoIP environment from objective and subjective testing point of view. This reference signal characteristic is defined very broadly by ITU-T Recommendation P.862.3. That is the reason to investigate an impact of this characteristic on speech quality prediction more in-depth. We assess the variability of PESQ’s predictions with respect to Active-Speech-Ratio and network conditions, as well as their accuracy, by comparing the predictions with subjective assessments

    Natural history of Arabidopsis thaliana and oomycete symbioses

    Get PDF
    Molecular ecology of plant–microbe interactions has immediate significance for filling a gap in knowledge between the laboratory discipline of molecular biology and the largely theoretical discipline of evolutionary ecology. Somewhere in between lies conservation biology, aimed at protection of habitats and the diversity of species housed within them. A seemingly insignificant wildflower called Arabidopsis thaliana has an important contribution to make in this endeavour. It has already transformed botanical research with deepening understanding of molecular processes within the species and across the Plant Kingdom; and has begun to revolutionize plant breeding by providing an invaluable catalogue of gene sequences that can be used to design the most precise molecular markers attainable for marker-assisted selection of valued traits. This review describes how A. thaliana and two of its natural biotrophic parasites could be seminal as a model for exploring the biogeography and molecular ecology of plant–microbe interactions, and specifically, for testing hypotheses proposed from the geographic mosaic theory of co-evolution

    Electrically injected spin-polarized vertical-cavity surface-emitting lasers

    Full text link
    We report the design, fabrication, and characterization of an electrically injected, spin-polarized, vertical-cavity surface-emitting laser. We have demonstrated spin injection from the ferromagnetic semiconductor (Ga,Mn)As into In0.2Ga0.8As/GaAsIn0.2Ga0.8As∕GaAs quantum wells, spin transport across a distance of ∌ 0.25 Όm∌0.25ÎŒm for temperatures ranging from 80 to 105 K80to105K, and spin detection through optical polarization measurements with coherent light emission. Controlled switching between right- and left-elliptically polarized modes is achieved with a maximum degree of circular polarization of 4.6% measured at 80 K80K.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87839/2/091108_1.pd

    SSGAN: Secure Steganography Based on Generative Adversarial Networks

    Full text link
    In this paper, a novel strategy of Secure Steganograpy based on Generative Adversarial Networks is proposed to generate suitable and secure covers for steganography. The proposed architecture has one generative network, and two discriminative networks. The generative network mainly evaluates the visual quality of the generated images for steganography, and the discriminative networks are utilized to assess their suitableness for information hiding. Different from the existing work which adopts Deep Convolutional Generative Adversarial Networks, we utilize another form of generative adversarial networks. By using this new form of generative adversarial networks, significant improvements are made on the convergence speed, the training stability and the image quality. Furthermore, a sophisticated steganalysis network is reconstructed for the discriminative network, and the network can better evaluate the performance of the generated images. Numerous experiments are conducted on the publicly available datasets to demonstrate the effectiveness and robustness of the proposed method

    Face-Fusion of Icosahedral Boron Hydride Increases Affinity to γ‐Cyclodextrin: closo,closo‐[B₂₁H₁₈]⁻ as an Anion with Very Low Free Energy of Dehydration

    Get PDF
    [Abstract] The supramolecular recognition of closo,closo‐[B₂₁H₁₈]⁻ by cyclodextrins (CDs) has been studied in aqueous solution by isothermal titration calorimetry and nuclear magnetic resonance spectroscopy. These solution studies follow up on previous mass‐spectrometric measurements and computations, which indicated the formation and stability of CD ⋅ B₂₁H₁₈⁻ complexes in the gas phase. The thermodynamic signature of solution‐phase binding is exceptional, the association constant for the γ‐CD complex with B₂₁H₁₈⁻ reaches 1.8×10⁶ M⁻Âč, which is on the same order of magnitude as the so far highest observed value for the complex between γ‐CD and a metallacarborane. The nature of the intermolecular interaction is also examined by quantum‐mechanical computational protocols. These suggest that the desolvation penalty, which is particularly low for the B₂₁H₁₈⁻ anion, is the decisive factor for its high binding strength. The results further suggest that the elliptical macropolyhedral boron hydride is another example of a CD binder, whose extraordinary binding affinity is driven by the chaotropic effect, which describes the intrinsic affinity of large polarizable and weakly solvated chaotropic anions to hydrophobic cavities and surfaces in aqueous solution.K.I.A. and W.M.N. are grateful to the DFG for grant NA-686/8 within the priority program SPP 1807 “Control of London Dispersion Interactions in Molecular Chemistry”. J.H., J.F., and D.H. thank the Czech Science Foundation (grant number 17-08045S) and M.I.F.P., M.C.L, and J.A.S.L. thank the regional government Xunta de Galicia for financial support (Project Grupo Potencial Crecemento -GPC- ED431B 2017/59). J.M.O.-E. acknowledges financial support from the Spanish MICINN through project CTQ2018-094644-B-C22German Research Foundation; NA‐686/8Czech Science Foundation; 17‐08045SXunta de Galicia; ED431B 2017/5

    Sequential analysis of biomarkers in cerebrospinal fluid and serum during invasive meningococcal disease

    Get PDF
    The aim of the present study was to determine the profile of different inflammatory molecules in serum and cerebrospinal fluid (CSF) during invasive meningococcal disease (IMD). Their relationship with IMD severity was also assessed. A cohort of 12 patients with IMD was investigated. Paired serum and CSF samples were obtained at the time of diagnostic and follow-up lumbar puncture and were examined using LuminexÂź analysis. IMD severity correlated with serum interleukin-6 (IL-6) and interleukin-1 receptor antagonist (IL-1ra) on admission. Furthermore, the CSF levels of IL-1ÎČ, IL-1ra, IL-6, IL-8, macrophage inflammatory protein-1ÎČ (MIP-1ÎČ), and monocyte chemoattractant protein-1 (MCP-1) were significantly higher than their respective serum levels. The strongest correlations were found between serum concentrations of IL-1ÎČ and IL-1ra, IL-6, IL-8, and MIP-1ÎČ, whereas the strongest correlations in CSF were found between endotoxin and IL-8, IL-17, MIP-1ÎČ, and MCP-1. As was expected, the concentrations of inflammatory molecules in both serum and CSF significantly decreased after antibiotic treatment. With regard to kinetics, a severe course of IMD correlated positively with rapid declines of CSF IL-6 and cortisol levels. Sequential multiple analyses revealed patterns of inflammatory responses that were associated with the severity of IMD, as well as with the compartmentalization and kinetics of the immune reaction

    The Critical Exponent is Computable for Automatic Sequences

    Full text link
    The critical exponent of an infinite word is defined to be the supremum of the exponent of each of its factors. For k-automatic sequences, we show that this critical exponent is always either a rational number or infinite, and its value is computable. Our results also apply to variants of the critical exponent, such as the initial critical exponent of Berthe, Holton, and Zamboni and the Diophantine exponent of Adamczewski and Bugeaud. Our work generalizes or recovers previous results of Krieger and others, and is applicable to other situations; e.g., the computation of the optimal recurrence constant for a linearly recurrent k-automatic sequence.Comment: In Proceedings WORDS 2011, arXiv:1108.341
    • 

    corecore