747 research outputs found

    Superconducting and structural properties of plasma sprayed YBaCuO layers deposited on metallic substrates

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    The properties of plasma sprayed Y-Ba-Cu-O coatings deposited on metallic substrates are studied. Stainless steel, nickel steels and pure nickel are used as substrate. Y-Ba-Cu-O deposited on stainless steel and nickel steel reacts with the substrate. This interaction can be suppressed by using an yttria-stabilized zirconia (YsZ) diffusion barrier. However, after heat treatment the Y-Ba-Cu-O layers on YsZ show cracks perpendicular to the surface. As a result the critical current density is very low. The best results are obtained for Y-Ba-Cu-O deposited on pure nickel; here no cracks perpendicular to the surface are observed. The critical current increases with the anneal temperature but annealing for longer than 10 h does not seem to improve the superconducting properties any further

    L'Ecologisme en Allemagne et en France : deux modes différents de construction d'un nouvel acteur politique

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    SummaryThe N-terminally truncated variant of photoactive yellow protein (Δ25-PYP) undergoes a very similar photocycle as the corresponding wild-type protein (WT-PYP), although the lifetime of its light-illuminated (pB) state is much longer. This has allowed determination of the structure of both its dark- (pG) as well as its pB-state in solution by nuclear magnetic resonance (NMR) spectroscopy. The pG structure shows a well-defined fold, similar to WT-PYP and the X-ray structure of the pG state of Δ25-PYP. In the long-lived photocycle intermediate pB, the central β sheet is still intact, as well as a small part of one α helix. The remainder of pB is unfolded and highly flexible, as evidenced by results from proton-deuterium exchange and NMR relaxation studies. Thus, the partially unfolded nature of the presumed signaling state of PYP in solution, as suggested previously, has now been structurally demonstrated

    Magnetar-like X-Ray Bursts from a Rotation-powered Pulsar, PSR J1119-6127

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    Two energetic hard X-ray bursts have recently triggered the Fermi and Swift space observatories from the rotation powered pulsar, PSR J1119-6127. We have performed in depth spectral and temporal analyses of these two events. Our extensive searches in both observatory data for lower luminosity bursts uncovered 10 additional events from the source. We report here on the timing and energetics of the 12 bursts from PSR J1119-6127 during its burst active phase of 2016 July 26 and 28. We also found a spectral softer X-ray flux enhancement in a post burst episode, which shows evidence of cooling. We discuss here the implications of these results on the nature of this unusual high-field radio pulsar, which firmly place it within the typical magnetar population.Comment: Revised version, accepted for publication in ApJL. An expanded version of Table 1, as well as the light curves of all Fermi/GBM detected bursts can be found at http://magnetars.sabanciuniv.edu/psrj1119.ph

    Conditions for the freezing phenomena of geometric measure of quantum discord for arbitrary two-qubit X states under non-dissipative dephasing noises

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    We study the dynamics of geometric measure of quantum discord (GMQD) under the influences of two local phase damping noises. Consider the two qubits initially in arbitrary X-states, we find the necessary and sufficient conditions for which GMQD is unaffected for a finite period. It is further shown that such results also hold for the non-Markovian dephasing process.Comment: 4 pages, 2 figure

    Solving variational inequalities defined on a domain with infinitely many linear constraints

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    We study a variational inequality problem whose domain is defined by infinitely many linear inequalities. A discretization method and an analytic center based inexact cutting plane method are proposed. Under proper assumptions, the convergence results for both methods are given. We also provide numerical examples to illustrate the proposed method

    Genome-wide DNA methylation patterns associated with sleep and mental health in children: a population-based study

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    Background: DNA methylation (DNAm) has been implicated in the biology of sleep. Yet, how DNAm patterns across the genome relate to different sleep outcomes, and whether these associations overlap with mental health is currently unknown. Here, we investigated associations of DNAm with sleep and mental health in a pediatric population. Methods: This cross-sectional study included 465 10-year-old children (51.3% female) from the Generation R Study. Genome-wide DNAm levels were measured using the Illumina 450K array (peripheral blood). Sleep problems were assessed from self-report and mental health outcomes from maternal questionnaires. Wrist actigraphy was used in 188 11-year-old children to calculate sleep duration and midpoint sleep. Weighted gene co-expression network analysis was used to identify highly comethylated DNAm ‘modules’, which were tested for associations with sleep and mental health outcomes. Results: We identified 64 DNAm modules, one of which associated with sleep duration after covariate and multiple testing adjustment. This module included CpG sites spanning 9 genes on chromosome 17, including MAPT – a key regulator of Tau proteins in the brain involved in neuronal function – as well as genes previously implicated in sleep duration. Follow-up analyses suggested that DNAm variation in this region is under considerable genetic control and shows strong blood–brain concordance. DNAm modules associated with sleep did not overlap with those associated with mental health. Conclusions: We identified one DNAm region associated with sleep duration, including genes previously reported by recent GWAS studies. Further research is warranted to examine the functional role of this region and its longitudinal association with sleep

    Direct Classification of Type 2 Diabetes From Retinal Fundus Images in a Population-based Sample From The Maastricht Study

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    Type 2 Diabetes (T2D) is a chronic metabolic disorder that can lead to blindness and cardiovascular disease. Information about early stage T2D might be present in retinal fundus images, but to what extent these images can be used for a screening setting is still unknown. In this study, deep neural networks were employed to differentiate between fundus images from individuals with and without T2D. We investigated three methods to achieve high classification performance, measured by the area under the receiver operating curve (ROC-AUC). A multi-target learning approach to simultaneously output retinal biomarkers as well as T2D works best (AUC = 0.746 [±\pm0.001]). Furthermore, the classification performance can be improved when images with high prediction uncertainty are referred to a specialist. We also show that the combination of images of the left and right eye per individual can further improve the classification performance (AUC = 0.758 [±\pm0.003]), using a simple averaging approach. The results are promising, suggesting the feasibility of screening for T2D from retinal fundus images.Comment: to be published in the proceeding of SPIE - Medical Imaging 2020, 6 pages, 1 figur
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