5,513 research outputs found

    Effect of superlattice modulation of electronic parameters on the density of states of cuprate superconductors

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    Recent scanning tunneling microscopy on BSCCO 2212 has revealed a substantial spatial supermodulation of the energy gap in the superconducting state. We propose that this gap modulation is due to the superlattice modulations of the atoms in the structure, and hence the parameters in a microscopic model of the CuO2 plane. The gap modulation is estimated using renormalized mean field theory for a t- t′ -J model on a superlattice. The results compare well with experiment. © 2007 The American Physical Society.published_or_final_versio

    Flexible coping psychotherapy for functional dyspeptic patients: A randomized, controlled trial

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    OBJECTIVE: This study tested the efficacy of a new psychotherapy, flexible coping psychotherapy (FCP), specifically designed for enhancing coping flexibility of patients with functional dyspepsia (FD). The design of this psychotherapy is based on the general cognitive-behavioral model and previous findings on FD. METHODS: We adopted a randomized, controlled design to examine the differences between the target (FCP) and control (supportive psychotherapy [SPP]) conditions. Coping flexibility and outcome measures reported by 75 Chinese FD patients (18-65 years; 35% men) were assessed before and 12 months after treatment. RESULTS: Results revealed that participants who received the FCP reported an increase in coping flexibility as well as reductions in self-rated dyspeptic symptom severity (SDSS), gastroenterologist-rated dyspeptic symptom severity, and anxiety levels (p values <.01). Participants who received the SPP reported reductions in SDSS and anxiety levels (p values <.0001). Although both groups reported a decrease in SDSS, only the SDSS level of the FCP group was comparable to that of a healthy community sample (p = .28). CONCLUSIONS: These findings suggest that FCP is a potentially effective intervention for treating FD symptoms. Its effectiveness may be attributable to the specific components of FCP rather than common psychotherapeutic factors such as emotional support and empathy per se. Copyright © 2007 by American Psychosomatic Society.postprin

    Magnetoelectric photocurrent generated by direct interband transitions in InGaAs/InAlAs two-dimensional electron gas

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    We report the observation of magnetoelectric photocurrent generated via direct interband transitions in an InGaAs/InAlAs two-dimensional electron gas by a linearly polarized incident light. The electric current is proportional to the in-plane magnetic field, which unbalances the velocities of the photoexcited carriers with opposite spins and consequently generates the electric current from a hidden spin photocurrent. The spin photocurrent can be evaluated from the measured electric current, and the conversion coefficient of spin photocurrent to electric current is self-consistently estimated to be 10-3-10 -2 per Tesla. The observed light-polarization dependence of the electric current is well explained by a theoretical model which reveals the wave vector angle dependence of the photoexcited carrier density. © 2010 The American Physical Society.published_or_final_versio

    PSS14 VALIDATION OF THE EYELASH SATISFACTION FOLLOW-UP QUESTIONNAIRE FOR FOLLOW-UP SELF-ASSESSMENT OF EYELASH SATISFACTION

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    Recent hypotheses on the action of antidepressants imply a modulation of excitatory amino acid transmission. Here, the effects of long-term antidepressant application in rats with the drug tianeptine were examined at hippocampal CA3 commissural associational (c/a) glutamate receptor ion channels, employing the whole-cell patch-clamp technique. The drug's impact was tested by subjecting rats to daily restraint stress for three weeks in combination with tianeptine treatment (10 mg/kg/day). Whereas stress increased the deactivation time-constant and amplitude of the N -methyl-d-aspartate (NMDA) receptor-mediated excitatory postsynaptic currents (EPSCs), it did not affect the alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA)/kainate receptor-mediated EPSCs. Concomitant pharmacological treatment of stressed animals with tianeptine resulted in a normalized scaling of the amplitude ratio of NMDA receptor to AMPA/kainate receptor-mediated currents and prevented the stress-induced attenuation of NMDA-EPSCs deactivation. Both paired-pulse-facilitation and frequency-dependent plasticity remained unchanged. Both in control and stressed animals, however, tianeptine treatment strengthened the slope of the input-output relation of EPSCs. The latter was mimicked by exposing hippocampal slices in vitro with 10 mum tianeptine, which rapidly increased the amplitudes of NMDA- and AMPA/kainate EPSCs. The enhancement of EPSCs could be blocked by the intracellular presence of the kinase inhibitor staurosporine (1 mum), suggesting the involvement of a postsynaptic phosphorylation cascade rather then presynaptic release mechanisms at CA3 c/a synapses. These results indicate that tianeptine targets the phosphorylation-state of glutamate receptors at the CA3 c/a synapse. This novel signal transduction mechanism for tianeptine may provide a mechanistic resolution for its neuroprotective properties and, moreover, a pharmacological trajectory for its memory enhancing and/or antidepressant activity

    First record of the bacterial endosymbiont Wolbachia for phytophagous hoverflies from genus Merodon (Diptera : Syrphidae)

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    Wolbachia is a widespread bacterial endosymbiont among arthropod species. It influences the reproduction of the host species and also mitochondrial DNA diversity. Until now there were only a few studies that detected Wolbachia infections in hoverflies (Diptera: Syrphidae), and this is the first broader study with the aim of examining the incidence of Wolbachia in the hoverfly genus Merodon. The obtained results indicate an infection rate of 96% and the presence of both Wolbachia supergroup A and B, which are characteristic for most of the infected arthropod species. Additionally, the presence of multiple Wolbachia strains in the Merodon aureus group species was detected and the mitochondrial DNA COI-based relationships of the group are discussed in the light of infection. Finally, we discuss plant-mediated horizontal transmission of Wolbachia strains among the studied hoverfly species.Peer reviewe

    Semi-parametric estimation of the Wilshire creep life prediction model: an application to 2.25Cr-1Mo steel

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    The Wilshire equation is a recent addition to the literature on safe life prediction. While the effect of temperature on creep life is reasonably understood, the effect of stress isn’t. The Wilshire equation deals with this by partitioning over sub ranges of stress, but this approximation can lead to poor life time predictions. This paper introduces a semi-parametric procedure that allows the data itself to identify the stress relationship. When applied to 2.25Cr-1Mo steel it was found that the stress relationship is non-linear, and this semi-parametric version of the Wilshire model had better predictive performance compared to any partitioned Wilshire model. This approach contains a limit to valid extrapolation and the isothermal predictions for creep life have a more realistic pattern of behaviour

    Deep Q-Network-Driven Catheter Segmentation in 3D US by Hybrid Constrained Semi-Supervised Learning and Dual-UNet

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    Catheter segmentation in 3D ultrasound is important for computer-assisted cardiac intervention. However, a large amount of labeled images are required to train a successful deep convolutional neural network (CNN) to segment the catheter, which is expensive and time-consuming. In this paper, we propose a novel catheter segmentation approach, which requests fewer annotations than the supervised learning method, but nevertheless achieves better performance. Our scheme considers a deep Q learning as the pre-localization step, which avoids voxel-level annotation and which can efficiently localize the target catheter. With the detected catheter, patch-based Dual-UNet is applied to segment the catheter in 3D volumetric data. To train the Dual-UNet with limited labeled images and leverage information of unlabeled images, we propose a novel semi-supervised scheme, which exploits unlabeled images based on hybrid constraints from predictions. Experiments show the proposed scheme achieves a higher performance than state-of-the-art semi-supervised methods, while it demonstrates that our method is able to learn from large-scale unlabeled images.Comment: Accepted by MICCAI 202

    Molecular dynamics simulations of oscillatory Couette flows with slip boundary conditions

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    The effect of interfacial slip on steady-state and time-periodic flows of monatomic liquids is investigated using non-equilibrium molecular dynamics simulations. The fluid phase is confined between atomically smooth rigid walls, and the fluid flows are induced by moving one of the walls. In steady shear flows, the slip length increases almost linearly with shear rate. We found that the velocity profiles in oscillatory flows are well described by the Stokes flow solution with the slip length that depends on the local shear rate. Interestingly, the rate dependence of the slip length obtained in steady shear flows is recovered when the slip length in oscillatory flows is plotted as a function of the local shear rate magnitude. For both types of flows, the friction coefficient at the liquid-solid interface correlates well with the structure of the first fluid layer near the solid wall.Comment: 31 pages, 11 figure

    Wisdom of groups promotes cooperation in evolutionary social dilemmas

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    Whether or not to change strategy depends not only on the personal success of each individual, but also on the success of others. Using this as motivation, we study the evolution of cooperation in games that describe social dilemmas, where the propensity to adopt a different strategy depends both on individual fitness as well as on the strategies of neighbors. Regardless of whether the evolutionary process is governed by pairwise or group interactions, we show that plugging into the "wisdom of groups" strongly promotes cooperative behavior. The more the wider knowledge is taken into account the more the evolution of defectors is impaired. We explain this by revealing a dynamically decelerated invasion process, by means of which interfaces separating different domains remain smooth and defectors therefore become unable to efficiently invade cooperators. This in turn invigorates spatial reciprocity and establishes decentralized decision making as very beneficial for resolving social dilemmas.Comment: 8 two-column pages, 7 figures; accepted for publication in Scientific Report

    A critical assessment of the pairing symmetry in NaxCoO2.yH2O

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    We examine each of the symmetry-allowed pairing states of NaxCoO2.yH2O and compare their properties to what is experimentally and theoretically established about the compound. In this way, we can eliminate the vast majority of states that are technically allowed and narrow the field to two, both of f-wave type states. We discuss the expected features of these states and suggest experiments that can distinguish between them. We also discuss odd-frequency gap pairing and how it relates to available experimental evidence
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