136,961 research outputs found

    Reduction in pain-related fear is not associated with improvement in spinal biomechanics but with decrease in movement-evoked pain in patients with chronic low back pain.

    No full text
    While a causal relationship between pain-related fear and spinal movement avoidance in patients with chronic low back pain (CLBP) has frequently been postulated, evidence supporting this relationship is limited. This study aimed to test if decreases in pain-related fear or catastrophizing were associated with improvements in spinal biomechanics, accounting for possible changes in movement-evoked pain. Sixty-two patients with CLBP were assessed before and after an interdisciplinary rehabilitation program (IRP). Pain-related fear was assessed with general and task-specific measures. Lower and upper lumbar angular amplitude and velocity as well as paraspinal muscle activity were recorded during five daily-life tasks to evaluate spinal biomechanics. Relationships were tested with multivariable linear regression analyses. The large decreases in pain-related fear and catastrophizing following the IRP were scarcely and inconsistently associated with changes in spinal biomechanics (< 3% of the models reported a statistically significant association). Results remained comparable for activities inducing more or less fear, for specific or general measures of pain-related fear, and for analyses performed on the entire population or limited to subgroups of patients with higher levels of task-specific fear. In contrast, reductions in task-specific pain-related fear were significantly associated with decreases in movement-evoked pain in all tasks (r = 0.26-0.62, p ≤ 0.02). This study does not support an association between pain-related fear and spinal movement avoidance. However, it provides evidence supporting a direct relationship between decreased pain-related fear and decreased movement-evoked pain, possibly explaining some mechanisms of the rehabilitation programs

    Bulk and surface modified polycrystalline CuWO4 films for photoelectrochemical water oxidation

    No full text
    Polycrystalline CuWO4 film is an emerging photoanode material for photoelectrochemical (PEC) water splitting with a small bandgap to absorb visible light and excellent stability in a neutral electrolyte. However, its PEC performance is quite low mainly due to its poor charge transfer characteristics. To enhance the performance of the CuWO4 photoanode, two modification strategies are employed; SnO2 as an electron transfer layer to improve the bulk charge separation efficiency of CuWO4 and cobalt phosphate as a co-catalyst to augment the surface charge separation efficiency at the interface of CuWO4||electrolyte. The two modifications enhance the PEC activity two times to 0.13 mA/cm2 @ 1.23 VRHE for water oxidation and 0.24 mA/cm2 @ 1.23 VRHE for hole scavenger oxidation, and exhibit an excellent stability in a neutral electrolyte. Although the performance is still very low compared to well-developed metal oxide photoanodes, this work shows possibility of further improvement with further developments of synthesis method as well as applying other elaborate modification strategies

    Comment réduire l'empreinte environnementale de l'habitat

    No full text
    Comment améliorer le parc de logements existant ? Les propriétaires peuvent-ils rendre la vie de leurs locataires plus durable ? Quels leviers pour réduire la surface de logement par habitant

    Transducer for reading information stored on an optical record carrier, single photon detector based storage system and method for reading data from an optical record carrier

    No full text
    Transducer ( 24, 240, 241 ) for reading information stored 1n an optical record carrier ( 1 ), comprising at least one solid-state single photon detector, for example a single photon avalanche diode ( 24 ) for acquisition of a 2D or 3D image of at least a portion of the optical record carrier

    Potent Virustatic Polymer-Lipid Nanomimics Block Viral Entry and Inhibit Malaria Parasites In Vivo

    No full text
    Infectious diseases continue to pose a substantial burden on global populations, requiring innovative broad-spectrum prophylactic and treatment alternatives. Here, we have designed modular synthetic polymer nanopartides that mimic functional components of host cell membranes, yielding multivalent nano-mimics that act by directly binding to varied pathogens. Nanomimic blood circulation time was prolonged by reformulating polymer-lipid hybrids. Femtomolar concentrations of the polymer nanomimics were sufficient to inhibit herpes simplex virus type 2 (HSV-2) entry into epithelial cells, while higher doses were needed against severe acute respiratory syndrome comnavirus 2 (SARS-CoV-2). Given their observed virustatic mode of action, the nanomimics were also tested with malaria parasite blood-stage merozoites, which lose their invasive capacity after a few minutes. Efficient inhibition of merozoite invasion of red blood cells was demonstrated both in vitro and in vivo using a preclinical rodent malaria model. We envision these nanomimics forming an adaptable platform for developing pathogen entry inhibitors and as immunomodulators, wherein nanomimic-inhibited pathogens can be secondarily targeted to sites of immune recognition

    Revisiting the Impact of Morphology and Oxidation State of Cu on CO2 Reduction Using Electrochemical Flow Cell

    No full text
    Electroreduction of carbon dioxide (CO2) in a flow electrolyzer represents a promising carbon-neutral technology with efficient production of valuable chemicals. In this work, the catalytic performance of polycrystalline copper (Cu), Cu2O-derived copper (O(I)D-Cu), and CuO-derived copper (O(II)D-Cu) toward CO2 reduction is unraveled in a custom-designed flow cell. A peak Faradaic efficiency of >70% and a production rate of ca. -250 mA cm(-2) toward C2+ products have been achieved on all the catalysts. In contrast to previous studies that reported a propensity for C2+ products on OD-Cu in conventional H-cells, the selectivity and activity of ethylene-dominated C2+ products are quite similar on the three types of catalysts at the same current density in our flow reactor. Our analysis also reveals current density to be a critical factor determining the C-C coupling in a flow cell, regardless of Cu catalyst's initial oxidation state and morphology

    Viral diversity is linked to bacterial community composition in alpine stream biofilms

    No full text
    Biofilms play pivotal roles in fluvial ecosystems, yet virtually nothing is known about viruses in these communities. Leveraging an optimized sample-to-sequence pipeline, we studied the spatiotemporal turnover of dsDNA viruses associated with stream biofilms and found an astounding diversity to be structured by seasons and along the longitudinal gradient in the stream. While some vOTUs were region- or season-specific, we also identified a large group of permanent biofilm phages, taxonomically dominated by Myoviridae. Comparison of the observed viral distribution with predictions based on neutral community assembly indicated that chance and dispersal may be important for structuring stream biofilm viral communities. Deviation from neutral model predictions suggests that certain phages distribute efficiently across distant locations within the stream network. This dispersal capacity appears to be linked to EPS depolymerases that enable phages to efficiently overcome the biofilm barrier. Other phages, particularly vOTUs classified as Siphoviridae, appear locally overrepresented and to rely on a lysogenic life cycle, potentially to exploit the spatial distribution of bacterial populations in stream biofilms. Overall, biofilm viral and bacterial community turnover were significantly coupled. Yet, viral communities were linked to the presence of the most abundant bacterial community members. With this work, we provide a foundational ecological perspective on factors that structure viral diversity in stream biofilms and identify potentially important viral traits related to the biofilm mode of life

    Understanding Deep Neural Function Approximation in Reinforcement Learning via ϵ-Greedy Exploration

    No full text
    This paper provides a theoretical study of deep neural function approximation in reinforcement learning (RL) with the ϵ-greedy exploration under the online setting. This problem setting is motivated by the successful deep Q-networks (DQN) framework that falls in this regime. In this work, we provide an initial attempt on theoretical understanding deep RL from the perspective of function class and neural networks architectures (e.g., width and depth) beyond the ``linear'' regime. To be specific, we focus on the value based algorithm with the ϵ-greedy exploration via deep (and two-layer) neural networks endowed by Besov (and Barron) function spaces, respectively, which aims at approximating an α-smooth Q-function in a d-dimensional feature space. We prove that, with T episodes, scaling the width m=O~(Td2α+d)m = \widetilde{\mathcal{O}}(T^{\frac{d}{2\alpha + d}}) and the depth L=O(logT)L=\mathcal{O}(\log T) of the neural network for deep RL is sufficient for learning with sublinear regret in Besov spaces. Moreover, for a two layer neural network endowed by the Barron space, scaling the width Ω(T)\Omega(\sqrt{T}) is sufficient. To achieve this, the key issue in our analysis is how to estimate the temporal difference error under deep neural function approximation as the ϵ-greedy exploration is not enough to ensure "optimism". Our analysis reformulates the temporal difference error in an L2(dμ)L^2(\mathrm{d}\mu)-integrable space over a certain averaged measure μ, and transforms it to a generalization problem under the non-iid setting. This might have its own interest in RL theory for better understanding ϵ\epsilon-greedy exploration in deep RL

    Experimental Investigation of Tunable Acousto-Optic Frequency Combs

    No full text
    We demonstrate novel approach for generation of optical combs in frequency shifting loop based on acousto-optic interaction. This approach provides comb multiplication with different line spacing and generation of dual-comb for spectroscopy applications. (c) 2021 The Author(s
    corecore