81 research outputs found

    The FERONIA Receptor Kinase Maintains Cell-Wall Integrity during Salt Stress through Ca2+ Signaling

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    Cells maintain integrity despite changes in their mechanical properties elicited during growth and environmental stress. How cells sense their physical state and compensate for cell-wall damage is poorly understood, particularly in plants. Here we report that FERONIA (FER), a plasma-membrane-localized receptor kinase from Arabidopsis, is necessary for the recovery of root growth after exposure to high salinity, a widespread soil stress. The extracellular domain of FER displays tandem regions of homology with malectin, an animal protein known to bind di-glucose in vitro and important for protein quality control in the endoplasmic reticulum. The presence of malectin-like domains in FER and related receptor kinases has led to widespread speculation that they interact with cell-wall polysaccharides and can potentially serve a wall-sensing function. Results reported here show that salinity causes softening of the cell wall and that FER is necessary to sense these defects. When this function is disrupted in the fer mutant, root cells explode dramatically during growth recovery. Similar defects are observed in the mur1 mutant, which disrupts pectin cross-linking. Furthermore, fer cell-wall integrity defects can be rescued by treatment with calcium and borate, which also facilitate pectin cross-linking. Sensing of these salinity-induced wall defects might therefore be a direct consequence of physical interaction between the extracellular domain of FER and pectin. FER-dependent signaling elicits cell-specific calcium transients that maintain cell-wall integrity during salt stress. These results reveal a novel extracellular toxicity of salinity, and identify FER as a sensor of damage to the pectin-associated wall

    Epidemiology of recurrent hand, foot and mouth disease, China, 2008–2015

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    Using China’s national surveillance data on hand, foot and mouth disease (HFMD) for 2008–2015, we described the epidemiologic and virologic features of recurrent HFMD. A total of 398,010 patients had HFMD recurrence; 1,767 patients had 1,814 cases of recurrent laboratory-confirmed HFMD: 99 reinfections of enterovirus A71 (EV-A71) with EV-A71, 45 of coxsackievirus A16 (CV-A16) with CV-A16, 364 of other enteroviruses with other enteroviruses, 383 of EV-A71 with CV-A16 and CV-A16 with EV-A71, and 923 of EV-A71 or CV-A16 with other enteroviruses and other enteroviruses with EV-A71 or CV-A16. The probability of HFMD recurrence was 1.9% at 12 months, 3.3% at 24 months, 3.9% at 36 months, and 4.0% at 38.8 months after the primary episode. HFMD severity was not associated with recurrent episodes or time interval between episodes. Elucidation of the mechanism underlying HFMD recurrence with the same enterovirus serotype and confirmation that HFMD recurrence is not associated with disease severity is needed. © 2018, Centers for Disease Control and Prevention (CDC). All rights reserved

    Gravity-Based Kinetostatic Modeling of Parallel Manipulators Using Screw Theory

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    Abstract The pose accuracy of parallel manipulators (PMs) is a key index to measure their performance. Establishing the gravity-based kinetostatic model of a parallel robot provides an important basis for its error composition and accuracy improvement. In this paper, a kinetostatic modeling approach that takes real gravity distribution into consideration is proposed to analyze the influence of gravity on the infinitesimal twist and actuator forces of PMs. First, the duality of the twist screw and constraint wrenches are used to derive the gravity-attached constraint wrenches independent of the external load and the limb stiffness matrix corresponding to the kinematics-based constraint wrenches. Second, the gravity model of the mechanism is established based on the screw theory and the principle of virtual work. Finally, the analytical formulas of the infinitesimal twist and the actuator force of PMs are obtained, and the influences of the external load, platform gravity, and rod gravity on the stiffness of the mechanism are decoupled. The non-overconstrained 3RPS and overconstrained 2PRU-UPR PMs are taken as examples to verify the proposed method. This research proposes a methodology to analyze the infinitesimal deformation of the mechanism under the influence of gravity

    Local Ternary Cross Structure Pattern: A Color LBP Feature Extraction with Applications in CBIR

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    With the advent of medical endoscopes, earth observation satellites and personal phones, content-based image retrieval (CBIR) has attracted considerable attention, triggered by its wide applications, e.g., medical image analytics, remote sensing, and person re-identification. However, constructing effective feature extraction is still recognized as a challenging problem. To tackle this problem, we first propose the five-level color quantizer (FLCQ) to acquire a color quantization map (CQM). Secondly, according to the anatomical structure of the human visual system, the color quantization map (CQM) is amalgamated with a local binary pattern (LBP) map to construct a local ternary cross structure pattern (LTCSP). Third, the LTCSP is further converted into the uniform local ternary cross structure pattern (LTCSPuni) and the rotation-invariant local ternary cross structure pattern (LTCSPri) in order to cut down the computational cost and improve the robustness, respectively. Finally, through quantitative and qualitative evaluations on face, objects, landmark, textural and natural scene datasets, the experimental results illustrate that the proposed descriptors are effective, robust and practical in terms of CBIR application. In addition, the computational complexity is further evaluated to produce an in-depth analysis

    Electrostrictive cross-phase modulation of periodic pulse trains in optical fibers

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    The pond-ditch circulation system (PDCS) is a promising solution for the restoration of rural wastewater. However, the underlying nitrogen removal mechanisms and roles of functional genes in nitrogen transformation processes have not yet been quantified at the molecular level. In this study, PDCSs have been found to have high removal efficiencies when the chemical oxygen demand (COD) and total nitrogen (TN) was high (> 70%; 62.7-93.9%, respectively). Meanwhile, the presence of simultaneous nitrification, anaerobic ammonium oxidation (anammox), and denitrification processes were the primary nitrogen removal mechanisms in the PDCSs. According to the stepwise regression analysis and path analysis, two key functional gene groups, nosZ/(nirS + nirK) and (nxrA/amoA), were driving these major processes for TN and ammonia nitrogen (NH4+-N), respectively. Moreover, the key functional gene group narG/nxrA was affecting processes related to nitrate-nitrogen (NO3--N) and nitrite-nitrogen (NO2--N) conversion. Furthermore, results from the N-15 isotope pairing technique suggested that for PDCSs, anammox was mainly responsible for nitrogen removal due to its high contribution to total N-2 production (50.3%) in the ditch; denitrification, on the other hand, was primarily attributed to nitrogen removal, rather than the anammox process, in two ponds (41.3-43.1%)

    Electrocatalytic oxidation of ethylene glycol and glycerol on nickel ion implanted-modified indium tin oxide electrode

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    AbstractThe electrochemical behaviour of direct ethylene glycol and glycerol oxidation on a novel nickel ion implanted-modified indium tin oxide electrode (NiNPs/ITO) was investigated. The investigation is used to verify the feasibility of using the NiNPs/ITO electrode in the ethylene glycol and glycerol fuel cells. The size and morphology of nickel nanoparticles (NiNPs) on the substrate surface was determined by scanning electron microscopy (SEM). The cyclic voltammetry (CV) technique was utilized to characterize the typical electrochemical behaviours of the NiNPs/ITO electrode. In alkaline medium (0.2 M NaOH), a good redox behaviour of Ni(III)/Ni(II) coupled at the surface of modified electrodes can be observed. Electrochemical performances were measured by current–time curve technology. We find that the NiNPs/ITO electrode exhibits a satisfactory electrocatalytic activity toward ethylene glycol and glycerol with good stability, making it a prime candidate for use in ethylene glycol and glycerol fuel cells

    Referral criteria to palliative care for patients with Parkinson?s disease: a systematic review

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    10.1080/03007995.2022.2146405Current Medical Research and Opinion392267-27

    A stable simultaneous anammox, denitrifying anaerobic methane oxidation and denitrification process in integrated vertical constructed wetlands for slightly polluted wastewater

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    Anaerobic ammonium oxidation (anammox), denitrifying anaerobic methane oxidation bacteria (DAMO) have received great attention for their excellent performance in nitrogen removal. However, not much study focused on the co-existence of anammox, DAMO, and denitrification in constructed wetlands, not to mention the advantage of their application in mitigating the necessary byproduct nitrous oxide (N2O), methane (CH4) from the biodegradation process. In this study, the result indicated the construction of integrated vertical constructed wetlands (IVCWs) contributed to the high-efficient stable simultaneous anammox, DAMO and denitrification (SADD) process for the nutrients removal, with denitrification being the least contributor to nitrogen reduction. Besides the succession of SADD process was largely the driver for the variation of N2O, CH4 emission. The structural equation method (SEM) further suggested that the three biological pathways of qnorB/bacteria, archaea/qnorB, and anammox/nirK accounted for the N2O production, as were top-controlled by mcrA/DAMO in IVCWs. Besides the anammox-associated nitrifier denitrification was the main source for N2O production. And that the trade-off effect between the CH4 and N2O production was exerted by the DAMO, while the influence was far from satisfactory under the methane constraints. (C) 2020 Elsevier Ltd. All rights reserved
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