17 research outputs found

    Impaired Inflammatory Responses in Murine Lrrk2-Knockdown Brain Microglia

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    LRRK2, a Parkinson's disease associated gene, is highly expressed in microglia in addition to neurons; however, its function in microglia has not been evaluated. Using Lrrk2 knockdown (Lrrk2-KD) murine microglia prepared by lentiviral-mediated transfer of Lrrk2-specific small inhibitory hairpin RNA (shRNA), we found that Lrrk2 deficiency attenuated lipopolysaccharide (LPS)-induced mRNA and/or protein expression of inducible nitric oxide synthase, TNF-α, IL-1β and IL-6. LPS-induced phosphorylation of p38 mitogen-activated protein kinase and stimulation of NF-κB-responsive luciferase reporter activity was also decreased in Lrrk2-KD cells. Interestingly, the decrease in NF-κB transcriptional activity measured by luciferase assays appeared to reflect increased binding of the inhibitory NF-κB homodimer, p50/p50, to DNA. In LPS-responsive HEK293T cells, overexpression of the human LRRK2 pathologic, kinase-active mutant G2019S increased basal and LPS-induced levels of phosphorylated p38 and JNK, whereas wild-type and other pathologic (R1441C and G2385R) or artificial kinase-dead (D1994A) LRRK2 mutants either enhanced or did not change basal and LPS-induced p38 and JNK phosphorylation levels. However, wild-type LRRK2 and all LRRK2 mutant variants equally enhanced NF-κB transcriptional activity. Taken together, these results suggest that LRRK2 is a positive regulator of inflammation in murine microglia, and LRRK2 mutations may alter the microenvironment of the brain to favor neuroinflammation

    A 31.2pJ/disparity?? pixel stereo matching processor with stereo SRAM for mobile UI application

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    An energy-efficient and high-speed stereo matching processor is proposed for smart mobile devices with proposed stereo SRAM (S-SRAM) and independent regional integral cost (IRIC). Cost generation unit (CGU) with the proposed S-SRAM reduces 63.2% of CGU power consumption. The proposed IRIC enables cost aggregation unit (CAU) to obtain 6.4?? of speed and 12.3% of the power reduction of CAU with pipelined integral cost generator (PICG). The proposed stereo matching processor, implemented in 65nm CMOS process, achieves 82fps and 31.2pJ/disparity-pixel energy efficiency at 30fps. Its energy efficiency is improved by 77.6% compared to the state-of-the-art

    Development and Evaluation of Tri-Axial Fiber Bragg Grating Force Sensor for Catheter

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    Abstract: Avoiding the electromagnetic interference is one of the most difficult technical challenge during catheterization. The use of an optical fiber force sensor in the catheter can be an alternative. Herein, two flexure structures were designed for catheter tip and simulated using ANSYS to verify their sensitivity and durability. Fiber Bragg Grating sensors were configured to measure the tri-axial force exerted on the catheter tip. Calibrated result shows that an optical fiber force sensor can measure an axial force of up to 50 gF with an accuracy of 1 gF. Our calibration results demonstrate reliable measurement with high accuracy with repeatability

    Substrate-Controlled Asymmetric Total Synthesis and Structure Revision of (−)-Bisezakyne A

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    The first asymmetric total synthesis and subsequent structure revision of (−)-bisezakyne A, a Laurencia C<sub>15</sub> acetogenin from Alpysia oculifera, has been accomplished. Our substrate-controlled synthesis of this oxolane natural product features a highly stereoselective “protecting-group-dependent” intramolecular amide enolate alkylation strategy for the synthesis of the key 9,10-<i>trans</i>-9,12-<i>cis</i>-10-hydroxytetrahydrofuran intermediate through “nonchelate” control. In addition, our synthesis determined the absolute configuration of the halogenated marine natural product

    Development of Force Sensor System Based on Tri-Axial Fiber Bragg Grating with Flexure Structure

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    Fiber Bragg grating (FBG) sensors have an advantage over optical sensors in that they are lightweight, easy to terminate, and have a high flexibility and a low cost. Additionally, FBG is highly sensitive to strain and temperature, which is why it has been used in FBG force sensor systems for cardiac catheterization. When manually inserting the catheter, the physician should sense the force at the catheter tip under the limitation of power (&lt;0.5 N). The FBG force sensor can be optimal for a catheter as it can be small, low-cost, easy to manufacture, free of electromagnetic interference, and is materially biocompatible with humans. In this study, FBG fibers mounted on two different flexure structures were designed and simulated using ANSYS simulation software to verify their sensitivity and durability for use in a catheter tip. The selected flexure was combined with three FBGs and an interrogator to obtain the wavelength signals. To obtain a calibration curve, the FBG sensor obtained data on the change in wavelength with force at a high resolution of 0.01 N within the 0.1&ndash;0.5 N range. The calibration curve was used in the force sensor system by the LabVIEW program to measure the unknown force values in real time

    DNPU: An Energy-Efficient Deep-Learning Processor with Heterogeneous Multi-Core Architecture

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    Investigating factors affecting bus/minibus accident severity in a developing country for different subgroup datasets characterised by time, pavement, and light conditions

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    Developing countries are primarily associated with poor roadway and lighting infrastructure challenges, which has a considerable effect on their traffic accident fatality rates. These rates are further increased as bus/minibus drivers indulge in risky driving, mainly during weekends when traffic and police surveillance is low to maximise profits. Although these factors have been mentioned in the literature as key indicators influencing accident severity of buses/minibuses, there is currently no study that explored the complex mechanisms underpinning the simultaneous effect of pavement and light conditions on the generation of accident severity outcomes while considering weekly temporal stability of the accident-risk factors. This study seeks to investigate the variations in the effect of contributing factors on the severity of bus/minibus accidents in Ghana across various combinations of pavement and light conditions and to identify the exact effects of weekdays and weekends on severity outcomes using a random parameter ordered logit model with heterogeneity in the means to account for unobserved heterogeneity in the police-reported data. Preliminary analysis demonstrated that accident-risk factors used in the models were temporally unstable, warranting the division of the data into both weekend and weekday time-periods. A wide variety of factors such as sideswipes, median presence, merging, and overtaking had significantly varying effects on bus/minibus accident severities under different combinations of pavement and light conditions for both weekdays and weekends. Insights drawn from this study, together with the policy recommendations provided, can be employed by engineers and policymakers to improve traffic safety in developing nations

    Biodegradability, DBP formation, and membrane fouling potential of natural organic matter: Characterization and controllability

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    Various natural organic matter (NOM) constituents were evaluated in terms of their biodegradability, disinfection byproduct (DBP) formation potentials,and membrane fouling. The biodegradability of NOM was evaluated with respect to biodegradable dissolved organic carbon (BDOC) and its inhibition control. NOM was divided into (i) colloidal and noncolloidal NOM, using a dialysis membrane with a molecular weight cutoff of 3500 Da and (ii) hydrophobic, transphilic, and hydrophilic NOM constituents, using XAD-8/4 resins. The colloidal, and noncolloidal hydrophilic, NOM were identified as being more problematic than the other components, exhibiting relatively higher biodegradability and reactivity toward DBP formation potential. A higher biodegradability especially can provide a high risk of membrane biofouling, if a membrane is fouled by highly biodegradable NOM. Colloidal, and noncolloidal hydrophilic, NOM constituents were also shown as major foulants of negatively charged membranes due to their high neutral fractions. Filter adsorber (F/A) types of activated carbons were evaluated in terms of removals of NOM, DBP formation potential, and BDOC and were compared to conventional processes and a nanofiltration membrane. The F/A process exhibited a comparatively good efficiency, especially in DBP and BDOC control, but was not so good at removing NOM. This suggests that F/A could potentially be combined with a membrane process to minimize the DBP formation potential and bio-/organic-fouling (i.e., F/A process as a pretreatment for a membrane process)close526

    A 2.71 nJ/Pixel Gaze-Activated Object Recognition System for Low-Power Mobile Smart Glasses

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    A low-power object recognition (OR) system with intuitive gaze user interface (UI) is proposed for battery-powered smart glasses. For low-power gaze UI, we propose a low-power single-chip gaze estimation sensor, called gaze image sensor (GIS). In GIS, a novel column-parallel pupil edge detection circuit (PEDC) with new pupil edge detection algorithm XY pupil detection (XY-PD) is proposed which results in 2.9x power reduction with 16x larger resolution compared to previous work. Also, a logarithmic SIMD processor is proposed for robust pupil center estimation, <1 pixel error, with low-power floating-point implementation. For OR, low-power multicore OR processor (ORP) is implemented. In ORP, task-level pipeline with keypoint-level scoring is proposed to reduce the number of cores as well as the operating frequency of keypoint-matching processor (KMP) for low-power consumption. Also, dual-mode convolutional neural network processor (CNNP) is designed for fast tile selection without external memory accesses. In addition, a pipelined descriptor generation processor (DGP) with LUT-based nonlinear operation is newly proposed for low-power OR. Lastly, dynamic voltage and frequency scaling (DVFS) for dynamic power reduction in ORP is applied. Combining both of the GIS and ORP fabricated in 65 nm CMOS logic process, only 75 mW average power consumption is achieved with real-time OR performance, which is 1.2x and 4.4x lower power than the previously published work
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