171 research outputs found

    Representations for the Drazin inverse of the sum P+Q+R+S and its applications

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    AbstractLet P, Q, R and S be complex square matrices and M=P+Q+R+S. A quadruple (P,Q,R,S) is called a pseudo-block decomposition of M ifPQ=QP=0PS=SQ=QR=RP=0andRD=SD=0,where RD and SD are the Drazin inverses of R and S, respectively. We investigate the problem of finding formulae for the Drazin inverse of M. The explicit representations for the Drazin inverses of M and P+Q+R are developed, under some assumptions. As its application, some representations are presented for 2×2 block matricesAB0CandABDC, where the blocks A and C are square matrices. Several results of this paper extend the well known representation for the Drazin inverse ofAB0Cgiven by Hartwig and Shoaf, Meyer and Rose in 1977. An illustrative example is given to verify our new representations

    V2XP-ASG: Generating Adversarial Scenes for Vehicle-to-Everything Perception

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    Recent advancements in Vehicle-to-Everything communication technology have enabled autonomous vehicles to share sensory information to obtain better perception performance. With the rapid growth of autonomous vehicles and intelligent infrastructure, the V2X perception systems will soon be deployed at scale, which raises a safety-critical question: \textit{how can we evaluate and improve its performance under challenging traffic scenarios before the real-world deployment?} Collecting diverse large-scale real-world test scenes seems to be the most straightforward solution, but it is expensive and time-consuming, and the collections can only cover limited scenarios. To this end, we propose the first open adversarial scene generator V2XP-ASG that can produce realistic, challenging scenes for modern LiDAR-based multi-agent perception systems. V2XP-ASG learns to construct an adversarial collaboration graph and simultaneously perturb multiple agents' poses in an adversarial and plausible manner. The experiments demonstrate that V2XP-ASG can effectively identify challenging scenes for a large range of V2X perception systems. Meanwhile, by training on the limited number of generated challenging scenes, the accuracy of V2X perception systems can be further improved by 12.3\% on challenging and 4\% on normal scenes. Our code will be released at https://github.com/XHwind/V2XP-ASG.Comment: ICRA 2023, see https://github.com/XHwind/V2XP-AS

    Notch Signaling Mediates TNF-α-Induced IL-6 Production in Cultured Fibroblast-Like Synoviocytes from Rheumatoid Arthritis

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    It has been reported that Notch family proteins are expressed in synovium tissue and involved in the proliferation of synoviocyte from rheumatoid arthritis (RA). The aim of this paper was to investigate whether Notch signaling mediated TNF-α-induced cytokine production of cultured fibroblast-like synoviocytes (FLSs) from RA. Exposure of RA FLSs to TNF-α (10 ng/ml) led to increase of Hes-1, a target gene of Notch signaling, and a marked upregulation of Notch 2, Delta-like 1, and Delta-like 3 mRNA levels. Blockage of Notch signaling by a γ-secretase inhibitor (DAPT) inhibited IL-6 secretion of RA FLSs in response to TNF-α while treatment with recombinant fusion protein of Notch ligand Delta-like 1 promoted such response. TNF-α stimulation also induced IL-6 secretion in OA FLSs; however, the Hes-1 level remained unaffected. Our data confirm the functional involvement of Notch pathway in the pathophysiology of RA FLSs which may provide a new target for RA therapy

    Automated Driving Systems Data Acquisition and Processing Platform

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    This paper presents an automated driving system (ADS) data acquisition and processing platform for vehicle trajectory extraction, reconstruction, and evaluation based on connected automated vehicle (CAV) cooperative perception. This platform presents a holistic pipeline from the raw advanced sensory data collection to data processing, which can process the sensor data from multiple CAVs and extract the objects' Identity (ID) number, position, speed, and orientation information in the map and Frenet coordinates. First, the ADS data acquisition and analytics platform are presented. Specifically, the experimental CAVs platform and sensor configuration are shown, and the processing software, including a deep-learning-based object detection algorithm using LiDAR information, a late fusion scheme to leverage cooperative perception to fuse the detected objects from multiple CAVs, and a multi-object tracking method is introduced. To further enhance the object detection and tracking results, high definition maps consisting of point cloud and vector maps are generated and forwarded to a world model to filter out the objects off the road and extract the objects' coordinates in Frenet coordinates and the lane information. In addition, a post-processing method is proposed to refine trajectories from the object tracking algorithms. Aiming to tackle the ID switch issue of the object tracking algorithm, a fuzzy-logic-based approach is proposed to detect the discontinuous trajectories of the same object. Finally, results, including object detection and tracking and a late fusion scheme, are presented, and the post-processing algorithm's improvements in noise level and outlier removal are discussed, confirming the functionality and effectiveness of the proposed holistic data collection and processing platform

    Differentiating the relationships between traditional and new media use and sleep quality during the COVID-19 pandemic: roles of psychological distress and age

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    BackgroundNumerous studies have consistently demonstrated a decline in sleep quality during the COVID-19 pandemic. The primary objective of this study is to explore the impact of engaging with pertinent epidemic information through the media amid the COVID-19 crisis on individuals’ sleep quality and the underlying mechanisms through which this influence operates.MethodsAn online cross-sectional study design was employed. A total of 1,063 British adults (36.2% males; Mage = 38.85, SDage = 13.36, ranging from 18 to 77 years old) participated in the study and completed our questionnaires, which included media usage frequency during the pandemic, the 10-item Kessler Psychological Distress Scale (K10), the Insomnia Severity Index (ISI), and the Ten-item Personality Inventory (TIPI).ResultsPearson’s correlation analyses indicated that there was no significant correlation between COVID-19-related traditional media use (television, radio, newspaper) and psychological distress or sleep quality. However, exposure to information related to COVID-19 through new media use (Facebook, Tik Tok, Twitter) was correlated with greater psychological distress and poorer sleep quality. A moderated mediation analysis showed that psychological distress fully mediated the relationship between new media use and poor sleep, which was moderated by age, with the association between psychological distress and poor sleep quality being stronger among older adults.ConclusionExposure to information of COVID-19 via new (but not traditional) media use deteriorated sleep quality through greater psychological distress, and this relationship was stronger among older adults

    Replication Stress Induces Micronuclei Comprising of Aggregated DNA Double-Strand Breaks

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    BACKGROUND: Micronuclei (MN) in mammalian cells serve as a reliable biomarker of genomic instability and genotoxic exposure. Elevation of MN is commonly observed in cells bearing intrinsic genomic instability and in normal cells exposed to genotoxic agents. DNA double-strand breaks are marked by phosphorylation of H2AX at serine 139 (γ-H2AX). One subclass of MN contains massive and uniform γ-H2AX signals. This study tested whether this subclass of MN can be induced by replication stress. PRINCIPAL FINDINGS: We observed that a large proportion of MN, from 20% to nearly 50%, showed uniform staining by antibodies against γ-H2AX, a marker of DNA double-strand breaks (DSBs). Such micronuclei were designated as MN-γ-H2AX (+). We showed that such MN can be induced by chemicals that are known to cause DNA replication stress and S phase arrest. Hydroxyurea, aphidicolin and thymidine could all significantly induce MN-γ-H2AX (+), which were formed during S phase and appeared to be derived from aggregation of DSBs. MN-γ-H2AX (-), MN that were devoid of uniform γ-H2AX signals, were induced to a lesser extent in terms of fold change. Paclitaxel, which inhibits the disassembly of microtubules, only induced MN-γ-H2AX (-). The frequency of MN-γ-H2AX (+), but not that of MN-γ-H2AX (-), was also significantly increased in cells that experience S phase prolongation due to depletion of cell cycle regulator CUL4B. Depletion of replication protein A1 (RPA1) by RNA interference resulted in an elevation of both MN-γ-H2AX (+) and MN-γ-H2AX (-). CONCLUSIONS/SIGNIFICANCE: A subclass of MN, MN-γ-H2AX (+), can be preferentially induced by replication stress. Classification of MN according to their γ-H2AX status may provide a more refined evaluation of intrinsic genomic instabilities and the various environmental genotoxicants

    KRT6A Promotes Lung Cancer Cell Growth and Invasion Through MYC-Regulated Pentose Phosphate Pathway

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    Keratin 6A (KRT6A) belongs to the keratin protein family which is a critical component of cytoskeleton in mammalian cells. Although KRT6A upregulation in non-small cell lung cancer (NSCLC) has been reported, the regulatory mechanism and functional role of KRT6A in NSCLC development have been less well investigated. In this study, KRT6A was confirmed to be highly expressed in NSCLC tissue samples, and its high expression correlated with poor patient prognosis. Furthermore, overexpression of KRT6A promotes NSCLC cell proliferation and invasion. Mechanistically, KRT6A overexpression is sufficient to upregulate glucose-6-phosphate dehydrogenase (G6PD) levels and increase the pentose phosphate pathway flux, an essential metabolic pathway to support cancer cell growth and invasion. In addition, we discovered that lysine-specific demethylase 1A (LSD1) functions upstream to promote KRT6A gene expression. We also found that the MYC family members c-MYC/MYCN are involved in KRT6A-induced G6PD upregulation. Therefore, this study reveals an underappreciated mechanism that KRT6A acts downstream of LSD1 and functions as a pivotal driver for NSCLC progression by upregulating G6PD through the MYC signaling pathway. Together, KRT6A and LSD1 may serve as potential prognostic indictors and therapeutic targets for NSCLC
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