Detection of Sensor Attack and Resilient State Estimation for Uniformly Observable Nonlinear Systems having Redundant Sensors

This paper presents a detection algorithm for sensor attacks and a resilient state estimation scheme for a class of uniformly observable nonlinear systems. An adversary is supposed to corrupt a subset of sensors with the possibly unbounded signals, while the system has sensor redundancy. We design an individual high-gain observer for each measurement output so that only the observable portion of the system state is obtained. Then, a nonlinear error correcting problem is solved by collecting all the information from those partial observers and exploiting redundancy. A computationally efficient, on-line monitoring scheme is presented for attack detection. Based on the attack detection scheme, an algorithm for resilient state estimation is provided. The simulation results demonstrate the effectiveness of the proposed algorithm

Towards Neural Decoding of Imagined Speech based on Spoken Speech

Decoding imagined speech from human brain signals is a challenging and important issue that may enable human communication via brain signals. While imagined speech can be the paradigm for silent communication via brain signals, it is always hard to collect enough stable data to train the decoding model. Meanwhile, spoken speech data is relatively easy and to obtain, implying the significance of utilizing spoken speech brain signals to decode imagined speech. In this paper, we performed a preliminary analysis to find out whether if it would be possible to utilize spoken speech electroencephalography data to decode imagined speech, by simply applying the pre-trained model trained with spoken speech brain signals to decode imagined speech. While the classification performance of imagined speech data solely used to train and validation was 30.5 %, the transferred performance of spoken speech based classifier to imagined speech data displayed average accuracy of 26.8 % which did not have statistically significant difference compared to the imagined speech based classifier (p = 0.0983, chi-square = 4.64). For more comprehensive analysis, we compared the result with the visual imagery dataset, which would naturally be less related to spoken speech compared to the imagined speech. As a result, visual imagery have shown solely trained performance of 31.8 % and transferred performance of 26.3 % which had shown statistically significant difference between each other (p = 0.022, chi-square = 7.64). Our results imply the potential of applying spoken speech to decode imagined speech, as well as their underlying common features.Comment: 4 pages, 2 figure

Long-term risks of complicated grief and insomnia in student survivors of the Sewol ferry disaster in South Korea: A four-year observational follow-up study

Background: The Sewol ferry disaster in April 2014 resulted in the drowning of 304 people. Of the 325 students on board, 250 died and 75 were rescued. The measure of stress caused by bereavement and sleep problems is common and can be a chronic health concern for disaster survivors. The aim of this study was to determine longitudinal predictive factors of complicated grief and insomnia among student survivors of the disaster. Methods: This study centered on 67 student survivors who were enrolled in the disaster registry after graduating from high school. The self-report data as presented by the participants were collected at baseline (27 months after the disaster, T1) and again at two years later (51 months after the disaster, T2). Thirty-one participants completed both T1 and T2 surveys. The noted predictive variables, in this case, were event-related rumination, coping strategy, social support, attachment, meaning in life, and adverse childhood experiences. The outcome variables were complicated grief and insomnia. Results: Dysfunctional coping (T1) was positively associated with complicated grief (T2) (coefficient = 0.070; p<0.001). Intrusive rumination (T1) (coefficient = -0.114; p<0.001), social support (T1) (coefficient = -0.031; p<0.001), and meaning in life – search (T1) (coefficient = -0.082; p<0.001) were negatively associated with insomnia (T2). In contrast, dysfunctional coping (T1) (coefficient = 0.041; p = 0.012), adverse childhood experiences (T1) (coefficient = 0.280; p = 0.007), and insomnia (T1) (coefficient = 0.166; p<0.001) were positively associated with insomnia (T2). Conclusions: Dysfunctional coping influenced how student survivors of the Sewol ferry disaster suffered from complicated grief and insomnia over time. In this case, the findings from the current study indicate that interventions that target coping strategies should be provided to improve the resolution of grief and sleep among survivors. [Ethiop.J. Health Dev. 2020;34(Special issue-3):97-106] Keywords: Sewol ferry disaster, student survivors, coping strategy, complicated grief, insomni

Potential role and mechanism of IFN-gamma inducible protein-10 on receptor activator of nuclear factor kappa-B ligand (RANKL) expression in rheumatoid arthritis

Introduction IFN-gamma inducible protein-10 (CXCL10), a member of the CXC chemokine family, and its receptor CXCR3 contribute to the recruitment of T cells from the blood stream into the inflamed joints and have a crucial role in perpetuating inflammation in rheumatoid arthritis (RA) synovial joints. Recently we showed the role of CXCL10 on receptor activator of nuclear factor kappa-B ligand (RANKL) expression in an animal model of RA and suggested the contribution to osteoclastogenesis. We tested the effects of CXCL10 on the expression of RANKL in RA synoviocytes and T cells, and we investigated which subunit of CXCR3 contributes to RANKL expression by CXCL10. Methods Synoviocytes derived from RA patients were kept in culture for 24 hours in the presence or absence of TNF-α. CXCL10 expression was measured by reverse transcriptase polymerase chain reaction (RT-PCR) of cultured synoviocytes. Expression of RANKL was measured by RT-PCR and western blot in cultured synoviocytes with or without CXCL10 and also measured in Jurkat/Hut 78 T cells and CD4+ T cells in the presence of CXCL10 or dexamethasone. CXCL10 induced RANKL expression in Jurkat T cells was tested upon the pertussis toxin (PTX), an inhibitor of Gi subunit of G protein coupled receptor (GPCR). The synthetic siRNA for Gαi2 was used to knock down gene expression of respective proteins. Results CXCL10 expression in RA synoviocytes was increased by TNF-α. CXCL10 slightly increased RANKL expression in RA synoviocytes, but markedly increased RANKL expression in Jurkat/Hut 78 T cell or CD4+ T cell. CXCL10 augmented the expression of RANKL by 62.6%, and PTX inhibited both basal level of RANKL (from 37.4 ± 16.0 to 18.9 ± 13.0%) and CXCL10-induced RANKL expression in Jurkat T cells (from 100% to 48.6 ± 27.3%). Knock down of Gαi2 by siRNA transfection, which suppressed the basal level of RANKL (from 61.8 ± 17.9% to 31.1 ± 15.9%) and CXCL10-induced RANKL expression (from 100% to 53.1 ± 27.1%) in Jurkat T cells, is consistent with PTX, which inhibited RANKL expression. Conclusions CXCL10 increased RANKL expression in CD4+ T cells and it was mediated by Gαi subunits of CXCR3. These results indicate that CXCL10 may have a potential role in osteoclastogenesis of RA synovial tissue and subsequent joint erosion

Pancreas ductal adenocarcinoma with cystic features on cross-sectional imaging: radiologic-pathologic correlation

Most pancreatic ductal adenocarcinomas (PDAs) show solid growth pattern, but ductal adenocarcinomas may demonstrate intratumoral cystic appearance or accompany peritumoral non-neoplastic cystic lesions, thus mimicking cystic pancreatic tumors on imaging studies. The histopathologic findings for PDA with cystic feature are divided into neoplastic and non-neoplastic cysts. Neoplastic cystic changes include large-duct type cysts (microcystic appearance), neoplastic mucin cysts (macrocystic appearance), colloid carcinomas (mucinous noncystic adenocarcinomas), and degenerative cystic change usually caused by hemorrhagic necrosis of tumor. Non-neoplastic cystic changes include retention cysts caused by ductal obstruction and pseudocysts caused by tumor-associated pancreatitis. Depending on the presence, size, number, and configuration of cystic changes, PDA should be differentiated from various types of cystic neoplasms. This pictorial essay provides histopathologic classification of PDAs with cystic features along with the corresponding cross-sectional imaging findings, and their differential diagnosis