643 research outputs found

    MOS2, a Protein Containing G-Patch and KOW Motifs, Is Essential for Innate Immunity in Arabidopsis thaliana

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    SummaryInnate immunity is critical for sensing and defending against microbial infections in multicellular organisms. In plants, disease resistance genes (R genes) play central roles in recognizing pathogens and initiating downstream defense cascades [1]. Arabidopsis SNC1 encodes a TIR-NBS-LRR-type R protein with a similar structure to nucleotide binding oligomerization domain (Nod) proteins in animals [2, 3]. A point mutation in the region between the NBS and LRR of SNC1 results in constitutive activation of defense responses in the snc1 mutant. Here, we report the identification and characterization of mos2-1, a mutant suppressing the constitutive defense responses in snc1. Analysis of mos2 single mutants indicated that it is not only required for resistance specified by multiple R genes, but also for basal resistance. Map-based cloning of MOS2 revealed that it encodes a novel nuclear protein that contains one G-patch and two KOW domains and has homologs across the animal kingdom. The presence of both G-patch and KOW domains in the MOS2 protein suggests that it probably functions as an RNA binding protein critical for plant innate immunity [4, 5]. Our discovery on the biological functions of MOS2 will shed light on functions of the MOS2 homologs in animals, where they may also play important roles in innate immunity

    Factor analyses of a social support scale using two methods

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    Purpose: Evaluation and comparison of the factor structure of the Medical Outcomes Study Social Support Survey (MOS-SSS) using both confirmatory factor analysis (CFA) and exploratory factor analysis (EFA) with two samples of people living with HIV/AIDS in China. Methods: Secondary analyses were conducted with data from two comparable samples of 320 people living with HIV/AIDS from the same hospital using the same inclusion criteria. The first sample of 120 was collected in 2006, and the second sample of 200 was collected in 2012. For each sample, CFA was first performed on the original four-factor structure to check model fit, followed by EFA to explore other factor structures and a subsequent CFA for model fit statistics to be compared to the original four-factor CFA. Results: In both samples, CFA on the originally hypothesized four-factor structure yielded an acceptable model fit. The EFA yielded a two-factor solution in both samples, with different items included in each factor for the two samples. Comparison of CFA on the a priori four-factor structure and the new two-factor structure in both samples indicated that both factor structures were of acceptable model fit, with the four-factor model performing slightly better than the two-factor model. Conclusion: Factor structure of the MOS-SSS is method-dependent, with CFA supporting a four-factor structure, while EFA yielded a two-factor structure in two separate samples. We need to be careful in selecting the analytic method when applying the MOS-SSS to various samples and choose the factor structure that best fits the theoretical model

    Integral and Rxte/Asm Observations on Igr J17098-3628

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    To probe further the possible nature of the unidentified source IGR J17098-3628, we have carried out a detailed analysis of its long-term time variability as monitored by RXTE/ASM, and of its hard X-ray properties as observed by INTEGRAL. INTEGRAL has monitored this sky region over years and significantly detected IGR J17098-3628 only when the source was in this dubbed active state. In particular, at \ge 20 keV, IBIS/ISGRI caught an outburst in March 2005, lasting for \sim5 days with detection significance of 73σ\sigma (20-40 keV) and with the emission at << 200 keV. The ASM observations reveal that the soft X-ray lightcurve shows a similar outburst to that detected by INTEGRAL, however the peak of the soft X-ray lightcurve either lags, or is preceded by, the hard X-ray (>>20 keV) outburst by \sim2 days. This resembles the behavior of X-ray novae like XN 1124-683, hence it further suggests a LMXB nature for IGR J17098-3628. While the quality of the ASM data prevents us from drawing any definite conclusions, these discoveries are important clues that, coupled with future observations, will help to resolve the as yet unknown nature of IGR J17098-3628.Comment: 15 pages, 7 figure, accepted in PAS

    Are AlphaZero-like Agents Robust to Adversarial Perturbations?

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    The success of AlphaZero (AZ) has demonstrated that neural-network-based Go AIs can surpass human performance by a large margin. Given that the state space of Go is extremely large and a human player can play the game from any legal state, we ask whether adversarial states exist for Go AIs that may lead them to play surprisingly wrong actions. In this paper, we first extend the concept of adversarial examples to the game of Go: we generate perturbed states that are ``semantically'' equivalent to the original state by adding meaningless moves to the game, and an adversarial state is a perturbed state leading to an undoubtedly inferior action that is obvious even for Go beginners. However, searching the adversarial state is challenging due to the large, discrete, and non-differentiable search space. To tackle this challenge, we develop the first adversarial attack on Go AIs that can efficiently search for adversarial states by strategically reducing the search space. This method can also be extended to other board games such as NoGo. Experimentally, we show that the actions taken by both Policy-Value neural network (PV-NN) and Monte Carlo tree search (MCTS) can be misled by adding one or two meaningless stones; for example, on 58\% of the AlphaGo Zero self-play games, our method can make the widely used KataGo agent with 50 simulations of MCTS plays a losing action by adding two meaningless stones. We additionally evaluated the adversarial examples found by our algorithm with amateur human Go players and 90\% of examples indeed lead the Go agent to play an obviously inferior action. Our code is available at \url{https://PaperCode.cc/GoAttack}.Comment: Accepted by Neurips 202

    Physiological Ischemic Training Promotes Brain Collateral Formation and Improves Functions in Patients with Acute Cerebral Infarction

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    Objectives: To observe the effectiveness and mechanisms of physiological ischemic training (PIT) on brain cerebral collateral formation and functional recovery in patients with acute cerebral infarction.Methods: 20 eligible patients with acute cerebral infarction were randomly assigned to either PIT group (n = 10) or Control group (n = 10). Both groups received 4 weeks of routine rehabilitation therapy, while an additional session of PIT, which consisted of 10 times of maximal voluntary isometric handgrip for 1 min followed by 1 min rest, was prescribed for patients in the PIT groups. Each patient was trained with four sections a day and 5 days a week for 4 weeks. The Fugl-Meyer Assessment (FMA), the Modified Barthel Index (MBI), and the short-form 36-item health survey questionnaire (SF-36) were applied for the evaluation of motor impairment, activity of daily living, and quality of life at the baseline and endpoint. MRI was applied to detect the collateral formation in the brain. The concentration of vascular endothelial growth factor (VEGF) and endothelial progenitor cells (EPCs) number in plasma were also tested at the endpoint.Results: Demographic data were consistent between experimental groups. At the endpoint, the scores of the FMA, MBI, and SF-36 were significantly higher than that at baseline. As compared to the Control group, the score of FMA and SF-36 in PIT group was significantly higher, while no significant difference was detected between groups in terms of MBI. Both groups had significantly higher cerebral blood flow (CBF) level at endpoint as compared to that at baseline. Moreover, the CBF level was even higher in the PIT group as compared to that in the Control group after 4 weeks of training. The same situations were also found in the plasma VEGF and EPCs assessment. In addition, positive correlations were found between FMA score and CBF level (r = 0.686, p < 0.01), CBF level and VEGF concentration (r = 0.675, p < 0.01), and VEGF concentration and EPC number (r = 0.722, p < 0.01).Conclusion: PIT may be effective in increasing the expression of VEGF and recruitment of EPCs and in turn promote the formation of brain collateral circulation. The positive correlations may demonstrate a potential association between biological and functional parameters, and PIT may be able to improve the motor function, activity of daily living, and quality of life in patients with stroke.Interdisciplinary Division of Biomedical Engineerin

    Risk of Vertebral Fracture in Patients Diagnosed with a Depressive Disorder: A Nationwide Population-Based Cohort Study

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    OBJECTIVE: Previous studies have reported that depression may play a crucial role in the occurrence of vertebral fractures. However, a clear correlation between depressive disorders and osteoporotic fractures has not been established. We explored the association between depressive disorders and subsequent new-onset vertebral fractures. Additionally, we aimed to identify the potential risk factors for vertebral fracture in patients with a depressive disorder. METHODS: We studied patients listed in the Taiwan National Health Insurance Research Database who were diagnosed with a depressive disorder by a psychiatrist. The comparison cohort consisted of age- and sex-matched patients without a depressive disorder. The incidence rate and hazard ratios of subsequent vertebral fracture were evaluated. We used Cox regression analysis to evaluate the risk of vertebral fracture among patients with a depressive disorder. RESULTS: The total number of patients with and without a depressive disorder was 44,812. The incidence risk ratio (IRR) between these 2 cohorts indicated that depressive disorder patients had a higher risk of developing a subsequent vertebral fracture (IRR=1.41, 95% confidence interval [CI]=1.26-1.57,

    Fatigue and sleep disturbance related to perceived stress in Chinese HIV-positive individuals: A mixed methods study

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    Background Few studies of HIV+ individuals in China have examined the associations between HIV-related stress with sleep disturbance and fatigue, which are common complaints among people living with HIV/AIDS (PLWHA). We carried out this study to examine the relationships among perceived stress, sleep disturbance, and fatigue in PLWHA in China. Methods A mixed methods study design was used during data collection in Shanghai, China, from December 2009 to March 2010. Qualitative in-depth interviews were conducted with 19 HIV+ females. Additionally, cross-sectional audio computer-assisted self-interviews (ACASI) were conducted to collect quantitative data from a convenience sample of 107 HIV+ patients (84% were male) including the following scales: 1) Perceived Stress Scale for PLWHA, 2) General Sleep Disturbance Scale, and 3) Fatigue Scale. Results The major themes that emerged from the in-depth interviews were around life stress with HIV, sleep disturbance, and fatigue. Participants presented varying amounts of stress around worrying about whether to disclose their diagnosis and whether they might transmit the disease to their family. In addition, in the cross-sectional data, 40% of the participants reported clinically significant sleep disturbances (GSDS \u3e 3) with an average of 3 nights of disturbed sleep in the past week (M=2.87, SD=1.21) and moderate fatigue severity (M=5.24, SD=2.27). In mediation analyses, the data suggests that the relationship between perceived stress and fatigue was largely (53%) mediated through sleep disturbance. Conclusions Chinese PLWHA described how stress had caused them to become sleepless and fatigued. The quantitative data also demonstrated significant levels of sleep disturbance and fatigue, where were due to perceived stress with HIV disease. A systematic self-management intervention to decrease perceived stress should be designed and implemented in mental health resource-limited settings such as China in order to reduce sleep disturbance and fatigue

    In Silico

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    Alzheimer’s disease (AD) is caused by the hyperphosphorylation of Tau protein aggregation. FKBP52 (FK506 binding protein 52) has been found to inhibit Tau protein aggregation. This study found six different kinds of anthocyanins that have high binding potential. After analyzing the docking positions, hydrophobic interactions, and hydrogen bond interactions, several amino acids were identified that play important roles in protein and ligand interaction. The proteins’ variation is described using eigenvectors and the distance between the amino acids during a molecular dynamics simulation (MD). This study investigates the three loops based around Glu85, Tyr113, and Lys121—all of which are important in inducing FKBP52 activation. By performing a molecular dynamic simulation process between unbound proteins and the protein complex with FK506, it was found that ligand targets that docked onto the FK1 domain will decrease the distance between Glu85/Tyr113 and Glu85/Lys121. The FKBP52 structure variation may induce FKBP52 activation and inhibit Tau protein aggregation. The results indicate that anthocyanins might change the conformation of FKBP52 during binding. In addition, the purple anthocyanins, such as cyanidin-3-glucoside and malvidin-3-glucoside, might be better than FK506 in regulating FKBP52 and treating Alzheimer’s disease
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