410 research outputs found

    Royal jelly promotes DAF-16-mediated proteostasis to tolerate β-amyloid toxicity in C. elegans model of Alzheimer’s disease

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    Numerous studies have demonstrated that dietary intervention may promote health and help prevent Alzheimer\u27s disease (AD). We recently reported that bee products of royal jelly (RJ) and enzyme-treated royal jelly (eRJ) were potent to promote healthy aging in C. elegans. Here, we examined whether RJ/eRJ consumption may benefit to mitigate the AD symptom in the disease model of C. elegans. Our results showed that RJ/eRJ supplementation significantly delayed the body paralysis in AD worms, suggesting the β-amyloid (Aβ) toxicity attenuation effects of RJ/eRJ. Genetic analyses suggested that RJ/eRJ-mediated alleviation of Aβ toxicity in AD worms required DAF-16, rather than HSF-1 and SKN-1, in an insulin/IGF signaling dependent manner. Moreover, RJ/eRJ modulated the transactivity of DAF-16 and dramatically improved the protein solubility in aged worms. Given protein solubility is a hallmark of healthy proteostasis, our findings demonstrated that RJ/eRJ supplementation improved proteostasis, and this promotion depended on the transactivity of DAF-16. Collectively, the present study not only elucidated the possible anti-AD mechanism of RJ/eRJ, but also provided evidence from a practical point of view to shed light on the extensive correlation of proteostasis and the prevention of neurodegenerative disorders

    Decision-making after continuous wins or losses in a randomized guessing task: implications for how the prior selection results affect subsequent decision-making

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    BACKGROUND: Human decision-making is often affected by prior selections and their outcomes, even in situations where decisions are independent and outcomes are unpredictable. METHODS: In this study, we created a task that simulated real-life non-strategic gambling to examine the effect of prior outcomes on subsequent decisions in a group of male college students. RESULTS: Behavioral performance showed that participants needed more time to react after continuous losses (LOSS) than continuous wins (WIN) and discontinuous outcomes (CONTROL). In addition, participants were more likely to repeat their selections in both WIN and LOSS conditions. Functional MRI data revealed that decisions in WINs were associated with increased activation in the mesolimbic pathway, but decreased activation in the inferior frontal gyrus relative to LOSS. Increased prefrontal cortical activation was observed during LOSS relative to WIN and CONTROL conditions. CONCLUSION: Taken together, the behavioral and neuroimaging findings suggest that participants tended to repeat previous selections during LOSS trials, a pattern resembling the gambler’s fallacy. However, during WIN trials, participants tended to follow their previous lucky decisions, like the ‘hot hand’ fallacy

    Sex difference in the effect of Internet gaming disorder on the brain functions: evidence from resting-state fMRI

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    Objective: Studies have shown that males are more prevalence than females in Internet gaming disorder (IGD). This study was set to explore the sex difference on the effect of IGD in resting states of the brain. Methods: Resting-state fMRI data were collected from 58 recreational Internet game users (RGU, male = 29) and 46 IGD subjects (male = 23). Regional homogeneity (ReHo) was used to calculate group difference between the subjects. A two-way ANOVA was used to explore the IGD-by-sex interactions. Correlations between addiction severity and the ReHo values were also calculated. Results: Significant sex-by-group interactions were found associated with the brain features in the right posterior cingulate (rPCC), left middle occipital gyrus (lMOG), right middle temporal gyrus (rMTG), and right postcentral gyrus (rPG). Post-hoc analysis revealed that comparing with same-sex RGUs, male IGD showed decreased ReHo in the rPCC, and the ReHo in the rPCC was also negatively associated with Internet addiction test (IAT) scores for male subjects. Moreover, male IGDs showed increased ReHo, but female ones showed decreased ReHo, in both lMOG and rMTG, when comparing with same-sex RGUs. Conclusions: Sex differences were observed in brain regions that are responsible for executive control, visual and auditory perception. These sex differences should be taken into consideration in future studies and the treatment of IGD

    Conflict-Based Cross-View Consistency for Semi-Supervised Semantic Segmentation

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    Semi-supervised semantic segmentation (SSS) has recently gained increasing research interest as it can reduce the requirement for large-scale fully-annotated training data. The current methods often suffer from the confirmation bias from the pseudo-labelling process, which can be alleviated by the co-training framework. The current co-training-based SSS methods rely on hand-crafted perturbations to prevent the different sub-nets from collapsing into each other, but these artificial perturbations cannot lead to the optimal solution. In this work, we propose a new conflict-based cross-view consistency (CCVC) method based on a two-branch co-training framework which aims at enforcing the two sub-nets to learn informative features from irrelevant views. In particular, we first propose a new cross-view consistency (CVC) strategy that encourages the two sub-nets to learn distinct features from the same input by introducing a feature discrepancy loss, while these distinct features are expected to generate consistent prediction scores of the input. The CVC strategy helps to prevent the two sub-nets from stepping into the collapse. In addition, we further propose a conflict-based pseudo-labelling (CPL) method to guarantee the model will learn more useful information from conflicting predictions, which will lead to a stable training process. We validate our new CCVC approach on the SSS benchmark datasets where our method achieves new state-of-the-art performance. Our code is available at https://github.com/xiaoyao3302/CCVC.Comment: accepted by CVPR202

    Functional Neural Changes and Altered Cortical–Subcortical Connectivity Associated with Recovery from Internet Gaming Disorder

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    Background and aims: Although studies have suggested that individuals with Internet gaming disorder (IGD) may have impairments in cognitive functioning, the nature of the relationship is unclear given that the information is typically derived from cross-sectional studies. Methods: Individuals with active IGD (n = 154) and those individuals no longer meeting criteria (n = 29) after 1 year were examined longitudinally using functional magnetic resonance imaging during performance of cue-craving tasks. Subjective responses and neural correlates were contrasted at study onset and at 1 year. Results: Subjects’ craving responses to gaming cues decreased significantly at 1 year relative to study onset. Decreased brain responses in the anterior cingulate cortex (ACC) and lentiform nucleus were observed at 1 year relative to onset. Significant positive correlations were observed between changes in brain activities in the lentiform nucleus and changes in self-reported cravings. Dynamic causal modeling analysis showed increased ACC–lentiform connectivity at 1 year relative to study onset. Conclusions: After recovery from IGD, individuals appear less sensitive to gaming cues. This recovery may involve increased ACC-related control over lentiform-related motivations in the control over cravings. The extent to which cortical control over subcortical motivations may be targeted in treatments for IGD should be examined further

    Altered brain functional networks in Internet gaming disorder: independent component and graph theoretical analysis under a probability-discounting task

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    Internet gaming disorder (IGD) is becoming a matter of concern around the world. However, the neural mechanism underlying IGD remains unclear. In present study, we used independent component analysis (ICA) and graph theoretical analysis (GTA) to explore the potential changed networks in IGD subjects compared to recreational game user (RGU) under a probability-discounting task. Imaging and behavioral data were collected from 18 IGD and 20 RGU subjects. Behavioral results showed the IGD subjects, comparing to RGU, prefer risky options to the fixed ones and spent less time in making risky decisions. In imaging results, the ICA analysis revealed that the IGD showed stronger functional connectivity (FC) in reward circuits and executive control network, as well as lower FC in anterior salience network (ASN) than RGU; for the GTA results, the IGD showed impaired FC in reward circuits and ASN compared to RGU. Taken all, these results suggest that IGD subjects were more sensitive to rewards and, at the same time, they usually neglect the potential punishment under a risky circumstance. Besides this, they were more impulsive in decision-making as they could not control their impulsivity effectively. This might explain why IGD subjects cannot stop their gaming behaviors even facing serve negative consequences

    Boundary element simulation of oscillating foil with leading-edge separation

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    Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.Includes bibliographical references (leaves 107-110).In this thesis, we develop a numerical model to account for the leading-edge separation for the boundary element simulation of the oscillating foil with potential flow assumption. Similar to the trailing-edge separation, the leading-edge separation is modeled by a thin shear layer. Because the leading edge is rounded which is different from the sharp trailing edge, the location for leading-edge separation is extremely difficult to predetermine especially when the flow is unsteady. For unsteady flows, the position of the leading-edge separation may vary with time. However, we present a criterion that is related to the adverse pressure gradient to predict the location for the leading-edge separation. Because of the Lagrange scheme of the wake relaxation in the boundary element simulation, the leading-edge wake sheet goes into or through the thin foil easily. In order to solve the problem of the wake penetration into the foil, we present an algorithm to deal with the penetration of the leading-edge wake into the foil body. We simulate the oscillating foil in heaving-pitching motions with our leading-edge model by the boundary element method to compare with the experiments.(cont.) Without accounting for leading-edge separation, the predictions of the thrust coefficient and the propulsion efficiency of a heaving-pitching foil are good only when the Strouhal number or the maximum angle of attack is small. With our model of the leading-edge separation, the predictions are improved significantly at a larger range of Strouhal numbers or maximum angles of attack because leading-edge separation becomes significant at large Strouhal numbers or maximum angles of attack. Further possible improvements of this leading-edge separation model are discussed.by Xiaoxia Dong.S.M

    Meta-analyses of the functional neural alterations in subjects with Internet gaming disorder: similarities and differences across different paradigms

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    Internet gaming disorder (IGD) has become a global public health concern due to its increasing prevalence and potential negative consequences. Researchers have sought to identify which brain regions are associated with this disorder. However, inconsistent results have been reported among studies due to the heterogeneity of paradigms and subjects. The present research aimed to combine the results of individual studies to provide a more coherent and powerful explanation. By selecting 40 studies utilizing a qualified whole-brain analysis, we performed a comprehensive series of meta-analyses that employed seed-based d mapping. We divided the existing experimental paradigms into 3 categories: game-related cue-reactivity, executive control, and risk-reward-related decision-making tasks. We divided all studies into three subgroups according to their paradigms. In cue-reactivity tasks, patients with IGD exhibited significant hyperactivation in the bilateral precuneus and bilateral cingulate and significant hypoactivation in the insula, but there were no differences in the striatum. In executive control tasks, patients with IGD displayed significant hyperactivation in the right superior temporal gyrus, bilateral precuneus, bilateral cingulate, and insula and hypoactivation in the left inferior frontal gyrus. In risky decision-making paradigms, IGD patients exhibited significant hyperactivation in the left striatum, right inferior frontal gyrus, and insula and hypoactivation in the left superior frontal gyrus, left inferior frontal gyrus, and right precentral gyrus. Our study aimed to discover the similarities among all studies and to explore the uniqueness of the different paradigms. This study further confirmed the critical role of reward circuitry and executive control circuitry in IGD but not under all conditions

    Decreased Effective Connection from the Parahippocampal Gyrus to the Prefrontal Cortex in Internet Gaming Disorder: A MVPA and spDCM Study

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    OBJECTIVES: Understanding the neural mechanisms underlying Internet gaming disorder (IGD) is essential for the condition's diagnosis and treatment. Nevertheless, the pathological mechanisms of IGD remain elusive at present. Hence, we employed multi-voxel pattern analysis (MVPA) and spectral dynamic causal modeling (spDCM) to explore this issue. METHODS: Resting-state fMRI data were collected from 103 IGD subjects (male = 57) and 99 well-matched recreational game users (RGUs, male = 51). Regional homogeneity was calculated as the feature for MVPA based on the support vector machine (SVM) with leave-one- out cross-validation. Mean time series data extracted from the brain regions in accordance with the MVPA results were used for further spDCM analysis. RESULTS: Results display a high accuracy of 82.67% (sensitivity of 83.50% and specificity of 81.82%) in the classification of the two groups. The most discriminative brain regions that contributed to the classification were the bilateral parahippocampal gyrus (PG), right anterior cingulate cortex (ACC), and middle frontal gyrus (MFG). Significant correlations were found between addiction severity (IAT and DSM scores) and the ReHo values of the brain regions that contributed to the classification. Moreover, the results of spDCM showed that compared with RGU, IGD showed decreased effective connectivity from the left PG to the right MFG and from the right PG to the ACC and decreased self-connection in the right PG. CONCLUSIONS: These results show that the weakening of the PG and its connection with the prefrontal cortex, including the ACC and MFG, may be an underlying mechanism of IGD

    A Fast Level Set Method for Synthetic Aperture Radar Ocean Image Segmentation

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    Segmentation of high noise imagery like Synthetic Aperture Radar (SAR) images is still one of the most challenging tasks in image processing. While level set, a novel approach based on the analysis of the motion of an interface, can be used to address this challenge, the cell-based iterations may make the process of image segmentation remarkably slow, especially for large-size images. For this reason fast level set algorithms such as narrow band and fast marching have been attempted. Built upon these, this paper presents an improved fast level set method for SAR ocean image segmentation. This competent method is dependent on both the intensity driven speed and curvature flow that result in a stable and smooth boundary. Notably, it is optimized to track moving interfaces for keeping up with the point-wise boundary propagation using a single list and a method of fast up-wind scheme iteration. The list facilitates efficient insertion and deletion of pixels on the propagation front. Meanwhile, the local up-wind scheme is used to update the motion of the curvature front instead of solving partial differential equations. Experiments have been carried out on extraction of surface slick features from ERS-2 SAR images to substantiate the efficacy of the proposed fast level set method
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