13 research outputs found

    Improving Generalization in Visual Reinforcement Learning via Conflict-aware Gradient Agreement Augmentation

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    Learning a policy with great generalization to unseen environments remains challenging but critical in visual reinforcement learning. Despite the success of augmentation combination in the supervised learning generalization, naively applying it to visual RL algorithms may damage the training efficiency, suffering from serve performance degradation. In this paper, we first conduct qualitative analysis and illuminate the main causes: (i) high-variance gradient magnitudes and (ii) gradient conflicts existed in various augmentation methods. To alleviate these issues, we propose a general policy gradient optimization framework, named Conflict-aware Gradient Agreement Augmentation (CG2A), and better integrate augmentation combination into visual RL algorithms to address the generalization bias. In particular, CG2A develops a Gradient Agreement Solver to adaptively balance the varying gradient magnitudes, and introduces a Soft Gradient Surgery strategy to alleviate the gradient conflicts. Extensive experiments demonstrate that CG2A significantly improves the generalization performance and sample efficiency of visual RL algorithms.Comment: accepted by iccv202

    Are serum levels of inflammatory markers associated with the severity of symptoms of bipolar disorder?

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    BackgroundTo explore the relationship between serum levels of inflammatory markers and symptomatic severity of bipolar disorder (BD).Materials and methodsA cross-sectional study was conducted on 126 BD patients with current depressive episode (BDD), 102 BD patients with current mixed or (hypo)manic episode (BDM) and 94 healthy controls (HC). All participants were drug-naïve and had no current active physical illness associated with inflammatory response or history of substance abuse. Fasting serum levels of CRP, leptin (LEP), adiponectin (ADP), visfatin (VIS), TNF-α, IL-2, IL-6, IL-10, IL-17), and monocyte chemoattractant protein-1 (MCP-1) were measured with enzyme-linked immunosorbent assay (ELISA). Symptomatic severity of BD was assessed with HAMD-17 and YMRS. Generalized linear model was used to determine the association between the serum levels of inflammatory markers and symptomatic severity of BD.ResultsThe serum levels of IL-6, IL-10 and IL-17, and the IL-6/IL-10 ratio were significantly lower in mild BDD than in HC. In moderate BDD, the serum levels of MCP, IL-6 and IL-17 were significantly lower than in HC. In severe BDD, the serum level of ADP, MCP-1, IL-10 and IL-17and the IL-17/IL-10 ratio were significantly lower than in HC. The serum levels of TNF-α and the IL-6/IL-10 ratio were significantly higher in mild BDM than in HC. In moderate BDM, the serum level of VIS, IL-2, and IL-17 were significantly higher than in HC, but the IL-6/IL-10 ratio was significantly lower than in control. In severe BDM, the serum levels of IL-6 and IL-17 and the ratios of IL-6/IL-10 and IL-17/IL-10 were significantly lower than in HC, but the neutrophil/lymphocyte ratio was significantly higher than in HC.ConclusionIn BDD, immune-inhibition is persistently predominant, while in mild-to-moderate BDM, immune system is activated but inhibited in severe BDM. The dynamic change of serum inflammatory markers suggests that alteration of peripheral inflammatory markers in BD is state-dependent instead of trait-marked

    Validation of the Chinese version of the "Mood Disorder Questionnaire" for screening bipolar disorder among patients with a current depressive episode

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    <p>Abstract</p> <p>Background</p> <p>The Mood Disorder Questionnaire (MDQ) is a well-recognized screening tool for bipolar disorder, but its Chinese version needs further validation. This study aims to measure the accuracy of the Chinese version of the MDQ as a screening instrument for bipolar disorder (BPD) in a group of patients with a current major depressive episode.</p> <p>Methods</p> <p>142 consecutive patients with an initial DSM-IV-TR diagnosis of a major depressive episode were screened for BPD using the Chinese translation of the MDQ and followed up for one year. The final diagnosis, determined by a special committee consisting of three trained senior psychiatrists, was used as a 'gold standard' and ROC was plotted to evaluate the performance of the MDQ. The optimal cut-off was chosen by maximizing the Younden's index.</p> <p>Results</p> <p>Of the 142 patients, 122 (85.9%) finished the one year follow-up. On the basis of a semi-structured clinical interview 48.4% (59/122) received a diagnosis of unipolar depression (UPD), 36.9% (45/122) BPDII and 14.8% (18/122) BPDI. At the end of the one year follow-up,9 moved from UPD to BPD, 2 from BPDII to UPD, 1 from BPDII to BPDI, the overall rate of initial misdiagnosis was 16.4%. MDQ showed a good accuracy for BPD: the optimal cut-off was 4, with a sensitivity of 0.72 and a specificity of 0.73. When BPDII and BPDI were calculated independently, the optimal cut-off for BPDII was 4, with a sensitivity of 0.70 and a specificity of 0.73; while the optimal cut-off for BPDI was 5, with a sensitivity of 0.67 and a specificity of 0.86.</p> <p>Conclusions</p> <p>Our results show that the Chinese version of MDQ is a valid tool for screening BPD in a group of patients with current depressive episode on the Chinese mainland.</p

    The pursuit of profit and socially responsible behavior in market exchange : an experimental analysis

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    Enlightened by Bartling, Weber and Yao’s (2015) experimental study on market socially responsible behavior, this paper aims to studies the effect of varying production cost of “externality-free” product on socially responsible behaviors in market setting. We observe persistent positive levels of social responsibility showing in consumers’ and firms’ behaviors even when the production cost of externality-free product goes up. However, higher production cost of fair product drags down the level of social responsibility significantly. In other words, although consumers and firms’ concern about social welfare and their willingness of behaving in socially responsible manners usually emerges naturally, they also concern about their own profit, limiting or even discouraging their willingness of behaving ethically in certain circumstances.Bachelor of Art

    Prevalence of insulin resistance and its associated factors in drug-naïve patients with bipolar disorder among Han Chinese population

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    Abstract Background Metabolic syndrome (Mets) is commonly seen in bipolar disorder (BD). As the key component and early biological index of Mets, insulin resistance (IR) among BD has received more and more attention. However, little is known about the prevalence of IR and its associated factors in drug-naïve patients with (BD), especially among Han Chinese population. Methods A cross-sectional study was conducted on 125 drug-naïve patients with bipolar disorder (BD) and 85 healthy controls (HC). The Homeostatic Model Assessment of insulin resistance (HOMA-IR) was calculated, and IR was defined as HOMA-IR greater than the 75th percentile value for health controls (2.35). Clinical characteristics of BD were collected through semi-structural interview performed by a trained interviewer with background of psychiatric education. Results Among the measured anthropocentric variables including BMI, waist circumference, abdomen circumference, hipline, and hip-waist ratio, waist circumference was found to be the most closely related to IR (0R = 1.070, 95%CI = 1.031–1.110, P < 0.001). Male was another factor that was associated with IR (OR = 2.281, 95%CI = 1.107–4.702, P = 0.025). After adjusted for gender and waist circumference, the risk of IR was significantly higher in bipolar disorder than in healthy controls (OR = 2.66, 95%CI = 1.364–5.214, P = 0.004). No significant association was found between IR and any of the observed physical and mental comorbidities, any characteristic of illness course including age onset, number of mixed episodes, types of current state, duration of current episode, duration of illness course, rapid cycling, number of mood episodes, and subgroup of BD. Hypersomnia was the only symptomatic feature that was significantly associated with IR (OR = 0.316, 95%CI = 0.124–0.803, P = 0.016). Conclusions Bipolar disorder increases two-to-three-fold risk of IR, both circumference and male are the risk factors of IR but hypersomnia act as a protective factor

    Graphene Actively Mode-Locked Lasers

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    Actively mode-locked lasers offer varying degrees of flexibility for a wider range of applications than their passively modulated counterparts, due to their capability for electrically controlled ultrahigh repetition rate operation. Graphene based electrooptic modulators with unique advantages of broad operation bandwidth and ultrafast speed are suitable for light modulation in various optoelectronic applications. Here, an actively mode-locked laser with a graphene based electrooptic modulator is reported for the first time. The active mode-locking technique combined together with the intracavity nonlinear pulse shortening effect allows the generation of transform-limited 1.44 ps pulses with pulse energy of 844 pJ. The electrically controlled repetition rate of generated pulses, a key performance advantage of active mode-locking, is also demonstrated. These results provide a practical and effective approach for actively mode-locked lasers with broad operation bandwidth and compact footprint, which contributesa new way for applications of two-dimensional (2D) layered materials in ultrafast lasers.Peer reviewe
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