218 research outputs found

    Improving accuracy and precision of value-at-risk forecasts

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    SegNeXt: Rethinking Convolutional Attention Design for Semantic Segmentation

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    We present SegNeXt, a simple convolutional network architecture for semantic segmentation. Recent transformer-based models have dominated the field of semantic segmentation due to the efficiency of self-attention in encoding spatial information. In this paper, we show that convolutional attention is a more efficient and effective way to encode contextual information than the self-attention mechanism in transformers. By re-examining the characteristics owned by successful segmentation models, we discover several key components leading to the performance improvement of segmentation models. This motivates us to design a novel convolutional attention network that uses cheap convolutional operations. Without bells and whistles, our SegNeXt significantly improves the performance of previous state-of-the-art methods on popular benchmarks, including ADE20K, Cityscapes, COCO-Stuff, Pascal VOC, Pascal Context, and iSAID. Notably, SegNeXt outperforms EfficientNet-L2 w/ NAS-FPN and achieves 90.6% mIoU on the Pascal VOC 2012 test leaderboard using only 1/10 parameters of it. On average, SegNeXt achieves about 2.0% mIoU improvements compared to the state-of-the-art methods on the ADE20K datasets with the same or fewer computations. Code is available at https://github.com/uyzhang/JSeg (Jittor) and https://github.com/Visual-Attention-Network/SegNeXt (Pytorch).Comment: SegNeXt, a simple CNN for semantic segmentation. Code is availabl

    The role of the transcription factor Rbpj in the development of dorsal root ganglia

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    <p>Abstract</p> <p>Background</p> <p>The dorsal root ganglion (DRG) is composed of well-characterized populations of sensory neurons and glia derived from a common pool of neural crest stem cells (NCCs), and is a good system to study the mechanisms of neurogenesis and gliogenesis. Notch signaling is known to play important roles in DRG development, but the full scope of Notch functions in mammalian DRG development remains poorly understood.</p> <p>Results</p> <p>In the present study, we used <it>Wnt1-Cre </it>to conditionally inactivate the transcription factor Rbpj, a critical integrator of activation signals from all Notch receptors, in NCCs and their derived cells. Deletion of <it>Rbpj </it>caused the up-regulation of <it>NeuroD1 </it>and precocious neurogenesis in DRG early development but led to an eventual deficit of sensory neurons at later stages, due to reduced cell proliferation and abnormal cell death. In addition, gliogenesis was delayed initially, but a near-complete loss of glia was observed finally in <it>Rbpj</it>-deficient DRG. Furthermore, we found P75 and Sox10, which are normally expressed exclusively in neuronal and glial progenitors of the DRG after the NCCs have completed their migration, were co-expressed in many cells of the DRG of <it>Rbpj </it>conditional knock-out mice.</p> <p>Conclusions</p> <p>Our data indicate that Rbpj-mediated canonical Notch signaling inhibits DRG neuronal differentiation, possibly by regulating <it>NeuroD1 </it>expression, and is required for DRG gliogenesis <it>in vivo</it>.</p

    Potential biomarkers relating pathological proteins, neuroinflammatory factors and free radicals in PD patients with cognitive impairment: a cross-sectional study

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    BACKGROUND: Cognitive impairment strikingly reduces the quality of life of Parkinson’s disease (PD) patients. Studies find that pathological proteins, neuroinflammatory factors and free radicals may involve in the pathogenesis of cognitive impairment of PD, however, results are inconclusive. METHODS: We recruited 62 PD patients and 31 healthy controls. PD patients were identified with cognitive impairment, including PD with mild cognitive impairment (PD-MCI) and PD with dementia (PDD) according to the diagnostic criteria for PD-MCI and PDD issued by Movement Disorder Society Task Force. The levels of pathological proteins, including β-amyloid 1–42 (Aβ1-42),Total-tau (T-tau) and phosphorelated tau (P-tau), neuroinflammatory factors,including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), interferon-γ (INF-γ) and prostaglandin E(2) (PGE(2)), free radicals, including hydroxyl radical (·OH), hydrogen peroxide (H(2)O(2)) and nitric oxide (NO) in cerebrospinal fluid(CSF) were detected. The levels of above factors in CSF were compared among healthy controls and patients with and without cognitive impairment. Correlation analyses were performed between Montreal Cognitive Assessment (MoCA) score and the levels of above factors in CSF. RESULTS: T-tau level in CSF from PD-CI patients are significantly elevated comparing with those without cognitive impairment and controls (P = 0.016 and 0.004, respectively). The levels of P-tau (S396) and · OH in PD-CI patients are significantly higher than controls (P = 0.001 and 0.014, respectively). IL-6 levels in PD-CI patients are strikingly enhanced comparing with those without cognitive impairment (P = 0.005). MoCA score is negatively correlated with the levels of T-tau (r = -0.340), P-tau (S396) (r = -0.448), IL-6 (r = -0.489) and · OH (r = -0.504) in PD-CI patients. CONCLUSIONS: Elevated levels of T-tau, P-tau (S396), IL-6 and · OH in CSF are significantly correlated with cognitive impairment in PD patients. This investigation may suggest the potential biomarkers relating pathological proteins, neuroinflammatory factors and free radicals in PD patients with cognitive impairment

    Eliminating Plasmodium falciparum in Hainan, China: a study on the use of behavioural change communication intervention to promote malaria prevention in mountain worker populations

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    BACKGROUND: In the island of Hainan, the great majority of malaria cases occur in mountain worker populations. Using the behavioral change communication (BCC) strategy, an interventional study was conducted to promote mountain worker malaria prevention at a test site. This study found the methods and measures that are suitable for malaria prevention among mountain worker populations. METHODS: During the Plasmodium falciparum elimination stage in Hainan, a representative sampling method was used to establish testing and control sites in areas of Hainan that were both affected by malaria and had a relatively high density of mountain workers. Two different methods were used: a BCC strategy and a conventional strategy as a control. Before and after the intervention, house visits, core group discussions, and structural surveys were utilized to collect qualitative and quantitative data regarding mountain worker populations (including knowledge, attitudes, and practices [KAPs]; infection status; and serological data), and these data from the testing and control areas were compared to evaluate the effectiveness of BCC strategies in the prevention of malaria. RESULTS: In the BCC malaria prevention strategy testing areas, the accuracy rates of malaria-related KAP were significantly improved among mountain worker populations. The accuracy rates in the 3 aspects of malaria-related KAP increased from 37.73%, 37.00%, and 43.04% to 89.01%, 91.53%, and 92.25%, respectively. The changes in all 3 aspects of KAP were statistically significant (p < 0.01). In the control sites, the changes in the indices were not as marked as in the testing areas, and the change was not statistically significant (p > 0.05). Furthermore, in the testing areas, both the percentage testing positive in the serum malaria indirect fluorescent antibody test (IFAT) and the number of people inflicted decreased more significantly than in the control sites (p < 0.01). CONCLUSION: The use of the BCC strategy significantly improved the ability of mountain workers in Hainan to avoid malarial infection. Educational and promotional materials and measures were developed and selected in the process, and hands-on experience was gained that will help achieve the goal of total malaria elimination in Hainan

    Sh-MARCH8 Inhibits Tumorigenesis via PI3K Pathway in Gastric Cancer

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    Background/Aims: To identify new treatment strategies for gastric cancer and to elucidate the mechanism underlying its pathophysiology, we transfected sh-MARCH8 into the human gastric cancer cell lines MKN-45 and AGS to investigate the roles of MARCH8 in gastric cancer. Methods: We used genetic engineering to construct the sh-MARCH8 interference plasmid and transfected it into gastric cancer cells. Colony formation assays and cell viability measurements were performed to detect the viability and proliferation of cancer cells. Wound healing assays were performed to estimate the migration and proliferation rates of the cells. Cell invasion assays were used to estimate the invasive abilities of the cells. Cell apoptosis analysis was performed by using flowing cytometry. Western blot analysis was performed to estimate the expression levels of proteins. Statistical analysis was performed using the SPSS 18.0 software. Student’s t-test was used to determine the significance of all pairwise comparisons of interest. Results: We observed that the transfection of sh-MARCH8 inhibited the survival and proliferation of MKN-45 and AGS cells. The migration and invasion of the MKN-45 and AGS cells were significantly decreased, and apoptosis was induced in comparison with the control cells. These results were further confirmed by data showing that sh-MARCH8 increased the BAX/BCL2 ratio in MKN-45 and AGS cells. We also observed that sh-MARCH8 inactivated the PI3K and ß-catenin stat3 signaling pathways by changing protein expression levels or the phosphorylation of related proteins. Conclusion: These data suggested that sh-March8 reduced viability and induced apoptosis of the MKN-45 and AGS cells through the PI3K and ß-catenin stat3 signaling pathways. Taken together, our data revealed that transfection of sh-MARCH8 into the MKN-45 and AGS gastric cancer cell lines inhibited their growth, and this approach may be useful as a novel strategy for gastric cancer therapy
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