20 research outputs found
Shock Models Driven by a Cluster Process with Lévy Perturbation and their Applications in Insurance Risk
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Co-saliency detection via inter and intra saliency propagation
No full textThe goal of salient object detection from an image is to extract the regions which capture the attention of the human visual system more than other regions of the image. In this paper a novel method is presented for detecting salient objects from a set of images, known as co-saliency detection. We treat co-saliency detection as a two-stage saliency propagation problem. The first inter-saliency propagation stage utilizes the similarity between a pair of images to discover common properties of the images with the help of a single image saliency map. With the pairwise co-salient foreground cue maps obtained, the second intra-saliency propagation stage refines pairwise saliency detection using a graph-based method combining both foreground and background cues. A new fusion strategy is then used to obtain the co-saliency detection results. Finally an integrated multi-scale scheme is employed to obtain pixel-level co-saliency maps. The proposed method makes use of existing saliency detection models for co-saliency detection and is not overly sensitive to the initial saliency model selected. Extensive experiments on three benchmark databases show the superiority of the proposed co-saliency model against the state-of-the-art methods both subjectively and objectively
Co-saliency detection via inter and intra saliency propagation
No full textThe goal of salient object detection from an image is to extract the regions which capture the attention of the human visual system more than other regions of the image. In this paper a novel method is presented for detecting salient objects from a set of images, known as co-saliency detection. We treat co-saliency detection as a two-stage saliency propagation problem. The first inter-saliency propagation stage utilizes the similarity between a pair of images to discover common properties of the images with the help of a single image saliency map. With the pairwise co-salient foreground cue maps obtained, the second intra-saliency propagation stage refines pairwise saliency detection using a graph-based method combining both foreground and background cues. A new fusion strategy is then used to obtain the co-saliency detection results. Finally an integrated multi-scale scheme is employed to obtain pixel-level co-saliency maps. The proposed method makes use of existing saliency detection models for co-saliency detection and is not overly sensitive to the initial saliency model selected. Extensive experiments on three benchmark databases show the superiority of the proposed co-saliency model against the state-of-the-art methods both subjectively and objectively
Inverse nonnegative local coordinate factorization for visual tracking
No full textRecently, nonnegative matrix factorization (NMF) with part based representation has been widely used for appearance modelling in visual tracking. Unfortunately, not all the targets can be successfully decomposed as "parts" unless some rigorous conditions are satisfied. To avoid this problem, this paper introduces NMF's variants into the visual tracking framework in the view of data clustering for appearance modelling. Firstly, an initial target appearance model based on NMF is proposed to describe the target's appearance with the incorporated local coordinate factorization constraint, orthogonality of the bases, and L1,1 norm regularized sparse residual error constraint. Secondly, an inverse NMF model is proposed, in which each learned base vector is regarded as a clustering center in a low-dimensional subspace. Potential target samples (from the foreground) will be clustered around base vectors; while the candidate samples (from the background) are very likely to spread irregularly over the entire clustering space. Such difference can be fully exploited by the inverse NMF model to produce more discriminative encoding vectors than the conventional NMF method. Further, incremental updating model is introduced into the tracking framework for online updating the initial appearance model. Experiments on Object Tracking Benchmark (OTB) suggest that our tracker is able to achieve promising performance when compared to some state-of-the-art methods in deformation, occlusion, and other challenging situations
Superimposed features and deformation mechanism of Early Mesozoic folds in the Sangzhi-Shimen area, northern Hunan
No full textA series of Jurassic-type folds have continuously developed in the Mesozoic from the Sangzhi-Shimen area in northern Hunan. The analysis of the fold superimposition characteristics is of great significance to explore the deformation period and deformation mechanism of the Sangzhi-Shimen complex oblique folds, and also for the theoretical study of fold deformation controlled by faults. Based on the measurement of geological structure section and analysis of fold superimposition characteristics in Sangzhi-Shimen area, two fold structures in Indosinian and early Yanshanian were identified. The low-angle unconformity contact between the Jurassic and the Middle Triassic in the study area, and the high-angle unconformity contact between the Cretaceous and the Pre-Cretaceous reflect two deformation events of Indosinian and Early Yanshanian movement. It can be further inferred that the folds in the Sangzhi-Shimen area can be divided into two phases: the Indosinian movement and the early Yanshanian movement.The Indosinian fold axial trace mainly showed NEE to near EW; the early Yanshanian fold axial trace can be divided into two groups, one is NEE-near EW, the other is NNE. Two groups of early Yanshanian folds and pre Indosinian folds are superimposed to form two types of superposed folds, the enhanced type and the oblique limited type. The former is controlled by the inherited activities of the Indosinian NEE-near EW reverse fault; the latter is controlled by NNE trending reverse fault, which formed by NWW trending regional compressive stress in early Yanshanian, and it is limited by the pre NEE-near EW trending structure.This deformation mechanism well explains that the fold axis and thrust fault in the study area have no east or Southeast inclined polarity
Protective effects of pioglitazone on vascular endothelial cell dysfunction induced by high glucose via an inhibition of IKKα/β-NFκB signaling mediated by PPARγ in vitro
No full textPioglitazone (PIO), a synthetic ligand for peroxisome proliferator activated receptor γ (PPARγ), is clinically used to treat type 2 diabetes mellitus. However, little is known on its endothelial protective effects and the underlying mechanisms. In this study, we sought to investigate PIO’s endothelial protective effects and its likely mechanisms. 95% confluent high glucose concentration (HG, 33 mM)-injured WT-HUVECs and PPARγLow-HUVECs were first pretreated with 10 μM of GW9662 for 30 minutes, and then treated with various concentrations of PIO (5, 10, 20 μM) for 24 hours. Finally, the levels of NO, endothelin 1(ET1), tumor necrosis factor alpha (TNFα) and interleukin 6 (IL6) were detected. The cells were utilized to determine the cell viability, caspase3 activity, the levels of inhibitory κB kinase α/β (IKKα/β) mRNA, IKKα/β, and nuclear factor κB (NFκB) p65. Severe dysfunction and activation of IKKα/β-NFκB signaling occurred after exposure of HUVECs to HG. Conversely, treatment with PIO significantly attenuated the dysfunction and the activation of IKKα/β-NFκB signaling induced by HG in a dose-dependent manner. Moreover, the protective effects of PIO were completely abrogated by GW9662 or down-regulation of PPARγ. Taken together, PIO protects HUVECs against the HG-induced dysfunction through the inhibition of IKKα/β-NFκ B signaling mediated by PPARγ.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
Comparison of pollution diffusion between river mouth inflow (RMI) and beach uniform inflow (BUI) in sudden water accident
No full textRecently high-frequency sudden pollution originated from an explosion of industrial plants, transportation accidents and oil spills was often continuously diffused into downstream water. In this paper, the features of pollution diffusion including the boundary shape, concentration gradients and covered area from the two typical sudden water accidents of river mouth inflow (RMI) and beach uniform inflow (BUI) were investigated and compared by utilizing computational fluid dynamic (CFD) model and lab-scale experiments. It was found that a circular boundary shape was formed when diffusion velocity was slower than threshold velocity of 0.0016 m/s, however, a long strip of boundary was replaced at the speed of more than 0.0016 m/s from RMI, using CFD simulation under lab-scale. The coincidence degree of diffusion over time in terms of covered area and boundary shape between CFD simulation and the lab-scale experiment was reached to 97.6–99.6% both in RMI and BUI. The result indicated that CFD was applied to simulate the pollution diffusion from the two patterns of sudden water accidents under full-scale. Results showed that a sharp peak was capable of appearing in mainstream and there was a ring current appearing in side wing from RMI. However, the mainstream with a gentle peak and the side wing with symmetrical diffusion were arising in BUI. In addition, a high concentration gradients and a clear concentration contours were both exhibited in RMI and BUI. The results may assist in offering emergency response to control sudden pollution diffusion, further supporting the scope of pollution hazard assessment and ecological remediation to recover pollution region.The author acknowledges the financial support from the National Natural Science Foundation of China (No. 31070401), the College Natural Science Foundation of Major Project of Anhui, China, the Foundation of Provincial Key Laboratory of Biotic Environment and Ecological Safety in Anhui
Humus composition of mineral-microbial residue from microbial utilization of lignin involving different mineral types
No full textThis study explored the mineral contribution of lignin to humus (HS) formation through the change of HS composition in microbial–mineral residue (MMR). The liquid shake flask culture method was adopted to collect the MMR formed through the microbial utilization of lignin in the presence of goethite, bayerite, δ-MnO2, kaolinite, and montmorillonite. The carbon (C) contents of humic-like acid (HLA), fulvic-like acid (FLA), and humin-like (HLu) in MMR, represented as CHLA, CFLA, and CHLu, respectively, coupled with the ΔlogK of the HLA alkali-soluble extract and CHLA/CFLA ratio were analyzed at 10, 30, 60, and 110 d. In terms of improving HLA aggregated on minerals, the following rule was observed: goethite > bayerite > montmorillonite > kaolinite ≈δ-MnO2. Goethite was most likely to adsorb organic molecules with a high degree of polymerization. Compared with kaolinite and montmorillonite, goethite, bayerite, and δ-MnO2 were more helpful for decreasing the molecular weight and the degree of HLA condensation. Goethite, δ-MnO2, and montmorillonite presented the greatest advantages in enhancing the relative proportions of CHLA, CFLA, and CHLu, respectively, in MMR. In MMR formed in the presence of kaolinite, goethite, and bayerite, CHLA was decreased by 14.8%, 12.0%, and 5.8%, respectively, at the end of culture, whereas the CHLA associated with δ-MnO2 was increased by 12.0%. δ-MnO2 contributed the most to the conversion of CFLA to CHLA. Due to expandability and a much greater adsorption capacity, montmorillonite was most beneficial to the accumulation of CHLu.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
The role of APOBEC3C in modulating the tumor microenvironment and stemness properties of glioma: evidence from pancancer analysis
No full textBackgroundIt is now understood that APOBEC3 family proteins (A3s) are essential in tumor progression, yet their involvement in tumor immunity and stemness across diverse cancer types remains poorly understood.MethodsIn the present study, comprehensive genome-wide statistical and bioinformatic analyses were conducted to elucidate A3 family expression patterns, establishing clinically relevant correlations with prognosis, the tumor microenvironment(TME), immune infiltration, checkpoint blockade, and stemness across cancers. Different experimental techniques were applied, including RT–qPCR, immunohistochemistry, sphere formation assays, Transwell migration assays, and wound-healing assays, to investigate the impact of A3C on low-grade glioma (LGG) and glioblastoma multiforme (GBM), as well as its function in glioma stem cells(GSCs).ResultsDysregulated expression of A3s was observed in various human cancer tissues. The prognostic value of A3 expression differed across cancer types, with a link to particularly unfavorable outcomes in gliomas. A3s are associated with the the TME and stemness in multiple cancers. Additionally, we developed an independent prognostic model based on A3s expression, which may be an independent prognostic factor for OS in patients with glioma. Subsequent validation underscored a strong association between elevated A3C expression and adverse prognostic outcomes, higher tumor grades, and unfavorable histology in glioma. A potential connection between A3C and glioma progression was established. Notably, gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses implicated A3C in immune system-related diseases, with heightened A3C levels contributing to an immunosuppressive tumor microenvironment (TME) in glioma. Furthermore, in vitro experiments substantiated the role of A3C in sustaining and renewing glioma stem cells, as A3C deletion led to diminished proliferation, invasion, and migration of glioma cells.ConclusionThe A3 family exhibits heterogeneous expression across various cancer types, with its expression profile serving as a predictive marker for overall survival in glioma patients. A3C emerges as a regulator of glioma progression, exerting its influence through modulation of the tumor microenvironment and regulation of stemness
