46 research outputs found

    Cloze Test Helps: Effective Video Anomaly Detection via Learning to Complete Video Events

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    As a vital topic in media content interpretation, video anomaly detection (VAD) has made fruitful progress via deep neural network (DNN). However, existing methods usually follow a reconstruction or frame prediction routine. They suffer from two gaps: (1) They cannot localize video activities in a both precise and comprehensive manner. (2) They lack sufficient abilities to utilize high-level semantics and temporal context information. Inspired by frequently-used cloze test in language study, we propose a brand-new VAD solution named Video Event Completion (VEC) to bridge gaps above: First, we propose a novel pipeline to achieve both precise and comprehensive enclosure of video activities. Appearance and motion are exploited as mutually complimentary cues to localize regions of interest (RoIs). A normalized spatio-temporal cube (STC) is built from each RoI as a video event, which lays the foundation of VEC and serves as a basic processing unit. Second, we encourage DNN to capture high-level semantics by solving a visual cloze test. To build such a visual cloze test, a certain patch of STC is erased to yield an incomplete event (IE). The DNN learns to restore the original video event from the IE by inferring the missing patch. Third, to incorporate richer motion dynamics, another DNN is trained to infer erased patches' optical flow. Finally, two ensemble strategies using different types of IE and modalities are proposed to boost VAD performance, so as to fully exploit the temporal context and modality information for VAD. VEC can consistently outperform state-of-the-art methods by a notable margin (typically 1.5%-5% AUROC) on commonly-used VAD benchmarks. Our codes and results can be verified at github.com/yuguangnudt/VEC_VAD.Comment: To be published as an oral paper in Proceedings of the 28th ACM International Conference on Multimedia (ACM MM '20). 9 pages, 7 figure

    Interaction of influenza virus NS1 protein with growth arrest-specific protein 8

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    NS1 protein is the only non-structural protein encoded by the influenza A virus, and it contributes significantly to disease pathogenesis by modulating many virus and host cell processes. A two-hybrid screen for proteins that interact with NS1 from influenza A yielded growth arrest-specific protein 8. Gas8 associated with NS1 in vitro and in vivo. Deletion analysis revealed that the N-terminal 260 amino acids of Gas8 were able to interact with NS1, and neither the RNA-binding domain nor the effector domain of NS1 was sufficient for the NS1 interaction. We also found that actin, myosin, and drebrin interact with Gas8. NS1 and β-actin proteins could be co-immunoprecipitated from extracts of transfected cells. Furthermore, actin and Gas8 co-localized at the plasma membrane. These results are discussed in relation to the possible functions of Gas8 protein and their relevance in influenza virus release

    Evidence for an association of HLA-DRB1*15 and DRB1*09 with leprosy and the impact of DRB1*09 on disease onset in a Chinese Han population

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    <p>Abstract</p> <p>Background</p> <p>Human leukocyte antigens (HLAs) have been proposed to modulate the immune response to <it>Mycobacterium leprae</it>. The association of HLA-DRB1 with leprosy has been reported in several populations, but not in a Chinese population.</p> <p>Methods</p> <p>The polymerase chain reaction-sequence-specific oligonucleotide probe with Luminex100 (PCR-SSOP-Luminex) method was used to genotype HLA-DRB1 alleles in 305 leprosy patients and 527 healthy control individuals.</p> <p>Results</p> <p>The HLA-DRB1*15 allele was significantly more prevalent among leprosy patients than healthy controls, whereas the frequency of the HLA-DRB1*09 allele was lower among leprosy patients, especially those with early-onset disease.</p> <p>Conclusion</p> <p>HLA-DRB1 alleles are associated with leprosy susceptibility in a Chinese population. The HLA-DRB1*09 allele was found to be protective exclusively in a subset of early-onset leprosy patients.</p

    Mimotopes selected with neutralizing antibodies against multiple subtypes of influenza A

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    <p>Abstract</p> <p>Background</p> <p>The mimotopes of viruses are considered as the good targets for vaccine design. We prepared mimotopes against multiple subtypes of influenza A and evaluate their immune responses in flu virus challenged Balb/c mice.</p> <p>Methods</p> <p>The mimotopes of influenza A including pandemic H1N1, H3N2, H2N2 and H1N1 swine-origin influenza virus were screened by peptide phage display libraries, respectively. These mimotopes were engineered in one protein as multi- epitopes in Escherichia coli (E. coli) and purified. Balb/c mice were immunized using the multi-mimotopes protein and specific antibody responses were analyzed using hemagglutination inhibition (HI) assay and enzyme-linked immunosorbent assay (ELISA). The lung inflammation level was evaluated by hematoxylin and eosin (HE).</p> <p>Results</p> <p>Linear heptopeptide and dodecapeptide mimotopes were obtained for these influenza virus. The recombinant multi-mimotopes protein was a 73 kDa fusion protein. Comparing immunized infected groups with unimmunized infected subsets, significant differences were observed in the body weight loss and survival rate. The antiserum contained higher HI Ab titer against H1N1 virus and the lung inflammation level were significantly decreased in immunized infected groups.</p> <p>Conclusions</p> <p>Phage-displayed mimotopes against multiple subtypes of influenza A were accessible to the mouse immune system and triggered a humoral response to above virus.</p

    Construction and Connectivity Stress Analysis of Urban Ecological Network in the Nansha New District

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    Optimizing the ecological network structure and enhancing habitat connectivity are key to ensuring urban ecological security, and the combination of urban big data can more accurately reveal the stress effects of the spatial heterogeneity of human activities on ecological connectivity. In recent years, numerous studies have focused on urban ecological networks; however, they have been limited by the accuracy of correction resistance data and the lack of source corridor identification methods, which makes it challenging to establish ecological networks with attributes. Thus, small- and medium-sized urban ecological network construction and connectivity stress analysis are lacking. In this study, a comprehensive resistance surface was constructed based on Point of Interest(POI) data and land use data; an ecological network with quantitative attributes was constructed using the InVEST habitat quality analysis and circuit theory, and the stress factors and disturbance intensity affecting the corridor connectivity of the network were clarified. Three main conclusions were drawn from the above analysis. First, the overall habitat quality of Nansha New District is good, and the centrality of ecological source areas ranges from 26.8 to 69.26. This centrality is inversely correlated with the source area's weighted center of gravity distance and positively correlated with the source area. The connectivity of most ecological corridors is between 17.56 and 92.56 and is inversely proportional to the corridors' length and resistance. Second, the ecological network of Nansha New District consists of 18 high habitat quality sources, 40 optimal ecological corridors, and 125.70 km² of potential corridors, spatially showing an introverted spatial pattern of "dense in the middle and sparse in the north and south." The corridors in the middle are more densely distributed and shorter in length and have higher connectivity and a concentrated distribution of sources. The north and south ends are scattered with low-level sources and the formation of more long-distance corridors with low connectivity. Finally, the main threatening factors of corridor connectivity in Nansha New District are four types of POI facilities, namely, companies, transportation facilities, shopping consumption, and life services. The numbers of corridors mainly coerced by companies, transportation facilities, life services, and shopping consumption POI are 23, 10, 5, and 2, respectively. Reducing and controlling the number of the above four types of POIs in the latent corridors will effectively enhance the connectivity of ecological networks and alleviate the isolation of source areas, reducing the trend of source islanding and habitat fragmentation. The research results can provide a concrete entry point for the maintenance of an excellent ecological background in Nansha New District in terms of spatial scope and facility renovation, which is of practical significance for the construction of a high-quality urban development benchmark

    Mechanocatalytic Solvent-Free Esterification of Sugarcane Bagasse

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    Esterification is a versatile way to produce the derivatives of lignocellulose with developed properties. However, the traditional heterogeneous esterification of lignocellulose suffered from the drawbacks of low efficiency, additional reaction medium and heating. In the present study, an efficient method was developed to produce the functionalized sugarcane bagasse (SCB) by ball milling without any additional solvents and heating. The effects of pulverization time, rotation speed, the kind of linear chain anhydrides, the ratio of anhydrides to SCB, with or without pyridine catalyst and the dosage of catalyst were investigated on weight percent gain (WPG) of SCB esters. The results indicated that the high efficiency of this mechanocatalystic esterification was probably due to the destroyed crystalline structure and the promoted penetration of the esterifying reagent onto SCB bulk caused by ball milling. The maximum WPG of SCB acetate, propionate and butyrate reached 33.3%, 33.6% and 32.4%, respectively. The physicochemical structure of the esterified SCB was characterized with Fourier transform infrared spectra (FT-IR), solid state cross-polarized magic angle spinning 13C nuclear magnetic resonance (CP/MAS 13C-NMR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The direct evidence of the esterification occurrence was provided with FT-IR and solid-state CP/MAS 13C-NMR. The thermal stability of SCB increased upon the mechanocatalytic esterification. The results implied that the relatively homogeneous modification was achieved with this semi-homogeneous esterification method by ball milling

    Rhamnolipids produced by indigenous Acinetobacter junii from petroleum reservoir and its potential in enhanced oil recovery

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    Biosurfactant producers are crucial for incremental oil production in microbial enhanced oil recovery (MEOR) processes. The isolation of biosurfactant-producing bacteria from oil reservoirs is important because they are considered suitable for the extreme conditions of the reservoir. In this work, a novel biosurfactant-producing strain Acinetobacter junii BD was isolated from a reservoir to reduce surface tension and emulsify crude oil. The biosurfactants produced by the strain were purified and then identified via electrospray ionization-Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR-MS). The biosurfactants generated by the strain were concluded to be rhamnolipids, the dominant rhamnolipids were C26H48O9, C28H52O9, and C32H58O13. The optimal carbon source and nitrogen source for biomass and biosurfactant production were NaNO3 and soybean oil. The results showed that the content of acid components increased with the progress of crude oil biodegradation. A glass micromodel test demonstrated that the strain significantly increased oil recovery through interfacial tension reduction, wettability alteration and the mobility of microorganisms. In summary, the findings of this study indicate that the newly developed BD strain and its metabolites have great potential in MEOR

    α-Lipoic Acid Attenuates LPS-Induced Cardiac Dysfunction Through a PI3K/Akt-Dependent Mechanism

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    Myocardial dysfunction is an important manifestation of sepsis/septic shock. Activation of Phosphatidylinositol 3-kinase(PI3K)/protein kinase B (Akt) signaling pathway has been shown to improve cardiac performance during sepsis/septic shock. We have reported previously that α-lipoic acid (LA) activates PI3K/Akt pathway in neuronal cells. It is possible, therefore, that treatment with LA will attenuate cardiac dysfunction during sepsis/septic shock through a PI3K/Akt-dependent mechanism. To test this possibility, we treated mice with LA prior to lipopolysaccharide (LPS) challenge. Cardiac function was analyzed by echocardiography 6 h after LPS challenge. LPS significantly suppressed cardiac function as evidenced by decreases in EF% and FS% in mice. However, LA pretreatment significantly attenuated cardiac dysfunction following LPS challenge. LA pretreatment also improved survival in LPS-challenged mice. Furthermore, LA markedly attenuated the LPS-induced inflammatory response in myocardium, as evidenced by decreases in the upregulation of VCAM-1, ICAM-1 and iNOS, as well as myocardial leucocytes infiltration. Moreover, LPS challenge significantly decreased the phosphorylation levels of Akt and Gsk-3β, which was prevented by LA pretreatment. More importantly, inhibition of PI3K/Akt signaling by Wortmannin (WM) completely abrogated the LA-induced protection in cardiac dysfunction following LPS challenge. Collectively, our results demonstrated that LA improved cardiac function during endotoxemia. The mechanism was through, at least in part, preserved activation of the PI3K/Akt signaling

    HSPA12B Attenuates Acute Lung Injury During Endotoxemia in Mice

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    Acute lung injury (ALI) is a critical manifestation of sepsis/septic shock. Heat shock protein A12B (HSPA12B), an endothelial cell-expressed heat shock protein, shows a negative regulation of lipopolysaccharide (LPS)-induced inflammation in myocardium and endothelial cells. However, it is unclear whether HSPA12B exerts protective effects against ALI during sepsis/septic shock. In this study, we treated HSPA12B transgenic mice (Tg) and wild type littermates (WT) with LPS for 6 h to induce endotoxemia. LPS treatment significantly caused pulmonary injuries as evidenced by microarchitecture destruction, vascular leakage and neutrophil recruitment in lungs of WT mice. However, the LPS-induced pulmonary injuries were significantly attenuated in Tg mice. Moreover, the LPS-induced activation of extracellular signal-regulated kinases (ERKs) and upregulation of intercellular adhesion molecule-1 (ICAM-1) and Cyclooxygenase-2 (Cox-2) were inhibited in Tg lungs compared with that in WT mice. Additionally, Tg lungs showed a significant lower level of vascular endothelial growth factor (VEGF) compared with WT mice. Our results demonstrate a pulmonary protective effect of HSPA12B against endotoxin challenge, which indicates management of HSPA12B expression could serve as a potential therapeutic target for ALI during sepsis/septic shock
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