395 research outputs found

    OFAR: A Multimodal Evidence Retrieval Framework for Illegal Live-streaming Identification

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    Illegal live-streaming identification, which aims to help live-streaming platforms immediately recognize the illegal behaviors in the live-streaming, such as selling precious and endangered animals, plays a crucial role in purifying the network environment. Traditionally, the live-streaming platform needs to employ some professionals to manually identify the potential illegal live-streaming. Specifically, the professional needs to search for related evidence from a large-scale knowledge database for evaluating whether a given live-streaming clip contains illegal behavior, which is time-consuming and laborious. To address this issue, in this work, we propose a multimodal evidence retrieval system, named OFAR, to facilitate the illegal live-streaming identification. OFAR consists of three modules: Query Encoder, Document Encoder, and MaxSim-based Contrastive Late Intersection. Both query encoder and document encoder are implemented with the advanced OFA encoder, which is pretrained on a large-scale multimodal dataset. In the last module, we introduce contrastive learning on the basis of the MaxiSim-based late intersection, to enhance the model's ability of query-document matching. The proposed framework achieves significant improvement on our industrial dataset TaoLive, demonstrating the advances of our scheme

    ЭКСПЕРИМЕНТАЛЬНОЕ ИЗУЧЕНИЕ ТЕПЛОВЫХ И ДЕФОРМАЦИОННЫХ ПОЛЕЙ В ПРОЦЕССЕ РАЗРУШЕНИЯ ЭШЕЛОНИРОВАННЫХ РАЗЛОМОВ И ИЗМЕНЕНИЯ ГЕОЛОГИЧЕСКИХ УСЛОВИЙ

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    The article presents results of experimental studies using a bi-axial servo-control system to apply load on samples with extensional and compressional en echelon faults. During the experiments, variations of temperature and thermal images were recorded synchronously by a multi-path contact-type thermometric apparatus and a thermal image system, respectively. A digital CCD camera was employed to synchronously collect images of specimens’ surfaces. The digital speckle correlation method (DSCM) was utilized to analyze the images and to define displacements and strain fields. Our experimental results show that temperature fields have clear responses to opposite stress states in the jog areas of both types of the en echelon faults. Prior to failure of the jog area, its temperature is the highest at the compressional en echelon faults and the lowest at the extensional en echelon faults. Records by DSCM give evidence that mean strain of the jog area is the highest at compressional en echelon faults and the lowest at the extensional en echelon faults. It is revealed that deformation of the en echelon faults occurs in two stages, developing from stress build-up and fault propagation in the jog area to unstable sliding along the fault. Correspondingly, the mechanism of heating-up converts from strain heating into friction heating. During the period of transformation of the temperature rising mechanism, three events are observed in the jog area and its vicinity. Analyses of our experimental results demonstrate that variations of temperatures in the jog area can be indicative of fault sliding and suggest sliding directions. Observations and studies of temperature changes during transformation of the temperature rising mechanism at sensitive portions of faults are of great importance for early detection of precursors of unstable slip on active faults.В статье представлены результаты экспериментального изучения эшелонированных разломов растяжения и сжатия с приложением нагрузки к двуосной автоматически регулируемой модели. В ходе эксперимента производились синхронные замеры температур и тепловых сигналов. Для этого были использованы, соответственно, многоканальный термометрический прибор контактного типа и система регистрации тепловых сигналов. Синхронные снимки поверхностей экспериментальных образцов были получены при помощи цифровой видеокамеры на основе устройства с зарядовой связью. Был применен цифровой метод спекл-корреляции (DSCM) для анализа снимков и определения смещений и деформационных полей. Была установлена очевидная реакция тепловых полей на состояния напряжения противоположных типов в зонах сочленения эшелонированных разломов обоих типов. Перед полным разрушением зоны сочленения самые высокие значения температуры зарегистрированы на эшелонированных разломах сжатия, самые низкие – на эшелонированных разломах растяжения. С помощью метода DSCM самые высокие значения среднего напряжения в зоне сочленения дислокаций зарегистрированы на эшелонированных разломах сжатия, самые низкие – на эшелонированных разломах растяжения. В процессе деформирования эшелонированных разломов выявлены две стадии, развивающиеся от накопления напряжений и прорастания разлома в зону сочленения дислокаций до неустойчивого скольжения по разлому. Соответственно трансформируется механизм нагревания – с нагревания напряжением до нагревания трением. В самой зоне сочленения дислокаций и поблизости от неё в процессе трансформирования механизма повышения температуры наблюдались три фазы. Анализ полученных нами экспериментальных данных показал, что вариации температуры в зоне сочленения дислокации могут указывать на смещения по разлому и позволяют предположить направление смещения. Наблюдение за изменениями температуры и их изучение в процессе трансформирования механизма повышения температуры на чувствительных отрезках разломов имеют большое значение в плане раннего выявления предвестников неустойчивого смещения по активным разломам

    Recent Development of the Synthesis and Engineering Applications of One-Dimensional Boron Nitride Nanomaterials

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    One-dimensional (1D) nanomaterials with novel photoelectric, magnetic, mechanical, and electronic transport properties have long been the research focus throughout the world. Herein, the recent achievements in preparation of 1D boron nitride nanomaterials, including nanotubes, nanowires, nanoribbons, nanorods, and nanofibres are reviewed. As the most intriguing and researched polymorph, boron nitride nanotubes (BNNTs) are introduced thoroughly involving their functionalization and doping. The electronics and engineering applications of 1D boron nitride nanomaterials are illustrated in nanoscale devices, hydrogen storage, polymer composites, and newly developed biomedical fields in detail

    Prevalence of ideal cardiovascular health and its relationship with relative handgrip strength in rural northeast China

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    ObjectivesWe aimed to investigate ideal cardiovascular health (CVH), its relationship with handgrip strength, and its components in rural China.MethodsWe conducted a cross-sectional study of 3,203 rural Chinese individuals aged ≥35 years in Liaoning Province, China. Of these, 2,088 participants completed the follow-up survey. Handgrip strength was estimated using a handheld dynamometer and was normalized to body mass. Ideal CVH was assessed using seven health indicators (smoking, body mass index, physical activity, diet, cholesterol, blood pressure, and glucose). Binary logistic regression analyses were performed to assess the correlation between handgrip strength and ideal CVH.ResultsWomen had a higher rate of ideal cardiovascular health (CVH) than men (15.7% vs. 6.8%, P < 0.001). Higher handgrip strength correlated with a higher proportion of ideal CVH (P for trend <0.001). After adjusting for confounding factors, the odds ratios (95% confidence interval) of ideal CVH across increasing handgrip strength tripartite were 1.00 (reference), 2.368 (1.773, 3.164), and 3.642 (2.605, 5.093) in the cross-sectional study and 1.00 (reference), 2.088 (1.074, 4.060), and 3.804 (1.829, 7.913) in the follow-up study (all P < 0.05).ConclusionIn rural China, the ideal CVH rate was low, and positively correlated with handgrip strength. Grip strength can be a rough predictor of ideal CVH and can be used to provide guidelines for improving CVH in rural China

    Turning a native or corroded Mg alloy surface into an anti-corrosion coating in excited CO2

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    Despite their energy-efficient merits as promising light-weight structural materials, magnesium (Mg) based alloys suffer from inadequate corrosion resistance. One primary reason is that the native surface film on Mg formed in air mainly consists of Mg(OH)2 and MgO, which is porous and unprotective, especially in humid environments. Here, we demonstrate an environmentally benign method to grow a protective film on the surface of Mg/Mg alloy samples at room temperature, via a direct reaction of already-existing surface film with excited CO2. Moreover, for samples that have been corroded obviously on surface, the corrosion products can be converted directly to create a new protective surface. Mechanical tests show that compared with untreated samples, the protective layer can elevate the yield stress, suppress plastic instability and prolong compressive strains without peeling off from the metal surface. This environmentally friendly surface treatment method is promising to protect Mg alloys, including those already-corroded on the surface.China. Ministry of Science and Technology. National Key Research and Development Program (No. 2017YFB0702001)National Natural Science Foundation of China (51621063)National Natural Science Foundation of China (51601141)National Natural Science Foundation of China ( 51401239)Shaanxi Sheng (China). Science and Technology Department (2016KTZDGY-04-03)Shaanxi Sheng (China). Science and Technology Department (2016KTZDGY-04-04)China Postdoctoral Science Foundation (2016M600788)China University of Petroleum. Science Foundation (No. 2462018BJC005)China University of Petroleum. Science Foundation (C201603)National Science Foundation (U.S.) (ECCS-1610806

    Spin-glass ground state in a triangular-lattice compound YbZnGaO4_4

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    We report on comprehensive results identifying the ground state of a triangular-lattice structured YbZnGaO4_4 to be spin glass, including no long-range magnetic order, prominent broad excitation continua, and absence of magnetic thermal conductivity. More crucially, from the ultralow-temperature a.c. susceptibility measurements, we unambiguously observe frequency-dependent peaks around 0.1 K, indicating the spin-glass ground state. We suggest this conclusion to hold also for its sister compound YbMgGaO4_4, which is confirmed by the observation of spin freezing at low temperatures. We consider disorder and frustration to be the main driving force for the spin-glass phase.Comment: Version as accepted to PR

    Comparative transcriptome analysis of PBMC from HIV patients pre- and post-antiretroviral therapy

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    Infections of the human immunodeficiency virus (HIV) trigger host immune responses, but the virus can destroy the immune system and cause acquired immune deficiency syndrome (AIDS). Highly active antiretroviral therapy (HAART) can suppress viral replication and restore the impaired immune function. To understand HIV interactions with host immune cells during HAART, the transcriptomes of peripheral blood mononuclear cells (PBMC) from HIV patients and HIV negative volunteers before and two weeks after HAART initiation were analyzed using RNA sequencing (RNA-Seq) technology. Differentially expressed genes (DEGs) in response to HAART were firstly identified for each individual, then common features were extracted by comparing DEGs among individuals and finally HIV-related DEGs were obtained by comparing DEGs between the HIV patients and HIV negative volunteers. To demonstrate the power of this approach, minimum numbers of patients (one HIV alone; one HIV + tuberculosis, TB; one HIV + TB with immune reconstitution inflammatory syndrome during HAART) and two HIV negative volunteers were used. More than 15,000 gene transcripts were detected in each individual sample. Fourteen HAART up-regulated and eleven down-regulated DEGs were specifically identified in the HIV patients. Among them, nine up-regulated (CXCL1, S100P, AQP9, BASP1, MMP9, SOD2, LIMK2, IL1R2 and BCL2A1) and nine down-regulated DEGs (CD160, CD244, CX3CR1, IFIT1, IFI27, IFI44, IFI44L, MX1 and SIGLEC1) have already been reported as relevant to HIV infections in the literature, which demonstrates the credibility of the method. The newly identified HIV-related genes (up-regulated: ACSL1, GPR84, GPR97, ADM, LRG1; down-regulated: RASSF1, PATL2) were empirically validated using qRT-PCR. The Gene Set Enrichment Analysis (GSEA) was also used to determine pathways significantly affected by HAART. GSEA further confirmed the HAART relevance of five genes (ADM, AQP9, BASP1, IL1R2 and MMP9). The newly identified HIV-related genes, ADM (which encodes Adrenomedullin), a peptide hormone in circulation control, may contribute to HIV-associated hypertensions, providing new insights into HIV pathology and novel strategies for developing anti-HIV target. More importantly, we demonstrated that comparative transcriptome analysis is a very powerful tool to identify infection related DEGs using a very small number of samples. This approach could be easily applied to improve the understanding of pathogen-host interactions in many infections and anti-infection treatments

    Blow to the northeast? Intraspecific differentiation of populus davidiana suggests a northeastward skew of a phylogeographic break boundary in East Asia

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    Aim There is increasing interest in the role that biological traits, and historical and biogeographic processes, play in the formation of phylogeographic patterns. An arid belt that once existed in northern China might have affected many plants, but this has yet to be tested in an arid-tolerant, wind-dispersed species. Here, we tested how intrinsic and extrinsic factors have affected the phylogeography of Populus davidiana. Location East Asia. Methods Genetic variation was surveyed across 40 populations (555 individuals) covering the Chinese range of P. davidiana, using 16 nuclear microsatellite loci (nSSRs) and four chloroplast fragments (cpDNA). Demographic and migration hypotheses were tested using coalescent-based approaches, and the present and past potential distributions were predicted using species distribution modelling. Results Molecular data divide P. davidiana into two lineages, north-eastern China (NECR) and central and northern China (CNCR); however, the dividing line is around 118ºE for nSSRs, but 122ºE for cpDNA. The range and habitat of the two lineages barely overlap at present, and their ecological separation may have initiated around the Pliocene-Quaternary boundary, when major intraspecific cpDNA clades diverged. NECR and CNCR experienced post-glacial north-eastward and northward range shifts respectively. Bi-directional historical gene flow was detected between NECR and CNCR for both bi-parentally inherited nSSRs and maternally inherited cpDNA. Demographic inferences suggest a severe bottleneck for CNCR and especially NECR, around the latest Pleistocene. Main conclusions The phylogeographic break within P. davidiana reflects the impacts of biogeographic history, climate and biological traits. Its plumed, wind-dispersed seeds might be especially significant because prevailing south-western spring winds may have moved the NECR-CNCR boundary further east than similar phylogenetic breaks in other species, and also moved the cpDNA boundary relative to that for nuclear markers. Biological traits, therefore, should also be considered when examining the genetic and ecological differentiation between closely related taxa

    Identification of SNPs and Candidate Genes Associated With Salt Tolerance at the Seedling Stage in Cotton (Gossypium hirsutum L.)

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    Salt tolerance in cotton is highly imperative for improvement in the response to decreasing farmland and soil salinization. However, little is known about the genetic basis underlying salt tolerance in cotton, especially the seedling stage. In this study, we evaluated two salt-tolerance-related traits of a natural population comprising 713 upland cotton (Gossypium hirsutum L.) accessions worldwide at the seedling stage and performed a genome-wide association study (GWAS) to identify marker-trait associations under salt stress using the Illumina Infinium CottonSNP63K array. A total of 23 single nucleotide polymorphisms (SNPs) that represented seven genomic regions on chromosomes A01, A10, D02, D08, D09, D10, and D11 were significantly associated with the two salt-tolerance-related traits, relative survival rate (RSR) and salt tolerance level (STL). Of these, the two SNPs i46598Gh and i47388Gh on D09 were simultaneously associated with the two traits. Based on all loci, we screened 280 possible candidate genes showing different expression levels under salt stress. Most of these genes were involved in transcription factors, transporters and enzymes and were previously reported as being involved in plant salt tolerance, such as NAC, MYB, NXH, WD40, CDPK, LEA, and CIPK. We further validated six putative candidate genes by qRT-PCR and found a differential expression level between salt-tolerant and salt-sensitive varieties. Our findings provide valuable information for enhancing the understanding of complicated mechanisms of salt tolerance in G. hirsutum seedlings and cotton salt tolerance breeding by molecular marker-assisted selection
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