24 research outputs found

    Shrinking the Semantic Gap: Spatial Pooling of Local Moment Invariants for Copy-Move Forgery Detection

    Full text link
    Copy-move forgery is a manipulation of copying and pasting specific patches from and to an image, with potentially illegal or unethical uses. Recent advances in the forensic methods for copy-move forgery have shown increasing success in detection accuracy and robustness. However, for images with high self-similarity or strong signal corruption, the existing algorithms often exhibit inefficient processes and unreliable results. This is mainly due to the inherent semantic gap between low-level visual representation and high-level semantic concept. In this paper, we present a very first study of trying to mitigate the semantic gap problem in copy-move forgery detection, with spatial pooling of local moment invariants for midlevel image representation. Our detection method expands the traditional works on two aspects: 1) we introduce the bag-of-visual-words model into this field for the first time, may meaning a new perspective of forensic study; 2) we propose a word-to-phrase feature description and matching pipeline, covering the spatial structure and visual saliency information of digital images. Extensive experimental results show the superior performance of our framework over state-of-the-art algorithms in overcoming the related problems caused by the semantic gap.Comment: 13 pages, 11 figure

    Towards an Accurate and Secure Detector against Adversarial Perturbations

    Full text link
    The vulnerability of deep neural networks to adversarial perturbations has been widely perceived in the computer vision community. From a security perspective, it poses a critical risk for modern vision systems, e.g., the popular Deep Learning as a Service (DLaaS) frameworks. For protecting off-the-shelf deep models while not modifying them, current algorithms typically detect adversarial patterns through discriminative decomposition of natural-artificial data. However, these decompositions are biased towards frequency or spatial discriminability, thus failing to capture adversarial patterns comprehensively. More seriously, successful defense-aware (secondary) adversarial attack (i.e., evading the detector as well as fooling the model) is practical under the assumption that the adversary is fully aware of the detector (i.e., the Kerckhoffs's principle). Motivated by such facts, we propose an accurate and secure adversarial example detector, relying on a spatial-frequency discriminative decomposition with secret keys. It expands the above works on two aspects: 1) the introduced Krawtchouk basis provides better spatial-frequency discriminability and thereby is more suitable for capturing adversarial patterns than the common trigonometric or wavelet basis; 2) the extensive parameters for decomposition are generated by a pseudo-random function with secret keys, hence blocking the defense-aware adversarial attack. Theoretical and numerical analysis demonstrates the increased accuracy and security of our detector with respect to a number of state-of-the-art algorithms

    Synthesis, Fungicidal Activity and Mode of Action of 4-Phenyl-6-trifluoromethyl-2-aminopyrimidines against Botrytis cinerea

    No full text
    Anilinopyrimidines are the main chemical agents for management of Botrytis cinerea. However, the drug resistance in fungi against this kind of compounds is very serious. To explore new potential fungicides against B. cinerea, a series of 4-phenyl-6-trifluoromethyl-2-amino-pyrimidine compounds (compounds III-1 to III-22) were synthesized, and their structures were confirmed by 1H-NMR, IR and MS. Most of these compounds possessed excellent fungicidal activity. The compounds III-3 and III-13 showed higher fungicidal activity than the positive control pyrimethanil on fructose gelatin agar (FGA), and compound III-3 on potato dextrose agar (PDA) indicated high activity compared to the positive control cyprodinil. In vivo greenhouse results indicated that the activity of compounds III-3, III-8, and III-11 was significantly higher than that of the fungicide pyrimethanil. Scanning electron micrography (SEM) and transmission electron micrography (TEM) were applied to illustrate the mechanism of title compounds against B. cinerea. The title compounds, especially those containing a fluorine atom at the ortho-position on the benzene ring, could maintain the antifungal activity against B. cinerea, but their mechanism of action is different from that of cyprodinil. The present study lays a good foundation for us to find more efficient reagents against B. cinerea

    The Effect of (1S,2R-((3-bromophenethyl)amino)-N-(4-chloro-2-trifluoromethylphenyl) cyclohexane-1-sulfonamide) on Botrytis cinerea through the Membrane Damage Mechanism

    No full text
    In recent years, Botrytis cinerea has led to serious yield losses because of its resistance to fungicides. Many sulfonamides with improved properties have been used. (1S,2R-((3-bromophenethyl)amino)-N-(4-chloro-2-trifluoromethylphenyl)cyclohexane-1-sulfonamide) (abbreviation: SYAUP-CN-26) is a new sulfonamide compound that has excellent activity against B. cinerea. This study investigated the effect of SYAUP-CN-26 on electric conductivity, nucleic acids leakage, malondialdehyde (MDA) content, and reducing sugars and membrane structure reduction of B. cinerea. The results showed that the cell membrane permeability of B. cinerea increased with increasing concentrations of SYAUP-CN-26; meanwhile, the sugar content decreased, the malondialdehyde content increased, and relative electric conductivity and nucleic acid substance leakage were observed in the cell after exposure to 19.263 mg/L SYAUP-CN-26 for 24 h. After 48 h of exposure to 1.823 mg/L and 19.263 mg/L SYAUP-CN-26, the cell membranes of B. cinerea mycelia were observed to be damaged under propidium iodide (PI) and transmission electron microscopy (TEM) observations. It is assumed that SYAUP-CN-26 was responsible for the damage of cell membrane. Overall, the results indicate that SYAUP-CN-26 could inhibit the growth of B. cinerea cells by damaging the cell membranes

    Synthesis of 2-Acyloxycyclohexylsulfonamides and Evaluation on Their Fungicidal Activity

    Get PDF
    Eighteen N-substituted phenyl-2-acyloxycyclohexylsulfonamides (III) were designed and synthesized by the reaction of N-substituted phenyl-2-hydroxyl- cycloalkylsulfonamides (I, R1) with acyl chloride (II, R2) in dichloromethane under the catalysis of TMEDA and molecular sieve. High fungicidal active compound N-(2,4,5-trichlorophenyl)-2-(2-ethoxyacetoxy) cyclohexylsulfonamide (III-18) was screened out. Mycelia growth assay against the Botrytis cinerea exhibited that EC50 and EC80 of compound III-18 were 4.17 and 17.15 μg mL−1 respectively, which was better than the commercial fungicide procymidone (EC50 = 4.46 μg mL−1 and EC80 = 35.02 μg mL−1). For in vivo activity against B. cinerea in living leaf of cucumber, the control effect of compound III-18 was better than the fungicide cyprodinil. In addition, this new compound had broader fungicidal spectra than chlorothalonil

    Baseline Sensitivity to and Succinate Dehydrogenase Activity and Molecular Docking of Fluxapyroxad and SYP-32497 in Rice Sheath Blight (<i>Rhizoctonia solani</i> AG1-IA) in China

    No full text
    Rice sheath blight caused by Rhizoctonia solani occurs worldwide and is mainly controlled by fungicides. SYP-32497 is a novel succinate dehydrogenase inhibitor, which interferes with the succinate ubiquinone reductase in the mitochondrial respiratory chain of fungi. This study aimed to evaluate the baseline sensitivity of R. solani from 13 major rice producing areas in China to SYP-32497 and fluxapyroxad. The study also explored the cause for the activity discrepancy between SYP-32497 and fluxapyroxad via an enzyme activity inhibition test and molecular docking. A total of 360 R. solani isolates were sensitive to SYP-32497 and fluxapyroxad. Baseline sensitivities were unimodally distributed with mean values of 0.00667 ± 0.00475 and 0.0657 ± 0.0250 μg mL−1, respectively, for SYP-32497 and fluxapyroxad. Enzyme activity assays and molecular docking results revealed that SYP-32497 exhibited a much higher SDH inhibition (IC50 = 0.300 μg mL−1) than to fluxapyroxad (IC50 = 1.266 μg mL−1) because of its excellent SDH binding ability via hydrogen bonding, π-cation, and hydrophobic interactions. These results suggest that SYP-32497 is a good suitable control agent for alternative rice sheath blight

    CWAN: Covert Watermarking Attack Network

    No full text
    Digital watermarking technology is widely used in today’s copyright protection, data monitoring, and data tracking. Digital watermarking attack techniques are designed to corrupt the watermark information contained in the watermarked image (WMI) so that the watermark information cannot be extracted effectively or correctly. While traditional digital watermarking attack technology is more mature, it is capable of attacking the watermark information embedded in the WMI. However, it is also more damaging to its own visual quality, which is detrimental to the protection of the original carrier and defeats the purpose of the covert attack on WMI. To advance watermarking attack technology, we propose a new covert watermarking attack network (CWAN) based on a convolutional neural network (CNN) for removing low-frequency watermark information from WMI and minimizing the damage caused by WMI through the use of deep learning. We import the preprocessed WMI into the CWAN, obtain the residual feature images (RFI), and subtract the RFI from the WMI to attack image watermarks. At this point, the WMI’s watermark information is effectively removed, allowing for an attack on the watermark information while retaining the highest degree of image detail and other features. The experimental results indicate that the attack method is capable of effectively removing the watermark information while retaining the original image’s texture and details and that its ability to attack the watermark information is superior to that of most traditional watermarking attack methods. Compared with the neural network watermarking attack methods, it has better performance, and the attack performance metrics are improved by tens to hundreds of percent in varying degrees, indicating that it is a new covert watermarking attack method

    Sub-chronic toxicity of broflanilide on the nervous system of zebrafish (<i>Danio rerio)</i>

    No full text
    The new insecticide broflanilide, which possesses high insecticidal activity against agricultural pests, acts on the γ-aminobutyric acid receptor in the insect nervous system. At present, few studies assessed its effect on the nervous system of zebrafish, especially its sub-chronic toxicity on the zebrafish brain. In this study, the sub-chronic toxicity of broflanilide on the zebrafish brain was assessed. After 21 days of exposure at 36.3 μg/L, broflanilide caused oxidative damage to the zebrafish brain, increased the levels of reactive oxygen species and malondialdehyde, and inhibited the activities of superoxide dismutase, catalase, and glutathione peroxidase. Overall, these changes result in brain cell apoptosis, and inhibited growth and development. Moreover, broflanilide affects the release of acetylcholinesterase, γ-aminobutyric acid, 5-hydroxy tryptamine, and dopamine as well as the expression of related genes in the brain, leading to abnormal zebrafish behaviour. These results corroborate the sub-chronic toxicity of broflanilide on zebrafish brain, which helps the further understanding of the potential environmental risk of broflanilide.</p

    Design, Synthesis and Fungicidal Activity of 2-Substituted Phenyl-2-oxo-, 2-Hydroxy- and 2-Acyloxyethylsulfonamides

    No full text
    Sulfonyl-containing compounds, which exhibit a broad spectrum of biological activities, comprise a substantial proportion of and play a vital role, not only in medicines but also in agrochemicals. As a result increasing attention has been paid to the research and development of sulfonyl derivatives. A series of thirty-eight 2-substituted phenyl-2-oxo- III, 2-hydroxy- IV and 2-acyloxyethylsulfonamides V were obtained and their structures confirmed by IR, 1H-NMR, and elemental analysis. The in vitro and in vivo bioactivities against two Botrytis cinerea strains, DL-11 and HLD-15, which differ in their sensitivity to procymidone, were evaluated. The in vitro activity results showed that the EC50 values of compounds V-1 and V-9 were 0.10, 0.01 mg L−1 against the sensitive strain DL-11 and 3.32, 7.72 mg L−1 against the resistant strain HLD-15, respectively. For in vivo activity against B. cinerea, compound V-13 and V-14 showed better control effect than the commercial fungicides procymidone and pyrimethanil. The further in vitro bioassay showed that compounds III, IV and V had broad fungicidal spectra against different phytopathogenic fungi. Most of the title compounds showed high fungicidal activities, which could be used as lead compounds for further developing novel fungicidal compounds against Botrytis cinerea
    corecore