27 research outputs found
Forgery-aware Adaptive Vision Transformer for Face Forgery Detection
With the advancement in face manipulation technologies, the importance of
face forgery detection in protecting authentication integrity becomes
increasingly evident. Previous Vision Transformer (ViT)-based detectors have
demonstrated subpar performance in cross-database evaluations, primarily
because fully fine-tuning with limited Deepfake data often leads to forgetting
pre-trained knowledge and over-fitting to data-specific ones. To circumvent
these issues, we propose a novel Forgery-aware Adaptive Vision Transformer
(FA-ViT). In FA-ViT, the vanilla ViT's parameters are frozen to preserve its
pre-trained knowledge, while two specially designed components, the Local-aware
Forgery Injector (LFI) and the Global-aware Forgery Adaptor (GFA), are employed
to adapt forgery-related knowledge. our proposed FA-ViT effectively combines
these two different types of knowledge to form the general forgery features for
detecting Deepfakes. Specifically, LFI captures local discriminative
information and incorporates these information into ViT via
Neighborhood-Preserving Cross Attention (NPCA). Simultaneously, GFA learns
adaptive knowledge in the self-attention layer, bridging the gap between the
two different domain. Furthermore, we design a novel Single Domain Pairwise
Learning (SDPL) to facilitate fine-grained information learning in FA-ViT. The
extensive experiments demonstrate that our FA-ViT achieves state-of-the-art
performance in cross-dataset evaluation and cross-manipulation scenarios, and
improves the robustness against unseen perturbations
Whole-genome sequencing of cultivated and wild peppers provides insights into Capsicum domestication and specialization
As an economic crop, pepper satisfies people's spicy taste and has medicinal uses worldwide. To gain a better understanding of Capsicum evolution, domestication, and specialization, we present here the genome sequence of the cultivated pepper Zunla-1 (C. annuum L.) and its wild progenitor Chiltepin (C. annuum var. glabriusculum). We estimate that the pepper genome expanded similar to 0.3 Mya (with respect to the genome of other Solanaceae) by a rapid amplification of retrotransposons elements, resulting in a genome comprised of similar to 81% repetitive sequences. Approximately 79% of 3.48-Gb scaffolds containing 34,476 protein-coding genes were anchored to chromosomes by a high-density genetic map. Comparison of cultivated and wild pepper genomes with 20 resequencing accessions revealed molecular footprints of artificial selection, providing us with a list of candidate domestication genes. We also found that dosage compensation effect of tandem duplication genes probably contributed to the pungent diversification in pepper. The Capsicum reference genome provides crucial information for the study of not only the evolution of the pepper genome but also, the Solanaceae family, and it will facilitate the establishment of more effective pepper breeding programs
Juglone Inhibits Listeria monocytogenes ATCC 19115 by Targeting Cell Membrane and Protein
Foodborne disease caused by Listeria monocytogenes is a major global food safety problem. A potential solution is the antimicrobial development of the highly bioactive natural product juglone, yet few studies exist on its antibacterial mechanism against L. monocytogenes. Thus, we aimed to elucidate the antibacterial mechanism of action of juglone against L. monocytogenes by determining the resultant cell morphology, membrane permeability, membrane integrity, and proteome changes. The minimum inhibitory concentration of juglone against L. monocytogenes was 50 μg/mL, and L. monocytogenes treated with juglone had longer lag phases compared to controls. Juglone induced L. monocytogenes cell dysfunction, leakage of potassium ions, and membrane potential hyperpolarization. Confocal laser scanning microscopy and field-emission-gun scanning electron microscope assays revealed clear membrane damage due to juglone treatment. Fourier transform infrared analyses showed that L. monocytogenes responded to juglone by some conformational and compositional changes in the molecular makeup of the cell membrane. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis showed that juglone either destroyed proteins or inhibited proteins synthesis in L. monocytogenes. Therefore, our findings established juglone as a natural antibacterial agent with potential to control foodborne L. monocytogenes infections
Cyanobacterial bloom mitigation by sanguinarine and its effects on aquatic microbial community structure
Sanguinarine has strong inhibitory effects against the cyanobacterium Microcystis aeruginosa. However, previous studies were mainly limited to laboratory tests. The efficacy of sanguinarine for mitigation of cyanobacterial blooms under field conditions, and its effects on aquatic microbial community structure remain unknown. To elucidate these issues, we carried out in situ cyanobacterial bloom mitigation tests. Our results showed that sanguinarine decreased population densities of the harmful cyanobacteria Microcystis and Anabaena. The inhibitory effects of sanguinarine on these cyanobacteria lasted 17 days, after which the harmful cyanobacteria recovered and again became the dominant species. Concentrations of microcystins in the sanguinarine treatments were lower than those of the untreated control except during the early stage of the field test. The results of community DNA pyrosequencing showed that sanguinarine decreased the relative abundance of the prokaryotic microorganisms Cyanobacteria, Actinobacteria, Planctomycetes and eukaryotic microorganisms of Cryptophyta, but increased the abundance of the prokaryotic phylum Proteobacteria and eukaryotic microorganisms within Ciliophora and Choanozoa. The shifting of prokaryotic microbial community in water column was directly related to the toxicity of sanguinarine, whereas eukaryotic microbial community structure was influenced by factors other than direct toxicity. Harmful cyanobacteria mitigation efficacy and microbial ecological effects of sanguinarine presented in this study will inform the broad application of sanguinarine in cyanobacteria mitigation. (C) 2019 Elsevier Ltd. All rights reserved.</p
Potential Application of Luteolin as an Active Antibacterial Composition in the Development of Hand Sanitizer Products
Antibacterial hand sanitizers could play a prominent role in slowing down the spread and infection of hand bacterial pathogens; luteolin (LUT) is potentially useful as an antibacterial component. Therefore, this study elucidated the antibacterial mechanism of LUT against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) and developed an antibacterial hand sanitizer. The results showed that LUT had excellent antibacterial activity against both E. coli (minimum inhibitory concentration (MIC) = 312.5 μg/mL, minimal bactericidal concentration (MBC) = 625 μg/mL), and S. aureus (MIC = 312.5 μg/mL, MBC = 625 μg/mL). Furthermore, LUT induced cell dysfunction in E. coli and S. aureus, changed membrane permeability, and promoted the leakage of cellular contents. Confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) analysis showed that LUT treatment affected cell structure and disrupted cell membrane integrity. The Fourier transform infrared analysis (FTIR) also confirmed that the LUT acted on the cell membranes of both E. coli and S. aureus. Overall, the application of LUT in hand sanitizer had better inhibition effects. Therefore, this study could provide insight into expanding the application of LUT in the hand sanitizer markets
Enhanced adsorption of Cd(II) using a composite of poly(acrylamide-co-sodium acrylate) incorporated LDH@MoS 2
On-ground demonstration of laser-link construction for space-based detection of gravitational waves
Laser acquisition and pointing system is subject to establish a 10 6 km magnitude inter-satellite laser link with root ultra-high pointing precision of 10 nrad/ Hz (1 mHz-1 Hz) in space-based gravitational wave detection missions. For the unprecedented challenge, a dedicated laser link construction scheme with three different detectors is proposed. After initial pointing with star trackers, CMOS/CCD cameras intend to suppress the laser pointing error to 1 grad . QPDs are subsequently used to achieve the final requirement. With various detectors and technologies, the scheme need intensive verification and study. We first design and build an on-ground laser link construction experimental system, which can simulate the whole process and recreate the actual critical working condition as realistic as possible by comprehensively considering the simulation of optical system, far field beam receiving characteristics and target precision. Results are well in agreement with the requirements and confirm the scheme under realistic conditions, which have not yet been fully tested experimentally
Hierarchically Porous CuO Hollow Spheres Fabricated via a One-Pot Template-Free Method for High-Performance Gas Sensors
CuO hollow spheres with hierarchical pores, that is,
quasi-micropores
(1.0–2.2 nm), mesopores (5–30 nm), and macropores (hollow
cores, 2–4 μm), have been synthesized via a simple one-pot
template-free method. The CuO hollow spheres also show a hierarchical
architecture, namely, the primary CuO nanograins, the quasi-single-crystal
nanosheets assembled by nanograins, and the spheres composed of the
nanosheets. A mechanism involving an “oriented attachment”
growth step followed by an “Ostwald ripening” process
has been proposed for the hierarchical structure and pore formation
of the typical CuO hollow spheres. With such unique hierarchical pores
and architecture, the CuO hollow spheres display excellent sensing
performance toward H<sub>2</sub>S as gas sensing material, such as
low detection limit of 2 ppb, high sensitivity at parts per billion
level concentration, broad linear range, short response time of 3
s, and recovery time of 9 s. The excellent performance is ascribed
to a synergetic effect of the hierarchical structure of the unique
CuO spheres: the quasi-micropores offer active sites for effectively
sensing, the mesopores facilitate the molecular diffusion kinetics,
and the macropores serve as gas reservoirs and minimize diffusion
length, while good conductivity of the quasi-single-crystal nanosheets
favors fast charge transportation, which contribute to the high sensitivity,
quick response, and recovery of the H<sub>2</sub>S sensor, respectively