Search

In recent years, the use of action face anti-spoofing (FAS) tasks has become widespread in various identity security authentication scenarios. However, the current performance of action FAS is susceptible to the impact of lighting conditions and the scale of the action. Furthermore, due to the simplicity of facial action behavior, it is unable to withstand highly realistic 3D counterfeit face attacks. To address these issues, this paper proposes a spatio-temporal-based action FAS framework that combines dynamics and texture information around local keypoint areas of the face. To tackle the issue of action scale, we integrate a clip of face action video into a single face keypoint-based feature map, incorporating motion trajectories and motion history cues. Specifically, we develop two essential features in the spatiotemporal domain: Keypoints Trajectory Invariant Feature (KTIF) and Keypoints Motion History Feature (KMHF). These features are constructed by utilizing the absolute position of keypoints and the relative bias position of keypoints between frames. Additionally, to further enhance the security level of the action FAS task, we propose a novel representation called Keypoints Neighbourhood Texture Difference Feature (KNTDF). This representation utilizes an Encoder-Decoder module with center difference convolution (CDC) to effectively address the issue of 2D/3D spoofing at the image noise level. Finally, by embedding the Swin-transformer architecture with a channel attention module and skip fusion strategy, the above three deep representations are fused and further classified for both the face action classification (FAC) task and the face anti-spoofing task. The experimental results show that the proposed method performs well on both tasks. Especially for action FAS, compared to the majority of existing work, it demonstrates significant capabilities in overcoming lighting conditions and motion scales.

Oriented object detection is an important research topic in remote sensing. The detection of oriented objects in remote sensing images remains a daunting challenge due to their complex backgrounds, various sizes, diverse aspect ratios, and especially arbitrary orientations. In recent years, keypoint-based anchor-free object detectors have demonstrated outstanding performance in this field. However, in current anchor-free detectors, object keypoints are primarily generated using the Gaussian kernel function, which assumes a circular form. This representation falls short in accurately conveying an object’s size and orientation. To address the aforementioned issue, this article proposes a keypoint-based oriented object detector called MRSDet, which innovatively adopts the Tricube kernel, scales, and rotates it, to better generate the center keypoint heatmap of the object. Besides, to improve the model’s detection performance on oriented objects and improve its ability to perceive object keypoints and boundary boxes, we also design a large receptive field mask (LRFM) module, which is based on large convolution kernel decomposition and semantic segmentation masks. Taking the box boundary-aware vectors (BBAVectors) method as a baseline, we conduct experiments on multiple types of remote sensing datasets such as HRSC2016, UCAS-AOD, and SSDD+ datasets to verify the effectiveness and generalizability of the proposed method.

This study was designed to depict prevalence and antimicrobial resistance characteristics of Proteus mirabilis(P. mirabilis) strains in 4 chicken farms and to probe the transfer mechanism of resistance genes. A total of 187 P. mirabilisisolates were isolated from 4 chicken farms. The susceptibility testing of these isolates to 14 antimicrobials showed that the multidrug resistance (MDR) rate was as high as 100%. The β-lactamase resistance genes blaOXA-1, blaCTX-M-1G, blaCTX-M-9Gand colistin resistance gene mcr-1were highly carried in the P. mirabilisisolates. An MDR strain W47 was selected for whole genome sequencing (WGS) and conjugation experiment. The results showed that W47 carried 23 resistance genes and 64 virulence genes, and an SXT/R391 integrated conjugative elements (ICEs) named ICEPmiChn5 carrying 17 genes was identified in chromosome. ICEPmiChn5 was able to be excised from the chromosome of W47 forming a circular intermediate, but repeated conjugation experiments were unsuccessful. Among 187 P. mirabilisisolates, 144 (77.01%, 144/187) isolates carried ICEPmiChn5-like ICEs, suggesting that ICEs may be the major vector for the transmission of resistance genes among MDR chicken P. mirabilisstrains in this study. The findings were conducive to insight into the resistance mechanism of chicken P. mirabilisstrains and provide a theoretical basis for the use of antibiotics for the treatment of MDR P. mirabilisinfections in veterinary clinic.