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[Objective]The number, location, and crown spread of nursery stock are important foundations data for their scientific management. Traditional approach of conducting nursery stock inventories through on-site individual plant surveys is labor-intensive and time-consuming. Low-cost and convenient unmanned aerial vehicles (UAVs) for on-site collection of nursery stock data are beginning to be utilized, and the statistical analysis of nursery stock information through technical means such as image processing achieved. During the data collection process, as the flight altitude of the UAV increases, the number of trees in a single image also increases. Although the anchor box can cover more information about the trees, the cost of annotation is enormous in the case of a large number of densely populated tree images. To tackle the challenges of tree adhesion and scale variance in images captured by UAVs over nursery stock, and to reduce the annotation costs, using point-labeled data as supervisory signals, an improved dense detection and counting model was proposed to accurately obtain the location, size, and quantity of the targets.[Method]To enhance the diversity of nursery stock samples, the spruce dataset, the Yosemite, and the KCL-London publicly available tree datasets were selected to construct a dense nursery stock dataset. A total of 1 520 nursery stock images were acquired and divided into training and testing sets at a ratio of 7:3. To enhance the model's adaptability to tree data of different scales and variations in lighting, data augmentation methods such as adjusting the contrast and resizing the images were applied to the images in the training set. After enhancement, the training set consists of 3 192 images, and the testing set contains 456 images. Considering the large number of trees contained in each image, to reduce the cost of annotation, the method of selecting the center point of the trees was used for labeling. The LSC-CNN model was selected as the base model. This model can detect the quantity, location, and size of trees through point-supervised training, thereby obtaining more information about the trees. The LSC-CNN model was made improved to address issues of missed detections and false positives that occurred during the testing process. Firstly, to address the issue of missed detections caused by severe adhesion of densely packed trees, the last convolutional layer of the feature extraction network was replaced with dilated convolution. This change enlarges the receptive field of the convolutional kernel on the input while preserving the detailed features of the trees. So the model is better able to capture a broader range of contextual information, thereby enhancing the model's understanding of the overall scene. Secondly, the convolutional block attention module (CBAM) attention mechanism was introduced at the beginning of each scale branch. This allowed the model to focus on the key features of trees at different scales and spatial locations, thereby improving the model's sensitivity to multi-scale information. Finally, the model was trained using label smooth cross-entropy loss function and grid winner-takes-all strategy, emphasizing regions with highest losses to boost tree feature recognition.[Results and Discussions]The mean counting accuracy (MCA), mean absolute error (MAE), and root mean square error (RMSE) were adopted as evaluation metrics. Ablation studies and comparative experiments were designed to demonstrate the performance of the improved LSC-CNN model. The ablation experiment proved that the improved LSC-CNN model could effectively resolve the issues of missed detections and false positives in the LSC-CNN model, which were caused by the density and large-scale variations present in the nursery stock dataset. IntegrateNet, PSGCNet, CANet, CSRNet, CLTR and LSC-CNN models were chosen as comparative models. The improved LSC-CNN model achieved MCA, MAE, and RMSE of 91.23%, 14.24, and 22.22, respectively, got an increase in MCA by 6.67%, 2.33%, 6.81%, 5.31%, 2.09% and 2.34%, respectively; a reduction in MAE by 21.19, 11.54, 18.92, 13.28, 11.30 and 10.26, respectively; and a decrease in RMSE by 28.22, 28.63, 26.63, 14.18, 24.38 and 12.15, respectively, compared to the IntegrateNet, PSGCNet, CANet, CSRNet, CLTR and LSC-CNN models. These results indicate that the improved LSC-CNN model achieves high counting accuracy and exhibits strong generalization ability.[Conclusions]The improved LSC-CNN model integrated the advantages of point supervision learning from density estimation methods and the generation of target bounding boxes from detection methods.These improvements demonstrate the enhanced performance of the improved LSC-CNN model in terms of accuracy, precision, and reliability in detecting and counting trees. This study could hold practical reference value for the statistical work of other types of nursery stock.

T‐2 toxin is a member of class A aspergilloides toxins, one of the most prevalent mycotoxins that contaminate feed and food. Direct ingestion of animals or feed contaminated by T‐2 toxin can cause various animal diseases. Butyrate is an organic fatty acid featuring a four‐carbon chain, which is commonly found in the form of sodium butyrate (NaB). NaB has several biological functions and pharmacological effects. However, the role of sodium butyrate in alleviating T‐2 toxin–induced hepatorenal toxicity has not been explored. In this study, 240 juvenile quails were evenly assigned into 4 groups. The experimental setup comprised four groups: The control group received a standard diet; the toxin group received a diet containing 0.9 mg/kg T‐2 toxin; the butyrate group received a diet containing 0.5 g/kg NaB; and the T‐2 treatment group received a diet containing both 0.9 mg/kg T‐2 toxin and 0.5 g/kg NaB. We evaluated the histopathological changes in the kidney and liver on Days 14 and 28 and explored the molecular mechanisms involving oxidative stress, inflammation, and expression of nuclear xenobiotic receptors (NXRs). Our results showed that T‐2 toxin exposure–induced inflammation in the liver and kidney by activating the oxidative stress pathway and modulating expression of NXRs to regulate related CYP450 isoforms, ultimately leading to histopathological injury in the liver and kidney, whereas sodium butyrate ameliorated this injury. These results offer novel insights into the molecular mechanisms underlying the protective effects of sodium butyrate in mitigating T‐2 toxin–induced hepatorenal injury in juvenile quails. Practical Application: The mechanisms of T‐2 toxin toxicity have been well described in experimental animals, but studies in birds are limited. With the development of society, the market scale of quails farming has been expanding, and the value of quails meat and eggs is increasing; there is an urgent need to clarify the harm of T‐2 toxin to quails and its mechanism. [ABSTRACT FROM AUTHOR]

In order to study the dynamic response of offshore platforms in complex marine environments (combined action of wind, wave and current loads), the offshore jacket platform model was established by using finite element software, the strength of its ultimate load structure was checked, and different working conditions were simulated and analyzed to grasp its dynamic response characteristics and rules, and finally its fatigue life was predicted by combining with S-N curve. The results show that the natural vibration period of the jacket structure is much smaller than the wave period, and the resonance basically does not occur. Under the extreme storm, the strength and stiffness of the jacket structure meet the requirements, and with the increase of wave height and wave velocity, the maximum equivalent stress and maximum displacement are significantly improved, the maximum stress increases by more than 182.76%, and the displacement increases by more than 182.72%, and the maximum stress area occurs at the intersection of the diagonal brace support. The fatigue life of the jacket structure is predicted to be 44.19 years, which meets the design requirements. [ABSTRACT FROM AUTHOR]

The maturity grading of walnuts during harvesting relies on experience. In this paper, walnut images in a natural environment were collected to construct a dataset, and deep learning algorithms were utilized to combine walnut internal physical and chemical indicators to carry out research on walnut maturity detection methods and further research on walnut oil content prediction by combining walnut images with walnut oil content indicators. The main contents of this paper include collecting walnut images in a natural environment, constructing datasets, and using deep learning algorithms combined with internal physical and chemical indexes of walnuts to study walnut maturity detection and oil content prediction methods. First, two walnut image acquisition schemes were designed, and a total of 9504 images were collected from 23 August to 21 September 2021. The dataset was expanded to 18,504 images through data preprocessing and image enhancement. A self-supervised Gaussian attention network (GATCluster) walnut ripeness detection method based on image clustering is proposed to develop ripeness criteria through unsupervised clustering, and the accuracy of the criteria is verified by analysis of variance (ANOVA). The maturity detection accuracy of the test set of 1500 images is 88.33%. Secondly, a walnut oil content prediction method based on improved ResNet34 is proposed. The feature extraction capability is improved by introducing the Squeeze-and-Excitation Networks (SENet) channel attention mechanism and the convolutional self-attention module. The prediction results on 50 images show that the root mean square error, average absolute percentage error, and regression coefficient are 2.96, 0.103, and 0.8822, respectively. The experiments show that the method performs well in predicting the oil content of walnuts at different maturity levels. [ABSTRACT FROM AUTHOR]

Dental caries is a bacterial infectious disease that destroys the structure of teeth. It is one of the main diseases that endanger human health [R. H. Selwitz, A. I. Ismail, and N. B. Pitts, Lancet 369(9555), 51–59 (2007)]. At present, dentists use both visual exams and radiographs for the detection of caries. Affected by the patient's dental health and the degree of caries demineralization, it is sometimes difficult to accurately identify some dental caries in x-ray images with the naked eye. Therefore, dentists need an intelligent and accurate dental caries recognition system to assist diagnosis, reduce the influence of doctors' subjective factors, and improve the efficiency of dental caries diagnosis. Therefore, this paper combines the U-Net model verified in the field of biomedical image segmentation with the convolution block attention module, designs an Attention U-Net model for caries image segmentation, and discusses the feasibility of deep learning technology in caries image recognition so as to prepare for the next clinical verification. After testing, the Dice similarity coefficient, mean pixel accuracy, mean intersection over union, and frequency-weighted intersection over the union of teeth segmentation with Attention U-Net are 95.30%, 94.46%, 93.10%, and 93.54%, respectively. The Dice similarity coefficient, mean pixel accuracy, mean intersection over union, and frequency-weighted intersection over the union of dental caries segmentation with Attention U-Net are 85.36%, 91.84%, 82.22%, and 97.08%, respectively. As a proof of concept study, this study was an initial evaluation of technology to assist dentists in the detection of caries. There is still more work needed before this can be used clinically. [ABSTRACT FROM AUTHOR]