Estimating ecological indicators of karst rocky desertification by linear spectral unmixing method

AbstractCoverage rates of vegetation and exposed bedrock are two key indicators of karst rocky desertification. In this study, the abundances of vegetation and exposed rock were retrieved from a hyperspectral Hyperion image using linear spectral unmixing method. The results were verified using the spectral indices of karst rocky desertification (KRDSI) and an integrated LAI spectral index: modified chlorophyll absorption ratio index (MCARI2). The abundances showed significant linear correlations with KRDSI and MCARI2. The coefficients of determination (R2) were 0.93, 0.66, and 0.84 for vegetation, soil, and rock, respectively, indicating that the abundances of vegetation and bedrock can characterize their coverage rates to a certain extent. Finally, the abundances of vegetation and bedrock were graded and integrated to evaluate rocky desertification in a typical karst region. This study suggests that spectral unmixing algorithm and hyperspectral remote sensing imagery can be used to monitor and evaluate karst rocky desertification

Vision Backbone Enhancement via Multi-Stage Cross-Scale Attention

Convolutional neural networks (CNNs) and vision transformers (ViTs) have achieved remarkable success in various vision tasks. However, many architectures do not consider interactions between feature maps from different stages and scales, which may limit their performance. In this work, we propose a simple add-on attention module to overcome these limitations via multi-stage and cross-scale interactions. Specifically, the proposed Multi-Stage Cross-Scale Attention (MSCSA) module takes feature maps from different stages to enable multi-stage interactions and achieves cross-scale interactions by computing self-attention at different scales based on the multi-stage feature maps. Our experiments on several downstream tasks show that MSCSA provides a significant performance boost with modest additional FLOPs and runtime

Rapid detection of porcine circovirus type 4 via multienzyme isothermal rapid amplification

Porcine circovirus type 4 (PCV4) is a newly emerging pathogen that was first detected in 2019 and is associated with diverse clinical signs, including respiratory and gastrointestinal distress, dermatitis and various systemic inflammations. It was necessary to develop a sensitive and specific diagnostic method to detect PCV4 in clinical samples, so in this study, a multienzyme isothermal rapid amplification (MIRA) assay was developed for the rapid detection of PCV4 and evaluated for sensitivity, specificity and applicability. It was used to detect the conserved Cap gene of PCV4, operated at 41°C and completed in 20 min. With the screening of MIRA primer-probe combination, it could detect as low as 101 copies of PCV4 DNA per reaction and was highly specific, with no cross-reaction with other pathogens. Further assessment with clinical samples showed that the developed MIRA assay had good correlation with real-time polymerase chain reaction assay for the detection of PCV4. The developed MIRA assay will be a valuable tool for the detection of the novel PCV4 in clinical samples due to its high sensitivity and specificity, simplicity of operation and short testing time

Characteristic analysis of hydraulic hybrid vehicle based on limit cycle

The theory of limit cycles was applied to hydraulic hybrid vehicle (HHV) to analyze the dynamic characteristics of the system. The exact mathematical models based on configuration diagram of HHV were built to study on equilibrium points, nonexistence of limit cycle and stability of equilibrium points. The analysis showed that if the Young’s modulus of fluid is neglected, the equilibrium points of the system will be distributed on both sides of the initial function. In addition, there is a unique equilibrium point according to the practical signification of the system parameters. The nonexistence analysis showed that there is no limit cycle for the system, no matter how the viscosity coefficient B changes. The stability analysis of equilibrium points showed that the system is asymptotically stable about the equilibrium point at B⩾0 and the equilibrium point is the center point of the system at B=0. Finally, the phase diagrams of global topological structure of HHV system were entirely described according to qualitative analysis of the singular points at infinity

Research on the Visual Guidance System of Zoning Casting Grinding Based on Feature Points

Compared to traditional rough casting grinding (RCG), the individualization of castings is very different, which makes it difficult to realize the automation of casting grinding. At this stage, the primary method is manual grinding. In this study, the regional casting grinding system based on feature points is adopted to achieve the personalized grinding of castings and improve the grinding efficiency and the automation level of the manufacturing process. After preprocessing the point cloud, the fast point feature histogram (FPFH) descriptor is used to describe the features of each region and construct the local template. The position of the local region is obtained by template matching. The random sample consensus (RANSAC) algorithm is used to calculate the plane and fit the point cloud to obtain the contact point trajectory of the grinding head. Then, according to different polishing methods, different polishing poses are generated. The simulation experimental results show that the system has good adaptability, and the consistency of finished products is good

Research on the Visual Guidance System of Zoning Casting Grinding Based on Feature Points

Compared to traditional rough casting grinding (RCG), the individualization of castings is very different, which makes it difficult to realize the automation of casting grinding. At this stage, the primary method is manual grinding. In this study, the regional casting grinding system based on feature points is adopted to achieve the personalized grinding of castings and improve the grinding efficiency and the automation level of the manufacturing process. After preprocessing the point cloud, the fast point feature histogram (FPFH) descriptor is used to describe the features of each region and construct the local template. The position of the local region is obtained by template matching. The random sample consensus (RANSAC) algorithm is used to calculate the plane and fit the point cloud to obtain the contact point trajectory of the grinding head. Then, according to different polishing methods, different polishing poses are generated. The simulation experimental results show that the system has good adaptability, and the consistency of finished products is good

A Cryptand-Type Aluminum Tris(salophen) Complex: Synthesis, Characterization, and Cell Imaging Application

Metal salen/salophen complexes have been used as fluorescent probes for cell imaging with various metal centers. Herein we synthesized cryptand-type aluminum salophen complexes LAl3 and the corresponding mononuclear compound LAl. X-ray crystal diffraction verifies the cryptand-type structure of LAl3 with C3h symmetry. Both LAl3 and LAl show moderate green fluorescence with quantum yields of 0.17 and 0.05, respectively. The hydrophilic and cationic nature of these aluminum salophen complexes renders them enhanced cellular uptake. Both complexes are internalized into cells by energy-dependent pathways and they distribute in lysosomal organelles

Preparation of PAN@TiO2 Nanofibers for Fruit Packaging Materials with Efficient Photocatalytic Degradation of Ethylene

Ethylene causes faster deterioration of perishable crops during postharvest transportation and storage. The present study aimed to develop TiO2-coated nanofibers with efficient photocatalytic activities to enhance the degradation of fruit-emitted ethylene. The consecutive electrospinning of polyacrylonitrile (PAN) and TiO2 deposition was successfully performed to produce PAN@TiO2 nanofibers. The scanning electron microscopy results indicate the uniform distribution of TiO2 nanoparticles on the surface of the PAN nanofiber. The PAN@TiO2 composite nanofibers exhibited enhanced photocatalytic activity for ethylene degradation under low-intensity UV light irradiation. Furthermore, a tomato fruit-ripening test confirmed the effectiveness of the PAN@TiO2 nanofibers. The PAN@TiO2 nanofibers exhibited effective ethylene degradation and slowed the color shift and softening of the tomatoes during storage. The results suggest great potential for use of the PAN@TiO2 composite nanofibers as ethylene scavenging packaging material for fresh fruits and vegetables

Effect of Postoperative Analgesia with the Combination of Dexmedetomidine and Butorphanol after Posterior Spinal Surgery

Background and Objective: Opioid medications used to be the key method for the pain management after spine surgery; most of the opioids may cause many adverse reactions. The purpose of this research was to observe the role of dexmedetomidine combined with butorphanol in the pain management of patients after posterior spinal surgery.Methods: This research was conducted in the First Hospital Affiliated to Jinzhou Medical University, China from May 2018 to January 2019. Sixty patients who underwent posterior spinal surgery were equally divided into two groups randomly: Group B who received butorphanol 0.125 mg/kg and Group DB who received dexmedetomidine (DEX) 0.1 &mu;g/kg/hour plus butorphanol 0.125 mg/kg. The patient-controlled analgesia was conducted to deliver a bolus dose of 0.5 ml. followed by an infusion of 2 ml/hour and a lockout time of 15 minutes. Heart rate, mean arterial pressure, respiration rate, pulse oxygen saturation, visual analog scale score (VAS), and Ramsay sedation score were recorded as follows: 1 hour (T1), 2 hours (T2), 6 hours (T3), 12 hours (T4), and 24 hours (T5) post‑surgery. The total number of buttons pressing of patient controlled intravenous analgesia (PCIA) and supplementary analgesic agents was observed and adverse drug reactions and total rate of patient satisfaction were evaluated statistically.Results: VAS scores at different intervals in DB group were significantly lower compared with the B group after surgery; while the score of Ramsay sedation was remarkably higher in DB group. The total number of buttons pressing of PCIA was less than that of the B group and the frequency of nausea was notably lower in DB group (p &lt; 0.05). The total rate of satisfaction with analgesia in DB group was higher after surgery.Conclusion: DEX could enhance the analgesic effect of butorphanol after posterior spinal surgery with lesser adverse reactions</p