Pseudomonas thivervalensis K321, a promising and effective biocontrol agent for managing apple Valsa canker triggered by Valsa mali.

Plant growth-promoting rhizobacteria (PGPR) have been reported to suppress various diseases as potential bioagents. It can inhibit disease occurrence through various means such as directly killing pathogens and inducing systemic plant resistance. In this study, a bacterium isolated from soil showed significant inhibition of Valsa mali. Morphological observations and phylogenetic analysis identified the strain as Pseudomonas thivervalensis, named K321. Plate confrontation assays demonstrated that K321 treatment severely damaged V. mali growth, with scanning electron microscopy (SEM) observations showing severe distortion of hyphae due to K321 treatment. In vitro twigs inoculation experiments indicated that K321 had good preventive and therapeutic effects against apple Valsa canker (AVC). Applying K321 on apples significantly enhanced the apple inducing systemic resistance (ISR), including induced expression of apple ISR-related genes and increased ISR-related enzyme activity. Additionally, applying K321 on apples can activate apple MAPK by enhancing the phosphorylation of MPK3 and MPK6. In addition, K321 can promote plant growth by solubilizing phosphate, producing siderophores, and producing 3-indole-acetic acid (IAA). Application of 0.2% K321 increased tomato plant height by 53.71%, while 0.1% K321 increased tomato fresh weight by 59.55%. Transcriptome analysis revealed that K321 can inhibit the growth of V. mali by disrupting the integrity of its cell membrane through inhibiting the metabolism of essential membrane components (fatty acids) and disrupting carbohydrate metabolism. In addition, transcriptome analysis also showed that K321 can enhance plant resistance to AVC by inducing ISR-related hormones and MAPK signaling, and application of K321 significantly induced the transcription of plant growth-related genes. In summary, an excellent biocontrol strain has been discovered that can prevent AVC by inducing apple ISR and directly killing V. mali. This study indicated the great potential of P. thivervalensis K321 for use as a biological agent for the control of AVC.

Optical coherence tomography for multicellular tumor spheroid category recognition and drug screening classification via multi-spatial-superficial-parameter and machine learning.

Optical coherence tomography (OCT) is an ideal imaging technique for noninvasive and longitudinal monitoring of multicellular tumor spheroids (MCTS). However, the internal structure features within MCTS from OCT images are still not fully utilized. In this study, we developed cross-statistical, cross-screening, and composite-hyperparameter feature processing methods in conjunction with 12 machine learning models to assess changes within the MCTS internal structure. Our results indicated that the effective features combined with supervised learning models successfully classify OVCAR-8 MCTS culturing with 5,000 and 50,000 cell numbers, MCTS with pancreatic tumor cells (Panc02-H7) culturing with the ratio of 0%, 33%, 50%, and 67% of fibroblasts, and OVCAR-4 MCTS treated by 2-methoxyestradiol, AZD1208, and R-ketorolac with concentrations of 1, 10, and 25 µM. This approach holds promise for obtaining multi-dimensional physiological and functional evaluations for using OCT and MCTS in anticancer studies.

Study on the prediction method of grasshopper occurrence risk in Inner Mongolia based on the maximum entropy model during the growing period.

Grasshoppers represent a significant biological challenge in Inner Mongolia's grasslands, severely affecting the region's animal husbandry. Thus, dynamic monitoring of grasshopper infestation risk is crucial for sustainable livestock farming. This study employed the Maxent model, along with remote sensing data, to forecast Oedaleus decorus asiaticus occurrence during the growing season, using grasshopper suitability habitats as a base. The Maxent model's predictive accuracy was high, with an AUC of 0.966. The most influential environmental variables for grasshopper distribution were suitable habitat data (34.27%), the temperature-vegetation dryness index during the spawning period (18.81%), and various other meteorological and vegetation factors. The risk index model was applied to calculate the grasshopper distribution across different risk levels for the years 2019-2022. The data indicated that the level 1 risk area primarily spans central, eastern, and southwestern Inner Mongolia. By examining the variable weights, the primary drivers of risk level fluctuation from 2019 to 2022 were identified as accumulated precipitation and land surface temperature anomalies during the overwintering period. This study offers valuable insights for future O. decorus asiaticus monitoring in Inner Mongolia.

Enhancing epidural needle guidance using a polarization-sensitive optical coherence tomography probe with convolutional neural networks.

Epidural anesthesia helps manage pain during different surgeries. Nonetheless, the precise placement of the epidural needle remains a challenge. In this study, we developed a probe based on polarization-sensitive optical coherence tomography (PS-OCT) to enhance the epidural anesthesia needle placement. The probe was tested on six porcine spinal samples. The multimodal imaging guidance used the OCT intensity mode and three distinct PS-OCT modes: (1) phase retardation, (2) optic axis, and (3) degree of polarization uniformity (DOPU). Each mode enabled the classification of different epidural tissues through distinct imaging characteristics. To further streamline the tissue recognition procedure, convolutional neural network (CNN) were used to autonomously identify the tissue types within the probe's field of view. ResNet50 models were developed for all four imaging modes. DOPU imaging was found to provide the highest cross-testing accuracy of 91.53%. These results showed the improved precision by PS-OCT in guiding epidural anesthesia needle placement.

Inhibitory effects of Bacillus vallismortis T27 against apple Valsa canker caused by Valsa mali.

Apple Valsa canker caused by the pathogenic fungus Valsa mali, are one of the most destructive diseases of woody plants worldwide. One rhizosphere microbe strain, designated as T27 and subsequently identified as Bacillus vallismortis based on morphological and phylogenetic analyses, was studied as a potential biocontrol agent. Inoculation assay showed the B. vallismortis T27 suppressed the mycelial growth of V. mali with 81.33% antifungal effect on dual culture plates and caused hyphal deformities, wrinkles. The T27 fermentation broth significantly suppress the fungi's ability to acidify the surrounding environment. The addition of T27 cell-free supernatant (CFS) caused the pH of the fungal culture medium to increase from 3.60 to 5.10. B. vallismortis T27 showed the presence of Surfactin, IturinA and Bacilysin antimicrobial biosynthetic genes by the PCR assay. In addition, the B. vallismortis T27 was able to promote plant growth by producing siderophores and solubilizing phosphorus. The application of 2% fermentation broth of T27 resulted in a significant increase of 55.99% in the height of tomato plants and a 33.03% increase in the fresh weight of tomatoes. Under laboratory and field conditions, the B. vallismortis T27 exhibited strong antifungal activities on detached twigs and intact plants. The treatment of T27 resulted in a 35.9% reduction in lesion area on detached twigs. Furthermore, when applied to intact plants, T27 demonstrated a scar healing rate of 85.7%, surpassing the 77.8% observed in the treatment with tebuconazole. Comparative transcriptome analysis showed down-regulation of the genes associated with the fungal cell wall and cell membrane's synthesis and composition during V. mali treated with the B. vallismortis T27. In addition, gene transcription level analysis under treatment with B. vallismortis T27 revealed a significant increase in the expression levels of genes associated with diterpene biosynthesis, alanine, aspartic acid and glutamate metabolism, and plant hormone signaling in the apple, consistent with qRT-PCR and RNA-seq results. In this study, B. vallismortis T27 isolated from rhizosphere soil and identified as a novel biological control agent against apple Valsa canker. It exhibited effectively control over Valsa canker through multiple mechanisms, including disrupting the fungal cell membrane structure, altering the fungal growth environment, activating the plant MAPK pathway, and inducing upregulation of plant terpene biosynthetic genes. These findings highlight the potential of B. vallismortis T27 as a promising and multifaceted approach for managing apple Valsa canker.

Analysis of Spatiotemporal Variation in Habitat Suitability for Oedaleus decorus asiaticus Bei-Bienko on the Mongolian Plateau Using Maxent and Multi-Source Remote Sensing Data.

O. decorus asiaticus is a major grasshopper species that harms the development of agriculture on the Mongolian Plateau. Therefore, it is important to enhance the monitoring of O. decorus asiaticus. In this study, the spatiotemporal variation in the habitat suitability for O. decorus asiaticus on the Mongolian Plateau was assessed using maximum entropy (Maxent) modeling along with multi-source remote sensing data (meteorology, vegetation, soil, and topography). The predictions of the Maxent model were accurate (AUC = 0.910). The key environmental variables affecting the distribution of grasshoppers and their contribution were grass type (51.3%), accumulated precipitation (24.9%), altitude (13.0%), vegetation coverage (6.6%), and land surface temperature (4.2%). Based on the assessment results of suitability by Maxent model, the model threshold settings, and the formula for calculating the inhabitability index, the 2000s, 2010s, and 2020s inhabitable areas were calculated. The results show that the distribution of suitable habitat for O. decorus asiaticus in 2000 was similar to that in 2010. From 2010 to 2020, the suitability of the habitat for O. decorus asiaticus in the central region of the Mongolian Plateau changed from moderate to high. The main factor contributing to this change was accumulated precipitation. Few changes in the areas of the habitat with low suitability were observed across the study period. The results of this study enhance our understanding of the vulnerability of different regions on the Mongolian Plateau to plagues of O. decorus asiaticus and will aid the monitoring of grasshopper plagues in this region.

Effect of Zr2Al4C5 Content on the Mechanical Properties and Oxidation Behavior of ZrB2-SiC-Zr2Al4C5 Ceramics.

ZrB2-SiC-Zr2Al4C5 multi-phase ceramics with uniform structure and high density were successfully prepared through the introduction of in situ synthesized Zr2Al4C5 into ZrB2-SiC ceramic via SPS at 1800 °C. A systematic analysis and discussion of the experimental results and proposed mechanisms were carried out to demonstrate the composition-dependent sintering properties, mechanical properties and oxidation behavior. The results showed that the in situ synthesized Zr2Al4C5 could be evenly distributed in the ZrB2-SiC ceramic matrix and inhibited the growth of ZrB2 grains, which played a positive role in the sintering densification of the composite ceramics. With increasing Zr2Al4C5 content, the Vickers hardness and Young's modulus of composite ceramics gradually decreased. The fracture toughness showed a trend that first increased and then decreased, and was increased by about 30% compared with ZrB2-SiC ceramics. The major phases resulting from the oxidation of samples were ZrO2, ZrSiO4, aluminosilicate and SiO2 glass. With increasing Zr2Al4C5 content, the oxidative weight showed a trend that first increased then decreased; the composite ceramic with 30 vol.% Zr2Al4C5 showed the smallest oxidative weight gain. We believe that the presence of Zr2Al4C5 results in the formation of Al2O3 during the oxidation process, subsequently resulting in a lowering of the viscosity of the glassy silica scale, which in turn intensifies the oxidation of the composite ceramics. This would also increase oxygen permeation through the scale, adversely affecting the oxidation resistance of the composites with high Zr2Al4C5 content.

VmPma1 contributes to virulence via regulation of the acidification process during host infection in Valsa mali.

Valsa mali is a destructive phytopathogenic fungus that mainly infects apple and pear trees. Infection with V. mali results in host tissue acidification via the generation of citric acid, which promote invasion. Here, two plasma membrane H+-ATPases, VmPma1 and VmPma2, were identified in V. mali. The VmPma1 deletion mutant (∆VmPma1) displayed higher intracellular acid accumulation and a lower growth rate compared to the wild type. In contrast, the VmPma2 deletion mutant (∆VmPma2) showed no obvious phenotypic differences. Meanwhile, loss of VmPma1, but not VmPma2, in V. mali led to a significant decrease in growth under acidic or alkaline conditions compared with WT. More importantly, ∆VmPma1 showed a greater reduction in ATPase hydrolase activity and acidification of the external environment, more sensitivity to abiotic stress, and weaker pathogenicity than ∆VmPma2. This evidence indicates that VmPma1 is the main gene of the two plasma membrane H+-ATPases. Transcriptomic analysis indicated that many metabolic processes regulated by VmPma1 are strictly pH-regulated. Besides, we identified two genes (named VmAgn1p and Vmap1) that contribute to the pathogenicity of V. mali by differentially regulating external acidification capacity. Overall, our findings show that VmPma1 plays a pivotal role in pathogenicity by affecting the acidification of V. mali.

Heavy Metal Contamination and Ecological Risk Assessment of Swine Manure Irrigated Vegetable Soils in Jiangxi Province, China.

Heavy metal are often added to animal fodder and accumulate in the soils with swine manure. In this study, heavy metal (Cu, Pb, Cd, Zn, As and Cr) concentrations were determined in agricultural soils irrigated with swine manure in Jiangxi Province, China. Results showed that the average concentrations of Cu, Zn, As and Cr (32.8, 93.7, 21.3 and 75.8 mg/kg, respectively) were higher than the background values, while Pb and Cd (15.2 and 0.090 mg/kg, respectively) were lower than the background values. Contamination factors [Formula: see text] indicated that they were generally moderate for Cu, Zn, As and Cr and generally low for Pb and Cd. The contamination degree (C d ) was calculated to be 7.5-10.0 indicating a moderate degree of contamination. The geoaccumulation index (Igeo) indicated that the soils were unpolluted with Zn, Cd and Pb, while unpolluted to moderately pollute with Cr, Cu and As. The single ecological risk factor [Formula: see text] revealed that the six heavy metals all belonged to low ecological risk. The ecological risk indices suggested that all the sampling sites were at low risk level.