Search Results (590)

Priority effects—the phenomenon where early-arriving species influence the establishment, growth, and reproduction of later-arriving species during community assembly—play a critical role in determining the invasion success of exotic species. However, how priority effects are influenced by nitrogen (N) availability remains understudied. The invasive species Bidens frondosa has rapidly expanded its range in China over the past few years. Yet it remains unclear how priority effects in B. frondosa versus native species may mediate invasion success, as well as how nutrient levels may alter these effects. Addressing these questions is essential for understanding the mechanisms driving B. frondosa invasion and for developing effective management strategies. In a greenhouse experiment, we manipulated the planting order of B. frondosa and its native congener B. biternata, then measured the growth and competitiveness of B. frondosa and B. biternata in both control and N addition treatments. Planting order greatly impacted the growth and competitiveness of both B. frondosa and B. biternata. Early arrival had more positive effects on B. frondosa than B. biternata, while late arrival more strongly inhibited B. frondosa than B. biternata. For B. frondosa, priority effects lessened with nitrogen addition, but the opposite occurred for B. biternata. Thus, priority effects may favor B. frondosa invasion, while late arrival, particularly under nitrogen addition, may curb its spread. As such, sowing early-germinating native species represents a useful management strategy for controlling B. frondosa invasions. Full article

This study investigates the scheduling problem of return communication tasks for unmanned aerial vehicle (UAV) swarms, where disaster relief environmental global positioning is hampered. To characterize the utility of these tasks and optimize scheduling decisions, we developed a time window-constrained scheduling model that operates under constraints, including communication base station time windows, battery levels, and task uniqueness. To solve the above model, we propose an enhanced algorithm through integrating Dueling Deep Q-Network (Dueling DQN) into adaptive large neighborhood search (ALNS), referred to as Dueling DQN-ALNS. The Dueling DQN component develops a method to update strategy weights, while the action space defines the destruction and selection strategies for the ALNS scheduling solution across different time windows. Meanwhile, we design a two-stage algorithm framework consisting of centralized offline training and decentralized online scheduling. Compared to traditionally optimized search algorithms, the proposed algorithm could continuously and dynamically interact with the environment to acquire state information about the scheduling solution. The solution ability of Dueling DQN is 3.75% higher than that of the Ant Colony Optimization (ACO) algorithm, 5.9% higher than that of the basic ALNS algorithm, and 9.37% higher than that of the differential evolution algorithm (DE). This verified its efficiency and advantages in the scheduling problem of return communication tasks for UAVs. Full article

In this work, the feasibility of simulating the thermal inactivation of Brochothrix thermosphacta in beef during heating processing based on hyperspectral imaging (HSI) in the wavelength range of 400–1000 nm was investigated. The Weibull and modified Gompertz kinetic models for the thermal inactivation of B. thermosphacta in beef heated in the range 40–60 °C were developed based on the full wavelength, featured spectral variables, and their principal component scores of HSI information, respectively. Notably, the specific wavebands at 412 nm and 735 nm showed a strong correlation with the surviving B. thermosphacta population during the beef heating process. The partial least squares regression models had a satisfactory ability in quantifying B. thermosphacta in beef, with an R_v² and RMSE of 0.826 and 0.341 log CFU/g, respectively. Furthermore, the Weibull model coupled with the HSI at 735 nm was suitable for kinetic modeling of the thermal inactivation of B. thermosphacta in beef, with an R² value of 0.937. Consequently, this work suggests the potential of the HSI technique for quantifying and monitoring microbes in meat during heating and can be applied for the thermal inactivation kinetic modeling of microorganisms. Full article

Pulmonary hypertension syndrome (PHS), a metabolic disorder causing economic losses in broilers, arises from hypoxia-induced portal hypertension and liver cirrhosis, triggering mitochondrial oxidative damage, excessive ROS production, and altered mitochondrial biogenesis. This study explored terpinen-4-ol (T4O), known for antimicrobial and anti-inflammatory properties, in mitigating PHS. Broilers were divided into four groups, including PHS-affected birds with/without T4O supplementation. Analyses revealed that PHS birds exhibited reduced antioxidant capacity, elevated MDA and ROS levels, increased mitochondrial numbers, and upregulated expression of oxidative stress markers (Keap1, HO-1, Nrf-2) and mitochondrial biogenesis regulators (PGC-1α, Nrf-1, Tfam). T4O administration enhanced antioxidant activity, reduced ROS and MDA, suppressed compensatory mitochondrial proliferation, and downregulated Keap1/Nrf-2 and mitochondrial biogenesis pathways. These effects suggest that T4O alleviates hypoxia-driven oxidative stress and mitochondrial dysfunction in broilers. Findings highlight T4O’s potential as a therapeutic agent to mitigate PHS-related losses in poultry production. Full article

Plant protein phosphatase 2C (PP2C) is recognized as one of the most critical protein family in plants and plays a pivotal role in disease resistance responses. However, the involvement of tomato PP2C family members in resistance to bacterial wilt caused by Ralstonia solanacearum remains poorly understood. In this study, we found that silencing SlPP2C28 increased tomato susceptibility to R. solanacearum; then, we introduced the tomato gene SlPP2C28, which exhibits a strong response to R. solanacearum, into the Nicotiana benthamiana genome via Agrobacterium-mediated transformation, generating high-expression transgenic lines OE-2 and OE-3. Following inoculation with R. solanacearum, the transgenic tobacco plants displayed reduced wilting symptoms, delayed disease onset, lower disease index, reduced stem cross-section damage, decreased internal bacterial colonization, diminished accumulation of reactive oxygen species in leaves, enhanced expression of SlPP2C28, up-regulated expression of defense-related genes NbSOD, NbPOD, and NbPAL along with an increase in the activities of their corresponding enzymes, and elevated expression levels of pathogenesis-related genes NbPR1a, NbPR2, NbPR4, and NbPR10. Collectively, these findings demonstrate that the SlPP2C28 gene has the function of enhancing resistance to bacterial wilt disease. Full article

Rockfill particle gradation significantly influences mechanical performance in earth–rockfill dam construction, yet on-site screening is often time-consuming, labor-intensive, and structurally invasive. This study proposes a rapid and non-destructive detection method using mobile-based photography and an end-to-end image segmentation approach. An enhanced YOLOv8-seg model with an integrated dual-attention mechanism was pre-trained on laboratory images to accurately segment densely stacked particles. Transfer learning was then employed to retrain the model using a limited number of on-site images, achieving high segmentation accuracy. The proposed model attains a mAP50 of 97.8% (base dataset) and 96.1% (on-site dataset), enabling precise segmentation of adhered and overlapped particles with various sizes. A Minimum Area Rectangle algorithm was introduced to compute the gradation, closely matching the results from manual screening. This method significantly contributes to the automation of construction workflows, cutting labor costs, minimizing structural disruption, and ensuring reliable measurement quality in earth–rockfill dam projects. Full article

The converter valve is the core component of the ultra-high voltage direct current (UHVDC) transmission system, and its fault detection is very important to ensure the safe and stable operation of the transmission system. However, the voiceprint signals collected by converter stations under complex operating conditions are often affected by background noise, spikes, and nonlinear interference. Traditional methods make it difficult to achieve high-precision detection due to the lack of feature extraction ability and poor noise robustness. This paper proposes a fault-aware variational self-encoder model (FAVAE-AS) based on a weak correlation between attention and self-supervised learning. It extracts probability features via a conditional variational autoencoder, strengthens feature representation using multi-layer convolution and residual connections, and introduces a weak correlation attention mechanism to capture global time point relationships. A self-supervised learning module with six signal transformations improves generalization, while KL divergence-based correlation inconsistency quantization with dynamic thresholds enables accurate anomaly detection. Experiments show that FAVAE-AS achieves 0.925 accuracy in fault detection, which is 5% higher than previous methods, and has strong robustness. This research provides critical technical support for UHVDC system safety by addressing converter valve acoustic anomaly detection. It proposes an extensible framework for industrial intelligent maintenance. Full article

Soil salinity adversely affects crop growth and development, leading to reduced soil fertility and agricultural productivity. The indigenous salt-tolerant plant growth-promoting rhizobacteria (PGPR), as a sustainable microbial resource, do not only promote growth and alleviate salt stress, but also improve the soil microecology of crops. The strain H5 isolated from saline-alkali soil in Bachu of Xinjiang was studied through whole-genome analysis, functional annotation, and plant growth-promoting, salt-tolerant trait gene analysis. Phylogenetic tree analysis and 16S rDNA sequencing confirmed its classification within the genus Halomonas. Functional annotation revealed that the H5 genome harbored multiple functional gene clusters associated with plant growth promotion and salt tolerance, which were critically involved in key biological processes such as bacterial survival, nutrient acquisition, environmental adaptation, and plant growth promotion. The pot experiment under moderate salt stress demonstrated that seed inoculation with Halomonas sp. H5 not only significantly improved the agronomic traits of tomato seedlings, but also increased plant antioxidant enzyme activities under salt stress. Additionally, soil analysis revealed H5 treatment significantly decreased the total salt (9.33%) and electrical conductivity (8.09%), while significantly improving organic matter content (11.19%) and total nitrogen content (10.81%), respectively (p < 0.05). Inoculation of strain H5 induced taxonomic and functional shifts in the rhizosphere microbial community, increasing the relative abundance of microorganisms associated with plant growth-promoting and carbon and nitrogen cycles, and reduced the relative abundance of the genera Alternaria (15.14%) and Fusarium (9.76%), which are closely related to tomato diseases (p < 0.05). Overall, this strain exhibits significant potential in alleviating abiotic stress, enhancing growth, improving disease resistance, and optimizing soil microecological conditions in tomato plants. These results provide a valuable microbial resource for saline soil remediation and utilization. Full article

Accurate evaluation of the thermal conductivity of UO₂ with defects is very significant for optimizing fuel performance and enhancing the safety design of reactors. We employed a method that combines the Boltzmann transport equation with DFT+U to calculate the thermal conductivity of UO₂ containing fission products and irradiation-induced point defects. Our investigation reveals that the thermal conductivity of UO₂ is influenced by defect concentration, defect type, and temperature. Fission products and irradiation defects result in a decrease in thermal conductivity, but they have markedly different impacts on phonon scattering mechanisms. Metal cations tend to scatter low-frequency phonons (less than 5.8 THz), while the fission gas xenon scatters both low-frequency and high-frequency phonons (greater than 5.8 THz), depending on its occupancy at lattice sites. Uranium vacancies scatter low-frequency phonons, while oxygen vacancies scatter high-frequency phonons. When uranium and oxygen vacancies coexist, they scatter phonons across the entire frequency spectrum, which further results in a significant reduction in the thermal conductivity of UO₂. Our calculated results align well with experimental data across a wide temperature range and provide fundamental insights into the heat transfer mechanisms in irradiated UO₂. These findings are essential for establishing a thermal conductivity database for UO₂ under various irradiation conditions and benefit the development of advanced high-performance UO₂ fuel. Full article

In Taiwan, hydro-meteorological data are fragmented across multiple agencies, limiting the effectiveness of coordinated flood response. To address this challenge and the increasing uncertainty associated with extreme rainfall, a real-time disaster prevention platform has been developed. This system integrates multi-source data and geospatial information through a cluster-based architecture to enhance pluvial flood management. Built on a Service-Oriented Architecture (SOA) and incorporating Internet of Things (IoT) technologies, AI-based convolutional neural networks (CNNs), and 3D drone mapping, the platform enables automated alerts by linking sensor thresholds with real-time environmental data, facilitating synchronized operational responses. Deployed in New Taipei City over the past three years, the system has demonstrably reduced flood risk during severe rainfall events. Region-specific action thresholds and adaptive strategies are continually refined through feedback mechanisms, while integrated spatial and hydrological trend analyses extend the lead time available for emergency response. Full article

Melastoma dodecandrum is primarily propagated through stem cuttings, which limits genetic variation and constrains breeding efforts. To overcome this limitation and facilitate molecular breeding, the establishment of a reliable and efficient regeneration system is essential. This study investigated the effects of plant growth regulators (PGRs) and culture media on the in vitro regeneration system of M. dodecandrum. The highest rate of callus induction (96.67%) was achieved when sterile leaf explants were cultured on Murashige and Skoog (MS) basal medium supplemented with 2.00 mg·L⁻¹ 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.50 mg·L⁻¹ 6-benzylaminopurine (6-BA). For callus differentiation, the optimal formulation of MS + 2.0 mg·L⁻¹ 6-BA + 0.5 mg·L⁻¹ naphthylacetic acid (NAA) resulted in a differentiation frequency of 83.33%. The optimal PGR combinations for shoot proliferation were 1.5 mg·L⁻¹ 6-BA + 0.1 mg·L⁻¹ NAA and 0.5 mg·L⁻¹ 6-BA + 0.2 mg·L⁻¹ NAA. The optimal rooting media were MS medium supplemented with 0.1, 0.2, or 0.5 mg·L⁻¹ indole-3-butyric acid (IBA) or 1/2MS medium supplemented with 0.1 mg·L⁻¹ IBA. Additionally, this study investigated the dynamic changes in endogenous hormones during the regeneration process. The levels and ratios of hormones, including gibberellin (GA₃), abscisic acid (ABA), indole-3-acetic acid (IAA), and zeatin (ZT), collectively regulated the regeneration process. Elevated levels of ABA and GA₃ may promote callus initiation as well as the growth and development of adventitious roots during the early induction stage. Reduced levels of ABA and IAA favored callus differentiation into shoots, whereas elevated GA₃ levels facilitated proliferation of adventitious shoots. Throughout the regeneration process, fluctuations in ZT levels remained relatively stable. This study successfully established an in vitro regeneration system for M. dodecandrum using leaf explants, providing theoretical guidance and technical support for further molecular breeding efforts, genetic transformation, and industrial development. Full article

Uncaria rhynchophylla, a medicinal plant extensively used in traditional Chinese medicine, is an important plant source of terpenoid indole alkaloids (TIAs), but the mechanism of TIA biosynthesis at molecular level remains unclear. Geraniol synthase (GES) serves as a crucial enzyme in catalyzing the formation of geraniol from geranyl pyrophosphate (GPP) in various plants, but the functional characterization of the GES gene in U. rhynchophylla has not been investigated. In this study, a GES was identified and characterized through genome mining and bioinformatic analysis. Functional validation was performed via a protein catalysis experiment, transient expression in Nicotiana benthamiana, and methyl jasmonate (MeJA) induction experiments. The full-length UrGES gene was 1761 bp, encoding a protein product of 586 amino acids with an estimated 67.5 kDa molecular weight. Multiple sequence alignments and phylogenetic analysis placed UrGES within the terpene synthase g (TPS-g) subfamily, showing high similarity to known GESs from other plants. Enzymatic assays confirmed that recombinant UrGES catalyzed GPP conversion to a single product of geraniol. The transient expression of UrGES resulted in geraniol accumulation in N. benthamiana, further confirming its function in vivo. UrGES expression was observed in leaves, stems, and roots, where leaves had the highest transcript levels. Moreover, MeJA treatment significantly upregulated UrGES expression, which positively correlated with an increase in alkaloid content. This study functionally characterizes UrGES as a geraniol synthase in U. rhynchophylla, contributing to the current knowledge of the TIA biosynthetic pathway. These findings may offer insights for future metabolic engineering aiming to enhance TIA yields for pharmaceutical and industrial applications. Full article

Activity space offers a valuable perspective for analyzing urban travel behavior and evaluating the performance of transportation systems in increasingly complex urban environments. However, the research on measuring activity spaces in multimodal transportation contexts remains limited. This study investigates multimodal transportation activity spaces in Hangzhou using 2023 smart card data. Multimodal travel chains are extracted, and residents’ activity spaces are quantified using 95% confidence ellipses. By applying the XGBoost and GeoShapley models, this study reveals the nonlinear effects and geospatial heterogeneity in how built environment and socioeconomic factors influence activity spaces. The key findings show that the distance to the nearest metro station, commercial POIs, and GDP significantly shape activity spaces through nonlinear relationships. Moreover, the interaction between the distance to the nearest metro station and geographical location generates pronounced geospatial effects. The results highlight the importance of multimodal integration in urban transport planning and provide empirical insights for enhancing system efficiency and sustainability. Full article

The accurate measurement of a crack width in concrete infrastructure is essential for structural safety assessment and maintenance. However, existing image-based methods either suffer from overestimation in complex geometries or are computationally inefficient. This paper proposes a novel hybrid approach combining a fast skeleton-pruning algorithm and a crack-width measurement technique called edge-OrthoBoundary (EOB). The skeleton-pruning algorithm prunes the skeleton, viewed as the longest branch in a tree structure, using a depth-first search (DFS) approach. Additionally, an intersection removal algorithm based on dilation replaces the midpoint circle algorithm to segment the crack skeleton into computable parts. The EOB method combines the OrthoBoundary and edge shortest distance (ESD) techniques, effectively correcting the propagation direction of the skeleton points while accounting for their width. The validation of real cracks shows the skeleton-pruning algorithm’s effectiveness, eliminating the need for a specified threshold and reducing time complexity. Experimental results with both actual and synthetic cracks demonstrate that the EOB method achieves the smallest RMS, MAE, and R values, confirming its accuracy and stability compared to the orthogonal projection (OP), OrthoBoundary, and ESD methods. Full article

Farming is an important development direction of agriculture in the future, which is affected by various environmental factors, among which light plays an important role, and it is essential for the growth of organisms in nature. LED technology can regulate the growth and development of vegetables by adjusting the spectral composition of light. In order to explore light quality formulation with the aim of improving the quality and yield of celery, we set up six experimental treatments: W (white light), R (red light), B (blue light), 3R1B (red light/blue light = 3:1), 4R1B (red light/blue light = 4:1), and 5R1B (red light/blue light = 5:1). The results indicated that the 3R1B and 4R1B illumination treatments were conducive to promoting the growth of celery, enhancing plant height and root length. Specifically, the 3R1B treatment optimized the nutritional quality of celery by increasing the levels of soluble protein, soluble sugar, and total flavonoids while reducing nitrate and cellulose contents and elevating the anthocyanin content in petioles. Additionally, both treatments enhanced the contents of Ca and Mg in celery leaves and petioles. Furthermore, the 3R1B treatment promoted the accumulation of photosynthetic pigments, upregulated the activities of ANS and FNS enzymes, and induced the upregulation of gene expression levels of FNS and ANS, thereby enhancing the nutritional value of celery. Full article