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Keywords = proximal gradient

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25 pages, 4245 KB  
Article
Comprehensive Early Alert and Adaptive Local Response Framework for Wildfire Risk in Transmission Line Corridors Using Coupled Global Factors in Power System
by Tianliang Xue, Chengsi Xiang, Xi Chen and Lei Zhang
Processes 2026, 14(5), 752; https://doi.org/10.3390/pr14050752 - 25 Feb 2026
Viewed by 133
Abstract
Escalating global climate change has intensified the frequency and scale of wildfires in mountainous regions hosting transmission line infrastructure. These conflagrations act as extreme meteorological events, capable of generating localized heatwaves that compromise the air insulation of power lines and trigger protective relay [...] Read more.
Escalating global climate change has intensified the frequency and scale of wildfires in mountainous regions hosting transmission line infrastructure. These conflagrations act as extreme meteorological events, capable of generating localized heatwaves that compromise the air insulation of power lines and trigger protective relay operations, thereby posing systemic threats to regional grid stability. To enhance wildfire early-warning efficacy for grid security, this study formulates wildfire early warning for power transmission corridors as a regression-based risk prediction problem and proposes a hierarchical “global screening–local refinement” risk assessment framework. The primary contribution of this study lies in the integration of a machine-learning-based global wildfire risk screening model with tower-level spatial refinement using geographically weighted regression (GWR), enabling coordinated global–local wildfire risk characterization along power transmission corridors The framework employs a predictive model built on a Gradient Boosting Decision Tree algorithm, integrating geospatial and statistical analyses. A global risk model, utilizing historical data from the Himawari-8 satellite alongside meteorological, topographic, and anthropogenic variables, produces a composite risk index. This index is spatially interpolated via Kriging to generate stratified wildfire risk maps for broad-area assessment. For precise corridor-level analysis, these Globally Projected Risk Indices, along with localized terrain features, inter-tower clearance distances, and proximity to historical ignition points, are incorporated into a Geographically Weighted Regression model. This yields a spatially calibrated wildfire risk index along critical routes. The results show that the GBDT-based model achieved the best predictive performance among the evaluated regression models, with an R2 of 0.626 and a mean squared error of 0.178. This approach offers a scientifically robust and operationally viable reference for wildfire prevention strategies in power line maintenance. Full article
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23 pages, 3258 KB  
Article
Invisible Footprints: Exploring Microplastic Pollution in the Colombian Caribbean Sea
by René A. Rojas-Luna, Jonathan D. Ayala-Rodríguez, Carlos A. García-Alzate, Roberto García-Alzate, Jorge Trilleras, Jairo Humberto Medina-Calderon, Adriana Santos-Martínez, José Ernesto Mancera Pineda, Cesar A. Sierra and Victoria A. Arana
Water 2026, 18(4), 508; https://doi.org/10.3390/w18040508 - 19 Feb 2026
Viewed by 491
Abstract
Microplastic (MP) pollution poses a significant and emerging threat to global marine ecosystems; however, regional data for the Caribbean remain limited. This study presents a spatial and temporal characterization of MPs in surface and mid-waters of the Colombian Caribbean (Atlántico and Magdalena departments), [...] Read more.
Microplastic (MP) pollution poses a significant and emerging threat to global marine ecosystems; however, regional data for the Caribbean remain limited. This study presents a spatial and temporal characterization of MPs in surface and mid-waters of the Colombian Caribbean (Atlántico and Magdalena departments), which were analyzed as independent compartments due to methodological differences in sampling strategies. Sixteen sampling stations were established across two anthropogenic influence zones: Zone 1 (nearshore/bather zone) and Zone 2 (offshore). MPs were quantified and characterized according to shape, color, size, and polymer composition using attenuated total reflectance Fourier transform infrared microspectroscopy (µATR-FTIR) and multivariate techniques. MPs were detected in 100% of samples. Surface water MP abundance was higher in Magdalena (4.5 MPs m−3) than in Atlántico (1.7 MPs m−3). Mid-water MP concentrations reached maximum values during the high rainfall season in Atlántico, reflecting localized hydrological and anthropogenic influences rather than vertical gradients. Higher concentrations were generally observed in the nearshore Zone 1 compared to offshore Zone 2, although these differences were not consistently statistically significant. Fibers and fragments were the predominant shapes, and synthetic–natural polymer blends, polyethylene terephthalate (PET), polypropylene (PP), and polyacrylic acid (PAA) were the most prevalent. Generalized Additive Models (GAM) indicated that strong fluvial inputs and proximity to urban and riverine sources were factors driving MP distribution. Additionally, the detection of polymers reported in the literature as rare and high-risk, such as acrylonitrile butadiene styrene (ABS), acrylonitrile styrene acrylate (ASA), styrene–ethylene–butylene–styrene (SEBS), and polyvinyl stearate (PVS), highlights the complexity of MP sources in the region. Overall, these results provide the first spatial and temporal characterization of MPs in the surface and mid-water of the Colombian Caribbean and identify critical contamination hotspots that warrant targeted mitigation strategies. Full article
(This article belongs to the Special Issue Microplastics and Microfiber Pollution in Aquatic Environments)
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20 pages, 3747 KB  
Article
Impacts of the Built Environment in Typical Medical-Circle Catchments on Residents’ Activities: A Gradient Boosting Decision Tree Framework with Visual SHAP Interpretation
by Xiaotong Wang and Jialei Li
Buildings 2026, 16(4), 832; https://doi.org/10.3390/buildings16040832 - 19 Feb 2026
Viewed by 272
Abstract
Urban emergency medical services (EMSs) depend on time-critical accessibility, spatial demand distribution, and resilient transport networks. This study examines how built-environment characteristics shape spatiotemporal population intensity (as a proxy for latent EMS demand) within Shenzhen’s 10 min ambulance-accessible Emergency Medical Circle (EMC), using [...] Read more.
Urban emergency medical services (EMSs) depend on time-critical accessibility, spatial demand distribution, and resilient transport networks. This study examines how built-environment characteristics shape spatiotemporal population intensity (as a proxy for latent EMS demand) within Shenzhen’s 10 min ambulance-accessible Emergency Medical Circle (EMC), using high-resolution Baidu Huiyan mobile-device data. Human activity intensity was quantified in 200 × 200 m grids and modeled against 20 built-environment indicators using a Gradient Boosting Decision Tree (LightGBM), with SHAP employed for interpretable attribution. By analyzing the distribution density and variance of SHAP dependence patterns, pronounced diurnal shifts in dominant drivers were identified. Medical facility density anchors nocturnal demand, road network permeability dominates pre-dawn mobility, land-use entropy and functional diversity peak during the midday period, while transit hubs and mixed-use amenities consolidate evening activity. The results further reveal critical non-linear thresholds—such as medical facility density (~1.5–2.5 km−2) and building density (~45,000–60,000 m2 km−2)—beyond which marginal contributions diminish or become negative, indicating that proximity alone does not guarantee effective emergency coverage. These findings provide quantitative, time-sensitive guidance for EMC planning, highlighting the need for balanced facility dispersion, network prioritization, and demand-aware spatial design. By integrating high-resolution population dynamics with visually interpretable machine learning, this study advances a human-centered and operationally grounded framework for resilient emergency medical systems. Full article
(This article belongs to the Section Architectural Design, Urban Science, and Real Estate)
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18 pages, 3887 KB  
Article
The Interplay Between Topographic Gradients and Lake Effects on the Spatiotemporal Dynamics of Surface Environmental Variables in the Qinghai Lake Riparian Zone
by Fei Li, Minghao Liu, Zekun Ding, Chen Shi, Maoding Zhou and Yafeng Guo
Remote Sens. 2026, 18(4), 620; https://doi.org/10.3390/rs18040620 - 16 Feb 2026
Viewed by 290
Abstract
As a critical climate regulator on the Qinghai–Xizang Plateau, Qinghai Lake exerts important influences on surrounding surface environmental conditions. Using MODIS remote sensing data and topographic information from 2000 to 2024, this study analyzed the spatiotemporal variations in land surface temperature (LST), normalized [...] Read more.
As a critical climate regulator on the Qinghai–Xizang Plateau, Qinghai Lake exerts important influences on surrounding surface environmental conditions. Using MODIS remote sensing data and topographic information from 2000 to 2024, this study analyzed the spatiotemporal variations in land surface temperature (LST), normalized difference vegetation index (NDVI), and temperature vegetation dryness index (TVDI) in the 10-km riparian zone. The buffer was subdivided into five 2-km distance gradients to quantify the attenuation of lake effects and their interaction with topographic factors. The results indicate pronounced seasonal contrasts and distance-dependent differentiation of surface variables. LST exhibited clear seasonal variability, with peak values in the second and third quarters (Q2 and Q3). During Q2, the near-shore zone (0–2 km) remained notably cooler by approximately 2–3 °C (23.8 °C) than intermediate and distal zones (25.4–26.8 °C), indicating a moderate lake-related cooling effect during the early warm season. NDVI showed consistent seasonal phenology across all buffers, reaching maximum values in Q3, while mean NDVI values increased gradually with distance from the lake, ranging approximately from 0.48 in the near-shore zone to 0.51 in the distal zone. TVDI displayed distinct seasonal and spatial patterns, with relatively low and stable values in the near-shore zone throughout the year and a pronounced seasonal minimum in the distal zone during Q3 (0.57). These findings highlight strong seasonal and spatial heterogeneity of surface environmental conditions in the Qinghai Lake riparian zone. The observed patterns suggest that lake proximity and topographic gradients jointly influence hydrothermal conditions and vegetation dynamics at the landscape scale, providing quantitative evidence for understanding surface–environmental gradients in alpine lake systems. Full article
(This article belongs to the Section Remote Sensing in Geology, Geomorphology and Hydrology)
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20 pages, 3264 KB  
Article
An Assessment of the Multi-Input Spatiotemporal RF–XGBoost Hybrid Framework for PM10 Estimation in Lithuania
by Mina Adel Shokry Fahim and Jūratė Sužiedelytė Visockienė
Sustainability 2026, 18(4), 2022; https://doi.org/10.3390/su18042022 - 16 Feb 2026
Viewed by 199
Abstract
Air pollution remains a major public-health concern, and exposure to particulate matter (PM), particularly PM10 (with a diameter ≤ 10 µm), is associated with adverse respiratory and cardiovascular outcomes. Most research relies on a singular model for PM10 surface estimation. This [...] Read more.
Air pollution remains a major public-health concern, and exposure to particulate matter (PM), particularly PM10 (with a diameter ≤ 10 µm), is associated with adverse respiratory and cardiovascular outcomes. Most research relies on a singular model for PM10 surface estimation. This study is an assessment of a national-scale, daily PM10 estimation framework for Lithuania (2019–2024), using a hybrid machine-learning method that combines Random Forest (RF) and extreme gradient boosting (XGBoost) algorithms. Hourly PM10 observations were aggregated from 18 monitoring stations to obtain daily means and temporal means. The predictors integrated meteorological factors, such as temperature, wind, humidity, and precipitation, to determine satellite-based atmospheric composition from Sentinel-5P Tropospheric Monitoring Instruments (TROPOMI). Atmospheric components include nitrogen dioxide (NO2), carbon monoxide (CO), sulfur dioxide (SO2), ozone (O3), formaldehyde (HCHO), and the absorbing aerosol index (AI). Moderate-Resolution Imaging Spectroradiometers (MODIS) were used to record land-surface temperature and static spatial descriptors, such as elevation, land cover, Normalized Difference Vegetation Index (NDVI), population, and road proximity. The dataset was partitioned temporally into training (70%), validation (20%), and testing (10%). The hybrid model achieved an improved accuracy, compared with single-model baselines, reaching a coefficient of determination (R2) of 0.739 in validation and R2 = 0.75 in the tested dataset. Mean absolute error (MAE) was 3.15 µg/m3, and root mean square error (RMSE) was 3.98 µg/m3. The results indicate a slight tendency to overestimate PM10 concentrations at lower concentration levels. Feature-importance analysis revealed that short-term temporal persistence is the key to daily PM10 prediction, while meteorological variables provide secondary contributions. Temporal evaluation, using consecutive two-year windows, revealed a consistent improvement in predictive performance from 2019–2020 to 2023–2024, while station-level analysis showed moderate-to-strong agreement between the predicted and observed PM10 concentrations across monitoring stations, with R2 ranging from 0.455 to 0.760. This provides decision-support capabilities for air-quality management, the evaluation of mitigation measures, and integration of air-pollution considerations into sustainable urban planning strategies assessing public-health protection. Full article
(This article belongs to the Section Air, Climate Change and Sustainability)
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15 pages, 937 KB  
Article
An Improved MAPPO for Multi-Surface Vessel Collaboration
by Guangyu Wang, Feng Tian and Chengcheng Ren
Actuators 2026, 15(2), 121; https://doi.org/10.3390/act15020121 - 14 Feb 2026
Viewed by 296
Abstract
Collaborative control of multiple surface vessels remains a significant challenge in autonomous maritime operations, particularly within environments characterized by sparse rewards. Conventional Multi-Agent Proximal Policy Optimization (MAPPO) often suffers from inefficient credit assignment and slow convergence in such scenarios. To address these limitations, [...] Read more.
Collaborative control of multiple surface vessels remains a significant challenge in autonomous maritime operations, particularly within environments characterized by sparse rewards. Conventional Multi-Agent Proximal Policy Optimization (MAPPO) often suffers from inefficient credit assignment and slow convergence in such scenarios. To address these limitations, this paper proposes an enhanced MAPPO framework that integrates a counterfactual baseline—derived from Counterfactual Multi-Agent Policy Gradients (CMAPG)—into the Generalized Advantage Estimation (GAE) formulation. Furthermore, a Prioritized Experience Replay (PER) mechanism with importance sampling is incorporated to improve sample efficiency. The counterfactual baseline is necessary to provide precise, agent-specific learning signals within the on-policy paradigm, directly tackling the credit assignment problem. The PER mechanism, carefully adapted with importance sampling, is essential to break the sample-inefficiency barrier by strategically reusing valuable past experiences without compromising stability. This synergistic approach refines credit assignment by isolating individual contributions and maximizes the utility of valuable historical experiences. Simulation results and comparisons validate the enhanced control performance of the proposed controller. Full article
(This article belongs to the Special Issue Feature Papers in Actuators for Surface Vehicles)
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16 pages, 4206 KB  
Article
Spatialization Study of Monthly Global Solar Radiation in Sparse Observation Area Based on Environmental Similarity and Spatial Proximity
by Mao-Fen Li, Peng-Tao Guo, A-Xing Zhu and Xuan Yu
Atmosphere 2026, 17(2), 195; https://doi.org/10.3390/atmos17020195 - 12 Feb 2026
Viewed by 227
Abstract
Global Solar Radiation (Rs) is essential for ecological and climatic modeling, yet its spatialization is often hampered by sparse observation networks. Conventional methods demand a well-distributed set of stations with global representativeness—a requirement rarely met in practice. To address this gap, we propose [...] Read more.
Global Solar Radiation (Rs) is essential for ecological and climatic modeling, yet its spatialization is often hampered by sparse observation networks. Conventional methods demand a well-distributed set of stations with global representativeness—a requirement rarely met in practice. To address this gap, we propose a spatialization method based on environmental similarity and spatial proximity (ES-SP), which integrates the Law of Geographic Similarity and Tobler’s First Law of Geography. Using monthly Rs data from 11 stations in Tropical China (2015), we evaluated ES-SP against Ordinary Kriging (OK) and Local Polynomial Interpolation (LP) through leave-one-out cross-validation (LOOCV), with root mean square error (RMSE), relative RMSE, and mean absolute percentage error (MAPE) as accuracy metrics. Topographic and monthly meteorological covariates were selected dynamically via random forest (RF), and the performance differences among the three methods were tested statistically using the Wilcoxon signed-rank test. Results show that ES-SP outperforms both OK and LP in accuracy and stability, achieving the lowest error metrics in most months—e.g., RMSE as low as 37.23 MJ·m−2 in December and MAPE as low as 4.34% in August—along with a narrow interquartile range, indicating consistent performance across seasons. Spatially, ES-SP accurately reproduces the coastal–inland gradient during the rainy season (May) and the latitudinal gradient in the dry season (January), whereas OK yields overly smooth distributions that obscure local details, and LP exhibits extreme instability and unrealistic spatial discontinuities. The study demonstrates that the ES-SP method effectively overcomes the reliance on globally representative station samples, providing a robust technical pathway for generating continuous Rs datasets in data-sparse regions such as Tropical China. Further research should focus on extending the geographic scope and refining the covariate set to enhance generalizability. Full article
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18 pages, 9366 KB  
Article
Gastric and Small-Intestinal Morphological Remodeling After Intragastric Apelin-13 Administration in Unweaned Rats
by Sylwia Szymańczyk, Cezary Osiak-Wicha, Katarzyna Kras, Małgorzata Kapica, Iwona Puzio, Hanna Antushevich, Atsukazu Kuwahara, Ikuo Kato, Iwona Łuszczewska-Sierakowska and Marcin B. Arciszewski
Animals 2026, 16(3), 497; https://doi.org/10.3390/ani16030497 - 5 Feb 2026
Viewed by 323
Abstract
Apelin is a postnatal peptide implicated in gastrointestinal maturation, yet its combined effects on mucosa, enteric plexuses, and gut-derived appetite signals are not well defined. We investigated the impact of chronic intragastric apelin-13 on the stomach and small intestine of unweaned rats. Twelve [...] Read more.
Apelin is a postnatal peptide implicated in gastrointestinal maturation, yet its combined effects on mucosa, enteric plexuses, and gut-derived appetite signals are not well defined. We investigated the impact of chronic intragastric apelin-13 on the stomach and small intestine of unweaned rats. Twelve Wistar pups of both sexes received apelin-13 (100 nmol/kg body weight, twice daily) or saline from postnatal day 10 for 14 days. After euthanasia, gastric and small-intestinal samples were processed for histomorphometry, neurofilament immunohistochemistry of myenteric and submucosal plexuses, and quantitative staining for ghrelin and leptin. Apelin-13 increased gastric mucosal thickness and pit and gland height, enlarged zymogen cells, and reduced muscularis propria thickness, while leaving submucosa and parietal cell area unchanged. In the small intestine, apelin produced a clear proximal-distal gradient, with enhanced villus-mucosa indices proximally and reduced indices in mid-to-distal jejunum, alongside broader crypt remodeling. Enterocyte and goblet cell dimensions changed in parallel with these regional shifts. Myenteric and submucosal ganglia were also remodeled in a segment-dependent manner. Ghrelin immunoreactivity increased in most regions, whereas leptin showed opposite proximal and distal responses. Overall, early-life luminal apelin-13 reshapes gastric and intestinal architecture and local hormone expression. Full article
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25 pages, 761 KB  
Article
Deep Reinforcement Learning-Based Voltage Regulation Using Electric Springs in Active Distribution Networks
by Jesus Ignacio Lara-Perez, Gerardo Trejo-Caballero, Guillermo Tapia-Tinoco, Luis Enrique Raya-González and Arturo Garcia-Perez
Technologies 2026, 14(2), 87; https://doi.org/10.3390/technologies14020087 - 1 Feb 2026
Viewed by 257
Abstract
The increasing penetration of distributed generation in active distribution networks (ADNs) introduces significant voltage regulation challenges due to the intermittent nature of renewable energy sources. Electric springs (ESs) have emerged as a cost-effective alternative to conventional FACTS devices for voltage regulation, requiring minimal [...] Read more.
The increasing penetration of distributed generation in active distribution networks (ADNs) introduces significant voltage regulation challenges due to the intermittent nature of renewable energy sources. Electric springs (ESs) have emerged as a cost-effective alternative to conventional FACTS devices for voltage regulation, requiring minimal energy storage while providing fast, flexible reactive power compensation. This paper proposes a deep reinforcement learning (DRL)-based approach for voltage regulation in balanced active distribution networks with distributed generation. Electric springs are deployed at selected buses in series with noncritical loads to provide flexible voltage support. The main contributions of this work are: (1) a novel region-based penalized reward function that effectively guides the DRL agent to minimize voltage deviations; (2) a coordinated control strategy for multiple ESs using the Deep Deterministic Policy Gradient (DDPG) algorithm, representing the first application of DRL to ES-based voltage regulation; (3) a systematic hyperparameter tuning methodology that significantly improves controller performance; and (4) comprehensive validation demonstrating an approximately 40% reduction in mean voltage deviation relative to the no-control baseline. Three well-known continuous-control DRL algorithms, Twin Delayed Deep Deterministic Policy Gradient (TD3), Proximal Policy Optimization (PPO), and DDPG, are first evaluated using the default hyperparameter configurations provided by MATLAB R2022b.Based on this baseline comparison, a dedicated hyperparameter-tuning procedure is then applied to DDPG to improve the robustness and performance of the resulting controller. The proposed approach is evaluated through simulation studies on the IEEE 33-bus and IEEE 69-bus test systems with time-varying load profiles and fluctuating renewable generation scenarios. Full article
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17 pages, 26741 KB  
Article
Dual-Agent Deep Reinforcement Learning for Low-Carbon Economic Dispatch in Wind-Integrated Microgrids Based on Carbon Emission Flow
by Wenjun Qiu, Hebin Ruan, Xiaoxiao Yu, Yuhang Li, Yicheng Liu and Zhiyi He
Energies 2026, 19(2), 551; https://doi.org/10.3390/en19020551 - 22 Jan 2026
Viewed by 165
Abstract
High renewable penetration in microgrids makes low-carbon economic dispatch under uncertainty challenging, and single-agent deep reinforcement learning (DRL) often yields unstable cost–emission trade-offs. This study proposes a dual-agent DRL framework that explicitly balances operational economy and environmental sustainability. A Proximal Policy Optimization (PPO) [...] Read more.
High renewable penetration in microgrids makes low-carbon economic dispatch under uncertainty challenging, and single-agent deep reinforcement learning (DRL) often yields unstable cost–emission trade-offs. This study proposes a dual-agent DRL framework that explicitly balances operational economy and environmental sustainability. A Proximal Policy Optimization (PPO) agent focuses on minimizing operating cost, while a Soft Actor–Critic (SAC) agent targets carbon emission reduction; their actions are combined through an adaptive weighting strategy. The framework is supported by carbon emission flow (CEF) theory, which enables network-level tracing of carbon flows, and a stepped carbon pricing mechanism that internalizes dynamic carbon costs. Demand response (DR) is incorporated to enhance operational flexibility. The dispatch problem is formulated as a Markov Decision Process, allowing the dual-agent system to learn policies through interaction with the environment. Case studies on a modified PJM 5-bus test system show that, compared with a Deep Deterministic Policy Gradient (DDPG) baseline, the proposed method reduces total operating cost, carbon emissions, and wind curtailment by 16.8%, 11.3%, and 15.2%, respectively. These results demonstrate that the proposed framework is an effective solution for economical and low-carbon operation in renewable-rich power systems. Full article
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31 pages, 1934 KB  
Review
Prospective of Colorectal Cancer Screening, Diagnosis, and Treatment Management Using Bowel Sounds Leveraging Artificial Intelligence
by Divyanshi Sood, Surbhi Dadwal, Samiksha Jain, Iqra Jabeen Mazhar, Bipasha Goyal, Chris Garapati, Sagar Patel, Zenab Muhammad Riaz, Noor Buzaboon, Ayushi Mendiratta, Avneet Kaur, Anmol Mohan, Gayathri Yerrapragada, Poonguzhali Elangovan, Mohammed Naveed Shariff, Thangeswaran Natarajan, Jayarajasekaran Janarthanan, Shreshta Agarwal, Sancia Mary Jerold Wilson, Atishya Ghosh, Shiva Sankari Karuppiah, Joshika Agarwal, Keerthy Gopalakrishnan, Swetha Rapolu, Venkata S. Akshintala and Shivaram P. Arunachalamadd Show full author list remove Hide full author list
Cancers 2026, 18(2), 340; https://doi.org/10.3390/cancers18020340 - 21 Jan 2026
Viewed by 639
Abstract
Background: Colorectal cancer (CRC) is the second leading cause of cancer-related mortality worldwide, accounting for approximately 10% of all cancer cases. Despite the proven effectiveness of conventional screening modalities such as colonoscopy and fecal immunochemical testing (FIT), their invasive nature, high cost, and [...] Read more.
Background: Colorectal cancer (CRC) is the second leading cause of cancer-related mortality worldwide, accounting for approximately 10% of all cancer cases. Despite the proven effectiveness of conventional screening modalities such as colonoscopy and fecal immunochemical testing (FIT), their invasive nature, high cost, and limited patient compliance hinder widespread adoption. Recent advancements in artificial intelligence (AI) and bowel sound-based signal processing have enabled non-invasive approaches for gastrointestinal diagnostics. Among these, bowel sound analysis—historically considered subjective—has reemerged as a promising biomarker using digital auscultation and machine learning. Objective: This review explores the potential of AI-powered bowel sound analytics for early detection, screening, and characterization of colorectal cancer. It aims to assess current methodologies, summarize reported performance metrics, and highlight translational opportunities and challenges in clinical implementation. Methods: A narrative review was conducted across PubMed, Scopus, Embase, and Cochrane databases using the terms colorectal cancer, bowel sounds, phonoenterography, artificial intelligence, and non-invasive diagnosis. Eligible studies involving human bowel sound-based recordings, AI-based sound analysis, or machine learning applications in gastrointestinal pathology were reviewed for study design, signal acquisition methods, AI model architecture, and diagnostic accuracy. Results: Across studies using convolutional neural networks (CNNs), gradient boosting, and transformer-based models, reported diagnostic accuracies ranged from 88% to 96%. Area under the curve (AUC) values were ≥0.83, with F1 scores between 0.71 and 0.85 for bowel sound classification. In CRC-specific frameworks such as BowelRCNN, AI models successfully differentiate abnormal bowel sound intervals and spectral patterns associated with tumor-related motility disturbances and partial obstruction. Distinct bowel sound-based signatures—such as prolonged sound-to-sound intervals and high-pitched “tinkling” proximal to lesions—demonstrate the physiological basis for CRC detection through bowel sound-based biomarkers. Conclusions: AI-driven bowel sound analysis represents an emerging, exploratory research direction rather than a validated colorectal cancer screening modality. While early studies demonstrate physiological plausibility and technical feasibility, no large-scale, CRC-specific validation studies currently establish sensitivity, specificity, PPV, or NPV for cancer detection. Accordingly, bowel sound analytics should be viewed as hypothesis-generating and potentially complementary to established screening tools, rather than a near-term alternative to validated modalities such as FIT, multitarget stool DNA testing, or colonoscopy. Full article
(This article belongs to the Section Methods and Technologies Development)
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22 pages, 5614 KB  
Article
Modeling China’s Urban Network Structure: Unraveling the Drivers from a Population Mobility Perspective
by Haowei Duan and Kai Liu
Systems 2026, 14(1), 109; https://doi.org/10.3390/systems14010109 - 20 Jan 2026
Viewed by 362
Abstract
Intercity population flows are playing an increasingly pivotal role in shaping the spatial evolution and structural dynamics of urban networks. Drawing upon Amap Migration Data (2018–2023), this study maps China’s urban networks using social network analysis and identifies their key drivers using a [...] Read more.
Intercity population flows are playing an increasingly pivotal role in shaping the spatial evolution and structural dynamics of urban networks. Drawing upon Amap Migration Data (2018–2023), this study maps China’s urban networks using social network analysis and identifies their key drivers using a temporal exponential random graph model. The findings reveal three primary insights: First, the overall network exhibits “high connectivity and strong clustering” traits. Enhanced efficiency in intercity resource allocation fosters cross-regional factor flows, resulting in multi-tiered connectivity corridors. Industrial linkages and policy interventions drive the development of a polycentric and clustered configuration. Second, the individual city network exhibits a core–periphery dynamic structure. A diamond-shaped framework dominated by hub cities in the national strategic regions directs factor flows. Development of strategic corridors enables peripheral cities to evolve into secondary hubs by leveraging structural hole advantages, reflecting the continuous interplay between network structure and geo-economic factors. Third, driving factors involve nonlinear interactions within a multi-layered system. Path dependence in topology, gradient potential from nodal attributes, spatial counterbalance between geographic decay laws and multidimensional proximity, and adaptive self-organization are collectively associated with the transition of the urban network toward a multi-tiered synergistic pattern. By revealing the dynamic interplay between network topology and multidimensional driving factors, this study deepens and advances the theoretical connotations of the “Space of Flows” theory, providing an empirical foundation for optimizing regional governance strategies and promoting high-quality coordinated development of Chinese cities. Full article
(This article belongs to the Special Issue Data-Driven Urban Mobility Modeling)
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17 pages, 3642 KB  
Article
Spatiotemporal Analysis for Real-Time Non-Destructive Brix Estimation in Apples
by Ha-Na Kim, Myeong-Won Bae, Yong-Jin Cho and Dong-Hoon Lee
Agriculture 2026, 16(2), 172; https://doi.org/10.3390/agriculture16020172 - 9 Jan 2026
Viewed by 305
Abstract
Predicting internal quality parameters, such as Brix and water content, of apples, is essential for quality control. Existing near-infrared (NIR) and hyperspectral imaging (HSI)-based techniques have limited applicability due to their dependence on equipment and environmental sensitivity. In this study, a transportable quality [...] Read more.
Predicting internal quality parameters, such as Brix and water content, of apples, is essential for quality control. Existing near-infrared (NIR) and hyperspectral imaging (HSI)-based techniques have limited applicability due to their dependence on equipment and environmental sensitivity. In this study, a transportable quality assessment system was proposed using spatiotemporal domain analysis with long-wave infrared (LWIR)-based thermal diffusion phenomics, enabling non-destructive prediction of the internal Brix of apples during transport. After cooling, the thermal gradient of the apple surface during the cooling-to-equilibrium interval was extracted. This gradient was used as an input variable for multiple linear regression, Ridge, and Lasso models, and the prediction performance was assessed. Overall, 492 specimens of 5 cultivars of apple (Hongro, Arisoo, Sinano Gold, Stored Fuji, and Fuji) were included in the experiment. The thermal diffusion response of each specimen was imaged at a sampling frequency of 8.9 Hz using LWIR-based thermal imaging, and the temperature changes over time were compared. In cross-validation of the integrated model for all cultivars, the coefficient of determination (R2cv) was 0.80, and the RMSEcv was 0.86 °Brix, demonstrating stable prediction accuracy within ±1 °Brix. In terms of cultivar, Arisoo (Cultivar 2) and Fuji (Cultivar 5) showed high prediction reliability (R2cv = 0.74–0.77), while Hongro (Cultivar 1) and Stored Fuji (Cultivar 4) showed relatively weak correlations. This is thought to be due to differences in thermal diffusion characteristics between cultivars, depending on their tissue density and water content. The LWIR-based thermal diffusion analysis presented in this study is less sensitive to changes in reflectance and illuminance compared to conventional NIR and visible light spectrophotometry, as it enables real-time measurements during transport without requiring a separate light source. Surface heat distribution phenomics due to external heat sources serves as an index that proximally reflects changes in the internal Brix of apples. Later, this could be developed into a reliable commercial screening system to obtain extensive data accounting for diversity between cultivars and to elucidate the effects of interference using external environmental factors. Full article
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26 pages, 3455 KB  
Article
Analysis of Smoke Confinement in Underground Buildings: Design of Air Curtains Against Tunnel Fire
by Yuxiang Wang and Angui Li
Buildings 2026, 16(2), 263; https://doi.org/10.3390/buildings16020263 - 7 Jan 2026
Viewed by 286
Abstract
Tunnels have significantly expanded human activity spaces and alleviated urban congestion and environmental pollution on the surface. However, fires and associated smoke propagation in tunnels pose common and critical challenges in underground space utilization. Previous studies have primarily focused on smoke control under [...] Read more.
Tunnels have significantly expanded human activity spaces and alleviated urban congestion and environmental pollution on the surface. However, fires and associated smoke propagation in tunnels pose common and critical challenges in underground space utilization. Previous studies have primarily focused on smoke control under standard atmospheric conditions, emphasizing isolated parameters such as jet velocity or heat release rate (HRR), while overlooking key factors like environmental pressure and fire source proximity that influence smoke buoyancy and containment efficacy. One of the key problems remains unsolved: the comprehensive mechanisms governing transverse air curtain performance in variable-pressure and proximity scenarios. This study utilized Fire Dynamics Simulator (FDS6.7.1) software to conduct numerical simulations, aiming to elucidate the underlying incentives and explore the phenomena of smoke–thermal interactions. The analysis systematically evaluates the influence of four critical parameters: HRR (1–15 MW), fire-to-curtain distance (5–95 m), air curtain jet velocity (6–16 m/s), and ambient pressure (40–140 kPa). Results show that (1) jet velocity emerges as the dominant factor, with exponential enhancement in thermal containment efficiency at velocities above 10 m/s due to intensified shear forces; (2) escalating HRR weakens isolation, leading to disproportionate downstream temperature rises and diminished efficacy; (3) fire proximity within 10 m disrupts curtain integrity via high-momentum smoke impingement, amplifying thermal gradients; and (4) elevated ambient pressure dampens smoke buoyancy while augmenting air curtain momentum, yielding improved containment efficiency and reduced temperatures. This paper is helpful for the design and operation of thermal applications in underground infrastructures, providing predictive models for optimized smoke control systems. The contour maps reveal the field-distribution trends and highlight the significant influence of the air curtain and key governing parameters on the thermal field and smoke control performance. This work delivers pivotal theoretical and practical insights into the advanced design and optimization of aerodynamic smoke control systems in tunnel safety engineering Full article
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Article
Traditional Cultivation and Land-Use Change Under the Balaton Law: Impacts on Vineyards and Garden Landscapes
by Krisztina Filepné Kovács, Virág Kutnyánszky, Zhen Shi, Zsolt Miklós Szilvácsku, László Kollányi and Edina Klára Dancsokné Fóris
Land 2026, 15(1), 106; https://doi.org/10.3390/land15010106 - 6 Jan 2026
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Abstract
The Balaton region is Hungary’s most important recreational area, known for Central Europe’s largest freshwater lake and its traditional vineyard and horticultural landscapes. Since 1990, vineyard and orchard abandonment and intensified shoreline urbanization have increasingly threatened both landscape character and ecological balance. This [...] Read more.
The Balaton region is Hungary’s most important recreational area, known for Central Europe’s largest freshwater lake and its traditional vineyard and horticultural landscapes. Since 1990, vineyard and orchard abandonment and intensified shoreline urbanization have increasingly threatened both landscape character and ecological balance. This study analyses land-use changes in the Balaton hinterland and evaluates the effectiveness of regional land-use regulation between 1990 and 2018, with a focus on the 2000 Balaton Law (BKÜRT), which sought to preserve traditional land uses by permitting construction only where at least 80% of vineyard parcels remained cultivated. Spatial–temporal analysis was based on CORINE Land Cover (CLC) data from 1990 to 2018, supplemented by change layers from the Copernicus Land Monitoring Service. The CORINE Land Cover classification is a three-level hierarchical system (5 Level-1 groups, 15 Level-2 classes, and 44 Level-3 classes) developed by the EEA to provide standardized, satellite-based land cover information across Europe. Land cover was aggregated into major categories (using Level-1 and Level-2 classes) relevant to the Hungarian landscape. To address CLC limitations related to representing vineyards as relatively homogeneous units despite substantial differences in the density and scale of built structures, detailed case studies were conducted in three C1 vineyard zones—Alsóörs, Paloznak, and Szentantalfa—using historical aerial photographs, Google Earth imagery, and the Hungarian Ecosystem Map (NÖSZTÉP). Despite the restrictive regulatory framework, the CLC database showed that the share of vineyards in the vineyard regulation zone (C-1, C-2) decreased between 1990 and 2018 from 45.4% to 35.8% (the share of gardens and fruit plantations had changed from 9.7% to 15.5%). In the whole Balaton region, there was an approximately 18% decline in vineyard areas. Considering the M-2 horticultural zone, the garden coverage increased from 18.9% in 1990 (17.7% in 2000) to 30.5% (share of vineyards changed from 54.3% (54.6% in 2000) to 38.8%). At the regional level, gardens and fruit plantations had a smaller decrease (3.2%). Although overall trends were more favorable than at the national level, regulatory measures proved insufficient to prevent the conversion of vineyards and orchards in sensitive areas, particularly on slopes overlooking the lake, in proximity to tourist hubs, and in areas exposed to strong development pressure. By 2018, the C1 zone had expanded spatially but became less targeted, as the proportion of vineyards within it decreased. Boundary refinements failed to substantially improve regulatory precision or effectiveness. The case studies reveal a gradient of regulatory strictness reflecting differing landscape protection priorities and stages of vineyard transformation, with Alsóörs responding to long-standing, partly irreversible changes while attempting to slow further landscape alteration. To counter ongoing negative trends, more targeted and enforceable regulations are required, including a clearer separation of cultivated and recreational land uses, a maximum building size of 80 m2 for recreational properties, and a reassessment of vineyard zone boundaries to better reflect active cultivation and protect sensitive landscapes. Full article
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