Search Results (21,170)

Accurate and spatially representative estimation of Global Horizontal Irradiance (GHI) is critical for solar energy planning in tropical regions characterized by strong atmospheric variability and complex topography. This study aims to evaluate the performance and robustness of four semi-empirical satellite-derived GHI models, Beyer, Perez, Hammer, and Rigollier, under heterogeneous tropical conditions in West Java, Indonesia. Hourly GHI data for 2022 were derived from GK2A satellite observations and validated against ground measurements from eight stations representing coastal, lowland, and mountainous areas. Model performance was assessed at annual and seasonal scales using relative Root Mean Square Error (rRMSE) and relative Mean Bias Error (rMBE). The results show significant variability in model performance across locations, with the average annual rRMSE computed per model and averaged over the eight stations being similar among models: 41.10% (Perez), 41.18% (Beyer), 42.44% (Hammer), and 42.49% (Rigollier). Perez showed the most consistent performance, with station-level rRMSE values ranging from 35.36% to 43.32% and rMBE ranging from −18.20% to 22.09%. Seasonal analysis indicates higher errors during the rainy season, 41.16% (Perez), 45.23% (Beyer), 42.74% (Hammer), and 46.34% (Rigollier), while lower errors were observed during the dry season, particularly for Beyer (36.16%) and Rigollier (36.29%). Spatial analysis indicates higher irradiance in coastal and lowland areas compared to mountainous regions. These findings emphasize the importance of climate- and topography-aware model selection for reliable solar resource assessment in tropical environments. Full article

Digital terrain models (DTMs) are essential elevation datasets that represent the morphology of the Earth’s surface and play a critical role in applications, such as urban planning, civil engineering, infrastructure design, and environmental assessment. However, the excessive cost remains the major challenge in obtaining accurate terrain models. Recent advancements in low-cost inertial navigation and motion-sensing technologies offer significant potential to enhance the cost-effectiveness of surveying projects. This study investigates the vertical accuracy and operational usability of a handheld inertial measurement unit (IMU) device (Moasure 2) for DTM generation in urban environments through the comparison with traditional total station and digital levels procedures. It also assesses the device compliance with The American Society for Photogrammetry and Remote Sensing (ASPRS) Positional Accuracy Standards. For this purpose, a comprehensive field survey was conducted in a small urban area characterized by varied terrain morphology. The vertical accuracy of the Moasure 2 was acceptable for many urban mapping applications based on a rigorous analysis of checkpoint data and error patterns, which were quantitatively assessed relative to reference surfaces. Profile-based validation showed that the elevation differences between similar terrain types were mainly within ±25 cm, with minimal bias and symmetric error distributions. The findings indicate that Moasure 2 can be a viable alternative tool for fast DTM generation in low-cost urban projects. It offers significant advantages in terms of portability, ease of use, and reduced fieldwork time compared to conventional methodologies. Furthermore, this study addresses the critical gap in the validation of the new IMU-based surveying technology and provides evidence for choosing appropriate equipment for urban terrain modeling. Full article

Social media has become a critical channel for public health communication during the COVID-19 pandemic, yet how official health messaging aligns with broader public discourse remains insufficiently understood. This study develops an end-to-end infoveillance framework to examine the dynamic relationship between Centers for Disease Control and Prevention (CDC) communications and general public discourse on social media. We analyzed 17,524 CDC tweets and 67,895 public discourse tweets. Biterm Topic Model (BTM) was used to extract topics from each corpus, and a novel topic consistency scoring system integrating cosine similarity with daily public topic prominence was developed to quantify temporal alignment between official health communication and public discourse. Two complementary sentiment measures were incorporated: expected sentiment (average emotional tone) and net sentiment (overall emotional intensity). Temporal relationships were examined using autoregressive integrated moving average with exogenous variables (ARIMAX) models. Results show that topic alignment increased over time across CDC topics, while expected sentiment remained consistently negative. Higher alignment was associated with immediate and delayed changes in expected sentiment and stronger emotional intensity in net sentiment based on ARIMAX results. These findings suggest that topic alignment reflects public attention rather than agreement with official communications and is associated with more negative emotional responses. This framework provides a scalable, generalizable approach to investigating and evaluating public engagement with official health communication. Full article

African pygmy hedgehogs (APHs) are increasingly kept as companion animals, yet evidence-based nutritional recommendations for this species remain limited. Commercial cat or kitten diets are still commonly used by owners and veterinarians in practice, despite being formulated exclusively for domestic cats rather than for hedgehogs with omnivorous–insectivorous feeding habits. This cross-sectional study evaluated the association between dietary regimen and serum biochemical parameters associated with renal function in APHs. Blood samples were collected from 19 client-owned APHs aged 12–68 months: 10 hedgehogs fed a commercial kitten diet and 9 fed a commercial APH-specific diet. Serum concentrations of blood urea nitrogen, creatinine, phosphorus, and calcium were measured, and the nutritional composition of the two diets was compared using manufacturer declarations and targeted laboratory analyses. Hedgehogs fed the commercial kitten diet had significantly higher serum blood urea nitrogen (p = 0.0133), creatinine (p = 0.0279), and phosphorus (p = 0.0279) concentrations than those fed the APH-specific diet, whereas serum calcium concentrations did not differ significantly (p = 0.3846). These differences occurred despite similar dietary phosphorus content, while the commercial kitten diet had higher declared fat and lower fiber content. The findings suggest that dietary regimen may be associated with alterations in renal biochemical profiles in APHs and support the use of species-appropriate diets in clinical practice. Full article

To achieve non-contact and continuous monitoring of body length in Micropterus salmoides and overcome the stress damage and subjective error associated with traditional manual measurement, this paper proposes an improved YOLOv8-based multi-target tracking framework for intensive recirculating aquaculture systems. The system employs a geometric measurement framework based on monocular vision that achieves conversion from pixel coordinates to actual body length through camera calibration, water-surface refraction correction, and pose projection correction. Under a collaborative optimization framework integrating detection and tracking, the model incorporates multi-scale feature enhancement, lightweight re-identification (ReID), and a robust data association mechanism, which improves system stability under conditions of high fish density, variable illumination, and turbid water. A shallow feature fusion path is introduced to enhance small-target perception, and a MobileNetV3_ReID model is adopted to extract highly discriminative appearance features, which improves identity consistency while maintaining model compactness. In the data association stage, a hybrid cost matrix integrating IoU, cosine similarity, and motion consistency is constructed, and optimal matching is realized through the Hungarian algorithm. Dynamic threshold adjustment and an exponential moving-average feature-update strategy are introduced to effectively suppress identity switching. Experiments were conducted on an overhead video dataset of Micropterus salmoides collected at a recirculating aquaculture system facility. The results show that the proposed method achieves 82.7% mAP50 while maintaining a real-time throughput of 88 FPS, with MOTA reaching 76.9% and IDF1 reaching 81.5%—the latter representing an improvement of 3.2 percentage points over BoT-SORT and 5.3 percentage points over the YOLOv8 baseline tracker. The number of identity switches (IDSW) decreased from 89 in the baseline configuration to 39, a reduction of 56.2%. Crucially, these component-level improvements translate into a body length error (BLE) of 5.2 ± 1.8% (MAE = 1.35 cm, Pearson r = 0.972), representing a 38.8% improvement over the baseline BLE of 8.5% and satisfying the 5–10% tolerance required for aquaculture growth monitoring. Ablation analysis confirms that both detection enhancements (contributing −1.3% BLE) and tracking optimizations (contributing −2.0% BLE) are necessary to achieve this application-level accuracy. Full article

Semantic communication has emerged as a promising paradigm for next-generation wireless networks, offering substantial efficiency gains by prioritizing the transmission of task-relevant meaning over bit-level accuracy. However, while its benefits in bandwidth reduction and intelligent data representation are well established, its potential to provide intrinsic reconstruction resistance without relying on conventional cryptographic mechanisms remains largely unexplored. This paper investigates whether semantic communication system architectures themselves can contribute to intrinsic reconstruction resistance for image transmission. We propose an autoencoder-based semantic communication framework in which images are encoded into latent representations and transmitted over a wireless channel, with decoding performed using architecture-specific neural networks. Unlike traditional secure communication approaches that depend on encryption, the proposed method leverages architectural uniqueness and representation-level abstraction to limit unauthorized reconstruction. To systematically analyze this, we evaluate eight adversarial scenarios encompassing variations in encoder–decoder architecture and initialization, including both matched (worst-case) and maximum mismatched (best-case) conditions. The system is modeled using a standard Alice–Bob–Mallory framework, where an adversary attempts to reconstruct intercepted semantic representations without full architectural knowledge. Performance is evaluated using peak signal-to-noise ratio (PSNR) and structural similarity index measure (SSIM) for reconstruction quality, alongside semantic accuracy measured via a convolutional neural network (CNN)-based classifier and embedding cosine similarity to assess information leakage. Experimental results demonstrate that architectural mismatches substantially degrade both visual reconstruction and semantic interpretability for unauthorized receivers, while matched configurations enable substantial recovery. It is important to emphasise that the proposed approach does not provide cryptographic confidentiality; rather, it offers architecture-dependent resistance to unauthorised semantic reconstruction under restricted adversarial assumptions. Overall, the results show that semantic communication systems can exhibit intrinsic reconstruction resistance through architecture-dependent latent-space organisation, reducing reliance on additional cryptographic overhead under restricted adversarial assumptions, while also highlighting limitations when adversaries possess full architectural and initialisation knowledge. Full article

Background: Posterior malleolar fractures are commonly assessed using two-dimensional measurements and morphology-based classification systems. However, ankle fracture morphology is inherently three-dimensional, and the reproducibility of CT-based volumetric segmentation for malleolar fracture fragments has not been sufficiently established. Objectives: This study aimed to evaluate the relationship between lateral and posterior malleolar fragment volumes in homogeneous supination–external rotation (SER)-type trimalleolar ankle fractures and to assess the intraobserver and interobserver reproducibility of a manual CT-based three-dimensional volumetric segmentation workflow. Methods: This retrospective musculoskeletal imaging study included 71 patients with SER-type trimalleolar ankle fractures who underwent preoperative computed tomography (CT). Posterior and lateral malleolar fracture fragments were segmented on thin-slice axial CT images using a standardized manual contour-based slice-by-slice workflow. Fragment volumes were calculated using dedicated volumetric imaging software. The association between lateral and posterior malleolar fragment volumes was assessed using Spearman correlation and multivariable linear regression analyses. Measurement reproducibility was evaluated using intraclass correlation coefficients for absolute agreement [ICC(A,1)] and Bland–Altman analyses. Results: The median lateral and posterior malleolar fragment volumes were 8.63 cm³ (interquartile range [IQR], 7.18–10.71) and 2.64 cm³ (IQR, 1.88–4.24), respectively. A weak but statistically significant positive correlation was observed between lateral and posterior malleolar fragment volumes (Spearman rho = 0.313, p = 0.008). In multivariable linear regression analysis, lateral malleolar fragment volume remained independently associated with posterior malleolar fragment volume after adjustment for age, sex, and body mass index (B = 0.316, standardized β = 0.39, p = 0.002). Intraobserver and interobserver reproducibility were excellent for all volumetric measurements, with ICC(A,1) values ranging from 0.996 to 0.999. Bland–Altman analyses demonstrated low mean bias and narrow limits of agreement across all comparisons. Geometric agreement was also excellent, with Dice similarity coefficient values ranging from 0.93 to 0.96 across intraobserver and interobserver segmentation comparisons. Full article

Secondary dengue infections are often linked to more severe clinical outcomes, yet pre-existing antibodies may exert either protective or pathogenic effects. To evaluate the role of acute-phase dengue antibodies in pediatric dengue, we analyzed clinical and laboratory features, viremia, and antibody profiles in children infected with DENV-1. We conducted a retrospective study of patients under 18 years diagnosed with DENV-1 in Salta, Argentina. Viremia was quantified by real-time RT-PCR; acute-phase IgG antibodies (within 7 days from symptom onset) against DENV, DENV-1, and DENV-NS1 were measured by immunoassays, and neutralizing antibodies by plaque reduction neutralization tests. Among 151 patients (median age 12 years), 62% presented dengue with warning signs and one case progressed to severe dengue. Viremia was higher in probable primary infections than in probable secondary infections and did not correlate with disease severity. Probable secondary infections were characterized by acute-phase antibody profiles that did not associate with DENV viremia. Age-stratified analyses revealed that adolescents exhibited higher viremia levels than younger children in probable primary infections, while viremia levels were comparable across age groups in probable secondary infections. Furthermore, children younger than 10 years displayed acute-phase antibody levels similar to those of adolescents. In adolescents with probable secondary infections, anti-DENV and anti-DENV-1 IgG were inversely correlated with platelet counts, whereas neutralizing and anti-DENV-NS1 antibodies showed no association. Collectively, these findings indicate that probable secondary DENV infections in our pediatric cohort were characterized by acute-phase antibodies that were not associated with viremia control, and that in adolescents, anti-DENV and anti-DENV-1 IgG antibodies likely associated with platelet depletion. These results highlight important implications for vaccine design, underscoring the need for vaccines that elicit strong neutralizing responses while minimizing cross-reactivity and the risk of antibody dependent enhancement. Full article

Background/Objectives: Trabecular bone exhibits brittle behaviour governed by microscale deformation and damage, yet quantifying crack progression is difficult because classical fracture-mechanics approaches do not apply to architecturally discontinuous porous tissue. This pilot study evaluates whether synchrotron X-ray computed tomography (XCT) combined with digital volume correlation (DVC) can provide a practical, geometry-normalised approach for quantifying crack-opening behaviour in human trabecular bone. Methods: Semicylindrical specimens from femoral heads of hip-fracture donors (n = 5) and non-fracture controls (n = 5) underwent stepwise three-point bending during XCT imaging. Full-field displacement maps were used to measure crack mouth opening displacement (CMOD), crack length (a), and their ratio CMOD/a, used here as a geometry-normalised comparative descriptor of brittle response rather than an intrinsic material property. Automated phase-congruency crack detection (PCCD) was compared with manual measurement. Results: XCT–DVC resolved three-dimensional displacement discontinuities during crack initiation and propagation in all specimens. Hip-fracture donors exhibited significantly lower critical crack-opening ratios (CMOD/a)* than Controls (median 0.31 vs. 0.47; p = 0.008) and reached instability at lower applied loads. Total crack extension (Δa*) was similar between groups. Automated crack tracking using phase-congruency-based segmentation showed excellent agreement with manual measurements (r² = 0.98), supporting reliable extraction of crack geometry from DVC displacement fields. Conclusions: In this small pilot sample, XCT–DVC provided a feasible, geometry-normalised approach for comparing crack-opening behaviour where classical fracture-mechanics parameters cannot be applied. The close agreement between automated and manual crack measurements supports the reproducibility of the displacement-based measurement pipeline. The lower critical CMOD/a in hip-fracture specimens may indicate a more brittle comparative response. However, given the small sample, differing sex distribution, and lower bone volume fraction in the hip-fracture group, these findings are preliminary and require confirmation in larger cohorts. Establishing whether the observed difference reflects intrinsic tissue brittleness, architectural factors, or both is an important objective for future work in microstructure-matched cohorts. Full article

HI35, defined as the mean annual number of days on which apparent temperature exceeds 35 °C, is introduced in this paper as a country-level heat exposure metric. Unlike vulnerability indicators, HI35 is treated as an exogenous climatic exposure variable and not as a direct measure of vulnerability or as an endogenous outcome. By combining HI35 with World Bank Environmental, Social, and Governance (ESG) indicators, this study applies unsupervised clustering algorithms to derive an exposure–vulnerability typology of countries. The Environmental, Social, and Governance pillars are analyzed separately through dedicated clustering procedures, supported by robustness checks and an additional country taxonomy based on principal component analysis and hierarchical clustering. The results identify heterogeneous country profiles in which similar levels of heat exposure coexist with different ESG-based vulnerability conditions, including environmental pressures, fragility, institutional capacity, innovation, water access, nutrition, and governance quality. Conversely, countries with relatively low heat exposure may display differentiated social or institutional vulnerability profiles. The empirical evidence suggests that heat exposure and ESG-based vulnerability are conceptually distinct but jointly relevant dimensions for classifying climate-risk profiles. No causal relationship is inferred between ESG indicators and HI35; the analysis is descriptive, classificatory, and based on unsupervised learning. Conceptually, HI35 captures the occurrence of extreme heat events, while ESG indicators describe the environmental, social, and institutional conditions associated with sensitivity, resilience, and adaptive capacity. Full article

Tropospheric delay poses a major limitation to high-precision InSAR observations, particularly in high mountain and canyon regions. To address this issue, this study proposes a combined model (EiMLP) that integrates gross error identification with a multilayer perceptron (MLP) for topography-dependent tropospheric delay correction. The gross error identification module detects unwrapped phase jumps based on phase gradients, followed by an MLP model that reconstructs the atmospheric phase using unwrapped phase and elevation information from a single interferogram. The proposed method is validated in the Baihetan Hydropower Station area and compared with traditional correction methods. Experimental results demonstrate that the proposed method achieves a Structural Similarity Index Measure (SSIM) of 0.970 and a Root Mean Square Error (RMSE) of 0.673 rad for the simulated atmospheric phase. After atmospheric correction, the average phase standard deviation of the interferograms is reduced by 83%, and the topography-related correlation is significantly suppressed. Furthermore, after correction by the proposed method, the signals that are masked by atmospheric errors in the original interferograms can be clearly revealed, indicating the potential for slope instability. These findings indicate that the EiMLP model, operating on a single interferogram, exhibits robust applicability and provides a reliable reference for future InSAR tropospheric delay correction. Full article

This study examines the evolving patterns and zoning characteristics of gas migration and storage zones during coal seam mining, taking the 215 fully mechanized longwall face at Huangling No. 2 Coal Mine as the engineering background. By integrating theoretical analysis, physical similarity simulation experiments, and field measurements, the research systematically explores the zonal linkage evolution mechanism of mining-induced depressurization gas migration and storage zones, together with the associated depressurization gas extraction technology. A flow regime determination equation, driven by the fracture expansion coefficient and permeability, is established on the basis of the fluid Reynolds number criterion. According to differences in gas flow states and medium morphology, the mining-induced fracture field is divided into five distinct zones: a high-permeability zone dominated by turbulent transport, a medium-to-high permeability zone with transitional flow as the secondary dominant region, a low-permeability zone featuring linear laminar flow with micro-permeability, an extremely low-permeability zone characterized by linear laminar flow in a locked state, and a zone of abrupt permeability change associated with gas enrichment. The dynamic evolution of depressurization gas migration and storage zones and their regional linkage mechanisms are clarified. On the basis of these findings, a dynamic targeted layout strategy for high-level boreholes is proposed that is consistent with the spatiotemporal evolution of the overburden permeability field. Field engineering practice shows that the optimized high-level borehole layout maintains the overall gas extraction rate at the drilling site stably above 70%, with a peak value of 93.7%, thereby ensuring safe and efficient mining of the working face. Full article

Production system may affect meat quality and muscle metabolic characteristics in Tibetan sheep. In this study, the biceps femoris muscles of twelve 3-year-old Tibetan sheep with similar body weights were used as experimental materials during a 6-month experimental period. The housed group (n = 6) was defined as the control group (C group), whereas the grazing group (n = 6) was defined as the L group. Meat quality measurement, nutritional composition analysis, untargeted lipidomics, and amino acid metabolomics (AAM) were integrated to investigate the effects of contrasting grazing and house-feeding production systems on meat quality and metabolic characteristics in Tibetan sheep. The results showed that cooking loss and drip loss were significantly decreased, whereas water-holding capacity (WHC) was significantly increased in the L group. However, shear force was also increased, indicating that grazing and house-feeding systems were associated with differences in muscle WHC and shear force. The L group exhibited significant alterations in lipid composition and increased concentrations of several n-3 polyunsaturated fatty acids and increased levels of omega-3 polyunsaturated fatty acids (n-3 PUFAs), including α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), suggesting that grazing and house-feeding systems were associated with differences in the lipid nutritional profile of muscle. Lipidomic analysis showed that the differential lipids were mainly enriched in triacylglycerols (TGs), phosphatidylethanolamines (PEs), and phosphatidylcholines (PCs), and several PUFA-containing TGs and membrane lipid molecules were closely associated with meat quality traits. AAM analysis showed that branched-chain amino acids (BCAAs), including L-leucine and L-valine, as well as N,N-dimethylglycine, were upregulated in the L group, whereas kynurenine and 1-methyl-L-histidine were downregulated. These findings suggest that BCAA metabolism and tryptophan–kynurenine metabolism were associated with metabolic differences observed between production systems in muscle metabolic adaptation. However, amino acid metabolomics analysis revealed that no amino acid metabolites remained significant after FDR correction, and thus the observed pathway-level changes (e.g., BCAA metabolism and tryptophan–kynurenine pathway) should be interpreted as nominal and exploratory findings. Overall, the results indicate that feeding systems were associated with alterations in the lipid and amino acid metabolic profiles of the biceps femoris muscle in Tibetan sheep, which were further associated with differences in muscle WHC, shear force, lipid nutritional composition, and the profile of flavor precursors. This study provides a theoretical basis for optimizing plateau meat sheep production systems and developing high-quality Tibetan sheep meat products. Full article

Background: Neurovascular coupling (NVC) is a fundamental mechanism that dynamically matches retinal blood flow to neuronal metabolic demand. While dynamic vessel analysis (DVA) has been established for assessing NVC through flicker-light stimulation, the potential of optical coherence tomography angiography (OCTA) to detect NVC during physiological stimuli, such as dark-to-light adaptation, remains unexplored. Methods: In this prospective cross-sectional study, OCTA imaging was performed in both eyes of 22 healthy participants under dark-adapted (scotopic) and light-adapted (photopic) conditions. Each condition was measured three times consecutively. Macular and peripapillary vessel density (VD) were quantified. Results: After adjustment for measurement order and scan quality, light adaptation significantly increased peripapillary small VD (Δ = +1.30%, p = 0.046; 95% CI: 0.03–2.56%). Peripapillary all VD demonstrated a similar trend but remained borderline significant (Δ = +1.19%, p = 0.069). In contrast, macular VD showed no significant association with light adaptation (Δ = −0.91%, p = 0.11; 95% CI: −2.02 to 0.21%), but was significantly affected by scan quality (Δ = 1.62%, p < 0.001, 95% CI: 1.23–2.02%). Conclusions: In healthy older adults, OCTA detected an increase in peripapillary VD associated with dark-to-light adaptation, reflecting retinal vascular reactivity consistent with neurovascular coupling. The pronounced influence of scan quality and measurement order underscores their importance as critical confounding factors that must be carefully controlled in functional and longitudinal OCTA studies. Together, these findings highlight OCTA’s promise as a non-invasive tool for assessing retinal neurovascular reactivity, while emphasizing the need for scan quality standardization and order correction to ensure reliable interpretation. Full article

Filament–wound carbon fiber composites are widely used in lightweight structural applications, where their mechanical performance is strongly affected by manufacturing-induced heterogeneities. In this study, the tensile behavior of carbon fiber composite specimens produced by filament winding was investigated using Digital Image Correlation (DIC) to obtain full-field strain measurements. Uniaxial tensile tests were performed while monitoring the spatial distribution of strain over the specimen surface. Beyond conventional global stress–strain characterization, DIC enabled the identification of significant strain heterogeneity both within individual specimens and among different specimens manufactured under the same nominal conditions. Localized strain concentrations were observed to develop in specific regions, revealing non-uniform deformation patterns that were not captured by global measurements alone. The results demonstrate that, despite similar global mechanical responses, substantial variability exists at the local scale. This intra and inter-specimen heterogeneity highlights the influence of filament winding architecture and local variability on tensile performance. The study underscores the limitations of relying solely on global measurements and emphasizes the capability of DIC to provide deeper insight into strain distribution and damage initiation mechanisms. These findings support the use of full-field optical techniques as a powerful tool for the mechanical characterization and quality assessment of filament–wound composite structures. Full article