Search Results (1,299)

The increasing complexity of urban traffic networks has highlighted the potential of Multi-Agent Reinforcement Learning (MARL) for Traffic Signal Control (TSC). However, most existing MARL methods assume homogeneous observation and action spaces among agents, ignoring the inherent heterogeneity of real-world intersections in topology and signal phasing, which limits their practical applicability. To address this gap, we propose HAPS-PPO (Heterogeneity-Aware Policy Sharing Proximal Policy Optimization), a novel MARL framework for coordinated signal control in heterogeneous road networks. HAPS-PPO integrates two key mechanisms: an Observation Padding Wrapper (OPW) that standardizes varying observation dimensions, and a Dynamic Multi-Strategy Grouping Learning (DMSGL) mechanism that trains dedicated policy heads for agent groups with distinct action spaces, enabling adequate knowledge sharing while maintaining structural correctness. Comprehensive experiments in a high-fidelity simulation environment based on a real-world road network demonstrate that HAPS-PPO significantly outperforms Fixed-time control and mainstream MARL baselines (e.g., MADQN, FMA2C), reducing average delay time by up to 44.74% and average waiting time by 59.60%. This work provides a scalable and plug-and-play solution for deploying MARL in realistic, heterogeneous traffic networks. Full article

Air pollutants pose a growing public health concern in Puerto Rico (PR), particularly from rapid industrialization, military activities, environmental changes and natural disasters. A total of 193 pollutants, comprising the 187 hazardous air pollutants and the 6 criteria air pollutants—including particulate matter (PM), carbon monoxide (CO), volatile organic compounds (VOC), and heavy metals—coincide with rising respiratory disease rates (e.g., lung cancer) documented in national and regional health registries. This study aimed to review major air pollutants in PR, their molecular carcinogenic mechanisms (mostly focused on respiratory-related cancers), and the geographic areas impacted significantly. We conducted an extensive literature search utilizing peer-reviewed scientific articles (PubMed and Web of Science), governmental reports (EPA, WHO, State of Global Air), public health registries, (Puerto Rico Central Cancer Registry and International Agency for Research on Cancer) and local reports. Data on pollutant type, source, molecular pathways, and carcinogenic properties were extracted and synthesized. Our analysis identified ethylene oxide (EtO), polycyclic aromatic hydrocarbons, and PM from industrial sites as key pollutants. The municipalities of Salinas and Vieques, hubs of industrial activity and military exercises, respectively, emerged as critical hotspots where high concentrations of monitored pollutants (e.g., EtO, formaldehyde, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and diesel PM) are associated with a significant prevalence of cancer and respiratory diseases. These agents, known to induce genomic instability and chromosomal aberrations, were correlated with elevated local cancer incidence. Our findings underscore the urgent need for targeted public health interventions and support a multi-pronged strategy that includes: (1) enhanced regulatory oversight of EtO and other hazardous air pollutant emissions; (2) community-based biomonitoring of high-risk populations; and (3) investment in public health infrastructure and a transition to cleaner energy sources. Integrating rigorous environmental science with public health advocacy is essential to strengthen PR’s cancer-control continuum and foster resilience in its most vulnerable communities. Full article

The glycemic index (GI) of rice is a complex trait, affected by amylose content (AC), size, and packaging of starch granules (SGs). In this study, the electron microscopy results of starch morphology of nine rice genotypes showed varying AC (6.93–36.9%), and the predicted GI (pGI: 41.07–82.46) in relation to genetic factors revealed that smaller SG surface area (20.06 µm²) and irregular morphology (Hap 3-3 P-11, pGI = 41.07) were associated with a lower pGI, while larger SG surface area (47.68 µm²) and spherical structure were associated with a higher pGI (NON-HAI, pGI = 82.46). The expression of starch biosynthesis and packaging-related genes (OsSSIIb, OsSSIIc, OsSBEIIa, OsISA1, OsISA3, OsGBP, OsFLO6, and OsBT1) revealed downregulation of OsGBP and OsISA3 genes in low pGI lines IRRI-147 (pGI = 56.2) and Hap 3-1-p-18 (pGI = 41.79), respectively, while higher levels of expression of the OsBT1 gene in Makro (pGI = 59.06) and OsSSIIb in Swarna (pGI = 58.06) were observed. All these genotypes had similar AC (~30%), but the difference in expression pattern was correlated with starch granule morphology, suggesting its role in influencing pGI. Further, analysis of allelic variation in eight starch-related genes across 20 rice genotypes showed that allelic variants of only OsGBP were correlated with AC, where allele group 2 showed lower AC (9.62%), while all other allele groups showed consistently high AC (22–24%). These findings underscore the critical role of starch granule morphology and OsGBP allelic variation in determining AC and GI, providing actionable insights for developing low GI rice varieties using tools like CRISPR. Full article

As the world is technologically advancing, the integration of FSO communication in non-terrestrial platforms is transforming the landscape of global connectivity. By enabling high-data-rate inter-satellite links, secure UAV–ground channels, and efficient HAPS backhaul, FSO technology is paving the way for sustainable 6G non-terrestrial networks. However, the stringent requirement for precise line-of-sight (LoS) alignment between the optical transmitter and receivers poses a hindrance in practical deployment. As non-terrestrial missions require continuous movement across the mission area, the platform is subject to vibrations, dynamic motion, and environmental disturbances. This makes maintaining the LoS between the transceivers difficult. While fine-pointing mechanisms such as fast steering mirrors and adaptive optics are effective for microradian angular corrections, they rely heavily on an initial coarse alignment to maintain the LoS. Coarse pointing modules or gimbals serve as the primary mechanical interface for steering and stabilizing the optical beam over wide angular ranges. This survey presents a comprehensive analysis of coarse pointing and gimbal modules that are being used in FSO communication systems for non-terrestrial platforms. The paper classifies gimbal architectures based on actuation type, degrees of freedom, and stabilization strategies. Key design trade-offs are examined, including angular precision, mechanical inertia, bandwidth, and power consumption, which directly impact system responsiveness and tracking accuracy. This paper also highlights emerging trends such as AI-driven pointing prediction and lightweight gimbal design for SWap-constrained platforms. The final part of the paper discusses open challenges and research directions in developing scalable and resilient coarse pointing systems for aerial FSO networks. Full article

Background: Substituted hydroxyapatites (HAps) are widely used in oral-care formulations for enamel repair; however, head-to-head comparisons among commercial grades remain limited. Objective: To compare four commercial HAps: A (Kal-HAp), B (FL-HAp), C (FL-HAp-SC), and D (microRepair^®, a biomimetic Zn–carbonate-substituted HAp) and to evaluate their ability to form an enamel-like coating in vitro. Methods: We characterized the powders by X-ray diffraction (crystalline phase, Landi crystallinity index), FTIR-ATR (phosphate/carbonate bands), SEM/EDS (morphology, surface Ca/P), and DLS (particles size, ζ-potential). In vitro, human enamel sections were treated with 5% slurries in artificial saliva; surface coverage was quantified by image analysis on SEM. Results: All commercial materials analyzed in this work were composed of HAp. Differences were observed between HApin terms of crystallinity-range [2 Theta 8.0–60.0°], carbonate substitution (ATR [carbonate group evaluated −870 cm⁻¹]), and particle size (DLS [in a range 0.1–10,000 nm], Z-mean [mV]). On enamel, all samples form a hydroxyapatite layer; coverage differed between groups ([A] 28.83 ± 7.35% vs. [B] 31.11 ± 3.12% vs. [C] 57.20 ± 33.12% vs. [D] 99.90 ± 0.12%), with the biomimetic Zn–carbonate-substituted HAp showing the highest coverage, and the post-treatment Ca/P ratio approached values similar to those of dental enamel. Conclusions: Complementary physic-chemical signatures (crystallinity, carbonate substitution, and morphology) relate to enamel-surface coverage in vitro, providing evidence base for selecting HAp grades for enamel-repair formulations, which is a practical implication for product design. Full article

Analysis of selection signatures in the genomes of farm animals enables the detection of genomic regions affected by selection and contributes to the identification of genes underlying adaptive and productive traits. This research aimed to identify loci under selection pressure and to detect candidate genes in Dzhalgin Merino sheep by performing a comparative genomic analysis with the related Australian Merino and Rambouillet breeds. A total of 293 animals were included in the analysis, comprising Dzhalgin Merino (n = 53), Australian Merino (n = 50), Australian Industry Merino (n = 88), and Rambouillet (n = 102). Whole-genome SNP genotyping data for Dzhalgin Merino were generated within this study, while data for Australian Merino, Australian Industry Merino, and Rambouillet were obtained from the SheepHapMap project. For the purposes of analysis, Australian Merino and Australian Industry Merino were combined into a single group (n = 138). To enhance the reliability of the results, three independent methods were employed to detect selection signatures: the fixation index (FST), analysis of linkage disequilibrium variation (varLD), and the cross-population number of segregating sites by length (xp-nSL). The study showed that Dzhalgin Merino have unique genetic signatures potentially associated with adaptation and productivity, which opens up new opportunities for their selection. The identified genes can become the basis for developing new breeding programs aimed at improving both the productive qualities and the adaptive abilities of the breed. Further research should be aimed at a detailed investigation of gene structure within loci under selection pressure and at clarifying the mechanisms by which these genes influence animal phenotypes. A total of 185 genes were identified within genomic regions exhibiting selection signatures. Among these, particular attention was given to EPHA6, MLLT3, ROBO1, KIAA0753, MED31, SLC13A5, and ELAVL4, which are involved in biological processes such as growth, development, and reproduction. The identified genes represent potential targets for breeding programs aimed at increasing productivity and adaptive capacity of the breed. Full article

In recent years, apatite-based materials have garnered significant interest, particularly for applications in tissue engineering. Apatite is most commonly employed as a coating for metallic implants, as a component in composite materials, and as scaffolds for bone and dental tissue regeneration. Among its various forms, hydroxyapatite (HAP) is the most widely used, owing to its natural occurrence in human and animal hard tissues. An emerging area of research involves the use of fluoride-substituted apatite, particularly fluorapatite (FAP), which can serve as a direct fluoride source at the implant site, potentially offering several biological and therapeutic advantages. However, substituting HAP with FAP may lead to unforeseen changes in material behavior due to the differing physicochemical properties of these two calcium phosphate phases. This study investigates the effects of replacing hydroxyapatite with fluorapatite in ceramic–polymer composite materials incorporating β-1,3-glucan as a bioactive polymeric binder. The β-1,3-glucan polysaccharide was selected for its proven biocompatibility, biodegradability, and ability to form stable hydrogels that promote cellular interactions. Nitrogen adsorption analysis revealed that FAP/glucan composites had a significantly lower specific surface area (0.5 m²/g) and total pore volume (0.002 cm³/g) compared to HAP/glucan composites (14.15 m²/g and 0.03 cm³/g, respectively), indicating enhanced ceramic–polymer interactions in fluoride-containing systems. Optical profilometry measurements showed statistically significant differences in profile parameters (e.g., Rp: 134 μm for HAP/glucan vs. 352 μm for FAP/glucan), although average roughness (Ra) remained similar (34.1 vs. 27.6 μm, respectively). Microscopic evaluation showed that FAP/glucan composites had smaller particle sizes (1 μm) than their HAP counterparts (2 μm), despite larger primary crystal sizes in FAP, as confirmed by TEM. XRD analysis indicated structural differences between the apatites, with FAP exhibiting a reduced unit cell volume (524.6 ų) compared to HAP (528.2 ų), due to substitution of hydroxyl groups with fluoride ions. Spectroscopic analyses (FTIR, Raman, ³¹P NMR) confirmed chemical shifts associated with fluorine incorporation and revealed distinct ceramic–polymer interfacial behaviors, including an upfield shift of PO₄³⁻ bands (964 cm⁻¹ in FAP vs. 961 cm⁻¹ in HAP) and OH vibration shifts (3537 cm⁻¹ in FAP vs. 3573 cm⁻¹ in HAP). The glucan polymer showed different hydrogen bonding patterns when combined with FAP versus HAP, as evidenced by shifts in polymer-specific bands at 888 cm⁻¹ and 1157 cm⁻¹, demonstrating that fluoride substitution significantly influences ceramic–polymer interactions in these bioactive composite systems. Full article

Chromium-doped hydroxyapatite (7CrHAp) and chromium-doped hydroxyapatite in chitosan matrix (7CrHAp-CH) coatings were synthesized in order to address the need for biomaterials with improved physico-chemical and biological properties for biomedical applications. Both chromium-doped hydroxyapatite (7CrHAp) and chromium-doped hydroxyapatite in chitosan matrix (7CrHAp-CH) coatings could represent promising materials for biomedical applications due to their superior properties. This study aims to evaluate the physico-chemical and in vitro biological properties of 7CrHAp and 7CrHAp-CH coatings to determine the impact of chitosan incorporation on the physico-chemical and biological features. The results reported in this study indicate that addition of chitosan improves surface uniformity and biological properties, highlighting their potential for uses in biomedical applications. In this study, coatings of chromium-doped hydroxyapatite (7CrHAp, with x_Cr = 0.07) and its composite variant embedded in a chitosan matrix (7CrHAp-CH) were systematically analyzed using a suite of characterization techniques: X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and metallographic microscopy (MM). The results of the XRD analysis revealed that the average crystal size was 19.63 nm for 7CrHAp and 16.29 nm for 7CrHAp-CH, indicating a decrease in crystallite size upon CH incorporation. The films were synthesized via the dip coating method using stable suspensions, whose stability was assessed through ultrasonic measurements (double-distilled water serving as the reference medium). The values obtained for the stability parameter were 2.59·10⁻⁶ s⁻¹ for 7CrHAp, 8.64·10⁻⁷ s⁻¹ for 7CrHAp-CH, and 3.14·10⁻⁷ s⁻¹ for chitosan (CH). These data underline that all samples are stable: CH is extremely stable, followed by 7CrHAp-CH (very stable) and 7CrHAp (stable). The in vitro biocompatibility of the 7CrHAp and 7CrHAp-CH coatings was evaluated with the aid of the MG63 cell line. The cytotoxic potential of these coatings towards MG63 cells was quantified using the MTT assay after 24 and 48 h of incubation. Our results highlight that both 7CrHAp and 7CrHAp-CH coatings exhibit high biocompatibility with MG63 cells, maintaining cell viability above 90% at both incubation times, thus supporting osteoblast-like cell proliferation. Furthermore, the antimicrobial efficacy of both 7CrHAp and 7CrHAp-CH samples was evaluated in vitro against the Pseudomonas aeruginosa 27853 ATCC (P. aeruginosa) reference strain. The in vitro antibacterial activity of the 7CrHAp and 7CrHAp-CH coatings was further evaluated against Pseudomonas aeruginosa 27853 ATCC (P. aeruginosa), Escherichia coli ATCC 25922 (E. coli) and Staphylococcus aureus ATCC 25923 (S. aureus) reference strains. In addition, atomic force microscopy (AFM) analysis was also used to investigate the ability of P. aeruginosa, E. coli and S. aureus cells to adhere and to develop colonies on the surfaces of the 7CrHAp and 7CrHAp-CH coatings. The results from the biological assays indicate that both coatings exhibit promising antibacterial properties, highlighting their potential for being used in biomedical applications, particularly in the development of novel antimicrobial devices. Full article

Background/Objectives: Polymeric barrier membranes (BMs) are usually used in guided bone regeneration to isolate the bone defect from the surrounding tissue, favoring bone apposition. This study proposes a third-generation BM made of polycaprolactone (PCL), loaded with different concentrations of nano-hidroxyapatite (nHAP) and gentamicin (GEN), and fabricated by electrospinning. Methods: The mechanical properties of the polymer, together with the fabrication procedure, offer porosity with interconnectivity to permit cell adhesion and proliferation. Bacterial contamination of the BM can induce infection at the bone level, leading to unfavorable clinical outcomes of the regeneration procedure. Results: Therefore, BMs have been proposed as carriers for local GEN antibiotic therapy, demonstrating antibacterial properties against S. aureus, S. mutans, and P. aeruginosa, depending on the drug concentration, while being negligibly affected by the nHAP content. X-ray diffraction, FTIR-ATR, and SEM allowed for BM structural characterization, demonstrating the presence of GEN/nHAP and establishing the fiber diameter, which influences the mechanical properties in dry and wet conditions and the drug release behaviorA BM cytotoxicity assessment, performed over 1 and 5 days, revealed that a high nHAP concentration provided protection against cytotoxicity, in contrast to GEN, and that cell proliferation and cell adhesion increased in the presence of nHAP. The BM’s bioactivity was demonstrated by mineralization after 21 days in simulated body fluid in an SEM/EDX analysis. Conclusions: The electrospun 15 wt.% nHAP and 2 wt.% GEN-loaded third-generation BM could be a promising alternative for guided bone regeneration. Full article

Nitrogen is an essential macronutrient for crop growth. Although sorghum can tolerate poor soils, its low-nitrogen (LN) tolerance mechanisms remain underexplored. We conducted a genome-wide association study (GWAS) and RNA sequencing (RNA-seq) to dissect LN tolerance mechanisms in a diverse panel of 232 sorghum accessions. Phenotypic analyses revealed extensive variation in nitrogen-use efficiency traits, with shoot dry weight and shoot nitrogen accumulation in (SNAcc) showing the highest diversity. GWAS identified 10 quantitative trait loci harboring pleiotropic single-nucleotide polymorphisms (SNPs), including q1 (Chr3: 8.59–8.68 Mb), which is associated with biomass and nitrogen accumulation. Transcriptome profiling under LN stress revealed 6208 differentially expressed genes, with nitrate transporters showing genotype-specific regulation. Integration prioritized SORBI_3004G286700, where Hap2 accessions (14.66%) showed superior agronomic performance under LN conditions. We also identified pivotal transcription factors (TFs) that govern LN tolerance in sorghum, notably bHLH35 (SORBI_3007G051800) and three WRKY TFs, demonstrating constitutive upregulation in tolerant genotypes, whereas three previously uncharacterized TFs (MYB, bZIP, and B3) exhibited > 5-fold genotype-specific induction under LN. The integration of GWAS and transcriptome analyses offers an effective strategy for exploring candidate genes and elucidating nitrogen adaptation mechanisms in sorghum, while providing actionable molecular targets for precise breeding of nitrogen-efficient cultivars. Full article

Background: Eravacycline exhibits potent activity against multidrug-resistant pathogens and holds promise for the management of hospital-acquired and ventilator-associated pneumonia (HAP/VAP). However, sensitive and robust bioanalytical methods to quantify eravacycline in human pulmonary epithelial lining fluid (ELF) for pharmacokinetic (PK) and pulmonary penetration studies in these infections remain limited. Methodology: A simple, rapid, and sensitive LC-MS/MS method was developed for the quantification of eravacycline in bronchoalveolar lavage fluid (BALF). Using urea as a volume normalizer, ELF concentrations were calculated from the eravacycline concentrations in BALF. This method was applied in a clinical study evaluating the pulmonary penetration after intravenous infusion in patients with HAP and VAP. Results: The developed LC-MS/MS method exhibited good linearity in the range of 1–200 ng/mL for quantifying eravacycline in BALF. In BALF, intra-day precision ranged from 1.4% to 6.0%, and inter-day precision from 1.6% to 9.9%, with accuracy between 98.0% and 102.4%. Matrix effects were within 97.4% to 107.6% for BALF samples from six different individuals, with extraction recoveries ranging from 103.5% to 107.2%. Stability studies demonstrated that eravacycline remained stable under various conditions, including storage at room temperature, freeze–thaw cycles, long-term (–70 °C) storage, and post-treatment handling. The method was successfully applied to clinical samples from four HAP or VAP patients, with measured eravacycline pulmonary penetration ratios of 4.29, 17.40, 5.22 and 4.70, indicating efficient pulmonary distribution. The measured eravacycline concentrations ranged from 0.0243 to 0.0436 μg/mL in BALF. The corresponding urea-corrected ELF concentrations ranged from 0.570 to 1.617 μg/mL. Conclusions: This study described a detailed and validated method for quantifying eravacycline concentrations in ELF from patients, providing a reliable analytical approach for investigating the pulmonary distribution of eravacycline. Full article

The development of bioactive glasses (BGs) and ceramics, such as β-Tricalcium phosphate (β-TCP), Hydroxyapatite (HAp), and apatite-wollastonite (A-W), has revolutionized regenerative medicine (RM), offering innovative solutions for bone and tissue repair, due to the ability of these materials to bond with living bone tissue. Despite significant advancements, evaluating the bioactivity and biological responsiveness of these biomaterials remains a critical challenge. This review provides a comprehensive synthesis of the available methodologies, critically analyzing their advantages, disadvantages, and the possible gap between in vitro and in vivo assessments, including false positives and false negatives. Classical immersion tests techniques for bioactivity evaluation in simulated physiological solutions, such as simulated body fluid (SBF), Tris-buffer (TRIS), or phosphate-buffered saline (PBS) solutions, are discussed, along with the more innovative Simulated Wound Fluid (SWF). Additionally, traditional standardized methods, such as MTT, BrdU, EdU, and XTT, as well as emerging methods like qPCR and immunocytochemistry, used to study cellular behavior, proliferation, adhesion, and differentiation, are compared. Staining assays, including crystal violet, neutral red, and alizarin red, have also been investigated for their effectiveness in evaluating cellular adhesion and quantification. Notably, while all techniques have shown promise in studies involving BGs and ceramics, a multi-parametric approach remains the most reliable strategy for assessing bioactivity and biological responsiveness, highlighting the need for comprehensive studies to validate the results. Finally, the choice between static and dynamic approaches represents a further critical issue, as it significantly affects assay outcomes. Full article

Cysticercosis in wild and domestic ungulates, caused by the larval metacestode stages of Taenia hydatigena and Taenia multiceps (formerly known as Cysticercus tenuicollis and Coenurus cerebralis, respectively), is a widespread parasitic disease and poses a significant concern worldwide, particularly in endemic regions. Although Taenia species have been extensively studied globally, their epidemiology and genetic diversity in Kazakhstan remain poorly understood. In this study, wild (roe deer, red deer, moose) and domestic (cattle, sheep) ungulates, serving as intermediate hosts for Taenia spp., were examined for cysticerci in muscle tissues and internal organs. Phylogenetic analysis and pairwise nucleotide variation assessments of the cox1 and nad1 genes were conducted. An overall prevalence of 5.2% was recorded among 1370 ruminant carcasses (cattle = 773, sheep = 563, roe deer = 25, moose = 9), with infection rates of 0.6% in cattle, 1.1% in sheep, 8.0% in roe deer, and 11.1% in moose. Cattle, sheep, and moose were infected with T. hydatigena, while roe deer were infected with T. multiceps. DNA sequence analysis of all isolates revealed four nad1 gene haplotypes for T. hydatigena, with Hap_3 being the most common (10 isolates). Phylogenetic analysis showed that T. multiceps isolates from roe deer clustered within the clade defined by the reference sequences for this species. This study provides important baseline data on the prevalence and genetic variation in T. hydatigena and T. multiceps in Kazakhstan and lays the groundwork for future research on the epidemiology and population genetics of Taenia species in the region. Full article

This study investigates the design and optimization of a free-space optical (FSO) wireless communication network employing high-altitude platforms (HAPs). The objective is to explore the parameters that affect the quality and viability of such a network and to develop a method for minimizing installation costs while maximizing performance. The methodology includes clustering ground nodes using the k-means algorithm and adjusting the emission solid angles for each HAP. Furthermore, to more closely reflect real-world conditions, our analytical investigations also consider the effects of atmospheric turbulence. The network’s performance is evaluated under both daytime and nighttime operational scenarios, taking into account background noise and the layered effects of atmospheric turbulence. These considerations ensure that the results presented in this paper more accurately reflect real-world conditions. The results demonstrate significant performance gains through appropriate parameter selection. Additionally, deploying multiple HAPs enhances network flexibility and resilience. It was shown that in certain scenarios specific combinations of per-HAP configurations offer more than a 70% increase in throughput with a small increase in the cost. The paper’s insights fill an important gap between theoretical FSO network models and the practical design considerations needed for real deployments. Full article

The successful integration of Terrestrial and Non-Terrestrial Networks (T/NTNs) in 6G is poised to revolutionize demanding domains like Earth Observation (EO) and Intelligent Transportation Systems (ITSs). Still, it requires Distributed Machine Learning (DML) frameworks that are scalable, private, and efficient. Existing methods, such as Federated Learning (FL) and Split Learning (SL), face critical limitations in terms of client computation burden and latency. To address these challenges, this paper proposes a novel hierarchical DML paradigm. We first introduce Federated Split Transfer Learning (FSTL), a foundational framework that synergizes FL, SL, and Transfer Learning (TL) to enable efficient, privacy-preserving learning within a single client group. We then extend this concept to the Generalized FSTL (GFSTL) framework, a scalable, multi-group architecture designed for complex and large-scale networks. GFSTL orchestrates parallel training across multiple client groups managed by intermediate servers (RSUs/HAPs) and aggregates them at a higher-level central server, significantly enhancing performance. We apply this framework to a unified T/NTN architecture that seamlessly integrates vehicular, aerial, and satellite assets, enabling advanced applications in 6G ITS and EO. Comprehensive simulations using the YOLOv5 model on the Cityscapes dataset validate our approach. The results show that GFSTL not only achieves faster convergence and higher detection accuracy but also substantially reduces communication overhead compared to baseline FL, and critically, both detection accuracy and end-to-end latency remain essentially invariant as the number of participating users grows, making GFSTL especially well suited for large-scale heterogeneous 6G ITS deployments. We also provide a formal latency decomposition and analysis that explains this scaling behavior. This work establishes GFSTL as a robust and practical solution for enabling the intelligent, connected, and resilient ecosystems required for next-generation transportation and environmental monitoring. Full article