Search Results (13,611)

Background/Objectives: Short Interspersed Nuclear Elements (SINEs) constitute major components of mammalian genomes, but the structural diversity and evolutionary dynamics of their characteristic 3′ poly(A) tails have not been fully characterized. Methods: Based on the custom-developed SINEtail-scan pipeline, 1,018,332 SINEs with tail in the pig reference genome (Sus scrofa 11.1) were identified and systematically classified, revealing the diversity of tail sequence structures. According to nucleotide composition and microsatellite repeat patterns, the tail sequences were divided into 16 different structural types. Results: A-rich sequences predominated (66.3%), while non-A-rich tails exhibited characteristic architectures including AT-format, AC-format, and AG-format repeats. Temporal analysis spanning 85 million years demonstrated progressive tail modification, with A-rich proportions declining from 84.2% in recent insertions to 31.9% in ancient elements, accompanied by accumulation of complex non-A-rich structures. Comparative genomic analysis across 10 pig genome assemblies identified 308 SINE tail insertions within protein-coding sequences, of which 45 (14.6%) exhibited inter-individual structural polymorphism. Detailed investigation of a polymorphic insertion in the VWA8 gene revealed a 16-bp tail variant causing a frameshift mutation and C-terminal protein structure divergence. Conclusions: These findings establish SINE tail sequences as dynamic evolutionary substrates undergoing continuous modification through slippage-mediated mechanisms, with implications for genome evolution, population genetics, and gene function modulation in mammals. Full article

Background: The subtribe Pleurothallidinae is a diverse group within Orchidaceae with a complex taxonomic history. Comparative plastome analysis can provide insights into genome evolution and facilitate phylogenetic reconstruction. Methods: Here we analyzed 25 complete chloroplast genomes representing 15 genera, including 14 newly assembled genomes, to investigate plastome evolution in this subtribe. Results: All genomes exhibited the typical quadripartite structure (148, 246–158, 138 bp) with conserved gene content (128–134 genes). While most protein-coding genes were under purifying selection, we detected signatures of positive selection in specific lineages. Notably, ndhF in Lepanthes tachirensis showed a markedly elevated Ka/Ks ratio (3.65), which may be associated with adaptation to an extensive distributional range. ENC-plot analysis indicated that natural selection, rather than mutation pressure alone, shapes codon usage bias, with patterns varying among species from different geographic regions. Nucleotide diversity analysis identified eight hypervariable intergenic regions (psbK-psbI, atpI-rps2, petN-psbM, psbB-psbT, petD-rpoA, rpoA-rps11, rps3-rpl22, ccsA-ndhD) suitable as candidate molecular markers. Phylogenetic analysis confirmed that Lepanthes and Pleurothallis are non-monophyletic as traditionally defined. Conclusions: These findings expand plastome resources for Pleurothallidinae, reveal lineage-specific patterns of selection, and provide molecular markers for future taxonomic and evolutionary studies. Full article

To address the challenge that traditional dam model materials are difficult to simultaneously meet the requirements of microstructural similarity, dynamic damage simulation, and environmental friendliness, a novel microparticle mortar simulated concrete was developed. This new material consists of cement, sand, gypsum, mineral oil, water, and baryte sand. Through systematic material mechanical tests, the effects of each component on the material’s strength, density, and elastic modulus were revealed, and the optimal mix ratio was determined. This enabled precise control of low elastic modulus and had a high density, while the material is environmentally friendly, non-toxic, and compatible with direct contact with natural water. Its mechanical properties are highly similar to those of the prototype concrete. Based on a 1:70 geometric scale, a shaking table model test of the concrete gravity dam-reservoir system was conducted. The dynamic response and damage evolution under empty and full reservoir conditions were compared and analyzed. The study shows that this material can accurately simulate the stress-strain relationship and failure mode of prototype concrete. Under the full reservoir condition, the dam’s fundamental frequency showed only a 2.72% deviation from the numerical simulation, and as the seismic excitation amplitude increased, the changes in the fundamental frequency effectively reflected the accumulation of damage. Under the design seismic motion, the measured accelerations and stress responses for both empty and full reservoir conditions were in good agreement with numerical calculations. Under overload conditions, the acceleration amplification factor at the dam crest decreased with damage accumulation, and the dam neck was identified as the seismic weak zone. As the peak ground acceleration (PGA) increased from 0.15 g to 0.70 g, the fundamental frequency changes effectively reflected the damage accumulation process in the dam, while the hydrodynamic pressure at the dam heel showed a linear increase (457% increase). The experimentally measured hydrodynamic pressure distribution was between the rigid dam and elastic dam hydrodynamic pressures, reflecting the real fluid-structure interaction effect. This study provides a reliable material solution and data support for dam seismic physical model testing. Full article

The snailfish family (Liparidae) represents one of the most rapidly speciating and ecologically diverse lineages of marine fishes, with species distributed across a broad bathymetric range from intertidal zones to the hadal depths. Despite their ecological and evolutionary significance, phylogenetic relationships and adaptive mechanisms within Liparidae remain poorly resolved due to morphological conservatism, phenotypic plasticity, and limited genomic resources due to challenges such as sampling difficulties and a reliance on partial mtDNA markers. In this study, we sequenced, assembled, and annotated the complete mitochondrial genomes of two snailfish species, Liparis chefuensis and Liparis tanakae, collected from the Yellow Sea. The mitogenome of L. chefuensis is 18,870 bp in length, encoding 13 protein-coding genes (PCGs), 2 rRNAs, and 22 tRNAs, while that of L. tanakae spans 17,485 bp and contains 13 PCGs, 2 rRNAs, and 23 tRNAs. Phylogenetic reconstruction based on the concatenated sequences of 13 mitochondrial PCGs from 15 liparid species revealed that L. chefuensis clusters within the subgenus Lyoliparis, contradicting its previous classification under Careliparis and suggesting a need for taxonomic reassessment. Notably, we identified distinct patterns of tRNA gene rearrangement in the cluster between ND2 and COI, which suggest a link to both phylogeny and habitat depth. Shallow-water species (<30 m) possess the tRNA^Trp-tRNA^Tyr-tRNA^Ala-tRNA^Asn-tRNA^Cys (WYANC) arrangement, whereas deep-water species (>100 m) display the derived tRNA^Trp-tRNA^Asn-tRNA^Cys-tRNA^Tyr-tRNA^Ala-tRNA^Cys/tRNA^Ala (WNCYAC/A) configurations. These rearrangements are hypothesized to originate from tandem duplication events followed by random gene loss, potentially reflecting adaptive evolution to deep-sea environments. Additionally, L. tanakae exhibits a markedly higher number of non-canonical G–U and A–C base pairs in its tRNA secondary structures, indicating substantial structural divergence. Our findings not only provide essential mitogenomic resources for snailfish systematics and species identification but also propose that tRNA rearrangements in mitochondrial genomes may serve as genomic innovations facilitating deep-sea colonization. This study enhances our understanding of mitochondrial genome evolution and environmental adaptation in marine fishes. Full article

Indoor environmental quality directly affects public health and quality of life, among which odor pollution is one of the primary drivers of indoor environmental complaints. Traditional research and management approaches, which rely predominantly on mass concentrations of individual chemical compounds, are fundamentally inadequate for addressing the inherent sensory complexity, dynamic evolution, and subjective perception of indoor odors. Through a systematic literature review, this paper for the first time establishes an integrated research framework for indoor odor pollution across the whole-life-cycle management of the built environment, structured around “source–evolution–evaluation–control”. This framework systematically analyzes emission characteristics of building-related pollution sources, revealing the profound impact of indoor dynamic chemical and biological transformation processes on odor properties. Sensory analysis, instrumental measurements, and intelligent sensing approaches are critically compared in terms of their underlying principles and application boundaries. From an engineering perspective, the effectiveness and limitations of source prevention, ventilation dilution, and terminal purification strategies are comprehensively evaluated. The analysis demonstrates that effective indoor odor management must transcend passive and fragmented mitigation practices, and that its future development depends on the deep integration of environmental chemistry, sensory science, materials science, and artificial intelligence. Finally, this review proposes that by constructing regulation systems based on real-time sensing, digital twins, and intelligent decision-making, indoor odor management can fundamentally shift from reactive complaint-driven responses to proactive health-oriented protection. This paradigm transformation provides a systematic theoretical foundation and a technological roadmap for achieving healthy, comfortable, and sustainable building environments. Full article

In the fabrication of ultrathin multilayer ceramic capacitors (MLCCs), the long-term stability of ceramic slurries is a critical yet often overlooked factor that can significantly influence coating uniformity, interfacial adhesion, and process reproducibility. Despite its industrial importance, the time-dependent evolution of slurry dispersion structures during storage and its direct impact on green sheet properties remain insufficiently understood. This study examined the time-dependent physicochemical evolution of barium titanate (BaTiO₃)-based green sheet slurries, which behave as colloidal gel-like dispersion systems, and their influence on the structural, optical, and interfacial properties of the resulting sheets. Dynamic light scattering revealed progressive yet uniform particle aggregation, while viscosity measurements indicated a gradual ~10% decrease over 960 h, reflecting reduced dispersion stability and progressive weakening of the slurry gel network during extended storage. The slurry, consisting of BaTiO₃ particles, polymeric binders, and plasticizers, forms a three-dimensional transient gel network, in which particle–particle and particle–binder interactions govern rheological behavior. The observed viscosity decrease and turbidity reduction indicate gel network relaxation and partial gel–sol–like transition behavior driven by aggregation. Cross-sectional scanning electron microscopy demonstrated that these changes produced a measurable reduction in final green sheet thickness, despite identical processing conditions. Furthermore, peel tests revealed that interfacial adhesion strength increased with storage time, attributable to localized solid enrichment within the slurry gel matrix and enhanced bonding at the release film interface. The reduced coating thickness also contributed to lower optical haze, reflecting a shortened light-transmission path. Collectively, these findings demonstrate that even moderate aggregation in a ceramic network-forming dispersion system substantially alters coating behavior, adhesion, and optical performance. The results underscore the importance of managing gel-network stability and rheology to ensure reliable green sheet fabrication and storage in MLCC manufacturing. Full article

The Lower North River (LNR) exhibits a distinctive anabranching pattern in the Pearl River Basin, China. However, research has predominantly focused on vertical channel adjustments relying on in situ measurements, while the large-scale spatiotemporal dynamics of the anabranching planform have received limited attention. To address this gap, this study quantified the evolution of the anabranching planform from 1990 to 2022 using remote sensing images, focusing on anabranching intensity and island morphology, and analyzed driving factors using hydrological observations. Results revealed three evolutionary phases driven by shifting dominance of human interventions. During the first phase (1990–2004), the LNR experienced a moderate decline in anabranching intensity and widespread shrinkage of river islands, primarily attributed to sediment starvation induced by upstream dams. In the second phase (2004–2013), the decline in anabranching intensity accelerated and the proportion of expanding islands increased, driven by unregulated sand mining and channel regulation. In the third phase (2013–2022), the rapid decline in anabranching intensity decelerated and the islands shifted from a shrinkage-dominated to a stable-dominated state following the implementation of strict mining management and the physical confinement imposed by engineering structures. These findings reveal distinct morphological responses of the LNR to flow–sediment regimes and anthropogenic physical interventions, offering insights into the sustainable management of large anabranching rivers worldwide in the Anthropocene. Full article

This study reveals the effects of artificial space-like proton irradiation on three meteorite samples that are Northwest Africa (NWA) 4560 LL3.2 and NWA 5838 H6 chondrite meteorites, as well as the Dhofar (Dho) 007 eucrite. We used low-vacuum scanning electron microscopy (LV-SEM) and Raman Spectroscopy to examine the structure and composition of olivine and pyroxene grains in the meteorites before and after the irradiation events. This article focuses on the strongest and most intense irradiation, which was performed by protons up to 12 keV with a fluence value of 10¹⁹ ions/cm² that lasted ~30 h. According to the Raman spectra, significant lattice disruption in all analyzed silicates occurred, and a more extensive amorphous, glassy layer developed under the strongest irradiation conditions. Relative to the second irradiation, peak 1 (820.0 cm⁻¹) shifts slightly negatively (–0.46 cm⁻¹) with a small FWHM increase (+0.88 cm⁻¹), while peak 2 (850.3 cm⁻¹) shifts positively in both parameters (+0.40 and +4.04 cm⁻¹) in NWA 4560 olivines. In NWA 5838 olivines, both olivine peaks (820.5 and 850.8 cm⁻¹) shift positively (+7.40 and +7.90 cm⁻¹) and broaden (+2.75 and +4.29 cm⁻¹). In Dho 007 pyroxenes, peak 1 (997.1 cm⁻¹) shifts positively (+3.01 cm⁻¹) with an FWHM decrease (−0.46 cm⁻¹), peak 2 (669.7 cm⁻¹) shifts slightly negatively (−0.75 cm⁻¹) while broadening strongly (+29.23 cm⁻¹), and peak 3 (327.7 cm⁻¹) shifts positively (+0.86 cm⁻¹) with reduced FWHM (−4.55 cm⁻¹). Three characteristic amorphous bands appear in all examined meteorite silicates, located at ~550–1000 cm⁻¹, ~1100–1700 cm⁻¹, and ~1700–1850 cm⁻¹. Olivines in NWA 4560 and NWA 5838 exhibited similar responses across all irradiation events. In contrast, Dho 007 pyroxenes showed variable compositional changes without a consistent or well-defined pattern in our SEM dataset. The Fo decrease in our experiments likely results from preferential Mg sputtering in the olivine lattice, leading to relative Fe enrichment, similar to but more pronounced than after the first irradiation. Pyroxenes exhibit a comparable response, with Fs and En increasing and Wo sharply decreasing, reflecting preferential Ca loss relative to Mg alongside Fe enrichment. Investigating these processes improves the interpretation of planetary remote sensing data and advances our understanding of planetary surface evolution, while also clarifying how surface materials respond to space environmental conditions. Full article

Human metapneumovirus genotype B (HMPV-B) is an important respiratory pathogen, requiring detailed elucidation of the evolutionary and antigenic features of its fusion (F) gene. Using 500 sequences collected between 1982 and 2024, we investigated the molecular evolution, phylodynamics, and structural epitope landscape of the HMPV-B F gene. Time-scaled phylogeny dated the divergence of sublineages B1 and B2 to around 1937, and Bayesian Skyline Plot analysis showed that these sublineages exhibited distinct demographic trajectories over time. The F gene evolved at a rate of 1.01 × 10⁻³ substitutions/site/year; however, amino acid variation remained limited, consistent with pervasive purifying selection, with 39% of codons under strong negative selection and little consensus evidence for positive selection. Conformational B-cell epitope prediction demonstrated a high degree of conservation across neutralizing antibody binding regions (sites Ø and I–V), and amino acid substitutions occurring within these sites were not predicted to substantially alter epitope architecture. Together, these findings indicate that the HMPV-B F gene evolves under strong evolutionary constraint while maintaining stable antigenic features, supporting the potential for antibody-based strategies that target neutralizing antibody binding regions of the F protein. Full article

The Southwest China vortex (SWV) is a high-impact mesoscale cyclonic vortex that typically originates over Sichuan Province, China, and frequently produces hazardous rainfall. Yet systematic knowledge of the structural and microphysical properties of SWV precipitation remains insufficiently quantified. Using Global Precipitation Measurement Dual-frequency Precipitation Radar (GPM/DPR) observations from 2014 to 2022, this study investigates the vertical structure and macro- and microphysical characteristics of SWV precipitation, and quantifies their differences across life-cycle stages and precipitation types. The mature stage is characterized by higher echo tops, stronger radar reflectivity, higher strong-echo altitudes, and larger near-surface rainfall, together with a clearer melting-layer bright band and a stronger post-melting shift toward larger drops and lower number concentrations. The developing stage is weakest and shows the largest fraction of coalescence–breakup balance signatures, whereas the dissipating stage features enhanced evaporation- and breakup-related signals. Among precipitation types, deep strong convection exhibits the greatest vertical extent with enhanced ice/mixed-phase growth; stratiform precipitation produces stronger radar echoes and higher rainfall rates than deep weak convection despite similar echo-top heights; and shallow precipitation is characterized by smaller drops, higher concentrations, and active warm-rain spectral evolution. These findings provide satellite-based constraints for microphysics parameterization evaluation and improved numerical prediction of SWV-related rainfall over complex terrain. Full article

This paper proposes an Enhanced Projection-Iterative-Methods-based Optimizer (EPIMO) to overcome the limitations of its predecessor, the Projection-Iterative-Methods-based Optimizer (PIMO), including deterministic parameter decay, insufficient diversity maintenance, and static exploration–exploitation balance. The enhancements incorporate three core strategies: (1) an adaptive decay strategy that introduces stochastic perturbations into the step-size evolution; (2) a mirror opposition-based learning strategy to actively inject structured population diversity; and (3) an adaptive adjustment mechanism for the Lévy flight parameter $\beta$ to enable phase-sensitive optimization behavior. The effectiveness of EPIMO is validated through a multi-stage experimental framework. Systematic evaluations on the CEC 2017 and CEC 2022 benchmark suites, alongside four classical engineering optimization problems (Himmelblau function, step-cone pulley design, hydrostatic thrust bearing design, and three-bar truss design), demonstrate its comprehensive superiority. The Wilcoxon rank-sum test confirms statistically significant performance improvements over its predecessor (PIMO) and a range of state-of-the-art and classical algorithms. EPIMO exhibits exceptional performance in convergence accuracy, stability, robustness, and constraint-handling capability, establishing it as a highly reliable and efficient metaheuristic optimizer. This research contributes a systematic, adaptive enhancement framework for projection-based metaheuristics, which can be generalized to improve other swarm intelligence systems when facing complex, constrained, and high-dimensional engineering optimization tasks. Full article

Mid-channel bars are fundamental fluvial geomorphic units that regulate sediment transport, channel stability, and riparian ecosystems, and their spatiotemporal evolution provides critical insights for sustainable river management. This study examines the structural reorganization and migration dynamics of mid-channel bars along the mainstem of the transboundary Yalu River using multi-temporal Sentinel-2 imagery acquired in 2019, 2022, and 2024. An automated extraction framework combining a dense atrous U-Net (DA-UNet) with multispectral indices was developed to robustly identify mid-channel bars under complex water–land transition conditions. Based on the extracted results, changes in bar number, area, size composition, morphological characteristics, and centroid migration were systematically analyzed. The results reveal a pronounced reorganization of mid-channel bars systems over the study period: although the number of bars increased from 111 to 136, the total area decreased from 168.97 km² to 165.00 km², indicating a transition from a “few-large” to a “many-small” configuration. Size-based analysis further shows an increase in small and medium bars, while large bars remained relatively stable, leading to a more differentiated multi-scale structure. These findings highlight the effectiveness of integrating multi-temporal remote sensing and deep learning for long-term monitoring of geomorphic dynamics and provide scientific evidence to support sustainable river regulation and transboundary watershed management. Full article

We propose a novel mathematical framework for understanding consciousness as a dynamical phenomenon governed by nonlinear integrable equations. The central hypothesis identifies conscious state dynamics with the Painlevé VI equation and its confluence limits, providing a unified description of stability, bifurcation, and collapse across cognitive regimes. In this approach, consciousness is modeled as an emergent phase sustained near criticality, where coherent quantum-like structures and classical decoherence coexist in a regulated balance. The theory is formulated in terms of isomonodromic deformations on $\mathrm{SL}(2,\mathbb{C})$ character varieties, allowing conscious states to be characterized by monodromy data and their controlled evolution. This geometric setting naturally encodes memory, attention, and transitions between conscious and unconscious phases, while confluence processes account for irreversible loss of coherence. A two-stage quantum-to-classical transition is identified, separating microscopic coherence from macroscopic stabilization. The framework yields universal signatures such as critical slowing down, scaling laws near transition points, and robustness under perturbations, linking consciousness dynamics to broader classes of critical phenomena observed in physics and complex systems. By replacing heuristic assumptions with a mathematically constrained dynamical structure, this work extends existing quantum consciousness models and provides a tractable platform for comparison with neural, biological, and informational data. Full article

Natural-fiber biocomposites are increasingly viewed as promising materials for sustainable engineering. However, their broader adoption remains constrained by coupled challenges related to interfacial compatibility, moisture sensitivity, environmental durability, processing limitations, and end-of-life trade-offs. Rather than treating fiber selection, matrix chemistry, processing routes, durability, and sustainability as independent considerations, this review emphasizes their interdependence through the fiber–matrix interface, which governs stress transfer, moisture transport, and long-term property evolution. It provides a comprehensive and integrative analysis of natural-fiber–reinforced polymer composites, encompassing plant-, animal-, and emerging bio-derived reinforcements combined with bio-based, biodegradable, and selected synthetic matrices. Comparative analysis across the literature demonstrates that interfacial engineering consistently dominates mechanical performance, moisture resistance, and property retention, while mediating trade-offs among stiffness, toughness, recyclability, and biodegradability. Moisture transport and environmental ageing are examined using thermodynamic and diffusion-controlled frameworks that link fiber chemistry, interfacial energetics, swelling, and debonding to performance degradation. Fire behavior and flame-retardant strategies are reviewed with attention to heat-release control and their implications for durability and circularity. Processing routes, including extrusion, injection molding, compression molding, resin transfer molding, and additive manufacturing, are assessed with respect to fiber dispersion, thermal stability, scalability, and compatibility with bio-based systems. By integrating structure–property relationships, processing science, durability mechanisms, and sustainability considerations, this review clarifies how natural-fiber biocomposites can be designed to achieve balanced performance, environmental stability, and circular life-cycle behavior, thereby providing guidance for the development of systems suitable for near-term engineering applications. Full article

Against the backdrop of rapid urbanization and climate change, energy burden inequity arises between existing and new residential buildings due to generational differences in building envelopes. This study develops a demand-side energy burden equity assessment framework based on energy simulations of typical existing and new apartments in representative cities across China’s five major climate zones. The framework integrates multi-climate conditions, long-term evolution under different Shared Socioeconomic Pathways, and adaptable retrofit implications. Results indicate that demand-side energy burden inequity is widespread but structurally heterogeneous across climate zones, with the largest disparity observed in heating-dominated regions (up to 95.69 kWh/m² in Harbin). Under future warming, three scaling pathways emerge: convergence in heating-dominated regions (up to −27%), divergence in cooling-dominated and mixed regions (up to +382%), and offsetting effects driven by heating–cooling structural shifts in cold regions (up to −5%). Retrofit analysis shows that combined envelope upgrades achieve substantial inequity reduction (88–152%), though with diminishing marginal returns, while single targeted measures already yield high benefits in cooling-dominated and mild regions (74% and 83%, respectively). The findings provide differentiated and forward-looking evidence to support equity-oriented interventions in urban residential retrofitting and policy design. Full article