Search Results (68)

Solar filaments (and their limb counterparts, prominences) are critical tracers of the Sun’s magnetic topology and key precursors to coronal mass ejections (CMEs). Precise identification and continuous tracking of these features are essential for understanding solar eruptive mechanisms and improving space weather forecasting. This systematic review evaluates the evolution of automated detection methodologies, addressing the challenge of processing the exponentially growing volume of high-resolution solar observations. We identify deep learning architectures, particularly U-Net variants and Mask R-CNN, as the most promising current paradigms. Compared to traditional image processing, these data-driven models demonstrate superior robustness against noise and variable observing conditions, achieving high-precision segmentation (>90% accuracy) with sub-second inference speeds. This leap in computational efficiency and accuracy directly facilitates real-time operational monitoring and enables large-scale statistical analysis of filament evolution across solar cycles. We conclude that future breakthroughs lie in developing physics-informed AI and standardized benchmarks to bridge the gap between pixel-level segmentation and physical interpretation, ultimately creating detection systems that are both operationally reliable and scientifically meaningful. Full article

Neurons achieve their highly polarized architecture by coordinating cytoskeletal systems across space and time, enabling axons to extend over remarkable distances and dendrites to elaborate complex arbours. Early neuroanatomists described intracellular “neurofibrils,” yet these structures remained poorly understood until electron microscopy resolved them into three distinct polymer systems: microtubules, actin filaments, and intermediate filaments. Although this framework clarified neuronal ultrastructure, it simultaneously established a conceptual hierarchy in which microtubules and actin were regarded as the principal drivers of neurite growth, while intermediate filaments were relegated to a passive, supportive role. Unlike prior reviews that document vimentin dynamics primarily from a cell-biological standpoint, this review integrates historical, conceptual, and epistemological perspectives to examine both how and why that hierarchy arose and how it has been dismantled. This review traces how that hierarchy arose and why it has been increasingly reconsidered in favour of intermediate filaments, focusing on vimentin as a case study. Evidence from live cell imaging, molecular manipulation, and genetic models shows that vimentin is dynamically regulated rather than static. Vimentin networks remodel continuously, exchange subunits with soluble pools, and move in coordination with microtubules. Most recently, sparse single-filament labelling combined with correlative volume electron microscopy has demonstrated that individual vimentin filaments remain motile even within dense perinuclear networks previously assumed to be static, a finding that fundamentally redefines what filament density implies about cytoskeletal organization. In neural and neural precursor cells, vimentin expression is developmentally regulated and is prominent during early differentiation stages associated with neurite initiation giving way to neurofilaments in mature neurons. Functional studies further link vimentin to neurite formation and extension, cytoskeletal coordination, organelle positioning, and cellular stress responses. Philosophical analysis reveals that these empirical advances were inseparable from shifts in imaging technology and conceptual framing, and that epistemic risks including model dependency and confirmation bias can be mitigated through methodological pluralism and explicit model disclosure. Taken together, these findings support a revised understanding of intermediate filaments as active, context-dependent contributors to neuronal development and plasticity, and illustrate the value of integrating biological evidence with historical and philosophical reflection. Full article

As a prominent frontier in ultrafast laser–matter interaction, femtosecond laser filamentation holds great potential for atmospheric pollutant detection and remote sensing. However, its practical application in the open atmosphere is severely hampered by atmospheric turbulence, which induces beam wander, wavefront distortion, and intensity scintillations. In this study, we numerically investigated the propagation dynamics of femtosecond laser filaments in a turbulent medium and elucidated the underlying physical mechanisms. The results show that, compared to linear propagation, the nonlinear self-guiding effect inherent to filamentation effectively suppresses turbulence-induced beam wander. Furthermore, by employing vortex beams carrying orbital angular momentum (OAM), we significantly suppressed the stochastic generation of multiple filaments, thereby notably improving the stability of long-range filament propagation in complex atmospheric conditions. These findings provide new insights into the physical mechanisms and novel strategies for improving the robustness of laser filamentation technology in real-world turbulent environments. Full article

We report the stereoscopic observations of two recurrent streamer waves in a single streamer structure, utilizing coordinated observations from the SOHO, STEREO, and SDO missions. Contrary to the long-held view that fast coronal mass ejections (CMEs) are necessary drivers, we demonstrate that these recurrent waves were excited by two consecutive slow CMEs (<500 km s⁻¹ accompanied by only modest flare activity. Three-dimensional reconstruction reveals that the first and second waves propagated with significant decelerations of −7.93 m s⁻² and −10.26 m s⁻², respectively. Their average amplitudes were $0.41R_{\odot }$ and $0.77R_{\odot }$, wavelengths were $4.02R_{\odot }$ and $6.17R_{\odot }$, and periods were 2.66 and 2.53 h, respectively. While the amplitude of the first wave declined with heliocentric distance (consistent with conventional energy convection), the second wave exhibited an intriguing increasing trend in amplitude. Both waves showed a linear increase in wavelength and period with distance, indicating a non-stationary and dispersive medium. Crucially, despite the disparity in driver energy and wave scales, the periods and their change rates remained nearly identical for both events. This provides compelling case-specific evidence that the streamer wave period is primarily determined by the inherent eigenmodes of the streamer plasma slab rather than the specific characteristics of the trigger. We conclude that the generation of observable streamer waves is a combined consequence of the streamer’s structural stability and the energy transfer efficiency of the triggering disturbance. Full article

Background/Objectives: Endometrial cancer frequently develops resistance to therapy, partly due to the ability of tumor cells to adapt to cellular stress through non-apoptotic mechanisms. Mitochondrial dysfunction and cytoskeletal remodeling are increasingly recognized as key components of stress adaptation; however, their structural relationship under pharmacological stress in three-dimensional (3D) tumor models remains poorly characterized. The present study aimed to investigate the ultrastructural and phenotypic effects of lithium chloride (LiCl)-induced stress in 3D endometrial cancer spheroids, with a particular focus on mitochondrial alterations and intermediate filament organization. Methods: Three-dimensional spheroids generated from Ishikawa endometrial cancer cells were exposed to lithium chloride at concentrations of 1, 10, or 50 mM for defined time periods. Cell viability, proliferative activity, and clonogenic capacity were assessed using Trypan Blue exclusion, BrdU incorporation, and soft agar assays. Ultrastructural changes were examined by transmission electron microscopy to evaluate mitochondrial morphology, cytoplasmic organization, and intermediate filament distribution. Results: LiCl exposure resulted in a dose- and time-dependent reduction in cell viability, proliferation, and clonogenic potential in 3D spheroids. Ultrastructural analysis revealed pronounced mitochondrial swelling, cristae disorganization, and membrane-associated mitochondrial alterations. These changes were consistently accompanied by conspicuous accumulation and reorganization of intermediate filaments in close spatial proximity to damaged mitochondria, suggesting a structural association between cytoskeletal remodeling and mitochondrial injury. Across all experimental conditions, classical apoptotic ultrastructural features, including chromatin condensation and apoptotic body formation, were not observed. Conclusions: Together, these observations indicate that lithium chloride elicits a stress phenotype in 3D endometrial cancer spheroids that primarily manifests at the organelle and cytoskeletal levels, rather than through classical apoptotic execution. Although descriptive in nature, the present study highlights intermediate filament accumulation as a prominent structural feature of lithium-induced mitochondrial stress and establishes a structural reference point for future studies aimed at further investigating mitochondrial–cytoskeletal relationships during pharmacological stress in endometrial cancer. Full article

We present a stereoscopic analysis of coronal streamer deflection induced by a CME-driven shock, utilizing multi-viewpoint coronagraph observations from STEREO-Ahead, STEREO-Behind, and SOHO. Driven by the continuous impact of the shock, the streamer deflection propagates outward, exhibiting distinct morphological variations across the three different lines of sight. Our analysis reveals that speeds derived directly from two-dimensional (2D) images differ significantly from those obtained via three-dimensional (3D) reconstruction. Specifically, the 2D projected speeds measured from STEREO-Ahead, STEREO-Behind, and SOHO are 445, 476, and 336 km s⁻¹, respectively. Furthermore, while 2D measurements suggest a constant propagation speed, the 3D reconstruction reveals a pronounced deceleration of approximately −36 m s⁻². Significant discrepancies are also noted in the deflection amplitude between the 2D and 3D results. Since the propagating streamer deflection effectively traces the shock’s movement, we propose that measuring the deflection speed offers a robust alternative for deriving actual shock velocities in the outer corona, where direct white-light detection remains challenging. Full article

We report new fossil larval specimens that have characters of the group Megaloptera, i.e., are either megalopteran or megalopteran-like larvae from the Triassic, Cretaceous, or Eocene. Fossils from the latter two times are preserved in amber. One of the new fossils reveals that some earlier reported presumed megalopteran-like fossils, that have been already suspected to be beetles, are indeed more likely beetles of the group Myxophaga. A quantitative morphological comparison supports that most fossil megalopteran (and megalopteran-like) larvae did not differ significantly from extant megalopteran larvae, indicating no major losses of morphology over time. However, two newly reported fossil specimens from Kachin amber indeed separate from the other larvae, representing an extinct morphotype. The morphotype is characterised by a prominent terminal filament, indicating that the specimen is a representative of Sialidae. However, unlike most of the known larvae of this group, it possesses a rather elongate prothorax and strongly curved mandibles. These two characters are more commonly known in larvae of Corydalidae. It seems most likely that the presence of these characters in the new morphotype does not represent a plesisomorphy, but is more likely the product of convergent evolution. Full article

Phosphorus is a key nutrient regulating algal growth and eutrophication in aquatic systems, yet its isolated effect on microalgae-based wastewater treatment remains underexplored. This study evaluated how varying phosphorus loads drive microalgal community structure and purification performance in controlled photobioreactors fed synthetic wastewater. The synthetic wastewater was formulated with constant carbon and nitrogen but graded phosphorus at C/N/P ratios of 100/5/1, 100/5/10, and 100/5/20 under 6000 lux, a 14 h photoperiod, and 24 ± 2 °C with a 15-day hydraulic retention time. Monitoring of chlorophyll a, pH, total and volatile suspended solids, and algal composition showed that phosphorus enrichment significantly increased chlorophyll a (up to 43.9 µg/L at 20 mg P/L) and particulate biomass (TSS and VSS), while pH remained near neutral to slightly alkaline, with no significant differences among the three bioreactors. Although the same core taxa—Chlorella spp., Scenedesmus spp., Navicula spp., and filamentous algae were present across all bioreactors, their relative abundances shifted significantly with phosphorus concentration. A two-way ANOVA confirmed a highly significant interaction between bioreactor (P level) and genus (p < 0.001), demonstrating phosphorus-driven changes in the microalgal community. Notably, filamentous cyanobacteria (Anabaena spp.) were undetectable in the low- and medium-phosphorus treatments but emerged prominently only at the highest phosphorus level (20 mg/L). Nutrient removal efficiencies peaked in this high-phosphorus bioreactor (C), achieving 85% for bCOD, 78% for nitrogen, and >70% for phosphorus. These results show that phosphorus loading drives predictable shifts in microalgal community composition toward fast-growing algae and cyanobacteria and that these shifts likely contribute to enhanced nutrient removal. The findings support optimization of phosphorus supply and hydraulic residence time in low-cost, sunlight-driven systems to improve polishing performance for small settlements in arid regions. Full article

With the rapid advancement of modern electronic devices and wireless communication systems, electromagnetic pollution has become a prominent issue, prompting the development of high-performance electromagnetic interference (EMI) shielding materials. Although traditional metal shielding materials exhibit excellent conductivity, there are many limitations such as high weight, poor flexibility, susceptibility to corrosion, and high cost. To overcome these challenges, in this study, we design and fabricate core-spun yarns using polyester filaments as the core and an aluminum-foil-wrapped layer as the conductive outer component, and further weave them into three conductive fabrics with different structural parameters. Through systematic investigation of their surface morphology, air permeability, electrical properties, and EMI shielding performance, DT5W27 demonstrates optimal overall performance: electrical conductivity of 2722.64 S·m⁻¹, shielding effectiveness of 37.29 dB, and electromagnetic wave attenuation rate of 99.99%. Specifically, even after 100 bending, twisting cycles, and exposure to solutions with pH values ranging from 3 to 9, the fabric maintains high shielding performance. The fabrication process is facile and low cost, and these composites have good flexibility, outstanding EMI shielding performance, exceptional mechanical durability, and chemical stability. These advantages make them have broad application potential in protective clothing and lightweight shielding materials. Full article

The use of plastic materials in the maritime industry is increasing day by day. Plastics are particularly preferred in watercraft due to their lightweight, resistance to water-related damage (such as mold and wear), optical clarity, and high corrosion resistance. In recent years, plastics produced by 3D printing have gained prominence in applications traditionally dominated by conventional plastic materials. Therefore, producing marine-grade materials—such as acrylonitrile butadiene styrene (ABS), which has long been used in the maritime sector—through 3D printing, and understanding their long-term performance, has become increasingly important. In this study, the mechanical behavior, surface roughness, and color changes of ABS+ materials in three different colors (yellow, green, and blue) and with three different infill ratios (50%, 75%, and 100%) were investigated after a salt spray test. Following the salt spray exposure, tensile and bending tests, hardness measurements, surface roughness analyses, and color measurements were conducted and compared with reference samples. The results were evaluated based on filament color and infill ratio. This study underscores the importance of color selection—along with mechanical strength—when designing 3D-printed materials for long-term use in saltwater environments. Full article

Riboflavin (vitamin B₂) is an essential micronutrient required for all living organisms. It is naturally synthesized by plants and most microorganisms, including the bacterium Bacillus subtilis, the filamentous fungus Ashbya gossypii, and the yeast Candida famata—all of which are known to be riboflavin overproducers. The choice of production organism in industrial applications depends on factors such as yield, ease of cultivation, and the availability of genetic tools. As a result, several microorganisms are commonly used, and their relative prominence can shift over time with advances in metabolic engineering and process optimization. This review presents a comparative analysis of riboflavin biosynthesis across prokaryotic and eukaryotic systems, with a particular focus on regulatory mechanisms governing flavinogenesis. Special attention is given to recent advances in metabolic engineering strategies, including the application of CRISPR/Cas9 genome editing in Bacillus subtilis and Ashbya gossypii. In yeast systems, significant improvements in riboflavin production have been achieved primarily through the manipulation of transcriptional regulators (e.g., SEF1, SFU1, TUP1) and metabolic genes. The role of other important genes (PRS3, ADE4, ZWF1, GND1, RFE1, VMA1, etc.) in riboflavin overproduction in C. famata is described. The review also explores the use of alternative, low-cost feedstocks—including lignocellulosic hydrolysates and dairy by-products—to support more sustainable and economically viable riboflavin production. Although considerable progress has been achieved in genetic optimization and bioprocess development, further work is required to fine-tune metabolic flux and maximize riboflavin synthesis, particularly under industrial conditions. This review highlights key opportunities for future research aimed at refining metabolic interventions and expanding the use of renewable substrates for environmentally sustainable riboflavin production. Full article

The Télescope Héliographique pour l’Etude du Magnétisme et des Instabilités Solaires (THEMIS) has been operating in the Canary Islands since 1998. A total of 187 publications are listed in the THEMIS database. The telescope was upgraded in 2019 with adaptive optics and was fully operational in 2024. When operated in polarimetric mode, the telescope is calibration-free and has a high polarimetric sensitivity, which enables important results to be obtained. We will summarize a few of these results, obtained mainly during coordinate campaigns with the multi-spacecraft, outlined as follows: the horizontal magnetic field in prominences, the existence of flux rope in flare regions, and the magnetic field interchange reconnection between jets and filaments. Full article

Background/Objective: Actinomyces is a genus of anaerobic gram-positive bacteria. It forms part of human body microbiota commonly in the oral cavity and genital tract. During pregnancy, the organism may cause the rare chorioamnionitis, where the maternal genital tract or other sites such as the oral cavity will be the likely source of the pathogen. This condition may increase the risk of foetal morbidity and mortality, and preterm birth. Methods: The placenta of a 33-year-female, primigravida, who presented with preterm labour and eventual delivery of baby at 20 weeks gestation was sent for histopathological examination. Her antenatal and clinical history were reviewed, to identify possible aetiology for her preterm birth. Results: She is noted to have presented with sudden per-vaginal creamy coloured discharge with no associated odour and no irritation. The discharge became blood staining associated with labour pain, this followed by premature spontaneous rupture of membrane and pre-mature labour. Laboratory tests revealed leucocytosis, neutrophilia, monocytosis, high CRP and elevated derived fibrinogen. The patient was delivered of a live male baby weighing 0.35 kg, who died shortly after birth. Placenta microscopic examination revealed patchy severe acute chorioamnionitis and prominent clusters of Gram-positive filamentous bacteria with histopathologic features of Actinomyces spp. The mother before discharged was treated with oral antibiotic. Conclusions: The intrauterine Actinomyces spp. infection is associated with preterm birth and neonatal mortality, early diagnosis during ante-natal could perhaps prevent preterm birth and reduce the associated neonatal mortality. Full article

Additive Manufacturing (AM), commonly known as 3D printing, has gained significant traction across various industries due to its versatility and customization potential. However, the process remains time-consuming, with print durations ranging from hours to days depending on the complexity and size of the object. In many cases, errors occur due to object misalignment, material stringing due to nozzle overflow, and filament blockages, which can lead to complete print failures. Such errors often go undetected for extended periods, resulting in substantial losses of time and material. This study explores the implementation of traditional computer vision, image processing, and machine learning techniques to enable real-time error detection, specifically focusing on stringing-related anomalies. To address data scarcity in training machine learning models, we also release a new dataset and improve upon the results achieved by the Obico server model, one of the most prominent tools for stringing detection. Our contributions aim to enhance process reliability, reduce material wastage, and optimize time efficiency in AM workflows. Full article

This study reports two new species of Ampharete and one new record of a species of Amphicteis (Ampharetidae) from the Korean subtidal zone, based on an integrative approach. Ampharete koreana sp. nov. is characterized by paleal chaetae several times thicker than notochaetae, with short filamentous tips. It more closely resembles A. finmarchica but differs in the shape of its paleae, interbranchial gap, thoracic uncini, and pygidial cirri and shows a 2% genetic divergence in histone H3 and in 18% of mtCOI genes. Ampharete namhaensis sp. nov. shares with A. petersenae the absence of paleae and the presence of 16 abdominal uncinigers, a rare combination of traits among known Ampharete species. However, A. petersenae differs in having a marked interbranchial gap, prominent eyes on the prostomium, double the number of abdominal uncini and buccal tentacles, and in its distribution (southern Korea for A. namhaensis sp. nov. vs. North Atlantic and Arctic-adjacent waters for A. petersenae). The Korean Amphicteis specimens examined in this study closely resemble A. glabra in key morphological features, including fine paleae tips, 14 thoracic and 15 abdominal uncinigers, and approximately eight paleae. However, given the need for a comprehensive revision of Amphicteis and the potential for cryptic diversity within the genus, these specimens are provisionally designated as Amphicteis sp. cf. A. glabra. Full article