Search Results (800)

The formation and evolution of haze layers in planetary atmospheres play a critical role in shaping their chemical composition, radiative balance, and optical properties. In the outer solar system, the atmospheres of Titan and the giant planets exhibit a wide range of compositional and seasonal variability, creating environments favorable for the production of complex organic molecules under low-temperature conditions. Among them, Uranus—the smallest of the ice giants—has, since Voyager 2, emerged as a compelling target for future exploration due to unanswered questions regarding the composition and structure of its atmosphere, as well as its ring system and diverse icy moon population (which includes four possible ocean worlds). Titan, as the only moon to harbor a dense atmosphere, presents some of the most complex and unique organics found in the solar system. Central to the production of these organics are chemical processes driven by low-energy photons and electrons (<50 eV), which initiate reaction pathways leading to the formation of organic species and gas phase precursors to high-molecular-weight compounds, including aerosols. These aerosols, in turn, remain susceptible to further processing by low-energy UV radiation as they are transported from the upper atmosphere to the lower stratosphere and troposphere where condensation occurs. In this review, I aim to summarize the current understanding of low-energy (<50 eV) photon- and electron-induced chemistry, drawing on decades of insights from studies of Titan, with the objective of evaluating the relevance and extent of these processes on Uranus in anticipation of future observational and in situ exploration. Full article

Silicon has a striking similarity to carbon and is found in plant cells. However, there is no specific role that has been assigned to silicon in the life cycle of plants. The amount of silicon in plant cells is species specific and can reach levels comparable to macronutrients. Silicon is used extensively in artificial intelligence, nanotechnology, and the digital revolution, and thus can serve as an informational molecule such as nucleic acids. The diverse potential of silicon to bond with different chemical species is analogous to carbon; thus, it can serve as a structural candidate similar to proteins. The discovery of large amounts of silicon on Mars and the moon, along with the recent development of enzyme that can incorporate silicon into organic molecules, has propelled the theory of creating silicon-based life. The bacterial cytochrome has been modified through directed evolution such that it could cleave silicon–carbon bonds in organo-silicon compounds. This consolidates the idea of utilizing silicon in biomolecules. In this article, the potential of silicon-based life forms has been hypothesized, along with the reasoning that autotrophic virus-like particles could be used to investigate such potential. Such investigations in the field of synthetic biology and astrobiology will have corollary benefits for Earth in the areas of medicine, sustainable agriculture, and environmental sustainability. Full article

Understanding the activity patterns of a species is essential for developing sound conservation and management plans. In this study, we used a camera-trapping technique to determine the activity patterns of bharal (Pseudois nayaur) in a marginal population in Wolong National Nature Reserve, Sichuan, China. Our results showed that these animals preferred to be active in the daytime from 08:00 to 20:00, with an activity peak between 10:00 and 14:00. In addition, we found that the species had a seasonal activity pattern with higher activity frequency in summer than in winter and that bharal were most active in a temperature range of 3–11 °C and at night with a waxing crescent moon, implying that the activity rhythm of the species is an adaptation to a subtropical high-altitude alpine area with vertical zonation in temperature. The pattern of movement and activity was also correlated with the moon phase. Full article

In response to the increasing demand for high-precision navigation of satellites operating in the cislunar space, this study introduces an onboard orbit determination algorithm considering both convergence and computational efficiency, referred to as the Sliding-Window Batch Processing (SWBP) algorithm. This algorithm combines the strengths of data batch processing and the sequential processing algorithm, utilizing measurement data from multiple historical and current epochs to update the orbit state of the current epoch. This algorithm facilitates rapid convergence in orbit determination, even in instances where the initial orbit error is large. The SWBP algorithm has been used to evaluate the navigation performance in the Distant Retrograde Orbit (DRO) and the Earth–Moon transfer orbit. The scenario involves a low-Earth-orbit (LEO) satellite establishing satellite-to-satellite tracking (SST) links with both a DRO satellite and an Earth–Moon transfer satellite. The LEO satellite can determine its orbit accurately by receiving GNSS signals. The experiments show that the DRO satellite achieves an orbit determination accuracy of 100 m within 100 h under an initial position error of 500 km, and the transfer orbit satellite reaches an orbit determination accuracy of 600 m within 3.5 h under an initial position error of 100 km. When the Earth–Moon transfer satellite exhibits a large initial orbital error (on the order of hundreds of kilometers) or the LEO satellite’s positional accuracy is degraded, the SWBP algorithm demonstrates superior convergence speed and precision in orbit determination compared to the Extended Kalman Filter (EKF). This confirms the proposed algorithm’s capability to handle complex orbital determination scenarios effectively. Full article

A Digital Elevation Model (DEM) provides accurate topographic data for planetary exploration (e.g., Moon and Mars), essential for tasks like lander navigation and path planning. This study proposes the first latent diffusion-based algorithm for DEM generation, leveraging a conditional decoder to enhance reconstruction accuracy from RGB satellite images. The algorithm performs the diffusion process in the latent space and uses a conditional decoder module to enhance the decoding accuracy of the DEM latent vectors. Experimental results show that the proposed algorithm outperforms the baseline algorithm in terms of reconstruction accuracy, providing a new technical approach to efficiently reconstruct DEMs for extraterrestrial planets. Full article

Two of the renowned figures of Edo-era Kokugaku (National Learning), Motoori Norinaga and Ueda Akinari, famously debated the merits of their scholarly approaches to Japanese antiquity during the latter half of the eighteenth century. Their intellectual dispute was the result of the radical conclusions reached by Tō Teikan in his Shōkōhatsu (An Outburst of Provocations; 1781) in which he argued that the Korean peninsula and China influenced ancient Japan, and that Japan’s first emperor, Jimmu, was from Ryukyu. While Akinari supported the notion of continental influence on ancient Japan, Norinaga did not, and while the former was mostly agnostic about Jimmu’s Ryukyuan roots, the latter opposed that as well. Norinaga, however, was not opposed to the idea of ancient ties between Ryukyu and Japan, an issue with which Akinari’s silence seemed to signify some degree of agreement. This commonality between these two intellectual giants demonstrated the extent to which Japanese intellectuals of the Edo period viewed the Ryukyu Kingdom (now Okinawa Prefecture) as occupying an ambivalent geopolitical space, in which it was neither fully foreign nor fully native. At the same time, Akinari’s historiographical approach to Japanese antiquity, which emerged in his debate with Norinaga, exerted an influence on nineteenth-century depictions of Ryukyu’s historical and cultural ties to Japan, chiefly Kyokutei Bakin’s Chinsetsu yumiharizuki (Fantastic Tales of the Moon Bow; 1811). Full article

A moon jellyfish (Aurelia aurita) is a representative of the phylum Cnidaria, commonly found in the northern seas of the globe. The regenerative abilities of cnidarians have recently been associated with extracellular vesicles (EVs) secreted by these organisms. In this study, a method for the isolation of EVs from the oral arms of A. aurita is presented. The methodology includes differential centrifugation, size-exclusion chromatography, and ultrafiltration. The isolates were characterized with tunable resistive pulse sensing, cryogenic transmission electron microscopy, capillary electrophoresis (CE), and electrophoretic light scattering (ELS). Small (<150 nm in diameter) EVs were abundant in the isolates. The EVs were found to carry nucleic acids, indicating their role in signaling. Additionally, the difference in zeta potential values measured with ELS and CE indicates high glycation in the vesicles analyzed. Although the method developed was effective in isolating EVs from small sample volumes (0.5 mL), the EV yield was insufficient for omics analysis. Thus, the scaling up of the isolation process is required for comprehensive biochemical analysis and biological activity assessment in A. aurita-derived EVs. Full article

With the launch of the Artemis program and the International Lunar Research Station project, the construction of lunar bases has emerged as a global research focus. In situ manufacturing technologies for robust lunar regolith-based building materials are critical to ensuring building safety under the Moon’s extreme environmental conditions. This paper reviews the relevant advancements in two areas: solidification technologies for lunar regolith-based construction materials and simulation techniques of extreme lunar environments. This review reveals that, although significant advancements have been made in solidification technologies, the development of lunar environment simulation technologies, particularly for 1/6 g gravity, has lagged, thereby hindering the assessment of the in situ applicability of these solidification methods. To address these limitations, this paper introduces a newly developed comprehensive lunar extreme environment simulation system based on superconducting magnetic suspension technology and its potential applications in lunar regolith-based construction material solidification. This review highlights the current progress and challenges in solidification techniques for lunar regolith-based building materials, aiming to enhance researchers’ attention to the extreme environmental conditions on the lunar surface. Full article

The development of efficient and sustainable water recycling systems is essential for long-term human missions and the establishment of space habitats on the Moon, Mars, and beyond. Humidity condensate (HC) is a low-strength wastewater that is currently recycled on the International Space Station (ISS). The main contaminants in HC are primarily low-molecular-weight organics and ammonia. This has caused operational issues due to microbial growth in the Water Process Assembly (WPA) storage tank as well as failure of downstream systems. In addition, treatment of this wastewater primarily uses adsorptive and exchange media, which must be continually resupplied and represent a significant life-cycle cost. This study demonstrates the integration of a membrane-aerated biological reactor (MABR) for pretreatment and storage of HC, followed by brackish water reverse osmosis (BWRO). Two system configurations were tested: (1) periodic MABR fluid was sent to batch RO operating at 90% water recovery with the RO concentrate sent to a separate waste tank; and (2) periodic MABR fluid was sent to batch RO operating at 90% recovery with the RO concentrate returned to the MABR (accumulating salinity in the MABR). With an external recycle tank (configuration 2), the system produced 2160 L (i.e., 1080 crew-days) of near potable water (dissolved organic carbon (DOC) < 10 mg/L, total nitrogen (TN) < 12 mg/L, total dissolved solids (TDS) < 30 mg/L) with a single membrane (weight of 260 g). When the MABR was used as the RO recycle tank (configuration 1), 1100 L of permeate could be produced on a single membrane; RO permeate quality was slightly better but generally similar to the first configuration even though no brine was wasted during the run. The results suggest that this hybrid system has the potential to significantly enhance the self-sufficiency of space habitats, supporting sustainable extraterrestrial human habitation, as well as reducing current operational problems on the ISS. These systems may also apply to extreme locations such as remote/isolated terrestrial locations, especially in arid and semi-arid regions. Full article

Wildlife–vehicle collisions (WVCs) pose a growing threat to road safety and wildlife conservation. This research explores the relationship between the moon phases and the occurrence of nighttime WVCs in Serbia from 2015 to 2023. A total of 2767 nighttime incidents were analyzed to assess whether the full moon is associated with an increased collision frequency. The results revealed a statistically significant rise in the average annual number of WVCs during full moon nights compared to other nights, indicating that increased lunar illumination may affect animal movement and impact collision rates. However, no statistically significant differences were observed when comparing the frequency of WVCs across all four lunar phases. Spatial analysis identified the South Bačka and Podunavlje districts as the most at-risk regions for WVCs during full moon periods. As the first study of its kind in Serbia, this research provides new insights into the spatial and temporal patterns of WVCs. The findings can assist in developing focused mitigation strategies, such as improved signage, speed control strategies, and awareness campaigns, especially in regions with increased risk during full moon nights. Full article

Federated learning (FL) has emerged as a prominent distributed machine learning paradigm that facilitates collaborative model training across multiple clients while ensuring data privacy. Despite its growing adoption in practical applications, performance degradation caused by data heterogeneity—commonly referred to as the non-independent and identically distributed (non-IID) nature of client data—remains a fundamental challenge. To mitigate this issue, a heterogeneity-aware and robust FL framework is proposed to enhance model generalization and stability under non-IID conditions. The proposed approach introduces two key innovations. First, a heterogeneity quantification mechanism is designed based on statistical feature distributions, enabling the effective measurement of inter-client data discrepancies. This metric is further employed to guide the model aggregation process through a heterogeneity-aware weighted strategy. Second, a multi-loss optimization scheme is formulated, integrating classification loss, heterogeneity loss, feature center alignment, and L2 regularization for improved robustness against distributional shifts during local training. Comprehensive experiments are conducted on four benchmark datasets, including CIFAR-10, SVHN, MNIST, and NotMNIST under Dirichlet-based heterogeneity settings (alpha = 0.1 and alpha = 0.5). The results demonstrate that the proposed method consistently outperforms baseline approaches such as FedAvg, FedProx, FedSAM, and FedMOON. Notably, an accuracy improvement of approximately 4.19% over FedSAM is observed on CIFAR-10 (alpha = 0.5), and a 1.82% gain over FedMOON on SVHN (alpha = 0.1), along with stable enhancements on MNIST and NotMNIST. Furthermore, ablation studies confirm the contribution and necessity of each component in addressing data heterogeneity. Full article

Background and Objectives: Medication overuse headache (MOH) presents unique clinical challenges in older adults due to age-related changes and comorbidities. However, data on MOH characteristics and treatment responses in this population remain limited. This study investigated the clinical features, treatment patterns, and short-term outcomes of MOH in older patients. Methods: We analyzed data from the RELEASE registry, a nationwide, multicenter prospective cohort of MOH patients in South Korea. Participants were stratified into older (≥65 years) and younger (<65 years) groups. We compared clinical features, treatment patterns, and 3-month outcomes, and identified factors associated with treatment response in the older group. Results: Among 791 patients, 72 (9.1%) were older. Compared to younger patients, older patients reported more monthly headache days (30.0 vs. 27.0, p = 0.012), more days using acute medication (30.0 vs. 20.0, p < 0.001), and fewer headache-free days (0.0 vs. 3.0, p = 0.012). They also experienced more severe headache days (12.5 vs. 10.0, p = 0.056). Despite this, older patients showed lower disability, with significantly lower Migraine Disability Assessment scores (30.0 vs. 46.0, p < 0.001) and a trend toward lower Headache Impact Test-6 scores (64.5 vs. 66.0, p = 0.065). In multivariable analysis, poor adherence to preventive treatment (≤24%) was significantly associated with non-response (OR 0.13, 95% CI: 0.02–0.96, p = 0.045) at 3 months. Conclusions: Older patients with MOH showed distinct clinical features, including higher headache frequency and severity but relatively lower disability. Improving adherence to preventive treatment may enhance treatment response. Age-specific management strategies are needed. Full article

The Lunar Augmented Navigation Service (LANS) is the lunar equivalent of GNSS for future lunar explorations. It offers users accurate position, navigation, and timing (PNT) capabilities on and around the Moon. The Augmented Forward Signal (AFS) is a standardized signal structure for LANS, and its recommended standard was published online on 7 February 2025. This work presents software-defined radio (SDR) implementations of the LANS AFS simulator and receiver, which were rapidly developed within a month of the signal specification release. Based on open-source GNSS software, including GPS-SDR-SIM and Pocket SDR, our system provides a valuable platform for future algorithm research and hardware-in-the-loop testing. The receiver can operate on embedded platforms, such as the Raspberry Pi 5, in real-time. This feature makes it suitable for lunar surface applications, where conventional PC-based SDR systems are impractical due to their size, weight, and power requirements. Our approach demonstrates how open-source SDR frameworks can be rapidly applied to emerging satellite navigation signals, even for extraterrestrial PNT applications. Full article

This study investigates the spatial distribution of transition metals—iron (Fe), titanium (Ti), and chromium (Cr)—within the Dryden crater on the Moon using hyperspectral data from the Moon Mineralogy Mapper (M³). By applying spectral parameters and false color composite techniques, geospatial maps of chromite distribution and FeO, TiO₂ wt.% distribution were generated at a resolution of ~140 m. The findings reveal distinct elemental enrichments along geomorphologically active regions such as crater walls, terraces, and central peaks, highlighting impact-driven material differentiation, the influence of morphology, degradation, and space weathering. These results enhance our understanding of lunar crustal evolution and support future exploration and resource utilization efforts. Full article

Ocean acidification, caused by increased atmospheric CO₂, threatens marine organisms that depend on calcium-based structures such as jellyfish statoliths. This study investigated the effects of low pH on the morphology and statolith formation of ephyrae in Aurelia coerulea, comparing two developmental pathways to form ephyra: polyp-strobilation and planula-strobilation. Under the pH 6.8 condition, polyps failed to produce viable ephyrae, whereas planula-strobilation succeeded in releasing ephyrae with normal morphology, though statoliths were absent. Under the pH 7.8 condition, both strobilation types produced normal-shaped ephyrae with reduced statolith size but increased statolith number compared with the control (pH 8.1), suggesting a compensatory response to acidification. Statolith morphology differed between pathways: planula-strobilated ephyrae had needle-shaped statoliths with high aspect ratios, indicating a rapid, early-stage crystallization process. Despite their minimal body size and statolith development, planula-strobilated ephyrae maintained the functional mass of statoliths necessary for survival. This rapid, morphologically minimized development suggests that planula-strobilation is an adaptive reproductive strategy in response to environmental stress. Our findings suggest that A. coerulea possesses a flexible life history strategy that may facilitate its resilience to ongoing ocean acidification scenarios. Full article