Search Results (247)

Caves and other subterranean ecosystems are characterized by stable, low temperatures, high humidity, and limited nutrient input, creating unique environments for extremophilic microorganisms. Among them, fungi play key roles in organic matter degradation, mineral interactions, and biogeochemical cycling, yet the diversity and adaptations of cold-adapted fungi in cave habitats remain insufficiently explored. This study investigated psychrophilic and psychrotolerant fungi inhabiting the stone surfaces of Ravništarka Cave in Eastern Serbia. Biofilm samples were collected from nine sites and analyzed using culture-based isolation on both nutrient-rich and diluted media, followed by incubation at 10 °C, 25 °C, and 37 °C. Fungal identification combined morphological characteristics with molecular analyses of the ITS region and BenA gene, while ecological roles were assigned using FUNGuild. A total of 41 fungal species were documented, spanning Ascomycota (53.1%), Basidiomycota (43.7%), and Mortierellomycota (3.1%) phyla. The genus Penicillium exhibited the greatest species richness, with 14 taxa documented, including P. chrysogenum, P. glandicola, and P. solitum, all previously associated with cold or oligotrophic environments. The psychrotolerant species Mortierella alpina was the only representative of Mortierellomycota. Ecological guild assignment revealed fungi functioning at different trophic levels, highlighting their multifunctional ecological roles in extreme subterranean habitats. Full article

The nymphaeum originated as a monument dedicated to the nymphs and defined as a natural cave with a water source. Over time, it has been transformed into an artificial cave with the presence of fountains, statues and wall paintings. The nymphaeum is exposed to specific environmental conditions, leading to biodeterioration caused by vegetal organisms that find an ideal environment for their growth. This study aimed to document the vegetation present inside and outside the Carolei’s Nymphaeum, as well as the biofilm on the interior walls, particularly the painted walls. The biological work is part of a large-scale project involving building materials, thermo-hygrometric parameters, and partial pilot restoration work. Multiple approaches were used for biological analysis by combining microscopic, culture, and molecular techniques. We identified Pteridophytes, Angiosperms, and mosses, as well as fungal taxa, cyanobacteria, and chlorophytes in the biofilms. The results indicate that there is a very heterogeneous organism composition with significant biodeterioration potential. Biodeterioration is one of the major problems in the prevention, conservation, and restoration of cultural heritage, and the data gathered in this research may help to enhance the understanding of issues and develop suitable strategies for restoration, upkeep, and accessibility and usability. Full article

Autonomous ground vehicles (AGVs) are of major importance in exploration missions since they perform difficult tasks in changing or harmful environments. Mapping and exploration is crucial in hazardous areas, or areas inaccessible to humans, demanding autonomous navigation. This paper proposes a lightweight, low-cost AGV platform, which will be used in resource-constrained situations and aimed at scenarios like exploration missions (e.g., cave interiors, biohazard environments, or fire-stricken buildings) where there are serious security threats to humans. The proposed system relies on simple ultrasonic sensors when navigating and applied traversal algorithms (e.g., BFS, DFS, or $A^{*}$) during path planning. Since on-board microcomputers have limited memory, the traversal data and direction decisions are stored in a file located on an SD card, which supports long-term, energy-saving navigation and risk-free backtracking. A fish-eye camera set on a servo motor captures three photos ordered from left to right and stores them on the SD card for further off-line processing, integrating each frame into a low-frame-rate video. Moreover, when the battery level falls below 50%, the exploration path does not extend further and the AGV returns to the base station, thus combining a secure backtracking procedure with energy-efficient decisions. The resultant platform is low-cost, modular, and efficient at augmenting; thus it is suitable for exploring missions with applications in search and rescue, educational robotics, and real-time applications in low-infrastructure environments. Full article

This paper reviews the apparent impact of how changes in nitrate, sulphate activities, and moisture affect the surface pH of rock art paintings at Cueva del Ratón, in the Sierra de San Francisco in Baja California Sur, Mexico. The data was collected after atypical weather events caused rain and mist in this normally arid area. The rock art paintings had been previously examined over several years and observed the unexpected formation of silica skins over some surfaces; such coatings are not often experienced in arid environments. The local geology of the cave and the availability of moisture can dramatically alter the microbiological activity on faecal material and development of surface acidity from such reactions which interacts with both the host rock and the pigments. Through a series of surface pH measurements and localised measurements on chloride, sulphate and nitrate it appears that both nitrate and sulphate concentrations have a significant impact on the surface pH, which is controlled by a diffusion-based movement of moisture from the closed to the open end of the shelter. The exfoliation of the rock surface and formation of the silica skins involves chemical reactions as contrasted with diffusion-controlled reactions which distribute the metabolites of the yeasts, moulds and bacteria, which are dominated by the availability of water through drip lines. The results are particularly relevant due to changing weather patterns in the last decade, caused by climate change, with an increase in hurricanes directly affecting the Baja California peninsula. The use of disposable test strips for semi-quantitative assessment of how these major anions impact on the decay mechanisms was a novel response to budget constraints and the remoteness of the location. Full article

Bats are ecologically vital mammals, serving as pollinators, seed dispersers, and bioindicators of ecosystem health. Many species inhabit natural caves, which offer optimal conditions for survival but present challenges for direct ecological monitoring due to their dark, complex, and inaccessible environments. Traditional monitoring methods, such as mist-netting, are invasive and limited in scope, highlighting the need for non-intrusive alternatives. In this work, we present a portable multisensor platform designed to operate in underground habitats. The system captures multimodal data, including near-infrared (NIR) imagery, ultrasonic audio, 3D structural data, and RGB video. Focusing on NIR imagery, we evaluate the effectiveness of the YOLO object detection framework for automated bat detection and counting. Experiments were conducted using a dataset of NIR images collected in natural shelters. Three YOLO variants (v10, v11, and v12) were trained and tested on this dataset. The models achieved high detection accuracy, with YOLO v12m reaching a mean average precision (mAP) of 0.981. These results demonstrate that combining NIR imaging with deep learning enables accurate and non-invasive monitoring of bats in challenging environments. The proposed approach offers a scalable tool for ecological research and conservation, supporting population assessment and behavioral studies without disturbing bat colonies. Full article

Underground mining environments are highly hazardous, often prone to gas explosions, cave-ins, and fires that may trap miners during emergencies. The accurate, real-time localization of miners is vital for effective self-escape and rescue operations. Although the Mine Improvement and New Emergency Response (MINER) Act of 2006 mandates communication and tracking systems, most current solutions rely on low-power devices and line-of-sight methods that are ineffective in GPS-denied, dynamic subsurface conditions. Delay-Tolerant Networking (DTN) has emerged as a promising alternative by supporting message relay through intermittent links. In this work, we propose a deep learning framework that combines Convolutional Neural Networks (CNNs) and Long Short-Term Memory (LSTM) networks to predict miner locations using simulated DTN-based movement data. The model was trained on a simulated dataset of 1,048,575 miner movement entries, predicting miner locations across 26 pillar classes. It achieved an 89% accuracy, an 89% recall, and an 83% F1-score, demonstrating strong performance for real-time underground miner localization. These results demonstrate the model’s potential for the real-time localization of trapped miners in GPS-denied environments, supporting enhanced self-escape and rescue operations. Future work will focus on validating the model with real-world data and deploying it for operational use in mines. Full article

Southeast Asia is a biodiversity hotspot for bats that can carry lyssaviruses, causing zoonotic diseases. This study detects and quantifies IgG antibodies against Lyssavirus glycoproteins in cave-dwelling bat populations on Cat Ba Island, northern Vietnam, to determine their past exposure history and the prevalence of immune responses. Samples were collected from five caves, encompassing three families and five key species (Hipposideros armiger, H. alongensis, H. poutensis, Taphozous melanopogon, and Myotis pilosus). Using ELISA with the Platelia™ Rabies II kit,(Bio-Rad Laboratories, Marnes-la-Coquette, France) 29.0% (18/62) of the bats tested positive, indicating prior exposure. The detection rate was slightly higher in females (35.7%) than in males (30.4%). Lyssavirus-specific antibodies were detected in four species, with the highest levels found in M. pilosus, followed by H. alongensis, H. armiger, and H. poutensis; no positives were found in T. melanopogon samples. One bat exhibited high seroconversion value (>4 EU/mL). The findings provide serological evidence of widespread lyssaviruses exposure in asymptomatic bats on Cat Ba Island, confirming their role as reservoirs that elicit an immune response without exhibiting rabies symptoms. This highlights the role of caves in facilitating close contact among bats, which may increase viral transmission, highlighting the need for continued surveillance in these unique roosting environments. Full article

This study presents a comprehensive treatment system for addressing leakage challenges in underground structure construction within complex karst terrains, demonstrated through the case of Baiyun Station in Guangzhou. Integrating advanced geological investigation, dynamic grouting techniques, and adaptive structural remediation strategies, this methodology effectively mitigates water inflow risks in structurally heterogeneous karst environments. Key innovations include the “one-trench two-drilling” exploration-grouting system for karst cave detection and filling, a multi-stage emergency water-gushing control protocol combining cofferdam sealing and dual-fluid grouting, and a zoned epoxy resin injection scheme for structural fissure remediation. Implementation at Baiyun Station achieved quantifiable outcomes: karst cave filling rates increased from 35.98% to 82.6%, foundation pit horizontal displacements reduced by 67–68%, and structural seepage repair rates reached 96.4%. The treatment system reduced construction costs by CNY 12 million and shortened schedules by 45 days through optimized pile formation efficiency (98% qualification rate) and minimized rework. While demonstrating superior performance in sealing > 0.2 mm fissures, limitations persist in addressing sub-micron fractures and ensuring long-term epoxy resin durability. This research establishes a replicable framework for underground engineering in karst regions, emphasizing real-time monitoring, multi-technology synergy, and environmental sustainability. Full article

The Guyang Cave contains an extensive collection of late Northern Wei (late fifth to early sixth century) statue and stele combinations. While existing scholarship has recognized the exceptional nature of these statue–stele pairings, their systematic stylistic classification and contextual interpretation have yet to receive sustained scholarly attention. This investigation analyzes ten paradigmatic cases, organized into three distinct stylistic groups. The discussion subsequently focuses on four particularly representative examples that epitomize divergent approaches to stele implementation. These stylistic differentiations emerge as direct responses to specific spatial contingencies within the cave’s architecture. Instead of being merely decorative, these innovative configurations served as ritual instruments, amplifying patrons’ devotional objectives within the cave’s competitive environment. Ultimately, this study contributes to the theoretical discourse on “ritual art” by revealing how spatial negotiations between patrons manifested as a dynamic ritual process—one that both informed and was sustained by artistic creation in the Guyang Cave. More broadly, in the late Northern Wei period, artistic expression and ritual practice emerged as mutually constitutive elements in the dynamic formation of religious and cultural traditions. Full article

Interest in using warm-season grasses, including switchgrass (SG) (Panicum virgatum L.), as a bioenergy crop has increased in Europe. This study evaluated the effects of harvesting regimes with two cuts per year on the productivity, chemical composition and biochemical methane potential of the SG cultivars ‘Dacotah’, ‘Foresburg’ and ‘Cave in Rock’ in environments with cool and moderate climates in Europe with minimal fertilizer application. The results of two harvest years suggest that the biomass yield, chemical composition and energy potential depend on the grass cultivars and harvesting time. Significant effects (p < 0.05) of the harvest date and cultivar were observed for most of the measured parameters for biomass and silage quality. All three SG cultivars harvested on August 8 produced the lowest (p < 0.05) volume of methane per kg of biomass (181–202 normal litres (NL) per kg⁻¹ volatile solids (VS)) compared to the biomass of the respective cultivar harvested on 14 July (287–308 NL kg⁻¹ VS) or on October 3, as regrowth after the first cut made in mid-July (274–307 NL kg⁻¹ VS). The stands of all three SG cultivars, when the first harvest was completed in mid-July, achieved a higher annual area-specific methane yield than those harvested first in August (1128–1900 Nm³ ha⁻¹ and 888–1332 Nm³ ha⁻¹, respectively). Depending on the harvest regime and cultivar, the annual gross energy presented as a lower heating value varied from 31.8 GJ ha⁻¹ to 68.0 GJ ha⁻¹. It is concluded that SG growing under the cool temperate climate of Northern Europe could be an interesting alternative crop for methane production. Our study proves that the cultivar choice also plays an important role. Full article

Hopanoids are a series of important lipid biomarkers in the bacterial cellular membranes that are found ubiquitously in different spatial and temporal environments. Squalene-hopane cyclase, a key and prerequisite molecular component of the hopanoid biosynthesis pathway, is encoded by the sqhC gene. To investigate the composition, niche, and distribution of microbial sqhC-containing communities, we analyzed hopanoid producer data and environmental parameters across different ecosystems on the basis of sequencing reads of peat samples from increasing gradient depths across peatland profile C in the Dajiuhu Peatland, as well as data collected from available published papers. The results indicated that the acidic Dajiuhu Peatland harbored mainly Acidobacteria (59.16%) among its sqhC-containing groups. The main composition of hopanoid producers in the peatland was different from that in other ecosystems, with Alphaproteobacteria found in soil (37.78%), cave (48.21%), hypersaline lagoon (34.04%), and marine (32.59%) ecosystems; Betaproteobacteria, Gammaproteobacteria, and Deltaproteobacteria found in reef (100%), acid mine drainage (55.00%), and estuary, mangrove, and harbor (39.66%) ecosystems; and an unknown cluster found in freshwater (29.43%) and hot spring (89.58%) ecosystems. Compared with other phyla or sub-phyla, Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria were the most widespread, occurring in eight ecosystems. Peatland was significantly separated from the other nine ecosystem modules in the occurrence network, and the marine ecosystem had the greatest impact on the eco-network of sqhC microbes. An RDA indicated that pH, DO, salinity, and TOC had significant impacts on sqhC-containing microbial communities across the different ecosystems. Our results will be helpful to understanding the diversity, composition, and distribution of the sqhC community and its response to multiple environmental factors across different ecosystems. Full article

In the operation period of long-distance water delivery tunnels, safety may be impacted by the risks that arise from different aspects including the complex geological conditions with fault fracture zones and karst caves, the diverse environment affecting structural safety and stability, and the construction defects of tunnels. It is crucial to assess and mitigate potential risks to ensure operation safety. To address this challenge, this study presents a systemic risk assessment for the operation safety of a real project of a water delivery tunnel. The potential risks of this project were first summarized based on the analytical hierarchy process (AHP), and a model that integrates the AHP and fuzzy comprehensive evaluation (FCE) was built to effectively quantify and categorize risks for the project in its operation stage. Results of the assessment indicate that the risk of this tunnel operation can be classified at a moderate grade with a calculted specific risk score of 43.935, with the high-risk factors including segment lining cracking, flow control, and regular maintenance. In response to the high-risk factors, the preventative and control measures are proposed to guide effective risk management. The model presented offers an efficient risk assessment tool for water delivery tunnels, aiding decision makers making more rational management decisions in complex and uncertain environments. Full article

This study investigates how local gastronomic products with strong cultural and heritage value can contribute to destination identity and sustainable rural tourism development. Focusing on cave-aged cheeses, it emphasizes the case of Roquefort-sur-Soulzon (France), where traditional cheese-making and natural cave-aging have been successfully integrated into tourism experiences that reflect terroir, authenticity, and rural heritage. To explore tourist motivations, a survey of 416 visitors was conducted. Factor analysis and Structural Equation Modeling (SEM) were used to identify the main drivers behind cheese-related tourism. The analysis revealed three key motivational factors: Traditional Gastronomy, linked to interest in regional food practices; Cheese Experience, emphasizing the unique appeal of Roquefort cheese; and Heritage Tourism, reflecting a desire to connect with rural identity and sustainable traditions. These results support the hypothesis that culturally significant local food products can serve as central elements in shaping place identity and attracting visitors through immersive, heritage-based experiences. The study concludes that food heritage can be a powerful tool for rural development, offering economic, cultural, and experiential value. It also identifies similar opportunities in Serbian regions such as Pirot and Sokobanja, where traditional kačkavalj cheese and natural cave environments present strong potential for tourism growth rooted in local identity. Full article

The archaeological complex of the Benzú rock shelter and cave, located in Ceuta (Spain), represents a heritage site of significant scientific and historical value that is currently at risk due to natural processes and, in particular, the activity of a nearby quarry. This site has been occupied from the Palaeolithic to the Bronze Age and consequently has been the subject of systematic research since 2002, focusing on its stratigraphic sequence, lithic technology, exploitation of marine resources, and the connection between both shores of the Strait of Gibraltar. With the aim of preserving this endangered heritage, a methodology based on advanced digital technologies such as photogrammetry, 3D laser scanning, and GNSS georeferencing has been implemented. These tools have enabled the creation of high-precision, three-dimensional models of the rock shelter and the cave, which are useful for both documentation and monitoring of their structural condition. In addition, fracture networks have been identified, revealing a high degree of geotechnical vulnerability, exacerbated by blasting activities at the nearby quarry. The project has produced a digital twin of the site in an open access format, serving not only for preventive conservation but also for its enhancement through virtual tours, augmented reality, and accessible outreach activities. This digitalization has been essential to facilitate the access to heritage, particularly in areas that are physically difficult to access. Finally, the integration of these digital resources into institutional policies for the sustainable management of heritage is proposed, highlighting the importance of interdisciplinary approaches that combine archaeology, geotechnology, and scientific communication. The experience at Benzú is presented as a replicable model for the protection, interpretation, and dissemination of heritage sites located in fragile and threatened environments. Full article