Snow cover, the extensive terrestrial habitat in Antarctica, sometimes exhibits vivid coloration, yet the structure and function of its microbial communities remain poorly characterized. Using metagenomic sequencing of red snow (RS) and green snow (GS) from the Fildes Peninsula, we found that bacterial, eukaryotic, and archaeal relative abundances were 85.82%, 13.52% and 0.16%, respectively. β-Diversity differed significantly between RS and GS across these three domains (P < 0.05). Dominant bacterial phyla included Bacteroidota (RS: 62.61%; GS: 38.72%) and Pseudomonadota (RS: 32.80%; GS: 54.10%). Among eukaryotes, Chlorophyta (RS: 58.10%; GS: 52.98%) and Basidiomycota (RS: 14.80%; GS: 8.08%) were prevalent. Nanobdellota dominated archaea, with lower abundance in RS than GS. In the algal community, Sanguina, Gonium and Chloromonas were significantly enriched in red snow, while Chlorella and Micractinium were enriched in green snow (P < 0.05). Marker genes associated with carbon (C), nitrogen (N), phosphorus (P) and sulfur (S) cycles were identified in green and red snow. Aerobic respiration and phosphate regulation were significantly enriched in red snow, while CO oxidation, fermentation, and denitrification were significantly enriched in green snow. Key microbial genera associated with these functional pathways also varied. In the denitrification of red snow, Stutzerimonas was the most abundant genus, while Janthinobacterium was abundant in green snow. Nitrification-related genes were detected only in red snow based on the present metagenomic data. The network of the red snow microbial community was potentially more complex and resistant based on topology, which not only benefited its own long-term survival but might also have potentially influenced the positive feedback effect of snowmelt by maintaining a low-albedo snow surface. This provided an ecological implication under climate warming: the expansion of red snow patches showed the potential to the increase nitrate runoff export, which would affect nitrogen nutrient levels in coastal Antarctic waters. Overall, this study used metagenomics to compare the multidomain (bacteria, archaea and eukaryotes) composition and diversity between red snow and green snow, and directly linked key microbial taxa with functional genes of biogeochemical cycles. This study provided new insights into the biological characteristics and functional potential of Antarctic colored snow.
Alpine tundra vegetation, also shaped by snow persistence, is expected to undergo shifts in plant community composition under climate change as snow cover duration declines, with potential consequences for soil biogeochemistry and microbial communities. However, the relationships among snow-driven vegetation types, soil carbon (C) and nitrogen (N) forms, and prokaryotic community functional organization remain poorly understood. In this study, we investigated soil C and N forms and the functional organization of prokaryotic communities across three vegetation types shaped by different snow cover duration: snowbed communities dominated by Salix herbacea (SB, with long snow cover duration), alpine sedge swards dominated by Carex curvula (CC, with short snow cover duration), and intermediate transitional plant assemblages. C-related forms were mainly associated with vegetation type, with higher C content in CC than in SB. Conversely, mineral N forms varied primarily with timing within the snow free season, with higher concentrations in the early snow free season, indicating different spatial and temporal controls on soil C and N dynamics. Microbial community composition differed among vegetation types, whereas alpha diversity varied little. Despite this, prokaryotic functional groups differed markedly. CC were associated with higher relative abundance of cellulolytic prokaryotes, whereas SB were enriched in N-related functional groups inferred from FAPROTAX assignments, suggesting potential differences in N cycling-related microbial functions among vegetation types. These results show that soil biogeochemistry and microbial functional organization in alpine tundra soils are shaped by both snow-driven vegetation types and timing across the snow free period. Under climate change, reduced snow cover duration and SB contraction may cause the loss of a microhabitat with specific functional biodiversity, with potential consequences for soil C and N cycling.
Leaf Area Index (LAI) is a fundamental parameter linking vegetation structure with surface energy and carbon exchange in Earth system models. However, the underestimation of LAI caused by snow cover remains a persistent limitation of existing satellite products. Here, we develop a global snow-free LAI dataset covering the years 1985-2020 at 500 m resolution. The method compiles over 2700 leaf lifespan records from the TRY plant trait database, spanning observations for numerous plant species, and aggregates them into plant functional type (PFT)-specific values. It then identifies snow-affected regions using MODIS data and applies a leaf-lifespan-based correction to PFT-specific LAI values. The physiologically constrained snow-free LAI effectively corrects the underestimation of LAI in snow-affected regions. Simulations with the Common Land Model indicate that snow-free LAI improves albedo simulations over snow-covered regions by better representing vegetation masking effects and reducing positive albedo bias. Additionally, the snow-free LAI increases net radiation and gross primary productivity, and reduces snow depth. This snow-free LAI dataset provides a reliable input for modeling vegetation-snow interactions in Earth system models, supporting more accurate simulations of surface energy, water and carbon dynamics.
Snow algae darken snowpacks and accelerate melt world-wide. Although elevation strongly structures mountain snowfields, its influence on snow algal traits and their effects on snowpack reflectance remains unclear. Here, we investigated snow algal blooms across an elevational range of 1059-3423 m above sea level (asl) in the Cascade Range (California, Oregon, Washington) and the Rocky Mountains (Utah, Wyoming, Montana). We analyzed 294 snow samples and quantified algal community composition, algal cell density, cell size, pigment concentrations, and snow albedo. We further examined elevation-dependent patterns within Sanguina nivaloides-dominated blooms (117 of 206 bloom samples). Across samples spanning clean snow and algal blooms, algal cell density emerged as the strongest biological predictor of albedo, whereas pigment-related variables showed no consistent effects. Within Sanguina nivaloides-dominated blooms, neither relative abundance nor algal cell density varied systematically with elevation. Instead, mean cell size increased with elevation, while per-cell pigment concentrations declined, leading to higher astaxanthin ratios driven primarily by reductions in Chla per cell. These elevation-dependent shifts in cell size and pigment balance were consistent across both mountain ranges, indicating phenotypic acclimation to increasing environmental stress with elevation. Together, these findings link cellular-scale acclimation of a widespread snow algae to radiative processes shaping mountain snowpacks. Las algas de la nieve oscurecen los mantos nivosos y aceleran el deshielo a escala global. Aunque la altitud estructura fuertemente las condiciones físicas de los campos de nieve de montaña, su influencia sobre los rasgos funcionales de las algas de la nieve y sus efectos sobre la reflectancia de la nieve siguen siendo inciertos. En este estudio investigamos floraciones de algas de la nieve a lo largo de un gradiente altitudinal de entre 1.059 y 3.423 m s.n.m. en la cordillera de las Cascadas (California, Oregón y Washington) y las Montañas Rocosas (Utah, Wyoming y Montana). Analizamos 294 muestras de nieve y cuantificamos la composición de la comunidad algal, la densidad y el tamaño celulares, las concentraciones de pigmentos y el albedo de la nieve. Además, examinamos los patrones asociados a la altitud en las floraciones dominadas por Sanguina nivaloides (117 de las 206 muestras con floraciones). En el conjunto de muestras, que abarcó desde nieve limpia hasta floraciones de algas, la densidad celular de las algas emergió como el predictor biológico más robusto del albedo, mientras que las variables relacionadas con los pigmentos no mostraron efectos consistentes. Dentro de las floraciones dominadas por Sanguina nivaloides, ni la abundancia relativa ni la densidad celular variaron sistemáticamente con la altitud. En cambio, el tamaño celular medio aumentó con la altitud, mientras que las concentraciones de pigmentos por célula disminuyeron, dando lugar a relaciones astaxantina : clorofila a más elevadas, impulsadas principalmente por una reducción del contenido de clorofila a por célula. Estos cambios asociados a la altitud en el tamaño celular y el balance de pigmentos fueron consistentes en ambos sistemas montañosos, lo que sugiere una aclimatación fenotípica al incremento del estrés ambiental con la altitud. En conjunto, estos resultados vinculan la aclimatación a escala celular de una alga de la nieve ampliamente distribuida con los procesos radiativos que determinan las propiedades de los mantos nivosos de montaña.
Alpine snowpacks provide valuable archives of atmospheric deposition, yet the southern slopes of the Greater Caucasus remain underrepresented in high-altitude geochemical monitoring networks. This study investigated the hydrochemical composition of fresh snow, annual snowpack, and perennial snowfields across an altitudinal transect from 1838 to 2857 m a.s.l. within the Caucasian State Nature Biosphere Reserve to characterize depositional sources and evaluate how snow archive type and landscape structure influence geochemical signal preservation. Major ions were determined by titrimetric and turbidimetric methods, while trace elements and rare earth elements were quantified by ICP-AES and ICP-MS. Complementary soil and vegetation samples assessed landscape controls on elemental accumulation. Marine-associated ions, including Na, Mg, Cl, and Sr, remained detectable across the transect at sites approximately 50 km inland from the Black Sea, indicating orographic transport and scavenging of maritime aerosols during south-westerly circulation. Forest canopy interception reduced sub-canopy snowpack elemental concentrations by approximately 70 to 80 percent relative to open alpine environments, establishing montane forest sites as the most conservative local deposition baseline. Rare earth element concentrations exceeded upper crustal Clarke values by factors of 2 to 5 and corresponded to REE-enriched Paleogene volcanic lithologies of the Mzymta basin, supporting their use as robust lithogenic tracers. Because fresh snow, annual snowpack, and perennial snowfields preserve atmospheric chemistry over fundamentally different temporal scales, they cannot be treated as interchangeable monitoring archives. A spatially distributed annual snowpack sampling design anchored by montane forest reference sites is recommended for integrated seasonal atmospheric monitoring in topographically complex mountain terrain.
Despite popular belief that adverse weather impacts the risk of falls, a multifactorial and leading cause of injury among older adults, this association is largely understudied. This study examined which individual characteristics are associated with increased risks of sustaining an injurious fall on snow/ice among Canadian older adults. This cross-sectional secondary analysis used baseline data from the Canadian Longitudinal Study on Aging. Participants who retrospectively reported an injurious fall within 12 months of baseline testing were included (n = 2,587; agemean: 63.7 ± 10.4 years; 59.8% female). The main outcome was an injurious fall on snow/ice, with select sociodemographic factors as independent variables. Participants who fell on snow/ice (n = 254) were compared with those who fell elsewhere (n = 2,333) based on demographics, health, and fall injury status. Participants who fell on snow/ice were younger (62.1 vs. 63.9 years; p = .006), more likely to be male (50.8% vs. 39.0%; p < .001), less likely to be retired (41.7% vs. 51.0%; p = .004), and reported fewer chronic conditions (3.5 vs. 4.1; p = .003). Logistic regression showed that men were 36% more likely to fall on snow/ice than women and that for every additional year of age, men had a reduced risk of injurious fall on snow/ice. Middle-aged Canadian men are at higher risk for injurious falls on snow/ice. Results suggest that targeted public health guidelines may be needed for men under 65 to reduce this risk. More studies are needed to understand if this finding is generalizable to other countries with snow/ice.
Ultra-High Molecular Weight Polyethylene (UHMWPE), the standard base material in ski manufacturing, offers excellent gliding performance but exhibits limited mechanical and scratch resistance on hard and icy snow conditions. In this work, stainless steel is proposed as a mechanically robust alternative, and its inherently higher friction against snow is addressed through surface engineering. The snow friction behavior of 301H stainless steel surfaces decorated with fishbone-like microstructures combined with Laser-Induced Periodic Surface Structures (LIPSSs) was investigated using a custom-built snow tribometer. Several pattern designs, with different pitch distances and depths, were engraved using femtosecond laser pulse irradiation. We conducted morphological, physical, and chemical investigations through microscopy, static contact angle measurements, and X-ray Photoelectron Spectroscopy analyses. Results indicate that the gliding performance is not directly related to the modifications in surface chemistry and wetting behavior of the samples but is affected by the geometry and orientation with respect to the sliding direction of the specific micro- and nano-features. Overall, we achieved friction coefficient values comparable to those found in UHMWPE with a fast and economically sustainable single-step laser-texturing process. This approach allows the industrial up-scaling of the fishbone-texture design to real-size alpine ski prototypes.
Background and Objectives: Severe snowfall and icing are associated with weather-related trauma presentations, especially in cities unaccustomed to prolonged winter conditions. However, the clinical characteristics of these injuries and their implications for surgical management remain incompletely understood. This study aimed to describe injury patterns, treatment approaches, and factors associated with the need for surgery among patients presenting with extremity trauma during an intense snowfall and icing episode in Diyarbakır. Materials and Methods: This single-center retrospective observational study included patients presenting to the emergency department with extremity trauma during a severe snowfall and icing period. Demographic characteristics, injury features, imaging modality, ambient temperature, anatomical localization, and treatment approaches were analyzed. Patients were categorized according to nonoperative versus operative management. Factors associated with the need for surgery were evaluated using univariable and multivariable logistic regression analyses. Receiver operating characteristic analysis was used to assess the discriminative ability of age and ambient temperature for predicting the need for surgery. Results: A total of 943 patients were included. The largest age group was 18-44 years (38.6%), and 55.9% were male. Fractures were identified in 50.7% of cases, whereas 46.7% had no fracture and 2.7% had joint dislocation. Upper-extremity injuries predominated (65.2%), with distal segment involvement observed in 55.0% of cases. Most presentations occurred on days with mean ambient temperatures ≤ 0 °C (81.5%). Overall, 82.1% of patients were managed nonoperatively, while 17.9% required surgical treatment. In multivariable analysis, increasing age and the use of computed tomography were independently associated with the need for surgery, whereas ambient temperature was not. Conclusions: Fall-related extremity injuries during severe snowfall and icing were predominantly upper-extremity and distal injuries, and most were managed nonoperatively. The need for surgery was more strongly associated with patient age and injury complexity than with ambient temperature alone. These findings describe a distinct trauma profile during short-term winter events in mild-climate cities.
Microplastic (MP) pollution has been increasingly documented in remote high-altitude environments worldwide, including the European Alps, Himalayas, Andes, and polar snowfields, where atmospheric transport delivers plastic particles even to regions far from emission sources. Despite this growing body of evidence, the occurrence of MPs in the mountainous regions of Türkiye remains unknown. This study presents the first nationwide investigation of MP contamination in alpine snow, conducted across eleven sites, including Mount Ağrı, Süphan, Kaçkar, Erciyes, Uludağ, and Sandras. MPs were detected at all locations, with an average concentration of 286 ± 91 MPs/L with the highest concentration detected at Sandras Mountain (908 MPs/L) and the lowest at Uzundere-Uzunkavak, Erzurum (16 MPs/L). Across the eleven sites, the mean relative shape composition was 71.2 ± 6.1% fibres, 23.8 ± 5.8% fragments, and 5.0 ± 4.5% films (summing to 100% as percentages of all detected MPs). Polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), nylon (PA), and polymethyl methacrylate (PMMA) were identified as the primary polymers. Spatial variability suggested both atmospheric deposition and local human activities contributed to contamination. Backward trajectory analysis indicated that microplastic deposition in snow was influenced by both long-range atmospheric transport from Africa and the Mediterranean and short-range local emissions, highlighting the combined impact of transboundary and regional processes on microplastic distribution. These first-season findings provide a preliminary baseline that even isolated alpine snowpacks of Türkiye can receive measurable MP inputs of both regional and long-range origin, highlighting the need for sustained, multi-season monitoring of high-mountain ecosystems within national and transboundary mitigation frameworks.
Knee injuries in snow sports are common, occurring in both professional and amateur athletes. The anatomic distribution of injuries varies significantly between alpine skiing and snowboarding, reflecting not only technical variation, but also the inherent differences in equipment between the two pastimes, including ski morphology, boots and bindings. While knee injuries, particularly to the ACL, predominate in skiing, they are relatively less common in snowboarding. Nevertheless, as snowboarding becomes increasingly popular, with more challenging terrain and jumps of higher magnitude, knee injuries including ACL tears will likely continue to increase in prevalence.
Polychlorinated biphenyls (PCBs) persist for decades when released into the environment and bioaccumulate in aquatic and terrestrial environments, resulting in harmful concentrations of PCBs in fishes, birds, and humans. Approximately 310,000 metric tons of PCBs were produced at a facility in Anniston, Alabama from 1929-1971. Hundreds of metric tons of PCB-contaminated waste were suspected to have been released into local environments. This study was the first systematic exposure assessment of the degree and extent of PCBs and potential co-contaminants-polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, Pb, and Hg-in avian tissues downstream of the Anniston facility. We collected 122 egg and 36 nestling tissue samples from across four exposure areas downstream of the facility and a reference site. A total of seven bird species were collected, but samples were predominantly Carolina wren (resident, Thryothorus ludovicianus) and barn swallow (migratory, Hirundo rustica). Concentrations of Pb and Hg in bird tissues collected from the exposure areas were less than toxicity reference values, suggesting Pb or Hg exposures alone were unlikely to affect birds. Total PCB concentrations in avian eggs and nestlings collected from exposure areas were among the greatest ever recorded in birds collected in North America. The PCB congener profiles in this study, paired with results from previous soil and sediment sampling, suggest that PCB-contaminated sediment and soil were the likely source of elevated PCBs in the avian tissues. The PCB concentrations observed in birds downstream of the Anniston facility were at magnitudes that likely affect populations of both resident and migratory birds that utilize the area for foraging and reproduction.
The characteristics of frost damage of highways under hydrothermal conditions are driven by large temperature differences, high soil moisture content, and disparities in both the temporal and spatial distribution of snow depth. The ground surface temperature (GST) model, which characterizes random dynamic variations in snow depth, was coupled with a thermal-hydro-mechanical model of frozen soil. Utilizing the coupled model, variations in GST and heat flux across six snow depth scenarios were computed, along with the evolution of the subgrade temperature field and pavement deformation. Furthermore, the response of the thermal state of the ground surface and the thermal behavior of the subgrade to fluctuations in four snow depth ranges were systematically examined, and the influence mechanism of snow on the subgrade thermal stability was revealed. In view of the preceding analysis, a comparison and evaluation were made of the regulatory effects of conventional and improved thermal regulation measures on the deformation characteristics of the subgrade top surface, under conditions of two extreme snow depths and four snow depth fluctuation ranges. This study provides direct guidance for the control of frost damage in snow-covered permafrost subgrades subjected to stochastic periodic thermal disturbances.
To address the issues of poor sustained-release behavior and limited long-term efficacy associated with conventional salt-storage materials, this study developed the epoxy-resin-encapsulated slow-release salt-storage filler to enhance both the engineering performance and the deicing/snow-melting capacity of salt-storage pavements. In this study, attapulgite was optimized and selected as the salt storage carrier through the adoption of pesticide coating technology and experimental testing, wherein a deicing salt blend with a CaCl2 to NaCl mass ratio of 2:1 was loaded via a wet adsorption method. Subsequently, using dimethicone as the surface modifier, the optimal encapsulation process was determined to involve the dilution ratio of epoxy resin to cyclohexanone of 4:1 and the curing agent dosage of 30% by weight. The results indicated that the recommended content of the filler should not exceed 5%. The filler reduced the high-temperature stability and water stability of the mixture, while the low-temperature crack resistance first increased and then decreased, peaking at the 2% filler content with an improvement of 12.2%. The water stability was the most significantly affected by the filler content. Ice-snow melting performance tests demonstrated that the salt-storage mixture with 5% filler achieved the deicing rate of 56.35% at -5 °C, meeting the industry standard requirements. The self-prepared slow-release salt-storage filler exhibited superior long-term ice-snow melting performance to V-260, with the slow-release duration extended by 60%. The salt release process was divided into three distinct stages: rapid dissolution, stable release and slow dissolution. The 60 °C was determined as the optimal temperature for the accelerated immersion testing, which the accelerated test could effectively simulate the natural immersion process. Based on the prediction model established accordingly, the functional service life of snow-melting for this slow-release salt-storage asphalt pavement in northern area was estimated be approximately 4.07 years. The slow-release salt-storage filler fabricated in this work possesses both remarkable sustained-release behavior and deicing efficacy. The findings provide the technical foundation for the development of novel salt-storage pavement materials, performance characterization, and mechanistic analysis of snow-ice melting.
AbstractUnderstanding seasonal water budgets of wildlife is critical, as climate change alters water availability. Rocky Mountain mule deer (Odocoileus hemionus hemionus) mainly obtain water from their diet and drinking water; however, winter access to these resources varies with snow cover. To assess reliance on water sources by mule deer during winter, we longitudinally sampled female deer in Utah's Bear River Mountains, a montane region with deep snow and ample drinking water sources, and Pine Valley, a semiarid region with little snow. We implanted physiological biologgers to record heart rate and collected serum samples at the onset and end of winter over 2 yr. We measured the triple oxygen stable isotope composition of a body water sample (Δ'17OBW) distilled from serum. We then compared measured Δ'17OBW to predictions generated from two isotope models of water and oxygen fluxes that differed in their estimates of metabolic rate, based on either heart rate or body mass. Close agreement between measured and predicted Δ'17OBW validated our assumptions, although estimating metabolic rate via heart rate did not improve model predictions. Our results indicate that in the Bear River Mountains, deer increased their water drinking when snow cover limited foraging but that in Pine Valley, they relied on consistent food water input because of minimal snow cover. Estimates suggest that some deer in Pine Valley were seasonally independent from drinking water. Applying Δ'17OBW modeling enhances wildlife conservation by providing novel inferences about how individuals obtain water, informing proactive management in the face of climate change.
Cryospheric landforms play a critical role in alpine hydrology and ecosystems. Using historical and contemporary data spanning nearly six decades (1967-2024), we assessed elevation change for glaciers, rock glaciers, and perennial snowfields and the thermal response of streams in the Teton Range, Wyoming, United States. Glaciers and snowfields thinned at -0.84 ± 0.07 meters per year (m year-1) and -0.59 ± 0.04 m year-1 between 2014 and 2022, a ~7-fold increase relative to 1967-2014, driven by warming summer temperatures. In contrast, rock glaciers are near equilibrium (-0.05 ± 0.05 m year-1) and saw no change in rate. Since 2015, snowfield-fed streams have warmed rapidly (+3.4°C), whereas glacier- and rock glacier-fed streams have warmed at lower magnitudes (+0.9° and +0.6°C, respectively). Our results demonstrate the greater resilience of rock glaciers to atmospheric warming, highlighting the critical role that these features will play as glaciers and perennial snowfields are lost.
Lead (Pb) concentrations and isotopic ratios (206Pb/207Pb and 208Pb/207Pb) in Antarctic snow serve as unique tracers of atmospheric pollution transport into the Southern Hemisphere. We investigated Pb sources and transport pathways to coastal Dronning Maud Land (cDML), East Antarctica, through the analysis of nine surface snow cores collected from three different ice rises. To isolate the atmospherically derived fractions, snow samples were subjected to 60-day weak-acid leaching prior to trace-element and Pb isotope analyses. The Pb concentrations range from 9.97-29.8 pg g-1 (mean = 18.7 ± 6.4 pg g-1). Enrichment factors for Pb in the operationally defined labile fraction (EFPb=70-110; mean = 93) calculated relative to upper continental crust values (Pb/Ba ≈ 0.03), indicate substantial non-crustal enrichment, consistent with anthropogenic Pb input. The 206Pb/207Pb ratios ranges from 1.13 to 1.16, and 208Pb/207Pb ratios from 2.41 to 2.43 are consistent with dominant contributions from South American emission sources. A five source Bayesian isotope mixing model (MixSIAR) was employed to quantify the relative contributions of major Pb sources to the cDML region. Model estimates that Argentina (∼40%) and Brazil (∼36%) together account for 74-82% of Pb deposition across the three ice rises, with smaller contributions from Chile (∼15%), Australia (∼5%), and local Antarctic sources (Skarvsnes; ∼4%). These results demonstrate that cDML snow archives hemispheric-scale industrial emissions, with South America as the primary contributor. The findings provide a regionally constrained modern baseline for monitoring global pollution transport and highlight Antarctica's sensitivity to anthropogenic atmospheric contamination in the Southern Hemisphere.
Small object detection under adverse weather remains challenging due to weather-induced domain shifts and sparse visual cues of small targets. In contrast to R-YOLO/QTNet and conventional UDA methods, which mainly rely on weather-specific restoration/enhancement or global feature/magnitude alignment, SABDR explicitly targets cross-weather small object adaptation through bidirectional domain translation, degradation-aware receptive-field modeling, feature-statistics modulation, and style-direction alignment. Specifically, the Bidirectional Dynamic Domain Adaptation Network, termed BiDDC-Net, translates between source and target domains and dynamically adjusts receptive fields according to weather severity. The Style-Aware Domain Adaptation Module, termed AIFI-DA, enhances discriminative small-object channels using feature statistics. SDA is further used as a complementary training-time regularizer to encourage style-direction consistency without directly matching feature magnitudes. Experiments are conducted on Cityscapes→Foggy Cityscapes and MOT-Fly→Foggy/Rainy/Snowy MOT-Fly, including newly added rainy and snowy MOT-Fly settings, with both YOLOv5s and YOLO26 evaluated on all MOT-Fly weather conditions. SABDR achieves 47.7 mAP50 on Cityscapes→Foggy Cityscapes, and obtains 96.0%/96.8%, 66.7%/77.1%, and 95.0%/95.6% mAP50 on Foggy, Rainy, and Snowy MOT-Fly with YOLOv5s/YOLO26, respectively. The improvements on MOT-Fly are reported under a fixed single-seed setting and should therefore be interpreted as single-run empirical gains rather than statistically validated improvements. These results demonstrate its effectiveness under the evaluated fog/rain/snow cross-weather small object detection settings.
Carnivores frequently rely on scent and visual markings for intraspecific communication, delineating territorial boundaries, attracting mates and assessing competitors. However, studying such behaviours in rare and elusive species poses significant challenges. To enhance our understanding of the diel marking behaviours of common leopard (Panthera pardus), from November, 2019 to June, 2023, we conducted a comprehensive camera-trap survey in Luolong county of Tibet, China. Our monitoring encompassed 159 locations yielded 1,208 (excluded 700 unknown sex) individual leopard detections over 60,000 trap days, allowing us to quantify the frequency and temporal patterns of marking behaviours. Of these, 153 detections involved territorial marking in snowy conditions, while 355 occurred in snow-free environments. Female leopards in mixed forests and shrublands exhibited higher diurnal activity in snow-presence days. Male leopards engaged in a range of behaviours - including sniffing and rolling - primarily within mixed, coniferous and shrubland habitats. Male leopards engaged more frequently in behaviours such as sniffing, scraping, urine spraying, body rubbing, vocalizations, rolling and scat deposition with notable differences in scraping frequency compared to females. Female leopards displayed similar behaviours but at reduced levels particularly in scraping activities. The number of scrapes observed at camera-trap sites appears to be an indicator of leopard visitation rates suggesting its usefulness for optimizing monitoring efforts. Our findings contribute valuable insights into how environmental factors influence social communication strategies in leopards, enhance our understanding of male and female leopard territorial and making behaviours in various environments, and benefit for the conservation and monitoring of carnivore populations.
Cannabis use has been associated with persistent perceptual disturbances, but systematic clinical characterization remains limited, particularly regarding multimodal sensory involvement. To characterize persistent perceptual disturbances following cannabis use, focusing on symptom profiles, temporal patterns, and clinical features. This exploratory observational study was conducted across the Valle d'Aosta and Piemonte regions of Italy between 2020 and 2025. We characterized 13 patients with persistent visual/auditory symptoms following cannabis exposure through comprehensive clinical assessment, neurological examination, neuroimaging, and standardized questionnaires. Given the small sample size, analysis focused on clinical characterization rather than statistical inference. Thirteen patients (10 males, mean age 24.3 ± 4.1 years) had used natural cannabis (69.2%) or synthetic cannabinoids (30.8%). Visual snow was universal (100%), with high rates of trailing phenomena (92.3%), halos (84.6%), and color changes (76.9%). A novel finding was the presence of auditory hypersensitivity in 61.5% of patients. Symptoms emerged at a mean of 3.2 ± 2.4 weeks following cannabis cessation. All neurological investigations were normal. Comorbid anxiety disorders were present in 84.6% of patients; functional impairment was severe in 30.8%, moderate in 46.2%, and mild in 23.1%. This exploratory study describes persistent multimodal sensory disturbances in patients after cannabis exposure. Consistent visual snow, frequent auditory hypersensitivity, and normal neurological investigations suggest a distinct phenotype warranting systematic investigation. While preliminary and requiring validation in larger samples, these findings highlight a potentially underrecognized cannabis complication meriting clinical attention.