Formation of marine oil snow by soot particles generated from burning of oils.

This study aims to investigate the interactions between marine oil snow (MOS) formation and soot particles derived from two distinct oils: condensate and heavy oil. Experimental findings demonstrate that the properties of oil droplets and soot particles play a key role in MOS formation. Peak MOS formation is observed within the initial days for condensate, while for heavy oil, peak formation occurs at a later stage. Furthermore, the addition of oils and soot particles influences the final concentrations of polycyclic aromatic hydrocarbons (PAHs) in MOS. Remarkably, the ranking order of PAHs with different rings in various MOS samples remains consistent: 4- > 3- > 5- > 2- > 6-ring. Specific diagnostic ratios such as Phe/Ant, Ant/(Ant + Phe), BaA/(Chr + BaA), and LMW/HMW effectively differentiate petrogenic and pyrogenic sources of PAHs in MOS. And stable ratios like Flu/(Pyr + Flu), InP/(InP + BghiP), and BaF/BkF are identified for source analysis of soot MOS.

Light-absorbing impurities in glacial environments over western Himalaya from reanalysis data and in situ observations.

In context with the scientific evidence of aerosol deposition induced snow and glacier melt, this paper provides baseline information about the spatiotemporal variability of aerosols and snow-ice chemistry filling the data and knowledge gap over the western Himalaya, India based on recently published paper [1]. A systematic approach was employed that entailed analysis of aerosol variability over four decades using MERRA-2 (Modern-Era Retrospective analysis for Research and Applications) data over five major mountain ranges in the western Himalaya. Further, data about nine physicochemical parameters was generated over three selected glaciers in the study area. HYSPLIT (HYbrid Single Particle Lagrangian Integrated Trajectory) model simulated air mass sources at weekly intervals. This dataset is valuable for future investigations aimed at understanding and characterizing the impacts of light-absorbing impurities on radiative forcing, albedo changes, snow-melt, glacier recession and water quality in the western Himalaya.

Phenological responses of alpine snowbed communities to advancing snowmelt.

Climate change is leading to advanced snowmelt date in alpine regions. Consequently, alpine plant species and ecosystems experience substantial changes due to prolonged phenological seasons, while the responses, mechanisms and implications remain widely unclear. In this 3-year study, we investigated the effects of advancing snowmelt on the phenology of alpine snowbed species. We related microclimatic drivers to species and ecosystem phenology using in situ monitoring and phenocams. We further used predictive modelling to determine whether early snowmelt sites could be used as sentinels for future conditions. Temperature during the snow-free period primarily influenced flowering phenology, followed by snowmelt timing. Salix herbacea and Gnaphalium supinum showed the most opportunistic phenology, while annual Euphrasia minima struggled to complete its phenology in short growing seasons. Phenological responses varied more between years than sites, indicating potential local long-term adaptations and suggesting these species' potential to track future earlier melting dates. Phenocams captured ecosystem-level phenology (start, peak and end of phenological season) but failed to explain species-level variance. Our findings highlight species-specific responses to advancing snowmelt, with snowbed species responding highly opportunistically to changes in snowmelt timings while following species-specific developmental programs. While species from surrounding grasslands may benefit from extended growing seasons, snowbed species may become outcompeted due to internal-clock-driven, non-opportunistic senescence, despite displaying a high level of phenological plasticity.

Marine bacteria Alteromonas spp. require UDP-glucose-4-epimerase for aggregation and production of sticky exopolymer.

The physiology and ecology of particle-associated marine bacteria are of growing interest, but our knowledge of their aggregation behavior and mechanisms controlling their association with particles remains limited. We have found that a particle-associated isolate, Alteromonas sp. ALT199 strain 4B03, and the related type-strain A. macleodii 27126 both form large (>500 µm) aggregates while growing in rich medium. A non-clumping variant (NCV) of 4B03 spontaneously arose in the lab, and whole-genome sequencing revealed a partial deletion in the gene encoding UDP-glucose-4-epimerase (galEΔ308-324). In 27126, a knock-out of galE (ΔgalE::kmr) resulted in a loss of aggregation, mimicking the NCV. Microscopic analysis shows that both 4B03 and 27126 rapidly form large aggregates, whereas their respective galE mutants remain primarily as single planktonic cells or clusters of a few cells. Strains 4B03 and 27126 also form aggregates with chitin particles, but their galE mutants do not. Alcian Blue staining shows that 4B03 and 27126 produce large transparent exopolymer particles (TEP), but their galE mutants are deficient in this regard. This study demonstrates the capabilities of cell-cell aggregation, aggregation of chitin particles, and production of TEP in strains of Alteromonas, a widespread particle-associated genus of heterotrophic marine bacteria. A genetic requirement for galE is evident for each of the above capabilities, expanding the known breadth of requirement for this gene in biofilm-related processes. IMPORTANCE: Heterotrophic marine bacteria have a central role in the global carbon cycle. Well-known for releasing CO2 by decomposition and respiration, they may also contribute to particulate organic matter (POM) aggregation, which can promote CO2 sequestration via the formation of marine snow. We find that two members of the prevalent particle-associated genus Alteromonas can form aggregates comprising cells alone or cells and chitin particles, indicating their ability to drive POM aggregation. In line with their multivalent aggregation capability, both strains produce TEP, an excreted polysaccharide central to POM aggregation in the ocean. We demonstrate a genetic requirement for galE in aggregation and large TEP formation, building our mechanistic understanding of these aggregative capabilities. These findings point toward a role for heterotrophic bacteria in POM aggregation in the ocean and support broader efforts to understand bacterial controls on the global carbon cycle based on microbial activities, community structure, and meta-omic profiling.

Modeling Habitat Suitability of Snow Leopards in Yanchiwan National Reserve, China.

Snow leopards (Panthera uncia) are elusive predators inhabiting high-altitude and mountainous rugged habitats. The current study was conducted in the Yanchiwan National Nature Reserve, Gansu Province, China, to assess the habitat suitability of snow leopards and identify key environmental factors inducing their distribution. Field data collected between 2019 and 2022 through scat sampling and camera trapping techniques provided insights into snow leopard habitat preferences. Spatial distribution and cluster analyses show distinct hotspots of high habitat suitability, mostly concentrated near mountainous landscapes. While altitude remains a critical determinant, with places above 3300 m showing increased habitat suitability, other factors such as soil type, human footprint, forest cover, prey availability, and human disturbance also play important roles. These variables influence ecological dynamics and are required to assess and manage snow leopard habitats. The MaxEnt model has helped us to better grasp these issues, particularly the enormous impact of human activities on habitat suitability. The current study highlights the importance of altitude in determining snow leopard habitat preferences and distribution patterns in the reserve. Furthermore, the study underscores the significance of considering elevation in conservation planning and management strategies for snow leopards, particularly in mountainous regions. By combining complete environmental data with innovative modeling tools, this study not only improves local conservation efforts but also serves as a model for similar wildlife conservation initiatives around the world. By understanding the environmental factors driving snow leopard distribution, conservation efforts can be more efficiently directed to ensure the long-term survival of this endangered species. This study provides valuable insights for evidence-based conservation efforts to safeguard the habitats of snow leopards amidst emerging anthropogenic pressure and environmental fluctuations.

Identification of tritium-contaminated areas using a tritium survey on the snow cover, the case of Semipalatinsk test site.

The article presents research findings on the content of tritium in the snow cover of test locations 'Balapan' and 'Sary-Uzen' in the territory of the Semipalatinsk Test Site. Based upon results, a number of tritium-contaminated areas were revealed. At the 'Balapan' site, elevated tritium concentrations in the snow were revealed in the vicinity of the 'Atomic lake' close to the 'Karazhyra' deposit and at the location of Lake 'Kishkensor'. At the 'Sary-Uzen' site, elevated tritium concentrations in the snow were discovered near borehole 101, at object 'Lazurite' and at an unnamed creek outflowing from the mountain range. Maximal of tritium activity concentration in the snow were 45 Bq/kg and 36 Bq/kg at the 'Balapan' and 'Sary-Uzen' sites, respectively. Background tritium concentrations in the snow cover of the STS territory were found to be 4.6-12 Bq/kg.

Traumatic Triceps and Medial Ulnar Collateral Ligament Rupture in an Adolescent Mogul Skier: A Case Report.

Triceps tendon ruptures are uncommon injuries that account for less than 1% of all upper extremity tendon injuries. Medial ulnar collateral ligament injury (mUCL), while common in overhead athletes as a result of valgus forces during the throwing mechanics, has scarcely been reported in non-overhead, throwing individuals. Traumatic assault to the elbow may result in the rupture of the triceps tendon with concomitant mUCL injury. As such an injury pattern typically presents in middle-aged males, weightlifters, or American football players from eccentric overloading of the elbow. We present an adolescent, elite-level, competitive skier with traumatic onset distal triceps rupture with concomitant medial ulnar collateral ligament rupture suffered via a fall on an outstretched hand (FOOSH) mechanism. Magnetic resonance imaging (MRI) showed acute full-thickness avulsion of the distal triceps tendon occurring at the olecranon enthesis. An open tendon repair was performed, and the patient was able to report significant symptom resolution over the course of six months postoperatively and successfully return to elite-level competition. This was a unique and rare case of triceps tendon rupture with concomitant mUCL injury in an adolescent via a non-contact, high-velocity injury mechanism. While a rare injury combination, this case nevertheless identifies an area of research not currently extensively covered-trampoline training and associated injuries in adolescents. This case, therefore, not only adds a novel dimension to the understanding of triceps and mUCL injuries in young athletes but also underscores the need for heightened awareness and specific safety protocols in sports training involving equipment like trampolines.

Global systematical and comprehensive overview of mountainous flood risk under climate change and human activities.

Snow-covered mountainous regions are crucial for the hydrologic cycle. Any changes in the cryosphere are critical and directly impact the hydrologic cycle and socio-environment of the downstream. It is likely to occur more extreme events of precipitations, raising the risk of flooding worldwide. Glacier melting is increasing, thus the formation of the moraine-dammed lake called glacial lake, whose outburst may be a catastrophic disaster. Due to steep topography, flash floods with high energy can sweep away infrastructure, electric power stations, property, and livelihood and even change the channel morphology, hence the whole environment. In this article, we present the causes of flooding in mountainous regions and historical trends of mountainous flooding and its management policies. Carbon emission is a driver to increase the temperature of the globe and which is triggering the flash floods in mountainous regions is illustrated using data from different sources. The discussion section includes how technology helps to achieve a climate-resilient environment. Understanding river morphology, mapping and monitoring risks, and simulating essential natural processes are necessary for reducing the cascading hazards in the mountains. There is still a gap in modern data collection techniques in mountainous regions. More advanced technology for regional and global collaborations, climate change adaption, and public awareness can build the climate resilience cryosphere.

Understanding the hydrological performance of green and grey roofs during winter in cold climate regions.

Green and grey roofs have emerged as promising and sustainable measures for effectively managing stormwater in urban catchments. However, there is a gap in the literature in understanding and modelling the hydrological performance of these roofs during winter and snow-covered periods in cold climate regions. The present study attempted to address this gap by validating the use of a snow module in simulating the dynamics of snow accumulation and melting of green and grey roofs. Then, the validated model was used to identify and separate the different events that occur in winter (melt only, rainfall only, rain-on-snow) to assess the hydrological performance of six different configurations of green and grey roofs in Trondheim, Norway. The snow module accurately simulated snow accumulation and melting of green and grey roofs. The results showed that rain-on-snow events in winter have longer duration compared to other events including rainfall events in summer. Consequently, rain-on-snow events yield a higher amount of inflow to the roofs compared to rainfall events in summer, despite summer events having higher intensities. The retention and detention performances of green and grey roofs were found to be lowest for rain-on-snow events compared to other types of events, but still yielding significantly lower peak runoffs when compared to standard black roofs. The decrease in retention and detention performances in winter were attributed to the long duration of events, accumulation effect of snow, freezing of roof surface layers, and reduction of evapotranspiration. The study highlights the importance of considering winter conditions in the design of green and grey roofs in cold climates to enhance stormwater management.

Concentration and risk assessment of metals in snow cover monitoring in urban and rural areas.

INTRODUCTION AND OBJECTIVE: Snow cover serves as a unique indicator of environmental pollution in both urban and rural areas. As a seasonal cover, it accumulates various pollutants emitted into the atmosphere, thus providing insight into air pollution types and the relative contributions of different pollution sources. The aim of the study is to analyze the distribution of trace elements in snow cover to assess the anthropogenic influence on pollution levels, and better understand ecological threats. MATERIAL AND METHODS: The study was conducted in rural areas around the village of Wólka in the Lublin Province of eastern Poland, and in urban districts of the city of Lublin, capital of the Province. Samples were analyzed using Inductively Coupled Plasma-Mass Spectrometry, the Enrichment Factor (EF), and ecological risk indices (RI), were calculated to evaluate the contamination and potential ecological risks posed by the metals. RESULTS: The findings indicate higher concentrations of metals like sodium and iron in urban areas, likely due to road salt use and industrial activity, respectively. Enrichment factors showed significant anthropogenic contributions, particularly for metals like sodium, zinc, and cadmium, which had EF values substantially above natural levels. The potential ecological risk assessment highlighted a considerable ecological threat in urban areas compared to rural settings, primarily due to higher concentrations of metals. CONCLUSIONS: The variation in metal concentrations between urban and rural snow covers reflects the impact of human activities on local environments. Urban areas showed higher pollution levels, suggesting the need for targeted pollution control policies to mitigate the adverse ecological impacts. This study underscores the importance of continuous monitoring and comprehensive risk assessments to effectively manage environmental pollution.

Temperature dependence of the rain-gas and snow-gas partition coefficients for nearly a thousand chemicals.

Compared to the particle-gas partition coefficients (KPG), the rain-gas (KRG) and snow-gas (KSG) partition coefficients are also essential in studying the environmental behavior and fate of chemicals in the atmosphere. While the temperature dependence for the KPG have been extensively studied, the study for KRG and KSG are still lacking. Adsorption coefficients between water surface-air (KIA) and snow surface-air (KJA), as well as partition coefficients between water-air (KWA) and octanol-air (KOA) are vital in calculating KRG and KSG. These four basic adsorption and partition coefficients are also temperature-dependent, given by the well-known two-parameters Antoine equation logKXY = AXY + BXY/T, where KXY is the adsorption or partition coefficients, AXY and BXY are Antoine parameters (XY stand for IA, JA, WA, and OA), and T is the temperature in Kelvin. In this study, the parameters AXY and BXY are calculated for 943 chemicals, and logKXY can be estimated at any ambient temperature for these chemicals using these Antoine parameters. The results are evaluated by comparing these data with published experimental and modeled data, and the results show reasonable accuracy. Based on these coefficients, temperature-dependence of logKRG and logKSG is studied. It is found that both logKRG and logKSG are linearly related to 1/T, and Antoine parameters for logKRG and logKSG are also estimated. Distributions of the 943 chemicals in the atmospheric phases (gas, particle, and rain/snow), are illustrated in a Chemical Space Map. The findings reveal that, at environmental temperatures and precipitation days, the dominant state for the majority of chemicals is the gaseous phase. All the AXY and BXY values for logKSG, logKRG, and basic adsorption and partition coefficients, both modeled by this study and collected from published work, are systematically organized into an accessible dataset for public utilization.

Efficacy of multicomponent interventions on injury risk among ice and snow sports participants-a systematic review and meta-analysis.

BACKGROUND: Ice and snow sports, which are inherently high risk due to their physically demanding nature, pose significant challenges in terms of participant safety. These activities increase the likelihood of injuries, largely due to reduced bodily agility and responsiveness in cold, often unpredictable winter environments. The critical need for effective injury prevention in these sports is emphasized by the considerable impact injuries have on the health of participants, alongside the economic and social costs associated with medical and rehabilitative care. In the context of ice and snow sports environments, applying the E principles of injury prevention to evaluate intervention measures can guide the implementation of future sports safety and other health promotion intervention measures in this field. When well executed, this approach can substantially reduce both the frequency and severity of injuries, thereby significantly enhancing the safety and long-term viability of these challenging sports. OBJECTIVE: The objective of this study was to rigorously assess and statistically substantiate the efficacy of diverse injury prevention strategies in ice and snow sports, aiming to bolster future safety measures with solid empirical evidence. DESIGN: Systematic review and meta-analysis. METHODS: The overarching aim of this research was to meticulously aggregate and scrutinize a broad spectrum of scholarly literature, focusing on the quantifiable efficacy of diverse, multicomponent intervention strategies in mitigating the incidence of injuries within the realm of ice and snow sports. This endeavour entailed an exhaustive extraction of data from esteemed academic databases, encompassing publications up to September 30, 2023. In pursuit of methodological excellence and analytical rigor, the study employed advanced bias assessment methodologies, notably the AMSTAR 2 and GRADE approaches, alongside sophisticated random-effects statistical modelling. This comprehensive approach was designed to ensure the utmost validity, reliability, and scholarly integrity of the study's findings. RESULTS: Fifteen papers, including 9 randomized controlled trials, 3 case‒control studies, and 3 cohort studies with 26,123 participants and 4,382 injuries, were analysed. The findings showed a significant reduction in injury rates through various interventions: overall injury prevention (RR = 0.50, 95% CI 0.42-0.63), educational training (RR = 0.50, 95% CI 0.34-0.73), educational videos (RR = 0.53, 95% CI 0.34-0.81), protective equipment (RR = 0.64, 95% CI 0.46-0.87), and policy changes (RR = 0.28, 95% CI 0.16-0.49). Subgroup analysis revealed potential heterogeneity in compliance (p = 0.347). Compared to controls, multicomponent interventions effectively reduced injury rates. CONCLUSION: This systematic review and meta-analysis demonstrated that multicomponent interventions significantly prevent injuries in ice and snow sports. By applying the E principles of injury prevention and constructing a framework for practical injury prevention research in ice and snow sports, we can gradually shift towards a systemic paradigm for a better understanding of the development and prevention of sports injuries. Moreover, sports injury prevention is a complex and dynamic process. Therefore, high-quality experiments in different scenarios are needed in future research to provide more reliable evidence, offer valuable and relevant prevention information for practitioners and participants, and help formulate more effective preventive measures in practice.

Long-Read-Based Hybrid Genome Assembly and Annotation of Snow Algal Strain CCCryo 101-99 (cf. Sphaerocystis sp., Chlamydomonadales).

Polar regions harbor a diversity of cold-adapted (cryophilic) algae, which can be categorized into psychrophilic (obligate cryophilic) and cryotrophic (nonobligate cryophilic) snow algae. Both can accumulate significant biomasses on glacier and snow habitats and play major roles in global climate dynamics. Despite their significance, genomic studies on these organisms remain scarce, hindering our understanding of their evolutionary history and adaptive mechanisms in the face of climate change. Here, we present the draft genome assembly and annotation of the psychrophilic snow algal strain CCCryo 101-99 (cf. Sphaerocystis sp.). The draft haploid genome assembly is 122.5 Mb in length and is represented by 664 contigs with an N50 of 0.86 Mb, a Benchmarking Universal Single-Copy Orthologs (BUSCO) completeness of 92.9% (n = 1,519), a maximum contig length of 5.3 Mb, and a guanine-cystosine (GC) content of 53.1%. In total, 28.98% of the genome (35.5 Mb) contains repetitive elements. We identified 417 noncoding RNAs and annotated the chloroplast genome. The predicted proteome comprises 14,805 genes with a BUSCO completeness of 97.8%. Our preliminary analyses reveal a genome with a higher repeat content compared with mesophilic chlorophyte relatives, alongside enrichment in gene families associated with photosynthesis and flagella functions. Our current data will facilitate future comparative studies, improving our understanding of the likely response of polar algae to a warming climate as well as their evolutionary trajectories in permanently cold environments.

Comparative analysis of bacterial diversity in accumulated snow and exposed sediments across Antarctic Islands.

The Antarctic continent hosts exceptional niches, making it an ideal environment for studying polyextremophilic microorganisms. These organisms are uniquely shaped by the geographic niches and variations in soil types. Here we present, a culture-independent approach using DNA metabarcoding to assess the bacterial communities associated with accumulated snow and exposed sediments across different Antarctic islands situated in the Larsemann Hills, Antarctica. The exposed sediments (ES) were found to be more diverse than the accumulated snow (AS) sediments as represented by the alpha diversity metrics. Out of the total 303 amplicon sequence variants (ASVs) found at the genus level, 93 were unique to accumulated snow sediments and 97 were unique to exposed sediments. The bacterial community composition in accumulated snow was dominated by the phylum Actinobacteriota (24.7%). However, Pseudonocardia (11.9%), Crossiella (11%), and Rhodanobacter (9.1%) were the predominant genera. In contrast, in the exposed sediments, Bacteroidota (24.6%) was the most prevalent phylum, with Crossiella (17.1%), Rhodanobacter (11.1%), and Blastocatella (10%) as the most abundant genera. Metagenomic imputations revealed the abundance of gene families responsible for carbon metabolism, coping with environmental stresses through DNA repair mechanisms, and carbon fixation.

The Pressure of Headache at the United Kingdom CSF Disorders Day 2023.

Headache in intracranial disorders drives significant disability in our patients. Management principles for secondary headaches require a multidisciplinary approach with expertise from the neurological, neuro-ophthalmological, neuroradiological, and neurosurgical specialities. The Pressure of Headache was the theme of the annual United Kingdom CSF Disorders Day and saw speakers and panellists from Australia, Europe, and the United States. Among the topics presented were the newest concepts underpinning idiopathic intracranial hypertension management and spontaneous intracranial hypotension. Advances in our knowledge of cerebrospinal fluid secretion and the visual snow syndrome debate were particular highlights. This review provides a summary of the research on headache disorders that overlap the neuro-ophthalmological axis of care for patients.

Using the Sensible Heat Flux Eddy Covariance-Based Exchange Coefficient to Calculate Latent Heat Flux from Moisture Mean Gradients Over Snow.

In absence of the high-frequency measurements of wind components, sonic temperature and water vapour required by the eddy covariance (EC) method, Monin-Obukhov similarity theory (MOST) is often used to calculate heat fluxes. However, MOST requires assumptions of stability corrections and roughness lengths. In most environments and weather situations, roughness length and stability corrections have high uncertainty. Here, we revisit the modified Bowen-ratio method, which we call C-method, to calculate the latent heat flux over snow. In the absence of high-frequency water vapour measurements, we use sonic anemometer data, which have become much more standard. This method uses the exchange coefficient for sensible heat flux to estimate latent-heat flux. Theory predicts the two exchange coefficients to be equal and the method avoids assuming roughness lengths and stability corrections. We apply this method to two datasets from high mountain (Alps) and polar (Antarctica) environments and compare it with MOST and the three-layer model (3LM). We show that roughness length has a great impact on heat fluxes calculated using MOST and that different calculation methods over snow lead to very different results. Instead, the 3LM leads to good results, in part due to the fact that it avoids roughness length assumptions to calculate heat fluxes. The C-method presented performs overall better or comparable to established MOST with different stability corrections and provides results comparable to the direct EC method. An application of this method is provided for a new station installed in the Pamir mountains. Supplementary Information: The online version contains supplementary material available at 10.1007/s10546-024-00864-y.

Death Following a Skiing Incident: Severe Exsanguination Due to Rupture of the Left Renal Artery.

With the growing popularity of winter sports, it is necessary to pay more attention to the types of traumatic injuries that a person can sustain in various incidents related to their practice. We present a case in which an adult man died as a result of a collision with a tree while skiing. Although the deaths are associated with different types and severity of craniocerebral injuries in the majority of the cases, here we are dealing with an abdominal injury with rupture of the stomach, pancreas, and left renal artery. The exact localization of the resulting traumatic injuries and the mechanism of their occurrence were examined. Both macroscopic autopsy findings (gross pathology) and histologically proven ones are presented and described. Presenting this case, we want to raise awareness of the different types of injuries received while skiing, as well as to emphasize the possibility of death in the absence of visible external injuries over the victim's body.

The analysis of ecological security and tourist satisfaction of ice-and-snow tourism under deep learning and the Internet of Things.

This paper aims to propose a prediction method based on Deep Learning (DL) and Internet of Things (IoT) technology, focusing on the ecological security and tourist satisfaction of Ice-and-Snow Tourism (IST) to solve practical problems in this field. Accurate predictions of ecological security and tourist satisfaction in IST have been achieved by collecting and analyzing environment and tourist behavior data and combining with DL models, such as convolutional and recurrent neural networks. The experimental results show that the proposed method has significant advantages in performance indicators, such as accuracy, F1 score, Mean Squared Error (MSE), and correlation coefficient. Compared to other similar methods, the method proposed improves accuracy by 3.2%, F1 score by 0.03, MSE by 0.006, and correlation coefficient by 0.06. These results emphasize the important role of combining DL with IoT technology in predicting ecological security and tourist satisfaction in IST.