Search Results (4,124)

Wind energy is an important form of clean energy, and its rational utilization represents a crucial solution for mitigating the energy crisis and global warming. In this study, wind energy potential and its long-term changes in the South China Sea (SCS) are evaluated using ERA5 100 m wind data from 1944 to 2023, validated against ASCAT observations. High wind speeds and high wind power density (WPD) are concentrated southwest of Taiwan and southeast of Vietnam. Annual wind availability exceeds 6457 h across most regions, reaching up to 8283 h in optimal locations. WPD and capacity factor peak in winter (up to 2.4 × 10⁸ Wh·m⁻² and >50% capacity factor), with the most stable conditions occurring in the southwestern Taiwan Strait, southeast of the Pearl River Delta, and the Beibu Gulf. Empirical orthogonal function analysis reveals that the first mode of winter WPD accounts for 65.7% of the total variance, with a statistically significant increasing trend since 1990. The interannual variation in wind energy resources in the SCS during winter is controlled by the combined effects of sea surface temperature (SST) anomalies in the tropical Pacific and the Arctic Barents Sea. Specifically, in the years with strong wind anomalies in the SCS, mega-La Niña-type SST patterns in the tropical Pacific trigger anomalous cyclonic circulation in the SCS and the eastern Philippine Sea, while warm anomalies in the Arctic Barents Sea surface drive a wave-like structure of “anticyclone–cyclone–anticyclone” from Siberia to South China. The coupling of the two systems jointly promotes the strengthening of the South China Sea monsoon, leading to increased wind speeds and elevated WPD in the northern SCS. These findings provide a scientific basis for wind farm siting and long-term operational planning in the region. Full article

In Norway, children are entitled to all individual and collective rights under the UN Convention on the Rights of the Child (CRC), while parents play an important role in facilitating access to these rights. However, conflicts may arise when a teenager’s right to freedom of association clashes with their parents’ religious beliefs and identity. This article studies the ontological (in)security challenge faced by Muslim parents in Norway when their teenage children choose to participate in confirmation rites. The article explores how Muslim parents navigate the tension between their responsibility to pass on religious beliefs and identity to their children and their children’s assertion of the right to freedom of association with peer groups. The study is based on a pilot survey of Muslim parents whose children participated in confirmation rites at the Norwegian Humanist Association (NHA). Full article

Rivers are a key pathway for the transport of plastics into the ocean. Studies of plastic pollution in Arctic rivers remain limited due to the inaccessibility of sampling sites and work in extreme weather conditions. This work presents the results of a three-year (2019–2021) survey of floating large microplastics (0.5–5 mm) and meso/macroplastics (>5 mm) in the Northern Dvina River, an actively navigated river that drains a densely populated region into the White Sea. Sampling was conducted during the ice-free periods (May–October) along a ∼3.5 km transect using a Neuston net, providing a multi-year dataset spanning three ice-free seasons. A critical methodological advancement was the calculation of plastic river–sea flux using the discharge of the sampled surface layer (upper 20 cm), which constitutes only ∼3% of the river’s total discharge, rather than the total discharge itself. Observed microplastic concentrations (average 0.003 items ${\mathrm{m}}^{-3}$) were low compared to many European rivers, and lower than those reported in the adjacent Barents and Kara Seas. Microplastic abundance was significantly lower during the high-water season than during the low-water season, which resulted in practically no seasonal variability in microplastic fluxes from the river to the White Sea (average 0.3 items ${\mathrm{s}}^{-1}$). A notable finding was that in some cases, meso/macroplastics outnumbered microplastics by item count, underscoring the river’s role as a significant source of larger plastic debris. A geospatial assessment of Arctic rivers’ pollution potential was performed, using socio-economic indicators such as near-delta population density and port activity. This study identified the Northern Dvina River as a major contributor of microplastics among the Arctic rivers. Full article

Arctic sea ice is a critical indicator of global climate dynamics, directly influencing maritime navigation, polar biodiversity, and offshore engineering safety. The precise mapping of diverse ice types, such as frazil ice, slush, melt ponds, and open water, is essential for environmental monitoring; however, it remains a formidable challenge in satellite remote sensing. These difficulties arise from low-contrast imagery, overlapping spectral signatures, and the subtle textural nuances characteristic of polar regions. Traditional entropy-based thresholding techniques often falter when segmenting these complex scenes, as they typically rely on Gaussian distribution assumptions that do not align with the stochastic nature of Arctic data. To address these limitations, this paper presents a novel unsupervised segmentation framework based on symmetric cross-entropy (SCE). Unlike standard directional measures, SCE provides a more robust objective function for multi-level thresholding by simultaneously maximizing intra-class cohesion and minimizing inter-class ambiguity. The proposed method uses an optimized search strategy to identify intensity levels that best delineate complex Arctic features. We conducted an extensive entropy-based comparative study that benchmarked SCE against 25 state-of-the-art entropy measures, including Shannon, Kapur, Rényi, Tsallis, and Masi entropies. Our experimental results demonstrate that the SCE method: (i) achieves superior accuracy by consistently outperforming established models in segmentation precision and boundary definition; (ii) provides visual clarity by producing segments with significantly reduced noise, making them ideal for identifying small-scale melt ponds and slush zones; and (iii) demonstrates computational robustness by providing stable threshold values even in datasets with non-Gaussian class distributions and poor illumination. Ultimately, these improvements deliver high-quality ice feature data that enhance risk assessment, operational planning, and predictive modeling. This research marks a major step forward in Arctic sea studies and introduces a valuable new tool for wider image processing and computer vision communities. Full article

The Arctic region holds immense strategic value in terms of scientific expedition, maritime transportation, and resource development, which makes reliable and secure satellite navigation services in this area crucial. This study first calculates and analyzes key performance indicators of BeiDou System (BDS). These indicators include the number of visible satellites, Position Dilution of Precision (PDOP) values, and observation elevation angles at typical monitoring points in the Arctic region. To improve BDS’s coverage capabilities and further enhance its contribution to global satellite navigation in the Arctic region, two methods are proposed in this paper: (1) to introduce regional services such as PPP, SABS and a regional short message service to BDS Inclined Geosynchronous Orbit (IGSO) satellites and (2) to increase the inclination angle of BDS IGSO satellites to 60 degrees. A comparative analysis between the proposed design and the existing system was conducted. The results show that: (1) utilizing IGSO satellites for regional services can significantly improve coverage in the Arctic region, and (2) adjusting the IGSO satellite inclination to 60 degrees could enhance the performance of BDS’s Radio Navigation Satellite Service (RNSS) and other regional services. Full article

The effects of environmental factors on zooplankton within the marginal ice zone (MIZ) of the Barents Sea remain poorly understood. To address this knowledge gap, we investigated mesozooplankton communities across the central, northern, and northeastern regions in April 2016. Abundance and biomass ranged from 90 to 997 individuals m⁻³ and from 1.1 to 48.6 mg dry mass m⁻³ (0.3 to 13.6 g dry mass m⁻²), respectively. Oithona similis was the most abundant taxon, while calanoid copepods, including Calanus spp., Metridia longa, and Pseudocalanus spp., dominated total biomass. The spatial distribution of mesozooplankton communities was closely linked to the physical properties of water masses. Cluster analysis identified two distinct assemblages associated with Polar Front Water and Arctic Water. Redundancy analysis and generalized linear models identified temperature, mean salinity, mean chlorophyll a concentration, and sea ice concentration as significant predictors of abundance and biomass. The dominance of older life stages within major copepod taxa indicated a winter status for the mesozooplankton community. Regional and temporal comparisons of mesozooplankton biomass with prior May–June data from central and northwestern areas highlighted higher productivity in the northern and northeastern MIZ. This increase is potentially related to the warming trends observed in the Arctic since the 2000s. Our research provides novel insights into Arctic marine zooplankton assemblages and serves as a valuable baseline for future ecological monitoring and modeling of the Barents Sea ecosystem in the context of global climate change. Full article

This study investigates the transformation of river runoff and its sensitivity to changes in large-scale atmospheric circulation in the Zhaiyk–Caspian water management basin during the period of 1951–2023. The analysis is based on hydrometeorological observations data, the Vangengeim–Girs classification of macro-circulation patterns, and the Arctic Oscillation (AO) and North Atlantic Oscillation (NAO) indices. Correlation analysis, the Mann–Kendall test, Sen’s slope estimator, and the Pettitt test were applied to identify trends, structural shifts, and the spatial coherence of hydroclimatic changes. The results show that interannual variability in river runoff is characterized by a degree of spatial coherence, with correlation coefficients between annual streamflow records at most gauging stations reaching up to 0.95. It is demonstrated that the most pronounced changes in the hydrological regime occur during the cold season and are expressed in a statistically significant increase in winter runoff, while no significant long-term trend in annual runoff is observed. Structural shifts in winter runoff are predominantly associated with the late 1990s, whereas changes in the temperature regime are detected earlier and exhibit spatial coherence. The findings indicate that the contemporary transformation of river runoff is primarily driven by rising air temperatures and the associated intra-annual redistribution of flow. Full article

Background/Objectives: Accurate ploidy determination is essential for understanding population structure and evolutionary history for breeding and domestication. The Chrysanthemum arcticum (Arctic daisy) complex, comprising C. arcticum and subspecies arcticum and polaré, exhibits variability in ploidy variation with reports ranging from diploid (2n = 2x = 18) to octoploid (2n = 8x = 72). Methods: The objective of this study was to assess ploidy levels in n = 225 genotypes from n = 46 wild, native populations of the three taxa collected across mainland Alaska, Attu Island (Alaska), and Hudson Bay (Canada) using flow cytometry, and using C. nankingense (2n = 2x = 18) as the diploid reference. Results: Genome sizes were from 5.27 to 20.69 pg (2C), corresponding to diploid through hexaploid. Triploids were the most frequent (64%) before, as well as after, applying the reference standard bias (10% correction). All ploidy levels were present in multiple geographic regions, with no clear spatial, taxonomic, or latitudinal segregation. The high incidence of triploids, most of which were self-compatible and highly fertile, may reflect genetic instability, underlying aneuploidy (which is common in several Chrysanthemum polyploids), or systematic bias from reference standard differences. Inconsistencies between flow cytometry estimates and observed reproductive compatibility, such as successful crossings with known diploids, suggest additional genomic complexity. Potential historical influences creating genomic instability, including environmental disturbances (chemical, radiation warfare remnants) from World War II military activities at Attu Island and Hudson Bay, are discussed. Conclusions: This study shows the challenges of accurately determining ploidy levels in the C. arcticum trifecta complex and highlights the need for other approaches, including high-density SNP genotyping and chromosome imaging, to resolve ploidy questions and guide future breeding strategies. Full article

Merkel Cell Polyomavirus is an oncogenic virus associated with Merkel Cell Carcinoma (MCC). However, considering viral detection in respiratory specimens and similarities between MCC and neuroendocrine lung cancer, its plausible role in the respiratory tract is disputed. MCPyV-mediated oncogenesis involves viral antigens interfering with host signaling as a DNA Damage Response (DDR). In the current study, respiratory models, including lung cancer cell lines (A549 and H1299), and non-malignant bronchial systems (HBEC-KT and a 2D ALI model) were used to investigate DDR genes’ expression following MCPyV infection. Once the capability to support viral replication and transcription was assessed using qPCR and RT-qPCR, respectively, the mRNA levels of DDR genes, including ATM, ATR, Chk1, Chk2, H2AX, Rad51, p53 and p21, were examined. Our findings showed MCPyV replication in all cellular systems, as proven by the detection of viral DNA and transcripts. Viral infection induced an overexpression of DDR genes, suggesting a role of the virus in manipulating DDR to favor its replication or contribute to tumor progression. These preliminary results provide in vitro models for studying the interplay between MCPyV and DDR within malignant and non-malignant contexts across the respiratory tract, laying the basis for future research exploring the clinical relevance of DDR activation in virus-driven malignancies. Full article

During a study of cyanobacterial colonization on coal ash dumps at the Apatity Thermal Power Plant (Murmansk Region, NW Russia), two strains of Nostoc-like morphotypes were collected, cultivated, and examined using a polyphasic approach. Both strains KPABG–133801 and KPABG–133804 exhibited high similarity in the 16S rRNA gene (99.93%) and identical 16S–23S ITS regions. Phylogenetically, they provided robustly supported affinity to the genus Pseudoaliinostoc, which currently comprises eight species predominantly distributed in Southeast Asia. The similarity of the 16S rRNA gene (95.74–97.25%), the divergence in the 16S–23S ITS rRNA region (18.56–26.28%), and the unique hypothetical secondary structures of conserved helices (D1–D1′, Box–B, V3) strongly suggest that these Arctic strains represent a new species, Pseudoaliinostoc murmanicum, which is described and illustrated in this study. The species forms bright blue-green colonies that gradually turn olive-green with age and is characterized by elongated cells in young trichomes, vegetative cell width of less than 3.2 µm, and the presence of akinetes wider than 3.5 µm. Full article

Background: Undernutrition and cachexia are common in advanced cancer and often linked to systemic inflammation. While inflammation is associated with poorer prognosis, accelerated weight loss, and reduced treatment tolerance, its direct impact on food intake remains insufficiently investigated. Aim: To examine the association between systemic inflammation and energy and protein intake over time in patients with advanced cancer. Methods: A total of 170 patients from the Palliative Radiotherapy and Inflammation Study were included. Nutritional status was assessed using PG-SGA SF. Dietary intake was recorded using repeated 24 h recalls. Systemic inflammation was defined as CRP > 10 mg/L. Mixed linear models were applied to evaluate the association between inflammation energy and protein intake over time. Results: Systemic inflammation (CRP >10 mg/L) was present in 87 (51%) patients and associated with significantly lower energy (−3.6 kcal/kg, p = 0.04) and lower protein intake (−0.25 g/kg, p = 0.003). Patients with inflammation were more often undernourished and had shorter survival. Conclusions: Systemic inflammation is likely associated with clinically relevant reductions in energy and protein intake in advanced cancer. CRP may help identify patients for whom standard nutritional support is insufficient. Full article

Universities play a dual role as sites of learning and as institutions that certify student competence through assessment. The rapid diffusion of generative artificial intelligence (GenAI) challenges this certification function by altering the conditions under which assessment evidence is produced. When powerful AI tools are widely available, grades may increasingly reflect a combination of individual understanding and external cognitive support rather than solely independent competence. This study examines how changes in assessment format interact with GenAI availability to reshape observable performance outcomes in higher education. Using exam grade data from a compulsory undergraduate course delivered over five years (2021–2025; N = 1066), the study exploits a naturally occurring change in assessment conditions as a natural experiment. From 2021 to 2024, the course was assessed using an AI-permissive take-home examination, while in 2025 the assessment shifted to an AI-restricted, supervised in-person examination. Course content, intended learning outcomes, grading criteria, examiner continuity, and the structural design of the examination tasks remained stable across cohorts. The results reveal a pronounced shift in grade distributions coinciding with the format change. Failure rates increased sharply in 2025, mid-range grades declined, and the proportion of top grades remained largely unchanged. Statistical analysis indicates a significant association between examination period and grade outcomes (χ²(5, N = 1066) = 60.62, p < 0.001), with a small-to-moderate effect size (Cramér’s V = 0.24), driven primarily by the increase in failing grades. These findings suggest that AI-permissive and AI-restricted assessment formats may not be measurement-equivalent under conditions of widespread GenAI use. The results raise concerns about construct validity and the credibility of grades as signals of independent competence, while also highlighting tensions between certification credibility and assessment authenticity. Full article

Microplastics (MPs) and microfibres (MFs) are widespread contaminants that are found in natural environments worldwide. Although their presence has been documented in Arctic snow, sea ice and marine systems, data on their occurrence in Greenland glacier surface ice remain limited. Because of their small size, persistence, and mobility, MPs and MFs pose significant risks to both habitats and species, reaching even the most remote areas. Monitoring these environments is crucial for assessing the extent of pollution, while dissemination activities are essential for transferring scientific knowledge to local communities and fostering active engagement in adopting sustainable behaviours. A preliminary survey was conducted on a glacier in Greenland, collecting samples along the routes travelled by the Extreme E staff during the electric off-road racing series expedition in the region. Preliminary results confirmed the presence of MPs and MFs in the study area with high abundances. Fibrous and small-sized microparticles were the most prevalent types detected. The most common synthetic material was polyethylene terephthalate (PET), while natural and regenerated MFs were predominantly cellulosic. A deeper understanding of MP and MF contamination in extreme environments was achieved, highlighting the importance of environmental education and public awareness as key tools in mitigating pollution and promoting sustainable strategies. The integration of different sectors can synergistically promote sustainability efforts and address the urgent challenges of climate change and environmental pollution. Full article

Waterfalls are common natural heritage objects. Their assessments often focus on physical properties of waterfalls and/or visitors’ judgments. However, local conditions determining the visibility of waterfalls also matter. These conditions can be understood as visual accessibility. It is proposed to assess the latter semi-quantitatively regarding physical availability of different views of waterfalls, the scalability of these views, opportunities for taking natural photographs and recreation, seasonality, the presence of physical barriers for observation, the influence of natural shadows, and the presence of safety challenges. The assessment procedure is objective because it deals with real landscape peculiarities and not with perceived aesthetics. Several small waterfalls visited by crowds of tourists in two different regions of Russia were used to exemplify the proposed approach. It was established that the Risyoksky and Batareysky waterfalls in the Murmansk Region (Russian Arctic) have limited visual accessibility, and that of the Sakhraysky, Oselkovy, and Filimonova waterfalls in the Republic of Adygeya (Russian South) is moderate. Generally, visual accessibility complicates the perception of waterfalls, and the outcomes of its assessment hold practical importance in natural heritage and tourism management. Full article

Freezing cold injury (FCI) is a localized injury caused by prolonged exposure to sub-zero temperatures, posing a significant health risk to military personnel operating in extreme climates. This study aimed to explore how FCI affects the health and lives of soldiers in the Norwegian Armed Forces (NAF), addressing the broader context of its impact on military readiness and the personnel’s well-being. Sixteen participants with a history of grade 2 FCI were recruited through the Norwegian Armed Forces Health Registry and interviewed. Systematic content analysis was used to identify key themes related to the causes and consequences of FCI, as well as the influence of military culture. The findings indicate that FCI results from interacting environmental, behavioural, and systemic factors. Environmental contributors included cold exposure and limited opportunities to eat or drink. Behavioural and individual contributors included reduced awareness of bodily cues in cold conditions and the need to remove gloves for weapon handling under time pressure. Systemic contributors, particularly military cultural norms emphasizing strict discipline and toughness, were perceived to discourage early symptom reporting and the use of preventive measures. Most participants (11/16) reported long-term consequences, including chronic physical discomfort, functional limitations, and negative impacts on their careers and daily lives. This study highlights the significant short- and long-term consequences of FCI, which extend beyond physical harm to affect soldiers’ overall health, functioning, and career progression. The findings emphasize the need for targeted preventive measures to mitigate the risks of FCI and protect military personnel in extreme climates. Full article