Search Results (916)

The response of Arctic vegetation to climate warming exhibits pronounced spatial heterogeneity, driven partly by widespread permafrost degradation. However, the role of thermokarst lake development in mediating vegetation-climate interactions remains poorly understood, particularly across heterogeneous landscapes of northeastern Siberia. This study integrated multi-source remote sensing data (2001–2021) with trend analysis, partial correlation, and a Shapley Additive Explanation (SHAP)-interpreted random forest model to examine the drivers of normalized difference vegetation index (NDVI) variability across five levels of thermokarst lake coverage (none, low, moderate, high, very high) and two vegetation types (forest, tundra). The results show that although greening dominates the region, browning is disproportionately observed in areas with high thermokarst lake coverage (>30%), highlighting the localized reversal of regional greening trends under intensified thermokarst activity. Air temperature was identified as the dominant driver of NDVI change, whereas soil temperature and soil moisture exerted secondary but critical influences, especially in tundra ecosystems with extensive thermokarst lake development. The relative importance of these factors shifted across thermokarst lake coverage gradients, underscoring the modulatory effect of thermokarst processes on vegetation-climate feedbacks. These findings emphasize the necessity of incorporating thermokarst dynamics and landscape heterogeneity into predictive models of Arctic vegetation change, with important implications for understanding cryospheric hydrology and ecosystem responses to ongoing climate warming. Full article

Human non-polio enteroviruses (NPEVs) cause a plethora of infections in humans, ranging from mild to severe neurological diseases including aseptic meningitis. NPEVs are the leading cause of aseptic meningitis in both children and adults worldwide. In Russia, reports of NPEV infections have surged, especially in the post-COVID era starting in 2022, with elevated infection rates into 2023. A comprehensive examination of the whole genome is crucial for understanding the evolution of NPEV genes and for predicting potential outbreaks. This study focused on identifying the circulating NPEV strains in the Ural Federal District and Western Siberia, using Sanger sequencing and next-generation sequencing (NGS) methodologies. Biological samples were collected from (n = 225) patients diagnosed with aseptic meningitis. Bioinformatics analysis targeted the nucleotide sequences of the major capsid protein (partial VP1) gene fragment, and the assembly of whole NPEV genomes. A total of 159 NPEVs were characterized, representing 70.7% of the collected samples. The main capsid variants forming the predominant genotypic profile included E30 (n = 39, 24.3%), E6 (n = 31, 19.3%), and CVA9 (n = 25, 15.6%). Using NGS, we successfully assembled 13 whole genomes for E6, E30, EV-B80, CVA9, CVB5, E11, and EV-A71 and 3 partial genomes for E6 and EV-B87. This molecular-genetic analysis provides contemporary insights into the genotypic composition, circulation patterns, and evolutionary dynamics of the dominant NPEV associated with aseptic meningitis in the Ural Federal District and Western Siberia. The laboratory-based monitoring and epidemiological surveillance for genetic changes and evolutionary studies are important for improving prevention and healthcare. Full article

Microplastics, defined as particles up to 5 mm in size, present a significant environmental and health concern due to their ubiquity, capacity to accumulate in organisms, and potential to cause toxic effects, inflammation, and endocrine disruption. A major challenge in addressing this issue is the lack of a universal method for sample preparation and analysis across different environmental matrices. This study addresses this gap by applying a custom-developed method for isolating microplastics from freshwater, followed by a comparative analysis of their abundance using three techniques: spectral (μ-FTIR) and thermal (TGA and pyro-GC-MS). The study was conducted on water samples from the Ob River near Novosibirsk, a major industrial center in Siberia. Field processing entailed filtering 20 L water volumes through a polyamide fabric with a nominal 100 µm pore size. Subsequent characterization established that the entire population of detected particles fell within the 100 to 500 µm interval. The results revealed microplastic concentrations of 0–10,000 particles/m³ (μ-FTIR), 6–19 mg/m³ (TGA), and 0.47–2.96 mg/m³ (pyro-GC-MS). Critically, the data showed spatially variable contamination, with higher microplastic levels identified near industrial wastewater discharge stations and urban recreational areas. Full article

Microplastic pollution of ecosystems is considered a modern problem. Freshwater ecosystems, despite the interest shown in their study, remain poorly understood. Lake Baikal (Russia) is one of the least studied freshwater ecosystems in this regard. This large lake is distinguished from others by its high level of biodiversity and clean drinking water. The aim of this study is a multi-matrix investigation of microplastic pollution in one of the lake’s bay. The following matrices are used: surface water, water column, sediment, macrophytes, macroinvertebrates, and fish, as well as ice and snow during the winter. The results show that certain locations exhibit high concentrations of microplastic particles. In some cases, this was due to the properties or characteristics of these locations (littoral zones near the water’s edge, macrophytes with mucus sheaths, ice and snow (potentially, the near-surface water layer after ice melt)), while in others, it was due to localized pollution (pier and ship mooring areas). An analysis of the polymer types of the detected microplastic particles reveals the presence of both common (polypropylene, polyethylene terephthalate, polystyrene, polyethylene, polyvinyl chloride) and rare (polyvinyl alcohol and alkyd resin). Moreover, in some locations, the latter two polymers predominate, a phenomenon rarely observed in other studies. Further research was recommended to focus on the chronic effects of microplastic particles on organisms associated with areas of elevated particle concentrations. Full article

Polyethylene (PE) films are widely used as waterproofing materials on the surfaces of metal pipelines. Poor adhesion of PE films to a metal substrate reduces durability, leading to shorter service life and higher economic costs. The current research aims to study the modification of PE films in atmospheric pressure gliding arc plasma (GAP). The adhesion properties of the modified films were investigated using the contact angle method and adhesion work calculations. During the modification process, the GAP treatment duration and deflector nozzle angle of attack were optimized to 10 s and 135°, respectively. It was established that the adhesion work increased from 62.1 to 141.3 mJ/m² after 10 s GAP modification compared to untreated PE. GAP modifying of PE films for 30 s or more is impractical, as the increase in the adhesion work ceases after that. It was found that surface roughness R_max increased by up to 4.1 times after 10 s GAP modification compared with nontreated PE. The PE films acquired hydrophilic properties after plasma modification, due to changes in the polymer surface’s chemical structure. The results of IR spectroscopy studies indicated oxidation of the film surface, an increase in the concentration of surface polar groups (-COOH, OH, C=O), and the formation of double bonds (C=C), which led to improved adhesive properties. A study of the electret properties showed that the observed decline and subsequent stabilization of values occurred within the first 24 h. Mechanical tests indicated improved performance of the GAP-modified PE films compared to the non-treated ones in the PE–mastic–PE and PE–mastic–steel systems. Due to their enhanced contact properties, the modified PE films are of interest as a base material for creating waterproofing materials. Full article

Apatite is a key indicator mineral whose chemical signature can reveal the genesis and evolution of ore-forming systems. However, correctly interpreting these signatures requires a robust discrimination between apatite types formed by different geological processes, such as metamorphism and hydrothermal activity. This study aims to chemically characterize and genetically classify apatite samples from the Slyudyanka deposit (Siberia, Russia) to establish discriminative geochemical fingerprints for metamorphic and hydrothermal apatite types. We analyzed 80 samples of apatite using total reflection X-ray fluorescence (TXRF) and inductively coupled plasma mass spectrometry (ICP-MS). The geochemical data were processed using principal component analysis (PCA) and k-means cluster analysis to objectively discriminate the apatite types. Our analysis reveals three distinct geochemical groups. Metamorphic veinlet apatite is defined by high U and Pb, low REE, Sr, and Th, and suprachondritic Y/Ho ratios. Massive metamorphic apatite from silicate–carbonate rocks shows extreme REE enrichment and chondritic Y/Ho ratios. Hydrothermal–metasomatic apatite features high Sr, Th, and As, with intermediate REE concentrations and chondritic Y/Ho ratios. Furthermore, we validated the critical and anomalous Y concentrations in the metamorphic veinlet apatite by cross-referencing TXRF and ICP-MS data, confirming the reliability of our measurements for this monoisotopic element. We successfully established diagnostic geochemical fingerprints that distinguish apatite formed in different geological environments at Slyudyanka. The anomalous Y/Ho ratio in metamorphic veinlet apatite serves as a key discriminant and provides insight into specific fractionation processes that occurred during the formation of phosphorites in oceanic environments, which later transformed to apatites during high-grade metamorphism without a change in the Y/Ho ratio. This work underscores the importance of multi-method analytical validation for accurate geochemical classification. Full article

The genetic diversity of the ospA gene of the Borrelia burgdorferi sensu lato species complex encoding outer surface protein A has been widely investigated. However, the information on the genetic variability of Borrelia isolates from Siberia for this gene is limited. In this study, we analyzed complete ospA gene sequences from 36 Borrelia isolates from Western Siberia, comprising 6 Borrelia afzelii, 16 Borrelia bavariensis, 1 Borrelia garinii, and 13 “Candidatus Borrelia sibirica” isolates. The obtained ospA gene sequences of B. afzelii were conserved and formed a single clade. In contrast, B. bavariensis sequences were highly variable, segregating into two distinct clades consistent with the phylogeography of Asian isolates. Notably, the B. bavariensis samples identified in molted Ixodes trianguliceps and Ixodes apronophorus were first characterized for the ospA gene; the obtained sequences corresponded to those from I. persulcatus. This study provides the first characterization of the ospA gene in “Candidatus B. sibirica”, revealing highly conserved sequences (99.8–100% intraspecific identity). The ospA gene sequences of “Candidatus B. sibirica” shared less than 88.7% identity with those of other Borrelia genospecies. Phylogenetic analysis placed “Candidatus B. sibirica” in a unique, well-supported clade, confirming its distinct phylogenetic status and suggesting potential ecological specialization in nidicolous Ixodes species. Full article

Sb-rich avicennite (first discovery in Russia) was found at the Khokhoy gold deposit, 120 km west of Aldan, Aldan district, Republic of Sakha (Yakutia), Eastern Siberia, Russia. The mineral of critical metal thallium forms irregularly shaped grains up to 0.25 mm in size, in association with amgaite, weissbergite, goethite, gold, and unidentified Tl-bearing phases. Aggregates of colloform structure prevail, represented by rhythmic-, concentric-zonal, kidney-shaped, and spherulitic varieties. Avicennite is black in color, with metallic luster, and it fractures unevenly. No cleavage is observed. The density value of avicennite, obtained using its empirical formula and the unit cell parameters calculated from the powder X-ray diffraction data, is 8.548 g/cm³. In reflected light, avicennite is light gray and isotropic. Internal reflections are absent. Reflection is very low; the reflectivity curve is of mixed type with a small maximum in the blue part. Its chemical composition (average value on 10 analyses, wt.%): Tl₂O₃—85.36, V₂O₅—0.73, As₂O₅—0.85, Sb₂O₅—12.98, Total—99.92; It corresponds to the following empirical formula (calculation for three atoms of O): Tl_1.40Sb⁵⁺_0.30V⁵⁺_0.03As⁵⁺_0.03O₃. The unit cell parameters calculated from the powder X-ray diffraction data are as follows: the mineral is cubic, a = 10.496(6) Å, V = 1156(2) Å3. Full article

Rhaponticum carthamoides (Maral root) is an important medicinal plant species in Siberia and Kazakhstan. The aim of this study was to evaluate the effect of cultivation time (three or five weeks) and immersion frequency (i.e., every 1.5 h, 3 h, or 6 h) on the growth of R. carthamoides shoots in a temporary immersion PlantForm bioreactor; it examines the effect of cultivation on the accumulation and productivity of caffeoylquinic acid derivatives, shoot biomass and propagation. Both growth time and frequency of immersion affected the increase in biomass and phenolic compound production. The highest dry weight (9.35 g/L) was observed for shoots grown for five weeks and immersed every 1.5 h; optimal synthesis (4.5 mg/g DW) and productivity of caffeoylquinic acid derivatives (16 mg per bioreactor) was noted following immersion every three hours. The main class of synthesized compounds was mono-caffeoylquinic acid derivatives (3.3 mg/g DW; 11.85 mg/bioreactor) with chlorogenic acid predominating (2.9 mg/g DW; 10.4 mg/bioreactor), as determined by HPLC-PDA. The antioxidant activity of bioreactor-grown shoot extract was assessed in vitro using three cell-free assay systems: hydroxyl radical (OH^•) scavenging, hydrogen peroxide (H₂O₂) reduction, and superoxide anion (O₂^•−) scavenging. Our findings indicate that the PlantForm bioreactor can be successfully used to grow R. carthamoides shoots and produce valuable caffeoylquinic acid derivatives. Full article

Chemical fungicides play a key role in protecting crops, but their use can result in environmental problems. We tested a novel fungicide, composed of endophytic microorganisms, for its effect on wheat yield, grain quality, plant development, and the rhizosphere microbiome, assessed by 16S and ITS metabarcoding. The fungicide increased the grain yield, the effect being similar to a well-known commercial bacterial fungicide, without affecting its quality. Ascomycota, Zygomycota and Mucoromycota together comprised 80% of the mycobiome. Mucoromycota/Mucoromycetes/Rhizopodaceae/Rhizopus arrhizus were significantly decreased. The dominant (≥10%) bacterial phyla were Pseudomonadota, Acidobacteriota, Bacteroidota and Actinomycetota, but their fungicide-related differences were small or random. Different modes of fungicide application (seeds only, seeds plus one or two foliar applications) had no effect on wheat characteristics. Neither of the fungicide’s agents (Raoultella ornithinolytica and Pantoea allii) were found in the rhizosphere. The changes in the mycobiome seemed more pronounced than in the bacteriobiome. The proposed preparation is concluded to have good prospects as a fungicide. However, the low species/strain resolution of the DNA metabarcoding did not allow us to fully interpret shifts in the microbiome diversity, both agronomically and environmentally. These aspects need more comprehensive investigation, using methodology with higher species resolution. Full article

Local agri-food markets are a key link in the sustainability and resilience of rural communities, as they merge producers and consumers, create jobs and ensure food security. This paper analyzes the state and perspectives of the development of local markets in rural regions of Russia, relying on demographic, economic, structural and innovation indicators. The results show marked regional differences: in urbanized areas the share of the rural population is low and markets are weak, while in Siberia and the Far East, local markets remain vital, albeit under pressure from depopulation. Structural shifts in favor of plant production, along with worsening price parity, indicate reduced profitability of small producers, but also open opportunities for diversification through processing and branding. Analysis of production concentration shows that sectors with more dispersed production (vegetables, milk) enable greater flexibility and resilience of local markets. Highly concentrated sectors remain vulnerable to market shocks. The findings confirm that local markets can be not only guardians of tradition, but also drivers of modernization and growth. The work thereby makes an empirical contribution to the understanding of the sustainability of rural markets and shows that, with targeted policies that link demographic stability, economic incentives, digital tools and ecological practices, local markets can become a pillar of sustainable development and a significant instrument for strengthening the resilience of the agri-food sector in Russia and beyond. Methodologically, the article applies a mixed approach: (i) quantitative analysis of several sets of statistical data (Rosstat, supplementary FAO/OECD/Eurostat) through descriptive indicators and indices (incl. input/output price parity), as well as cluster typology of regions; and (ii) qualitative mapping of findings to contemporary policies and practices. This framework allows structural trends to be directly linked to implications for local food markets. Full article

Transparent conductive electrodes that combine flexibility with effective electromagnetic interference (EMI) shielding are important for next-gen flexible electronics and 5G/6G communication devices. Achieving high optical transparency, low sheet resistance, and broadband shielding performance remains a sophisticated task. This work demonstrates a solution: the synthesis and comprehensive characterization of flexible In₂O₃/Ag/In₂O₃ (IAI) structures on polyethylene terephthalate substrates. The optimized structure with a 13.2 ± 1.1 nm silver interlayer achieves an incredible combination of properties: high optical transmittance (82.59% at 500 nm), low sheet resistance (6.4 ± 0.8 Ω/sq), and insignificant optical haze (1.04%). Broadband EMI shielding measurements from 10 MHz to 1 THz reveal a uniform shielding effectiveness of 25–30 dB across band from radiowave to terahertz. The IAI structures also show outstanding mechanical resilience, maintaining their electrical and shielding performance under repeated bending. This unique set of attributes positions IAI thin films as a prospective material for transparent EMI shielding in advanced telecommunications and flexible optoelectronics. Full article

Borrelia burgdorferi sensu lato (s.l.) persistence in reservoir hosts is essential for the maintenance of the spirochaetes in the enzootic cycle. In this study, we investigated the persistence of Siberian B. burgdorferi s.l. strains in naturally infected voles and their transmission to Ixodes ticks. A long-term study conducted in 2013–2024 demonstrated the presence of Borrelia afzelii, Borrelia bavariensis, and, rarely, “Candidatus Borrelia sibirica” DNA in blood samples of small mammals. Among these, B. bavariensis exhibited the highest genetic diversity. All identified Borrelia species persisted in naturally infected Clethrionomys spp. voles throughout their lifespan (up to 50 weeks), providing the first evidence of long-term persistence of B. bavariensis and “Candidatus B. sibirica” in these hosts. Notably, the persistence of two Borrelia genospecies or several genovariants of a single genospecies within the same vole was common. Xenodiagnosis with laboratory-reared Ixodes spp. confirmed efficient transmission of all identified Borrelia genospecies to Ixodes persulcatus after 35–42 weeks of B. burgdorferi s.l. persistence. Moreover, B. bavariensis was transmitted to Ixodes pavlovskyi and I. persulcatus/I. pavlovskyi interspecies hybrids after at least 23 weeks of pathogen persistence. These findings demonstrate the reservoir competence of Clethrionomys spp. for B. afzelii, B. bavariensis, and “Candidatus B. sibirica”. Full article

Artemisia dracunculus L., commonly known as tarragon, is a popular culinary herb and a valuable source of bioactive extracts and phytocompounds. Its wide distribution across regions of the Northern Hemisphere demonstrates the species’ high adaptability to diverse growing conditions and has led to the development of chemoraces that differ in chemical composition. North Asian populations of A. dracunculus remain poorly studied, and plants growing in Siberia have not yet been examined. Given the vast areas occupied by tarragon, the species is a promising candidate for industrial use. Liquid chromatography–mass spectrometry (LC–MS) profiling identified 80 compounds in Siberian tarragon samples, including hydroxycinnamates (HCys), coumarins, flavonoid aglycones (FlAs), and glycosides (FlGs). Among these, 62 phenolics were reported for the first time as A. dracunculus metabolites, highlighting the uniqueness of the North Asian accessions, particularly in their diversity of flavone O-glycosides and methylated flavanone aglycones. The highest levels of HCy, FlA, and FlG were 21.84, 52.53, and 54.44 mg/g, respectively, yielding a total phenolic content of 128.81 mg/g in the dry plant material—a high value. The concentrations of certain compounds exceeded 1%, making tarragon a noteworthy source of rare metabolites, including naringenin 7-O-methyl ester, thermopsoside, tilianin, and naringenin 7,4′-di-O-methyl ester. Thus, the existing knowledge of the chemical profile of tarragon has been expanded by new data on phenolic compounds from the North Asian populations of the species, which may be used to develop new A. dracunculus varieties with improved metabolic profiles and bioactive properties. Full article

Hydroclimatic and geomorphological prerequisites for mudflow hazard were studied using data on several of the largest flood events in the Khamar-Daban mountain area (Lake Baikal, East Siberia) for the period from 1966 to 2022. The data include flood-forming precipitation and atmospheric circulation patterns, the amount of related suspended sediment discharge in the years of high floods, as well as terrain features favorable for the formation of catastrophic floods and mudflows. Floods and mudflows in the area can arise under conditions of extremely high daily precipitation (up to 200 mm or more) after the territory becomes moistened by prolonged rainfall under meridional air transport. The maximum water discharge correlates with a multifold increase in the suspended sediment discharge and turbidity. The increase in sediment discharge associated with maximum water discharge (floods) of ≤10% probability is apparently due to 4–9 times higher flow rates. On the other hand, the formation of the solid runoff component in the area is controlled geomorphologically by slope processes depending on slope steepness, elevation contrasts, and the thickness of soft sediments subject to denudation and transport. The geomorphological conditions are most favorable for the development of mudflows and catastrophic floods in the catchments of the Bezymyannaya, Slyudyanka, Khara-Murin, and Utulik rivers. Floods and mudflows are especially hazardous on the southern shore of Lake Baikal, encircled by the Khamar-Daban Range, where active mudflow processes pose risks to the towns of Slyudyanka and Baikalsk, as well as to the sludge storage facilities of the abandoned Baikal Pulp and Paper Mill. Full article