Floating Riverine Litter Flux to the White Sea: Seasonal Changes in Abundance and Composition

Arctic rivers bring litter from their basins to the sea, but accurate data for the Arctic do not exist yet. This study presents the first assessment of floating macro litter input (>2.5 cm) from the Northern Dvina and Onega rivers to the White Sea. The observations were performed based on the European Marine Strategy Framework Directive (MSFD) methodology and using the mobile application of the Joint Research Centre (Ispra, Italy). The results of observations from May 2021 to November 2021 show that 77% of floating objects were of natural origin (mainly leaves, wood and bird feathers). Of the particles of anthropogenic origin, 59.6% were represented by various types of plastics, 27.7% were processed wood, 8.5% paper/cardboard, 2.7% metal, 1.1% were rubber and <1% textiles. The average monthly input of anthropogenic macro litter by the Northern Dvina varies from 250 to 1700 items/hour, and by Onega from 520 to 2350 items/hour. The level of pollution of the studied rivers was found to be higher than in some Europeans rivers but lower than in China. The mass discharge of macroplastics in the Northern Dvina River was compared with the estimates of the discharge of meso- and microplastics; that allowed us to show that the discharge of macroplastics in mass units is much higher than of micro- and mesoplastics.publishedVersio

Calcium Signaling Initiated by Agonists in Mesenchymal Stromal Cells from the Human Adipose Tissue

Mesenchymal stromal cells (MSCs) from different sources represent a heterogeneous population of proliferating non-differentiated cells that contain multipotent stem cells capable of originating a variety of mesenchymal cell lineages. By using Ca2+ imaging and the Ca2+ dye Fluo-4, we studied MSCs from the human adipose tissue and examined Ca2+ signaling initiated by a variety of GPCR ligands, focusing primarily on adrenergic and purinergic agonists. Being characterized by a relative change of Fluo-4 fluorescence, agonist-induced Ca2+ responses were generated in an “all-or-nothing” fashion. Specifically, at relatively low doses, agonists elicited undetectable responses but initiated quite similar Ca2+ transients at all concentrations above the threshold. The inhibitory analysis and Ca2+/IP3 uncaging pointed at the phosphoinositide cascade as a pivotal pathway responsible for agonist transduction and implicated Ca2+-induced Ca2+ release (CICR) in shaping agonists-dependent Ca2+ signals. Altogether, our data suggest that agonist transduction in MSCs includes two fundamentally different stages: an agonist initially triggers a local, gradual, and relatively small Ca2+ signal, which next stimulates CICR to accomplish transduction with a large and global Ca2+ transient. By involving the trigger-like mechanism CICR, a cell is capable of generating Ca2+ responses of virtually universal shape and magnitude at different agonist concentrations above the threshold

Thermochemical characteristics of the formation of aqueous solutions of imino acids

The calorimetry methods are an important source of thermodynamic information in the physicochemistry of solutions of biologically active substances, including amino acids. The goal of the work was to prepare a thermodynamic description of the formation of an aqueous solution of heterocyclic imino acids, proline and hydroxyproline, that have different structures and sizes of the side radical, in a wide range of concentrations, which can be used for a qualitative analysis of changes occurring in their solutions. Thermochemical measurements of the formation of an aqueous solution of imino acids in the concentration range 1.0·10-3 – 40.0·10-3 mol/kg was performed on a MID-200 differential heat-conducting microcalorimeter at 293 K. The equilibrium moment in the solution formation was determined by the output of the thermokinetic curve to the zero line. The enthalpy of the formation of an aqueous solution of imino acids was calculated by the integration of the time dependence of thermal power. It is shown that the increase in the equilibrium time, the increase in the maximum heat flow, and the decrease in the rate of change of the heat flow during the dissolution of hydroxyproline is due to the formation of intra and intermolecular bonds in the Hypro structure with the participation of the OH group. The difference in the structure of imino acids is reflected in the sign of the thermal effect and the form of the concentration dependence of the enthalpy of formation of aqueous solutions. The exoeffect of proline dissolution is due to the stabilisation of the water structure influenced by imino acid

Mercury in the Barents region – River fluxes, sources, and environmental concentrations

Arctic rivers are receiving increased attention for their contributing of mercury (Hg) to the Arctic Ocean. Despite this, the knowledge on both the terrestrial release sources and the levels of Hg in the rivers are limited. Within the Arctic, the Barents region has a high industrial development, including multiple potential Hg release sources. This study presents the first overview of potential Hg release sources on Norwegian and Russian mainland draining to the Barents Sea. Source categories cover mining and metallurgy industry; historical pulp and paper production; municipal and industrial solid waste handling; fossil fuel combustion; and past military activities. Available data on Hg in freshwater bodies near the identified potential release sources are reviewed. Levels of Hg were occasionally exceeding the national pollution control limits, thereby posing concern to the local human population and wildlife. However, the studies were sparse and often unsystematic. Finally, we present new data of Hg measured in five Barents rivers. These data reveal strong seasonality in the Hg levels, with a total annual flux constituting 2% of the panarctic total. With this new insight we aspire to contribute to the international efforts of reducing Hg pollution, such as through the effective implementation of the Minamata Convention. Future studies documenting Hg in exposed Barents freshwater bodies are warranted.publishedVersio

The origins and spread of domestic horses from the Western Eurasian steppes

This is the final version. Available on open access from Nature Research via the DOI in this recordData availability: All collapsed and paired-end sequence data for samples sequenced in this study are available in compressed fastq format through the European Nucleotide Archive under accession number PRJEB44430, together with rescaled and trimmed bam sequence alignments against both the nuclear and mitochondrial horse reference genomes. Previously published ancient data used in this study are available under accession numbers PRJEB7537, PRJEB10098, PRJEB10854, PRJEB22390 and PRJEB31613, and detailed in Supplementary Table 1. The genomes of ten modern horses, publicly available, were also accessed as indicated in their corresponding original publications57,61,85-87.NOTE: see the published version available via the DOI in this record for the full list of authorsDomestication of horses fundamentally transformed long-range mobility and warfare. However, modern domesticated breeds do not descend from the earliest domestic horse lineage associated with archaeological evidence of bridling, milking and corralling at Botai, Central Asia around 3500 BC. Other longstanding candidate regions for horse domestication, such as Iberia and Anatolia, have also recently been challenged. Thus, the genetic, geographic and temporal origins of modern domestic horses have remained unknown. Here we pinpoint the Western Eurasian steppes, especially the lower Volga-Don region, as the homeland of modern domestic horses. Furthermore, we map the population changes accompanying domestication from 273 ancient horse genomes. This reveals that modern domestic horses ultimately replaced almost all other local populations as they expanded rapidly across Eurasia from about 2000 BC, synchronously with equestrian material culture, including Sintashta spoke-wheeled chariots. We find that equestrianism involved strong selection for critical locomotor and behavioural adaptations at the GSDMC and ZFPM1 genes. Our results reject the commonly held association between horseback riding and the massive expansion of Yamnaya steppe pastoralists into Europe around 3000 BC driving the spread of Indo-European languages. This contrasts with the scenario in Asia where Indo-Iranian languages, chariots and horses spread together, following the early second millennium BC Sintashta culture

Mechanical activation in utilising milling byproducts: a way to improve effectiveness

The study focuses on obtaining the finely ground wheat germ flour mix by employing dry mechanical activation. During the study, wheat germ is ground using DESI-11 disintegrator and mechanically activated in PM-10 centrifugal mill with the rotor speed of 1050 rpm. According to the study findings, the finely ground wheat germ flour mix obtained by dry mechanical activation possesses increased bulk density and improved water absorption capacity when compared to the product obtained from wheat germ without mechanical activation applied. The average particle size is reduced from 114 μm to 52 μm. The study findings indicate that obtaining the finely ground wheat germ flour mix by dry mechanical activation prevents the occurrence of the caking effect as well as improves the quality of baked products

Contribution of the atmospheric channel to lead contamination of soils in the Arctic territories

Although the Arctic territories have long been considered “the gold standard of purity”, global climate change and environmental pollution are having a significant impact on the state of Arctic ecosystems. In particular, industrial complexes combined with transboundary transport are having a negative impact. The aim of this work is to determine the contribution of atmospheric Pb to the contamination of soils of the Arctic territories using the trajectory statistics method which combines correlation and factor statistical processing approaches while taking the actual lead content in the upper soil horizon into account. In order to assess the transfer of pollutants, an analysis of multiannual air mass tracts and impurity transfer trajectories to certain points was carried out. The objects of study are the soil of the Khorey-Ver settlement, the basin of the Shapkin and Sula rivers, northeastern and southern Svalbard and the islands of the Southern Archipelago of Novaya Zemlya. It was established that the primary contribution to airborne pollution of the Nenets Autonomous District (NAO) during the summer period comes from sources located within a radius of about 400 km. Aerogenic influence of the mainland on the territory of Svalbard is practically absent, with the main atmospheric transport of substances coming from nearby marine areas. The transfer of impurities from the mainland to the Novaya Zemlya District is also insignificant. During the summer months, there is practically no airborne lead contamination of the island territories. Some influences on the territory of Novaya Zemlya and the NEO can be traced to sources on the Kola Peninsula, the coasts of the Barents and Kara seas, as well as long-distance transport from the southern regions. On the territory of the NAO, the number of heavy metal (HM) precipitations increases from west to east, possibly indicating a stronger impact of emissions from the Norilsk industrial hub than from the enterprises of the Kola Peninsula on this territory. In terms of seasonal dynamics, the island points are characterised by an increase in HM fluxes during the winter period; conversely, for the NAO territory, such an increase takes place during the summer. This discrepancy is primarily due to the changing nature of the atmospheric circulation

Floating Riverine Litter Flux to the White Sea: Seasonal Changes in Abundance and Composition

Arctic rivers bring litter from their basins to the sea, but accurate data for the Arctic do not exist yet. This study presents the first assessment of floating macro litter input (&gt;2.5 cm) from the Northern Dvina and Onega rivers to the White Sea. The observations were performed based on the European Marine Strategy Framework Directive (MSFD) methodology and using the mobile application of the Joint Research Centre (Ispra, Italy). The results of observations from May 2021 to November 2021 show that 77% of floating objects were of natural origin (mainly leaves, wood and bird feathers). Of the particles of anthropogenic origin, 59.6% were represented by various types of plastics, 27.7% were processed wood, 8.5% paper/cardboard, 2.7% metal, 1.1% were rubber and &lt;1% textiles. The average monthly input of anthropogenic macro litter by the Northern Dvina varies from 250 to 1700 items/hour, and by Onega from 520 to 2350 items/hour. The level of pollution of the studied rivers was found to be higher than in some Europeans rivers but lower than in China. The mass discharge of macroplastics in the Northern Dvina River was compared with the estimates of the discharge of meso- and microplastics; that allowed us to show that the discharge of macroplastics in mass units is much higher than of micro- and mesoplastics

On one method for solving transient heat conduction problems with asymmetric boundary conditions

Using additional boundary conditions and additional required function in integral method of heat-transfer we obtain approximate analytical solution of transient heat conduction problem for an infinite plate with asymmetric boundary conditions of the first kind. This solution has a simple form of trigonometric polynomial with coefficients exponentially stabilizing in time. With the increase in the count of terms of a polynomial the obtained solution is approaching the exact solution. The introduction of a time-dependent additional required function, setting in the one (point) of the boundary points, allows to reduce solving of differential equation in partial derivatives to integration of ordinary differential equation. The additional boundary conditions are found in the form that the required solution would implement the additional boundary conditions and that implementation would be equivalent to executing the original differential equation in boundary points. In this article it is noted that the execution of the original equation at the boundaries of the area only (via the implementation of the additional boundary conditions) leads to the execution of the original equation also inside that area. The absence of direct integration of the original equation on the spatial variable allows to apply this method to solving the nonlinear boundary value problems with variable initial conditions and variable physical properties of the environment, etc