bluuebunny/crossref_metadata_2025 huggingface dataset:
Nature of the Eclipsing Polar 1RXS J184542.4+483134
Authors: Kochkina V. Yu. , Kolbin A. I. , Borisov N. V. , Bikmaev I. F.
Published: April 2024

We have carried out a comprehensive study of the poorly investigated eclipsing polar1RXS J184542.4+483134 with a short orbital period Porb ≈ 79 min. An analysis of its long-term lightcurves points to a change in the position and sizes of the accretion spot as the accretion rate changes.Narrow and broad components, which are probably formed on the ballistic segment of the accretion streamand on the magnetic trajectory, respectively, are identified in the emission line profiles. An inversion ofthe line profiles from emission to absorption due to the obscuration of the accretion spot by the accretionstream is observed. Based on the eclipse duration and the radial velocities of the narrow line component,we impose constraints on the white dwarf mass, 0.49 ≤ M1/M ≤ 0.89, and the orbital inclination,79.7◦ ≤ i ≤ 84.3◦. An analysis of the cyclotron spectra points to the presence of two accretion spotswith magnetic field strengths B1 = 28.4+0.1−0.2 MG and B2 = 30 − 36 MG. The main spot has a complexstructure that apparently has a dense core and a less dense periphery emitting a spectrum with cyclotronharmonics. Polarization observations reveal a circular polarization sign reversal during the orbital periodand an anticorrelation of the polarization with the brightness of the polar. Our modeling of polarizationobservations using the simple model of an accreting white dwarf shows that the polarization propertiescan be interpreted in terms of two-pole accretion with different optical depths of the accretion spots(τ1/τ2 ∼ 10). An analysis of the Swift/XRT observations points to a predominance of bremsstrahlungin the X-ray radiation from the system.
A Method for Estimating the Spatial Period of Energy Release in Solar Flares
Authors: Ledentsov L. S.
Published: April 2024

A method for estimating the spatial period of energy release in solar flares is proposed toanalyze the present-day satellite observations of arcades of flare coronal loops. The method is based on theapplication of a Fourier analysis to the difference images of flare arcades in the far ultraviolet. The operationof the method is demonstrated with the observations of the Bastille Day flare from the TRACE spacecraftin the 171 ˚A channel. The mean spatial period of energy release in the Bastille Day flare determined bythe proposed method is 5–8 Mm, in good agreement with the scenario for the development of thermalinstability of the preflare current layer in solar flares.
Current Sheet as an Optimal Synchrotron Maser on a Radio Pulsar
Authors: Koryagin S. A.
Published: April 2024

Using a relativistic plasma with an isotropic monoenergetic distribution of electrons andpositrons as an example, we show that in the maser regime the maximum possible amplification ofsynchrotron radiation at a distance of one wavelength is achieved in a medium where the magnetic energydensity is of the order of the particle energy density. This ratio of the energy densities corresponds to a(Harris-type) current sheet. We have obtained an electron Lorentz factor of 350 and a magnetic fieldstrength of 10 kG in the maser radio emission region for the Crab pulsar. Our estimate suggests thatthe optical and coherent radio emissions of the object originate from one synchrotron source in the form ofa current sheet. The diameter of the source must exceed the light-cylinder radius approximately by a factorof 6 for the maser wave field to interact with particles in the linear regime, in particular, to keep its phasevelocity higher than the speed of light in a vacuum—a necessary condition for the synchrotron instability.
Generation of an Induced Pluripotent Stem Cell Line, ICGi043-A, by Reprogramming Peripheral Blood Mononuclear Cells from Parkinson’s Disease Patient with p.G2019S Mutation in LRRK2 Gene
Authors: Grigor’eva E. V. , Pavlova S. V. , Malakhova A. A. , Yarkova E. S. , Sorogina D. A. , Minina J. M. , Miliukhina I. V. , Nikolaev M. A. , Pchelina S. N. , Medvedev S. P. , Zakian S. M.
Published: April 2024

The pathological variant p.G2019S in the LRRK2 gene leads to the occurrence of a hereditary form of Parkinson’s disease (PD) and affects 7% of patients with a familial form of the disease. However, the mechanisms that trigger pathological events during the development of the disease are not yet fully understood. We obtained iPSCs (ICGi043-A line) from peripheral blood mononuclear cells of a patient with a hereditary form of PD associated with the genetic variant c.6055GA (p.G2019S, rs34637584) in the LRRK2 gene using transfection with episomal vectors. iPSCs rapidly proliferate in dense monolayer cell colonies, are positive for endogenous alkaline phosphatase, have a normal karyotype (46,XX), express pluripotency markers (OCT4, SOX2, NANOG, TRA-1-60, SSEA-4) and are able to differentiate into three germ layers (ecto-, endo- and mesoderm), which confirms their pluripotent status. Future directed differentiation of the obtained iPSCs into dopaminergic neurons will allow the creation of an in vitro cell model of PD associated with the pathological variant c.6055GA in the LRRK2 gene, and contribute to understanding the pathogenesis of PD.
Generalized Form of Barbs of the Barbus (=Labeobarbus) intermedius Complex in Lake Tana: Vectors of Morphological Variability at Different Stages of Postnatal Ontogenesis
Authors: Mironovsky A. N.
Published: April 2024

Fishes of the Barbus (=Labeobarbus) intermedius complex (Actinopterigii, Cyprinidae), known in Russian-language literature as Large African Barbs, are widely distributed in Africa water bodies. A special feature of the morphological diversity of this group of fish is the sympatric coexistence of morpho-ecological forms in local populations. The most famous example of such coexistence takes place in Lake Tana located in the north of Ethiopia, where, according to different authors, up to 15 morpho-ecological forms (morphotypes) live. The diagnostic features of the barbs of Lake Tana morphotypes are clearly manifested upon reaching a standard length (SL) of about 15 cm. With a shorter length, representatives of most morphotypes are indistinguishable from each other. This suggests that in ontogenesis, the main vectors of morphological variability of the Tana Lake barbs may be different before and after individuals reach a length of 15 cm. The aim of this study was to test this assumption. The results obtained confirm that in this population, the standard length (SL), equal to about 15 cm, delimits two stages of postnatal ontogenesis in the studied group of fish. In individuals with SL 15 cm, the main vector of variability is a consequence of changes in morphological proportions as the individual grows. In individuals with SL 15 cm, the main vector of variability is most likely associated with the trophic resource partitioning. The original approach used in the study is considered promising in analyzing the peculiarities of variability at different stages of ontogenesis not only of the studied group, but also of other systematic groups.
Transgenic Lines of Human Induced Pluripotent Stem Cells ICGi022-A-6 and ICGi022-A-7 with Doxycycline-Inducible Variants of Programmable Nuclease AsCas12a
Authors: Pavlova S. V. , Valetdinova K. R. , Malankhanova T. B. , Polivtsev D. E. , Malahova A. A. , Grigor’eva E. V. , Shevchenko A. I. , Zakian S. M. , Medvedev S. P.
Published: April 2024

Genome editing in human pluripotent stem cells using programmable nucleases makes it possible to create models of hereditary pathologies using directed transgenesis, gene knockout, and replacement of individual nucleotides in DNA sequences. Using CRISPR/SpCas9-mediated homologous recombination at the AAVS1 locus, clones of human induced pluripotent stem cells (iPSCs) ICGi022-A (Malakhova et al., 2020) were obtained, which carry transgenes of two variants of the nuclease AsCas12a (also known as AsCpf1), recognizing different PAM consensuses, and the reverse doxycycline transgene-dependent transactivator – M2rtTA. For each AsCas12a variant, the lines ICGi022-A-6 (AsCas12a, PAM 5'-TTTV-3') and ICGi022-A-7 (AsCas12a, PAM 5'-TYCV-3') were obtained. Using Western blot analysis, it was shown that the addition of doxycycline to the culture medium causes activation of the expression of AsCas12a(TTTV) and AsCas12a(TYCV) proteins. The resulting transgenic iPSC clones were subjected to molecular and cytogenetic analysis. Using quantitative PCR and immunocytochemical analysis, it was shown that they have a high level of mRNA expression of gene markers of pluripotent cells, namely OCT4, NANOG and SOX2, as well as specific expression of protein marker OCT4, SOX2, SSEA-4 and TRA-1-60. In addition, using iPSCs spontaneous differentiation into embryoid bodies, it was found that transgenic clones can give derivatives of all three primitive germ layers: ectoderm, mesoderm and endoderm. Cytogenetic analysis showed that transgenic iPSC clones have a normal karyotype, 46,XX.
Influence of Bacterial Mutualists and Phytopatogenes on Changes in Concentrations of cAMP and H2O2 in Pea Seedles of Rondo Varieties and its Clutterless and Superclub Mutants
Authors: Lomovatskaya L. A. , Zakharova O. V. , Goncharova A. M. , Romanenko A. S.
Published: April 2024

Changes in the concentrations of hydrogen peroxide and cyclic adenosine monophosphate (cAMP) in the roots of seedlings of pea cv. Rondo and its supernodulating mutant Nod3 and anodulating K14 were studied during infection with Rhizobium leguminosarum bv. vicea (strain RCAM 1022) or Pseudomonas syringae pv. pisi (strain 1845). It was shown that 360 min after infection of pea seedlings of the Rondo variety, the level of endogenous hydrogen peroxide slightly differed from the control. In the roots of Nod3 seedlings, this level significantly decreased, and in the roots of K14 it significantly increased when infected with the 1845 strain, but remained unchanged when exposed to bacteria of the RCAM 1022 strain. and young root hairs of Rondo seedlings, while strain 1845 had no effect on this parameter. Both types of bacteria had no effect on the concentration of cAMP in the roots of seedlings of the Nod3 mutant, whereas in K14, under the influence of RCAM 1022, the cAMP level almost doubled, and under the influence of 1845, it decreased. It is assumed that hydrogen peroxide and cAMP may be involved in the formation of supernodulating and nodulating phenotypes of mutants, as well as in the formation of resistance to a specific pathogen, Pseudomonas syringae pv. pisi. It is possible that this phenomenon can be used to diagnose the resistance of newly created mutants and pea varieties to the blight pathogen.
Decolorization of Dyes in the Bioelectrochemical System Depending on the Immobilization of Shewanella oneidensis MR-1 Cells on the Anode Surface and Electrical Stimulation of the External Circuit
Authors: Samkov A. A. , Chugunova Yu. A. , Kruglova M. N. , Moiseeva E. V. , Volchenko N. N. , Khudokormov A. A. , Samkova S. M. , Karaseva E. V.
Published: April 2024

The effect of the polarity of the electrical stimulation of the external circuit of the bioelectrochemical systems, as well as the immobilization of Shewanella oneidensis MR-1 cells containing the DyP peroxidase gene on the rate of discoloration of dyes of different types was found. For the crystal violet triphenylmethane dye, the maximum decolorization rate by suspended S. oneidensis MR-1 cells 2.05 ± 0.07 μM/h was noted in the case of connecting a 1.2 V direct polarity DC voltage source. One of the minimum rates was observed in the case of reverse polarity of the connection. In the case of cells immobilized on the anode, the rate was higher, reaching 2.91 ± 0.09 μM/h and did not decrease with increasing substrate concentration. The lowest values were also noted for the reverse connection of the voltage source. In case of the azo dye congo red, the maximum rate was found for a source with direct connection and an open circuit (0.26 ± 0.01 and 0.29 ± ± 0.02 μM/h, respectively), the minimum value is 0.11 ± 0.02 μM/h for reverse connection. For the crystal violet decolorization products, a significant decrease in the intensity of the main absorption peak at 590 nm band was found, with no notable hypsochromic shift. The qualitative changes in the decolorization products composition are indicated by the appearance, in case of a direct polarity of the ionistor connection, of a new absorption maximum in the region of 360 nm. The results may be of interest for the development of new methods of bioelectrochemical cleaning.
Synergistic Interaction of Arabinases of Different Types of Action in the Bioconversion of Sugar Beet Pulp and Apple Pomace
Authors: Semenova M. V. , Kuryshkina M. S. , Sinitsyn A. P.
Published: April 2024

The interaction of endoarabinase (endoA) with exo-type enzymes was studied during their joint hydrolysis of branched arabinane (BAra), sugar beet pulp (SBP) and apple pomace (AP). It was shown that mixtures of endoA with arabinofuranosidase (AF) or arabinoxylan-arabinofuranhydrolase (AXH) with endoA content of 20 and 40%, respectively, were the most effective in the hydrolysis of BAra. As a result of the optimization of the complex of arabinases, cellulases and pectinase, almost complete conversion of AP into monosaccharides (arabinose, glucose, fructose) was carried out. During the hydrolysis of SBP, the conversion rate of hemicellulose (arabinane) was more than 50%, cellulose – 75%.
Prospects for the Application of Sensor Elements for Detecting the Presence of Bacteria in Real Time
Authors: Lachinov A. N. , Lachinov A. A. , Karamov D. D. , Galiev A. F. , Kuzina E. V. , Korshunova T. Yu.
Published: April 2024

A study was made of the response of a sensor element based on polydiphenylenephthalide to a change in the composition of the air medium during the cultivation of Enterobacter asburiae UOM 3 bacteria in a liquid nutrient medium. Registration of changes in the resistance of the sensor element in response to volatile organic compounds released by bacterial cells was carried out by measuring the current-voltage characteristics at specified time intervals. The results showed the relationship between the number of bacteria and the change in the resistance of the sensor element, due to the release of waste products of microorganisms. With an increase in the titer of bacteria by 3 orders of magnitude, the resistance of the sensor under the influence of volatile organic compounds accumulated in the medium decreased by 2 orders of magnitude. It is assumed that sensors based on polydiphenylenephthalide can be used to determine the presence of bacteria in various materials and media.
RNA Interference in Plant Protection from Fungal and Oomycet Infection
Authors: Maksimov I. V. , Shein M. Yu. , Burkhanova G. F.
Published: April 2024

Phytopathogenic fungi pose a threat to food security, limiting the biological potential of agricultural crops and reducing the quality of products. New plant protection methods based on natural systemic and cellular phytoimmunity are being developed to date, where a unique mechanism, described by the term “RNA interference” (RNAi), occupies a special place. RNAi regulates the expression of target genes in a homologically dependent manner and, with the involvement of a protein complex designated as RISC (RNA-induced silencing complex), on the one hand, it protects plants from pathogens, but on the other hand, pathogens use it as a virulence factor. Cases of bilateral exchange of small RNAs between plants and pathogens affecting them through extracellular vesicles have been described. This review discusses the role of small RNAs, as well as DCL, AGO, and RdR proteins, in the infection of plants with pathogenic fungi and oomycetes, and the prospects for using RNAi in the development of environmentally friendly, modern plant protection products.
Relationship between the Composition of Root Exsudates and the Efficiency of Interaction of Wheat Plants with Microorganisms
Authors: Shaposhnikov A. I. , Belimov A. A. , Azarova T. S. , Strunnikova O. K. , Vishnevskaya N. A. , Vorobyov N. I. , Yuzikhin O. S. , Bespalova L. A. , Tikhonovich I. A.
Published: April 2024

Plant roots secrete various organic substances into the rhizosphere, which are a source of nutrition for microorganisms and largely determine the nature of plant-microbe interactions. The composition of the main fractions of root exudates in ten modern varieties of wheat was determined: amino acids, organic acids and sugars. Reliable qualitative and quantitative differences between varieties for individual components of exudates were revealed, which determined the peculiarities of cultivar clustering on this trait. Relationships between exudation and the effectiveness of plant interaction with the growth-promoting rhizobacterium Pseudomonas fluorescens SPB2137 and the phytopathogenic fungus Fusarium culmorum 30 in laboratory systems, as well as with the resistance of varieties to diseases in the field, were found. The number of P. fluorescens SPB2137 in the root zone positively correlated with the amount of many amino acids, as well as maltose, secreted by the roots. The stimulating effect of rhizobacteria on root growth positively correlated with the amount of released glucose and melibiose. The relationship between the nature of root exudation and root colonization or the susceptibility of varieties to F. culmorum 30 was not found. The analysis of correlations between the incidence of wheat varieties in the field and the intensity of exudation of certain substances, as well as with the biocomposition index of amino acid exudation, was carried out. The role of root exudate components in the formation of effective plant-microbial systems is discussed.
Acylated Flavonoids from Cucumis sativus Inhibit Activity of Human Pancreatic Lipase
Authors: Olennikov D. N. , Kashchenko N. I.
Published: April 2024

Lipid metabolism disorders are a large group of diseases for the treatment of which various strategies are used including the use of pancreatic lipase inhibitors reduced the intake and adsorption of lipids. This study was the first shown that agricultural wastes of cucumber (Cucumis sativus) can be a source of the effective lipase inhibitors. As a result of the chromatographic separation of C. sativus leaves metabolites, seven acylated flavonoids were identified, including three new derivatives of isovitexin characterized by UV, NMR spectroscopy and mass spectrometry data as isovitexin-2"-O-glucoside-6"'-O-ferulate (1), isovitexin-2"-O-glucoside-6"'-O-p-coumarate (2), and isovitexin-2"-O-(6"'-O-feruloyl)-glucoside-6"'-O-ferulate (3). The quantitative HPLC data showed that the total content of the acylated flavonoids in the leaves of Russian varieties C. sativus amounted to 3.78–7.44 mg/g of dry plant weight. Isolated compounds demonstrated the ability to inhibit the human pancreatic lipase and the effectiveness of compound 3 was the greatest and exceeded the activity of the reference compound Orlistat. This study has shown that C. sativus leaves can be the useful source of biologically active phytocomponents with hypolipidemic activity.
Comparison of Biochemical Properties of Recombinant Alpaca (Vicugna pacos) Chymosins Produced in Pro- and Eukaryotic Expression Systems
Authors: Belenkaya S. V. , Elchaninov V. V. , Chirkova V. Y. , Shcherbakov D. N.
Published: April 2024

Based on the yeast Kluyveromyces lactis, a strain-producer of recombinant alpaca prochymosin (Vicugna pacos) was developed. A comparative analysis of the biochemical properties of recombinant alpaca chymosin obtained in the expression systems of K. lactis and Escherichia coli was carried out. It was found that the recombinant alpaca chymosin synthesized in K. lactis exceeds the analog obtained in E. coli by 12.9 times in the number of enzyme turnovers, and by 2.9 times in catalytic efficiency. Compared to chymosin expressed in E. coli, the enzyme obtained in a eukaryotic producer has a thermal stability threshold increased by 5°C. Replacing a prokaryotic producer with a eukaryotic one enhances the negative sensitivity of the milk-clotting activity of recombinant alpaca chymosin to an increase in substrate pH in the range of 6.1–6.9, which is accompanied by an increase in the duration of coagulation by 8–35%. With an increase in the concentration of CaCl2 in the substrate, the coagulation activity of the target enzyme synthesized in E. coli was 12–14% higher than that of its analogue obtained in K. lactis.
Fatty Acid Profiles Change and the Volatile Organic Compounds Formation During the Cow’S Milk Fermentation with Probiotic Lacticaseibacillus paracasei Strains
Authors: Moiseenko K. V. , Shabaev A. V. , Glazunova O. A. , Savinova O. S. , Fedorova T. V.
Published: April 2024

In this work, a comparative analysis of the profile of fatty acids (FA) and volatile organic compounds (VOCs) for skimmed cow’s milk fermented by four different probiotic strains of Lacticasibacillus paracasei (ABK, KF1, MA2 and MA3) was carried out. Analysis of FA and VOC profiles was performed using gas chromatography with mass spectrometric detection (GC-MS). For additional visualization of odor changes and its intensity in the fermented milk samples, the E-nose “electronic nose” odor analyzer was used. In total, presence of 42 different FA was detected in all samples, of which 17 were saturated, 8 monounsaturated, and 5 polyunsaturated. The strain-specific differences between the studied samples were of a complex nature and could not be explained only by the variation in the contribution of several individual FAs. The FA-nutritional indices, characterizing the nutritional and biological value of the samples, were different for milk fermented by different strains. Analysis of VOCs showed that the main odor-forming compounds in the studied samples were FAs and their reaction products, 2-heptanone, 2-nonanone, and 2-nonanol, formed as a result of the following chain of transformations: β-oxidation → decarboxylation → reduction. The aroma of L. paracasei fermentation products, predicted on the basis of the odors of individual VOCs, generally coincided with their organoleptic assessment – a flavor typical of fermented milk (yogurt, curdled milk) with floral and fruity notes.
Mechanisms of Control by Pseudomonas fluorescens of Barley Root Rot Caused by Fusarium culmorum
Authors: Shakhnazarova V. Yu. , Syrova D. S. , Lebedinskii M. I. , Vishnevskaya N. A. , Shaposhnikov A. I. , Borodina E. V. , Strunnikova O. K.
Published: April 2024

In this paper, we found out why in the presence of the rhizobacterium Pseudomonas fluorescens 2137, the intensity of barley fusarium root rot caused by Fusarium culmorum 30 decreases, if there is no obvious decrease in the amount of fungus in the roots in the presence of the bacterium. It has been suggested that (1) the presence of rhizobacteria stimulates the defence reactions in barley, (2) rhizobacteria reduces the production of trichothecene toxins by F. culmorum 30, a known factor of aggressiveness of the fungus. The responses of barley to the colonization of its roots by fungus and bacteria were studied in sterile vermiculite for 11 days by the intensity of expression of the LOX, PAL, PR4 and PR1 genes. The production of F. culmorum 30 trichothecene toxins was evaluated by the expression level of the TRI13 gene. As a result, it was found that P. fluorescens 2137 induced the expression of all studied defence genes already in diurnal barley roots, but only in the presence of F. culmorum 30. In the presence of the bacterium, the expression level of the TRI13 gene did not decrease, however, a decrease in the number of diseased plants suggests that P. fluorescens 2137 is capable of detoxifying trichothecene toxins produced by the fungus or inducing this ability in barley.
Using New Bioinformatics Strategies at the Design Stage of Genome-edited Plants
Authors: Yakovleva I. V. , Kamionskaya A. M.
Published: April 2024

The identification of risks associated with novel agricultural products of plant origin obtained via genome editing is an important aspect of genetic engineering. An extensive discussion is currently ongoing worldwide to clarify the similarities and differences between the “old” risks of “classic” GM plants and the “new” ones associated with genome editing, the lack of existing methods for identification and assessment of new risks. We propose here the concept of “safe by design” as applied to protection that is a new interesting tool that introduces good known standards of safety into plant bioengineering. This approach states that design options are identified to minimize or prevent risks and off-target of genome editing at the concept stage. The correlation between experimentally determined and in silico predicted off-target gRNA activity is a major challenge in the CRISPR system application. Today the most studies are focused on efficiency of gRNA design, while we pay attention specifically to the bioinformatics search and study of potential promoters, as the potential risk associates with a possible unplanned change in the transcriptional activity of promoters. We conveyed these strategies in the form of a risk assessment framework for regulation of new genetic technologies.
The concept of ressentiment and modernity: in search of elusive comparator
Authors: Fishman Leonid G.
Published: April 2024

This article examines the transformation of the ressentment concept in political struggle. Originally, the concept of ressentiment emerged from right-wing ideological positions and was used to «expose» the supposedly «true» background of the actions and ideologies of left-wing and progressive forces. However, over time leftists and liberals also adopted it. They started finding in their opponents almost all the same features that the right accused them of having. The reasons that made this reversal possible are analyzed. The attention is drawn to the reference to normativity, normality, exemplarity, a certain natural order from both right-wing classics of the concept of ressentiment (F. Nietzsche and M. Scheler). The example of this normativity, the fictitious Nietzschean-Schlerian aristocrat, serves in the basic concept of ressentiment as an example of «master» and an object of comparison, a comparator. In modern societies, however, there is no such universally recognized superior social subject. Various political forces and social groups qualify for his place. Thus, all adversaries get the opportunity to accuse each other of ressentiment, and the right-wing monopoly on the use of this concept is overtaken.
The unsolved issue of arms control: anti-missile dilemma
Authors: Mizin Victor I.
Published: April 2024

The issue of missile defense (ABM) remains one of the key topics of the discussion on arms control at the present stage. Without its eventual forthcoming solution, it is impossible to further advance towards reducing the military threat on a global scale, and mutual reduction of the nuclear weapons capabilities of Russia and the United States, Russia and NATO, as well as to strengthen global strategic stability overall. At the same time, this issue is a serious irritant in Russia’s relations with its Western counterparts, and, above all, with the NATO military-political alliance led by the United States. Consequently, finding mutually acceptable solutions in this area would help restore trust between Russia and her counterparts and create prerequisites for moving towards a safer and more stable world. А number of tangible priority steps are suggested. Those measures might create certain ways out of the current negotiating impasse over the missile defense issue and help adopt pragmatic measures that would not violate the national security of any states. This process might take place in case of normalization of relations between Moscow and Washington.
J. Biden’s Green agenda: slogans and realites
Authors: Roginko Sergey A.
Published: April 2024

The activities of the US administration in the field of climate change and national climate policy are studied as well as the impact of this policy on the United States’ position in the global community. A new problem has been identified: the attempt to put the climate agenda at the forefront of US domestic and foreign policy has not yet led to significant practical results. The analysis of the effect of the US climate legislation (adopted in August 2022) is given. The predictions on the dynamics of national greenhouse gas emissions and the forecast of the US’ fulfillment of obligations to decarbonize the economy by 2030 are offered. The prospect of changes in the US role in the global climate agenda in the light of the fundamental changes in the world order revealed in 2022 is assessed.
EU-Russia economic relations in conditions of restrictions
Authors: Belov Vladislav B. , Kotov Aleksandr V.
Published: April 2024

The article examines the fundamental changes in the foreign economic strategy of Russia in 2022 and evolution of foreign trade relations between the EU and the Russian Federation. The study hypothesis is that the new mechanism of «sanctions’ interaction» between the EU and Russia is emerging. Moscow withstood the pressure of unprecedented restrictions, while Brussels has significantly reduced the competitiveness of its own economic and political space. This problem is particularly relevant because the EU developed a system for monitoring compliance with the adopted ten packages of sanctions, measures to stimulate the exchange of data between countries, and is finalizing the rules for interpreting and applying restrictive measures. It is identified that the EU and German initiatives had a significant negative impact on economic cooperation with Russia in 2022. The consequences of the complex pressure of the European Union on Russia and on their business are demonstrated. Particular attention is paid to the FRG, Russia’s main foreign economic partner, that plays a major role in shaping the EU sanctions policy. The forecast for the development of relations is made. The results of calculations of new proportions of EU-Russian and German-Russian trade are presented. Structural shifts in key product groups are analyzed. Significant reduction in exports from the European Union of a number of industrial and technological goods is formed. It is determined that EU imports of energy resources from Russia increased significantly in value terms at the end of the year, but the physical volumes of export have significantly decreased. The development of economic cooperation in non-sanctioned countries of Central Asia and the South Caucasus in the long-term may serve as a “bridge” between the economic and political spaces of the EU and Russia. The matrix of corporate strategies of European companies in terms of presence in the Russian market was developed. It is substantiated that 40% of companies continue to work in Russia. It is concluded that “double risks” develop: for the economic relations of European and Russian companies in the EU economic space due to tightening control and for the remaining European companies in Russia, which are still under pressure from the media.
Transit migration management in the Western Balkans
Authors: Gorokhov Stanislav A. , Agafoshin Maksim M. , Dmitriev Ruslan V.
Published: April 2024

The European migrant crisis has turned the Western Balkans states into the most important transit region from Asia and Africa to the European Union. Being the main recipient of migrants the EU carries an active migration management policy on the territory of the Western Balkan region. The main purposes of the EU’s migration policy are to reduce the scale of illegal migration and reform the asylum system by means of securitization and externalization. In turn, the Western Balkans states heading for European integration are forced to follow all the political decisions of the EU authorities in the field of migration, hoping for an early entry into the organization. However, these decisions lead to an increase in migration pressure on the countries of the region, actually turning the Western Balkans into a buffer zone that performs the function of filtering the flows of illegal migrants.
Internal political crisis in Bulgaria (2021-2023)
Authors: Podchasov Nikolay A.
Published: April 2024

Political processes in Bulgaria from 2021 to 2023 are studied. That period was marked by several crisis developments, of which the most prominent was the inability of the political circles to form a stable government. The hypothesis is that the cause of the instability was the split of the political elite into the “center” and “flanks”. The parties at the center of the political spectrum had been the de facto rulers of the country for the larger part of the previous decade. This was one of the factors for the unification of the opposition, which resulted in the isolation of the “centrists” since the beginning of 2021. However, opposition organizations and movements that were aiming to replace the former center were unable to agree among themselves on the formation of a stable coalition due to various circumstances. This situation resulted in a political crisis that ended in June 2023, when the leading right-wing parties entered into an agreement with the “centrists”, abandoning the policy of isolation. The impact that these events could have on the future development of the leading political actors in Bulgaria is evaluated.
The least developed countries: ICT landscape and possible directions of support
Authors: Egerev Sergey V.
Published: April 2024

The ICT landscape in Least Developed Countries (LDCs) is characterized by a diverse array of infrastructure, services and public perceptions of new technologies. The dynamics of informatization within these countries are examined, focusing on the connectivity parameter to rank the 48 countries in this group. Additionally, critical components of infrastructure are highlighted, and socio-technical problems associated with ICT development are addressed, including the prevention of non-use, cargo cult mentality, and the challenge of developing local digital platforms. The analysis reveals the following key findings. 1. The notion that the future of ICTs in LDCs should rely solely on mobile communications is deemed premature due to the impact of the pandemic. 2. It is imperative to adapt services for the segment of the population in LDCs that will continue to utilize the Internet through “fixed computers with fixed access + 2G telephones” in the forthcoming years. 3. The UN agencies’ objectives of achieving widespread adoption of digital government, distance education, and e-commerce services are not always immediately attainable for LDCs. Consequently, it is concluded that the directions of international support for this process should be recalibrated in the post-Covid era.
Native Iron in Siberian Traps
Authors: Tomshin M. D. , Kopylova A. G. , Vasilyeva A. E.
Published: April 2024

The results of study of intrusive traps with a large-scale occurrence of native iron allowed us to identify general patterns of their composition and origin. Intrusive bodies are weakly differentiated; they feature a similar structure and mineralogical, petrochemical and geochemical composition. Two associations of rock-forming minerals were found in all the studied bodies, i.e. early deep (pre-chamber) and intra-chamber. Native iron forms nodular segregation, with a subordinate amount of cohenite, troilite and magnetite-wustite. Natural reduced iron can concentrate many elements, such as Ni, Co, Au and PGE. Their content in metal increases by hundreds or even thousands of times compared to the hosting silicate part. The formation of native iron is based on the fluid-magmatic interaction between magma substance and reducing components of the fluid, primarily of methane-hydrogen composition. As a result, dispersion of a primarily homogeneous basalt liquid into silicate and metallic components occurs. In the process of transfer, finely dispersed phases of iron form droplet-liquid segregations with a monomolecular layer of gas on their surface that prevents enlargement of metallic droplets. In the hypabyssal chamber, magma degassing occurs, including degassing from metallic spherules. The processes of droplet fusion and formation of native phase segregations begin.
Conditions and Magmas Sources of Summit and Flank Eruptions of the Klyuchevskoy Volcano in 2020–2021: Isotope (Sr-Nd-Pb-O)-Geochemical Data
Authors: Cherkashin R. I. , Bergal-Kuvikas O. V. , Chugaev A. V. , Larionova Yu. O. , Bindeman I. N. , Khomchanovsky A. L. , Plutakhina E. Y.
Published: April 2024

In 2021 a unique event occurred on Klyuchevskoy volcano (Kamchatka). After more than 30 years dominance of terminal eruptions a flank vent was formed. It was named after corresponding member of the Academy of Sciences USSR G.S. Gorshkov. The eruption began immediately after the end of the summit crater activation in 2020–2021 at an altitude of 2850 m in the northwestern part of the volcano, where no manifestations of flank volcanism were observed earlier. This paper presents geochemical and isotopic Sr-Nd-Pb-O data for lavas of the summit and flank eruptions of the Klyuchevskoy volcano in 2020–2021. A comparative petrographic analysis was carried out and the chemical composition of the Ol, Cpx, Pl phenocrysts of these lavas was analyzed. The lavas of both eruptions are alumina andesitic basalts of normal alkalinity. Variations of basic oxides in the lavas of the summit eruption and in the lavas of the G.S. Gorshkov vent are SiO2 53.1–53.2 wt. % and 51.6–53.2 wt. %, MgO 5.6 wt. % and 5.5–6.0 wt. %; respectively. Estimates of temperatures and pressures of plagioclase crystallization showed that for lavas of the summit eruption they were 1210–1118°С and 12.3–3.6 kbar, for lavas of the flank vent 1203–1119°С and 9.0–3.3 kbar. The content of the main elements, the proximity of the conditions of plagioclase generations, and the features of variations in the chemical composition of Ol, Cpx, and Pl phenocrysts in the lavas of both eruptions indicate the genetic relationship of the magmas that fed the summit and flank eruptions. The lavas of the summit eruptions of 2016, 2020–2021, as well as the lavas of the previous summit eruptions of the Klyuchevsky volcano, are characterized by highly sustained Sr-Nd-Pb isotopic characteristics: 87Sr/86Sr = 0.703625–0.703626, 143Nd/144Nd = 0.513085–0.513102, 206Pb/204Pb = 18.3148–18.3179). Isotopic ratios 207Pb/204Pb (15.5022–15.5107) and 208Pb/204Pb (37.9597–38.0143) are significantly higher for the lavas of the last summit and flank eruptions than for all Klyuchevskoy’s lavas of the past, which indicates more complex processes of magma evolution at crustal levels. The values of δ18O = 6.49–7.39 rel. units (SMOW) in the lavas of the considered eruptions are consistent with previously published data on the Klyuchevsky volcano. The lavas of the Gorshkov vent are enriched with Ba, Zr, Sr and other incompatible elements at constant values of MgO in comparison with the lavas of the last summit eruptions, which indicates differences in the ways of evolution of their magmas. Sharply increased values of the 87Sr/86Sr ratio (0.703673–0.703743) in the lavas of the G.S. Gorshkov vent, not previously observed in the lavas of the Klyuchevsky volcano, testifies to intensive assimilation of crustal matter by the initial melts in the northwestern part of the volcano.
The Effects of Alkalis Content on Zircon Solubility in Silicate Melts
Authors: Borisov A. A. , Koshlyakova A. N.
Published: April 2024

The experimental study of the effects of alkalis content on zircon solubility in multicomponent model silicate melts was conducted in temperature range 1300–1400°С and at 1 atm total pressure. It was demonstrated that the addition to the melt of Na2O and K2O results in comparable increase of zircon solubility. The advantages and disadvantages of the parameters describing zircon solubility are shortly discussed.
Crystal Size Distribution as a Key to Protocumulus Evolution in Layered Intrusions: Experiments, Calculations and Practice of CSD Extraction
Authors: Sobolev S. N. , Ariskin A. A. , Nikolaev G. S. , Pshenitsyn I. V.
Published: April 2024

The paper provides a review of calculation and experimental approaches to reproducing three types of crystal size distributions (linear, bimodal, lognormal CSD), and also systematizes publications on CSD data in rocks of ten layered massifs. For a more detail discussion, the results for plagiodunite samples from the Yoko-Dovyren massif (Northern Baikal region, Russia), harzburgite from the marginal zone of the Monchegorsk pluton, and urtites from the Lovozero intrusion (Murmansk region, Russia) were selected. Possible causes and scenarios for the formation of three types of CSDs discovered for these objects are presented.
Experimental and Mathematical Modeling of Borderline Changes in the Brain under Radiation Exposure
Authors: Fedorov V. P. , Ushakov I. B.
Published: April 2024

In model experiments on rats irradiated in doses and exposure regimes comparable to those in the liquidators of the consequences of the Chernobyl accident, changes in neurons of various parts of the brain were studied depending on the dose of Y-irradiation and the dose rate of exposure. It was established that throughout the experiment, both in control and irradiated animals, undulating changes were observed in various neuromorphological parameters of nerve cells with stochastic extrema in separate dose-time intervals. In a number of cases, the changes were of a borderline nature, when they were no longer the norm and at the same time were not yet a pathology. Although the level of significance of such changes fluctuated in relation to the age control within functionally insignificant limits, their presence testified to the instability of the structural and functional organization of nerve cells and the intensity of functioning. At the same time, γ- irradiation had a grea-ter influence on the change in most indicators of the state of neurons than the time of the recovery period, which indicated a rather high response of nerve cells to radiation exposure. Over time, changes in nerve cells were repaired and their parameters corresponded to the age control. It should be assumed that with an increase in the dose or dose rate of radiation exposure, as well as against the background of other harmful and dangerous factors associated with radiation accidents, changes in neurons will become more unidirectional.
Comparative Estimate of Plutonium and Radiocesium in Muscle of Grayling (Thymallus baicalensis) of the Yenisei River
Authors: Zotina T. A. , Melgunov M. S. , Dementyev D. V. , Alexandrova Yu. V.
Published: April 2024

The paper presents the data on the content of plutonium (239,240Pu) in the muscles of the Baikal grayling Thymallus baicalensis, inhabiting the middle reaches of the Yenisei River in the vicinity of the radioactive discharge point of the Mining and Chemical Combine, in 2011–2019. The content of 239,240Pu in grayling muscles varied within 7–32 mBq/kg dry weight. Highest value was recorded in 2019, a year after the increase in the volume of controlled plutonium discharges. The ratio of activity concentrations 239,240Pu/137Cs in grayling muscles compared to the similar ratio in other hydrobionts of the Yenisei indicates a lower bioavailability of plutonium for fish.
Association Between Single Nucleotide Polymorphisms of Apoptosis and Cell Cycle Control Genes and the Risk of Cancer Development in Chronically Exposed Persons
Authors: Blinova E. A. , Yanishevskaya M. A. , Korechenkova A. V. , Akleyev A.V.
Published: April 2024

The objective of the paper was to study the association between single nucleotide polymorphisms of genes involved in the cell cycle control (ATM rs664677, MDM2 rs2279744, CDKN1A rs1801270) and apoptosis (BCL-2 rs2279115, BAX rs4645878, TNFα rs361525) and the risk of solid cancer development in persons of different ethnicity exposed to chronic radiation. The study included 915 residents of the Techa riverside settlements belonging to two ethnic groups (Slavs and Turks) who were affected by chronic low dose rate exposure in the low to and medium dose range. 310 persons out of them had solid cancers. Genotyping of polymorphic regions of genes regulating cell cycle and apoptosis was performed by real-time PCR method. The study showed that the rs2279744*C allele of the MDM2 gene was associated with an increased risk of cancer development (OR = 2.29; 95% CI 1.23–4.28; p = 0.007), while the rs1801270*A allele of the CDKN1A gene showed a protective effect against cancer development (OR = 0.55; 95% CI 0.35–0.85; p = 0.01) in exposed individuals of the Turkic ethnic group. The combined effect of the identified polymorphisms and soft tissue exposure dose statistically significantly modifies the risk of cancer development in chronically exposed persons of the Turkic ethnic group, with the greatest contribution being made by the carriage of the rs2279744*C allele of the MDM2 gene.
Tritium in the Water System of the Pyshma River Floodplain
Authors: Chebotina M. Ya.
Published: April 2024

The paper presents data on the concentration of tritium in the water of the river Pyshma, which is under the influence of the Beloyarsk NPP named after Kurchatov, and drinking water of settlements located in the coastal zone of the river. It was found that the content of radionuclide in the water of the river at a distance of up to 400 km below the dam of the Beloyarsk reservoir varies within 13–26 Bq/l and significantly decreases along the course of the river. In the coastal part of the river, above-background tritium pollution enters the drinking water of wells and chinks. It is shown that in water samples from wells, the tritium concentration significantly decreases with increasing depth and distance from the dam of the Beloyarsk reservoir; in the water of private wells, such a relationship was not reliably recorded. The concentration levels of tritium in the spring water of 7 settlements located along the Pyshma river at different distances from the dam of the Beloyarsk re-servoir, almost 2 times higher than in the water of deep chinks, have similar values and do not depend on the distance.
Stimulation of Mesenchymal Stem Cells Proliferation from the Femur of Wistar Rats by Nanosecond Microwave Radiation: Dependence on the Number of Pulses
Authors: Gostyuhina А. А. , Bolshakov М. А. , Samoylova А. V. , Doroshenko O. S. , Svetlik M. V. , Kutenkov О. P. , Zaitsev K. V. , Rostov V. V.
Published: April 2024

The effect of nanosecond repetitively pulsed microwave radiation (RPM, 50–4000 pulses, pulse repetition rate of 13 Hz, peak power flux density of 140 W/cm2, carrier frequency of 10 GHz) on the stimulation of me-senchymal stem cells (MSC) proliferation was studied. The effect of exposure was assessed by the change in the number of cells in the culture after a single irradiation with a different number of pulses. The most pronounced effect exerted by the impact with 100 and 50 pulses, and the effect is realized with a maximum speed after 24 hours.
High Thermosensitivity of MDA-MB-231 Cells as a Prerequisite for Thermoradiosensitization of Triple-negative Breast Cancer in Clinical Practice
Authors: Yakimova A. O. , Kabakov A. E.
Published: April 2024

The work is dedicated to the analysis of thermal sensitivity and efficiency of thermosensitization to γ-radiation of three cell lines of breast cancer of different molecular subtypes. It has been established that the cells of the studied lines differ in the sensitivity to hyperthermia and, as a result, in the effectiveness of thermoradiosensitization, which raises the question of finding criteria for assessing the rationale of using hyperthermia in each specific case. It has been shown that the level of heat-responsive expression of HSP70 gene and also the level of cell genomic instability can serve as such criteria. It was found that the efficiency of thermoradiosensitization is significantly higher in MDA-MB-231 cells compared to the cells of other studied lines. The data obtained suggest that the use of hyperthermia as a radiotherapy-sensitizing co-treatment may be particularly promising toward triple negative breast cancer.