bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of Thyroid Hormones in Adaptation to Volcanic Contamination of Freshwater Habitats in Charr of the Genus Salvelinus (Salmonidae)
Authors: Esin E. V. , Shulgina E. V. , Pavlova N. S. , Zlenko D. V.
Published: April 2024

The balance between phenotypic plasticity and adaptive specialization in response to environmental pressures remains a hot topic in evolutionary biology. In fish, one of the strongest impact factors is the chemical pollution of habitats. In an attempt to assess the consequences of heavy pollution of fresh waters for resident fishes, we studied Kamchatkan charr, which undergo paedomorphosis in the case of isolation in streams of volcanic areas contaminated with heavy metals. Experiments were carried out on the resistance of charr to metal mixtures during normal development and in six experimental groups with therapeutically altered intensity of metabolism and the secretory activity of thyroid gland. Water from volcanically contaminated streams was found to be lethally toxic for embryos and early juveniles of unadapted charr. The success of acclimation to toxic exposure was correlated with an increase in thyroid status. In experiments, the group with significantly elevated thyroid status showed a significant decrease in mortality and attenuation of oxidative stress in solutions of heavy metals. Under natural conditions, hyperthyroidism provokes a redistribution of the charr’s organism resources from somatic growth and morphological differentiation to stress counteracting and accelerated maturation, which is necessary for the long-term survival of the population under conditions of increased risk of individual mortality. Our experiments highlight the role of thyroid hormones in the rapid response to habitat pollution and the subsequent adaptation of fish populations to chronic deterioration.
On Widening the Hybrid Zone for Chars of Genus Salvelinus, Kundscha S. leucomaenis and Northern Dolly Varden S. malma (Salmonidae), in Rivers of Kamchatka Peninsula
Authors: Kuzishchin K. V. , Gruzdeva M. A. , Semenova A. V.
Published: April 2024

The data on widening the zone for hybridization between the chars of the genus Salvelinus, kundscha S. leucomaenis and northern dolly varden S. malma (Salmonidae), in rivers of the Kamchatka Peninsula are reported. If the hybrids between the kundscha and the northern dolly varden could be previously observed only in the Utkholok River in the northwest of the peninsula, the mass hybridization between these species have occurred in two more nearby rivers, the Kvachina and Snatolveem Rivers since 2009. A microsatellite analysis has shown that hybrid specimens are characterized by intermediate values for allelic diversity, when compared to that in the representatives of parental species, while the mean expected heterozygosity values for hybrids are higher than that in Dolly Varden and kundscha fish. The analysis results for maternal inheritance in hybrid specimens from the Kvachina River coincide with that obtained in the surveys previously performed in the Utkholok River. Thus, the same haplotype specific for the kundscha fish was revealed in all the hybrid specimens, which can indicate that the hybrids originate from kundscha females and Dolly Varden males. The appearance and coloration of kundscha × northern dolly varden hybrids in the Kvachina and Snatolveem Rivers are similar to that in the specimens in the Utkholok River. Rather similar chacteristics of hybrid specimens in all three rivers can give reason to consider that a mechanism of their occurrence in the Kvachina and Snatolveem Rivers is simalr to that in the Utkholok River, since the kundscha eggs are inseminated by the Dolly Varden dwarf males. The increased local biological production of rivers due to increased sizes of spawning stocks of pink salmon Oncorhynchus gorbuscha along with large-scale climate changes in the North Pacific are considered as a possible cause of disturbances of isolation between species. It is quite probable that these two factors have contributed to improving the environmental conditions for fattening the Dolly Varden fish in the freshwater phase of their life cycle and, as a resultl of this process, increasing the number of Dolly Varden male fish matuaring in the river.
European River Lamprey Lampetra fluviatilis (Petromyzontidae) of the Pskov Lakeland: Current State of Isolated Populations
Authors: Zvezdin A. O. , Kucheryavyy A. V. , Kolotei A. V. , Polyakova N. V. , Pavlov D. S.
Published: April 2024

Small freshwater (resident) populations of the European river lamprey Lampetra fluviatilis from an isolated from the sea upper part of a river system with numerous lakes (the upper reaches of tributaries of the Daugava River and Lake Peipus, Pskov Oblast, Russia) have been studied. Adult individuals of the lamprey have been attributed to common and large size groups; adults are similar to other resident lamprey from the Baltic Sea basin. The presence of larvae of different size and age groups indicates regular spawning of the European river lamprey in the studied watersheds. Analysis of the modern and historical (before the isolation) distribution of lamprey revealed a reduction in habitats and a decrease in the number of individuals. Dam-associated disruption of migration routes led to the disappearance of anadromous form, and consequently, disappearance of resident lamprey from most of the studied waterbodies. We attribute the decrease in the number of rivers inhabited by lamprey and abundance of the lamprey both to anthropogenic factors (direct blocking of an access of anadromous form of the lamprey to spawning grounds by hydraulic construction) and to the characteristics of the studied area. The richness of the river system with lentic waterbodies makes it suitable for lamprey inhabitation with an influx of large anadromous individuals capable of crossing such reservoirs in search of spawning sites.
Proof-of-Concept Study of Liposomes with a Set of SARS-CoV-2 Viral T-Cell Epitopes as a Vaccine
Authors: Tretiakova D. S. , Alekseeva A. S. , Onishchenko N. R. , Boldyrev I. A. , Egorova N. S. , Vasina D. V. , Gushchin V. A. , Chernov A. S. , Telegin G. B. , Kazakov V. A. , Plokhikh K. S. , Konovalova M. V. , Svirshchevskaya E. V. , Vodovozova E. L.
Published: April 2024

Potential nonameric epitopes of CD8+ T lymphocytes were selected from the composition of structural, accessory, and non-structural proteins of SARS-CoV-2 virus (13 peptides) and a 15-mer epitope of CD4+ T lymphocytes, from the S-protein, based on the analysis of publications on genome-wide immunoinformatic analysis of T-cell epitopes of the virus (Wuhan strain), as well as a number of clinical studies of immunodominant epitopes among patients recovering from COVID-19 disease. The peptides were synthesized and five compositions of 6–7 peptides were included in liposomes from egg phosphatidylcholine and cholesterol (~200 nm size) obtained by extrusion. After double subcutaneous immunization of conventional mice, activation of cellular immunity was assessed by the level of cytokine synthesis by splenocytes in vitro in response to stimulation with relevant peptide compositions. Liposomal formulation exhibiting the best result in terms of the formation of specific cellular immunity in response to vaccination was selected for further experiments. Evaluation of the protective efficacy of this formulation in an infectious mouse model showed a positive trend in the frequency of occurrence of hyaline-like membranes in the lumen of the alveoli, as well as a somewhat lower severity of microcirculatory disorders. The latter circumstance can potentially help reduce the severity of the disease and prevent its adverse outcomes. A method to produce liposome preparations with peptide compositions for long-term storage is under development.
Synthesis and Biological Activity of Esters Based on Cycloalkenedicarboxylic Acids
Authors: Firstova A. A. , Kofanov E. R. , Kovaleva M. I.
Published: April 2024

Previously undescribed esters based on N-substituted imides of cycloaliphatic carboxylic acids have been synthesized in high yields and efficient methods for their preparation have been presented. Toxicological studies of the obtained compounds were carried out using various test objects (Chlorella vulgaris, Allium cepa, Drosophila melanogaster). It was shown that the studied compounds are not active against D. melanogaster, increase the frequency of mutations in C. vulgaris and have the ability to induce chromosomal rearrangements in A. cepa. The synthesized compounds can be used in the development of antitumor drugs.
Three-Dimensional Structure of Fab Fragment of Monoclonal Antibody LNKB-2 Complexed with Antigenic Nonaptide from Human Interleukin-2
Authors: Goryacheva E. A. , Artemyev I. V. , Pletnevа N. V. , Pletnev V. Z.
Published: April 2024

The three-dimensional structure of the antigen-binding fragment (Fab) of the monoclonal antibody LNKB-2 in complex with the synthetic antigenic nonapeptide of human interleukin-2 (IL-2; Lys-Pro-Leu-Glu-Glu-Val-Leu-Asn-Leu-O) was determined by X-ray method at a resolution of 2.6 Å in crystal space group P212121. The peptide adopts a somewhat distorted α-helical conformation, close to that of fragment 64–72 of the IL-2 antigen. Four out of the six hypervariable loops in the antigen-binding site of the Fab fragment are involved in nonapeptide association through hydrogen bonding, salt bridge formation, and hydrophobic interactions. Moreover, Tyr residues of an antibody play an important role in antigen-antibody recognition.
Bacterial Cold Shock Proteins as a Factor of Adaptation to Stresses
Authors: Grigorov A. S. , Azhikina T. L.
Published: April 2024

Bacteria have evolved a number of mechanisms to cope with stresses and adapt to changing environmental conditions. A family of bacterial proteins containing a functional cold shock domain are highly conserved nucleic acid-binding proteins that modulate transcription and post-transcriptional events in bacteria. For many bacteria, these proteins have been shown to regulate the expression of various genes involved in virulence and resistance of bacteria to stresses. The review discusses the new data on the mechanisms of action and the roles of cold shock proteins in the regulation of expression in intracellular bacterial pathogens.
Synthesis and Transfection Efficiency of Disulfide Policationic Amphiphiles
Authors: Petukhov I. А. , Puchkov P. А. , Morozova N. G. , Zenkova М. А. , Maslov М. А.
Published: April 2024

The synthesis of new polycationic amphiphiles containing a disulfide group in their structure has been carried out. Cationic liposomes were formed on the basis of the obtained compounds and helper lipid 1,2-dioleoyl-sn-glycero-3-phosphatidylethanolamine, which demonstrated the absence of toxicity to HEK293 and HeLa cells and high delivery efficiency of fluorescently labeled oligodeoxyribonucleotide. The efficiency of plasmid DNA delivery depended on the cell line and structure of the amphiphile, with liposomes based on tetracationic amphiphiles being the most effective transfectants. These liposomes may be used for in vitro transfection of eukaryotic cells as well as for further in vivo biological tests.
How Conventional Approaches to the Use of Polymer-Containing Composites in Molecular Diagnostics Are Changing
Authors: Kapustin D. V.
Published: April 2024

Known approaches to the isolation of biopolymers, in particular nucleic acids (NAs), from biological samples are based on the binding of molecules to a sorbent (“positive selection”) with their subsequent elution using a suitable eluent. The review article discusses the physicochemical processes underlying the development of methods for isolating of NAs from biological samples. It has been shown that methods including the selective solid-phase extraction (i.e., reversible sorption) provide the possibility of miniaturization and automation of the corresponding processes. The review discusses the advantages of an alternative approach to NAs isolation based on the use of special sorbents that bind proteins and other components of biological samples, while these sorbents exhibit sorption inertness with respect to NAs (“negative selection”). Approaches providing the creation of such composite polymer-containing sorbents, which are designed for the sample preparation during molecular diagnostics, as well as the methods of their effective use are considered. It has been demonstrated that due to an interdisciplinary approach using a complex of synthetic and analytical methods, it is possible to combine as a single object of study the composite materials that are very different in structure and properties. Such nanostructured composites (based on porous silica, synthetic membranes, glass multicapillaries) contain fluoropolymers and polyanilines. The results of the use of such composites for selective isolation of NAs and/or proteins from biological samples are discussed. Alternative applications of such composites in molecular diagnostics, in particular, in mass spectrometry, are considered. Directions for expanding of the field of application of polymer-containing composites due to simultaneous use of the sorption properties of the obtained composites surface and the properties of sorbate molecules are outlined. It has been shown that both polymeric and low molecular weight modifiers of the same chemical nature are suitable for the technological preparation of such composites.
Convenient Preparation of tert-Butyl Amino Acid Esters from tert-Butanol
Authors: Azev V. N. , Chulin A. N. , Molchanov M. V. , Miroshnikov A. I.
Published: April 2024

A preparation of tert-butyl esters of amino acid is described that proceeds from protected amino acids and tert-butanol using anhydrous magnesium sulfate and an excess of boron trifluoride diethyl etherate as additional reagents. The method affords tert-butyl esters in good yields and a variety of amino acid side chains and substituents tolerate the reaction conditions.
Dynamics of 24 Self-Assembling H-(RADA)4-OH Peptides Complexed in Bi-Layered Structure with Layers in syn and anti Orientation
Authors: Danilkovich A. V. , Tikhonov D. A. , Lipkin V. M.
Published: April 2024

H-(RADA)4-OH peptide in water tends to form biolgels at physiological conditions. Thusly made scaffold is formed of fibrils resulted from peptides self-assembling. Fibrils have two external hydrophilic layers, while hydrophobic one is situated between of them. Bio gels by the H-(RADA)4-OH peptides are considered to be a prominent source for designed extra cellular matrix aimed to cell cultures of different types. Little is known about detailed structure the filament structure and β-sheets peptide composition. We have designed and studied molecular dynamics of bi-layered protofilament structures with β-sheets formed of parallel or anti-parallel peptide chains. Method of molecular dynamics was used to study H-(RADA)4-OH peptide complexes at 80 and 300 K. While the most stable peptide complex was found to consist of anti-parallel peptides, had the lowest free energy and the least deviation of atom coordinates, yet another stable structure of the peptide complex was identified as 24-mer of parallel peptides with two β-sheets placed in syn orientation. These results underlined the importance of factors, directing the initial stages of the H-(RADA)4-OH peptide self-assembling in solution.
Evolution of Peptide Biopharmaceuticals
Authors: Ivanov V. T. , Deigin V. I.
Published: April 2024

Peptides are small molecule substances involved in numerous essential physiological functions such as human growth and development, stress, regulation of the emotional state, sexual behavior, and immune responses. Their mechanisms of action are based on receptor-ligand interaction, which leads to highly selective effects. These properties and low toxicity allow them to be considered potent drugs. The production of peptide preparations became possible at the beginning of the 20th century after a method for the selective synthesis of peptides was developed. However, after the successful synthesis of the first peptide drugs, many issues related to increasing stability, bioavailability, half-life, and the ability to move through cell membranes remained unresolved. The review considers the historical path of development of the synthesis and production of peptides, as well as modern approaches to the creation of peptide drugs and their use in biopharmaceutics, including the development of original peptide drugs in Russia.
Multifunctional Proteins and Their Role in the Vital Activity of Cells
Authors: Korshunov D. A. , Sereda E. E. , Kondakova I. V.
Published: April 2024

The function of a newly discovered protein is often assessed by matching its new sequence to sequences of proteins with known functions. However, protein superfamilies can contain homologous elements that catalyze different reactions. Some homologous proteins differ in that they perform a second or even a third function and are called moonlighting proteins, which can be translated as mate proteins or underwork proteins. Also, such proteins are called multifunctional. In addition to these, the superfamilies of proteins with multiple functions also include pseudoenzymes that have a common catalytically active domain but no catalytic activity, as well as metamorphs and morpheins. This review discusses examples of such proteins, their diversity of functions, and their importance in the life of the cell.
Synthesis of Synthethic Analogs of Glycolipids Containing A (Type 2) Tetrasaccharide
Authors: Petrakova D. O. , Savchenko M. S. , Popova I. S. , Tuzikov A. B. , Paramonov A. S. , Chizhov A. O. , Bovin N. V. , Ryzhov I. M.
Published: April 2024

Glycolipids are the components of cellular membrane containing glycan and lipid parts. Transport of glycolipids from membrane and vice versa from extracellular space into the membrane is possible. This opens opportunity for modification of cellular membrane via embedding of glycolipids. In practice, synthetical analogs of glycolipids are significantly more convenient than natural glycolipids for such application, as the properties of the synthetical analogs can be varied and other bioactive components besides glycans can be introduced into their structure. This research describes synthesis of the eight synthetical glycolipids containing the same glycan part – A (type 2) tetrasaccharide but varying in the composition of lipid part or including several glycan residues. Obtained set of synthetic glycolipids will allow to study the influence of structural variations on the ability to present tetrasaccharide antigen on the cellular surface.
The Role of RIG-I-Like Receptors in the Activation of Innate Immune in Tuberculosis
Authors: Skvortsova Y. V. , Bychenko O. S. , Azhikina T. L.
Published: April 2024

Tuberculosis still claims over a million lives every year. The infection process can be regarded as an imbalance between the immune response and Mycobacterium tuberculosis growth. To successfully survive in an infected organism, M. tuberculosis must overcome the mechanisms of innate immunity, including those aimed at recognition of pathogen nucleic acids. RIG-I-like receptors (RLRs) is a system of intracellular sensors of foreign RNA, which is involved in the recognition of viruses and bacterial pathogens. RIG-I, MDA5, and LGP2 receptors interact directly with RNA in the cell cytoplasm and trigger a cascade of interactions leading to the synthesis of type I interferons and pro-inflammatory cytokines. To date, it has been proven that RLR activation during tuberculosis is among the most important components of innate immunity. Their role in the activation of type I interferons is undoubted, however, can be not only protective, but also detrimental. The review considers the latest data on the RLRs functioning in M. tuberculosis infection.
Synthesis of Fluorescent-Labeled Nucleotides for Labeling of Isothermal Amplification Products
Authors: Shershov V. E. , Kuznetsova V. E. , Zasedatelev A. S. , Vasiliskov V. A. , Shekalova E. Yu. , Shtylev G. F. , Shishkin I. Yu. , Levashova A. I. , Lapa S. A. , Chudinov A. V.
Published: April 2024

The synthesis of fluorescently labeled nucleotides containing a zwitterionic indodicarbocyanine dye attached via a trans-alkene spacer at the C5 position of the pyrimidine base was carried out, and their substrate efficiency was tested under conditions of recombinase polymerase amplification (RPA). As a result of RPA, the formation of full-sized target products of the ebpS gene fragment of the causative agent of bacterial pneumonia (Staphylococcus aureus) and a high density of fluorescent label embedding occurred.
Early Developmental Stages of the Carpet Sole Liachirus melanospilos (Bleeker, 1854) (Pleuronectiformes: Soleidae) from the South China Sea (Central Vietnam)
Authors: Shadrin A. M. , Semenova A. V. , Thanh Nguyen Thị Hai
Published: April 2024

Late embryonic and larval development of the carpet sole Liachirus melanospilos was followed until completion of metamorphosis and transition to the juvenile state. Illustrations and morphological descriptions of the early developmental stages are presented. The material of L. melanospilos was obtained from ichthyoplankton samples (Central Vietnam) and incubated under laboratory conditions at a temperature of about 24°C. Ta-xonomic identification of the species was carried out based on the analysis of a partial sequence of the mitochondrial cytochrome c oxidase subunit 1 (COI) gene.
Findings of Pogonophores (Annelida: Siboglinidae) in the Kara Sea Associated with the Regions of Dissociation of Seafloor and Cryogenic Gas Hydrates
Authors: Malakhov V. V. , Rimskaya-Korsakova N. N. , Osadchiev A. A. , Semiletov I. P. , Karaseva N. P. , Gantsevich M. M.
Published: April 2024

The discovery of new occurrences of pogonophores Siboglinum sp. and Nereilinum sp. from the St. Anna Trough (northwestern portion of the Kara Sea) has been described in this paper. Previously, occurrences of pogonophores (Crispabrachia yenisey and Galathealinum karaense) were reported in the southern part of the Kara Sea, in the estuary of the Yenisei River. Two areas in the Kara Sea where pogonophores were found coincide with the regions of distribution of two types of gas hydrates: oceanic seafloor gas hydrates, and gas hydrates associated with permafrost. Gas hydrate deposits in the permafrost are confined to the coastal regions of the Kara Sea. A methane flux forms in areas of dissociation of gas hydrates under the influence of river runoff. This methane source is vital for the survival of pogonophores. The existence of pogonophores in the St. Anna Trough indicates the presence of a methane flux associated with the inflow of Atlantic water, which causes dissociation of seafloor gas hydrates. The possible role of Arctic warming is apparent in both processes.
First Finding of Egg Masses of the Whip Sculpin Gymnocanthus intermedius (Temminck et Schlegel, 1843) (Cottidae) in Peter the Great Bay (Sea of Japan)
Authors: Panchenko V. V. , Balanov A. A.
Published: April 2024

For the first time, we report the finding of egg masses and an egg-guarding male of the whip sculpin Gymnocanthus intermedius (Temminck et Schlegel, 1843) in Peter the Great Bay (Sea of Japan). Bottom eggs were found in the post-wintering period during a scuba dive at a depth of 12 m. Exact data on the depth of occurrence and structure of the egg masses, the number of eggs per mass, and the sex of the guarding parent fish are provided. Egg characteristics and the substrate, on which the egg masses were laid, are described. The diagnostic features of the male that allowed it to be assigned to G. intermedius are given.
Alopiidae – A New Record of the Thresher Shark Family for the Fauna of Russia
Authors: Dolganov V. N. , Kim L. N.
Published: April 2024

The capture of a thresher shark Alopias vulpinus (TL 136.5 cm) in Peter the Great Bay (Sea of Japan) on September 5, 2022 is reported. A description of the specimen, including surface morphometric parameters, vertebraе counts, the number of tooth rows, and the number of intestinal valve turns, is presented.
Dimensional and Physiological-Biochemical Parameters of Erythrocytes and Gill and Heart Indices in Some Benthic Fish of the Black Sea Coast of the Southeastern Crimea
Authors: Silkin M. Yu. , Chernyaeva V. N. , Silkin Yu. A. , Silkina E. N.
Published: April 2024

The dimensional and physiological-biochemical parameters of erythrocytes, as well as the gill and heart indices were studied in five species of marine benthic fish. The black scorpionfish Scorpaena porcus Linnaeus, 1758 and the shore rockling Gaidropsarus mediterraneus Linnaeus, 1758 differed from the other species in a larger mass of the heart and gill apparatus, which indicates more efficient transport capabilities of the circulatory system of these fish. The linear size characteristics of erythrocytes of a cartilaginous fish, the thornback ray Raja clavata Linnaeus, 1758, were 1.5–2 times higher than those of erythrocytes of S. porcus, which were the largest among the studied teleosts. The sizes of erythrocytes of three other teleost species differed insignificantly. The amount of hemoglobin per unit surface area of erythrocyte, which reflects the efficiency of hemoglobin saturation with oxygen, insignificantly varied (0.05 to 0.071 pg/mm2) among the bony fish stu-died. In contrast, in the thornback ray this parameter was 2.7–3.8 times lower. The intracellular glycogen concentration, which characterizes the degree to which the erythrocyte is independent of glycemic fluctuations, was highest in cells of S. porcus (305.2 ± 35.1 mg %), while it was lowest in erythrocytes of the thornback ray R. clavata (142.8 ± 15.1 mg %). The ecto-ATPase activity was higher in large erythrocytes of S. porcus, R. clavata, and Uranoscopus scaber (4.8, 3.1, and 1.6 µmol Pin/min/mL of erythrocytes, respectively) than in smaller erythrocytes of Crenilabrus tinca and Gaidropsarus mediterraneus (0.5 and 0.4, µmol Pin/min/mL of erythrocytes, respectively). This confirms the assumption that erythrocytes use the thermal energy from hydrolysis of extracellular ATP to “warm up” their own membrane, which leads to the change in the rheological characteristics of blood in the capillary blood flow.
The Summer Distribution of Sculpin Fish (Cottidae) on the Continental Margin of the Sea of Japan from Cape Povorotny to Cape Mapatsa
Authors: Panchenko V. V. , Vdovin A. N.
Published: April 2024

We identified Gymnocanthus detrisus as the absolute dominant species in the taxocene of sculpins (family Cottidae), caught below 20 m water depth in the aquatic area between Cape Povorotny and Cape Mapatsa. Myoxocephalus polyacanthocephalus, Gymnocanthus herzensteini, Enophrys diceraus and Triglops pingelii are dominant as well. Subdominant species are Triglops septicus, Icelus cataphractus, Hemilepidotus gilberti, Myoxocephalus brandtii, Myoxocephalus jaok, Taurocottus bergii and Gymnocanthus pistilliger. Other types of fishes identified in this area are insignificant in abundance. Sculpins aggregate at greater depth in the southern aquatic areas, from Cape Povorotny to Olga Bay, and from Olga Bay to Cape Belkin, than in the northern areas, between Cape Belkin and Cape Zolotoy, particularly between Cape Zolotoi and Cape Mapatsa. We attribute this phenomenon to the differences in water regimes. The highest densities of sculpins are generally typical for the southern area. Conversely the lowest densities are typical in the northern area. However, some species prefer northern areas. The minimum depths habitat for different species varying from less than 20 m to 82 m; the maximum depths range from 80 to 530 m. Due to the high species diversity, aggregations of sculpins are observed in a wide bathymetric range from 20 to 300 m, with peak values at depths of 150–200 m. Sculpins live in summer at water temperatures above 0.4°C. The shallow water species of sculpins tolerate much greater temperature ranges then deep water species. Hence, the stenotherm increases in deep water species.
Macroalgal Flora Findings in Peter the Great Bay, of the Sea of Japan
Authors: Belous O. S. , Skriptsova A. V.
Published: April 2024

This article is one of a series of publications concerning new and little-known macroalgae of Peter the Great Bay, Sea of Japan. Our study was carried out from February, 2021 to July, 2022. A total of eight species are described, of which six are new species for this aquatic region. Three species are also newly reported for the flora of the Far Eastern seas of Russia; two species were previously noted in the bay, but not described. We provided all of these species with detailed descriptions and illustrations.
Differences in the Diet of Reproductively Isolated Ecotypes of Killer Whales (Orcinus orca Linnaeus, 1758) in the Seas of the Russian Far East
Authors: Filatova O. A. , Fedutin I. D. , Belonovich O. A. , Borisova E. A. , Volkova E. V. , Ivkovich T. V. , Ismail M. E. , Meschersky I. G. , Titova O. V. , Fomin S. V. , Shpak O. V.
Published: April 2024

A systematic analysis of the species composition of the prey of killer whale Orcinus orca Linnaeus, 1758 was carried out. The results of observations of killer whales hunting for different types of prey and the data from an analysis of the contents of their stomachs were summarized; the species affiliation of the prey was compared with the affiliation of predators to the R- or T-type based on a genetic analysis. It has been shown that killer whales of the Far Eastern seas of Russia have a pronounced foraging specialization, which correlates with the haplotype of the mitochondrial DNA control region. Killer whales with the NT1 and GAT haplotypes previously described for mammal-eating T-type killer whales from the northeast Pacific (also called Bigg’s killer whales) have been observed preying on marine mammals but not on fish. Killer whales with the SR haplotype, previously described for fish-eating R-type killer whales from the northeastern Pacific, preyed only on fish. Two new T-type killer whale haplotypes have been discovered; animals with these haplotypes have been observed preying on large baleen whales. The importance of traditions and social learning in the differentiation of ecological niches in cetaceans has been noted. The specialization to hunt certain prey transmitted from mother to calves allows killer whales of different ecotypes to avoid food competition and acquire morphological and behavioral adaptations that facilitate hunting for a particular type of prey.
Minerals with Mixed Anion Radicals in Fumarole-Transformed Crush Microxenolites as a New Phenomenon of Modern Volcanism
Authors: Silaev V. I. , Vergasova L. P. , Filippov V. N. , Smoleva I. V. , Moskaleva S. V. , Khazov A. F. , Makeev B. A. , Shablinsky A. P.
Published: April 2024

Microxenoliths of sedimentary-marine carbonatoliths in fumaroles of the crater zone of the Second Cone of the BTFE Northern Breach, which were exposed to exhalative-pneumatolytic fluids with the formation of many compounds with mixed carbonate-sulfate-chloride anionic radicals, which are considered as two interclass and nine intertype crystal chemical hybrids, are studied at the expense of carbonates. The pattern of heterogeneity of mineral parasteresis revealed in the altered microxenoliths is interpreted by us as the result of a successive epigenetic transformation of primary carbonates, first into sulfate-carbonates, then into carbonate-sulfates, and then into chloride-carbonate-sulfates and chlorides. Judging by the absence of signs of phase heterogeneity, the investigated crystal-chemical hybrids are homogeneous solid-phase mixtures of carbonates, sulfates, and chlorides in different proportions. The carbonates in microxenoliths in terms of carbon isotope composition (δ13СPDB = –5.34 ± 0.62‰) and oxygen (δ18OSMOW = 24.09 ± 1.05‰) correspond to carbonates of sedimentary-marine limestones redeposited under conditions of volcanic transport. The isotopic composition of sulfate sulfur (δ34S = 1.5–2‰) varies within the range of fluctuations established for sulfates of volcanogenic origin. In carbon particles associated with microxenoliths, the isotopic compositions of carbon (δ13CPDB = –27.37 ± 2.97‰) and nitrogen (δ15NAir = 6.74 ± 2.48‰) tend to be similar to the mode of distribution of such values in the products of modern continental volcanism. The identified crystal-chemical hybrids are a typomorphic feature of the fumarous-exhalative facies and are considered as a previously unknown phenomenon of modern volcanism.
Regime of Strong Holocene Earthquakes of the Kultor Fault Zone in the Northern Issyk-Kul Lake Region (Tien Shan) According to Radiocarbon Dating Data
Authors: Korzhenkova L. A. , Korzhenkov A. M. , Makeev V. M. , Mazeika J. V. , Rodkin M. V. , Strelnikov A. A. , Fortuna A. B.
Published: April 2024

Morphostructures of the northern slope of the Kungey Ala-Too Range and its southern foothills (adyrs) were studied with use of tectonic geomorphology and paleoseismology methods. Radioisotope (radiocarbon and luminescence) dating data analysis in dug trenches demonstrates the lateral migration of the strong seismic activity along the Kultor Fault zone (northern Issyk-Kul Lake region). It was confirmed that the strong recent seismic activity is concentrated in the adyr zone and located along adyr faults. At least 7 morphogenic earthquakes occurred along the fault zone during Holocene. During common era the reoccurrence of morphogenic earthquakes was 200‒300 years. The strongest seismic catastrophes with М ~ 7.5 (Io = Х) have been apparently occurred in VII and XV centuries along the disjunctive. During this event the seismic sources reached the surface forming the fault scarps with lengths up to 70‒80 km.
The Large (M ≥ 6.0) Earthquakes Seismic Precursors in the Junction Zone of the Kuril-Kamchatka and Aleutian Island Arcs
Authors: Konovalova A. A. , Saltykov V. A.
Published: April 2024

The article describes the behavior of the series of seismic precursors before the activation of 2016‒2019 in an area with a tectonically complex geodynamic environment at the boundaries of the Pacific, North American, and Eurasian lithospheric plates. In order to clarify the location of possible focal areas of future strong earthquakes, a comprehensive approach to the application of allocated precursors was considered: quiescence by parameters RTL and Z-function, variations of the slope of the recurrence graph γ and areas of seismic ruptures dS. For the first time, in relation to Kamchatka, for anomalies to parameter dS, interpreted as seismic activations, the presence of a predictive component before the onset of foreshock activation is shown by the example of an increase in its values before the events that are the strongest for the areas where their focal areas are located: the Near islands Aleutian earthquake with Mw = 7.8 on July 17, 2017 and the Uglovoye Podnyatiye earthquake on December 20, 2018, Мw = 7.3, is demonstrated. The total length of the anomalous region, currently existing and including successive stages of quiescences and foreshock activations is ~900 km, which allows for the possibility of a new strong earthquake with a magnitude exceeding all previously recorded in this area in the junction zone of three lithospheric plates.
Analysis of Swarm Earthquakes on the Territory of the Elbrus Volcanic Center
Authors: Dudarov Z. I. , Dmitrieva I. Yu. , Sayapina А. А. , Bagaeva S. S.
Published: April 2024

The paper presents the results of the analysis of swarm seismic events recorded in 2018 in the area of the Elbrus volcanic center by the North Caucasian seismological network of the FRC GS RAS. The standard method of station processing shows the hypocenters of recorded events in the area of the Elbrus volcanic center. The hypocenters of seismic events in swarm sequences were refined using the LOS software package, a complex combined location algorithm, methods of minimizing the time discrepancy in the source and grid search with depth enumeration. The described approach improves the reliability of location due to accounting for inaccuracies associated with incorrectly taken times of phase arrivals and minor deviations in travel times, depending on the velocity model of the medium used. According to the results of the study of the focal mechanisms of the strongest earthquakes, the type of movement was established, which is consistent with the kinematics of the Elbrus-Mineralnye Vody fault zone. Correlation analysis of the waveforms of the vertical component filtered in the frequency range of 1‒10 Hz, including P and S waves, for the nearest station shows a high coincidence of the analyzed data (correlation coefficient R ≥ 0.85), which indicates a high probability that events have similar sources and paths propagation of seismic waves. Comparison of the power spectral density of individual earthquakes in swarm sequences also demonstrates high similarity.
Quasilinear Approximation for Modeling Difference-Frequency Acoustic Wave in a Diffracting Pump-Wave Beam
Authors: Tyurina A. V. , Yuldashev P. V. , Esipov I. B. , Khokhlova V. A.
Published: April 2024

A quasilinear approach is considered to simulate generation of a difference-frequency acoustic wave by the interaction of two intense high-frequency diffracting pump beams with close frequencies. The boundary condition corresponds to dual-frequency excitation of an existing parametric source used for underwater research. It is shown that the linear field of primary waves has a high directivity with a total beam divergence angle of several degrees; therefore, the nonlinear-diffraction problem is solved numerically in the parabolic approximation. The pump wave field is calculated in the linear approximation; the solutions obtained at each step of the numerical grid along the beam axis are used to calculate nonlinear sources in the equation for a three-dimensional difference-frequency beam. The one- and two-dimensional distributions of the pressure field and the directivity pattern are analyzed for three values of a difference frequency. Numerical solutions obtained with realistic boundary conditions at the source and description of diffraction effects are compared with the known approximate analytical results for the quasilinear approach.
Method for Optimal Analytical Approximation of Time Samplings in Analyzing Nonstationary Periodic Signals
Authors: Vishnyakov A. N. , Makashov S. Yu.
Published: April 2024

An algorithm has been developed for determining the frequency and amplitude of the harmonic components of a weakly nonstationary acoustic signal, which also contains random noise and drift of the constant component. The algorithm was tested on a signal simulating flight of an aircraft over a measurement point. For a model source simulating a the propeller of UAV, the possibility of determining the harmonic amplitudes of a propeller with varying revolutions and under noise interference conditions was demonstrated using the unique scientific installation the TsAGI AC-2 anechoic chamber with flow.
Phonon Spectroscopy of Solid Dielectrics
Authors: Nikitov S. A. , Taranov A. V. , Khazanov E. N.
Published: April 2024

A method for studying solid dielectrics under conditions of nonstationary propagation of subterahertz phonons is presented. The method analyzes the transport characteristics of thermal phonons in the helium (He) temperature range (2–4 K) in diffusion mode and makes it possible to investigate the following: the kinetic characteristics of thermal phonons in single crystals of solid solutions; the contribution to phonon scattering from the concentration, type, and positions of a substitutional impurity, defects comparable with the wavelength (clusters, phase inhomogeneities, dislocations), low-energy excitations of various nature, including those associated with the formation of an equilibrium configuration of vacancies in the anionic sublattice with respect to substitutional impurity cations; equilibrium criteria in the system of nonequilibrium phonons–low-energy excitations; peculiarities of the phonon spectrum of nanostructured materials; the relationship between the diffusion coefficient of subterahertz phonons and the system of grain boundaries (GB), grain size, conditions for the formation of a “gap” in the phonon spectrum of nanostructured ceramics; spectral properties of GB, their relationship with the technological conditions of synthesis, to evaluate the average thickness and acoustic impedance of GB for a sample; the features of thermal phonon transport in amorphous dielectrics (glasses and glasslike materials) near the thermal conductivity “plateau,” the possibility of “gap” formation in the spectrum of phonon states; subterahertz phonon transport in ceramics based on ferroelectrics, electrolyte solid solutions, and cermets.
Validation of a Two-Point Jet–Wing Interaction Noise Model for a Realistic Configuration
Authors: Bychkov O. P. , Faranosov G. A.
Published: April 2024

For the case of a realistic small-scale “double-stream nozzle–high-lift wing” configuration, a previously developed simplified semiempirical method for calculating the low-frequency noise of jet–wing interaction is tested. As input data for calculating the noise, we used the results of measuring the amplitude and convective velocity of perturbations in the near field of a turbulent jet near the trailing edge of an extended flap. The measurements were performed with a pair of pressure sensors flush-mounted on the lower surface of the wing model. It is demonstrated that the results of the calculated estimate for the spectral characteristics and directivity of the interaction noise agree well with direct noise measurements in the far field both under static conditions and in the presence of coflow simulating the effect of flight.
Localization and Ranking of Aircraft Noise Sources in Flight Tests and Comparison with Acoustic Measurements of a Large-Scale Wing Model
Authors: Zaytsev M. Yu. , Kopiev V. F. , Velichko S. A. , Belyaev I. V.
Published: April 2024

The noise of a modern regional aircraft was measured using the beamforming method during flight tests in the landing approach configuration with extended landing gear and deflected high-lift devices (slats and flaps). The localization and ranking of aircraft noise sources for full-scale Reynolds numbers has been carried out. Comparison of the flight test results with the results of acoustic measurements of airframe noise for a large-scale wing model obtained earlier at DNW-NWB showed good agreement between noise measurements of the large-scale model, scaled to full size, with the results for the airframe noise of an aircraft wing in flight tests.
Internal Antisymmetric Lamb Waves
Authors: Mokryakov V. V.
Published: April 2024

A class of antisymmetric solutions of Lamb wave equations with zero strains and stresses on the surface, so-called internal Lamb waves, is studied. Two types of such solutions are found: the first corresponds to the Lamé phase velocity; the second, to phase velocities exceeding the velocity of the expansion wave in an unbounded medium. It is proved that internal waves with the same phase velocity form series, while the frequencies of members of one series are multiples of the frequency of the first member of the series. The same is true for wavenumbers. The profiles of deformed plates and distributions of the maximum stress and shear values are presented.
The Use of Focused Ultrasound Beams with Shocks to Suppress Diffusion Effects in Volumetric Thermal Ablation of Biological Tissue
Authors: Pestova P. A. , Karzova M M. , Yuldashev P. V. , Khokhlova V. A.
Published: April 2024

The article presents the results of numerical simulation of an experiment on irradiatingex vivobovine liver sample by the therapeutic array of the MR-HIFU clinical system (Sonalleve V1 3.0T, Profound Medical Corp., Canada). Continuous quasi-linear and pulsed shock-wave exposures with the same time-averaged power are compared. Volumetric thermal lesions were generated by moving the focus of the array in its focal plane along discrete trajectories consisting of two or four concentric circles with a maximum radius of 4 mm. The effect of using the criteria for controlling the thermal dose during treatment and ending the sonication on the shape, volume, and exposure time of generating thermal lesion were analyzed. The acoustic field in tissue was calculated using the Westervelt equation; the temperature field was simulated with the inhomogeneous heat conduction equation; and the lesion boundary was determined according to the thermal dose threshold. In the quasi-linear mode corresponding to the clinical one, thermal diffusion leads to elongation of the lesion by a factor of 2–3 along the beam axis compared to the transverse dimension of the trajectory. The use of pulsed shock-wave exposures with switching off the inner circles of the trajectory as they reach the threshold value of the thermal dose makes it possible to significantly suppress the thermal diffusion effects in the axial direction of the beam and obtain localized thermal lesion of a given shape with a thermal ablation rate comparable to the clinical case.
Acoustic Studies of the Melting and Crystallization of Eutectic Gallium–Silver Alloys in Porous Glasses
Authors: Pirozerski A. L. , Charnaya E. V. , Abdulamonov Kh. A. , Nedbai A. I. , Kumzerov Yu. A. , Fokin A. V. , Khomutova A. S.
Published: April 2024

The paper presents the results of acoustic studies of the melting and crystallization of Ag–Ga alloys with a silver content of 1.5 and 3 at % embedded into porous glasses with an average pore size of 13 nm. The temperature dependences of the velocity of longitudinal ultrasonic waves are measured by a modified pulse-phase method at a frequency of 7 MHz in the 200–325 K range for complete and partial cooling–heating cycles. The temperature dependences of the ultrasonic velocity showed regions corresponding to phase transitions. Significant changes in the phase diagram of the bulk alloy due to nanostructuring have been revealed. It is shown that segregates with different crystal structures are formed in the pores for alloy of different compositions.
Diffraction of a Whispering Gallery Mode at a Jumply Straightening of the Boundary
Authors: Zlobina E. A. , Kiselev A. P.
Published: April 2024

Diffraction of a high-frequency small-number whispering gallery mode running along a concave boundary, which turns into a flat one so that its curvature experiences a jump, is studied. The cases of rigid (Neumann) and soft (Dirichlet) boundary conditions are considered. Within the framework of the parabolic equation method, a mathematically correct scattering problem is obtained which is solved explicitly and investigated asymptotically in detail. Analytic expressions are found for all emerging wavefields. In particular, an edge wave diverging from the point of non-smoothness of the boundary is described. For the rigid condition, its amplitude is proportional to the magnitude of curvature jump, but not for the soft condition.
Comparative Analysis of the Acoustic Characteristics of Composite and Metal Panels Under Sound and Pseudosound Excitation
Authors: Zverev A. Ya.
Published: April 2024

The results of experimental studies to determine the acoustic and vibroacoustic characteristics of a panel made of a polymer composite material are presented in comparison with the characteristics of a reinforced metal panel of comparable mass and relative stiffness. A comparative analysis of the characteristics was carried out for an unlined panel and a panel lined with a vibration-absorbing material in the case of their excitation by sound and pseudosound fields of pressure fluctuations