bluuebunny/crossref_metadata_2025 huggingface dataset:
Muscarinic and Nicotinic Acetylcholine Receptors in the Regulation of the Cardiovascular System
Authors: Osipov A. V. , Averin A. S. , Shaykhutdinova E. R. , Dyachenko I. A. , Tsetlin V. I. , Utkin Y. N.
Published: April 2024

Many different receptors and ion channels regulating ion currents are involved in the regulation of the cardiovascular system (CVS). The functioning of the CVS occurs via mechanisms of both nervous and humoral regulation, and in both cases, acetylcholine receptors of different families and subtypes with different localization participate in the regulation processes. It has been shown that acetylcholine receptors are located on the cell membranes directly of the heart and blood vessels; and this review examines the mechanisms of regulation of the functions of the CVS with the participation of only those cholinergic receptors that are located in the tissue of the heart and blood vessels. In general, both muscarinic and nicotinic cholinergic receptors are widely represented in the tissues of the CVS. While muscarinic acetylcholine receptors are generally involved in the regulation of vascular tonus and contractility of the heart, the nicotinic acetylcholine receptors are mainly involved in the regulation of a number of important pathophysiological processes directly affecting the functioning of the CVS. Regulation of the functioning of cholinergic receptors can be considered as an addition to existing methods for the treatment of diseases of the CVS, including such diseases as atherosclerosis and heart failure. The use of blockers and activators of cholinergic receptors for the study and/or treatment of pathological conditions of the CVS is discussed.
A Route to Synthesize Ionizable Lipid ALC-0315, a Key Component of the Lipid Matrix of an mRNA Vaccine
Authors: Boldyrev I. A. , Shendrikov V. P. , Vostrova A. G. , Vodovozova E. L.
Published: April 2024

Ionizable lipid ALC-0315 – ((4-hydroxybutyl)azanediyl)bis(hexane-6,1-diyl)bis(2-hexyldecanoate) – is a part of the lipid matrix of the mRNA vaccine for the prevention of infection with the SARS-CoV-2 virus manufactured by Pfizer/BioNTech. This lipid provides effective assembly of the vaccine particle, protection of mRNA from premature degradation, and after endocytosis, promotes the release of nucleic acid into the cytoplasm for further processing. In this paper, a simplified and economical method for producing ALC-0315 is proposed, which can be used in the production of mRNA vaccines.
Fluorescence Decay Analysis of the Model Compounds as an Approach to Photophysical Engineering of Fluorescent Proteins
Authors: Baleeva N. S. , Baranov M. S. , Bogdanov A. M.
Published: April 2024

Studying of structure-function relationships between a chromophore and its protein environment plays a key role in photophysical engineering of fluorescent proteins (FPs), specifically, in the guided designing of their new variants with a higher fluorescence quantum yield (FQY). Known approaches to FQY increasing mostly rely on suppression of the excited state nonradiative processes, but no tools have been suggested for the tuning of the radiative rate constant (kr), which is also a potentially “adjustable” value. Here, we propose an experimental approach in which the synthetic chromophore of FP models the “fixation” of the most important radiationless constants and allows monitoring of the fluorescence lifetime flexibility (as an indicator of the kr value). As a proof-of-concept, we studied the time-resolved fluorescence behavior of the green and blue FP chromophore analogs in diverse chemical environments. The conformationally locked analog of the GFP chromophore in most cases showed monophasic fluorescence decay kinetics with a lifetime of 2.7–3.0 ns, thus adequately modeling the typical behavior of GFPs with the highest FQYs. Under the conditions of stimulated ionization of this chromophore, we observed increased (up to 4.3–4.6 ns) fluorescence lifetimes, which can be interpreted in terms of an increase in the radiative constant (kr). The conformationally locked analog of the Sirius chromophore showed biexponential fluorescence decay kinetics, partly simulating the properties of the blue FPs. In an acetic acid solution, this compound exhibited distinct fluorescent properties (elevated fluorescence intensity with a major lifetime population of ~4 ns), which can be interpreted as the emission of an unusual cationic form of the chromophore.
Regiospecific Preparation of a Suitably Protected β-Branched Aspartic Acid Dipeptide
Authors: Azev V. N. , Baidakova L. K. , Chulin A. N. , Tuzikov A. B. , Kislitsyn P. G. , Molchanov M. V. , Miroshnikov A. I.
Published: April 2024

A new efficient synthetic approach for the preparation of Nα-protected β-L-aspartyl-L-aspartic acid dipeptide was elaborated. The distinctive features of the developed approach include utilization of readily available starting materials (Cbz-asparagine and dimethyl aspartate), aspartimide formation suppression employing electrostatic effect in a final deprotection step and an employment of a novel reagent (NaNO2/aqueous trifluoroacetic acid) for transformation of protected asparagine derivative into the corresponding aspartic acid. The developed method allowes preparation of aspartic acid derivatives that find application in carbohydrate polivalent interaction studies as well as in preparation of microbicidal dendrimeric constructs.
Induction of the Antioxidant Activity by Selenium Compounds in the Aspergillus niger Mycelium
Authors: Poluboyarinov P. A. , Kuznetsova A. V. , Moiseeva I. Ya. , Mikulyak N. I. , Kaplun A. P.
Published: April 2024

Investigation of the antioxidant activity (AOA) induction by selenium compounds (Na2SeO3, diacetophenonyl selenide (DAPS-25), L-selenocystine) in various organisms is interesting as a protection from stress induced cell membranes damages. A comparative analysis of the antioxidant activity of 23 amino acids was performed by coulometric titration with electrogenerated bromine and iodine. The activity decreases in the order: cystine tryptophan selenocystine tyrosine 3,3'-dimethyl-L-selenocystine methionine. Only amino acids with sulfhydryl and selenol groups as more active reductants can interact with the electrogenerated iodine: cysteine selenocysteine threo-3-methyl-L-selenocysteine. Probably the correction of the antioxidant status at the amino acids level is based on the sulfhydryl and selenol groups in radicals. In case they are not enough, cystine, selenocystin, tryptophan, tyrosine, and methionine will act as scavenger-reductants. It was found that selenium compounds dose-dependently induce the total antioxidant activity of the A. niger mycelium and affect indicators of the antioxidant status (amino acid composition and catalase activity), which in turn stimulates the biomass accumulation. DAPS-25 and sodium selenite treatment at the high doses (0.025 mg Se/L) caused the greatest effect on the total AOA induction (3.4–5.5 times). Lower concentrations (0.0025–0.00025 mg Se/L) had a lesser effect (25.8–41.7%). Activity in samples with L-selenocystin increased by 1.6–43.3%. It is noted that the iodine antioxidant activity in the mycelium was generally lower than the bromine one.
Synthesis of Liposomes Conjugated with CpG Oligonucleotide and Loaded with a Set of T-Cell Epitopes of the SARS-CoV-2 Virus
Authors: Tretiakova D. S. , Azhikina T. L. , Boldyrev I. A. , Svirshchevskaya E. V. , Vodovozova E. L.
Published: April 2024

The synthesis of lipid conjugate of immunostimulatory oligodeoxyribonucleotide CpG-ODN (PD-CpG-DOPE) is described. Liposomes loaded with a composition of T-cell epitopes of the SARS-CoV-2 virus (7 peptides) and carrying PD-CpG-DOPE conjugate in the membrane, including lyophilized liposomes suitable for long-term storage, were prepared. In vitro experiments on mouse peritoneal exudate cells showed a tendency to increase the immunogenicity of liposomes with peptides when PD-CpG-DOPE conjugate was introduced into the lipid bilayer, compared with the addition of the (commercial) phosphorothioate derivative of CpG-ODN in solution.
Long-term Monitoring of Pollution of the Coastal Water Area of Ussuriysk Bay with Metals: Case Study of “Green” Oysters Magallana gigas (= Crassostrea gigas) (Thunberg, 1793)
Authors: Shulkin V. M. , Kavun V. Ya.
Published: April 2024

In September 2021, the content of heavy metals Pb, Cu, Cd, Zn, Ni, Fe, and Mn was estimated in the tissues of the oyster Magallana gigas (= Crassostrea gigas) (Thunberg, 1793) and in the silty fraction of bottom sediments from mollusk habitats in coastal waters around the Muravyov-Amursky Peninsula, including the most polluted area off the western coast of Ussuri Bay of the Sea of Japan. It has been shown that, despite the reclamation of the landfill located here in 2010, being the main source of metal pollution, copper is present in high concentrations in bottom sediments and tissues of oysters, giving them a green color. The mollusks living in this area also retain a high concentration of zinc. The concentrations of Pb, Cd, and Ni in oyster tissues over the past 20 years have decreased by 2–5 times in accordance with the decrease in the number of mobile forms of these metals in bottom sediments; however, they are still 3–6 times higher than regional estimates for polluted water areas. With abnormal accumulation of copper, manganese, on the contrary, demonstrates a decrease in the concentration in the tissues of oysters from the most polluted stations, reflecting the deterioration of the physiological state of mollusks. The results obtained indicate the need to continue the remediation of the western coast of Ussuri Bay and monitor the pollution of coastal waters with metals.
Composition of Leukocytes of the Peripheral Blood of Plunderfish Pogonophryne sp. (Perciformes: Artedidraconidae) and Grey Rockcod Lepidonotothen squamifrons (Günther, 1880) (Perciformes: Nototheniidae) from the Ross Sea
Authors: Gordeyev I. I. , Mikryakov D. V. , Balabanova L. V.
Published: April 2024

A comparative study of the composition of peripheral blood leukocytes of plunderfish and grey rockcod or squama caught in the Ross Sea has been carried out. Blood smears revealed cells of different morphofunctional characteristics and structure: lymphocytes, monocytes, neutro- and eosinophils, and blast cells. An analysis of the leukogram showed that the white blood of the studied species has a lymphoid character. In the rockcod leukogram, the proportion of lymphocytes is significantly higher, while that of monocytes and blast forms is lower. In the plunderfish, in comparison with grey rockcod, the leukocyte cells of the same name are usually larger.
Biochemical and Ultrastructural Changes in the Microalgae Tisochrysis lutea (Bendif et Probert) (Haptophyta) at different stages of growth in enhancement culture
Authors: Orlova T. Yu. , Markina Zh. V. , Karpenko A. A. , Kharlamenko V. I. , Zinov A. A.
Published: April 2024

In our study we investigated the growth, biochemical composition, and ultrastructure of Tisochrysis lutea microalgae in enrichment culture during 30 days experiment. The number of T. lutea cells increased throughout the experiment. We noted an increase in the size and number of lipid droplets containing fatty acids and carotenoids, including fucoxanthin, in the exponential and stationary phases of their growth. It has been established that the total content of carotenoids reaches a maximum in the stationary phase and decreases in the dying phase. During the stationary phase, exocytosis is observed in cells with the release of lipid droplets. This study demonstrates the potential of the T. lutea clone MBRU_Tiso-08 from the Marine Biobank Bioresource Collection of the NSCMB FEB RAS as a raw material for domestic biotechnology aimed at the combined extraction of carotenoids (including fucoxanthin) and lipids (including docosahexaenoic and eicosapentaenoic fatty acids).
Blood Cell Morphology of the Beluga Whale Delphinapterus leucas (Pallas, 1776)
Authors: Mischenko P. V. , Yachmen V. A. , Andrianova E. N. , Zakharenko P. G.
Published: April 2024

Clinical blood analysis, combined with cytomorphological examination is an important diagnostic tool for assessing the physiological state of animals. The cytomorphological features of blood cells have been described for terrestrial mammals, and well-illustrated veterinary atlases have been created, in which normal and pathological forms of animal blood cells are displayed. However, such information is virtually non-existent for marine mammals. In this article, we present the results of a study of the morphology of the blood cells of the beluga (also known as white) whale Delphinapterus leucas, obtained by supravital staining of blood smear preparations with brilliant cresyl blue, methylene blue, and utilizing the standard Romanowsky–Giemsa staining technique. We describe the main types of blood cells of marine mammals: erythrocytes, segmented neutrophils, eosinophils, monocytes, lymphocytes, band neutrophils, as well as rare basophils.
Biological Features of Atlantic Cod Gadus Morhua L., 1758 (Gadiformes: Gadidae) of the Murmansk Coast: Race Composition and Fishing
Authors: Stroganov A. N. , Yaragina N. A. , Filina E. A. , Ponomareva E. V.
Published: April 2024

The biological features of Atlantic cod in the coastal zones of the Murman for 1999–2006 were studied. The age composition, growth rate and maturation, feeding habits and structure of otoliths were analyzed. Histological and genetic studies were carried out. It was shown that young cod mainly lives and spawns in Western Murman bays. Older cod leaves the bays due to insufficient food supply. The growth rate of young coastal cod is comparable to that of cod in the open part of the Barents Sea. With age, the cod of open sea areas noticeably overtakes the cod that lives in the coastal zone in growth. It was noted that cod spawns in the bays with both coastal and Atlantic types of otoliths. Studies of genetic polymorphism indicate a high degree of genetic si-milarity between cod groups in the Norwegian and Barents Seas, which is evidenced under the influence of currents (branches of the Norwegian Atlantic Current, the Murmansk Coastal Current) and against the background of migrations at different stages of ontogeny of cod individuals from coastal and open water areas.
Colonial Nesting Sea Birds (Charadriiformes: Laridae) of Peter the Great Bay, the Sea of Japan
Authors: Tiunov I. M. , Katin I. O.
Published: April 2024

The paper presents the recent data on the distribution and breeding abundance and distribution of the Mongolian Gull, Slaty-backed Gull, Black-tailed Gull and the Common Tern nesting within Peter the Great Bay of the Sea of Japan. Over the past 30 years, all species of gulls increased their abundance, while the Common Tern has almost ceased to nest on the islands of the bay.
Spatial Distribution, Size and Age Composition of Population of Mya japonica Jay, 1857 (Bivalvia: Myidae) in Peter the Great Bay, Sea of Japan
Authors: Selin N. I.
Published: April 2024

In July–August 2022, the spatial distribution and the composition of local aggregations of the bivalve mollusc Mya japonica Jay, 1857 in the Vostok Bay (Peter the Great Bay of the Sea of Japan) were studied. M. japonica occurred almost throughout the entire bay in a wide range of depths from 0 to 22 m at water temperatures from –1.9 to 25°С and salinity from 0 to 34‰. M. japonica was the most abundant in the shallow areas of the bays, closed from the direct wave impact, where, at a depth of up to 4–5 m, the density of the mollusc reached 27 ind./m2, and the biomass was almost 4 kg/m2, which averaged 56% of the total macrozoobenthos biomass. With increasing depth and moving from the dead-end of the bay to the open sea, the abundance of M. japo-nica decreased by one or two orders of magnitude. Local settlements differed significantly in size and age composition, size-frequency distribution of molluscs, indicating the nature of the replenishment of the benthic population with juveniles, as well as the proportion of commercial size individuals, which ranged from 37 to 98%. The reasons for the revealed features of the distribution and structure of the population of M. japonica are discussed.
Results of Long-Term Observations of the Electric Field of the Atmosphere During the Eruption of Volcano Ebeko in the Period 2018‒2020
Authors: Akbashev R. R. , Makarov E. O.
Published: April 2024

In order to study the processes of formation of Volume charges in the eruptive clouds of the eruptions of the Ebeko volcano in the period 2018‒2020, observations of the atmospheric electric potential gradient in the city of Severo-Kurilsk were carried out. 179 cases were recorded when the propagation of an eruptive cloud occurred in cloudless or low-cloud conditions and was accompanied by a response in variations of the atmospheric electric potential gradient. Four types of responses in variations of the potential gradient of the electric field of the atmosphere are revealed, it is shown that the type of recorded response is determined by the conditions of propagation of the eruptive cloud relative to the point of registration, and also determined by the relative location of the lower and upper regions of the eruptive cloud at the time of registration of the response. At the same time, the negative volume charge prevails in the eruptive cloud, which is localized in the upper region of the eruptive cloud, the positive volume charge is localized in the lower region. The data of field observations are consistent with the results of numerical modeling.
How to Choose a Magnitude Interval to Evaluate the Slope of the Magnitude-frequency Graph
Authors: Pisarenko V. F. , Skorkina A. A. , Rukavishnikova T. A.
Published: April 2024

In modern seismological practice, to describe the distribution of magnitudes, the Gutenberg-Richter law is widely used, one of the parameters of which is the b-value (the slope of the magnitude-frequency graph on a log scale). Authors propose new approaches to the problem of adequate and efficient statistical estimation of this parameter. The problem of the correct choice of the magnitude interval is discussed, on which the straightness of the Gutenberg-Richter law is observed with an acceptable degree of accuracy and which should be used to estimate the b-value. An efficient method of accounting for discreteness and aggregation of magnitudes in earthquake catalogs (the maximum likelihood method for discrete distributions) is proposed. The problem of changes in time of the lower limit of representative earthquakes registration is considered and a statistical approach is proposed for their description.
Fundamentals of the Phenomenological Theory of Earthquakes
Authors: Guglielmi A. V. , Klain B. I. , Zavyalov A. D. , Zotov O. D.
Published: April 2024

Phenomenology is a unity of principles and methods for investigating the essence of phenomena. This article is a brief review of a series of works carried out by the authors over the past ten years. The general thrust of the works is that phenomenological ideas of physics are used to analyze earthquakes. A perfect model of phenomenological theory is thermodynamics. Maxwell’s electrodynamics is also a perfect example of phenomenological theory. Earthquake phenomenology is still far from reaching that level. In the system of rational knowledge of geodynamics, we have so far reached the status of a preliminary view of the subject, methods, and tasks of the future phenomenological theory of earthquakes. Nevertheless, already at this stage it is clearly visible the perspective of the proposed approach to the construction of the theory. The article shows by concrete examples that it is useful to use phenomenological representations of general physics when searching for the bases of the theory and when processing and analyzing specific manifestations of seismicity.
Acoustic Resonance Spectroscopy with an Uncalibrated Microwave Path
Authors: Alekseev S. G. , Luzanov V. A. , Raevsky A. O. , Balashov V. V. , Lopukhin K. V. , Polzikova N. I.
Published: April 2024

Acoustic resonance spectroscopy (ARS) is an informative analytical method that yields information about thicknesses and acoustic properties of layers in a multilayer structure representing a high-overtone bulk acoustic wave resonator (HBAR). Since the HBAR spectrum has many resonance features, the development of automatic methods for its processing is an urgent task. In this study, a method for extracting ARS data from a signal distorted by a RF measuring path without additional measurements of reference impedances (calibration) is proposed, which brings the spectrum to a form convenient for automatic processing and significantly expands the range of the ARS application. The method is especially relevant for processing HBAR spectra with a low excitation efficiency. As an example of such processing, the central frequencies and effective widths of more than a thousand resonant peaks are determined and, based on this, the frequency dependence of the acoustic attenuation is established for a new material: optical ceramics based on doped yttrium aluminum garnet nanoparticles.
Spatial Processing of Acoustic Signals in Oceanic Waveguides on a Wind Noise Background
Authors: Raevskii M. A. , Burdukovskaya V. G.
Published: April 2024

The articles studies how the correlation characteristics of noise generated by wind sources affect the efficiency of spatial processing of signals received by a horizontal array in oceanic waveguides with a rough sea surface. The array gain values are analyzed for three spatial processing methods: the standard PA method, optimal linear processing, and optimal quadratic processing. Numerical simulation results for winter hydrological conditions in the Barents Sea and Pacific Ocean are presented. The authors focus on dependence of the array gain on the distance to the source. The array gain values calculated using the wind noise model and traditional noise model uncorrelated on its elements are compared.
Adaptive Active Wideband Acoustic Noise Cancellation System with Dynamic Calibration
Authors: Lvov A. A. , Karaseva V. A. , Potapov O. A. , Sokov A. M.
Published: April 2024

The article contains the operational principle of adaptive active wideband acoustic noise cancellation system. The algorithm of operation of these systems provides to work with changes of the medium, acoustic or electrical parameters of their elements, is described. A modification of this algorithm is proposed, which can increase the efficiency of the system and reduce the level of residual noise during system calibration. The results of simulation the modified algorithm of an active noise cancellation system are presented.
Increasing the Frequency Resolution when Measuring Vibrations of Rotating Bodies with Fixed Beam Laser Vibrometry
Authors: Artelnyi V. V. , Rodionov A. A. , Stulenkov A. V.
Published: April 2024

Laser Doppler vibrometry is actively used in experimental studies because of its noncontact measurement technique. When using a stationary laser to measure the vibrations of rotating bodies and Fourier transform to process the results of such measurements, a problem arises, associated with a decrease in the frequency resolution of the spectra with increasing rotation rate of the body. As a result, at sufficiently high rotation rates, closely spaced discrete components may cease to be resolved. This paper proposes a method for solving such a problem using the least squares method. The operability of this processing method has been demonstrated on experimental data.
Scattering of a Plane Sound Wave by a Spherical Interface of Two Media with Sound Absorption in the Acoustic Boundary Layer
Authors: Grigorieva N. S. , Legusha F. F. , Safronov K. S.
Published: April 2024

The scattering of a plane sound wave by a spherical interface between two liquid or gaseous media is simulated. The influence of heat conductivity and viscosity is taken into account; the results of G. Kirchhoff’s classical work on sound propagation in a viscous and heat-conducting medium are used. A spherical surface can have any wave dimension. The results are compared with the field scattered by a solid sphere, which is an ideal heat conductor.
Peculiarities in the Transformation of the Profile of Acoustic Nonlinear Waves Reflected from a Stepped Structure
Authors: Bakhtin V. K. , Gurbatov S. N. , Deryabin M. S. , Kasyanov D. A.
Published: April 2024

The article presents the results of studying the reflection of an intense acoustic beam from stepped structures. The case of high Reynolds numbers is considered, when a sawtooth wave profile formed in the incident beam, and an obstacle in the form of a step was located normal to the acoustic axis and behind the discontinuity coordinate. When reflected from the obstacle, the acoustic beam incident on it splits into two parts, between which there is a path difference, specified by the stepped structure itself. The experiment focused on obstacles that create a path difference between the two parts of the beam during reflection, equal to 0, λ/3, λ/2, λ, etc. A broadband membrane hydrophone was used to record the shape of the profile of nonlinear waves of the incident and reflected acoustic beams at an arbitrary spatial point. This made it possible to analyze the evolution of the beam shape with increasing distance from the obstacle, as well as to study its transverse structure. The effect of doubling the characteristic frequency of a signal as an acoustic beam is reflected from a stepped structure is shown, which creates a path difference of λ/2 between the two parts of the reflected beam. It is demonstrated that the dynamics of nonlinear effects in intense beams reflected from stepped structures is similar to the transformation of the profile of acoustic waves generated by dual-frequency pump signals.
An Information-Statistical Approach to Analyzing Acoustic Emission Signals
Authors: Erofeev V. I. , Ilyakhinsky A. V. , Rodyushkin V. M. , Ryabov D. A. , Khlybov A. A.
Published: April 2024

A new information-statistical approach is proposed that makes it possible to consider acoustic emission (AE) from the standpoint of synergetics based on representation of processes that govern the state of the object under study, a statistical model (image) in the form of a probability density function. It is shown that the multidimensional Dirichlet distribution has a set of properties that can be used to determine the integral metric for estimating the plastic deformation process from observed AE signals. As a quantitative measure in analyzing the plastic deformation process using AE signals, it is proposed to use the self-organization parameter. Regular mechanical tests of structural carbon steel 20 with a pearlite–ferrite structure were carried out to demonstrate that the information-statistical self-organization parameter is the most informative when describing AE-related processes.
Broadband Acoustic Field in a Shallow-Water Waveguide with an Inhomogeneous Bottom
Authors: Sidorov D. D. , Petnikov V. G. , Lunkov A. A.
Published: April 2024

A broadband (35–1000 Hz) sound field formed by a point source in a shelf zone with inhomogeneous bottom sediment structure is studied using numerical modeling. The shelf depth is about 30 m and the maximum distance is 10 km. The transitional zone from the bottom with a sound speed of 1400 m/s to the bottom with a speed of 1600 m/s is chosen as the model inhomogeneity. The normal mode theory and wide-angle parabolic equations are used for sound field calculations. Numerical experiments show that the manifestation of horizontal refraction is noticeable at low frequencies (below 100 Hz). It leads to an increase in the amplitude of the low-frequency sound pulse propagating along the transitional zone by more than 10 dB in comparison with a similar waveguide with a homogeneous bottom. At frequencies above 100 Hz, the dominant effect is the mode coupling, causing the appearance of quasi-periodic oscillations of modal amplitude in the frequency domain. The conclusions from the simplified model are confirmed by calculations for the real structure of bottom sediments in the Kara Sea.
Study of the Acoustic Characteristics of Suspensions Based on Glycerol and Synthetic Diamond Microparticles Using a Resonator with a Longitudinal Electric Field
Authors: Semenov A. P. , Zaitsev B. D. , Teplykh A. A. , Borodina I. A.
Published: April 2024

The acoustic properties of suspensions based on pure glycerol and diamond powder with a particle size of 1–2 μm and different concentrations were studied using a resonator with a longitudinal electric field. A disk resonator made of langasite with round electrodes on both sides of the plate with a frequency of 4.1MHz, operating on a longitudinal acoustic wave, was completely immersed in a liquid container with the studied suspension. Based on the measured frequency dependences of the real and imaginary parts of theelectric impedance of the resonator using an equivalent electromechanical circuit, the longitudinal elastic modulus and longitudinal viscosity coefficient of the samples were determined. Comparison of the experimental dependences of the longitudinal elastic modulus, viscosity coefficient, and longitudinal acoustic wavevelocity on the volume concentration of diamond particles in the suspension with the calculated dependences demonstrated good agreement.
Visualizing Ultrasound Sources Using Signal Time Reversal in the Particle Dynamics Model
Authors: Sukhanov D. Ya. , Kuzova A. E.
Published: April 2024

A method is proposed for solving the inverse problem of reconstructing acoustic wave sources from field measurements on some surface using wavefront reversal in the particle dynamics method. In this method, the studied medium is represented as a set of interacting particles (material points or solid bodies), for which classical equations of motion are written. The paper considers the representation of a medium as a set of particles in a body-centered cubic crystal lattice. The case of a linear dependence of the force of attraction of particles on distance is considered. The advantage of this approach is the ability to take into account wave propagation in arbitrarily inhomogeneous media using a single numerical model. The possibility of visualizing two spherical acoustic wave sources in water behind an obstacle has been demonstrated numerically and experimentally, despite the presence of transverse waves in the considered model of a solid body; their influence is negligible in this case. The method was tested experimentally on a soundproof screen with an aperture simulating a sound-emitting object of complex shape. A wave from a point source of short pulses passes through the aperture. Using a receiving acoustic sensor mounted on a two-dimensional scanner, the spatiotemporal distribution of sound vibrations on the water surface was measured. By processing the datausing wavefront reversal in the particle model, the image of the aperture in the soundproof screen was reconstructed.
Features of Plankton Metabolism: Results of Automated Measurements in the Mozhaisk Reservoir
Authors: Goncharov A. V. , Puklakov V. V. , Grechushnikova M. G. , Yumina N. M.
Published: April 2024

Plankton metabolism determines fluctuations in the oxygen concentrations of a water body, its ecological condition, and exchange of СО2 with the atmosphere. We used an automated device that allowed us to make mass measurements of intraday values of the gross primary production (GPP) and respiration (R) of plankton. During our studies of the Mozhaisk reservoir (Russia) in the summer of 2017, we established an important fact: the maximum values of GPP are observed essentially earlier in the daytime than those of R. This is explained by the fact that GPP is related to solar radiation (the maximum values are observed at noon), whereas R is related to the temperature of water, which reaches its maximum several hours after in the afternoon. As a result, the maximum value of dissolved oxygen is observed in the second half of the day, when GPP and R become even. The device we have designed may be used for continuous monitoring of metabolism of plankton and of its responses to various hydrometeorological, hydrochemical and anthropogenic impacts.
New Records of Sphaerius acaroides (Coleoptera, Sphaeriusidae) from Russia Extend the Known Distribution of Myxophaga to Siberia
Authors: Prokin A. A. , Salnitska M. A. , Sazhnev A. S. , Stolbov V. A. , Sheykin S. D.
Published: April 2024

Abstract—А beetle species Sphaerius acaroides Waltl, 1838, widespread in Europe, Caucasus region and Iran, is here recorded from Tatarstan Republic and Tyumen Oblast (Russia) for the first time. The Tyumen record is the easternmost hitherto known and it is the first Siberian record for this species, genus, family and suborder. Molecular analysis based on the mitochondrial gene cytochrome oxidase I (COI) showed that the specimen from Tyumen Oblast, which is morphologically identical with the European specimens, undoubtedly belongs to S. acaroides. All phylogenetic reconstructions revealed S. acaroides as a well-supported clade. The analysis based on pairwise distance (p-distance) between studied samples showed the distance on the intraspecific level not exceeding 1.1%. The largest distance observed between specimens from Tyumen and north-west Germany, still shows only variability between the conspecific populations.
Amphimonhystrella tropica sp. n. and Oncholaimus mekongis sp. n. (Nematoda) from the Mouth of the Mekong River, Vietnam
Authors: Gagarin V. G. , Gusakov V. A.
Published: April 2024

Illustrated descriptions of two new nematode species, Amphimonhystrella tropica sp. n. and Oncholaimus mekongis sp. n., found in the mouth of the Mekong River (Vietnam) are given. А. tropica is close to A. major Gagarin, Nguyen Dinh Tu, 2021 and A. paramonovi Phan Ke Long, Nguyen Dinh Tu, Gagarin by body size. It differs from first species in pharyngostoma shape, thiker body, longer tail and spicules, and absence of posterior uterus sac. It differs from second species in thicker body, longer spicules and another gubernaculum structure. Daptonema paramonovi Phan Ke Long, Nguyen Dinh Tu, Gagarin, 2020 is transferred to the genus Amphimonhystrella Timm, 1961: A. paramonovi (Phan Ke Long, Nguyen Dinh Tu, Gagarin, 2020) comb. nov. Dichotomy and pictorial keys for the identification of males of valid species of the genus Amphimonhystrella are given. Oncholaimus mekongis sp. n. is close to O. balli (Kreis, 1934) and O. menzeli Schneider, 1973 by body size and spicules length. It differs from both species in the presence of big spiny seta before to cloaca, position of ventral papillae at tail of males, thicker body, shorter outer labial setae and longer and slender males tail.
Otolith Biometry of Pikeperch Sander lucioperca from the Lakes Region of Turkey
Authors: Koca H. U. , Küçükköse A. G.
Published: April 2024

The present study aimed to confirm the existence of relationships between the otolith size (otolith length, otolith breadht, otolith area, and otolith weight) and the size of Sander. lucioperca (L., 1758) from Eğirdir and Beyşehir Lake, Turkey. The length-weight relationships were defined as W = 0.0030L3.386 (R2 = 0.993) for females, W = 0.0032L3.309 (R2 = 0.987) for males from the Eğirdir Lake, and W = 0.0033L3.339 (R2 = 0.977) for females, W = 0.0024L3.410 (R2 = 0.976) for males from the Beyşehir Lake. No significant relations total length and otolith length (OL), otolith breadth (OB), area (A), and otolith weight (OW) were found both the sexes and all the localities. The maximum coefficient of determination were observed between total length and OL, A and OW, while the minimum was observed for OB. The results showed that can be used for the monitoring of stocks in pikeperch populations benefit otolith size.
Is Aquatic Fern Salvinia natans (Salviniaceae) Rare in Russia?
Authors: Konotop N. K. , Vinogradova Yu. S. , Chemeris E. V. , Bobrov A. A.
Published: April 2024

According to publication and literature, herbarium data, materials of Internet resources, the change in distribution of aquatic fern Salvinia natans (Salviniaceae) on Russian territory was traced since the beginning of XX century until 2021, and the current boundaries of its range were determined. Among the bioclimatic and temperature indicators that determine the distribution of S. natans, the minimum and maximum temperatures in October and January and the maximum temperatures in April and July showed the highest statistical significance, which is associated with important stages of the life cycle of S. natans. Comparison of species localities with climatic and temperature indicators for the time periods of 1960–1969, 2010–2018, 2011–2021 showed that up to 2021 in the European part, West Siberia, and the Far East there was significant spreading of S. natans to the north (more than 200 km). A notable increase in the number of records of the species has been found since the 2000s in different regions. For example, in the Ivanovo Region from 2018 to 2021 their number has increased more than three time. The expansion of the species occurs against the background of a noticeable increase in average annual temperatures and changes in other bioclimatic indicators. If present temperature trends continue, S. natans will expand its range even further north, east, and west in European Russia, north and west in West Siberia and the Far East. Due to the ongoing expansion of S. natans, the premises for the exclusion of the species from a number of regional Red Data Books were discussed.
Winter Dynamics of Drifting Invertebrates’ Vertical Distribution in a Small Salmon River
Authors: Astakhov M. V.
Published: April 2024

The composition of the winter syrton of a small salmon river was dominated by mayfly larvae (Ephemeroptera), dipteran larvae (Diptera), and adult water mites (Hydracarina). The presence of a significant linear dependence of the number of drifters entering the nets on the volume of water filtered by the nets has not been proven, so we used not the syrton density (ind./m3), but the data of actual catches. The vertical distribution of drifting invertebrates of different taxonomic affiliation had its own characteristics. Under conditions of good illumination of the water column, the drift intensity of invertebrates increased in the daytime. This fact is probably indirectly related to the low water temperature, which limits the swimming ability of drift-feeding fish, which because of this become more vulnerable to fish-feeding warm-blooded predators, and therefore in winter during daylight hours lead a predominantly inactive and secretive way of life. In December, most daytime drifters migrated near the surface of the water column, and in January, on the contrary, near the bottom. The latter may be due to the overwhelming effect of lower daytime air temperatures, since until mid-February the riverbed was not completely covered with ice. After a heavy February snowfall, the upper layers of the river flow turned out to be isolated from the effect of air temperature, and the level of illumination of the water column during the day began to correspond to the period of late twilight. As a result, fish became less accessible to warm-blooded semiaquatic predators, the intensity of invertebrate drift in the daylight hours decreased sharply, and the distribution of drifters throughout the water column vertical became fairly uniform.
The Genus Hydrocharis L. (Hydrocharitaceae): Community Ecology, and Tolerance to Abiotic Factors
Authors: Efremov A. N. , Sviridenko B. F. , Li Zhi Zhong , Mesterhazy A. , Chatchuangh E. Ngansop , Toma C. , Grishina V. S. , Murashko Yu. A.
Published: April 2024

The genus Hydrocharis L. combines free-floating, occasionally rooting obligate pleistophytes and rooting hydrohelophyte, which are edificators and subedificators in freshwater vegetation communities. How ecologically similar are these closely related species? It has been found that Hydrocharis dubia (Blume) Backer. and H. morsus-ranae L. are conditionally freshwater alkaliphilic mesoeutrophic, ortho-, mesoalluviophilic detrito-, psammopelophiles. Ecologically H. chevalieri (De Wild.) is isolated, it is a freshwater acidoneutrophilic meso-, mesoeutrophic, ortho-mesoalluvialophilic species indifferent to the mechanical composition of bottom sediments. The coenocomplex of H. chevalieri is characterized by abundance of helophyte communities; in the composition of the coenocomplex of two other species hydatophyte and pleistophyte communities play a key role. Communities with species of the genus Hydrocharis are characterized by simple synmorphology, relatively high species richness, and a high proportion of low-abundance species.
Microanatomy and Ultrastructure of the Mesonephros of Cyprinids Inhabiting the Territory of Kazakhstan
Authors: Flerova E. A.
Published: April 2024

The ultrastructure of three species of cyprinids inhabiting the territory of Kazakhstan has been studied. It is shown that the microanatomy of the trunk bud of the Kushakevich char Iskandaria kuschakewitschi, the common marinka Schizothorax intermedius and the Tibetan char Noemacheilus stoliczkai has a common body plan with freshwater cyprinids. Larger area of nephrogenic tissue, greater number of mitochondria on sections of proximal tubules and leukocyte sections, three types of vesicles in cells with radially arranged vesicles, larger diameter of distal tubules, diversity of mitochondria of epitheliocytes of distal tubules of the studied species, compared with previously studied representatives of carp reservoirs of the Upper Volga, testify to the adaptive ability of the cellular structures of the mesonephros to maintain water-salt homeostasis, as well as the functioning of the cellular link of immunity in the life of the rivers of Kazakhstan with a seasonal increase in water temperature up to 27°C. The diversity of the ultrastructure of granules of neutrophils and eosinophils depends on the stage of the life cycle and the characteristics of the functional activity of cells.
Protein Profile of the Incubation Medium and Cestode Extract from the Intestines of Various Fish Species
Authors: Frolova T. V. , Izvekova G. I.
Published: April 2024

The protein composition of the incubation medium and extracts of various types of cestodes inhabiting the intestines of freshwater fish was investigated. Proteins with apparent molecular weights from 10 to 312.5 kDa were found in both biological media of worms. In most of the investigated worms, 64 to 82% of the protein bands in the incubation medium and the extract have an apparent molecular weight below 50 kDa. An assumption was made about the importance of these proteins in the vital activity of helminths and the need to concentrate further efforts on the study of this particular component of the proteome.
Biological Characteristics of Taimen Hucho taimen from Left Tributaries of Lower Lena River
Authors: Karpova L. N. , Mikodina E. V. , Ruban G. I.
Published: April 2024

Age composition and fecundity of taimen Hucho taimen (Pallas, 1773) spawners at spawning grounds located in left tributaries of the Lena River (Muna and Motorchuna rivers) analyzed. Spawning season take place during May–June. Spawners age varies from 8 to 17 years. Absolute fecundity of taimen from Muna and Motorchuna rivers is more than in taimen from western part of species range, and smaller than in populations from eastern part of range. Taimen individuals from river under study are part of large population of the species in the Lena River. They forage and overwinter in the Lena River and enter its tributaries including Muna and Motorchuna rivers only for reproduction. It is typical for taimen from basins of other large rivers (Kama, Yenisei, Amur). Stock abundance of taimen is not large. Spawners at spawning sets needs special protection measures.
Ecological Features and Opportunities for Economic Use of the Solovetsky Archipelago Freshwater Ichthyofauna
Authors: Novoselov A. P. , Dvoryankin G. A.
Published: April 2024

The species composition and taxonomic diversity of the Solovetsky Archipelago freshwater ichthyofauna were revealed, and a description of the current state of the fish was given. The belonging of fish to freshwater faunistic complexes and ecological groups (nature of feeding and mode of natural reproduction) was examined. Currently, 14 species of fish were found in the inland waters of the Solovetsky Islands, including local and alien species with varying degrees of acclimatization effect. A possible annual catch of freshwater fish has been established, which could be considered optimal. If it is necessary to organize freshwater aquaculture, pasture cultivation in the lakes of the Solovetsky Archipelago of the whitefish complex seems promising. It is based on the collection and fertilization of eggs at temporary fish breeding stations, its subsequent incubation at fish farms and the release of reared juveniles into feeding lakes.
Broadening the Taxonomic Composition of Diatoms (Bacillariophyta) in Tundra Water Bodies of Adjacent Territories of the Lena Delta Wildlife Reserve (Yakutia, Russia) Using Electron Microscopy1
Authors: Genkal S. I. , Gabyshev V. А.
Published: April 2024

Using the electron microscopy, 435 diatom algae from 78 genera of 14 different types of tundra water bodies located in the vicinity of the Ust-Lensky State Reserve, north of the Arctic Circle, on the northern exposure of the slope of the Primorsky Ridge (the eastern spur of the Kharaulakh Range of the Verkhoyansk Mountain system) 435 diatom algae from 78 genera were revealed. Among them, 24 taxa of the species rank and 1 of the generic rank are new to the flora of Russia. Most of the identified species, which are new to the flora of Russia, are found in Europe and are characteristic of oligotrophic water bodies and watercourses. Of all the species under study, 66 species belonging to 28 genera have been identified to the genus, with the largest number of them belonging to the genera Planothidium (7) and Gomphonema (10).
Relationship between Fecundity and the Number of Vertebrae in the Roach Rutilus rutilus of the Rybinsk Reservoir
Authors: Komova N. I.
Published: April 2024

The data on the number of vertebrae in the vertebral column regions in different relative fecundity groups of roach are given. The average value of the number of vertebrae in the abdominal region turned out to be the smallest in low fecundity fishes. When comparing the average values of relative fecundity in females with different numbers of vertebrae in the vertebral column, a group of low fecundity fishes was identified. In it, individuals with 17 vertebrae in the abdominal region had a statistically significantly lower relative fecundity, and those with 16 in the caudal and a total of 40 vertebrae in the vertebral column had a significantly higher fecundity than individuals with a different number of vertebrae in these regions. In highly fecundity females, no differences in fecundity between fish with different numbers of vertebrae in regions were noted.
Comparison of Cryoresistance of Testicular and Urinal Spermatozoa of the Toad Bufo bufo (Amphibia, Anura, Bufonidae) during Slow Freezing
Authors: Shishova N. V. , Kaurova S. A. , Uteshev V. K. , Gakhova E. N.
Published: April 2024

A comparative study of the morphofunctional parameters of testicular (non-activated) and urinal (activated) spermatozoa of the common toad Bufo bufo (L., 1758) before and after cryopreservation was carried out. Cryopreservation was performed by a slow method. Sucrose (10%) and dimethylformamide (12%) were used as cryoprotectants. It was shown that the pool of testicular spermatozoa contains significantly more cells with abnormal morphology both before and after cryopreservation. The osmoticity of the base medium for the cryoprotective solution (Ringer’s solution for amphibians – 230 mOsm or urinal plasma – 45 mOsm) had little effect on the survival of testicular and urinal spermatozoa during cryopreservation. Comparison of the morphological and functional characteristics of spermatozoa before and after freezing-thawing indicates that the cryoresistances of testicular and urinal spermatozoa differ slightly.