bluuebunny/crossref_metadata_2025 huggingface dataset:
Avachinsky and Koryaksky Group of Volcanoes: Geophysical Inhomogeneity of the Lithosphere and Deep Processes (Kamchatka)
Authors: Loginov V. A. , Gontovaya L. I. , Senyukov S. L.
Published: April 2024

The article presents the results of our gravimetric, seismic and electromagnetic research, as well as the data on deep seismicity of the lithosphere in the area of the active Avachinsky and Koryaksky group of volcanoes, which is the part of the East Kamchatka volcanic belt. We managed to develop the comprehensive geophysical model of the Earth’s crust and lithospheric mantle of this area. Based on the distribution scheme of the Earth’s crust geophysical inhomogeneities in general, and particularly beneath Avachinsky Volcano, we revealed specific features for both intracrustal fluid saturation and conduits through which deep fluids rise to the upper part of the crust. According to the comprehensive model, stresses arising at the margins of zones with different defluidisation conditions, in particular, in the lower part of the crust, and characterizing by contrasting electrical conductivity values, are one of the most important reasons for active seismicity beneath active volcanoes. The general scheme of the deep lithospheric processes and the volcanoes magma feeding system specific features are based on the obtained results and the data on the local seismic tomography. It is assumed that Avachinsky Volcano, being a part of the active Avachinsky and Koryaksky group of volcanoes, is connected with the asthenospheric layer at a depth of ~70–120 km, from which fluid/melts enter into the magma chamber located in the lower crust and then, under the influence of the heat from the lower crustal source, the peripheral chamber is formed in the upper crust beneath the volcano’s cone.
Microseisms as a Tool for Geophysical Research. A Review
Authors: Besedina A. N. , Tubanov Ts. A.
Published: April 2024

Considering seismic ambient noise as a tool for geophysical research, the spatial and temporal characteristics of the noise itself are of a great interest. Characterization of energy and frequency distributions of the microseisms is an important stage of the research. The review considers the main mechanisms of generation of microseismic oscillations in a wide frequency range, including primary and secondary microseisms (0.05–0.3 Hz), low-frequency oscillations (0.2–50 mHz), high-frequency oscillations (2–60 Hz), lake microseisms (0.5–2 Hz). The paper also describes the most popular techniques used for processing and analyzing a continuous data of seismic ambient noise; a wide range of geophysical problems was demonstrated, which use the results of seismic monitoring.
Geometry and Rheology of Plumes: Common Features in the Probabilistic Gravity Models
Authors: Petrishchevsky A. M.
Published: April 2024

By means of the gravity models reflecting a rheological states of geological environments 3D distribution of density contrast in the heads of six plumes (Yellowstone, Emeishan, Indigiro-Kolyma, Sea of Okhotsk, Indigiro-Kolyma, and Maya-Selemdzha) up to the depth of 200 km are studied and compared with all geological-geophysical data. According to the obtained data, astenospheric parts of plumes have mushroom-like shape, and astenosperic magmas spread under the lithosphere bottom and more rare ‒ under the crust bottom. At the distance of 250‒300 km from central trunks of plumes they are narrowed to diameter of 200–300 km at a depth of 100‒120 km. In heads of the majority of plumes astenospheric magmas merge with the subcrustal viscous layer and approach the Earth’s surface to 40‒50 km. In the majority of the considered plumes their lithospheric and crustal fragments are curved towards the Earth’s surface, In the upper crust layers upwards are sometimes complicated by local downwards (Yellowstone and May-Selemdzha plumes) that is explained by sagging of the dome roofs over the magmatic chambers into subcrustal viscous layer and in asthenosphere. Plumes are often accompanied by zones of the lithosphere stretching (rifts) therefore in the lower lithospheric and crustal sections of plumes linear zones of the lowered viscosity are mapped. The structural position of considered plumes is controlled by borders of lithospheric plates and large segments of the second rank. Identical geometry and rheology of plumes created at different times (Triassic‒Neogene) in the regions which are far removed from each other (the North East Russia, North West of the USA, Southern China, Sea of Okhotsk) demonstrate universality of the tectonic situations promoting penetration of mantle streams into upper layers of the Earth. The main of them are the lithosphere stretching zones, in particular ‒ sites of crossing of multidirectional fractures of a lithosphere and crust.
Model of a New Peripheral Near-Surface Magmanic Chamber of the Elbrus Volcanic Center
Authors: Milyukov V. K. , Myasnikov A. V.
Published: April 2024

Intracrustal magmatic structures have pronounced resonant properties, due to which these structures are able to generate secondary seismic waves at their own frequencies. Based on strain data obtained with a 75-meter laser interferometer ‒ strainmeter, resonance modes are identified and parameters of magmatic structures of the Elbrus volcanic center are estimated. Such resonant modes are unique for each magmatic formation and determine the size and physical-mechanical properties of this magmatic structure. This paper analyzes the local formation, which manifested itself as a some compact area of numerous weak seismic pulses registered in the Elbrus region by the seismometers of the Geophysical Service of the Russian Academy of Sciences in 2011. The results of studies based on seismic and strain data, as well as the results of microseismic sounding, showed the presence of a new peripheral near-surface magmatic chamber in the Elbrus volcanic center. The characteristic size of this new magmatic chamber is 2.5‒3 km.
The Effect of the Step Height on the Wall Pressure Fluctuations near Its Side Edge in the Turbulent Boundary Layer
Authors: Kuznetsov S. V. , Golubev A. Yu.
Published: April 2024

Wall pressure fluctuations in a turbulent flow are a source of noise and vibrations in elastic structures immersed in a flow. This paper presents the results of an experimental study on the effect produced by the height of a step on the spatiotemporal structure of wall pressure fluctuations in the vicinity of its side edge in the turbulent boundary layer. Measurements were performed in a subsonic low-noise wind tunnel of the Moscow Complex of the Zhukovsky Central Aerohydrodynamic Institute. The height of a step was varied from 3 to 17% of the incident-boundary-layer thickness. It has been shown that the area of the most intensive pressure fluctuations is located near the frontal side corner of the step. The characteristic Strouhal number determining the spectra of pressure fluctuations behind the leading edge of the step was established. An essential effect of the step height on the spatiotemporal structure of the pressure field in the vicinity of the side edge was shown. The obtained results evidence the existence of a strong correlation with the field of pressure fluctuations in the incident turbulent boundary layer in the case of steps with a small height.
Estimation of the Thickness Profile of a Human Skull Phantom by Ultrasound Methods Using a Two-Dimensional Array
Authors: Asfandiyarov Sh. A. , Rosnitskiy P. B. , Tsysar S. A. , Yuldashev P. V. , Khokhlova V. A. , Sinitsyn V. E. , Mershina E. A. , Sapozhnikov O. A.
Published: April 2024

The paper presents the results of evaluating the thickness profile of a skull phantom using a two-dimensional ultrasound array consisting of piezoelectric elements with a center frequency of 2.1 MHz. Two pulse-echo ultrasound methods were used in the experiment: the A-mode elementwise measurements and scanning with a focused probing beam created by the entire array using delay-and-sum (DAS) beamforming. The obtained thickness profiles are compared with the reference thickness profile obtained using X-ray computed tomography. It was shown that ultrasound DAS beamforming with a focused probing beam makes it technically possible to estimate the thickness profile of the skull phantom.
Dispersion and Energy Characteristics of Bending Waves in a Plate Lying on a Two-Parameter Elastic Foundation
Authors: Erofeev V. I. , Lisenkova E. E.
Published: April 2024

The propagation of bending waves in a plate resting on a two-parameter elastic foundation is considered. In contrast to the classical Kirchhoff model, the mathematical model used here takes into account not only the kinetic and potential energies of bending vibrations, but also the kinetic energy due to the inertia of rotation of the plate elements during bending. The dispersion equation, phase velocity, energy transfer velocity, and energy characteristics of waves propagating in the plate are analyzed depending on the ratio of the coefficients determining the shear and compression stiffness of the elastic foundation. Conditions are found under which waves with phase and group velocities having opposite directions (frequently called “backward” waves), can exist in the plate. It is demonstrated that such waves significantly change the behavior of the energy flux. In addition, relations are found that relate the kinematic and average energy characteristics of the waves.
Ultrasound Control of Viscoelastic Properties of Petroleum Dispersion Systems
Authors: Mullakaev M. S. , Mullakaev R. M. , Esipov I. B.
Published: April 2024

It is demonstrated that exposing petroleum disperse systems to ultrasound significantly decreases their viscoelastic properties. The operating parameters of exposure of high-viscosity oil to ultrasound were experimentally determined in order to reduce its effective viscosity and pour point. The results of pilot tests of the developed ultrasound module indicate that exposing high-viscosity oil to ultrasound in flow mode can significantly upgrade existing technology for transporting high-viscosity oil.
The Influence of Random Internal Waves on the Characteristics of a Horizontal Antenna in a Shallow Sea
Authors: Raevskii M. A. , Burdukovskaya V. G.
Published: April 2024

The effect of random internal waves on the gain and pattern of a horizontal antenna array in a shallow sea has been investigated. An algorithm for calculating the correlation matrix of the point source field at the grating aperture is proposed. The antenna gain is analyzed for different spatial processing methods: the beam forming method, the optimal linear processing method, and the optimal quadratic processing method. The effect of internal waves on the directivity pattern is described by the dispersion of the angular response of the grating. Numerical simulation results are presented for a model summer-type waveguide and an exponential Brunt–Väisälä frequency profile. The empirical internal wave spectrum proposed earlier from the SWARM95 experiment is used. The dependences of the antenna array characteristics on the number of its elements, orientation with respect to the source, radiation frequency, and the acoustic characteristics of the bottom are analyzed.
The Sommerfeld Integral in Problems of Simulating the Diffraction of Acoustic Waves Using a Triangular Lattice
Authors: Makarov O I. , Shanin A. V. , Korolkov A. I.
Published: April 2024

Analytical solutions are obtained for two problems for a discrete analogue of the Helmholtz equation on a triangular lattice: (1) the problem of radiation from a point source on a plane; (2) the problem of diffraction on a half-line with Dirichlet boundary conditions. It is shown that in these problems, the complete field can be represented as an integral of an algebraic function over a family of contours located on some complex manifold. The solution to the first problem is found as an integral of some differential form over this manifold, and the asymptotics of the far field for this solution is obtained. The second problem is solved using an analogue of the Sommerfeld integral. It is checked that the obtained solution coincides with the solution of this problem by the Wiener–Hopf method.
The Sound Field Intensity Distribution in the Deep Sea in the “Depth—Angle–Time” Phase Space
Authors: Virovlyansky A. L. , Kazarova A. Yu.
Published: April 2024

The transition from the traditional representation of the wave field in the vertical section of an underwater sound channel as a function of depth and time to the distribution of this field in the 3D phase space “depth–angle–time” is considered. For this purpose, the method of coherent states developed in quantum theory is used. The meaning of the proposed transition is that the field intensity distribution in the specified phase space is less sensitive to sound velocity fluctuations than in the original 2D depth–time space. This fact can be used in solving inverse problems. As an example, we consider the reconstruction of the coordinates of a source in a waveguide from measurements of the field intensity distribution of this source in phase space.
On Variations of the Sound Signal Propagation Time under a Stationary Ice Cover
Authors: Petnikov V. G. , Shatravin A. V. , Lunkov A. A.
Published: April 2024

In experiments on a stationary acoustic track under a solid ice cover, estimates of possible sound signal propagation time variations at distances of ∼4 km with a period of more than 100 s were obtained. The experiments were carried out on Lake Baikal in the spring period, when the vertical profile of the sound speed has two sections characteristic of freshwater areas: an upper layer with a near constant sound speed and a lower layer with linear growth of sound speed. Under these conditions, the variations of the propagation time did not exceed ~10–4 s. Numerical modeling showed that the variations of propagation times due to the variability of the medium are minimal for the case when the sound source and receiver are located in the upper layer. It is demonstrated that in this case it is acceptable to take the sound speed in the upper quasi-homogeneous layer as the effective value of the sound speed, which determines the propagation time. The obtained results allowed us to formulate recommendations on under-ice acoustic positioning of autonomous underwater vehicles.
Models of the Formation of Doppler Spectrum of Surface Reverberation for Sound Waves of the Meter Range
Authors: Salin M. B. , Ermoshkin A. V. , Razumov D. D. , Salin B. M.
Published: April 2024

Narrowband spectra of sound scattered on the surface wave in the frequency range from 500 to 3000 Hz have been analyzed. Experimental results and theoretical models are reviewed. Previously published work by the authors is reviewed and new results are presented. The first characteristic case considered is forward scattering, where the sound transmitter and receiver are substantially separated from each other in space, and a continuous emission of a sinusoidal signal is produced. For this case, it is shown that the modulation spectrum of the scattered signal repeats the frequency spectrum of the surface wave with a certain coefficient and small corrections. The second considered characteristic case is a monostatic location, where the receiver and transmitter are combined and tone-pulse signals are emitted. Previously, for this case, it was implicitly expected that the reverberation spectrum would be generated by Bragg scattering on surface waves corresponding to half of the sound wavelength, and hence the spectrum of the scattered signal would be discrete. However, the experimental results indicate that the monostatic scattering spectra have a smooth bell-shape. Explaining this requires taking the effects of modulation of short surface waves by the long-wave component into account. Additionally, to explain the experimental phenomenon, the authors include a model of sound scattering on air bubbles, which are located in the near-surface layer of water and make oscillatory movements in the field of orbital currents of surface waves.
Local Method for Separating Sound and Pseudosound Pressure Fluctuations
Authors: Bychkov O. P. , Faranosov G. A.
Published: April 2024

A new method for separating acoustic and pseudosound pressure fluctuations is proposed, based on analysis of signals at a pair of closely located points, so that the total size of the measurement zone is much smaller than the correlation scale of pseudosound perturbations. It is suggested that hydrodynamic fluctuationspropagate at a velocity significantly lower than the sound velocity and obey the “frozen-in” perturbation model, which makes it possible, in real time or during data postprocessing, to convert the spatial derivative of the signal into a temporal derivative, which, after time integration, yields an estimate for pseudosound perturbationsat the measurement point. A theoretical model of the approach and test results using model examples and numerical simulation data are presented.
Natural Oscillations of an Elastic Half-Strip with a Different Arrangement of Fixation Areas of Its Edges
Authors: Nazarov S. A.
Published: April 2024

Eigenfrequencies and trapped modes are studied in an isotropic and homogeneous elastic half-strip. For different configurations of rigidly clamped and the traction-free zones, information was obtained about the absence or presence of eigenfrequencies below, and in some cases even above, the cutoff point of the continuous spectrum. Estimates of the multiplicity of the discrete spectrum are derived and various asymptotic representations of trapped modes and their frequencies are constructed.
Thermal Interference When Recording Turbulent Pressure Fluctuations on the Surface of a Floating Device
Authors: Kudashev E. B. , Yablonik L. R.
Published: April 2024

Thermal interference is studied when recording turbulent pressure fluctuations on the surface of a floating device at specified experimental parameters of temperature stratification of an aquatic medium. The effect of distortion of the spectral levels of pressure fluctuations recorded by a sound receiver in the field of temperature inhomogeneities is studied using the example of measurements of turbulent pressure fluctuations in the boundary layer during the vertical ascent of a device from a specified depth. At moderate flowvelocities exceeding 1–2 m/s, the temperature susceptibility of a piezoceramic receiver is shown to be decisively determined by its characteristic “thermal” frequency. The parameters of the threshold critical frequency, below which the temperature signal (thermal interference) prevails over the useful signal generated by pressure fluctuations, are determined. With respect to the receivers used in experiments on a floating device [7], the values of the threshold critical frequency are 130 and 215 Hz.
New Representative of the Genus Aulacoseira (Bacillariophyta) from Chukotka (Russia)
Authors: Genkal S. I.
Published: April 2024

A new species of diatoms, Aulacoseira сhukotkaensis sp. nov., has been described using scanning electron microscopy. The new species has morphological similarity to other Aulacoseira taxa but can be distinguished from A. alpigena by the number of rows of areolae in 10 µm and the length and shape of spines, from A. helvetica by the valve height and the number of areolae rows in 10 µm, and from A. pardata by the shape of spines and the number of rows of areolae in 10 µm.
Composition and Structure of Benthal Algocenoses of a Large Eutrophic River (Example of the Oka River, Russia) II. Abundance Indicators and Species Diversity of Communities
Authors: Khedairia T. , Okhapkin A. G. , Yakimov B. N.
Published: April 2024

The indicators of quantitative development (abundance, biomass) and spatial heterogeneity of the characte-ristics of the species structure (species diversity, evenness, dominance) of the benthal algocenoses of the mouth of a large eutrophic-hypertrophic river in the period after the recession of the flood are characterized. The similarity and difference in the species structure in different types of benthal communities with a more complex organization of epilithon and epiphyton at the initial stage of substrate colonization was demonstrated. Relationships of these indicators with the determining factors of the environment in the absence of biogenic limitation were revealed.
Problems and Prospects of Applications of Cyanobacteria (Review)
Authors: Polyak Yu. M. , Sukharevich V. I.
Published: April 2024

This review focuses on cyanobacteria and their metabolites with beneficial properties for humans. Cyanobacteria metabolites are uniquely diverse. Many of them exhibit antibacterial, antifungal, anti-carcinogenic, immunosuppressive, antioxidant types of activity, etc. The problems and prospects of using biologically active products of cyanobacteria metabolism are discussed. The issues of obtaining pharmaceuticals and other valuable products (pigments, enzymes, amino acids, vitamins, biodegradable plastic) are considered, and the potential of cyanobacteria as a source of biofuels is evaluated.
The Invasion of the Alien Species Bonnemaisonia hamifera Hariot in Coastal Phytocenoses Near the Southern Coast of Crimea (the Black Sea)
Authors: Sadogurskiy S. Ye. , Belich T. V. , Sadogurskaya S. A.
Published: April 2024

Based on the results of hydrobotanical research in 2015–2021, it has been found that the global expansion of the Bonnemaisonia hamifera Hariot filamentous sporophyte stage had reached the Southern Coast of Crimea (SCC) by 2017. At present, the invader is registered in all horizons of the SCC phytal. Massively developing in the epiphyton of native species, it inhibits their growth, and in some areas it becomes one of the dominants. This changes the appearance, structure, and production indicators of algal communities (up to their degradation in some areas), which makes it possible to attribute this invasive species to the “transformers” category. It has been shown that the invasion develops rapidly, its vector coincides with the direction of the Main Black Sea Current. Eutrophication can play a stimulating role. Presumably, the species is already present on the southwestern and western coasts of the Crimean Peninsula and will populate the western and northwestern regions of the Black Sea in the next one or two years; expansion into the Sea of Azov is also likely. B. hamifera invasion may threaten biological diversity of the of the entire Azov-Black Sea basin, which under the conditions of its relative isolation can lead to ecological catastrophe that will affect all countries in the region. Currently, there are no ways that could stop or slow down the process of invasion.
New Species of Section Typha (Typha L., Typhaceae) from the Northern Part of Sakhalin Island
Authors: Krasnova A. N. , Efremov A. N.
Published: April 2024

A description of a new species, the coastal cattail Typha litoralis, collected in the coastal areas of the Sea of Okhotsk is given. Habitually, the plants differ from T. latifolia and T. laxmannii, has been reported Sakhalin Island and the Kuril Islands. The new species is morphologically closest to T. krasnovae Doweld.
Dependence of the Distribution of Alien Species of Macrozoobenthos on the Type and Composition of Soil in the Volga and Kama Reservoirs
Authors: Kurina E. M. , Seleznev D. G. , Sherysheva N. G.
Published: April 2024

The result of studies of macrozoobenthos in the reservoirs of the Volga and Kama cascades is an assessment of the biotopic confinement of alien species. A reliably significant dependence of the abundance of polychaetes Hypania invalida, mollusks Dreissena bugensis, and amphipods Dikerogammarus haemobaphes on the size fraction of the soil was revealed. The dependence of the distribution of invaders – representatives of different trophic groups on the type of biotope is shown.
Distribution of the Mass Species of Benthic Crustacean on Nearshore Slope the Ladoga Lake
Authors: Zuyev Yu. A.
Published: April 2024

The species list and distribution of crustacean of a nearshore zone of the Valaam Island (Ladoga Lake) have been investigated by sampler-syringe, dredge and video records. On the depth 1–25 m the five species of crustacean: Asellus aquaticus (Linnaeus, 1758), Monoporeia affinis (Lindström, 1855), Pallaseopsis quadrispinosa (G.O. Sars, 1867), Gmelinoides fasciatus (Stebbing, 1899), Mysis relicta Lovén, 1862 were described. For the first time the vertical distribution of naturalized Baikal amphipods G. fasciatus were inventoried and their features of joint residence with local species were characterized. The distribution of the alien species reliably connected with wave intensity, types of grounds and depth range. The most numerous local species P. quadrispinosa distribution affects by depth range. The types of grounds do not influence on the quantity of all indigenous crustacean in the nearshore zone. In all condition the local species successfully compete with G. fasciatus. All these species inhabit of littoral have higher resistance for wave action as compared with non-indigenous species. It guarantees existence of refuges which can safe diversity of the indigenous species. The obtained data on the spatial distribution of crustaceans make possible to characterize the benthic communities of the little-studied parts of the littoral and sublittoral and, as a result, the food base of bentophagous fishes.
Diatom Algae of Different Types of Middle Ural Reservoirs (Sverdlovsk Region, Russia)
Authors: Genkal S. I. , Eremkina T. V.
Published: April 2024

For the first time, diatoms from the Beloyarskoe, Chernoistochinskoe and Nizhnetagilskoe reservoirs of the Sverdlovsk region are studies using electron microscopy. The data on the species composition of Bacillariophyta of the Chernoistochinskoe Reservoir are significantly supplemented. A total of 216 taxa of species and intraspecific rank from 63 genera are identified in these three reservoirs. Among them 17 taxa are new to the flora of Russia, 14 forms from 11 genera are identified only to the genus. The maximum taxonomic diversity is recorded in the Nizhnetagilskoe reservoir (179).
Impacts of the High-Pressure Bratskoye Hydroelectric Power Station on the Zooplankton of the Bratskoye Reservoir
Authors: Gerasimov Yu. V. , Poddubnaya N. Ya. , Vakhnenko A. F. , Semenova A. S. , Zhdanova S. M. , Tsvetkov A. I. , Pavlov D. D. , Bolotov S. E. , Borisenko E. S.
Published: April 2024

During the growing season of 2022, the studies were carried out in the water area of the Bratsk Reservoir (the Angara River) and in the near-dam site of the Bratsk high-level hydroelectric power station. The ecological effects of the hydroelectric dam on the zooplankton in the regulated section of the river were studied and the impact of the zooplankton downstream drift on the feeding conditions of the fish in the Bratsk Reservoir was assessed. It is established that the water column stratification is a significant factor in the ecological differentiation of plankton communities in the upper reaches of the hydroelectric power station. Unlike the warmed-up layer of the epilimnion, a specific, poor in species, low-abundant and low-productive plankton develops in the cold-water hypolimnion, which enters the dam intakes. A rigorous analysis does not reveal a transformation of the community composition, a statistically significant decrease in abundance and productivity, increased mortality of invertebrates during their passage through the dam, deterioration of the water ecological quality in the lower reaches of the hydroelectric power station. Both live and dead zooplankton drifting downstream from the reservoir makes up a significant proportion of the diet of fish, which during the feeding period come as close as possible to the hydroelectric power station and form aggregations exceeding those in the water area of the Bratsk Reservoir in density. The data obtained testify to the effective adaptation of lake-river planktocenosis to the specific natural and technogenic mode of operation of a large hydraulic structure. The local impact of the Bratsk hydroelectric power station has no ecologically significant negative effect on the plankton of the Bratsk Reservoir and the Angara River ecosystems and has a positive effect on the fish population in the lower reaches through the enrichment of its forage base.
Communities of Fungi on Plates Coated with Antifouling Paint Modified by Nanoparticles
Authors: Kopytina N. I. , Andreeva N. A. , Sizova O. S. , Mosunov A. A. , Evstigneev V. P. , Bocharova E. A.
Published: April 2024

In the Sevastopol Bay (Black Sea), in the autumn period of 2021, fungal complexes were studied on plexiglass plates painted with anti-fouling enamel Bioplast-52 (control) and coatings based on it modified with nanoparticles (NP) Zn-FeO, ZnO and Fe-SiO. 16 species of fungi belonging to seven genera, five families, five orders, three classes of the Ascomycota division have been identified. The species composition was dominated by representatives of the genera Aspergillus (7 species) and Alternaria (4 species). The total number of fungal species isolated on substrates varied from 3 (with ZnO NP) to 8 (Bioplast-52) and with Zn-FeO NP), and by exposure time – from 3 (fourteenth day) to 14 species (sixty-first day). There were no representatives of the genera Aspergillus and Alternaria on the coating modified with Fe-CuO NP; only species of the genus Aspergillus were found on the coating with ZnO NP, the smallest number and number of fungal species were found on these coatings. Fe-CuO and ZnO nanoparticles enhanced the antifouling properties of Bioplast-52 enamel.
Content of Sodium, Potassium, Calcium, Magnesium in Organism of Larva of Sibling Species Сhironomus balatonicus and Сhironomus plumosus in Dependence on Salinity1
Authors: Martemyanov V. I. , Markiyanova M. F.
Published: April 2024

The tolerant salinity ranges are 0.008–6 and 0.09–9.3 g/L, respectively, for Ch. plumosus L., 1758 and Ch. balatonicus Devai, Wülker et Scholl, 1983. In the tolerant range of salinity, the level of sodium, potassium, calcium, magnesium in the body of Ch. balatonicus was regulated within 33.9–77.1, 7.7–13.7, 11.9–37.6, 54.7–110.6 mmol/kg wet weight, respectively. The concentration of sodium, potassium, calcium, magnesium in the body of Ch. plumosus was maintained within of 62.7–80.8, 10.6–18, 6.7–12, 2.9–6 mmol/kg wet weight in stage III larvae and 49.6–62.3, 9.7–14.8, 42.5–62.2, 47.9–83.4 mmol/kg wet weight in individuals of IV age. In the optimal salinity range of 0.8–5.3 g/L, the sodium concentration in the body of Ch. balato-nicus was maintained at a constant level, decreased in the critically low zone of 0.8–0.09 g/L, and increased in the critically high zone of 5.3–9.3 g/L. In the critically low and high salinity zone, the organism’s ability to survive is reduced. The content of sodium in the body of freshwater aquatic organisms serves as a reliable criterion for assessing the optimal, critically low and high salinity zones.
Some Species of Gobies of the Genus Pomatoschistus Previously Unknown in the Black Sea as Identified by the Data on the 16S rRNA Mitochondrial DNA Gene Variability
Authors: Slynko E. E. , Karpova E. P. , Mironovsky A. N. , Slynko A. Yu. , Kozhara A. V. , Mavrin A. S.
Published: April 2024

Using the analysis of the 16S rRNA of mtDNA nucleotide sequences, the taxonomic composition of gobies of the genus Pomatoschistus of the Black Sea was refined. Among the 12 individuals of the genus Pomatoschistus studied in the Black Sea (Odessa Bay and Kazachiya Harbour, Sevastopol), the species P. marmoratus and P. quagga are reliably identified by haplotypes of the 16S gene. When comparing the parameters of the genetic variation of the most abundant species P. marmoratus from the Black Sea with populations of the Mediterranean Sea, it was found that the Black Sea population of P. marmoratus has all the features of a marginal population, which is probably due to the relatively recent naturalization of this species in the Black Sea. The species P. quagga is for the first time indicated for the Black Sea.
Morphological and Genetical Identification of Harpacticella inopinata Sars (Harpacticoida, Copepoda) from Lake Baikal and the Enisey River
Authors: Fefilova E. B. , Popova E. I. , Mayor T. Y. , Novikov A. A. , Velegzhaninov I. O. , Golubev M. A. , Bakashkina A. S.
Published: April 2024

The work presents the results of comparative studies of the morphology and genetics of the Baikal subendemic – the harpacticoid copepod Harpacticella inopinata Sars, 1908. The material was obtained from the southern part of Baikal Lake and the Yenisei River within the of Krasnoyarsk city in 1969, 2017–2022. It is shown that morphological variability within the species appeared most in the structure of the antenna exopodite, the number of pores and sensillas on the integument of thoracic somites. The genetic variation of the studied sample of H. inopinata was described by four clades with a distance between them of 0.26, the genetic distances between individuals within the detected genetic groups did not exceed 0.005. It was determined that H. inopinata from geographically remote habitats (Baikal Lake and Yenisei River) forms a single morphological and genetic group. Analysis of the genetic diversity of H. inopinata confirms the relatively recent Baikal origin of the species in the Yenisei, probably associated with an anthropogenic moving into the river.
Seasonal Dynamics of Growth and Production Monoporeia affinis (Amphipoda: Pontoporeiidae) in a Subarctic Lake: the Role of Temperature and Trophic Conditions
Authors: Maximov A. A. , Maximova O. B. , Usov N. V.
Published: April 2024

The growth and production of glacial relic amphipods Monoporeia affinis (Lindström, 1855) in a small subarctic lake were studied based on detailed seasonal observations in 2019–2021. Growth and production were closely related to trophic conditions (chlorophyll a concentration). The maximum values were observed at low water temperatures (~5°C) in early summer, coinciding with the spring maximum of chlorophyll. The summer warming of bottom waters was accompanied by a decrease in the growth rate of amphipods, which is apparently associated with the consumption of most of the primary production in the pelagic zone. It is concluded that current climatic conditions can adversely affect glacial relicts even in cold-water lakes of the subarctic zone.
Cardiac Activity of Pontastacus leptodactylus Esch. (Decapoda) under Prolonged Exposure to High Salinity: on the Possibility of Using Freshwater Crayfish in Testing of Brackish Waters
Authors: Sladkova S. V. , Kuznetsova T. V. , Lyubimtsev V. A. , Kholodkevich S. V.
Published: April 2024

In this study, we analyzed the characteristics of the cardiac activity of crayfish during long-term keeping of animals in an environment with high salinity (6.5‰) in order to find out the fundamental possibility of using them as bioindicators in bioelectronic systems for monitoring the quality of marine coastal waters under high anthropogenic load. Similar salinity values were noted for many bays of the Baltic Sea sub-regions, for example, the Tallinn and Bothnian bays, which are characterized by intense anthropogenic load. It was found that an increase in water salinity from 0 to 6.5‰ caused an initial short-term increase in heart rate (HR) by 30%. It has been shown that crayfish can not only successfully survive for 1 month in high salinity water, but also change the characteristics of cardiac activity to a small extent. Some features were revealed in crayfish in water with altered salinity. During exposure to saline solution, crayfish showed a clear diurnal rhythm of cardiac activity. The rhythmicity of the heart rate disappeared a few days before the molt in both fresh and salt water. The study made it possible to draw a conclusion about the possibility of using freshwater crayfish in bioelectronic systems for continuous monitoring of the functional state of representatives of the local biota and for identifying the biological effects of pollutants in both fresh and brackish water.
Composition and Content of Carotenoids of Gastropod Tritia reticulata in Black Sea
Authors: Borodina A. V. , Zadorozhny P. A.
Published: April 2024

The results of a two–year study of the composition and content of carotenoids of sea snails Tritia reticulata (L., 1758), living in a mixed bottom community of bivalve mollusks in the sandy zone of the upper sublitoral (depth 0–1 m) of the Cossack Bay of Sevastopol, are presented. The highest content of total carotenoids was detected in June (1.8–2.09 mg/100 g of crude mass), the average Cossack Baymples for both years was 1.54 mg/100 g of crude mass. In the qualitative composition of T. reticulata taken from the pastures of bivalves on sandy-silt soil, 15 free carotenoids were identified: b-carotene, echinenone, hydroxyechinenone, astaxanthin, didehydroastaxanthin, diadinoxanthin, diatoxanthin, fucoxanthin, halocintiaxanthin, fucoxanthinol, mactraxanthin, heteroxanthin, lutein, zeaxanthin, alloxanthin and esters of the last 4 carotenoids. The po-ssibility of metabolic transformations of carotenoids is discussed.
Assessment of Morphometric Variations Among the Populations of Asian Sheat Catfish Wallago attu (Siluridae) from Five Indian Rivers
Authors: Kumar G. , Kashyap A. , Serajuddin M.
Published: April 2024

Morphological variations of the Asian sheat catfish, Wallago attu (Bloch and Schneider, 1801) sampled from the rivers Gomti, Ganga, Yamuna at Lucknow, Kanpur and Agra districts in Northern India, river Hooghly at Kolkata in Eastern India and river Pampa at Kerala in Southern India were analyzed in the present study. Images of 261 specimens of W. attu were taken without harming the fish to evaluate the morphometric variation using 8 digitized homologous landmarks for truss analysis and geometric morphometrics. Size corrected morphometric variables were analyzed using analysis of variance (ANOVA), multivariate analysis of variance (MANOVA), principal component analysis (PCA) and discriminant function analysis (DFA). Coefficients of all PCs were positively and negatively correlated to 31 significant (p 0.001) truss measurements due to variations in size and shape. Morphometric measurements lying in the head region such as head length (HL), eye diameter (ED), inter-orbital length (IOL) and snout length (SNL) contributed most to differentiate the populations in truss analysis. The ED, HL, SNL and IOL of Yamuna fish was significantly (p 0.001) smaller than the other fish populations. This could be attributed to the heavy pollution load in the Yamuna River and differences in the feeding regimes of fish. PCs and relative warps depicted differences in geometric analysis because of body shape variations among different river populations. The scatter plot in DFA revealed the presence of three distant and different phenotypic groups of W. attu among five wild river populations of fish with 70.5 and 83.9% of correct classification of fish into their original groups in truss and geometric analysis respectively. A single homogenous stock of fish was found to be in the rivers Gomti, Ganga and Hooghly because of a high level of intermixing (maximum misclassification) among the three river populations, whereas Yamuna and Pampa populations were two non-overlapping isolated groups due to negligible intermixing. These variations in the present study might be the effect of geographical isolation and river fragmentation due to the change in habitat that restricts fish movements. This is the first report on the morphometric assessment of W. attu that provides base line data for further confirmatory stock studies that would be useful for conservation and sustainable management of this vulnerable fish.
Novel potential mechanisms of regulatory B cell-mediated immunosuppression
Authors: Zheremyan E. A , Ustiugova A. S , Radko A. I , Stasevich E. M , Uvarova A. N , Mitkin N. A , Kuprash D. V , Korneev K. V
Published: April 2024

B lymphocytes play an important role in the regulation of immune response in both normal and pathological conditions. Traditionally, the main functions of B cells were considered to be antibody production and antigen presentation, but in recent decades there have been discovered several subpopulations of regulatory B lymphocytes (Bregs) which maintain immunological tolerance and prevent overactivation of the immune system. Memory (mBregs, CD19+CD24hiCD27+) and transitional (tBregs, CD19+CD24hiCD38hi) subpopulations of Bregs are usually considered in the context of studying the role of these B cells in various human pathologies. However, the mechanisms by which these Breg subpopulations exert their immunosuppressive activity remain poorly understood. In this work, we used bioinformatic analysis of open-source RNA sequencing data to propose potential mechanisms of B cell immunosuppression. Analysis of differential gene expression before and after activation of these subpopulations allowed us to identify six candidate molecules that may determine the functionality of mBregs and tBregs. IL4I1-, SIRPA-, and SLAMF7-dependent mechanisms of immunosuppression may be characteristic of both Breg subsets, while NID1-, CST7-, and ADORA2B-dependent mechanisms may be predominantly characteristic of tBregs. An in-depth understanding of the molecular mechanisms of anti-inflammatory immune response of B lymphocytes is an important task for both basic science and applied medicine and can facilitate the introduction of new approaches to the therapy of complex diseases.
Therapy induced tumor cell senescence: mechanisms and ways to overcome
Authors: Zamkova M. A , Persiyantseva N. A , Tatarskiy V. V , Shtil A. A
Published: April 2024

The plasticity of tumor cells due to the multiplicity of molecular regulation allows to evade the cytocidal effects of chemo- and/or radiation therapy. Metabolic adaptation of survived cells is based on transcriptional reprogramming. Because of the similarities with the natural cell aging, specific features of survived tumor cells comprise the phenotype of therapy induced senescence. Most importantly, the senescent cells differ from the parental since they become less responsive to drugs and form the aggressive progeny. The importance of the problem is explained by general biological significance of transcriptional reprogramming as a mechanism of adaptation to stress, and by the emerging perspective of its pharmacological targeting. We analyze the mechanisms of regulation of therapy induced tumor cell senescence, as well as the new drug combinations to prevent this clinically unfavorable phenomenon.
Inhibitors of galactonolactone oxidase from Trypanosoma cruzi based on allylpolyalkoxybenzenes
Authors: Chudin A. A , Zlotnikov I. D , Krylov S. S , Semenov V. V , Kudryashova E. V
Published: April 2024

Inhibition of the biosynthetic pathways of compounds essential for T. cruzi is considered by researchers as one of the possible mechanisms of action of potential drugs against Chagas disease. As one of these mechanisms, we consider inhibition of galactonolactone oxidase from T. cruzi (TcGAL), which catalyzes the final step in the synthesis of vitamin C, an antioxidant that T. cruzi is unable to assimilate from outside and must synthesize itself. In this work, for the first time, a class of effective inhibitors of TcGAL was found - allylbenzenes from plant sources. A non-competitive mechanism of action of apiol has been established and it has been found that natural allylpolyalkoxybenzenes (APAB) - apiol, dillapiol, etc. are effective inhibitors of TcGAL with IC50 = 20-130 µM. It was found that the conjugation of APAB with triphenylphosphonium, which ensures the selective delivery of biologically active substances to mitochondria, makes it possible to increase the efficiency and/or the maximum percentage of inhibition compared to unmodified APAB.
Effect of the large-conductance calcium-dependent k+ channel activator NS1619 on the function of mitochondria in the heart of dystrophin-deficient mice
Authors: Dubinin M. V , Starinets V. S , Chelyadnikova Y. A , Belosludtseva N. V , Mikheeva I. B , Penkina D. K , Igoshkina A. D , Talanov E. Y , Kireev I. I
Published: April 2024

Dystrophin-deficient muscular dystrophy (Duchenne dystrophy) is characterized by impaired ion homeostasis, in which mitochondria play an important role. In the present work, using a model of dystrophin-deficient mdx mice, we revealed a decrease in the efficiency of potassium ion transport and the total content of this ion in heart mitochondria. We evaluated the effect of chronic administration of the benzimidazole derivative NS1619, which is an activator of the large-conductance Ca2+-dependent K+ channel (mitoBKCa) on the structure and function of organelles and the state of the heart muscle. It was shown that NS1619 improves K+ transport and increases the content of the ion in the heart mitochondria of mdx mice, but this is not associated with changes in the level of the mitoBKCa protein and the expression of the encoding gene. The effect of NS1619 was accompanied by a decrease in the intensity of oxidative stress, assessed by the level of lipid peroxidation products (MDA products) and normalization of the mitochondrial ultrastructure in the heart of mdx mice. In addition, we found positive changes in the tissue, expressed in a decrease in the level of fibrosis in the heart of dystrophin-deficient animals treated with NS1619. It was noted that NS1619 had no significant effect on the structure and function of heart mitochondria in wild-type animals. The paper discusses the mechanisms of influence of NS1619 on the function of mouse heart mitochondria in Duchenne muscular dystrophy and the prospects for applying this approach to correct pathology.
Recognition of γ-subunit by β-subunit. Stabilization of the GTP-bound state of translation initiation factor 2 in archaea and eukaryotes
Authors: Nikonov O. S , Nikonova E. Yu , Tarabarova A. G , Mikhaylina A. O , Kravchenko O. V , Nevskaya N. A , Nikonov S. V
Published: April 2024

Eukaryotic and archaeal translation initiation factor 2 (e/aIF2) functions as a heterotrimeric complex. It consists of three subunits (α,β, γ). The α- and β-subunits are linked to the γ-subunit by hydrogen bonds and van der Waals interactions, but do not contact each other. Although the main functions of the factor are performed by the γ-subunit reliable formation of αγ- and βγ-complexes is necessary for its proper functioning. In this work, we made mutations in the recognition part of the βγ interface and showed that both in eukaryotes and archaea, the hydrophobic effect plays a decisive role in the recognition of subunits. The shape and properties of the hollow on the surface of the γ-subunit facilitates the transition of the disordered recognition part of the β-subunit into the α-helix containing approximately the same number of residues in archaea and eukaryotes. In addition, based on the newly obtained data, it was concluded that in archaea and eukaryotes, the transition of the γ-subunit to the active state leads to additional contact between its switch 1 and the C-terminal part of the β-subunit, which stabilizes the helical conformation of the switch.