bluuebunny/crossref_metadata_2025 huggingface dataset:
Microseismicity of the Persian Gulf and the Zagros Mountain Massif According to Bottom Seismological Observations
Authors: Kovachev S. A. , Krylov A. A.
Published: April 2024

Bottom seismological observations in the Persian Gulf over a short period made it possible to detect weak earthquakes with magnitudes (ML = –0.2–2.9), whose sources are located in the mantle under its water area and under the Zagros mountain range. On the section built across the coastline of the Persian Gulf, under the Zagros Mountains, the projections of the sources of the detected earthquakes form seismic focal layers, steeply dipping into the mantle to the northeast to depths of 120–180 km. The spatial distribution of strong and medium earthquakes, obtained from the updated earthquake catalog of the US Geological Survey and the ISC International Seismological Catalog, does not contradict the distribution of sources of micro- and weak earthquakes, but complements it, forming a separate seismic focal layer. According to the data obtained as a result of bottom seismological observations, the entire thickness of the earth’s crust of the region and the upper mantle, and not only the upper layers of the crust, as presented in a number of publications, are seismically active. It is possible that collision processes and accompanying phenomena (mantle seismicity and destruction of the granitic layer of the earth’s crust) are associated with the presumed presence and rotation of the earth’s surface with the center of rotation in the area of about. Cyprus.
Improvement of Methods for Studying the Electrophysicala Viscous Properties of Liquids
Authors: Shamsutdinova E. S. , Anisimkin V. I. , Fionov A. S. , Smirnov A. V. , Kolesov V. V. , Kuznetsova I. E.
Published: April 2024

To control the physical properties of polar and nonpolar liquid media, the parameters of model systems based on paraffin and silicone oils, as well as glycerin, were measured using electrophysical and acoustoelectric methods. Electrophysical studies were performed with an Agilent E4980A LCR meter and a measuring cell consisting of an Eppendorf tube and two coaxial nickel electrodes forming a cylindrical capacitor. The permittivity of the liquid was determined from the formula for the capacitor. For the acoustic part of the problem, ST,X-quartz was used as the piezoelectric plate, on which a fluoroplastic cell for liquid was placed. The measurements were carried out in three stages: measurement of the phase and amplitude of the acoustic wave (i) without contact with the liquid, (ii) in contact with a pure test liquid, and (iii) in contact with the test liquid with a filler. Microparticles of pharmaceutical activated carbon and the surfactant sorbitan monooleate were used as fillers. The viscosity of the suspensions was determined from the difference between the attenuation of an acoustic wave in the presence of the pure liquid and liquid with filler.
Acoustoelectronic Method for Measuring the Velocity of Ultrasonic Waves in Liquids
Authors: Koltsova I. S. , Khomutova A. S.
Published: April 2024

The article considers a new acoustoelectronic method for measuring the velocity of ultrasonic waves in a liquid. It is shown that by changing the angle between the direction of propagation of an ultrasonic wave and the normal to the surface of a piezoquartz receiver placed in the studied liquid, it is possible determine the propagation velocity of this wave in the liquid. This method has been used at a wave frequency of 3 MHz to measure sound speeds in distilled water, glycerin, and freon. The experimental values of the velocities obtained agree satisfactory with the tabulated data.
Active Control of Jet–Wing Interaction Noise Using Plasma Actuators in a Narrow Frequency Band
Authors: Kopiev V. F. , Bychkov O. P. , Kopiev V. A. , Faranosov G. A. , Moralev I. A. , Kazansky P. N.
Published: April 2024

For a jet located near the wing, instability waves present in jet mixing layer scatter on the wing trailing edge, leading to additional noise generation. In this article, the possibility of reducing this noise by active cancellation of natural instability waves has been experimentally studied. The active control system consists of near-field microphones from which the feedback signal is taken, a data processing module for signal filtering, and a high-frequency dielectric barrier discharge plasma actuator. Decrease in pressure perturbations in the near field of a turbulent jet associated with axisymmetric instability waves in a narrow frequency band was demonstrated. It was shown that this reduction leads to a corresponding noise decrease in the far field.
Phase Conjugation of Sound Beams in Piezoelectric Semiconductors in an Alternating Magnetic Field
Authors: Bunkin A. F. , Mikhalevich V. G. , Streltsov V. N.
Published: April 2024

The propagation of a linearly polarized transverse sound wave in a semiconductor layer with a certain crystallographic structure with a sufficiently high concentration of conduction electrons is considered. The semiconductor layer is located in a spatially uniform magnetic field directed perpendicular to the plane of incidence of the sound wave and modulated with the sound frequency. The relationship between the plasma subsystem and acoustic oscillations in the layer is achieved due to the internal piezoelectric field. It is shown that propagation of a sound beam under these conditions is accompanied by a counterpropagating sound wave with a conjugated wave front. The conversion coefficient of direct and phase-conjugated waves is found.
Пузырьки в проточном акустическом резонаторе
Authors: Vikulova T. S. , Didenkulov I. N. , Kulinich V. V. , Pronchatov-Rubtsov N. V. , Sakharov D. V.
Published: April 2024

The article presents the results of an analytical and numerical study of bubble motion in a resonator with flow under the action of the radiation force and viscous friction force. The cases of weak and strong acoustic fields are considered.
Acoustics of Periodic and Multiple Drop Impacts on a Water Surface
Authors: Chashechkin Yu. D. , Prokhorov V. E.
Published: April 2024

High-speed video filming of surface currents and synchronized acoustic measurements of the underwater sound signals of falling drops were performed in a laboratory tank. During successive falling, the main structural elements of collision of a single drop with the surface are preserved in distorted form in the flow pattern: cavity, splashes, crown, and splash; shock pulses accompanying each contact are stably repeated in the phonogram. In addition, rare resonance packets are observed. For multiple falling drops, the flow pattern changes dramatically: the main structural elements of the drop impact flow disappear, and the surface is covered with floating bubbles. The phonogram assumes the form of a noise signal, in the spectrum of which separate linear sections stand out.
Sound Generation by Metro Trains during Braking and Its Suppression Method
Authors: Suchkov S. G. , Yavchunovsky V. Ya. , Timofeev A. I. , Nikolaevtsev V. A. , Suchkov D. S. , Tretinnikov V. V.
Published: April 2024

The causes of acoustic noise occurring during braking of electric vehicles, in particular, in the metro, were analyzed. The spectrum of such noise was measured, and it is shown that high-frequency discrete tones are excited by braking resistors, applied for electrodynamic braking of electric vehicles. Three proposed mechanisms of electromechanical interaction in a Fecral plate, which is a braking resistor element, were considered: the Ampère force and linear and nonlinear magnetostriction. It was shown that predominant odd harmonics indicate the presence of a significant piezomagnetic effect and the inverse effect of linear magnetostriction in the Fecral alloy. A phenomenological approach was used to calculate the piezomagnetic tensor elements for Fecral. Calculations by the finite element method showed that asymmetric cuts introduced into the plate may significantly decrease intensity of acoustic vibrations excited by the braking resistor.
The Influence of Bottom Sediment on the Propagation of Caustic Beams in Oceanic Waveguides
Authors: Petukhov Yu. V. , Borodina E. L.
Published: April 2024

Numerical modeling with the use of mode theory was used to investigate the regularities of the spatial (depth and horizontal distance) distribution of the acoustic field intensity formed by multiple interaction of a caustic beam with a layered bottom in a shallow oceanic waveguide with an underwater sound channel open to the bottom. It has been established that at the values of the sound velocity at the upper boundary in the sedimentary layer, less than the sound velocity at the bottom in the water layer, the formation of a multi-beam structure of the acoustic field is possible. It was found that, starting from certain distances, newly formed beams can play the main role in the spatial distribution of the acoustic field intensity.
Selective Excitation of Waveguide Modes Using a Horizontal Array of Monopoles
Authors: Makarov D. V. , Sosedko E. V.
Published: April 2024

The spatial structure of a far-field acoustic wavefield created by a sparse horizontal array of nondirectional emitters is considered. It is shown that the array can selectively excite certain modes of the acoustic wavefield. The number of an excited mode depends on the angle with respect to the array axis. The results of numerical simulation are presented for two models of a waveguide and for an array mounted at the ocean bottom. It is shown that the efficiency of single mode excitation grows with an increase in the modal number. The angular dependence of the excited modal spectrum is studied. It is shown that this dependence consists of several branches corresponding to the most excited modes
Discrete Acoustics: ARMA-modeling of Time Processes, Theory
Authors: Bobrovnitskii Yu. I. , Karpov I. A.
Published: April 2024

In physics, in particular, acoustics, time is traditionally considered as a continuous coordinate. Some exception is signal processing, where sampling is necessary for calculations on computers. But all acoustic problems are formulated and solved using time-continuous models described by differential equations and their solutions in the form of continuous time functions. Meanwhile, these problems can be formulated and solved in an equivalent way using discrete-time models described by finite-difference equations and their solutions in the form of time series. As the experience of some other fields of science, for example, control theory, shows, the discrete approach has a number of advantages over the continuous approach, the useof which greatly facilitates the solution of many problems. This paper aims to partially fill the gap in acoustics that exists here and is aimed at creating the theoretical foundations of a discrete-time approach to solving acoustic problems. The paper is limited to the consideration of one oscillatory system widely used in acoustics— a linear structure with N degrees of freedom consisting of lumped inertial, elastic and dissipative elements, to which, in particular, the finite element method leads. For several continuous models of this system, equivalentdiscrete-time models are constructed in the paper, finite-difference equations are derived and their solutions are obtained. The criterion of equivalence of continuous and discrete models in the paper is the mathematically exact equality of the corresponding solutions at all discrete points in time. Based on this criterion, analytical relations have been established between the parameters of continuous and discrete models and their equations, which make it possible to build its discrete-time model based on a continuous model of the systemand, conversely, to build its continuous model based on a known discrete model. Special attention is paid in the paper to the forced vibrations of the system under the action of kinematic excitation, which is important in many acoustic problems, whereas in the literature only force excitation is considered. The paper also discussesone of the most useful properties of discrete modeling—the simplicity of constructing discrete models based on experimentally measured signals. A corresponding example is given. Note that the term “ARMAmodel” is an abbreviation for “autoregressive and moving average model”, generally accepted in control theory, systems theory and other fields of science.
Non-Metric Multidimensional Scaling Analysis of Composition of Trichopterofauna from Two Protected Areas (Republic of Mordovia, Russia)
Authors: Borisova N. V. , Ruchin A. B. , Khapugin A. A. , Semishin G. B.
Published: April 2024

The fauna of caddisflies was studied from two protected areas of federal significance such as Mordovia State Nature Reserve (Temnikov district, Republic of Mordovia) and National Park “Smolny” (Ichalki district and Bolshoe Ignatovo district, Republic of Mordovia). The material was collected from May to October 2008, 2009, 2013–2021. There were 677 specimens from 59 caddisfly species from 12 families. The largest family Limnephilidae includes 29 species, there were 9 species each in the families Phryganeidae and Leptoceridae. Limnephilus sericeus and Holocentropus dubius dominated in the collections (12 and 10% from the total amount respectively), Hydropsyche angustipennis (8.9%), Hagenella clathrata (8.7%), Phryganea grandis (7.5%), Hydropsyche pellucidula (7.1%), Halesus tesselatus (6.6%) were numerous. Eighteen species of caddisflies (Rhyacophila fasciata, Holocentropus dubius, Agrypnia varia, Oligostomis reticulata, Anabolia concentrica, Anabolia furcata, Chaetopteryx villosa, Halesus digitatus, Limnephilus binotatus, Limnephilus extracatus, Limnephilus fuscicornis, Limnephilus ignavus, Limnephilus sericeus, Limnephilus sparsus, Limnephilus vittatus, Micropterna lateralis, Molanna albicans, Ceraclea excisa) supplement the known information on the fauna of the Republic of Mordovia, where 73 species from 14 families are currently recorded. The species Molanna albicans is indicated for the first time for the fauna of the Middle Volga region. Non-metric multidimensional scaling analysis revealed similarities and differences in the composition of trichopterofauna among the study sites. There was the maximum similarity among the sites with more diverse biotopes. There were indicated preferred habitats of some species.
Diversity of Edible Aquatic Insects Inhabiting Rice Fields in Central Thailand
Authors: Maneechan Witwisitpong , Prommi Taeng On
Published: April 2024

Abstract—Rice fields occupy great biodiversity and support a variety of living organisms, including edible aquatic insects. The goal of this study was to assess the richness and diversity of edible aquatic insects living in rice fields. A sampling of aquatic insects and physico-chemical parameters of the rice field water were made after irrigation. Three replications of sampling by aquatic net were collected from the bottom along the edge of the rice plots. The richness and diversity indices were analyzed. A total of 10 501 individuals, comprising 64 genera of aquatic insects belonging to six orders, were collected at different study sites. Among aquatic insects, the order Hemiptera occupied the highest abundance of the total insects collected. Richness showed a range of 14 to 50. The Shannon–Wiener diversity index (H′) showed a range of 1.877 to 3.450, whereas Simpson`s diversity index (D) showed a range of 0.7665 to 0.9605. Canonical Correspondence Analysis and non-parametric Spearman correlation revealed that some insect species were correlated positively with pH, temperature, turbidity, alkalinity, and nutrients (nitrate and phosphate), and had a negative correlation with electrical conductivity and total dissolved solids.
Abiotic Factors and Their Role in the Development of Phytoplankton in the Lower Volga
Authors: Mineeva N. M. , Poddubny S. A. , Stepanova I. E. , Tsvetkov A. I.
Published: April 2024

Based on field observations carried out during the 2015–2020 summer low water period, the interannual variability of abiotic characteristics and chlorophyll content in the Lower Volga is considered. In years with different thermal conditions and water content, the temperature, transparency, color and electrical conductivity of water are characterized by small variability and demonstrate changes from north to south, according to the zonal features of the Volga cascade. The average nutrient content (0.81–0.99 mg/L Ntot and 101–134 μg/L Ptot) changes insignificantly in the Saratov and Volgograd reservoirs, but decreases in the unregulated lower part of the Volga. The content of N-N\({\text{O}}_{3}^{ - }\) and P-P\({\text{O}}_{4}^{{3 - }}\) in the total nitrogen and phosphorus pool respectively, is 4–9 and 69–74%, the ratio Ntot/Ptot 10 indicates a possible nitrogen limitation of phytoplankton. The Chl a content corresponds to the mesotrophic category in the Saratov and Volgograd reservoirs (5.3 ± 0.6 and 7.2 ± 0.9 μg/L), and eutrophic in the lower section (13.9 ± 1.5 μg/L). The trophic status of the Lower Volga has not changed in comparison with the last decade of the 20th century. It was found that abiotic factors have a weak effect on the Chl a content in the Saratov reservoir, moderate in the Volgograd reservoir and almost completely control the development of phytoplankton in the unregulated lower part of the Volga (R2 = 0.21, 0.59, and 0.91). The data obtained supplement the observations of previous years and form the basis for long-term monitoring of ecosystems of large artificial reservoirs.
The Species Composition and Distribution of Free-Living Nematodes (Nematoda) in the Area of the Methane Seep Posolskaya Bank of Lake Baikal
Authors: Naumova T. V. , Gagarin V. G. , Cherbakov D. Yu. , Sitnikova T. Ya.
Published: April 2024

The Posolskaya Bank methane seep (southern Baikal, depths of ~300–500 m) is characterized by weak metha-ne discharge and the deep occurrence of gas hydrates. The species composition and distribution of nematodes from 44 samples of meiozoobenthos on the seeps (gas unloading point and gas hydrate) and background stations were analyzed. 31 species of nematodes from 12 genera, 8 families and 6 orders were identified; 94% of them were found at background stations and/or in other areas of the lake. The ratio of Baikal endemic and Siberian-Palearctic species was 6 : 1. Endemic species of the genera Paratrilobus and Tripyla dominated occurrence frequency and population density. The data obtained on the heterogeneous distribution of nematodes, the relationship between the density of their population and the presence of filaments of sulfur bacteria, copepod detritus, and ferromanganese crusts in the bottom sediments, as well as the habitation of worms with different types of food. These data are discussed.
Mycobiota of Dead Reed Fragments Immersed in Water (Yaroslavl Region, Russia)
Authors: Voronin L. V. , Kopytina N. I.
Published: April 2024

The mycobiota on dead submerged plant parts of Phragmites australis reed (leaves, stems, leaf sheaths) was studied in lakes – Pleshcheyevo, Mostetskoye, a lake in the Zavolzhsky district of Yaroslavl and the Kotorosl river (Yaroslavl region, Russia). The kingdom Fungi is represented by 53 species belonging to 33 genera, 25 families, 12 orders, and 7 classes in 2 taxonomic phyla: Mucoromycota (4 species), Ascomycota (48). The kingdom Chromista (fungi-like organisms) includes 8 species belonging to 3 genera, 2 families, 2 orders, and 1 class under phylum Oomycota. For the first time, 23 species of micromycetes were found on reeds. Representatives of the orders Pleosporales (16 species), Helotiales (11), Saprolegniales (7), Hypocreales (5) prevailed. The number of species of fungi on fragments of plants in different aquatic bodies varied from 16 to 39, the statistically significant difference in the species composition of communities of dead reeds was found between a lake in the Zavolzhsky district of Yaroslavl and the Kotorosl River (R = 0.646, significance level of sample statistic 0.1%).
Pike Cannibalism, Paratenic Hosts and Trematode Life Span as Factors Influencing the Distribution of Azygia lucii in the Definitive Host Population
Authors: Zhokhov A. E. , Pugacheva M. N.
Published: April 2024

The ratio of the body length of the trematodes Azygia lucii and the body length of pikes in the population of the Rybinsk Reservoir was studied. The material was collected in September–October from 2018 to 2021. A total 386 pike was divided into seven size classes according to body length (range 4.7–83 cm). The prevalence of A. lucii increased from 14.2% in underyearlings to 46.2% in pikes 9+. The distribution of the trematodes in all size classes was aggregated. The usual intensity of invasion was 1–3 trematodes in all classes; the proportion of fish with this intensity of invasion varied from 62.5 to 83.3%. A total of 259 worms were measured. The body length of the found worms ranged from 0.49 to 3.5 cm. The average length of A. lucii increased with host size from 1.39 cm in underyearlings to 2.39 cm in older pikes. The largest trematodes (3–3.5 cm long) were found in the largest pikes. Distribution/redistribution of trematodes in the pike population occurs due to pike cannibalism. Due to this, a group of trematodes is formed in large pikes, consisting of worms of different ages and sizes. An important role in the formation of such groups of trematodes is played by paratenic hosts. Their significance depends on their infection rate and the proportion in diet of pike in a particular reservoir. Features of the biology of A. lucii (large body size, short contact of trematodes with mollusks) suggest a long lifespan of marites.
Helminths of Gray Toad Fingerlings (Bufo bufo) of Protected Areas of the Urals and Analysis of Its Parasitofauna in Russia
Authors: Burakova А. V. , Malkova E. A.
Published: April 2024

Helminths of gray toad fingerlings Bufo bufo (Linnaeus, 1758) have been studied in some specially protected natural areas (protected areas) the Urals. Four species of helminths belonging to the Nematoda type were found. Common to the studied amphibian populations are 2 species of nematodes – Oswaldocruzia filiformis and Rhabdias bufonis. The species composition of geohelminths does not differ in fingerlings and sexually mature amphibians, infection in adult toads is higher than in fingerlings. The analysis of the helminth fauna of the gray toad showed that the nematodes Oswaldocruzia filiformis and Rhabdias bufonis dominate in Bufo bufo in most regions of Russia. The richest species composition of trematodes is noted in gray toads of the fauna of Mordovia.
Brevilinea kevei (Bacillariophyta)—a New Genus and Species for the Flora of Russia
Authors: Genkal S. I. , Eremkina T. V.
Published: April 2024

This scanning electron microscopy study of phytoplankton from the Nizhny-Tagil Reservoir has revealed a small-sized genus and species of diatoms, Brevilinea kevei, new to the flora of Russia. Small differences from the original description in the minimum values of the valve width and a higher variability range of the number of striae in 10 µm allow the authors to refine the species description. New data on the location make it possible to clarify the ecology and geographical range of Brevilinea kevei.
Polychlorinated Biphenyls in the Bream Abramis brama from the Volga Ples the Rybinsk Reservoir: Fish Age Effect and Human Health Risk Assessment
Authors: German А. V. , Mamontov А. А. , Mamontova E. A.
Published: April 2024

Bream, Abramis brama (L.), is an important commercial species and the object of monitoring pollution of freshwater bodies with polychlorinated biphenyls (PCBs). However, the dependence of the PCB content on the age of the bream has been studied very poorly. In this regard, the concentrations of 32 PCB congeners were measured in the carcasses of female bream of different ages in the pre-spawning period. It is shown that the concentration of PCBs in the body lipids increases from 257 to 449 ng/g over a period of 8 to 19 years. In terms of wet weight, the concentration of PCBs increases from 19.8 to 57.9 ng/g over a period of 8 to 13 years and then decreases to 21 ng/g at the age of 19 years. The largest share was 5-XB – from 46 to 58%, then 6-XB – from 17 to 29%, 4-XB – from 12 to 18%, 3-XB – from 4 to 8%, 7-XB – from 4 to 6% and 2-XB – from 0.1 up to 0.5%. PCB concentrations 5/8, 28, 31, 44, 49, 52, 74, 70/76, 87/115, 95/66 do not depend on age (R2  0.5); PCBs 97, 99, 105, 90/101, 110, 118. They have an average dependence (0.5 R2 0.6); PCBs 138, 153, 180, 183, 128/167 and 170/190 strongly depend (R2 ≥ 0.7). With age, the congener composition changes towards an increase in highly chlorinated PCBs. The content of PCBs in the carcass of bream of the Volga Ples of the Rybinsk reservoir does not exceed the existing in Russia MPC in fish, amounting to 2 mg/kg of raw weight. The average indicator of non–carcinogenic risk exceeds 1 (0.82–2.39), which indicates the possible development of non-carcinogenic diseases in target organs and systems. The indicator of carcinogenic risk exceeds the level of negligible risk (1 × 10–6) and corresponds to the range 2 – the maximum permissible risk or the upper limit of acceptable risk (1 × 10–6–1 × 10–4). These risks are subject to constant monitoring, the population is recommended to limit the consumption of large fish with a high fat content.
Daptonema brzeskii sp. n. and D. rivale sp. n. (Nematoda, Monhysterida, Xyalidae) from Mekong River Mouth, Vietnam
Authors: Gusakov V. A. , Gagarin V. G. , Dinh Cu Nguyen
Published: April 2024

Two new nematode species of the genus Daptonema, D. brzeskii sp. n. and D. rivale sp. n., are described and illustrated based on the material collected from Mekong River Delta, Vietnam. Daptonema brzeskii sp. n. is close to D. lutosum Gagarin, 2021, D. dihystera Gagarin, Nguyen Vu Thanh, 2005 and D. hyalocella Aryuthaka, Kito, 2012 in the presence of postvulval uterus sac, and it is close to D. paraoxyuroides Nguyen Dinh Tu, Gagarin, Nguyen Vu Thanh, Nguyen Thi Xuan Phuong, Nguyen Thanh Hien, 2014 in the shape of spicular apparatus. From the former species it differs in the thinner body, slenderer tail, narrower labial region, shorter outer labial setae and spicules, larger pharyngostoma, and vulva located farther from the anterior body end. It differs from D. dihystera in the shorter body, narrowed labial region, shorter outer labial setae and spicules, and larger pharyngostoma. Daptonema brzeskii sp. n. differs from D. hyalocella in the thinner body, amphidial fovea located closer to the anterior body end, shorter outer labial setae, longer spicules, presence of gubernaculum, larger pharyngostoma, and vulva located farther from the anterior body end. From D. paraoxyuroides, D. brzeskii sp. n. differs in the presence of postvulval sac, longer body, slenderer tail, shorter outer labial setae and gubernaculum. Daptonema rivale sp. n. is similar to D. setihyalocella Aryuthaka, Kito, 2012 in shape of spicular apparatus and to D. brzeskii sp. n. in the shape of pharyngostoma. Daptonema rivale sp. n. differs from D. setihyalocella in the shorter and comparatively thinner body, shorter outer labial setae, spicules, and gubernaculum, bigger pharyngostoma, and vulva located farther from the anterior body end. Daptonema rivale sp. n. differs from D. brzeskii sp. n. in the longer body and outer labial setae, less slender tail, and vulva located farther from anterior body end.
New Data on the Distribution of the Bulgarian Spined Loach Cobitis strumicae (Teleostei: Cobitidae) in Turkey
Authors: Ozpicak M. , Yilmaz S. , Saygin S. , Polat N.
Published: April 2024

This study reports the presence of Cobitis strumicae Karaman, 1955 in Terme Stream (Samsun-Black Sea-Turkey). Molecular and morphometric approaches were used together to prove the existence of the species in Terme Stream. The family Cobitidae represents a unique element of ichthyofauna. Even while sexual dimorphism can take many different forms, taxonomy studies have only used a small number of morphological features, leaving many concerns unanswered. In addition to the assessments of phenotypic traits (Gambetta’s longitudinal zones, Canestrini’s scales, suborbital spine morphology, barbel and mental lobe morphology), mitochondrial cytochrome b gene (cyt b) (1140 bp) sequence variation was studied in molecular analysis. We present the phylogenetic relationships of morphologically diagnosable subgenus Bicanestrinia from Asia Minor and Balkans in here. Samples from Terme (Accession Numbers: ON116344 and ON116345) and GENBANK were combined in the phylogenetic analysis. Our findings offered a significant distribution update of C. strumicae from Terme Stream, a southern coastal Black Sea drainage, and support the vicariance theory, according to the results of this study.
Distribution of Topmouth Gudgeon Pseudorasbora parva (Cyprinidae) in Waterbodies and Watercourses of Republic of Dagestan, Russia
Authors: Barkhalov R. M. , Stolbunov I. A. , Artaev O. N. , Turbanov I. S. , Rabazanov N. I. , Khlopkova M. V. , Karabanov D. P.
Published: April 2024

The study provides information on the modern distribution of a species alien to the ichthyofauna of Republic of Dagestan, topmouth gudgeon Pseudorasbora parva (Temminck et Schlegel, 1846) (Cyprinidae). It has been established that this species is found in the rivers Manasozen, Gamriozen, Ulluchay, Rubas, Avar Koisu (a tributary of the Sulak River, in the area of the Gotsatlinskaya HPP), as well as in Lake Mochokh. The wide distribution of P. parva is associated with ecological plasticity, migratory activity, high growth rate, accelerated puberty and high level of survival of the offspring of this species of fish.
Biological Indicators of Water Quality of Drenova Reservoir (Bosnia and Herzegovina)1
Authors: Golub D. , Dmitrović D. , Lolić S. , Šukalo G. , Dekić R. , Tošić R.
Published: April 2024

This paper presents the state of biota of Drenova reservoir in Bosnia and Herzegovina (BH) as water quality indicator. The Drenova reservoir has a multiple role: protection of the Vijaka river basin from floods, provision of water for the Prnjavor fishpond, as well as sport fishing. Bearing in mind the multifunctionality of this reservoir, but also the scarcity of data on the biota of this water body, in 2017, research on phytoplankton, zooplankton, macrozoobenthos and ichthyofauna was performed. Based on the obtained results (qualitative and quantitative composition, saprobic index according to Pantle Buck, Shannon index), it was established that the water of Drenova reservoir, as far as phytoplankton and zooplankton community is concerned, corres-ponds to the transition from oligosaprobic to β-mesosaprobic waters while macrozoobenthos and ichthyofauna refer to β-mesosaprobic water. A small number of representatives of phytoplankton (both qualitatively and quantitatively) is noticeable, as well as the absence of species common to this type of aquatic ecosystems in the observed period. The state of macrozoobenthos taxa is expected considering the properties of the substrate of this accumulation. Ichthyocenosis is characterized by a small number of species, but also by a small number of individuals within those species.
Hofmaenneria baikalensis sp. n. and Paratrilobus longisomus sp. n. (Nematoda) from Lake Baikal
Authors: Naumova T. V. , Gagarin V. G.
Published: April 2024

Illustrated descriptions of two new species of free-living nematodes Hofmaenneria baikalensis sp. n. and Paratrilobus longisomus sp. n. found in the Lake Baikal (Russia) are given. Hofmaenneria baikalensis sp. n. is close to H. keoladeoensis Khan et al., 2005, H. niddensis (Skwarra, 1921) Schneider, 1940 and H. sitnikovae Gagarin, Naumova, 2010. It differs from these three species in a presence of crystals in the body cavity and presence of three oval cardial glands. Paratrilobus longisomus sp. n. is close in the body size to P. expugnator (Tsalolichin, 1976) and P. rapis Gagarin, 1991 but it has a relatively shorter and slenderer tail and presence of subterminal seta at the tail end.
Status of Local Populations of Isolated Mountain Lakes in the Altai by Histological Parameters and Elemental Composition of the Eye Lens of Peled Fish Coregonus peled
Authors: Nikiforov-Nikishin A. L. , Nikiforov-Nikishin D. L. , Kochetkov N. I.
Published: April 2024

This paper examines the state of the population of a native fish species in three lakes of the Altai Mountains. Analysis of the age and weight composition showed that in the studied water bodies in conditions of oligotrophic mountain lakes the pelad Coregonus peled Gmelin, 1788 population showed different growth dynamics. The age distribution of fish varied in different lakes, so in Lake Kedelu-Kol individuals of four age groups (1+ …4+) were present, and in Lake Kidelu only yearlings were caught. Histological examination of the liver and gills of fish showed the absence of significant abnormalities, both of parasitic and toxicological nature. Calculation of the histopathological index showed that the prevalence and severity of pathological abnormalities were significantly lower (p  0.05) in Lake Kidelu. The analysis of the elemental composition of peled lens confirmed the absence of a significant level of pollution in the studied water bodies and the high quality of the aquatic environment. The presence in some samples of trace amounts of heavy metals may be associated with the geomorphological features of the region involved in the formation of the hydrochemical composition of the water of the studied lakes. The data obtained in the study indicate that the peled populations in the isolated mountain lakes of the
First Find of the Invasive Amphipod Gmelinoides fasciatus in the Basin of Lake Vodlozero (Russia)
Authors: Baryshev I. A.
Published: April 2024

For the first time, the presence of the invasive amphipod Gmelinoides fasciatus (Stebbing, 1899) was established in the watercourse of the basin of Lake Vodlozero (Novguda River, a tributary of the Ileksa River), which is located on the territory of the National Park “Vodlozersky” (North-West Russia). The new habitat is at a considerable distance from the previously known ones. The shortest route through water bodies (Ileksa River–Vodlozero Lake–Sukhaya Vodla River–Vodla River–Onega Lake) is about 180 km. This raises questions about the path and mode of spread of the invasive species. Along with migration through water bodies, it is proposed to consider the version of introduction of amphipods by tourists, in particular fishermen, with equipment or bait. A detailed survey of the littoral zone of Lake Vodlozero is recommended to determine the extent of the invasive settlement.
Finding of the American Signal Crayfish Pacifastacus leniusculus (Decapoda: Astacidae) in the Leningrad Region (Russia)
Authors: Tamulyonis A. Yu. , Stratanenko E. A. , Zuyev Yu. A.
Published: April 2024

The American signal crayfish Pacifastacus leniusculus (Dana, 1852) was first found in the lake Zaprudnoye of the Saimaa Canal system between lake Saimaa (Finland) and Vyborgsky Bay (Russia). The Saimaa Canal belongs to a large lake-river network connecting the waters of the Gulf of Finland and Lake Ladoga. On this basis, a wide distribution of P. leniusculus is predicted in the water bodies of the Leningrad Region and the North-West of Russia as a whole. The captured part of the population was 9 individuals. The sex ratio in the population was significantly biased toward males: 8 ♂ и 1 ♀.
Peripheral Blood Cells Composition of the Baikal Seal
Authors: Gordeev I. I. , Boltnev E. A. , Suvorova T. A. , Mikryakov D. V. , Balabanova L. V.
Published: April 2024

The cellular composition of the peripheral blood of the Baikal seal Phoca sibirica (Gmelin, 1788) has been studied. In blood smears, various cells were found: large and small lymphocytes, monocytes, neutro-, eosino- and basophils. Analysis of the leukogram showed the predominance of neutrophils and lymphocytes among white blood cells. The proportion of the content of various forms of leukocytes corresponded to similar data of marine representatives of true seals (Phocidae).
Influence of the Rate of Changes in the COX1 Gene on Body Size and Sexual Selection in Carp Hybridization
Authors: Stolbunova V. V. , Borovikova E. A.
Published: April 2024

The influence of mtDNA cytochrome c-oxidase I gene fragment variability on body length was studied in twelve species of cyprinids, which may have hybrids with Rutilus rutilus L. and Abramis brama L., and in reciprocal hybrids (RA, AR) and alloplasmatic backcrosses (ARR, RAA) of roach (R) and bream (A). It has been established that the rate of nucleotide substitutions in COX1 is negatively related not only to body size but also to fish life span, which differentiates them into two groups: group I – species with a high rate of COX1 changes and a relatively small body size and group II – species with low sequence variability and relatively large body size. The boundary for the distinguished groups runs between species the same genus Leuciscus leuciscus and L. idus: with a twofold decrease in the rate of substitutions in ide, a twofold increase in body size and lifespan occurs, which indicates a decrease in the rate of cellular respiration and free radical leak, and the exact mitonuclear match respiratory complexes. Presumably, the decrease in the rate of COX1 changes in species of group II and in bleak Alburnus alburnus is associated with an increase in the size of genome, which provides additional protection of genes from chemical mutagens and, regardless of body size, reduces the rate of aerobic metabolism. It has been experimentally shown that mtDNA affects body length. When bream mtDNA is included in the roach nuclear genome, ARR backcrosses have the body length of a bream and high viability, while RAA backcrosses with roach mtDNA and the bream nuclear genome inherit the roach body length and reduce viability. Species of group II are not able to effectively use the highly polymorphic mtDNA of species of group I, which is also manifested by a violation of the inheritance of a longer bream body length in RA hybrids and leads to reproductive isolation. Group I species, such as Rutilus rutilus, can include mtDNA of both groups in their genome, which underlies sexual selection in hybridization. Accordingly, sexual size dimorphism has a genetic origin, and body size for a potential partner can be a signal for determining the mitonuclear compatibility of genomes in respiratory complexes.
The Current Trophic State and Water Quality of Lake Onego
Authors: Tekanova E. V. , Kalinkina N. M. , Makarova E. M. , Smirnova V. S.
Published: April 2024

The trophic state and water quality of Lake Onegо were assessed under climate warming and changes in anthropogenic load over the past 30 years. The water body retains its natural oligotrophic state during the summer stratification according to the concentration of chlorophyll a. A small amount of readily mineralizable organic matter in water determines the low level of development of saprophytic bacteria, corresponding to xenosaprobic and β-oligosaprobic waters. Only the Kondopogskaya Bay of Lake Onego is characterized by a higher level of trophy (mesotrophic) and water saprobity (β-mesosaprobic) due to pollution by wastewater from the pulp and paper mill and waste from trout farms. Local “bloom” of cyanobacteria of in the open area of the lake was observed during the anomalous heating of the epilimnion in the summer of 2022 for the first time in the 50-year history of research. The increase in the concentration of humic substances in the water of the bays as a result of climate warming at this stage did not lead to a change in the level of saprophytic bacteria.
New Data on Parasites of Pungitius pungitius (Pisces, Gasterosteidae) in the Volga River Basin
Authors: Mineeva O. V. , Semenov D. Yu.
Published: April 2024

During the study of parasites of the ninespine stickleback Pungitius pungitius, a resident in the Volga basin, intestinal nematodes Pseudocapillaria tomentosa and Rhabdochona denudata were found. Both species are recorded for the first time in the parasite fauna of the host of the European part of Russia. Data on the occurrence and intensity of fish invasion by worms are presented.
Encapsulins: structure, properties, application in biotechnology
Authors: Chmelyuk N. S , Oda V. V , Gabashvili A. N , Abakumov M. A
Published: April 2024

In 1994 a new class of prokaryotic compartments was discovered, collectively called “encapsulins” or “nanocompartments”. Encapsulin shell protomer proteins self-assemble to form icosahedral structures of various diameters (24-42 nm). Inside of nanocompartments shells, one or several cargo proteins, diverse in their functions, can be encapsulated. In addition, non-native cargo proteins can be loaded into nanocompartments, and shell surfaces can be modified via various compounds, which makes it possible to create targeted drug delivery systems, labels for optical and MRI imaging, and to use encapsulins as bioreactors. This review describes a number of approaches to the application of encapsulins in various fields of science, including biomedicine and nanobiotechnologies.
Effect of chemical chaperones on processes of protein aggregation proceeding in different kinetic regimes
Authors: Mikhaylova V. V , Eronina T. B , Chebotareva N. A , Kurganov B. I
Published: April 2024

The formation and accumulation of protein aggregates adversely affect intracellular processes in a living cell and are a negative factor in the production and storage of protein preparations. Chemical chaperones can prevent protein aggregation, but this property is not universal and depends on the structure of the target protein and the kinetics of its aggregation. In this work, we studied the effect of betaine (Bet) and lysine (Lys) on test systems based on thermal aggregation of muscle glycogen phosphorylase b (Phb) at 48°C, UV-irradiated Phb (UV-Phb) at 37°C and apo-form of Phb (apo-Phb) at 37°C and characterized by the order of aggregation with respect to the protein (n) equal to 0.5, 1 or 2, respectively. Dynamic light scattering, differential scanning calorimetry, and analytical ultracentrifugation have shown that Bet protects Phb and apo-Phb from aggregation, but accelerates the aggregation of UV-Phb. At the same time, Lys prevents UV-Phb and apo-Phb aggregation, but increases the rate of Phb aggregate formation. The mechanisms of chemical chaperone action on the tertiary and quaternary structures and the kinetics of thermal aggregation of the target proteins are discussed. Comparison of the effect of chemical chaperones on test systems with different kinetic regimes of aggregation provides more complete information about the mechanism of their action.
Imbalance of angiogenic and growth factors in the placenta in maternal hyperhomocysteinemia
Authors: Arutjunyan A. V , Kerkeshko G. O , Milyutina Yu. P , Shcherbitskaia A. D , Zalozniaia I. V , Mikhel A. V , Inozemtseva D. B , Vasilev D. S , Kovalenko A. A
Published: April 2024

Numerous studies have shown that various adverse factors of different nature and action mechanisms have similar negative influence on placental angiogenesis, resulting in insufficiency of placental blood supply. One of the risk factors for pregnancy complications with placental etiology is an increased level of homocysteine in the blood of pregnant women. However, the effect of hyperhomocysteinemia (HHcy) on the development of the placenta and, in particular, on the formation of its vascular network is at present poorly understood. The aim of this work was to study the effect of maternal HHcy on the expression of angiogenic and growth factors (VEGF-A, MMP-2, VEGF-B, BDNF, NGF), as well as their receptors (VEGFR-2, TrkB, p75NTR), in the rat placenta. The effects of HHcy were studied in the morphologically and functionally different maternal and fetal parts of the placenta on the 14th and 20th day of pregnancy. The maternal HHcy caused increase in the levels of oxidative stress and apoptosis markers accompanied by an imbalance of the studied angiogenic and growth factors in the maternal and/or fetal part of the placenta. The influence of maternal HHcy in most cases manifested in a decrease in the protein content (VEGF-A), enzymatic activity (MMP-2), gene expression (VEGFB, NGF, TRKB), and accumulation of precursor form (proBDNF) of the studied factors. In some cases, the effects of HHcy differed depending on the placental part and stage of development. The influence of maternal HHcy on signaling pathways and processes controlled by the studied angiogenic and growth factors could lead to incomplete development of the placental vasculature and decrease in the placental transport, resulting in fetal growth restriction and impaired fetal brain development.
5,7-diamino-3,5,7,9-tetradeoxynon-2-ulosonic acids in capsular polysaccharides of acinetobacter baumannii
Authors: Knirel Y. A , Kasimova A. A , Arbatsky N. P , Shneider M. M , Popova A. V , Brovko F. A , Shashkov A. S , Senchenkova S. N , Perepelov A. V
Published: April 2024

The polysaccharide capsule that surrounds the bacterial cell plays an important role in pathogenesis of infections caused by the opportunistic pathogen Acinetobacter baumannii by providing protection from external factors. Structures of the capsular polysaccharide (CPS) produced by individual A. baumannii isolates and the corresponding CPS biosynthesis gene clusters can be highly diverse but many from them are related. A large proportion of the A. baumannii CPS types contain an isomer of 5,7-diamino-3,5,7,9-tetradeoxynon-2-ulosonic acid. Three of these isomers, namely acinetaminic acid (L-glycero-L-altro isomer), 8-epiacinetaminic acid (D-glycero-L-altro isomer), and 8-epipseudaminic acid (D-glycero-L-manno isomer), have not been found so far in naturally-occurring carbohydrates from other species. In the CPSs of A. baumannii, the higher monosaccharides of this class carry N-acyl substituents at positions 5 and 7, and in some CPSs, the N-acetyl and N-(3-hydroxybutanoyl) groups are both present. The present review addresses the structures and genetics of biosynthesis of the CPSs of A. baumannii that contain di-N-acyl derivatives of 5,7-diamino-3,5,7,9-tetradeoxynon-2-ulosonic acids.
Evolution of restriction-modification systems with one restriction endonuclease and two DNA methyltransferases
Authors: Fokina A. S , Karyagina A. S , Rusinov I. S , Moshensky D. M , Spirin S. A , Alexeevski A. V
Published: April 2024

Some restriction-modification systems contain two DNA methyltransferases. In the present work, we have classified such systems according to the families of catalytic domains present in restriction endonucleases and both DNA methyltransferases. The evolution of restriction-modification systems of one class was studied in detail. Systems in this class include an endonuclease with a NOV_C family domain and two DNA methyltransferases, both with DNA_methylase family domains. The phylogenetic tree of DNA methyltransferases from systems of this class consists of two clades of the same size. Two DNA methyltransferases of each restriction-modification system of the class belong to different clades. This indicates independent evolution of the two methyltransferases. We detected multiple cross-species horizontal transfers of systems as a whole, as well as cases of gene transfer between systems.