bluuebunny/crossref_metadata_2025 huggingface dataset:
Detection of Echo Signals Taking Into Account the Multipath Effect of the Waveguide and the Multispecularity of the Reflector
Authors: Drachenko V. N. , Kuznetsov G N. , Mikhnyuk A. N.
Published: April 2024

In the shelf zone, an experimental study was conducted on the possibility of increasing the probability of detecting echo signals against an noise background as a result of taking into account the multipath waveguide model and design features of the reflector. The possibility of increasing the tracking range and reducing the probability of false alarms is experimentally substantiated with an algorithm that uses the duration of the time interval during which a sequence of signals reflected from one reflector is observed due to the multipath propagation of signals and multispecularity of the reflected signal, if the target structure is complex and includes several offset reflectors. Recommendations are given on the choice of intervals, the sampling lengths within which summation of the energy of the reflected signals is possible. It is shown that as a result of signal power accumulation using an algorithm that partially takes into account the echo signal model, the target tracking time increases and false alarms decrease.
Improvement of optoacoustic angiographic images using one-dimensional deconvolution with adaptive real-time self-calibration
Authors: Timanin E. M. , Mikhailova I. S. , Fiks I. I. , Kurnikov A. A. , Kovalchuk A. V. , Orlova A. G. , Ugarova O. A. , Frenz M. , Jaeger M. , Subochev P. V.
Published: April 2024

This work introduces a method of one-dimensional deconvolution with Tikhonov regularization for enhancing three-dimensional optoacoustic images in vivo. The method employs adaptive self-calibration to eliminate frequency-dependent distortions associated with ultrasound propagation and detection. By adapting to the inhomogeneous frequency characteristics of the examined medium, the method eliminates the need for additional calibration experiments. The processing time for three-dimensional optoacoustic data of size 200x200x100 voxels is less than 5 ms, facilitating the real-time enhancement of angiographic images and improving the effective spatial resolution by more than 50%.
Distribution, Size-Morphological Structure and Production of Heterotrophic Bacterioplankton in Gorky Reservoir
Authors: Kuznetsova E. V. , Kosolapov D. B. , Mikryakova I. S. , Kosolapova N. G. , Maslennikova T. S. , Skopina M. Yu.
Published: April 2024

The abundance, biomass, size-morphological structure, growth rate and production of bacterioplankton, the intensity of primary phytoplankton production and dark fixation of CO2, as well as the abundance and biomass of heterotrophic nanoflagellates were determined in a large plain eutrophic reservoir (Gorky Reservoir, Middle Volga). The abundance, biomass, and production of bacterioplankton were relatively high and averaged 7.6 × 106 cells/mL, 117.9 mg C/m3, and 59.2 mg C/(m3 × day), respectively. Heterotrophic nanoflagellates reached a high level of quantitative development – 6.9 × 103 cells/mL, 47.9 mg C/m3. Their biomass averaged 41.6 ± 18.4% of the bacterioplankton biomass, which indicates that, in addition to bacteria, nanoflagellates used other food sources. Small rods and cocci dominated among the size-morphological bacterioplankton groups and accounted for 36.3 and 33.3% of its total abundance, respectively. Small rods averaged more than a half (56.2%) of the total biomass and were the most stable component of the community. The growth rate and production of bacterioplankton increased in those parts of the reservoir where the medium-sized cocci and coccobacilli accounted for from 18.2 to 29.3% of the total abundance. The highest bacterial activity was recorded in the area affected by the warm waste waters of the Volgorechensk State District Power Plant. Based on the data obtained, the reservoir divided on the upper river section and the lower lake section.
Spatial and Age-Related Changes in the Food Spectrum of the Common Bream Abramis brama in the Middle and Lower Course of the Northern Dvina River (Russia)
Authors: Novoselov A. P. , Lukina V. A. , Matveev N. Yu. , Matveeva A. D.
Published: April 2024

Data on spatial and age-related changes in the qualitative composition of food spectra (species and taxonomic diversity of invertebrates used as food objects) and quantitative characteristics (dominant types of food) of the common bream Abramis brama (L., 1758) are presented. Changes in nutrition and the ratio of prevailing taxonomic groups in different age groups are shown as the bream grows in the middle and lower reaches of the Severnaya Dvina River. Analysis of the results showed that the composition food’s lump included both representatives of the bottom fauna and planktonic organisms. Amphibiotic insect larvae, mollusks, and aquatic vegetation were the most numerous among the feeding objects. In addition, juvenile fish were present in the food lump of some age groups. Age variability in bream nutrition is reflected in the size-breadth of the food spectrum – in juveniles and older individuals, the components of nutrition are significantly less than in middle-aged fish.
Nuclear Cytoplasmic Conflict in Hybrids of Roach Rutilus rutilus and Bream Abramis brama as a Consequence of the Divergence Species in Body and Genome Sizes
Authors: Stolbunova V. V. , Kodukhova Yu. V.
Published: April 2024

Species divergence in body size is often associated with changes in genome size and the rate of evolution of mitochondrial DNA (mtDNA), which can lead to problems of nuclear-cytoplasmic compatibility and embryonic genome activation and reduce the fitness of hybrids. The bream Abramis brama (L.) is larger than the roach Rutilus rutilus (L.) in body and genome sizes. In the first generation of hybrids according to the ITS1 region of ribosomal DNA, a change in the donor genome of male to the level of the maternal species was previously established, which can affect the inheritance of traits from the male and, in particular, body size. Body length and height, a complex of diagnostic morphological characters, and genotyping (ITS1 rDNA and cyt b mtDNA) of underyearlings and mature individuals of bream, roach, F1 hybrids and underyearlings of backcrosses (Fb) were analyzed. Sexually mature hybrids of both directions of crossing are close in body length to R. rutilus, which indicates a violation of the paternal effect when inheriting the body length of a larger of species. Violation of the inheritance of bream body length in hybrids of cross R. rutilus × A. brama (♀ ♂, RA) is considered as a developmental deviation, which, obviously, can affect the adaptation of hybrids and determines the rarity of this variant in nature. At the same time, alloplasmic ARR backcrosses restore the body length of the bream even in the presence of the roach nuclear genome, which indicates the influence of mitochondrial genes on the development of this trait. The observed decrease in the fitness of first-generation hybrids with roach mtDNA may be associated with to an insufficient level of transcription of ribosomal genes due to a decrease in the number and variability of copies of the donor bream rDNA. Moreover, the high level of changes of mtDNA roach indicate a suboptimal mitochondrial-nuclear correspondence of respiratory a complexes in hybrids RA, which negatively affects key physiological processes, including growth and development of a large body size. Presumably, the development of large body size, as a complex trait with high aerobic fitness, is blocked in RA hybrids for energy reasons. The paper shows that differences families of repeated sequences rDNA and mtDNA in terms of the number and variability of copies in genome of R. rutilus and A. brama can lead to regulatory nuclear-cytoplasmic incompatibility of genomes and affect the fitness of hybrids already in the first generation.
Features of the Organization of the Tegument in Cystacanth and Adult Acanthocephalan Acanthocephalus tenuirostris
Authors: Davydenko T. V. , Nikishin V. P.
Published: April 2024

A comparative light- and electron-microscopic study of the tegument of a formed cystacanth and a mature acanthocephalan Acanthocephalus tenuirostris (Achmerov et Dombrowskaja – Achmerova, 1941) was carried out. It was shown that, in addition to morphometric differences, the tegument of cystacanth differs from that of the adult acanthocephalan by terminal expansions of invaginates of the outer tegument membrane, presumably due to the secretion of glycocalyx material. In the tegument of an adult acanthocephalan, a process of detachment from the nuclei of small fragments was found, which may be an analogue of the well-known process of nuclear fragmentation that occurs at the early stages of postembryonic development. It has been shown that in many cases tegument lacunae are not completely limited by dense formations resembling fibrils on sections.
Diet and Feeding Ecology of the Invasive Gambusia holbrooki (Teleostei: Poeciliidae) in Lotic and Lentic Habitats (Northwestern Part of Turkey)
Authors: Saç Gülşah
Published: April 2024

Received October 13, 2021; revised April 22, 2022; accepted August 15, 2022Abstract—In order to understand the success of the invasion of a non-native fish, it is important to determine its fundamental competition characteristics such as its tolerance to habitat differences and feeding plasticity. This study aimed to determine the invasive characteristics of Gambusia holbrooki Girard, 1859 by investigating the diet and feeding ecology of this non-native fish inhabited in lotic and lentic habitats. A total of 164 G. halbrooki specimens (SL 1.4–4.3 cm) were investigated from the lotic habitats, while 101 (SL 1.6–3.3 cm) ones were from the lentic habitats. The food spectrum of the fish in lotic habitats was composed of 11 food items predominantly of the Diptera (80.9, MI%) and Plant (11.8, MI%). In lentic habitats, the species consumed 10 different food types, and Diptera (96.0, MI%) was followed by the low values of zooplankton groups (Cladocera; 2.2, MI% and Copepoda; 0.8, MI%). The fish that inhabited both lotic and lentic habitats have shown a generalist feeding strategy; while the importance of each food item in the diet indicated the generalization, Diptera presented with high values was the evidence of a relatively narrow niche of the fish in both habitats. An ontogenetic shift was observed in the diet of G. holbrooki and while the diet of juveniles was more limited, the diversity and sizes of food items consumed have increased in parallel with the increase in the size of the fish. With these results, it was thought that G. holbrooki could show a food competition with native fish species in the region by feeding mainly on Diptera, which is also an important food source for most of the native fishes and their young individuals.
Vegetation of Lakes and Springs in the Western Kazakhstan
Authors: Sergaliev N. Kh. , Sarsenova B. B. , Idrisova G. Z. , Akhmedenov K. M. , Gubasheva B. E.
Published: April 2024

The vegetation of 5 lakes and 40 springs of Western Kazakhstan was considered. The relationship between the degree of mineralization and the composition of vegetation was revealed. The anthropogenic factor influences the vegetation of lakes and springs by increasing the number of ruderal and halophytic plants. With a decrease in the water level in lakes, processes of active salinization of the water area and the coastal part are observed, an indicator of which is vegetation. In the territories adjacent to the springs, the dominant role of mesotrophs and megatrophs in the structure of the flora of the springs was noted, which indicates the predominance of soils and soils with sufficient and excessive content of nutrients in the studied area. The flora of the region’s springs has a low degree of similarity. Cluster analysis of the flora of spring tracts confirmed the heterogeneity of quantitative species composition.
The Influence of Abiotic Factors on the Structural and Functional Characteristics of the Diatom Algae Cerataulina pelagica (Сleve) Hendey
Authors: Stelmakh L. V.
Published: April 2024

Using the electron microscopy method, the species identity of the diatom Cerataulina pelagica, isolated in pure culture from the coastal waters of the Black Sea in September 2021, was confirmed. The range of optimal temperature values for the development of this species was identified. The impact of light and biogenic substances on its main structural and functional characteristics has been studied. Acclimation of C. pelagica to various light intensities was carried out by changing the efficiency of photosystem II, the C/Chl a ratio, and the specific growth rate. The morphometric parameters of cells (volume, surface area, and specific surface area) changed slightly in the studied light range – 8.5–510 μE/(m2 · s). The transfer of C. pelagica cells, which have the maximum intracellular pool of nutrients, to seawater depleted in nutrients caused a rapid increase in the C/Chl a ratio, as well as a decrease in the efficiency of photosystem II, the relative rate of electron transport, and the specific growth rate. A high degree of toxicity with copper ion in low concentrations in relation to the studied species was shown.
Horizontal Heterogeneities of Functioning of Phyto- and Zooplankton in a Lake With Wind Currents
Authors: Tolomeev A. P. , Dubovskaya O. P. , Kravchuk E. S. , Anishchenko O. V. , Drobotov A. V.
Published: April 2024

A hypothesis about the formation of horizontal heterogeneities of zooplankton and phytoplankton for the lake subjected to regular daily changes in wind currents has been tested. Formation of horizontal heterogeneities is based on a combination of low-amplitude vertical migration of zooplankton and epilimnion wind currents: surface currents, which bring water depleted in zooplankton to the downwind shore (in the direction in which the wind is blowing), and compensatory above-thermocline ones, which bring zooplankton-enriched water to the upwind shore (against the wind). The spatial separation of phytoplankton and zooplankton may result in the weakening of trophic links between these trophic levels. The hypothesis was tested in 2020 in the pelagic zone of Lake Shira (Khakassia, Russia), a brackish meromictic water body with simple bathymetry and a simple food web. The epilimnion horizontal heterogeneities were assessed using a survey across the lake by measuring biological and physical parameters with a submersible fluorimeter probe and a plankton net at 11 stations and recording the dynamics of wind speed and direction. Differences in the values of primary production, plankton destruction, and intensity of phytoplankton grazing by zooplankton near the downwind and upwind shores were estimated using the bottle method in 3 experiments. The experiments confirmed the expected differences in the functioning of the trophic cascade near the northeastern (more often upwind during the day and downwind at night) and south-southwestern (downwind during the day and upwind at night) shores. Namely, the concentration of chlorophyll a, the gross and net primary production of phytoplankton (estimated by bottle and fluorescent methods), and the daily intensity of zooplankton feeding (based on chlorophyll) were higher near the southern coast, while the biomass of net zooplankton and the respiration rate of the plankton community were higher near the northeastern shore, which coincided with the pattern of phyto- and zooplankton distribution over the lake according to the sampling data under similar weather conditions. The hypothesis was confirmed and supplemented by the data on the evening-night vertical migrations of zooplankton.
Spatiotemporal Variation of Planktonic Rotifers in Surface Water of a Eutrophic Reservoir in the Southern Subtropical Region of China (2011‒2020)
Authors: Gao Yuan , Lai Zini , Liu Erchun , Yang Wanling , Liu Qianfu
Published: April 2024

The trophic status of a reservoir in the southern subtropical region of China was evaluated by non-biological environmental factors from 2011 to 2020. The relationship between the community structure of planktonic rotifers and eutrophication was examined based on the species composition, dominant species, standing crop, and biodiversity index of the planktonic rotifers in the surface water. The results showed that the reservoir was continually slightly eutrophic. The dominant species of planktonic rotifers were mesosaprobic species such as Polyarthra trigla and Brachionus angularis. The overall abundance fluctuated between 438 and 1360 ind./L; biomass fluctuated between 520 and 1613 μg/L, and the biodiversity index fluctuated between 1.27 and 2.43. Redundancy analysis showed that chlorophyll a content, water transparency, total phosphorus, and water temperature had significant impacts on the abundance of planktonic rotifers. The results demonstrate a close relationship between the community structure of planktonic rotifers and eutrophication. In other words, eutrophication was the main cause of the changes in the community structure of planktonic rotifers in surface water.
Finding of the Blue Tilapia Oreochromis aureus (Cichlidae) in the Gorky Reservoir (Volga River)
Authors: Kodukhova Yu. V. , Karabanov D. P.
Published: April 2024

A new find of blue tilapia Oreochromis aureus (Steindachner, 1864) from the Volga River, area of the Kostroma state district power station (57.46736 N, 41.18503 E) is described. Data on morphology and nucleotide diversity (COI, 16S and 18 loci) for O. aureus are given. It is assumed that the vector of invasion is associated with human activity. There is a high probability of the formation of a large population of blue tilapia in this area.
Influence of Heterogeneity of Bottom Sediments on the Formation of Bacteriobenthos in the Lake of Southern Urals
Authors: Sherysheva N. G. , Reznikova I. V.
Published: April 2024

For the first time general quantitative (number, biomass) and structural (morphological, dimensional) indicators of bacteriobenthos in different morphotypes of bottom sediments of the lake Kandry-Kul (Republic of Bashkortostan) were determined. The total number of bacteria was 1.8–11.8 × 109 cl./ml, and the biomass was 106–1344 mcg/mL. Two types of seasonal dynamics of abundance and biomass of deep-wate and coastal bacteriobenthic communities were identified. The influence of heterogeneity of bottom sediments on quantitative indicators and morphological structure of lake bacteriobenthos is considered. The increase in pelitic and aleritic fractions in the mechanical composition of silts contributes to an increase in the total number of bacteria and the restructuring of the morphological structure of bacteriobenthos towards an increase in the number of coccous forms. The proportion of cocci increases with an increase in the percentage of saprophytes in the total number of bacteria.
Pigment Characteristics of Macrophytes from the Rybinsk Reservoir
Authors: Sigareva L. E. , Timofeeva N. A.
Published: April 2024

The first data on the pigment characteristics of higher aquatic plants in the Rybinsk Reservoir (Upper Volga, Russia) are presented. The average content of chlorophyll a is 7.5 ± 0.6 mg/g organic matter in leaves, and 4.0 ± 1.4 mg/g organic matter in stems, or 6.1 ± 0.5 and 3.3 ± 1.2 mg/g dry plant material, respectively. The average carbon/chlorophyll a ratio is 76 ± 6.2 in leaves and 408 ± 150 in stems. Helophytes, which dominate in the reservoir in terms of biomass and overgrowth area, are distinguished by a record concentration of organic matter (90.2 ± 0.8%). The concentration of chlorophyll a and the relative content of carotenoids depend on environmental conditions and plant species.
Diversity Methods of the Strike Teleostei in Connection with Morphology Their Jaw Apparatus (Review)
Authors: Gromova E. S. , Makhotin V. V.
Published: April 2024

The paper provides a review features of the strike Teleostei methods – suction, ram and bite, in different representatives at the definitive stage of development with characteristic morphology traits their feeding apparatus at qualitative level. In the paper we describe new traits of construction jaw apparatus some Teleostei species, those testifie in favour application them several methods of the strike separately or at a time during feeding.
Patterns of Phenetic Diversity and Taxonomy of the Ide Leuciscus idus (Cypriniformes, Cyprinidae) from Water Bodies of Russia and Adjacent Countries
Authors: Kozhara A. V. , Mavrin A. S. , Slynko E. E. , Mironovsky A. N.
Published: April 2024

Using the methods of population morphology, we studied the structure of phenetic diversity of the ide Leuciscus idus (L.) from the water bodies of the Russian Federation and some neighboring countries. We analysed our own collection and literature data on meristic characters of external morphology, axial skeleton, as well as the pharyngeal teeth formula. The main features contributing to population differentiation were the number of lateral line scales, total vertebrae count, caudal and pre-caudal vertebrae ratio. It was shown that the strong positive relationships of the first two features with the geographical latitude of fish habitats is associated, first of all, not with the direct influence of physical factors functionally dependent on latitude, but with particular (sub)speciation processes in river basins and dispersal of evolutionarily derived forms to the north. The results obtained are discussed in terms of evolutionary trends in the subfamily Leuciscinae and call for a taxonomic revision of the L. idus species in its current volume with elevation of the former subspecies L. idus oxianus to a species rank.
Cases of Spontaneous Increase of Methemoglobin Concentration in Fish Blood during the Annual Cycle
Authors: Soldatov A. A.
Published: April 2024

The dynamics of the content of erythrocytes number and concentration of methemoglobin in the blood of the thermophilic mullet (Chelon auratus Risso, 1810) and the cold-loving flounder (Platichthys flesus L., 1758) during the annual cycle was studied. The degree of maturity of the circulating erythrocyte mass was judged on the basis of acid erythrograms construction. A pronounced negative relationship was found between the number of red blood cells and the concentration of methemoglobin in the blood of both types (r = –0.681; –0.778). It has been shown that the youngest generation of red blood cells appears in the peripheral bed of both species in the post–spawning period (1.5–2.0 months), which reflects the active production of erythrocytes by hematopoietic tissue. The rest of the time, there is a gradual aging of the circulating erythrocyte mass. This leads to a decrease in the number of red blood cells in the blood and is accompanied by an increase in the concentration of methemoglobin. The latter, apparently, determines the production of erythropoietins in the kidneys and activates the processes of erythropoiesis in hematopoietic tissue (pre-spawning period).
The Effect of Morphophysiological Changes in Immune Organs on Lysozyme in Male Pike Esox lucius
Authors: Subbotkin M. F. , Subbotkina T. A.
Published: April 2024

The concentration of lysozyme in liver, kidney, spleen and serum, as well as the size of immune organs in male pike Esox lucius L. vary in different seasons of year. The enzyme concentrations in organs and serum are weakly interrelated. The organs by the absolute values of mass show a strong relationship with each other, while the correlation between their somatic indices is very weak. The size of the organs affects the concentration of lysozyme in the organs and serum. The liver plays a major role in annual fluctuations of lysozyme concentration in all the organs and serum. Kidney has a leveling effect on the concentration of the enzyme in liver and serum, whereas liver has the opposite effect. The most profound morphophysiological changes in organs and lysozyme as an indicator of nonspecific immunity coincide with the reproduction period of fish.
First Data on Species Composition and Development Cladocera (Crustacea: Branchiopoda) in Mire Ecosystems (Kaliningrad Region, Russia)
Authors: Semenova A. S. , Napreenko M. G.
Published: April 2024

The original data on Cladocera fauna in standing-water and stream habitats of mire ecosystems were obtained for the first time in the Kaliningrad region during the research study on large raised bogs (Zehlau and Bolshoye) and drainage canals of 6 peatlands affected by peat extraction. In the studied wetland ecosystems, 41 species of Cladocera were recorded in total, including a number of rare and vulnerable taxa (Flavalona rustica, Scapholeberis microcephala, Streblocerus serricaudatus and Holopedium gibberum). The four species of Cladocera are new species for the Kaliningrad region which were not reported here before. Cladocera played a vital role in the studied bog pools and waterlogged habitats in peatlands as a key group of organisms that forms here a significant part of the zooplankton biomass due to the abundance and intensive production in the water bodies. The secondary filter feeders and predators were the most abundant in bog ecosystems. The cladoceran fauna in the intact bog ecosystems, especially the Zehlau raised bog, was the most diverse and unique. Nevertheless, the cladoceran assemblages in the disturbed ecosystems of drainage canals retained certain features of the natural water bodies. The latter fact is important in applied respect enabling to consider these canals as refugia that have potentials for natural restoration of the cladoceran fauna during the peatland rewetting programme on the Carbon Polygon in the Kaliningrad region.
Fauna of the Cladoceran and Copepods Crustaceans (Crustacea: Cladocera, Copepoda) of Dood Tsagaan Lake (Darhad Basin, Mongolia) in Modern Times
Authors: Sheveleva N. G. , Ayuushsuren Ch. , Tuvshinzhargal N. , Zaitseva Е. P. , Sukhanova L. V.
Published: April 2024

The paper presents the results of the study the qualitative and quantitative composition of the planktonic Crustacea of Dood Tsagaan Lake (northwestern Mongolia) (Cladocera, Diaptomidae, Cyclopidae) in modern times. Comparative analysis of the species composition of crustaceans according to new data and data obtained in the last century (1962–1963) showed that during our studies the composition of crustaceans was increased by five species of Cladocera and by three species of Copepoda, 2 species of them are from the order Cyclopoida and one from the order Calanoida. Ultrastructural studies of the main morphological parts of the copepods crustaceans Mixodiaptomus incrassatus (Sars, 1903), Acanthodiaptomus paulseni (Sars, 1903) and Cyclops glacialis Flossner, 2001 were carried out for the first time using a scanning electron microscope (SEM). Detailed study of morphometric and morphological characters including the use of SEM showed that C. glacialis inhabiting Dood Tsagaan Lake is identical to the species described in lakes (Turgun Kharhiraa Uvs aimag and Nogoon nuur) in northwestern Mongolia. The biomass of M. incrassatus, an important food object for whitefish and other fish species, was found to reach 1100 mg/m3 in the modern period.
Hematological Parameters of the Australian Red-Clawed Crayfish Cherax quadricarinatus (Decapoda: Parastacidae) when Exposed to Air
Authors: Skafar D. N. , Strelkova O. V. , Shumeyko D. V.
Published: April 2024

The effect of exposure on the hematological parameters of the red claw crayfish Cherax quadricarinatus Von Martens 1868 was studied. Hemolymph was taken immediately after extraction from the water after 2, 4, 8 hours of exposure on the shore and 24 and 72 hours after returning to the water. Determined total hemocyte counts (THC), hemogram, general protein and hemocyanin disease. The dynamics of the growth of hematological parameters in the temporal aspect was revealed: THC and the proportion of granulocytes increased to reveal the entire pattern of growth, the proportion of agranulocytes and the total content of protein and hemocyanin. After exposure on the shore, the color of the hemolymph changed from bluish with a grayish tint to cloudy gray-green (deviation from the norm). The data obtained indicate the development of compensatory factors and pathological properties in response to stress, the occurrence of symptoms in the air, which can be used in practice in assessing the state of the red claw cancer in the process of transport.
Impact Algae Blooms on the Coastal Zone of the Curonian Lagoon of the Baltic Sea
Authors: Aleksandrov S. V. , Smirnova M. M.
Published: April 2024

Lagoon ecosystem of the freshwater Curonian Lagoon belongs to hypertrophic water bodies, and its coastal zone is of fishery and recreational importance. Long-term monthly data (2014–2015) on chlorophyll and hydrochemical parameters were analyzed. The seasonal dynamics of chlorophyll a (phytoplankton abundance) in the whole Russian water area of the Curonian Lagoon and the influence on hydrochemical and microbiological indicators in the coastal zone near the Curonian Spit National Park (UNESCO World Heritage Site) were considered. During the period of intensive development of Cyanobacteria (“hyperblooming” of water), their acute accumulation in Russian water areas, estimated by chlorophyll, is determined by the wind regime, which causes the local accumulation in separate areas. Algae accumulation in the coastal zone (including the Curonian Spit National Park) in summer and autumn can form harmful hydrochemical and microbiological conditions, corresponding to hypertrophic and hypersaprobic levels, multiple excess of MPC (by BOD5 and ammonia nitrogen, anaerobic zone).
A GIS Based Study to Investigate of the Ecological Impacts of Successive Dams on Surface Water Quality: A Review of the Sakarya Basin, Türkiye
Authors: Köse Esengül
Published: April 2024

The present study aimed to assess the status of successive dams on surface water quality, especially in reducing organic pollution levels, and their effects on the ecological life were investigated. Water samples were collected seasonally from three dam’s monitoring stations. Temperature, pH, dissolved oxygen, electrical conductivity, turbidity, ammonium nitrogen, nitrite nitrogen, nitrate-nitrogen, sulfate, total phosphorus, chemical oxygen demand, biochemical oxygen demand and total hardness parameters were measured in surface waters. The Geographic Information System (GIS) was used to produce thematic maps of the investigated parameters. Stations used as point feature layers were mapped using quantitative labeling via symbology. The results were compared with Turkish Regulation, 2015 and EC Directive on the quality of fresh waters needing protection or improvement to support fish life (2006) guidelines. According to the results of the analysis, Dams that are located one after the other contribute to the partial cleaning of the water by resting. Sarıyar, Gökçekaya, and Yenice Dams were built on the Sakarya River, which is one of Türkiye’s biggest and most significant river systems, for electric supply and utility of water for irrigation and fishery activities. Gökçekaya Dam Lake was built between Sarıyar Dam and Yenice Dam, which are situated in the same line of Sakarya River. Gökçekaya and Yenice Dams are fed by Sarıyar Dam Lake and do not receive fresh water. The fact that the three dams are established one after the other aids in the water’s resting and the aids in removing the suspended solids/suspended load. But, this research show that domestic, industrial, agricultural wastes carried by the branches of the rivers caused algal blooms in Dam lakes, especially which are not fed with fresh water. Due to organic pollution the decrease in dissolved oxygen, especially from time to time, negatively affects the ecological life in the lakes.
State of Zooplankton and Zoobenthos of the Water Bodies of the Pyasino Lake Basin after a Man-Made Accident1
Authors: Kupriyashkin A. G. , Prokudin A. V. , Shapkin A. M.
Published: April 2024

The taxonomic composition and quantitative characteristics of zooplankton and zoobenthos of some reservoirs of natural origin of the Norilsk industrial district and adjacent territories after a man-made accident have been determined. In most sample collection points, all age groups of many invertebrates are marked. The Daldykan River above the confluence of the Bezymianny Сreek and the source of the Pyasina River represent a poorly disturbed watercourses and can serve as a norm for organizing recovery activities.
New Data on the Fauna of Dragonflies (Insecta, Odonata) of the South-Eastern Belarus
Authors: Ostrovsky A. M.
Published: April 2024

The purpose of the study was the ecological and faunal study of dragonflies of the south-east of Belarus. New data for 38 species are reported. Three dragonfly species of them are new for this region: Erythromma viridulum, Epitheca bimaculata, Leucorrhinia pectoralis. Zoogeographically, trans-Eurasian and European dragonfly species predominate. The most numerous is the family Libellulidae. Most of the collected dragonfly species are widespread and numerous on the territory of the south-east of Belarus. Rare for the region are Sympecma fusca, S. paedisca, Erythromma viridulum, Ophiogomphus cecilia, Epithecia bimaculata, Somatochlora metallica, Orthetrum brunneum and Leucorrhinia rubicunda. The location is indicated and brief information about the distribution and ecological and biological characteristics of each species is given.
Checklist of Syngnathidae Parasites in the Black Sea and the Sea of Azov
Authors: Polyakova T. A. , Kornyychuk Yu. M. , Pronkina N. V.
Published: April 2024

For the first time data on parasite diversity of Syngnathidae fishes inhabiting the Black and the Sea of Azov, the rivers flowing into these seas and their estuaries accumulated in more than 30 articles and books during almost one century of investigations were summarized. A high level of parasitic organisms’ richness is registered to date: 64 species from 45 genera, 35 families, 14 classes, 10 phyla have been recorded here from 8 species of Syngnathidae fish hosts: Syngnathus abaster Risso, 1827, S. acus L., 1758, S. schmidti Popov, 1927, S. tenuirostis Rathke, 1837, S. typhle L., 1758, S. variegatus Pallas, 1814, Nerophis ophidion (L., 1758), Hippocampus hippocampus (L., 1758). Host-parasite and parasite-host lists are provided, the results for Kinetoplastida, Sporozoa, Microsporidia, Myxozoa, Ciliophora, Platyhelminthes (Monogenea, Trematoda, Cestoda), Nematoda, Acanthocephala, Annelida, and parasitic Arthropoda are presented. Platyhelminthes and Ciliophora (19 and 18 species, respectively) turned out to be the most species-rich taxa of Syngnathidae parasites, while Trematoda was the richest (15 species) class among flatworms. The largest number of parasite species is known from three fish hosts: S. abaster parasite fauna comprises 54 species of 10 phyla (84% of total parasite fauna of this fish family in the region), S. typhle – 27 parasite species belonging to 6 phyla (38%) and relatively pure parasites fauna in H. guttulatus, 14 species of 6 phyla (22%).
Content of Pigments in the Bottom Sediments in a Small Valley–Channel Reservoir
Authors: Sigareva L. E. , Timofeeva N. A. , Zakonnov V. V.
Published: April 2024

This paper presents the first data on the content of plant pigments in the bottom sediments of the Uvod Re-servoir (Volga basin, Russia), unique in its hydrological regime, which support the hypothesis of more intensive carbon accumulation in small water bodies. It is established that the average concentration of chlorophyll a and its transformation products at the stations is 62.6 ± 10.0 μg/g dry sediment, 35.2 ± 4.5 mg/(m2 mm) of wet sediment, and 0.73 ± 0.09 mg/g organic matter of sediments. The ratio of organic carbon to the pigment concentration varies within 400–6000 depending on the type of bottom sediments, which significantly exceeds the values known for macrophytes and phytoplankton. Despite the features of hydrodynamics and geomorphology of the reservoir, the spatial distribution of sedimentary pigments is consistent with the structure of the bottom sediment complex, which is typical for water bodies of different types. A decrease in differences between the pigment concentrations in the sandy and silty biotopes of the Uvod Reservoir compared to the Upper Volga was noted. Average concentration of chlorophyll a with pheopigments (58.5 ± 6.7 μg/g of dry sediment), calculated considering the areas of bottom sediments of different types, in the Uvod Reservoir is 2.3 times higher than in the Gorky Reservoir (25.3 ± 1.5 μg/g), from which water inflows through the Volga–Uvod Canal. According to the content of sedimentary pigments, the trophic state of the reservoir is mesotrophic. Features of eutrophication in the Uvod Reservoir are more distinctly expressed than in the Gorky Re-servoir.
Zooplankton of the Hollows of the South-Pribelomorian Mire Ilasskoye (Russia)
Authors: Sobko E. I. , Zubov I. N. , Ponomareva T. I.
Published: April 2024

The paper presents the data of the study of the fauna of zooplankton communities of the hollows of the South-Belomorian mires (Arkhangelsk oblast), carried out in may-august 2021. The zooplankton of the hollows the mire Ilasskoye contains 37 species of planktonic invertebrates, including 15 species of rotifers, 18 species of cladocerans, and 4 species of copepods. The planktonic fauna is represented mainly by phytophilic, sphagnophilic, acidophilic species of rotifers and crustaceans. Differences in the species size of zooplankton depending on the level of watering of the hollows are revealed. The high rates of quantitative development are characteristic for the zooplankton communities (649.7 ± 53 thous. ind./m3; 4.36 ± 0.4 g/m3). The trophic structure of zoocenoses was dominated by secondary filtrators and verticators, among which the crawling-floating forms of cladocerae and rotifers prevailed, which indicates the predominant role of detritus in the circulation of substances and energy in water bodies of this type.
Non-specific porins from the outer membrane of Yersinia pseudotuberculosis effect on mice brain cortex tissues
Authors: Portnyagina O. Yu , Ivashkevich D. N , Duizen I. V , Shevchenko L. S , Novikova O. D
Published: April 2024

It was found that with a single immunization of OmpF and OmpC mice with Yersinia pseudotuberculosis porins, against the background of an increasing titer of specific antibodies, pathological changes develop in the deep layers of the cerebral cortex, characterized by dystrophic changes in cells. At the same time, an increased level of caspase 3 expression is observed in neurons, which indicates the induction of proapoptotic signaling pathways. The results obtained indicate the potential ability of nonspecific pore-forming proteins of the outer membrane of Gram-negative bacteria to initiate the development of degenerative changes in brain cells.
Acylation of the rat brain proteins is affected by the inhibition of pyruvate dehydrogenase in vivo
Authors: Aleshin V. A , Sibiryakina D. A , Kazantsev A. V , Graf A. V , Bunik V. I
Published: April 2024

Organism adaptation to metabolic challenges requires coupling of metabolism to gene expression. In this regard, acylations of histones and metabolic proteins acquire significant interest. We hypothesize that adaptive response to inhibition of a key metabolic process, catalyzed by the acetyl-CoA-generating pyruvate dehydrogenase (PDH) complex, is mediated by changes in the protein acylations. The hypothesis is tested by intranasal administration to animals of PDH-specific inhibitors acetyl(methyl)phosphinate (AcMeP) or acetylphosphonate methyl ester (AcPMe), followed by the assessment of physiological parameters, brain protein acylation, and expression/phosphorylation of PDHA subunit. At the same dose, AcMeP, but not AcPMe, decreases acetylation and increases succinylation of the brain proteins with apparent molecular masses of 15-20 kDa. Regarding the proteins of 30-50 kDa, a strong inhibitor AcMeP affects acetylation only, while a less efficient AcPMe mostly increases succinylation. The unchanged succinylation of the 30-50 kDa proteins after the administration of AcMeP coincides with the upregulation of desuccinylase SIRT5. No significant differences between the levels of brain PDHA expression, PDHA phosphorylation, parameters of behavior or ECG are observed in the studied animal groups. The data indicate that the short-term inhibition of brain PDH affects acetylation and/or succinylation of the brain proteins, that depends on the inhibitor potency, protein molecular mass, and acylation type. The homeostatic nature of these changes is implied by the stability of physiological parameters after the PDH inhibition.
A novel donepezil-caffeic acid hybrid: synthesis, biological evaluation, and molecular docking studies
Authors: Kılıçaslan D. , Kurt A. H , Köse M. , Çeşme M. , Güngör Ö. , Oztabag C. K , Doganer A.
Published: April 2024

A novel donepezil-caffeic acid (DP-CA) hybrid molecule was designed, synthesis, and investigated by molecular modeling. Its biological activity and protective effect were investigated by the IR spectroscopy, 1H and 13C NMR spectroscopy, and mass spectrometry. DP-CA was highly active against acetylcholine esterase and inhibited it at the micromolar concentrations. Fluorescence and UV-Vis spectroscopy studies showed strong binding of DP-CA to DNA. Moreover, DP-CA exhibited protective effects against H2O2-induced toxicity in U-118 MG glioblastoma cells. Finally, molecular docking showed a high affinity of DP-CA in all concentrations, and the active 4EY7 site exhibited essential residues with polar and apolar contacts. Taken together, these findings indicate that DP-CA could be a prospective multifunctional agent for the treatment of neurodegenerative diseases.
Alteration of the MEK1/2–ERK1/2 signaling pathway in the retina with age and with the development of amd-like retinopathy
Authors: Muraleva N. A , Kolosova N. G
Published: April 2024

Age-related macular degeneration (AMD) is a complex neurodegenerative disease that is a major cause of irreversible visual impairment in developed countries. Although age is the greatest risk factor for AMD, molecular explanations of this clinical observation are not known. Growing evidence shows that dysregulation of MAPK pathways contributes to aging and neurodegenerative diseases; however, information about the upregulation of MAPKs in this context is still controversial. Among these kinases, ERK1 and ERK2 participate in the maintenance of proteostasis through the regulation of protein aggregation induced by endoplasmic-reticulum stress and other stress-mediated responses in the cell. Here, to assess the contribution of alterations of MEK1/2-ERK1/2 signaling-pathway activity to the development of AMD, we compared its changes with age in the retina of control (Wistar) rats and OXYS rats, which develop AMD-like retinopathy spontaneously. We showed that ERK1/2 signaling-pathway activity increases during physiological aging in the Wistar retina. The manifestation and dramatic progression of AMD-like pathology in OXYS rats co-occurred with hyperphosphorylation of ERK1/2 and MEK1/2 as key ERK1/2 signaling-pathway kinases in the retina. Besides, progression of the retinopathy was accompanied by ERK1/2-dependent tau protein hyperphosphorylation and enhancement of ERK1/2-dependent phosphorylation of CryaB at Ser45 in the retina.
The role of C1473G polymorphism in triptophanhydroxylase-2 gene in the acute ethanol effects on c-fos gene expression and metabolism of biogenic amines in brain of mice
Authors: Bazovkina D. V , Fursenko D. V , Naumenko V. S , Kulikov A. V
Published: April 2024

Tryptophan hydroxylase-2 is a key enzyme in the synthesis of the neurotransmitter serotonin, which plays an important role in the mechanisms of regulation of a wide range of physiological functions and behaviors. In this work, we studied the effect of acute ethanol administration on the expression of the c-fos early response gene and the metabolism of serotonin and catecholamines in the brain structures of B6-1473C and B6-1473G congenic mice, which differ in the C1473G single-nucleotide substitution in the Tph2 gene and enzyme activity. Acute alcoholization led to a significant increase in c-fos gene expression in the frontal cortex and striatum of B6-1473G mice and the hippocampus of B6-1473C mice. The introduction of ethanol caused a decrease in the index of serotonin metabolism in the nucleus accumbens in B6-1473C mice, as well as in the hippocampus and striatum of B6-1473G mice. Also, ethanol led to a decrease in the level of norepinephrine in the hypothalamus in B6-1473C mice. Thus, the C1473G polymorphism in the Tph2 gene has a significant effect on changes in the c-fos gene expression pattern and metabolism of biogenic amines in the brain induced by acute ethanol administration.
Epigenetic mechanisms of the maternal hyperhomocysteinemia influence on the placenta functional state and the offspring nervous system plasticity
Authors: Arutjunyan A. V , Milyutina Yu. P , Shcherbitskaia A. D , Kerkeshko G. O , Zalozniaia I. V
Published: April 2024

According to modern concepts, the susceptibility to certain diseases, especially to cognitive and neuropsychiatric disorders, can be formed during the period of embryonic development. Adverse factors that affect the mother during pregnancy increase the risk of the pathology development in the postnatal period. Despite the relationship found between elevated maternal blood levels of the amino acid homocysteine (Hcy) and fetal brain formation impairments, as well as cognitive deficits in offspring, the role of brain plasticity in the development of these pathologies is still insufficiently studied. This review allows to be acquainted with the available data on the negative impact of hyperhomocysteinemia (HHcy) on the neural plasticity. An important aspect of the problem considered in the review is the possible influence of maternal HHcy on the offspring brain plasticity through the epigenetic mechanisms. Data on changes in intracellular methylation potential, activity of DNA methyltransferases, and DNA methylation in brain cells under the influence of HHcy are presented, and possible effects of HHcy on histone modifications and microRNA expression are considered. Since placenta plays a key role in the transport of nutrients and modulation of signals from mother to fetus, its dysfunction due to epigenetic mechanisms disturbances may affect the development of the fetal CNS. In this regard, the review presents data on the impact of maternal HHcy on the epigenetic regulation in the placenta. The data presented in the review are not only of theoretical significance, but are also of interest for understanding the role of epigenetic mechanisms in the pathogenesis of diseases for which HHcy is a risk factor (pregnancy pathologies accompanied by delayed fetal brain development, cognitive impairments in childhood and neuropsychiatric and neurodegenerative disorders later in life), as well as the search for approaches to their prevention using neuroprotectors.