bluuebunny/crossref_metadata_2025 huggingface dataset:
ANTICONVULSANT EFFICACY OF INHIBITION OF SYNAPTIC AND EXTRASYNAPTIC GABA-TRANSPORTERS IN PREVENTION OF HYPERBARIC OXYGEN SEIZURES
Authors: Alekseeva O. S. , Gerda B. A. , Zhilyaeva A. S. , Demchenko I. T.
Published: April 2024

Hyperbaric oxygen (HBO2) inhibits GABAergic neurotransmission in the brain, which can lead to the development of a seizure disorders known as “oxygen epilepsy”. Deficiency in GABAergic transmission in HBO2, resulting from a decrease in the level of synaptic GABA, can be compensated by inhibition of neuronal and glial GABA transporters (GAT). The present study compared the anticonvulsant efficacy of two types of GABA transporters with tiagabine, a GAT-1 inhibitor, and SNAP 5114, a GAT-3 inhibitor. Anticonvulsant effects were assessed after administration of drugs into the lateral cerebral ventricle of rats 30 min before the start of hyperbaric oxygen exposure at 5 ATA. In separate experiments, the concentration of GABA in the striatum of rats was measured when breathing oxygen at a pressure of 5 ATA after GAT inhibition with tiagabine or SNAP 5114. New results obtained in the study were: (1) inhibition of GAT-1 or GAT-3 prevented the development of “oxygen epilepsy” in rats; (2) among the two inhibitors used, TGB was found to be more effective in preventing oxygen convulsions compared to SNAP 5114; (3) the combined use of TGB + SNAP 5114 caused an additive anticonvulsant effect; (4) oxygen convulsions appeared when GABA in the brain decreased by 30–40% of the initial level; (5) GAT-1 inhibition with tiagabine increased extracellular GABA 2.9-fold and 1.7-fold with SNAP 5114. GAT-1 and GAT-3 inhibition increased GABA to a level sufficient to restore impaired inhibitory neurotransmission in HBO2, and prevented the development of hyperbaric oxygen convulsions.
Molecular Dynamics Model of Liquid Tin in the Scheme of the Embedded Atom Model
Authors: Belashchenko D. K.
Published: April 2024

Results from calculating the properties of liquid tin using the EAM (Embedded Atom Model) interparticle potential are analyzed, and the surface properties of tin are calculated according to molecular dynamics (MD). Calculations based on the EAM generally agree better with experiments for the properties of liquid tin than ones based on the MEAM. The accuracy of the Gibbs–Helmholtz equation for the relationship between surface tension and surface energy is evaluated.
Interaction between 2(4)-Aminopyridines and Ions of Platinum and Transition Metals in Aqueous Solutions under Conditions Approximating Their Extraction Isolation and Separation
Authors: Ageeva L. S. , Borsch N. A. , Kuvardin N. V. , Egelskiy I. V.
Published: April 2024

A study is performed of the interaction between 2(4)-aminopyridines (2(4)-AP) and Pd(II), Pt(II), Pt(IV) and accompanying ions Ni(II), Co(II), Fe(II, III), Cu(II) in aqueous solutions close to the conditions of their extraction isolation and separation. It is shown that platinum metal ions form stable neutral and cationic complexes with both 2-AP and 4-AP that can be isolated from aqueous solutions. The tendency to form cationic complexes diminishes in the order Pd(II) Pt(II) Pt(IV) and 4-AP 2-AP. With the exception of Cu(II), ions of 3d-elements do not form stable complexes under these conditions. Cu(II) forms complexes with 2(4)-AP that are subject to hydrolysis when isolated from aqueous solutions. Features of 2(4)-AP when interacting with metal ions are discussed. It is proposed that analogs of 2(4)-AP with long hydrocarbon radicals be used for the extraction concentration of platinum metals from hydrometallurgical solutions of complex composition.
Segregation of Gallium in Diluted Al–Ga Solid Solutions, According to Data from Auger Spectroscopy
Authors: Ashkhotov O. G. , Ashkhotova I. B. , Magkoev T. T.
Published: April 2024

Electron Auger spectroscopy is used to study the surface segregation of gallium in diluted solid solutions of Al–Ga with volume concentrations of 1.1, 2.4, 4.2, 7.4 wt % Ga at temperatures of room temperature to 573 K. Considerable segregation of gallium is observed for all of the studied alloys. Values obtained for the surface concentration of Ga are used to construct the dependence of the energy of segregation on the surface concentration of Ga atoms at different temperatures
Mechanisms of Reactions between Cobalamins and Diethylamine Diazenium Diolate in Neutral Aqueous Solutions
Authors: Derevenkov I. A. , Cherevina E. A. , Makarov S. V.
Published: April 2024

Reactions between diethylamine diazenium diolate (DEANONO) and aqua-, methyl-, cyano-, sulfito- and glutathionylcobalamins, cobalamin(II), and aquahydroxocobinamide were studied at pH 7.4 and 25.0°C using ultraviolet-visible spectrometry. Kinetic curves are simulated according to the mechanism proposed in the ChemMech program. It is shown that methyl-, cyano-, and sulfito-cobalamins do not react with DEANONO. The reaction between aquacobalamin and DEANONO does not produce nitrosylcobalamin (NOCbl) because of the relatively rapid decomposition of DEANONO and the slow interaction between the initial reagents. It is established that glutathionylcobalamin is converted into NOCbl due to interaction with nitric oxide released during the decomposition of DEANONO and the transfer of the nitroxyl of DEANONO molecules to Co(III) ions. Cobalamin(II) is converted to NOCbl by the rapid binding of NO released during the decomposition of DEANONO. It is shown that the reaction between aquahydroxocobinamide and DEANONO includes the rapid coordination of DEANONO to Co(III) ions and slower decomposition of the complex into nitrosylcobinamide and other products.
Alkaline Carbonization of Polyacrylonitrile for the Preparation of Microporous Carbon Materials
Authors: Efimov M. N. , Zhilyaeva N. A. , Muratov D. G. , Vasilev A. A. , Yushkin A. A. , Karpacheva G. P.
Published: April 2024

A method has been proposed for the synthesis of activated carbon materials (ACMs) based on polyacrylonitrile (PAN) by activation with potassium hydroxide under the action of IR heating. Two approaches to the chemical activation of the polymer precursor were presented: formation of ACM based on PAN preliminarily heat-treated at 200°C and based on PAN carbonized at 700°C by impregnation with an aqueous alkali solution followed by heating to 800°C. Due to the use of IR radiation, the heating can be performed at a rate of 50 K/min, and the exposure time at a given temperature can be reduced to 2 min. The dependence of the specific surface area and porosity of ACM according to BET on the synthesis conditions was studied. The proposed approaches lead to the formation of ACMs with specific surface areas of 1091 and 2121 m2/g, respectively.
Structural Archetypes of the Earth’s Surface and N. A. Bulienkov’s T-Knot
Authors: Kuz’min V. I.
Published: April 2024

The author discusses the relationship between the structure of Bulienkov’s T-knot and ring geological structures on the Earth’s surface that have formed over eons. The positions of atoms in Bulienkov’s T‑knot correspond to the vertices of Platonic solids: two tetrahedra, an icosahedron, and an octahedron (27 positions in total, including the central one). If we place the central atom of Bulienkov’s T-knot at the center of a sphere (geoid) and project the remaining positions radially onto its surface, we can restore the classical ring structures known in geology on its surface using the projections as centers. Bulienkov’s T-knot allows us to obtain not only a clear hierarchical relationship between the icosahedral, octahedral, and tetrahedral models of the Earth’s ring structures, but to identify/confirm critical zones on the Earth known for anomalous geological structures and processes as well.
Temperature Dependence of Direct Current Conductivity in TiO2/Epoxy Polymer Dielectric Nanocomposites
Authors: Rabenok E. V. , Novikov G. F. , Bogdanova L. M. , Bukichev Yu. S. , Dzhardimalieva G. I.
Published: April 2024

A study is performed of the effect TiO2 nanoparticles have on the temperature dependence of the direct current conductivity of epoxy polymers. The value of direct current conductivity is determined by analyzing the frequency dependence of the complex permittivity in the 102–105 Hz range of frequencies. Two characteristic regions are found on the temperature dependence of direct current conductivity: the Vogel–Fulcher–Tammann dependence above the glass transition temperature (Tg), and the Arrhenius dependence below Tg, due apparently to a change in the mechanism of conduction after the freezing of ionic mobility at temperatures Tg. It is found the calculated energy of activation of the Arrhenius process changes upon raising the concentration of TiO2 nanoparticles.
High-Temperature Bending Tests of Reaction-Sintered Silicon Carbide-Based Ceramic Materials
Authors: Markov M. A. , Vikhman S. V. , Belyakov A. N. , Dyuskina D. A. , Kashtanov A. D. , Perevislov S. N. , Chekuryaev A. G. , Bykova A. D.
Published: April 2024

The high-temperature strength properties of silicon carbide-based ceramic materials reaction-sintered in air and vacuum are proved by experimental data. The ultimate bending strength of pressed and cast ceramic material samples at temperatures up to 1400°C was measured as a criterion. High-temperature tests demonstrate the guaranteed strength of ceramics above 100 MPa. An example of the manufacture of a complex shaped ceramic product using the hot slip casting processing under pressure into additive water-soluble forms is given. An approval of the combined technology makes it possible to manufacture bladed ceramic elements with a thickness of about 1 mm.
Luminescent Europium(III) Compounds with Quinaldic Acid
Authors: Kalinovskaya I. V.
Published: April 2024

Heteroligand luminescent europium(III) complexes with quinaldic acid and neutral ligands were prepared. The compounds obtained were characterized by elemental analysis, X-ray diffraction, thermal gravimetric analysis, and IR spectroscopy. The composition of the complexes was determined. In the course of thermolysis, the nitrogen-containing ligand molecule is eliminated in one step with exo- and endothermic effects. The compounds are thermally stable up to 260°С. The synthesized coordination compounds were introduced into low-density polyethylene to obtain luminescent polymer materials.
Binders Based on Solution of Polyvinyl Butyral in Di(1-methacryloxy-3-chloro-2-propyl) Methylphosphonate–2-Hydroxyethyl Methacrylate Mixture for Difficultly Combustible Glass-Reinforced Plastics
Authors: Borisov S. V. , Kuvshinova D. R. , Kudryavtseva D. A. , Kamenev Yu. N. , Solomatina A. A. , Kochetkov V. G. , Vaniev M. A. , Kochnov A. B. , Novakov I. A.
Published: April 2024

Binders based on solutions of polyvinyl butyral (molecular mass 43 000 and 57 000 g mol–1) in a mixture of two monomers, di(1-methacryloxy-3-chloro-2-propyl) methylphosphonate and 2-hydroxyethyl methacrylate, were developed for difficultly combustible glass-reinforced plastics (oxygen index up to 45.5 vol %). Under the conditions of redox initiation, the gel effect is reached in 82 to 418 min. The glass-reinforced plastic prepared by vacuum infusion from T11 glass fabric and the binder developed (at the binder content no higher than 35.2 wt %) exhibits the elastic modulus in bending across the warp of up to 17.9 GPa and the breaking stress in static bending across the warp of up to 178.4 MPa.
Сatalysts for Electrooxidation of Biomass Processing Products
Authors: Sherstyuk O. V. , Kuznetsov A. N. , Kozlov D. V.
Published: April 2024

In recent years, active research has been carried out in the field of catalysts for the electrooxidation of water-soluble products of biomass processing on the anodes of electrolysers, coupled with the process of producing hydrogen at the cathodes of these devices. Biomass processing products that are promising for electrooxidation are glycerol, glucose, furfural and 5-hydroxymethylfurfural. The review examines studies of catalysts for the electrooxidation of glycerol, glucose, furfural, and 5-hydroxymethylfurfural based on metals of various groups. Electrooxidation of these organic compounds on catalysts based on noble metals (platinum group metals and gold) and their alloys begins in the potential range from 0.3 to 0.7 V [reversible hydrogen electrode (RHE)], reaching a maximum at ~1 V (RHE). The main disadvantage of catalysts based on noble metals is their high cost. Nickel and сobalt are considered promising among the non-noble metals studied as components of catalysts for these reactions. But in the presence of catalysts based on these metals, the electrooxidation reactions of the noted organic compounds begin at potentials above 1 V (RHE). Glyceraldehyde, dihydroxyacetone, glyceric, tartronic, glycolic, oxalic, glyoxalic and mesoxalic acids can be obtained from the electrooxidation of glycerol. Valuable products of the electrooxidation of glucose, furfural, and 5-hydroxymethylfurfural are gluconic, 2-furancarboxylic, and 2,5-furandicarboxylic acids, respectively.
Catalytic Activity of Highly Dispersed Systems PdО/Mn0.20Ce0.80O2–δ and PdО/M0.05Mn0.15Ce0.80O2–δ, where M = Cu, Bi, in Complete Oxidation of Methane
Authors: Liberman E. Yu. , Kleusov B. S. , Simakina E. A. , Kon'kova T. V. , Grunskiy V. N. , Stoyanova A. D. , Denisenko A. V.
Published: April 2024

Highly dispersed solid solutions Mn0.20Ce0.80O2–δ and M0.05Mn0.15Ce0.80О2–δ, where M = Cu, Bi, were prepared by coprecipitation followed by heat treatment. The materials were characterized by X-ray diffraction analysis, energy-dispersive X-ray spectroscopy, low-temperature nitrogen adsorption, transmission electron microscopy, and gas chromatography. The compounds prepared exhibit high activity in complete oxidation of methane. The solid solutions show promise as palladium supports. The 0.5% PdО/Mn0.20Ce0.80O2–δ and 0.5% PdО/Cu0.05Mn0.15Ce0.80O2–δ samples synthesized surpass in the catalytic activity the reference catalyst 0.5 PdО/γ-Al2O3. Thus, it is appropriate to use the complex oxide formulations as supports of the active component.
Isoprene Polymerization in the Presence of Phosphate Catalytic Systems Based on a Mixture of Neodymium and Gadolinium Salts
Authors: Novikova E. S. , Levkovskaya E. I. , Senderskaya E. E. , Chernyavskiy G. G. , Belorukova T. S.
Published: April 2024

Coordination polymerization of isoprene in the presence of Ziegler–Natta catalytic systems based on a mixture of neodymium and gadolinium bis(2-ethylhexyl) phosphates at the neodymium/gadolinium molar ratios of 25/75, 50/50, and 75/25 was studied. These catalytic systems exhibit high catalytic activity in isoprene polymerization, equal to that of the catalytic system based on neodymium bis(2-ethylhexyl) phosphate. The influence of the Nd/Gd ratio on the molecular-mass characteristics and microstructure of the polymers obtained was examined. The kinetic parameters of the isoprene polymerization using catalytic systems based on a mixture of neodymium and gadolinium salts were determined. The possibility of using such systems in the synthesis of stereoregular cis-1,4-polyisoprene with the optimum level of molecular masses was demonstrated
Adsorption of Rhodamine G from Aqueous Solutions onto Particles of Few-Layer Graphene Prepared by Self-Propagating High-Temperature Synthesis
Authors: Podlozhnyuk N. D. , Voznyakovskiy A. A. , Voznyakovskiy A. P. , Kidalov S. V. , Bogacheva E. A.
Published: April 2024

The ability of few-layer graphene prepared by self-propagating high-temperature synthesis to adsorb Rhodamine G was studied. The dependences of the sorption capacity of few-layer graphene particles on the Rhodamine G concentration in aqueous solution, solution temperature, and adsorption time were determined. The adsorption of Rhodamine G on the surface of few-layer graphene is satisfactorily described by the Langmuir and Freundlich models. The process occurs under mixed diffusion control and can be described by a pseudo-second-order rate equation.
Synthesis and Study of Mixed Diesters of Synthetic Petroleum Acids and Fatty Acids
Authors: Sadieva N. F. , Nasibova G. G. , Iskenderova S. A. , Efendieva L. M. , Cherepnova Yu. P. , Alieva S. G. , Mazamova T. A.
Published: April 2024

The paper deals with the synthesis and study of mixed (unsymmetrical) 1,4-butanediol diesters of petroleum acids and aliphatic fatty acids (С6–С8). High yield of the target product (90.3%) was reached under the following conditions: temperature 110–120°С, catalyst amount 1.3 wt % (based on the acid), acid : alcohol molar ratio 2 : 1.4. The physicochemical parameters and structures of the products were determined. The mixed 1,4-butanediol esters obtained are well compatible with polyvinyl chloride, forming colorless elastic compounds. The diesters were tested as antioxidants enhancing the thermal oxidation resistance of diesel fuel. The amount of the precipitate formed by oxidative polymerization and polycondensation of diesel fuel due to the presence of heteroatomic compounds decreases from 4.6 to 1.0 mg/100 mL fuel on adding 0.004 wt % diesters prepared.
Impact of Conditions of Methyl Methacrylate Suspension Polymerization on the Particle Size Distribution of the Polymer
Authors: Ladilova N. Yu. , Kulikova G. L. , Kornienko P. V. , Shirshin K. V. , Shirshin K. K.
Published: April 2024

The impact of operational conditions for carrying out methyl methacrylate suspension polymerization during stabilization of the system with dispersants of different chemical natures: poly-2-acrylamido-2-methylpropanesulfonic acid and Mg(OH)2, was studied. The role of the contribution of the chemical nature of the dispersant, which reduces the interfacial tension between the monomer and aqueous phases, to the particle size distribution of the polymer particles is shown. When polymerizing methyl methacrylate in the presence of water-insoluble Mg(OH)2, the interfacial tension diminishes, which brings about the formation of a highly dispersed polymer without the use of high-speed dispersion of the reaction mass.
Impact of the Composition of Rubbers Filled with Carboxymethyl Cellulose on Their Properties
Authors: Cherezova E. N. , Galikhanov M. F. , Karaseva Yu. S. , Nakyp A. M.
Published: April 2024

The impact of the amount of water-swellable filler sodium carboxymethylcellulose of Polycell-9B grade (particle size 1.0–2.0 mm) on the complex of physical and mechanical properties of limited swelling rubbers based on nitrile butadiene rubber of BNKS-28 AMN grade with a sulfur vulcanizing system was studied. The composition with a ratio of the rubber compound without swelling filler to sodium carboxymethylcellulose was varied in the range (65–35) : (35–65) (wt. parts). It was established that the introduction of a swelling filler into the rubber compound has virtually no effect on the time to achieve the optimal vulcanization time and is 10 min at a temperature of 170°C. It was shown that the introduction of sodium carboxymethylcellulose leads to a decrease in the deformation-strength properties of rubbers, however, the strength characteristics of modified rubbers allow the use of the developed rubber compositions for the manufacture of sealing elements of water-swellable packers. It was revealed that with an increase in the proportion of the swelling filler, sodium carboxymethylcellulose, the vulcanizate exhibits a higher sorption capacity in aqueous media with different pH.
Enhancement of the Fracture Toughness of Carbon-Reinforced Plastics by Introducing a Thermoplastic Phase into an Epoxy Matrix
Authors: Kutovaya I. V. , Aleksanova A. A. , Erdni-goryaev E. M. , Lipatov Ya. V. , Afanas'eva E. S. , Morozov O. S. , Babkin A. V. , Kepman A. V.
Published: April 2024

The effect of modifying additives of polyphenylene sulfone or a nonwoven polyamide material on the thermal and mechanical properties of carbon fabric/epoxy resin polymer composite materials prepared by vacuum forming and vacuum infusion was studied. The addition of 10 wt % polyphenylene sulfone leads to slight improvement of the mechanical properties of the composite material, whereas introduction of the nonwoven material leads to a 15% decrease in the compression strength and to a 6% decrease in the interlayer shear strength. The specific peel work increases by 15 and 270% for the composites modified with polyphenylene sulfone and nonwoven cloth, respectively. Introduction of 4 wt % nonwoven material enhances the fracture toughness of the polymer composite material by a factor of 3.7.
THE COLD-LOVING ROTIFER, SYNCHAETA LAKOWITZIANA LUCKS 1912 (ROTIFERA, SYNCHAETIDAE), IN LAKE PLESHCHEYEVO, YAROSLAVL REGION, RUSSIA
Authors: Zhdanova S. M.
Published: April 2024

In the deep-water stratified Lake Pleshcheyevo, a cold-water species of rotifer belonging to the “northern invaders”, Synchaeta lakowitziana, was discovered for the first time. The rotifer was recorded in the winter-spring (March–May) and late autumn (November) periods at water temperatures of 1.9–12.9°С. The trophi morphology of the rotifer is described.
THE TUNDRA SWAN, CYGNUS COLUMBIANUS (ANATIDAE), IN THE EASTERN ASIAN ARCTIC: TRENDS AND RANGES OF DIFFERENT FLYWAY POPULATIONS
Authors: Solovyeva D. V. , Barykina D. A. , Kirtaev G. V. , Danilova V. V. , Rozenfeld S. B.
Published: April 2024

The tundra of the eastern Asian Arctic is inhabited by at least three flyway populations of the Tundra swan: the East Asian continental migratory flyway population of C. c. bewickii; the western Pacific flyway population of C. c. bewickii, and the western (American) flyway population of C. c. columbianus. The main objective of the present paper is to assess population trends by comparing information on the historical (the only one in the tundra of northeastern Asia) bird aerial survey in 1993–1995 with the data of our aerial survey held in 2020–2021. Another aim was to estimate the proportion of breeding birds in different flyway populations. The size of the zone of intergradation C. c. bewickii and C. c. columbianus in Chukotka and the level of hybridization have so far remained poorly studied, this issue required clarification. Aerial survey data for 2020–2021 were processed using QantumGIS 9.16.5 software. The system included the following layers: a vector layer of the world map; routes of aerial surveys for 2020 and 2021; and polygons of counts for 1993–1995. The system made it possible to calculate the length of the survey. Estimates for each region were calculated for the extrapolation area given in the historical survey. Between 1993–1995 and 2020–2021, an increase in the numbers of all three flyway populations of the Tundra swan was revealed on the breeding grounds. The East Asian continental flyway population increased 3.86 times, vs. 3.05 times for the West Pacific flyway population (while the documented growth of this population was 2.1 times, according to mid-winter counts over the same period). The Western (American) flyway population grew 2.5 times. We believe that the northern border of the summer range of the Tundra swan has significantly shifted to the north, following the summer climate change and the northward shift of the subarctic tundra zone. Registration of nests and broods in areas where only non-breeding birds were recorded during the historical survey is additional evidence of a northward displacement of the range. Kymyneyveem R (about 175.6° W) borders the areas of dominance of C. c. bewickii and C. c. columbianus. The switch in dominance has been triggered off, as there is no zone where both subspecies would occur in equal proportions. The overlap area of both subspecies extends for 600 km along the Arctic coast.
Contribution to the knowledge of the oribatid mite genus Aleurodamaeus (Acari, Oribatida, Aleurodamaeidae), with description of a new species from Ethiopia
Authors: Ermilov S. G. , Hugo-Coetzee E. A. , Rybalov L. B.
Published: April 2024

A new species of the genus Aleurodamaeus (Oribatida, Aleurodamaeidae) is described from heather forest litter in central Ethiopia. Aleurodamaeus aethiopicus sp. n. differs from all related species of the genus by the presence of a thick cerotegument with specific ornamentations (densely cellular with a median longitudinal interruption) on the notogaster. An identification key to all known species of Aleurodamaeus is provided.
FEEDING INTENSITY AND BOTH FOOD AND ENERGY REQUIREMENTS OF THE MIDDAY GERBIL (MERIONES MERIDIANUS, GERBILLIDAE, RODENTIA) IN CAPTIVITY
Authors: Omarov R. R. , Omarov K. Z.
Published: April 2024

Studies on the age characteristics of the quantitative and qualitative aspects of nutrition and energy of the Midday gerbil in captivity showed that the consumption of various types of food ranges from 4.2 to 7.5 g of dry matter per individual per day, depending on the age of the animals and the quality of the feed offered. The absolute dry matter intake reaches the maximum at air humidity levels close to 50–55%. The absolute values of food consumption by adult animals are 1.3–1.5 times higher than those of young ones. The relative level (per 10 g of body weight) of feed intake is 1.1–1.3 times, and the relative energy requirements are 1.2–1.5 times higher in young animals than in adults. Considering that the relative energy requirements of young gerbils are higher, while the absolute values of their nutrition are lower than those of adults, they need more nutritious feeds in comparison with adults to ensure an energy balance. Consequently, in nature, young animals should be more demanding for food quality, and therefore any changes in the quantity and quality of food resources will primarily affect the condition and survival of young individuals.
THE TURUCHAN PIKA (OCHOTONA TURUCHANENSIS) AS AN ECOSYSTEM ENGINEER: THE INFLUENCE ON THE GROWTH OF THE COMMON NETTLE (URTICA DIOICA) ON TALUSES
Authors: Popov S. V. , Borisova N. G. , Chimitov D. G. , Lenkhoboeva S. Yu. , Starkov A. I.
Published: April 2024

The abundance of the common nettle on taluses was found to be strongly correlated with the abundance of such signs of Turuchan pika activities as feces, latrines, and haypiles collected by pikas under stones. We believe this is the activities of pikas that provide nitrates and thus facilitate the growth of the common nettle, a ruderal nitrophilous plant, on taluses. On the other hand, pikas selectively store nettles. As a result, pikas can be considered as both “ecosystem engineer” and “niche constructors”.
SPIDERS (ARANEI) OF THE PERIGLACIAL LANDSCAPES OF THE TSEI GORGE, NORTH OSSETIA-ALANIA, CAUCASUS, RUSSIA
Authors: Babenko A. B. , Ponomarev A. V.
Published: April 2024

In the framework of a comprehensive study of arthropods taking part in the primary successions of the periglacial landscapes in the North Caucasus, spiders were collected from 10 sites of different ages (ranging from 1 to 170 years) in the upper reaches of the Tsei Gorge at altitudes of 2071 to 2336 m a.s.l. As the glacier retreats, meadow communities are formed at the site of bare near-glacial areas, these being first replaced by shrubs in areas aged 10–14 years, and then by forest communities on 30–35-year old surfaces. Spiders appear almost immediately after the retreat of the glacier, and representatives of at least three families are found already in the area that was freed from ice just a year ago. This pioneer complex consists not only of representatives of the alpine fauna, but it also includes species without pronounced altitudinal preferences. However, the primary assemblage is short-lived, being completely replaced in 10–15 years, especially sharp rearrangements of the spider populations being noted during the transition from meadow to the forest stage of succession. In 30–35 years following the retreat of the glacier, the spider complexes reach a level of diversity that is quite comparable with that in developed communities of the mountain forest belt. A comparison of the periglacial assemblages of Caucasian spiders with those formed under similar conditions in the southern and northern mountains of Western Europe indicates a profound regional specificity not only at the level of species, but even at the level of families.
ASSOCIATIVE LEARNING AND MEMORY IN TRICHOGRAMMA TELENGAI (HYMENOPTERA, TRICHOGRAMMATIDAE)
Authors: Fedorova M. A. , Farisenkov S. E. , Timokhov A. V. , Polilov A. A.
Published: April 2024

Miniaturization constrains insects with the task of preserving vital body functions in spite of significant reductions in body size. The effects of miniaturization on the functioning of the insect nervous system were investigated in the parasitoid Trichogramma telengai. Despite a decreased number of neurons and their volume, T. telengai demonstrated the ability for associative learning and memory retention for up to 6 h after training. Our thermal setup, in which we trained and tested the microinsects, based on the Morris water maze principle makes it possible to compare the associative learning abilities of animals from different taxonomic groups. Our data expand the understanding of the effects of miniaturization on the cognitive abilities of animals and will allow us to determine which structural factors limit the minimum size of the functional insect brain.
GEOGRAPHIC VARIATIONS IN THE SHAPE OF THE UPPER TOOTHROW OF THE ARTCIC FOX (VULPES LAGOPUS L. 1758): EFFECTS OF ASYMMETRY AND ALLOMETRY
Authors: Gasilin V. V. , Nanova O. G.
Published: April 2024

Geographic variations in the shape of the upper cheek toothrow were studied using geometric morphometrics. For this, 288 specimens from 19 localities (North America, Eurasia, and Pacific and Arctic islands) were employed. Monomorphism of the toothrow for mainland foxes, both from North America and Eurasia, as well as the foxes from Greenland and St. Lawrence Island was found. The Arctic foxes of four Pacific island populations, i.e. two from the Commander Islands and two from the Pribilof Islands, differ significantly from the mainland counterparts in toothrow shape. The Arctic foxes from the Mednyi Island, the Bering Island and the Pribilof Islands differ from each other by toothrow shape as well. The Mednyi Island Arctic foxes show the shortest toothrow, a wide hard palate, and the most massive teeth. On the contrary, the Pribilof Islands Arctic foxes are the most small-toothed. Allometry does not affect geographic variations in the shape of the Arctic fox toothrow. High-level fluctuating asymmetry is found in the Mednyi Island and St. George Island Arctic foxes. Most probably the high level of fluctuating asymmetry is conditioned by both the extremely low genetic diversity as the result of a dramatic numbers decline in the recent past and the strong impact of heavy metals as the result of a coastal diet. We suppose that the same reasons. i.e. low genetic diversity and coastal diet, could have determined the high level of fluctuating asymmetry of the Arctic fox toothrow on the St. George Island.
NEW OR LITTLE-KNOWN SPECIES OF GROUND BEETLES (COLEOPTERA, CARABIDAE) FROM THE SAKHALIN ISLAND
Authors: Sundukov Yu. N.
Published: April 2024

Information concerning 20 new or little-known species of ground beetles found in the south of Sakhalin is presented. Of these, two species (Bembidion pliculatum Bates, 1883, Apristus grandis Andrewes 1937) are new to the fauna of Russia, while further five species (Dyschirius tristis Stephens 1827, Bembidion pseudolucillum Netolitzky 1938, Trechus nigricornis arsenjevi (Jeannel 1962), Harpalus nigrans A. Morawitz 1862, Lebia bifenestrata A. Morawitz 1862) represent the first formal records from Sakhalin Island. The earlier records of 13 species from this island are supported by additional material: Carabus canaliculatus sichotensis Born 1914, Dyschirius aeneus ovicollis Putzeys 1873, Eobroscus lutshniki (Roubal 1928), Bembidion hiogoense Bates 1873, B. lucillum lucillum Bates 1883, B. varium (Olivier 1795), Pterostichus longinquus Bates 1873, Agonum consimile (Gyllenhal 1810), Amara erratica (Duftschmid 1812), A. hicksi Lindroth, 1968, Harpalus platynotus Bates 1873, Chlaenius inops inops Chaudoir 1856, and Parena tripunctata (Bates 1873).
HAIR ARCHITECTURE OF THE DON HARE (LEPUS TANAITICUS, LEPORIDAE, LAGOMORPHA) FOUND FOR THE FIRST TIME IN THE PLEISTOCENE OF YAKUTIA
Authors: Chernova O. F. , Boeskorov G. G.
Published: April 2024

Using scanning electron microscopy (REM), we studied the architecture (external and internal design) of the hairs of an adult Pleistocene Don hare, a frozen mummy of which was first found in Yakutia. The architecture of the guard hairs of the Don hare, like that of other representatives of the genera Lepus and Oryctolagus, is shown to be unique (a furrowed shaft, a kind of columnar medulla and a chevron cuticle ornament). This varies in different areas of the pelage and is adapted to the habitation of this species in the extreme conditions of the Arctic (long fur, strongly developed hair medulla and its corrugated septum, peculiar hair on the soles of paws). A comparative morphological analysis of the hair of the (1) Don hare and Mountain hare (Holocene, Chukotka) has been performed, revealing a great similarity between these two species, (2) extinct and Recent species of hares, (3) hares and pikas, (4) hares and a number of other mammalian species. The features of hair architectonics in the hares and some other mammals are discussed in terms of species identification and adaptive traits.
THERIOLOGICAL INVESTIGATIONS IN PLAGUE FOCI IN THE TERRITORY OF RUSSIA AND NEIGHBORING COUNTRIES
Authors: Matrosov A. N. , Sludsky A. A. , Kuznetsov A. A. , Martsokha K. S.
Published: April 2024

Information on theriologists’ contributions to the development of the theory of natural plague foci is reviewed. Ecological and epizootological monitoring is one of the main aspects for surveying this dangerous infection. Zoologists participating in research on the infectious pathology of zoonoses have allowed for a breakthrough to be achieved in the study of enzootic factors, epizootology, focal paleogenesis and the evolution of parasitic systems, the patterns of the functioning of natural and anthropurgic foci, their biocenotic and spatial structure, the development of methods for evaluating the state of pathogen host and vector populations, host population control and other measures of preventing the human diseases. As a result of long-term research, a new conceptual apparatus and methods of medical mammalogy have been developed, and criteria and protocols of research and prevention activities in zoonosеs foci have been defined. New digital and geoinformation technologies, as well as Earth remote sensing are presently being implemented, all this providing epidemiological prosperity of human populations for plague and other natural focal diseases in enzootical territories.
A “LOST WORLD” OF MAMMALS IN EASTERN INDOCHINA: RUSSIAN STUDIES IN VIETNAM
Authors: Rozhnov V. V. , Abramov A. V.
Published: April 2024

The review is devoted to mammalogical research in Vietnam. A brief history of the study of mammals in eastern Indochina from the 17th century to the present is given. The main attention is paid to Soviet and Russian research carried out within the framework of the activities of the Joint Russia-Vietnam Tropical Research and Technological Center (established since 1987). The main topics of the mammalogical research and scientific publications of Russian scientists are analyzed.
MODERN RECORDS OF THE EUROPEAN HEDGEHOG (ERINACEUS EUROPAEUS, ERINACEIDAE, EULIPOTYPHLA) IN SOUTHEASTERN FENNOSCANDIA
Authors: Belkin V. V. , Fyodorov F. V. , Ilyukha V. A. , Futoran P. A.
Published: April 2024

Southeastern Fennoscandia, which encompasses the Republic of Karelia and the adjacent districts of the Leningrad and Arkhangelsk regions, until lately remained an area of Russia’s European North especially poorly prospected as regards the status of the European hedgehog (Erinaceus europaeus). Modern (2001–2022) records of this species obtained through the authors’ original observations and based on reports received from respondents, altogether covering 212 hedgehogs and 182 encounters, are analyzed. Spatio-temporal patterns in the species’ records in the region are demonstrated, viz. an expanding distribution area and a growing frequency of encounters from northwest to southeast. The northernmost records are shown (64.368° N, 30.383° E), including yearlings (63.624°–63.924° N, 30.466°–30.901° E, northern taiga subzone), as well as the first reports of the species east of Lake Onego both in Karelia and the Arkhangelsk Region. The studies have revealed habitat preferences and the rate of use of urban territories in the north of the distribution range: high shares of records come from deciduous (34.0% of the total number of animals reported) and mixed (19.3%) forest sites, as well as farmland (10.8%), second-home communities (16.5%), and rural settlements (9.0%). Hedgehog encounters in cut-over places, pine and spruce stands, wetlands, abandoned hamlets, and solitary buildings in the woods were few (0.5–6.1%). Most of the records were a result of accidental sightings by humans (80.8%), while domestic dogs spotted 19.2% of the hedgehogs. The earliest encounters in spring were recorded on 25.04–11.05, the latest in autumn on 2–17.09. The number of hedgehog encounters during their active life period was the lowest in April (1.1%), growing sharply in May and June (16.7 and 17.8%, respectively), peaking in July and August (30.0 and 24.4%), and falling sharply in September (10.0%). Some of the population parameters were determined: an average brood was 2.8 young of the year, whose share amounted to 24.5% of the total number of records; active single animals prevailed among adults (86.3%), and much smaller shares belonged to active pairs (7.6%) and females with litter (6.1%). The main cause of the deaths was road killing by vehicles (77.4%). Climate warming and forest structure alterations may be reasons to expect further expansions of the area of hedgehog encounters, e.g., to transformed and urbanized boreal areas.
REVIEW OF THE GENUS PARATRILOBUS MICOLETZKY 1922 (NEMATODA, TRIPLONCHIDA)
Authors: Gagarin V. G. , Naumova T. V.
Published: April 2024

The world fauna of the nematode genus Paratrilobus Micoletzky 1922 is reviewed. At present, 10 valid species of this genus are recognized. A character matrix using the main morphological features of males is compiled. Pictorial and dichotomous keys for species identification are given.
AGE STRUCTURE, GROWTH AND REPRODUCTION OF THE TWO-STREAKED SNAKE-EYED SKINK (ABLEPHARUS BIVITTATUS, REPTILIA, SCINCIDAE) IN THE TALYSH MOUNTAINS (ARDABIL PROVINCE, IRAN)
Authors: Kidov A. A. , Kondratova T. E. , Ivolga R. A. , Lyapkov S. M.
Published: April 2024

The age, growth, and fertility of two populations of Ablepharus bivittatus in the Talysh Mountains are presented. Altogether, 59 individuals were studied from two localities in the Ardabil Province, Iran, one being the village of Khanegah-e-Oliya in Nemin shahrestan and the other the village of Majara in Khalkhal shahrestan. The age of the lizards was determined using skeletochronology. The average age of females was 3.6 ± 1.15 years (maximum 6 years), in males 2.6 ± 1.24 (maximum 5 years). On the sections of tubular bones of many individuals, lines of growth retardation are noted, corresponding to hibernation and aestivation. Lizards grow intensely during the first 3 years of life, but then their growth slows down. Animals in the age groups of 3 years and older do not differ in body length. The age of pregnant lizards is 2–5 years, on average 3.7 ± 0.91 years. The fertility of females does not depend on age.
DIVERSITY OF STRUCTURAL VARIANTS OF THE m1 ANTEROKONID IN THE VOLE GENERA STENOCRANIUS AND ALEXANDROMYS (ARVICOLINI, RODENTIA): QUALITATIVE AND QUANTITATIVE APPROACHES
Authors: Pozdnyakov A. A. , Pavlinov I. Ya.
Published: April 2024

75 images of anteroconid morphotypes for five vole species were studied using traditional and GM methods: Stenocranius gregalis, Alexandromys middendorffii, A. mongolicus, A. mujanensis, and A. oeconomus. The morphotypical space is three-dimensional within the framework of the traditional approach, the axes being formed by (1) the complexity of the curve of the lingual and (2) labial sides of the anterior loop, and (3) the number of closed triangles. The total number of morphotypes for four species of Alexandromys is 56, 30 of them having been actualized (the degree of completeness of the morphospace is 53.6%). The thin plate and Procrustean distance analysys were used in the quantitative approach. The distribution of morphotypes in the space of the first two relative deformations, both for individual species and for their complex, corresponds to an arcuate configuration, the first of which is mainly associated with the complication/simplification of the buccal side of the antheroconid, while the second with the bilateral complication/simplification and simultaneous extension/compression of the antheroconid. The part of the potential morphospace that corresponds to a moderately complicated and maximally elongated antheroconid remains unoccupied. The distribution of morphotypes for the complex of species in the space of the first two axes of multidimensional scaling forms a single and almost homogeneous cloud that almost evenly fills the total morphospace. The correlation coefficients between the matrices of morphogenetic and Procrustean distances between morphotypes calculated for each of the species vary from 0.56 to 0.73.
VOCALIZATION OF BLACK-HOODED ORIOLE (ORIOLUS XANTHORNUS, ORIOLIDAE, PASSERIFORMES, AVES): FEMALE SINGING AND DUETTING
Authors: Kolesnikova Y. A. , Van Linh Nguyen
Published: April 2024

Singing is known to play significant roles in songbird communication. For a long time, singing was believed to be a male attribute, whereas rare episodes of female singing were seen as deviations. However, there has been more and more research on female vocals in recent times, suggesting this in no way to be a rare event. In this study, we investigated the vocalization of the Black-hooded oriole (Oriolus xanthornus) in the Nam Cat Tien National Park, southern Vietnam. We identified two singing variants significantly differing in both maximum frequency and frequency range, these parameters being higher in variant 2. Variant 1 appeared to be more often, being performed in various situations: spontaneous singing, territorial interactions, and duets. Variant 2 occurred only in duets or in territorial interactions where the bird focal pair also performed in duets. No syntax variation was found between the different singing variants. In addition, no variation was revealed in the syntax of variant 1 in the different situations (spontaneous singing and duets). In one observation, we reliably discovered that the male used variant 1, vs the female that used variant 2. Variant 1 is likely to usually be used by males, vs variant 2 usually being used by females. We also identified two types of calls for this species.
ALLELE DIVERSITY OF THE MAJOR HISTOCOMPATIBILITY COMPLEX GENE DRB1 IN TWO SPECIES OF HAMSTER OF THE GENUS ALLOCRICETULUS Argyropulo 1932
Authors: Meschersky I. G. , Feoktistova N. Y. , Gureeva A. V. , Surov A. V.
Published: April 2024

For the first time, the allelic diversity of exon 2 of the DRB1 gene (class II of the major histocompatibility complex, MHC) was determined by NGS sequencing in natural populations of two species of the genus Allocricetulus: Eversmann’s hamster (A. eversmanni) and the Mongolian hamster (A. curtatus). These species are genetically close, but allopatric and demonstrate different habitat preferences. Eversmann’s hamster inhabits the steppes and is often associated with agrocenosis, while the Mongolian hamster occures semi-deserts and deserts, where anthropogenic pressure is practically absent. Our analysis revealed a significant effect of positive selection on the diversity of alleles of the DRB1 gene in both study species. However, Eversmann's hamster is characterized by a large average distance between alleles, but a smaller proportion of heterozygous individuals, while the Mongolian hamster is characterized by a larger individual variety of alleles. Thus, despite the extensive range of Eversmann’s hamster, we noted significantly less functional diversity of adaptive genes, which may be due to an increased anthropogenic exposure.
COMPOSITION AND DISTRIBUTION OF MACROINVERTEBRATES ASSOCIATED WITH LUBOMIRSKIA BAIKALENSIS SPONGES (SPONGILLIDA, LUBOMIRSKIIDAE) DURING AN ECOLOGICAL CRISIS IN LAKE BAIKAL
Authors: Mekhanikova I. V. , Sitnikova T. Y. , Khanaev I. V.
Published: April 2024

This study was carried out in the littoral zone of Lake Baikal during a large-scale ecological crisis that affected all parts of the ecosystem, including populations of endemic sponges of the family Lubomirskiidae. Sponges play important roles in biotic communities of the rocky littoral of the lake, ensuring water purity and serving as a specialized habitat for a variety of organisms. In the last decade, mass disease and mortality of sponges were reported in different areas of Lake Baikal, which can lead to irreversible changes in the structure of littoral communities. We studied the taxonomic richness, distribution, and abundance of the main groups of macroinvertebrates, such as amphipods and gastropods, living on diseased branched Lubomirskia baikalensis sponges in three basins of Lake Baikal (2015, 2020, 2021, 2022) and made historic comparisons. The taxonomic richness of amphipods, including 35 species or subspecies, as well as further 5 taxa identified only to genus, increased and had 20 taxa more than 30 years ago. A total of 22 gastropod species or subspecies were found on the sponge, 20 of them for the first time. The species composition, dominant species complex and quantitative characteristics of sponge-associated amphipods and gastropods varied in different lake areas as evidenced by underwater observations. The abundance of all macroinvertebrate groups, as well as dominant amphipod and gastropod groups per unit weight of sponges decreased from south to north. The abundance of the invertebrates associated with diseased sponges was similar to the records of the pre-crisis period. Baikal sponges host invertebrates from several ecological groups with different feeding strategies (grazers, scrapers and filter feeders) providing a temporary refuge for most of them. In order to restore the abundance of sponges and preserve the populations of key invertebrate species, we propose to set up sponge “farms” in the least polluted areas of Lake Baikal.
ANALYSIS OF THE AMPHIPOD FAUNA OF CONTINENTAL RESERVOIRS IN THE NORTHWEST OF RUSSIA’S EUROPEAN PART
Authors: Berezina N. A.
Published: April 2024

The faunal composition of Amphipoda crustaceans of mainland water bodies in northwestern Russia is analyzed. To compile a checklist of amphipod species, data from original collections made in 1998–2021, the collections of the Zoological Institute, and literary information are used. To date, 29 species of amphipods have been recorded from the continental waters of the region. An arealogical analysis of the faunal composition reveals six groups or distribution patterns: Holarctic, West Palearctic, and North Atlantic estuaries, and further three groups of emigrants (settlers) from the Baikal-Siberian, Ponto-Caspian, and Arctic regions. The greatest species richness is recorded in estuarine sections of Baltic Sea rivers in the territories of the Leningrad and Kaliningrad regions, as well as fresh water bodies of the Republic of Karelia. In terms of species richness, estuarine species amphi-Atlantic in distribution and representatives of allochthonous faunas (invasive species) from the Ponto-Caspian basin dominate the region. The most common in the region are representatives of Holarctic and Palearctic patterns, as well as species of Arctic and Baikal-Siberian origins. Among them, the following species are most often to be recorded in lakes: Gammarus lacustris, Monoporeia affinis, Palaseopsis quadrispinosa and Gmelinoides fasciatus, vs G. zaddachi, G. oceanicus, G. tigrinus and Pontogammarus robustoides in estuarine brackish waters. Human-mediated introductions, both intentional and accidental, must have facilitated the appearance of invasive species in the fauna of Russia’s northwestern region. In the future, an increase in species richness in the region can be expected to occur in two ways: through the introduction of marine species into fresh waters and due to speciation.