bluuebunny/crossref_metadata_2025 huggingface dataset:
Soil Enzyme Activity in Natural and Ploughed Catenas as Parameters of Physiological State of Microbial Communities
Authors: Chernysheva E. V. , Dushchanova K. S. , Khomutova T. E. , Borisov A. V.
Published: April 2024

The study of soil microbial biomass and enzymatic activity of natural and anthropogenically transformed ecosystems was carried out. The catenas of virgin luvisols and chernozems of the Belogorye Natural Reserve and the catenas of arable soils were studied under similar geomorphological and lithological conditions. The activities of enzymes involved in the cycles of carbon (β-glucosidase and xylosidase), nitrogen (chitinase), and phosphorus (acid and alkaline phosphatase) was studied. It has been established that a decrease in soil microbial biomass as a result of ploughing is not accompanied by an equivalent decrease in the enzymatic activity of the soil. Differences in the enzymatic activity of different soils types were revealed, which indicates differences in the structure of the microbial community and the type of phytocenoses. Patterns of changes in the enzymatic activity of soils in watershed areas, in the transit and accumulative parts of catenas have been established. The values of specific enzymes activities (enzymatic activities per unit of microbial biomass) were calculated. The obtained patterns of changes in the specific enzymatic activity of arable soils indicate that, despite the loss of organic matter and a decrease in microbial biomass as a result of plowing, the physiological efficiency of the microbial community of agrochernozem is higher than in virgin soil. High specific enzymatic activity in arable soils is associated with higher rate of enzyme production by soil microorganisms due to land use changes.
Platelet Activation and Mechanisms of Thromboembolism Formation in Patients with Severe COVID-19. Alternative Mechanisms of Hemostasis System Activity
Authors: Kuznik B. I. , Smolyakov Y. N. , Tsybikov N. N. , Shapovalov K. G.
Published: April 2024

The review highlights the mechanism of development of hypercoagulation and thrombosis in severe forms of COVID-19. The introduction of the SARS-CoV-2 virus into the host organism is carried out by the interaction of the spike protein S with the angiotensin-converting enzyme ACE-2, which is located in type 2 alveocytes, vascular endothelium, kidneys, liver and other organs. In the event of a serious condition in patients with COVID-19, both nonspecific and adaptive immunity are activated. Stimulation of the complement system with the appearance of C3a, C3b, C5a fragments and the membrane attack complex (MAC) creates conditions for the development of hypercoagulability. The involvement of the renin-angiotensin-aldosterone system in this process and the appearance of angiotensin 2 (Ang-2) further increase the intensity of hypercoagulability. When the SARS-CoV-2 virus enters cells, the protective reaction of the adaptive immune system can turn into a pathological one (a cytokine storm develops), characterized by a high level of pro-inflammatory cytokines IL-1α, IL-6, Il-8, TNF-α, IL-17, etc.) and chemokines (CCL-2, CCL-11, etc.), which ultimately leads to the development of thromboangiopathy or otherwise immunothrombosis in seriously ill patients with COVID-19. Patients with more severe lesions may develop a condition similar to DIC. At the same time, patients with COVID-19 have mild thrombocytopenia, elevated levels of fibrinogen, D-dimer, fibrinogen degradation products (FDP), which indicates intense thrombus formation, as well as short PT and APTT, due to a largely increased level of FVIII. In COVID-19, along with the classical one, an alternative pathway (bypassing thrombin) of regulation of the hemostasis system and thrombus formation appears, mainly associated with the influence of the spike protein S (PS, PROS1) of the SARS-CoV-2 virus and papain-like protease (PROS1). Protein S directly affects the conversion of fibrinogen to fibrin, as well as the activation of individual plasma coagulation factors. The alternative pathway of blood coagulation is also due to the activation of the complement system via the lectin pathway with the inclusion of metalloproteinases MASP-1, 2 and 3. In addition, the S protein activates tPA, which may be accompanied by hyperfibrinolysis. In seriously ill patients with COVID-19, platelets play an important role in the occurrence of thromboembolic complications. During the release reaction, platelets are released from the cytoplasm into the blood α and dense granules containing inflammatory cytokines and chemokines, which enhances the cytokine storm and, consequently, thrombus formation. By acting on the spike protein S, platelets enhance an alternative way of regulating the hemostasis system and thrombus formation.
Comparative Studies of Complex Products Based on Heparins of Animal and Plant Origin
Authors: Uspenskaya M. S. , Lyapina L. A. , Sorokoletov S. M. , Lyapina M. G. , Kalugina M. D.
Published: April 2024

Complex preparations based on heparins of animal and vegetable origin with the inclusion of glutamic acid in a weight ratio of 1 : 4 were obtained. High molecular weight (HMН) and low molecular weight (LMWH) commercial preparations of heparins were used as heparins of animal origin, heparinoid was used as heparin of plant origin, isolated from the roots of the peony Akademik Sadovnichy (heparinoid). Their influence on the state of plasma hemostasis under in vitro conditions was studied in a comparative aspect. It has been established that all complex compounds have anticoagulant activity, which, according to the results of our studies, is realized by a different mechanism of their action on blood coagulation – on the internal, external, or general pathways of blood coagulation. HMН complexes with glutamic acid had an antithrombin effect, affecting the internal and general coagulation pathways, while LMWH complexes with glutamic acid, exerting anti-Xa activity, affected the internal pathway of coagulation activation, and the combination of heparinoid with glutamic acid inhibited factors not only internal, but also external ways of blood coagulation. In addition, the latter compound exhibited weak antithrombin activity. It was also shown that all heparin complexes prevented fibrin polymerization, increasing the fibrin depolymerization activity of plasma, and in the heparinoid compound, this activity was higher by 10–17% compared to other commercial agents. Thus, the best anticoagulant in terms of efficacy and safety is the heparinoid complex with glutamic acid.
Modern Methods of Account of Game Animals
Authors: Prosekov A. Yu. , Kaledin A. P. , Beketov S. V. , Golubeva O. N. , Ostapchuk A. M.
Published: April 2024

Modern approaches to the organization of hunting are based on the principles of sustainable development, requiring a combination of biodiversity conservation and economic efficiency, which is impossible without improving the accuracy and objectivity of data on the number of hunting animals. The proposed review article discusses various types and methods of accounting for hunting animals: winter route accounting, questionnaire and expert methods, run-through accounting, air accounting, salary and tape accounting. At the same time, the main emphasis is placed on the analysis of winter route accounting of animals as the main method for estimating the number of most hunting animals in the Russian Federation. As a possible complement or an independent alternative to accounting for the number of hunting animals, the prospects for the use of aerial accounting using unmanned aerial vehicles are considered.
The Ecosystem of Lake Tolpanjärvi, Western Karelia, Preserved in Natural State
Authors: Sterligova O. P. , Ilmast N. V. , Kuchko Ya. A. , Savosin E. S. , Savosin D. S.
Published: April 2024

The results of the study of Lake Tolpanjärvi’s ecosystem are reported. Its hydrological and geochemical indices, as well as the current condition of biotic communities (zooplankton, benthos and fish population), were studied and analyzed. Analysis of the chemical composition of water indicates the low organic matter content (total phosphorus 0.007 mg/l, nitrogen 0.26 mg/l) of the lake. The Tolpanjärvi is an oligotrophic lake, as indicated by the abundance of zooplankton (with a biomass of less than 1 g/m3) and zoobenthos (biomass 0.44 g/m2). The lake is of an oligosaprobic class (2nd quality class, clean natural water), as evidenced by its saprobity index estimated using Pantle–Bukk’s method. The quantitative indices of zoobenthos varied from 120 individuals/m2 and 0.08 g/m2 in the profundal zone to 1200 inds./м2 and 0.86 g/m2 in the quiet littoral zone. The lake is more similar in the chironomid index (К – 2.00) to clean natural water. It is inhabited by 8 fish species of 5 families. The fish population is dominated by the whitefish Coregonus lavaretus, the perch Perca fluviatilis and the roach Rutilus rutilus. Two ecological forms of whitefish, differing in both the number of gill rakers (sparsely-rakered 18–24 and medium-rakered 28–36) and biological indices (linear-weight growth рост, maturation, fertility and feeding), occur in the lake. Stable highly diverse ecosystems were shown to form the basis for the preservation of the gene pool and for assessment of the current condition of water bodies heavily affected by human activities.
Assessment of Detritus Biomass in Forest Ecosystems
Authors: Tarasov S. I.
Published: April 2024

The current method for estimating the biomass of dead organic matter in forest ecosystems is analyzed. The main attention is paid to the study of the adequacy of mathematical models used to estimate the density of decomposing wood. The failure of the traditional approach to estimating the density index, both for an individual decomposing dead tree, and in calculating the average index characterizing the density of the wood of the totality of dead trees is shown. We consider the possibility of applying the concept of effective density to estimate the biomass of dead wood remains as the most corresponding to their heterogeneous structure. We propose a method based on representations of interval analysis, which allows, using standard values of the density of healthy wood, to estimate the density index of rotting wood of the corresponding decomposition class of the debris classification system.
The Modern Concept of Hormesis: Overview of the Issue and Significance for Ecology
Authors: Erofeeva E. A. , Gelashvili D. B. , Rozenberg G. S.
Published: April 2024

Currently, it has been established that when living organisms are exposed to various environmental factors (abiotic, biotic, and anthropogenic), hormesis is a fairly common phenomenon. Hormesis is found in different groups of organisms and at almost all levels of the organization of living systems from the cell to ecosystem level. At the same time, a comprehensive analysis of the significance of hormesis for ecology has not been carried out. This review analyzes the modern concept of hormesis, as well as its significance for various fields of ecology.
Brevibacillus laterosporus as a Biological Control Agent
Authors: Smirnova T. A. , Zubasheva M. V. , Shevlyagina N. V. , Smirnov Y. A. , Zhukhovitsky V. G.
Published: April 2024

The article analyzes and summarizes the literary and own results of studies of the properties of Brevibacillus laterosporus (Bl) as an agent of biocontrol of insects, microorganisms, invertebrates. The review provides data on the morphology and characteristics of the biological properties of Bl. New crystal-bearing strains were reported. The structural features of spores and Bl crystals identified by electron microscopy are discussed. Data on crystal formation in different bacilli are analyzed. Bl crystals have mosquitocidal activity. Data on the antimicrobial properties of Bl, including the activity of Bl against drug-resistant bacteria, are presented. The antimicrobial, fungicidal and cyanolytic activities of Bl strains make it possible to use them as producers of insecticides, antibiotics, bacteriocins and as environmentally friendly bacterial agents of biocontrol.
Genus Betula L.: Species-Specific Population-Genetic Features and Taxonomy Problems
Authors: Vetchinnikova L. V. , Titov A. F.
Published: April 2024

The article summarizes and systematizes the results of studies by Russian and foreign authors related to the population-genetic features of the main members (silver birch Betula pendula Roth, downy birch Betula pubescens Ehrh, curly (or Karelian) birch Betula pendula Roth var. carelica (Mercklin) Hämet-Ahti) of the birch genus (Betula L.) growing in the forest zone of Europe. Information is provided about forming of birch populations in the region and about its migration pathways when recolonizing the territory after the Ice Age. We demonstrate that due to certain geographic and climatic affiliations there appeared zones of hybridization between different birch species, which had an effect on the subsequent evolution of this genus. Attention is given to the role of hybridization in shaping the genetic structure of the birch population in the north-western part of continental Europe, where introgression has generated unusual genotypes and haplotypes, among which curly birch has probably become differentiated. We argue that the introgressive hybridization of species observed now and then in the birch genus may be of the main reasons for the problems with definite taxonomic identification of silver birch and downy birch. It is also remarked that curly birch, although meeting the conventional biological criteria of a species, is still regarded a variety of silver birch. Having analyzed the population-genetic features of members of the genus Betula L., the authors conclude that the species status of silver birch and downy birch should be retained in spite of the identification difficulties and that instating curly birch as a separate biological species is advisable. We emphasize the importance and relevance of studying the population-genetic features of both common and rare members of the Betula genus to enable the development of efficient methods and practices of their selective breeding and reproduction of the most valuable genotypes as a solid scientific foundation for sustainable forest management.
Monocyte Subpopulations Analysis in Patients under Cardiac Surgery in Conditions of Modified Extracorporeal Circulation Using Hemodiafiltration
Authors: Zemskov V. M. , Kozlova M. N. , Solovieva M. S. , Balbutsky A. V. , Shishkina N. S. , Kulikova A. N. , Demidova V. S. , Zemskov A. M. , Popov V. A. , Plotnikov G. P. , Sharanda A. V. , Kornelyuk R. A. , Vasiliev O. S.
Published: April 2024

In patients undergoing cardiosurgical operations under conditions of extracorporeal circulation, continued high-volume controlled hemodiafiltration was used, the content of subpopulations of monocytes M1, M2, M3, CD4+ monocytes and total monocytes was studied in the circulation before surgery and on days 3 and 10 after it. Previously unknown data have been discovered that can be used in the diagnosis and prognosis of cardiac surgery.
Optical Spectra of Composite Materials Based on Molybdenum-
Containing Nanoparticles and High-Pressure Polyethylene
Authors: Fionov A. S. , Kolesov V. V. , Fionova V. A. , Taratanov N. A. , Golovanov E. V. , Dzhangurazov E. B. , Beshtoev B. Z. , Voronov A. S. , Yurkov G. Yu.
Published: April 2024

Molybdenum-containing composite nanomaterials are synthesized by the thermal decompositionof molybdenum hexacarbonyl in a solution-melt of polyethylene in mineral oil. The concentration of a metalcontainingfiller in the composite materials varied from 1 to 20 wt %. A technique for preparing film samplesfor spectroscopic studies is developed, and the samples obtained are studied by UVI, IR, and Raman spectroscopy.It is found that additional absorption bands appear in the IR range, whose intensity depends on theconcentration of molybdenum-containing nanoparticles in the composite materials. The spectral characteristicsof Raman scattering show that all samples are characterized by the stretching of the C–C bond. In thevisible light region, the spectrum of nanocomposites has a flat edge of its own absorption located in the regionof wave numbers (18–31) × 103 cm–1.
Composite Materials Based on Polytetrafluoroethylene Microgranules and Nickel-Containing Nanoparticles: Synthesis, Composition, and Magnetic Properties
Authors: Kirillov V. E. , Yurkov G. Yu. , Korobov M. S. , Voronov A. S. , Solodilov V. I. , Buznik V. M.
Published: April 2024

Polymer composites with nanoparticles localized on the surface of polytetrafluoroethylene microgranulesare synthesized by the method of thermal decomposition of metal-containing nickel salts. The synthesizednanoparticles are characterized by transmission electron microscopy (TEM) and X-ray diffractionanalysis. The size of the nanoparticles ranged from 3.5 to 8 nm, depending on the precursor. It follows fromthe data obtained that the particles have a complex composition. The study of magnetic properties shows thatthe system of magnetic nickel-containing nanoparticles in the samples at room temperature is in a ferromagneticor superparamagnetic state. The blocking temperature and coercive force are calculated for each sample.
Magnetic Resonance Imaging Study of Water Absorption
of Polymer Composite Materials Subjected to Mechanical
and Temperature Impact
Authors: Morozov E. V. , Il’ichev A. V. , Bouznik V. M.
Published: April 2024

The results of a study of water absorption processes by samples of polymer composite materials(PCMs) based on fiberglass, subjected to low-speed impact with controlled impact energy and alternatingtemperature cycling are presented. Using magnetic resonance imaging (MRI), the distribution of absorbedwater in the fiberglass structure is visualized and the dynamics of its accumulation in various areas of the sampleare studied. It is found that mechanical impact leads to a nonuniform distribution of the absorbed waterin the samples and a significant accumulation of free water in the areas of destruction and adjacent layers inthe event of a violation of the integrity of the outer layer of the material. It is shown that cyclic alternatingtemperature effects do not lead to a noticeable change in the water absorption processes and are comparablein effect to mechanical nondestructive effects. The results obtained using MRI are in close agreement withthe data of traditional weight measurements, which shows the effectiveness of the method in diagnosingdefects and mechanical damage to PCMs exposed to the aquatic environment.
Dielectric Properties of Composites Based on Ethylene Vinyl Acetate Filled with a Hollandite-Like Ceramic Material K1.5Co0.75Ti7.25O16
Authors: Vikulova M. A. , Tsyganov A. R. , Artyukhov D. I. , Gorokhovsky A. V. , Gorshkov N. V.
Published: April 2024

Polymer-matrix composites based on ethylene vinyl acetate (EVA) and KxCoyTi8 – yO16 solid solutionwith a hollandite-like structure (KCoTO(H)) are obtained and studied as promising materials for componentsof electronic devices. The filler is synthesized by modifying X-ray amorphous potassium polytitanate(PPT) K2O·nTiO2 (n = 4.3) in a CoSO4·7H2O solution under alkaline conditions, followed by thermal treatmentat 900°C. The structure of the synthesized material and the morphology of particles are studied by X-rayphase analysis (XPA) and scanning electron microscopy (SEM), respectively. KCoTO(H) is introduced in theEVA polymer matrix by mixing a preliminarily prepared polymer solution and a dispersion of filler powder inan appropriate solvent in amounts of 10, 20, 30, 40, and 50 vol %. The frequency behavior of the permittivity,dielectric loss tangent, and conductivity of the obtained composites is studied by impedance spectroscopy. Itis established that an increase in the KCoTO(H) content in the composite contributes to the growth of all thestudied dielectric characteristics of a relatively pure EVA polymer matrix in the entire frequency range of0.1 kHz–1 MHz (the maximum values are noted at a 50 vol % of the filler and f = 102 Hz: ε = 518, tanδ = 4,and σ = 1.35 S/cm).
Influence of Internal Microarchitecture on the Shape of Individual
Implants Made from Vinylidene Fluoride Copolymer by 3D Printing
with High-Temperature Crystallization
Authors: Vorobyev A. O. , Kulbakin D. E. , Chistyakov S. G. , Mitrichenko A. D. , Dubinenko G. E. , Akimchenko I. O. , Gogolev A. S. , Choynzonov E. L. , Bouznik V. M. , Bolbasov E. N.
Published: April 2024

The healing potential of individual polymer implants for the reconstruction of extensive craniofacialdefects after cancer resection is largely determined by the internal architecture of the implant. The architectureof an implant during polymer crystallization could affect the structure and shape of the implant at themicro and macro levels. In this study, the relationship between the internal architecture (triply periodic minimumsurface structure (gyroid), cube, grid, and honeycomb) and shape changes of individual implants by3D printing with a vinylidene fluoride-tetrafluoroethylene copolymer after crystallization is examined at afilling density of 70%. Using the method of differential scanning calorimetry, it is established that crystallizationleads to the rearrangement of the crystalline structure of the implant into electrically active (ferroelectric)crystalline phases. Moreover, the type of internal architecture affects the change in the shape of theimplant after crystallization. The results of the computed tomography show that structures with a triply periodicminimum surface (gyroid) provide the minimal deformation of the implant during crystallization, whichmakes such structures optimal for manufacturing implants for replacing bone defects in the zygomatic-orbitalcomplex.
Investigation of the Interaction of Hydrogen Fluoride with Quartz
by Measuring Surface Conductivity
Authors: Agroskin V. Ya. , Bravy B. G. , Vasiliev G. K. , Guriev V. I. , Kashtanov S. A. , Chernyshev Yu. A.
Published: April 2024

The change in surface conductivity under the influence of hydrogen fluoride (HF) gas on quartz isexperimentally studied. It is shown that the surface conductivity of quartz changes by a factor of more than108 during the reaction. Possible heterogeneous chemical processes determining the observed experimentalresults are considered.
Influence of the Polymer Matrix Composition on the Size Range
of Silver Nanoparticles Formed in a Succinyl Chitosan Solution
Under the Action of Microwave Radiation
Authors: Aleksandrova V. A. , Futoryanskaya A. M.
Published: April 2024

A new composite based on succinyl chitosan (SCTZ) and silver nanoparticles (NPs) with theinclusion of an additional component, polyethylene oxide (PEO), is developed. Microwave radiation and Dglucoseas a reducing agent are used to form silver NPs by reduction from metal ions. The presence of silverNPs in the obtained colloidal solutions is judged by the appearance of absorption bands in the electron plasmonresonance spectra ( max = 420 nm). It is shown that the introduction of an additional component in thepolymer matrix leads to a significant narrowing of the size range of the formed silver NPs.
The Existence Regions for Direct Three-Body Recombination
of Cesium and Bromide Ions in the Presence of Krypton,
Xenon, and Mercury Atoms
Authors: Azriel’ V. M. , Akimov V. M. , Ermolova E. V. , Kabanov D. B. , Kolesnikova L. I. , Rusin L. Yu. , Sevryuk M. B.
Published: April 2024

Within the framework of the quasiclassical trajectory method on semiempirical diabatic potentialenergy surfaces, we have considered the existence regions for direct three-body recombination Cs+ + Br– +R → CsBr + R (R = Kr, Xe, Hg) in the case where the encounters of the Cs+ and Br– ions are central and thedelay parameter vanishes. The recombination regions are determined using a much more precise procedurethan in the previous works. Particular attention is paid to the recombination opacity functions and to the roleof the orientation angles in the outcome of a three-body collision. The performed calculations demonstratea great complexity of the structure of the recombination regions.
Adaptation of the Kinetical Scheme to Ethylene Combustion
Conditions at Temperatures Above 1200 K
Authors: Filimonova E. A. , Dobrovolskaya A. S.
Published: April 2024

In the paper authors present original methods for analyzing the kinetic scheme and reaction rateconstants for calculation of the ignition delay time and the laminar velocity of the combustion wave forC2H4–O2–Ar and C2H4-air mixtures. The kinetic scheme under consideration will further be applied inproblems of plasma-assisted combustion in a supersonic flow using a discharge. After made changes to thereaction system, a good agreement between the calculation results and experimental data was obtained.
The Effect of the Turbulence Coefficient on the Formation
of a Turbulent Process: 2. Existing Scenarios for the Occurrence
and Development of Turbulence
Authors: Lebed I. V.
Published: April 2024

Some characteristic features of three scenarios for the occurrence and development of turbulenceare presented: the Landau-Hopf scenario, the scenario of transition to turbulence on a strange attractor, andthe scenario followed by the solutions of the multimoment hydrodynamics equations. The analysis of the presentedcharacteristic features allows us to conclude that these scenarios can be used to interpret turbulence.It is shown that only one of the scenarios satisfactorily interprets the experimental data: the scenario followedby the solutions of the multimoment hydrodynamics equations supplemented with stochastic components.The Landau-Hopf scenario leads to a system that has lost stability in the wrong direction. The scenario of thetransition to turbulence on a strange attractor correctly reproduces only the initial stage of the evolution ofthe liquid layer in the Bénard experiment, namely, heat transfer in the resting layer and convective shafts.Analysis of the behavior of solutions of the Lorentz model leaves no hope for the ability of this scenario tointerpret turbulence
Empirical Model of the Charge Carriers’ Photogeneration
in Organic Solar Cells
Authors: Lukin L. V.
Published: April 2024

A model of the photocurrent generation of charge carriers in blends of donor (D) and acceptor (A)materials structured on the nanoscale is considered. The absorption of a quantum of light in one of thesematerials creates a molecular exciton, which can reach the interface between the D and A phases and form aninterfacial charge transfer (CT) exciton on this interface, which dissociates into an electron-hole pair. Theprobabilities of the dissociation of CT excitons into free current carriers are calculated as a function of theelectric field and the thermalization length of the electron-hole pair.
An Electrostatic Mechanism for the Formation of Hybrid
Nanostructures Based on Gold Nanoparticles
and Cationic Porphyrins
Authors: Povolotskiy A. V. , Soldatova D. A. , Lukyanov D. A. , Solovieva E. V.
Published: April 2024

interaction of cationic porphyrin with gold nanoparticles (GNPs) coated with polymer shellswith positive and negative surface potentials in an aqueous solution is studied. The criteria for the formationof hybrid molecular-plasmon nanostructures based on the determination of the luminescence quenchingmechanism according to the Stern-Volmer equation and the change in the shape of the porphyrin luminescencespectrum are established. The effect of the sign of the zeta potential of GNPs on the formation of hybridmolecular-plasmon nanostructures due to electrostatic interaction is established.
Kinetics of the Decay of Excited Singlet State into a Pair
of T-Excitons in Rubrene Films: Mechanism and Manifestation
of Exciton Migration
Authors: Shushin A. I. , Umanskii S. Ya. , Chaikina Yu. A.
Published: April 2024

The kinetics of the decay (splitting) of the excited singlet -state of rubrene molecules into a pair oftriplet-excitons (T-excitons) in rubrene films, usually represented in terms of the kinetics of the decay of fluorescence(KDF) from the -state, is analyzed in detail. The KDF is known to be significantly controlled bythe process of diffusive migration and annihilation of the generated T-excitons. In the analysis, two migrationmodels are considered: the two-state model (TSM), treating the migration effect as a result of transitionsbetween the [TT] state of coupled T-excitons (at small TT-distances r) and the [T+T]-state of freely migratingЕ-excitons (at large distances r), as well as the free migration model (FMM), neglecting the effect of the [TT]state. Within the TSM and FMM, the expressions for are derived, which are applied to describe the KDF ,measured in amorphous rubrene films. Within the experimentally investigated range of times, , the TSM isshown to reproduce the behavior of the experimental KDF much more accurately than the FMM. At longertimes a substantial difference () between and the FMM-predicted KDF is found, which is far beyond theexperimental error (3%).
Influence of an Ultralow Graphene Content on the Physical
and Mechanical Characteristics of Uhmwpe-Based Composites
Authors: Zabolotnov A. S. , Gostev S. S. , Maklakova I. A. , Novokshonova L. A. , Krasheninnikov V. G. , Gudkov M. V.
Published: April 2024

The polymerization filling method is used to obtain nanocomposites based on ultrahigh molecularweight polyethylene (UHMWPE) and graphene at with an ultralow content of 0.0065–0.019 vol %. Themelting points and degrees of crystallinity of the obtained composites are close to the corresponding characteristicsof unfilled UHMWPE. The strain-strength properties under the tension of the samples of theobtained composites are studied depending on the content of graphene. It is shown that the tensile strengthof the composites increases significantly with an increase in the graphene content to 0.012 vol % comparedto unfilled UHMWPE with a subsequent decrease. The relative elongation changes in a similar way.
Relationship of the magnetic compass and vision in birds: in search of a receptor cell
Authors: Astakhova L. A. , Rotov A. Yu. , Chernetsov N. S.
Published: April 2024

The existence of the magnetic compass system was first shown in birds. Since then, a large amount of data has been accumulated on the performance of the avian magnetic compass and its relationship with visual reception. The current dominant concept is that the receptor for the magnetic compass in birds is located in the retina. The most popular hypothesis for the mechanism of operation of magnetic field receptors is the radical pair model, and a candidate for the role of the primary magnetoreceptor molecule is cryptochrome, and more specifically, its isoform, cryptochrome 4a. In recent years, data have been published on the interaction of cryptochrome with some proteins involved in the phototransduction cascade, as well as promising data from electrophysiological studies combining light and magnetic stimuli. In addition, a number of morphological studies of the avian retina also allow us to narrow down the range of promising cells for the role of a magnetoreceptor, and the double cone is currently the most likely candidate. In this review, we discuss the latest research data in this area.
Magnetic Navigation of Animals, Contrast Sensitivity of Vision, and the Weber-Fechner Law
Authors: Binhi V. N.
Published: April 2024

It is known that some animals can react to very small changes in the magnetic field – a thousand times smaller than the geomagnetic field – and use this to navigate the Earth’s magnetic landscape. However, the nature of the molecular magnetic sensor remains unclear, although it has been established that the magnetic sense is associated with vision. It is generally accepted that the operation of a magnetic sensor is based on a magnetochemical reaction. Cryptochromes of photoreceptors lining the retina contain photoinduced spin-correlated pairs of radicals involved in the formation of a nerve impulse and sensitive to a magnetic field. Therefore, the animal could sense the magnetic field as a change in the brightness of large visual fields and orient itself by their contrast. However, the sensitivity of individual sensors – of radical pairs – is known to be very low. Previously, it has been assumed that this difficulty is overcome by a statistical increase in contrast sensitivity due to the parallel processing by the brain of the primary signals of millions of photoreceptors. In the present work, this hypothesis is tested. It has been found that the threshold sensation of brightness contrast almost linearly depends on the logarithm of the angular size of contrasting stimulus, which is typical for the physiology of sensations that obey the Weber-Fechner law. Contrast sensitivity increases with the number of photoreceptors involved in stimulus recognition, however this increase is not quantitatively sufficient to reliably explain the magnetic navigation of animals.
Changes in the spectral characteristics and the coherence of the rat olfactory bulb local field potentials under xylazine-tiletamine-zolazepam anesthesia
Authors: Kiroy V. N. , Kosenko P. O. , Shaposhnikov P. D. , Saevskiy A. I. , Aslanyan E. V.
Published: April 2024

Local field potentials (LFP) recorded in the olfactory bulb (OB) are known to be largely generated in local neural networks, are directly related to the processing of olfactory information, and are influenced by various factors, including anesthetics. Using 8-electrode arrays implanted in the dorsal regions of 6 adult male Norway rats OBs, the effects of xylazine-tiletamine-zolazepam (XTZ) anesthesia on the spectral characteristics and coherence of the LFP in the frequency range 1–150 Hz were studied in 2 hours long chronic experiments. It is shown that the most significant changes in the rat OB LFP under XTZ-anesthesia are observed in the high γ frequency band. A statistically significant increase in the power (2–4 times) and coherence (up to 50%) of this band was observed in the LFP of all animals within 10–15 minutes from the anesthesia onset. At the same time, during wakefulness, the dominant frequencies of this band were 70–80 Hz, and within 10–15 minutes from the anesthesia onset they increased to 110–130 Hz. During anesthesia, a gradual shift of these dominant frequencies to a lower range (90–110 Hz) was observed, while their total power, in contrast to the coherence, was statistically significantly reduced when the animal started recovering from anesthesia
What did adaptive optics give us for understanding the mechanisms of human color vision
Authors: Maximova E. M.
Published: April 2024

Information on the color vision of animals and humans, the history and methods of its study is briefly presented. The results of fundamental research in this area obtained using adaptive optics and scanning laser ophthalmoscopy (AOSLO) in combination with densitometry, phase-sensitive optical coherence tomography (AO-PSOCT), and calcium imaging (Ca++ imaging) are described. These methods made it possible for the first time in vivo to see the mosaic of human retinal L, M, S cones, to build maps of the location of cones of three different types, to study color perception during stimulation of single cones.
“Acoustic window” in the mandibular of dolphins: evaluation of the bone thickness
Authors: Sysueva E. V. , Popov V. V.
Published: April 2024

The mandibular sound conduction hypothesis suggests that dolphins have functionally replaced the external pinna with an “acoustic window” in the low jaw. Using industrial tomography, the lower jaws 3D models of the odontocetes six species were built. In the obtained models, the analysis of the bone thickness in the area of the supposed “acoustic window” showed a dependence of the bone wall thickness on the size of the animal. The area of the greatest thinning of the lateral wall of the lower jaw in the studied samples was determined mainly in the upper angle of the proximal part of the lower jaw or near the lower angle of the lower jaw, and not in the center, as previously assumed.
Automatic evaluation of the internal parameters of the onboard camera of a spacecraft from video data of dockings with the iss
Authors: Zinov V. A. , Konovalenko I. A.
Published: April 2024

The KURS radio engineering system for measuring motion parameters during rendezvous and docking has some disadvantages: the accuracy of measurement with multiple reflections of the wave can drop, the technical equipment is available on both docking vehicles (active and passive parts), it is expensive both in terms of energy resources and in terms of cost. An analysis of existing visual systems has shown that such systems successfully solve the problems of visual odometry on UAVs, robots, and similar devices. However, to use such systems, it is necessary to know the internal parameters of the camera (calibration). Classical calibration using a checkerboard pattern is difficult to perform in outer space. In connection with all of the above, this paper proposes methods for estimating the focal length of the camera, based on the analysis of the available video sequence with the footage of the process of rendezvous of spacecraft. The proposed approaches are based on the maximum likelihood method (MLE) and maximum a posteriori estimation (MAP) of the functional depending on the Euler angles and focal length. The results of these methods are compared, showing the advantages of MAP over MLE and the possibility of their practical application.
Analysis of the gaze fixations in performance of mental recall of the route on a city map. Effects of landmark type and gender
Authors: Kushnir A. B. , Mikhailova E. S. , Gerasimenko N. Yu. , Kazarezova I. A.
Published: April 2024

A psychophysiological eye-tracking experiment was conducted to investigate map navigation (including tasks of familiarization with the map, route memorization and recall of the route) as a function of landmark type (no landmarks, object landmarks, verbal landmarks, both types of landmarks) and gender. It was found that the number of fixations decreased and the fixation duration increased during recall compared to map familiarization and route memorization. The effect of task type on eye movements varied between route proximity areas. In the proximal areas, the number of fixations decreased during recall in comparison to memorization, while in the distal (“off route”) area the effect was opposite. These changes were pronounced in the male participants and did not reach statistical significance in the females. Men switched more frequently from the proximal to the distal area during memorization, thus forming a connection between the route and the remote environment. In contrast, women’s gaze was more often directed to the distal area during route recall. The map with object landmarks differed from the other maps in the lower number and longer fixation duration, indicating the advantage of object landmarks and, possibly, a preference for the object visual cognitive style among our participants.
Electroretinographic examinations of the crew members of the 8-month international experiment SIRIUS 20/21
Authors: Neroev V. V. , Tsapenko I. V. , Kotelin V. I. , Zueva M. V. , Manko O. M. , Aleskerov A. M. , Podyanov D. A.
Published: April 2024

Before and after the 8-month international experiment SIRIUS 20/21, a complex of electrophysiological testing of the visual system was performed, including registration of standard photopic electroretinograms (ERG), flicker ERG response on flickering with a frequency of 8.3, 10, 12 and 24 Hz, photopic negative response, and pattern-ERG. The aim of the work was an objective assessment of changes in the functional activity of retinal neurons in ground station crew members associated with long-term isolation and the influence of a complex of stress factors. The results obtained indicate a moderate activation of the bioelectrical activity of photoreceptors and bipolar cells and a slight decrease in the function of retinal ganglion cells after isolation experiment. The revealed changes may reflect the adaptation of the visual sensory system of the testers to physical and psycho-emotional stress in the experimental conditions. Further study of the specifics of changes in electroretinographic markers with a longer duration of the experiment is necessary to expand the understanding of stress resistance and adaptation of the visual system during prolonged exposure to extreme environmental conditions.
Classification of crops by NDVI time series of reduced dimensionality
Authors: Pavlova M. A. , Sidorchuk D. S. , Bocharov D. A.
Published: April 2024

The paper considers the problem of classification of agricultural crops. As is known, to solve this problem, it is much more efficient to use not instantaneous remote sensing data or calculated vegetation indices, but their historical series. Time series formed by index values for a fixed spatial point at different dates are characterized by a high level of missing values, caused primarily by cloudiness on some dates. A study of known methods of time series approximation has been carried out. The question of whether reducing the dimensionality of the approximated time series can improve the quality of crops classification is also investigated. In the experimental part of the work, NDVI time series calculated from the Sentinel-2 multispectral satellite data were used. The classification of corn, sunflower, wheat and soybeans was studied. The paper shows that UMAP usage for dimensionality reduction leads to 1.5 times increase of classification quality in terms of average the F1-measure compared to using the original dimension data. A new crop classification method based on cubic spline approximation of NDVI time series, extraction of features of low dimension by the UMAP algorithm and their classification by the k nearest neighbors method is proposed.
The response of adult adzuki been borer Ostrinia scapulalis to light stimuli in a wind tunnel
Authors: Zhukovskaya M. I. , Selitskaya O. G. , Schenikova A. V. , Miltsyn A. A. , Grushevaya I. V. , Kononchuk A. G. , Frolov A. N.
Published: April 2024

The attraction of nocturnal insects to light is a known phenomenon with unknown physiological mechanisms. Moths of the pyralid family are characterized by the most pronounced response to light, but the spectral preferences of these insects have not been studied. The adzuki been borers Ostrinia scapulalis, which live on dicotyledonous plants, are the ancestral form for the Asian and European corn borers, widespread pests of corn. Using a wind tunnel modified to deliver light stimuli, we tested the responses of males and females to light stimuli with wavelengths of 532, 440 and 365 nm at 2 lux, capable of stimulating photoreceptors of compound eyes (with maximum sensitivity of 352, 413, 480 and 530 nm) as well as simple ocelli, whose sensitivity had the main peak in ultraviolet and additional one in the green spectrum (360 and 520 nm). It turned out that ultraviolet was the most attractive stimulus. A small percentage of insects responded to green light, but showed a freezing reaction near the light source. The least attractive was blue light, which also caused freezes. Thus, the flight of O. scapulalis adults is induced by short-wavelength light, the response is more consistent with the sensitivity of the ocelli than the compound eyes; blue and green light leads to a masking effect.
Problems and prospects of new methods of light stimulation in visual rehabilitation
Authors: Zueva M. V. , Kotelin V. I. , Neroeva N. V. , Fadeev D. V. , Manko O. M.
Published: April 2024

Neurodegenerative retinal diseases such as age-related macular degeneration, glaucoma, and diabetic retinopathy remain the leading causes of low vision and blindness worldwide. Visual rehabilitation of patients who are visually impaired due to neurodegenerative diseases of the retina requires solving problems associated with a violation of the structure of neural networks and a deficiency of visual functions provided by these networks. Despite certain successes in the application of innovative methods of therapy, it is important to develop new approaches to visual rehabilitation to improve the quality of life of visually impaired patients. In visual rehabilitation, not only medical, but also various non-pharmacological therapy strategies are widely used to protect and restore the structure of the retina and its function. Among them, a separate niche is occupied by the technologies of vision stimulation therapy (phototherapy), the analysis of the main aspects of which is the task of this review. The vector of new research in the field of phototherapy is aimed at developing methods that can maximize the plasticity of the visual system to increase the effectiveness of its protection and recovery in neurodegenerative pathology. In this regard, new technologies of fractal phototherapy have great potential in visual rehabilitation.
Retinal electronic prostheses
Authors: Firsov M. L.
Published: April 2024

Electronic retinal implants are a promising technology for partially restoring vision after severe neurodegenerative diseases. The basic idea is to replace damaged photoreceptors with electronic devices that convert light signals into electrical impulses stimulating bipolar or ganglion cells in the retina. In this review, we will look at the history of this technology, the current state of the art, and the different designs and operating principles of retinal implants.
Inertial mass in the balance body of Pomacea Diffusa. Experiment on the biosatellite “Bion-11”
Authors: Gorgiladze G. I.
Published: April 2024

The inertial mass in the balance organ-statocyst of Pomacea diffusa was studied from the moment of hatching from eggs until the end of the life cycle, as well as the effects of weightlessness on the inertial mass during a 14-day orbital flight on the biosatellite “Bion-11”. As the snails grew older, the diameter of the statocyst increased from 150 μm to 650 μm, and the inertial mass contained in it increased from 11–13 statoconia to 700 statoconia. The internal structure of the statoconia had a layered structure with a nucleus in its central region. The main mineral element that gives statoconia heaviness is calcium carbonate, presented in the form of aragonite crystals. A 14-day exposure in weightlessness led to noticeable changes in the morphometric pattern of the inertial mass in the statocyst of flight snails in comparison with the control snails of synchronous tracking. In most of the statoconia, the form factor, length, and width indicators increased, which could indicate the stimulating effect of weightlessness on the inertial mass in the balance organ of Pomacea diffusa.
Discrimination of rippled spectra in listeners with hearing loss at two experimental paradigms
Authors: Nechaev D. I. , Milekhina O. N. , Tomozova M. S. , Supin A. Ya.
Published: April 2024

Frequency resolving power (FRP) of hearing was measured in listeners 30 to 82 years old as a maximal resolved ripple density (ripples/oct) of rippled-spectrum signals. The rippled-spectrum signal should be distinguished either from another rippled signal with different positions of ripples on the frequency scale or from a “flat”-spectrum signal with no spectral ripples. Signals had either 2-oct wide frequency band centered at 1, 2, or 4 kHz, or had a wide frequency band 0.125–8 kHz. Listeners older than 60 had substantially increased tonal thresholds (haring loss). If the listener should distinguish a rippled test signal from a rippled reference signal, FRP correlated with the tonal threshold: the higher threshold, the lower FRP. For all the signals, the trend of the dependence was from –0.04 to –0.07 ripples/oct·dB. It is suggested that in this case, the test and reference signals were discriminated by the spectral mechanism and depended on the interrelation between the ripple density and acuteness of the frequency-tuned filters. If the listener should distinguish the ripple test signal from a flat reference signal, the FRP dependence on tonal threshold was not statistically significant for 2-oct-wide signals on condition that the signal level was above threshold. Or the wide-band signal, the FRP dependence on tonal threshold was statistically significant with a trend of –1.23 ripples/oct·dB. It is suggested that in this case, the test and reference signal were discriminated by the temporal-processing mechanism and depended on the perceived frequency range.