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Based on ground-based observations of cosmic rays (CRs) on the global network of neutron monitors, the Yakutsk complex of muon telescopes, and the URAGAN muon hodoscope (Moscow), the spectra of CR variations and anisotropy during the Forbush effects of March 15 and 23, 2023 were calculated using the spectrographic global survey method. It is shown that the spectrum of CR variations during these periods is not described by a power function in a wide range of rigidities. It was found that the Earth was in a loop-shaped structure of the interplanetary magnetic field on March 15 and that it entered a magnetic cloud with closed field lines on March 23. [ABSTRACT FROM AUTHOR]

Inhibition of β-lactamases involved in the development of bacterial resistance to β-lactam antibiotics is promising for restoring their effectiveness as antibacterial drugs. In this work, we screened the inhibitory activity against some serine β-lactamases of class A among humic substances of various origins, which represent complex organic matrices, as well as their narrow fractions obtained by separating preparations by acidity and polarity. The structural and group composition of broad fractions was characterized by 13C NMR spectroscopy; the molecular composition of narrow fractions was characterized by Fourier transform-ion cyclotron resonance mass spectrometry. The widest specificity of inhibition against various ESBL (TEM-12, TEM-17, TEM-18) and the inhibitor-resistant β-lactamase TEM-34 was possessed by the fraction of humic acids of brown coal CHA-I, isolated at pH 9: the values of residual activity of TEM -12, TEM-17, TEM-18, and TEM-34 were (%) 52 ± 5, 52 ± 5, 40 ± 4, and 58 ± 6, respectively. The data obtained for the most active narrow fraction turned out to be comparable to the effectiveness of sulfohydantoins, a promising new class of inhibitors. This indicates the feasibility of further work on the fine fractionation of natural humic substances using 2D chromatography, which will open a new, extensive source of β-lactamase inhibitors of non-β-lactam nature. [ABSTRACT FROM AUTHOR]

Industrial effluents are often used to grow crops, including vegetables. Wastewaters contain not only organic matter and other nutrients but also heavy metals, which contribute to soil pollution and their further accumulation in vegetables. For this reason, a laboratory experiment was performed to assess zinc accumulation and translocation in the following chain: industrial effluents–soil–parts of radish (Raphanus sativus L.). The industrial effluents contained zinc in a concentration similar to its maximum permissible level in irrigation water (Effluent 1) and about 40 times higher than the established level (Effluent 2). Zinc concentrations in effluents, soil, and radish were determined by inductively coupled plasma optical emission spectrometry. The contamination factor, bioconcentration factor, translocation factor, and estimated daily intake of zinc were calculated. The antioxidant activity and the phenol content in radish biomass were also determined. The levels of zinc in different parts of radish ranged between 37.76 and 588 mg/kg dry weight and followed the order: non-edible roots of radish ≥ leaves ≥ edible roots. Zinc content in the edible and non-edible parts of radish irrigated with Effluent 2 was up to 5 times higher than the maximum permissible value of 117 mg/kg dry weight established by the Ministry of Health of the Russian Federation. The values of bioconcentration factors varied from 0.33 to 2.44 for radish roots, and the maximum bioaccumulation capacity was revealed for the control plants. According to this work, the values of the estimated daily intake of zinc were lower than the safe daily dietary intake established for zinc by World Health Organization. [ABSTRACT FROM AUTHOR]

Hypoxic preconditioning is known to protect against various functional disorders, including skeletal muscle dysfunction. Na,K-ATPase, which plays an important role in adaptation to hypoxia, is critical for maintaining the performance of skeletal muscles, which co-express the α1 and α2 isozymes of the enzyme. Persistent dysfunction of α2 Na,K-ATPase isozyme is characteristic of the motor inactivity of skeletal muscles. In this study, we tested our hypothesis that mild hypoxia is able to improve Na,K-ATPase in disused soleus muscle. Rats were subjected to simulated high-altitude (3000 m above sea level) hypobaric hypoxia (HH) for 3 h using a hypobaric chamber. Then, 18 h after control or HH conditions, rats were subjected to 6 h of hindlimb suspension (HS), a model of skeletal muscle disuse. Isolated soleus muscles were tested. HH itself stably increased the α2 Na,K-ATPase isozyme membrane abundance and its electrogenic activity. These effects were accompanied by a decrease in serum level of circulating endogenous ouabain, a specific ligand for Na,K-ATPase. HS itself caused loss of electrogenic activity of α2 Na,K-ATPase, but pretreatment with HH protected against this impairment. This protective effect was accompanied by an increase in the α2 Na,K-ATPase membrane abundance without a change in total protein content, suggesting an increase in the α2 Na,K-ATPase traffic from the intracellular pool to the sarcolemma; serum ouabain level was significantly increased. We suggest that these findings open a new field for further studies and may have therapeutic implications for disuse-induced skeletal muscle pathology. [ABSTRACT FROM AUTHOR]

One of the most important problems for research is the problem of time series clustering. Clustering is important in the tasks of identifying common dynamic changes between series and searching for patterns in the behavior of dynamics and, finally, for forecasting. The article discusses the problem of assessing the statistical significance of clustering. Currently, there are a number of approaches to assessing significance. These include asymptotic criteria, as well as criteria based on comparison of clustering results on analyzed groups with clustering results on simulated data, which are generated on the basis of the null hypothesis of group homogeneity. However, these approaches cannot be used to solve many time series clustering problems because of the difficulty of proving that convergence conditions are met and because of the difficulty of choosing an adequate null hypothesis and specification of the distribution from which the data are generated. The paper proposes an alternative approach designed to assess the significance of hierarchical agglomerative clustering using the maximum of a set of correlation coefficients calculated for different time lag values as a measure of similarity between time series. The approach is based on comparing the clustering results obtained from the original lagged correlation matrix with the clustering results obtained from the original one by random permutations of off-diagonal elements while maintaining symmetry. The paper presents the results of applying the developed method to the problem of temporal clustering, containing the values of the daily increase in the number of COVID-19 illnesses. [ABSTRACT FROM AUTHOR]

Laser Doppler anemometry (LDA) is one of the main non-contact methods for measuring the velocity characteristics of flows and pressure pulsations. Determining the quantitative patterns of the flow of multiphase liquids in small-sized channels is known to be a difficult task. The authors demonstrate the eventual use of LDA to study cavitation flows in slits with a height of 1.2 mm. The cavitation flow is created by means of the NACA0012 hydrofoil. The experimental equipment is positioned using a micro-displacement device. The distortion of the luminous flux through the channel walls is taken into account. This paper presents an algorithm for searching the central region of the slit. A method for filtering noise effects is described. The results of measuring the average flow velocity near the cavitating hydrofoil in the slit are provided in the article. [ABSTRACT FROM AUTHOR]

Comprehensive research has been implemented to raise the efficiency of the geochemical survey of stream sediments (SSs) that formed under the cryolithogenesis conditions. The authors analysed the composition, structure and specific features of the formation of exogenous anomalous geochemical fields (AGFs) identified through SSs of large river valleys of IV order. In our case, these were the valleys of Maly Ken, Ken and Tap Rivers. These rivers are located in the central and southern parts of the Balygychan–Sugoy trough enclosed in the Magadan region, North–East of Russia. The authors proposed a new technique to sample loose alluvium of SSs in the large river valleys along the profiles. The profiles were located across the valleys. The AGFs of Au, Ag, Pb, Zn, Sn, Bi, Mo and W were studied. Correlations between elements have been established. These elements are the main indicator elements of Au–Ag, Ag–Pb, Sn–Ag, Mo–W and Sn–W mineralization occurring on the sites under study. The results obtained were compared with the results of geochemical surveys of SSs. It is concluded that the AGFs recognized along the profiles reflect the composition and structure of eroded and drained ore zones, uncover completely and precisely the pattern of element distribution in loose sediments of large water flows. The alluvium fraction < 0.25 mm seems to be most significant in a practical sense, as it concentrated numerous ore elements. Sampling of this fraction in the river valleys of IV order does not cause any difficulty, for this kind of material is plentiful. The developed technique of alluvium sampling within large river valleys is efficient in searching for diverse mineralization at all stages of prognostic prospecting. It is applicable for geochemical survey of SSs performed at different scales both in the North–East of Russia, as well as other regions with similar climatic conditions, where the SSs are formed under the cryolithogenesis conditions. [ABSTRACT FROM AUTHOR]

The degree of salinity, the freezing point, and the amount of unfrozen water are key factors in predicting the temperature, humidity, and mechanical behavior of saline permafrost soils used in construction as foundations for buildings. The results of the experimental studies are presented and a method for calculation of the amount of unfrozen water in saline soils is proposed. The calculated and experimental data show good convergence for both sandy and clay soils of different salinity and water content. [ABSTRACT FROM AUTHOR]

New high-precision photometric measurements of the V957 Cep system ( , , , B6 V+B8 V), as well as an integrated approach to determining orbital parameters based both on photometric solutions of the light curves and the study of the course of residual deviations of the minima timings from the linear formula made it possible for the first time to accurately measure the apsidal motion rate: /year, which coincided with the theoretical value under the condition of the orbital and axial rotation synchronism: /year. The physical parameters of the component stars were obtained: K, , , K, M2 = 3.0 ± , . This set of parameters corresponds to stars of zero age, recently descended to ZAMS. The secondary component is a pulsating variable star of the Cephei type. [ABSTRACT FROM AUTHOR]

Under conditions of intense anthropogenic impact, the territory of modern Donbass is geochemically contrasting environment. Concentrations of rare earth elements (Sc, La, Ce, Nd, Sm, Eu, Tb, Dy, Yb) in the natural ecosystems of the Northern Azov region (Central Donbass) were determined by indicator plants using neutron activation analysis. An open landscape experiment was carried out using moss Ceratodon purpureus (Hedw.) Brid. which has a high information response in the assessment of technogenic impacts. It allowed to establish the levels of regional contamination with rare earth elements, to identify correlation groups of related processes in the structural and functional features of indicator. The identified localities of geochemical heterogeneities in ecotopes are responsible for the adaptation of plants under stressful conditions. The most informative structural units of plants indicating the contamination with rare earth elements are abnormalities in the structure (terates, teratomorphs), violation of the morphogenesis processes of the embryonic apparatus of plants and areas of vegetative organs. Correlation analysis and principle component analysis were applied to reveal the relationship between the elements and abnormalities in the structure of plants. Relative accumulation factor, contamination factor and enrichment factor were calculated to evaluate the level of environment pollution and to identify the origin of elements. [ABSTRACT FROM AUTHOR]

Ground-based observations of cosmic rays by the spectrographic global survey method were used to study the ground-level enhancement in cosmic ray intensity on August 24, 2002. Spectra of variations of primary cosmic rays and their anisotropy were obtained. Based on measurements from the GOES spacecraft and global network of cosmic ray stations, the differential rigidity spectra of accelerated particles in the vicinity of the Sun were calculated. The maximum rigidity to which solar particles were accelerated was estimated. [ABSTRACT FROM AUTHOR]

In this paper, we study a division between market corruption—impersonal bribery—and network corruption that operates through social connections. We provide a thorough theoretical discussion of this division, compare it with other categorizations of corruption, and also demonstrate differences between market and network corruption existing in practice. Using data from the World Economic Forum in the period from 2007 to 2016 we measure market and network corruption across about 150 countries all over the globe and show that network corruption is more related to countries' cultural backgrounds and more harmful to investments than market corruption. Overall, our paper argues that the market-network dimension, unfairly abandoned in the literature, may be useful for better understanding of such a complex phenomenon as corruption. [ABSTRACT FROM AUTHOR]

The results of calculating the atmospheric transmission spectrum and modeling lidar signals in the informative range of greenhouse gas sounding (CO2 and H2O) on horizontal tropospheric paths using the two-channel infrared lidar system under development are presented. It is shown that the lidar system operation spectral range of 4878–4894 cm–1 (2043–2050 nm) is preferable for simultaneous probing of CO2 and H2O. In this range, the level of lidar signals lies in the range of 10–6–10–10 W and exceeds the equivalent power photodetector noise. Based on the results of the calculations, the technical appearance of the developed two-channel infrared lidar system is determined. [ABSTRACT FROM AUTHOR]

The existing and recently acquired data on the isotope ages and compositions of volcanogenic Au–Ag deposits and occurrences of the Evensk group (Okhotsk–Chukotka volcanogenic belt, Northeast Russia) are summarized. The K–Ar isotope and Rb–Sr isochron ages of Au–Ag ores from the studied deposits and occurrences are 82.7 ± 3–77.5 ± 3 Ma and 84.1 ± 2–79.7 ± 5 Ma, respectively. Au–Ag mineralization was formed within ~5 Ma. Au–Ag mineralization typical of productive ore stages and practically unaffected by later thermal processes is characterized by low initial 87Sr/86Sr(0) = 0.7055–0.7059 ratios, which are close to the initial 87Sr/86Sr(0) ratios in wall-rock metasomatites (0.7033–0.7082) and unaltered host rocks (0.7045–0.7048), thus indicating a pronounced predominance of mantle Sr in the ores. The composition points of ore Pb on the 207Pb/204Pb–206Pb/204Pb evolution diagram are grouped in close proximity to the Pb isotope composition points in the depleted mantle with a trend towards the subduction-related volcanic rocks typical of the continental margin. A close genetic relationship between the ore and magmatic processes has been confirmed. It is assumed that this relationship is due to the functioning of a single mantle basaltic chamber, which served as a source of metal-bearing fluids and is probably the primary source of Au and Ag. [ABSTRACT FROM AUTHOR]

The elastic (Young's modulus) and relaxation (amplitude-independent internal friction) properties of metallic V and its low-activated alloys (V–4Cr–4Ti, V–W–Cr, V–Ta–Cr–Zr) have been studied by dynamic mechanical spectroscopy in the low-frequency range (0.5–30.0 Hz) and in the temperature range of 25–400°C in their annealed states. The solid-solution concentrations and diffusion characteristics (diffusion activation energies) of the C, O, N interstitial atoms have been determined. The changes in the obtained characteristics in comparison with their values for the cold-deformed states of the investigated materials have been determined. [ABSTRACT FROM AUTHOR]

The results of investigations of the effect of thermomechanical treatment (TMT) regimes on the regularities of phase transformations, microstructure, and mechanical properties of low-activation alloys of the V–4Ti–4Cr–(C, O, N) system are summarized. The mechanisms of these transformations and the relationship between the microstructure and the level of strength and plasticity are established. The TMT regimes are presented that provide a uniform bulk distribution of nanosized particles of stable oxycarbonitride, a significant increase in their density (dispersion), and an increase in the thermal stability of the microstructure. It is shown that these regimes lead to a significant (by 30–60%) increase in the short-term strength of alloys in a wide (from 293 to 1073 K) temperature range with preservation of a sufficiently high plasticity. [ABSTRACT FROM AUTHOR]

Mathematical models of complex systems rely on parameter values to produce a desired behavior. As mathematical and computational models increase in complexity, it becomes correspondingly difficult to find parameter values that satisfy system constraints. We propose a Markov Chain Monte Carlo (MCMC) approach for the problem of constrained model parameter generation by designing a Markov chain that efficiently explores a model's parameter space. We demonstrate the use of our proposed methodology to analyze responses of a newly constructed bistability-constrained model of protein phosphorylation to perturbations in the underlying protein network. Our results suggest that parameter generation for constrained models using MCMC provides powerful tools for modeling-aided analysis of complex natural processes. [ABSTRACT FROM AUTHOR]

From ground-based observations of cosmic rays (CR) at the global network of neutron monitors, Yakutsk suite of muon telescopes, and the URAGAN muon hodoscope (Moscow), through the modified method of the spectrographic global survey we investigated variations in CR of magnetospheric and atmospheric origin for September, 2017. We demonstrated the possibility to use the data on the unstable charged component of secondary CRs for the study of CR variations without the need to introduce corrections for temperature effect. Obtained were temporal variations in the planetary system of the CR rigidities of geomagnetic cutoff (RGC) and in the mass average air temperature at the points of observation of the charged components. Based on the data on the RGC planetary system variations within the axisymmetric model for the Earth bounded magnetosphere, we calculated the parameters for some magnetospheric current systems during the 2017 September geomagnetic disturbances. [ABSTRACT FROM AUTHOR]

The xBiFeO3–(1–x)PbZr0.9Ti0.1O3 composites synthesized by the solid-phase reaction were characterized using complex methods to determine their structure and physical properties. According to the results of X-ray diffraction analysis, it was found that the synthesized composites have a rhombohedral perovskite structure with the space symmetry group R3с, and there are no impurities or second phases present in either the ferrite or ferroelectric phases. According to the results of impedance spectroscopy, it was found that the nature of the relaxation in the composites is non-Debye, suggesting a complex conduction mechanism involving multiple relaxation processes. With an increasing proportion of ferroelectric PbZr0.9Ti0.1O3 (PZT) phase, the composites exhibit dual-arc behavior in the Cole-Cole diagrams obtained from the impedance spectroscopy measurements. The dual-arc behavior shows the contribution of both the bulk (grain) and grain boundary to the conduction mechanism in the temperature range of 160–230 °C. The dynamics of the crystal lattice in the composites were studied using optical and FTIR spectroscopy. The magnetization curves M(H) of the composites are characterized by weak ferromagnetism, which is due to the substitution of (Ti/Zr)4+ by Fe3+ in the crystal lattice. This substitution leads to structural distortions and the appearance of ferromagnetic ordering in the composite materials. [ABSTRACT FROM AUTHOR]

A mobile lidar was designed for ozone sensing at wavelengths of 299 and 341 nm and put into operation. The lidar covers the altitude range from 0.1 to 12 km with a spatial resolution of lidar signals from 1.5 to 150 m. The specification of the mobile lidar is given; the results of an in situ experiment on laser sensing of the atmosphere in Tomsk are presented. The lidar echoes and ozone profiles retrieved confirm the information content of lidar measurements in the troposphere. The lidar and satellite (MetOp) measurements are compared. [ABSTRACT FROM AUTHOR]

Because Ancathia igniaria (Spreng.) DC. (Cirsium igniarium Spreng.) has been segregated as a monotypic genus from the genus Cirsium on the basis of phylogenetic data, chemotaxonomic differences are of interest to detect in the composition of polyphenolic components of aerial plant parts. Phenolic compounds are of chemotaxonomic significance in a number of genera and families. The polyphenolic profile of aerial parts was therefore compared for Cirsium esculentum (Siev.) C.A. Mey., Cirsium serratuloides (L.) Hill, and A. igniaria. The last two species were for the first time examined in this context. The compounds were identified against known standard via high–performance liquid chromatography (HPLC). The species of the genus Cirsium were found to have similar compositions of simple phenols, but differ in the set of flavonoids. Six to eight phenolic compounds were detected in the species, and three simple polyphenols (syringin, chlorogenic acid, and ethyl gallate) proved to be common. The flavonoid profiles of aerial parts included rutin in both Cirsium species. Cymaroside and quercetin-3-O-β-D-diglucoside-O-α-L-rhamnoside were species specific for C. serratuloides; salipurposide and hyperoside, for C. esculentum. An extract of A.igniaria aerial parts contained cinaroside (like in C. serratuloides), chrysin 7-O-glucoside, and eriodictyol. A greater difference in flavonoid composition was observed between the genera Cirsium and Ancathia. Data on phenolic compound composition are of importance for chemosystematics and use of plants as medicinal raw materials. The total content of coumarins, aglycones, and flavonoid glycosides in the species was determined by a spectrophotometric method. The contents of flavonoids and coumarins in C. esculentum and C. serratuloides were comparable and exceeded their contents in A. igniaria. Thus, A. igniaria proved to differ from the genus Cirsium in the quantitative and qualitative composition of phenolic compounds. [ABSTRACT FROM AUTHOR]

Abstract—The territory of modern central Donbass was considered as an experimental site for the implementation of an ingredient biomonitoring program. Bryophytes were transplanted and exposed in the geolocalities directly influenced by coal mining and processing complexes, metallurgical and chemical industry, ruderal and residential ecotopes. For bryobionts with a wide amplitude of resistance to technogenic pollution (Amblystegium subtile (Hedw.) Schimp., Brachythecium campestre (Muell.Hal.) Bruch et al., Bryum argenteum Hedw., Bryum caespiticium Hedw., Bryum capillare Hedw., Ceratodon purpureus (Hedw.) Brid and Pylaisia polyantha (Hedw.) Schimp.), the following criteria of anthropotolerance were selected: (1) the ability to accumulate elements, (2) the ability to accumulate specific pollutants, (3) structural and functional reactions and manifestation of atypical morphogenesis (teratogenesis) of plant organisms and (4) shifts in the characteristics of the survival strategy of species under conditions of deep transformation of the Donbass landscape systems. Peculiarities in the accumulation of Na, Mg, Al, Si, P, S, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Zr, Mo, Cd, Sb, I, Cs, Ba, La, Ce, Nd, Sm, Eu, Tb, Dy, Yb, Hf, Ta, W, Hg, Pb, Th, U in indicator plants used as seasonal phytotest monitors to assess the pollution of natural environment has been defined. At a radical violation of geochemical cycles in plant life support systems, cases of specific chlorosis and necrosis of point localization, hypo- and hypergenesis and deformation, as well as fasciation, prolification, dystopia, oligomerization of vegetative organs, peculiarities in the development of individual groups of cells in the integumentary, and conformational tissues of the leaf apparatus of bryobionts have been recorded. The revealed abnormalities were used as a phytoindication characteristics when conducting an express analysis of the level of technogenic stress in field diagnostics. The coefficients of biological absorption and technogenic concentration of elements in biosubstrates were calculated when assessing the geochemical contrast of the environment. The difference in the accumulative capacity of bryobionts for individual elements or their associative groups in different ecotopes was defined. The related morphogenetic heterogeneity of the structure and elemental composition of plants is an individual case of compliance with V.I. Vernadsky's ideas of the concentration, information and environment-forming functions of living matter. [ABSTRACT FROM AUTHOR]

An algorithm was developed for processing lidar sensing data at wavelengths of 299/341 nm for a vertical atmospheric sensing trace with spatial resolution of 1.5–150 m. The program includes the following main functions: recording the data for lidar sensing of the atmosphere; converting the format of the binary data file dat to text txt; retrieval of ozone concentration profiles. By the software developed on the basis of the created algorithm for processing the lidar sensing data it is possible to obtain ozone concentration profiles from 4 to 20 km. The data recording units for lidar sensing of the atmosphere and retrieval of ozone concentration profiles provide visual monitoring of recorded echo signals and retrieved ozone concentration profiles. An example of retrieving the ozone concentration profile from the lidar data is provided. [ABSTRACT FROM AUTHOR]

A time series is an extremely abundant data type arising in many areas of scientific research, including the biological sciences. Any method that compares time series data relies on a pairwise distance between trajectories, and the choice of distance measure determines the accuracy and speed of the time series comparison. This paper introduces an optimal transport type distance for comparing time series trajectories that are allowed to lie in spaces of different dimensions and/or with differing numbers of points possibly unequally spaced along each trajectory. The construction is based on a modified Gromov–Wasserstein distance optimization program, reducing the problem to a Wasserstein distance on the real line. The resulting program has a closed-form solution and can be computed quickly due to the scalability of the one-dimensional Wasserstein distance. We discuss theoretical properties of this distance measure, and empirically demonstrate the performance of the proposed distance on several datasets with a range of characteristics commonly found in biologically relevant data. We also use our proposed distance to demonstrate that averaging oscillatory time series trajectories using the recently proposed Fused Gromov–Wasserstein barycenter retains more characteristics in the averaged trajectory when compared to traditional averaging, which demonstrates the applicability of Fused Gromov–Wasserstein barycenters for biological time series. Fast and user friendly software for computing the proposed distance and related applications is provided. The proposed distance allows fast and meaningful comparison of biological time series and can be efficiently used in a wide range of applications. [ABSTRACT FROM AUTHOR]

The results of studying thin films and superlattices of rare-earth helimagnets Dy and Ho using a neutron reflectometer are presented. Neutron reflectometry is shown to allow the magnetic phase transitions in these nanostructures to be studied and information about the periodicity of magnetic helices in them to be collected. It is proposed to create a neutron reflectometer capable of conducting polarization analysis on the DARIA compact neutron source, optimized for studying long-period magnetic ordering in rare-earth helimagnets, and the possible directions of this optimization are indicated. [ABSTRACT FROM AUTHOR]

To generalize experimental data on the thermophysical characteristics of soils at positive and negative temperatures and reduce the scope of the experimental work, there is a need to systematize and expand the calculation of the thermal conductivity of soils. This paper proposes a method for calculating the thermal conductivity of fine soils in frozen and thawed states. The calculation models include a shell model combined with a model with interpenetrating components. The calculated thermal conductivity values were compared with experimental data. [ABSTRACT FROM AUTHOR]

The motion of ferromagnetic liquid entering the distilled water stream in the channels of the tesla micromixer M-4 configuration with a characteristic size of 400 m was investigated in this paper. The interface between two liquids in a magnetic field and without it was considered. The source of the magnetic field was located on different sides relative to the feeding ferromagnetic liquid. It has been shown that when an object is located in a magnetic field, the solubility of the ferrofluid in the base liquid increases. A significant part of the ferroparticles of colloidal liquid in small channels is attracted to the source of the magnetic field (up to 80%), which allows reasonably assuming that the use of ferroparticles for the transportation of medicines is promising. [ABSTRACT FROM AUTHOR]

We report here studies using an experimental model of autism created by prenatal administration of valproic acid to produce a comparative analysis of behavioral disorders in female and male rats, along with indicators of relative levels of expression of the Drd1 dopamine receptor gene in brain structures playing a significant role in disorders of social behavior and the development of anxiety – the prefrontal cortex, amygdala, cerebellum, and hippocampus. The state of anxiety in the valproate model of autism was found to develop only in males, while disorders of social behavior were typical of rats of both sexes, though the nature of these disorders differed in females and males: in the three-chamber social test, males preferred to spend more time in the compartment with a familiar animal, while females preferred to spend significantly less time with a novel, unfamiliar rat, as compared with control animals. Sex-related differences were found in the relative levels of expression of the Drd1 gene in the prefrontal cortex, amygdala, and cerebellum: the relative level of Drd1 expression was greater in the prefrontal cortex and amygdala in females, while males, conversely, showed significantly lower expression in the cerebellum in relation to both males of the control group and females. Analysis of the results obtained here indicates that there is a need to consider changes in the relative levels of Drd1 expression in all study areas simultaneously, evaluating the overall changes in the expression profiles of this gene, which may underlie sex-related differences in both communication disorders and other possible behavioral changes in the valproate model of autism in rats. [ABSTRACT FROM AUTHOR]

This paper discusses a method for determining the anti-wear properties of motor oils after temperature control in the temperature range from 160 to 280°C. Optical density, viscosity, and wear scar diameter are considered. The effect of degradation products on the anti-wear properties of the oils under study was evaluated. The degree of influence of degradation products on anti-wear properties is shown, which is determined by the dependence of the change of diameter of the wear spot of thermostated oils on the absorption coefficient of the light flux. It is noted that the decomposition products have an ambiguous effect on the anti-wear properties of motor oils, which vary from 0.32 to 0.26 mm, and significant changes occur at a coefficient of KP = 0.05 of all studied oils, while the minimum diameter of the wear spot is characterized by mineral oil, partially synthetic and synthetic oils have values greater than 1.2 times and the reason for this is their heterogeneous composition, which depends on the quality of the additives used and their tendency to decomposition. As an assessment of anti-wear properties, a criterion is proposed that characterizes the concentration of degradation products and is recommended for classifying motor oils into groups of performance properties. The data obtained on the anti-wear properties of motor oils make it possible to compare oils of the same purpose and create a databank that will allow equipment designers to reasonably select oils depending on the temperature conditions of the tribocouples. [ABSTRACT FROM AUTHOR]

The long-term dynamics of the Northern Dvina delta was studied with the comparison of space images of 1977 and 2020. A map of delta dynamics, compiled by them, shows that the islands at the delta coastline keep increasing and join to the delta, channel islands in the main branches are increasing, and small watercourses in delta islands become narrower and disappear. However, this long-term tendency of the continuing increase in delta area is now accompanied by the processes of shore erosion in islands at delta coastline from the side of the Dvina Bay. [ABSTRACT FROM AUTHOR]

In the last decade, the mass mortality of endemic sponges has been observed in the coastal zone of Lake Baikal. This paper presents the results of observations of the Baikal sponge fauna within the transects established throughout Baikal in 2015. The types of damage of Baikal sponges have been characterized based on visual descriptions. Between 2015 and 2020, a downward trend has been revealed for the average projective cover of healthy sponges of various body forms on the Baikal bottom. For encrusting, branched, and globular forms, the decrease in this index is 3.6, 2, and 4 times, respectively. The total area occupied by healthy and damaged sponges of various forms have reduced more than twice (from 238 to 110 m2). [ABSTRACT FROM AUTHOR]

This work is the first to study the influence of crystallite sizes and structural defects on the crystal structure and physical properties of bismuth ferrite BiFeO3 (BFO). Rotatable Bridgman anvils were used to generate the structural defects, with the uniaxial pressures ranging from 0.5 to 1 GPa. According to the X-ray diffraction analysis (XRD), the symmetry space group R3c remains unchanged over the entire pressure range. From the results of the complex impedance spectroscopy, it was found that the relaxation has a non-Debye character and the activation energy increased from 1.48 eV to 2.48 eV for the starting and mechanically activated samples at 1 GPa, respectively. The crystal lattice dynamics were studied by optical and FTIR spectroscopies, and it has been found that Eg varied in the range of 2.18–2.33 eV, whereas the force constant showed variation in the range of 2.2–2.4 N/cm, depending on the applied mechanical activation pressure. The magnetization curves M(H) have been described by the law of approach magnetization to saturation (LAS). Also, a possible critical crystallite size of 70 nm has been determined, at which Hc and Mr reach their maximum values. [ABSTRACT FROM AUTHOR]

Mutations in the MYH9 gene result in macrothrombocytopenia often associated with hemorrhages. Here, we studied the function and structure of platelets in three family members with a heterozygous mutation R1933X in the MYH9 gene, characteristic of closely related disorders known as the May-Hegglin anomaly and Sebastian syndrome. The examination included complete blood count, blood smear microscopy, platelet flow cytometry (expression of P-selectin and active integrin αIIbβ3 before and after activation), the kinetics of platelet-driven contraction (retraction) of blood clots, as well as scanning/transmission electron microscopy of platelets. Despite severe thrombocytopenia ranging (36–86) × 109/l, none of the patients had hemorrhages at the time of examination, although they had a history of heavy menstruation, spontaneous ecchymosis, and postpartum hemorrhage. Flow cytometry showed background platelet activation, revealed by overexpression of P-selectin and active αIIbβ3 integrin above normal levels. After TRAP-induced stimulation, the fractions of platelets expressing P-selectin in the proband and her sister were below normal response, indicating partial platelet refractoriness. The initiation of clot contraction was delayed. Electron microscopy revealed giant platelets with multiple filopodia and fusion of α-granules with dilated open canalicular system, containing filamentous and vesicular inclusions. The novel concept implies that the R1933X mutation in the MYH9 gene is associated not only with thrombocytopenia, but also with qualitative structural and functional defects in platelets. Platelet dysfunction includes impaired contractility, which can disrupt the compaction of hemostatic clots, making the clots weak and permeable, therefore predisposing patients with MYH9 gene mutations to the hemorrhagic phenotype. [ABSTRACT FROM AUTHOR]

The article presents the results of an experimental study of the cavitation flow around the NACA 0012 series foil in a slit channel with a width of 1.2 mm. The aspect ratio of the streamlined body was 0.02. To identify the main features of the two-phase flow, high-speed visualization was performed using the Photron FASTCAM NOVA S12 camera with a sampling frequency of 20 kHz. The internal structure of cavities was detected. The main frequencies of cavities formation in the flow were determined using digital processing of visualization data. The close location of the channel walls was shown to significantly affect the return flow propagation under the cavity and its separation. [ABSTRACT FROM AUTHOR]

The article suggests a method of mapping the natural and anthropogenic landscapes of river deltas based on satellite imagery in the publicly accessible information system Google Earth. In this system, images from the Landsat satellite help to identify a common landscape contour network. The contours are interpreted using super-high resolution images QuickBird and GeoEye, which are included in the system. Using detailed information for overview mapping with a hundred-times difference between the scales of interpretation and the drawn maps poses certain difficulties. The article considers different variants of the given method on the example of mapping the deltas of the Niger, Indus, Irrawaddy, Zambezi and the Huanghe River. [ABSTRACT FROM AUTHOR]

A review of the joint studies of the Chair of Land Hydrology and the Laboratory of Aerospace Methods, the Faculty of Geography, Moscow State University, on river delta dynamics based on space photographs is given. The article presents the basic principles of studying delta dynamics, including the choice of space photographs made at different times, ensuring their geometric, spectral, and content comparability; the roles of the visual and automated methods of image processing are characterized. A brief characteristic is given to the fund of the required space photographs and maps. The results of studies of the long-term dynamics of deltas based on old maps and modern images are discussed, along with studies of delta dynamics associated with climate changes (the Lena, Yenisei, and Northern Dvina), large-scale level variations in the Aral and Caspian seas (the Amu-Darya, Ural, Terek, Sulak, and Kura), and the intense economic development (the Danube), as well as delta transformations caused by changes of river flow direction (the Huang He). [ABSTRACT FROM AUTHOR]

This experimental investigation concerns the transfer of flows and mixing inside a symmetrical T-shaped microchannel for different inlet flow rate ratios and various Reynolds numbers of 3 to 400, the ratio of liquid flow rates in the two inlet channels varying from 0.01 to 1. Maps of the flow patterns are constructed. Two additional steady flow regimes are determined, which do not form at a symmetric feeding fluid flow. The influence of the flow rate ratios on the flow regimes and transitions is investigated and discussed. It is found that different inlet flow rate ratios significantly affect the flow characteristics, enhancing the mixing and delaying the transition to the unsteady flow regime in the outlet channel of T-micromixer. [ABSTRACT FROM AUTHOR]

We address variations in the rigidity spectrum and anisotropy of cosmic rays (CRs) during the 1998 Aug 24 Ground Level Enhancements (GLEs) from the satellite (GOES-10) and ground-based observations at the global network of neutron monitors by using the Spectrographic Global Survey techniques. We also determined CR differential rigidity spectra for different hours of the investigated event. The accelerated proton maximal rigidity in the GLE was shown to be 2.5 GV. [ABSTRACT FROM AUTHOR]

The growing interest of developers of magnetic systems in strands based on the Nb3Sn superconducting compound with a high critical current density in magnetic fields above 12 T leads to the need to test various combinations of alloying elements in the superconducting layer. It also requires study of their effect on the microstructure and properties of this layer. Titanium and tantalum are the most commonly used alloying elements in the production of Nb3Sn-based superconductors. The effects of each of these elements on the electrical properties of Nb3Sn have been studied for many years. However, many questions remain about the combined effects of these elements. We study the features of the microstructure of two Nb3Sn-based strands with a diameter of 1 mm, which have the same design and titanium content, but with different tantalum contents: 4.0 and 7.5 wt %. [ABSTRACT FROM AUTHOR]

An experimental study of a cavitating NACA0012 hydrofoil with aspect ratio 0.02 in a slit channel was carried out using a high-speed visualization at sampling rate more than 100 kHz. The features of the formation and development of cavities in a quasi-two-dimensional turbulent flow were studied. The most energetic modes of unsteady cavitation flow around the hydrofoil were obtained using dynamic mode decomposition. The presence of the second and third modes in the cavitation flow is shown here for the first time. It was shown that each of these modes corresponds to a certain period of development of the unsteady cavity. Experimental data on the reverse motion of the vapor–gas mixture into the inner region of supercavitation are presented. [ABSTRACT FROM AUTHOR]

We present the first high accuracy UBV RI(RI)c light curves of poor investigated eclipsing star V1103 Cas = GSC 3682 736 ( , , , B3 V). The geometric orbit of the system was built, the following physical characteristics of the system were found: T1 = 16 110 ± 400 K, M1 = 5.9 ± 0.3 , R1 = 4.41 ± 0.08 , T2 = 16 010 ± 400 K, M2 = 5.4 ± 0.3 , R2 = 3.77 ± 0.08 . The age of the components is 59 mln years. The photometric parallax , is close to GAIA DR1 value: . We found fast apsidal motion deg/year which is much bigger than the theoretical value under synchronism condition: deg/year. WDS catalogue is erroneously states that the star is the close optical pair. [ABSTRACT FROM AUTHOR]

Cannabinoids and their endogenous and synthetic analogs impact blood pressure and contribute to the incidence of hypertension. It was previously reported that the endocannabinoid system plays an important role in developing hypertension; however, it was also shown that cannabinoids elicit profound hypotension associated with hemorrhagic, cardiogenic, and endotoxic shock. This study aimed to test acute and chronic effects of an endogenous ligand of cannabinoid receptor anandamide (AEA) on blood pressure and kidney injury in vivo in conscious Dahl salt-sensitive (SS) rats. We demonstrated that acute i.v. bolus administration of a low or a high doses (0.05 or 3 mg/kg) of AEA did not affect blood pressure for 2 h after the injection in Dahl SS rats fed a normal salt diet (0.4% NaCl). Neither low nor high doses of AEA had any beneficial effects on blood pressure or kidney function. Furthermore, hypertensive rats fed a HS diet (8% NaCl) and chronically treated with 3 mg/kg of AEA exhibited a significant increase in blood pressure accompanied by increased renal interstitial fibrosis and glomerular damage at the late stage of hypertension. Western blot analyses revealed increased expression of Smad3 protein levels in the kidney cortex in response to chronic treatment with a high AEA dose. Therefore, TGF-β1/Smad3 signaling pathway may play a crucial role in kidney injury in SS hypertension during chronic treatment with AEA. Collectively, these data indicate that prolonged stimulation of cannabinoid receptors may result in aggravation of hypertension and kidney damage. [ABSTRACT FROM AUTHOR]

The results of a study of the radial distribution of the mechanical stresses, oxygen concentration, and optical inhomogeneity in antimony-doped germanium crystals 200 mm in diameter, with the electrical resistivity ranging from 10.5 to 18.5 Ω cm and grown by the Czochralski method, are presented. It has been established that the residual stresses calculated from X-ray diffraction data are correlated with the results of numerical simulation of thermoelastic stresses and are interrelated with the values of the optical inhomogeneity and the concentration of the dissolved oxygen present in germanium in an atomically dispersed state. [ABSTRACT FROM AUTHOR]

Metabolism of a new neuroprotector GZK-111 (N-phenylacetylglycyl-L-proline ethyl ester) in rat blood plasma was studied by HPLC-mass spectrometry. Four biotransformation products were identified. It is concluded that the main ways of GZK-111 biotransformation are hydrolysis of the ester bond by esterases followed by degradation of the resulting metabolite, as well as reactions leading to the formation of phenylacetic acid and cycloprolylglycine that exhibits neuropsychotropic activity. [ABSTRACT FROM AUTHOR]

X-ray absorption near-edge structure (XANES) spectra are the fingerprint of the local atomic and electronic structures around the absorbing atom. However, the quantitative analysis of these spectra is not straightforward. Even with the most recent advances in this area, for a given spectrum, it is not clear a priori which structural parameters can be refined and how uncertainties should be estimated. Here, we present an alternative concept for the analysis of XANES spectra, which is based on machine learning algorithms and establishes the relationship between intuitive descriptors of spectra, such as edge position, intensities, positions, and curvatures of minima and maxima on the one hand, and those related to the local atomic and electronic structure which are the coordination numbers, bond distances and angles and oxidation state on the other hand. This approach overcoms the problem of the systematic difference between theoretical and experimental spectra. Furthermore, the numerical relations can be expressed in analytical formulas providing a simple and fast tool to extract structural parameters based on the spectral shape. The methodology was successfully applied to experimental data for the multicomponent Fe:SiO2 system and reference iron compounds, demonstrating the high prediction quality for both the theoretical validation sets and experimental data. [ABSTRACT FROM AUTHOR]

The use of novel and effective probiotic-based immunostimulating preparations, prebiotics, metabiotics, and phytobiotics is considered as a promising direction for the creation of new complex feed additives for aquaculture enterprises to increase the health and productivity of the cultivated hydrobionts. The information on the products of anaerobic solid-phase fermentation of plant substrates is presented as the basis for new probiotic-based additives for aquacultures. Biologically active feed additives ProStor and GerbaStor containing probiotics and medicinal herbs and their effects on aquaculture are discussed. Specific features of their application in aquatic environments with targeted action on hydrobionts are analyzed. [ABSTRACT FROM AUTHOR]

We review some results of diagnostics for the electromagnetic characteristics of the heliosphere and of the Earth magnetosphere within the model for cosmic ray modulation by large-scale heliospheric electromagnetic fields. The results were obtained through the spectrographic global survey from ground-based cosmic ray observations at the worldwide network of neutron monitors. [ABSTRACT FROM AUTHOR]

The Forbush effect and geomagnetic storm in April 1990 are studied using data from ground-based measurements of cosmic rays on the worldwide network of stations. Variations in spectra, the anisotropy of cosmic rays, and changes in the planetary system of geomagnetic cutoff rigidities are calculated. The distance to the subsolar point, the radius of the ring current, and the ring current's contribution to the Dst index during the investigated events are determined. [ABSTRACT FROM AUTHOR]

We found that the known spectroscopic binary and variable BU CMi = HD65241 ( , A0 V) is a quadruple doubly eclipsing 2+2 system. Both eclipsing binaries are detached systems moving in an eccentric orbits: pair "A" with the period () and pair "B" with the period (). All four components have nearly equal sizes, temperatures and masses in the range , and A0 spectra. We found the mutual orbit of both pairs around the system barycenter with a period of 6.6 years and eccentricity = 0.7. We detected in pairs "A" and "B" the fast apsidal motion with the periods years and UB = 26.3 years, respectively. The orbit of each pair shows small nutation like oscillations in periastron longitude. The system is young and it seems that its components does not yet reached the Zero Age Main Sequence (ZAMS). The photometric parallax calculated from the found parameters coincides perfectly with the GAIA DR2 . [ABSTRACT FROM AUTHOR]