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Based on the proposed methodology, the essence of which is to identify the profiles of electrophysical parameters of planar objects of eddy-current testing by means of surrogate optimization in the active PCA-space of reduced dimensionality, the effectiveness of the approach is proved by modeling the process of measurement control using apriori accumulated information about an object, in particular, multifrequency probing. The particularity of these studies is the consideration of previously collected information not only on profile variations, but also on the effect of various object probing frequencies on the signal of the surface probe. The functions of the storage device and information carrier were performed by a neural network metamodel, characterized by a high computational efficiency. Numerical experiments have determined the accuracy indicators of the proposed improved method for determining the distributions of magnetic permeability and electrical conductivity along the subsurface layer of a metal object with changes in a microstructure. The analysis of the modeling results indicates a significant reduction in the level of computational resources required to solve the problem and an increase in the accuracy of profile identification. [ABSTRACT FROM AUTHOR]

The paper proposes a method of simultaneous reconstruction of the electrical conductivity and magnetic permeability profiles of planar metal research objects based on the results of single measurements by eddy current probes using surrogate optimization techniques in a reduced compact subspace design and accumulating the full amount of the most important a priori information about the modes of electromagnetic objects. In addition to the information on the response of probe signals to changes in electrophysical parameters, a priori information includes the data on multifrequency sensing and changes in the lift-off between metal research objects and eddy current probes. All the main stages for the implementation of the method of solving the inverse problem are demonstrated, namely, creating a uniform computer quasi-design of the experiment with improved 2D-projections based on LPτ-Sobol's sequences; creating surrogate models on fully connected deep neural networks; reducing the dimensionality of the full design space using the principal components method of PCA; reconstructing profiles as a result of surrogate optimisation in a compact subspace. Numerical examples of the method are also presented in the paper. [ABSTRACT FROM AUTHOR]

In this paper, recent results regarding generalized continuum mechanics on oriented Riemannian manifolds are reviewed and summarized. The mass, the momentum and the energy conservation laws are given. Thermodynamics arising in such media is also considered as a Lagrangian manifold endowed with a Riemannian structure. Thermodynamic model of moving media takes into account deformation and stress arising in a media in motion. [ABSTRACT FROM AUTHOR]

Results obtained from assessments of changes in the psychoemotional state of children with disabilities using musical influences are presented. As compared with the resting state, exposure to music increased the spectral power of the δ rhythm in the right and posterior parts of the brain by 10–20 μV2/Hz. Average spectral power values of the α‑, β‑, θ‑, and γ‑bands while listening to genres such as classical and jazz were close to the average values at rest. [ABSTRACT FROM AUTHOR]

New methods for identifying the material properties of planar objects as a result of measurements by the eddy current method are proposed. The methods are based on the latest surrogate strategies and advanced optimization techniques that improve efficiency and reduce resource consumption of problem solutions, and balance computational complexity with the accuracy of the results. High-performance metamodels for global surrogate optimization are based on deep truly meaningful fully connected neural networks, serving as an additional function of accumulating apriori information about objects. High accuracy of the approximation of the multidimensional response surface, which is determined by the "exact" electrodynamic model of the testing process, is ensured by performing calculations according to the computer design of a homogeneous experiment with a low weighted symmetric centered discrepancy. The results of numerical experiments performed for full and reduced dimensional search spaces, which can be obtained by linear transformations using the principal component method, are presented. The verification of the methods proved their sufficiently high accuracy and computational performance. [ABSTRACT FROM AUTHOR]

We propose here a system consisting of a participatory device for recording brain electrical activity (BEA), a personal computer, and intelligent software to assess the level of user experience of patients in a virtual reality (VR) environment. The experimental group of subjects (patients) consisted of 39 disabled children, i.e., boys and girls aged 12–16 years, with behavioral disorders. The study results showed that the average level of presence in VR, as assessed in terms of the frequency ranges in the original BEA signal, increased on immersion into virtual space. [ABSTRACT FROM AUTHOR]

In this paper we consider thermodynamics of a moving medium. We expand thermodynamic phase space with two additional quantities: deformation and stress. A geometrical interpretation of such thermodynamics as Lagrangian manifolds is given. With a pseudo-Riemannian structure arising on such manifolds, a co-existence curve of phases is found. An example regarding the van der Waals state equation is considered. [ABSTRACT FROM AUTHOR]

In order to establish the projection properties of computer uniform designs of experiments on Sobol's sequences, an empirical comparative statistical analysis of the homogeneity of 2D projections of the best known improved designs of experiments was carried out using the novel objective indicators of discrepancies. These designs show an incomplete solution to the problem of clustering points in low-dimensional projections graphically and numerically, which requires further research for new Sobol's sequences without the drawback mentioned above. In the article, using the example of the first 20 improved Sobol's sequences, a methodology for creating refined designs is proposed, which is based on the unconventional use of these already found sequences. It involves the creation of the next dimensional design based on the best homogeneity and projection properties of the previous one. The selection of sequences for creating an initial design is based on the analysis of numerical indicators of the weighted symmetrized centered discrepancy for two-dimensional projections. According to the algorithm, the combination of sequences is fixed for the found variant and a complete search of the added one-dimensional sequences is performed until the best one is detected. According to the proposed methodology, as an example, a search for more perfect variants of designs for factor spaces from two to nine dimensions was carried out. New combinations of Sobol's sequences with better projection properties than those already known are given. Their effectiveness is confirmed by statistical calculations and graphically demonstrated box plots and histograms of the projection indicators distribution of the weighted symmetrized centred discrepancy. In addition, the numerical results of calculating the volumetric indicators of discrepancies for the created designs with different number of points are given. [ABSTRACT FROM AUTHOR]

Soils of boreal forests are crucial carbon reserves. The response of soil carbon emission to climate change significantly affects the concentration of carbon dioxide in the atmosphere. Soil carbon emission models frequently show a nonlinear response to temperature, but soil moisture is an important limiting factor, often overlooked in energy limited ecosystems. We suggest a statistical model of soil CO2 emission constrained by soil moisture and temperature for different ecosystems in the boreal zone. We tested this modelling strategy using direct measurements of seasonal soil CO2 emission near the research observatory ZOTTO near the Bor settlement, Central Siberia, Russia, in 2012- 2017. Soil moisture explained a significant amount of variability of soil emission: the adjusted R2 was twice higher than in the baseline model. Although the temperature-only model describes the annual variability of carbon dioxide emissions quite well, the addition of moisture measurement significantly refines the quality of prediction of the seasonal component dynamics. Models including both temperature and soil moisture could serve as a promising tool to analyze the carbon cycle in boreal forest ecosystems. [ABSTRACT FROM AUTHOR]

At the present stage of development of information technology, virtual reality is widely used in various areas of human life, including for assessing the psychoemotional state of health. Spectral analysis of maximal EEG power in diff erent frequency ranges may allow markers for anxious-phobic disorders to be identifi ed. This report describes an experiment carried out to assess the psychoemotional state of people with acrophobia in various states: at rest, being in a virtual reality helmet, and on exposure to a stressful stimulus (at a height in a virtual reality scene). Plots of the maximum power distribution density in individual EEG frequency bands are given. The values obtained can be used as criteria for assessing phobic anxiety disorders using virtual reality technology. [ABSTRACT FROM AUTHOR]

The northeastern Siberian craton stores numerous placers of diamonds that differ in morphology and texture, and originate from different types of primary deposits, primarily kimberlites. Analyses of mantle zircons selected from samples of alluvial and coarse clastic sediments in the watersheds of the Olenek and Kyutyungde rivers in the Anabar‐Olenek subprovince of the Yakutian diamond province provide constraints on kimberlite magmatism events in the area. The new U–Pb ages and typical kimberlitic signatures of the Kyutyungde zircons trace‐element patterns reveal three main magmatic events that produced kimberlites: Middle Paleozoic (Late Devonian to Early Carboniferous), Jurassic and Triassic. The Jurassic zircons (177–149 Ma) are mainly related to kimberlites in the proximal Kuoika‐Molodo and Khorbusuon fields. Triassic zircons (240–221 Ma) were probably released during large‐scale erosion of the eastern Anabar shield, however, the presence of such zircons in the Kyutyungde area indicates that kimberlites of the respective magmatic stage may exist within the immediate vicinity of the area. The only Middle Paleozoic zircon sample (358.6 Ma, D3‐C1 boundary) may originate from a proximal kimberlite within the Kyutyungde area. The presence of Middle Paleozoic kimberlitic zircons, along with harzburgite–dunitic pyropes, indicates that the primary deposit of diamonds and related minerals may exist near or within the Kyutyungde area. Late Ediacaran–Early Cambrian (573–473 Ma) mantle zircons found in Early Cambrian conglomerates of the area, along with other mantle minerals including Cr spinel of a diamond assemblage, record another Precambrian event of potentially diamondiferous magmatism in the Kyutyungde basin. [ABSTRACT FROM AUTHOR]

This report describes an international summer course, "Tree Rings, Climate, Natural Resources, and Human Interaction", held in Cheriomushki, Russia, in the summer of 2018. The course was attended by 12 participants from six countries (Belgium, India, Lebanon, Poland, Russia, and South Africa) and instructors fromthe USA and included basic training in dendrochronology skills and dendroclimatology and dendroecology projects. This report focuses on a nested May-July Palmer Drought Severity Index (PDSI) reconstruction from annual rings of Pinus sylvestris trees growing in the region and also explores false-ring (FR) occurrence in samples collected during the course. Four chronologies, one developed during the course from Maina District, Khakassia, Russia, are used in the reconstruction, which was based on principal component (PC) regression. The nested reconstruction demonstrated a strong statistical relationship between PDSI and tree-ring growth and allowed for an assessment of climate variability on both interannual and interdecadal time scales. FR occurrence in tree cores collected along an elevational transect from a site along the Yenisei River north of Cheriomushki was found to differ depending on the position of trees on the slope. The frequency of FRs and the location of the FR within the annual ring also appear to be related to seasonal precipitation anomalies. [ABSTRACT FROM AUTHOR]

Climate change projections forecast most significant impacts on high-latitude forest ecosystems. Particularly, climate warming in boreal regions should increase fire severity and shorten its return interval. These processes can change the dynamics of boreal forests as younger stands become more dominating with a shift from gymnosperm to angiosperm. However, despite angiosperm's phenological and physiological traits have a high potential for ecophysiological and dendroclimatological studies in Siberia, they have been rarely investigated due to their short-term lifespan in comparison with gymnosperm. Modeling tree growth is a common way to understand tree growth responses to environmental changes since it allows using available experiment or field data to interpret observed climate–growth relationships based on the biological principles. In our study, we applied the process-based Vaganov–Shashkin (VS) model of tree-ring growth via a parameterization approach VS-oscilloscope for the first time to an angiosperm tree species (Betula pubescens Ehrh.) from continuous permafrost terrain to understand its tree-radial growth dynamic. The parameterization of the VS model provided highly significant positive correlations (p < 0.05) between the simulated growth curve and initial tree-ring chronologies for the period 1971–2011 and displayed the average duration of the growing season and intra-seasonal key limiting factors for xylem formation. Modeled result can be valid at the regional scale for remote birch stands, whereas, justification of the local non-climatic input data of the model provided precise site-specific tree growth dynamic and their substantiated responses to driving factors. [ABSTRACT FROM AUTHOR]

A Navier–Stokes system on a curve is discussed. The quotient equation for this system is found. The quotient is used to find some solutions of Navier–Stokes system. Using asymptotic virial expansion of the Planck potential, we reduce the quotient equation to a series of systems of ordinary differential equations. [ABSTRACT FROM AUTHOR]

Global climate change impacts the functioning and productivity of forest ecosystems at various spatiotemporal scales across a wide range of biomes. Although summer temperatures are considered the main driver of boreal tree growth, the importance of soil moisture availability is likely to rise with decreasing latitude and increasing warming. Here, we combine dendrochronological measurements with evidence from tree growth modeling and remote sensing to quantify the effect of climate on phenology and productivity of Scots pines (Pinus sylvestris L.) in southern Siberia. Between 1960 and 2017, pine ring widths along a latitudinal transect from 53° to 56°N were mainly controlled by the availability of summer soil moisture. This finding challenges the common belief that summer temperatures are the predominant growth control in boreal forests. Moreover, we show that earlier growing season onsets can compensate for warming-induced drought stress. Despite the phenotypic plasticity of Scots pines to adapt to warmer and drier conditions, we speculate that predicted climate change will likely exceed the species' physiological tolerance in much of Eurasia's forest-steppe by the end of the twenty-first century. [ABSTRACT FROM AUTHOR]

Existing scientific studies devoted to the design of eddy-current probes with a priori given configuration of the electromagnetic excitation field, which provide a uniform eddy current density distribution, consider a wide class of such, but are limited to the case when the probe is stationary relative to the testing object. Therefore, the actual problem is the synthesis of moving tangential eddy current probes with a frame excitation system that provides a uniform eddy current density distribution in the testing object, the solution of which is proposed in this study. Amathematical method for nonlinear surrogate synthesis of excitation systems for frame moving tangential surface eddy current probes, which implements a uniform eddy current density distribution of the testing zone object, is proposed. A metamodel of the volumetric structure of the excitation system of the frame tangential eddy current probe, applied in the process of surrogate optimal parametric synthesis, has been created. The examples of nonlinear synthesis of excitation systems using modern metaheuristic stochastic algorithms for finding the global extremum are considered. The numerical results of the obtained solutions of the problems are presented. The efficiency of the synthesized structures of excitation systems in comparison with classical analogs is shown on the graphs of the eddy current density distribution on the object surface in the testing zone. [ABSTRACT FROM AUTHOR]

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Northern and tundra forest ecosystems are especially vulnerable to climate impact because of their high sensitivity to changes in temperature. An important issue is how the growth and productivity of the main forest-forming species in the permafrost zone of Siberia are changing under conditions of current climate change. In this study, the Vaganov-Shashkin imitation model of tree growth (the VS-model) has been used to estimate the effect of climatic factors on the growth of Cajander larch (Larix cajanderi Mayr.) in northeastern Yakutia and Dahurian larch (Larix gmelinii Rupr. (Rupr.) in the east of Taimyr) with a 1-day time resolution and to determine the extent to which the interaction of climatic parameters (temperature/precipitation) and physiological processes is reflected in the width and anatomical structure of tree rings. Despite the location of the study sites in northern regions with harsh conditions, where temperature is the main limiting factor, we have managed to identify the days of the growing season on which soil moisture had a greater impact on the growth of trees than air temperature. [ABSTRACT FROM AUTHOR]

Comprehensive studies of peridotitic xenoliths from the Udachnaya kimberlite (Yakutian diamond province, Siberian craton) confirm that garnet shows inverse correlation of its volumetric percentage with its Cr2O3 contents in refertilizated peridotites, but no such correlation is observed in depleted peridotites. The correlation relationship plots as an isosceles hyperbola, which is consistent with the existing knowledge of origin of refertilized peridotite. The bulk content of aluminum is proportional to the garnet percentage both in depleted and refertilized peridotites, but Al2O3 in the rock correlates with Cr2O3 in garnet only in the refertilized varieties, while the two parameters are independent in depleted mantle rocks. According to the modeling of refertilization-related composition changes in the Udachnaya peridotites, garnet percentages are directly proportional to the amount of clinopyroxene (Gnt = 0.879*Cpx + 0.022, R2 = 0.78) and inversely proportional to that of olivine (Gnt = 0.026/Ol3.141, R2 = 0.79). As the shares of Gnt and Cpx increase from minimum values, orthopyroxene first increases (to 0.16) and then decreases since 0.65 Ol, 0.09 Cpx, and 0.10 Gnt. This model can constrain the place of the parent rock in the refertilization series knowing Cr2O3 contents in separate garnet grains. The average refertilization degree of lithospheric mantle in the region estimated from the compositions of more than 800 garnet xenocrysts in the Udachnaya kimberlite is expressed in the rock modal composition as: Ol = 0.72, Opx = 0.15, Gnt = 0.07, and Cpx = 0.06 (median values). [ABSTRACT FROM AUTHOR]

A mathematical method for nonlinear surrogate synthesis of frame surface eddy current probes providing a uniform eddy current density distribution in the testing object area is proposed. A metamodel of a frame movable eddy-current probe with a planar excitation system structure, used in the algorithm for surrogate optimal synthesis was created. The examples of a nonlinear synthesis of excitation systems with the application of the modern metaheuristic stochastic algorithms for finding the global extremum are considered. The numerical findings of the problem analyses are presented. The efficiency of the synthesized excitation structures was demonstrated on the basis of the eddy current density distribution graphs on the surface of the control zone of the object in comparison with classical analogues. [ABSTRACT FROM AUTHOR]

Sulfide-bearing polymineralic inclusions in mantle-derived chromium pyrope garnets of lherzolite paragenesis from lamprophyres of the Chompolo field (Aldan shield, southern Siberian craton) have been studied. The inclusions are composed of either only sulfides or sulfides in association with other minerals (carbonates, silicates, oxides, etc.). The sulfide part of the inclusions is represented by up to four minerals. Among the sulfides, minerals rich in Cu and Ni have been found, whereas Fe sulfides (pyrrhotite, troilite) are absent. This distinguishes the inclusions studied from the majority of sulfide inclusions in mantle minerals and diamonds, as well as in mantle xenoliths from kimberlites. The formation of polymineralic inclusions in chromium garnets of the Chompolo field is attributed to the effect of a carbonate–silicate metasomatic melt/fluid on mantle peridotites, as evidenced by the mineral suite associated with the sulfides. The research results indicate significant differences in the nature of metasomatic processes that occurred in the lithospheric mantle of the southern and central parts of the Siberian craton. [ABSTRACT FROM AUTHOR]

Norway spruce (Picea abies L.) is among the most sensitive coniferous species to ongoing climate change. However, previous studies on its growth response to increasing temperatures have yielded contrasting results (from stimulation to suppression), suggesting highly site-specific responses. Here, we present the first study that applies two independent approaches, i.e. the nonlinear, process-based Vaganov-Shashkin (VS) model and linear daily response functions. Data were collected at twelve sites in Slovenia differing in climate regimes and ranging elevation between 170 and 1300 m a.s.l. VS model results revealed that drier Norway spruce sites at lower elevations are mostly moisture limited, while moist high-elevation sites are generally more temperature limited. Daily response functions match well the pattern of growth-limiting factors from the VS model and further explain the effect of climate on radial growth: prevailing growth-limiting factors correspond to the climate variable with higher correlations. Radial growth correlates negatively with rising summer temperature and positively with higher spring precipitation. The opposite response was observed for the wettest site at the highest elevation, which positively reacts to increased summer temperature and will most likely benefit from a warming climate. For all other sites, the future radial growth of Norway spruce largely depends on the balance between spring precipitation and summer temperature. [ABSTRACT FROM AUTHOR]

Significant alterations of cambial activity might be expected due to climate warming, leading to growing season extension and higher growth rates especially in cold-limited forests. However, assessment of climate-change-driven trends in intra-annual wood formation suffers from the lack of direct observations with a timespan exceeding a few years. We used the Vaganov-Shashkin process-based model to: (i) simulate daily resolved numbers of cambial and differentiating cells; and (ii) develop chronologies of the onset and termination of specific phases of cambial phenology during 1961–2017. We also determined the dominant climatic factor limiting cambial activity for each day. To asses intra-annual model validity, we used 8 years of direct xylogenesis monitoring from the treeline region of the Krkonoše Mts. (Czechia). The model exhibits high validity in case of spring phenological phases and a seasonal dynamics of tracheid production, but its precision declines for estimates of autumn phenological phases and growing season duration. The simulations reveal an increasing trend in the number of tracheids produced by cambium each year by 0.42 cells/year. Spring phenological phases (onset of cambial cell growth and tracheid enlargement) show significant shifts toward earlier occurrence in the year (for 0.28–0.34 days/year). In addition, there is a significant increase in simulated growth rates during entire growing season associated with the intra-annual redistribution of the dominant climatic controls over cambial activity. Results suggest that higher growth rates at treeline are driven by (i) temperature-stimulated intensification of spring cambial kinetics, and (ii) decoupling of summer growth rates from the limiting effect of low summer temperature due to higher frequency of climatically optimal days. Our results highlight that the cambial kinetics stimulation by increasing spring and summer temperatures and shifting spring phenology determine the recent growth trends of treeline ecosystems. Redistribution of individual climatic factors controlling cambial activity during the growing season questions the temporal stability of climatic signal of cold forest chronologies under ongoing climate change. [ABSTRACT FROM AUTHOR]

Symmetries and the corresponding fields of differential invariants of the inviscid flows on a curve are given. Their dependence on thermodynamic states of media is studied, and a classification of thermodynamic states is given. [ABSTRACT FROM AUTHOR]

New insights into the intra-annual dynamics of tree-ring formation can improve our understanding of tree-growth response to environmental conditions at high-resolution time scales. Obtaining this information requires, however, a weekly monitoring of wood formation, sampling that is extremely time-intensive and scarcely feasible over vast areas. Estimating the timing of cambial and xylem differentiation by modeling thus represents an interesting alternative for obtaining this important information by other means. Temporal dynamics of cambial divisions can be extracted from the daily tree-ring growth rate computed by the Vaganov–Shashkin (VS) simulation model, assuming that cell production is tightly linked to tree-ring growth. Nonetheless, these predictions have yet to be compared with direct observations of wood development, i.e., via microcoring, over a long time span. We tested the performance of the VS model by comparing the observed and predicted timing of wood formation in black spruce [ Picea mariana (Mill.)]. We obtained microcores over 15 years at 5 sites along a latitudinal gradient in Quebec (Canada). The measured variables included cell size and the timing of cell production and differentiation. We calibrated the VS model using daily temperature and precipitation recorded by weather stations located on each site. The predicted and observed timing of cambial and enlarging cells were highly correlated (R 2 = 0.8); nonetheless, we detected a systematic overestimation in the predicted timing of cambial cells, with predictions delayed by 1–20 days compared with observations. The growth rate of cell diameter was correlated with the predicted growth rate assigned to each cambial cell, confirming that cell diameter developmental dynamics have the potential to be inferred by the tree-ring growth curve of the VS model. Model performances decrease substantially in estimating the end of wood formation. The systematic errors suggest that the actual relationships implemented in the model are unable to explain the phenological events in autumn. The mismatch between the observed and predicted timing of wood formation in black spruce within our study area can be reduced by better adapting the VS model to wet sites, a context for which this model has been rarely used. [ABSTRACT FROM AUTHOR]

Uniform multi-dimensional designs of experiments for effective research in computer modelling are highly demanded. The combinations of several one-dimensional quasi-random sequences with a uniform distribution are used to create designs with high homogeneity, but their optimal choice is a separate problem, the solution of which is not trivial. It is believed that now the best results are achieved using Sobol's LPτ-sequences, but this is not observed in all cases of their combinations. The authors proposed the creation of effective uniform designs with guaranteed acceptably low discrepancy using recursive Rd-sequences and not requiring additional research to find successful combinations of vectors set distributed in a single hypercube. The authors performed a comparative analysis of both approaches using indicators of centred and wrap-around discrepancies, graphical visualization based on Voronoi diagrams. The conclusion was drawn on the practical use of the proposed approach in cases where the requirements for the designs allowed restricting to its not ideal but close to it variant with low discrepancy, which was obtained automatically without additional research. [ABSTRACT FROM AUTHOR]

Soil CO2 emission is one of the most important components of the global carbon cycle. This study analyzes the seasonal dynamics of soil emission for various land cover types in the middle taiga subzone of central Siberia during five growing seasons. It is shown that, throughout a vast area covered by pine forests and their derivatives formed on sandy soils, seasonal CO2 emission values are determined primarily by the moisture conditions and only secondarily by the temperature regime and ecosystem type. The effect of the forest type is manifested only under the most favorable moisture conditions. A new approach is proposed: divide the growing season into dry and moist periods depending on the threshold soil moisture for areas with different vegetation types. [ABSTRACT FROM AUTHOR]

Symmetries and the corresponding algebras of differential invariants of inviscid fluids on a spherical layer are given. Their dependence on thermodynamical states of the medium is studied, and a classification of thermodynamical states is given. [ABSTRACT FROM AUTHOR]

Tree-ring anatomical structure is the key to understanding of adaptive specifics of xylem of various species to climate change. This is especially significant in the permafrost zone due to likely permafrost degradation. We compared anatomic features of annual rings of Dahurian larch (Larix gmelinii (Rupr.) Rupr., Larix cajanderi Mayr.), Scots pine (Pinus sylvestris L.) and Siberian spruce (Picea obovata Ledeb.) growing in the permafrost zone in Central Siberia for 1960–2011. Climatic factors affecting tree radial growth and anatomic features of tracheids of coniferous species were revealed. [ABSTRACT FROM AUTHOR]

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This article proposes a new use of the Hilbert−Huang transform (HHT) in the preliminary processing and analysis of EEG signals. EEG signal recordings are analyzed using HHT to study patterns of changes in patients with mental disorders. Variants of EEG signals in different coordinate systems are analyzed. Results from analysis of EEG signals demonstrated a relationship between the amplitude−time parameters of HHT and the presence of mental disorders in patients. [ABSTRACT FROM AUTHOR]

Key message: This study shows great potential of the well-validated VS-Oscilloscope (a visual accurate parameterization of the VS-model) for assessment of spatial-temporal cambium phenology, which is illustrated based on the analysis of comprehensive datasets from central Siberia.Abstract: Tree-growth response to changing climate varies depending on tree species, forest type, and geographical region. Process-based models can help us better understand and anticipate these outcomes. To characterize growth sensitivity to different climate parameters, we applied the VS-Oscilloscope analytical package, as a precise visual parameterization tool of the Vaganov-Shashkin model, to two contrasting habitats: one with tree-ring growth limitation by soil moisture (in the southern part of central Siberia) and the another with temperature limitation (in the middle part of central Siberia). We speculate that specific parameter values of the Vaganov-Shashkin model and their variability under local conditions and species are the key to understand different physiological processes in conifers. According to the simulation results for the temperature-limited site, wider rings of Picea obovata can result from a longer growing season. However, for the soil moisture-limited site, the final sizes of the tree rings of Pinus sylvestris were not affected by the length of the growing season but were primarily defined by the intra-seasonal variations in soil moisture, even under cold conditions. For the two sites, we obtained a 20-day difference between the two phenological dates, in which the early date could be associated with cambial initiation and the late date with the appearance of the first enlarging cell. In the case of central Siberia, the time period was half that of the southern Siberia. Such differences could be explained by both geography and species-specific responses to phenology. To test this hypothesis, additional tree-ring and climatic data for contrasted habitats would be needed. [ABSTRACT FROM AUTHOR]

Copyright of Electrical Engineering & Electromechanics is the property of National Technical University, Kharkiv Polytechnic Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Using a wide range of different physical and chemical methods, it was found that the oxidative stress caused by addition of hydrogen peroxide to the incubation medium has a significant effect on the conformation of haematoporphyrin, influencing the oxygen-binding properties of haemoglobin in red blood cells. Morphofunctional characteristics of red blood cells change; in particular, we have observed the transformation of erythrocytes, their transition into echinocytes. In erythrocytes, in response to increased lipid peroxidation (LPO) antioxidant enzymes become active. The use of natural antioxidants (β-carotene and resveratrol) works towards reducting the level of oxidative processes. Resveratrol has the greatest antioxidant effect. [ABSTRACT FROM AUTHOR]

Abstract Several thousand clinopyroxene, garnet, and phlogopite inclusions of mantle rocks from Jurassic and Triassic kimberlites in the northeastern Siberian craton have been analyzed and compared with their counterparts from Paleozoic kimberlites, including those rich in diamond. The new and published mineral chemistry data make a basis for an updated classification of kimberlite-hosted clinopyroxenes according to peridotitic and mafic (eclogite and pyroxenite) parageneses. The obtained results place constraints on the stability field of high-Na lherzolitic clinopyroxenes, which affect the coexisting garnet and decrease its Ca contents. As follows from analyses of the mantle minerals from Mesozoic kimberlites, the cratonic lithosphere contained more pyroxenite and eclogite in the Mesozoic than in the Paleozoic. It virtually lacked ultradepleted harzburgite-dunite lithologies and contained scarce eclogitic diamonds. On the other hand, both inclusions in diamond and individual eclogitic minerals from Mesozoic kimberlites differ from eclogitic inclusions in diamond from Triassic sediments in the northeastern Siberian craton. Xenocrystic phlogopites from the D'yanga pipe have 40Ar/39Ar ages of 384.6, 432.4, and 563.4 Ma, which record several stages of metasomatic impact on the lithosphere. These phlogopites are younger than most of Paleozoic phlogopites from the central part of the craton (Udachnaya kimberlite). Therefore, hydrous mantle metasomatism acted much later on the craton periphery than in the center. Monomineral clinopyroxene thermobarometry shows that Jurassic kimberlites from the northeastern craton part trapped lithospheric material from different maximum depths (170 km in the D'yanga pipe and mostly < 130 km in other pipes). The inferred thermal thickness of cratonic lithosphere decreased progressively from ~ 260 km in the Devonian-Carboniferous to ~ 225 km in the Triassic and to ~ 200 km in the Jurassic, while the heat flux (Hasterok-Chapman model) was 34.9, 36.7, and 39.0 mW/m2, respectively. Dissimilar PT patterns of samples from closely spaced coeval kimberlites suggest different emplacement scenarios, which influenced both the PT variations across the lithosphere and the diamond potential of kimberlites. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the effect of hyperoxia, calcium ions and pH value on the composition of major phospholipids in human erythrocyte membranes and erythrocytes' oxygen-transport function. To create a model of hyperoxia, we saturated the incubated mixture with oxygen by constant passing of oxygen-air mixture through the incubation medium. To assess the effect of elevated calcium ion concentrations, CaCl2 was added to the incubation medium. An incubation medium with different pH was used to study the effect of various pH values. Lipids were extracted from erythrocytes and chromatographic separation was carried out in a thin layer of silica gel deposited on a glass plate. The thiobarbituric acid (TBA)-active products and the content of diene conjugates (DC) in erythrocytes were determined. The oxygen-binding capacity of haemoglobin was evaluated using Raman spectroscopy. The obtained results indicated that hyperoxia causes deep changes both in the composition and character of bilayer lipids of erythrocyte membranes, which affects the functional characteristics of erythrocytes, primarily the oxygen-transport properties of erythrocyte haemoglobin. It should be noted that a combination of Ca2+ ions and change in the pH value intensify the processes associated with disruption of phospholipids' composition. The findings indicate that the lipid phase is one of the key elements in the functioning of erythrocytes in norm as well as during development of various pathological processes. [ABSTRACT FROM AUTHOR]

Symmetries and the corresponding algebras of differential invariants of inviscid fluids on a sphere are given. Their dependence on thermodynamical states of media is studied, and a classification of thermodynamical states is given. [ABSTRACT FROM AUTHOR]

Algebras of symmetries and the corresponding algebras of differential invariants for plane flows of inviscid fluids are given. Their dependence on thermodynamical states of media are studied and a classification of thermodynamical states is given. [ABSTRACT FROM AUTHOR]

Rapoport–Leas model of motion of a two-phase flow on a plane is considered. Travelling-wave solutions for these equations are found. Wavefronts of these solutions may be circles, lines and parabolae. Ordinary differential equations for pressure and saturation on the wavefronts are established. [ABSTRACT FROM AUTHOR]

A two-dimensional Buckley-Leverett system governing motion of two-phase flow is considered. Travelling-wave solutions for these equations are found. Wavefronts of these solutions may be circles, lines and parabolae. Values of pressure and saturation on the wave fronts are found. [ABSTRACT FROM AUTHOR]

Background: This study examines the effect of graduated hyperglycaemia on the state and oxygen-binding ability of hemoglobin, the correlation of phospholipid fractions and their metabolites in the membrane, the activity of proteolytic enzymes and the morphofunctional state of erythrocytes. Methods: Conformational changes in the molecule of hemoglobin were determined by Raman spectroscopy. The structure of the erythrocytes was analyzed using laser interference microscopy (LIM). To determine the activity of NADN-methemoglobinreductase, we used the P.G. Board method. The degree of glycosylation of the erythrocyte membranes was determined using a method previously described by Felkoren et al. Lipid extraction was performed using the Bligh and Dyer method. Detection of the phospholipids was performed using V. E. Vaskovsky method. Results: Conditions of hyperglycaemia are characterized by a low affinity of hemoglobin to oxygen, which is manifested as a parallel decrease in the content of hemoglobin oxyform and the growth of deoxyform, methemoglobin and membrane-bound hemoglobin. The degree of glycosylation of membrane proteins and hemoglobin is high. For example, in the case of hyperglycaemia, erythrocytic membranes reduce the content of all phospholipid fractions with a simultaneous increase in lysoforms, free fatty acids and the diacylglycerol (DAG). Step wise hyperglycaemia in incubation medium and human erythrocytes results in an increased content of peptide components and general trypsin-like activity in the cytosol, with a simultaneous decreased activity of μ-calpain and caspase 3. Conclusions: Metabolic disorders and damage of cell membranes during hyperglycaemia cause an increase in the population of echinocytes and spherocytes. The resulting disorders are accompanied with a high probability of intravascular haemolysis. [ABSTRACT FROM AUTHOR]