154 research outputs found
Assessment of the genetic distances between some species of the family Bradybaenidae (Mollusca, Pulmonata)
On the basis of inter-simple sequence repeat (ISSR) loci and the nucleotide sequences of nuclear (18S and ITS-1) and mitochondrial genes (COI and 16S), a phylogenetic analysis of the three species of terrestrial mollusks of the family Bradybaenidae (Mollusca, Pulmonata), Bradybaena fruticum Mull., Bradybaena schrencki Midd., and Bradybaena transbaicalia Shileyko, was conducted to clarify their taxonomic statu
Spin-fluctuation theory beyond Gaussian approximation
A characteristic feature of the Gaussian approximation in the
functional-integral approach to the spin-fluctuation theory is the jump phase
transition to the paramagnetic state. We eliminate the jump and obtain a
continuous second-order phase transition by taking into account high-order
terms in the expansion of the free energy in powers of the fluctuating exchange
field. The third-order term of the free energy renormalizes the mean field, and
fourth-order term, responsible for the interaction of the fluctuations,
renormalizes the spin susceptibility. The extended theory is applied to the
calculation of magnetic properties of Fe-Ni Invar.Comment: 20 pages, 4 figure
Soil quality indicators of arable lands in the Russian Federation
The study presents three groups of Soil Quality Indicators (SQI) of arable lands in the Russian Federation, such as agroclimate conditions, soil parameters and negative soil characteristics. The selection of SQI meets the requirements of the crop growth model for calculating the standard crop yield. The application of SQI in the Grain Equivalent Model allows ranking quality of the soils of agricultural lands in the country. The share of the best quality Chernozems with the standard yield of grain crops exceeding 4 t/ha is about 10%. At the same time, arable Chernozems occupy nearly 66% of total area of agricultural lands. More than 74% of the arable lands including podzolized and leached Chernozems in the northern part and Chernozems southern in the southern part of the agricultural zone are characterized by medium quality with the standard yield of grain crops 2-4 t/ha. About 10% of the arable land occupied by Chestnut solonetzic and saline soils are of poorer quality with the standard yield of grain crops less than 1 t/ha. The proposed indicators are included in the government programs for valuating and monitoring the quality of agricultural lands. The universal validity of indicators is a basis for the development of a new generation of standards for the protection and rational use of soils based on modern digital technologies and GIS approaches
Development of the conceptual framework for soil protection and management in the European Union
The concepts defining the policy of soil protection and rational use (SPRU) in the European Union (EU) are considered. It is found that the focuses of SPRU have evolved significantly since the early 1990s. Initially the SPRU was not considered separately, it was associated with the protection of other environment components, for example, soil соntamination resulting from air pollution or the disposal of industrial and municipal wastes. In 2006 the stand-alone EU Soil Protection Strategy was established. This document was focused on soil protection against physical degradation (erosion, compaction, sealing, etc.) and on preservation of soil functions. The new Soil Strategy 2030 is based on the provisions of the previous Strategy document and is primarily aimed at improving soil health. Special attention is paid to the conservation of soils as a spatial resource and its efficient use in the system of a circular (closed-loop economy) economy. Looking at the evolution of the EU policy towards the SPRU, it can be concluded that the main development has led to an understanding of the importance of soil health and awareness of the need to conserve soil as multi-target spatial and functional basis for human health, wildlife and climate
The restricted two-body problem in constant curvature spaces
We perform the bifurcation analysis of the Kepler problem on and .
An analogue of the Delaunay variables is introduced. We investigate the motion
of a point mass in the field of the Newtonian center moving along a geodesic on
and (the restricted two-body problem). When the curvature is small,
the pericenter shift is computed using the perturbation theory. We also present
the results of the numerical analysis based on the analogy with the motion of
rigid body.Comment: 29 pages, 7 figure
History of aviation physiology
Relevance. In studying the history of medical and biological disciplines, an important part is the identification of the stages of their formation and development. In this regard, it seems important to make a historical and scientific analytical review of the development of ideas about aviation physiology, covering different stages of the history of science and reflecting the contribution of researchers from different regions. It will be useful for teaching historical and scientific and special disciplines, as well as for researchers involved in the study of aviation physiology. The need to understand how the human body functions in flight arose along with the development of aeronautics. The study is devoted to the analysis of the main stages in the development of aviation physiology. The purpose of the study - to characterize the stages of formation and development of aviation physiology. Research methods. In preparing this publication, articles in publications included in the RSCI, PubMed, and Scopus were mainly used. Preference was given to materials published in the last 15 years. The main results present the stages of development of aviation physiology with a description of the contribution of the main researchers in this field. The achievements of domestic scientists, doctors, physiologists I.M. Sechenov, L.A. Orbeli, G.M. Zarakovsky are analyzed, their scientific priorities in the development of this scientific direction are presented. The process of formation and development of aviation physiology as a direction of biomedical knowledge is presented. Before the advent of aviation (19th century), hypoxia was studied in the study of balloon flights. With the advent of high-speed and maneuverable aircraft, aviation physiology began to study the body’s response to overloads caused by highly maneuverable flights. Conclusion . The development of aviation physiology can be divided into two stages. 1. Pre-aviation, within which the emergence of this area of medico-biological knowledge takes place. 2. Aviation, at this stage scientists have the opportunity to study different multidirectional overloads and their effect on the human body. Currently, aviation physiology is one of the important branches of physiology, aviation and space medicine
Ranking of acidic soils by priority of liming in the Russian Federation
Excessively acidic soils account for one third of arable land in the Russian Federation (35.1 million ha). Over the post-reform period (1990–2019), the relative share of acidic soils increased by 2%, due to a sharp decrease in the area of liming, and thus restoration of acidic properties of genetically acidic soils previously limed, as well as the involvement in agricultural use of some abandoned fields and fallows covered by acidic soils. This paper demonstrates a new approach to prioritize areas for liming by the example of the Vladimir region. The study makes use of newly established database “Soils of agricultural lands in the Russian Federation” which includes 10,000 soil quality typological unites and 57,678 soil quality mapping units (SQMU). National “Grain equivalent model” calculates the standard yields for grain crops by each SQMU. The GIS analysis allows joining spatial distribution of soil acidity and standard yields of grains in order to determine the priority areas for lime application. Acidic soils with the highest grains standard yield are proposed to be considered as high-priority ones for liming. Application of the given method in two districts of the Vladimir region showed significant reduction in the payback period of liming
Asymmetrical current generator operating modes in battery charging
This paper presents the investigation of the different operating modes of the asymmetrical quasi-sinusoidal output current inductive-switch generator. The purpose of investigation is to find the most effective operation mode where an acceptable output current quality is combined with relatively small dynamic losses in switches. Depending on the algorithm of the generator switches, there are four operating modes. The calculations describing the generator operating principle were obtained for each operating mode
Exploring the Therapeutic Potential of Defective Interfering Particles in Reducing the Replication of SARS-CoV-2
SARS-CoV-2 still presents a global threat to human health due to the continued emergence of new strains and waning immunity among vaccinated populations. Therefore, it is still relevant to investigate potential therapeutics, such as therapeutic interfering particles (TIPs). Mathematical and computational modeling are valuable tools to study viral infection dynamics for predictive analysis. Here, we expand on the previous work on SARS-CoV-2 intra-cellular replication dynamics to include defective interfering particles (DIPs) as potential therapeutic agents. We formulate a deterministic model that describes the replication of wild-type (WT) SARS-CoV-2 virus in the presence of DIPs. Sensitivity analysis of parameters to several model outputs is employed to inform us on those parameters to be carefully calibrated from experimental data. We then study the effects of co-infection on WT replication and how DIP dose perturbs the release of WT viral particles. Furthermore, we provide a stochastic formulation of the model that is compared to the deterministic one. These models could be further developed into population-level models or used to guide the development and dose of TIPs
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