Natural and medical sciences

While transiting to an innovation economy, cities are the most important centres of concentration of intellectual capital. However, their distribution around the territory of the country is not even. Various Russian cities also demonstrate significant differences between the systems of new scientific knowledge reproduction. The article focuses on the mesoscale study of spatial patterns in concentration of national centres of competence. The scientific cen­tres are classified according to their ability to produce scientific knowledge and their number in the Russian Federation regions is assessed. The most im­portant clusters of research centres in Russia have been identified.

The agricultural land dynamics is one of the central issues of land use in Europe and Russia. Each historical period is characterized by its own model of agricultural land use. The analysis of its dynamics in the North-West of Rus­sia and the Baltic countries was based on the following parameters: the area of cultivated agricultural land and the rate of change, the grain yield and its dy­namics. Database analysis from 1848—52 until 2015—18 allowed to identify the stages of the agricultural land management dynamics. The stages of ex­pansion and contraction, intensification and transition to extensive agricul­tural production are caused by combined influence of natural, socio-economic and political factors. The periods of decline in agricultural land use coincided with years of economic and political crises. The onset of periods of recovery matches a change in state policy, general economic growth and a rise in the technological level of agriculture, as well as changes in the domestic and for­eign markets. Over the past decade, there has been an increase in cultivated land area in the Baltic countries and the Kaliningrad region, and crop yields are growing throughout the region. Given the characteristic features of agri­cultural land management dynamics, subregions and the main trends in their development were determined.

The issues of employment have a certain importance while assessing the socio-economic situation throughout the country. The published statistical da­ta analysis presents a good background for comparing employment indicators of the Kaliningrad region with the national average as well as with the indica­tors of its closest neighbours among the Russian regions — the Pskov and the Smolensk regions. Despite the fact that economic and demographic situation in the Kaliningrad region is more favorable than in the majority of other Rus­sian regions, disparities between availability and quality of labor resources, and the needs of the region’s economy have been established. The authors also note that  one of the prerequisites to reduce disparity is the implementation of Human Capital Development Program, based on the use of the capabilities of the Geographic Information System, and created by «Netrika» company.

Artificial electromagnetic fields are a byproduct of the electrical or elec­tronic devices as an inevitable consequence of the modern scientific and tech­nical progress, and at the same time poorly studied environmental impact fac­tor.  Research of current levels and spatial distribution of electromagnetic fields in Kaliningrad aimed at mapping, defining statistically significant characteristics for types of land use and building types, revealing abnormal areas and their correspondence to hygienic standards and levels safety. The conducted research of electromagnetic fields of industrial frequency has shown that intensity of electric fields in the central part of Kaliningrad reaches con­siderable values only in immediate proximity to a high-voltage line. Magnetic fields of industrial frequency are extended everywhere and extremely uneven­ly that has been presented in the original map. Hygienic standards of magnet­ic induction are observed, but safety levels are exceeded in the abnormal loca­tions caused by underground cables.

The article focuses on changes in the composition of the Pregolya water eco-systems in the city of Kaliningrad due to the anthropogenic transfor­mation of the coastal area from 2013 to 2018. The work identifies the modern structure of the Pregolya eco-systems. The research included standard meth­ods of studying the aquatic vegetation.  The lower current of the river Preg­olya within the Kaliningrad city borders is studied for the period from 2013—2019. The associations are named in the traditions of the dominant system. It is established that the total number of species in the direct impact zone and downstream has remained the same. However, the structure of plant commu­nities and their species composition has changed. Some species have fell out of communities or reduced their projective coverage; some communities in the city center have disappeared. Inherent to the β-mesosaprobic and eutrophic waters, Lemna minor, Cladophora glomerata have increased their abundance in communities, acting as dominants and codominants. The most significant changes in the river vegetation have been identified for two districts. Since 2013, associations with the dominance of Phragmites australis, Scirpus lacus­tris, Sagittaria sagittifolia, Butomus umbellatus, Carex acuta, Potamogeton lucens, etc. have disappeared in the construction zones. In 2019 several loca­tions witnessed the initial stages of restoration of plant communities that were destroyed here earlier.  

The areas of disturbed bedding, which are considered as glaciodislocations are one of the structural features of the Quaternary strata of the Kaliningrad Region. Known for a century and a half and characterized by a variety of forms, they have not yet been practically studied, and there is very little knowledge of  their formation mechanisms. Meanwhile, some of the disloca­tions, such as the glacial blocks, may be of interest as amber deposits. The aim of the work is to characterize and systematize the unique glaciotectonic for­mations observed in the surface, mainly Quaternary, sediments of the Kali­ningrad Peninsula. Based on the classification proposed by E. A. Levkov (1980), some glacio-dislocations have been systematized. Formations of active ice — folded-scaly dislocations, glaciodiapirs and glacial blocks, and “dead” ice — glaciokarst disturbances, injective forms, have been identified and char­acterized.

The study is focused on features of hydrometeorological conditions in the southeastern Baltic Sea and their trends assessment for 2005—2019 (climatic half period). The authors used the data from field observations of atmospheric pressure, wind direction and speed, and air temperature from the automatic hydrometeorological station located offshore, as well as the satellite data from the infrared and microwave (radar images) ranges to determine sea ice and sea surface temperature, respectively. The research also reveals characteristic fea­tures of long-term dynamics of hydrological conditions in the south-eastern part of the Baltic Sea for 2005—2019. The average annual atmospheric pres­sure is close to regular and equals to 1014.6 ± 1.7 hPa; its growth is estimated at a rate of 0.10 hPa/year. South-west and west winds prevail and they in­crease their speed during cold season. Increase in the number of storms is shown (+ 2 storms/15 years), however, the duration of storms has decreased and the maximum recorded wind speed has declined. The average annual air temperature over the south-eastern part of the Baltic Sea has increased by 1.6°C compared to the middle of the XX century and it rises annually at a rate of 0.04° С/year. The sea surface temperature simultaneously is rising with a slower rate (0.02° С/year) and the maximum area of the ice field ob­served in the sea is decreasing (– 112,5 km2/year).

Interest in nitrogen-containing heterocycles can be brought about by the possibility of obtaining organic compounds with new properties by introduc­ing various substituents into the structure. The aim of this work is to aminate quinoid structures with dibenzothiazine to produce condensed heterocycles with a bridged nitrogen atom. It is the N-substituted derivatives that form a bridge between the dibenzothiazine molecule and the substituent that are con­sidered as the most promising substances. When aminating benzoquinone and its derivatives with dibenzothiazine, we can expect an increase in the potential biological activity and inhibitory properties of new compounds. The presence of copper affects the intensity and direction of the reaction when reactants in­teract. Practice-wise, the work can expand the spectrum of quinone and dibenzothiazine derivatives containing biologically active fragments.

The article focuses on normative values of the liver shear wave elas­tography and comparison of various works in elastography of the internation­al and Rus­sian research. A variety of normal values of liver stiffness during shear wave elastography obtained by different authors when measuring on various devices are presented. The normal range of liver stiffness measure­ments in healthy peo­ple var­ies widely: the normal liver elasticity values may vary in range of 1.5—7.5 kPa on measuring by transient elastography (Fi­broScan, Echosens); 2.4—6.2 kPa on measuring by point shear wave elas­tography (iU elite, Philips); 2.6—6.2 kPa on measuring by 2D shear wave elastography (Aixplorer, Supersonic Imagine). The liver shear wave velocity varies in the range of 0.71—1.71 m/s on measur­ing by the point shear wave elastography. The given data of the normal liver stiffness measurement and shear wave velocity in healthy people could not be taken as the reference data for assessing the normal values. Consensus is needed on the subject of normal values of the liver stiffness measurements and shear wave velocity in the liver tissue. Considering the discrepancy between the re­sults of normal liver stiff­ness values in the sonographic equipment of various manufacturers dynamic observation upon liver stiffness values should be per­formed using the same machine in the same individual on the depth of 2—5 cm from liver capsule, preferably by the same operator. Caution should be given while using thresh­old values of the normal liver stiffness on different equipment because it influ­ences the assessment of the liver stiffness measurements and, consequently fi­brosis stage.