Hydrological changes in the White Sea during the historical period inferred from analysis of dinocysts

According to available historical evidence, colonization of the White Sea region began in the 9th–8th centuries B.C. [2]. This unique region with ancient residence sites experiences progressively increasing anthropogenic load against the background of natural climatic changes. The intense economic development of the region requires complex ecological and paleogeographic studies aimed at detailed reconstruction of past sedimentation settings. The analysis of dinocysts, which makes it possible to reconstruct various parameters of water masses washing the Arctic shelf, has become a promising method in paleohydrological studies, widely used in recent years [10, 11]. Dinoflagellates, which represent one of the main phytoplankton groups in the Arctic Seas, the White Sea included, form cysts with biopolymer envelopes, which are preserved in sediments. Thus, information on glacial–hydrological conditions is recorded in marine sediments. In the White Sea, this method was first used for the study of bottom sediments only in 2003 [3, 15]. In this communication, we present the first results obtained during the thorough study of dinocysts in bottom sediment cores from the White Sea, which cover the last 250 years. The study of this microfossil group made it possible to reconstruct in detail changes in glacial–hydrological settings in the sea and reveal their relations with known climatic–hydrological events that occurred in neighboring regions during the historical period

Quaternary palynostratigraphy of the Pechora Sea

By combining the lithologic, original palynologic and published micropaleonthological data we reconstructed paleogeographical events On the Pechora shelf during the Younger Dryas and Holocene time. Our paleoenvironmental reconstructions are based On the regularities in formation of pollen-and-spores assemblages in the surface sediments of the Pechora Sea. The main stages in paleogeography of the Pechora Sea during the Late Pleistocene were emphasized. The Late Valdai sediments in the Pechora Sea region were accumulated under the influence of fluvioglacial flows probably from the melting ice cap on Kolguev Island and, also, coastal glaciers. Climate deterioration considerably changed coastal vegetation as reflected in the depleted taxonomic and quantitative composition of palynospectra. The pollen data suggest that Open steppe-like plant communities with Artemisia, Poaceae, Asteraceae and Caryophyllaceae dominated dry ecotopes On watersheds, whereas tundra-like communities with Betula nana, arctic Salix, Dryas, Saxifraga, Carex and Brassicaceae were common in more humid coastal lowlands. The overlying silts and loamy sands are believed to have been accumulated during early deglaciation, i.e., Older Dryas and Alleröd. During this phase the glacial sedimentation was rather rapidly replaced by a glaciomarine deposition. Progressive climate warming caused prominent changes in coastal vegetation. Discontinuous treeless tundra-steppe associations were replaced by dwarf and shrub ernik tundra. A "complex vegetation cover" of forest-tundra apparently existed in the northern part of the Kola Peninsula and in the Northern Dvina Lowland. By the end of the Alleröd alder-bushes and horsetails occupied riverbanks, and spruce occurred in the forest-tundra communities on the adjacent hinterland

Dinoflagellate cysts in the surface sediments of the White Sea

Dinoflagellate cysts were studied in 42 samples from the surface sediments of the White Sea. The total concentration of dinocysts varies from single cysts to 25 000 cyst/g of dry sediments, which reflects the biological productivity in the White Sea waters and the regional particular features of the sedimentation processes. The highest concentrations are observed in silts; they are related to the regions of propagation of the highly productive Barents Sea waters in the White Sea. Generally, the spatial distribution of dinocysts species in the surface sediments corresponds to the distribution of the major types of water masses in the White Sea. The cysts of the relatively warm-water species (Operculodinium centrocarpum, Spiniferites sp.) of North Atlantic origin that dominate in the sediments indicate an intensive intrusion of the Barents Sea water masses to the White Sea along with hydrological dwelling conditions in the White Sea favorable for the development of these species during their vegetation period. The cold-water dinocyst assemblage (Islandinium minutum, Polykrikos sp.) is rather strictly confined to the inner parts of shallow-water bays, firstly, those adjacent to the Onega and Severnaya Dvina river mouths

Informal Sperm Donation in Russia

Received 3 June 2021. Accepted 24 September 2021. Published online 11 October 2021.Rising infertility across the globe has created a growing demand for assisted reproductive technologies (ART). In recent years, apart from sperm donation in formal settings such as fertility clinics, informal donation practices have emerged and spread across Russia. These reproductive donation practices have become possible due to the development of social networks and private online platforms. We conducted a pilot study (eleven semi-structured interviews) of the informal sperm donation in Russia and analysed donorrecipient interactions, donors’ expectations and experiences of finding recipients online. We focus on donors’ motivations and on the meanings, which donors invest in this practice that consumes significant resources on their part (medical tests and artificial insemination costs, travel and accommodation expenses, sometimes mutually agreed financial support of future offspring). We interpreted the practices that coalesced around informal donation from the perspective of symbolic interactionism, because it allowed us to showcase how actors reflected on and formulated the meanings of their actions in the absence of externally imposed rules (legal regulations, established moral conventions). Since informal donation practices do not fit into the traditional schemes of interpretation, such research requires the actors involved in informal donation either to create their own schemes or to modify the existing conceptual frames in creative ways. The study shows that informal donors do not only provide their genetic material but also spend time and invested considerable resources to ensure their procreation, including eventual financial support of the child. At the same time, these men are not interested in marital relations or paternal relations with their offspring. Thus, the informal sperm donors do not associate the parental project with traditional family and its values. We conclude that ART engendered a new phenomenon, which might be described as extramarital reproduction. Assisted reproduction outside marriage gains footing in Russia and requires more detailed further study

Reproductive toxicity of carbon nanostructured material - a promising carrier of drugs in laboratory mice

At the same time, the purpose of this study was to evaluate the reaction of the reproductive system on the carbon nanostructured material "Taunit (multi-walled carbon nanotubes), that was injected to laboratory miceyesBelgorod State Universit

The influence of the microstructure morphology of two phase Ti-6Al-4V alloy on the mechanical properties of diffusion bonded joints

The influence of ultra fine grained (UFG) and coarse grained (CG) microstructure of the titanium alloy Ti-6Al-4V on the strength of a diffusion bonded (DB) joint was studied using a laboratory DB fixture and a new shear test rig. The DB process was carried out at 725°C and 825°C during 2 and 4 hours in a vacuum furnace. Coarsening of grain structure resulting from different DB cycles was quantified. The chain pores were observed at 725°C for both microstructure conditions bonded during 2 hours. The increase of bonding time up to 4 hours leads to subsequent elimination of the pores. The UFG samples bonded at 725°C showed a higher level of the shear strength than CG samples for both bonding times. The CG material demonstrated the highest shear strength after 4 hours of DB bonding at 825°C. The increase of the creep deformation of UFG samples when compared to the CG condition was observed as a result of DB at of 725° C during 4 hours

The numerical field analysis of excitation modes and of the different types of the armature reaction in a powerful turbogenerator

Представлены принцип и результаты численно-полевого анализа разных режимов возбуждения и видов реакции якоря турбогенератора. Показаны выбор факторов возбуждения магнитного поля и метод определения на его основе магнитного потокосцепления, ЭДС и фазовых соотношений между ними и токами. Представлены картины магнитных полей во всех режимах, а также дан принцип построения соответствующих векторных диаграмм. Проведенные исследования могут быть основой совершенствования проектирования турбогенераторов и других электрических машин.Principle and the results numerical field analysis of the different excitation modes and of the different types of the armature reaction of powerful turbogenerator are presented. A selection of the factors of the magnetic field excitation in the idle mode, the rated load and short-circuit, as well as those specific modes that are characterized by longitudinal demagnetizing and magnetizing and more cross-reaction of the armature excitation of the magnetic field only the stator winding along the longitudinal and transverse axes of the rotor is shown. The principle, which allows by the results of the calculation of the magnetic field in each mode to determine the key electromagnetic values (magnetic flux and EMF) and the phase relationship between them and the currents is considered. The pictures of the magnetic fields are graphically presented in all modes, and also principle of construction of the corresponding vector diagrams is presented on the basis of calculation of these fields. In the original received vector diagrams it is possible to qualitatively and quantitatively identify the share and role of the magnetic field of the rotor and the stator magnetic field. The conducted research can be the basis for improving the system of study, analysis and design of turbogenerators and other electric machines because the considered method of analysis of magnetic fields is quite universa

Analysis of harmonic composition of the alternating magnetic field associated with the rotating rotor of a turbogenerator in the modes of no-load and short-circuits

Представлен численно-полевой метод расчета переменной составляющей магнитного поля на поверхности вращающегося ротора турбогенератора. Он основан на многопозиционных расчетах магнитного поля с поворотами ротора и изменениями токов в обмотке статора. В фиксированных точках поверхности выделяется переменная составляющая магнитной индукции и для ее временной функции выполнен гармонический анализ. Разработанный метод универсален с точки зрения режимов возбуждения, конструкции и насыщения магнитопровода. Теоретические основы апробированы расчетными исследованиями в режимах холостого хода и короткого замыкания турбогенератора.The method of calculating the alternating component of the magnetic field at the surface of the rotating rotor of a turbogenerator is presented. It is based on multiposition numerical calculations of the magnetic field with the turns of rotor and changes of currents in the stator winding. Discrete time functions of the alternating component of the magnetic induction are selected in points of the surface. For them, the harmonic analysis is conducted. The developed method is universal in terms of modes of excitation, designs and saturation of the magnetic core. The theory is confirmed by computational researches in the modes of no-load and short circuit of a large turbogenerator. In it, the alternating component of the magnetic induction on the rotor surface in the short-circuit mode is on an order of magnitude greater than in the no-load mode. Values and harmonic composition of the alternating component of the magnetic induction differ substantially at different points of the rotor surface. Harmonics are ponderable in the range from the level determined by the phase structure of stator winding to the level determined by the tooth structure of its core. The results obtained are qualitatively fit into the classical notion of oscillatory processes of the magnetic field on the rotor surface, but now the value and harmonic composition of the alternating component of the mag-netic induction are received adequate numerical filling. The result of work can be used for designing of a turbogenerators and other synchronous machine

Extralinguistic Conditions of Language Variability in National Languages

The article is aimed at studying the concept of the existence of socially motivated language variants.  They are explained by sociolinguistic differentiation and specific use of language in different situations of communication. The dialectical connection of the objective world, the society and a language gives the latter a special dynamic character. It is manifested in active language processes at all linguistic levels and in language usual innovations. Sociolinguistic variants do not only show different images of the world, but also reflect the changes of the world depending on the culture, which, in turn, is reflected in the specifics of linguistic phenomena. Language norms, in this case, correlate not only with communicative attitudes, but also with the cultural ones. In the context of linguistic variability, the speakers of codified standard language, who can switch from one sociocultural language to another one, in the official or informal communication can choose and use various sociolinguistic language variants in their everyday life. It explains the novelty of the research, which is closely related to the typological study of the paradigm of national language situations, determined by the presence of various social strata and groups in the United States, Germany, France, the Czech Republic, Russia and other countries. The authors view the language situation as a socially-motivated model of speech behavior of a native speaker in the social language space