Northern (Arctic) Federal University

Wildfires are an increasingly important factor in boreal forest biome. The fire cycle have significant effects on the cycling of nutrients within and through an ecosystem. Past research shows that major elements, nutrients, and organic matter in stream water can be altered for decades after a wildfire. Here we examine how stream chemistry might be used to characterize biogeochemical effects of fire across the continuous permafrost taiga of the Central Siberia. By comparing the results of laboratory combustion of organic horizons, soil solution chemistry in burned and unburned watersheds, and stream chemistry in a chronosequence of watersheds with a well-described fire history, we assess possible proxies in stream water chemistry for wildfire severity and timing in this landscape. Our results suggest that the time since last wildfire can be estimated by sulfates (SO 4 2− ) and nitrates (NO 3 − ) concentrations, and that the soil active layer thickness (ALT, the soil depth at which soil thaws annually) increase by wildfires is reflected in bicarbonates (HCO 3 − ) concentrations. Phosphate (PO 4 3− ), although it is released from organic matter by combustion, is unchanged in stream water following fire. Chloride (Cl − ) produces a useful marker for hydrologic conditions at the time of sampling, allowing a relatively small number of stream water samples to be used to characterize past fire regime. Concentrations of SO 4 2− , NO 3 − and HCO 3 − in stream runoff can thus be used as a specific fingerprint of fire history in the northern taiga larch and birch forests of the Central Siberia, since an increase in their concentrations in stream runoff reflects fire occurrence in the catchment area. • Wildfires increase concentrations of major ions in pyrogenic organic layers, topsoil and streams. • Phosphorus is liberated by organic matter combustion, but retained in subsoil. • Wildfires affect stream HCO 3 − , SO 4 2− , Cl − and NO 3 − concentrations at decadal scales. • Stream bicarbonate can serve as a proxy for the active layer depth and wildfire timing • Sulfate in stream water is the most reliable indicator of time since fire disturbance in the catchments.

The article is devoted to the study of the activity of radionuclides of natural and anthropogenic origin in the bottom sediments of the Pechora River delta lakes, which represent the largest river in the European sector of the Arctic Ocean Basin. The study revealed that the average activities of the radionuclides 137Cs, 210Pb, 226Ra, 232Th and 40K in the lake bottom sediments are 2.7, 22.6, 18.3, 25.4 and 535.9 Bq/kg, respectively. The mean values of total alpha and beta activities of the bottom sediments are 334.8 and 720.7 Bq/kg, respectively. These values are commensurate with the global average, thereby signifying a minimal level of natural and anthropogenic radioactivity in the Pechora delta lakes’ sediments. The data on physical and chemical parameters demonstrated that the flooded lakes of the Pechora delta are characterized by a relatively weak manifestation of sedimentation and biological processes. This is due to the hydrological regime of the delta (flooding of lakes during flood periods, daily tides) which prevents active accumulation of fine mineral and organic material in the lakes. The profound impact of hydrological conditions within the Pechora delta is evident in the disorderly vertical distribution of physico-chemical parameters and radionuclide activities across the depth of bottom sediment columns. The data obtained on radionuclide activities and physico-chemical parameters has enabled the estimation of the role played by flooded delta lakes as a component of the Pechora estuary system in the accumulation of pollutants. However, the vertical distribution of radionuclides in bottom sediments of these lakes has been found to be an unreliable indicator of the chronology of pollutant loads in the Pechora basin. This is due to the Pechora delta’s complex hydrological regime, which ensures the uneven flow of mineral and organic material into the lakes over time. The study of lake chronology is complicated by the manifestation of thermoabrasion (destruction) of lake shores, which is characteristic of permafrost development areas and which ensures the inflow of additional volumes of terrigenous material into lake basins.

Ten samples of Atlantic salmon ( Salmo salar L.) caught in the Mezen River in the Mezensky District of the Arkhangelsk Region were prepared by the methods traditional for this place: cooking, frying, baking and salting. Methods for fish preparation, utensils and auxiliary materials were chosen based on the data of survey of the local population. The study assessed experimentally an effect of four methods of culinary processing on the concentration of six elements in the fish fillet: mercury (Hg), arsenic (As), lead (Pb), cadmium (Cd), zinc (Zn) and copper (Cu). Analysis of the results of the experiment demonstrates changes in all six elements in the Atlantic salmon fillet upon culinary processing irrespective of the chosen method, although each method affected these indicators in different degrees. As a result of the study, it has been established that the cooking process led to a decrease in the level of mercury and arsenic in Atlantic salmon in the highest degree. This method of fish preparation is also preferable for the maximum preservation of essential elements — zinc and copper. With that, arsenic and lead are drawn into the broth during cooking. It has been shown that it is best to salt Atlantic salmon to reduce a concentration of cadmium. Salting also demonstrated a significant reduction in the levels of mercury in the fish fillet. However, salting also reduces the concentration of essential zinc and copper. Frying and baking demonstrated the similar effect on changes in the levels of cadmium and copper. It has been confirmed that fish preparation at a high temperature (frying, baking) facilitates a decrease in the levels of essential zinc and copper.

Introduction. The problem of studying civic identity is relevant in the context of modern social changes affecting the development of the younger generation of our country. Adolescence requires special attention in the study of civic identity and its components, particularly the subjective assessment of knowledge related to civic identity as a criterion of the cognitive component. This is due to the sensitivity of identity formation in early (15–18 years old) and late (19-23 years old) youth. The instability of the civic position, coupled with exposure to external influences, creates a risk of developing negative forms of civic self-determination. The aim of the study. To identify the dynamics of the factor structure of the subjective assessment of their knowledge related to civic identity among young people of adolescent age during their transition from the early period of adolescence (15-18 years) to the late (19-23 years). Methods. The “I know” questionnaire by I.V. Kozhanov was modified (the Cronbach's alpha coefficient is 0.86). The results were analysed using factor analysis with the statistical analysis package SPSS Statistics 22.00 for Windows. The study sample consisted of 280 young people (students) from Arkhangelsk in the early and late periods of adolescence. Results. The dynamics of the factor structure of the subjective assessment of one's knowledge as a criterion of the cognitive component of civic identity in the transition of young people from early to late adolescence was identified and described; the leading components of civic identity in the content of the factor structure in the periods of early and late adolescence were identified. Conclusions. Qualitative changes in the factor structure of the subjective assessment of knowledge about civic identity during the transition from early to late adolescence are manifested by: 1) increasing the overall information content of the identified factor structure, 2) distributing knowledge about the structural components of civic identity more evenly, and 3) shifting the focus of knowledge from the all-Russian to the ethnic component of civic identity as they grow older.

The article explores the specifics of adapting historical narratives for children in a theatrical performance by the Arkhangelsk Puppet Theatre. We analyze key strategies for transforming complicated texts, including material selection, plot simplification, introduction of game elements, and visual images. Attention is paid to dramatic techniques such as time scale compression, mythologization of historical events, and changes in the narrative structure to preserve the essence of the literary work while making it accessible to children’s understanding. We show how metaphorical images, interactive elements and a multilayered sound score contribute to the involvement of young viewers and their emotional acquisition of the complex material. The work reveals the educational potential of such adaptations, which transmit historical knowledge and form axiological orientations through gaining artistic experience. The research is based on a comprehensive methodology that combines theatrical, narrative, and pedagogical approaches to identifying effective mechanisms for interacting with children in the theater.

In this work, it has been shown that the scattering of ultrashort X-ray pulses is determined not only by their duration, but also by their shape. It has been shown that the dependence of scattering spectra on the pulse shape has a simple analytical form. Simple criteria have been found for the presence of the effect of the pulse shape on the diffraction pattern, which is especially important in the X-ray diffraction analysis of materials. As an example, the scattering of ultrashort pulses of three different shapes—Gaussian, Mexican hat, and rectangular—on a diamond crystal has been considered.

In March 2019, hydrochemical and microbiological studies were carried out in meromictic Lake Bol’shie Khruslomeny artificially separated from the major basin of the White Sea. It was shown that the hydrochemical parameters of lake water in March 2019 were in close agreement with those recorded in March 2017, which confirms the meromictic status of the water body. In the present work, the method developed previously in GSB monocultures has been used for the first time to separate the bacteriochlorophylls of green sulfur bacteria (GSB) from the absorption spectra of lake water. According to the calculations, the proportion of BChl e in brown-colored GSB at the peak of community development reached one-third of the total content of BChl (d + e). It has been shown that even the low content of brown-colored sulfur bacteria stably surviving in lake water can considerably mask the green pigment of green-colored sulfur bacteria. Chlorobium phaeovibrioides was predominant in the community of the chemocline layer among anoxygenic phototrophic bacteria (APB) (97.9–99.8% of the total APB community). Thiocapsa rosea, Thiocystis gelatinosa, and Thiohalocapsa halophila were also found. The microscopic studies of brown-colored isolates of the species Chlorobium phaeovibrioides demonstrated the high diversity of morphotypes of cells and cell aggregates (twisted filaments, twisted helices, short chains) typical of green-colored bacteria of the species Chlorobium phaeovibrioides (DSM 265) (formerly Chlorobium vibrioforme subsp. thiosulfatophilum DSM 265).