bluuebunny/crossref_metadata_2025 huggingface dataset:
Response of actinidia deliciosa plants to abiotic stress in the Russian subtropical zone
Authors: Abilfazova Yu. S.
Published: September 2024

The article presents a general description of the culture of Actinidia deliciosa, grown in the humid subtropics of Russia. The work was carried out since 2017 at the site of the Adler experimental station of the branch of the Federal Research Center of the N.I. Vavilov All-Russian Institute of Plant Genetic Resources and in the laboratory of plant physiology and biochemistry of the Subtropical Scientific Center of the Russian Academy of Sciences, Sochi. Physiological and biochemical indicators were determined that reflect the resistance of actinidia plants planted in 1988 to environmental stress factors to identify the most adapted varieties to the conditions of the humid subtropics of the Krasnodar Territory. The soil is alluvial meadow with low humus. The varieties studied were late ripening Hayward; Ellison, Abbott and Bruno – early; Monty – medium; Tomuri (pollinator of kiwi female varieties). The indicator organ is physiologically mature actinidia leaves, which were selected from May to September against the backdrop of a natural increase in air temperature. Water deficit was in 2022–2023 is 29.62–36.46%, the minimum is for the Ellison and Monty varieties (29.62–30.21), the maximum is Abbott (36.46%). The dry matter content is 25.47–35.53%, the water content of leaf blades is 46.09-62.66%. The Monti, Hayward and Tomuri varieties are the most resistant to the weather and climatic conditions of the Russian subtropical zone.
Preservation of the seed collection during the Great Patriotic War
Authors: Zakharova O. A. , Kucher O. D.
Published: September 2024

The article examines the historically significant period of N.I. Vavilov’s activities and his team in conducting 108 expeditions and collecting plant seeds in more than 1000 countries worldwide. By 1940, the collection was the largest in the world. Vavilov’s research aimed to study the genetic potential of seeds, establish centers of origin for wild and cultivated plants, their role in human practical activities, and the formation and replenishment of the collection initiated before the revolution by the founders of applied botany. Additionally, the article analyzes the challenging periods experienced by the collection, such as the formation of Soviet Russia, the Siege of Leningrad, and participation in the restoration of the devastated agriculture after Victory in World War II. Special attention is paid to the involvement of employees of the Federal Research Center “N.I. Vavilov All-Russian Institute of Plant Genetic Resources” (VIR) in preserving the collection during the Siege of Leningrad. The practical application of the research results lies in understanding the importance of preserving plant genetic resources for food security and sustainable development of rural regions. The publication emphasizes not only the historical value of the seed collection but also its contemporary significance as an important resource for scientific research and practical use in agriculture. The scientific article also highlights the heroic efforts of VIR employees, who endured the harsh conditions of the Siege of Leningrad but continued to carefully preserve plant seeds, contributing to the survival and revival of agriculture in our homeland. The dedication and professionalism of the employees to the cause are underscored. Thus, the article reveals the historical and practical significance of the VIR seed collection, an important national genetic resource that continues to serve the goals of agricultural science and practice.
Toxicological characteristics of the drug Hyperico
Authors: Sklyarov O. D. , Rakhmatullin E. K. , Babicheva O. V. , Litvinov N. A.
Published: September 2024

The article presents the results of a study of the toxicity of the drug Hyperico. It has been established that the drug is low-toxic and safe for animals with daily use. It does not provoke the development of pathological reactions. According to the classification of Hodge and Sterner (1943), Hyperico can be classified as toxicity class 6 – relatively harmless. The LD50 value of the drug after intragastric administration to white rats was ≥ 36400 mg/kg, to mice – ≥ 45400 mg/kg, irritation of the mucous membranes of the digestive tract was not observed. According to GOST 12.1.007.76, Hyperico belongs to the 4th hazard rating, that is low-hazard substances. Based on the results of the study, a reasonable conclusion can be made that Hyperico does not have a toxic effect on calves. There are no contraindications for conducting clinical trials of the drug Hyperico.
EFFECT OF COMPANY SIZE, FINANCIAL MISTAKES AND CHANGE MANAGEMENT REGARDING AUDITOR SWITCHING
Authors: Puji Lestari Utami , Aniqotunnafiah Aniqotunnafiah , Aeni Nur
Published: September 2024

research objectives of this study are, to analyze the influence of company size on auditor switching in food and beverage sub-sector manufacturing companies in 2017-2021. To analyze the influence of Financial Distress on Auditor Switching in Food and Beverage Sub-Sector Manufacturing Companies in 2017-2021. To analyze the effect of Management Changes on Auditor Switching in Food and Beverage Sub-Sector Manufacturing Companies in 2017-2021. The type of research used is quantitative and type research data Which used in study This is data secondary. Population Which used in study This is company manufacturers listed on the Indonesian Stock Exchange (BEI). Sample selection carried out using a purposive sampling method. Data analysis method using analysis statictics descriptive and analysis regression logistics. This research using 110 samples data company. results following, Company size has no effect on auditor switching food and beverage sub-sector manufacturing companies. Financial distress positive and significant effect on auditors switching in food and beverage sub-sector manufacturing companies. Substitution management No influential to auditors switching on food and beverage sub-sector manufacturing companies. Keywords :  Switcing Auditor, Company Size, Financial Distress, Change of Management
ASPEK - ASPEK YANG BERPENGARUH TERHADAP MINAT BERWIRAUSAHA PADA MAHASISWA
Authors: Risnawati Heni , Mudiarti Hasna , Muttaqin Ibnu
Published: September 2024

The aim of this research is to analyze the influence of entrepreneurial knowledge, family environment and freedom to work on students' interest in entrepreneurship at Pancasakti University, Tegal. The research method used is quantitative research. The sampling technique was purposive sampling which had the criteria of UPS Tegal accounting students who had taken entrepreneurship courses. Data collection using a G-Form questionnaire distributed to students. The research results simultaneously show that entrepreneurial knowledge, family environment and freedom to work influence students' entrepreneurial interest. Partially, entrepreneurial knowledge has a significant effect on entrepreneurial interest. The family environment has a significant influence on students' entrepreneurial interest. Freedom to work has a significant effect on students' entrepreneurial interest. Keywords; Entrepreneurship knowledge, Family environment, Freedom in entrepreneurship, Interest in entrepreneurship
ANALISIS FAKTOR-FAKTOR YANG MEMPENGARUHI KETEPATAN WAKTU PENYAMPAIAN LAPORAN KEUANGAN PERUSAHAAN (Studi Pada Perusahaan Sektor Makanan dan Minuman Periode 2020-2022)
Authors: Manasikana Arina , Putra Yanuar Surya , Riyanti Budi
Published: September 2024

All publicly traded firms are required by OJK laws to file their annual reports on time. Financial reports become more valuable if they are submitted following the designated reporting time, which is why timely submission of financial reports is intended to enable users to examine reports in a timely and pertinent manner. The purpose of this study is to ascertain, partially or concurrently, the impact of return on assets, debt-to-equity ratio, current ratio, business age, and audit opinion on the punctuality of financial report submission in manufacturing enterprises in the food and beverage sector. Secondary data for the 2020–2023 period released by the BEI is what was used. This study uses tools from logistic regression analysis and is explanatory. The study's findings indicate that the variables return on assets, debt to equity ratio, current ratio, age of the company, and audit opinion have no significant impact on how quickly a company submits its financial reports. The factors of return on assets, debt-to-equity ratio, current ratio, firm age, and audit opinion all significantly impact how quickly food and beverage companies produce their financial reports.Keywords: Financial reports, return on assets, debt to equity ratio, current ratio, audit opinion
Identification of toxin-producing cyanobacteria in water reservoirs of Kirov region and assessment of their relationship with water toxicity to hydrobionts
Authors: Sysolyatina M.A. ,   Vyatka State University, Moskovskaya Str., 36, Kirov, 610000, Russia, Sidelev S.I. ,   P.G. Demidov Yaroslavl State University, Sovetskaya Str., 14, Yaroslavl, 150003, Russia, Kutyavina T.I. ,   Vyatka State University, Moskovskaya Str., 36, Kirov, 610000, Russia
Published: September 2024

Molecular genetic methods of analysis were used for the first time detection of cyanotoxin biosynthesis genes (microcystin, cylindrospermopsin, anatoxin-a, and saxitoxins) in organisms inhabiting the two largest water reservoirs of Kirov region (Belokholunitsky and Omutninsky) located in the northeast of the Russian Plain in the southern taiga subzone. The mcyE gene responsible for microcystin production was detected in all phytoplankton samples, and the anaC gene responsible for anatoxin-a production was detected in the most samples. 14 cyanobacteria taxa were found in the phytoplankton of the studied reservoirs. Microcystis and Dolichospermum are the most probable microcystin producers. The most probable anatoxin-a producers in Belokholunitsky reservoir are Aphanizomenon flos-aquae and Dolichospermum planctonicum, and in Omutninsky reservoir – Cuspidothrix issatschenkoi and Dolichospermum flos-aquae. Water from the studied reservoirs had an acute toxic effect on luminescent bacteria Escherichia coli (“Ecolum” test system) and protozoa Paramecium caudatum Ehrenberg, but was non-toxic to Entomostracans Daphnia magna Straus.
Hyperspectral imaging of sediment cores - a case study of Lake Khorlakel (Western Caucasus)
Authors: Alexandrin M.Y. ,   Institute of Geography RAS, 29 building 4 Staromonetny lane, Moscow, 119017, Russia, Molenkamp N.B. ,   Institute of Geography RAS, 29 building 4 Staromonetny lane, Moscow, 119017, Russia
Published: September 2024

The study focuses on the hyperspectral imaging of sediment cores – a novel analytical method providing high-resolution biogenic markers – with sediment core of Lake Khorlakel (Western Caucasus) as a case study.
Palaeosedimentation in Khotavets lake (Mologa-Sheksna lowland) inferred from the results of explicit GPR survey and drilling data
Authors: Bobrov N.Yu. ,   St Petersburg State University, Universitetskaya Emb., 7/9, St Petersburg, 199034, Russia, Sadokov D.O. ,   Shenzhen MSU-BIT University, International University Park Road, 1, Dayun New Town, Longgang District, Shenzhen, Guangdong Province, 518172, P.R. China,   ITMO University, Lomonosova Str., 9, St. Petersburg, 191002, Russia, Sapelko T.V. ,   Institute of Limnology of the Russian Academy of Sciences, SPC RAS, Sevastianova Str., 9, St Petersburg, 196105, Russia, Terekhov A.V. ,   Arctic and Antarctic Research Institute, Beringa Str., 38, St Petersburg, 199397, Russia, Babushkin M.V. ,   Darwin State Nature Biosphere Reserve, vil. Borok, 44, 162723, Russia, Mukhin A.K. ,   Darwin State Nature Biosphere Reserve, vil. Borok, 44, 162723, Russia, Beliaeva O.M. ,   St Petersburg State University, Universitetskaya Emb., 7/9, St Petersburg, 199034, Russia
Published: September 2024

Late Glacial – Holocene sedimentary record has been obtained from a lake basin at the north of East-European Plain, and AMS14C-dated. Coring results were coupled with the ground penetrating radar (GPR) survey, which enabled for the sedimentary sequences’ chronology to be upscaled for the whole basin and beyond. A prominent peat layer (presumably of Allerød age) has been suggested as a marking horizon to correlate with the Late Glacial lacustrine dynamics in the area. Laminated silt with low organic matter content (of the Younger Dryas age), underlain by sandy silt deposits were discovered both from the boreholes and via the geophysical survey. The lower surface of these strata forms wavy and hummocky bottom relief. Organic muds (accumulated in the Holocene) cover the mineral deposits equally.
Holocene geochemical record of Lake Kasplya (Smolensk oblast, Russia) bottom sediments and its interpretation
Authors: Andreev R.A. ,   Lomonosov Moscow State University, Leninskie Gory, 1, Moscow, 119234, Russia,   Institute of Geography, Russian Academy of Sciences, Staromonetny per. 29, Moscow, 119017, Russia, Shasherina L.V. ,   Institute of Geography, Russian Academy of Sciences, Staromonetny per. 29, Moscow, 119017, Russia, Konstantinov E.A. ,   Institute of Geography, Russian Academy of Sciences, Staromonetny per. 29, Moscow, 119017, Russia, Manakova O.I. ,   Lomonosov Moscow State University, Leninskie Gory, 1, Moscow, 119234, Russia
Published: September 2024

This research focuses on the reconstruction of Lake Kasplya (Smolensk oblast) history in Holocene based on the interpretation of the bulk inorganic and organic geochemistry records. We derived bulk inorganic geochemistry for the lake bottom sediment record using X-ray fluorescence and conducted a principal component analysis (PCA) using geochemistry and lithogenic data. Based on PCA, we obtained a three-component model, which describes 73% of the variance. Each component represents a factor that contributes to the geochemical and lithogenic records: lithogenic, chemically altered matter, and organic matter inputs to the lake.
Polyunsaturated long-chain alkenones in the lake sediments of North-Minusinsk valley (southern Siberia) as a paleo-indicator of climate change
Authors: Bulkhin A.O. ,   Institute of Biophysics Siberian Branch of the Russian Academy of Sciences (IBP SB RAS), Akademgorodok Str., 50/50, Krasnoyarsk region, Krasnoyarsk, 660036, Russia, Zykov V.V. ,   Institute of Biophysics Siberian Branch of the Russian Academy of Sciences (IBP SB RAS), Akademgorodok Str., 50/50, Krasnoyarsk region, Krasnoyarsk, 660036, Russia, Boyandin A.N. ,   Institute of Biophysics Siberian Branch of the Russian Academy of Sciences (IBP SB RAS), Akademgorodok Str., 50/50, Krasnoyarsk region, Krasnoyarsk, 660036, Russia, Marchenko D.N. ,   Institute of Biophysics Siberian Branch of the Russian Academy of Sciences (IBP SB RAS), Akademgorodok Str., 50/50, Krasnoyarsk region, Krasnoyarsk, 660036, Russia,   Siberian Federal University (SibFU), 79 Svobodny Pr., Krasnoyarsk region, Krasnoyarsk, 660041, Russia, Anishchenko O.V. ,   Institute of Biophysics Siberian Branch of the Russian Academy of Sciences (IBP SB RAS), Akademgorodok Str., 50/50, Krasnoyarsk region, Krasnoyarsk, 660036, Russia, Kabilov M.R. ,   Institute of Chemical Biology and Fundamental Medicine Siberian Branch of the Russian Academy of Sciences, 8 Ac. Lavrentieva ave., Novosibirsk, 630090, Russia, Rogozin D.Y. ,   Institute of Biophysics Siberian Branch of the Russian Academy of Sciences (IBP SB RAS), Akademgorodok Str., 50/50, Krasnoyarsk region, Krasnoyarsk, 660036, Russia,   Siberian Federal University (SibFU), 79 Svobodny Pr., Krasnoyarsk region, Krasnoyarsk, 660041, Russia
Published: September 2024

The research of biochemical thermo- and salt-sensitive markers - long-chain alkenones in sediments of lakes of the North Minusinsk valley is an important contribution to the understanding of climatic changes in this region. We found that the total concentration of alkenones in the top layers of bottom sediments of saline lakes increases significantly at a salinity of about 20 g l-1. Also, it was found that the average chain length of alkenones in the surface sediments rises with increasing salinity and thus can be used as an indicator of salinity, and the ratio of alkenones C37/C38 varies widely, suggesting that this index can be used as a paleo-indicator of salinity. The high correlation between ￼, ￼ and ￼ indices with salinity indicates their potential for paleosalinity reconstruction. The obtained functional dependences were additionally verified in the core of bottom sediments of Lake Utichie-3 and confirmed the possibility of using alkenones as a paleo-indicator of climatically determined salinity changes in endorheic lakes. The taxonomic composition of haptophyte algae and alkenone composition in the studied lakes were comparable to lakes in prairie regions of North America.
Anthropogenic activity in prehistory on the background of Holocene climate changes in the south-eastern Baltic region
Authors: Druzhinina O. ,   Herzen University, 48, Nab. Mojki, Saint-Petersburg, 191186, Russia, Gedminienė L. ,   Nature Research Centre, Vilnius, 08412, Lithuania, Skhodnov I. ,   Scientific Research Centre Peribaltic Archaeology, Kaliningrad, 236000, Russia, Burko A. ,   Herzen University, 48, Nab. Mojki, Saint-Petersburg, 191186, Russia
Published: September 2024

Data on natural palaeoarchives combined with archaeological materials from prehistoric sites of the south-eastern Baltic provide a picture of ancient anthropogenic activity and main stages of evolution of local communities starting from the Mesolithic. Modern Analog Technique (MAT) method applied for the Kamyshovoe lake palynological data is used to reconstruct the seasonal temperature and precipitation trends and values during the Holocene. During the Mesolithic, climate conditions changed from those close to the late Glacial through a period of warmer and wetter climate with parameters close to the present day to conditions of climatic optimum, when temperature was several degrees higher that modern ones. These climate conditions existed during the first part of the Neolithic as well, while from about 5500 cal yr BP the climate changed towards colder temperatures and a shift in seasonal moisture content: summers became wetter and winters less snowy. For the Bronze Age, relative temperature stability along with significant precipitation fluctuations are reconstructed. Since the Iron Age, temperatures remain close to modern ones and several “wetter” episods are distinguished.
Lake sedimentation conditions in the lower part Seyda River (north of Komi Republic, Russia) according to palynological and diatom data
Authors: Golubeva Yu.V. ,   Institute of Geology named N.P.Yushkin, Federal Research Center «Komi Scientific Center of Ural Branch of the Russian Academy of Sciences», Pervomayskaya Str., 54, Syktyvkar,167982, Russia, Marchenko-Vagapova T.I. ,   Institute of Geology named N.P.Yushkin, Federal Research Center «Komi Scientific Center of Ural Branch of the Russian Academy of Sciences», Pervomayskaya Str., 54, Syktyvkar,167982, Russia
Published: September 2024

The aim of the study is to investigate sedimentation processes during the Late Glacial and Holocene in the eastern Bolshezemelskaya Tundra. The coastal outcrop SD-5, 16 m high, in the lower reaches of the Seyda River (Komi Republic) was studied. Analytical methods included palynological and diatom analysis, and 14C dating. When characterizing the stages of sediment formation, algae Pediastrum, Desmidiales, and other non-pollen palynomorphs were also identified. The lithological structure of the outcrop and the results obtained made it possible to trace the transformations of the periglacial paleo-reservoir and the four main stages of sedimentation associated with them. The banded clay at its base was deposited in a periglacial lake under periglacial conditions. The overlying layer of interbedded sands accumulated as a result of the descent of the periglacial paleo-reservoir. The peat exposed in the roof of the section was initially formed (12125±49 – 8719±44 14C BP) in a cold deep-water lake that arose in place of a periglacial reservoir. The vegetation cover consisted of yernik and wormwood-chenopodium thickets. Later (up to ~ 4500 14C BP) the shallows were overgrown with wetland plants. The improvement of the climate contributed to the advance of birch and later (7705±43 14C BP) spruce forests. Then, starting from ~ 4500 14C BP, the swamp massif drained and froze, and modern plant communities developed.
A reflection of modern vegetation of the Zhizhgin Island (White Sea) in pollen spectra of lake sediments
Authors: Levkova D.N. ,   Herzen State Pedagogical University of Russia, 48 Nab. Moyki, St. Petersburg, 191186, Russia, Sapelko T.V. ,   Institute of Limnology RAS – SPC RAS, 9 Sevastianova str., Saint-Petersburg, 196105, Russia, Leontiev P.A. ,   Herzen State Pedagogical University of Russia, 48 Nab. Moyki, St. Petersburg, 191186, Russia, Kublitskiy Yu.A. ,   Herzen State Pedagogical University of Russia, 48 Nab. Moyki, St. Petersburg, 191186, Russia, Repkina T.Yu. ,   Institute of Geography RAS, 29 Staromonetnyy lane, Moscow, 119017, Russia
Published: September 2024

The first data on the composition of pollen spectra of subrecent lake sediments were obtained from surface samples of Lake Vodonosnoye and Lake Chernyaevskoye sediments on Zhizhgin Island, which is located in the southern part of the White Sea. Currently, woody vegetation on the island grows in small areas and consists mainly of shrubby birch and willow and oppressed pine. The pollen spectra generally reflect the modern vegetation of the island. The pollen spectra include pollen of tree species and grasses, which occupy large areas of open meadows and wetlands. Picea and Pinus pollen found in significant quantities is partly introduced. Abies and Tilia pollen are also likely introduced. The results of pollen analysis of surface samples will be used for pollen analysis of sediment sequences of the investigated lakes, which will allow for correct interpretation of the data obtained and a more correct reconstruction of the island’s vegetation in the past.
Evolution of Lake Ladoga as recorded in litho- and biostratigraphy of a small coastal lake
Authors: Ludikova A.V. ,   Institute of Limnology of the Russian Academy of Sciences – SPC RAS, Sevastyanova str. 9, St. Petersburg, 196105, Russia, Kuznetsov D.D. ,   Institute of Limnology of the Russian Academy of Sciences – SPC RAS, Sevastyanova str. 9, St. Petersburg, 196105, Russia, Subetto D.A. ,   Herzen State Pedagogical University of Russia, Moika River emb. 48, St. Petersburg, 191186, Russia, Belkina N.A. ,   Northern Water Problems Institute, Karelian Research Centre, Alexander Nevsky pr. 50, Petrozavodsk, 185910, Russia
Published: September 2024

The study is focused on the litho- and biostratigraphic record of Lake Lavijarvi, presently a small lake in the closest vicinity from the Ladoga coast, and formerly a sheltered bay of Lake Ladoga. Several stages of its evolution were revealed that are characterized with different organic matter content in the sediments, diatom assemblages composition and abundances of siliceous microalgae remains. It has been demonstrated that at the earlier stages, the environments in the basin of Lake Lavijarvi were similar to those in Lake Ladoga. Later in the Holocene, local factors became more pronounced, and the conditions different from those in the open-water part of Lake Ladoga established in the basin of Lake Lavijarvi. The regression of Lake Ladoga resulted in the isolation of Lake Lavijarvi and the beginning of its small-lake stage after ca. 3900 cal. BP.
The history of lake Antyukh-Lambina (Kandalaksha coast of the White Sea) based on the study of bottom sediments
Authors: Grekov I.M. ,   Herzen University, Moika river 48-12, 191186, Saint-Petersburg, Russia, Syrykh L.S. ,   Herzen University, Moika river 48-12, 191186, Saint-Petersburg, Russia, Nazarova L.B. ,   Kazan (Volga) Federal University, Kremlyovskaya str 18, 420008, Kazan, Russia
Published: September 2024

We performed a comprehensive analysis of the sediment cores from lake Antyukh-Lambina. Studied area is situated on the Kandalaksha coast of the White Sea. The lake is connected to lake Kolvitskoye by a narrow strait. We have identified several stages in the lake development from brackish to freshwater conditions, since the early Holocene. The desalination and increased organic matter in the sediment have led to an increase in diversity chironomid and cladocera species. Using chironomid analysis, we performed quantitative reconstructions of mean July air temperatures and water depths. The results showed that both parameters have increased gradually since the early Holocene.
Spatiotemporal features of the distribution of Cd, Hg, Pb in bottom sediments of small lakes in the south of Western Siberia formed in various types of sedimentogenesis
Authors: Malov G.I. ,   V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, Ave. Academician Koptyug, 3, Novosibirsk, 630090, Russia, Strahovenko V.D. ,   V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, Ave. Academician Koptyug, 3, Novosibirsk, 630090, Russia, Ovdina E.A. ,   V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, Ave. Academician Koptyug, 3, Novosibirsk, 630090, Russia, Malov V.I. ,   V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, Ave. Academician Koptyug, 3, Novosibirsk, 630090, Russia
Published: September 2024

The paper presents data on the weight contents of Cd, Hg, Pb in bottom sediments of small lakes in the south of Western Siberia. For sapropel deposits of natural moisture of different types and classes, formed under conditions of all types of sedimentogenesis (humid, arid and nival), the average calculated volumetric contents of Cd, Hg, Pb: 0.05 g/m3, 0.01 g/m3, 3 g/m3, respectively. It was revealed that their volumetric quantity per 1 m3 in sapropel deposits of natural humidity of small lakes does not increase during the Holocene period, varying from lake to lake regardless of the type of sedimentogenesis and composition of bottom sediment.
Holocene vegetation dynamics of the Yamal Peninsula based on palaeobotanical data from relict peat bog deposits
Authors: Korona O.M. ,   Institute of Plant and Animal Ecology, Ural Branch of the Russian Academy of Sciences, ul. 8 Marta, 202, Yekaterinburg, 620144, Russia, Trofimova S.S. ,   Institute of Plant and Animal Ecology, Ural Branch of the Russian Academy of Sciences, ul. 8 Marta, 202, Yekaterinburg, 620144, Russia, Zhilich S.V. ,   Institute of Archaeology and Ethnography, Siberian Branch of the Russian Academy of Sciences, Lavrentyev prospect, 17, Novosibirsk, 630090, Russia, Lapteva E.G. ,   Institute of Plant and Animal Ecology, Ural Branch of the Russian Academy of Sciences, ul. 8 Marta, 202, Yekaterinburg, 620144, Russia
Published: September 2024

We have performed a comprehensive paleoecological study of the peat bog deposits from six localities of the Seyakha, Yuribey and Khadytayakha rivers in the subarctic tundra zone on the Yamal Peninsula. Radiocarbon dating, as well as pollen and plant macrofossil analyses were used to track the chronological changes of the plant communities on the peninsula along the North-South transect in the Late Glacial and Postglacial periods. It was found that open woodland with tree birch and spruce existed in the Yuribey river valley during the Bölling-Allerød interstadial (between 14.7 and 12.7 cal. ka BP). Shrub tundra with Betula nana was widespread in this area during the Younger Dryas, between 12.6 and 11.7 cal. ka BP, under climatic conditions similar to modern ones. The spread of arboreal species (Betula sect. Betula, Picea obovata, Larix sibirica) and associated boreal herbaceous plants began later (between 10.2 and 9.7 cal. ka BP) as climatic conditions improved. The most favorable conditions for tree birch and larch existed in the Seyakha river valley between 10.2 and 8.7 cal. ka BP, whereas the best conditions for the same species and spruce in the Yuribey river valley were observed between 10.2 and 4.4 cal. ka BP. It was much warmer than it is today, and open woodland or even closed forests were widespread. Forest degradation and spread of open landscapes with tundra communities occurred in the Seyakha river valley after 8.7–8.5 cal. ka BP and in the Yuribey river valley after 4.7–4.3 cal. ka BP. Climatic conditions became similar to modern ones. Today, arboreal species grow in the Khadytayakha river valley, forming extrazonal forest communities in the subarctic tundra zones.
Paleoecology of peatland in the vicinity of the dune massif – Linde tukulan (Central Yakutia)
Authors: Pavlova M.R. ,   Melnikov Permafrost Institute, Siberian Branch of the Russian Academy of Science, Merzlotnaya Str., 36, Yakutsk, 677010, Russian, Lytkin V.M. ,   Melnikov Permafrost Institute, Siberian Branch of the Russian Academy of Science, Merzlotnaya Str., 36, Yakutsk, 677010, Russian, Shaposhnikov G.I. ,   Melnikov Permafrost Institute, Siberian Branch of the Russian Academy of Science, Merzlotnaya Str., 36, Yakutsk, 677010, Russian
Published: September 2024

Results of investigation of peatland uncovered within an ancient deflationary basin in the south-eastern part of the Linde tukulan (Central Yakutia) are presented. On the basis of lithological, palynological and radiocarbon data, we reconstruction structure of peatland, performed a preliminary reconstruction of the end Late Pleistocene ‒ Holocene landscape and climatic conditions of the peatland and surrounding areas. Three stages of the peatland development were identified: 1) Younger Dryas – Early Holocene, 2) first half of the Holocene, 3) Late Holocene.
Sediment geochemistry of Lake Portlubol (Murmansk region): natural anomalies and reconstruction of anthropogenic events in the catchment
Authors: Slukovskii Z.I. ,   Institute of the North Industrial Ecology Problems of Kola Science Center of RAS, Academgorodok Str., 14a, Apatity, 184209, Russia, Dauvalter V.A. ,   Institute of the North Industrial Ecology Problems of Kola Science Center of RAS, Academgorodok Str., 14a, Apatity, 184209, Russia
Published: September 2024

The article presents the first data on the content of a wide range of rare elements in modern sediments of Lake Portlubol, located in the north of the Murmansk region (Arctic zone of the Russian Federation). The authors identified extremely elevated concentrations of U and Mo compared to the clarke and background levels, which is associated with the geological features of the study area. Also, in the upper layers of the sediment core of Lake Portlubol, an increase in the content of Pb, Cd, Ni, Cu and some other elements was noted, which probably entered the reservoir as a result of emissions from industrial enterprises in the region and neighboring territories. Despite the identified geochemical anomalies in the sediments, the lake can be considered background, since the established anthropogenic load is small compared to lakes in urban and industrial areas of the Murmansk region.
Early Holocene transgression in the central of Svalbard: research results and problems of reconstruction
Authors: Soloveva D.A. ,   Arctic and Antarctic Research Institute, Beringa Str., 38, Saint-Petersburg, 199397, Russia, Okunev А.S. ,   FSBI «VNIIOKEANGEOLOGIA», Angliyskiy av., 1, Saint-Petersburg, 190121, Russia, Kupriyanova N.V. ,   FSBI «VNIIOKEANGEOLOGIA», Angliyskiy av., 1, Saint-Petersburg, 190121, Russia
Published: September 2024

The report presents the results of the study of Holocene marine sediments and terrace levels in the central part of West Spitsbergen Island. The results of the study showed that the postglacial transgression in the study area reached marks of 30-35 m and 40-45 m in the north and south of the study area, respectively. The early Holocene marine sediments were formed in shallow-water, predominantly ice-sea conditions with an unstable coastline. The sea level retreat was rapid and was accompanied by a general cooling.
Okenone and other fossil photopigments from the bottom sediments of Lake Shira, as a proxy of recent changes in the hydrological regime of the lake
Authors: Zykov V.V. ,   Institute of Biophysics, Siberian Division of the Russian Academy of Sciences (IBP SB RAS), Akademgorodok Str., 50/50, Krasnoyarsk region, Krasnoyarsk, 660036, Russia, Rogozin D.Y. ,   Institute of Biophysics, Siberian Division of the Russian Academy of Sciences (IBP SB RAS), Akademgorodok Str., 50/50, Krasnoyarsk region, Krasnoyarsk, 660036, Russia,   Siberian Federal University (SibFU), 79 Svobodny Ave, Krasnoyarsk region, Krasnoyarsk, 660041, Russia
Published: September 2024

Studying the pigment composition of bottom sediments of the meromictic Lake Shira allows us to learn about the past of the reservoir. Analysis of carotenoids of frozen cores of the upper layers of bottom sediments, and comparison with field observations shows the relationship between the hydrological regime of the lake and the content of okenone, a carotenoid of purple sulfur bacteria.
The age and size of the last glacial-underground lake of the Chui basin (Gorny Altai)
Authors: Zolnikov I.D. ,   Sobolev Institute of Geology and Mineralogy, Siberian Branch Russian Academy of Sciences, Koptyuga 3, Novosibirsk, 630090, Russia, Novikov I.S. ,   Sobolev Institute of Geology and Mineralogy, Siberian Branch Russian Academy of Sciences, Koptyuga 3, Novosibirsk, 630090, Russia, Kurbanov R.N. ,   Institute of Geography, Russian Academy of Sciences, Staromonetny Lane 29, Moscow 119017 Russia, Filatov E.A. ,   Sobolev Institute of Geology and Mineralogy, Siberian Branch Russian Academy of Sciences, Koptyuga 3, Novosibirsk, 630090, Russia, Glushkova N.V. ,   Sobolev Institute of Geology and Mineralogy, Siberian Branch Russian Academy of Sciences, Koptyuga 3, Novosibirsk, 630090, Russia, Levitskaya P.S. ,   Institute of Geography, Russian Academy of Sciences, Staromonetny Lane 29, Moscow 119017 Russia
Published: September 2024

Chronology and size of the last glacier-dammed lake in the Chuya Basin is still actively debated, because it is inextricably linked with the problem of the age and scale of the last glacial megaflood, which passed through the Chuya, Katun, and Ob valleys. For the first time, direct dating of lacustrine sediments of the last glacial-dammed lake of the Chuya Basin reaching up to 1980 m has been carried out. Obtained ages corresponds to the last glacial maximum (MIS-2) and confirms the glaciation of this age in the area within the valet connecting Chuya and Kurai basins.
Limno-glacial deposits: Sources of sediments and processes of sedimentation
Authors: Subetto D.A. ,   Herzen State Pedagogical University of Russia, 48 Moika Emb. 48, St.Petersburg, 191186, Russia, Strakhovenko V.D. ,   Herzen State Pedagogical University of Russia, 48 Moika Emb. 48, St.Petersburg, 191186, Russia,   V.S. Sobolev Institute of Geology and Mineralogy SB RAS, 3 Academician Koptyug Ave., Novosibirsk, 630090, Russia, Belkina N.A. ,   Herzen State Pedagogical University of Russia, 48 Moika Emb. 48, St.Petersburg, 191186, Russia,   Northern Water Problems Institute KarRC RAS, 50 Alexander Nevsky Ave., Petrozavodsk, 185030, Russia, Rybalko A.E. ,   Herzen State Pedagogical University of Russia, 48 Moika Emb. 48, St.Petersburg, 191186, Russia,   FGBU ‘VNIIOkeangeologiya’, 1 Angliyskiy Pr., St.Petersburg, 190121, Russia,   Institute of Earth Sciences SPBSU, 33-35, 10th line V.O. St.Petersburg, 199178, Russia, Potakhin M.S. ,   Herzen State Pedagogical University of Russia, 48 Moika Emb. 48, St.Petersburg, 191186, Russia,   Northern Water Problems Institute KarRC RAS, 50 Alexander Nevsky Ave., Petrozavodsk, 185030, Russia, Kublitskiy Yu.A. ,   Herzen State Pedagogical University of Russia, 48 Moika Emb. 48, St.Petersburg, 191186, Russia, Orlov A.V. ,   Herzen State Pedagogical University of Russia, 48 Moika Emb. 48, St.Petersburg, 191186, Russia,   Northern Water Problems Institute KarRC RAS, 50 Alexander Nevsky Ave., Petrozavodsk, 185030, Russia, Kulik N.V. ,   Herzen State Pedagogical University of Russia, 48 Moika Emb. 48, St.Petersburg, 191186, Russia,   Northern Water Problems Institute KarRC RAS, 50 Alexander Nevsky Ave., Petrozavodsk, 185030, Russia, Anisimov N.V. ,   Herzen State Pedagogical University of Russia, 48 Moika Emb. 48, St.Petersburg, 191186, Russia,   Vologda State University, 15 Lenina str., 160000, Vologda, Russia, Malov V.I. ,   Herzen State Pedagogical University of Russia, 48 Moika Emb. 48, St.Petersburg, 191186, Russia,   V.S. Sobolev Institute of Geology and Mineralogy SB RAS, 3 Academician Koptyug Ave., Novosibirsk, 630090, Russia
Published: September 2024

The article presents the theoretical postulates of limno-glacial type of sedimentation and examines its features on the example of the Onego Ice Lake.
Biological diversity and structure of sub-ice algal-bacterial communities in the Maloye More Strait (Lake Baikal)
Authors: Bashenkhaeva M.V. ,   Limnological Institute of the Siberian Branch of the Russian Academy of Sciences, st. Ulaanbaatarskaya, 3, 664033 Irkutsk, Russia, Zakharova Yu.R. ,   Limnological Institute of the Siberian Branch of the Russian Academy of Sciences, st. Ulaanbaatarskaya, 3, 664033 Irkutsk, Russia, Petrova D.P. ,   Limnological Institute of the Siberian Branch of the Russian Academy of Sciences, st. Ulaanbaatarskaya, 3, 664033 Irkutsk, Russia, Khanaev I.V. ,   Limnological Institute of the Siberian Branch of the Russian Academy of Sciences, st. Ulaanbaatarskaya, 3, 664033 Irkutsk, Russia, Likhoshway Ye.V. ,   Limnological Institute of the Siberian Branch of the Russian Academy of Sciences, st. Ulaanbaatarskaya, 3, 664033 Irkutsk, Russia
Published: September 2024

An analysis of the taxonomic structure and diversity of sub-ice algal-bacterial communities in the Maloye More Strait of Lake Baikal in two different ecotopes (the bottom surface of the ice and the water column) was carried out. According to high-throughput sequencing of the 18S rRNA fragment and microscopy, the dinoflagellates Gymnodinium baicalense and green algae Binuclearia lauterbornii predominated on the bottom surface of the ice, while the diatoms Ulnaria acus and Fragilaria radians and green algae of the genus Monoraphidium> and Koliela predominated in the water column. In the bacterial communities, the most abundant phyla were Actinobacteria, Proteobacteria and Bacteroidetes.
Colourless sulphur bacteria in the ecosystem of Lake Baikal
Authors: Chernitsyna S.M. ,   Limnological Institute, Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia, Bukin S.V. ,   Limnological Institute, Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia, Elovskaya I.S. ,   Limnological Institute, Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia, Sitnikova T.Ya. ,   Limnological Institute, Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia, Zemskaya T.I. ,   Limnological Institute, Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia
Published: September 2024

The morphology and phylogenetic analysis of three genera of colourless sulphur bacteria found in different regions of Lake Baikal were studied. Based on 16S rRNA gene analysis, Baikalian Thioploca sp. belongs to the cluster of freshwater representatives of this genus from different lakes and is identical to the species T. ingrica. A new species of Ca. Thiothrix namsaraevi was discovered in the Zmeiny hot spring using whole genome analysis. Single filaments with sulphur inclusions from the Hakusy hot spring were identified as Beggiatoa sp. with 99% homology to uncultivated representatives of the genus.
Features of microbial communities in fresh lakes of Buryatia
Authors: Dagurova O.P. ,   Institute of General and Experimental Biology, Siberian Branch of the Russian Academy of Sciences, Sakhyanovoi st., 6, Ulan-Ude, 670047, Russia, Zaitseva S.V. ,   Institute of General and Experimental Biology, Siberian Branch of the Russian Academy of Sciences, Sakhyanovoi st., 6, Ulan-Ude, 670047, Russia, Tsydenova B.V. ,   N.L. Dobretsov Geological Institute of the Siberian Branch of the Russian Academy of Sciences, Sakhyanovoi st., 6a, Ulan-Ude, 670047, Russia, Kozyreva L.P. ,   Institute of General and Experimental Biology, Siberian Branch of the Russian Academy of Sciences, Sakhyanovoi st., 6, Ulan-Ude, 670047, Russia, Buryukhaev S.P. ,   Institute of General and Experimental Biology, Siberian Branch of the Russian Academy of Sciences, Sakhyanovoi st., 6, Ulan-Ude, 670047, Russia, Dambaev V.B. ,   Institute of General and Experimental Biology, Siberian Branch of the Russian Academy of Sciences, Sakhyanovoi st., 6, Ulan-Ude, 670047, Russia, Barkhutova D.D. ,   Institute of General and Experimental Biology, Siberian Branch of the Russian Academy of Sciences, Sakhyanovoi st., 6, Ulan-Ude, 670047, Russia
Published: September 2024

The taxonomic composition of microbial communities of eight large fresh lakes of Buryatia was studied. These lakes are Baikal, Kotokel, Gusinoye, Shchuchye and lakes of the Eravno-Kharginskaya group (Isinga, Gunda, Sosnovoe, Bolshoe Eravnoe). They have water management, fishery and recreational significance. At the phylum level, the microbial communities of the studied lakes were similar but the phyla abundance was varied. They consisted of typical freshwater taxa Pseudomonadota, Actinobacteriota, Bacteroidota, Cyanobacteriota, Firmicutes, Planctomycetes and Verrucomicrobia. At the genus level, Acinetobacter and Pseudomonas were numerous in all lakes. Other dominant taxa were Flavobacterium, hgcI clade in the fresh lakes of the Baikal region and Exiguobacterium, Klebsiella in the Eravno-Kharginskaya lakes. The feature of Eravno-Kharginskie lakes was the abundance of the genera Exiguobacterium and Klebsiella, as well as the detection of sanitary-significant bacteria. These facts may indicate pollution as a result of pressing various factors, including anthropogenic ones.
Phototrophic bacterioplankton of four stratified boreal ferruginous lakes of the Northern Hemisphere: comparative analysis of vertical 16S rRNA profiles
Authors: Gorbunov M.Yu. ,   Samara Federal Research Center of the Russian Academy of Sciences, Institute of Ecology of the Volga Basin of the Russian Academy of Sciences, st. Komzina, 10, Togliatti, 445003 Russia
Published: September 2024

The aim of the study was to analyze the phototrophic bacterioplankton composition and vertical structure of Lake Linevo, a polyhumic iron-rich lake in the Raifa section of the Volga-Kama Nature Reserve (Tatarstan, Russia), and three other ferruginous boreal lakes in Russia, Finland, and Canada. The results demonstrated the presence of identical phylogenetic groups and dominant operational taxonomic units, but the inntensity of development and overall structure of the phototrophic bacterioplankton community was nevertheless different. Highest abindance was detected in Lake Linevo which had a number of unique features when compared to the other studied lakes. In particular, it had the largest number of phototrophic bacteria and a significant abundance and diversity of phototrophic Chloroflexales that were scarce in the other lakes. It seems desirable to further characterize the oxygen-depleted zone of this lake in more detail and, if possibly, to apply metagenomic and whole-genome analysis methods that have already been used in lakes Lovojärvi and L227 as well as many other boreal brown-water lakes.
Characterization of Saccharimonadia bacteria in Lakes Baikal and Khubsugul: taxonomic and functional diversity
Authors: Gutnik D.I. ,   Limnological Institute Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia, Potapov S.A. ,   Limnological Institute Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia, Krasnopeev A.Y. ,   Limnological Institute Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia, Tikhonova I.V. ,   Limnological Institute Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia, Bukin Yu.S. ,   Limnological Institute Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia, Gladkikh A.S. ,   Saint Petersburg Pasteur Institute, 14 Mira Street, Saint Petersburg, 197101, Russia, Klyuchnikova E.O. ,   Saint Petersburg Pasteur Institute, 14 Mira Street, Saint Petersburg, 197101, Russia, Sbarzaglia V.A. ,   Saint Petersburg Pasteur Institute, 14 Mira Street, Saint Petersburg, 197101, Russia, Aslamov I.A. ,   Limnological Institute Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia, Belykh O.I. ,   Limnological Institute Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia
Published: September 2024

Ultra-small bacteria are ubiquitous in the environment, but for some time they have remained out of scientific focus. One of the reasons is their small size. Ultramicrobacteria, which are defined as bacteria with a cell size of less than 0.1 µm3, can pass through a filter with a pore size of 0.2 µm. Moreover, there are some difficulties associated with their cultivation. Currently, relatively pure cultures have been obtained, but mostly for dominant phyla. Rare phyla are represented only by single strains. At the same time, ultramicrobacteria are found in a wide range of environments, and their high-ordered, small genomes and unique physiological features attract the increasing attention of researchers. The development of metagenomics allows us to partially overcome cultivation limitations, and in this article, we present metagenomic assemblies derived from water samples of the largest oligotrophic lakes on the Earth, Baikal (Russian Federation) and Khubsugul (Mongolia). In this study, we carried out the taxonomic and functional analysis of reconstructed genomes of Saccharimonadia class bacteria (phylum Patescibacteria), which is intended to expand our knowledge of rare representatives of microbial communities and supplement the already available information regarding the inhabitants of the oldest ecosystems.
Growth patterns of bacterial cultures depending on the nitrogen availability
Authors: Kan G.V. ,   Limnological Institute Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia, Suslova M.Yu. ,   Limnological Institute Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia, Tikhonova I.V. ,   Limnological Institute Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia, Lipko I.A. ,   Limnological Institute Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia, Belykh O.I. ,   Limnological Institute Siberian Branch of the Russian Academy of Sciences, Ulan-Batorskaya Str., 3, Irkutsk, 664033, Russia
Published: September 2024

Morphological and ultrastructural growth patterns of bacterial cultures in response to the nitrogen availability were demonstrated using cultivation and scanning electron microscopy (SEM). It was found that strains of Pseudomonas sp. 1CB and Streptomyces sp. 21A are able to grow only in the medium with available nitrogen. Rhizobium sp. 2A formed biofilm on glass in medium with nitrate and in medium without available nitrogen. In a non-nitrogenous medium, an increase in the diameter of bacterial cells was observed due to the intensive secretion of polysaccharide mucus, which can be considered a mechanism of protection of the nitrogenase complex from the damaging effect of oxygen.