bluuebunny/crossref_metadata_2025 huggingface dataset:
Research Progress on New Highly Efficient Foam Drainage Agents for Gas Wells (A Review)
Authors: Sun Y. Q. , Zhang Y. P. , Liu Q. W. , Fan Z. Z. , Li N. , Wei A. Q.
Published: April 2024

This paper reviews the research background and significance of foam drainage agents, foaming and foam stability mechanisms, and analyzes the advantages and drawbacks of conventional foam drainage agents. With the development of natural gas applications, the exploitation of gas fields becomes more stringent. A new type of foam drainage agent characterized by a wide applicability should be developed based on the particular needs of gas wells. A new foam drainage agent not only resolves the deficiency of conventional foam drainage agents, but also deals with the problem of high costs. It has a higher foam stability and provides a standard for the further design of special conventional and unconventional foam drainage agents for gas fields. Moreover, the polymer addition dramatically improves the performance of foam drainage agents. A Gemini surfactant opens up a new possibility for foam drainage agents. The use of nanoparticles provides the further enhancement of the foam stability for different types of gas reservoirs. The future application trends for foam drainage agents are also discussed. A low-cost and environmentally friendly natural gas promoting a low-carbon green energy, should be developed and used. Highly efficient, environmentally-friendly and recyclable low-cost foam drainage agents would become a hotly debated research point.
Distribution and General Biological Features of Snow Crab (Chionoecetes opilio) in the Chukchi and East Siberian Seas
Authors: Gorbatenko K. M. , Kiyashko S. I. , Morozov T. B. , Glubokov A. I.
Published: April 2024

Hydrobiological surveys (plankton and benthos, including snow crab) were carried out in the summer of 2003–2020 in the south-western region of the Chukchi Sea. At the west, east, and north edges of C. opilio distribution area in the Chukchi Sea the amounts of the crabs were 5–10 times lower due to the limit of species’ tolerance to hydrological factors and inappropriate trophic base – low mass of zoobenthos. Some gatherings of snow crab C. opilio in northern regions of the Chukchi and the East-Siberian Seas can be considered as dependent, which depends on income from southern regions of the Chukchi Sea. The southern regions of the Chukchi Sea are some kinds of the nursery for development and growth of snow crab larvae and youth until 1–2 years age, from where they migrate into northern deeper regions of the Chukchi Sea, and then more fare into north-eastern region of the East-Siberian Sea.
Discovery of New Hydrothermal Ore Fields “Korallovoe” (13°07′ N) and “Molodezhnoe” (13°09′ N) in the Middle Atlantic Ridge
Authors: Makoviz A. M. , Musatov A. E. , Sergeeva I. A. , Cherkashev G. A. , Narkevsky E. V. , Shipov R. V. , Zhidkov Z. V. , Kryukov D. A. , Dobretsova I. G. , Skakovsky V. L. , Kaminsky D. V. , Stepanova M. S. , Bich A. S. , Savin A. S.
Published: April 2024

During the 41th scientific cruise of the R/V “Professor Logachev” in 2019, two new ore fields were discovered within the Russian exploration area of the Mid-Atlantic Ridge. The “Korallovoye” ore field is located in the middle part of the rift valley ridge and lies on a gentle slope in the depth range of 2800–2850 m. The “Molodezhnoye” ore field is located at a distance of approximately 5 km northeast of the “Korallovoye” field and lies on a less steeper section of the slope between 3500 and 3550 m in depth. The “Korallovoye” and “Molodezhnoye” fields are confined to the outcrop of a gabbro-peridotite massif on the western side of the Mid-Atlantic Rift valley. The total number of discovered ore fields in the Russian exploration area has been increased to 14 sites.
Reserves and Distribution of Sand Capacities on the Marine Underwater Coastal Slope of the Anapa Bay-Bar
Authors: Dunaev N. N. , Biryukov E. A. , Maev P. A. , Kosyan R. D. , Krylenko V. V.
Published: April 2024

The Anapa sandy bay-bar and the territories bordering it occupy one of the leading places in Russia as a recreational sanatorium-resort area, sea tourism and children’s recreation, the role of which as a resort of federal significance has now significantly increased. Unfortunately, in recent decades, areas with progressive erosion have been observed on the seashore of this bay-bar. To substantiate the forecast of further development of the coast and the choice of ways to stabilize it, a number of studies have been carried out, including the determination of sand reserves from which the bay-bar is composed, a number of measures for their conservation have been proposed and potential replenishment opportunities have been considered. The presented work considered and analyzed the results of geophysical studies on the marine underwater coastal slope of the Anapa bay-bar, first performed to assess the volume and distribution of wave field sand deposits within the coastal zone as a possible source of beach formation and, accordingly, an increase in the volume of sand in the bay-bar as a whole.
Oceanographic Investigations in the Tropical Atlantic (Cruise 52 of the Research Vessel “Akademik Boris Petrov”)
Authors: Morozov E. G. , Zavialov P. O. , Frey D. I.
Published: April 2024

Information is presented on the work performed to study the flow of Antarctic Bottom Water along the entire length of the Vema Fracture Zone in the tropical part of the North Atlantic Ridge and Russian-Brazilian field studies in the largest river plume of the World Ocean, on the shelf of the northern part of Brazil near the mouth of the Amazon River. A total of 46 stations were completed in the Vema Fracture Zone and 28 stations offshore Brazil. The new expedition that took place was an important step in the development of international scientific cooperation between the BRICS countries: Russia and Brazil.
Application to the World Ocean of the Theory of Transformation of a Mesoscale Vortex into a Submesoscale Vortex Thread When the Vortex Elongates by an Inhomogeneous Barotropic Flow
Authors: Zhmur V. V. , Belonenko T. V. , Novoselova E. V. , Suetin B. P.
Published: April 2024

This paper is a continuation of the authors’ research [5]. We apply some aspects of the theory about strong horizontal stretching of large-scale mesoscale eddies in the World ocean based on ‘the ellipsoidal eddies’ theory to the ocean conditions. Two areas are considered, characterized by increased eddy manifestation. They are the Lofoten Basin in the Norwegian Sea and the Agulhas Current area. We also discuss the condition of the Atlantic Ocean and the World Ocean. The main purpose of this paper is to check the feasibility of the physical conditions for unbounded eddy elongation in the real ocean and estimate the fraction of mesoscale ocean eddies that are elongating into filaments and redistributing energy from the mesoscale to the submesoscale. We estimate the share of eddies in the World Ocean that are strongly elongated. We propose the maps of the geographical location of unlimited eddy elongation zones and give the interpretation of the obtained results. We also describe the effect of a decrease in the vortices’ self-energy due to the tensile action of the background flow. We suppose that it is a possible mechanism for energy transfer from the vortex to the flow and a manifestation of the negative viscosity effect.
Thiosulfate in the Upper Part of the Black Sea Anoxic Water Column
Authors: Dubinin A. V. , Rimskaya-Korsakova M. N. , Ocherednik O. A. , Pakhomova S. V.
Published: April 2024

Thiosulfate is a sulfur compound in an intermediate oxidation state between sulfate and sulfide. It emerges during processes of sulfide oxidation in bacterial and chemical reactions. Thiosulfate plays a prominent role in oxidation of sulfide and its presence may clear the mechanism of redox reactions in the biogeochemical cycles of sulfur and carbon. This work presents the distribution of thiosulfate, determined by derivatization technique with reagent 2,2'-Dithiobis(5-nitropyridine), in the upper part of the Black Sea anoxic water column in 2018–2021. Observations were carried out annually at the station located seaward of Gelendzhik in the area of continental slope. Independently of observation time the concentration of thiosulfate rises depth wards simultaneously with increase of sulfide. The thiosulfate concentration above limit of detection 0.01 µM are found at water depth with density (σθ) of 16.3 kg/m3 and sulfide concentration of 8–11 µM. Thiosulfate reaches its maximum values of 0.30 µM at maximal studied depth of 600 m. We suggest that in the absence of oxidants in the anoxic waters the thiosulfate appearance is attributed to the process of sulfate reduction in reductive part of sulfur cycle. The thiosulfate disappears in the upper part of anoxic water column before the sulfide.
89th Cruise (1st Stage) of the Research Vessel Akademik Mstislav Keldysh: Climate Experiment in Interaction with the Tu-134 Optic Flying Laboratory
Authors: Klyuvitkin A. A. , Novigatsky A. N. , Glukhovets D. I. , Shevchenko V. P. , Belan B. D. , Kravchishina M. D.
Published: April 2024

A unique climate experiment was carried out to study the composition of the air and the characteristics of the underlying surface in the Russian sector of the Arctic and Siberia. Synchronized research onboard the RV Akademik Mstislav Keldysh and the unique scientific facility (USF) flying laboratory Tu-134 Optik were carried out in the South Kara Sea. Validation of airborne and satellite algorithms for calculating the characteristics of the sea surface layer was carried out in the cruise. For the first time on the Arctic shelf, data were obtained on the concentration of methane in the natural system of troposphere–atmospheric surface layer–water column–bottom sediments. The fluxes of greenhouse gases were simultaneously estimated from the shelf area and adjacent land. A related research of the conditions and processes of recent and ancient sedimentation was carried out in the South Kara Sedimentary Basin, where huge hydrocarbon (HC) reserves are localized.
The Lipid Profile of the Tissues of the Gray Whale (Eschrichtius robustus): to the Relationship of Composition of Lipids and Their Physiological and Biochemical Role in Maintaining Tissue Function
Authors: Mamaev M. S. , Murzina S. A. , Voronin V. P. , Litovka D. I. , Rozhnov V. V.
Published: April 2024

A study was made of the composition of lipids in different tissues of gray whales Eschrichtius robustus, and the lipid profiles of tissues with different functional loads were compared. Five types of tissues (skin, muscle, liver, outer and inner layers of fat) were collected from seventeen individuals of eastern gray whales during the permitted aboriginal fishing in the village. Lorino of the Chukotka Autonomous Okrug in the summer of 2020. For all of the listed tissues, the composition of total lipids and their individual lipid classes was studied by high-performance thin-layer chromatography (HPTLC), the identification and description of lipid profiles of different types of tissues was carried out, which made it possible to identify their general and specific features of lipid metabolism according to the studied parameters. Comparative analysis of lipid profiles of tissues revealed individual lipid classes that make the greatest contribution to discrimination between different tissues. Both the content of total lipids and individual lipid classes varied significantly in different tissues. At the same time, 93% of the differences between tissues are two functions that are most closely related to the content of metabolically associated diacylglycerols (DAG), monoacylglycerols (MAG), triacylglycerols (TAG) and waxes, mainly energetic lipids, in tissues. The paper discusses the relationship between the qualitative and quantitative composition of lipids and the functional load and the physiological role of tissues. The metabolic features of the accumulation and consumption of lipid classes during the feeding period were noted. The revealed differences in certain parameters of lipid metabolism of the outer and inner layers of fat are due to different metabolic activity of tissues and their function in the body, which, among other things, is provided by lipids.
Spatial Variability of Macro- and Mesozooplankton in the Bransfield Strait in January 2020
Authors: Gorbatenko K. M. , Yakovenko V. A.
Published: April 2024

The spatial distribution of the biomass of macro- and mesozoopankton species, as well as the size and sex structure of the species Euphausiasuperba (krill), Salpathompsoni, and Ihlearacovitzai in Bransfield Strait during the Antarctic summer of 2020 were studied. Krill is at the heart of the food chain of the Antarctic ecosystem because numerous populations of seabirds, seals and whales feed on krill. In recent decades, the Antarctic ecosystem has been under significant changes caused by global warming, but the nature and extent of this impact on krill stocks, especially its juveniles in the Bransfield Strait, remains insufficiently studied. In recent decades, the Antarctic ecosystem has been experiencing significant changes associated with global warming, but the nature and extent of this impact on krill stocks, especially its juveniles in the Bransfield Strait, remains insufficiently studied. At the same time, this particular region is a highly productive zone of the Antarctic ecosystem and one of the areas where concentrations of Antarctic krill accumulate. The aim of this study was to study the spatial variability of the structure, numbers and biomass of zooplankton in the Bransfield Strait during the Antarctic summer of 2020. Zooplankton samples in Bransfield Strait were collected with Bongo net in January 2020. The samples were processed on the research vessel in the intervals between sampling according to the standard procedure. At all stations studied, the main zooplankton biomass was by salps (S. thompsoni and I. racovitzai). According to the index of coenotic significance, salps were of primary importance in the zooplanktocenosis, in which E. superba occupied the third place with biomass ranged from 6.3 to 96.3 mg/m3, and krill was meet only in the northwestern deep-water part of the Bransfield Strait. This is due to food competition between salps (S. thompsoni, I. racovitzai) and krill. The presence of krill in the deep-water part of the Bransfield Strait is explained by its introduction from the Bellingshausen Sea due to the prevalence of western winds. The biomass of other zooplankton species in all areas of the strait happened very small in comparison with that of salps and krill and was distributed uniformly. When comparing the ratio of the biomass of the above species obtained during the expedition with the data of the 90s and 2000s, there is a clear trend of an increase in salps and a decrease in E. superba, that is probably associated with the general trend of an increase in water temperature in the Antarctic waters. Thus, the example of Bransfield Strait clearly shows a negative correlation between the biomass of salps and krill.
Modeling of the Distribution and Relationship with Abiotic Environmental Factors of Juvenile and Adult Antarctic Krill Euphausia superba Based on Actual Hydrophysical Measurements
Authors: Murzina S. A. , Voronin V. P. , Bitiutskii D. G. , Orlov A. M.
Published: April 2024

The results of statistical processing of the occurrence of krill individuals depending on some environmental factors, based on the actual data of hydrophysical measurements, at the studied stations in the Powell Basin of the Weddell Sea, the Bransfield Strait and Antarctic Sound, as well as off the South Orkney Islands in the austral summer of 2022 are discussed. Data were obtained on the association of the main abiotic environmental factors and their values, which are optimal for juvenile and mature krill individuals, and a number of abiotic environmental factors that affect the distribution of Antarctic krill in the studied region were identified. The results of such statistical modeling are important for monitoring the state of Antarctic ecosystems and their components under changing environmental factors, including current trends in climate change.
The Earth’s Crust Structure of the Persian Gulf According the Results of Deep Seismic Sounding
Authors: Kovachev S. A. , Ganzha O. Yu.
Published: April 2024

The article presents the results of seismic work performed by the DSS method in the Persian Gulf. Bottom analog type seismographs and seismic airgun sources were used in the works. The bottom seismographs were placed and the shooting was carried out according to three regional profiles with a length from 100 to 250 km. The main result of these studies was to obtain velocity-depth model of the sedimentary cover and the Earth’s crust up to Moxo boundary, which was revealed at a depth of about 43 km in the water area. Given that the thickness of the upper crust is only 4–5 km, and the speed characteristics of the remaining layers, the crust type can be attributed to the subcontinental Archean type. This situation (complete absence or drowning of the upper layer of the Earth’s crust) is typical for the waters closest to the Persian Gulf: the Black Sea, the Caspian Sea, the Mediterranean and the Red Seas. A structure was found in the Earth’s crust of the studied area, which may be a brachianticline having an isometric dome-shaped shape, which corresponds to the folding of the platform type in the areas of salt-dome tectonics. No faults have been found in the Earth’s crust of the Persian Gulf water area adjacent to the Bushehr Peninsula.
A New Radiolarian Genus Alexialeks gen. nov. and New Species from the Early Permian of the South Urals of Russia
Authors: Afanasieva M. S.
Published: April 2024

Analysis of the morphology of radiolarian skeletons from the Lower Permian of the South Urals made it possible to revise the taxonomic assignment of Helioentactinia uralica Kozur et Mostler, 1989 and two different morphotypes of Helioentactinia sp. and assign them to three species within the new genus Alexialeks gen. nov.: A. uralicus (Kozur et Mostler, 1989), A. alius sp. nov. and A. distinctus sp. nov. Three pathways are recognized in the evolution of Alexialeks gen. nov. in the Asselian, Sakmarian, Artinskian, and Kungurian (Early Permian). The diagnoses of the genus Multisphaera Nazarov et Afanasieva in Afanasieva, 2000, emend. nov. and subfamily Multisphaerinae Nazarov et Afanasieva in Afanasieva, 2000, emend. nov. are emended. The validity of the subfamily Multisphaerinae Nazarov et Afanasieva in Afanasieva, 2000, emend. nov. is confirmed. A hypothesis is proposed that a primary inner sphere with a rudimentary four-ray spicule and numerous rod-like spines may represent a transitional form of the internal framework of the skeleton from an n-ray spicule to a true microsphere.
New Data on the Neopleistocene Mammal Fauna from the Region of the Natural Park “Lenskie Stolby” (Middle Lena River Basin, Yakutia)
Authors: Boeskorov G. G. , Maschenko E. N. , Ponomarev I. V. , Solomonov N. G. , Nogovitsyn P. R. , Shchelchkova M. V. , Stepanov A. D. , Oleinikov O. B.
Published: April 2024

The data on new finds of the remains of Mammoth fauna mammals in the basin of Middle Lena River (Yakutia, the area of natural park “Lenskiye Stolby (Lena Pillars)” and adjacent territories) is represented in the article. Based on these data, the species composition of the mammoth fauna list of large mammalian species from this region was specified. 11 species of large mammals were identified, among which, for the first time for this region, the presence of a cave lion was established. A series of new radiocarbon datings allowing to note that mass burials of the Pleistocene mammalian remains were mainly formed in this region during the Karginian interstadial (60 (55)–24 thousand years ago, MIS-3). The obtained radiocarbon dates and species composition are consistent with the data that the Karginian interstadial was the most favorable for the distribution of the mammoth fauna in the territory of Yakutia. The results of the studies show that in the Late Pleistocene, the ecological preferences of Ovis nivicola differed from the modern ones. For the first time, the distribution of Panthera spelaea is revealed in the region of the middle reaches of the Lena River.
Electrocoryssopini—a New Tribe of the Subfamily Conoderinae (Coleoptera: Curculionidae) from Baltic Amber
Authors: Legalov A. A.
Published: April 2024

A new tribe Electrocoryssopini trib. nov., with a new genus Electrocoryssopus gen. nov. and a new species E. andrushchenkoi sp. nov., is described from Eocene Baltic amber. The new tribe is similar to the Recent tribes Coryssopodini and Sphadasmini, but differs in the prosternum not having a rostral channel, slightly convex coarsely faceted eyes, femora without teeth, and tibiae lacking uncus.
The Punctae of the Shell of Brachiopod Genus Syringothyris Winchell (Order Spiriferida)
Authors: Afanasjeva G. A.
Published: April 2024

The punctae of brachiopod genus Syringothyris Winchell, 1863 (order Spiriferida) are described and relation of punctae and fibrous secondary layer is characterized. Taxonomic significance of punctae and systematic position of the genus Syringothyris are considered.
New Bivalves of the Genus Streblopteria (Pectinida, Streblochondriidae) from the Permian of Northeast Russia
Authors: Biakov A. S.
Published: April 2024

The problems of taxonomy of Permian pectinoid bivalves are briefly considered in the context of the study well-known Upper Paleozoic genus Streblopteria M’Coy and its historical development in Northeast Russia. Two new stratigraphically important species have been described from the Lower and Middle Permian deposits of the Omolon massif: S. parenensis sp. nov. and S. gracilicosta sp. nov.
On the Systematic Status of Genus Bathropyramis Haeckel (Radiolaria, Nassellaria)
Authors: Amon E. O. , Vishnevskaya V. S.
Published: April 2024

Systematic position and status of the genus Bathropyramis Haeckel, 1882, restituo et emend. Amon et Vishnevskaya, nov. (Radiolaria, order Nassellaria, family Plectopyramididae) are considered, evaluated and revised. The diagnosis of reinstated genus Bathropyramis is clarified, and descriptions of the most ancient species Bathropyramis filatovae Vishnevskaya, 2001, emend. Amon et Vishnevskaya, nov., from Callovian of the Koryak Highlands, and B. sanjoaquinensis Campbell et Clark, 1944, emend. Amon et Vishnevskaya, nov. from Upper Maastrichtian of the Koryak-Kamchatka region, Cinclopyramis victori (Lipman, 1960), emend. Amon et Vishnevskaya, nov., from Eocene of Kamchatka are given.
Fossil Organisms and Their Role in the Formation of Black Oncolites of Kalancha Formation of Vendian in the Baikal-Patom Highlands of Eastern Siberia
Authors: Litvinova T. V.
Published: April 2024

With the help of an electron microscope, the remains of microorganisms and biogenic ultramicrostructures were identified in the black oncolites of the Kalancha Formation and the rocks containing them. As a result of the research it was revealed that only in oncoliths as opposed to containing rocks are other remnants of microorganisms widely distributed: recrystallized filamentous cyanobacteria, fossilized colonies of tubular organisms, as well as individual coccoid formations of biogenic origin. Based on the new factual material, the features of the vital activity of organisms and their participation in the construction of the concentric structure of black oncoliths are analyzed, the features of the interaction of biogenic and abiogenic factors are established.
On the Dimorph Pair Lobosphinctes/Planisphinctes (Ammonoidea: Perisphinctidae) from the Topmost Bajocian–Lowermost Bathonian of the Kuban River Basin (Northern Caucasus, Russia)
Authors: Mitta V. V. , Sherstyukov M. P.
Published: April 2024

Upper Bajocian–Lower Bathonian perisphinctids are studied based on new collections from the upper part of the Upper Djangura Subformation in the interfluve of the Kuban and Urup rivers (Karachay-Cherkessia). Lobosphinctes costulatosus (Buckman) and Planisphinctes tenuissimus (Siemiradzki) are redescribed, and P. pirkli Mitta, sp. nov. is described; shells of Lobosphinctes loczyi (Papp) are identified. These taxa, found ex situ, are confined to the Densicosta and Bomfordi Subzones of the Upper Bajocian Parkinsoni Zone. Lobosphinctes dzhissaensis Mitta, sp. nov. is described from the Lower Bathonian (Zigzag Zone, Beds with Oraniceras scythicum).
A New Antelope Tavridia gromovi gen. et sp. nov. (Artiodactyla, Bovidae) from the Lower Pleistocene of the Taurida Cave in the Crimea
Authors: Vislobokova I. A.
Published: April 2024

A description of a new form of the small antelopes from the Lower Pleistocene of the Taurida cave in the Crimea is given. The new genus and species Tavridia gromovi was identified from a fragment of the skull roof with a horn core and the lower jaw. This small antelope differed from all known forms in the structural features of the horn cores and the dental system. According to the sum of characters, it is assigned to the tribe Antilopini (Eurasia and Africa, Middle Miocene to Recent). The discovery of T. gromovi in the Crimea testifies to the significant diversity of this group of antelopes in the middle of the Early Pleistocene.
New Caddisflies (Insecta: Trichoptera, Necrotauliidae, Philopotamidae) from the Jurassic of Asia and Their Triassic Ancestors
Authors: Sukatsheva I. D. , Sinitshenkova N. D.
Published: April 2024

From the Jurassic of Asia, new representatives of the caddisfly order from the families Necrotauliidae and Philopotamidae are described. From the Upper Jurassic (Karabastau Formation) locality of Karatau in South Kazakhstan, Karataulius martae sp. nov., Archiphilopotamus expectatus sp. nov. and Juraphilopotamus inopinatus sp. nov., while from the Middle Jurassic (Itat Formation) locality Kubekovo, Krasnoyarsk Territory, Necrotaulius communis sp. nov. and Juraphilopotamus similis sp. nov. are described. Keys for species of the genera Archiphilopotamus Sukatsheva, 1985 and Juraphilopotamus Wang, Zhao et Ren, 2009 are given. Data on the stratigraphic and geographical distribution of the Mesozoic representatives of the Philopotamidae are given.
A New Fossil Plant from the Late Devonian Strata of Northern Timan (Russia)
Authors: Snigirevsky S. M. , Lyubarova A. P.
Published: April 2024

Remains of a new fossil plant Petrosjania salarina gen. et sp. nov. were found in the Upper Devonian deposits of the Northern Timan (eastern coast of the Chesha Bay of the Barents Sea). This plant has a number of features characteristic of different groups of higher plants: Barrandeinoid stems (characteristic of the Barrandeinales), flabelloid leaves on stems (Devonian groups incertae sedis) and axilar leaves (characteristic of many plants, including horsetails), fibrous root system (typical for Pteridophyta, Monocotyledones). The systematic position of the new fossil plant, its morphology and possible relationships are discussed.
On the organization of the nuclei in the tegument of some Palaeacanthocephala and Archiacanthocephala
Authors: Nikishin V. P , Ponomarev D. V
Published: April 2024

The giant tegument nuclei of the acanthocephalans of the classes Archiacanthocephala and Palaeacanthocephala are fragmented at the final stage of cystacanthus formation in the intermediate host, but remain connected with each other during later life. It can be assumed that the fragments of each giant tegument nucleus are united with each other forming an independent network that ensures the vital activity of the tegument, the volume of which increases repeatedly during the period of intensive growth of the parasite in the definitive host.
Acaricidal effect of secondary metabolites from symbiotic bacteria Xenorhabdus bovienii and X. nematophila of entomopathogenic nematodes on spider mite Tetranichus urticae (Trombidiformes, Tetranichidae)
Authors: Danilov L. G , Ivanova G. P , Kaplin V. G , Varfolomeeva E. A
Published: April 2024

In laboratory, the highest mortality rates of Tetranychus urticae after the use of metabolic products of symbiotic bacteria with a titer of 1 × 107 were observed in Xenorhabdus bovienii at 6-8 days post application (dpa) in the experiment with live and at 8 dpa of autoclaved culture (about 95%). In experiments with live and autoclaved culture with a titer of 1 × 107, the mortality mites at 8 dpa in X. bovienii was almost the same, but in X. nematophila it was slightly higher in autoclaved culture. At 8 dpa, the efficacy of the live and autoclaved metabolic products of Xenorhabdus bovienii and X. nematophila against the spider mite with a titer of 1 × 105 was about 1.4 times lower compared to the culture with a titer of 1 × 107. The relationship between the mortality of spider mites (%) and the exposure time (days) to bacterial metabolism products most reliably reflects by the polynomial dependence with the accuracy of approximation 0.93-1.0. In the greenhouse, the effectiveness of the bacterial metabolic products of X. bovienii against spider mite was highest in experiments with live culture with a titer of 1 × 108. In experiments with live culture of X. bovienii with a titer of 1 x 107 (in vivo) the mortality rate of spider mites on leaves of shrub Dracaena sanderiana at 8 dpa increased from 84% on the ground floor to 90% on the second floor. The overall efficacy of the bacterial metabolic products of X. bovienii (in vivo, titer 1 × 107) against adults, larvae and nymphs of T. urticae on the leaves of perennial marsh grasses ( Potenderia cordata , Thalia geniculata and T. dealbata ) was about 98-99%.
On the origin of ixodid ticks (Parasitiformes, Ixodidae)
Authors: Leonovich S. A
Published: April 2024

Different hypotheses on the origin of ixodid ticks, vectors of numerous dangerous transmissive diseases of humans and animals are analyzed basing on literary and partly own data. According to latest molecular-genetic and paleontological data, pro-ixodid ticks appeared not in mid-Mesosoic, as it was believed earlier, but most likely in the middle of Devonian. Among Parasitiformes, mites of the order Holothyrida Thon, 1905 form the most closely related to Ixodidae sister group.
Semibalanus balanoides (L.) and Balanus crenatus Bruguière (Balanidae) are intermediate hosts of fimbriarioides intermedia (fuhrmann, 1913) and two species of the genus Microsomacanthus (Cestoda, Hymenolepididae), parasites of sea ducks from the atlantic sector of the Arctic and Northern Pacific
Authors: Regel K. V
Published: April 2024

Metacestode infestation of Semibalanus balanoides and Balanus crenatus, collected in the Barents and White Seas and in the northern part of the Sea of Okhotsk in 2020 and 2021, correspondingly, has been studied. 313 S. balanoides from Mogilnaya Bay of Kildin Island (Barents Sea) and isolated mature wrinkled barnacles B. crenatus, 2 and 4 specimens from the Pechora Sea and Kandalaksha Bay of the White Sea, respectively, were examined in 2020. Metacestodes Fimbriarioides intermedia (Fuhrmann, 1913) (Cyclophyllidea, Hymenolepididae) were found in 1.0 ± 0.6% of S. balanoides in the Barents Sea with an invasion intensity (I I) of 2-5 specimens, and in one of two B. crenatus from the Pechora Sea (I I = 15). For the first time in both B. crenatus from the Pechora Sea, taken from the valves of the mussel Mytilus edulis, metacestodes Microsomacanthus sp. I (I I = 13 and 20) with proboscis hooks 38-41 (39.4 ± 0.1) µm long, blades of 9.5-11 (10.7 ± 0.1) µm were obtained. One of four B. crenatus from the Kandalaksha Bay was infected with another Microsomacanthus sp. II (I I = 19) with proboscis hooks 44.0-49.5 (45.7 ± 0.5) µm long and blades - 14.0-16.0 (14.8 ± 0.07) µm. 362 S. balanoides were collected and dissected in Gizhiginskaya Bay of the northern part of the Sea of Okhotsk in 2021, of which 8.0 ± 1.4% were infected with F. intermedia metacestodes (I I = 1-19). Study results of the infestation of S. balanoides on the Koni-Pyagin coast of the Sea of Okhotsk (according to the collections of 2006-2007) were supplemented and clarified. Description of metacestodes and the taxonomic affiliation of cysticercoids Microsomacanthus spp. are given.
On the duration of the activity period in Dermacentor reticulatus (Fabricius, 1794) (Parasitiformes, Ixodidae) ticks in the taiga zone of Western Siberia
Authors: Romanenko V. N
Published: April 2024

The ixodid tick Dermacentor reticulatus (Fabricius, 1794) possesses a one-year life cycle. It is believed that adults of this species demonstrate exclusive life expectancy, can winter repeatedly, and possess a summer diapause in July. During five summer seasons, the author had tagged all the ticks collected by flagging (flag 60×120) with unrepeated marks. On the whole, 2013 tick specimens were marked. The greatest number of marked ticks was observed in the first month (319 specimens), later, from 2nd to 9th months marked ticks were collected in numbers varying from 1 to 28 specimens (16.6 ± 2.72 on average), and since 9th to 13th months, 4.5 ± 1.8 specimens. 15 ticks lived for more than a year, and the last tagged tick was collected after 463 days after the start of the experiment. Apparently, Dermacentor reticulatus are unable to winter twice in the taiga zone, because all the wintered ticks (80 specimens), according to tags, had wintered only once.
Evolution of life cycles of nematodes parasitizing woody plants as a result of ecological and phylogenetic co-adaptations with hosts and vectors
Authors: Ryss A. Yu.
Published: April 2024

Fundamental aspects in the evolution of nematodes parasitizing woody plants are reviewed. 1) Nematode faunal lists of natural refigia are useful to predict the risks of opportunistic pathogens becoming true pathogens in the forest and park communities. 2) Nematode composition in natural refugia gives a chance to identify nematode antagonists of insect vectors of dangerous fungal and nematode infections, which can be potentially used as of the biological agents for woody plants’ protection. 3) Dauers of the ancestors of wood-inhabiting nematodes played a role as a survival stage in the detritus decomposition succession, and they later acquired the functions of dispersion and adaptations for transmission using insect vectors. 4) When inspecting wilted trees, it is necessary to use dauers for diagnostics, as sexually mature nematodes may absent in tree tissues. 5) Plant parasitic nematodes originated from members of the detritus food web and retained a detritivorous phase in the life cycle as a part of the propagative generation. 6) Vectors in the life cycles of plant parasitic nematodes are inherited from the ancestral detritivorous nematode associations, rather than inserted in the dixenic life cycle of the ‘nematode-fungus-plant’ association. 7) Despite the significant difference in the duration of the nematode-tree and nematode-vector phases of the life cycle, the actual parasitic nematode specificity is twofold: firstly to the vector and secondly to the natural host plant (as demonstrated in phytotests excluding a vector).
The distribution of monogeneans of the genus Ligophorus on gills of the soiuy mullet Planiliza haematocheilus
Authors: Pronkina N. V. , Dmitrieva E. V.
Published: April 2024

The distribution on the host gills of three monogenean species of Ligophorus Euzet et Suriano, 1977, parasitising soiuy mullet Planiliza haematocheilus (Temminck & Schlegel, 1845) in the Black and Azov seas was studied. Specimens of L. pilengas and L. llewellyni prefer to localize on the same gill sites, namely, I-III gill arches and their medial sectors. The third species, L. kaohsianghsieni , was distributed on the gills more crowdedly, with about 80% of its specimens being present on II gill arch, occurring on the medial and ventral sectors approximately equally. In general, most monogeneans were found on the largest in area and well-watered gill arches and sectors, as well as the anterior hemibranchies, however within these areas they preferred to attach to proximal half of filaments with less amount of water current. The presence of congeners on gills had no significant effect on the distribution of L. pilengas and L. llewellyni . Increasing infrapopulation number resulted in a more uniform distribution of monogeneans on gills; their proportion upsurges significantly on the faster growing anterior hemibranchs as fish size increased.
Gypsiferous Gazha Soils of the Subboreal Zone of Eurasia
Authors: Yamnova I. A. , Chernousenko G. I.
Published: April 2024

Gypsiferous soils (gazha soils – loose powdery gypsum) developed underdifferent bioclimatic conditions–forest-steppe, steppe, semidesert, and desertof the subboreal zone – are analyzed. Their morphological, micromorphological, mineralogical, and chemical properties are described. Gazha horizons of these soils may have different geneses: sedimentation, in situ weathering of hard gypsum rocks, and hydrogenic precipitation from groundwater. Despite the different origins of the gazhahorizon of these soils, its morphology and properties have much in common: the gypsum content of 50%, its powdery character with crystal size of 0.25 mm, the presence of calcium carbonates and soluble salts with a predominance of sodium and magnesium sulfates. However, in some cases, the field determination of the gazhahorizon and the chemical determination of gypsum give incorrect information about its presence; mineralogical analysis is necessary to determine the composition of the salts. An analysis of the micromorphological structure clearly demonstrates the genesis of gypsum: under hydrogenous conditions, when gypsum precipitates from groundwater or from lake and river water, the predominantly gypsum material with subparallel microstructure is formed, while in the in situ gazha or gazha originated from the lateral (colluvial) processes, gypsum is deposited together with plasmic material.
Fluorine and Iodine in Soils of the Kulunda Plain
Authors: Konarbaeva G. A. , Smolentseva E. N.
Published: April 2024

The content and distribution of fluorine (F) and iodine (I) have been studied using the example of a four soils located on the terrace of Kuchukskoye Lake in the Altai kray. Soil sections are located on various elements of the micro relief within the boundaries of the lake terrace. The textural-carbonate stratified chernozem (Calcic Chernozem (Loamic, Areninovic, Bathyraptic)) occupies the top of the micro relief. The Solonchak quasi-gleyed (Calcic Solonchak (Loamic, Sulphatic, Humic) is located in a micro-depression. The absolute difference in elevation between these soils is 1 m. Solonetz dark quasi-gleyed salted (Protosalic Solonetz (Loamic, Humic) and texture-carbonate quasi-gleyed salted (Calcic Gleyic Chernozem (Loamic, Endosalic) are confined to the slope between the Calcic Chernozem and Solonchak. The total content of halogens and their mobile forms were determined: water-soluble for F and salt-soluble for I. The content of total F in soils averaged 277.40 mg/kg (lim 59.83–541.10 mg/kg), water-soluble – 3.47 mg/kg (lim 0.04–16.45 mg/kg). Statistical calculations proved that the content of total F strongly correlates with the content of clay, carbonates and water-soluble sodium-cation, and the value of the correlation coefficient depends on the type of soil and its position on the micro relief. Water-soluble F has a high positive correlation with similar parameters in the Chernozem and in the Solonetz. The results showed that the content of total I in the studied soils is higher than in zonal soils of this territory, averages 13.61 mg/kg of soil (5.27–15.21 mg/kg) and moderately depends on the content of clay and carbonates. The influence of the soil type and its position on the micro relief was not revealed on the content of total I. The average content of salt-soluble I is 0.71 mg/kg (0.01–1.86 mg/kg). For all studied soils except Solonchak the relationship of the content of salt-soluble I with the content of clay, carbonates and water-soluble sodium cation has been established. No significant correlation between the above-mentioned parameters has been established for the Solonchak. The revealed heterogeneity of the spatial distribution of F and I in in the studied soils should be taken into account when conducting regional assessments of the status of these halogens.
Microbiological Activity of Chernozem in the Combined Use of Potassium Chloride with Nitrogen Fertilizers
Authors: Pavlov K. V. , Morachevskaya E. V. , Vlasova A. P. , Manucharova N. A.
Published: April 2024

In order to assess the possible toxic effect of potassium chloride used in conjunction with mineral nitrogen fertilizers the authors studied the structural and functional components of the microbial complex of chernozem, in particular, its prokaryotic component. The object of research was soil samples of typical chernozem, selected from the vegetation experience with variants with the introduction of nitrogen-phosphorus and ni-trogen-phosphorus-potassium fertilizers. To obtain a stable effect of easily soluble salts on the microbial community of the soil, long-term composting of soil samples was carried out with alternating cycles of moistening and drying of the soil. During the first two years of composting, the researches detected the suppression of carbon dioxide emissions; however the suppression leveled out only 5 years later. The initial reduction in carbon dioxide emissions, as well as denitrification activity, reached twofold values. The negative effect was manifested when the content of chlorides and nitrates in the soil was significantly lower than the gradation established for slightly saline soils. Prolonged composting of samples of fertile chernozem under the action of potassium chloride led to a decrease in the number and biomass of the metabolically active prokaryotic complex, which confirms its toxic effect on the microbial community of the soil. The representatives of the prokaryotic complex that are resistant and sensitive to the increased content of chlorides and nitrates in the soil have been identified. Among the representatives of the Bacteria domain, almost all were sensitive, with the exception of two phyllum Firmicutes and Verrucomicrobia. For some representatives of the phylogenetic group Actinobacteria, sensitivity to chlorine ions is confirmed at the generic level (Streptomyces and Micromonospora). For the Archaea domain, representatives of the Euryarchaeota phylum are identified as the most resistant to the presence of chlorides. Thus, the suppression of the microbiological activity of chernozem during the introduction of potassium chloride explains the previously identified decrease in the availability of nutrients for plants.
Cyanobacteria and Algae in Biological Soil Crusts of Frost Boils in the Mountain Tundra of the Urals
Authors: Patova E. N. , Novakovskaya I. V. , Sivkov M. D.
Published: April 2024

Diversity of cyanobacteria and eukaryotic algae was recovered from biological soil crusts formed on bare spots in tundras of the Ural mountains. The research was carried out in two typical tundra types, dominated by shrub-moss-lichen and dwarf birch-lichen-moss communities. In total, 46 species belonging to five divisions were identified: Cyanobacteria (19), Ochrophyta (1), Bacillariophyta (2), Chlorophyta (22), Charophyta (2). Core species of the biological crusts come from Cyanobacteria (Stigonema minutum, Gloeocapsopsis magma, Schizothrix fuscescens, Dasygloea cf. lamyi, Fischerella muscicola, Nostoc commune, Scytonema hofmannii) and Chlorophyta (Sporotetras polydermatica, Coccomyxa simplex, Elliptochloris bilobata, E. subsphaerica, Lobochlamys culleus, Pleurastrum terricola). The low diversity of algae and cyanobacteria results from harsh environmental conditions of their habitat: extreme fluctuation of upper ground temperatures, acidic soils with low base content, and reduced levels of nitrogen, phosphorus and other crucial biogenic elements. The total number of cyanobacterial and algal cells per g of soil was estimated at 0.03 to 34.19 million. Based on the acetylene reduction method, the average nitrogen fixation rates in biological crusts ranged from 0.009 to 0.015 mg С2Н4 m–2h–1. The activity varied between soil crust types from 1.48 to 2.25 mg С2Н4 m–2h–1. In future, regular observations are planned on the studied sites to reconstruct and predict succession processes in cryogenic landscapes under mountain tundra conditions.
Influence of Permanent Crops and Fallow on the Thermal and Optical Properties of Typical Chernozem
Authors: Mamontov V. G. , Lazarev V. I. , Ryzhkov O. V. , Belyaeva S. A.
Published: April 2024

Using the thermal method and IR spectroscopy, a typical chernozem (Haplic Chernozem (Loamic, Pachic)) of various land uses was studied. According to the data obtained, the organic matter of the chernozem mainly consists of weakly thermally stable aliphatic compounds such as polysaccharides. This is evidenced by the mass loss in the low-temperature region, which varies within 68.15–71.54%, and the intense absorption band at 1083 cm-1, which determines the shape of the IR spectra of the chernozem. Under the influence of extensive agricultural use, the mineralization of labile aliphatic compounds and an increase in stable cyclic structures in the composition of the organic matter of chernozem occurred. This is indicated by a decrease in the Chernikov–Konchits Z coefficient from 3.16 to 2.47–2.73 and the intensity of most absorption bands in the IR spectra. The most noticeable negative impact on the organic matter of a typical chernozem was caused by bare fallow.
Evaluation of the Chitinolytic and Antibiotic Activity of the Streptomyces avidinii INA 01467 and Micromonospora aurantiaca INA 01468
Authors: Teregulova G. A. , Sineva O. N. , Markelova N. N. , Sadikova V. S. , Uvarov G. V. , Kovalenko M. A. , Manucharova N. A.
Published: April 2024

The evaluation of antibiotic and chitinolytic activity in actinomycetes isolated from sod-podzolic soil (Albic Retisol (Loamic)) was carried out Moscow region (56°07′15″ N, 37°30′54″ E). Based on cultural and morphological features and analysis of the 16S rRNA gene, the isolated strains were assigned to Streptomyces avidinii INA 01467 and Micromonospora aurantiaca INA 01468. Evaluation of the antibiotic activity of isolated actinomycete cultures showed that the strains exhibit both antibacterial activity against gram-positive bacteria and antifungal activity against collection strains of fungi Sac. cerevisiae INA 01042, C. albicans ATCC 14053, F. oxysporum VKPM F-148. The ability to synthesize antifungal compounds increased when growing on a medium with chitin in the strain Streptomyces avidinii INA 01467, including against the phytopathogenic strain Fusarium oxysporum VKPM F-148. Using the Real-Time PCR (Real-Time-PCR) method, the presence of functional genes of shitA, responsible for the synthesis of group A chitinase enzymes, was established in the studied bacterial strains of Streptomyces and Micromonospora. The largest amount of the gene is found when growing on chitin in the strain Streptomyces avidinii INA 01467 and reaches about 15 × 103 copies per ml. The results showed the presence of chitinase and antibiotic activity in the studied strains, including against phytopathogenic fungi, which allows them to be used in plant protection technologies and soil bioremediation.