Erwinia are widely known as phytopathogenic bacteria, but among them, there are also plant-friendly strains that can promote plant growth (PGPR). The Erwinia-like strain OPT-41 was isolated from Triticum aestivum seedlings as a potential PGPR. The cells (0.9–1.3 × 1.5–3.1 µm) of this microorganism are Gram-negative, rod-shaped, motile (with peritrichous flagella), and non-spore- and non-capsule-forming. The 16S rRNA gene sequence analyses showed it is located in the Erwiniaceae family and has a pairwise similarity above the species delineation threshold of 98.65% with several of its members: Erwinia tasmaniensis (99.21%), Candidatus Pantoea bathycoeliae (98.93%), Pantoea agglomerans (98.87%), Erwinia endophytica (98.83%), Erwinia persicina (98.82%), Erwinia billingiae (98.76%) and Erwinia aphidicola (98.75%). Whole genome-based taxonomy performed on the Type (Strain) Genome Server clarified the status of strain OPT-41, detecting it as a potential new species in the genus Erwinia. The microorganism under study was the most closely related to the type strain of E. phyllosphaerae, demonstrating 27.2% similarity in dDDH, 83.44% similarity in OrthoANIu, and 1.9% difference in G+C content. The major fatty acids of strain OPT-41 were 9 C16:1, C14:0, and C16:0. A combination of genome-based taxonomy and traditional polyphasic taxonomy clearly indicated that strain OPT-41 belongs to a novel Erwinia species, for which the name E. plantamica sp. nov was proposed. OPT-41 (=IBPPM 712=VKM B-3873D=CCTCC AB 2024361) has been designated as the type strain. In addition, OPT-41 was found to have low degradation potential for host plant pectins and proteins and be friendly in Triticum aestivum and Hordeum vulgare crops.
Modern gyrotrons provide radiation in a wide range of frequencies and powers, which is used in a variety of areas of fundamental and applied research connected with the problem of plasma formation and heating.The A.V. Gaponov-Grekhov Institute of Applied Physics of the Russian Academy of Sciences is conducting a wide range of studies of gas discharge in a magnetic field under electron cyclotron resonance conditions. For these studies, gyrotron radiation with frequencies from 24 to 75 GHz and a peak power of up to 200 kW is used. The use of such high-frequency and powerful microwave systems has made it possible to obtain original results in the development of sources of intense ion beams of different types, to build compact and powerful neutron generators, to study fundamental kinetic processes in highly nonequilibrium plasma with hot electrons, and to simulate a number of astrophysical phenomena in the magnetospheres of the Earth and other planets.Studies of atmospheric pressure discharge in focused beams of gyrotron radiation with a frequency of up to 1 THz have shown significant prospects for creating of effective sources of extreme ultraviolet radiation with 13.5 and 11.2 nm wavelength based on such plasma, as well as plasma-chemical complexes, for example, for the decomposition of carbon dioxide and other compounds that require innovative methods for effective processing.The brief overview of the recent plasma studies using high power gyrotron radiation in frequency range from 24 GHz to 1 THz are presented, the future prospects of proposed technologies are discussed.
Long-term studies are crucial in ecology, environmental change assessment, resource management and biodiversity conservation. Stercorarius maccormicki (hereinafter – south polar skua) are predators that can threaten populations of bird species of the orders Sphenisciformes and Procellariiformes. At many places in Antarctica, abundance trends for the skua are not known or have not been updated. This study is an attempt to answer the question: how did a south polar skua population react to changes in environmental conditions during 1956–2013? The objectives of the study was (1) to establish the dynamics of the breeding skua population on the Haswell Islands, i.e. Haswell Island and the small islands of the Haswell Archipelago during 1956–2013, and (2) to explain the reasons of the changes in the studied population. A secondary research question was whether there were changes in the spatial distribution of the breeding skua population on the Haswell Archipelago during the study period? The studies have been carried out on the Haswell Archipelago (Davis Sea), mainly in Antarctic Specially Protected Area №127 «Haswell Island and adjacent emperor penguin rookery on fast ice». Ground count was the main method for determining the size of bird colonies. South polar skua bred on 3–8 islands of the Haswell Archipelago. In the study period, the population size of the south polar skua has changed on the Haswell Archipelago. A decrease in the number of individuals (-52%) was observed between 1956–1957 and 1966–1967 breeding seasons. Between 1966–1967 and 1999–2000 breeding seasons, the skua population declined by 30.7% and reached the lowest value of 18 pairs. Population growth (344.4%) was recorded between 1999–2000 and 2009–2010 breeding seasons, with an increase of 33.8% and reaching the maximum value (83 pairs) in 2010–2011 breeding season. By 2012–2013 breeding season, the south polar skua population has declined by 13.2%. On Haswell Island, between 1956–1957 and 2012–2013 breeding seasons, there was a change in skua abundance that was similar to the change in the total breeding population on Haswell Archipelago during the entire period. On the small islands of the Haswell Archipelago, the number of breeding south polar skuas declined (-80%) between 1956–1957 and 1962–1963 breeding seasons. The breeding seasons of 1962–1963, 1966–1967 and 1999–2000 were characterised by the lowest number of individuals. Between 1999–2000 and 2009–2010 breeding seasons, the number of south polar skuas increased by 400%. A decrease in abundance (-41.6%) occurred between 2009–2010 and 2010–2011, followed by the consequent increase (by 36.3%) by 2012–2013 breeding season. During the study period, changes in the abundance of south polar skuas on the Haswell Archipelago were independent of changes in average daily November temperatures between 1956–1957 and 2012–2013 breeding seasons (Mann-Whitney test U = 0, p = 0.0017, n = 7 (asymptotic (2-sided))), when they were laying eggs and heating them. The number of south polar skuas changed independently of changes in the number of individuals of their prey, represented by Aptenodytes forsteri, Pygoscelis adeliae, and Fulmarus glacialoides (respectively U = 49, p = 0.0006, n = 7; U = 16, p = 0.029, n = 4; U = 16, p = 0.029, n = 4 (asymptotic (2-sided))). The high mortality of eggs, chicks and local weather conditions could influence the breeding success of the south polar skua, which could have a delayed effect on their long-term dynamics. Human activities have influenced the skua population, but have not been studied quantitatively. On the Haswell Archipelago, the reasons for historical changes in abundance of the breeding skua population remain largely unclear.
Two types of gyrotron magnetic systems, flat busses with concentrator and balanced winding solenoid (quasi-force-free), are described. These low inductance indestructible magnets provide the generation of microsecond strong magnetic fields, more than 50T, with high efficiency capacitor energy transfer. The results of magnetic field and mechanical stress calculations are presented.
Pollutant degradation and heavy-metal resistance may be important features of the rhizobia, making them promising agents for environment cleanup biotechnology. The degradation of phenanthrene, a three-ring polycyclic aromatic hydrocarbon (PAH), by the rhizobial strain Rsf11 isolated from the oil-polluted rhizosphere of alfalfa and the influence of nickel ions on this process were studied. On the basis of whole-genome and polyphasic taxonomy, the bacterium Rsf11 represent a novel species of the genus Neorhizobium, so the name Neorhizobium phenanthreniclasticum sp. nov. was proposed. Analysis of phenanthrene degradation by the Rsf1 strain revealed 1-hydroxy-2-naphthoic acid as the key intermediate and the activity of two enzymes apparently involved in PAH degradation. It was also shown that the nickel resistance of Rsf11 was connected with the extracellular adsorption of metal by EPS. The joint presence of phenanthrene and nickel in the medium reduced the degradation of PAH by the microorganism, apparently due to the inhibition of microbial growth but not due to the inhibition of the activity of the PAH degradation enzymes. Genes potentially involved in PAH catabolism and nickel resistance were discovered in the microorganism studied. N. phenanthreniclasticum strain Rsf11 can be considered as a promising candidate for use in the bioremediation of mixed PAH–heavy-metal contamination.
Self-consistent steady-state structure of a thin plasma filament maintained in atmospheric pressure argon by a rotating transverse electric field of ∼1 cm wavelength is simulated numerically under conditions when the local plasma resonance condition is satisfied at some surface inside the filament. The equilibrium radial distributions of the plasma parameters (temperature and density) and the field amplitude inside the filament are calculated based on the solution of the heat equation and the Maxwell equations. It is shown that the occurrence of strong resonant peaks of the radial component of the electric field and the power of Joule losses in the region of critical density at the periphery of the filament provide the energy deposition sufficient to achieve a relatively high gas temperature and a strongly supercritical plasma density in its central region. In relation to the values of these basic parameters of the filament and the lower limit of the external radiation power supporting it, the results obtained are in satisfactory agreement with the data of the earlier experiment.
The diet and feeding behavior of South Polar Skuas (Stercorarius maccormicki) are well studied within the species’ breeding range but are poorly understood on the Haswell Islands. The aim of this study was to determine how South Polar Skuas use available resources during the pre-breeding and breeding periods at the Haswell Archipelago (66°31′ S, 93°01′ E, Davis Sea, Southern Ocean) under conditions of prolonged human activity. I studied pellets, spontaneous regurgitation, and stomach contents of feathered birds to study the diet of skuas and used direct observations of their feeding behavior. South Polar Skuas at the Haswell Islands fed primarily on the Emperor Penguin (Aptenodytes forsteri) colony and on terrestrial resources in the Adélie Penguin (Pygoscelis adeliae) and fulmarine petrel colonies. The dominant prey of skuas were breeding Antarctic penguins. Emperor Penguins and Adélie Penguins make up the bulk of the skuas’ diet in the pre-breeding and breeding periods. Surface feeding at sea was observed in the post-breeding period. In recent decades, kitchen waste supported the skua population. Scavenging (placenta and feces of Weddell seals [Leptonychotes weddellii], frozen eggs, chicks and adults of breeding bird species, kitchen refuse) is the dominant strategy for obtaining food. Adélie Penguin eggs and chicks were the main food items of the South Polar Skuas in the Haswell Archipelago. Skua predation could potentially influence the breeding success of Adélie Penguins and fulmarine petrels, but the extent of the impact is unknown. The impact of the South Polar Skua on Emperor Penguins is negligible because skuas feed mainly on frozen chicks and eggs of the species.
Study of rhizospheric microbial communities of plants growing under different environmental conditions is important for understanding the habitat-dependent formation of rhizosphere microbiomes. The rhizosphere bacterial communities of four amaranth cultivars were investigated in a laboratory pot experiment. Amaranthus tricolor cv. Valentina, A. cruentus cv. Dyuimovochka, and A. caudatus cvs. Bulava and Zelenaya Sosulka were grown for six months in three soils with different anthropogenic polyelemental anomalies and in a background control soil. After the plant cultivation, the rhizosphere soils were sampled and subjected to metagenomic analysis for the 16S rRNA gene. The results showed that the taxonomic structure of the amaranth rhizosphere microbiomes was represented by the dominant bacterial phyla Actinobacteriota and Proteobacteria. A feature of the taxonomic profile of the rhizobiomes of A. tricolor cv. Valentina and A. cruentus cv. Dyuimovochka was a large abundance of sequences related to Cyanobacteria. The formation of the amaranth rhizosphere microbiomes was largely unaffected by soils, but cultivar differences in the formation of the amaranth rhizosphere microbial structure were revealed. Bacterial taxa were identified that are possibly selected by amaranths and that may be important for plant adaptation to various habitat conditions. The targeted enrichment of the amaranth rhizosphere with members of these taxa could be useful for improving the efficacy of amaranth use for agricultural and remediation purposes.
One of the most challenging problems in intrusion detection is the development of techniques that are able to detect novel and unseen attacks. Currently, the researchers are investigating applicability of the deep learning techniques to solve this task, as the deep learning models are known for their ability to reveal spatial as well as temporal patterns in data flows. However, their usage often requires converting tabular data to matrix-based structures. This paper presents an approach to constructing images from the raw sequence of bytes representing network flow, discusses several options to generate them, and evaluates their impact on the performance of intrusion detection model. The experiments are conducted using the CICIDS2017 dataset. The obtained results show that the proposed data preprocessing technique allows one to achieve high accuracy in attack detection, and as this approach does not require knowledge of protocol structure, it could serve as a basis for development of protocol-independent preprocessing techniques in intrusion detection tasks.
Natural and technical phytoremediation approaches were compared for their efficacy in decontaminating oil-polluted soil. We examined 20 oil-contaminated sites of 800 to 12,000 m2 each, with different contamination types (fresh or aged) and levels (4.2–27.4 g/kg). The study was conducted on a field scale in the industrial and adjacent areas of a petroleum refinery. Technical remediation with alfalfa (Medicago sativa L.), ryegrass (Lolium perenne L.), nitrogen fertilizer, and soil agrotechnical treatment was used to clean up 10 sites contaminated by oil hydrocarbons (average concentration, 13.7 g/kg). In technical phytoremediation, the per-year decontamination of soil was as high as 72–90%, whereas in natural phytoremediation (natural attenuation with native vegetation) at 10 other oil-contaminated sites, per-year decontamination was as high as that only after 5 years. Rhizodegradation is supposed as the principal mechanisms of both phytoremediation approaches.
Приводятся результаты первых экспериментов по изучению объемной генерации отрицательных ионов водорода при использовании плотной газодинамической плазмы ЭЦР-разряда, который поддерживался непрерывным микроволновым излучением гиротрона (28 ГГц/5 кВт). ЭЦР водородный разряд зажигался в вакуумной камере, помещенной в магнитное поле, создаваемое системой из двух последовательно соединенных магнитных ловушек. Была проведена оптимизация параметров системы с целью получения максимальной средней плотности тока отрицательных ионов j = 25 мА/см 2 . Определена область генерации отрицательных ионов, измерены зависимости плотности их тока от давления газа и мощности микроволнового излучения, показана перспективность дальнейшей оптимизации по напряжению экстракции.
Microbial-assisted phytoremediation is considered a more effective approach to soil rehabilitation than the sole use of plants. Mycolicibacterium sp. Pb113 and Chitinophaga sp. Zn19, heavy-metal-resistant PGPR strains originally isolated from the rhizosphere of Miscanthus × giganteus, were used as inoculants of the host plant grown in control and zinc-contaminated (1650 mg/kg) soil in a 4-month pot experiment. The diversity and taxonomic structure of the rhizosphere microbiomes, assessed with metagenomic analysis of rhizosphere samples for the 16S rRNA gene, were studied. Principal coordinate analysis showed differences in the formation of the microbiomes, which was affected by zinc rather than by the inoculants. Bacterial taxa affected by zinc and the inoculants, and the taxa potentially involved in the promotion of plant growth as well as in assisted phytoremediation, were identified. Both inoculants promoted miscanthus growth, but only Chitinophaga sp. Zn19 contributed to significant Zn accumulation in the aboveground part of the plant. In this study, the positive effect of miscanthus inoculation with Mycolicibacterium spp. and Chitinophaga spp. was demonstrated for the first time. On the basis of our data, the bacterial strains studied may be recommended to improve the efficiency of M. × giganteus phytoremediation of zinc-contaminated soil.
The results of the first experiments on studying the volume production of negative hydrogen ions using a dense gasdynamic plasma of an electron cyclotron resonance (ECR) discharge sustained by continuous wave (CW) microwave radiation from a gyrotron (28 GHz/5 kW) are described. The ECR hydrogen discharge is ignited in a vacuum chamber placed in a magnetic field created by a system of two consecutive magnetic traps. The system parameters are optimized to obtain the maximum average current density of negative ions at the level of j = 25 mA/cm2. The study involves the determination of the negative ion production area, me-asurement of the current density dependences on gas pressure and microwave radiation power, and demonstration of potential optimization opportunities for extraction voltage.
We present the results of experimental studies of the intensity of vacuum ultraviolet self-radiation (VUV) of the discharge in hydrogen sustained in an open magnetic trap by the high-power radiation of a gyrotron (frequency f = 28 GHz and power P gyr = 5 kW) under conditions of electron cyclotron resonance (ECR) in the continuous regime. The optimum system parameters were determined for the generation of VUV radiation by the plasma of the ECR discharge. It was shown that the radiation power in the wavelength range λ = 120–160 nm reaches W = 0.75 kW, which corresponds to an efficiency of η = 20%.
We consider a laser discharge in xenon jet as a source of extreme ultraviolet (EUV)-light. For realistic plasma parameters, it is shown that the plasma with multiply charged ions, initially arising in the focal region of a laser beam, expands due to photoionization of a surrounding gas and consecutive electron heating by a conductive thermal flux from the region of the laser power deposition. The theoretical model agrees well with the available experiments aimed at the development of a point-like EUV-light source for high-resolution lithography.
In the quasi-gasdynamic high-current ion source described in this work, the plasma is sustained by high-power millimeter-wave radiation under the electron cyclotron resonance (ECR) condition. In such facilities, it is possible to achieve high volumetric energy input of up to $250$ $W/cm^3$ and obtain pure proton beams with a minimum amount of impurities and molecular ions. Experiments conducted on the GISMO facility demonstrated the possibility of a proton beam formation with a current of $50$ mA and an extremely high ($99.9$\%) content of atomic ions.
The Pallas’s Gull Ichthyaetus ichthyaetus is a fish-eating predator listed in the category of recovering species of the Red Book of the Russian Federation. The purpose of the research was to study the state of the Pallasʹs Gull in the fairway (navigable zone) of the Volga–Kama reservoirs, in Russia and to assess their role in the current distribution of the species. In the summer and autumn of 2020–2022, at 11 reservoirs of the Volga and Kama rivers, counts of Pallasʹs Gulls were carried out from the bow deck of the R/V Akademik Topchiev. The transect length was 4633.5 km; the duration of observations was 364.3 h. A comprehensive bird count was applied in the direction of the vessel’s movement on transects with a fixed counting strip width of 200 m (100 m in each direction from the bow of the vessel). Birds were usually fixed on 30-min transects. The Pallas’s Gulls were found in 7 of the 11 reservoirs studied, and their status varied between common and very rare. The species was more abundant in the Gorky reservoir than in the Cheboksary, Kuibyshev, Saratov, and Nizhnekamsk reservoirs. The smallest abundance was recorded in the Volgograd and Rybinsk reservoirs. The Pallas’s Gull shows a steady annual presence on most reservoirs. The results indicate that in the Volga Basin, the range of Pallas’s Gull has expanded further north by more than 1000 km over the past 30 years from the species’ original areas of sustainable breeding in the North Caspian. Adult individuals of the Pallasʹs Gull (83.4% of the age composition of the population) play the main role in the dispersal. The most favorable clusters of the stable presence of the species were lake-shaped fragments of the Gorky and Kuibyshev reservoirs. On the territory of the East European Plain, the Volga–Kama reservoirs are important, if not decisive, in expanding the range of Pallas’s Gull to the north.
Recent approaches based on feature transformation to images with further application of the pre-trained deep analysis models have been adopted for different cyber security tasks such as malware detection, intrusion and anomaly detection. The transfer learning (TL) is a technique for solving a new task using experience or knowledge transfer from a solution of the related task. Such approach allows speeding up the process of the problem solution or increasing its performance. This paper reviews existing approaches based on transfer learning with particular focus on data preprocessing step, discusses their advantages and disadvantages. The paper ends up with the proposed approach to feature extraction based on the traffic packets transformation to images, and evaluates its efficiency using Secure Water Treatment data set (SWaT) that models functioning of the modern water treatment facility.
This article proposes a scheme for matching microwave radiation with a magnetized plasma of an electron cyclotron resonance (ECR) discharge in an open magnetic trap, using the effect of depolarization—the transformation of the ordinary wave into the extraordinary one upon reflection from the metal walls of a plasma chamber. An analysis of the efficiency of such a transformation is carried out, and it is shown that for grazing (less than 15° with metal surface) angles of incidence; it is possible to achieve an efficiency exceeding 90%.
The possibility of generating a substance with a high energy density during the deceleration of protons, which are accelerated by the laser-plasma method in a layer of a substance with a high charge, gold, is analyzed for the parameters of laser pulses that are planned to be obtained at the XCELS installation. It is shown that in this case, the formation of a substance is possible with record pressure values of more than 1 Gbar at a solid-state density, which corresponds to a specific energy release of tens of megajoules per gram. A specific feature of the deceleration process with such a high specific energy release is that the properties of the decelerating substance change during interaction. It is demonstrated that the ionization multiplicity of gold ions reaches 40–50, and the temperature of the resulting plasma is 1 keV. This leads to a decrease in the slowing-down power of the substance and to a modified curve of the specific energy release.