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The paper presents a new robust video watermarking method. Its main idea consists in adding temporal sinusoidal sequences to each pixel of the video signal. The two-dimensional field of their phases corresponds to the watermark image. Simple and fast algorithms for embedding and extracting watermarks are described. The results of experimental studies demonstrate the high watermark extraction quality, robustness to some attacks, including temporal desynchronization, and high visual quality of the protected video.

In a space of tree-structured object representations, the accuracy of object classification in terms of an error probability depending on the amount of processed information is studied. For a given set of objects, the lower bound to the average error probability as a function of the average mutual information between the objects and the decisions about their classes is given. Using multilevel discriminant functions in the set of object representations, a guided search algorithm for an object class-label decision is proposed, and a computational profit of the guided search relative to the exhaustive search is shown analytically. In the source datasets of face and signature objects given by the grayscale images as well as in an ensemble of these datasets, we calculate the experimental dependences of the average error probability and the average mutual information on the algorithm parameter which defines the above-mentioned computational profit. Also, for both source datasets and their ensemble, we give numerical values of the lower bounds to the error probability that allow us to estimate the redundancy of the algorithm error probability for different values of the computational profit.

The goal of registering point clouds in a 3D space is to find an orthogonal transformation that maximizes the consistent overlap of two point clouds. The most common registration method using purely geometric characteristics is the Iterative Closest Points (ICP) algorithm. The disadvantage of the classical ICP variants is the dependence on the initial location of the point clouds. Coarse registration algorithms are used to find a suitable initial registration of two clouds. In this paper, we propose a new algorithm for extracting common parts and coarse registration of point clouds.

Trematodes of Plagiorchis genus are widespread endoparasites with a life cycle involving several hosts. The present work on the study of the second intermediate hosts of the genus Plagiorchris was carried out in the basin of Chany Lake, located in the forest-steppe of Western Siberia, where pass the migration routes of many species of aquatic and near-water birds - the final hosts of these trematodes. The work was carried out in 2014-2015 in the reed zone of the Fadikha Lake, which is the habitat of the first intermediate hosts of plagiorchids - snails. Representatives of the classes Insecta, Malacostraca, Gastropoda were studied to identify the potential second intermediate hosts of the genus Plagiorchis. In the Chany Lake basin, metacercariae of Plagiorchis genus (P. elegans и P. multiglandularis) were found only in insects from the order Odonata: the largest part of infected were larvae of Sympetrum vulgatum (68 %), followed by species S. flaveolum (18 %), S. sanguineum (9 %) and Aeshna serrata (5 %). The prevalence of metacercariae of the detected trematode species for 4 Odonata species during the study years varied in the range from 3.3 to 45.5 %, the intensity of invasion - from 2 to 4 trematodes per 1 odonate larva. Infection with metacercariae increased with the age of odonate larvae. The tendency of a positive relationship between the infection (prevalence) of the first (snails) and the second (odonate larvae) intermediate hosts was revealed. A reliable relationship has been established between the prevalence of the invasion of odonate larvae and the abundance of their populations, which varies throughout the season. Seasonal changes in the infection of odonates with metacercariae of Plagiorchris genus are associated with the phenology of these insects: periods of increased infection were recorded on the eve of the mass emergence of odonates, when the number of odonate larvae in the reservoir is extremely high, and vice versa, periods of decline in infection were noted after the mass metamorphosis of odonates.

The paper contains original data on the composition and structure of Oligochaeta communities in the zone of influence of wastewater from a pulp and paper industry (the Vychegda River, the Northern Dvina River basin). 40 species and forms of oligochaetes have been identified. We found species having been earlier identified only in tributaries, in floodplain water bodies and in lakes of the Vychegda River basin. By the diversity index (Shannon index (H_N) and Simpson index (D_S)), evenness index (Pielow index (E)), and Whittaker (βw ) indices, the studied section of the river exceeds the control section by the species diversity. There is a significant increase in abundance and biomass of oligochaetes in comparison with section higher up the river. Based on the correlation analysis between the quantitative development indicators of oligochaetes with the environmental parameters (type of substrate, presence of algal growths and macrophyte, depth, chemical composition), the assessment of biotopic confinement of species (F_j) and conjugate between species (r_A), we found out that the distribution of oligochaetes in the study area largely depends on the type of substrate. According to the obtained results on the assessment of diversity and distribution of oligochaetes in the zone of influence of wastewater from a pulp and paper industry, the appearance of technogenic parts with artificial substrate along the shore line leads to changes in the composition, diversity and quantitative development characteristics of benthic organisms.

An analysis of the variability in the development of Scutellaria baicalensis Georgi (Lamiaceae) plants collected from natural habitats (Zabaikalsky Krai, Amur Region, Primorye) and grown under the same culture conditions (Novosibirsk) is given. It has been established that in S. baicalensis, under new growing conditions, interpopulation differences in morphological characteristics and the timing of the onset of phenophases developed in nature are preserved. Data analysis shows the existence of significant differences ( t > 3) between the steppe Zabaykalsky and forest Primorsky cenopolations (CP) in plant height, number of pairs of leaves, number of shoots both in nature and during introduction. The flowering period in the Zabaykalsky CP comes earlier, compared to the Primorsky CP, both in nature and in culture. In Zabaykalsky CP in culture, individuals bloom in early July. In the Primorsky CP, the flowering period begins at the end of July-August, the seed ripening period is extended, especially in the first years of introduction. The formation of steppe Zabaykalsky and forest Primorsky ecotypes can be assumed.

The article presents the results of the analysis of the peculiarities of renewal of woody vegetation after a crown fire which broke out in 2010 in the beech-yew forest in the Termenlik district (965 m a. s. l.) on the south-eastern slope of Gimrinskiy Khrebet in the Foothill Dagestan (East Caucasus). For the description of the changes which occurred on the post-fire spot in 2019 there have been arranged eight sample areas (SA) 100 square metres each (10 × 10 m). A geobotanical description of the sample area has been conducted according to the generally accepted method which included the definition of the microrelief, the species composition (species richness) of the trees, their distribution in the layers and biometric parameters. For each treespecies there has been revealed a projective cover in percentage as well as the abundance, the sequence of penetration and distribution, the dynamics of the development of the above-ground part and there have been evaluated the results of their competitive interaction. Owing to the appearance of new species of seed origin with accelerated growth in the composition of the forest stand, such as Populus tremula L., Salix caprea L., Acer campestre L., Fraxinus excelsior L., a suggestion has been made about the change of the succession trend and the formation of a new reformed cenosis without participation of the basic dominant species of the primary forest, namely Fagus orientalis Lipsky., Carpinus caucasica L., Taxus baccata L., Acer platanoides L. There has been offered a method of mechanical removal of the dominant species P. tremula leading to the enhancement of the competitive advantages of the pioneer species characteristic of this locality. It is believed that such a method will lead to an increase in the competitive advantages of other species with a predictable consequence. Thus, in the studied community of the burned area, vegetation development will change towards the initial beech-yew forest for this area, and not a community dominated by aspen.

The paper summarizes the results of field studies of carbon dioxide and methane fluxes in peatland ecosystems on the territory of license areas of the Salym group of oil fields (Khanty-Mansi Autonomous Okrug). The largest fluxes of carbon dioxide and methane are observed in mesotrophic and eutrophic bogs, which are characterized by the maximum of biomass storages. Significant negative CO₂ fluxes (-1161.6 mg CO₂ m^-2∙h^-1) associated with photosynthesis have been recorded here, but they also have a high emission component of carbon exchange (ecosystem respiration) (more than 680 mg CO₂ m^-2∙h^-1). Methane emission reaches 23.9 mg CH₄ m^-2∙h^-1. In oligotrophic bogs, in the daytime, fluxes of СО₂ in range from -400 to -600 mg CO₂ m^-2∙h^-1 were recorded, and at night from + 160 to +840 mg CO₂ m^-2∙h^-1. Methane fluxes from hummocks in oligotrophic bog complexes were up to 1.1 mg CH₄ m^-2∙h^-1, and from decreases 3.9 mg CH₄ m^-2∙h^-1 from hollows. Large carbon dioxide and methane fluxes were registered from the surface of clear-cuts at a pine-dwarf-shrub-sphagnum bog, where, depending on the ground cover, the release of CO₂ can be from +46 to +480 mg CO₂ m^-2∙h^-1, and emission of CH₄ - up to 4.6 mg CH₄ m^-2∙h^-1.

According to the results of studies of the Vasyugan River in July 2019 and 2021 the species composition, taxonomic structure, dominant complex, abundance and biomass, indices of phytoplankton biodiversity were established for the first time. 166 species and intraspecific taxa of algae from 8 divisions have been identified, green algae (Chlorophyta division) form the basis of species richness. The dominant phytoplankton complex includes centric diatoms, green algae and non-heterocyst cyanoprokaryotes. Biodiversity indices indicate high species richness, close to average complexity and evenness of the phytoplanktocenosis structure. The trophic status of the river corresponds to the eutrophic category of waters, the water quality ranges from class 3 “satisfactory purity” to class 4 “polluted”.

An analysis of the phenological development of 13 taxa of North American maples for 2013-2020 was carried out. on the basis of the collection of the South Ural Botanical Garden-Institute of the Ufa Federal Research Center of the Russian Academy of Sciences. The sum of positive, effective and active temperatures, as well as the sum of precipitation required for the onset of the main phenophases, has been established. Most phenophases depend on weather conditions, except for the phases of the beginning and end of flowering, fruit ripening - they are genetically determined. This explains the large difference in the sum of temperatures and precipitation at the beginning of these phases in different species. The sum of positive temperatures at the beginning of flowering is 11-497 °C, the amount of precipitation is 33-80 mm. At the end of flowering, the sum of positive temperatures at the beginning of flowering is 149-722 °C, the amount of precipitation is 43-112 mm. The number of positive temperatures attributable to the phenophase of fruit ripening varies from 693 to 2662 °C, the amount of precipitation by this time is from 47.5 to 315 mm. The duration of vegetation of North American maples in Ufa, depending on the species, ranges from 140 (A. tschonoskii) to 172 days (A. rubrum ‘Sommer Red′).