Currently, it has been established that when living organisms are exposed to various environmental factors (abiotic, biotic, and anthropogenic), hormesis is a fairly common phenomenon. Hormesis is found in different groups of organisms and at almost all levels of the organization of living systems from the cell to ecosystem level. At the same time, a comprehensive analysis of the significance of hormesis for ecology has not been carried out. This review analyzes the modern concept of hormesis, as well as its significance for various fields of ecology.

In order to assess the state of affairs in a region with account for the economic, socio-demographic and environmental aspects, to find out the causes of backwardness, and to work out ameliorating measures, it is reasonable to regard each administrative-territorial unit (ATU) as an integral socio-environmentally-economic system (SEES). ATUs in the Nizhegorodskaya Oblast were chosen to evaluate the suggested approach to integral analysis of SEES conditions and developmental degree. The approach implies calculating the values of the generalized desirability function (GDF) and their assessment using principal components and SWOT analyses. The calculated GDF values for the years 2016–2018 made it possible to distinguish leaders and outsiders among ATUs. Among all ATUs, 78% fall into the two lower classes of GDF gradation, which means that conditions are poor there. The results were confirmed by statistical analysis and were interpreted analytically using SWOT analysis. The suggested methodology makes it possible to distinguish “pain spots” and “points of increase” and correct decision making aimed to promote sustainable development at a regional level.

The microbiological patterns of the passenger cabins of urban public transportation by the example of 41 buses from 16 routes was described for the first time. According to orographic features of the city of Nizhny Novgorod, all the bus routes were divided into three model groups designated as “High-bank,” “Low-bank,” and “Interdistrict.” The abundance of microorganisms and the species composition were estimated using an Autoflex MALDI mass spectrometer (Bruker Daltonics, Germany) and the BioTyper software. In the samples collected, 85 microbial species were detected, identified, and assigned to one of the following three groups according to their degree of pathogenicity: (1) opportunistic pathogens often causing infectious diseases; (2) opportunistic pathogens rarely causing infectious diseases, and (3) nonpathogenic microorganisms. To characterize the ecological structure of the microbial community of urban public transport, two similarity indices for the microbiocoenoses studied, the Sorensen binary index and the multidimensional Koch biotic dispersion index, were calculated. The species composition was analyzed at two hierarchical levels of the bus route groups (the intragroup and intergroup ones). At the intragroup level, a small number (1–3) of common species represented by Staphylococcus epidermidis, S. haemolyticus, and Acinetobacter lwoffii were found in each route group, which corresponds to a low Koch index value (0.1). At the intergroup level, 15 common species of microorganisms were found, which corresponds to the value of the Koch index calculated for the three route groups (0.26), i.e., 26% of species were common for the three route groups analyzed. Species of three groups of microorganisms were most comprehensively represented in the “Interdistrict” group: 45% species of Group 1, 53.8% species of Group 2, and 58.1% species of Group 3. Community structure analysis carried out using ecological indices (Shannon species diversity index, Simpson index of dominance, Margalef species richness index, and Pielou species evenness index) showed that an increase in the species diversity of microbial communities was accompanied by a regular decrease in dominance and an increase in evenness. Analysis of the group of dominant species identified in the buses of the three route groups revealed that the species similarity of the dominant species, estimated by the value of the Koch index, was only 0.14, which could be explained by the presence of only one common species (Acinetobacter lwoffii). Studies of the microbial community of urban transportation present a perspective for solving the sanitary, hygienic, and environmental aspects of the integrated problem of ensuring the ecological safety of the urban environment.

Abstract—A differentiated assessment of blood cells and types of micronuclei in the erythrocytes of marsh frogs (Pelophylax ridibundus) living in reservoirs of the Nizhny Novgorod region was performed. The water reservoirs differ by origin, morphology, and chemical composition. The specific abiotic conditions (a peat bog) and anthropogenic load resulted in the most pronounced change in the leukocyte differential count, corresponding to the neutrophilic type of leukemoid reaction, and in an increased micronucleus fraction in the erythrocytes. A moderate positive correlation between the increase in the number of disintegrated micronuclei and the content (mg/L) of nitrites in the reservoir was found (r = 0.72, p = 0.0179). The complex action of high concentrations of technogenic chemical pollutants (copper, chromium, and oil products) caused the activation of erythropoiesis and humoral immunity, which was confirmed by the nature of the leukemoid reaction of a lymphatic type. The cellular and humoral types of immune reaction aimed at self–foreign molecule differentiation provided stability of the frog ontogenesis under anthropogenic pressure. Integral leukocyte indexes, such as the blood cell indicator, the neutrophil–lymphocyte ratio, the lymphocyte–granulocyte index, and the index of leukocyte shift, which reflect the level of the body’s general reactivity, can be considered as population markers of the immune status of amphibians.

Abstract—Group-theoretical analysis of the pseudosymmetry of two-dimensional images of aquatic organisms of the classes Conjugatophyceae, Bacillariophyceae, Acantharia, and Asteroidea and the symmetry transformations in the ontogeny of echinoderms has been performed for the first time in the original BioPsLeaf and BioPsFlower software, and the results of the analysis are presented below. Published materials, including graphic illustrations from Haeckel’s book Künstformen der Natur were the sources of the two-dimensional images of aquatic organisms used in the study. The choice of aquatic organisms was largely determined by the Curie principle, which imposes restrictions on the symmetry groups of living organisms with consideration of the specific habitat. Analysis of the organisms from the considered classes showed that the invariance (symmetry) of a biological object that can be roughly described by the Cnv group of operations of the Schoenflies system could be generally characterized by two numerical parameters, i.e., the minimum values of the degrees of pseudosymmetry both among all of its local maxima for turn operations (ηr) and mirror reflections (ηb). Analysis of Asterina amurensis as an example showed that the complete starfish metamorphosis could be represented by symmetry transformations in the form of the following series:                                                                         С4v → С2v → Cs → C5v, which reflects the natural transition from rotational symmetry to bilateral and again to the rotational due to the biological characteristics of the organism at different stages of development. This series is consistent with the Curie principle: a system under external influence changes its point symmetry in such a way that only the symmetry operations in common with the symmetry operations of the influence are preserved. It is emphasized that exactly the group theory enables the characterization of an object’s invariance with respect to spatial transformations—in other words, its symmetry. In turn, the identification of invariants as a certain class of objects makes it possible to determine their structural basis and thus can help to find the invariable in the variable.

For the first time, the results of group-theoretical analysis of pseudo-symmetry in two-dimensional images of hydrobionts belonging to the classes Conjugatophyceae, Bacillariophyceae, Acantharia, and Asteroidea are presented, along with symmetry transformations in echinoderms ontogenesis. The analysis has been conducted using original software "BioPsLeaf and "BioPsFlower". The source of hydrobionts two-dimensional images, used in this study, was published materials including graphical illustrations from "Kunstformen der Natur" by Ernst Haeckel. The structure of the hydrobionts selected for the analysis is determined, in essence, by Curie principle, which imposes constraints on symmetry groups of living things with account for environmental conditions. For representatives of classes Conjugatophyceae, Bacillariophyceae, Acantharia, and Asteroidea it is found out that, in whole, the invariance (symmetry) of a biological object, approximately described by group C-n nu, according to the Schoenflies system, can be characterized by two numerical values, namely minimal values of pseudo-symmetry degree among all of its local maxima in both of turn operations (eta(r)) and mirror reflections (eta(b)). Using Asterina amurensis as an example, it is shown that complete metamorphosis of this starfish can be represented by symmetry transformations of the following sequence: C-4 nu -> C-2 nu -> C-s -> C-5 nu. It manifests natural transition from rotational symmetry to bilateral one and back to rotational one, which is due to organism's biology at early stages of development and agrees with Curie principle: under external impacts, point symmetry of a system changes in such a manner that only those symmetry operations retain that are common with symmetry operations of the impact. It is emphasized, that it is the group theory that allows characterizing object invariance in relation to space transformations, i.e., its symmetry. In its turn, finding invariants in some classes of objects means revealing their structural basis and helps to discover the unchangeable within the changeable.

Considering the problem of taxonomic diversity as a fractal object is the aim of this article. The prerequisites for such an approach were articles with varying degrees of detail and argumentation that substantiate taxonomic diversity from the standpoint of fractal geometry. Common to these papers is that the authors in their theoretical constructs start from the Willis rule (law) describing the rank distribution of the relationship between the number of taxa and their volume. The flora of the Samara Bend (the bend of the Volga River in its middle reaches) has become an object of the research. The authors distinguish seven basic floristic areas on the Samara Bend, the boundaries of which coincide with the respective landscapes. The authors discuss the efficiency of the Willis rule (law), which approximates the relationship between the number of taxa and their volume by rank distribution. The multifractal spectrum (a generalized geometric image of generic structure) of the taxonomic diversity of vascular plants of the Samara Bend is presented.

Traditional approaches to structural analysis of biotic communities, based on the data on species abundances, do not take into account phylogenetic relationships between these species. We propose a new approach to studying the scaling (scale dependence) of phylogenetic diversity by means of multifractal analysis in which the moments of phylogenetic diversity are used. The results of applying this approach to small mammal communities of Nizhny Novgorod region of the Volga Basin has shown that phylogenetic diversity scaling complies with the power law, which is indicative of the self-similarity of these communities. The multifractal spectra of phylogenetic diversity scaling markedly differ from the spectra of species diversity scaling, providing evidence that the proposed approach can provide novel information on the structure of biotic communities.

The role and contribution of discriminating indicators of the corolla geometry of five cultural forms of flowered primrose (Primula × polyantha Mill.) in the phenotypic variation of primrose as a potential bioindicator were studied. The proposed set of the corolla’s geometric characteristics (the average rotational pseudosymmetry (η r ), the average bilateral pseudosymmetry (η b ), the irregularity index (I r ), and the projective cover index (I pc )) allows us to discriminate significantly between the cultural forms of flowered primrose. The major contribution to discrimination is made by the rotary index of pseudosymmetry (η r ).

Phenomena having the property of a scale invariance (that is, maintaining invariable structure in certain range of scales) are typical for biosystems of different levels. In this review, main manifestations of the scale-invariant phenomena at different levels of biological organization (including ontogenetic aspects) are stated, and the reasons of such wide distribution of fractal structures in biology are discussed. Almost all biological systems can be described in terms of synergetics as open nonequilibrium systems that exist due to substance and energy flow passing through them. The phenomenon of self-organization is typical for such dissipative systems; maintenance of energy flow requires the existence of complex structures that emerge spontaneously in the presence of the appropriate gradient. Critical systems, which form as a results of their activity scale-invariant structures (that are a kind of distribution channels), are optimal relative to the efficiency of substance and energy distribution. Thus, scale invariance of biological phenomena is a natural consequence of their dissipative nature.

Exterior characters of worker honeybees of two breeds, Apis mellifera carnica Pollmann, 1879 and Apis mellifera caucasica Gorbatchev, 1916, were analyzed to estimate their discriminant role and contribution to interfamilial differences within the breed. Six characters were included in analysis: 3rd tergite width, 3rd tergite length, right forewing length, right forewing width, cubital index, and discoidal shift. The pattern of differences between the breeds with respect to the set of these characters was evaluated using discriminant analysis. Identification of honeybee breed is not a trivial task, but it was accomplished using the equations of classification function for each breed based on the set of the above characters. The character “wing length” proved to allow statistically significant discrimination among at least half of the families in each breed.

Явления, обладающие свойством масштабной инвариантности, то есть сохраняющие неизменной свою структуру в некотором диапазоне масштабов, характерны для биосистем разного уровня. В настоящем обзоре излагаются основные проявления масштабно-инвариантных явлений на различных уровнях биологической организации, включая онтогенетические аспекты, и обсуждаются причины такого широкого распространения фрактальных структур в биологии. Практически все биологические системы могут быть описаны с позиций синергетики как открытые неравновесные системы, существующие за счет проходящего через них потока вещества и энергии. Для таких диссипативных систем характерно явление самоорганизации: поддержание потока энергии требует существования сложных структур, формирующихся спонтанно при наличии соответствующего градиента. В отношении эффективности распределения вещества и энергии оптимальными являются критические системы, формирующие в результате своей деятельности масштабно-инвариантные структуры, которые и являются своего рода каналами-распределителями. Таким образом, масштабная инвариантность биологических явлений является естественным следствием их диссипативной природы.