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In parthenogenetic hybrid Darevskia armeniaca species, the development of early oogenesis and early meiosis were analyzed. It has been shown for the first time that the number of synаptonemal complexes (SCs) of bivalents during the stages of early pachуtena–diplotena of the meiotic prophase 1 is constantly equal to the haploid number, 19. The SC karyotype is presented. The results of comparative molecular–cytogenetic (C/CMA3/DAPI) analysis of the mitotic chromosomes (2n = 38: 34A + 2m + Zw-sex chromosomes) of parthenogenetic females and of the meiotic Zw-sex chromosomes (n = 19 bivalents) of a male D. armeniaca specimen with sex inversion have been presented. Finally, the results obtained demonstrate the absence of premeiotic endoreplication of chromosomes, standard early stages of meiosis, and the formation of the haploid number of SC-bivalents (n = 19) of homeological chromosomes in D. armeniaca.

Parthenogenetic species of Caucasian rock lizards of the genus Darevksia are important evidence for reticulate evolution and speciation by hybridization in vertebrates. Female-only lineages formed through interspecific hybridization have been discovered in many groups. Nevertheless, critical mechanisms of oogenesis and specifics of meiosis that provide long-term stability of parthenogenetic species are still unknown. Here we report cytogenetic characteristics of somatic karyotypes and meiotic prophase I nuclei in the diploid parthenogenetic species Darevskia unisexualis from the new population "Keti" in Armenia which contains an odd number of chromosomes 2n = 37, instead of the usual 2n = 38. We revealed 36 acrocentric chromosomes and a single metacentric autosomal chromosome, resulting from Robertsonian translocation. Comparative genomic hybridization revealed that chromosome fusion occurred between two chromosomes inherited from the maternal species, similar to another parthenogenetic species D. rostombekowi. To trace the chromosome behaviour in meiosis, we performed an immunocytochemical study of primary oocytes' spread nuclei and studied chromosome synapsis during meiotic prophase I in D. unisexualis based on analysis of synaptonemal complexes (SCs). We found meiotic SC-trivalent composed of one metacentric and two acrocentric chromosomes. We confirmed that the SC was assembled between homeologous chromosomes inherited from two parental species. Immunostaining of the pachytene and diplotene nuclei revealed a mismatch repair protein MLH1 loaded to all autosomal SC bivalents. Possible mechanisms of meiotic recombination between homeologous chromosomes are discussed.

The results of experiments on natural distribution of seeds of the giant hogweed (Heracleum sosnowskyi Manden.) in the winter period are presented. It was found that viable seeds are preserved on the umbrellas of this alien plant in winter. Falling of single seeds during the winter period is not much different from falling of seeds in the summer–autumn period. It was shown that seeds under the influence of various factors, in particular, under the influence of strong gusts of wind, can move up to 5 m from the mother plant. It was revealed that the seeds are also able to move together with broken umbrellas over distances many times greater than the distances of the natural scattering of single seeds. Experimental observations on the movement of umbrellas at a distance of 40 ± 9 m for 15 min suggest that the range of movement of umbrellas can be hundreds of meters on a flat surface of icy roads. The high germination of seeds left on the umbrellas allowed us to conclude that measures to control Sosnowsky’s hogweed should include the destruction of dead plants with seeds until a stable snow cover is formed.

The article presents the analysis of the influence of anthropogenic conditions on the dynamics of life forms of meadow plants using the indices of the average number and stability of life forms based on data from long-term monitoring of Zalidov meadows of Kaluga region. It is shown that regular mowing leads to an increase in rod-root plants and an abundance of economically insignificant species. With regular moderate grazing, the number of long root-growing life forms increases, and the abundance of high-value plant species increases. It has been established that for rational use of Zalidov meadows, haying and pasture regimes should be alternated. The issues of the applicability of the indices used to identify general trends in the development of the meadow community depending on anthropogenic impact are discussed.

Protection of the containment integrity is one of the key objectives pursued in managing a severe accident at an NPP. Possible hydrogen inflammation in the containment can be regarded as the most dangerous threat for the containment integrity. Inert state of a steam–air–hydrogen mixture can be secured by maintaining a high steam concentration. With a steam concentration above 55%, the mixture is in an non-flammable state whatever the concentrations of its other components. The containment reinforced concrete walls lined with metal sheets behave as heat sinks with a very high thermal inertia. Heat removal through walls may have a significant influence on the mixture composition in the containment or in its individual part (especially if the rooms have comparatively small volumes) if part of steam from the mixture undergoes long-term condensation, as a result of which its concentration in the mixture decreases. The article presents an investigation, by means of detailed modeling, of the heat transfer processes through the walls of containment rooms with a view to reveal factors that are of importance in considering hydrogen challenge. It is found that the wall surface area to the room volume ratio is a factor having an effect on the formation of dangerous hydrogen-containing mixture compositions. It is shown that the wall heat absorption capacity decreases only slightly in the course of an accident. In rooms with a small volume, there may be a real risk that the medium in them may quite quickly lose its inertness as a result of heat removal through the walls. The possibility of a detonation mixture to form is not even excluded. In the case of a severe accident, there will be a risk of dangerous hydrogen-containing mixture compositions formation in small rooms within the containment irrespectively of the strategies implemented for the containment’s main rooms unless special measures and means are taken, e.g., application of accident management strategies or installation of hydrogen recombiners.

Open access to occurrence records of the most dangerous invasive species in a standardised format have important potential applications for ecological research and management, including the assessment of invasion risks, formulation of preventative and management plans in the context of global climate and land use changes in the short and long perspective. The striped field mouse (Apodemus agrarius Pallas, 1771) is a common species in the temperate latitudes of the Palaearctic. Due to land use and global climate changes, several waves of expansion of the range of this species have been observed or inferred. By intrusion into new regions, the striped field mouse has become an alien species there. Apodemus agrarius causes significant harm to agriculture and is one of the most important pests of grain crops. In tree nurseries, A. agrarius destroys seeds of valuable tree species and gnaws at the bark of saplings of broadleaf species and berry bushes. It is one of the most epidemiologically important rodents, involved in the circulation of the causative agents of haemorrhagic fever with renal syndrome (HFRS) and many other zoonotic infections. The foregoing allows us to classify the striped field mouse as a dangerous invasive alien species in the expanding part of the range. A lot of data accumulated for this species are of interest from both ecological and applied points of view. The accumulation and aggregation of data on the occurrence records of A. agrarius is relevant for the study of ecology, biogeography and construction of the spatial distribution and ecological niche models in the context of global climate change. We have created a dataset of 1603 occurrence records of this species, collected from 1936 to December 2020 by various zoologists, previously published or original. These records relate to a significant part of the striped field mouse’s range in Russia (1264 records) and neighbouring countries (339 records). The dataset shows the position of the northern and central parts of A. agrarius range, the disjunction of the range in Transbaikalia and isolated populations in the north of the range. The data were obtained in different formats from literature, indicating different degrees of accuracy of geographic coordinates and with several variations of the species' name. In the process of aggregating and fixing errors, we created a set of georeferenced occurrence records, adopted a controlled vocabulary, removed duplicates and standardised the format of records using unified data structure. We examined the dataset for inconsistencies with the taxonomic position of A. agrarius and removed the incorrect records. This paper presents the resulting dataset of A. agrarius occurrence records in the territory of Russia and neighbouring countries in a standardised format. This is a validated and comprehensive dataset of occurrence records of A. agrarius, including both our own observations and records from literature. This dataset is available for extension by other researchers using a standard format in accordance with Darwin Core standards. In different countries, there are a lot of occurrence records for the striped field mouse, but the overwhelming part of them is presented in separate literary sources, stored in the form of maps and in zoological collections. Prior to this project, such information was not available to a wide range of researchers and did not allow the use of these spatial data for further processing by modern methods of analysis, based on geographic information systems (GIS technologies). The created dataset combines species occurrence records of many Soviet zoologists who studied the distribution of the striped field mouse over a significant part of its recent range, in Russia and neighbouring countries (within the former USSR). The final set of records was created by combining the species occurrence records using a uniform data structure, checking geographic coordinates and removing duplicate and erroneous records. The dataset expands the available information on the spatial and temporal distribution of the dangerous invasive species in Russia and neighbouring countries of the former USSR (Estonia, Latvia, Lithuania, Belarus, Ukraine, Moldova, Georgia, Azerbaijan, Kazakhstan and Kyrgyzstan).

Background Caucasian rock lizards of the genus Darevskia are unique taxa, including both bisexual and parthenogenetic species. The parthenogenetic species have originated as a result of natural hybridisation between females and males of different bisexual species. The species involved in interspecific hybridisation are called parental. However, sympatric zones (SZ) of unisexual and bisexual rock lizards of the Caucasus are still poorly studied, although they are very important for understanding the role of hybrid individuals of different origin in reticulate evolution. This paper presents the location of the SZs of parthenogenetic and their parental bisexual rock lizards of the genus Darevskia in Armenia and adjacent territories of Georgia and Nagorno-Karabakh. We summarised the locations of the SZs identified from 1957 to the present, based on our field survey data gathered in 2018-2019 and records from publications and museum collections. This dataset includes 39 SZs of three types: SZ of parental bisexual species, SZ of parental species with unisexual species and SZ of the parthenogenetic species. For each zone, species composition, geographical and altitudinal distribution are presented. New records expand our knowledge of the geographical and altitudinal distribution of SZs in these species and provide additional data for understanding the mechanisms of reticulate evolution and hybridogeneous speciation in the past, present and future. New information The new records, including geographical and altitudinal distributions of three types of SZs, are presented, which expand the previously-known list to 39 locations of contact zones for parthenogenetic and its bisexual parental species of rock lizards of the genus Darevskia in Armenia and the adjacent territories of Georgia and Nagorno-Karabakh.

The results of recent studies on invasions of alien species in the Holarctic are given in a review format. Most of these studies were presented at the Fifth International Symposium “Invasions of Alien Species in the Holarctic,” which was held in Russia in 2017. For this review, we used recent publications in the Russian Journal of Biological Invasions and other journals. The main trends in studies of invasions of alien species in the Holarctic are highlighted.

The bivalve Dreissena polymorpha (Pallas, 1771) was shown to significantly decrease the biomass of cyanoprokaryotes in water collected from Lake Mikolajskoe (Poland) including potentially toxic species Cylindrospermopsis raciborskii (Woloszynska) Seenayya et Subba Raju. However, the mollusks increased the biomass of large filaments of green algae which are of low nutritional quality for zooplankton.

The purpose of this study was to determine how zebra mussels affected cladoceran community structure under eutrophic conditions. We conducted a mesocosm study where we manipulated the presence of zebra mussels and the presence of large-bodied Daphnia (Daphnia magna and Daphnia pulicaria). We also conducted a complimentary life-table experiment to determine how water from the zebra mussel treatment affected the life history characteristics of the cladoceran species. We anticipated that small- and large-bodied cladoceran species would respond differently to changes in algal quality and quantity under the effects of zebra mussels. Large-bodied Daphnia successfully established in the zebra mussel treatment but failed to grow in the control. We did not observe positive relationships between food concentrations and cladoceran abundances. However, the phosphorus content in the seston indicated that food quality was below the threshold level for large-bodied cladocerans at the beginning of the experiment. We believe that zebra mussels quickly enhanced the phosphorus content in the seston due to the excretion of inorganic phosphorus, thus facilitating the development of large-bodied Daphnia. In conclusion, our results suggest that zebra mussels can alter the phosphorus content of seston in lakes and this can affect the dynamics of crustacean zooplankton.

The population diversity of the frit fly Meromyza saltatrix from Poland, Mongolia, and several regions of the Russian Federation was analyzed by morphometric and molecular data on the mtDNA locus COI. Two phenotypes that correspond to two haplogroups (19 haplotypes) were identified by the absence or presence of black setae on the lower surface of the genae. A remarkable clinal variability among populations was demonstrated by the total area and area of the projecting part of the anterior processes of postgonites (APP), which play a critical role in the success of male copulation. Each parameter analyzed divided populations into four groups. Close populations with a natural barrier vary in the total area of the anterior process of the postgonite. We found an increased number of mutations including transversions in frit flies from Mongolia. Populations from Zvenigorod, South Ural Nature Reserve, and Mongolia might be of a later origin. The presence of particular haplogroup in the West European population of M. saltatrix with black setae, which is a unique feature of West European species of Meromyza, and their similarity to the Crimean population by the morphometrics of the APP is an indication of the possible isolation of this population in southern Europe during Quaternary glaciations with subsequent expansion to the northern part of the geographical area.

The results of analysis of the frequencies of t-alleles and heterozygous +/t individuals of house mice of different subspecies (musculus, bactrianus, tataricus, wagneri, and gansuensis) are presented for the natural populations inhabiting eight cities and five regions of Russia and adjacent countries of Eastern Europe and Asia. It is shown that the frequencies of t-alleles are 0.18 ± 0.03 in small samples (1–30 individuals) and 0.09 ± 0.06 in medium-sized samples (31–60 individuals). The factors that reduce the frequencies of t-alleles in natural populations and the mechanisms that prevent invasion and fixation of t-mutant alleles in the Mus musculus genome are discussed.

Phosphorus and nitrogen concentrations in the trophogenic zone in lakes are main factors determining the trophic state of lakes. The goal of this work was to assess the impacts of enrichment of lake water with nutrients, as well as the presence of large crustaceans, Dreissena polymorpha and fish on the process of phosphorus regeneration by zooplankton (rotifers and crustaceans) in experimental mesocosms. The experiment was carried out for 32 days and consisted of 12 treatments, each replicated in triplicate. The mesocosms were filled with 270 L of natural pelagic water from the eutrophic Lake Mikolajskie and kept on the shore of the lake. Fish did not to have any impact on phosphorus regeneration rates in any of the treatments, whereas the presence of bivalves increased phosphorus regeneration rates. Phosphorus regeneration rates did not affect phosphorus sedimentation in any of the treatments, but the loss of total phosphorus and its increased regeneration rates resulted in markedly decreasing turnover times of phosphorus in all treatments of the experiment. Nutrient enrichment mainly affected phosphorus regeneration by phytophagous and predatory crustaceans and had no impact on phosphorus regeneration by rotifers when large Cladocera were absent. Processes of phosphorus regeneration and uptake included in internal phosphorus cycling were under strong influence of biological factors, which acted quickly, through the changing trophic structure of zooplankton communities, which in turn changed the flow of phosphorus in trophic chains.

One of the main objectives of severe accident management at a nuclear power plant is to protect the integrity of the containment, for which the most serious threat is possible ignition of the generated hydrogen. There should be a monitoring system providing information support of NPP personnel, ensuring data on the current state of a containment gaseous environment and trends in its composition changes. Monitoring systems’ requisite characteristics definition issues are considered by the example of a particular power unit. Major characteristics important for proper information support are discussed. Some features of progression of severe accident scenarios at considered power unit are described and a possible influence of the hydrogen concentration monitoring system performance on the information support reliability in a severe accident is analyzed. The analysis results show that the following technical characteristics of the combustible gas monitoring systems are important for the proper information support of NPP personnel in the event of a severe accident at a nuclear power plant: measured parameters, measuring ranges and errors, update rate, minimum detectable concentration of combustible gas, monitoring reference points, environmental qualification parameters of the system components. For NPP power units with WWER-440/270 (230) type reactors, which have a relatively small containment volume, the update period for measurement results is a critical characteristic of the containment combustible gas monitoring system, and the choice of monitoring reference points should be focused not so much on the definition of places of possible hydrogen pockets but rather on the definition of places of a possible combustible mixture formation. It may be necessary for the above-mentioned power units to include in the emergency operating procedures measures aimed at a timely heat removal reduction from the containment environment if there are signs of a severe accident phase approaching to prevent a combustible mixture formation in the containment.

The results of analysis on Sosnowsky’s hogweed (Heracleum sosnowskyi Manden) invasion using long-term monitoring data in the valleys of 14 large and medium rivers of the East European Plain performed in 2008–2016 by the Complex Expedition for the Study of Historical Waterways were presented. A schematic map of the distribution of H. sosnowskyi in the valleys of big and medium rivers with georegistration and landscape description of each point of detection was created. General characteristics of spatial distribution were formulated; the vectors of invasion (anthropochoria, hydrochoria) and the most important factors determining the penetration of H. sosnowskyi into river valleys were identified. The data on H. sosnowskyi confinement to certain structural elements of the landscape of river valleys with definite geomorphological and soil characteristics were presented. It was shown that phytocenotic association of invasive species in natural and anthropogenic communities was associated with towpaths and basic banks in valleys of large and medium rivers. It was established that the banks of rivers formed by rocks with a high content of solid detrital material were most favorable for H. sosnowskyi invasion, and raw floodplains and abrasion sandy banks were unfavorable. The results obtained expand significantly the understanding of the invasive habitat and the confinement of plants to the floodplain sites and can be used in forecasting, preventing the spread of H. sosnowskyi, and developing the measures to control the hogweed.

The integrity assessment of the Reactor Pressure Vessel (RPV) is essential for the safe and Long Term Operation (LTO) of a Nuclear Power Plant (NPP). Hardening and embrittlement of RPV caused by neutron irradiation and thermal ageing are main reasons for mechanical properties degradation during the operation of an NPP. The thermal ageing-induced degradation of RPV steels becomes more significant with extended operational lives of NPPs. Consequently, the evaluation of thermal ageing effects is important for the structural integrity assessments required for the lifetime extension of NPPs. As a part of NRG's research programme on Structural Materials for safe-LTO of Light Water Reactor (LWR) RPVs, WWER-440 surveillance specimens, which have been thermal aged for 27 years (∼200,000 h) at 290 °C in a surveillance channel of Armenian-NPP, are investigated. Results from the mechanical and microstructural examination of these thermal aged specimens are presented in this article. The results indicate the absence of significant long term thermal ageing effect of 15Cr2MoV-A steel. No age hardening was detected in aged tensile specimens compared with the as-received condition. There is no difference between the impact properties of as-received and thermal aged weld metals. The upper shelf energy of the aged steel remains the same as for the as-received material at a rather high level of about 120 J. The T41 value did not change and was found to be about 10 °C. The microstructure of thermal aged weld, consisting carbides, carbonitrides and manganese-silicon inclusions, did not change significantly compared to as-received state. Grain-boundary segregation of phosphorus in long term aged weld is not significant either which has been confirmed by the absence of intergranular fracture increase in the weld. Negligible hardening and embrittlement observed after such long term thermal ageing is attributed to the optimum chemical composition of 15Cr2MoV-A for high thermal stability.

A key issue in the study of unisexual (parthenogenetic) vertebrate species is the determination of their genetic and clonal diversity. In pursuing this aim, various markers of nuclear and mitochondrial genomes can be used. The most effective genetic markers include microsatellite DNA, characterized by high variability. The development and characterization of such markers is a necessary step in the genetic studies of parthenogenetic species. In the present study, using locus-specific PCR, for the first time, an analysis of allelic polymorphism of four microsatellite loci is performed in the populations of parthenogenetic species Darevskia armeniaca. In the studied populations, allelic variants of each locus are identified, and the nucleotide sequences of each allele are determined. It is demonstrated that allele differences are associated with the variation in the structure of microsatellite clusters and single nucleotide substitutions at fixed distances in flanking DNA regions. Structural allele variations form haplotype markers that are specific to each allele and are inherited from their parental bisexual species. It is established which of the parental alleles of each locus were inherited by the parthenogenetic species. The characteristics of the distribution and frequency of the alleles of microsatellite loci in the populations of D. armeniaca determining specific features of each population are obtained. The observed heterozygosity of the populations at the studied loci and the mutation rates in genome regions, as well as Nei’s genetic distances between the studied populations, are determined, and the phylogenetic relationships between them are established.

The analysis of restoration of the number of Eurasian beaver (Castor fiber L.) in the reserves of the European part of Russia and the prediction of possible changes in ecosystems after its introduction into the reserves (Laplandsky, Darwinsky, Prioksko-Terrasny, Central Forest, Oksky, Mordovsky, Khopersky, Voronezhsky and Rdeysky) is presented. The purpose of this work is to analyse the patterns of restoration of the number of beavers based on long-term ground-based observation data and a qualitative description of possible changes in ecosystems after the introduction of beavers. The analysis of the population dynamics of the beavers in the reserves located in the north, south and in the centre of the range was carried out based on long-term monitoring data from 15 to 80 years. It is shown that the patterns of beaver population dynamics can be described using four types of patterns: eruptive; single-stage with quasi-periodic oscillations, multi-stage with quasi-periodic oscillations and a logistic trend of population change with periodic oscillations around it. It is revealed that the impact of beavers on landscapes depends on the population density, terrain features and forage resources of the territory. It is shown that in the future the beaver remains a constant component of ecosystems in the major part of the range. Possible changes in the biotic and abiotic characteristics of ecosystems as a result of beaver activity are analysed.

Mechanical testing and microstructural investigation on VVER-440 15Cr2MoV welds were carried out after irradiation and after recovery annealing treatment at two different temperatures (340 °C and 475 °C) for 100 h. The welds are part of the last surveillance chain of an Armenian nuclear power plant and have been irradiated for ~200,000 h at 270 °C, receiving extreme high fluence values (3.2 × 1025 m−2, E>0.5 MeV). Prolonged irradiation caused severe hardening and embrittlement. The increase of the yield strength and corresponding decrease in the uniform elongation are, 606 MPa and 10.2% respectively, when compared to the as-received state. Annealing at 340 °C did not show noteworthy recovery of the tensile properties. The recovery annealing treatment for 100 h at 475 °C resulted a significant recovery of the yield strength and relative uniform elongation (82% and 97% respectively) in conjunction with the disappearance of the irradiation-induced black-dot damage. The contribution of the observed irradiation-induced microstructural features to the total measured hardening was modelled using the Russel-Brown dispersion hardening model to qualitatively explain the observed hardening and recovery of the tensile properties after irradiation and annealing treatment respectively.

This paper is dedicated to the creation of a facility for the experimental study of a phenomenon of background acoustic emission (AE), which is detected in the main circulation loop (MCL) of WWER power units. The analysis of the operating principle and the design of a primary feed-and-blow down system (FB) deaerator of NPP as the most likely source of continuous acoustic emission is carried out. The experimental facility for the systematic study of a phenomenon of continuous AE is developed. A physical model of a thermal deaerator is designed and constructed. A thermal monitoring system is introduced. An automatic system providing acoustic signal registration in a low frequency (0.03–30 kHz) and high frequency (30–300 kHz) bands and study of its spectral characteristics is designed. Special software for recording and processing of digitized electrical sensor signals is developed. A separate and independent principle of study of the most probable processes responsible for the generation of acoustic emission signals in the deaerator is applied. Trial series of experiments and prechecks of acoustic signals in different modes of the deaerator model are conducted. Compliance of basic technological parameters with operating range of the real deaerator was provided. It is shown that the acoustic signal time-intensity curve has several typical regions. The pilot research showed an impact of various processes that come about during the operation of the deaerator physical model on the intensity of the AE signal. The experimental results suggest that the main sources of generation of the AE signals are the processes of steam condensation, turbulent flow of gas-vapor medium, and water boiling.

The impacts of fish and nutrient enrichment on the biomass of small and large cladoceran species were studied in mesocosms under eutrophic conditions. Fish shifted the ratio between small and large species to favour small cladocerans compared to control mesocosms, while nutrient enrichment favoured large cladocerans. Both fish vital activity and nutrient enrichment increased total and blue-green algae concentrations. While chlorophyll concentrations increased in response to fish and nutrient enrichment, there were no significant effects of fish on total cladoceran biomass and the relative proportion of large species due to high variability among replicates within treatments. However, fish and nutrient enrichment affected average total cladoceran biomass and the biomass of large species compared to control conditions.

The article provides data on allelic and genotypic diversity of Ukrainian and Armenian populations of a parthenogenetic lizard of Darevskia armeniaca. The individual genotypes of studied specimens were established due to combination of alleles of three microsatellite loci. It is supposed that in the introduced Ukrainian population after the invasion two new genotypes appeared. Molecular mechanisms of the emergence of these new genotypes are suggested. Values of observed heterozygosity and genetic Fst-distances for the introduced Ukrainian population, native Armenian population and group of other Armenian populations are provided.

Among vertebrates, true parthenogenesis is known only in reptiles. Parthenogenetic lizards of the genus Darevskia emerged as a result of the hybridization of bisexual parental species. However, uncertainty remains about the mechanisms of the co-existence of these forms. The geographical parthenogenesis hypothesis suggests that unisexual forms can co-exist with their parental species in the &ldquo, marginal&rdquo, habitats. Our goal is to investigate the influence of environmental factors on the formation of ecological niches and the distribution of lizards. For this reason, we created models of species distribution and ecological niches to predict the potential geographical distribution of the parthenogenetic and its parental species. We also estimated the realized niches breadth, their overlap, similarities, and shifts in the entire space of predictor variables. We found that the centroids of the niches of the three studied lizards were located in the mountain forests. The &ldquo, maternal&rdquo, species D. mixta prefers forest habitats located at high elevations, &ldquo, paternal&rdquo, species D. portschinskii commonly occurs in arid and shrub habitats of the lower belt of mountain forests, and D. dahli occupies substantially an intermediate or &ldquo, position along environmental gradients relative to that of its parental species. Our results evidence that geographical parthenogenesis partially explains the co-existence of the lizards.

The article presents the genetic parameters of the populations of lizards of the Darevskia raddei complex (D. raddei nairensis and D. raddei raddei) and the populations of D. valentini calculated on the basis of the analysis of variability of 50 allelic variants of the three nuclear genome microsatellite-containing loci of 83 individuals. It was demonstrated that the Fst genetic distances between the populations of D. raddei nairensis and D. raddei raddei were not statistically significantly different from the Fst genetic distances between the populations of different species, D. raddei and D. valentini. At the same time, these distances were statistically significantly higher than the Fst distances between the populations belonging to one species within the genus Darevskia. These data suggest deep divergence between the populations of D. raddei raddei and D. raddei nairensis of the D. raddei complex and there arises the question on considering them as separate species.

Results of the long-term analysis of the Eurasian beaver (Castor fiber) and its settlements in the Pushta River basin and Moksha River floodplain lakes in the southeastern part of the Mordovia State Nature Reserve during the period of 1940–2013 are described. The numbers of beaver settlements and animals living there 73 years after they were reintroduced have stabilized in the ranges of 20–29 settlements and 65–96 individuals. The performed integrated analysis of environmental conditions, climate, hydrological network, and the effects of predators, diseases, spatial arrangement of settlements, size of the settlemetns, number of dams in settlements, specific foraging features, and food resources, as well as mathematical data processing using the classic models of population dynamics (Malthus, Beverton–Holt, and Ricker) and a time series analysis, suggests that the dynamics is at a climax stage with a fluctuation at low abundance level. A hypothetical theoretical qualitative model of the long-term beaver population dynamics is discussed for different restoration rates of food resources. Using this model, it is shown that typical of the population dynamics in the Berezinsky Biosphere Reserve and Oksky Nature Reserve as well as Allegheny National Forest is a high restoration rate of food resources (type I dynamics). On the other hand, characteristic of the population dynamics in the Lapland, Il’menskii, PechoraIlych, and Mordovia nature reserves is a low restoration rate of food resources (type II dynamics). It is inferred that the further development of the beaver population in the Mordovia Nature Reserve will mainly depend on the functional (the rate of food restoration in abandoned habitats as well as the growth scale and rate of black alder stands in the abandoned beaver settlements) and random (cold winters, winter floods, and droughts) factors influencing the beaver population dynamics in the nature reserve.

Anecdotal evidence suggests that socioeconomic shocks strongly affect wildlife populations, but quantitative evidence is sparse. The collapse of socialism in Russia in 1991 caused a major socioeconomic shock, including a sharp increase in poverty. We analyzed population trends of 8 large mammals in Russia from 1981 to 2010 (i.e., before and after the collapse). We hypothesized that the collapse would first cause population declines, primarily due to overexploitation, and then population increases due to adaptation of wildlife to new environments following the collapse. The long-term Database of the Russian Federal Agency of Game Mammal Monitoring, consisting of up to 50,000 transects that are monitored annually, provided an exceptional data set for investigating these population trends. Three species showed strong declines in population growth rates in the decade following the collapse, while grey wolf (Canis lupus) increased by more than 150%. After 2000 some trends reversed. For example, roe deer (Capreolus spp.) abundance in 2010 was the highest of any period in our study. Likely reasons for the population declines in the 1990s include poaching and the erosion of wildlife protection enforcement. The rapid increase of the grey wolf populations is likely due to the cessation of governmental population control. In general, the widespread declines in wildlife populations after the collapse of the Soviet Union highlight the magnitude of the effects that socioeconomic shocks can have on wildlife populations and the possible need for special conservation efforts during such times.

The results of comparative analysis of tree and shrub resources quantitative characteristics in the active and abandoned beaver habitats within the territory of the Tadenka River basin, Prioksko-Terrasny Nature Reserve, where beavers have been dwelling for more than 60 years, are presented. Using one-way ANOVA analysis with the settlement type (active or abandoned) as a factor, it was shown that long-term foraging by beaver leads to a decrease in the species richness of trees (P = 0.068). Different hypotheses of the impact produced by beaver selective foraging on various forest layers (overstorey and undestorey) are discussed. Factors promoting thinning and changes in the age structure of the overstorey and undestorey are considered. There were observed changes in the species composition, accompanied by an increase in the proportion of low preference and nonfood species. The conclusion is made that, if the foraging zone does not exceed 50 m at the beginning of habitat utilization, it extends up to 165 m in the absence of predators when the habitat is used repeatedly. This observation is confirmed by Fisher’s exact test (P = 0.005), Yates’ chisquared test (P = 0.002), and the likelihood ratio test (P = 0.0002). In the case of beavers recolonizing their abandoned habitats with unrecovered food resources in the Tadenka River basin, a distant zone within 50 to 165 m from the bank becomes the main zone for tree-shrub foraging.

The basic results of the Armenian RPV surveillance program are presented. A change in Δ T k – neutron fluence trend curve shape is observed at a fluence of more than 4 × 10 20 cm −2 for both base metal and weld. The prediction of radiation embrittlement of Armenian RPV materials was performed on the basis of surveillance data and information from the IAEA International Database on RPV materials. Because the original weld surveillance data could not be used for the Armenian RPV weld embrittlement assessment, an analysis of selected data from the Database was carried out. Six welds and two base metals of WWER-440 steel with P and Cu contents similar to Armenian welds were selected and their embrittlement results were compared with the Russian Regulatory Guide prediction. It is demonstrated that the Guide corresponding to A f = 24.64 (chemistry factor for Armenian RPV weld No. 4) predicts the irradiation embrittlement of the selected steels conservatively. According to the Guide prediction the T k for weld No. 4 should not exceeded 145 °C by 2016. It is also demonstrated that the Armenian base metal irradiation embrittlement is substantially less than the Guide prediction.

Our goal is to assess consequences of the introduction of alien North American (Castor сanadensis (Cc)) beaver into the Nature Reserves inhabited by Eurasian beaver (Castor fiber (Cf)) in European Russia using a mathematical model. For this reason, we have developed a two-species model of population dynamics. Long-term (1934–2015) monitoring data on Cf population dynamics in six Nature Reserves are used in computer modelling of competitive interactions between native Cf and alien Cc. The Reserves are located in the European part of Russia in the north, south, and central part of Cf range. We have simulated the dynamics of both species populations after the introduction of Cc into the habitats occupied by Cf. The model demonstrates that Cf is displaced by Cc in all the Reserves after the introduction of 2 – 24 individuals of Cc. However, the duration of exclusion of one species by the other varies as a function of ecological conditions, initial number of individuals, and fecundities. Our model shows that, in case of introduction of 12 Cc beavers, the size of Cf population starts to decrease after 31–146 years as a result of competition. We study the conditions providing the coexistence of both species and find that Cc population dynamics after Cf exclusion can be described by four patterns: irruptive (Lapland Reserve), single-stage (Prioksko-Terrasny Reserve), multi-stage (Darwin, Central-Forest, and Khoper Reserves) and logistic population growth (Oka Reserve). Species biology in terms of the fecundity, family size, rate of individual development until sexual maturity, life-span, and the age structure of populations are compared between species to detect the mechanisms providing the competitive advantage of Cc over Cf.

The results of the modeling of the origin and development of the oceanic fouling biocenoses in the pelagic zone are presented. The models are relatively simple, but they are characterized by major peculiarities of the natural communities. The fouling communities are model objects to study the appearance and development of biological systems, invasions of hydrobionts, application of the bioindicator species, etc. The presented models take into account the most important interactions of the main fouling species (Lepadidae crustaceans are the dominating species) in typical regions and depths for such invasion and at the favorable abiotic environmental factors that are comparatively stable. The interaction between the meroplanktonic larvae of Lepas and Conchoderma (Lepadidae), represented by C. virgatum, L. anatifera, L. anserifera, and L. hillii, and the most widespread predators (crabs Planes minutus and the fish species) is modeled as the system of differential equations. In particular, the model covers the dynamics of colonies of fouling species, the “attractiveness” of these colonies to other fouling species, and the feeding rates of the predators consuming both the fouling species and associated fauna. The computing experiments showed that the population density changed markedly in the different age groups of Lepas and Conchoderma. The predator stress on Conchoderma was significantly higher than that on Lepas. The “attractiveness” of the biofouling organisms to cypris larvae and predators keeping near the substrate has a major impact on their density dynamics. The models showed that the crabs and especially fish had the strongest effect on the biocenoses of oceanic biofouling communities, limiting the population density of fouling species. When the presence of fish was excluded from the model, the abundance of Conchoderma increased rapidly and became similar to the abundance of Lepas. The model showed that the most important factors limiting the oceanic fouling are the settling rate of Lepadidae larvae to the substrate, “attractiveness” of the fouling organisms to predators, and the consumption of these animals by the predators. The models are in good correlation with experimental data of oceanographic buoy areas. Usage of the mathematical models for forecasting and assessing the invasion rates of biofouling organisms and the further development of their biocenoses is very promising and cannot be totally replaced by the other research methods. Analogous models can be developed for other communities and marine environments, for example, for the forecasting of hydrobiont invasions into the marine and freshwater bodies of Russia.

A parametric time-discrete model for the beaver population dynamics starting from their invasion (1948) to the present day (2011) in the Tadenka River basin is described. It is shown that the population size tends to a stationary state in the presence of a quasi-periodic component of 14–26 years. Model estimates for the dynamics suggest that the periodic component has a sawtooth shape with the number of beavers increasing from minimum to maximum in each period for 6 years and decreasing from maximum to minimum during the remaining part of the period. The oscillation amplitude of the quasi-periodic component is approximately six individuals and displays a weak trend of increase. It is assumed that further development of this beaver population will depend on many random events influencing the factors that control beaver population size, such as specific geomorphological features of the area, restoration rate of food resources in the abandoned habitats, scale of beaver settlement development, and its rate. Stability analysis of the stationary solution and assessment of the model adequacy suggest that the proposed discrete model is appropriate for quantitatively describing the dynamics of the local beaver populations in other areas depending on the availability of food resources.

The results of analysis of the European beaver (Castor fiber) population dynamics in the Prioksko-Terrasnyi Nature Reserve and its settlements in the Tadenka River basin during 1948–2009 are described. It is shown that, 50 years after beaver reintroduction in the Tadenka River basin, the number of settlements stabilized in the range 9–12. It is found that a slow increase in the number of settlements is mainly associated with the initially adverse environmental conditions on the Tadenka River and subsequent increase in the capacity of habitats as a result of construction activities and use of distant forage resources. The preformed integrated analysis of the settlement distribution, sizes of the occupied areas, number of dams in settlements, specific foraging features, and food resources, as well as mathematical processing of time series data and construction of a model, suggests that the beaver population of the Tadenka River has reached the climax of its development. The further development of this population will mainly depend on functional factors (geomorphologic characteristics of the terrain, the rate of food restoration in abandoned habitats, and the scale and rate of development of the black alder (Alnus glutinosa) communities in the abandoned beaver settlements) influencing the dynamics of the beaver population in the reserve.

The character of TRD (transmission ratio distortion) was analyzed using the database formed on the basis of the results obtained for a collection of mice carrying different t haplotypes during 30 years of experimental observations. Quantitative TRD parameters were determined in male mice with T/t w genotypes from natural populations in crosses with females from laboratory collections. The TRD value varied in the range from 0.41 to 0.74. The frequencies of t haplotypes in natural Mus musculus populations from different regions (Moscow, Moscow oblast, Tajikistan, Lithuania, and Mongolia) varied from 12% (Tigrovaya Balka, Tajikistan) to 44% (Ulan-Bator, Mongolia). The factors and mechanisms determining a low frequency of t haplotypes in natural populations are discussed.

A general concept for creation of a problem-oriented Web portal on alien species invasions in the Russian Federation (http://www.sevin.ru/invasive) is described. The portal contains the information model for representing taxa that fits in its metadata structure the metadata structure of the continental, regional, and various national public centers of North America, Europe, Africa, Asia, and Australia. Functional tasks, organizational and functional structure of the Web portal, and conceptual framework of the integrated database (DB) for various taxa are considered by the example of plant and insect quarantine species. It is shown that the generalized DB structures of the portals of the Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences and the international public centers on various organisms (fish, mammals, birds, insects, plants, etc.) can be represented as three blocks—taxonomic, geographic, and bibliographic. A verbal description of the functional capabilities of the Severtsov Institute of Ecology and Evolution web portal is given.

The t-complex includes a complex system of genes localized in the proximal region of chromosome 17 of house mouse Mus musculus. The results of microsatellite analysis of laboratory stocks of house mice carrying t12, tw5, tw12, and tw73 haplotypes and wild mice from natural populations of Russia (Volgograd, Rostov, Saratov oblasts, and Kalmykia), Armenia, Bulgaria, Iran, and Mongolia performed by the PCR method with the use of eight pairs of D17Mit primers (16, 21, 23, 28, 32, 57, 63, 78) are presented. These pairs of primers amplify microsatellite DNA sequences on mouse chromosome 17 in the region from 7.6 to 18.8 cM that correspond to inversions (In (17) 3.4). Each pair of primers recognized three to six variants of nucleotide sequences ranging in size from 90–120 bp (D17Mit 16) to 300–330 bp (D17Mit 57). In most cases, two variants of nucleotide sequences were detected in each individual, i. e., most individuals were heterozygous for the microsatellite loci under study. The highest similarity of the spectra of microsatellite DNA fragments was revealed in laboratory stocks of house mice carrying the tw5 and tw73 haplotypes. The spectra of animals from the Rostov and Volgograd oblasts appeard to be most similar to them. The microsatellite spectra of individuals from Iran closely resemble the spectrum of an individual from Armenia. It was demonstrated that amplified microsatellite fragments localized in the region of the t-complex can be used to identify representatives of the Mus genus from wild populations.

Microsatellites, or short tandem repeats, are abundant across genomes of most organisms. It is evident that the most straightforward and conclusive way of studying mutations in microsatellite-containing loci is to use clonally transmitted genomes or DNA sequences inherited in multigeneration pedigrees. At present, little is known about the origin of genetic variation in species that lack effective genetic recombination. DNA fingerprinting in 43 families of the parthenogenetic lizard species Darevskia armeniaca (131 siblings), using (GACA)(4), (GGCA)(4), (GATA)(4), and (CAC)(5) probes, revealed mutant fingerprints in siblings that differed from their mothers in several restriction DNA fragments. In some cases, the mutant fingerprints detected in siblings were also found in population samples. The mutation rate for new restriction fragment length estimated by using multilocus probes varied from 0.8 x 10(-2) to 4.9 x 10(-2) per band/per sibling. Probably, the most variations detected as restriction fragment length polymorphism have germ-line origin, but somatic changes of (CAC)(n) fingerprints in adult lizards were also observed. These results provide new evidence of existing unstable regions in genomes of parthenogenetic vertebrate animals, which provide genetic variation in unisexual populations.

Using multilocus DNA fingerprinting with microsatellite probes (CAC)5, (GACA)4, (GGCA)4, and (GATA)4, intraspecific variation of the Southeast Asian lizards belonging to the genus Leiolepis (bisexual species Leiolepis reevesii and triploid parthenogenetic species Leiolepis guentherpetersi) was first examined. The L. guentherpetersi lizards were characterized by monophyletic DNA fingerprint profiles for the loci detected by the (GACA)4, (GGCA)4, and (CAC)5 probes, in terms of intrapopulation similarity index constituting S = 0.96. This was different from the individual-specific profiles of the lizards from bisexual, presumably parental species, L. reevesii (S = 0.6; P 0.05). The results of DNA fingerprinting analysis of the same L. guentherpetersi samples with the (GATA)4 hybridization probe were unexpected. Variability of parthenogenetic species L. guentherpetersi at the (GATA)n markers was remarkably higher than that at other DNA markers (S = 0.35; P = 3.08 × 10−11), being comparable to the variation of the (GATA)n DNA markers in bisexual species L. reevesii (P = 0.74). The reasons for high polymorphism of the (GATA)n-containing loci in L. guentherpetersi still remain unclear. This polymorhism is probably associated with high instability of the loci, which can be revealed by means of family analysis of parthenogenetic offspring.

Using multilocus DNA fingerprinting, we have examined variability of (TCT) n microsatellite and M13 minisatellite DNA repeats in populations, families, and tissues of parthenogenetic Caucasian rock lizards Darevskia unisexualis (Lacertidae). It has been shown for the first time that population and family DNA samples of D. unisexualis (75 samples in total) have individually specific DNA fingerprinting patterns of (TCT) n fragments. Analysis of inheritance of (TCT) n microsatellites in 46 first-generation progeny in 17 parthenogenetic D. unisexualis families revealed their extremely high instability. Mutant TCT fingerprint phenotypes were found in virtually each animal of the progeny. Moreover, varying fragments in the progeny and their original variants in the mothers were shown to simultaneously contain (TCT) n and (TCC) n polypyrimidine clusters. At the same time, no variability of (TCT) n fragments has been detected in the tissues and organs of mature parthenogenetic lizards and in the analogous tissues of the two-week-old progeny of this year. This suggests the absence of somatic mosaicism and methylation of the corresponding loci in the samples. Along with the hyperinstability of (TCT/TCC) n polypyrimidine clusters, we have shown that the population and family DNA fingerprinting patterns of M13 minisatellites were invariable and monomorphic in the same DNA samples of D. unisexualis.Our results indicate that mutations at loci containing polypyrimidine microsatellites significantly contribute to the total genomic variability of parthenogenetic lizards D. unisexualis.

Population and family samples of two morphological forms (mutant and normal with respect to dorsal color) of parthenogenetic lizard species Darevskia armeniaca were examined by means of DNA fingerprinting using M13 mini- and (GACA) n and (TCC) n microsatellite DNA markers. The morphological forms examined were characterized by clonally inherited, species-specific patterns of the DNA markers, which were different from the species-specific DNA fingerprints of the other parthenogenetic species of the genus Darevskia (D. dahli, D. unisexualis, and D. rostombekovi). The mean index of similarity (S) obtained for a sample of 36 individuals from three isolated populations using three types of DNA markers was 0.966. This was similar to those observed in D. dahli (0.962) (P > 0.05), but higher than that in D. unisexualis (0.950) (P < 0.05) and D. rostombekovi(0.875) (P < 0.01). Inheritance of M13 minisatellite and (TCC) n microsatellite DNA markers in the F1 offspring of parthenogenetic lizards was examined. It was shown that variability and clonal diversity of the fingerprint phenotypes observed in the populations and families of D. armeniaca could be at least partly explained by RFLP mutations in microsatellite repeats.

Methods of estimating within- and between-population gene diversity in parthenogenetic species using mini- and microsatellite DNA markers and modified Wright's FST statistic are presented with special reference to model populations of lizards of the genus Darevskia(D. dahli, D. armeniaca, D. unisexualis). We used DNA fingerprinting data for several populations of these species examined earlier. The effects of variation in M13 minisatellite, (GACA)n- and (TCC)n-microsatellite loci on the formation of within-population gene diversity in parthenogenetic species D. dahli and D. armeniaca were shown to be different. The equality of the realized gene diversity Hand its maximum possible value Hmax in two populations of D. dahli (Hmax = 0.032, H = 0.031, P≪ 0.0431; Hmax = 0.024, H = 0.027, P = 0.09) and D. armeniaca (Hmax = 0.05, H = 0.053, P = 0.03; Hmax= 0.054, H = 0.055, P= 0.02) suggests that variation in (GACA)n loci substantially contributes to the maintenance of within-population genetic diversity. Analysis of between-population genetic diversity using loci M13, (GACA)n, and (TCC)n showed differentiation of D. dahli populations from northeastern and northwestern Armenia (FST = 0.0272, P = 3 × 10–13) and genetic homogeneity of the Armenian and introduced to the Ukraine populations of D. armeniaca characteristic of one clone (FST = 0, P = 1).

A technique for obtaining unbiased estimates of genetic parameters (allelic frequencies of RAPD loci, heterozygosity (H), Wright's Fstatistic, and Nei's genetic distances) in populations of the European (Capreolus capreolus L.) and Siberian (Capreolus pygargus Pall.) roe deer is presented. The technique employs jackknifing and multiple comparative analysis based on a modified Holmes's procedure for Bonferroni's test. It was demonstrated that samples from local groups of roe deer in the Trans-Ural region did not differ significantly in allelic frequencies (0.8, 0.81, and 0.78; P > 0.447) or Nei's genetic distances (0.0056, 0.0273, and 0.0218; P = 0.26), but they could be differentiated based on Wright's F statistic (0.0346, 0.0519, and 0.0450; P = 10–9). The parameters of within-population heterozygosity formed a gradient from the east to the west. Calibration estimates of molecular evolution rate in the family Cervidae obtained based on published data and Jukes–Cantor genetic distances estimated in this study demonstrated that the Siberian roe deer has split into two subspecies, C. pygargus pygargusPall. and C. pygargus tianschanicusSatunin in the interval between 229 and 462.3 thousand years ago. The species formation of the Siberian and European roe deer was dated between 1.375 and 2.75 Myr ago. Based on the results obtained we recommend the approaches used in the study for analysis of population genetic structure and phylogenetic relationships between populations, subspecies, species, and higher taxa.

Variation and clonal diversity in populations of the parthenogenetic rock lizard Darevskia rostombekovi was examined by means of multilocus DNA fingerprinting using mini- and microsatellite DNA markers M13, (GATA)4, and (TCC)50). The animals examined were shown to exhibit a clonally inherited, species-specific pattern of DNA markers (fingerprint profile) that is different from the species-specific patterns of parthenogenetic species D. dahli, D. armenica, and D. unisexualis. The mean intraspecific similarity indexS was 0.950 (0.003) for a sample of 19 animals from three isolated populations of North Armenia. This significantly differed from the estimate of this parameter for a sample of 21 animals including two individuals from mountainous, relict population from the vicinity of the Sevan Lake, which was equal to 0.875 (0.001). A comparison of DNA fingerprints showed differences between 21 individuals attaining 79 DNA fragments of 1801 mini- and microsatellite markers included in the analysis. The results obtained show that intraspecific variation in D. rostombekovi is higher than that in the previously studied parthenogenetic species D. dahli (S = 0.962) andD. unisexualis (S= 0.950) (P< 0.001). Taking into account that D. rostombekovi is considered monoclonal on the basis of allozyme data, the problem of clonal variability is discussed with regard to the evidence on nuclear DNA markers. It is suggested that the hybrid karyotype of D. rostombekovi, which is more unstable than that of D. dahli and D. unisexualis, generates a series of chromosomal rearrangements (mutations). This may lead to the appearance of a geographically isolated chromosomal race (clone) in the population inhabiting the southeastern coast of the Sevan Lake.

The results of the application of taxonomic distinctness and diversity indices for quantitative analysis of the dynamics of taxa in meadow communities using long-term monitoring data spanning 40 years from Zalidovskie meadows in the Kaluga Region are presented. It is shown that the magnitudes of the taxonomic distinctness and diversity indices changed following similar trends, i. e. having three intervals with values increasing in the second period while species richness decreased and falling in the third period while species richness increased. Additional analysis within the selected intervals and in their combinations using the Jaccard similarity index showed that after a critical change in the community structure during the second interval, the flora composition did not return to its original condition it used to have in the first period. These changes can be considered as characteristic of the succession in this site. We prove that indices of taxonomic distinctness and diversity can be used to analyze long-term dynamics of taxa of different ranks in meadow communities. They reveal the overall direction of change in the sward communities composition depending on the number of species and their positions in the taxonomic classification. The values of both indices increased when the number of related species decreased and vice versa.