The experimental model of chronic styrene intoxication is used to investigate bio-electrical indices of the functional state of the sensorimotor cortex, paraventricular and ventromedial hypothalamic nuclei in rabbits of different ages. It is shown that the effect of styrene on bioelectric activity of brain depends both on studied structures and animals’ age. The most profound changes in bioelectric activity of the sensorimotor cortex, the ventromedial nucleus of hypothalamus, and the paraventricular nucleus of hypothalamus are observed in the 4-, 12- and 36-month-old rabbits, in the 12- and 36-month-old rabbits, and in the 36-month-old rabbits, respectively. Analysis of amplitude-frequency indices of bioelectric activity of cortical and subcortical structures in the rabbits of different age indicates a high sensitivity of the sensorimotor cortex to styrene in comparison with hypothalamic nuclei. Chronic intoxication with styrene leads to the weakening of the functional state of the studied structures of the brain in the form of strengthening of slow waves and an increase in synchronization of bioelectric activity.

We report data on the age and growth of the Black Sea lizard in the Ubin River valley (Severskiy District of Krasnodar Krai, Russia, Northwest Caucasus). Using skeletochronological analysis, we have studied 111 finger phalanxes, including 59 from females and 52 from males. The average age of females in the studied samples is 5.6±0.12 years (from 4+ to 8+ years). Males have an average age of 4.58±0.12 (from 3+ to 6+ years). Lizards of different age groups have a high individual variability in size and body weight. This circumstance makes it impossible to determine the age of these animals on the basis of allocation of different size's groups. From studied females, 14 specimens aged 5+ to 8+ years (average age of 5.7±0.28 years) yielded offspring. Age variability in the reproductive performance has not been observed.

The species composition of floating hydrophytes on the water surface of Astrakhan and surrounding areas is investigated. Topical and fensive connections in their phytoconsortia are identified. Predominant in the hydrophyte consortia - Salvinia natans, Lemna minor, Spirodela polyrrhiza, Trapa natans are episubstrate and episubstrate and stational hydrophytes. Phytoconsortia of surface-floating hydrophytes include more than a hundred species of organisms. All four species are characterized by similar spectra of consortia because of the similarity of their life forms and merotopic structure. Consortium studied species act as a reserve gene pool, providing related organisms with diverse resources.

The chromosomal composition of Anopheles mosquitoes is studied in the adjacent breeding places on the territory of the Taldom district in the Moscow region. Nineteen samples of larvae from four breeding sites are examined. Two sibling species of the Anopheles maculipennis complex, i.e. An. messeae and An. maculipennis, are found in all mosquito habitats. The chromosomal inversions XL₁; XL₄; 2R₁; 3R₁; 3L₁; 3L₃ are identified in polymorphic species An. messeae. Inversion 3L₃ is unique. It is shown that the mosquitoes of habitats in the villages of Verbilki and Knyazchino belong to different populations of An. messeae. Each population has a certain karyotypic structure, stable in time. Significant differences in the chromosomal composition of the two populations are maintained during the eight-year observation period. These data indicate a weak influence of mosquito migration in the formation of the karyotypic population structure.

Modelling biochemical conditions of the intraorgan medium in type-2 spinal muscular atrophy in the organotypic tissue culture allowed us to detect the inhibiting effect on the growth of axons of sensory ganglia in 10-12-day chicken embryos. It is shown that the degree of growth inhibition of axons of spinal ganglia in chicken embryos correlates with the parameters of neurotrophin concentration in the blood serum of patient with type-2 spinal muscle atrophy (SMA). Neurotrophins hyperexpression inhibits the growth of the axon. That effect may be seen as a factor promoting further neurodegeneration in the nervous tissue.

We report the results of studies of plankton communities and macrobenthos in the Yuzhno-Kirinskoye gas condensate field offshore northeast Sakhalin in the summer-autumn period in 2014. We have found 51 species and intraspecific taxa of phytoplankton (selection coincided with the flowering periods); Zooplankton was represented by 50 ordinary (for this region) forms, with the dominating neritic complex. The summer ichthyoplankton is characterized by a high proportion of flounder roes with plasmolisis yolk. The basis of the autumn ichthyoplankton is formed by combfish. The macrobenthos is presented by 69 species. For the first time we have determined the content of heavy metals in Zooplankton in this region.

Data on selenium distribution and migration in a biogeochemical ‘soil - plant - insects’ food chain are presented for the first time under contrasting landscape and geochemical conditions of the Dniester valley ecosystems. The total soil selenium content is found to be the same in various ecosystem types, while in the floodplain ecosystems, plants accumulate 2.5 times more selenium than those growing in ecosystems on terraces and slopes. The ecosystem differentiation with respect to the selenium content in the first trophic level significantly affects the selenium content in the following links of the biogeochemical food chain. The results of the study show that the phenomenon of selenium biomagnification is observed in the floodplain food chain. An increase in the selenium concentration in terrace ecosystems is observed in passing from plants to phytophages and from them to myxophaga (or zoophages).

The paper summarizes regional monitoring data on pollution of the snow cover of agricultural lands in the Tver region from 1996 to 2015. It is found that the content of nitrate, chloride, and sulfate ions in some years significantly exceeded the background values. This can have a constant negative impact on the deposited media. Certain concentration coefficients and total pollution of snow generally show a decrease in or maintaining of the level of snow contamination in time in some areas.

We study the annual variation in water temperature in the river Ishim within the area of the town of Ishim. Temporary changes in water temperature in the river Ishim are tracked within each year of observation and compared with the average long-term observations. In general, annual water temperature variations in the studied period are similar in smooth changes and patterns characterized by an annual spring-summer temperature rise, a summer temperature maximum and an autumn temperature decrease. The maximum annual variation in water temperature in the river Ishim is registered, as a rule, in the second half of July. The dynamics of water temperature being observed shows periods of threshold temperatures (important in the fields of economy and human life) which vary in their duration. Intramonth differences are usually not significant, except for April-May and October-November, when we observed warming or cooling of the water.

At the present level of knowledge, historical geoecology is treated as the direction of applied geoecology, studying the spatial-specific effects of the last (or past) environment on humans, plants and animals. A conceptual generalization of historical geoecology is presented. We discuss the content of historical settlement geoecology, anthropochemical geoecology, historical and soil geoecology, historical and climatic geoecology, historical and economic geo-ecology, and historical and medical geoecology. We put forward an idea of geoecological traps, i.e. dangerous places in the environment where man can die from exposure to extreme natural or anthropogenic-natural processes.