New fossil leporid materials from the Lower Pleistocene deposits of the Taurida Cave in the central Crimea (Zuya village, Belogorsk district) are referred to Hypolagus brachygnathus (Kormos, 1930) and Lepus sp. The cooccurrence of Hypolagus and Lepus in the Early Pleistocene of Crimea is significant in terms of the question of the first appearance of Lepus in Europe, as well as the hypothesis of the competition with hares as one of the possible causes of extinction of Hypolagus.Stocks and biodegradation resistance of organic carbon in soils depend on the combination of external and internal determinants, which control not only the decomposition, but also the stabilization of organic matter (OM). The soil OM stability has been evaluated by (1) specific mineralization rate (SpMinR) for the forest ecosystems located in various climatic zones of Eurasia (temperate, Mediterranean, and tropical) and (2) biological stability index (IBS) determined for the main soil types of European Russia under natural vegetation and agricultural crops. It has been shown that the climate and vegetation type (land use) are the key factors determining the OM stability in soils. For example, close negative correlations of the SpMinR values with the annual precipitation and the mean annual air temperature have been found in soils of the Eurasian transect. It has been revealed that the portion of stable and biologically conserved OM and IBS values in soils under agricultural crops are significantly higher than in soils of natural cenoses.The influence of nanocomposites (NC) of selenium in matrices of arabinogalactan (Se/AG) and starch (Se/St) on in vitro vegetation of potato plants, peroxidase activity, and reactive oxygen species has been thoroughly studied. It has been shown that these nanocomposites of selenium have antimicrobial effect to the phytopathogenic bacterium Clavibacter michiganensis ssp. sepedonicus (Cms). In the present investigation, it has been shown that Se/AG NC (6.4% of Se) and Se/St NC (12.0% of Se) have no negative impact on the potato plants healthy and Cms infected, while stimulating their growth, number of leaves and weight of the vegetative part. Se/AG NC has shown a positive effect on potato plants by increasing its immune status by increasing the ROS content and increasing the peroxidase activity. With the use of the element analysis technique, it has been shown that scrutinized nanocomposites are not accumulated in potato plants after the bactericidal processing with the nanocomposites. Se/AG NC and Se/St NC as potential agents used for treatment of potato plants against pathogenic bacteria.The report is the first to confirm the hypothesis that algal mats provoke additional accumulation of heavy metals in the bottom sediments and a release of labile metals. This process, in turn, enforces pollution of the coastal zone. Our results give a new direction to studying of the "green tide" worldwide problem.The effect of food additive including antioxidant dihydroquercetin and polysaccharide arabinogalactan on the activity of metabolic enzymes in muscles and liver of artificially grown rainbow trout Oncorhynchus mykiss affected by bacterial infection was investigated. The results of the study indicated an increase in the resistance of trout to the action of bacterial infection with the enrichment of the diet with the studied bioactive components, apparently mediated, among other factors, by the activation of metabolic pathways of synthesis of energy and reducing equivalents.Laboratory experiments were performed to compare the electrical activity and behavior in Clarias fuscus during spawning. Each of the multiple matings of the male and female was preceded by an amplexus - a mutual pose in which the male tightly covers the female's head and remains in close contact with it until the end of mating. The spawning behavior of C. fuscus was accompanied by monopolar electrical pulses (MP) of two types single MPs, similar to those observed in other behavioral situations (aggression, hunting) and specific MPs, observed only during spawning bursts of serial MPs (burst MPs), at intervals which are comparable with their duration. Each recorded burst MPs (71) corresponded to one mating, and each recorded single MP (63) corresponded to an attack of one fish on another. In different behavioral situations (matings and attacks), MPs differ significantly in amplitude and duration; and for MPs in bursts, in their degree of asymmetry. It can be assumed that the involvement of MPs in the spawning behavior of C. fuscus is similar to that studied earlier in Clarias macrocephalus, and is a common feature for Clariidae.The external morphological, X-ray, and tomographic study of a frozen rodent mummy from the Upper Pleistocene Yedoma deposits on the Tirekhtyakh River (a Semyuelyakh River tributary, Abyi ulus, Republic of Sakha (Yakutia), Russia) showed its belonging to Lemmus sp. The radiocarbon age of the finding is 41 305-41 885 cal B.P. This is the first Pleistocene discovery of a frozen mummy of a genus Lemmus representative. In terms of the body and skull sizes, coat color, the lower incisor length, and the molar structure, the specimen studied is similar to the recent Lemmus sibiricus (Kerr, 1792). Comparison of the mitochondrial COB gene sequence with the DNA sequences presented in the GenBank database also testified to the maximum similarity with the Recent Siberian brown lemming.A concept of the comprehensive assessment of soil contamination is proposed. According to it, the conclusion regarding the presence of toxic substances in the analyzed sample is based on the inhibition of enzymatic reactions responsible for various functions of a living organism, such as luminescence, respiration, etc. These functions are taken as test functions in classical bioassays with the use of living objects (luminous bacteria, daphnia, algae, and others). The regularities of the impact of different classes of toxicants on the activity of particular enzymes or coupled oligo-enzyme chains have been established. These enzyme reactions are selected as potential test objects markers of contamination. Three enzyme systems with the maximal sensitivity to different classes of toxicants have been chosen for the set of enzymatic bioassays butyrylcholinesterase, NAD(P)HFMN-oxidoreductase + luciferase, and lactate dehydrogenase + NAD(P)HFMN-oxidoreductase + luciferase.  https://www.selleckchem.com/  The possibility to use enzymes instead of living organisms in the bioassay of natural complex systems has been shown.