Life Cycles of Ground Beetles (Coleoptera,Carabidae) from the Mountain Taiga and Mountain Forest-Steppe in the Eastern Sayan

Seasonal dynamics and demographic structure was studied in 15 dominant ground beetle species in the mountain taiga and mountain forest-steppe belts of the Eastern Sayan (Okinskoe Plateau). Life cycles of the dominant ground beetle species were classified by developmental time, seasonal dynamics, and intrapopulation groups with different reproduction timing. The strategies of carabid life cycles adapted to severe mountain conditions of the Eastern Sayan were revealed.     

Effectiveness of lipid peroxidation inhibition in biomembranes by antioxidants with and without hydrocarbon chains

The efficacy of lipid peroxidation inhibition by the natural antioxidant alpha-tocopherol and 2,2,5,7,8-pentamethyl-6-hydroxy-chromane (PMC), a derivative without hydrocarbon tail, as well as by the synthetic antioxidant 4-methyl-2,6-diterbutyl phenol (BHT) and its phospholipid derivative was studied in the membranes of rat liver microsomes and mitochondria. The presence of hydrocarbon tail in the antioxidant molecule determines the decrease of antioxidant efficiency in biomembranes. PMC and BHT exert a destructive effect on biomembranes, leading to an increase in their permeability to ions. This evidence suggests that the presence of hydrocarbon tail in the molecules of natural antioxidants provides not only for a relatively high antioxidant efficiency but also for a structural stability of biomembranes.     

Relation between the radioprotective effect of helium-neon laser radiation on bacterial cells and the time period between 2 types of irradiation

The effect of helium-neon laser radiation (lambda = 633 nm) given to E. coli K-12 cells of various genotypes 4 h following X- or alpha-irradiation was shown to increase the number of viable cells. The irreversible ingradient of a radiation injury to cells remained invariable during the first 60 min after irradiation its values being minimal.     

Thyroliberin and its analog lacking hormonal properties stimulate respiratory center activity in the frog Rana temporaria

It has been shown that thyroliberin and its synthetic analogue PR-546 injected into the lymphatic sacs (4.10(-7)-4.10(-9) g/kg) or applied to the medulla oblongata in the bulbar frogs (4.10(-10)-4.10(-12) g/kg) significantly increase the rate of motor respiratory volleys in the hypoglossal nerve. In preparations with the irregular level of the activity of the respiratory center, these drugs enhanced stabilization of the initial level of the rhythm of motor respiratory discharges.     

Features of the formation and dynamics of short-term image memory in the rat

Direct and indirect methods of delayed reactions showed that short-term image memory of rats elaborated on the basis of conditioned signals in poorly developed and its duration is not more than 1 s. While testing this memory, changes in the behaviour were seen, pointing to the development of "hard state" in the higher nervous activity of animals. Short-term image memory based on complex perception was shown to be well developed in rats, and by many characteristics it approximated to the memory of highly organized animals. The ability to reproduce the short-term image memory on the basis of conditioned signals is supposed to be a complex form of psychonervous activity of animals, and in rodents it appears to be at an initial stage of development.     

Investigation of Lactobacilli Strains during Lyophilization

The Freezing Points of three lactobacilli strains cultivated in skim milk and MRS-broth were determined. Their survival was analyzed after lyophilization. A maximal preservation of the cell number of the R1 strain was found. The fermentation activity of the laclobacilli was investigated before and after lyophilization in order to characterize their species identification. Copyright 1993, 1999 Academic Press.     

Cytochemical study of catalase activity in Candida boidinii during incubation on methanol

Catalase activity of the methanol-assimilating yeast Candida boidinii M-363 was determined cytochemically and biochemically. Electron microscopic investigations on ultrathin sections were made on cells from 16, 24, and 48h batch cultures in nutrient medium with methanol (or glucose as a control) as the sole source of carbon and energy. The electron-dense oxidation product of 3,3′-diaminobenzidine was found predominantly in the mitochondrial cristae and membranes. The mitochondria were increased in number, enlarged, sometimes aggregated, with variable form and size and they characteristically developed when the strain was grown on methanol. The significant development of these organelles and their intensive DAB staining correlated with the considerable increase in catalase activity. Biochemically, catalase in the cell-free extract was determined to be maximal along the exponential growth phase of the strain during its incubation on methanol. Enzyme analysis of the heavy mitochondrial fraction showed that it possessed catalase activity but not peroxidase activity. The results showed that not only peroxisomes but also mitochondria may be structurally and functionally responsible for the high catalase activity of some methanol-assimilating yeasts. What is more, the contribution of the mitochondria to the utilization of methanol may be significant.