EEG correlates of individual differences in performance efficiency of students during examination stress

Performance of cognitive tests and EEG spectral power were evaluated in 39 students aged from 19-21 years in two conditions: during common educational process and immediately before examination (stress condition). Before examination, the performance was better in subjects with low level of spectral density in the delta band (in the occipital, parietal, central and frontal cortical areas) and high level of the alpha-rhythm spectral density in all the cortical areas, A decrease in performance scores before examination was correlated with an increase in the delta activity (in the right frontal and temporal cortical areas) and rise of the anxiety level (tested by Spielberger).     

Effects of Exogenous Factors on Enzymes of Carbon Metabolism in Thermoacidophilic Bacteria of the GenusSulfobacillus

Aerobic thermoacidophilic chemolithotrophic bacteria Sulfobacillus thermosulfidooxidans1269^Tand Sulfobacillus thermosulfidooxidanssubsp. asporogenes41 were shown to be resistant to stress factors, including high concentrations of Zn²⁺(0.8 M) and supraoptimal concentrations of H⁺(pH 1.2). The growth and biomass gain rates decreased, but bacteria retained their functions. The activity of nearly all enzymes involved in carbon metabolism decreased. Glucose was primarily metabolized via the Entner–Doudoroff pathway. The activity of tricarboxylic acid cycle enzymes decreased compared to that in cells grown under normal conditions. After saturation of the growth medium with 5 vol % CO₂, sulfobacteria utilized glucose by the Embden–Meyerhof and pentose phosphate pathways under mixotrophic conditions.     

Effect of a polyoxydonium immunoregulator on the biological properties of microorganisms

The effect of the synthetic immunomodulator polyoxydonium (PO) on some biological properties of pathogenic bacteria (Shigella flexneri, Salmonella enteritidis), opportunistic bacteria (Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacteroides fragilis, Peptostreptococcus anaerobius, Prevotella melaninogenica, Propionibacterium propionicum, Clostridium difficile) and fungi (Candida albicans), isolated during enteric infections, enteric dysbiosis, pyoinflammatory diseases, was evaluated in a number of in vitro experiments. The study revealed that the recommended therapeutic concentration of PO decreased antilysozyme activity (ALA) and the anticomplement activity in Klebsiella, Shigella, Propionibacterium, Clostridium, bacteroids, fungi of the genus Candida, but increased ALA in nonhemolytic Escherichia. Under the action of PO an increased sensitivity of the microorganisms under study to definite antibiotics of the lincosamide, fluoroquinolon, carbapenem and cephalosporin groups was noted. The data obtained in this study reveal one of the possible mechanisms of the corrective action of PO on the microbiocenosis of the intestine in dysbiosis, enteric infections and pyoinflammatory diseases.     

Neutrophils and antioxidant activity of cervical secretion in women with the acute inflammation in the upper section of the reproductive tract

The functional activity of neutrophils, peroxidation products and antioxidative activity of cervical secretion in women with the acute inflammatory process in the upper section of the reproductive tract were under study. The most pronounced changes in the function of neutrophils were observed in women with the low antioxidative activity of cervical slime.     

Chromosomal mutations in Scots pine (<Emphasis Type="Italic">Pinus sylvestris</Emphasis> L.) growing in a hydromorphic environment: First case of a giant chromosome detection

Chromosomal mutations and mixoploidy have been revealed in the seedlings of Scots pine (Pinus sylvestris) growing in a hydromorphic environment. A giant chromosome was detected for the first time in gymnosperms.     

Ecological traits of the lichen flora of Khanty-Mansi Autonomous Okrug (Yugra)

A lichen biodiversity study conducted in the Khanty-Mansi Autonomous Okrug (district) reports 958 species in 199 genera and 72 families. Cetrelia alaskana (Llano) W. L. Culb. et C. F. Culb. is new to West Siberia; Graphis elegans (Borrer ex Sm.) Ach., Porpidia hydrophila (Fr.) Hertel et A. J. Schwab, and Sclerococcum sphaerale (Ach.) Fr. are new to Siberia; Acarospora fusca B. de Lesd., Cliostomum tenerum (Nyl.) Coppins et S. Ekman, Pertusaria corallina (L.) Arnold, and P. stalactiza Nyl. are new to Russia. High diversity of epilithic lichens is ecologically due to a variety of ecotopes that include mountain habitats on the eastern spurs of the Subarctic and Northern Urals in addition to plain ones.     

Concanavalin-binding proteins and cytokeratins in different tissues of the early amphibian gastrula (Rana temporaria, Xenopus laevis)]

Concanavalin A (con A), a lectin which specifically interacts with aD-mannose and aD-glucose, has a neutralizing effect on the explants of the early gastrula ectoderm of several amphibian species. Consequently, it was interesting to study con A-binding protein spectrum of the ectoderm and compare it to those of other early gastrula tissues. Animal pole ectoderm (APE), dorsal blastopore lip (DBL) and vegetal pole endoderm (VPE) were dissected from early gastrulae of Rana temporaria and Xenopus laevis. The extracts were subjected to SDS-PAGE with subsequent immunoelectroblotting on nitrocellulose membranes. The blots were sequentially treated with con A solution, horseradish peroxidase and diaminobenzidine. Spectra of the con A-binding glycoproteins were similar in APE, DBL and VPE of R. temporaria. Ten-twelve fractions with the molecular weight in the range from 30 to 150 kDa were stained in each blot. Fractions with the molecular weight of 150, 125, 104, 94 and 42 kDa showed more prominent lectin binding. Con A-binding protein spectra remained unchanged after freezing-thawing of the studied extracts, as well as after blots were treated with neuraminidase or sulphuric acid in order to remove sialic acid residues; the only exception was 42 kDa fraction. At the same time, a-methyl-D-mannoside pyranoside completely blocked con A binding by fractions of the studied extracts. In histological sections of R. temporaria early gastrula, all cells bound FITC-labelled con A. Similar data were obtained with tissues of X. laevis early gastrula. While electrophoretic pattern of X. laevis tissues drastically differed from that of R. temporaria, there were no significant differences between con A-binding protein spectra of X. laevis APE, DBL or VPE. Thus, all studied tissues of the amphibian early gastrula contain similar set of con A-binding proteins; however, only APE is capable of neutralization in response to con A action. These data favor our earlier assumption (see Mikha?lov et al., 1989) that con A reception and transmission of the corresponding signal do not determine the characteristics of the target cells response. APE, DBL and VPE extracts were assayed also for the presence of a protein similar to cytokeratin No. 8 characteristic of simple epithelia of mammals. Experiments were performed using immunoelectroblotting with monoclonal antibodies (mAB) against cytokeratin No. 8 from rat colon (mAB E2 and E7 kindly supplied by Dr. G. A. Bannikov). In R. temporaria embryos, cytokeratin 8 was detected in APE, but not in DBL or VPE. In X. laevis gastrulae all the tissues studied contained this cytokeratin.