Protein CTC from Aquifex aeolicus possesses a full-sized 5S rRNA-binding domain

Ribosomal 5S RNA is the only identified target for proteins of the CTC family. All known proteins of this family, except for CTC from Aquifex aeolicus, contain a full-sized 5S rRNA-binding domain. In the present study a mistake in the published A. aeolicus genome is corrected. It has been demonstrated that the ctc gene of this organism encodes the protein with a full-length 5S rRNA-binding domain. This protein binds specifically to the bacterial 5S rRNA. Thereby, our data show that CTC A. aeolicus is not an exception from the other known CTC proteins.     

Energetic aspects of CO oxidation in desulfovibrio desulfuricans

In cell suspension of Desulfovibrio desulfuricans B-1388, oxidation of CO as the only energy source is associated with reduction of SO42-. After a 2-h incubation of cells in 8% CO, 81% of the gas is converted. Oxidation of 1 mole CO results in formation of 0.23 mole H2S. Intracellular ATP content increases from 2.5 (control) to 8.3 nmoles/mg (during CO conversion). Dinitrophenol inhibits sulfate reduction and CO oxidation. CO dehydrogenase was detected in cytoplasmic and membrane cell fractions (59 and 34%, respectively).     

Comparative analysis of the psychophysiological parameters of the system quanta of performance in physically trained and untrained subjects

Physiological mechanisms of muscle activity have been studied in 14 athletes and 15 untrained students during cyclic physical exercises of various intensities, including the individual maximum. The principle of system quantization of behavior has been used to find opposite changes in the spectra of the tachograms of athletes and physically untrained students after the completion of the same physical exercises. It has been shown that, after cyclic physical load in trained and untrained subjects, opposite changes in the effectiveness of their testing activity occur.     

Feedback equilibrium control during human standing

Equilibrium maintenance during standing in humans was investigated with a 3-joint (ankle, knee and hip) sagittal model of body movement. The experimental paradigm consisted of sudden perturbations of humans in quiet stance by backward displacements of the support platform. Data analysis was performed using eigenvectors of motion equation. The results supported three conclusions. First, independent feedback control of movements along eigenvectors (eigenmovements) can adequately describe human postural responses to stance perturbations. This conclusion is consistent with previous observations (Alexandrov et al., 2001b) that these same eigenmovements are also independently controlled in a feed-forward manner during voluntary upper-trunk bending. Second, independent feedback control of each eigenmovement is sufficient to provide its stability. Third, the feedback loop in each eigenmovement can be modeled as a linear visco-elastic spring with delay. Visco-elastic parameters and time-delay values result from the combined contribution of passive visco-elastic mechanisms and sensory systems of different modalities     

Energy Metabolism and Spectral EEG Characteristics of Students with Different Neuroticism and Anxiety Levels in an Examination Stress Situation

Characteristics of the energy metabolism, external ventilation, and spectral characteristics of the EEG in an examination situation were studied in students with high and low neuroticism and situational anxiety. Higher energy expenditures, CO₂ concentration, and the value of O₂ in the exhaled air were observed in students with high neuroticism and situational anxiety during the stressful preexam situation. In addition, they were characterized by more pronounced -rhythm in the EEG spectra on right derivations and -rhythm in EEG spectra of both frontal and right central and parietal regions of the cortex. High values of the respiratory quotient, flow rate, and respiration frequency were observed in students with low neuroticism and situational anxiety before the examination at heightened energy expenditures. They did not display a more pronounced - and -rhythms in EEG spectra of the analyzed cortex areas.     

Physiological characteristics of system quanta of athletic performance

Physiological mechanisms of muscle activity during cyclic physical exercises of various intensity, including individual maximum exercise intensity, have been studied in 30 athletes. The system quantization of behavior showed that the spectral components of heart rate variability during attainment of individual maximum exercise intensity by athletes change in different directions. An increase in the individual maximum exercise intensity is accompanied by an increase in the maximum movement pace after each system quantum of muscle activity and is performed at a lower heart rate. This increases the absolute spectral power of the EEG β₂ range, and each system quantum of physical activity induces adequate triggering of autonomic mechanisms ensuring the activity. The results of this study may be used for professional selection or development of criteria of the endurance of athletes with regard to high cyclic exercise intensities.     

Relationship of spatial synchronization of θ-band bioelectric potentials of human EEG with the success of visual spatial task performance

Students (46 young men) were asked to memorize and reproduce the order and location (on a computer monitor) of signals. Two groups of subjects were formed according to how accurately they reproduced the true location and order of the signals. Subjects of the first group, in contrast to the second group, reproduced the signal location and order at a high accuracy and with few mistakes even in the first trials. EEGs were recorded prior to the test, during memorizing, and after completion of the task. In the initial state and after completion of the task, the two groups did not differ in the EEG θ-rhythm. During memorizing the signal sequence, an increase in the coefficients of coherence was recorded in the EEG θ band of the right brain hemisphere of the first-group of students; this was not characteristic of the second group. Three systems of connection with the foci of activity were determined in the right occipital, central, and frontal cortical areas, where the coherence of the EEG θ band was significantly higher during memorizing in the students that had exhibited a high accuracy of signal reproduction. Since the right hemisphere deals mainly with the perception of visual spatial information and it is more active in processing nonverbal and stereotyped signals, we have suggested that the students of two groups employed different strategies in solving the task during memorizing.     

Spatiotemporal patterns of macrophage migration inhibitory factor (Mif) expression in the mouse placenta

Background  

Macrophage migration inhibitory factor (MIF) has special pro-inflammatory roles, affecting the functions of macrophages and lymphocytes and counter-regulating the effects of glucocorticoids on the immune response. The conspicuous expression of MIF during human implantation and early embryonic development also suggests this factor acts in reproductive functions. The overall goal of this study was to evaluate Mif expression by trophoblast and embryo placental cells during mouse pregnancy.     

Autonomic correlates of individual differences in human intellectual activity

The individual differences in the autonomic support of intellectual activity, including simple and complex sensorimotor reactions, memorization and reproduction (on the screen of the monitor) of visual information, were studied. The rate of performing intellectual computer-aided tests is a relatively steady individual characteristic revealed in different kinds of activity. Students who reached a high speed and accurately performed intellectual visuomotor tasks were characterized by a high lability of autonomic indices, which manifests itself in a change in the absolute values and relationship of heart and respiration rates in accordance with activity stages. These changes were specific for each form of activity and were connected with the results of the tests. Under the initial conditions, these students were characterized by high values of TP and the power of the LF and HF ranges of heart rate variability at a LF/HF ratio close to unity.