Learning with simulation only--artificial skills.
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Biomedical subjects
Publications and source records attributed to B Johannes.
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As a ground-based reference study to a space experiment, a complex psychophysiological test battery (heart rate, blood pressure, skin conductance, finger temperature, forearm electromyogram during psychological loading task solving) was developed and first applied on two cohorts of subjects with different blood pressure levels at rest (53 hypertensive patients, and 30 normal controls). The data describing autonomic reactivity could be differentiated by cluster analysis into four Autonomic Outlet Types (AOT). The method was subsequently applied to 20 patients with systemic Lupus erythematosus and 13 subjects with rheumatoid arthritis to work out a discriminant function for classifying and testing it's validity. The AOT classification of all subjects showed a significant correlation with the different types of diseases.
A complex psychophysiological test battery was applied to twelve subjects during long-term spaceflights. This experiment was designed to assess the psychophysiological reactivity to acute psychological stressors. A set of noninvasive physiological measurements (electrocardiogram, electromyogram, blood pressure, skin conductance, peripheral skin temperature) was used to describe the reactivity of the autonomic nervous system and the cardiovascular system to an induced series of changes between mental activity load and quiet relaxation. It could be shown that under space conditions the subjects react differently than on earth. On the basis of significantly lower heart rates we concluded that an extended parasympathetic cardial influence is present during later periods of long-term space flights. The peripheral skin conductance reactivity, however, indicated a tendency to higher peripheral sympathetic tonus under microgravity. Assuming individually different pathways of sympathetic-parasympathetic traffic under psychological stress, the whole set of data could be classified into autonomic outlet types (AOT) based on clinical reference data. Most of the subjects changed their AOT during flight. After flight the subjects eventually fell back into their pre-flight patterns, but seven of twelve subjects showed a significantly different autonomic system reactivity at least once after landing that was similar to that of hypertensive patients, indicating an extended sympathetic overshoot directly post-flight. In conclusion it is assumed that sympathetic effects in one measurement do not exclude less sympathetic or even parasympathetic effects in others during adaptation to extreme environments.
TNF-receptor associated factors (TRAFs) comprise a family of adaptor proteins that act as downstream signal transducers of the TNF receptor superfamily and the Toll/interleukin-1 receptor family. The mammalian TRAFs 2, 5 and 6 are known to activate JNK- and NF-kappaB signaling pathways, whereas the function of the other three mammalian family members, TRAF 1, 3 and 4 is less well characterized. Vertebrate TRAFs have a very similar structure with the exception of TRAF1: aside the characteristic C-terminal TRAF domain, they share a N-terminal RING finger followed by five or, in the case of TRAF4, seven regularly spaced zinc fingers. Two TRAF homologues are present in the genome of Drosophila melanogaster, DTRAF1 and DTRAF2 (also known as DTRAF6) and both have been implicated in the Toll-receptor pathways leading to the activation of NF-kappa B and JNK. DTRAF1 is most closely related to mammalian TRAF4 which is predominantly expressed during nervous system development and in ephitelial progenitor cells. In order to gain insight into possible roles of DTRAF1 during development, we have performed a detailed transcriptional analysis of the gene at various embryonic and larval stages.
INTRODUCTION: Pharmacological and nonpharmacological treatment of brain syndrome is multifarious. Until now, plain external applications of physical stimuli, as used daily in geriatric care, were not explored regarding their influence on cognitive brain function. The aim of this randomized cross-over study was to examine the influence of dermatoreceptive stimuli on cognitive brain function of healty geriatric volunteers. METHODS: 24 healthy volunteers (23 women, 1 man) were randomized into 2 groups (cross-over design). Group A (mean age +/- SD: 68.8 +/- 6.2 years) was treated according to the following regime: at first a 10-12 degrees C cold stimulus for 10 s (a so-called Kneipp face shower) and afterwards a cold wet pack of 10-12 degrees C at the neck for 1 min. Group B (age 69.8 +/- 5.3 years) was subjected to an identical procedure but with warm thermoindifferent temperatures of 34-36 degrees C. After 1 week the two groups were interchanged. The parameters of interest were the critical flicker frequency (CFF) and the latencies of the event-related P300 potentials of the visually evoked potentials (VEP), which can be considered the electroencephalographic substrate of the cognitive functional ability. The CFFs and the P300 latencies and amplitudes were measured directly before and 10 min after the application of the above-mentioned stimuli. Furthermore, the CFFs were recorded a second and third time 30 and 60 min later. RESULTS: Following application of cold-water stimuli, the CFF increased from (mean +/- SE) 32.55 +/- 0.44 s(-1) to 33.06 +/- 0.44 s(-1) (p = 0.003) 10 min after the stimulus. 30 min later the CFF was still elevated at 32.95 +/- 0.47 s(-1) (p = 0.043). The P300 latencies decreased by 4.8% (p < 0.001) after cold-water application from 266.5 +/- 5.28 to 253.7 +/- 4.22 ms. After warm stimuli they increased from 258.69 +/- 3.71 to 266.17 +/- 5.03 ms (p = 0.01). The P300 amplitudes were elevated by 5% only with the cold stimuli (p = 0.004). CONCLUSION: Cold water applied locally to face and neck region is able to provoke significant improvements of cognitive abilities.
An overview of experimental investigations into the use of the voice pitch mode (F0 m) as a distance tool for the monitoring of emotional stress reactions is given. Seven experiments are summarized describing the relations between voice reaction and psychological and physical load in laboratory and field applications. The reactivity of F0 m to mental load depends on psychological personality traits. F0 m is less related to physical load. The evaluation of F0 m as voice stress indicator requires an individual calibration. This calibration has to include the assessment of the individual Autonomic Outlet Type (AOT) because the physiological relevance of voice reactions depends on the individual AOT. The calibration is based on statistical reference data which have to be improved in the future. The calibration has to be done under comparable environmental circumstances. A 3-yr application of the method on board Mir station documents the applicability of the procedure.
It was the aim of this study to investigate the time course of changes in the serum concentrations of vascular endothelial growth factor (VEGF) during a regular survival training programme combined with food and fluid deprivation and during a high altitude marathon run. We studied soldiers of the Austrian Special Forces performing survival training at sea-level and marathon runners of the Posta Atletica who crossed the border between Chile and Argentina at altitudes up to 4722 m. Baseline data collected before the 1-week of survival training showed that the soldiers had normal VEGF [n = 8, 246.7 (SD 118.5) pg.ml(-1)] serum concentrations which remained unchanged during the course of the study. Before the high altitude marathon the subjects showed normal VEGF serum concentrations [178 (SD 84.5) pg.ml(-1)]. After the run VEGF concentrations were found to be significantly decreased [41.0 (SD 41.6) pg ml(-1), P < 0.01]. It was concluded that prolonged physical stress during normobaric-normoxia did not alter the VEGF concentrations whereas during severe hypobaric-hypoxia decreased VEGF serum concentrations were measured, at least temporarily, after prolonged physical exercise which might have been due to changes in production, release, removal and/or binding of circulating VEGF.
Hairless, a major antagonist of the Notch signaling-pathway in Drosophila (Bang and Posakony, 1992; Maier et al., 1992), associates with Suppressor of Hairless [Su(H)], thereby inhibiting trans-activation of Notch target genes (Brou et al., 1994). These molecular interactions could occur either at the step of signal transduction in the cytoplasm or during implementation of the signal within the nucleus. We examined the subcellular distribution of Hairless, showing that it is a low abundant, ubiquitous protein that is cytosolic as well as nuclear. High levels of Hairless cause nuclear retention of Su(H), loss of Hairless reduces the amount of Su(H) in the nucleus.
This report will compare results of applications of the psychophysiological method "Assessment of Autonomic Outlet Type" (AOT) in space as well as at high altitudes. The aim was to find out whether it is possible to differentiate a subject's reaction to different environments by this method (Johannes et.al. 1995). This assessment as described below was first applied to clinically well defined cohorts and to healthy subjects. By means of cluster analysis it could be demonstrated that different reaction patterns exist. These different patterns were correlated to two groups of normal controls ([I] = non-responder/voice-responder and [II] = heart-responder) and two groups of patients with different clinical diagnoses (rheumatic diseases ([III] = autonomic-responder) and [IV] = hypertensives). Based on these clinical reference data the method provides for each "new" experiment a common classification of the complex regulatory reaction pattern of the autonomic nervous system (ANS) and the Cardiovascular system (CVS) to psychological stressors by means of a discriminant function. Since August 1997 the experiment has been applied to all Russian cosmonauts continuously each month. (Johannes et.al. 1998). At the same time numerous terrestrial experiments have been running parallel for comparison with the results from space. This report will focus on a study at altitudes of 3600 m.
Based on data of former clinical studies (Johannes et al. 1994) the experiment regulation was designed to assess and classify the actual psychophysiological reactivity of the cosmonauts. Beside this scientific main goal of the experiment it was for us of interest to check the data whether the development of arrhythmia can be seen under micro-g conditions when flight related stressful conditions prevail. This report will focus on the ECG analysis of one subject in whom this was actually the case.
The relation between the results of laboratory tests and results of the interesting professional work is a very difficult one. The same is true for the relation between training and real performance. The pilot controlled MIR-docking manoeuvre is in reality a very seldom but very important one. The training of this manoeuvre is a very special professional work and only for cosmonauts available. But the objective estimation of the performance and the used objective and subjective needs is nevertheless necessary. Even for the subjective "stress"-feelings during task solving it is often impossible to get reliable data without any physiological measurements. The use of electrodes, cables and equipments is hardly limited during real work. Sometimes only the voice is available over more or less quality communication channels. So it is the case during the training and the real pilot controlled MIR-docking manoeuvre. Based on findings in the literature and own experiments analyzing the relation between fundamental voice frequency (F0) and subjective stress feelings we tested the hypothesis that a on-line measurement of F0 can be used for stress evaluation during standardised training sessions of MIR-docking manoeuvres.
For the objective and valid identification of different human regulatory phenotypes it should be useful to analyze the behavior of different regulatory subsystems (Anochin 1976) in one multivariate design. Therefore in a DARA supported project a fully computerized and reliable laboratory assessment was developed and tested. We used a set of electrophysiological parameters that should indicate the activity of different functional regulation systems on different "behavioral levels". Skin conductance, skin temperature and voice pitch were used as indicators of sympathico-parasympathical activity. Breathing, heart rate variability and bloodpressure should indicate cardiovascular activity and electromyogram and mimic variablity were thought as indicators of locomotional external behavioral activity. To identify physiological reactions which are influenced by emotional stress we used voice stress measures. Even in the field of aviation and space medicine there exist data about the correlation of voice pitch with emotional excitation (Hecker et. al. 1968, Williams et.al. 1969, Friedrich, Vaic 1978, Vaic et.al. 1981,1982, Griffin, Williams 1987). In our former study (MOSAIC-study, Johannes 1990) the voice pitch and its variation range correlated with perceived emotional excitation but were independent of real bloodpressure variations. Two different types of pitch reaction to this experimental design were correlated to psychological personality scales and assigned subjects to "sensitizers" and "suppressors".
Fattening bulls (n = 8) and cows (n = 10) affected chronically with PCB were kept in barns on PCB-free feeding (silage, straw, concentrates). The cows were dried off. The kinetics of PCB-concentrations in hair, blood and feces were examined. Fattening bulls (mean 460 kg bw, german black and white and interbreeding german black and white and Simmental) with low (320 g) and medium (730 g) daily weight gain for a period of 5 months and 3 bulls with medium (640 g) weight gain within 18 months were examined. A drying off period of 3-5 months was recorded for the cows. The distribution of PCB in the carcass of some animals was registered in addition. The following results are to be emphasized: Reduction of PCB in the studied substrates in the fattening bulls depends on a high degree on daily weight gain. This is important in order to calculate biological half life times of PCB. By standardized weight gain of 10 kg in bulls, fed PCB-free diets for a 5 months period, a reduction of PCB-concentrations from 1 to 3% was found (hair and feces: 1%, blood 3%). Within a period of 18 months and with higher weights, in the examined substrates (blood, hair, feces) mean declines of the PCB-concentrations of 2% were found. On knowledge so far this value is an essential point to estimate biological half life times, because metabolic PCB-elimination is negligible.(ABSTRACT TRUNCATED AT 250 WORDS)
20 cows contaminated chronically with PCB were kept as nurse cows or in a tie-stall. The contamination in different substrates (hair, milk, blood, feces) was examined for a period up to 8 months. The distribution of PCB in the carcass of some animals was registered in addition. The system of keeping nurse cows turned out to be useful in order to overcome a contamination situation. Drying off gravid animals in the first step helps solving problems of handling contaminated milk. With low contaminated animals a short dry off period is sufficient, so that the milk--after calving--is marketable (report II, in preparation). In case of nurse cows with two calves post partum a continuous decline of PCB-concentrations in the milk can be observed. With biological half life periods of 2-4 months, milk with PCB 153-concentrations of 0.15-0.20 mg/kg fat will be marketable within this period. Cows milked by milking-machines show a decline of PCB in the milk similar to nurse cows. Two animals had a limited increase p.p., probably caused by mobilization of fat in the high lactation stage. Over longer periods, the biological half-life-periods were comparable to nursing cows. Hair is easy to sample and store; it is useful as a diagnostic substrate beside the milk in order to estimate the degree of contamination in individual animals. The ratio of PCB-concentrations between perirenal fat and hair is 1:0.95 (s = +/-0.192); the ratio of PCB-concentrations between perirenal fat and milk is 1:0.77 (s = +/- 0.122).(ABSTRACT TRUNCATED AT 250 WORDS)
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A complex psychophysiological test battery (ECG, blood pressure, SCL, finger temperature e.t.c.) was applied on two subjects in space. It could be shown that the subjects react under space conditions differently than on earth. The data received could be classified into four types of regulation. The subjects changed this type of regulation during the flight and returned to their former pattern after the flight.