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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records

Motor activity under weightless conditions

The material presented on the motor activity under weightless conditions (brief and long) leads to the conclusion that it is not significantly disrupted, if those being examined are secured at the workplaces. Some discoordination of movement, moderately expressed disruption of the precision of reproduction of assigned muscular forces, etc., were observed. Motor disorders decrease significantly in proportion to the length of stay under weightless conditions. This apparently takes place, as a consequence of formation of a new functional system, adequate to the conditions of weightlessness. Tests on intact and labyrinthectomized animals have demonstrated that signaling from the inner ear receptors is superfluous in weightlessness, since it promotes the onset of disruptions in the combined work of the position analyzers.

Kasyan, I. I.↗

Calorigenic effect of adrenaline in rats under conditions of restricted motor activity

In previous studies, it was demonstrated that long term restricted motor activity in rats induces a decrease in body weight, an increase in release of adrenaline, and a decrease in the release of noradrenaline with the urine, as well as a reduction in activity of the thymus gland and level of thyroxin in the blood. At the same time, a decrease was found in the internal body temperature that was accompanied by an increase in the rate of metabolism in the state of rest. An investigation is presented which attempts to clarify whether the calorigenic effect of adrenaline under conditions of increased metabolism in the period of immobility is exposed to changes.

Tomaszewska, L.↗

The influence of motor activity on the development of cardiac arrhythmias during experimental emotional stress

Experimental emotional stress which can produce various disorders of cardiac rhythm: sinus tachycardia, atrial fibrillation, ventricular, extrasystoles and paroxysmal ventricular tachysystoles was studied. In these conditions the adrenalin content in the blood and myocardium is increased 3 to 4 times. It is found that moderate motor activity leads to a relative decrease of adrenalin in the myocardium and arrest of cardiac arrhythmias.

Ulyaninskiy, L. S.↗

Motor activity of astronauts in unsupported state

The performance quality of movements away and approaches to an airlock by astronauts was tested during parabolic flights for weightlessness simulation. Coordination of movement, orientation and performance capacity of the astronauts were not singificantly disrupted. Observed physiological shifts are characterized by an increase in pulse and respiration rate and an increase in arterial pressure under g-forces, a gradual decrease in these indices during repeated stays in weightlessness or during the prolonged effect of it, by a reduction of the length of postrotational nystagmus and counterrotation illusions under weightless conditions.

Kasyan, I. I.↗

Restoration of physical performance capacity of athletes after prolonged restriction of their motor activity

The effects of different regimens of treatment following prolonged hypokinesia were studied in order to determine the most effective program. The types of programs considered were passive means, consisting of physical therapy; active means, consisting of athletic training; and a combined program. In the first stage of the experiment, the effects of a 10 day period of hypokinesia were studied. It was determined that the restoration programs must address the problems of: (1) increasing defense function and general tone of the body; (2) restore orthostatic stability; and (3) increase general endurance. In later stages, groups of athletes and nonathletes underwent 30 day periods of hypokinesia. Restoration was carefully monitored for groups treated with the various regimens. It was determined that the most effective treatment was a comprehensive program of passive and active therapy.

Soldatov, A. D.↗

Physiological changes, sleep, and morning mood in an isolated environment

BACKGROUND: Previous isolation studies have shown increased 24-h urine volumes and body weight gains in subjects. This project examined those and other physiological variables in relationship to sleep motor activity, subjective sleep quality, mood, and complaints during confinement. METHODS: Six male and two female subjects lived for 7 d in the National Space Development Agency of Japan's isolation chamber, which simulates the interior of the Japanese Experiment Module. Each 24-h period included 6 h of sleep, 3 meals, and 20 min of exercise. Each morning, subjects completed Sleep Sensation and Complaint Index questionnaires. Catecholamine and creatinine excretion, urine volume, and body weight were measured on the 2 d before and 2 d after confinement, and sleep motor activity was measured during confinement. RESULTS: Confinement produced no significant change in body weight, urine volume, or questionnaire results. In contrast, epinephrine, norepinephrine, and sleep motor activity exhibited significant differences during confinement (p < 0.05). Higher nocturnal norepinephrine excretion correlated with higher sleep motor activity. CONCLUSION: The 24-h epinephrine values were slightly higher than normal throughout the experiment, but lower than for subjects working under time-stress. High sympathetic activity (as indicated by norepinephrine) may have interfered with sleep.

NASA Discipline Space Human Factors↗

Contractile function of the myocardium with prolonged hypokinesia in patients with surgical tuberculosis

The changes in the myocardial contractile function with hypokinesia in surgical tuberculosis patients are discussed. The phase nature of the changes is noted, specifically the changes in the various systoles, diastole, and other parts of the cardiac cycle. The data compare these changes during confinement in bed with no motor activity to and with a return to motor activity after leaving the in-bed regimen.

Zakutayeva, V. P.↗

Influence of respiratory motor neurone activity on human autonomic and haemodynamic rhythms

Although humans hold great advantages over other species as subjects for biomedical research, they also bring major disadvantages. One is that among the many rhythmic physiological signals that can be recorded, there is no sure way to know which individual change precedes another, or which change represents cause and which represents effect. In an attempt to deal with the inherent complexity of research conducted in intact human subjects, we developed and used a structural equation model to analyse responses of healthy young men to pharmacological changes of arterial pressure and graded inspiratory resistance, before and after vagomimetic atropine. Our model yielded a good fit of the experimental data, with a system weighted R2 of 0.77, and suggested that our treatments exerted both direct and indirect influences on the variables we measured. Thus, infusions of nitroprusside and phenylephrine exerted all of their direct effects by lowering and raising arterial pressure; the changes of R-R intervals, respiratory sinus arrhythmia and arterial pressure fluctuations that these drugs provoked, were indirect consequences of arterial pressure changes. The only direct effect of increased inspiratory resistance was augmentation of arterial pressure fluctuations. These results may provide a new way to disentangle and understand responses of intact human subjects to experimental forcings. The principal new insight we derived from our modelling is that respiratory gating of vagal-cardiac motor neurone firing is nearly maximal at usual levels of arterial pressure and inspiratory motor neurone activity.

Non-NASA Center↗

Individual variation in circadian rhythms of sleep, EEG, temperature, and activity among monkeys - Implications for regulatory mechanisms.

Investigation of circadian rhythms in a number of variables related to sleep, EEG, temperature, and motor activity in rhesus monkeys on an LD 12:12 schedule. Circadian rhythms were found to appear in each of 15 variables investigated. Statistical procedures assessed the variables for evidence of common regulation in these aspects of their circadian rhythms: acrophase (timing), amplitude (extent of change), and level (24-hr mean value). Patterns appearing in the data suggested that the circadian rhythms of certain variables are regulated in common. The circadian modulation of activity in the beta and sigma frequency bands of the EEG was correlated with statistical significance in acrophase, level, and amplitude. The delta frequency band appeared to be under circadian rhythm regulation distinct from that of the other bands. The circadian rhythm of REM stage sleep was like that of beta activity in level and amplitude. The data indicate that REM stage may share some common regulation of circadian timing with both stage 3-4 sleep and with temperature. Generally, however, the circadian rhythm of temperature appeared to bear little relation to the circadian rhythms of motor activity, EEG, or sleep.

Crowley, T. J.↗

The negative effect of hypokinesia involving injury and preventive measures

The optimum length of bed rest for athletes suffering from broken bones is considered. Negative effects of hypokinesia induced by bed rest include general weakness and deconditioning of the muscles as well as sleeplessness, headaches, muscle pain, constipation, unstable pulse and arterial pressure, and changes in reflexes. This is considered to be the result of a vegetative dysfunction induced by the decreased flow of nerve impulses and a decrease in interoceptive and exteroceptive signals. The briefest possible period of bed rest, followed by an increase in motor activity, the prescription of a large quantity of LFK, and an active program of physical therapy are recommended. The symptomology associated with hypokinesia disappears after one month of free motor activity.

Izakson, K. A.↗

Water metabolism regulating mechanisms in hypokinesia

The range of daily fluctuations of the proportion of the amount of consumed water and its content in the body was evaluated by means of a water metabolism regulation factor. This index constitutes a relative measure of fluctuations of the constant of tritium water elimination from the body per 24 hours. It is established that under conditions of long term hypokinesia regulation of water metabolism is disturbed both in humans and in animals. Still more marked changes are observed 2 to 3 weeks after restoration of motor activity. The shifts noted are evidence of general biological regularity of disturbance of regulation systems in long term restriction of motor activity and in the early restoration period.

Krotov, V. P.↗

NASA Ames Research Center Unitary Plan Wind Tunnel Fall 2018 Outage - Motor 1 Activity: Stator Shift

The Unitary Plan Wind Tunnel consists of the 11 x 11- Foot Transonic Wind Tunnel and the 9 x 7 foot Supersonic Wind Tunnel. The four 65,000hp electric motors that drive the wind tunnel compressors require periodic maintenance. In order to inspect the motors without the removal of drive shaft components, the stator must be shifted away from the motor. This process is referred to as "Stator Shift". Video is mp4 formatted with runtime of 2 mins 54 secs.

Wind Tunnel↗

Light-Induced Alterations in Striatal Neurochemical Profiles

Much of our present knowledge regarding circadian rhythms and biological activity during space flight has been derived from those missions orbiting the Earth. During space missions, astronauts can become exposed to bright/dark cycles that vary considerably from those that entrain the mammalian biological timing system to the 24-hour cycle found on Earth. As a spacecraft orbits the Earth, the duration of the light/dark period experienced becomes a function of the time it takes to circumnavigate the planet which in turn depends upon the altitude of the craft. Orbiting the Earth at an altitude of 200-800 km provides a light/dark cycle lasting between 80 and 140 minutes, whereas a voyage to the moon or even another planet would provide a light condition of constant light. Currently, little is known regarding the effects of altered light/dark cycles on neurochemical levels within the central nervous system (CNS). Many biochemical, physiological and behavioral phenomena are under circadian control, governed primarily by the hypothalamic suprachiasmatic nucleus. As such, these phenomena are subject to influence by the environmental light/dark cycle. Circadian variations in locomotor and behavioral activities have been correlated to both the environmental light/dark cycle and to dopamine (DA) levels within the CNS. It has been postulated by Martin-Iverson et al. that DA's role in the control of motor activity is subject to modulation by circadian rhythms (CR), environmental lighting and excitatory amino acids (EAAs). In addition, DA and EAA receptor regulated pathways are involved in both the photic entrainment of CR and the control of motor activity. The cellular mechanisms by which DA and EAA-receptor ligands execute these functions, is still unclear. In order to help elucidate these mechanisms, we set out to determine the effects of altered environmental light/dark cycles on CNS neurotransmitter levels. In this study, we focused on the striatum, a region of the brain that receives a number of dopaminergic and glutamatergic input and is known to be involved in the modulation of locomotor and behavioral responses.

Sroufe, Angela E.↗

Occupational hypokinesia as a hygienic problem

Insufficient motor activity at the work place is discussed as a widely prevalent problem reducing worker efficiency and adversely affecting worker health. Some guidelines are provided for evaluating and promulgating measures to prevent and correct hypokinesia at the work place and compensate for it during off-hours. Suggestions included developing standards for optimal work-related motor activity and setting limits for its reduction.

Smirnov, K. M.↗