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Results 751 - 800 of 954
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Baevsky R M - - 1997
This article presents selected findings obtained with Holter monitoring from two crew members of the expedition, performed during a 175-day space mission on board orbital space station "MIR." Using mathematical processing of daily cardiointervals files, 5-minute sections of records were analyzed consecutively. Then, the average daily values of indices, the ...
Cohn J R - - 1997
As the power source for vocalization, the lower respiratory tract plays a key role in voice production. This is particularly true with sustained singing, where continued high ventilatory demands are present. Changes in pulmonary function that are insignificant with normal speech have been shown to lead to performance impairment. The ...
Kergoat H - - 1996
BACKGROUND: The microgravity environment of spaceflights alters the systemic circulation, decreasing the peripheral resistance, while increasing the heart rate and systemic blood pressure. HYPOTHESIS: Body orientation simulating fluid shifts associated with microgravity during spaceflights affects the neural retinal function. METHODS: Fifteen healthy adults between 18 and 26 yr of age ...
Chai P - - 1996
Hovering hummingbirds offer a model locomotor system for which analyses of both metabolism and flight mechanics are experimentally tractable. Because hummingbirds exhibit the highest mass-specific metabolic rates among vertebrates, maximum performance of hovering flight represents the upper limit of aerobic locomotion in vertebrates. This study evaluates the potential constraints of ...
Baldwin K M - - 1996
A Research Roundtable, organized by the American College of Sports Medicine with sponsorship from the National Aeronautics and Space Administration, met in November 1995 to define research strategies for effective exercise countermeasures to weightlessness. Exercise was considered both independently of, and in conjunction with, other therapeutic modalities (e.g., pharmacological nutritional, ...
Yumoto E - - 1996
The mucosal upheaval where the mucosal wave starts and propagates upward appears on the lower surface of the canine vocal fold during vibration. We investigated the vibratory behavior of the in vivo human vocal fold viewed from the tracheal side. Subjects consisted of 14 men and 6 women who had ...
Kanas N - - 1996
BACKGROUND: Interpersonal problems may negatively affect crews on long-duration space missions. These problems stem from crewmember tension and its displacement to the outside monitoring personnel and from disruptions in crew cohesion and unclear leadership roles. HYPOTHESES: We hypothesized that crew tension and dysphoria would transiently increase following stressful events and ...
Ramnani N - - 1996
1. Studies show that reversible inactivation of the anterior interpositus nucleus (AIP) of the cerebellum with muscimol (a GABAA agonist) prevents acquisition of the classically conditioned nictitating membrane response (NMR) in the rabbit. Here, we have used reversible inactivations of the AIP with muscimol to investigate the role of the ...
Tipton C M - - 1996
Despite the fact that the first human was in space during 1961 and individuals have existed in a microgravity environment for more than a year, there are limited spaceflight data available on the responses of the neuroendocrine and immune systems. Because of mutual interactions between these respective integrative systems, it ...
Tipton C M - - 1996
Since 1961, there have been more than 165 flights involving several hundred individuals who have remained in a space environment from 15 min to more than a year. In addition, plans exist for humans to explore, colonize, and remain in microgravity for 1000 d or more. This symposium will address ...
Convertino V A - - 1996
Exercise represents the primary countermeasure used during spaceflight to maintain or restore maximal aerobic capacity (VO2max), musculoskeletal structure, and orthostatic function. However, no single exercise or combination of prescriptions has proven entirely effective in restoring cardiovascular and musculoskeletal functions to preflight levels following prolonged spaceflight. As human spaceflight exposures increase ...
Knoll A H - - 1996
The repeated association during the late Neoproterozoic Era of large carbon-isotopic excursions, continental glaciation, and stratigraphically anomalous carbonate precipitation provides a framework for interpreting the reprise of these conditions on the Late Permian Earth. A paleoceanographic model that was developed to explain these stratigraphically linked phenomena suggests that the overturn ...
Shykoff B E - - 1996
Cardiac output (Q), heart rate (HR), blood pressure, and oxygen consumption (VO2) were measured repeatedly both at rest and at two levels of exercise in six subjects during microgravity exposure. Exercise was at 30 and 60% of the workload producing the individual's maximal VO2 in 1 G. Three of the ...
Schaal D W - - 1996
In this technical article, methods for collecting and representing response rates maintained by schedules of reinforcement are presented. First, the time in a session that each important event (e.g., responses, reinforcers) occurs is collected and stored by a computer. Another computer program is used, then, to convert each response to ...
Carroll L M - - 1996
Respiratory and glottal efficiency measures were collected from a pool of 40 classically trained singers with normal larynges. All singers had > or = 3 years of formal classical voice training and were active professional solo classical singers. Mean flow rates were obtained from all subjects to assess glottal efficiency. ...
Wegener G - - 1996
Insect flight is the most energy-demanding exercise known. It requires very effective coupling of adenosine triphosphate (ATP) hydrolysis and regeneration in the working flight muscles. 31P nuclear magnetic resonance (NMR) spectroscopy of locust flight muscle in vivo has shown that flight causes only a small decrease in the content of ...
Mori S - - 1996
BACKGROUND: Evidence in support of the sensory conflict hypothesis for space motion sickness (SMS) is still needed. HYPOTHESIS: We hypothesized that sensory conflict and recovery processes should be demonstrated in intact fish during initial days of microgravity exposure, as a disturbance and restoration of the dorsal light response (DLR; a ...
Laukkanen A M - - 1996
The voiced bilabial fricative/beta:/has been used as a vocal exercise. The present study investigated the effects of the exercise on voice production and voice source. This study compared vowel phonation on the syllable /a:p/ with the production of the exercise and vowel phonation before and immediately after the exercise. The ...
Groen E - - 1996
To assess a possible otolith contribution to effects observed following prolonged exposure to hypergravity, we used video oculography to measure ocular torsion during static and dynamic conditions of lateral body tilt (roll) before and after 1 h of centrifugation with a Gx-load of 3 G. Static tilt (from 0 to ...
Meeker L J - - 1996
The necessity of preventing physiologic deconditioning of astronauts exposed to long duration space flights is well known. A method under consideration to prevent this deconditioning is the use of periodic exposure to artificial gravity which could be provided by a centrifuge. This paper presents a design study for a human-powered ...
Fisher W W - - 1996
In the functional analysis described by Iwata, Dorsey, Slifer, Bauman, and Richman (1982/1994), reinforcer duration varied across conditions (e.g., brief attention vs. 30 s of escape); this may result in unequal exposure to the establishing operations for aberrant behavior. In this study, we compared the effects of unequal and equal ...
Anton H J - - 1996
Two species of newts (Urodela) and two types of clinostats for fast clinorotation (60 rpm) were used to investigate the influence of simulated weightlessness on regeneration and to compare results obtained with data from spaceflight experiments. Seven or fourteen days of weightlessness in Russian biosatellites caused acceleration of lens and ...
Machemer H - - 1996
The archaic eukaryote unicellular microorganism, Paramecium, is propelled by thousands of cilia, which are regulated by modulation of the membrane potential. Ciliates can successfully cope with gravity, which is the phylogenetically oldest stimulus for living things. One mechanism for overcoming sedimentation is negative gravitaxis, an orientational response antiparallel to the ...
Rahmann H - - 1996
This study presents qualitative and quantitative data concerning gravity-dependent changes in the swimming behaviour of developing cichlid fish larvae (Oreochromis mossambicus) after a 9 resp. 10 days exposure to increased acceleration (centrifuge experiments), to reduced gravity (fast-rotating clinostat), changed accelerations (parabolic aircraft flights) and to near weightlessness (2nd German Spacelab ...
Tattersall A J - - 1995
The demands of dynamic monitoring and fault diagnosis for flight engineer trainees were examined in relation to changes in heart rate (HR) and two spectral analysis measures (midfrequency: 0.07-0.14 Hz; high frequency: 0.15-0.40 Hz) of heart rate variability (HRV). Eleven trainee flight engineers were studied, as part of their training ...
McCarthy G W - - 1995
INTRODUCTION: Optimum treatment for aircrew who have developed anxiety associated with flight includes a flying phase for desensitization. However, standardized flight profiles are not found in the literature. In this study, a method of desensitization flying, which may increase the probability of a return to productive flying, was devised and ...
Sussingham J C - - 1995
Zero gravity conditions for astronaut training have traditionally used neutral buoyancy tanks, and with such tanks hypogravity conditions are produced by the use of supplemental weights. This technique does not allow for the influence of water viscosity on any reduced gravity exercise regime. With a water-foam fluid produced by using ...
Traon A P - - 1995
This study was performed to determine the effects of 28 d of head-down tilt (HDT) (simulated weightlessness) on cardiovascular responses to orthostatic stress induced by lower body negative pressure (LBNP) (before, during, and after HDT) and +60 degrees head-up tilt (before and after HDT) in 12 subjects. Half of them ...
Kozlovskaya I B - - 1995
The system of countermeasure of microgravity effects has been developed in Russia that allowed to perform safely long-term space flights. This system that includes different means and methods such as special regimens of physical exercises, axial loading ("Pingiun") and antigravity suits, low body negative pressure device (LBNP, "Chibis") and "cuffs" ...
Mooney V - - 1995
The purpose of this study was to demonstrate the effect of a once a week exercise program focused specially at lumbar extensor strengthening. This is a comparative study where workers volunteered to exercise were compared to workers who did not exercise. Low back claims for one year were noted to ...
Siegel E - - 1995
With reinforcement contingent on a single peck on either of two available keys (concurrent continuous reinforcement schedules) 4 pigeons, at 80% of free-feeding weights, preferred a smaller-sooner reinforcer (2.5 s of mixed grain preceded by a 0.5-s delay) to a larger-later reinforcer (4.5 s of mixed grain preceded by a ...
Dromey C - - 1995
This study examined changes in voice and speech production in a patient with Parkinson disease as he increased vocal intensity following 1 month of intensive voice treatment. Phonatory function and articulatory acoustic measures were made before and after treatment as well as 6 and 12 months later. Pre- to post-treatment ...
Södersten M - - 1995
Seventeen healthy women, 45 to 61 years old, were examined using videofiberstroboscopy during phonation at three loudness levels. Two phoniatricians evaluated glottal closure using category and ratio scales. Transglottal airflow was studied by inverse filtering of the oral airflow signal recorded in a flow mask (Glottal Enterprises System) during the ...
Clarke-Klein S M - - 1995
The purpose of this single-subject pilot study was to examine the efficacy of FM amplification for enhancing the discourse skills of a 4-year-old girl with a history of speech-language impairments, otitis media with effusion (OME), and motoric delays. Over a period of several weeks, language treatment sessions were conducted with ...
Griffin B - - 1995
The purpose of this study was to develop a definition of the supported singing voice based on physiological characteristics by comparing the subjects' concepts of a supported voice with objective measurements of their supported and unsupported voice. This preliminary report presents findings based on data from eight classically trained singers. ...
Sabol J W - - 1995
The purpose of this study was to investigate the effects of isometric-isotonic vocal function exercises, practiced regularly for 4 weeks, on parameters of voice production in the healthy singer. A total of 20 university graduate-level voice majors of similar age and vocal training were divided into experimental and control groups, ...
Emonson D L - - 1995
Today's battleground requires round-the-clock air support. Modern aircraft systems enable tactical aircraft to be flown in all weather conditions, day or night, and for prolonged periods. U.S. Air Force Tactical Air Command (TAC) aircrew who deployed to the Southwest Asia Area of Responsibility (SWA AOR) for Operation Desert Shield/Desert Storm ...
Laukkanen A M - - 1995
The glottal resistance, i.e. the ratio of subglottic pressure to glottal flow, and the laryngeal efficiency, i.e. the ratio of oral acoustic power to aerodynamic subglottal power (multiplication of subglottig pressure and glottal flow), were measured for 11 subjects (3 males) with normal voices and for 1 female patient with ...
Laukkanen A M - - 1995
Phonation into narrow glass tubes has been used as a voice training method. The present study examined phonatory and voice quality during and after tube phonation. The methods used were (a) electromyography with surface electrodes, (b) a dual-channel electroglottography from which the vertical larynx position was derived and (c) inverse ...
Tipton C M - - 1995
Measurements from mission specialists after space flights or from subjects subjected to head down tilt experiments have demonstrated a decrease in exercise performance. Similar decreases have been reported for rats that have participated in simulated microgravity studies using the head down-tail suspended method of Morey-Holton (HDS). Because it is unclear ...
Prier K R - - 1994
The central nervous system of the moth Manduca sexta contains a group of myoregulatory neuropeptides, the CAPs (Cardioacceleratory Peptides), which cause a physiologically important, dose-dependent increase in heart rate during wing inflation and flight in adult moths. We report here that the response of the adult heart to a subset ...
Kranz A R - - 1994
Comparison of experimental data obtained from short (SDEF) and long duration exposure flights (LDEF) have recently led to results which will be significant for longer and/or repeated sojourn of man in space. Under orbital conditions biological stress and damage are induced in test subjects by cosmic radiation, especially the high ...
Pissarenko N F - - 1994
A possibility of a manned mission to Mars without exceeding the current radiation standards is very doubtful during the periods of minimum solar activity since the dose equivalent due to galactic cosmic rays exceeds currently recommended standards even inside a radiation shelter with an equivalent of 30 g cm-2 aluminum. ...
Kopardekar P - - 1994
The directory assistance operators' task with a visual display terminal was simulated to determine the preferable work-rest schedule from among the three different work-rest schedules: 30 min of work followed by 5 min break (30-5); 60 min of work followed by 10 min break (60-10); and 120 min of work ...
Stemple J C - - 1994
Objective voice analysis including acoustic, aerodynamic, and laryngeal videostroboscopic measures demonstrated normal voice in 35 adult women. The subjects were then randomly divided into experimental, placebo, and control groups. The experimental group engaged in vocal function exercises. The placebo group engaged in a placebo exercise program. Objective measures taken after ...
Kitch J A - - 1994
Performers (10 actors/10 singers) rated via a self-report questionnaire the severity of their voice-related changes when vocally fatigued. Similar frequency patterns and perceptual features of vocal fatigue were found across subjects. Actors rated "power" aspects (e.g., voice projection) and singers rated vocal dynamic aspects (e.g., pitch range) of their voices ...
Lebona G T - - 1994
Baboons (Papio) were used to study the ascending aortic fold. The fold was present in two out of 20 hearts examined. Its position and shape was comparable to that observed in human subjects. The principal difference was the absence of paraganglia. The functional role of the baboon fold is unclear.
Wetzig J - - 1994
Two subjects were rotated eccentrically in a manner described before. In contrast to a normal control group settings of a luminous line to the subjective vertical were almost unrelated to the gravitoinertial summation vector of gravity and centrifugal forces about four weeks before and totally so shortly after space flight. ...
Spooner B S - - 1994
Developmentally arrested brine shrimp cysts have been reactivated during orbital spaceflight on two different Space Shuttle missions (STS-50 and STS-54), and their subsequent development has been compared with that of simultaneously reactivated ground controls. Flight and control brine shrimp do not significantly differ with respect to hatching rates or larval ...
Murthy G - - 1994
Exposure to lower body negative pressure (LBNP) with oral salt and water ingestion has been tested by astronauts as a countermeasure to prevent postflight orthostatic intolerance. Exercise is another countermeasure that astronauts commonly use during spaceflight to maintain musculoskeletal strength. We hypothesize that a novel combination of exercise and simultaneous ...
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