Aviat Space Envir Md
-
Aviat Space Envir Md · Jun 2001
A potential role for free radical-mediated skeletal muscle soreness in the pathophysiology of acute mountain sickness.
It has been suggested that free radicals may be implicated in the pathophysiology of acute mountain sickness (AMS) due to their ability to initiate and propagate cell membrane damage (3). Therefore, the present study was designed to: a) investigate the effects of an expedition to high altitude on metabolic indices of free radical-mediated oxidative stress and assess subsequent implications for skeletal/cardiac muscle damage; and b) determine whether these parameters were different in subjects who developed AMS after gradual ascent to 5100 m (base camp, BC) compared with those who remained healthy. ⋯ Localized free radical-mediated vascular damage of the blood-brain barrier in addition to systemic tissue damage causing overt skeletal muscle soreness may have contributed to the pathophysiology of AMS, the latter through its indirect effects on other non-specific constitutional symptoms such as fatigue and insomnia causing a deterioration in physical performance.
-
Aviat Space Envir Md · Mar 2001
A motion sickness maximum around the 0.2 Hz frequency range of horizontal translational oscillation.
Low frequency translational oscillation can provoke motion sickness in land vehicles, ships and aircraft. Although controlled motion experiments indicate a progressive increase in nauseogenicity as frequency decreases toward 0.2 Hz, few data are available on the existence of a definite maximum nauseogenic potential of motion around 0.2 Hz, or decreased nauseogenicity below this frequency. ⋯ A maximum nauseogenic potential around 0.2 Hz was substantiated.
-
Aviat Space Envir Md · Mar 2001
Effect of "inside-out" and "outside-in" attitude displays on off-axis tracking in pilots and nonpilots.
Pilots employing helmet-mounted displays spend sustained periods of time looking off-axis, necessitating the inclusion of attitude symbology on the helmet to maintain spatial awareness. We examined how fundamentally different attitude references, a moving-horizon ("inside-out") or a moving-aircraft ("outside-in"), affected pilot and nonpilot attitude control when looking on- or off-axis. Both a rear-view and a side-view outside-in perspective were depicted to investigate the effect of control-display compatibility. ⋯ Pilots are equally adept using outside-in and inside-out displays. Given that an outside-in display may better reflect a person's inherent frame of reference for orientation (as evidenced by the nonpilots' superior performance with it), the results seem to indicate that pilots, through experience, have adapted to an inside-out frame of reference.
-
Aviat Space Envir Md · Feb 2001
A questionnaire for the assessment of the multiple dimensions of motion sickness.
A limited number of attempts have been made to develop a questionnaire that assesses the experience of motion sickness. Further, many available questionnaires quantify motion sickness as a unidimensional construct. ⋯ The MSAQ is a valid instrument for the assessment of motion sickness. In addition, the MSAQ may be used to assess motion sickness as a multidimensional rather than unidimensional construct.
-
Aviat Space Envir Md · Dec 2000
Exposure to soda-lime dust in closed and semi-closed diving apparatus.
Chronic exposure to hyperbaric hyperoxia and venous gas microembolism have been shown to contribute to the long term health effects of diving, especially diver's lung function. Factors related to special diving equipment may add to these effects. This study was conducted to evaluate possible additional hazards for respiratory function of divers employing closed and semi-closed diving apparatus. ⋯ There is a relevant exposure to soda-lime dust in divers using closed-circuit rebreathing apparatus. This occupational exposure may contribute to chronic airway inflammation and subsequent development of small airway disease in divers.