Performance and health effects of mild hypoxic hypoxia in simulated 6-hour exposures between 2,438 and 3,048 metres
Bibliographic record
Abstract
Introduction: The Royal Canadian Air Force (RCAF) imposes a daily 4-hour (h)limit for operating unpressurized aircrafts, including helicopters, between 2,438 and 3,048 m (8,000 [8K] and 10,000 [10K] ft) if supplemental oxygen (O 2 ) is unavailable. This regulation may negatively impact RCAF operations because weight and space restrictions limit sufficient O 2 to achieve mission success. The effects of exposure durations beyond the 4-h limit are currently unknown, but extensions have the potential to improve operational effectiveness. This study examined the effects of hypoxic exposures on symptoms, mood and performance as a function of altitude and exposure duration. Methods: Seventeen military helicopter pilots were randomly exposed to two 6-h altitude levels (8K and 9.9K) on 2 separate days in a hypobaric chamber. Daily, participants periodically performed a simulated rotary wing flight task, and completed a cognitive test battery. Cerebral regional and finger pulse oxyheamoglobin saturation levels and heart rate were continuously monitored. Participants indicated their subjective hypoxia signs and symptoms, mood and fatigue. Results: Exposure to altitude significantly decreased cerebral and pulse O 2 saturations, but values remained steady during the 6-h exposure. No negative decrements were observed on cognition or simulation performance. Self-reported symptoms of fatigue and headache were reported at altitude with a slight increase with time. Discussion: No clear evidence of significant deficits on performance was observed in participants when exposed to mild levels of hypoxia for up to 6 h without supplemental O 2 .
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".