An Observational Study of Personal Ultraviolet Dosimetry and Acute Diffuse Reflectance Skin Changes at Extreme Altitude
Bibliographic record
Abstract
OBJECTIVE: To determine the level of UV radiation at extreme altitude and to assess the effect it has on the skin. METHODS: Fifteen expeditioners and 10 Sherpas were assessed during a climbing expedition on the north side of Mt Everest (8848 m). UV exposure measurement and diffuse skin reflectance spectrophotometry were performed at the beginning and end of the expedition. RESULTS: Over the course of the expedition, the expeditioners and Sherpas received a median dose of 93.6 (interquartile range [IQR], 61.0-102.8) and 102.5 (IQR, 72.2-117.8) minimal erythemal doses (MEDs) of UV radiation. The maximum dosage exceeded 106 ± 1.4 MEDs. Using reflectance spectrophotometry, expeditioner and Sherpa melanin-hemoglobin increased by 83.6% (IQR, -1.5 to 89.8%) and 24.7% (IQR, -22.4 to 61.5%) for exposed skin, respectively. The amount of subcutaneous lipid-water decreased by a factor of 196.6 (IQR, 52.1-308.4) and 46.7 (IQR, 1.8-1156.5), for expeditioners and Sherpas, respectively. CONCLUSIONS: This expedition's participants received massive doses of UV radiation during their time at high altitude. In many individuals this was similar to the annual exposure of northern European office-workers (100 MEDs). Diffuse skin reflectance spectroscopy revealed considerable subcutaneous lipid loss, skin dehydration, and increased melanin in keeping with these levels of exposure.
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 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) | 0.001 | 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".