UBC-Nepal Expedition: Motor Unit Characteristics in Lowlanders Acclimatized to High Altitude and Sherpa
Bibliographic record
Abstract
INTRODUCTION: With acclimatization to high altitude (HA), adaptations occur throughout the nervous system and at the level of the muscle, which may affect motor unit (MU) characteristics. However, despite the importance of MUs as the final common pathway for the control of voluntary movement, little is known about their adaptations with acclimatization. METHODS: Ten lowlanders and Sherpa participated in this study 7 to 14 d after arrival at HA (5050 m), with seven lowlanders repeating the experiment at sea level (SL), 6 months after the expedition. The maximal compound muscle action potential (M max ) was recorded from relaxed biceps brachii. During isometric elbow flexions at 10% of maximal torque, a needle electrode recorded the MU discharge rate (MUDR) and MU potential (MUP) characteristics of single biceps brachii MUs. RESULTS: Compared with SL, acclimatized lowlanders had ~10% greater MUDR, ~11% longer MUP duration, as well as ~18% lower amplitude and ~6% greater duration of the first phase of the M max (all P < 0.05). No differences were noted between SL and HA for variables related to MUP shape (e.g., jitter, jiggle; P > 0.08). Apart from lower near-fiber MUP area for Sherpa than acclimatized lowlanders ( P < 0.05), no M max or MU data were different between groups ( P > 0.10). CONCLUSIONS: Like other components of the body, MUs in lowlanders adapt with acclimatization to HA. The absence of differences between acclimatized lowlanders and Sherpa suggests that evolutionary adaptations to HA are smaller for MUs than components of the cardiovascular or respiratory systems.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| 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) | 0.002 | 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 source (direct Gemma or distilled Codex), 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".