Respiratory activity of four abdominal muscles during hypoxia
Bibliographic record
Abstract
The abdominal wall can contribute to ventilation, but there is little information about individual actions of the four muscles. EMG recordings from each muscle reveal differential recruitment with specific order of activation during hypercapnic ventilation (J App Phys 1996 80:1379). It is not known if equivalent differential activity occurs with hypoxia. Aim: Examine individual activity of four abdominal muscles during hypoxic stimulated ventilation, compared to hypercapnia. Methods: In N=8 subjects, fine wire electrodes were inserted with high resolution ultrasound into rectus abdominis (RECTUS), external oblique (EXTERN), internal oblique (INTERN) and transversus abdominis (TRANS). While supine, airflow, end tidal CO2, arterial oxygen saturation, moving average and raw EMG were recorded during progressive hypoxia (HYPOX) and CO2 rebreathing (CO2R). Results: Three of four abdominal muscles were activated during HYPOX, RECTUS remained silent: contrasting with all muscles active in CO2R. Muscles were activated in the same sequential order in HYPOX versus CO2R. However at matched minute ventilation or tidal volume (VT), activity of individual abdominal muscles was greatly decreased in HYPOX compared to CO2R (P<0.001). Raw EMG at matched VT of 1.5L in Fig 1. Conclusion: TRANS, INTERN, EXTERN are activated in the same sequential order in HYPOX and CO2R breathing, but individual abdominal muscle activity during HYPOX is greatly diminished compared to CO2R.
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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) | 0.001 | 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 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".