Aerobic scope falls to nil at <i>P</i> <sub>crit</sub> and anaerobic ATP production increases below <i>P</i> <sub>crit</sub> in the tidepool sculpin, <i>Oligocottus maculosus</i>
Bibliographic record
Abstract
The critical oxygen tension of whole-animal oxygen uptake rate, or P crit , has historically been defined as the oxygen partial pressure ( P O 2 ) at which aerobic scope falls to zero and further declines in P O 2 require substrate-level phosphorylation to meet shortfalls in aerobic ATP production, thereby time-limiting survival. Despite the inclusion of aerobic scope and anaerobic ATP production in the definition, little effort has been made to verify that P crit measurements, the vast majority of which are obtained using respirometry in resting animals, actually reflect the predictions of zero aerobic scope and a transition to increasing reliance on anaerobic ATP production. To test these predictions, we compared aerobic scope and levels of whole-body lactate at oxygen partial pressures ( P O 2 s) bracketing P crit obtained in resting fish during progressive hypoxia in the tidepool sculpin, Oligocottus maculosus . We found that aerobic scope falls to zero at P crit and, in resting fish exposed to P O 2 s < P crit , whole-body lactate accumulated pointing to an increased reliance on anaerobic ATP production. These results support the interpretation of P crit as a key oxygen threshold at which aerobic scope falls to nil and, below P crit , survival is time-limited based on anaerobic metabolic capacity.
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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 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.001 |
| 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".