Comparative responses of arterial oxygen saturation and heart rate during postnatal development in rats living at high and low altitude.
Bibliographic record
Abstract
We used pulse oximetry to measure arterial oxygen saturation (SpO2) and heart rate (HR) in 4 and 14 day‐old rats raised at HA (La Paz, Bolivia, 3,600 m/12,000ft) or at sea level (SL, Québec, Canada). SpO2 and HR were measured at 5 different levels of inspired PO2 (PiO2: 160 ‐ 60 mmHg – 10 min each), in awake rats maintained in a chamber flushed with room air or the desired gas mixtures. When exposed to a PiO2 of 160 mmHg, P4 HA rats had a similar SpO2 than P4 SL, but a lower HR. At lower PiO2, HA rats maintained a much higher SpO2 than SL rats. HR increased in HA rats (but not in SL rats) at low PiO2. Contrastingly, P14 HA rats exposed to a PiO2 of 160 mmHg had a lower SpO2 than SL (93.7±1.1% vs. 98.8±0.1%, p<0.0001), and similar SpO2 at lower PiO2. HR was higher in P14 HA rats vs. SL rats at all PiO2 levels. A group of SL rats was raised in hypoxia (13.5% O2 – similar to HA PiO2) between P4 and P14. This reduces SpO2 values measured at PiO2 below 160 mmHg, and enhances HR. Male and female rats had similar responses. We conclude that: a) 4‐day old rats raised at HA had efficient responses that help maintaining a high SpO2 under a wide range of PiO2 ‐ b) these responses are no longer apparent in P14. Since rats are not found under natural conditions at HA, success to develop adequate responses to hypoxia during early postnatal development might be critical for genetic adaptation to altitude. Founded by NSERC.
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 | 0.001 | 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 | 0.001 |
| 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".