Peripheral pulse pressure responses to postural stress do not reflect those at the carotid artery
Bibliographic record
Abstract
OBJECTIVE: Interpretation of baroreflex cardiovascular control requires accurate assessment of pulse pressure (PP) in central arteries under conditions of varying systemic or hydrostatic pressure. The objective of this study was to examine whether changes in PP during postural stress were similar in the peripheral versus carotid arteries. DESIGN: Protocol A: Pulse pressure was measured in both the left (Millar tonometer) and right (Colin Pilot) radial arteries, and in the finger (Finapres) in seated subjects (n = 7) who performed Valsalva's manoeuvre. Protocol B: PP was measured from the carotid (Millar tonometer), and from the finger and wrist kept at the level of the carotid artery, during supine and 60 degrees head-up postures. RESULTS: Protocol A: Pulse pressures during Valsalva's manoeuvre were highly correlated between all devices (r = 0.6-0.8). Protocol B: compared with supine, PP was reduced in both the finger and wrist during head-up-tilt (HUT) (P<0.05), but not in the carotid artery. CONCLUSIONS: During Valsalva manoeuvers the Millar and Colin tonometers similarly tracked PP over a wide range of rapidly changing pressures. This observation provided confidence for the further use of the hand-held device for central measurements during changes in posture. The results from Protocol B indicate that peripheral PP measurements are not suitable surrogates for carotid pulse pressures during HUT.
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 | 0.001 | 0.004 |
| 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 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".