The effects of a 5 second bend over maneuver on cerebral perfusion and autoregulation upon standing from squat
Bibliographic record
Abstract
PURPOSE To investigate the effects of maintaining a bent over posture (BOP) for 5 s upon rising from squat on cerebral autoregulation. METHODS 8 healthy subjects (24.4 ± 1.9 years) completed 1 min of quiet standing, followed by 1 min of squat, followed by rising from squat over a 1–2 s period and then no maneuver (CON) or a BOP maneuver for 5 s before standing upright. Middle cerebral artery blood velocity (MCABV (cm/s); Transcranial Doppler) and mean arterial blood pressure at heart level (MAP (mmHg); finger photoplethysmography) were continuously measured. Cerebral vascular conductance (CVC) was calculated from MCA blood pressure (MCABP) and MCABV. MCABP was estimated by accounting for the hydrostatic column between the heart and the MCA. RESULTS Data are mean Δ from bsl ± SD. BOP attenuated the decrease in MCABV during the first 5 s upon rising from squat compared to CON (−6.5 ± 2.5 vs. −12.1 ± 3.1, P<0.05). MAP hypotension during the same time period was abolished in BOP (+3.8 ± 10.0 vs. −12.9 ± 4.5, P<0.05). Upon restoring upright posture in BOP, the MAP nadir ~10 s after rising was virtually identical but the drop in MCABV was attenuated in BOP, indicating CVC was functionally increased (+0.41 ± 0.3 vs. +0.2 ± 0.1, P=0.1). CONCLUSIONS The BOP maneuver blunts disturbances to cerebral perfusion following rising from squat during the 5 s that it is maintained and enhances cerebral vasodilation at the MAP nadir after rising. NSERC.
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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".