Carotid sinus pressure changes during push-pull maneuvers.
Bibliographic record
Abstract
INTRODUCTION: The push-pull maneuver (PPM) is defined as a reduction in G-tolerance when positive acceleration (+Gz) immediately follows negative acceleration (-Gz) exposure, with the carotid baroreceptors presumably playing a dominant role in the ensuing BP (SBP) responses. The objective of this study was to determine whether application of neck pressure (NP) during the preceding -Gz phase maintains +Gz tolerance during subsequent +Gz. METHODS: There were 10 experienced men who were exposed to 3 centrifuge run types using a multi-axis centrifuge: a relaxed control run from +1.4 baseline to visual tolerance; a relaxed control PPM run (PPM-C) consisting of 5 s of -1 Gz followed by 15 s of +Gz to visual tolerance; and an experimental PPM run performed with pressurized neck (PPM-NP) consisting of -1 Gz for 5 s followed by 15 s of +Gz at the previous PPM-C G-tolerance level. RESULTS: Relaxed control G tolerance (3.6 _ 0.26 Gz) was greater vs. the PPM-C (3.0 +/- 0.21 Gz) and PPM-NP (3.1 +/- 0.20 Gz) conditions, but the two PPM conditions did not differ significantly. During -Gz, mean R-R interval for PPM-NP was significantly shorter than in the PPM-C from second 1 to second 3. During the +Gz phase, however, R-R interval responses between PPM-C and PPM-NP differed only at seconds 8 and 9. There were no differences in carotid sinus SBP between PPM-C and PPM-NP during -Gr. During +Gz, carotid sinus SBP was significantly depressed in PPM-NP and PPM-C conditions vs. Control. DISCUSSION: Application of NP during the -Gz phase, despite altering R-R interval, did not ameliorate SBP responses or reductions in G tolerance during subsequent +Gz exposure. Despite neck compression counteracting increased carotid hydrostatic pressure during -Gz, the carotid baroreceptor response is likely opposed by the aortic or other baroreceptors.
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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 | 0.000 |
| 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) | 0.000 | 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".