Changes in superficial blood distribution in thigh muscle during LBNP assessed by NIRS.
Bibliographic record
Abstract
INTRODUCTION: The present study was designed to determine how superficial blood distributed in the lower limb muscle during graded lower body negative pressure (LBNP). METHODS: Near-infrared spectroscopy (NIRS) was used to evaluate the blood volume change in the thigh muscles of seven volunteers during 35 min graded LBNP (rest, -10, -20, -30, -40, -50 mm Hg, and recovery). RESULTS: Deoxygenated and total hemoglobin (Hb) increased in proportion to the magnitude of LBNP applied to the thigh muscles. Oxygenated Hb rose significantly at -10 mm Hg LBNP, although the increase leveled off during subsequent increments of LBNP. Systolic pressure significantly decreased from 120 mm Hg at rest, to a value of 108 at -50 mm Hg LBNP. In contrast, mean and diastolic pressures were well maintained during graded LBNP. The increased total and deoxygenated Hb might indicate that blood was held in venous space, and the magnitude of rise in blood volume corresponded to the change in LBNP. On the other hand, oxygenated Hb change seems to reflect mainly blood accumulated in arterial space by interacting between mechanical stretch induced by LBNP and vasoconstriction caused by augmented sympathetic nerve activity. CONCLUSION: From these results, blood distribution in thigh muscles was different and was affected by the strength of LBNP. The data assessing oxygenation sites of Hb were found to be useful as indices of estimating superficial blood pooling in the muscle during LBNP.
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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".