Physical Activity, Sedentary Behavior, and Melatonin Among Rotating Shift Nurses
Bibliographic record
Abstract
OBJECTIVE: To determine the effect of physical activity and sedentary behavior on melatonin levels in a group of rotating shift nurses. METHODS: Physical activity and sedentary behaviors for 118 nurses were recorded during both a day shift and a night shift using activity diaries, and concentrations of urinary 6-sulfatoxymelatonin were analyzed for each shift. RESULTS: During the day shift, energy expended in moderate- and vigorous-intensity physical activity between 3 PM and 7 AM was negatively associated with melatonin levels (P = 0.024). During the night shift, energy expended in sedentary behaviors was negatively associated with melatonin levels (P = 0.008). CONCLUSIONS: Physical activity and energy expended in sedentary behavior are inversely associated with morning urinary melatonin concentrations. Nevertheless, energy expenditure explains a relatively small amount of melatonin variation, perhaps suggesting that peak melatonin is minimally affected by these patterns of physical activity.
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 | 0.001 |
| 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".