The influence of metabolic rate on the contribution of stable‐hydrogen and oxygen isotopes in drinking water to quail blood plasma and feathers
Bibliographic record
Abstract
Summary The stable‐hydrogen and oxygen isotopic composition of animal tissues are important tools for estimating the geographic origin of migrating animals. Estimating the origin of animals using H and O isotopes requires knowledge of how closely and consistently tissues reflect precipitation isotopes at the location in which the tissues were grown. One hypothesis to explain variation in isotope discrimination values in tissues from individuals residing at the same location is metabolic rate. Variation in metabolic rate between individuals could alter the relative proportions of drinking water and food atoms that are integrated into a tissue. Individuals with high metabolic rates ingest greater amounts of water compared with those with lower metabolic rates in order to balance metabolic water losses. Increased water consumption may increase the rate of hydrogen and oxygen atom turnover within the blood plasma, thereby limiting the extent to which tissue precursors isotopically exchange with their surroundings. A first test of this hypothesis was carried out by experimentally elevating the metabolic rate of J apanese quail ( C oturnix japonica ) over a 64‐day period. We spiked drinking water with 99·9% 2 H 2 O and 10% 18 O to trace the incorporation of drinking water to feather tissue while holding the isotopic value of the food constant. We observed a 15% increase in metabolic rate was associated with a 6% decrease in the relative contribution of drinking water hydrogen to feather keratin between treatments. In contrast, no differences in the relative contribution of drinking water oxygen to plasma or feathers were detected because of the small isotopic separation (e.g., only 9‰) between initial and final drinking water δ 18 O values. Results suggest a difference in metabolic rates between individuals residing in the same geographic location have the potential to partially obscure the relationship between precipitation and feather δ 2 H values.
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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 | 0.001 | 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".