Regulation of urea cycle related enzymes in response to freezing in the wood frog, Rana sylvatica
Bibliographic record
Abstract
The North American wood frog, Rana sylvatica, is one of the few vertebrate species that is capable of surviving freezing.Prevention of intracellular ice formation and maintenance of osmotic balance is facilitated by the production of large concentrations of urea during freezing in the liver.The regulatory roles of three enzymes critical to production of urea; glutamate dehydrogenase (GDH), carbamoyl phosphate synthetase I (CPS1), and ornithine transcarbamylase (OTC), were investigated in the liver in response to freezing.Freeze-exposed GDH had heightened substrate affinity and higher maximal activity than the control.Freeze-exposed GDH also had decreased acetylation and ADPribosylation.CPS1 from frozen frogs was demonstrated to have a higher affinity for ammonium and decreased lysine glutarylation relative to the control.Freeze-exposed OTC demonstrated improved affinity for ornithine and increased serine phosphorylation.Taken together, the results suggest that urea production is sustained in the liver of the wood frog during freezing.
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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".