Inhibitory effect of ammonia on urea flux across rumen epithelium depends on level of serosal urea
Bibliographic record
Abstract
Ruminants perpetually depend on their ability to transfer urea from blood to the rumen in order to maintain a positive N balance. Estimates indicate that 40 to 80% of endogenously-produced urea can be recycled to the rumen where it provides ruminally-available N for microbial growth (Lapierre and Lobley, 2001), so it is important to understand the regulatory mechanisms that control trans-epithelial urea transfer into the rumen. Increasing ruminal ammonia (NH3-N) concentration decreases trans-epithelial urea transfer from blood into the rumen (Abdoun et al., 2009); however, the mechanisms that are responsible for this response are uncertain. Facilitative urea transporter proteins (UT-B) are expressed in ruminal epithelium and the addition of phloretin, an inhibitor of UT-B function, reduces trans-epithelial flux of urea in isolated ruminal epithelium (Stewart et al., 2005), thus providing proof that these UT-B might have a functional role in ruminal urea transfer. However, the functional role of UT-B in mediating the effects of ruminal NH3-N on trans-epithelial flux of urea remains obscure. We evaluated the effects of mucosal NH3 and serosal urea concentrations on total and UT-B-dependent (i.e. phloretin-sensitive) urea flux across the isolated bovine ruminal epithelium.
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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 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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".