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Record W315501344 · doi:10.2754/avb200069030177

Melatonin Concentrations in the Gastrointestinal Tissues of Fetal Bovids

2000· article· en· W315501344 on OpenAlexaff
George A. Bubenik, Gregory M. Brown, R. R. Hacker, Luděk Bartoš

Bibliographic record

VenueActa Veterinaria Brno · 2000
Typearticle
Languageen
FieldNeuroscience
TopicCircadian rhythm and melatonin
Canadian institutionsUniversity of Guelph
Fundersnot available
KeywordsMelatoninCzechBiologyFetusPhysiologyZoologyAnimal scienceVeterinary medicinePathologyAndrologyMedicinePregnancyEndocrinology

Abstract

fetched live from OpenAlex

Day-time tissue levels of melatonin were determined in the rumen, reticulum, omasum, abomasum, jejunum, ileum and colon of cow fetuses of both sexes. The total body length of the fetuses was 14 to 53 cm which corresponds to the first half of pregnancy; the approximate gestation age was 85-150 days. The data were divided into five equal groups according to fetal length. Average total melatonin concentrations (34.0 to 49.8 pg/g) did not differ greatly between the developmental stages but nevertheless a positive correlation (r s = 0.35, P < 0.001) was established between melatonin levels and fetal length. Significantly higher concentrations of melatonin (P < 0.001) were found in the male GIT. Finally, colon tissues exhibited higher concentrations of melatonin than any other GIT segment. As the average day-time values in fetal GIT (30.2 pg/g) were substantially lower than GIT levels found in adult cows (50-270 pg/g), it could be hypothesized that melatonin levels in the fetal GIT are derived from the maternal circulation. However, higher melatonin levels in older fetuses, the detection of higher levels in males and substantially higher levels of melatonin in the fetal GIT as compared to blood levels in adult cows, may indicate either an independent fetal production of GIT melatonin or the capacity of fetal GIT to concentrate melatonin derived from the maternal circulation. In view of these discrepancies it can be only concluded that the origin of melatonin in the bovine fetal GIT is at present unknown. The significantly higher concentration of melatonin found in the colon (P < 0.05) may be related to the presence of meconium detected in most fetuses in that GIT segment. This finding may indicate that melatonin has a physiological function in the fetal digestive system.

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 distilled prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: Bench or experimental
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.479
Threshold uncertainty score0.822

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0010.000

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.

Opus teacher head0.033
GPT teacher head0.278
Teacher spread0.245 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one teacher head, not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designBench or experimental
Domainnot available
GenreEmpirical

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".

Quick stats

Citations4
Published2000
Admission routes1
Has abstractyes

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