Characterization and manipulation of the reproductive cycle of the female veiled chameleon, Chamaeleo calyptratus
Bibliographic record
Abstract
This thesis investigates the reproductive cycle of the female veiled chameleon ('Chamaeleo calyptratus') using the patterns of fecal metabolites of estrogen, progesterone, and testosterone by enzyme immuno assays (EIA) in conjunction with MRI screening of the follicular development in animals with and without administration of 2.8 mg/kg tamoxifen for 60 days. Additionally, the hormone patterns of anovulatory chameleons were compared with those which ovulated to obtain a better understanding of the pathogenesis of reproductive failure. The mean length of the reproductive cycle was 132.5 days. During the previtellogenic phase all hormones were at baseline levels. Estradiol rose during vitellogenesis, peaking late in vitellogenesis and falling during the ovulatory stage. Progesterone rose during the late vitellogenic stage, peaking in mid-gravidity and falling to baseline values at oviposition. Testosterone levels showed various estrogen-dependent peaks throughout vitellogenesis, but mirrored progesterone with a distinct peak during the time of ovulation and gravidity. This sequence of estradiol, testosterone and progesterone peaks was called a hormone complex. Although the absolute values of each hormone varied among animals, approximately 24 fold increases over mean progesterone baseline values (756.05 ng/g) and 7.5 fold increase over mean estrogen and testosterone baseline values (284 ng/g and 236.97 ng/g, respectively) were associated with biological events. Almost half (48%) of the study population did not lay eggs in the 18 months observation period but hormone analysis revealed a continuous cyclical pattern of hormone complexes. Productive hormone complexes were associated with oviposition, whereas non-productive complexes were reflective of ovulatory failure and subsequent atresia of follicles. Progesterone concentrations were significantly lower in nonproductive complexes (3303.64 ng/g) than in productive complexes (24884.85 ng/g). Various combinations of sequences of productive and non-productive complexes were identified. It is hypothesized that anovulatory cycles are a physiological adaptation to adverse environmental breeding conditions, and husbandry measures, such as nutrition and lack of seasons, are responsible for the progression into a pathological process. Implantation with intracoelomic tamoxifen (estrogen-receptor blocker) pellets did not show any significant effects on follicular development despite elevations in fecal estradiol concentrations compared to control animals with a sham implant.
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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 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".