Chronically Elevated Corticosterone Levels, via Cocoa Butter Injections of Corticosterone, Do Not Affect Stress Response, Immune Function, and Body Condition in Free-living Painted Turtles (Chrysemys picta)
Bibliographic record
Abstract
Chronic stress can result in elevated circulating levels of glucocorticoid hormones in vertebrates, which can affect their stress response, their immune function, and eventually their fitness. I tested the effect of chronic corticosterone (CORT) elevation on the acute stress responsiveness, immune function, and body condition of free-living painted turtles (Chrysemys picta) in Gatineau Park, using slow-release exogenous CORT administration. While Silastic implants did not predictably elevate circulating CORT concentrations in painted turtles, injections of CORT-laden cocoa butter kept circulating levels elevated for up to 3 weeks, to concentrations likely physiologically and ecologically relevant for the species. I measured the acute CORT stress response, parasitaemia, heterophil-to-lymphocyte ratios, and total leukocyte counts after 1 week and 3 weeks, and determined body condition after 1 week, 3 weeks, and 1 year. Compared to sham and control turtles, I observed no effect of treatment on these hormonal, immune, and body condition metrics of stress, possibly because CORT mediates resource allocation only in the presence of additional immune or energy challenges, because of the masking effect of extrinsic factors, or because free, not total, CORT appears to be biologically active.
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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".