Health of Tree Swallow ( Tachycineta bicolor ) Nestlings Exposed to Chlorinated Hydrocarbons in the St. Lawrence River Basin. Part II. Basal and Stress Plasma Corticosterone Concentrations
Bibliographic record
Abstract
Sixteen-day-old tree swallows (Tachycineta bicolor) were collected in 1999 and 2000 from nine sites within the vicinity of the St. Lawrence River in Canada and the United States to determine if organochlorine contaminant concentrations correlated with corticosterone levels. Basal plasma corticosterone levels were determined in chicks reared in nest boxes, and stress plasma corticosterone levels were determined in chicks after exposure to a 10-min standardized stress test. Mean basal plasma corticosterone concentrations ranged from 4 to 37 ng/ml in 1999, and from 5 to 20 ng/ml in 2000. Mean poststress plasma corticosterone levels ranged from 26 to 67 ng/ml in 1999, and from 26 to 109 ng/ml in 2000. In 1999 and 2000, basal corticosterone was negatively correlated with polychlorinated dibenzofuran (PCDF). Total PCDFs ranged from 4.8 to 120.5 ng/kg wet weight in chicks in 1999 and 2000 among sites. These results indicate that current levels of organochlorine contaminants in the St. Lawrence River and surrounding tributaries may be interfering with the glucocorticoid endocrine axis of tree swallows.
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 | 0.000 | 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) | 0.000 | 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".