Occurrence of compounds estrogenic to freshwater mussels in surface waters in an urban area
Bibliographic record
Abstract
Estrogens play a major role in the sexual differentiation, gonad development, and oocyte growth of most oviparous organisms. They also stimulate vitellogenesis, the formation of high-density glycolipophosphoprotein that serves as an energy source for the developing embryo. Surface waters from the St. Lawrence River, obtained in the vicinity of an urban area (Montreal, Quebec, Canada), were studied with respect to their estrogenic potential to the freshwater mussel Elliptio complanata. Estrogenicity was measured in water extracts by means of a competitive assay of estradiol binding to cytosolic proteins and by the vitellin-inducing ability of mussel hemolymph following direct extract injection. Surface-water samples drawn downstream of a municipal outfall plume and in a river draining a large farming and agricultural area had high levels of total and fecal coliform bacteria. High levels of estrogen competitors were also found and were able to induce vitellins in injected mussels. Moreover, the estrogen-competing potential of the extracts was found to be significantly correlated with total and fecal coliform bacteria (R = 0.9, p < 0.01) and with the levels of vitellins in the hemolymph (R = 0.62, p = 0.03). The results indicate that water samples drawn from within the municipal effluent plume and from a river draining an agricultural area are estrogenic to freshwater mussels. Thus, the environmental inputs of estrogens are likely to be associated with human sewage and pesticide products.
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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 | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 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".