Interlaboratory validation of organism recovery for use in 42-day sediment toxicity tests with<i>Hyalella azteca</i>
Bibliographic record
Abstract
Environment and Climate Change Canada has developed a 42-d sediment toxicity test that includes a reproduction endpoint with the freshwater amphipod Hyalella azteca. The new methodology conducts the entire exposure in sediment, in contrast to existing standardized methods whereby adults are transferred to a water-only exposure before release of their first brood at day 28. This midtest transfer to clean water was because of the results of a juvenile H. azteca recovery trial conducted in the 1990s concluding that reproductive endpoints could be biased because of low recovery of young amphipods from sediment. Using a new procedure and reduced volume of sediment, an interlaboratory recovery trial was conducted using 2-d to 5-d old H. azteca added to control sediment. A total of 29 technicians from 8 laboratories participated in the present study. The average recovery for all laboratories and all technicians was 76% (coefficient of variation [CV] = 30%). Based on an initial target recovery of at least 80%, 19 of 29 (66%) technicians met this criterion, with an average recovery for this group of 88% (CV = 8.3%). Factors that reduced recovery success included: not using a light table, technicians with minimal sediment testing experience, and the use of imported young amphipods with limited acclimation. Excluding those results, the overall average recovery, which included 17 participating technicians, increased from 76% to 88% and lowered the CV from 30% to 8.6%. Based on these results, Environment and Climate Change Canada will recommend ≥85% average recovery of young in control sediment and require ≥80% as a technician performance criterion in its new test design for the reproduction methodology. Environ Toxicol Chem 2017;36:1085-1089. © 2016 Crown in the right of Canada. Published by Wiley Periodicals Inc. on behalf of SETAC.
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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 | 0.028 | 0.024 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.002 | 0.002 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.002 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
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".