Levels of C<sub>10</sub>−C<sub>13</sub> Polychloro-<i>n-</i>Alkanes in Marine Mammals from the Arctic and the St. Lawrence River Estuary
Bibliographic record
Abstract
Marine mammals from various regions of the Arctic and the St. Lawrence River estuary were examined for the first time for levels of C 10 − C 13 polychloro- n- alkanes ( s PCAs). Respective mean total s PCA concentrations in the blubber of beluga whales ( Delphinapterus leucas ) from Saqqaq and Nuussuaq, western Greenland, were 0.23 ± 0.02 ( n = 2 ) and 0.164 ± 0.06 μg/g ( n = 2 ), similar to that in beluga from the Mackenzie Delta in the western Canadian Arctic 0.21 ± 0.08 μg/g ( n = 3 ). s PCAs levels were higher in beluga blubber from the St. Lawrence River (0.37 to 1.4 μg/g). Mean s PCA concentrations in the blubber samples from walruses ( Odobenus rosmarus ) (Thule, northwest Greenland) and ringed seal ( Phoca hispida ) (Eureka, southwest Ellesmere Island) were 0.43 ± 0.06 ( n = 2 ) and 0.53 ± 0.2 μg/g ( n = 6 ), respectively. Relative to commercial s PCA formulations, samples from the Arctic marine mammals showed a predominance of the shorter chain length lower percent chlorinated PCA congeners, the more volatile components of industrial formulations. This observation is consistent with long-range atmospheric transport of s PCAs to this region. The profiles of the belugas from the St. Lawrence River estuary, however, had higher proportions of the less volatile s PCA congeners, implying that contamination to this region is probably from local sources.
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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 | 0.000 |
| 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".