Quantifying maternal and dietary sources of 2,2′,4,4′,5,5′-hexachlorobiphenyl deposited in eggs of the ring dove (<i>Streptopelia risoria</i>)
Bibliographic record
Abstract
The influence of maternal versus dietary sources of polychlorinated biphenyls (PCBs) deposited to eggs of ring doves (Streptopelia risoria) was investigated. Mature birds that lay a clutch of two eggs every 12 to 15 d were fed a diet of pellets spiked with 2,2',4,4',5,5'-hexacholorobiphenyl (unlabelled isotope designated as [12C]PCB153) for 25 d. The birds were subsequently switched to a diet containing isotopically labeled [U-13C12]PCB153 at similar concentrations for an additional 63 d. The toxicokinetics of [12C]PCB153 and [13C]PCB153 were followed in egg and carcass samples with time. Isotopic ratios of PCB153 in yolk lipids were identical to those in carcass lipids after introduction of diet 2, and they did not resemble those of the food at the time of egg formation. The data indicate that the PCB composition of eggs directly reflects the composition of maternal tissues, not the diet, at the time of yolk formation. Egg yolk:carcass lipid concentration ratios for the two isotopes were significantly less than one, averaging 0.33+/-0.02 (mean +/- standard error). Lipid normalized egg:maternal tissue contaminant concentration ratios for persistent organochlorine chemicals in the literature were reviewed for other avian species. The results provide a preliminary data set that suggests egg:maternal tissue contaminant concentration ratios vary among species, particularly among species that invest different quantities of lipids to a clutch of eggs. The results support the hypothesis that dilution of contaminants in egg lipids relative to maternal lipids is related to the reproductive strategy employed by the species.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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 | 0.001 |
| 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 teacher head, 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".