The Absorption and Translocation of Polychlorinated Biphenyl Congeners by <i>Cucurbita pepo</i> ssp <i>pepo</i>
Bibliographic record
Abstract
The mobility of polychlorinated biphenyl (PCB) congeners within Cucurbita pepo ssp pepo cv. Howden (pumpkin), a PCB phytoextracting plant, was investigated through a comparison of field-weathered soil, root, shoot, and xylem sap congener profiles. This is the first study to show the presence of PCBs in xylem sap (range: 0.03-0.18 μg·mL(-1)), confirming that PCB translocation throughout the plant occurs via this medium. A comparison of soil (5.2 ± 2.5 μg·g(-1)), root (27.1 ± 2.1 μg·g(-1)), shoot (range: 1.9 ± 0.5 μg·g(-1) - 8.2 ± 1.4 μg·g(-1)), and xylem sap (0.09 ± 0.04 μg·g(-1)) samples showed significant differences in congener profiles, with lower chlorinated congeners (predominately trichlorinated ones) found within xylem sap in higher amounts than higher chlorinated congeners. The total PCB concentrations of xylem sap samples collected at various lengths along the primary plant shoot were not significantly different from each other, while those of primary shoot tissue samples significantly decreased (two-sample t test, p = 0.01) as the distance from the plant base increased. PCA analysis of individual congeners in the roots, shoots and xylem sap indicated that movement of the PCB congeners in the plant was affected by the number of chlorines in the molecule, and hence possibly log K(ow) and molecular weight, but not by planarity.
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) | 0.001 | 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) | 0.001 | 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".