The tri-national (2007) Maritimes data: some important and interesting observations
Bibliographic record
Abstract
The data for six elements, As, Cd, Cu, Ni, Pb and Zn, are investigated in soil samples collected by the Geological Survey of Canada (GSC) in the Maritime provinces (NB, NS and PEI) in 2007. Samples were collected from several soil horizons and intervals, 0-5 cm, A, 0-30 cm, B and C, by GSC, Environment Canada, and provincial agency staff, and in collaboration with soil scientists from Agriculture and Agri-Food Canada. A variety of analytical methods were investigated, ranging form a water leach to a 'total' mutli-acid digestion and Instrumental Neutron Activation (INA) applied to different sieved size fractions, <2 mm, <250 µm and <63 µm . Attention is focused on the data obtained using the Aqua Regia variant (4:1 HCl-HNO3) of the US-EPA 3050B protocol applied to the <2 mm fraction, with elements being determined in the digests by ICP-OES and ICPMS. An inspection of the data by soil horizon reveals systematic patterns of element distribution. For Pb and Cd levels decrease with depth until the B horizon is reached, they then increase and then fall with depth to the C horizon. For As, Cu, Ni, Pb and Zn levels increase with depth until the B horizon, where they drop, and than increase with depth to the C horizon. As a generalization, levels in the 0-5 cm interval and B horizons are similar, as are levels in the 0-30 cm interval and the C horizon. In general, observed levels in the 0-5 cm interval and B horizon are similar, and levels in the 0-30 cm interval are similar to the C horizon. The role of Fe and Organic carbon was investigated across the 0-5 cm, A, B and C horizons. It is shown that there are systematic variations with depth and that these major soil components exercise a control on trace element levels through their ability to sequester trace elements and bind them in mineral forms or with metallo-organic ligands. A variety of analytical protocols were applied to C horizon soils in an investigation of the amounts of elements that might be bioavailable, i.e. as estimates of bioaccessibility. These data show that bioaccessibility estimates using a water leach are 1.5 (Cd) to 3 (Pb) orders of magnitude than PBET estimates for gastric intake, and that PBET estimates are lower by a half to 1.5 orders of magnitude lower than the results of routine geochemical analyses employing aqua regia-like digestions. It is concluded that there are advantages to consistently sampling a single soil horizon or interval, and in the case of an interval, it should be as narrow as operationally feasible.
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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 | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.003 | 0.006 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 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".