Modern calibration of biomarkers in the marine channels of the Canadian Arctic Archipelago using the PIP25 approach
Bibliographic record
Abstract
Two lipid biomarkers, IP25 (a highly branched isoprenoid hydrocarbon; an ice proxy containing 25 carbon atom skeleton) and brassicasterol (phytoplankton derived biomarker), accumulate and become preserved in the marine sediments on the seafloor. IP25 is produced by sea ice algae (marine diatoms) while brassicasterol is produced by a suite of open-water algae (dinoflagellates, diatoms), allowing for determination of sea surface conditions in relation to sea ice conditions during accumulation. Absence of IP25 in marine sediments can indicate permanent sea ice coverage or absence of sea ice completely. High IP25 concentrations reveal sea ice conditions by which sea ice algae can thrive. High brassicasterol concentrations are an indicator of ice free surface conditions, whereas, an absence of brassicasterol would suggest sea ice coverage. Following extraction and quantification via Gas Chromatography Mass Spectroscopy, their respective concentrations can be related to each other in a ratio known as PIP25 (Phytoplankton-IP25 index) to reconstruct specific sea ice conditions (marginal ice zone, perennial ice cover, ice free, etc.). The PIP25 approach allows for currently accumulating IP25 and brassicasterol to be related to observed modern sea ice conditions, therefore providing a regionally appropriate calibration for the study of past conditions in the geological record. This study focuses on the modern calibration of these biomarkers in the marine channels of the Canadian Arctic Archipelago. * Indicates faculty mentor.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.003 | 0.003 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| 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".