Evolution of Tobacco-Specific Nitrosamines and Microbial Populations During Flue-Curing of Tobacco Under Direct and Indirect Heating
Bibliographic record
Abstract
Abstract Canadian tobacco was flue-cured using two different heating systems: direct-fired in which the exhaust gases were in contact with the tobacco and indirect in which only hot air, via a heat exchanger, contacted the tobacco. The concentrations of tobacco-specific nitrosamines (TSNAs) in tobacco cured by indirect heating did not increase during curing and were in the range 0.25-0.35 ppm. There were no changes in TSNA concentrations (range 0.13-0.3 ppm) in tobacco cured by direct firing during the first six days (0-144 h) of curing. However between 168 and 264 h, significant increases in TSNAs occurred (up to 1.91 ppm). TSNA concentrations in leaves at the bottom of the plant were significantly higher than in those found at higher plant position. There were no significant differences in TSNA concentrations in tobacco cured on different farms. The TSNA concentrations in tobacco cured by indirect heat were 87% ± 5% lower than in tobacco cured by direct heat. Subsequent processing of tobacco did not change the relative concentrations of TSNAs.
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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 | 0.000 | 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".