British Columbiaから採取された獣骨および人骨のAMS ^C年代
Bibliographic record
Abstract
We measured ^<14>C ages, carbon and nitrogen stable isotopic ratios of gelatin-collagens extracted from deer and human bones at British Columbia, Canada. The deer bone samples, samples #1〜#3,come from a site in the interior of British Columbia, designated as DhRa-02 site. The human bone samples, samples #4〜#6,are from the Pender Canal site, on North Pender Island, British Columbia. In general, reliable ^<14>C ages, carbon and nitrogen stable isotopic ratios can be obtained for collagens extracted from fossil bones, provided that the collagens have been preserved well from weathering in nature. Experimental yields of gelatin-collagens were higher than 0.7%, except for sample #1 with 0.25%. For sample #1,we tried to extract amino acid fractions by hydrolyzation and XAD-2 treatment and to measure its ^<14>C age. The age is the same as that of gelatin-collagen, about 1200 yrBP. Samples #1 and #2 are situated stratigraphically above a volvcanic ash, identified as Mazama tephra ca 6800 yrBP, and have post-ash dates, 1260 and 3010 yrBP, respectively. Sample #3 shows 3820 yrBP, younger than the age of Mazama tephra, though #3 comes from a pre-ash layer. Samples #4〜#6 have relatively high gelatin yields of 6〜9%, and show the ^<14>C ages of 3120〜3550 yrBP. The CO_2 yields from the gelatin-collagens of samples #1〜#6 are over 41%, consistent with the value of 40〜50% for gelatin-collagen extracted from fresh bones. Thus, the ^<14>C ages, carbon and nitrogen stable isotopic ratios obtained for the gelatin-collagens seem to be reliable. The deer bone samples #1〜#3 demonstrate δ^<13>C value of 〜-21‰ and δ^<15>N value of +5〜+8‰, which are the values of C3 millets. On the other hand, the human bone samples #4〜#6 show relatively high δ^<13>C value of -13‰ and δ^<15>N value of +18‰. It is thought that they ate marine products such as fishes and shellfishes, with δ^<13>C value of -15〜-20‰ and δ^<15>N value of +15〜+20‰, when they were alive. The high δ^<13>C and δ^<15>N values for the human bones are caused by the food resources.
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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 | 0.001 | 0.002 |
| Science and technology studies | 0.003 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.015 | 0.003 |
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".