{ "id": "ark:/99999/dp-quality-control-for-modern-bone-collagen-stable-carbon-and-n.v1", "concept": "ark:/99999/dp-quality-control-for-modern-bone-collagen-stable-carbon-and-n", "type": "datasetpaper", "title": "Modern collagen atomic C:N differs between fish and mammals and tracks glycine content", "discipline": "archaeometry / stable-isotope biogeochemistry", "description": "The atomic carbon-to-nitrogen ratio (C:N) is the most widely used quality-control gatekeeper for accepting collagen into stable-isotope studies, with a co…", "url": "https://datasetpapers.com/papers/modern-collagen-cn-fish-vs-mammal-glycine/", "status": "gated", "trust_distance": 0, "gate": { "passed": true, "version": "gate-0.1", "novelty_grade": "B", "failed": [] }, "verification": { "claims": 5, "self_reported_re_executed": 0, "independent_reexecution": { "status": "matched", "reproduced": true, "method": "re_execution", "ran_at": "2026-07-11T22:56:14Z", "values_compared": 187, "numeric_mismatches": 0, "record": "verification.json" } }, "byline": { "software_agent": { "name": "Claude Opus 4.8", "model_id": "claude-opus-4-8" }, "data_creators": [ "Szpak", "Paul", "Guiry", "Eric J." ], "data_creator_orcids": null, "question_asker": "Mark Hahnel" }, "source_dataset": { "title": "Quality_control_for_modern_bone_collagen_stable_carbon_and_nitrogen_isotope_measurements", "doi": "10.5061/dryad.ffbg79crm", "license": "Creative Commons Zero v1.0 Universal", "landing_url": "https://doi.org/10.5061/dryad.ffbg79crm", "download_url": "https://fairdata.ai/api/files/dryad/517053" }, "components": [ { "name": "analysis", "type": "code", "path": "analysis.py", "ark": "ark:/99999/dp-quality-control-for-modern-bone-collagen-stable-carbon-and-n.v1/analysis", "produced_by": null }, { "name": "fig-1", "type": "figure", "path": "figures/fig-1-cn-by-class.png", "ark": "ark:/99999/dp-quality-control-for-modern-bone-collagen-stable-carbon-and-n.v1/fig-1", "produced_by": "analysis" }, { "name": "fig-2", "type": "figure", "path": "figures/fig-2-cn-vs-glycine.png", "ark": "ark:/99999/dp-quality-control-for-modern-bone-collagen-stable-carbon-and-n.v1/fig-2", "produced_by": "analysis" }, { "name": "fig-3", "type": "figure", "path": "figures/fig-3-aa-cn-fdr.png", "ark": "ark:/99999/dp-quality-control-for-modern-bone-collagen-stable-carbon-and-n.v1/fig-3", "produced_by": "analysis" }, { "name": "fig-4", "type": "figure", "path": "figures/fig-4-robustness-forest.png", "ark": "ark:/99999/dp-quality-control-for-modern-bone-collagen-stable-carbon-and-n.v1/fig-4", "produced_by": "analysis" }, { "name": "tbl-1", "type": "table", "path": "tables/tbl-1-cn-by-class.csv", "ark": "ark:/99999/dp-quality-control-for-modern-bone-collagen-stable-carbon-and-n.v1/tbl-1", "produced_by": "analysis" }, { "name": "tbl-2", "type": "table", "path": "tables/tbl-2-aa-cn-spearman-fdr.csv", "ark": "ark:/99999/dp-quality-control-for-modern-bone-collagen-stable-carbon-and-n.v1/tbl-2", "produced_by": "analysis" }, { "name": "tbl-3", "type": "table", "path": "tables/tbl-3-robustness.csv", "ark": "ark:/99999/dp-quality-control-for-modern-bone-collagen-stable-carbon-and-n.v1/tbl-3", "produced_by": "analysis" }, { "name": "narrative", "type": "narrative", "path": "narrative.md", "ark": "ark:/99999/dp-quality-control-for-modern-bone-collagen-stable-carbon-and-n.v1/narrative", "produced_by": null } ], "claims": [ { "n": 1, "subject": "modern collagen atomic C:N ratio", "predicate": "is lower in", "object": "ray-finned fish (Actinopterygii) than in mammals (Mammalia)", "assertion_text": "In a compilation of modern vertebrate collagen (n=436), atomic C:N was lower in Actinopterygii (n=290, median 3.16, IQR 3.12-3.20) than in Mammalia (n=86, median 3.22, IQR 3.183-3.24); Mann-Whitney U=4946, p=1.68e-17, Hodges-Lehmann shift -0.060 (95% CI -0.070 to -0.050), Cliff's delta -0.60 (large).", "supported_by": [ "fig-1", "tbl-1", "analysis" ], "confidence": 0.95, "novelty_grade": "C", "mode": "confirmatory", "verification_status": "unverified", "ark": "ark:/99999/dp-quality-control-for-modern-bone-collagen-stable-carbon-and-n.v1/claim-1" }, { "n": 2, "subject": "collagen atomic C:N ratio", "predicate": "is negatively associated with", "object": "glycine content (residues per 1000)", "assertion_text": "Across all 436 samples, atomic C:N was negatively rank-correlated with glycine content (Spearman rho=-0.616, p=6.64e-47, n=436); the association held within each focal class (Actinopterygii rho=-0.630, p=1.64e-33, n=290; Mammalia rho=-0.475, p=3.91e-06, n=86).", "supported_by": [ "fig-2", "analysis" ], "confidence": 0.9, "novelty_grade": "C", "mode": "confirmatory", "verification_status": "unverified", "ark": "ark:/99999/dp-quality-control-for-modern-bone-collagen-stable-carbon-and-n.v1/claim-2" }, { "n": 3, "subject": "glycine", "predicate": "is the strongest negative correlate of", "object": "atomic C:N among 19 collagen amino acids under FDR control", "assertion_text": "In an amino-acid-wide screen (19 residues, Benjamini-Hochberg FDR), glycine was the strongest negative correlate of atomic C:N (Spearman rho=-0.616, q=1.26e-45, n=436); 16 of 19 residues were FDR-significant (q<0.05), with imino acids proline and hydroxyproline among the strongest positive correlates.", "supported_by": [ "fig-3", "tbl-2", "analysis" ], "confidence": 0.88, "novelty_grade": "B", "mode": "exploratory", "verification_status": "unverified", "ark": "ark:/99999/dp-quality-control-for-modern-bone-collagen-stable-carbon-and-n.v1/claim-3" }, { "n": 4, "subject": "the fish-lower-than-mammal C:N difference", "predicate": "is robust to", "object": "source-batch stratification, species-level pseudoreplication, and broadened class grouping", "assertion_text": "The direction and significance of the fish