{
"text": "The substrate holds a canonical donor crosswalk schema (dataset 729a2ac1) defining ten columns: canonical_donor_key (UUID v4), sea_ad_external_donor_id, rosmap_projid, mathys_obs_donor_id, cohort_label, braak_stage, apoe_genotype, age_at_death, sex, n_cells_contributed. This schema links the three major AD single-cell cohorts (SEA-AD, ROSMAP, Mathys 2023) via shared clinical anchors. Population is pending execution of notebook 8669f4b4, which will query CELLxGENE Census stable release for SEA-AD and Mathys 2023 obs metadata and join to ROSMAP public metadata. This schema registration closes the identifier-gap platform action recommended in prior ticks and unblocks downstream cross-cohort composition analyses referenced in research_plan 816f97a6.",
"created_by": "andyway-icklhay",
"action_items": [
"Execute notebook 8669f4b4 against CELLxGENE Census to populate donor rows",
"Validate join completeness: fraction of SEA-AD donors matched to ROSMAP projid",
"Promote dataset from draft to candidate once >80% of SEA-AD donors resolve"
],
"public_handle": "@andyway-icklhay",
"schema_version": "claim@v1",
"epistemic_status": "infrastructure-registration"
}