{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2018:NDP4ZJ2VVBMBJP4BWE3JDYQD2D","short_pith_number":"pith:NDP4ZJ2V","canonical_record":{"source":{"id":"1812.09797","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.soft","submitted_at":"2018-12-23T23:51:40Z","cross_cats_sorted":[],"title_canon_sha256":"16fff5572b296e2ce32240c57e2cef8aa72f6bb3a154400efe0618fb7e090743","abstract_canon_sha256":"201c83f68ffff0f3b517237b47aaf6e2c7d3c6582323d6b9a460337b1da2c6db"},"schema_version":"1.0"},"canonical_sha256":"68dfcca755a85814bf81b13691e203d0c043f696f61e8af9e95d760d57ee6aa4","source":{"kind":"arxiv","id":"1812.09797","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1812.09797","created_at":"2026-05-17T23:41:45Z"},{"alias_kind":"arxiv_version","alias_value":"1812.09797v1","created_at":"2026-05-17T23:41:45Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1812.09797","created_at":"2026-05-17T23:41:45Z"},{"alias_kind":"pith_short_12","alias_value":"NDP4ZJ2VVBMB","created_at":"2026-05-18T12:32:40Z"},{"alias_kind":"pith_short_16","alias_value":"NDP4ZJ2VVBMBJP4B","created_at":"2026-05-18T12:32:40Z"},{"alias_kind":"pith_short_8","alias_value":"NDP4ZJ2V","created_at":"2026-05-18T12:32:40Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2018:NDP4ZJ2VVBMBJP4BWE3JDYQD2D","target":"record","payload":{"canonical_record":{"source":{"id":"1812.09797","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.soft","submitted_at":"2018-12-23T23:51:40Z","cross_cats_sorted":[],"title_canon_sha256":"16fff5572b296e2ce32240c57e2cef8aa72f6bb3a154400efe0618fb7e090743","abstract_canon_sha256":"201c83f68ffff0f3b517237b47aaf6e2c7d3c6582323d6b9a460337b1da2c6db"},"schema_version":"1.0"},"canonical_sha256":"68dfcca755a85814bf81b13691e203d0c043f696f61e8af9e95d760d57ee6aa4","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-17T23:41:45.493490Z","signature_b64":"U/3W3qjSas69XWvymcld3/1Fasj0oaGK14voSM12VqC34IE+1fVU5hOiaSYbaJIzcQA6S//hsxCwSwTPdoMJDg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"68dfcca755a85814bf81b13691e203d0c043f696f61e8af9e95d760d57ee6aa4","last_reissued_at":"2026-05-17T23:41:45.493017Z","signature_status":"signed_v1","first_computed_at":"2026-05-17T23:41:45.493017Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1812.09797","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-17T23:41:45Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"fsYfdeYRXuzT0Cyl0sX3qVfcWTFVsfURfrMVRkR2cDO04aR8L1NAtAw10XuXbRZpAnZez9IpUJZOtqb2vYrBBA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-03T23:14:03.624898Z"},"content_sha256":"df323854d8f232fb287faab55779a4545cb90bc8c43b6b08e4e106812bf69cc3","schema_version":"1.0","event_id":"sha256:df323854d8f232fb287faab55779a4545cb90bc8c43b6b08e4e106812bf69cc3"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2018:NDP4ZJ2VVBMBJP4BWE3JDYQD2D","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Microbial range expansions on liquid substrates","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cond-mat.soft","authors_text":"Andrew W. Murray, Bryan T. Weinstein, David R. Nelson, Severine Atis","submitted_at":"2018-12-23T23:51:40Z","abstract_excerpt":"Despite the importance that fluid flow plays in transporting and organizing populations, few laboratory systems exist to systematically investigate the impact of advection on their spatial evolutionary dynamics. To address this problem, we study the morphology and genetic spatial structure of microbial colonies growing on the surface of a nutrient-laden fluid $10^4$ to $10^5$ times more viscous than water in Petri dishes, the extreme but finite viscosity inhibits undesired thermal convection and allows populations to effectively live at the air-liquid interface due to capillary forces. We disc"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1812.09797","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-17T23:41:45Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"eN/uycvOydjCj2yiluIH1oBfHMLngUDb9f8GIStUwWffDbhvRKnPlCBaaQK8H1DlnhiKfoK0HCgRIahECkHZCQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-03T23:14:03.625239Z"},"content_sha256":"c52e4507c4f87483bebde2dc273b7955fcd61c6267754cf7e6ceace6bdd61f76","schema_version":"1.0","event_id":"sha256:c52e4507c4f87483bebde2dc273b7955fcd61c6267754cf7e6ceace6bdd61f76"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/NDP4ZJ2VVBMBJP4BWE3JDYQD2D/bundle.json","state_url":"https://pith.science/pith/NDP4ZJ2VVBMBJP4BWE3JDYQD2D/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/NDP4ZJ2VVBMBJP4BWE3JDYQD2D/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-06-03T23:14:03Z","links":{"resolver":"https://pith.science/pith/NDP4ZJ2VVBMBJP4BWE3JDYQD2D","bundle":"https://pith.science/pith/NDP4ZJ2VVBMBJP4BWE3JDYQD2D/bundle.json","state":"https://pith.science/pith/NDP4ZJ2VVBMBJP4BWE3JDYQD2D/state.json","well_known_bundle":"https://pith.science/.well-known/pith/NDP4ZJ2VVBMBJP4BWE3JDYQD2D/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:NDP4ZJ2VVBMBJP4BWE3JDYQD2D","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"201c83f68ffff0f3b517237b47aaf6e2c7d3c6582323d6b9a460337b1da2c6db","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.soft","submitted_at":"2018-12-23T23:51:40Z","title_canon_sha256":"16fff5572b296e2ce32240c57e2cef8aa72f6bb3a154400efe0618fb7e090743"},"schema_version":"1.0","source":{"id":"1812.09797","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1812.09797","created_at":"2026-05-17T23:41:45Z"},{"alias_kind":"arxiv_version","alias_value":"1812.09797v1","created_at":"2026-05-17T23:41:45Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1812.09797","created_at":"2026-05-17T23:41:45Z"},{"alias_kind":"pith_short_12","alias_value":"NDP4ZJ2VVBMB","created_at":"2026-05-18T12:32:40Z"},{"alias_kind":"pith_short_16","alias_value":"NDP4ZJ2VVBMBJP4B","created_at":"2026-05-18T12:32:40Z"},{"alias_kind":"pith_short_8","alias_value":"NDP4ZJ2V","created_at":"2026-05-18T12:32:40Z"}],"graph_snapshots":[{"event_id":"sha256:c52e4507c4f87483bebde2dc273b7955fcd61c6267754cf7e6ceace6bdd61f76","target":"graph","created_at":"2026-05-17T23:41:45Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"paper":{"abstract_excerpt":"Despite the importance that fluid flow plays in transporting and organizing populations, few laboratory systems exist to systematically investigate the impact of advection on their spatial evolutionary dynamics. To address this problem, we study the morphology and genetic spatial structure of microbial colonies growing on the surface of a nutrient-laden fluid $10^4$ to $10^5$ times more viscous than water in Petri dishes, the extreme but finite viscosity inhibits undesired thermal convection and allows populations to effectively live at the air-liquid interface due to capillary forces. We disc","authors_text":"Andrew W. Murray, Bryan T. Weinstein, David R. Nelson, Severine Atis","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.soft","submitted_at":"2018-12-23T23:51:40Z","title":"Microbial range expansions on liquid substrates"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1812.09797","kind":"arxiv","version":1},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:df323854d8f232fb287faab55779a4545cb90bc8c43b6b08e4e106812bf69cc3","target":"record","created_at":"2026-05-17T23:41:45Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"201c83f68ffff0f3b517237b47aaf6e2c7d3c6582323d6b9a460337b1da2c6db","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.soft","submitted_at":"2018-12-23T23:51:40Z","title_canon_sha256":"16fff5572b296e2ce32240c57e2cef8aa72f6bb3a154400efe0618fb7e090743"},"schema_version":"1.0","source":{"id":"1812.09797","kind":"arxiv","version":1}},"canonical_sha256":"68dfcca755a85814bf81b13691e203d0c043f696f61e8af9e95d760d57ee6aa4","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"68dfcca755a85814bf81b13691e203d0c043f696f61e8af9e95d760d57ee6aa4","first_computed_at":"2026-05-17T23:41:45.493017Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-17T23:41:45.493017Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"U/3W3qjSas69XWvymcld3/1Fasj0oaGK14voSM12VqC34IE+1fVU5hOiaSYbaJIzcQA6S//hsxCwSwTPdoMJDg==","signature_status":"signed_v1","signed_at":"2026-05-17T23:41:45.493490Z","signed_message":"canonical_sha256_bytes"},"source_id":"1812.09797","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:df323854d8f232fb287faab55779a4545cb90bc8c43b6b08e4e106812bf69cc3","sha256:c52e4507c4f87483bebde2dc273b7955fcd61c6267754cf7e6ceace6bdd61f76"],"state_sha256":"3d568a5515158dfb1029fd9cce541e0ea69b6fb049966632778a33723eebadbe"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"2+UoVygCpqCMsYoShZ9mwTY2QUhuTM/ZYlJzcnmZS1d4pKwxm9JjEYB/eR1z4YBe9Iz5ge4JvCMJn+1BI4zhAQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-03T23:14:03.627228Z","bundle_sha256":"3906b53672e9846b226f56a68fa2cdbce3f74bd0bce03d32c1304925e08a41f3"}}