@prefix rdfs: . @prefix owl: . @prefix gacs: . @prefix skos: . @prefix rdf: . @prefix dc: . rdfs:label "Concept definition"@en ; a owl:Class . gacs:C8323 skos:definition gacs:def_4907c6ed . gacs:def_4907c6ed rdf:value "The tendency of a phenomenon to recur at regular intervals; in biological systems, the recurrence of certain activities (including hormonal, cellular, neural) may be annual, seasonal, monthly, daily, or more frequently (ultradian)."@en ; dc:source ; a .