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).
- periodicity of nuclear properties began to show up.
- circadian rhythms show persistent, stable periodicities of about 24 hours.
- regular irregularities occur with constant periodicity and are usually associated with partial heart block.
- in some cell lines there is a similar periodicity in changes of cell surface antigenicity or response to wheat germ agglutinin.
- algorithm analysis of periodicity of relational matrix