Figure 20
From: Transdisciplinary unifying implications of circadian findings in the 1950s
Terminology. "Circa" in "Circadian"."Diurnal" and "circadian" need not be used by us as synonyms. In our case, "diurnal" relates to the photofraction, and "circadian" means a cycle with a period of about 24 hours. Reasons for the use of "circa" in "circa-rhythms" include among several other considerations, inferential statistical uncertainties that qualify the estimate of period (top left), apart from a desynchronization (top right).