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Relating to or exhibiting periodic physiological activity that occurs more than once every 24 hours.

References in periodicals archive ?
Twenty-four hour cortisol release profiles in patients with Alzheimer's and Parkinson's disease compared to normal controls: Ultradian secretory pulsatility and diurnal variation.
10,11] Underlying this circadian rhythm, endogenous GC secretion exhibits an ultradian rhythm, characterized by hourly pulses which vary in amplitude over the 24-h period.
The rapid circadian (24 hour) and ultradian ( 24 hour) cycling of hormone levels poses diagnostic challenges since random measurements do not always detect abnormalities.
Ultradian variation of isoprene emission, photosynthesis, mesophyll conductance and optimum temperature sensitivity for isoprene emission in water-stressed Eucalyptus citriodora saplings.
The University of Newcastle, TypeZero Technologies LLC, Ultradian Diagnostics LLC, Universidad Autonoma de Madrid, Universitat Politecnica de Valencia, University of California, San Francisco, University of California, Santa Barbara, University of Cambridge, University of Florida, XERIS Pharmaceuticals, Inc.
Metabolic regulation of the ultradian oscillator Hes1 by reactive oxygen species," Journal of Molecular Biology, vol.
We have biological rhythms that maintain our health: ultradian, circadian, diurnal, infradian.
Circadian and ultradian activity rhythms of a freshwater gastropod, Helisoma trivolvis: the effects of social factors and eye removal.
Circadian and ultradian changes of functional parameters in human blood platelets.
This is your own natural stress control mechanism, known as the ultradian rhythm.