Infradian rhythms of the esophageal epithelium mitotic activity, corticosterone and thyroxin level in Japanese quail Coturnix japonica

Everyday dynamics of corticosterone and thyroxin levels on blood serum, as well as esophageal epithelium proliferation activity in Japanese quail males, have been investigated over a period of 16 days. It was estimated that different individuals synchronically exhibited a 4-day rhythm of the corticosterone serum level. The thyroxin level displayed a 3-day biorhythm. The mitotic index in the esophageal epithelium negatively correlated with the corticosterone level. The revealed infradian rhythms of the corticosterone and thyroxin levels, as well as esophageal epithelium mitotic index, should be taken into account while carrying out experiments concerning the determination of the hormone level and mitotic activity of epithelial tissues.     

A 12.175-Day Periodicity in Heliogeophysical,Atmospheric, and Biological Processes

Biophysics - The dynamics of several heliophysical and atmospheric processes were compared with 12.175- and 4.06-day biorhythms observed earlier in the mitotic activity of epithelial tissues and...     

Infradian rhythmics of markers of physiologic and metabolic processes in Wistar male rats

This work presents the results of the amplitude-phase structure of the physiological rhythms (locomotor activity) and steroid hormones production (common testosterone and cortisole) in gelded and intact Wistar male rats as well as rats exposed to an information load. The markers have been shown to depend on the social state of the animal. It was proved that there was a phase coincidence of the periods of the biological rhythms of common testosterone (intact rats), cortisole and locomotor activity for animals with different individualand typological features. It was shown that the oscillation period of infradian rhythms of the measured markers of physiologic and metabolic processes in the animals of all groups amounted to 4 days. It was found that infradian rhythms were not sensitive to factors of various genesis.     

The Dynamics of the Replacement of Primary Flight Feathers in Passerine Birds and Possible Synchronization Factors

Biophysics - Abstract—A study was made to investigate the dynamics of the replacement of primary flight feathers in several passerine bird species in natural and laboratory conditions. Birds...     

Is the Periodic “Spontaneous” Activity of Animals Determined by a Quasi-Rhythmic Factor of the External Environment?

Doklady Biological Sciences - We have studied the dynamics of the singing of garden bunting (Emberiza hortulana) and the dispersal of a flock of starlings (Sturnus vulgaris) for the night rest. The...     

Bigger male Eurasian nuthatches (Sitta europaea) behave more aggressively in playback-simulated territorial intrusion

Journal of Ethology - In animals, personality (or temperament) is associated with alternative response patterns in reaction to a potential stressor or challenging situation. Aggressiveness is one...