Circahoralian Rhythms of Body Temperature in Mammals and Birds with Different Metabolism Levels.

The time course of intraperitoneal body temperature has been analyzed in two species of mammals (laboratory C57Bl/6 mice and white-breasted hedgehogs (Erinaceus roumanicus) and in two species of passerine birds (common greenfinch Chloris chloris and Japanese quail Coturnix japonica) with different body weights. Similar sets of basic harmonics appearing synchronously in different individuals have been found in the body temperature spectra of the species studied. The level of basal metabolism in those animal species considerably vary; therefore, the period of fluctuations of body temperature in the range of 10-120 min is not determined by the internal characteristics of the body and, presumably, reflects the influence of an external biotropic environmental factor.

Body Temperature Dynamics in Small Mammals and Birds in 10-120-min Period Range.

The dynamics of intraperitoneal body temperature was analyzed in males of C57BL/6 mice and common greenfinches (Chloris chloris). Despite the membership in different classes, these mammals demonstrated the identical set of harmonics in body temperature spectra. The study revealed synchronicity of body temperature oscillations in distantly isolated animals. The data suggest that body temperature oscillations in 10-120-min (circahoralian) period range reflect the effect of an external environmental biotropic factor on temperature control in small mammals and birds.

[Local fractal analysis of noise-like time series by all permutations method for 1-115 min periods].

Results of local fractal analysis of 329-per-day time series of 239Pu alpha-decay rate fluctuations by means of all permutations method (APM) are presented. The APM-analysis reveals in the time series some steady frequency set. The coincidence of the frequency set with the Earth natural oscillations was demonstrated. A short review of works by different authors who analyzed the time series of fluctuations in processes of different nature is given. We have shown that the periods observed in those works correspond to the periods revealed in our study. It points to a common mechanism of the phenomenon observed.

Quantum paraelectricity coexisting with a ferroelectric metastable state in single crystals of NaNbO(3): a new quantum effect.

We experimentally show that, in contrast to the data having been collected so far, some single crystals of NaNbO(3) exhibit a dielectric permittivity of several thousand, at low T, and this value is saturated when approaching 0 K on cooling. Other sodium niobate crystals (having larger dielectric losses) present a first-order phase transition to a ferroelectric phase on cooling (at 80-200 K). The width of the thermal hysteresis in these crystals increases when the temperature of the phase transition obtained on heating decreases. The dielectric permittivity at the phase transition obtained on cooling shows a tendency to increase and saturate, when the thermal hysteresis increases. We identify the ground state of the sodium niobate crystal exhibiting the smallest dielectric losses (in the studied set of crystals) as a novel quantum paraelectric state coexisting with a metastable ferroelectric state. In principle, the crystal presenting the state of quantum paraelectricity can be considered as having the largest (among the crystals studied) thermal hysteresis, for which the low boundary is below 0 K.