The analysis of information coding in neurons requires methods that measure different properties of neuronal signals. In this paper we review the recently proposed measure of randomness and compare it to the coefficient of variation, which is the frequently employed measure of variability of spiking neuronal activity. We focus on the problem of the spontaneous activity of neurons, and we hypothetize that under defined conditions, spontaneous activity is more random than evoked activity. This hypothesis is supported by contrasting variability and randomness obtained from experimental recordings of olfactory receptor neurons in rats., L. Košťál, P. Lánský., and Obsahuje biblografii a biblografické odkazy
The UV-Vis absorption spectra of detergent-isolated hydrogen-and deuterium-bonded reaction centers (RCs) from Rhodobacter sphaeroides PUC 705Ba were examined as a function of temperature between 20 and 55 °C. The enthalpy and entropy of denaturation for the specimens was determined, revealing that their process of thermal denaturation is significantly different. Deuterium-bonded RCs are most stable at 37 °C, rather than at room temperature, and undergo a "cold denaturation" as the temperature is lowered to room temperature. At room temperature the addition of 1,3,5-heptanetriol brought the deuterium-bonded RC back to its more stable configuration. Hence the hydrogen bonding interactions in the RC do influence its conformation and this is reflected in the microenvironment of its associated pigments. and A. E. Ostafin ... [et al.].