Correlation studies of open and closed states fluctuations in an ion channel: Analysis of ion current through a large conductance locust potassium channel

Ion current fluctuations occurring within open and closed states of large conductance locust potassium channel (BK channel) were investigated for the existence of correlation. Both time series, extracted from the ion current signal, were studied by the autocorrelation function (AFA) and the detrended fluctuation analysis (DFA) methods. The persistent character of the short- and middle-range correlations of time series is shown by the slow decay of the autocorrelation function. The DFA exponent $\alpha$ is significantly larger than 0.5. The existence of strongly-persistent long-range correlations was detected only for closed-states fluctuations, with $\alpha=0.98\pm0.02$. The long-range correlation of the BK channel action is therefore determined by the character of closed states. The main outcome of this study is that the memory effect is present not only between successive conducting states of the channel but also independently within the open and closed states themselves. As the ion current fluctuations give information about the dynamics of the channel protein, our results point to the correlated character of the protein movement regardless whether the channel is in its open or closed state.Comment: 12 pages, 5 figures; to be published in Phys. Rev.

Trees damage caused by brown bears (Ursus arctos) in the Bieszczady Mountains

Debarking of trees and foraging on the phloem is an economical problem for forestry in North America. Scientists in America investigated the feeding behavior of black bears (Ursus americanus) during the spring while this problem was only partially investigated in Poland. In the Polish Carpathians most damage occurs on coniferous trees such as fir Abies alba, larch Larix decidua and spruce Picea abies

Występowanie pasożytów człowieka w wybranych populacjach na przykładzie badań przeprowadzonych w Śląskiej Wojewódzkiej Stacji Sanitarno-Epidemiologicznej

Frequency of human parasites in selected populations of Silesian region. Epidemiological evaluation of the most frequent human parasitoses in the group of children at age of seven years, in adult patients and in group of Polish citizens coming back from tropics between 1999-2003 was performed. All examined people were Silesian region inhabitants. The biggest average infection prevalence in children from all examined years concerned Enterobius vermicularis, in adult - Giardia intestinalis, while in group of population coming back from tropics - Entamoeba histolytica-like. High percentage of anti-Toxocara canis and Toxoplasma gondii antibodies presence can result from non randomly study group recruitment