Purinergic P2X receptors represent a novel structural type of ligand-gated ion channels activated by extracellular ATP. So far, seven P2X receptors subunits have been found in excitable as well as non-excitable tissues. Little is known about their structure, mechanism of channel opening, localization, and role in the central nervous system. The aim of this work is to summarize recent investigations and describe our contribution to elucidating the structure of the ATP binding site and transmembrane domains of the P2X receptor, we also discuss the expression and physiological roles played by the ATP and P2X receptors in the anterior pituitary and hypothalamus., H. Zemková, A. Balík, M. Jindřichová, V. Vávra., and Obsahuje bibliografii a bibliografické odkazy
The genus Hepatozoon Miller, 1908 (Apicomplexa: Adeleorina) is composed of intracellular haemogregarine parasites that are widely distributed among all tetrapod groups. The present study combines microscopic and molecular data on haemogregarine parasites from lizards in the western Mediterranean. We screened tissue samples and examined blood smears for the presence of species of Hepatozoon from four lizards, namely Algyroides marchi Valverde, endemic to Southeast Spain, Podarcis bocagei Seoane from Spain and Portugal, P. hispanica Steindachner from Spain, and P. lilfordi Günther from Cabrera, Balearic Islands (Spain). Our results show that prevalence and intensity of Hepatozoon parasites vary between and within lizard species from different regions. Algyroides marchi and P. bocagei from Spain had the lowest values, whereas P. hispanica had the highest. Phylogeny based on 18S rRNA gene sequences indicates that most of the new Hepatozoon sequences are part of a clade exclusive from North African and Iberian lizards, except for a single P. bocagei isolate that is found related to another clade including isolates from other reptile host species and rodents. Interestingly, isolates from Algyroides form a distinct monophyletic subgroup, which could be a signal of strict host-specificity within this host genus.
Podáváme přehled molekulárních simulací tekutin s důrazem na originální příspěvky českých pracovišť k rozvoji různých metod. Detailněji diskutujeme metody určení chemického potenciálu, reakční soubor umožňující přimý výpočet fázové rovnováhy v systémech s chemickou reakcí, simulace při konstantní entalpii, metody optimalizace simulací a molekulovou dynamiku polarizovatelných systémů. Zmiňujeme hlavní aktivity v oblasti simulací tekutin i problémy a omezení s výhledem dalšího rozvoje., Ivo Nezbeda, Jiří Kolafa, Martin Lísal., and Obsahuje seznam literatury
Later than in the wet of Europe, it was only in the course of the 12th century that the water wheel caught on in Bohemia and Moravia. At the same time hand-powered mills were still requently being used. Until the end of the 12th century most water mills as well as water courses were the property of princes, so permission to run an existing mil or to build a new one had to be granted. The location, design of and technology used in mediaeval mills in our vicinity have not been archaeologically researched. The hypotheritcal appearance of such mills and what equipment they had can be modelled based on the results of research abroad, since similar structures might also have been in use in mediaeval Bohemia and Moravia., Lucie Galusová, Martina Maříková., and Obsahuje seznam literatury
In the present paper we consider the problem of fitting parametric spatial Cox point process models. We concentrate on the moment estimation methods based on the second order characteristics of the point process in question. These methods represent a simulation-free faster-to-compute alternative to the computationally intense maximum likelihood estimation. We give an overview of the available methods, discuss their properties and applicability. Further we present results of a simulation study in which performance of these estimating methods was compared for planar point processes with different types and strength of clustering and inter-point interactions.
Conditions, under which the elements of a locally convex vector space are the moments of a regular vector-valued measure and of a Pettis integrable function, both with values in a locally convex vector space, are investigated.