Polishing of aspheric optical surfaces is done by different approach compared to traditional polishing of spheres and flats by full-aperture tools and methods. Zonal, sub-aperture methods of grinding polishing are used. These methods are meant not only for basic operations but also for deterministic form correction. Compared to full-aperture processing methods they require precise positioning of the tool and a stable and readily characterizable tool producing very smooth surface. Companies producing optical machines, developed wide range of sub-aperture processing tools and methods more or less fulfilling such requirements. Each method or tool has its strong and weak characteristics so it is necessary to consider actual application during choosing one. The article gives overview of methods used at present and their properties. and Leštění asférických ploch představuje zcela jiný přístup než leštění sférických a rovinných ploch. Jsou využívány metody zonálního broušení a leštění, a to jak za účelem náhrady celoplošného opracování povrchu, tak i pro korektivní leštění, které má za cíl zlepšit tvarovou přesnost vyrobené optické plochy. Na rozdíl od celoplošného obrábění sférických povrchů, vyžaduje tento přístup přesné polohování nástroje a stabilní, dobře charakterizovatelný nástroj zanechávající po opracování povrch s minimální drsností. Firmy zabývající se vývojem optických obráběcích strojů rozvinuly celou řadu přístupů k realizaci nástrojů s požadovanými vlastnostmi. Každý z přístupů má své výhody, obvykle však i řadu nevýhod, proto je důležité dobře zvolit nástroj s ohledem na jeho cílové použití. Článek podává přehled o aktuálně používaných metodách a nástrojích a jejich vlastnostech.
This essay is a response to the discussion paper by Daniela Tinková on Enlightenment and vernacularization. The author welcomes the approach that sees Enlightenment as a debate, since to see it as a battle is to confuse logical truth with fiction. It should be said, however, that Tinková’s model attributes an active role only to the elites, and overstates the idea of the disappearance of the state. In the 18th century we may not have had a national state, but we did have a state. A common fallacy among Czechs regarding the timing and mechanism of the emergence of the National Revival is to ignore that state and consequently espouse the unrealistic thesis that the national agitation arose among a free people in the repressive period preceding March 1848. They also fail to appreciate the importance of the constitutional monarchy post-1861, when for the first time Czechs were able to engage in free political debate. As a result it was not until the late 19th century that a belated Czech Enlightenment took hold, inspired largely by France and Scotland. Home-grown Enlightenment traditions had by then been forgotten.
The last step for biosynthesis of c type cytochromes, indispensable for photosynthesis in cyanobacteria and plants, involves heme transport across the membrane and its covalent attachment to the apoprotein. In cyanobacteria, heme attachment occurs in the thylakoid lumen and probably also in the periplasm and requires at least four proteins, believed to be organized in intrinsic membrane protein complex. To allow isolation and identification of such complex, CcsB protein was tagged with 6xHis tag on its N terminus and expressed under the strong psbAII promoter in the cyanobacterium Synechocystis sp. PCC 6803. Similarly, CcsA protein was tagged with FLAG tag under the control of the same promoter. Although expression of both proteins under strong cyanobacterial promoter did not increase steady state contents of the CcsB protein, the fusion tags did not influence properties of the CcsB and CcsA proteins and the resulting mutants had the same phenotype as the wild type. Protein fraction containing CcsBHis protein was partially isolated from the solubilised membranes under native conditions.
The genus Maxvachonia Chabaud et Brygoo, 1960 (Ascaridomorpha: Cosmocercidae) is a poorly known group of parasitic nematodes. Species of Maxvachonia are native to Madagascar-Australo-Papuan Region, where they are known to parasitise frogs, snakes and skinks. Unfortunately, most of Maxvachonia species have been inadequately described. In the present study, we report the native species Maxvachonia chabaudi Mawson, 1972 from the intestine of the invasive marine toad Rhinella marina (Linnaeus) in Australia for the first time. We speculate that the marine toads infected with M. chabaudi are likely related to their eating skinks or the similarity in diet/habitat/ecology between the toad and the skinks. The detailed morphology of M. chabaudi was studied using light microscopy and, for the first time, scanning electron microscopy, based on the newly collected specimens. Some characters important for the specific diagnosis of M. chabaudi are reported for the first time, including each lip with distinct inner flanges, the location of vulva varying from anterior to posterior of the oesophageal bulb and the presence of single medio-ventral precloacal papilla. An identification key to the species of Maxvachonia is provided.
The natriuretic peptides - atrial, brain and C-type - were discovered during the last tw enty years. Their effects on cardiovascular, renal, cerebral and other tissues through guanylyl cyclase were uncovered. Over the past decade natriuretic peptides (NPs) became a very useful tool in the management of heart failure patients. Results of many clinical trials have shown that BNP and NT-proBNP are helpful for diagnosis of heart failure. They are also independent markers of prognosis not only in heart failure patients but also in patients with other cardiovascular diseases. Recently published data document the utility of NPs in guiding treatment of heart failure patients. In this article, we focus on basic biochemical and physiological characteristics of NPs as well as on their significance in management of heart failure patients. Some limitations and pitfalls of NPs levels interpretation in diagnosing heart failure are also discussed., J. Krupička ... [et al.]., and Obsahuje seznam literatury
Areas built by Neogene volcanic complexes are located in the central and eastern part of Slovakia covering about 10 % of the territory. They belong to the Inner Western Carpathians. The research was divided into two phases. In the first one, primary data from the Geochemical atlas of SR concerning groundwater from neovolcanic complexes were statistically processed and analyzed. In the second phase, field and laboratory methods, methods of classification, statistical and graphical methods were used. The results showed that the chemical composition and physical properties of groundwater are formed by the character of the rock environment, by the depth of circulation and also by properties of source waters. Main features of chemical composition reflecting the neovolcanic origin of groundwater are low TDS value varying by analyzed samples between 85.82 mg l-1 (Veľká Lehota) and 396.48 mg l-1 (Pukanec), presence of SiO2 in the amounts up to 41.76 mg l-1 (Podzámčok), presence of aggressive CO2 in amounts up to 25.19 mg l-1 (Lučina). Five groundwater chemical types were distinguished. The most frequent was the Ca-MgHCO3-SO4 type. In majority cases only primary compounds of the groundwater composition were found. Only in the case of Remetské Hámre groundwater the anthropogenic compound - nitrates was estimated. and Oblasti budované neogénnymi vulkanickými komplexmi sa na Slovensku vyskytujú v jeho centrálnej a východnej časti, pričom tvoria približne 10 % celkovej rozlohy územia. Geologicky patria k Vnútorným Západným Karpatom. Výskumné práce boli rozložené do dvoch fáz. V prvej z nich boli štatisticky a graficky spracované zdrojové dáta z Geochemického atlasu SR týkajúce sa fyzikálnych vlastností a chemického zloženia podzemných vôd pochádzajúcich z neovulkanických komplexov. V druhej fáze boli vykonané terénne a laboratórne práce, použité klasifikačné, štatistické a grafické metódy na analýzu získaných dát. Výsledky výskumu ukázali, že chemické zloženie a fyzikálne vlastnosti podzemných vôd sú formované charakterom horninového prostredia, hĺbkou obehu a tiež vlastnosťami zdrojových vôd. Hlavnými parametrami odrážajúcimi pôvod podzemnej vody v neovulkanitoch sú nízke hodnoty celkovej mineralizácie, ktoré sa u analyzovaných vôd pohybovali medzi 85,82 mg l-1 (Veľká Lehota) a 396,48 mg l-1 (Pukanec), prítomnosť SiO2 v množstvách až do 41,76 mg l-1 (Podzámčok), prítomnosť agresívneho CO2 v množstvách až do 25,19 mg l-1 (Lučina). Bolo rozlíšených 5 chemických typov podzemných vôd. Najčastejšie sa vyskytoval typ Ca-Mg-HCO3-SO4. Vo väčšine prípadov boli v chemickom zložení podzemných vôd dokumentované iba primárne zložky. Len v prípade podzemnej vody z Remetských Hámrov bola určená antropogénna zložka - dusičnany.
Previously published multidisciplinary studies in the Miramichi and Bouctouche rivers (New Brunswick, Canada) noted significant changes in fish health parameters, including elevated tissue levels of organic contaminants and a wide range of physiological disturbances, in mummichog Fundulus heteroclitus (L.) from a site on the Miramichi River that received bleached kraft pulpmill and municipal effluent. The present study reports differences in the abundance of individual parasite species, as well as parasite infracommunity and component community composition, in mummichog from both rivers. These differences were evaluated in relation to host (size, condition, immune function, tissue organochlorine contaminant levels) and environmental (faecal coliform counts, salinity, temperature) data derived from the previously published studies. Overall, 18 parasite species were identified, the most common of which were Ascocotyle sp. larv., Ornithodiplostomum sp. larv., Posthodiplostomum sp. larv., and Proteocephalus filicollis (Rudolphi, 1802). There were broad differences in parasite community structure and composition between rivers and within rivers, the most prominent pattern being a pronounced difference between sites in the upper and lower estuary of each river that was likely driven by salinity. Mean infracommunity richness was also positively related to faecal coliforms (considered here as a surrogate measure of eutrophication via municipal sewage), and both were highest at the most polluted site. We noted no other significant relationships. Thus our data suggest that the parasite communities in these two estuaries were primarily structured by large upstream / downstream ecological gradients in salinity, and secondarily by eutrophication due to pollution by municipal and industrial effluents. Overall, our results highlight the value of coordinated multidisciplinary studies for understanding the factors that shape parasite abundance and community structure.