Measurements of ultrastructural characteristics of chloroplast thylakoids are important for studies of ontogenic or ecological limitations of leaf photosynthetic functions. Most frequently, volumetric proportion of thylakoids in the chloroplast is measured; however, such measurement does not provide a direct information about the surface area of thylakoids which is most important from the functional point of view. Therefore, we adapted the stereological method using "local vertical windows" for estimating thylakoid surface area in the chloroplast volume and compared thus obtained surface density results with results of conventional volume density measurements. The methods were tested in the study of chloroplast ultrastructure in the leaves of plants of two maize (Zea mays L.) hybrid combinations, 2013×CE810 and CE704×CE810, developing in control and chilling conditions. Correlation analysis revealed a tight relationship between the granal/intergranal thylakoid surface density and volume density results, both indicating that under chilling conditions the development of the system of thylakoids in maize leaves is suppressed, while the difference is more pronounced in CE704 than in CE810 genotype, known to have a better photosynthetic performance. and L. Kubínová, J. Kutík.
Materials on the basis of cycloolefin copolymers (COC) are suitable for subchondral defect repairs. The objective of this study was to evaluate the influence of surface modification of COC and COC/LLDPE blends on the viability and gene expression of chondrocytes. Human chondrocytes were incubated on the surface of the studied materials. Half of the materials were plasmatically modified with a subsequent type II collagen application. The gene expression of matrix metalloproteinases (MMP-1,-3,-13), pro-inflammatory cytokines (IL-1, TNF-alpha) and apoptotic molecules (BAX, Bcl-2) was evaluated using quantitative Taq-Man PCR after 48 h incubation. Chondrocyte viability was evaluated by the MTT test after 2, 4 and 8 days of incubation. The synthesis of MMPs was measured by ELISA assay in cell culture medium after 48 h of incubation. Chondrocytes incubated on plasmatically modified in contrast to unmodified materials demonstrated significantly increased gene expression of IL-1 (p<0.05), MMP-1 and MMP-3 (p<0.05 for both comparisons) as well as MMP-13 (p<0.001). Increased gene expression was confirmed by significantly increased production of active forms of particular MMPs into the cell culture medium. Unlike surface unmodified polymers, the modified materials showed timedependent reduction of chondrocyte viability. The gene expression of TNF-α and apoptotic molecules by chondrocytes was not significantly changed by different materials. Cycloolefin copolymers and their blends may represent suitable materials for tissue engineering, however, their surface modification followed by collagen type II application may, at least under in vitro conditions, reduce the viability of chondrocytes and induce their pro-destructive behavior. The potential benefit or disadvantage of surface modifications of materials for osteochondral defect repairs needs to be further elucidated., M. Polanská ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Brachylaimus fuscatus metacercaria develops unencysled in the terrestrial snail Ponsadenia duplocincta. For the first time in a larval stage of the genus Brachylaimus a distinctive surface structure has been observed. This structure of net-like interconnected ridges of the tegument was present on the whole body surface with the exception of the anterior part. Beside this structure scanning electron microscopy revealed five types of papillae. Three types, dome-like papillae, papillae with a finger-like process, and hollow papillae with a short cilium, were localized mainly in the suckers. Hollow papillae without a cilium were arranged in groups or singly around the ventral sucker and genital pore. Ribbed papillae were observed on the ventral body surface.
The surface tension of blood assessed in a group of 71 healthy subjects (24 men and 47 women) by the drop method at a temperature of 22 °C was 55.89 . 10~3 N.m-1, S.D. = 3.57 . 10~3 N.m-1. It did not correlate with age or sex of the examined subjects nor with any of the following variables: red cell sedimentation rate, blood haemoglobin levels, number of erythrocytes, total serum cholesterol, total serum triacylglycerols, creatinine blood levels, ALT and AST activity. The surface tension of blood and other body fluids can play an important part not only in the genesis and development of decompression sickness but also in other processes in the organism.
Dějinám surrealismu a funkcionalismu se už věnovalo mnoho badatelů. Málo však zatím víme o vzájemném vztahu obou těchto –ismů. V české architektuře se počátkem třicátých let 20. století zformoval kroužek vědeckých funkcionalistů kolem Karla Teigeho. Většinou šlo o přísné racionalisty, kteří u architektury popírali její umělecký statut a u architektonické formy opomíjeli její psychologické působení. Pod vlivem Teigeho se kriticky vymezovali vůči Le Corbusierovi. Když se však Teige začal sbližovat se surrealismem, sotva mohl pominout Bretonovy výpady proti přepjatému racionalismu v moderní architektuře, zvlášť když je Breton v roce 1935 zopakoval v Praze. Teigeho rovněž zaujala Bretonova výzva k překonání rozporů mezi skutečností a snem, vědou a uměním, racionalitou a emotivitou. Pražský teoretik neustoupil od ideálu vědecké architektury, avšak připustil, že funkcionalismus bude ještě vědečtější, začne-li pomocí psychoanalýzy zkoumat dopad své architektonické formy na lidskou duši. Teze a hypotézy tohoto druhu se objevily v knize Teigeho Sovětská architektura (1936), v předmluvě ke knize Ladislava Žáka Obytná krajina (1947), najdeme je též v textech architektů Karla Janů, Jiřího Štursy, Jiřího Voženílka, Jiřího Krohy, případně i Víta Obrtela, který však tehdy stál mimo okruh Teigeho. Pomocí psychoanalytických argumentů, převzatých zjevně od Georgese Bataille, začal též Teige kritizovat sklony sovětské architektury třicátých let k pompézní a výhružné monumentalitě. Zájem českých vědeckých funkcionalistů o surrealismus a psychoanalýzu nevyústil v nějakou „surrealistickou architekturu“. Vedl však k obohacení architektonické formy o emotivně působivé složky, ba k jistém sblížení funkcionalismu a organické architektury. Rovněž Le Corbusierova tvorba přestala být okruhem Teigeho tabuizovaná. Nejzajímavější svědectví o tomto obratu přináší Volmanova vila v Čelákovicích (1938–1939) od týmu Janů – Štursa, jakási koláž sesbíraná z takových lecorbusierovských elementů, jaké se během třicátých let staly předmětem debaty surrealistů. and To date, many art historians have devoted themselves to the study of the history of Surrealism and Functionalism. Still, we do not know very much of the actual interrelationship between both –isms. A group of scientific Functionalists formed itself around Karel Teige in Czech architecture in the early 1930s. These were mostly orthodox rationalists who denied that architecture could have any artistic status and who also ignored the psychological impact of architectural form. Under Teige’s leadership they pointed a critical finger at Le Corbusier. But as Teige began to get closer to Surrealism, he could hardly ignore Breton’s onslaughts against agitated rationalism in modern architecture, particularly so when Breton had repeated such attacks in Prague in 1935. Teige was also impressed by Breton’s call to overcome the contradictions existing between reality and dream, science and art, between rationality and emotivity. Even though the Prague theoretician had not abandoned his ideal of science-based architecture, he did admit that Functionalism would be still more scientific if, using psychoanalysis, it would explore the impact of its architectural form on the human soul. Theses and hypotheses of this kind appeared in Teige’s Sovětská architektura (Soviet Architecture, 1936), in a preface to the book by Ladislav Žák Obytná krajina (Inhabited Landscape, 1947), and may also be found in the texts written by architects Karel Janů, Jiří Štursa, Jiří Voženílek, Jiří Kroha, eventually Vít Obrtel, who, however, had stood outside Teige’s circle at that time. Employing psychoanalytical arguments taken over from Georges Bataille, Teige also began criticizing the tendencies in Soviet architecture of the 1930s towards what he called pompous and menacing monumentality. The interest of Czech scientific Functionalists in Surrealism and psychoanalysis did not lead to the emergence of any ‘Surrealist architecture’. It was, however, instrumental in enriching architectural form by adding emotional components, even leading to a certain affinity between Functionalism and organic architecture. Le Corbusier’s architecture also ceased to be tabooed by Teige’s circle. The most interesting testimony to that shift comes in the Volman Villa in Čelákovice near Prague (1938–1939), built by a team of architects Janů – Štursa, representing kind of collage collected from Le Corbusieresque elements, features that eventually came to be discussed by Surrealists during the 1930s.
A study of the actinosporean fauna of oligochaetes from a freshwater salmon farm in Northern Scotland was carried out from October 1996 to August 1998. Following the examination of 28,387 oligochaete worms belonging to the families Tubificidae, Lumbriculidae, Naididae and Enchytraeidae, five types of echinactinomyxon (four previously described), six types of raabeia (five previously described), three types of synactinomyxon (all previously described), four types of aurantiactinomyxon (three previously undescribed), one type of triactinomyxon (previously described), one type of neoactinomyxum (previously undescribed) and one type of siedleckiella (previously undescribed) were identified. The triactinomyxon type was released from unidentified immature oligochaetes. Of the twenty-one types of actinosporeans found, thirteen types were released from Tubifex tubifex (Müller), three types were released from Lumbriculus variegatus (Müller), three types from both L. variegatus and T. tubifex and two types from immature oligochaetes.
Soil samples were collected from the whole territory of the Czech Republic, and the presence of entomopathogenic nematodes from the families Steinernematidae and Heterorhabditidae was evaluated by Galleria traps method. Of the 342 samples studied, 53.8% were positive for entomopathogenic nematodes with only one positive for the heterorhabditid, Heterorhabditis megidis Poinar, Jackson ct Klein. 1987. Of steinernematid species, Steinernema kraussei (Steiner, 1923), Steinernema felliae (Filipjev, 1934), Steinernema affine (Bovicn, 1937), Steinernema intermedium (Poinar, 1985), Steinernema bicornutum Tallosi, Peters et F.hlers, 1995, and Steinernema sp. belonging to “glaseri" group were recovered. With several exceptions the nematodes occurred in all the ecosystems, subecosystcms and habitats studied. They were more frequently found in samples from tree than open habitats, from light than heavy soil, and their incidence was ubiquitous, rather than patchy. Dependence of entomopathogenic nematodes on insect incidence seemed to be elementary for both their incidence and abundance. The sampling sites with moderate to severe insect abundance were 66.5 % positive for nematodes while those with slight or no visible insect abundance only 15 %.
Myxozoan parasites of the genus Kudoa Meglitsch, 1947 are associated with post-mortem tissue degradation that causes great financial losses to commercial fisheries. Kudoa thyrsites (Gilchrist, 1924) is a species with a very wide host range including commercial tunas, mackerels, salmonids and flatfishes. A sample of 190 fishes of 18 species from the Madeira Archipelago and 30 Atlantic chub mackerel, Scomber colias Gmelin, and 30 blue whiting, Micromesistius poutassou (Risso), from the Portuguese mainland coast were examined for the presence of species of Kudoa. The prevalence of Kudoa spp. was 80% in M. poutassou and 60% in S. colias. No spore was detected in S. colias from Madeira, which was confirmed by specific PCR screening of the muscle from all individuals of S. colias. SSU rDNA analysis revealed that M. poutassou and S. colias from the Portuguese mainland coast were infected with K. thyrsites, an economically important myxozoan parasite. Both sequences were identical with sequences of the eastern Atlantic K. thyrsites genotype, including that from the type host of this parasite. This is the first report of K. thyrsites from M. poutassou and S. colias. The fact that spores of species of Kudoa were not detected in fishes screened in the Madeira Archipelago may be explained by various ecological factors, such as the absence of a continental shelf, a short insular shelf, and oceanic waters with low productivity, all resulting in reduced abundance of benthic organisms. Consequently, it is possible that as yet unknown annelid definitive hosts of Kudoa spp. are absent or very rare near Madeiran coasts.