A determination key to the structural types of seattered green using the air multispectral photography

Scattered green was studied in Czechoslovakia by means of the air multispectral photography and of the field observation. According to various repartition and canopy 19 structural types of seattered green were derived.     

Ecotoxicological contamination processes: Interaction with vegetation (a review)

Up-to-date crop production concentrates on the maximisation of plant matter production, both by optimum utilization of solar energy by plants and by the application of additional energy. Therefore a natural strategy is being developed aimed at combining the physiological functions of the assimilation organs with their external shaping and strengthening their variety in space and area. As demonstrated by many deposition studies, this effect is contradictory to the factors conditioning the low deposition capacity of plant covers. A high level of particle, gas and solution deposition increases the danger of food chain contamination and has a negative impact on plant production. Data concentrated on transport values of pollutants and their long-term dynamics in stands could be used for the selection of ideal crop types; therefore every effort should be directed towards selection and breeding.     

Lipid Composition in Scrapie-Infected Mouse Brain: Prion Infection Increases the Levels of Dolichyl Phosphate and Ubiquinone

Abstract: The neutral and phospholipid composition of mouse brain infected with scrapie prions was investigated. During the later stages of this disease, the level of dolichol decreased by 30% whereas the level of dolichyl phosphate increased by 30%. In terminally ill mice, there was also a 2.5-fold increase in both total ubiquinone and its reduced form. Furthermore, α-tocopherol was elevated at this stage by 50%. In contrast, no changes were observed in phospholipid amount, in phospholipid composition, and in phosphatidylethanolamine plasmalogen content during the entire disease process. The fatty acid and aldehyde composition of individual phospholipids remained unaltered as well. No modifications could be detected in cholesterol content. Thus, the majority of membrane lipids in scrapie-infected mouse brain are modified in neither quantity nor structure, but specific changes occur to a few polyisoprenoid lipids. This specificity indicates that, although prions accumulate in lysosomes, the infection process is not associated with a general membrane destruction caused by lysosomal enzyme leakage.     

Ontogenetic change in effectiveness of chemical defence against different predators in Oxycarenus true bugs

Many prey species change their antipredator defence during ontogeny, which may be connected to different potential predators over the life cycle of the prey. To test this hypothesis, we compared reactions of two predator taxa – spiders and birds – to larvae and adults of two invasive true bug species, Oxycarenus hyalinipennis and Oxycarenus lavaterae (Heteroptera: Oxycarenidae) with life-stage-specific chemical defence mechanisms. The reactions to larvae and adults of both true bug species strikingly differed between the two predator taxa. The spiders were deterred by the defences of adult bugs, but the larval defences were ineffective against them. By contrast, birds attacked the larvae considerably less often than the adult bugs. The results indicate a predator-specific ontogenetic change in defence effectiveness of both Oxycarenus species. The change in defence is likely linked to the life-stage-specific composition of secretions in both species: whereas secretions of larvae are dominated by unsaturated aldehydes, secretions of adults are rich in terpenoids, which probably serve dual function of defensive chemicals and pheromones. Our results highlight the variation in defence between different life stages and the importance of testing responses of different types of predators.     

Distinct subcellular localization of β-tubulin epitopes in the adult mouse brain

 A panel of monoclonal antibodies specific of α-tubulin (TU-01, TU-09) and β-tubulin (TU-06, TU-13) subunits was used to study the location of N-terminal structural domains of tubulin in adult mouse brain. The specificity of antibodies was confirmed b immunoblotting experiments. Immunohistochemical staining of vibratome sections from cerebral cortex, cerebellum, hippocampus, and corpus callosum showed that antibodies TU-01, TU-09, and TU13 reacted with neuronal and glial cells and their processes, whereas the TU-06 antibody stained only the perikarya. Dendrites and axons were either unstained or their staining was very weak. As the TU-06 epitope is located on the N-terminal structural domain of β-tubulin, the observed staining pattern cannot be interpreted as evidence of a distinct subcellular localization of β-tubulin isotypes or known post-translational modifications. The limited distribution of the epitope could, rather, reflect differences between the conformations of tubulin molecules in microtubules of somata and neurites or, alternatively, a specific masking of the corresponding region on the N-terminal domain of β-tubulin by interacting protein(s) in dendrites and axons. Accepted: 11 November 1996     

Body mass changes in waders (Charadrii) in a high arctic area at northern Taimyr, Siberia

Body mass data were collected for 5 species of tundra waders during 6 breeding seasons to study variation in nutrient reserves relative to high arctic climatic conditions and the stage of reproduction. Structural size was accounted for by the 1st Principal Component of external linear measurements: wing length, bill length and tarsus length. SandpipersCalidris spp. were on average lighter in phenologically late seasons, while mass of Turnstones (Arenaria interpres) was similar in all years. Mass of waders was lower during brood-rearing than during incubation. Body mass during pre-nesting was most variable between years, reflecting the unpredictable weather conditions in this period. Monogamous species (KnotsCalidris canutus and Turnstones) began to breed earlier, and were on average, as heavy during the pre-nesting period as during incubation. In contrast, species with a proven or suspected rapid double-clutch breeding system (Little StintsC. minuta and SanderlingsC. alba) began to breed later and had during the laying period masses close to those of adults attending broods, and lower than during incubation. Body mass of the two latter species and Curlew Sandpipers (Calidris ferruginea) varied during incubation, reaching peak at 7 to 13 days after clutch completion.

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Zusammenfassung Von fünf Tundra-Watvogelarten wurden in sechs Brutperioden Daten zur Körpermasse gewonnen, um die Dynamik der Energiereserven in Abhängigkeit von den klimatischen Bedingungen der Hocharktis und vom Fortpflanzungsstadium zu analysieren. Der Einfluß der Körpermaße auf die Masse wurde bei der statistischen Auswertung durch die Einbeziehung der 1. Hauptkomponente von Flügel-, Schnabel- und Tarsuslänge berücksichtigt. StrandläuferCalidris spec. erwiesen sich in späten Jahren als leichter, während in der Körpermasse von Steinwälzern (Arenaria interpres) keine Unterschiede festgestellt werden konnten. Die Körpermasse aller untersuchter Arten war während der Betreuung der Jungvögel geringer als während Brütezeit. Die Masse in der Zeit vor der Brut variierte in Übereinstimmung mit den wechselnden Wetterbedingungen in den einzelnen Jahren am stärksten. Monogame Arten (KnutCalidris canutus und Steinwälzer) begannen früher mit der Fortpflanzung; ihre Körpermasse in der Phase von der Brut und während der Brütezeit war im Mittel etwa gleich. Im Gegensatz dazu begannen Arten, bei denen ein Doppelbrutsystem nachgewiesen wurde oder vermutet wird (ZwergstrandläuferC. minuta und SanderlingC. alba), später mit dem Nestbau, wobei die Körpermasse auf ein Niveau absinkt, das dem während der Betreuung der Jungvögel nahekommt und geringer ist, als das während der Brütezeit. Bei den beiden letzten Arten sowie beim Sichelstrandläufer (Calidris ferrugunea) veränderte sich die Körpermasse während des Brütens und erreichte ein Maximum zwischen dem 7. und dem 13. Tag nach Beendigung der Eiablage.

     

Cytotaxonomic study ofTragopogon L. in czechoslovakia

Karyotypes ofTragopogon orientalis L. subsp.orientalis, T orientalis L. subsp.leiocarpos (Sauter)Trnka,T. pratensis L.,T. minor Miller,T. dubius Scop. subsp.dubius andT. dubius Scop. subsp.major (Jacq.)Vollmann were studied. The occurrence in Slovakia ofT. pratensis was karyologically proved.     

Identification of two Thormählen-positive compounds from melanotic urine by gas chromatography—mass spectrometry

The isolation of two Thormählen-positive compounds from the urine of a patient with malignant melanoma and the elucidation of their structure by gas chromatography—mass spectrometry is described. The compounds were isolated using a poly-N-vinylpyrrolidone column and separated by preparative thin-layer chromatography. After elution they were analyzed by gas chromatography and gas chromatography—mass spectrometry as their trimethylsilyl derivatives and after hydrolysis also as their tert.-butyldimethylsilyl derivatives. The results showed the main Thormählen-positive compound A to be the glucuronide of 5-hydroxy-6-methoxyindole, whereas the minor compound AX appeared to be the glucuronide of its isomer 6-hydroxy-5-methoxyindole.     

Amylase iso-enzymes in primates of the families Lemuridae,Cebidae, Cercopithecidae,Hylobatidae and Pongidae

This paper presents the first data in the alpha-amylase isoenzymes in primates of the families: Lemuridae, Cebidae, Cercopithecidae, Hylobatidae and Pongidae. By means of agar-gel electrophoresis of urine samples from 33 individuals belonging to ten species of the above mentioned families a total of 14 different variants of amylase heterogeneity were found.     

Species concept and morphological differentiation of strains traditionally assigned to Micrasterias truncata

The morphological and molecular differentiation of the Micrasterias truncata (Corda) ex Bréb species complex was investigated. In total, 17 strains traditionally assigned to M. truncata were isolated from different European localities (Czech Republic, southwest France, Ireland), and obtained from public culture collections. In addition, strains of the morphologically similar species, M. decemdentata (Nägeli) W. Archer and M. zeylanica F. E. Fritsch, were also included. Molecular phylogenetic analysis based on trnG^ucc intron sequences revealed five well supported clades. Two Australian strains assigned to M. truncata var. pusilla G. S. West formed a lineage sister to M. zeylanica. This was evident from a concatenated phylogeny based on small subunit rDNA and trnG^ucc intron sequences. The isolated position of these strains was also illustrated by parallel landmark‐based geometric morphometric analysis of cell shapes. The strains NIES 783 and NIES 784 probably represent a separate species. Particular analysis, including additional strains, is needed to resolve the relationship inside this lineage. The second phylogenetic lineage, containing two strains of M. truncata var. semiradiata (Kützing) Wolle, was also different from other strains on the basis of morphometric data. We suggest recognizing this variety as a separate species, Micrasterias semiradiata L.A. Brébisson ex F. T. Kützing. The remaining three clades formed a firmly supported group of the ‘core’M. truncata recognized by both molecular markers. However, neither any morphological, morphometric, nor geographical pattern was detected among members of these three clades. This pattern could be caused by a relatively recent origin of these lineages that may represent a sympatric, truly cryptic species. Strains attributable to traditional morphologically defined variety M. truncata var. neodamensis were nested within the ‘core’M. truncata.