Under a moderate water stress (pod water potential, Ψ№, - 1.5 MPa), induced by stopping irrigation for 3 d, the net photosynthetic rate (PN) decreased to 50 %, transpiration rate (£) to 85 %, stomatal conductance to 65 % and chlorophyll (Chi) content to 82 %, while the activities of photosystems (PS) and of some enzymes of the photosynthetic carbon reduction cycle (NAD- and NADP-glyceraldehyde-3-P dehydrogenases, aldolase) were almost without changes. The exceptions were ribulose-5-P kinase and 3-phosphoglycerate kinase, the activities of which were reduced to 55 and 79 %, respectively. Under a severe water stress (5 d without irrigation, VPW -2.1 MPa) all the above characteristics were strongly reduced (PN to 0.5 %, E to 57 %, PS1 to 62 %, PS2 to 37 %, enzyme activities to 48-68 %), but after rehydration the initial activities were restored. The reduction of PN in pods at a moderate water stress is probably related to the decline in activities of 3-phosphoglycerate kinase and ribulose-5-P kinase, while under a severe stress, when PN is lowered almost to zero, the decline in gs and electron transport activities is very important.
The paper present a model of sand sediment transport in water stream in vicinity of a high cylindrical column. It is assumed that an averaged turbulent flow is horizontally layered in vicinity of the cylinder. In each layer the flow around the cylinder is modelled as a potential flow generated by a vertical dipole line. Flow in viscous sub-layer on the surface of thecylinder is neglected. The presented flow model is approximate; however it is simple for use. Trajectories of saltating particles near the cylinder were calculated. Further investigation of such flow will allow a determination of zones where solid particles will collide with the column. That might be useful for prevention of its damage or destruction. and Obsahuje seznam literatury
The microsporidium Vittaforma corneae (Shadduck, Meccoli, Davis et Font, 1990) develops within the target cell cytoplasm. In the present study, green monkey kidney (E6) cells infected at 30°C, 35°C or 37°C with V. corneae developed enlarged multinucleate structures of up to 200 µm in any horizontal dimension made up either of a single cell or of multiple fused cells. A number of epithelial cell types (SW-480, HT-29, Caco-2 and HCT-8) were infected with V. corneae but did not induce the same highly organized structures, suggesting that for the structure to develop, the host cell must be capable of continued mitosis, and not be differentiated or be detaching from the surface matrix. Live cell imaging of infected E6 cells revealed large, multinucleate infected cells characterized by a central focus from which radiated parasite stages and host cell mitochondria. Immunocytochemistry identifying γ and α tubulin suggested that a single centrally-located microtubule organizing centre governed the distribution of parasite stages and host cell organelles, with mitochondria and parasites being eventually transported towards the periphery of the structure. Whole cell patch clamp analysis of infected cells indicated an average five-fold increase in total membrane capacitance, consistent with an enlarged single cell. Scanning electron microscopy revealed cell-like protrusions around the periphery of the structure with the intervening space being made up of parasites and cell debris. Clearly in the case of V. corneae-infected E6 cells the parasite-host cell relationship involves subverting the host cell cytoskeleton and cell volume control, providing the parasite with the same protected niche as does a xenoma.
Der 100. Geburtstag der bedeutenden Persönlichkeit der ethnographischen Forschung inspirierte die Bearbeitung ihrer persönlischen Bibliographie, die im September 1999 als Beilage der Volkundliche Revue herausgegeben wurde.
Die Tradition der Publikationsarbeit in Drahomíra Stránskás Familie war sicherlich eine gute Voraussetzung für umfangreiches Publizieren ihrer Forschungsergebnisse, mit dem sie kurz nach dem Abschluß des Studiums der Karls-Universität anfing. Im Laufe der Zeit erschienen 13 Bücher und selbständige Abhandlungen und über 370 Studien, geschweige denn von kleinen Berichten, Rezensionen usw.
Drahomíra Stránská war auch Autorin von Fragebögen, die mittels der Tschechoslawischen Gesellschaft für Volkskunde an die Korrespondenten im Terrain versandt wurden. Sie war Editorin von Katalogen, Organisatorin von kurzfristigen sowie Dauerausstellungen. In den 50er Jahren hielt sie Vorlesungen in Ethnographie an der Karls-Universität. Ihre Grundarbeit über Volksmöbel wurde nie herausgegeben. and Článek zahrnuje poznámkový aparát.
In the second half of the 20th century, new solutions for the catadioptrical telescopes with spherical surfaces, which could be produced in large series, were sought. One of them was designed by P. P. Argunov. He corrected optical defects of the double-mirrorr system with spherical surfaces using a twin-lens corrector located in front of its secondary mirrorr. Other variants of correctors for double mirrorr devices with spherical mirrorrs were also calculated by G. M. Popov and J. A. Klevcov. Many of them are now commercially manufactured and applied in astronomy. Several instruments, including the Argunov telescope with a diameter of 405 mm and a focal length of 4050 mm, were manufactured by IPP CAS (TOPTEC) in Turnov. This work informs the reader about the basic types of these systems and their optical properties. and Ve druhé polovině 20. století byla hledána nová řešení katadioptrických dalekohledů se sférickými plochami, které by bylo možné vyrábět ve velkých sériích. Jeden z nich navrhl P. P. Argunov. Optické vady dvojzrcadlového systému se sférickými plochami opravil pomocí dvojčočkového korektoru, umístěného před jeho sekundárním zrcadlem. Další varianty korektorů pro dvojzrcadlové přístroje se sférickými zrcadly byly spočteny i G. M. Popovem a J. A. Klevcovem. Řada z nich je dnes komerčně vyráběna a používána v astronomii. Několik přístrojů, včetně Argunovova dalekohledu o průměru 405 mm a ohniskové vzdálenosti 4050 mm, bylo vyrobeno v ÚFP AV ČR, v.v.i., - TOPTEC, Turnov (původně Vývojová optická dílna AV ČR, Turnov). Tato práce informuje čtenáře o základních typech těchto soustav a jejich optických vlastnostech.
Some analogies, related to propagation and interference of photons and electrons under the framework of linear electromagnetic (photon) and electron optics of actual so-called conductive (transporting) media, are presented in the article. The attention is directed concretely to correspondence of motion equations, dispersion relations and ray and interference aspects of balistic and diffuse propagating photons and electrons. The considerations are completed by conditions for the coherence of adequate waves and for the possibility of electrostatic and magnetostatic influence of the interference and the electrical conductance of electron waves and their diffuse fluctuations. and Článek prezentuje některé analogie, vztažené k šíření a interferenci fotonů a elektronů v rámci lineární elektromagnetické (fotonové) a elektronové optiky moderních tzv. mezoskopických vodivých (přenosových) prostředí. Pozornost je konkrétně zaměřena k přiměřenosti pohybových rovnic, disperzních vztahů a paprskových a interferenčních aspektů balisticky a difuzně se šířících fotonů a elektronů. Úvahy jsou doplněny podmínkami pro koherenci příslušných vln a pro možnost elektrostatického a magnetostatického ovlinění interference a vodivosti elektronových vln a jejich difuzních fluktuací.