Význam ultrafialových znaků v životě různých organismů byl dlouho opomíjen především z toho důvodu, že UV paprsky jsou pro lidský zrak za normálních okolností neviditelné. Jedna z možností, jak si můžeme ultrafialovou podobu živočichů či rostlin zviditelnit, je použití speciálně upraveného klasického či digitálního fotoaparátu. Druhý díl seriálu o ultrafialových vzorech na květech rostlin se zabývá vývojem techniky záznamu UV podoby různých organismů a popisem získávání fotografií, které doprovázejí tento text. Druhá část článku je věnována vybraným druhům našich nejběžnějších rostlin a charakterizaci jejich ultrafialových znaků., The significance of UV characteristics for the life of various organisms has been neglected for a long time. It stems mainly from the fact, that under normal circumstances, UV rays are invisible to the human eye. One of the ways to make the UV appearance of animals or plants visible is to use a specially adjusted classic or digital camera. This second paper deals with the UV patterns on flowers. It focuses on the development of techniques which allow us to capture the UV appearance of various organisms, and provides a methodology with which the accompanying photos were taken. The article also presents selected species of common native plants, with a description of their UV characteristics., and Pavel Pecháček.
The last part of this series about UV characters on plant flowers presents UV images of several other common plant species native to the Czech flora. Attention is also paid to the possibility of using herbarium material for research into the UV characters of plants. The article summarizes recently discovered knowledge along with the evolutionary and ecological factors behind the emergence and significance of UV characters on plant flowers, particularly their role in the communication of pollinators. and Pavel Pecháček.
Ultrakrátké světelné pulzy, tedy pulzy pikosekundové nebo kratší časové délky, jsou velmi významné ve vědě i ve stále větším počtu aplikací. Uvádíme základní vlastnosti světelných pulzů, způsob jejich generace lasery se synchronizací módů a připomínáme některé oblasti jejich použití., Ultra-short light pulses, with pulses of a picosecond or shorter duration, are very important in science as well as in a growing number of applications. We review the basic properties of these light pulses and techniques for their generation by modelocked lasers. We also describe some of their application areas., Petr Malý., and Obsahuje seznam literatury
The remarkable progress in laser technology leads also to a development of techniques of time-resolved optical spectroscopy. The ultrafast laser spectroscopy in the visible spectral region can be now used for investigation of rapid processes with the time resolution of about 10 fs. This paper reviews the experimental background and typical techniques of ultrafast laser spectroscopy. The potentional of ultrafast spectrocopy is illustrated with the results obtained by authors in the field of ultrafast relaxation processes in semiconductors and semiconductor nanostructures., Petr Malý, Petr Němec, František Trojánek., and Obsahuje bibliografii
Ultraslabá emise fotonů se vyskytuje prakticky u všech metabolicky aktivních biologických systémů. Jejím zdrojem jsou elektronově excitované stavy molekul vznikající v průběhu oxidativních reakcí biomolekul. Ultraslabá emise fotonů detekovatelná citlivými a nízkošumovými fotonásobiči a CCD kamerami může najít uplatnění v neinvazivních diagnostických metodách v zemědělství a biomedicíně., Ultra-weak photon emission is present in virtually all metabolically active biological systems. Its source is electronically excited states of molecules produced during the oxidation reactions of biomolecules. Ultra-weak photon emission detected with sensititive and low noise photomultipliers and CCD cameras can be exploited in non-invasive diagnostics in biomedicine and agriculture., Michal Cifra, Pavel Pospíšil., and Obsahuje seznam literatury
Genetic predisposition and social stress may represent important risk factors in etiology of hypertension associated with endothelial dysfunction. Perturbations of endothelial structural integrity are also critical for the pathogenesis of vascular diseases. We examined effect of chronic social stress on structure of aortic endothelium in bord erline hypertensive (BHR) and normotensive Wistar rats. Male BHR – offspring of Wistar mothers and SHR fathers and age-matched W were exposed to 6-week crowding stress (5 rats/cage, 200 cm2/rat). Aortic tissue was processed for electron microscopy and NO synthase activity measurement. Crowding stress significantly increased blood pressure in BHR compared to basal values (140±3 mm Hg vs. 130±3 mm Hg, p<0.05) and reduced enzyme activity by 37 % (p<0.01) in the aorta of BHR. Local slight structural alterations of endothelium were found in non-stressed BHR (p<0.001) when compared with Wistar rats. Chronic stress caused marked (p<0.005) subcellular injury of endothelial cells in aorta of BHR characterized by mitochondrial damage, presence of vacuoles, increased number of lysosomes, Weibel-Palade bodies, changes of intercellular connections and local disruption of endothelium, while only slight changes were seen in Wistar rats. Results suggest increased sensitivity of aortic endothelium of BHR to chronic crowding that may contribute to acceleration of arterial dysfunction., Ľ. Okruhlicová, K. Dlugošová, M. Mitašíková, I. Bernátová., and Obsahuje bibliografii a bibliografické odkazy
Impaired calcium homeostasis and altered expression of Ca2+-binding proteins are associated with cardiomyopathies, myocardial hypertrophy, infarction or ischemia. S100A1 protein with its modulatory effect on different target proteins has been proposed as one of potential candidates which could participate in these pathological processes. The exact localization of S100A1 in human heart cells on the ultrastructural level accompanied with biochemical determination of its target proteins may help clarify the role of S100A1 in heart muscle. In the present study the distribution of the S100A1 protein using postembedding (Lowicryl K4M) immunocytochemical method in human heart muscle has been determined quantitatively, relating number of antigen sites to the unit area of a respective structural component. S100A1 antigen sites have been detected in elements of sarcoplasmic reticulum (SR), in myofibrils at all levels of sarcomere and in mitochondria, the density of immunolabeling at Z-lines being about 3 times and at SR more than 5 times higher than immunolabeling of remaining structural components. The presence of the S100A1 in SR and myofibrils may be related to the known target proteins for S100A1 at these sites., B. Maco, A. Mandinová, M.B. Dürrenberger, B.W. Schäfer, B. Uhrík, C.W. Heizmann., and Obsahuje bibliografii
Endogenous development of Choleoeimeria rochalimai (Carini et Pinto, 1926) Lainson et Paperna, 1999 in the gall bladder of Hemidactylus mabouia (Moreau de Jonnes, 1818) front Belem, Brazil is reported at the fine structural level. Meronts and gamonts develop in the epithelial cells of the gall bladder. Infected cells become enlarged and displaced above the epithelial layer. Developing merozoites, dividing meronts and succession of developing microgamonts from initial nuclear division up to final microgamete differentiation are described. In addition to wall forming bodies, mature macrogamonts possess a large inclusion or cisterna with fine granular contents.
The ultrastructure of the endogenous stages - merozoites, microgamonts, macrogamonts and oocysts, of Sarcocystis muriviperae from the snakes Vipera palaestinae and Coluber jugularis is described. Snakes were infected via white mice fed on sporocysts obtained from naturally infected snakes of the same species. Snakes examined 4 days post-infection contained only young and premature gamonts. Infection in snakes sacrificed on day 7 post-infection consisted predominantly of mature microgamonts and macrogamonts; snakes examined on day 10 post-infection revealed only oocysts. The fine structure of the endogenous stages from the two snakes, including size and contents of the wall-forming bodies, was identical, confirming their suggested conspecificity. Observed endogenous stages also conformed in their major details with the same developmental stages of other Sarcocystis species studied from other snakes and mammalian definitive hosts and from in vitro culture. However, they differed from the latter in size and contents of the wall-forming bodies. The observed fertilization process was reminiscent of that described earlier in S. bovicanis.
In anabiotic statě mesophyll cells of both species were filled with vacuoles, chloroplasts were round and without outer envelope and starch. During an 8-d rewatering period cell water saturation deficit continuously (from 80-85 % to 15- 20 %) declined, eliptic shape of chloroplasts was restored, their outer membrane was recovered, grana stacks grew in size and were ordered, stroma was denser, and starch grains started to be formed. The processes were more rapid in Ramonda serbica than in Haberlea rhodopensis. The course of processes was different in irradiated plants than in those kept in the dark.