Vapor condensation, whether due to dew or fog, may add a stable and important source of water to deserts. This was also extensively assessed in the Negev, regarded as a dew desert. Dew deserts necessitate a large reservoir of vapor, and are therefore confined to near oceans or seas. Yet, examples of such deserts are scarce. Here we try to assess whether the Tabernas Desert in SE Spain can be regarded as a dew desert, and may therefore facilitate the growth of certain organisms that otherwise would not survive the dry season. We analyze some of the abiotic conditions of four relatively dry months (June, July, August, September) in the Tabernas and Negev deserts (with the Negev taken as an example of a dew desert) during 2003–2012. The analysis showed substantially lower values of relative humidity (by 10–13%) in the Tabernas in comparison to the Negev, with RH ≥95% being on average only 0.9–1.1 days a month in the Tabernas in comparison to 9.7–13.9 days in the Negev. Our findings imply that the Tabernas Desert cannot be regarded as a dew desert, suggesting that rain will be the main factor responsible for the food web chain in the Tabernas.
The cytology of a new microsporean parasite Microsporidium epithelialis sp. n. from the intestinal epithelial cells of the freshwater oligochaete Tubifex sp. (Tubificidae) is described. The microsporean occurred together with an actinosporean of the genus Triactinomyxon, which was found between the epithelial cells. The merogonic and sporogonie stages (mature spores included) of the microsporean parasite are monokaryotic. An individual sporophorous vesicle surrounds each spore. The fixed and stained spore has an average dimension of 1.9-2.5 x 0.9-1.2 pm. The spores are oval with a characteristic surface layer, showing ornamentation-like projections, which are in close contact to the exosporc. A short polar filament forming three to four coils traverses the polaroplast with two lamellar layers. The ultrastructure and other characteristic features of this microsporean parasite are distinct from those of the microsporean species described so far from oligochaetes.
Melatonin mediates many physiological processes in animals and plants. To examine the potential roles of melatonin in salinity tolerance, we investigated the effects of exogenous melatonin on growth and antioxidant system in cucumber under 200 mM NaCl stress conditions. The results showed that the melatonin-treated plants significantly increased growth mass and antioxidant protection. Under salinity stress, the addition of melatonin effectively alleviated the decrease in the net photosynthetic rate, the maximum quantum efficiency of PSII, and the total chlorophyll content. Our data also suggested that melatonin and the resistance of plants exhibited a concentration effect. The application of 50-150 μM melatonin significantly improved the photosynthetic capacity. Additionally, the pretreatment with melatonin reduced the oxidative damage under salinity stress by scavenging directly H2O2 or enhancing activity of antioxidant enzymes (including superoxide dismutase, peroxidase, catalase, ascorbate peroxidase) and concentrations of antioxidants (ascorbic acid and glutathione). Therefore, the melatonin-treated plants could effectively enhance their salinity tolerance., L. Y. Wang, J. L. Liu, W. X. Wang, Y. Sun., and Obsahuje seznam literatury
Experimental measurement is performed on a simple fibre-mass system: a moving mass coupled with the frame by a fibre. Dynamic response of the mass is measured. The same system is numerically investigated by means of a simple multibody model. The influence of the model parameters on the coincidence of results of experimental measurements and of simulations are evaluated. The simulations aim is to create a phenomenological model of a fibre, which will be utilizable in fibre modelling in the case of more complicated mechanical or mechatronic systems. and Obsahuje seznam literatury
This essay aims to describe hitherto unknown notes of aesthetics lectures given by August Gottlieb Meißner (1753-1807) at Prague University. It compares these notes (made by a certain Wagner, and deposited in the Wienbibliothek im Rathaus) with notes deposited in Czech libraries, and seeks to determine their place chronologically amongst notes made by others attending Meißner’s lectures over the years. The most important difference in content between the earlier known notes and Wagner’s is Meißner’s negative attitude towards the Schlegel brothers. This attitude slightly alters our existing notion of his views on the relationship between literature and morality. Taken alone, the collections of notes in Czech libraries had led one to conclude that this Prague ordinarius was an ardent libertine, who dared, even at a conservative Austrian university, to push for the autonomy of art, including a thorough split between art and morality, regarding not only works of art, but also, to a certain extent, the artists themselves. By contrast, the Vienna MS as a matter of priority restricts this split to art, and limits it to the higher, moral aims of the artist as citizen. His approach to questions of morality and to the Schlegel brothers demonstrates that while Meißner considered himself part of the liberally enlightened current of contemporaneous literature, which made moving the emotions the central aim of art, he was no longer an adherent of upandcoming Romanticism with its extreme conviction about unlimited authorial liberty, which stemmed from the philosophical Idealism of the times. This attitude to the Schlegel brothers also suggests that Wagner attended Meißner’s lectures in aesthetics and rhetoric in the winter of 1800/1., Tomáš Hlobil., and Obsahuje bibliografické odkazy
Let X be a completely regular Hausdorff space, E a boundedly complete vector lattice, Cb (X) the space of all, bounded, real-valued continuous functions on X, F the algebra generated by the zero-sets of X, and µ: Cb (X) → E a positive linear map. First we give a new proof that µ extends to a unique, finitely additive measure µ: F → E + such that ν is inner regular by zero-sets and outer regular by cozero sets. Then some order-convergence theorems about nets of E +-valued finitely additive measures on F are proved, which extend some known results. Also, under certain conditions, the well-known Alexandrov’s theorem about the convergent sequences of σ-additive measures is extended to the case of order convergence.