Low astigmatism in practice is corrected using a soft contact lens with spherical or rotationally aspheric design of optical surfaces. The refractive error is then corrected only partially and the residual is uncorrected refractive error has a certain influence on vision. In this contribution an analysis of the influence of such a correction is performed. It is compared experimentally the optimum sphero-cylindrical correction using trial spectacle lenses and the correction using a soft contact lens with aspheric design and dioptric power of a spherical equivalent. and V praxise u nízkého astigmatismu provádí korekce pomocí měkké kontaktní čočky se sférickým čirotačně asférickým designem optických ploch. Refrakční vada je poté korigována pouze částečně a zbytková nevykorigovaná refrakční vada má určitý vliv na kvalitu vidění. V tomto článku je analyzován vliv takovéto korekce. Je provedeno experimentální porovnání případu optimální sférocylindrické korekce pomocízkušební brýlové obruby a korekce měkkou kontaktní čočkou s asférickým designem a dioptrickou hodnotou sférického ekvivalentu.
Cílem textu je seznámit čtenáře se vznikem a principem periodického zákona a jeho přímou aplikcí, tj. periodickou tabulku prvků. První část textu se věnuje spojitosti mezi protonovým číslem a chemickými vlastnotmi prvků. Ve druhé části jsou poznatky z první části uvedeny do souvislostí s nejdůležitějšími atomárními vlastnostmi prvků: atomovým poloměrem, elektronegativitou, ionizační energií a elektronovou afinitou. Text je doplněn o řadu poznámek pod čarou, které rozšiřují nebo doplňují výklad. Poznamenejme ještě, že čtenář zběhlý v angličtině může další informace najít na anglické odnoži Wikipedie pod heslem Periodic table (http://en.wikipedia.org/wiki/Periodic_table)., Vít Svoboda., and Obsahuje bibliografii
Two stress imposing systems were used: a rapid stress developed by allowing excised leaves to loose water by transpiration, and a slow stress developed by withholding watering of potted plants. Carboxylating enzymes reacted differently on both types of stress. Rapid stress increased ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPCO) activation, but both activities (initial and total) showed little variation with stress. Under slow stress the activation did not change, although both activities decreased much under stress. Phosphoenolpyruvate carboxylase (PEPC) showed a deep decrease of activity under rapid stress, nevertheless, a certain recovery was found under extreme stress. On the other hand, under slow stress the activity of PEPC showed a linear increase with decreasing relative water content. The ratio between physiological and maximal activity increased slightly under both types of stress. The activity of malic enzyme did not change under rapid stress, and decreased linearly under slow stress. and J. Marques da Silva, M. C. Arrabaça.
In this study, we clarify the taxonomic status of Allencotyla pricei based on a re-examination of paratypes and voucher specimens. Four important characters are added to previous descriptions: the vagina is ventral; the cirrus is absent; the eggs are fusiform and have two polar filaments (one about 3.5 times longer than the other); and, there are two flat sclerites at each side of the dorsal trident-shaped sclerite in the clamps. A comparison of A. pricei with species from all the genera of the Heteraxininae, including Allencotyla mcintoshi, indicates that A. pricei has several exclusive characters, i.e., a ventral vagina, vaginal armature, two additional dorsal sclerites in the clamps, a ventral mouth, and a question mark-shaped ovary. The combination of characters found in A. pricei is not shared with any other species within the Heteraxininae. In view of these features, A. pricei is assigned to a new genus, Pseudoallencotyla gen. n., as P. pricei comb. n.
Leaf traits have long been recognized as influential factors in the acquisition and processing of resources by plants. However, there is less knowledge of between-species variations in seasonal changes in leaf traits and trait interrelationships. Therefore, we examined variations in leaf area (LA), dry biomass (DM), specific leaf area (SLA), and leaf gas-exchange parameters in one non-native and seven native tree species under field environmental conditions, in a karst area in China subjected to desertification. Measurements were taken three times during the growing season. The results show that the seven native trees had higher LA, DM, and water-use efficiency (WUE) than the non-native Cinnamomum camphora. In contrast, all the native tree species except Ligustrum lucidum had lower photosynthetic rates (PN) than the non-native species. In all species, the relationship between LA and DM was less variable than the relationship between SLA and LA. However, leaves of the non-native C. camphora and native species Sterculia lanceolata, Cleidiocarpon cavalerei and Cyclobalanopsis glauca were highly sensitive to seasonal conditions, leaves of Sapindus mukorossi and Ligustrum lucidum were less sensitive to seasonal changes, and leaves of Syzygium cumini and Cephalomappa sinensis were insensitive. An understanding of leaf traits will aid the selection of suitable species for land restoration. and L.-Y. Wei ... [et al.].