Činorodý zemědělec, který se denně pohybuje na poli a v lese, přesně ví, jaké druhy kamení se válejí v okolí jeho domku. Zkušenost generací mu napověděla, z čeho je vhodné stavět zídku, z čeho základ domu, jaká hlína byla dobrá na vymazání trámů na povalu nebo kachlů v kamnech a z čeho se pálily cihly a vápno. V lomu za vsí, odkud pochází kámen na podezdívku a který byl zatopen vodou po průvalu, se jako dítě koupal. Současné městské prostředí, které koncentruje stále větší počet obyvatel, takovou přímou zkušenost se skalami, kameny a půdou odepřelo již několikáté generaci lidí, která vnímá umělé prostředí s dominanntním asfaltem a betonem. Ojediněle použitý přírodní dekorační kámen ve formě plastiky či obkladu na zdi je už dovezený, nemá svůj přirozený tvar a postrádá kontinuitu svého geologického okolí in situ, tedy na místě svého vzniku. and Veronika Štědrá.
The aim of this study is to define the possible effects of vegetable oils used as vitamin E vehicle on the electrical activity of the rat heart. To test the possible effects of vitamin E vehicles we studied the effect of i.p. injected corn oil, hazelnut oil or peanut oil on the action potential parameters recorded in both papillary and left atrial muscle strips. Four experimental groups were used. The control group was injected (i.p.) with distilled water, while the three remaining groups received injections of corn oil, hazelnut oil, or peanut oil for five weeks (in a dose of 0.4 ml/kg/day - minimum amount of oil in which vitamin E could be dissolved). We used borosilicated (15-20 MΩ) capillary electrodes and intracellular action potentials (AP) were recorded in isolated papillary and left atrium muscle strips. While administration of three different types of vegetable oil had no significant effect on AP parameters of papillary muscle, they significantly prolonged the repolarization phase of AP in atrial strips. These results show that vegetable oils used as vitamin E vehicles may alter the electrical activity of the heart in a tissue-dependent manner. The present data indicate that the possible effect of vegetable oil vehicles should be kept in mind while evaluating the possible effects of in vivo vitamin E administration., S. Ozdemir, M. Ayaz, T. Tuncer, M. Ugur, B. Turan., and Obsahuje bibliografii
The present research was conducted to assess physiological responses of ‘Malas-e-Saveh’ (Malas) and ‘Shishe-Kab’ (Shishe) pomegranates to water of different salt content and electrical conductivity (1.05, 4.61, and 7.46 dS m-1). Both cultivars showed a reduced trunk length due to salinity. Relative water content and stomatal conductivity of both cultivars were significantly reduced under salt stress, but ion leakage increased. In both cultivars, total chlorophyll (Chl) and carbohydrates decreased with rise in salinity, while proline accumulation increased. With salinity increment, the Chl fluorescence parameters (maximum photochemical efficiency of PSII and effective quantum yield of PSII) declined significantly in both cultivars, with higher reduction observed in Shishe. Generally, more Na+ accumulated in shoots and more Cl- was observed in leaves. Cl- accumulation increased by salinity in leaves of Malas, but it was reduced in Shishe. The K+/Na+ ratio in leaves decreased in both cultivars by salinity increment. Malas was less affected by osmotic effects of NaCl, but it accumulated more Cl- in its leaves. Thus, Malas might be more affected by negative effects of salinity., M. Khayyat, A. Tehranifar, G. H. Davarynejad, M. H. Sayyari-Zahan., and Obsahuje bibliografii
The article examines the long-term changes and the age homogamy of marriages that took place in the Czech Republic between 1920 and 2000. The analysis of data acquired from a study of vital registration is divided into a descriptive part - describing the age structure of the marriage market and the absolute degree of age homogamy - and an exploratory part - creating a log-linear model of the structure and changes of relative age homogamy. Three hypotheses are formulated in connection with the latter part of the analysis, of which the hypothesis about increasing age homogamy seems acceptable. Results from the descriptive analysis and the models show that age homogamy has been increasing during the 20th century, both in the case of first marriages and remarriages. The hypothesis about the greater degree of age heterogamy in the case of remarriages can also be accepted, while the testing of the third hypothesis, that the older the marital partners are the more heterogamous their age structure, proved inconclusive and requires further investigation.
Parazitické stádium velkých mlžů (řád Unionida) vytváří velmi těsné spojení mezi těmito druhy a jejich rybími hostiteli. Tento článek představuje variabilitu mezidruhových interakcí na příkladech středoevropských druhů., The parasitic stage of freshwater mussels (order Unionida) constitutes a tight host-affiliate linkage between mussels and their host fish. This article presents the variability of interactions using the Central European species as a model group., and Karel Douda.
Velemyši, dříve nazývané krysy obláčkové, jsou největší myšovití hlodavci žijící endemicky na Filipínách. Velemyš dinagatskou (Crateromys australis), považovanou za potenciálně vyhynulou, se nám podařilo znovuobjevit 37 let od jejího posledního (a zároveň prvního) nálezu a vědeckého popisu. To bylo také impulzem k návrhu nového českého jména velemyši pro celou skupinu obláčkových krys. Velemyš dinagatská byla nalezena na severu ostrova Dinagat. Nyní je řazena mezi kriticky ohrožené druhy. Ohrožené jsou také ostatní druhy této skupiny, a to zejména kvůli masivní těžbě dřeva a nerostných surovin a tím ničením jejich přirozeného prostředí. Proto je cílená ochrana je nezbytná k přežití tohoto i ostatních druhů velemyší., Cloud rats are the largest murid rodents endemic to the Philippines. The Dinagat Cloud Rat (Crateromys australis), considered to be potentially extinct, was rediscovered in the north of Dinagat Island after 37 years from its first discovery and scientific description. We have also proposed a new Czech name. The species is now listed as critically endangered. All cloud rats are threatened by the destruction of their natural habitats by logging and mining. Targeted protection is therefore essential for their survival., and Milada Řeháková, Václav Řehák.