Maroko patří mezi státy ve Středozemí, kde se vyskytuje bohatá diverzita gekonů. Najdeme zde i několik endemických poddruhů, druhů a rodů. Nedávné molekulárně biologické studie naznačují, že některé populace mohou představovat kryptické druhy, tradičními metodami nerozlišované a dosud nepopsané., Morocco is one of the Mediterranean states with a rich diversity of geckos, including several endemic subspecies, species and genera. Recent molecular biological studies indicate that some populations may comprise cryptic species, not distinguished by traditional methods and previously not recognized., and Andrej Funk, Vladimír Vrabec, Marek Velechovský.
There are 15 members of the Wolf Spiders genus Alopecosa in the Czech Republic, most of which are rare and stenoecious. Although they have been studied for a long time, we do not have much information about their biology and reproduction. Members of this genus show a large variability in courtship and copulatory behaviour., K zajímavým rodům slíďáků náleží rod Alopecosa, na území České republiky známe výskyt 15 druhů rodu. Ačkoli ojedinělé záznamy o biologii a taxonomii rodu máme sice už z 18. stol., jejich studium pokračuje zejména v dnešní době, kdy se do popředí dostává výzkum rozmnožování., and Pavel Just.
We conducted an experiment to assess the predictive capability of a leaf optical meter for determining leaf pigment status of Acer mono Maxim., A. ginnala Maxim., Quercus mongolica Fisch., and Cornus alba displaying a range of visually different leaf colors during senescence. Concentrations of chlorophyll (Chl) a, Chl b, and total Chl [i.e., Chl (a+b)] decreased while the concentration of carotenoids (Car) remained relatively static for all species as leaf development continued from maturity to senescence. C. alba exhibited the lowest average concentration of Chl (a+b), Chl a, and Car, but the highest relative anthocyanin concentration, while Q. mongolica exhibited the highest Chl (a+b), Chl b, and the lowest relative anthocyanin concentration. A. mono exhibited the highest Chl a and Car concentrations. The relationships between leaf pigments and the values measured by the optical meter generally followed an exponential function. The strongest relationships between leaf pigments and optical measurements were for A. mono, A. ginnala, and Q. mongolica (R2 ranged from 0.64 to 0.95), and the weakest relationships were for C. alba (R2 ranged from 0.13 to 0.67). Moreover, optical measurements were more strongly related to Chl a than to Chl b or Chl (a+b). Optical measurements were not related to Car or relative anthocyanin concentrations. We predicted that weak relationships between leaf pigments and optical measurements would occur under very low Chl concentrations or under very high anthocyanin concentrations; however, these factors could not explain the weak relationship between Chl and optical measurements observed in C. alba. Overall, our results indicated that an optical meter can accurately estimate leaf pigment concentrations during leaf senescence - a time when pigment concentrations are dynamically changing - but that the accuracy of the estimate varies across species., Future research should investigate how species-specific leaf traits may influence the accuracy of pigment estimates derived from optical meters., G. Y. Li, D. P. Aubrey, H. Z. Sun., and Obsahuje bibliografii
Autoři pojednávají o vitamínu D, který má mezi ostatními vitamíny specifické postavení, poněkud z jiného úhlu pohledu. Přibližují jeho evoluční původ a historii jeho objevování. Nedostatek vitaminu D vyvolává křivici, nemoc, která je doložena už od starověku. V této souvislosti upozorňují autoři na světově uznávané zásluhy významného, dnes už téměř zapomenutého českého vědce E. H. Kodíčka. Přehledně také popisují metabolismus a transport vitaminu D v organismu a upozorňují, že vitamin D také hraje důležitou úlohu při vzniku chronických nesdělných chorob, jejichž počet celosvětově stále vzrůstá., The authors discuss vitamin D, which has a special position among vitamins, from a somewhat different perspective. They clarify its evolutionary origin and the history of its discovery. A deficiency of vitamin D causes rickets, a disease that has been documented since antiquity. In this context, the authors draw attention to a nearly forgotten Czech scientist E. H. Kodíček of significant merit. They also briefly describe the metabolism and transport of vitamin D in the body and point out that vitamin D also plays an important role in the development of non-communicable chronic diseases, the number of which is increasing worldwide., and Petr Šíma, Bohumil Turek.