V článku je popsán původ, domestikace a současný význam kapra obecného (Cyprinus carpio) jako nejdůležitějšího druhu rybničních chovů v Evropě. Stručně je vysvětlena technologie chovu kapra a její vlivy na ekosystémy rybníků., The origin, domestication process and present value of Common Carp (Cyprinus carpio) as the most important species in pond aquaculture in Europe is described. The technology of carp production and the impact of carp culture on the ecosystems of fishponds are briefly explained., Josef Matěna, Martin Flajšhans., and Obsahuj seznam literatury
Haldy (odvaly), které na Ostravsku vznikaly jako průvodní jev dolování černého uhlí v první polovině 20.stol, se již staly typickým krajinným prvkem této oblasti. Později zde byly snahy dolováním pozměněnou krajinu „uzdravit“ finančně nákladnými technickými rekultivacemi. Výstupy z našich studií prokázaly, že spontánní sukcese na nerekultivovaných haldách probíhá rychleji a společenstva bezobratlých jsou zde lépe strukturovaná. Navíc nerekultivované haldy podporují populace ochranářsky cenných druhů bezobratlých. Jednoznačně proto doporučujeme haldy ponechat spontánní sukcesi, před finančně náročnými technicky vedenými rekultivacemi., The spoil heaps in Ostrava were created during mining of black coal in the first half of the 20th century. Later, there were efforts to “heal” the landscape by technical reclamations, which are rather expensive. Our studies showed that spontaneous succession on non-reclaimed spoil heaps is faster then succession on their reclaimed counterparts. The communities of invertebrates on non-reclaimed spoil heaps are also more mature and contain rare species in comparison with the reclaimed ones., and Jiří Hodeček, Tomáš Kuras.
The article examines the Czech educational praxis toward integration of immigrant children. Although the number of immigrant children increased during past several years, Czech national educational policy still lacks specific measures which would systematically promote inclusive education and integration of immigrant children. The article aims to describe the experience of schools with integration of immigrant children at schools, and to identify the most important barriers that prevent full participation of immigrant children according to accounts of interviewees. Based on 21 in-depth interviews with representatives of school staff in 11 Prague public-sector základní škola (ISCED 1+2) with higher share of immigrant children (5-20 %), the paper provides insight into diverse into the ways how schools deal with immigrant children, families´ acculturation strategies and inclusive educational policy. The article concludes with a discussion of “immigrant paradox”, highly achieving minorities (particularly Vietnamese students)., Kateřina Vojtíšková., and Obsahuje seznam literatury
Herbivorous insects are often highly specialised, likely due to trade-offs in fitness on alternative host species. However, some pest insects are extremely adaptable and readily adopt novel hosts, sometimes causing rapid expansion of their host range as they spread from their original host and geographic origin. The genetic basis of this phenomenon is poorly understood, limiting our ability to predict or mitigate global insect pest outbreaks. We investigated the trajectory of early adaptation to novel hosts in a regionally-specialised global crop pest species (the cowpea seed beetle Callosobruchus maculatus). After experimentally-enforced dietary specialisation for nearly 300 generations, we measured changes in fitness over the first 5 generations of adaptation to 6 novel hosts. Of these, C. maculatus reproduced successfully on all but one, with reduced fitness observed on three hosts in the first generation. Loss of fitness was followed by very rapid, decelerating increases in fitness over the first 1-5 generations, resulting in comparable levels of population fitness to that observed on the original host after 5 generations. Heritability of fitness on novel hosts was high. Adaptation occurred primarily via changes in behavioural and phenological traits, and never via changes in offspring survival to adulthood, despite high heritability for this trait. These results suggest that C. maculatus possesses ample additive genetic variation for very rapid host shifts, despite a prolonged period of enforced specialization, and also suggest that some previously-inferred environmental maternal effects on host use may in part actually represent (rapidly) evolved changes. We highlight the need to examine in more detail the genetic architecture facilitating retention of high additive genetic variation for host shifts in extremely adaptable global crop pests., Thomas N. Price, Aoife Leonard, Lesley T. Lancaster., and Obsahuje bibliografii
Many insects masquerade as parts of plants, such as bark or leaves, or mimic poisonous organisms in order to defend themselves against predators. However, recent studies indicate that plants may mimic insects and other arthropods to deter herbivores. Here, I report visually similar white structures of plants and arthropods in Japan and suggest they are part of a mimicry complex. Young shoots covered with white trichomes or waxy substances may mimic wax-producing insects, such as woolly aphids, coccids and caterpillars, potentially resulting in reduced herbivory. Since wax-producing insects would reduce plant quality and quantity, be distasteful and attract natural enemies, herbivorous insects and mammals may avoid such white shoots. Furthermore, fungus-infected insects, gregarious braconid cocoons, spider egg sacs and froth made by froghopper nymphs or blasticotomid sawfly larvae are also conspicuously white and impose risks for herbivorous insects. Thus, these white structures may be mimicry models for white shoots and are likely to be part of a defensive mimicry complex. Although this study focuses on defence against herbivores, there are simultaneous physiological roles for white colouration that will not be discussed in depth here., Kazuo Yamazaki., and Obsahuje bibliografii