National Repository of Grey Literature 90 records found  previous11 - 20nextend  jump to record: Search took 0.00 seconds. 
Transfer of genetic information between parasite and its host
Soukal, Petr ; Hampl, Vladimír (advisor) ; Votýpka, Jan (referee)
Horizontal gene transfer (HGT) is considered a rare evolutionary event. It can take place between unrelated organisms that coexist in an intimate symbiotic relationship. Such relationship have some parasites with its host. HGT between eukaryotic parasite and its host was identified in some holoparazitic and hemiparazitic plants, the most important human protozoan parasites, microsporidias, human blood-flukes, parasitoids and fruit flies.
Comparison of molecular methods for identification of sand flies
Gottfried, Vítězslav ; Dvořák, Vít (advisor) ; Votýpka, Jan (referee)
Phlebotomine sand flies are vectors of important human and veterinary infectious diseases which are distributed mainly in subtropical and tropical areas around the world. The most important transmited infection is leishmaniosis. Over 900 species and subspecies of Phlebotominae subfamily have been described and classified into 32 genera. Their taxonomy has not been fully resolved yet. Morphological identification of each species is time-consuming, some species are even morphologically undefinable. For these reasons the molecular methods of identification are used. The methods described in this bachelor thesis study molecular structures and etologic displays. All these methods had been used for species identification of sand flies and are followed by examples of usage, adventages and disadvantages.
Host-parazite coevolution in aquatic environments
Hubová, Jana ; Petrusek, Adam (advisor) ; Votýpka, Jan (referee)
Antagonistic coevolution is a major driving force in the evolution of host and parasite. Parasites create on their host a time delay, negative frequency-dependent selection, which leads to oscillations in both genotypes of antagonists, as suggested by the Red Queen hypothesis derived for coevolution of host and parasite. The most commonly used systems for the study of host-parasite coevolution in an aquatic environment are (thanks to their features): diatom Asterionella and chytrid Zygorhizidium, aquatic snail Potamopyrgus and trematods Microphallus, water fleas Daphnia and their microparasites. Coevolution between host and parasite causes a number of phenomena, such as maintenance of genetic polymorphism, temporal oscillations of genotype frequencies, the persistence of sexual reproduction, parasite local and host adaptations. This thesis summarizes the current knowledge on the coevolution of the above-mentioned three host-parasite systems in the aquatic environment. Key words: Red Queen hypothesis, host-parasite coevolution, negative frequency-dependent selection, aquatic environments, Asterionella formosa, Potamopyrgus antipodarum, Daphnia.
Parous and nulliparous female detection in blood-sucking nematocera insects
Mračková, Marie ; Votýpka, Jan (advisor) ; Král, David (referee)
Nematocerous insects belong to the order Diptera, one of the largest and worldwide spread groups of insects. Haematophagous species act not only as tormentors, but also as vectors of various pathogens. The first section of this thesis reviews about insetct's reproductive systems, multiple blood-feeding, autogeny and development of ova; the information which are necessary for the transmission understanding. The principal topic of the thesis is reviewing methods for distinguishing parous and nulliparous females, which are commonly used for four Nematoceran groups: mosquitoes (Culidicade), black flies (Simuliidae), sand flies (Phlebotominae) and biting midges (Ceratopogonidae, the genus Culicoides). The section is focused mainly on family Culicidae, because the methods used for mosquitoes were the groundwork for developing methods suitable for the other groups. Some of the procedures, for example counting folicular dilatations or assessing the condition of tracheoles in the ovaries, are used for most of the studied groups; others, like pigmentation of the abdominal wall in the genus Culicoides, can be used only for one group. Knowledge of the female parity is very important for epidemiological and ecological studies, because only parous females, previously blood-fed on infected hosts, can transmit...
Sand flies as hosts of monoxenous and dixenous trypanosomatids
Vondráček, Oldřich ; Votýpka, Jan (advisor) ; Zídková, Lenka (referee)
Sandflies (Diptera: Psychodidae: Phlebotominae) are blood-sucking diptera and important vectors of various pathogens including protozoas from the order Kinetoplastida. In my bachelor work I am dealing with distribution and development of monoxenous and heteroxenous trypanosomatids in sandflies, with special attention to non-leishmania trypanosomatids.
Soil and terrain changes as a result of increased erosion and accumulation processes in selected locations
Votýpka, Jan ; Šefrna, Luděk (advisor) ; Zádorová, Tereza (referee)
Soil and terrain changes as a result of increased erosion and accumulation processes in selected locations Abstract Colluvial soils are formed in areas with increased intensity of soil erosion. Colluvial soils originate as a result of their position in terrain, they are usually found in places where has accumulated erosion material. Very often they are to be found at the around of slopes. Their accumulation horizon is deeper than 25 cm with a great amount of organic carbon buried in it. In my diploma thesis I will attempt to take a closer look at three locations, each having different types of dominant soils. The aim of this diploma thesis is to rebuild the original shape of the terrain before the beginning of the soil erosion process. Keywords: colluvial soil, soil erosion, soil accumulation, land use, digital terrain model (DTM)

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