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The impact of herbivores on plant population dynamics: The importance for biological control of invasive plants
Šulcová, Hana ; Dostál, Petr (advisor) ; Kindlmann, Pavel (referee)
Herbivory is one of the most important relations between plants and animals. The herbivores affect plant populations not only by grazing, but also by trampling and disturbing the vegetation. Herbivores have also great potential to affect the population dynamics of particular plant species. The aim of this thesis is to evaluate the effect of herbivores on plant population dynamics and to interpret it in relation to biological control of invasive plants. When evaluating the effect of herbivores, it is necessary to keep in mind the fact that herbivores don't affect only plants but also each other through direct as well as indirect competition. The use of different herbivore species to supress the invasive plants may not necessarily be effective. The range of the effect of herbivores on plant population dynamics depends also on the environmental conditions. Habitats with infrequent disturbances and high competition levels among plants increase the effect of biological control, because high competition facilitates competitive exlusion of the target plant species. Different life-histories of plants play are also important in terms of biological control mainly the life-span and the endurance of the seed bank affect the results. Monocarpic species with short-lived seed bank can be relatively easily reduced by...
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The Socialization of Czech Political Actors. The Attitude of Czech Politicians towards the Iraq Invasion in 2003
Vojtová, Veronika ; Šlosarčík, Ivo (advisor) ; Karásek, Tomáš (referee)
In the 1990s when enlargement of Euro-Atlantic organizations was slowly becoming reality, a theory exploring interaction between an organization and its member states gradually resigned from primary perception of the state as a socialized actor (socializee) and this concept was substituted by the notion of political actors. It was the theory of socialization that became more and more important in terms of examining impact of political organizations on political representatives of Member States, their behaviour and possible interaction between them. This recent and dynamic theory was often confronted with obstacles, especially in terms of its theoretical anchoring. Even within the framework of ongoing academic debate, this theory did not obtain clear recognition. Researches examining causal relationship between socialization and subsequent behaviour of politicians come up with various results. The aim of this thesis is to enter into this debate and verify the hypothesis assuming that the decisions of foreign policy actors are influenced by socialization of respective political actor. Verification of the hypothesis was carried out on example of Iraq in 2003 by the means of media coverage and official documents content analysis. Possible socialization of six foreign policy makers was examined on the...
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The role of dipeptidyl peptidase-IV and homologous proteases in migration and invasion.
Fejfarová, Edita ; Rösel, Daniel (referee) ; Bušek, Petr (advisor)
Migration and invasion are processes which naturally occur in organism during embryogenesis, immune reactions or wound healing. These processes are very important factors in some serious diseases like rheumatoid arthritis and carcinogenesis. There is no doubt about contribution of proteases in these processes-many of them degrade extracellular matrix and thereby facilitate the movement of cells. While dipeptidylpeptidase-IV cleaves solely two amino acids from N-terminus so it is not considerably involved in ECM degradation. DPPIV and its homologues recognize peptides with proline on penultimate position, which causes resistance to ordinary types of proteases. Substrates of DPPIV and its activity homologues include chemokines implicated in signalling of migration - their cleavage and thus inactivation present DPPIV and DPPIV-like molecules as modulators of cell migration signalling in choriocacinoma, neuroblastoma, on Sézary cells or epithelial cells migrating in response to injury. Another activity of some DPPIV-like proteases is binding to the extracellular matrix proteins, when are helping in the attachment of cells and thus affect the migratory ability of the cells like ovarian cancer cells, prostate cancer cells, melanoma cells or kidney cells. Effects on migration and invasion have also...
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The role of NADPH oxidase and ros in invadopodia formation
Hanušová, Kristýna ; Vrbacký, Marek (referee) ; Brábek, Jan (advisor)
Invadopodia as specific organelles enabling tumour cells movement, spreading over the organism and ultimately formation of metastasis are possible and promising targets of tumour therapy. Recently, many interesting facts about assembly and mechanism of function of invadopodia were discovered. Invadopodia are centres of ECM degradation by extra-cellular proteases facilitating an invasion of tumour cells. For creation of invadopodia a precisely localized increased production of ROS is necessary. ROS work as crucial signalling molecules and participate in many processes resulting in invadopodia formation. ROS in tumour cells are produced by specific extra-mitochondrial NADPH oxidases (Nox). Several regulatory molecules participating in activation and localization of Nox to invadopodia have been discovered recently (Tks organizer proteins). Furthermore, a regulatory role of Src kinase in ROS production and subsequent invadopodia formation was confirmed. Key words: ECM degradation, invadopodia, invasion, proteases, Nox, ROS, Src kinase, Tks proteins
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Biology and ecology of invasive species bryozoan Pectinatella magnifica
SKUHROVEC, Tomáš
Biology and ecology of invasive species bryozoan Pectinatella magnifica The aim of this bachelor theses is to create a literary overview containing available information about biology and ecology of the species Pectinatella magnifica. This invasive bryozoan originates from North America. Its occurrence in the Czech Republic was first recorded in the 30s of the twentieth century around the rivers Labe and Vltava. However its first massive presence was reported in the year 2003 in the sand pit Cep in the national protected landscape area Třeboňsko. From the reservoir Cep, it spread into other locations (sand pits Cep I, Vlkov, Veselí, Veselí I., Horusice and into ponds Hejtman, Nový Kanclíř, Staňkovský and Podřezaný, where it found suitable conditions for its life. It can be found in other locations in the Czech Republic as well, but its occurrence does not reach such big amounts. Outside our country it can be found in other European states and in some Asian countries. Pectinatella magnifica is a colonial fresh water animal preferring asexual reproduction. The colonies have yellow and brown colour, a structure of a hard gelatine and a spherical or oblong shape. Pectinatella magnifica is an effective filter feeding invertebrate, its diet consists of phytoplankton, especially diatoms. The most significant ecological factor effecting its seasonal dynamics is the temperature, as it is a thermophilic species preferring the optimal temperature of 20°C. If the temperature sinks bellow 20°C, the colonies start to decline and the hibernating units, called statoblasts, are released. Pectinatella magnifica tends to occur in slightly alkaline fresh water with a lower conductivity (bellow 200 S.cm-1). Regarding the trophy, water, qualified from oligotrophic to mesotrophic, is suitable for Pectinatella magnifica. It is found especially on submerged branches and on driftwood in the areas of river banks. Within this species, the association with other water animals has been proved, for example with small crustaceans and snails. In the cavity of coelom, the sexual evolution of parasitic species Trichonosema and Tetracapsula has been proved, these species represent a group of significant parasites of salmonids. To be able to estimate and describe the influence of this species, recently spreading in biotopes, which it inhabits, it is necessary to get acquainted with its biology.
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Distribution and selected ecological characteristics of \kur{Echinocystis lobata}
MÜLLEROVÁ, Anna
Echinocystis lobata is an European invasive species introduced from North America. Distribution of Echinocystis lobata was studied in the Pilsen region alongside main rivers, including Berounka, Úhlava, Úslava, Mže and Radbuza. The maps of distribution were created from information acquired from literature and field exploration. The germination experiments were conducted in climabox and garden experiments.
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Biological flora of Wild Cucumber (\kur{Echinocystis lobata} Torr. et A. Gray)
KUČEROVÁ, Radka
The thesis deals with biological flora of Wild Cucumber (Echinocystis lobata Torr. et A. Gray). The first chapter is directed to the systematic classification, further work deals with morphology, distribution, habitat conditions, life cycle, relationships with other organism and problems of invasion. Invasion is currently topical problem, because it occurs to force out of original species of plants.
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Ecological study of invasive species \kur{Lupinus polyphyllus}
HURTOVÁ, Jaroslava
Species Lupinus polyphyllus is one of the most hazardous invasive species in the Czech Republic and its increasing occurence represents a threat of native biodiversity not only in the flora of conservation areas. Influence of management experiments on invaded communities was studied on permanent plots founded on three localities in the Šumava National Park. The role of nitrogen fixed in this invasion was explored by analyzing of soil samples. Influence of allelopathic inhibition of invasive species on some coexisting native species was tested in the laboratory experiment.
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Distribution of wild cucumber, Echinocystis lobata Torr. et A. Gray, in the Hradec Králové region.
HOLEČKOVÁ, Veronika
The aim of this work was elaboration of known locations invasive liana Echinocystis lobata (Michx.) Torr. et A. Gray in Královéhradecký region, but completion of new locations from my own cross ? country research too. I have acquired 42 locations by literal excerption, three new locations by my own cross ? country research and next three locations by contacting several persons. Primary distribution area is in North America, but currently in the Czech Republic it takes place very fast, mainly off shores of rivers or brooks. From here this species is expanding to surroudings, first of all along water corse, on meadows and dust ? hole. I would like to show the reality how dangerous this species can be for natural habitats.
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