National Repository of Grey Literature 24 records found  beginprevious15 - 24  jump to record: Search took 0.00 seconds. 
Coevolution of avian ectoparasites in the tropics
Gajdošová, Magdalena ; Munclinger, Pavel (advisor) ; Votýpka, Jan (referee)
Host-parasite associations are born by cospeciations or by host switches. Feather lice have traditionally been used as model parasites for studying these events and underlying ecological factors. By now tens of analyses have addressed comparisons of host and parasite phylogenies to study cospeciations and host switches in lice, however, these analyses are strongly biased towards the temperate zone. Tropical environment could provide new insight into the origin of host-parasite interactions, because it is ecologically unique. This work aims to supplement the knowledge of host-parasite associations in lice using coevolution analyses of two feather lice genera and their passerine hosts in tropical rainforest in Cameroon. It shows that lice in the tropics cospeciate rarely. To assess whether host switches are non-random and occur preferentially between hosts with specific traits, this work also analyses relations between parasite genetic distances and hosts' trait similarities. No effect of host morphology and spatial distribution was found. However, genetic distances of the lice strongly correlate with genetic distances of their hosts.
An intensity of plumage bacterial load and resistence against bacteria-caused feather degradation in tropical birds of Afromontane areas of Cameroon
Kyptová, Markéta ; Javůrková, Veronika (advisor) ; Adamík, Peter (referee)
Microorganisms are considered to be a significant selective factor affecting bird's life strategies. The body cover, including feather, is occupied by a wide range of bacteria that are in their host in different interactions. Group of microorganisms degradate keratins of feather is still most studied and most species of birds have them in feather. This feather degrading bacteria can disrupt the wear and its function and thus cause great losses to its fitness. Therefore, it seems likely that these feathers degrading bacteria and microorganisms generally play a significant role in creating defence mechanisms against their negative effects. One of the most important defence mechanisms to protect feathers against the action of microorganisms is the deposition of melanin pigments. This diploma thesis deals with the analysis of the total bacterial load in feathers and its resistance against bacterial degradation in 47 species of birds trapped in afromontan areas of western Cameroon. The specific aim of the thesis was to determine differences in the total number of bacteria in plumage in species with different life strategies, especially feeding and reproductive strategies. At the same time, the phtilochronological analysis of the quality of the plumage was performed and in vitro experiments were tested...
Seasonality of reproduction in tropical birds
Kačírek, Vojtěch ; Sedláček, Ondřej (advisor) ; Tomášek, Oldřich (referee)
The aim of of this paper is to summarize the knowledge of reproduction seasonality of tropical birds. Work includes characteristics of individual tropical environment and changes in abiotic conditions, focusing on the question, in what sense are tropics aseasonal and what is not. The work includes an overview of methodologies for collecting data during field research focused on monitoring reproduction in birds. The main part of this work is to compare the differences between biogeographic regions, regions and their stimuli, which most commonly lead to the creation of seasonal reproduction, followed by a comparison of individual functional groups of birds (food guilds). Powered by TCPDF (www.tcpdf.org)
Language of advertising
Krchňáková, Leontina ; Kitzlerová, Jana (advisor) ; Rajnochová, Natalie (referee)
This work is devoted to the Russian language advertising, which examines in an independent system. It aims are analyzing the text of Russian advertising in terms of its information and formal structure. It focuses on a specific aesthetic qualities of language, which the text uses. Work is further focused on the categorization of neologisms and neologisation of the Russian advertising. Next focus is on loanwords from the English language. Used research methods are descriptive and comparative. The outcome of this work is the systematization of information and the formal structure in the advertising text, we have also been shown to frequent infiltration of artistic means in the language of advertising and its active neologisation. Work can be used as a suitable basis for specifics in Russian advertising texts or a different language studies, possibly for development of marketing strategies and marketing research.
Altitudinal migrations in animals and their study methods
Zenklová, Tereza ; Sedláček, Ondřej (advisor) ; Klvaňa, Petr (referee)
Migration as a response to the seasonality of the environment is common in many animal taxa. Strong fluctuation of the climate is usually connected to regions in the temperate zone, quite common is in the tropical regions as well. Typically, it is even more pronounced in high altitudes. In such environment, many animals could migrate altitudinaly as a response to changes in the climatic conditions or food abundance. But determinants of altitudinal and long-distance latitudinal migrations could be different. The objective of this work is to determine factors influencing altitudinal migrations in diverse taxa (particularly in birds and bats) and in different biogeographical regions. I am trying to find some common features of migrating species, such as diet or temperature and rain tolerance. Especially tropical species are partial migrants, which means that only some individuals of the population migrate. I will discuss common features of such migrating infividuals. Study methods of altitudinal migration will be a part of this research as well. The work will be primarily concentrated on tropical regions.
Carboniferous tropical ecosystems of euramerican province
Frojdová, Jana ; Opluštil, Stanislav (advisor) ; Sakala, Jakub (referee)
This thesis deals with the tropical terrestrial ecosystems of Late Carboniferous (Pennsylvanian) time. It is especially focussed on description of the Carboniferous tropical forest and its components. Introductory parts of the thesis deal with the general characteristics of Carboniferous period, including fauna and flora, distributions of continents and how was the climate of this period. Second part follows the characteristics of particular components of the Carboniferous tropical forest, i.e. of individual plant groups and genera, and their ecological demands. Characterised are plants and their assemblages in tropical lowlands as well as in upland areas, rarely preserved in sedimentary record. In the next part I characterise the dynamics of the forest of Carboniferous tropics and discuss potential mechanisms which controlled the floristic changes including plant extinction. The role of climate changes, which had great influence on vegetation, is discussed as the possible main control. In the separate chapter I describe extinction of arborescent lycopsids. Key words: ecosystem, tropical forest, lowland, climate changes
Tropical Solar Freezer
Trčálková, Miroslava ; Suchánek,, Petr (referee) ; Nový, Alois (advisor) ; Donaťáková, Dagmar (advisor)
The aim of this study was to design a tropical solar freezer, which would be entirely self-sufficient. The requirement was to install solar freezer to developing countries with insufficient technical infrastructure. The construction of solar freezer is located near Lake Victoria, in a town called Kisumu, Kenya in Africa. The main idea was to create a simple look that matches the use of the building. My suggestion was to create two separate buildings. The first is a small object, serving as a gatehouse. The second object is a large U-shaped, in which there are all the necessary facilities for the operation of freezer and facilities for staff. The supporting system consists of cast-in-place reinforced concrete columns. Solar panels located on the roof of freezers protect the building from direct sunlight. Diagonal steel rods fitted on the east and west facades constitute a significant feature of the building.
Power - plant
Studený, Jan ; Severa, Zdeněk (referee) ; Mléčka, Jan (advisor)
The "POWER - PLANT" deals with the rehabilitation of the former Central Power Conversion and Dale Schoeller (Nejedly I and III) in the village Libušín Mine. Will be newly designed for building the power plant technology with progressive fluidized bed boiler to biomass steam turbine with an output of 7 MW and absorption (trigeneration) unit producing heat, cooling and electricity, which also will function as a cooler primary circuits. The source of water for the power plant will not only former mining pit Nejedlý I which is currently flooded drinking water at about 12 ° C. This system uses high efficiency embedded fuel (biomass), which is ultimately required less. A greater proportion of electricity generated and part of the heat will be distributed to the public network. In most areas will be proposed publicly accessible greenhouses of steel-aluminum construction filled ETFE foil forming the heat insulating membrane filled with air. The reason is to create conditions for the cultivation of tropical and subtropical plants. Greenhouses will be connected to the absorption unit power (underground meanders through which water will circulate), the ventilation shaft mine and mine water - therefore it will be possible to manage the conditions of the internal environment of the building without the influence of the season and especially without mounting other technological devices. It will provide for cooperation with the absorption unit for cooling the primary circuit - therefore eliminating the need for cooling towers or fans. The project will build a detached departments of the Faculty of Mechanical Engineering in Prague - Institute of progressive technologies and systems for energy and the Faculty of Agronomy and Natural Resources CULS. The reason is to allow students and scientists actively and in practice mainly participate in the operation and especially the development of the issue. The public in the area besides themselves open to the greenhouses indoor and outdoor thermal swimming. Part of the entrance hall is a bistro and foremost lecture hall. The aim is decentralized botanical-energy complex of buildings that produce electricity, heat, cooling, and biomass, and creating recreational, educational and research conditions.
Structure and dynamics of arboreal ant communities along successional gradient in a mountain tropical forest of New Guinea
MOTTL, Ondřej
I analysed the structure and dynamics of a community of tropical arboreal mountain ants in Papua New Guinea over a succession gradient. There were 9 plots divided into 3 successional stages of forest (old (<50 years), middle-aged (20-30 years) and young (>13 years)). I found 24 species of arboreal ants in total. Gamma and alpha diversity differed over the successional gradient, and alpha diversity was correlated with tree size (DBH). Unexpectedly, beta diversity (number of ant species per tree) was low in middle-aged forest, i.e. it had the greatest ant species similarity between trees, probably due to forest structure (stem density and canopy connection). In contrast, the species composition of ant communities did not differ over a succession gradient, because most of the species were abundant in all forest stages. Similarly, there was also relatively little difference in composition of nest types between different successional stages. Here I have shown that succession had little impact on the structure and dynamics of tropical arboreal ant communities in high elevation, probably as a result of ants' adaptation to lower temperatures and ecological change to trophic generalists. But other factors such as absence of invasive species, food supply, and forest structure may play a significant role. In summary, local logging and shifted agriculture have relatively little impact on ant communities in mountain tropical forests. This is in contrast to similar studies from lowland rainforests and my results hence have a positive implication for tropical forest conservation of ants in mountain regions.

National Repository of Grey Literature : 24 records found   beginprevious15 - 24  jump to record:
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