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Infusorial Earth - Reactive Admixture for Cement Composites
Zimmermann, Štěpán ; Žižková, Nikol (referee) ; Rovnaníková, Pavla (advisor)
The aims of this bachelor´s thesis are the properties and the use of diatomaceous earth as a partial replacement of cement in concrete. It provides information about the origin of diatomaceous earth, sedimentation of dead diatoms and variety of algae, including chemical and physical properties of the diatoms according to origin. The paper also contains information about significant deposits of diatoms, the manner and intensity of mining, including treatment of raw diatomaceous earth for further use. The main use of diatomaceous earth is in the filtration, which represents more than half of total consumption. An important factor for use in building is a high content of amorphous SiO2 and associated pozzolana activity of diatomaceous earth. The experimental part was carried out research on the influence of diatomaceous earth as pozzolanic admixtures on the properties of cement mortars. Tested specimens were obtained by adding 10% diatomaceous earth by weight of cement in the cement mortars. As admixtures were use three diatomaceous earth of different chemical composition, particle size and pozzolanic activity. The evaluated parameters were mortar density, flexural and compressive strength. The microsture of mortars were also observed. Test results were compared with those determined by reference mortars.
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Abnormal shapes of diatoms induced by elevated concentrations of chemical substances.
Budd, Dagmar Marguerite ; Kulichová, Jana (advisor) ; Woodard, Kateřina (referee)
Traditional biomonitoring methods are compared in this thesis with a modern approach which uses fluctuation asymmetry to measure developmental instability and refines biomonitoring methods in order to emphasis the impact of toxigenic substances in freshwater environments. The next section provides information about different types of pollution, with the focus primarily on heavy metal contamination and the impact from increased concentration of these metals on diatom frustules, green algae and other protist organisms. The most common cause of teratological changes comes from heavy metals and the impact of them along with toxicity are analyzed here. What changes is the teratology at the intracellular level and the protist organism morphology, where the cause of the changes can be traced to these heavy metals. The thesis also compares the impact of the heavy metals among different protist organism groups and between each of them. It contains suggested phycoremediation, which in the future could be an ecological solution for the cleanup of rivers and streams. Keywords: fluctuation asymmetry, developmental instability, geometric morphometrics, teratologies, diatoms, morphological asymmetries, biomonitoring
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Diatoms as bioindicators for tracking freshwater salinization.
Severa, František ; Kopalová, Kateřina (advisor) ; Dobiáš, Jakub (referee)
The focus of this thesis is on the relationship of diatom (Bacilariophyta) communities to conductivity, and the utilization of this relationship for the monitoring of freshwater salinization. Salinization of freshwaters as a consequence of anthropogenic influences is emerging as a threat to many freshwater habitats due to increasing anthropogenic sources of salts (like use of de-icing salts on roads), wastewaters, and fertilizers. The problem is intensifying because salts are further concentrated through increased evaporation as a consequence to climatic changes. Salinization of ecosystems has a direct impact on the physiological processes of present organisms, and because the ability to adapt to this stress differs between organisms, results in the reorganization of communities. In this way, salinization can indirectly threaten ecosystem services that benefit mankind. Furthermore, salinization is a direct threat in terms of its influence on drinking water and crop irrigation. These forces also act on diatoms, which have long been used as bioindicators, and exhibit strong community links with conductivity. Like for other organisms, this tight relationship is caused by differences in adaptation mechanisms between species, which includes osmolytes, extracellular polymeric substances and adaptation of...
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Společenstva rozsivek oligo - mesotrofních rybníků Novohradských hor
HRUBÝ, František
This thesis focuses on diatoms of little studied water reservoirs of the Novohradské hory area. During the 2019, three seasonal samples were collected. At all five sampling sites various environmental parameters were measured. A total of 321 taxa were identified, a large proportion of which are classified as boreo-alpine, rare or indicative of very good water quality. The available data were used to calculate diatom indices and to determine the saprobity and trophy of the Novohradské hory reservoirs. The similarity of the communities of each sampling type was compared and discussed using the statistical program Canoco.
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Niche width of eukaryotic marine phytoplankton with respect to recent and future climate change.
Junková, Natálie ; Kulichová, Jana (advisor) ; Neustupa, Jiří (referee)
This paper describes the concept of niche breadth of photoautotrophic protists and attempts to introduce us to the basic concepts we may encounter when studying the ecological niche. The review clarifies what a niche is and its components fundamental and realized niche and presents some examples of organisms that are specialists or generalists. It uses diatoms, dinoflagellates and Haptophytes to describe how they can be affected by climate change. Since the number of environmental changes is steadily increasing, it is very difficult to predict the changes in the coexistence of generalists and specialists. The thesis presents some of the main methods used in measuring the width of the ecological niche of protists, which can be MaxEnt, ONE and the most frequently mentioned OMI (outlying mean index) method, which is described in more detail in the thesis. Given the focus of the thesis on photoautotrophic marine plankton, the most frequently mentioned organisms are diatoms, dinoflagellates and Haptophyta. Finally, I summarize the main ocean factors that could be affected by climate change, which are mainly pH, temperature, salinity or the amount of available nutrients (carbon, nitrogen, phosphorus, silicon and iron).
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The use of diatoms (Bacillariophyta) in paleolimnology
Aubrechtová, Martina ; Kulichová, Jana (advisor) ; Píšková, Anna (referee)
This thesis is a literature review summarizing methodology and the possibility of use of diatoms (Bacillariophyta) for paleoecological reconstructions of extinct lacustrine ecosystems. In addition, the theoretical part of the thesis is devoted to basic characteristics, evolutionary history and ecology of the group, lakes and the fossil record. In the practical part, two samples of sediments of a fossil lake that has been discovered and studied within the Morava Project in Strážnické Pomoraví are compared.
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Geometric morphometrics of diatom frustules.
Hubáčková, Kateřina ; Kulichová, Jana (advisor) ; Pichrtová, Martina (referee)
This bachelor thesis includes a theoretical and a practical part. In the theoretical part, I focused problematic parts of research of diatoms biology. I will discuss morphology of specific silica scale and its morphogenesis; life cycle, characteristic by the size diminution in vegetative phasis, and conception of taxonomy of these organisms which is rather complicated because of unclear species concept. Another part presents tools of geometric morphometrics which is rapidly developing method for investigation and quantification of biological shape. In the practical part, I present the results from own research. This experiment is preliminary study for diploma thesis and its purpose is to appropriate tools of geometric morphometrics and to present advantages of its methods. I will investigate morphological disparity of three strains of pennate diatoms cultivated in standard conditions studied by landmark methos. The aim of this study is to discover if small cells which have gone trough the long phasis of vegetative multiplication and are close to the sexual reproduction have diferent degree of morphological variability than the bigger ones just undergone by sexual process.
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Biogeography and habitat preferences for genus Luticola
Hanišová, Lucie ; Kopalová, Kateřina (advisor) ; Kulichová, Jana (referee)
The genus Luticola is one of the most species rich group belonging to the diatom class (Bacillariophyceace) containing 204 described species. The aim of this work is to summarize the available literature on the genus Luticola concerning its biogeography, habitat preferences of polar and temperate species, and their ecological treshold for important factors relating and forming their presence - pH and conductivity. Records suggest that the Luticola genus is presence worldwide, with higher species diversity in Europe, South America and the Antarctic region, the latter of which harbors a substantial amount of endemic species. In terms of habitat preference, records suggest that temperate species occur mostly in aquatic habitats, while polar species occupy terrestrial environments. Polar species also differ from temperate species by occupying narrower margin of pH values. However, both groups prefer low conductivity, and most species of the genus Luticola are located in environments with values up to 100 μS/cm. Key words: biogeography, conductivity, Luticola, pH.
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Diversity and relative biovolume of benthic diatom assemblages in relation to environmental conditions.
Šoljaková, Tereza ; Kulichová, Jana (advisor) ; Chattová, Barbora (referee)
iv ABSTRACT Benthic diatoms are due to a number of positive characteristics (such as high abundances, diversified communities, sensitive responses to environmental conditions, capturing long-term changes in the environmental conditions) currently the most commonly used bioindicators of the ecological status of freshwater ecosystems. However, due to problems associated with the use of traditional methods based on species composition (time-consuming identification, presence of species complexes, and requirements for calibration of water quality indexes for geographical regions) searching for alternative methods has been induced. The monitoring of the size structure of diverse diatom communities has been proposed as one of the methods. This approach would mainly eliminate the necessity of time-consuming determination of species. The main purpose of this thesis was therefore to determine the relationship between the size structure of benthic diatom communities, expressed as the relative biovolume, and selected environmental factors (pH, conductivity, habitat type) within freshwater lentic habitats. Furthermore, the variability of biovolume in dependence on environmental variables was compared with the change in species composition. If there would be a similar response pattern of both the biovolume and species...
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Phylogenetic, morphological and ecological context of microevolution in pennate diatoms
Veselá, Jana ; Neustupa, Jiří (advisor) ; Řeháková, Klára (referee) ; Vanormelingen, Pieter (referee)
Visual assessment of discontinuities in the morphological features of diatom cells has been widely used in the discovery and delimitation of diatom species. However, a multidisciplinary approach to species-level taxonomy has revealed hidden diversity within the traditional diatom morphospecies. Consequently, this work examined both the natural and clonal populations of diatoms by diverse traditional and modern approaches, in order to assess the diversity, ecology, and distribution of diatom species. Although a detailed investigation of natural diatom samples was confounded by uncertain morphological boundaries between the traditional diatom species, it recognized that the diversity was relatively high; even one new diatom species was described using the morphological species concept. The multivariate statistical analyses showed that the variation of natural communities of traditional diatom morphospecies reflected differences in the local environmental conditions, as well as microhabitat heterogenity within a region. Since each diatom morphospecies is most likely a complex of sibling species, the two model traditional morphospecies were investigated, in order to assess morphological variation, genetic diversity, and/or the reproductive compatibility of monoclonal cultures. Even though isolated...
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