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Diversity and distribution of the Euastrum humerosum / didelta (Desmidiales) species complex
Kupčíková, Eva ; Šťastný, Jan (advisor) ; Kollár, Jan (referee)
From 23 European and North American strains Euastrum humerosum/didelta species complex (Desmidiales) we have obtained 3 lineages in molecular marker trnGuuc group II intron. We did not acquire significant and homogenous results in SSU intron. It is probable that the lineages are very young. The lineages were significantly different in their shape and dimensions. We used the geometric morphometrics with the measuring of the lengths and breath of the semicells, isthmus and their ratios. The lineages differentiated in their dimensions and shape variable polar lobes and neck. SEM revealed the one central pore in cell wall on the contrary, with variant E. didelta var. bengalicum, which has two pores according the literature records. Key words: desmids, species, hidden diversity, molecular phylogenetics, geometric morphometrics, Euastrum, scanning electron microscopy
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Verification of species boundaries in clinically relevant Arthroderma species
Míková, Ivana ; Hubka, Vít (advisor) ; Dobiáš, Radim (referee)
The genus Arthroderma contains predominantly geophilic dermatophytes (naturally occuring in soil). Some species, especially those from Trichophyton terrestre complex, cause human and animal dermatomycosis. In the past, the species boundaries were determined mainly on the basis of biological species concept using in vitro mating experiments. But these nearly 70-years-old findings have not been tested by means of modern taxonomic methods. In total 194 species of the genus Arthroderma (including all available ex-type strains) originating predominantly in USA, Canada and Europe were studied in this thesis. They were mostly isolated from soil (n = 77), animals (n = 50), human clinical material (n = 41) and cave sediment (n = 9). The main goal of the thesis was to elucidate the species boundaries between species A. insingulare, A. lenticulare and A. quadrifidum, that were classified into the T. terrestre complex because of their seemingly identical asexual stage. Further, this work aimed to resolve the relationship between Arthroderma species using the multigene phylogeny and clarify which species are clinically relevant. A multigene phylogeny of the genus Arthroderma was based on the sequences of the ITS rDNA region, β-tubulin (TUB2) and translation elongation factor 1α (TEF1α) genes. The genus...
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Investigation of defects in thin metallic films
Hruška, Petr ; Čížek, Jakub (advisor)
In the present work Mg films prepared by RF magnetron sputtering were studied. Variable energy positron annihilation spectroscopy (VEPAS) was employed for investigation of defects in the Mg films. VEPAS characterization was combined with scanning electron microscopy and X-ray diffraction in order to determine grain size, phase composition and texture. The effect of different deposition rate and deposition temperature, annealing, various substrates and film thickness on the structure and amount of defects present in the Mg films was examined. Defect studies by VEPAS showed that positrons in studied Mg films are trapped at misfit dislocations and at vacancy-like defects in grain boundaries and their density can be reduced by the deposition at elevated temperature. 1
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Studium defektů v tenkých kovových vrstvách
Hruška, Petr ; Čížek, Jakub (advisor) ; Bulíř, Jiří (referee)
In the present work Mg films prepared by RF magnetron sputtering were studied. Variable energy positron annihilation spectroscopy (VEPAS) was employed for investigation of defects in the Mg films. VEPAS characterization was combined with scanning electron microscopy and X-ray diffraction in order to determine grain size, phase composition and texture. The effect of different deposition rate and deposition temperature, annealing, various substrates and film thickness on the structure and amount of defects present in the Mg films was examined. Defect studies by VEPAS showed that positrons in studied Mg films are trapped at misfit dislocations and at vacancy-like defects in grain boundaries and their density can be reduced by the deposition at elevated temperature. 1
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Internet Educational Atlas Focusing on Soil Arthropods
Dvořáková, Jana ; Mourek, Jan (advisor) ; Říhová, Dagmar (referee)
The main objective of this thesis was to create an educational website aimed at soil arthropods. It can be used primarily by teachers of biology and ecology, lecturers of extracurricular science education or by the students who are interested in this issue. This photographic atlas of soil arthropods consists of my own micro images obtained by the use of light and scanning electron microscope. The micro images are accompanied by text to each group of soil arthropods, which is divided into sections containing information about the systematic classification, anatomy and morphology, biology and importance, eventually representatives of the group. The atlas is accompanied by other materials usable in the classroom, such as didactic test, didactic game and proposals for group work, worksheet, field and laboratory work or educational presentations focused on soil arthropods. These materials can be downloaded from the website, along with the entire atlas of soil arthropods. The atlas is available on the following address: https://sites.google.com/site/pudniclenovci/. The review of the literature deals with the importance of arthropods in the soil and their mutual interactions. Then I describe the methods of study of arthropods (sampling, sample preparation for light and scanning electron microscopy and...
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Monitoring of Mycobacterium smegmatis floating biofilm development - morphological and proteome analysis
Sochorová, Zuzana ; Weiser, Jaroslav (advisor) ; Zikánová, Blanka (referee)
Microorganisms grow in planktonic form, but more often they adhere to a number of surfaces and create three-dimensional structures called biofilms. Floating biofilms, which are formed at the water-air interface, are one of the life strategies, which the bacteria can take. Non-pathogenic Mycobacterium smegmatis was used as a laboratory model for the study of this kind of biofilm. The understanding of mechanisms of their formation of this species may be applicable to the pathogenic species of the genus Mycobacterium, study of which in the laboratory brings a number of disadvantages. This diploma thesis focuses on the morphological and proteome analysis of the M. smegmatis floating biofilm. Using a stereo microscope and scanning electron microscopy was observed that bacteria clump and create the "nucleation centres" at the beginning of the biofilm development. This centers grow to the surroundings and connect afterwards. In the later stages of the development the centers fuse in compact layer, which then grows into the compact and multilayer biofilm. The key method in this study was two-dimensional electrophoresis of proteins. The proteome analysis of floating biofilm was performed with this method. The preparation of protein samples and the method for protein concentration measurement was optimized....
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The Rheological Behavior of Polymer Solutions Suitable for Electrospinning
Divínová, Nikol ; Voráč,, Zbyněk (referee) ; Chamradová, Ivana (advisor)
This diploma thesis deals with preparation and characterization of aqueous solutions of polyvinyl alcohol suitable for electrospinning. In the theoretical part method of electrospinning is described, including parameters which influence this process. Literary research also includes a chapter about rheology, which deals with the rheological properties of polymers, specifically PVA. The experimental part describes the preparation and rheological study of of aqueous solutions of polyvinyl alcohol, which were then spun. The morphology of prepared nanofibers was studied by using scanning electron microscopy (SEM). The effect of molecular weight, the solvent, concentration of solution, rheological properties, electrical conductivity and surface tension on the spinability, diameter and morphology of nanofibers is discussed.
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Studium adipokinetické hormonální odpovědi na infekci způsobenou entomopatogenní houbou druhu \kur{Isaria fumosorosea}
ČERNÝ, Jan
The goal of this bacholar thesis was to find out how to elicite the infection by entomopathogenic fungus Isaria fumosoroesa in the firebug Pyrrhocoris apterus. When firebugs were successfully infected by blastospors of these fungus, the level of AKH in the central neural system and metabolic activities were measured. The results revealed that the infection caused decrease of AKH level in the CNS and activation of energy sources (lipids) in haemolymph. The flow cytometry analyses indicated certain changes of hemocyte numbers and populations in the hemolymph after the infection.
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Influence of humidity on total sterilisation effect of dielectric barrier discharge
Kramárová, Petra ; Bartlová, Milada (referee) ; Kozáková, Zdenka (advisor)
The main subject of this diploma thesis is the study of the effect of humidity on the total sterilization effect of the dielectric barrier discharge. Sterilization is a process which can eliminate all forms of life. The plasma sterilization is one of the methods that are suitable for sterilization of temperature and chemical sensitive materials. This sterilization method was proved to be effective on the wide spectrum of procaryotic and eucaryotic microorganisms. Basically, the main inactivation factors for cells exposed to plasma are heat, UV radiation and various reactive species. Dielectric barrier discharge (DBD) operating at atmospheric pressure was used for the sterilization of the samples. The discharge was generated in dry air and in humid air. The plasma power densities were 2 160 mW.cm-3, 2 279 mW.cm-3 and 2 760 mW.cm-3 (dry air) or 2 326 mW.cm-3 and 2 850 mW.cm-3 (humid air). Humidity of air was achieved using a wash bottle filled with water through which air flowed into the DBD reactor. Fungi spores of Aspergillus niger were used as model microorganisms. Whatman paper No. 1 was used as the carrying medium. When comparing sterilization efficiency of humid and dry air operating at the same conditions, the higher sterilization effect was observed in humid air. The sterilization effect of the DBD generated in air was compared with results obtained during plasma generation in argon and nitrogen. At the same conditions, the highest sterilization effect was observed in argon, followed by humid air, nitrogen and dry air. It was found out that in our experimental setup the active species are probably the main inactivation mechanism. The influence of temperature on the inactivation of microorganisms was completely negligible. The discharge parameters were studied by means of the optical emission spectroscopy (OES). Plasma treated samples were analyzed employing scanning electron microscopy (SEM). Damage of the microorganisms due to the effect of plasma as well as plasma effect on the structure of the carrying medium was evaluated.
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