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The mycobiomes of vegetative organs of the dominant Mediterranean seagrass Posidonia oceanica (Posidoniaceae, Alismatales)
Soperová, Beáta ; Vohník, Martin (advisor) ; Kohout, Petr (referee)
Posidonia oceanica is a dominant seagrass of the Mediterranean Sea and its mycobiome has been increasingly studied, especially in recent years. Dozens of fungi associated with roots, rhizomes or leaves have been already described, but studies on the mycobiome of leaf sheaths are completely absent. One of the root-associated mycobionts is Posidoniomyces atricolor, which has not yet been isolated from any other organ. This thesis attempted to describe the mycobiome of vegetative organs of P. oceanica using two different methodological approaches - microscopic observation and molecular analyses. Microscopic observation confirmed the presence of fungal colonization in all vegetative organs except leaves. The conclusions from the microscopic part were subsequently verified by isolating and identifying several different endomycobionts, including P. atricolor, which has been also isolated for the first time from rhizomes and leaf sheaths. Leaf sheath mycobiome was then described for the first time ever.
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Development of Long-pitch Corrugation in Curves of Small Radii
Valehrach, Jan ; Kohout,, Martin (referee) ; Lidmila,, Martin (referee) ; Plášek, Otto (advisor)
Throughout the operation, the rails are worn and deteriorate. With the increasing speed of rolling stock, along with higher track loads and especially in the vicinity of major traffic hubs with a higher frequency of trains, defects that did not occur to such an extent before or were not considered to be significant, are brought to the forefront of the concerns of track infrastructure managers. Even though these defects are not directly restrictive to traffic operation, they are, in any case, a source of noise and vibration. One of these defects on the railway track is the micro-geometry defect of the running surface of the railhead. In directional curves with radii of less than 600 m or 700 m, defects known as long-pitch corrugation occur on the inner rail. In curves with 300 m or smaller radii, these waves are so distinct that they are a significant source of noise and vibration. In particular, vibrations affect the track surroundings and the track itself, as they cause other defects in the track structure. This dissertation deals with long-pitch corrugation, focusing on the monitoring of wave generation and development over time. The verification of the possibility to track the development of slip waves over time is the basis for possible future models predicting the development of defects. Numerous measurements of geometric parameters of the track and microgeometry of the railheads, specifically slip waves, have been carried out in the framework of the problem. Using RMS and peak-to-peak methods, the rate of development of defects over time and the relationship with other track parameters were evaluated. Based on the obtained development curves, intervals for further maintenance interventions were estimated. A part of the thesis focuses on the deficiency or excess of cant concerning the development of long-pitch corrugation.
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Methodology for designing the dead end tracks
Guziur, Petr ; Týfa,, Lukáš (referee) ; Kohout,, Martin (referee) ; Svoboda, Richard (advisor)
This work aim is designing of dead-end tracks with focus mainly on the friction buffer stop design. There are numerous factors in decision-making process of ending the dead-end track, such as position of the track in station, level of train control system, area capabilities, number and types of trains that regularly run on the track, etc. The recherche part of this work shows that friction buffer stop is the most suitable construction and preferred type of ending the dead-end track abroad. This is the reason for paying attention to that type of buffer stop with emphasis on the process of design itself. This work includes design of a program using a spreadsheet editor and Visual basic to make the design of friction buffer stop easier. There are described selected factors with highest impact on the design.
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Tetrahedrization as an alternative to volume data
Varga, Martin ; Kolingerová, Ivana (advisor) ; Kohout, Josef (referee)
Main goal of the thesis was to research or propose a suitable method for substitution of volume data including volume data derived from motion pictures by irregular tetrahedron-based grids. The method should minimize the loss of information and the size of the data. The thesis proposes a method for finding a suitable tetrahedron grid that substitutes the volume data without assuming anything about its inner structure. The proposed method can be applied on both volume data and volume data from motion pictures. The method consists of two steps. First a basic grid is generated by a simple incremental algorithm and then it is improved by a process of simulated annealing. The thesis proposes an unbiased measure for measuring the loss of information and evaluates the suitability of the proposed method for both types of data based on experiments. The thesis includes an implementation of the proposed method which demonstrates its use. The thesis also includes sample volume data and motion picture volume data which were used to test the suitability of the method.
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Nuclear magnetic resonance of Pb(x)Ba(1-x)(FeNb)0.5O3 perovskites
Adamec, Martin ; Chlan, Vojtěch (advisor) ; Kohout, Jaroslav (referee)
Temperature dependences of nuclear magnetic resonance spectra of isotopes 207 Pb, 137 Ba, and 93 Nb in polycrystalline samples of PbxBa1-x(FeNb)0.5O3, with x = 0 (BFN), 0.5 (PBFN), 1 (PFN) and in Pb(FeNb)0.5O3 single crystal (PFN SC) were acquired. Measured nuclear magnetic resonance spectra are analyzed in this work. The temperature dependence of the spectra show strong broadening with decreasing temperature. Part of the temperature dependences of nuclear magnetic resonance spectra did not comply with expected characteristics. Possible hypotheses for interpretation of such behavior are discussed in the text. Probable arrangement of Fe and Nb cations in PFN and BFN phases is deduced and, based on these differences, the contrast in Néel temperatures of these phases is explained.
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Biotic threats to garden monuments: algae, cyanobacteria and invasive plant species
Pergl, Jan ; Perglová, Irena ; Albrechtová, J. ; Antl, Tomáš ; Abarenkov, K. ; Baldrian, Petr ; Cihlářová, L. ; Klečka, Jan ; Kohout, Petr ; Kvasničková, Jana ; Maršálek, Blahoslav ; Maršálková, Eliška ; Pejchal, Miloš ; Petružálková, M. ; Petřík, Petr ; Pyšek, Petr ; Sádlo, Jiří ; Štefl, Lukáš ; Tedersoo, L. ; Větrovský, T. ; Vlk, Lukáš ; Vojík, Martin ; Vosátka, Miroslav ; Zezulka, Štěpán
Chateau, city parks and gardens are perceived as harmonious parts of the landscape. Unfortunately, even these areas have to face various threats, and they can be a threat to the surrounding environment. The exhibition /catalogue presents a look at the organisms that threaten parks. These threats cover unwelcomed invaders covering invasive plants and small microorganisms in the soil, on facades, statues or in water. On the other hand, some species that are intentionally brought to the parks can be risky not only the gardens themselves but also their surroundings.
Fulltext:  PDF
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Based on true story
Davydenko, Polina ; Kohout, Martin (referee) ; Gravlejs, Ivars (advisor)
In reaction to the process of collecting photo series, I decided to focus on how not to rely on safe shots. I have created a set of images from which viewer can read several meanings, thanks to the overall absence of narration and text. I am looking for stucture and possibly creating new images building on this found structure.
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Lower and Middle Turonian ammonites of the Bohemian Cretaceous Basin
Kohout, Ondřej ; Košťák, Martin (advisor) ; Vašíček, Zdeněk (referee)
This thesis addresses the systematics and taxonomics of the ammonite assemblages of the Lower and Middle Turonian of the Bohemian Cretaceous Basin (BCB). It describes nineteen species of fifteen genera. Amongst others it concerns: Watinoceras coloradoense (Henderson), Spathites (Jeanrogericeras) reveliereanum (Courtiller), Paramammites sp. cf. P. polymorphus (Perervinquière), and Lecointricecras carinatum (Kennedy et al.) from the BCB, which have been described for the very first time. Another important taxon that is described is Prionocyclus albinus (Fritsch), which has not been encountered in the BCB since the year 1872 when it was established as a holotype by A. Fritsch. This specimen is now deposited in the National Museum in Prague. Most of these significant taxa belong to the collection of Dr. J. Soukup. He collected the specimens in various locations near Žďánice u Kouřimi mainly in the first half of the 20th century. The locations no longer exist. Stratigraphically important zonal ammonites, primarily W. coloradoense and Fagesia catinus (Mantell), are a direct evidence of the presence of two ammonite zones in the lower Lower Turonian in this part of the BCB (the zones Watinoceras coloradoense/devonense and Fagesia catinus). They also illustrate a larger stratigraphical extent of...
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Nuclear magnetic resonance of Pb(x)Ba(1-x)(FeNb)0.5O3 perovskites
Adamec, Martin ; Chlan, Vojtěch (advisor) ; Kohout, Jaroslav (referee)
Temperature dependences of nuclear magnetic resonance spectra of isotopes 207 Pb, 137 Ba, and 93 Nb in polycrystalline samples of PbxBa1-x(FeNb)0.5O3, with x = 0 (BFN), 0.5 (PBFN), 1 (PFN) and in Pb(FeNb)0.5O3 single crystal (PFN SC) were acquired. Measured nuclear magnetic resonance spectra are analyzed in this work. The temperature dependence of the spectra show strong broadening with decreasing temperature. Part of the temperature dependences of nuclear magnetic resonance spectra did not comply with expected characteristics. Possible hypotheses for interpretation of such behavior are discussed in the text. Probable arrangement of Fe and Nb cations in PFN and BFN phases is deduced and, based on these differences, the contrast in Néel temperatures of these phases is explained.
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Metallic materials used for dental prostheses
Kožiol, Martin ; Kohout, Jan (referee) ; Věchet, Stanislav (advisor)
The topic of the bachelor's thesis is the use of metallic prosthesis and implants in dental medicine. The main point is to elaborate the summary of metallic materials and their mutual comparision in the terms of properties and individual application. For the clearly understand, there has to be defined a biocompatibility which along with mechanical properties serves for categorizing materials capable of application in the form of dental prosthesis. At the end is discussed about future of metallic materials in dental medicine.
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