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The source process of Greek earthquakes
Křížová, Dana ; Zahradník, Jiří (advisor) ; Málek, Jiří (referee) ; Šílený, Jan (referee)
Title: The source process of Greek earthquakes Author: Dana K ížová Department: Department of Geophysics Supervisor of the doctoral thesis: Prof. RNDr. Ji í Zahradník DrSc., Department of Geophysics Abstract: Investigations of moment tensor (MT) and its uncertainty are topical. This thesis is focused on isotropic component of three shallow earthquakes: Event A in Cretan Sea (Mw 5.3) and two events near Santorini island, B (Mw 4.9) and C (Mw 4.7). MT is inverted from full waveforms in an assumed 1D velocity model. The inverse problem is non-linear in centroid depth and time, and linear in six MT parameters, one is the MT-trace. Uncertainty of isotropic component is studied by a new approach (K ížová et al., 2013). The trace is systematically varied, and remaining parameters are optimized. The method reveals tradeoffs between the isotropic component, depth, time, and focal mechanism. From two existing velocity models, we prefer the one with lower condition number, in which a (positive) isotropic component is indicated for event B. To rapidly assess a likely existence of isotropic component, an empirical method is proposed (K ížová et al., 2016). It is based on comparison between depth- dependences of waveform correlation in full and deviatoric modes. Based on extensive synthetic tests, the method confirms a...
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Radar Altimeter for Ultralight Aircraft
Zahradník, Jiří ; Zemčík, Pavel (referee) ; Maršík, Lukáš (advisor)
In this bachelor thesis author designs a radar altimeter. In this thesis the emphasis is placed onto modular architecture and that is why this altimeter is designed as a group of independent modules communicating through BSD sockets. Software implementation is made in C++ and for sound generator is used library PulseAudio. Next topic is multithreading safety implementation of queue and stack which was made by template class to keep simplicity and generality.
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Morphine alkaloid metabolism in bacteria
Zahradník, Jiří ; Kyslík, Pavel (advisor) ; Lichá, Irena (referee)
Morphine alkaloids and their derivatives are pharmaceutically important substances. Huge production and consumption of these compounds predetermines them to be significant pollutants in the environment. Some of them have been detected in surface waters. The aim of this study was to characterize effects of morphine alkaloids on the physiology of three model organisms: Agrobacterium sp. R89-1, Escherichia coli XL-1 (Blue), and Raoultella sp. kDF8, and elucidation of the mechanisms leading to toxicity. The biotransformation potential and utilization ability were characterized for model organisms. It was demonstrated that the microorganism Agrobacterium sp. R89-1 is capable of rapid biotransformation of codeine to its 14-OH derivatives. The manifestation of morphine compounds toxic effects for the strain R89-1 is the highest. In contrast, microorganism Raoultella sp. KDF8 is able to utilize codeine as a carbon and energy source. The accumulation of 14-OH-derivatives was not observed. Escherichia coli XL-1 (Blue) is not able to biotransform or utilize codeine. Α, β-unsaturated ketones (morphinone, codeinone, 14-OH-morphinone and 14-OH-codeinone) were found as a most toxic intermediates of codeine metabolism. Bacterial cell growth (strains R89-1 and KDF8) in the presence of codeine is characteristic with...
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Polarization analysis of strong ground motions recorded during the aftershock sequence of the 2009 L'Aquila earthquake
Čejka, František ; Gallovič, František (advisor) ; Zahradník, Jiří (referee)
During broadband modelling of selected events from the aftershock sequence of the l'Aquila earthquake using 1-D model of media, we observe interesting difference between model and real particle polarization on high frequencies. There are two basic types of these polarization disorders. Polarization of particle motion keeps its linear form, but changes its direction or linear polarization changes its linear form to circle polarization. It offers the explanation that these disorders of polarization occur due to the 3D heterogeneities in the crust. In this work, we analyze polarization of published synthetic seismograms modeled with random 3D heterogenitites. It has been shown that the biggest disorders occur in directions in which parcticle movement heads toward the source, and that we can find examples, which qualitatively explain observed polarization disorders.
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Teleseismic Tomography of the Upper Mantle beneath the Bohemian Massif
Karousová, Hana ; Plomerová, Jaroslava (advisor) ; Růžek, Bohuslav (referee) ; Zahradník, Jiří (referee)
Passive seismic experiments, MOSAIC, BOHEMA I-III, EgerRift, or, PASSEQ, carried out in the region of the Bohemian Massif (BM), allowed a detailed study of velocity structure of the upper mantle. We present results of tomography studies of the upper mantle beneath the north-eastern and southern parts of the BM based on the data from the BOHEMA II and BOHEMA III experiments (2004-2006). Despite the fact that regions with the highest resolution of velocity perturbations differ in the models, tomography images are similar in overlapping parts. Models of the upper mantle show mostly low- velocity perturbations relatively to radially symmetric velocity model of the Earth beneath the BM. Limited high-velocity heterogeneity beneath the Moldanubian unit, extended in the NE-SW direction, reflects thickening of the lithosphere due to a collision of the BM with the Brunovistulian micro-plate during the Variscan orogeny. The tomography based on the data from the BOHEMA III experiment revealed significant high-velocity heterogeneity in the southern margin of the model with a subduction of the lithosphere beneath the Eastern Alps. Tomographic tests showed that effects of uncorrected velocity heterogeneities within the crust can appear as deep as 100 km and, therefore, they could lead to erroneous interpretation of...
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Y1 and Y2 transposases, mechanisms of transposition, biological function.
Zahradník, Jiří ; Lichá, Irena (advisor) ; Schierová, Michaela (referee)
Transposases are enzymes that catalyse cleavage, transmission and re-inserting of mobile genetic element into the DNA. Tyrosine transposase take between these enzymes completely independend status. Their uniqueness is determined by their structure and different mechanism of the transposition reaction, in which the covalent phosphotyrosine intermediate plays major role. Mandatory presence of the catalytic tyrosine gives name to these enzymes and it enables their further classification into a group that carries only a single catalytic tyrosine - Y1 transposases and a group carrying two tyrosines - Y2 transposases. This thesis summarizes the current knowledge about tyrosine transposases. It covers their occurrence, structure, reaction mechanism and biological function. The reaction mechanism of the most studied Y1 transposase, associated with IS608 element, is described in detail. The work also focuses on other members of the tyrosin transposases family which carry the characteristic HUH motive. These include transposases associated with the insertion sequence of IS200/IS605 family (Y1), transposases associated with REP elements (so called RAYT proteins), transposases associated with IS91 family (Y2), transposases of ISCRs family (Y1) and unusual eukaryotic transposases of the Helitron family (Y2)....
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Purification and characterization of selected enzymes from Rhizobium radiobacter R89 catalysing oxidation/reduction reactions of C-hydroxylated morphine skelets.
Zahradník, Jiří ; Šulc, Miroslav (advisor) ; Černá, Věra (referee)
The Rhizobiaceae bacteria are known for its varied nitrogen metabolism: especially its nitrogen fixation, so called diazotrofia, its capability of symbiosis with plants, or on the contrary plant pathogenesis (genus Agrobacterium). Rhizobium radiobacter R89 (stored in Czech Collection of Microorganism, in Brno as R89-1) is bacteria strain capable of codeine and morphine biotransformation to whole spectrum of pharmacologically significant derivates. This work is focused on purification and characterization of two selected enzymes that catalyze oxidation-reduction reactions, the crucial beginning of morphine skelets biodegradation. At the first, the biotransformational potential of the strain was evaluated and biochemical, molecular biological and bioinformatical approaches were employed to purify the responsible enzymes. Considering unsuccessful purification from Rhizobium radiobacter R89-1, the proteins structural genes were cloned and heterologously expressed in bacterial system and afterward characterized. Found protein sequence and enzyme characterization (basic kinetic measurements, substrate specificity and thermo- stability) have revealed different origin of the enzymes and clarify reasons why the original purification procedure was not successful.
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Rychlé interferenční vlny a 1D seismické modely kůry
Vackář, Jiří ; Zahradník, Jiří (advisor) ; Prokop Brokešová, Johana (referee)
A recent shallow earthquake in the Corinth Gulf, Greece (Mw 5.3) generated unusual long-period waves (periods > 5 seconds) between the P- and S-wave arrival. The 5-second period, being significantly longer than the source duration, indicates a structural effect. Observed seismograms were examined by methods of the frequency-time analysis. Disper- sion curves of the fast long-period (FLP) waves indicated group velocities ranging from 3 to 5.5 km/s for periods between 4 and 10 s, respectively, with large variations among the stations. The generalized dispersion curve splits into two major strips, probably related to lateral variations of the crustal structure. Forward simulations for several existing crustal models were made. A few partially successful models served for a sensitivity study, which showed that the FLP wave seemed to be mainly due to the low-velocity layers in the uppermost 4 kilometers of the crust. Finally the shallow crustal structure was retrieved by inverting observed seismograms by Neighborhood algorithm. The inversion confirmed that the FLP wave in seismograms at more than a single station cannot be explained with a 1-D crustal model. The path-dependent models provided a partial explanation for the strips revealed in the experimental dispersion curves. An alternative explanation is by...
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Isolation and purification of the environmental DNA from the horizon of the capping: stratification study
Zahradník, Jiří ; Šulc, Miroslav (advisor) ; Weignerová, Lenka (referee)
According to our contemporary knowledge soil is the most abundant source of microbial biomass. Unfortunately, only one percent of the microorganism species is available by classical cultivation techniques. Soil metagenomic DNA is a collection of the whole DNA including also uncultivated microorganism in the soil sample and provides information to study molecular aspects of microorganism and their DNA sequences inaccessible by other techniques. This work is focused on characterization and isolation of soil metagenomic DNA from deep horizon of capping. Evaluation in term of the isolation and techniques of recombination of DNA and stratification study are included in this work. Obtained collection of samples was preliminary characterized with the view of quality - content of clay, humic compounds and crude number of microorganism. The purified soil metagenomic DNA was quantitatively and qualitatively characterized for each sample. The quantification method and DNA quality determined the next applications and procedures of DNA techniques. Also the soil quality was discussed from this point of view. According to the results of DNA analysis, the three selected DNA samples were processed to DNA library with 16S rRNA DNA loci and after DNA sequencing analysis the phylogenetic study was performed. This...
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Seismic Site Effects (Data Analysis and Modelling)
Caserta, Arrigo ; Zahradník, Jiří (advisor) ; Růžek, Bohuslav (referee) ; Burjánek, Jan (referee)
A comprehensive study of the soil shaking under the seismic wave-field ex- citation is presented. It includes theoretical, geological, geotechnical, data analysis and numerical simulations aspects. The aim is to quantify the main parameters allowing the estimate of the soil shaking in urban areas for better mitigating seismic risk due to future earthquakes. The city of Rome has been chosen as a case study because of its high density of popula- tion and large concentration of historical monuments with high earthquake vulnerability. This study improves significantly the knowledge concerning the detailed near-surface geology of the chosen study area of Rome, ful- fills the absence both of knowledge concerning its geotechnical properties and earthquake data recordings in the city. Among others, it allows for a better explanation of the spatial damage pattern observed in the city due to earthquakes in the past. The main innovations include the construction and long-term operation a seismic array in the city, analysis of the natural seismic noise, and instrumental recordings of the 2009 L'Aquila earthquake sequence. The 3D array (including a borehole sensor at 70-m depth) is the first one in Italy planned, realized and operated within an urban area, and the first one that recorded a significant earthquake in...
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