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Applications of Bayesian Model Selection
Macek, Tomáš ; Večeř, Jan (advisor) ; Komárek, Arnošt (referee)
The Thesis deals with Bayesian model selection. In the theoretical part, readers will get to know with the priciple of Bayesian approach and the Thesis also states Bayes theorem, which has a key role in the given problematics. Next, it elucidates possibilities of choosing prior distribution and introduces Bayesian regression model, especially Zellner's method, which can be used to choose the most suitable model. In the practical part, this method is then implemented using R on real data from English Premier League football matches. From several statistics considered, the method will select the most suitable model, which means that it will select those statistics which are the most important for the match outcome. 1
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Vliv zbytků po zpracování technického konopí na senzorickou kvalitu kuřecího masa
Macek, Tomáš
This master thesis deals with the influence of hempseed cakes and hemp herbs contained in broiler feed mixtures on the sensory quality of chicken meat. Experimental groups of ROSS 308 broilers were given a feed mixture containing 1) 2.5 % hempseed cakes, 2) 2 % hempseed cakes + 0.5 % hemp herbs and 3) 1 % hemp herbs. The last group was Control that contained no hemp products. During the experiment, the amount of dry matter, nitrogenous substances and fat with final sensory evaluation of the breast and thigh muscles was determined. In terms of determination of dry matter, nitrogenous matter and fat content, no statistically significant difference was found between the groups (P > 0.05). The same statistical results were also found in sensory analysis, where no statistically significant differences (P > 0.05) were found in any descriptor. It can therefore be concluded that the addition of hempseed cakes or hemp herbs did not aggravate the proportion of dry matter, nitrogenous matter and fat or the sensory quality of chicken meat.
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Design of pneumatic cylinder testing equipment
Macek, Tomáš ; Pavlík, Jan (referee) ; Tůma, Zdeněk (advisor)
This diploma thesis deals with the design of test equipment for selected types of pneumatic cylinders. In the first, theoretical, part of the work is an analysis of the current state of knowledge in the field of pneumatic cylinders. Furthermore, the problems in the field of measurement and testing of pneumatic components are described here, selected linear position sensors are also described herein too. The second, practical, part deals with the choice of a suitable design variant and the actual solution of the test equipment design. A pneumatic circuit is also designed here. Part of the work is a 3D model of the test equipment and drawing documentation. The conclusion of the work is devoted to the overall evaluation of the work and recommendations for practice.
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Enzyme activity analysis of function domains belonging to model heme-containing sensor proteins
Prošková, Veronika ; Martínková, Markéta (advisor) ; Macek, Tomáš (referee) ; Vítek, Libor (referee)
EN This Ph.D. thesis focuses on the heme containing gas sensor proteins. These proteins are predominantly present in bacteria, in which play an important role in processes like, sporulation, antibiotic resistance and so on. Heme containing sensor proteins composed of two domains. First one is a globin domain, which contains the heme molecule. Interaction of heme with gas molecule acts as a signal for the activation/inactivation of the second functional domain. Part of this thesis is formed by a review, which summarized the current knowledge about heme containing sensor proteins. In the next part of this thesis we focused on three representatives from the group of oxygen sensor proteins - histidine kinase AfGcHK, diguanylate cyclase YddV and phosphodiesterase EcDOS. The main aim of this thesis was to solve the mechanism of interdomain/intraprotein signal transduction in two oxygen sensor proteins with globin fold of their sensor domain (AfGcHK, YddV). For this purpose, we used the kinetic analysis of their functional domain activity and the methods of structural biology. We also studied the mechanism of interprotein signal transduction in AfGcHK and its cognate partner RR protein. It was also tested, how the presence of sodium disulfide affects the functional properties of oxygen sensor proteins...
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Biogenní aminy v potravinách
Macek, Tomáš
The bachelor thesis deals with an issue of biogenic amines ocurring in food. It describes of biogenic amines formation, charakteristics, factors influencing their content, toxic effects on human health and also their degradation in the human body. Then the thesis focuses on biogenic amines occurrence in various types of food. It also describes microorganisms which are involved in biogenic amines formation. At the end of the thesis there is paid attention to prevention of biogenic amines occurence in food at levels that may cause health problems.
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Enzymatic and Metabolic Transformation of Silybin and its Congeners
Purchartová, Kateřina ; Křen, Vladimír (advisor) ; Macek, Tomáš (referee) ; Vítek, Libor (referee)
Natural flavonoids and flavonolignans feature beneficial properties for living organisms such as antioxidant and hepatoprotective effects, anticancer, chemoprotective, dermatoprotective and hypocholesterolemic activities. Their metabolism in mammals is complex, the exact structure of their metabolites still remains partly unclear and the standards are usually not commercially available. Hence, this project focused on the preparation of potential and defined biotransformation Phase II sulfated metabolites of silymarin flavonolignans: silybin, 2,3-dehydrosilybin, isosilybin, silychristin, silydianin and flavonoids quercetin, taxifolin, rutin and isoquercitrin. Pure sulfated derivatives were prepared using aryl sulfotransferase from Desulfitobacterium hafniense and aryl sulfotransferase from rat liver. Using heterologously expressed PAPS (3'-phosphoadenosine-5'-phosophosulfate) - independent arylsulfotransferase from Desulfitobacterium hafniense and cheap p-nitrophenyl sulfate as sulfate donor, sulfated flavonolignans and flavonoids were obtained in high yields. Silymarin flavonolignans afforded exclusively monosulfates at the position C-20 (C-19 in the case of silychristin), except 2,3-dehydrosilybin that yielded also the 7,20-O-disulfated derivative. Isoquercitrin and rutin were selectively sulfated...
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Molecular mechanisms of signal transduction in model heme-containing oxygen sensor proteins
Stráňava, Martin ; Martínková, Markéta (advisor) ; Obšil, Tomáš (referee) ; Macek, Tomáš (referee)
EN Heme containing gas sensor proteins play important role in bacterial physiology in regulating many processes such as cell differentiation, virulence, biofilm formation or intercellular communication. For their structure, typical modular architecture is characteristic where various sensor domains (usually at the N-terminus) regulate the activity of the catalytic or functional domains (usually at the C-terminus). In this dissertation thesis, we focused on three representatives from the group of oxygen sensing proteins, namely histidine kinase AfGcHK, diguanylate cyclase YddV, phosphodiesterase EcDOS and also on protein RR, which is the interaction partner of AfGcHK. The main aim of the thesis was to study intra-protein/inter-domain signal transduction in two representatives of heme sensor proteins with a globin fold of the sensor domain (AfGcHK, YddV) and in one representative with PAS fold of the sensor domain (EcDOS). Another objective was to describe inter-protein signal transduction in the two component signaling system AfGcHK-RR and structurally characterize these two interacting partners. Emphasis was also placed on the study of the interaction between model sensor domains and different signaling molecules and also on function of individual amino acids involved in the binding of these...
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Study of function and molecular architecture of fungal nitrilases applicable in biocatalysis
Veselá, Alicja Barbara ; Martínková, Ludmila (advisor) ; Macek, Tomáš (referee) ; Teisinger, Jan (referee)
Nitrilases are enzymes which catalyze the hydrolysis of a nitrile into the corresponding carboxylic acid and ammonia. These enzymes are potentially applicable in biocatalysis and bioremediation because of their advantages over the conventional (chemical) methods of nitrile hydrolysis (lower demand for energy, safety, simplicity, high yields, selectivity). In this work, genome mining was used to search for the sequences of hypothetical nitrilases from filamentous fungi. The amino acid sequences of previously characterized fungal nitrilases were used as the templates. Then the new synthetic genes together with other genes from our nitrilase library were expressed in E. coli and the substrate specificities of the enzymes thus produced were compared. Significant attention was focused on the relationships between the sequence of the enzyme and its substrate specificity. The arylacetonitrilases from Arthroderma benhamiae (NitAb) and Nectria haematococca (NitNh) were purified and characterized. Their substrate specificities, kinetic parameters, pH and temperature profiles and subunit and holoenzyme size were assessed. NitAb and NitNh together with other recombinant fungal nitrilases were employed in the hydrolysis of high concentrations of (R,S)-mandelonitrile in a batch or fed-batch mode. Nitrilase from...
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The Psychological Aspects of Navigation of the Blind
Franc, Jakub ; Kebza, Vladimír (advisor) ; Horáková Hoskovcová, Simona (referee) ; Macek, Tomáš (referee)
This dissertation thesis addresses the area of spatial navigation of the blind. The author theoretically deals with a complex interplay of psychological functions involved in spatial navigation with respect to the specific conditions of the blind. The empirical part of the thesis presents an experimental study in the population of the blind (N=44). This study focuses on effects of the stress recovery phase from shortly increased stress levels on the process of learning a new route. The experiment is placed in real-world settings and overcomes some of the methodological flaws typical for this research domain. The research evidence suggests that the recovery phase from shortly increased stress levels hinders the development of procedural knowledge of the route. However, this deterioration in route knowledge is not associated with the effects of the strsss phase itself, but affects only the recovery phase part of the route in which stress levels are returning to their original baseline levels (not necessarily the level of the resting conditions). Besides its theoretical conclusions, the value of the presented thesis is in its contribution to the advancements of research methods in the given field. The outcomes of this work are practically applicable to the development of navigation aids for the blind....
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Antimicrobial peptides isolated from the venom of hymenopterous insect
Monincová, Lenka ; Čeřovský, Václav (advisor) ; Macek, Tomáš (referee) ; Fusek, Martin (referee)
Rapid development of bacterial resistance and multiresitance to conventional antibiotics has resulted in an intensive search for alternative antimicrobial agents. Antimicrobial peptides (AMPs) belong to promising anti-infective candidates since they do not development bacterial resistance. They kill microbes by disturbing or permeabilizing the cytoplasmic membrane, or may target putative key intracellular compartments. Their advantages include fast action and selectivity between prokaryotic and eukaryotic cells. We have isolated several novel AMPs from the venom of wild bees: halictines (HAL-1 and HAL-2) from Halictus sexcinctus, lasiocepsin (Las) from Lasioglossum laticeps and macropin (MAC-1) from Macropis fulvipes. They are active against Gram-positive and Gram- negative bacteria and against yeast Candida albicans. While halictines and macropin have moderate hemolytic activity, Las shows no hemolytic activity. A novel AMP was isolated also from the mucus of Xiphydria camelus. This AMP belongs to the category of insect defensins. It contains 55 amino acid residues, three disulphide bridges and its C-terminus is amidated. CD and NMR studies of HAL-1, HAL-2 and MAC-1 revealed propensity to form amphipathic α-helical structure in the presence of sodium dodecyl sulfate or trifluoroethanol. For the...
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