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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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Peptide inhibitors immobilized on magnetic particles and Sepharose used for separation of stomach aspartate proteinases
Rajčanová, Michaela ; Kučerová, Zdenka (advisor) ; Fusek, Martin (referee) ; Pacáková, Věra (referee)
IN ENGLISH Human gastric juice contains mainly aspartate proteinases: pepsin A and pepsin C. Both pepsins are produced by gastric mucosa as inactive pepsinogens and they are activated to the corresponding pepsins in the acidic environment of the gastric lumen. The levels of pepsinogens in serum reflect the morphological and functional status of gastric mucosa. A subject of this thesis is a part of a long-term investigation that focuses on the elaboration of methods for separation gastric aspartate proteainases that would be suitable for diagnostic purposes. The preparation of new type ligands was a concrete subject of PhD. thesis that after their immobilization they can enable the separation of aspartate proteinases. Four heptapeptides containing D-leucinyl residue were synthetized (Val-D-Leu-Pro-Phe-Phe-Val- D-Leu, Val-D-Leu-Pro-Tyr-Phe-Val-D-Leu, Val-D-Leu-Pro-Tyr-Tyr-Val-D-Leu and Val-D- Leu-Pro-Phe-Tyr-Val-D-Leu. The prepared heptapeptides immobilized on agarose magnetic particles were used for the study of their interaction with porcine pepsin A and rat pepsin C. While porcine pepsin A was adsorbed to all heptapeptides immobilized to magnetic particles, rat pepsin C was not retarded. Similar results were obtained using heptapeptides immobilized to Sepharose. The situation was more complicated...
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New antimcrobial peptides isolated from the bee venom and the study of their action mechanism
Čujová, Sabína ; Čeřovský, Václav (advisor) ; Fusek, Martin (referee) ; Hlaváček, Jan (referee)
EN The growing emergence of bacteria resistant to conventional antibiotics is very alarming. This has prompted an intensive search for alternative antimicrobial agents which kill bacteria with different modes of action than do traditional antibiotics and do not develop drug resistance. Among these, antimicrobial peptides (AMPs) are considered as promising compounds against resistant pathogens. These positively charged peptides permeabilize or disrupt bacterial cell envelope which leads to leakage of cytoplasmic components and cell death. The aim of my dissertation thesis was the study of the action mechanism of novel antimicrobial peptides which I have isolated from the venom of different wild bees. I identified six novel AMPs which were named panurgines (PNG), codesane (COD) and antapines (ANTPs). These peptides were isolated from the venom of three different bee species (Panurgus calcaratus, Collete daviesanus and Anthophora plumipes). I was also involved in the structural studies of lasiocepsin (Las), the antimicrobial peptide identified in the venom earlier in our laboratory. All studied peptides possess activity against various strains of bacteria and low or moderate hemolytic activity. We prepared series of PNG, COD and ANTP analogs in order to study the effect of physicochemical properties...
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Highly time resolved measurement of atmospheric elemental and organic carbon at a typical background site in Central Europe.
Mbengue, Saliou ; Fusek, M. ; Schwarz, Jaroslav ; Holoubek, Ivan
Atmospheric organic (OC) and elemental (EC) carbon play an important role in atmospheric chemistry, climate change and public health. There have been relatively few studies dealing with EC and OC in rural background sites which are less influenced by urban and industrial emissions. Nevertheless, measurements at background areas are important for understanding the transport and transformation characteristics of anthropogenic air pollutants, and their effects on various aspects of regional and global environment changes. In this study, we focus on variability of EC and OC concentrations (considering various day categories and seasons) from a rural background site which is representative for Central European rural areas.\n
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Extreme Value Distributions with Applications
Fusek, Michal ; Skalská,, Hana (referee) ; Karpíšek, Zdeněk (referee) ; Michálek, Jaroslav (advisor)
The thesis is focused on extreme value distributions and their applications. Firstly, basics of the extreme value theory for one-dimensional observations are summarized. Using the limit theorem for distribution of maximum, three extreme value distributions (Gumbel, Fréchet, Weibull) are introduced and their domains of attraction are described. Two models for parametric functions estimation based on the generalized extreme value distribution (block maxima model) and the generalized Pareto distribution (threshold model) are introduced. Parameters estimates of these distributions are derived using the method of maximum likelihood and the probability weighted moment method. Described methods are used for analysis of the rainfall data in the Brno Region. Further attention is paid to Gumbel class of distributions, which is frequently used in practice. Methods for statistical inference of multiply left-censored samples from exponential and Weibull distribution considering the type I censoring are developed and subsequently used in the analysis of synthetic musk compounds concentrations. The last part of the thesis deals with the extreme value theory for two-dimensional observations. Demonstrational software for the extreme value distributions was developed as a part of this thesis.
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Statistics of extremes
Fusek, Michal ; Neubauer, Jiří (referee) ; Michálek, Jaroslav (advisor)
The thesis deals with extreme value distributions. The theoretical part is devoted to the basics of extreme value theory and to the characterization of extreme value distributions. There is the limit theorem for distributions of the maximum formulated and characteristics of the extreme value distributions deduced. There are parameter estimates for Weibull, lognormal and exponential distributions inferred using method of maximum likelihood and method of moments. There is also the theory of censored samples described. The practical part is devoted to statistical analysis of rainfall.
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Sampling procedures for inspection by attributes
Bartušek, Petr ; Fusek, Michal (referee) ; Michálek, Jaroslav (advisor)
This bachelor´s thesis deals with a description of sampling procedures for inspection by attributes. In the thesis there are described three discrete probability distributions – hypergeometric distribution, binomial distribution and Poisson distribution, including the convergence of their probability mass functions and cumulative distribution functions. The main aim of the thesis is a determination of a sampling plan for sampling procedures for inspection by attributes. The thesis is supplemented with three created programs, which are programmed in software Matlab.
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The choice of the best somatotype for a given sport using factor analysis
Bušík, Peter ; Fusek, Michal (referee) ; Michálek, Jaroslav (advisor)
This bachelor’s thesis deals with factor model, which is used for data reduction. The purpose is to find unobservable common factors, by which we are able to simply describe observed data. The thesis presents an estimation for parameters of factor analysis by the principal component method, a factor rotation by the varimax method and a way of estimating factor scores by the regression method. Using the computing programme STATISTICA, we apply the factor analysis on the data set, obtained in Korfball. Based on the results, we try to determine the best somatotype for players of this sport.
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Dependence Measures
Janda, Radek ; Fusek, Michal (referee) ; Michálek, Jaroslav (advisor)
This thesis focuses on characteristics of the dependence measures among random quantities, as well as its use in industry. The theoretical part focuses on examples of the characteristics used. Furthermore, the software Statistica is described here, for its possibilities of implementing such characteristics. On simple examples, the use of dependence measures is shown. In the practical part, the thesis focuses on statistical analysis of real industrial data, whilst implementing the theory mentioned above.
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