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This work deals with numerical modeling of electromagnetic induction in 3D environment with heterogeneous conductivity. We develop a program to solve Maxwell's equations in quasistatic approximation by using Continuous and Discontinuous Finite Elements. Their implementation in the numerical library deal.ii is discussed. The obtained numerical results are compared with each other and also with a quasianalytic solution for an environment with 1D heterogeneous conductivity. We discuss different numerical methods, limits of our code for practical use and possible future enhancements.

There are a large number of natural and synthetic environmental contaminants (ECs) known or suspected to mimic or interfere with male reproductive endocrine functions. Our current knowledge is largely addressed to ECs that induce oestrogen-induced feminization. However, there are several ECs that cause alternations in androgen production similar to oestrogenic ECs, but they do not induce vitellogenin-induced feminization. The mechanisms of action of these chemicals are still unclear due to the fact that androgen receptor (AR) functions in androgen-mediated male reproductive physiology are largely unknown. In the present study, we examined the effects of vinclozolin (VZ) (100, 400 and 800 ?g/L) and di-(2-ethylhexyl)-phthalate (DEHP) (1, 10 and 100 ?g/L) on male reproductive performance in goldfish following 30 days of exposure. Since both VZ and DEHP act as agonists and/or antagonists of hormonal receptors, estrogen receptor subtypes (er) and androgen receptor (ar) mRNA levels were studied. For studying their oestrogenic activity, one group of goldfish were exposed to 17?-estradiol (E2). In DEHP treated goldfish, sperm production, motility and velocity were decreased at 1, 100 and 10 ?g/L, respectively. Our previous study has shown that sperm production, motility and velocity were decreased in goldfish exposed to 800 ?g/L VZ. These suggest that DEHP and VZ are capable of interfering with spermatogenesis and sperm maturation. In E2 treated goldfish, none of the males produced sperm, indicating E2-suppressed spermatogenesis. Similar to E2 treated goldfish, 11-KT levels were decreased in goldfish exposed to ?10 and ?1 ?g/L DEHP at day 15 and 30, respectively. In VZ treated goldfish, 11-KT levels were decreased in goldfish exposed to 800 ?g/L VZ following 7 d, but increased in goldfish exposed to 100 ?g/L VZ following 30 d of exposure. E2 levels remained unchanged and increased in DEHP and E2 treated goldfish, respectively. In VZ treated goldfish, LH levels were increased at 100 ?g/L. In contrast, LH levels were decreased in DEHP and E2 treated goldfish following 15 d of exposure. There were also positive relationships between LH and 11-KT levels suggesting that inhibition or stimulation of androgen production were mediated by DEHP- or VZ-induced alternations in pituitary function. In VZ treated goldfish, gnrh3 mRNA levels were decreased following 7 d of exposure and increased at low dose following 30 d of exposure. kiss1 or kiss2 mRNA levels were also increased in VZ treated goldfish, while gpr54 mRNA remained unchanged. In DEHP treated goldfish, gnrh3, kiss1 and its receptor (gpr54) mRNA levels did not change during the period of exposure. In E2 treated goldfish, gnrh3 mRNA levels were decreased at day 7, but kiss1 and gpr54 mRNA levels were increased at day 30 of exposure. These results suggest that, in contrast to DEHP, VZ effects on pituitary and testicular functions are mediated by disruption of hypothalamus function and upstream neuroendocrine regulators. The brain ar and testicular lhr mRNA levels were changed in VZ and E2 treated goldfish depending on dose and period of treatment, however they remained unchanged in DEHP treated goldfish. These differences suggest that DEHP may act through an independent hormonal receptor pathway, while VZ acts through a receptor pathway. vtg, er and cyp19a1b remained unchanged in DEHP and VZ treated goldfish but increased in E2 treated goldfish. These indicate that neither VZ nor DEHP acts as oestrogenic compound to impair male fertility. In conclusion, DEHP and VZ reduced sperm quality in goldfish due to stimulation and inhibition of 11-KT production which were mediated by alternations in pituitary function to produce LH or by disruption of the transfer of Cholesterol to steroidogenesis. Upstream neuroendocrine regulators (gnrh3 and kiss-1/gpr54) were disrupted in VZ treated goldfish. Taken together, VZ and DEHP differentially act on brain and testis to impair fertility endpoints.

The master thesis is focused on a remanent magnetism of electromagnets of DC contactors. In the first part of the thesis deals with the formation of a magnetic field in different kinds of materials, description of their magnetization and sorting. The next part is focused on the principle and history of an electromagnet. Negative effects and remanent induction of the contactor are described in the end of the theoretical part. The second part is a practical part. First, the reaction times were measured on a pair of DC contactors. Using the obtained data, an electronic circuit was designed to minimize the difference in switching times of the given DC contactors.

Flavonoids are natural compounds commonly ingested in herbs and vegetables. They are believed to have a positive impact on human organism, in particular by their antioxidant, hepatoprotective and anti-cancer effects. In these days, it is possible to consume high concentrations of these compounds in form of dietary supplements. However it is not clear, whether flavonoids in such unnaturally high concentrations are still beneficial or rather harmful. It has already been proven, that flavonoids can influence the activity of biotransformation enzymes and interfere e.g. with the process of carcinogenesis and drug metabolism. For that reason it is important to investigate the impact of an increased intake of flavonoids. The aim of this thesis was to investigate the influence of dihydromyricetin (a potential drug to cure alcohol use disorder) and its structurally similar flavonoid myricetin on the activity of enzymes, cytochrome P450 2E1 (CYP2E1) and N­acetyltransferases 1 and 2 (NAT1/2). The research included the determination of the impact of a premedication by these flavonoids on the expression and activity of CYP2E1 and NAT1/2. The inhibition capacity of myricetin and dihydromyricetin towards the activity of CYP2E1 and NAT1/2 was also investigated. After the flavonoid premedication of rats the...

CHARLES UNIVERSITY IN PRAGUE Faculty of Science Department of Biochemistry Effects of chemopreventive compounds on cytochrome P450s Summary of Ph.D. Thesis RNDr. Jitka Křížková Supervisor: prof. RNDr. Petr Hodek, CSc. Prague 2010 Introduction 1 Introduction According to the World Health Organization statistics, cancer is one of the leading causes of death in the human population worldwide for more than 50 years. Moreover, colorectal and gastrointestinal tract cancers are one of the main types of cancer leading to overall cancer mortality. Prevention consisting in a healthy lifestyle and a natural diet is suggested to be one of the main approaches to reduce cancer risk. In recent years, the consumption and use of dietary supplements containing concentrated chemopreventive phytochemicals increased dramatically. Flavonoids, as the most popular representatives of chemopreventive compounds, present in foods (fruits, vegetables, herbs, beverages) and dietary supplements have the potential to modulate the activity of xenobiotic-metabolizing enzymes [Hodek et al., 2002]. Among proteins interacting with flavonoids, cytochrome P450s (CYPs), monooxygenases metabolizing xenobiotics (e.g. drugs, carcinogens), play the most prominent role. The two members of CYP1A subfamily, CYP1A1 and CYP1A2, are involved in the...

Hormonally induced artificial propagation of individually marked broodstock was performed identically at two sequential reproductive seasons. In both years, four separate groups of females were intraperitonealy injected by carp pituitary extrakt, Supergestran (containing GnRH analogue Lecirelin), Ovopel and Dagin (containing GnRH analogue and dopamine inhibitor) at 21 °C. In control group, no injection was carried out in broodstock. It observed the effect of treatment on the ovulation ratio, survival and growth of broodfisch, the ability of stripping in the next season and the effect on eggs.

The diploma thesis concerns the elaboration of excercises of inequality which were placed in mathematics olympics in 1951-1975, the clasification of inequality in agreement with the method of solution and showing other ways of solution. The thesis should serve as an addiltiolal study material for students interesed in mathematics.

This thesis presents the psychological concept of dreams and fairy tales and the possible similarities existing between them. Its main source is a depth psychology, psychoanalysis particularly. The thesis is consisting of two parts. In the first part, the theories of dreams and fairy tales are described and the possibilities for their interpretations are given. Then the affinity between dreams and fairy tales is presented including the theory of the Hungarian psychoanalytic Géza Róheim and the Israeli psychologist Ravit Raufman. Róheim assumes that fairy tales represent a social transformation of individual dreams. The development of this idea is: the fairy tales are inducting dreams that would be dreamed, anyway. But they finish better now, with the victory for the child. Raufman applies the methods with which fairy tales have been studied on dreams and defines the affinities between them. In the other part, the similarities between dreams and fairy tales are checked using collected dreams of children aged from 6 to 15. Dreams are interpreted with a special attention to a fourteen years old girl. The thesis also works with the dream of a young woman collected by Raufman. Finally, an explicit and implicit content and formal characteristics of the children's dreams are compared with the most famous...

The thesis deals with brief introduction of the quantile regression theory. The thesis is divided into three thematic parts. In the first part the thesis deals with general introduction to the quantile regression, with theoretical aspects regarding quantile regression and with basic approaches to estimation of quantile regression parameters. The second part of the thesis focuses on general and asymptotic properties of the quantile regression. Goal of this part is to compare the quantile regression with traditional OLS regression and outline its possible application. In the third part the thesis describes statistical inference, construction of the confidence intervals and testing statistical hypotheses about quantile regression parameters. The goal of this part is to introduce traditional approach and the approach based on resampling procedures and in the end of the day perform mutual comparison of different approaches eventually propose partial modification.