The cellular prion protein (PrPc) is essential for pathogenesis of fatal neurodegenerative prion diseases. Recently reported four cases of vCJD transmission by blood transfusion raise concerns about the safety of blood products. Proper understanding of PrPc in blood is necessary for development of currently unavailable blood screening tests for prion diseases. Flow cytometry is an attractive method for prion detection, however, the reports on the quantity of PrPc on human blood cells are contradictory. We showed that the majority of PrPc in resting platelets is present in the intracellular pool and is localized in α-granules. We demostrated that both, human platelets and red blood cells (RBC) express significant amount of PrPc and thus may play an important role in the transmission of prions by blood transfusion. Our results suggest a unique modification of PrPc on human RBC. Such modification of pathological prion protein could distort the results of blood screening tests for prions. Further we showed that the storage of blood prior to analysis and the choice of anti-prion antibody greatly affect the detection of PrPc by flow cytometry and we identified platelet satellitism as a factor contributing to the heterogeneity of PrPc detection in blood cells. Moreover, we demonstrated existence of...

This thesis focuses on various factors affecting effectiveness of aposematic signals against avian predators. Adult, wild-caught as well as hand-reared juvenile great tits (Parus major) were used as predators in the experiments. The thesis consists of the following four studies. In the first study, we compared the reactions of great tits from two geographically distant populations toward aposematic firebugs (Pyrrhocoris apterus) and their non-aposematic artificially made colour variant. The birds from the Bohemian population mostly avoided aposematic firebugs and attacked non-aposematic variant. Finnish birds, which lacked experience with firebugs from their natural environment, were less hesitant to attack both firebug colour forms. Although the Bohemian birds avoided the aposematic prey variant, they were not more neophobic than Finnish birds. We conclude that the geographic differences in reactions of the birds to aposematic prey can be explained by a different population-specific experience of the birds with local aposematic prey communities. In the second study, we compared effectiveness of two chemical defence strategies in leaf beetle larvae (Chrysomela lapponica) against great tits. The birds avoided larvae devoid of external secretions after the first attack, which indicates the presence...

This thesis focuses on to word problems and elementary school pupils. Research on mathematical word problems suggests that differences in success are not only due to different levels of pupils' cognitive abilities but that their motivation plays a role, too. Therefore, in this study, I focused on the context of word problem as a potential source of situational interest, which may affect the quality of pupils' cognitive function in the short term or permanently. I used my participation in a broader quantitatively oriented research on variables influencing the difficulty of word problems and using its methodology, I investigated the influence of different types of contexts on pupils' success in solving the problems. The examined aspect of context was attractiveness - the question was whether pupils would be more successful in solving word problems with elements of fairy tale, science fiction or humour than in similar problems with the same structure but with a neutral context. Pupils of the 3rd to 6th grades of primary school (n = 2 092) were divided into two groups of a comparable ability and each was presented with one of the variants - attractive or neutral. To evaluate the results quantitatively, the Item Response Theory was used allowed us to determine the difficulty of the problem depending on...

This diploma thesis in its theoretical and practical parts focuses on free play of children in pre-school facilities. Kindergarten is the place of early secondary socialization of the child and that's why one part of the diploma thesis is centred on this theme. The theoretical part helps for a deeper understanding of play, especially with 2-4 year old children and builds a foundation for the research. The practical part, based on one year's observation, monitors development of free play of a homogeneous group of children and finds how the quality of play changes with individuals as well as the group. Another focus lies on comparing two separate groups of children in their free play - one group having long term experience with free play and one without such regular experience. The main method of the research is observation. The results of the research points to the importance of free play for a pre-school age child and confirms the influence of free play in the process of early secondary socialization.

thesis: Children of pre-school age are entering stage of structural change of thinking. The way how they grasp solving mathematical tasks reflects whether these changes have already started. This work surveys visible intellectual outputs in the group of 20 children who passed set of experimental tasks at arithmetic learning environments "Stepping" and "Bus". Children were subsequently subjected to pedagogical diagnostics and results of this investigation and carried experiments were trade off. From comparison it can be concluded that results of both surveys correspond enough to facilitate the application of selected mathematical tasks as pedagogical diagnostic tools.

This master's thesis deals with queueing theory and its application in designing node models in packet-switched network. There are described general principles of designing queueing theory models and its mathematical background. Further simulator of packet delay in network was created. This application implements two described models - M/M/1 and M/G/1. Application can be used for simulating network nodes and obtaining basic network characteristics like packet delay or packet loss. Next, lab exercise was created, in that exercise students familiarize themselves with basic concepts of queueing theory and examine both analytical and simulation approach to solving queueing systems.

This diploma thesis deals with problem of design and calculation of membrane structure of stadium roof. This is a complex engineering problem, which includes many partial problems: finding of initial form of membrane, statically and architecturally suitable arrangement of catenaries, economical solution of boundary conditions (foundations). All components affect each other and cannot be dealt without mutual coordination. It always greatly depends on the experience and intuition of engineer who design such structure. Task which cannot be resolved according to the theory of the first order. Equilibrium forces on the deformed structure, which in many projected structures gives satisfactory results, did not correspond to reality. It is therefore necessary to consider equilibrium of forces on the deformed structure according to the theory of large deformations. Diploma thesis was entered with regard to the intention of the companies Ing. Software Dlubal s.r.o. and FEM consulting s.r.o., working together to develop software RFEM. These companies plan to complement this program system with a module MEMBRANE for searching of initial shapes of membrane structures. This work is a contribution to the creation of this module.

This doctoral thesis proposes a new algorithm for the reconstruction of impedance images in monitored objects. The algorithm eliminates the spatial resolution problems present in existing reconstruction methods, and, with respect to the monitored objects, it exploits both the partial knowledge of configuration and the material composition. The discussed novel method is designed to recognize certain significant fields of interest, such as material defects or blood clots and tumors in biological images. The actual reconstruction process comprises two phases; while the former stage is focused on industry-related images, with the aim to detect defects in conductive materials, the latter one concentrates on biomedical applications. The thesis also presents a description of the numerical model used to test the algorithm. The testing procedure was centred on the resulting impedivity value, influence of the regularization parameter, initial value of the numerical model impedivity, and effect exerted by noise on the voltage electrodes upon the overall reconstruction results. Another issue analyzed herein is the possibility of reconstructing impedance images from components of the magnetic flux density measured outside the investigated object. The given magnetic field is generated by a current passing through the object. The created algorithm for the reconstruction of impedance images is modeled on the proposed algorithm for EIT-based reconstruction of impedance images from voltage. The algoritm was tested for stability, influence of the regularization parameter, and initial conductivity. From the general perspective, the thesis describes the methodology for both magnetic field measurement via NMR and processing of the obtained data.

This work concentrates on the study of mathematical models of human behaviour in dynamic games; in particular games with aspects of cooperation, implementation of a model and experimentation with the model. The game DarkElf was chosen for this project. It is a strategic, turn based game with economic and military features, where the decisions made by players are simultaneously implemented at a predetermined time.

Reading comprehension as a prerequisite for successful strategy of word problems solving in mathematics DISSERTATION Mgr. Alena Sigmundová ABSTRACT The dissertation describes the results of an interdisciplinary research study examining the linguistic aspects of word problems in mathematics and the connection between comprehension of the text of word problems and the success of their solution. In the introduction the research is set into the framework of theoretical bases: the term word problem in mathematics and the concept of reading comprehension, including factors influencing the understanding of the text are characterized and the results of previous research studies are described. Subsequently the work presents a methodology, course and results of testing of pupils in three pilot studies and in the main survey and the conclusions from the semi-structured interviews. The research is based on the linguistic analysis of 18 word problems with low solution success, taken from international research surveys PISA 2012 and TIMSS 2007, as well as on the level of comprehension of the text of these tasks in the 8th and 9th grade primary schools, modifying selected language phenomena and detecting the effect of these reformulations. 773 pupils from 13 elementary schools participated in the research. The study...