Operation of railway vehicles at higher speeds is conditioned by assurance of a stable run of the vehicle in straight track with a high level of geometric parameters. This property is usually reached by retrofitting of a joint between the vehicle body and the bogies with an efficient damping with suitable characteristics. As the relative motion between the vehicle body and the bogies in the straight track shows low amplitudes and high velocities, special longitudinal dampers - so-called yaw dampers - are used for these purposes. The aim of this paper is a theoretical analysis of influence of yaw dampers characteristics on the stability limit of a locomotive performed by means of sensitivity analysis. and Obsahuje seznam literatury
The paper presents the results of research related to the application of GNSS solutions in short observational periods in geodynamical investigations. Authors used the 3-hour solution appointed from hour-long interval of about 30 chosen stations on mountainous terrains from over 100 which were worked out. The main aim was to check the correctness of such solutions by the comparison with the daily ones. Some outliers in East component could testify, that tropospheric or ionospheric models used in the data adjustment are not sufficient for so short-time solutions. The second principal problem, which was considered in the present work is the ability to detect diurnal and sub-diurnal oscillations in changes of permanent stations’ coordinates. Results show unambiguously, that such oscillations appear in all analysed stations. In the paper there are examples of stations with dominant oscillations in different frequencies. The clear homogeneous in the frequencies was not found among any group of stations. It is therefore difficult to affirm, if their origin comes purely from the geodynamical phenomena., Andrzej Araszkiewicz, Janusz Bogusz, Mariusz Figurski and Karolina Szafranek., and Obsahuje bibliografii
In this work we report on the implementation of methods for data processing signals from microelectrode arrays (MEA) and the application of these methods for signals originated from two types of MEAs to detect putative neurons and sort them into subpopulations. We recorded electrical signals from firing neurons using titanium nitride (TiN) and boron doped diamond (BDD) MEAs. In previous research, we have shown that these methods have the capacity to detect neurons using commerciallyavailable TiN-MEAs. We have managed to cultivate and record hippocampal neurons for the first time using a newly developed custom-made multichannel BDD-MEA with 20 recording sites. We have analysed the signals with the algorithms developed and employed them to inspect firing bursts and enable spike sorting. We did not observe any significant difference between BDD- and TiN-MEAs over the parameters, which estimated spike shape variability per each detected neuron. This result supports the hypothesis that we have detected real neurons, rather than noise, in the BDD-MEA signal. BDD materials with suitable mechanical, electrical and biocompatibility properties have a large potential in novel therapies for treatments of neural pathologies, such as deep brain stimulation in Parkinson’s disease.
This study deals with the application of the previously developed immobilized and perfused isolated hepatocytes as a cellular system for the study of representative phase 1 and phase II of biotransformation reactions. To illustrate phase I reactions, aminopyrine (0.17-4.25 mmol/1) and hexobarbital (0.2 mmol/1) were selected. For phase II reactions, glutathione transferase activity was evaluated by using l-chloro-2,4-dinitrobenzene (CDNB) as a substrate (0.125-2.0 mmol/1). Formaldehyde, that was formed from aminopyrine, increased steadily in the perfusion medium with time. The perfused hepatocytes eliminated hexobarbital at a much higher rate than the hepatocytes in suspension. At several time points the amount of CDNB-glutathione conjugate formed per one million hepatocytes in the bioreactor was almost twice the amount formed by the hepatocytes in suspension. The present data illustrate the successful application of the hepatocyte bioreactor in phase I and phase II of xenobiotic metabolism and indicate that the cells were metabolically more active than the cells in suspension.
It has been shown that, in addition to conventional contact electrode techniques, optical methods using fluorescent dyes can be successfully used for cardiac signal measurement. In this review, the physical and technical fundamentals of the method are described, as well as the properties of the most common systems for measuring action potentials and intracellular calcium concentration. Special attention is paid to summarizing limitations and trends in developing this method., M. Ronzhina, ... [et al.]., and Obsahuje seznam literatury
This work presents new application of the random field theory in medical imaging. Results from both integral geometry and random field theory can be used to detect locations with significantly increased radiotracer uptake in images from positron emission tomography (PET). The assumptions needed to use these results are verified on a set of real and simulated phantom images. The proposed method of detecting activation (locations with increased radiotracer concentration) is used to quantify the quality of simulated PET images. Dependence of the quality on the injection dose (amount of applied radiotracer) and patient's body parameters is estimated. It is used to derive curves of constant quality determining the injection dose needed to achieve desired quality of the resulting images. The curves are compared with the formula currently used in medical practice.
The aim of this article is to inform reader about the development steps which are used during the development of a critical control algorithm in aerospace industry. An article describes the motivation for use of automatic code generators for the development of critical control applications. A V-cycle model based design is introduced and its advantages and development practices that lead from design of a MATLAB/Simulink models to a real target application are depicted. and Obsahuje seznam literatury
SSCP (single-strand conformation polymorphism) analyses of ubiquitin genes were used to investigate evolutionary relationships within the subgenus Orinocarabus of the genus Carabus. After SSCP electrophoresis of PCR-amplified ubiquitin copies, population-specific band patterns were obtained. Ubiquitin-SSCP-analyses of the six central European Orinocarabus species, including three subspecies and thirteen populations, resulted in a dendrogram that differed from that based on morphology. Phylogenetic analysis of mitochondrial DNA (mtDNA) did not support the SSCP dendrogram, but was in good accordance with the taxonomy based on morphological characters. The reason for the discrepancies seems to be evolutionary conservation of the ubiquitin genes. The time that elapsed since the evolution of the closely related Orinocarabus species is too short for concerted evolution of the ubiquitin genes.
A synthesis of recent development of regime-switching models based on aggregation operators is presented. It comprises procedures for model specification dans identification, parameter estimation and model adequacy testing. Constructions of models for real life data from hydrology and finance are presented.