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Effect of cholesterol depletion on signalling cascade initiated with receptors coupled to G protein class Gq/G11
Ostašov, Pavel ; Svoboda, Petr (advisor) ; Teisinger, Jan (referee) ; Hof, Martin (referee)
Membrane domains are an important structure in plasamatic membrane. They concentrate various signaling molecules. Their main structural component is cholesterol and by its removal the membrane domains are disrupted. The aim of our work was to examine the effect of cholesterol depeletion on signaling initiated thyreothropin releasing hormone (TRH). Although its signaling cascade is located within membrane domains the receptor itself is not. We showed that cholesterol depletion by -cyclodextrin caused release of Gq/11 proteins and caveolin 2 from membrane domains. We also discovered that cholesterol depletion decreases potency of TRH to activate G proteins as well as induction of release of intracellular Ca2+ In the last part we investigated the effect of disruption of the cell membrane integrity by cholesterol depletion on thyrotropin-releasing hormone receptor (TRH-R) surface mobility and internalization in HEK293 cells stably expressing TRH-R-eGFP fusion protein. CLSM studies indicated that the internalization of receptor molecules initiated by TRH stimulation was significantly attenuated. The detailed analysis of recovery of TRH-R-eGFP fluorescence in bleached spots of different sizes indicated that cholesterol depletion results in an increase of overall receptor mobility. We suggest that migration of...
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Signalization in the ontogeny of bacterial colonies
Čepl, Jaroslav ; Markoš, Anton (advisor) ; Kuthan, Martin (referee)
Bacterial bodies (colonies) can develop complex patterns of color and structure. These patterns may arise as a result of both colony-autonomous processes (self-patterning) and environmental influences, including those generated by neighbor bodies. We have studied the interplay of intra-colony signaling (self-patterning) and inter-colony influences in related clones of Serratia rubidaea on rich media. We show that the mutual influencing of colonies, present in a common morphospace, is communicated by at least two putative signals. A model accounting for some aspects of colony morphogenesis and inter-colony interactions is proposed. Key words bacteria; Serratia sp.; airborne signals; colony morphogenesis
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The role of nest in reproduction of the Great Reed Warbler
Jelínek, Václav ; Procházka, Petr (advisor) ; Krist, Miloš (referee) ; Trnka, Alfréd (referee)
7 Abstract Bird nests protect eggs and nestlings, allowing the parents to leave their offspring and subsequently return to them. Their thermoregulatory properties reduce energetic costs of incubation and brooding of nestlings. For all these reasons, nests are key structures for the reproduction of a majority of avian species and as such they should be subject to natural selection. Several hypotheses describing selection pressures which affect the size of nests or some of their parts have been suggested. In my PhD thesis, I investigated some of them in the great reed warbler (Acrocephalus arundinaceus) - an open nesting passerine species with very variable nest size. For this purpose, I used a large dataset of several hundred measured great reed warbler nests, nest enlargement experiments and an experiment with artificial nests. In accordance with previous studies, we did not find that nest size affects the probability of common cuckoo (Cuculus canorus) brood parasitism, while it was influenced by other factors, such as timing of breeding, reed density around the nest and nest visibility from the nearest potential cuckoo perch site. More interestingly, we found that cuckoos adjust their nest-searching strategy in relation to availability of host nests. When host nests were scarce, cuckoos parasitized all of...
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Analysis of control traffic in mobile networks
Šubrt, Jan ; Krkoš, Radko (referee) ; Novotný, Vít (advisor)
The Bachelor´s thesis describe management procedures in mobile systems. This thesis is mainly focused on mobile systems GSM and LTE. Further are describe basic processes what are required before starting service. This basic procedures contains: inspection of radio signals, select the cell with the best parameters for connection, allocate channel to mobile station, authentication of subscriber and location update. Next part of thesis describe procedures in handover, initialize call session and data session. Last chapter describes laboratory task for subject Communication resources in mobile networks.
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Home Location Register Emulator
Juránek, Michal ; Ráb, Jaroslav (referee) ; Ščuglík, František (advisor)
This thesis presents basic structure and entities of mobile network GSM. It presents principles of signalling with focus on core network via signalling systems SS7 and SIGTRAN. Chosen protocol layers and signalling message types are presented. The thesis is concluded by the design and implementation of the application emulating home location register of mobile users.
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Controller for the Model Railway Based on FITKit
Kandrik, Ján ; Kotásek, Zdeněk (referee) ; Straka, Martin (advisor)
This work discusses a controller for model railroad derived from a state-of-art railway interlocking system, electronic signalbox. Work of interlocking and model railroad signalling issues are described among the design and implementation parts of such system. Also analyses creation of parts for the controller using FITkit, a microcontroller educational platform.
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Signalling Transmission for Internet Television
Burget, Radim ; Makáň, Florian (referee) ; Vodrážka,, Jiří (referee) ; Komosný, Dan (advisor)
A signalization in an Internet protocol environment is commonly used for monitoring quality of service and other parameters of a network. This thesis is involved in transmission of signalization through internet protocol networks and proposes scalable solution for small and even for large-scale internet television broadcasting. The main contribution of this thesis lies in design and validation of optimal hierarchical tree on the basis of resources assigned. This is done in respect to geographical distance, network distance of each particular member of the hierarchical structure. For the design of algorithms simulations and global experimental network were used.
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Converged solution of speech services
Mácha, Tomáš ; Kovář, Petr (referee) ; Novotný, Vít (advisor)
Development in VoIP technology is connected with the rapid growth of quality and data rate of the Internet connection. The application of the VoIP technology has become one of the key areas in telecommunication and networking. The main task of this thesis was to explore the questions of IP telephony and voice transmission over data networks according to H.323, SIP and Cisco architectures. Next focus was on designing and implementing experimental workplaces of mentioned architectures and their converged solutions. The purpose of the first chapter is to introduce the theory background of architectures required for implementation of real-time services in data networks and their comparison. The key objectives of the second and third part are to design and implement experimental workplaces containing signaling and proxy servers and hardware or software IP phones of several architectures. Illustration examples of different network topologies are included to demonstrate designed and realized VoIP solutions. Several tests of established communication are done using a packet analyzer. These tests examine duplex data transmission over IP. This article also contains two laboratory exercises designed according to gained practical experiences. The laboratory exercises provide an overview of theory and clearly indicate the possibilities of IP telephony.
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Adverse Effects of Monetary Policy Signalling
Matějů, Jakub ; Filáček, Jan
Assuming information asymmetry between private agents and the central bank about the state of the economy, an unexpected change in interest rates signals the central bank’s perceived state of the economy and facilitates an update of private expectations in an adverse, perhaps unintended way. This “updating channel” might counteract the standard transmission from interest rates to inflation and output. We develop a simple model laying down a theoretical basis for the adverse effects of monetary policy signalling. We also detect the presence of the updating channel in private forecasts of inflation in a cross-country sample of selected OECD countries.
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Zadejte název práce
Selep, Ján ; Bartoň, Petr (advisor) ; Bolcha, Peter (referee)
Creative Commons (CC) organization released in 2003 six licenses, which take part of the copyright protection and let other parts fall in the public domain. Consequently, they lower the price of works for future works (inputs) and as an outcome increase creativity and number of works created. On the other hand, CC licenses can serve also as a substitutes to the pure copyright. This thesis examine the impact by analysing United States copyright registration and CC linkback data. The results show insignificance of CC licenses impact on pure copyright licenses. Based on the results I found weak evidence for complementary relationship between the two. Finally, I show that there is no difference between the types of CC licenses as an determinants of number of pure copyright licenses.
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