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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 VoIP
Bílek, Tomáš ; Ščuglík, František (referee) ; Ráb, Jaroslav (advisor)
The thesis explores practical applications of VoIP technology at home, in combination with the opensource private branch exchange Asterisk. A substantial part of this work is the documentation of the functioning of the main parts of public switched telephone networks (PSTN) and VoIP networks. Also described are the principles of voice digitization, commonly used codecs and several VoIP protocols. The last part of the thesis focuses on the design, practical realization and verification of two home VoIP installations.
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Mobile Switching Centre Emulator
Králíček, Jan ; Ráb, Jaroslav (referee) ; Ščuglík, František (advisor)
This thesis attempts to provide basic overview of the topic of the GSM system and tries to design Mobile Switching Centre Emulator that could perform the operation Location Update. The first part of this thesis describes the principles and specifics of the GSM network (network structure, the operations required to support user mobility, network entities, etc.). The second part of this thesis describes the SS7 signaling protocols, SIGTRAN and MAP protocol. The final part deals with design of the emulator.
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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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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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Home security system - remote access module
Šarda, Petr ; Bradáč, Zdeněk (referee) ; Fiedler, Petr (advisor)
This thesis deals with remote access module for electric security systems (ESS). The design is based on valid standards that apply to a production of electric security system. It includes a design of module connection to the central that controls the module. There is also a communication protocol for connection with the central and with the user. The last step is development of web interface, which is realized on the selected development kit.
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