National Repository of Grey Literature 6 records found  Search took 0.01 seconds. 
The Maternal Synchronization of the Fetal Biological Clock in Laboratory Rat
Houdek, Pavel ; Bendová, Zdeňka (referee)
2 Abstract In mammals, the central biological clock is located in the suprachiasmatic nuclei of the hypothalamus (SCN). Neurons of the SCN display circadian rhythmic activity and coordinate physiological functions within a day. At the molecular level, the rhythmicity of these neurons is based on transcriptional-translational feedback loops in the expression of so-called clock genes. During ontogenesis, the spontaneous rhythmicity evolves in the SCN gradually from the prenatal period and is affected by the maternal organism signals. The mechanisms of the maternal entrainment were investigated in two publications, which this thesis is based on. The first publication aimed to determine when the clock gene expression begins to be rhythmic in the SCN during the prenatal development of the laboratory rat. Two 24-hour clock gene expression profiles in the fetal SCN were compared under physiological conditions at two different development stages. The result showed that all three measured clock genes (Bmal1, Per2 and Rev-erbα) were expressed rhythmically on the 21st day of the embryonic development. However, only the expression of gene Rev-erbα was found to be rhythmic at the embryonic day 19. In the second publication, we investigated the effect of the maternal hormone melatonin on the entrainment of the circadian...
Advantages and risks of introducing animal legal personality into Czech law system
Houdek, Pavel ; Stejskal, Vojtěch (advisor) ; Derlich, Stanislav (referee)
Advantages and risks of introducing animal legal personality into Czech law system The topic of my thesis is animal legal personality and consideration of advantages as well as negative aspects of introducing it into the Czech law. The aim of this work is to examine whether the animal legal personality is a solution that could lead to higher animal protection. In order to assess the benefits and risks of introducing legal personality of animals, I analyze the current legal status and investigate whether animals have any rights today. Furthermore, I concentrate on whether the integration of the legal personality of the animals into the legal system is at all possible, and seek such form that would make the integration acceptable. The work is divided into six chapters. In the first chapter I examine the history of the legal protection of animals with a focus on its development in the Czech lands. The second chapter is a summary of current legislation of animal rights, especially in the Czech Republic but also in other European countries. There is a sub-chapter here dealing with international law that has a direct impact on the Czech law. In the last sub-chapter I seek an answer whether, according to the applicable law of the Czech Republic, the animals already have any rights today. In the third chapter I...
Circadian system and memmory
Skálová, Kateřina ; Bendová, Zdeňka (advisor) ; Houdek, Pavel (referee)
Circadian system is a part of all living organisms. It controls suitable timing of their physiological functions and behaviour. The molecular mechanism of interlocking transcription-translational feedback loops of clock genes and their protein products forms the core of the circadian system. The main structures of this system in mammalian organisms are suprachiasmatic nuclei of the hypothalamus. Memory is also closely connected with circadian system. It is one of the most important abilities of organism for creating knowledge. Both memory and circadian system enable to the organism to adapt to changes in its external environment. The expression of clock genes was detected in brain structures involved in mediation of memory such as hippocampus, amygdale and basal ganglia. The oscillations of these clock genes influence the formation and retrieval of memory traces. The aim of this work is to summarize current knowledge about the relationship between the memory and the circadian system. Key words: circadian system, memory, clock genes, suprachiasmatic nuclei, hippocampus
Synchronization of circadian system during prenatal and early postnatal development
Houdek, Pavel ; Sumová, Alena (advisor) ; Novotná, Růžena (referee)
One of the few attributes common to almost all living organisms is an ability to generate and maintain endogenous rhythms, which are controlled by a biological clock. The processes, which recur with a period of about 24 hours, are known as the circadian rhythms. The circadian clock controls rhythms of molecular, physiological as well as behavioral processes and adapts their activity to regularly appearing changes in day and night or season. In case of mammals, central oscillator is located in the hypothalamic suprachiasmatic nuclei (SCN). The SCN clock entrains rhythms of peripheral oscillators located in cells of other tissues. The central oscillator itself is synchronized with external environment mainly by a light-dark cycle, however, other cues can entrain the SCN clock as well. For example, during prenatal development, entrainment of a fetal clock is entirely dependent on non-photic cues derived from maternal organism. This study aimed to investigate a mechanism of the communication between the maternal and fetal central oscillators. A hypothesis was tested whether maternal melatonin may play a role in entrainment of the circadian clock in the fetal SCN. Furthermore, a mechanism, how melatonin may entrain the fetal clock was investigated at molecular level. The results provided evidence, that...
Parametric Study on Flow Behind Backward-Facing Step in a Narrow Channel
Uruba, Václav ; Houdek, Pavel
Flow behind the backward-facing step in a narrow channel is studied using a simple CFD modelling using CFX code. Parametric study of the case changing the step height, flow velocity and thickness of the boundary layer in the channel inlet is performed to show qualitative influence of the above mentioned parameters on the flow.

See also: similar author names
4 HOUDEK, Petr
4 Houdek, Petr
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