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Variability in vertebrae numbers and the evolution of body size in geckos
Vohralík, Martin ; Kratochvíl, Lukáš (advisor) ; Frýdlová, Petra (referee)
In ectothermic vertebrates, body segmentation is often linked to final body length. This thesis focuses on the realtionship between final body length, ecological (temperature) and genetic (sex) factors and the count of body vertebrae in the Paroedura geckos, closely focusing on the Paroedura picta species. Individuals of this species were exposed to three different constant rearing temperatures, where they achieved different final sizes. We tested the correlation between the number of presacral vertebrae and final body size and the effect of rearing temperature and sex on the vertebrae number. The data point to high genetic and enviromental canalisation of the vertebrae count. Large conservation in the number of presacral vertebae were found even across the genus Paroedura regardless of the considerable evolutionary changes in body size. Powered by TCPDF (www.tcpdf.org)
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Discrimination and generalization of prey in lizards (Squamata: Sauria)
Vohralík, Martin ; Gregorovičová, Martina (advisor) ; Schořálková, Tereza (referee)
The ability to find and recognize palatable prey is fundamental for survival of any organism. Here we are discussing different ways of recognition of such a prey in order Squamata and the ways they learn this discrimination. Lizards are well known for their ability to analyse chemical cues brought from their tongue to the Jacobson's organ, which is completely separate from the nassal cavity in Squamata. However, the leading sense used for discrimination in Squamata can also be vision or other forms of chemoreception. Dominance of one sense can be assesed from morphology of tongue and abundance of taste buds or ecological strategy used for hunting a prey. Once the predator learns which cue to discriminate, it can generalise similar cues. Powered by TCPDF (www.tcpdf.org)
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Identification of rate type fluids suitable for modeling geomaterials
Tůma, Karel ; Málek, Josef (advisor) ; Čadek, Ondřej (referee) ; Vohralík, Martin (referee)
In the present thesis we study and compare different viscoelastic rate-type fluid models capable of describing response of geomaterials such as asphalt. Using new thermodynamic approach proposed by Rajagopal and Srinivasa (2000) we derive several classes of non-linear viscoelastic models that generalize standard Oldroyd-B and Burgers models. We show that the new models achieve better results in fitting experimental data with asphalt than the previously considered models (Oldroyd-B, Burgers, Rajagopal and Srinivasa (2000)). In particular they are able to capture the behavior of asphalt observed recently in experiments (torque overshoot and two relaxation mechanisms), which is not possible to describe by the other models. Using both the standard and the newly derived models we compute full simulations of viscoelastic flow with the finite element method in fixed domains and incorporating the Arbitrary Lagrangian-Eulerian description also in deforming domains. For example, we study rolling of asphalt or creation of ruts in the road with the real material parameters obtained by fitting the experiments. Powered by TCPDF (www.tcpdf.org)
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