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A light source with variable intensity
Koždoň, Jakub ; Mojrová, Barbora (referee) ; Boušek, Jaroslav (advisor)
This work is focused on description how the light impact human live, description of light sources and finally design and construction of light source with adjustable colour temperature and luminous flux. In introduction is mentioned the process of vision and how the light impact humans. In next part is characterization of currently used light sources, their construction, properties, benefits and drawback with their main parameters. Important part of this chapter is more extensive description of light emitting diodes with their operational parameters. The last two parts is focused on design and measuring the parameters of created light source with adjustable colour temperature and luminous flux and evaluating the results.
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Jak rostliny vnímají chlad: omická analýza
Karšulinová, Daniela
Plants of temperate zones have developed a sophisticated mechanism that helps them cope with freezing conditions. This process is called cold acclimation. From an agronomical point of view, comprehending this process is necessary to ensure crop yield and quality. This thesis entitled: "Jak rostliny vnímají chlad: omická analýza" describes the molecular mechanism behind the cold acclimation process, specifically the role of light and selected photoreceptors in this process. In the experimental part of the thesis, a mutant line (UVR8 line12-monomer) of model organism Arabidopsis thaliana, which has a partially activated signaling of the UV-B, and the control line (Ws-4) were used. These lines were exposed to cold and UV-B radiation to further study the interaction of the cold signaling pathway and UV-B radiation signaling. LC-MS profiling identified more than 6000 proteins, of which 3472 significantly changed their abundance. Moreover, lipidome analysis was performed using TLC Proteomic analysis revealed an increased abundance of proteins involved in biosynthesis of jasmonic acid. Based on this, a validation experiment with exogenous application of methyl jasmonic acid was performed.
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Cone mosaic in the retina of ray-finned fishes and its function for vision
Konvičková, Zuzana ; Musilová, Zuzana (advisor) ; Němec, Pavel (referee)
Ray-finned fishes comprise more than half of the vertebrate diversity, and they developed many unique strategies and adaptations to inhabit miscellaneous water environments. This thesis is dedicated to vision, which is an indispensable sense for most fishes. Special focus is laid on photoreceptor morphology and their arrangement in a two-dimensional pattern - cone mosaic. There are three morphological types of photoreceptors commonly found in ray-finned fishes - rods, single cones, and double cones. Triple and quadruple cones that have never been observed in any other vertebrate group sometimes occur too. In this thesis, I discuss the structure and function of individual photoreceptors. While rods are randomly distributed across the retina, cones often form a regular mosaic. Several basic mosaic types can be distinguished according to the position of double cones. Row and square mosaics are the most prevalent. Basic patterns can be further modified in certain fish species. In this thesis, I describe basic patterns, I focus on mosaic development, and I investigate the reasons for regular photoreceptor arrangement. The type of mosaic partly reflects phylogeny, but it is also strongly influenced by the environment and life strategy of the fish. Active fishes inhabiting bright environments are likely...
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Distribution of photoreceptor types in retina of fishes from extreme environments
Remišová, Kateřina ; Musilová, Zuzana (advisor) ; Němec, Pavel (referee)
Cichlid visual system is highly adaptive to the environment. Fish visual abilities are deter- mined by composition of opsin-based photosensitive pigments located in photoreceptor cells (rods and cones) as well as their distribution. In this thesis, four species of Lake Barombi Mbo cichlids were targeted: Stomatepia mariae, Konia eisentrauti, Konia dikume and Myaka myaka. Shallow-water cichlids K. eisentrauti and S. mariae express these types of cone opsin genes: LWS, RH2A (RH2Aβ more than RH2Aα), SWS2A and SWS2B. Contra- rily, both seasonally deep-water M. myaka and deep-water K. dikume lack expression of SWS2B and LWS in their retinae, but they express SWS2A and RH2Aα more than RH2Aβ, which corresponds to modified light conditions in deep water - a dimmer habitat lacking marginal parts of the spectrum (i.e., ultraviolet and red wavelengths). The photoreceptor distribution of selected species was investigated by means of fluorescent in situ hybridi- zation (FISH) in order to understand the performance and evolution of their visual per- ception with emphasis on the effect of depth. Distinctively, cichlid cones are arranged in a retinal mosaic consisting of short-wavelength sensitive single cones, each surrounded by four long-wavelength sensitive double cones. In this thesis, the same arrangement is...
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A light source with variable intensity
Koždoň, Jakub ; Mojrová, Barbora (referee) ; Boušek, Jaroslav (advisor)
This work is focused on description how the light impact human live, description of light sources and finally design and construction of light source with adjustable colour temperature and luminous flux. In introduction is mentioned the process of vision and how the light impact humans. In next part is characterization of currently used light sources, their construction, properties, benefits and drawback with their main parameters. Important part of this chapter is more extensive description of light emitting diodes with their operational parameters. The last two parts is focused on design and measuring the parameters of created light source with adjustable colour temperature and luminous flux and evaluating the results.
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