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Assessment of motor performance in primary school age
Polívka, Tomáš ; Bunc, Václav (advisor) ; Musálek, Martin (referee)
Title: Assessment of motor performance in primary school age Objective: The work had to determinate the condition of motor performance children. Children were from 7 to 11 years old. We wanted to demonstrate increase of motor performance as consequence of natural evolution. We investigated the condition of motor performance and a level of motor abilities. Methods: The main method was the test battery Unifittest 6- 60. This battery showed basic motor performance. We found the condition of movement regime of questionnaire. Results: Bmi moves in a normal category. The basic motor performance moves below average. Girls have the worst results in 11 years. Boys have the worst results in 10 years. Girls have the best results in 7 years. Boys have the best results in 8 years. Motor performace decreases with age. Movement regime don't neglected. The most children visit sports club at least once a week (42,9%). Some children visit sports clubs 3-4 times a week (37%). The most favorite sports are colective games, dancing and swimming. Conclusion: The results show decline of basic motor performance. Dominant physical abilities don't evolve in revelant age. Movement regime isn't neglected, but regime doesn't suffice for development. Children choose of many activities. Children commute to activities often. Key...
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Quantum Coherence for Light Harvesting
Paleček, David ; Dědic, Roman (advisor) ; Jonas, David M. (referee) ; Polívka, Tomáš (referee)
Almost all life on Earth depends on the products of photosynthesis - the biochemical process whereby solar energy is stored as chemical-rich compounds. The energy of captured photons is transferred through a network of pigment-protein complexes towards the reaction center. The reaction center is responsible for trans-membrane charge separation, which generates a proton motive force which drives all subsequent biochemical reactions. The ultrafast (femtosecond) nature of the primary processes in photosynthesis is the main reason for its astonishing efficiency. On this timescale, quantum effects start to play a role and can appear in measured spectra as oscillations. It has been hypothesized that these are evidence of wave-like energy transfer. To unveil the fundamental principals of ultrafast excitation energy transfer in both natural and artificial light-harvesting systems, advanced spectroscopy techniques have been utilized. Coherent two- dimensional electronic spectroscopy is a state of the art technique which allows the most complete spectroscopic and temporal information to be extracted from the system under study. This technique has allowed us to identify a new photophysical process where the coherence of the initially excited state is shifted to the ground state upon an energy transfer step. Coherence...
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Photosynthetic Apparatus of Green Sulfur Bacteria Studied by Coherent Two-Dimensional Electronic Spectroscopy
Dostál, Jakub ; Pšenčík, Jakub (advisor) ; Polívka, Tomáš (referee) ; Ihalainen, Janne (referee)
The process of photosynthesis begins with a capture of sunlight and its quick conversion into the chemical energy. Both these primary processes take place in a specially designed photosynthetic apparatus that is present in cells of all photosynthetic organisms. In green sulfur bacteria the apparatus consists of a massive light-harvesting antenna (chlorosome), intermediate antennas (baseplate complex and FMO proteins) and of the reaction center, where the conversion into the chemical energy occurs. The energy flow through the apparatus can be monitored by time-resolved spectroscopy techniques. Coherent two-dimensional electronic spectroscopy (2DES) in one of such techniques, which combines high temporal and spectral resolution, and therefore it is especially well suited for studying multichromophoric systems such as photosynthetic apparatus. This thesis describes the principles of the 2DES technique and outlines the basic facts about the photosynthetic apparatus of green sulfur bacterium Chlorobaculum tepidum. Finally, it summarizes the investigation of the photosynthetic machinery using 2DES. Results presented in this thesis provide new insights into the exciton diffusion and vibrational coherences within chlorosomes, excitonic structure of the baseplate and the overall energy flow through the entire...
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Bioapplications of novel nanostructured materials
Fučíková, Anna ; Valenta, Jan (advisor) ; Polívka, Tomáš (referee) ; Plášek, Jaromír (referee)
Title: Bioapplications of novel nanostructured materials Author: Anna Fučíková Department / Institute: Department of Chemical Physics and Optics, Faculty of Mathematics and Physics, Charles University in Prague Supervisor of the doctoral thesis: Doc. RNDr. Jan Valenta, Ph.D., Department of Chemical Physics and Optics, Faculty of Mathematics and Physics, Charles University in Prague Abstract: This work is aimed at development of new fluorescent labels based on silicon nanocrystals. Nanodiamonds and commercial CdSe quantum dots have been used as comparative materials. Silicon nanocrystals are relatively small (1-4 nm) compared to other studied nanomaterials. They are prepared by electro-chemical etching and their surface can be activated by various molecules which strongly influences luminescence properties. Luminescence quantum efficiency can be as high as 30 % and perfectly photostable even in biological environment. Si nanocrystals are biodegradable in a living organism within reasonable time scale and non-toxic. We are able to detect luminescence of single nanocrystals, even inside living cells, with use of our micro-spectroscopy apparatus. Nanodiamonds have weak luminescence; they are toxic at higher dosages and very stable in living bodies (without available technique how to remove them). Studied CdSe...
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Vliv redoxního stavu na zhášení excitace v bakteriochlorofylových agregátech
Paleček, David ; Dědic, Roman (advisor) ; Polívka, Tomáš (referee)
Harvesting only 4 % of light striking the Earth could possibly fulfill present energy demands of a mankind. Chlorosome of green sulfur bacteria is re- garded as suitable light-harvesting system for photosynthesis imitation. This work presents comparison of absorption and hole burning spectra of artificially prepared aggregates similar to chlorosomes with different compositions in order to verify the proposed role of quinones in excitation quenching and its redox de- pendence. Absorption spectra at room and helium temperature showed a resem- blance between artificial aggregates and chlorosomes. Hole burning experiments verified the role of quinones in excitation quenching under aerobic conditions. Even more pronounced excitation quenching was observed under anaerobic con- ditions. Significant improvements of the original experimental set-up provided better experimental data which raised many further question that are worth trying to answer in the future.
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The suitable neural network topology design for object recognition in the grass.
Polívka, Tomáš ; Pavlíček, Josef (advisor) ; Hanzlík, Petr (referee)
This thesis describes testing of artificial neural network depending on learning set for object recognition in grass. Values of experimenting with different topologies in Neuroph Studio were recorded. Testing was conducted on three sets of learning basic shapes. Verification of the ability of learning networks were tested using four basic shapes captured in the grass (square, rectangle, circle and triangle). When evaluating the most appropriate topology was defined by two main criteria. Number of successful recognition of shapes and distribution by recognized shapes.
The theoretical part describes the functionality and features of neural networks, image recognition using edge detection and existing applications for recognition of plant species.
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