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The impact of UV radiation on activity and content of Rubisco enzyme in beech
Cigánková, Michaela ; Urban,, Otmar (referee) ; Hrstka, Miroslav (advisor)
This bachelor thesis deals with the influence of UV radiation on content and activity of Rubisco enzyme in leaves of European beech (Fagus sylvatica). Plants were cultivated in ambient (UV), lower (UV-) and higher (UV+) UV-B radiation both at ambient (AC) and elevated (EC = 700 micromol mol-1) CO2 concentrations. Leaves sampling was done four times during the growth season, in the second part of July, at the beginning and in the end of August and in the middle of September. Rubisco activity was assayed spectrophotometrically, the content of Rubisco was determined by SDS-PAGE method and quantified by computer densitometry. The results confirmed a reduction of Rubisco content and down-regulation on Rubisco level at elevated CO2 concentration. With the exception of September sampling, the content of Rubisco was lower in UV+ at ambient concentration of CO2. The same was not demonstrated at elevated CO2 conditions. Hypothesis that UV-B radiation changes a ratio of large to small subunit of Rubisco was confirmed. The influence of UV-B radiation on Rubisco activity was not proved.
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Strength-strain analysis of dog prosthesis
Doležalová, Veronika ; Hrstka, Miroslav (referee) ; Vlach, Radek (advisor)
Bachelor thesis deals with strength-deformation analysis of dog prosthesis. Work contains introduction to problems of prosthesis and determination of kinematice during dog’s movements. The analysis was carried out using two approaches, both analytical and numerical. In conclusion, we compare the results of both computational approaches.
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Crack in prismatic bars
Meňhert, Samuel ; Hrstka, Miroslav (referee) ; Profant, Tomáš (advisor)
This thesis deals with summarization of information about fracture mechanics mainly with methods which estimate stress intensity factors. They play an important role in determination of behavior of cracks in engineering process. The main goal of this thesis will be familiarization with Kienzler hypothesis which deals with strain energy release rate and internal effects in a point of disrupted cross section and comparison with classic K-concept, when the stress intensity factors are determined by infinite series.
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Determination of basic chemical characteristics of blueberry pulp
Strapcová, Zuzana ; Hrstka, Miroslav (referee) ; Vespalcová, Milena (advisor)
This bachelor thesis deals with the investigation of selected chemical characteristics in the semifinished products of blueberries (Vaccinium myrtillus L.) and blueberries high (Vaccinium corymbosum L.). The theoretical part is described the botanical characteristics of both blueberries. The use of fruits is described in the next part. A description of the determination of the selected characteristic, refractometric of sugar dry mater, is described at the end of the theoretical part. In the experimental part, chemical characteristics were determined as total and soluble solids, pH, amount of titratable acids, reducing carbohydrates, phenolics and total anthocyanins in juice, pulp and extracts of blueberries. The purpose of the extracts was to find out how many total anthocyanins and phenolics are found in the skin of the fruit and which extract gives the highest yields. The results of the characteristics were compared across the wholefruit and semifinished products of the both blueberries. A mixture of water and ethanol in a ratio 50:50 was the most suitable solvent. The maximum extraction dependence was at twelfth and thirteenth hours of maceration. The maximum extraction dependence was determined by the above described chemical characteristics. Content of anthocyanin dyes expressed as delphinidin-3-glucoside was determined in extract of blueberry in 59,7 mg DGE100 g-1 and blueberries high in 19,6 mg DGE100 g-1. Total phenolics content expressed as gallic acid was determined in extract of blueberry in 890,9 mg GAE100 g-1 and blueberries high in 249,9 mg GAE100 g-1.
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Impact of nitrogen fertilization and drought on gliadins content in winter wheat
Odstrčilová, Eva ; Obruča, Stanislav (referee) ; Hrstka, Miroslav (advisor)
In this diploma thesis the impacts of both nitrogen fertilization and drought on the content of proteins of the gliadin fraction in case of a winter wheat variety Tiguan were observed. Selected samples were cultivated at two locations in a total duration of two years. Two different conditions were selected: one without the nitrogen fertilization (0 kg N/ ha) and the other with the nitrogen fertilization in 140 kg N/ ha concentration. Second observed factor was the drought which was ensured by roofs above the crops and their cultivation in common climatic environment. Gliadin fraction was separated by the A-PAGE method and the protein quantification carried out by a computer densitometry. Such nitrogen fertilization caused a significant increase of gliadins, especially -1,2 and -5 fractions. Stress induced by the drought caused an increase of gliadin content compared to the control sample, particularly in case of - and - fractions. The most important factor influencing the gliadin content in grains was therefore the nitrogen fertilization in a dry environment. The observed increase of gliadin content was lower in case of the sample which was fertilized in a humid environment than in case of the sample which was fertilized in the dry one.
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Monitoring of oxidative stability of products from shell fruits
Krňávková, Martina ; Hrstka, Miroslav (referee) ; Vítová, Eva (advisor)
The diploma thesis deals with the monitoring of oxidative stability of products, oils and butter, from nut fruits. The theoretical part concentrates on the topic of nut fruits, their properties, compositions which are closely related to the effects on the human health and the possibilities of technological processing. The lipid storage process, especially the most frequently occurring autooxidation reactions are described, followed by experimental part of the thesis. The changes in coconut, walnut, peanut oils and peanut butter samples are monitored during storage at 4 ° C and 20 ° C by determining the acid value, the peroxide value and the fatty acid composition by the GC-FID method. The lowest oxidation stability showed walnut oil due to the highest content of unstable polyunsaturated fatty acids – up to 88,7 %. During storage at 20 ° C there was a statistically significant increase in the content of primary oxidation products, determined as peroxide value PV = 2,55 ± 0,12 µgROOHg-1. An increase was also observed in samples of peanut butter, but it was mainly due to higher water activity, which is important for chemical reactions. The durability of this product after opening mentioned on the product label correlates with their low stability
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Impact of temperature and drought on gliadins and glutenins contents in four varieties of wheat
Tomasz, Teresa ; Vítová, Eva (referee) ; Hrstka, Miroslav (advisor)
This diploma thesis deals with an influence of high temperature and water shortage on the protein content of gliadin and glutenin fractions in four varieties of winter wheat: Bohemia, Tobak, Pannonia and var. Syria with designation S46 (IG142780). The crop was grown at 26, 29, 32, 35, 38 and 41 °C during anthesis under control irrigation treatment (with soil moisture higher than 70 %) or under drought stress (with soil moisture lower than 30 %). To separate gliadins, the A-PAGE method was used, and glutenins were separated by SDS-PAGE method. Proteins were quantified by computer densitometry. Significant influence of genotype on the gluten proteins was found. Variety Pannonia has high content of -, 5-gliadins, LMW and HMW glutenins, but low content of other gliadin fractions. It was the opposite in the other varieties. Due to temperature, as well as drought, there was an increase in the content of all gluten fractions, especially of HMW glutenins, 1,2-gliadins and total gliadins. The largest increase in the gluten fractions due to drought was observed in Syria variety. In other varieties simultaneous exposure to drought and heat caused decrease in gliadin content, but increase in glutenin content. Drought at high temperatures reduced gliadin-to-glutenin ratio, mostly in Bohemia variety. This ratio has increased due to the temperature, especially in Tobak variety. For Syria variety, no effect of stress conditions was found on gliadin-to-glutenin ratio.
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Analysis of glutenin fraction in winter wheat cultivated in ambient and elevated carbon dioxide concentrations
Čileková, Marta ; Vránová, Dana (referee) ; Hrstka, Miroslav (advisor)
Increasing carbon dioxide concentrations in the atmosphere has influence on plant’s photosynthesis and its metabolits. This bachelor thesis is focused on analysis of glutenin fraction in winter wheat (Triticum aestivum) var. Bohemia grown in ambient (AC) and elevated (EC; 700 mol.mol-1) carbon dioxide concentrations. Plants were cultivated in conditions with nitrogen fertilization (N+; 200 kg.ha-1) and without fertilization (N), in presence of UV-B radiation (UV+) and absence of UV-B radiation (UV), at drought (DRY) and with ambient irrigation (WET). Grain was harvested at 2014. The glutenin proteins were extracted from flour by isopropanol and DTT then separated by SDSPAGE and quantified by computer densitometry. Elevated carbon dioxide concentration decreased glutenin concentration in variant UV+ otherwise differences between AC and EC variants were nonsignificant. The nitrogen fertilization markedly increased glutenin content. Higher concentrations of glutenins were found in variants UV– WET and UV+ DRY. The highest concentrations of glutenins were found in conditions with presence of UV radiation, drought and nitrogen fertilization.
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