|
Very low energy STEM for biology
Frank, Luděk ; Nebesářová, Jana ; Vancová, Marie ; Paták, Aleš ; Müllerová, Ilona
Examination of tissue sections with transmitted electrons has been performed at energies of hundreds and tens of eV with thicknesses of sections of 10 nm or less. This was possible by employing the cathode lens principle working without lowest energy limitations with the help of biasing the sample to a high negative potential. The reflected and transmitted electrons were attracted with the same electric field to earthed detectors situated above and below the sample. Very high image contrasts have been obtained even for samples free of any heavy metal salts for contrast enhancement.
|
|
Sustainable tourism development of Vysocina Region
Veselá, Markéta ; Macháček, Jaroslav (advisor) ; Vondráková, Zuzana (referee)
The diploma thesis deals with the topic of sustainable tourism development at the regional level. This phenomenon is elaborated on the example of Vysocina Region. To evaluate sustainability of its development, the potential of this touristic destination is researched regarding various areas, including key products. These are subjected to comparisons with recommendations of significant tourism organization for the purpose of assessing the sustainability of tourism. The diploma thesis also includes a comparison with other Czech regions experience as a touristic destination. Vysocina Region has favourable initial conditions for its sustainable development, especially regarding supply of key products, which include both environmentally friendly goods and cultural attractiveness contributing to the personal development of individuals and promoting intercultural tolerance. The main issue appears to be the spatial imbalance of its development in the region, caused mainly by the concentration of tourist activities to certain areas and low local initiative in the less attractive areas. The diploma thesis proposes a number of solutions, such as utilization of geocaching and products of gastroturism, supporting the foundation of local destination management organisations, promoting cycling tourism and the foundation of highly visited tourist destinations.
|
|
Application of Monte Carlo simulations in banking
Boruta, Matěj ; Teplý, Petr (advisor) ; Fučík, Vojtěch (referee)
Currently, banking is exposed to huge market risks. One of those risks is occurrence of negative interest rates in the EU. Nowadays, it is important to use sophisticated and modern measurement tools and approaches to measure and manage banking risks. One of those methods is Monte Carlo simulation. This bachelor thesis is aimed at analysis and prediction of 3-month maturity Prague Interest Offer Rate (PRIBOR) for 3, 6 and 12 months with using Monte Carlo simulations. It was found that this method is suitable for prediction market variables with low volatility. If anybody uses this method, it is necessity to have in mind all pitfalls and assumptions, that this method includes, as an adequate random generated number of scenarios, approximation of correct probability distribution, independence of dataset and not least, as far as possible, to focus on factors generating randomness of market variable and not the prices, that express rather consequences of randomness than its cause. Further, the Monte Carlo prediction was compared with prognosis of the Czech Nation Bank and it was found that Monte Carlo prediction is more accurate for short term predictions. 12-month prediction of Monte Carlo simulation discovered also possible occurrence of negative interest rate at 0,05% level of probability in compare to the Czech National Bank prognosis, where was no negative interest rate predicted.
|
|
Design of processes of business department in IT company and measuring their performance
Schütz, Martin ; Oškrdal, Václav (advisor) ; Bruckner, Tomáš (referee)
The thesis deals with design of new processes of business department in IT company which provides server hosting, web hosting and domain registration services. These processes come from identification and analysis of current processes and the theory of business department management. Key Performance Indicators (KPIs) were set for selected processes which can be used for managing the company as a whole. Models of processes were created due to EPC notation. New processes were designed to continuously create data in CRM information system providing evidential and information support necessary for business department management, including the possibility of measuring its performance. Processes also automatize often repetitive activities and provide relevant information to other affected business units within the company. Contribution of the thesis lies in results of analysis of current identified processes containing solution proposals of discovered problems and newly created process models. Both can be used as a pattern for optimization of current processes in already existing organization or for designing new process models in new organization in the same or similar field of business.
|
|
Process Analysis As the Basis for the Implementation of a New Information System
Kmochova, Zdena ; Říhová, Zora (advisor) ; Svatá, Vlasta (referee)
The main objective of this thesis is to analyze the processes in the company POP service, Ltd., also to analyze the current problem in this company and to recommend and propose measures which eliminate the causes of the emergence of the problem. The causes originate from the aspects of the management of people and processes are identified through the analysis of processes associated with the problem and eliminated on the basis of proposals metrics and responsibilities for these processes. The theoretical part of the thesis is devoted to concepts in the field of process management. The theoretical part characterizes these concepts process management, business processes, process analysis and process modeling methods, process maps, graphical notation for writing business processes, business process improvement and analysis organization. In the second part of the thesis is presented the examined organizations POP service, Ltd.. Based on the analysis of the current state are defined vision, mission and goals of the organization. Then there is described a procedure of the analysis of the current state, which is process analysis and proposal of selected processes, metrics and responsibilities for these processes. Methods of analysis are SWOT analysis, analysis of the activities, structured interviews and process analysis. The result of this thesis is to analyze the selection of processes of the company POP service, Ltd., proposal metrics, define jobs and responsibilities and suggestions for improving the selected process.
|
|
Effect of low doses of herbicide paraquat on antioxidant defense in Drosophila
SÁBOVÁ, Michala
Disruption of cell equilibrium between production of free radicals and antioxidant defence is named oxidative stress. The main component of antioxidant mechanism is activity of antioxidant enzymes, which include superoxide dismutase (SOD) and catalase. In this study we evaluated the effect of herbicide paraquat on response of SOD and catalase, their transcription level and locomotion activity in Drosophila melanogaster. We exposed the flies to a wide range of paraquat concentration. Our results revealed that transcript and enzymatic levels of both SOD and catalase have a similar biphasic dose response with the peaks at 2,5 ?M paraquat concentration, resembling hormetic effect. Then, males were more sensitive than females. However, females had an increased locomotion activity. We found that paraquat susceptibility is increased in males and mating flies. Therefore, this study supports hypothesis of stress sensitivity elevation as a physiological cost of reproduction.
|
|
Plasma spraying from liquids: plasma liquid interaction and coating build up
Tesař, Tomáš ; Mušálek, Radek ; Medřický, Jan ; Lukáč, František
Plasma spraying from liquid feedstocks is a rapidly developing field of thermal spraying since the coatings prepared from liquids exhibit some unique features, such as high hardness, thermal shock resistance or low thermal and electric conductivity. The key factor influencing the final coating character and properties is the input material which may be in the form of a suspension or a solution. Parameters of the selected suspension (solids concentration, viscosity, surface tension, chemical composition, etc.) or solution (concentration, etc.) determine its interaction with the plasma jet which strongly influences the coating buildup. This proceeding introduces the problematics of the interaction between the liquid feedstock material with the plasma jet and presents the way of evaluation of the coating buildup.
|
|
Freezing technology of bull sperm in relation to its survivability and fertilization ability
Doležalová, Martina ; Stádník, Luděk (advisor) ; Jiří, Jiří (referee)
The aim of optimalization the insemination doses production is to provide the highest fertilization ability of spermatozoa during the demanding proces of processing fresh semen and its subsequent cryopreservation. Temperature changes causes spermatozoa damage during the cooling and freezing. Spermatozoa is exposed to cold shock and many others limiting factors, which leads to cell death and therefore to decline of fertilization ability of thawed insemination doses. For increasing spermatozoa resistance, exactly the plasma membrane resistance against cold shock was fraction of egg yolk LDL cholesterol (low density lipoprotein) at various concentrations into the comercially produced diluents added. It is believed that LDL acts possitively to plasma membrane and helps to maintain the fertilization ability of spermatozoa after thawing. Following step in the proces of insemination doses production is slow cooling of diluted semen and equilibration, when the straws are store at cooling box for 30 minutes to 240 hours. This period is necessary to penetrate of certain diluent components into the spermatazoa also maintain the balance between their intracellular and extracellular concentration. Also important is subsequent freezing temperature gradient of insemination doses. The most suitable freezing method is based on computer controlled temperature decline in freezing chamber which allows the precise control of ice crystals formation that could tear and kill the cell.
During 2012 to 2016 was repeatedly collected semen from the group of breeding bulls (n = 27, Holstein and Czech Fleckvieh breed) at AI centre. Semen which fulfill the standard entrance conditions in first step was evenly into several parts divided. For dilution the three types of comercially diluents AndroMed, Bioxcell and Triladyl with and without LDL addition were used. Into the diluents AndroMed and Bioxcell the concentration of LDL 4 %, 6 % and 8% into the dilent Triladyl 6 %, 8 % and 10 % was added. Diluted semen was filled into the glass capillares with volume 0,1 ml and temperature +4 °C. Subsequently the sample was placed to cold bath (0°C) for 10 minutes. Then the volume of capillare with physiological solution (37 °C) was mixed and for next 120 minutes was incubate. The effect of cold shock to proportion of live spermatozoa was evaluated by using Eosin and Nigrosine staining technique during heat test of spermatozoa survivability after spermatozoa heating and after 120 minutes of incubation.
The more suitable semen diluents which provide the higher spermatozoa resistance against cold shock were AndroMed and Bioxcell. Together the possitive effect of LDL addition into the diluents to lower decrease of proportion of live spermatozoa during heat test was found (P<0.05). The most suitable LDL concentration which had a favorable influence at spermatozoa resistance against cold shock was 6 % in diluent Bioxcell. Values of the proportion of live sperm were higher at the beginning of the heat test (+1.31% to + 3.2%) and after 120 minute incubation (+5.82% to +8.41%) compared to other diluents with and without addition of LDL.
In the next step the process of equilibration was optimized, is an important part of insemination doses production. The effect of the length of equilibration for subsequent fertilization ability of spermatozoa was evaluated using spermatozoa motility based of CASA and proportion of live spermatozoa after thawing and during heat survival test lasting 120 minutes (37 ° C). Suitable semen was diluted by comercially used diluent AndroMed based on soya lecithin, filled into the straws (0.25 ml), cooled and equilibrated in cooling box for 30, 120 and 240 minutes and freezed in programmable freezing box applying four types of freezing curves differing in temperature rate decline. There was used standard and by producer recommended 3. phase freezing curve, then 2. phase freezing curve, and 3. phase freezing curve with slower as well as rapid decline of temperature rate in freezing chamber, compared with standard freezing curve. The highest spermatozoa motility was found using 240 minutes of equilibration by +2.72% and +4.58% compared to other lengths of equilibration (P <0.05 to 0.01). The highest proportion of live spermatozoa was found using 120 minutes of equilibration (+6.87 % and +8.68 %). The highest average spermatozoa motility during heat test after thawing was achieved by using 2. phase freezing curve (from +2.97% to +10.37%, P <0.05), also in the proportion of live spermatozoa (from + 4.37% to +8.82%, P <0.01). When evaluating interaction between the length of equilibration and freezing curve (standard 3. phase and 2 . phase freezing curve), the highest average spermatozoa motility and proportion of live spermatozoa using 240 minutes of equilibration by both freezing curves was reached, there was no statistically significant differences. As well as, in all evaluated parts of this study the individual differences between ejaculate of bulls and within semen from one bull (P <0.05) as secondary effect were found.
To maintain good fertilization ability of semen during cryopreservation is necessary to increase the spermatozoa resistance against cold shock using addition of correct concentration of LDL into the commercially used diluents AndroMed and Bioxcell. Subsequently the fertilization ability of insemination dose is influenced by cooling, the length of equilibration and freezing. The length of equilibration 120 minutes and more as well as gentle way of freezing according to freezing curve, which ensures a gradual decrease of temperature in freezing chamber provided the higher average spermatozoa motility and proportion of live spermatozoa.
|
|
Total contents and speciation of arsenic and selenium in plants growing in soils with different physico-chemical properties
Tremlová, Jana ; Száková, Jiřina (advisor) ; Vymazal, Jan (referee)
This dissertation thesis deals with uptake, accumulation and transformation of arsenic and selenium in plants growing on soils with different chemico-physical soil properties. The contents of arsenic were investigated in 99 wild plant species, coming from 27 different families and 6 different vegetables growing in arsenic contaminated soils. The results suggest that there are species-specific mechanisms which protects certain plants from the excessive uptake of arsenic from the soil. On the other hand, there are plants using a strategy of accumulation, which theoretically may increase the risk of arsenic entry into the food chain, whether through grazing cattle and wildlife or through consumption of vegetables growing on arsenic contaminated soils. The most prevalent arsenic compounds are AsV and AsIII. Other arsenic compounds occure as minor species. An important finding was detection of arsenobetaine in Plantago lanceolata L. and Carex praecox Schreb ..
The contents of selenium were examined in 73 species of wild plants, coming from 29 different families. The results suggest that naturally low levels of selenium in the soil of selected locations along with a low capability of selenium uptake via collected plant species lead to the low content of selenium in plant biomass which may contribute to selenium deficient throughout the food chain. Foliar application of selenate on wild plant communities and on some types of vegetables in our case Brassica oleracea var. italica can have a positive impact on increasing the selenium content in the aboveground biomass of these plants and by extension, increase the selenium content in the human diet. Dominant selenium compounds in the aboveground biomass of the analyzed plants were SeVI and selenomethionine, with variable proportion of other commonly occurring organic selenium compounds, which is mainly affected by plant species.
|
|
Confidence Cycles and Liquidity Hoarding
Audzei, Volha
Market confidence has proved to be an important factor during past crises. However, many existing general equilibrium models do not account for agents’ expectations, market volatility, or overly pessimistic investor forecasts. In this paper, we incorporate a model of the interbank market into a DSGE model, with the interbank market rate and the volume of lending depending on market confidence and the perception of counterparty risk. In our model, a credit crunch occurs if the perception of counterparty risk increases. Our results suggest that changes in market confidence can generate credit crunches and contribute to the depth of recessions. We then conduct an exercise to mimic some central bank policies: targeted and untargeted liquidity provision, and reduction of the policy rate. Our results indicate that policy actions have a limited effect on the supply of credit if they fail to influence agents’ expectations. Interestingly, a policy of a low policy rate worsens recessions due to its negative impact on banks’ revenues. Liquidity provision stimulates credit slightly, but its efficiency is undermined by liquidity hoarding.
Fulltext:  PDF
|
guest ::
