|
Psychorheology of low-fat spreads
Štern, Petr ; Pokorný, J. ; Jedelská, M. ; Panovská, Z. ; Seifert, P. ; Svoboda, Z. ; Novák, B.
Statistically significant relations, either linear or semilogarithmic,were obtained between the rheological and sensory data. A close linear relationship between the sensory texture and the flavour was observed. On the basis of the rheological and sensory measurements, it may be concluded that the rheometry could be used for the prediction of the texture and flavour acceptances of fat emulsions with a fair degree of accuracy.
|
| |
|
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.
|
|
Optimization of network flow monitoring
Žádník, Martin ; Lhotka,, Ladislav (referee) ; Matoušek, Radomil (referee) ; Sekanina, Lukáš (advisor)
The thesis deals with optimization of network flow monitoring. Flow-based network traffic processing, that is, processing packets based on some state information associated to the flows which the packets belong to, is a key enabler for a variety of network services and applications. The number of simultaneous flows increases with the growing number of new services and applications. It has become a challenge to keep a state per each flow in a network device processing high speed traffic. A flow table, a structure with flow states, must be stored in a memory hierarchy. The memory closest to the processing is known as a flow cache. Flow cache management plays an important role in terms of its effective utilization, which affects the performance of the whole system. This thesis focuses on an automated design of cache replacement policy optimized to a deployment on particular networks. A genetic algorithm is proposed to automate this process. The genetic algorithm generates and evaluates evolved replacement policies by a simulation on obtained traffic traces. The proposed algorithm is evaluated by designing replacement policies for two variations of the cache management problem. The first variation is an evolution of the replacement policy with an overall low number of state evictions from the flow cache. The second variation represents an evolution of the replacement policy with a low number of evictions belonging to large flows only. Optimized replacement policies for both variations are found while experimenting with various encoding of the replacement policy and genetic operators. The newly evolved replacement policies achieve better results than other tested policies. The evolved replacement policy lowers the overall amount of evictions by ten percent in comparison with the best compared policy. The evolved replacement policy focusing on large flows lowers the amount of their evictions two times. Moreover, no eviction occurs for most of the large flows (over 90%). The evolved replacement policy offers better resilience against flooding the flow cache with large amount of short flows which are typical side effects of scanning or distributed denial of service activities. An extension of the replacement policy is also proposed. The extension complements the replacement policy with an additional information extracted from packet headers. The results show further decrease in the number of evictions when the extension is used.
|
|
Consumption of fiber in old age
ŠÁLEK, Jan
The theme of this bachelor thesis is the Consumption of fiber in the old age (seniors). Formerly, the dietary fiber was considered unnecessarily burdensome for human organism. Later, it was found that it has a relatively large impact on human health, especially by serving as a prebiotic for symbiotic bacteria inhabiting the gastrointestinal tract. There is still prevailing opinion that roughage divides into a soluble and insoluble, despite that some types of fiber cannot be definitely classified and placed into any of these groups because they have characteristics of both of them. The daily recommended dose is 30 g. The qualitative research was used for elaboration of the practical part. The first goal was to find out how much fiber seniors consume. The second aim was to compare the consumption of fiber among elderly people living alone and the elderly living in retirement homes built for them. The research group, at the first research question, consists of 20 seniors from the Southern Region aged over 65 years. The research group, at the second research question, consists of five retirement homes from the whole Czech Republic. All respondents were given a record sheet for one week, and instructions on how to fill it. Acquired menus were subsequently re-calculated through the program "Nutriservis Professional". The results show higher consumption of fiber than the average in the Czech Republic, but there is still almost a half missing to get the recommended daily dose. There was observed BMI and its impact on the consumption of fiber. No significant effect was found, because overweight had all interviewees except one respondent. The financial limit is visible for evaluated diet of homes for the elderly, therefore, there are no whole grain products, vegetables and almost no fruit. Despite these limitations, the average consumption of fiber is almost equal to elderly people living alone. In conclusion, there is a proposition how to, despite the low funds, increase the intake of roughage, and avoid or, at least, reduce the problems associated with its low consumption. Recommendations for respondents are individual and given under each evaluation.
|
|
Use of Festuca arundinacea for decorative lawns
Doskočil, Jan ; Svobodová, Miluše (advisor) ; Hrevušová, Zuzana (referee)
Use of Festuca arundinacea for decorative lawns
Summary
Festuca arundinacea is briefly bentgrass with broader and coarser leaves. Hardly perennial grass, native to Europe, is well known for its high resistance of dry weather, low intensity of maintenance and resistance of high use. These qualities gains thanks to its well-developed and deep root system, which is capable to gain water and nutrients from deeper parts of soil. Its use is in places with high use, like a race-course, edges of roads or vineyards alleyway. Today, in time of global warming, its usage becomes more important for park purposes and low-input turfs, where is its higher resistance against biotic and abiotic stresses, mainly against drought, utilized. Festuca arundinacea complement well with Poa pratensis in turf.
Goal of this work was to evaluate turfs with Festuca arundinacea and chosen grass species under different mowing frequency. According to hypothesis frequency shouldn´t affect turf coverage. Coverage should be same with different mixture composition with Festuca arundinacea.
The experiment was performed on experimental land of Czech university of Life Sciences Prague, Suchdol in 2015. Mixtures of Festuca arundinacea with Festuca rubra, Poa pratensis and Lolium perenne were seeded together with monocultures of these species in 2012. Mixture composition was 50/50 except mixture of Fesruca arundinacea and Poa pratensis, where the mixture was 75/25. There were conducted 63 plots, in 3 repetitions and in 3 different frequencies of mowing (by 14, 30 and 45 days). Each plot was 6 m2 big. The results were evaluated by analysis of variance ANOVA (P is smaller than 0.05) in program Statgraphics, version XV.
Influence of mixture composition to level of growth was significant. The highest level of growth has monoculture of Festuca arundinacea (10,6 cm). The lowest level of growth has monoculture of Lolium perenne (5,4 cm). Monoculture of Festuca arundinacea had the highest intensity of grow (0,07 cm/day) at 14-day frequency of moving. Lolium perenne has the lowest intensity of grow (0,02 cm/day). At 30-day frequency of mowing mixture of Festuca arundinacea with Poa pratensis has the highest intensity of grow (0,24 cm/day). The lowest intensity of grow has Lolium perenne (0,01 cm/day). The highest intensity of grow was at 45-day mowing frequency. The highest intensity of grow has mixture of Festuca arundinacea with Festuca rubra (0,75 cm/day). The lowest intensity of grow has monoculture of Lolium perenne (0,06 cm/day). Influence of mixture composition to coverage was statistically significant. The highest coverage has mixture of Festuca arundinace with Festuca rubra (81,3 %). The lowest coverage has monoculture of Lolium perenne (58,6%). Influence of frequency to level of growth was statistically significant. The highest level of growth has 45-day frequency of mowing (6 cm) and the lowest level of growth has 14-day frequency of mowing (3,8 cm). Influence of frequency to coverage was statistically significant. The highest coverage 14-day frequency of moving (76,5 %) and the lowest has 45-day frequency of growing (66,7 %).
The knowledge gained will be used for further compilation grass mixtures for park lawns. It turned out that it is better to prefer seeding mixtures with Festuca arundinacea than monocultures. To achieve high coverage and optimal intensity of growth with Festuca arundinacea was recommended to follow 30-day frequency of mowing.
|
|
Factors affecting postmortem changes in pork meat
Seilerová, Michaela ; Čítek, Jaroslav (advisor) ; Lebedová, Nicole (referee)
The thesis focused on the summary of the quality of pork. The main indicators of the quality of pork and of meat generally together with a chemical composition and the external and internal factors dealing with the quality of meat are described in the thesis. The various histological structure, the variable chemical content, technological features are found in meat. The structure and composition depends on a way of living, the function of the parts of an animal body, on lots of intravital factors (a kind of an animal, breed, male or female, age, the way of nutrition, the state of health). Meat is a valuable source of nutrients and essential acids for a man. The human organism is not able to synthesize the essential acids itself. Lipids are the important part of meat, their main function is storing energy. They are found as a reserve tissue in the subcutaneus parts of animals or among muscular fibre. The amount of carbohydrates contained in meat is not important, meat is low in carbohydrates. They are only important for meat maturation. Meat is high in minerals and vitamins. It is necesary for a man and should be a part of our diet. The important factor for a meat quality is described as a formation of muscular fibres. There are the thin fibres in the meat of a high quality and the thick and fat fibres in the meat of a low quality. The meat quality depends on a number and charactes of animal fibres. The meat of a high quality is for example loin - it is the meat with fine fibres. The next factor which has influence on a meat quality is course of post mortem changes.We can differentiate four stages in these processes: prae rigor, rigor mortis, aging of the meat and deep autolysis. Post mortem aiging processes can deviate from teh standard from variety of reasons and as concequences we can see quality deviation of the meat for example PSE, DFD, RSE, Hampshire efect and cold shortening.Also the breed has the influance on the quality of the meat namely sensitivity to stress,growth characteristic and parameters of slaughter value, other internal factors are age and sex. External factors which has the influance on the quality of the meat are transport of the animals to the slaughterhouse, attitude of the employees during chasing after the animals, the rest before slaughter, stunning itself,bleeding thereafter and cooling down after slaughtery.
|
|
Changes to the contents of proline and relative electrolyte leakage of the selected genotypes of poppies depending on the influence by low temperature
Kudrna, Jiří ; Hnilička, František (advisor) ; Orsák, Matyáš (referee)
The object of this thesis is to study the effect of low temperatures, proline content and relative elektrolyte leakage in a selected range of varieties of opium poppy.
Experiment included 18 poppy varieties with different contents of morphine. Poppy seeds for this experiment were provided by GB Oseva Pro s r.o., o.z.VÚO Opava a Český mák s.r.o.
Poppy seeds were sown in containers of a size of 7,5x7,5 cm. Used cultivation medium is mixture of garden substrate A with quartz sand in a ratio of 2: 1. Plants were grown under controlled conditions in grow chamber Conviron E8. Before starting the experiment, the temperature was at 10 ° C during day and 5 ° C over night. Light cycle was 13 hours light and 11 hours darkness. The maximum value of irradiance was 800 micromol. The experiment was initiated in phase of rosette develoment. At this developmental stage were the plants exposed to frost temperatures (-5 ° C) over night and chill temperatures (10 ° C) duringthe day. After a week the plants were regenerated for 1 week at 5 ° C over night and 10 C during the day.
All tested plants were in two day intervals measured of proline concentration after exposure to low temperature stress. At the same intervals as proline, were measured the values of relative elektrolyte leakage (Rel%).The obtained results show that the influence of low temperature causes increase of proline level. Control winter-crop variety Zeno exhibited the high kontent of proline (693.33 microg.g -1) in comparison with the spring poppy varieties. After regeneration were afected varieties Lazur, Opal, Buddha, Korneuburger Weisser, Aplaus, Major, Sokol, Zeno reduced the content of proline under the influence of higher temperatures. On the other hand the varieties Ofeus, Tatranský, Opex, Orbis, Maraton, Florián, Marianne and Albin were reversed with an increase of proline level. Proline concentration levels were constant and unchanged in case of varietes Postomi and Akvarel. Values of relative elektrolyte leakage were increased proportionately with length of exposure to low temperatures on the tested plants. The lowest value of membrane damage was after exposure to low temperatures observed in case of variety Zeno (23.53%). In the case of spring varieties was lowest membráně damage estimated in a variety Korneuburger Weisser (44.88%), while the highest was in the variety Orfeus (53.15%). It demonstrated the different responses of individual poppy varieties at low temperature. Most sensitive to low temperature were varieties Orfeus, Postomi, Akvarel, Orbis, Sokol and Marianne. As less sensitive to stress caused by low temperature seems to be spring varieties Opex, Buddha, Korneuburger Weisser, Albín.
|
guest ::
