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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.
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Corrosion behavior of plasma coatings CuAl10 and CuAl50 on magnesium alloy AZ 91
Kubatík, Tomáš František ; Stoulil, J. ; Stehlíková, K. ; Slepička, P. ; Janata, Marek
The most common magnesium alloy AZ 91 is widely used as a structural material, but its use is limited at higher temperatures and high humidity. Plasma spraying is a technology that allows to prepare protective metallic and non-metallic coatings on a wide variety of substrates including magnesium and its alloys. In this study, CuAl10 and CuAl50 were plasma sprayed on magnesium alloy AZ 91 with the aim to study corrosion resistance of the plasma sprayed coatings. The corrosion resistance of layers was evaluated by the method of electrochemical potentiodynamic measurement as well as long-term corrosion tests in a condensation chamber with 0.5 mol\nNaCl at the temperature of 35 °C for 1344 hours. Layers with 1, 2, 5 passes and passes of CuAl10 with the thickness ranging from 75 to 716 mm and CuAl50 with the thickness ranging from 64 to 566 mm were prepared. The increased corrosion velocity was observed in the case of thin layers of 2 and 5 passes due to the development of a galvanic corrosion couple. The CuAl10 layer prepared with ten passes has an outstanding corrosion resistance.
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Frequency stabilized semiconductor laser source for high-resolution interferometry
Řeřucha, Šimon ; Hucl, Václav ; Holá, Miroslava ; Čížek, Martin ; Pham, Minh Tuan ; Pravdová, Lenka ; Lazar, Josef ; Číp, Ondřej
We have assembled an experimental iodine stabilized Distributed Bragg Reflector (DBR) diode based laser system lasing at a wavelength that is in a close proximity to the wavelength of a stabilized He-Ne lasers traditionally used for metrological applications (λ=632.9 nm in vacuum). The aim was to verify whether such a system could be used as an alternative to the He-Ne laser while yielding wider optical frequency tuning range, higher output power and high frequency modulation capability. We have measured the basic characteristics of the laser source and then we have compared the performance of the laser system with that of a traditional frequency stabilized He-Ne laser with a series of experimental arrangements similar to those usually found in laser interferometry and displacement metrology applications. The results indicate that DBR diode laser system provides a good laser source for applications in dimensional (nano)metrology since it provides more output power and advanced tunability options than stabilized He-Ne lasers while maintaining fundamental requirements such as the frequency stability, coherence length and also a defined traceability.\n\n
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Noise, Transport and Structural Properties of High Energy Radiation Detectors Based on CdTe
Šik, Ondřej ; Lazar, Josef (referee) ; Navrátil, Vladislav (referee) ; Grmela, Lubomír (advisor)
Poptávka ze strany vesmírného výzkumu, zdravotnictví a bezpečnostního průmyslu způsobila v posledních letech zvýšený zájem o vývoj materiálů pro detekci a zobrazování vysokoenergetického záření. CdTe a jeho slitina CdZnTe. jsou polovodiče umožnují detekci záření o energiích v rozsahu 10 keV až 500 keV. Šířka zakázaného pásma u CdTe / CdZnTe je 1.46 -1.6 eV, což umožňuje produkci krystalů o vysoké rezistivitě (10^10-10^11 cm), která je dostačující pro použití CdTe / CdZnTe při pokojové teplotě. V mé práci byly zkoumány detektory CdTe/CdZnTe v různých stádiích jejich poruchovosti. Byly použity velmi kvalitní spektroskopické detektory, materiál s nižší rezistivitou a výraznou polarizací, detektory s asymetrií elektrických parametrů kontaktů a teplotně degenerované vzorky. Z výsledků analýzy nízkofrekvenčního šumu je patrný obecný závěr, že zvýšená koncentrace defektů způsobí změnu povahy původně monotónního spektra typu 1/f na spektrum s výrazným vlivem generačně-rekombinačních procesů. Další výrazná vlastnost degenerovaných detektorů a detektorů nižší kvality je nárůst spektrální hustoty šumu typu 1/f se vzrůstajícím napájecím napětí se směrnicí výrazně vyšší než 2. Strukturální a chemické analýzy poukázaly, že teplotní generace detektorů způsobuje difuzi kovu použitého při kontaktování a stopových prvků hlouběji do objemu krystalu. Část mé práce je věnována modifikaci povrchu svazkem argonových iontů a jejímu vlivu na chemické složení a morfologii povrchu.
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Subspace Modeling of Prosodic Features for Speaker Verification
Kockmann, Marcel ; Kenny, Patrick (referee) ; Nöth, Elmar (referee) ; Černocký, Jan (advisor)
Předložená disertační práce se zabývá ověřováním mluvčího pomocí prozodických příznaků zahrnujících hodnoty základního tónu, energie a délek řečových úseků. Studovali jsme dvě rozdílné techniky pro parametrizaci: první vede k dobře definované sadě menšího počtu příznaků, druhá k vysoko-dimenzionální sadě heterogenních prozodických příznaků. První část práce se věnuje vývoji příznaků reprezentujících prozodické kontury, zde jsme vyvinuli a ověřili několik modelovacích technik, s důrazem na modelování v reprezentativních podprostorech. Druhá část práce se zaměřuje na nové pod-prostorové modelovací techniky pro heterogenní prozodické parametry s velkou dimenzionalitou. Model je teoreticky odvozen a experimentálně ověřen na oficiálních datech z NIST evaluací ověřování mluvčího (NIST Speaker Recognition Evaluation). Ve srovnání s ostatními současnými prozodickými jsme dosáhli podstatně lepších výsledků. Na konci práce presentujeme také novou techniku pro elegantní kombinaci dvou prozodických systémů. Tato technika může být použita rovněž pro fúzi prozodického systému se standardním přesným cepstrálním systémem, což vede k dalšímu podstatnému zvýšení úspěšnosti verifikace.
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(Arbo)viruses in high European Arctic
ELSTEROVÁ, Jana
Since an ongoing climate change covers strongly the polar areas. Higher temperatures and related climate parameters bring the emergence of new parasites and their pathogens to higher latitudes. This may influence zoonotic diseases including arthropod-transmitted diseases. The tick species Ixodes uriae, parasitizing seabirds in the Arctic, may transmit many pathogens including various arboviruses, Borrelia spirochetes and Babesia apicomplexans. In the study we diagnosed 89 individuals of seabird tick Ixodes uriae and searched for arthropod-borne viruses from the genera Flavivirus, Alphavirus, Orthobunyavirus, Phlebovirus and Orbivirus using genus-specific primers. Moreover we searched for presence of Borrelia spp. and Babesia spp. DNA in the ticks. All samples were negative after PCR amplification for all tested pathogens. The result signalizes that tested pathogens might not be present in such high latitudes of European Arctic. Though, the possibility of introduction of these pathogens may be observable in near future due to quick changing of the Arctic ecosystem with the rising of migration of vertebrate hosts including humans to the polar areas. It is though important to continue to study potential presence of pathogens in polar areas. We are working on increase of the number of tick samples to confirm the presence or absence of the tick-borne pathogens in the European Arctic.
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The development of the crime on credits in the South Bohemia before 2014
BUŠKOVÁ, Tereza
The aim of this study is to analyze the development of committing a credit fraud offence under § 211 of the Act. no. 40/2009 Coll., the Penal Code (particularly the development of this crime and the development of the amount of the damage) and consequent comparing the selected macroeconomic indicators development in the period 2005-2014 in the region of South Bohemia. In this work secondary data analysis methods were used. Statistical data obtained from the South Bohemian branch of the Czech Statistical Office and statistical data from Crime Police of the Czech Republic was used as the source. The data evaluating the amount of detected cases of this crime committed by the offenders in the Region South Bohemia, according to the region where the fraud was commited, was analyzed. The analyzed file was 5,713 offenses and 4,219 offenders. The defined set was divided into seven parts (districts), according to the local jurisdiction of the territorial departments of the Czech Police. The observed data was compared with selected macroeconomic indicators. From the results it can be concluded that the highest rate of loan fraud offence (calculated per 1,000 inhabitants) is in the district Stra-konice. Conversely, the lowest crime in the same period is in the district Jindřichův Hradec. This work also re-vealed that the development of macroeconomic indicators has no effect on the development of this crime. In conclusion, it is recommended to promote economic education at primary and secondary schools, thus improving the financial literacy of the population. Furthermore, we can recommend the consistent use of, the Central Credit Register, which is already available, as well as supporting of changes in the legislation, so that the providers have an obligation to investigate the credit applicants more and make the offenders of this crime discouraged by higher penalties imposed for credit fraud.
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Monetary Policy and Macroprudential Policy: Rivals or Teammates?
Malovaná, Simona ; Frait, Jan
This paper sheds some light on situations in which monetary and macroprudential policies may interact (and potentially get into conflict) and contributes to the discussion about the coordination of those policies. Using data for the Czech Republic and five euro area countries we show that monetary tightening has a negative impact on the credit-to-GDP ratio and the non-risk-weighted bank capital ratio (i.e. a positive impact on bank leverage), while these effects have strengthened considerably since mid-2011. This supports the view that accommodative monetary policy contributes to a build-up of financial vulnerabilities, i.e. it boosts the credit cycle. On the other hand, the effect of the higher bank capital ratio is associated with some degree of uncertainty. For these and other reasons, coordination of the two policies is necessary to avoid an undesirable policy mix preventing effective achievement of the main objectives in the two policy areas.
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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.
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Gluten-free diet - reality in school facilities
JIRÁČKOVÁ, Marie
The topic of this bachelor thesis is gluten-free diet - reality in schools facilities. The goal of this work was to determine the number of school cafeterias in the Vysocina Region which provide gluten-free meals, to evaluate awareness of the canteen staff about preparation of the gluten-free diet and to describe the cooperation between the school cafeteria and family of the pupil with gluten-free diet. School meals are important to provide optimal intake of nutrition during the time the child spends in school, to establish proper eating habits and to better integrate the child into the group of its peers. Gluten-free diet is a necessary medical precaution especially for those with coeliac disease, in which case gluten can lead to villous atrophy, and for those with gluten allergy for whom gluten intake can cause anaphylactic shock. Adherence to the gluten-free diet is recommended also to those with non-coeliac gluten sensitivity diagnosis, although gluten causes only short-term complications, usually intestinal. The method of quantitative and qualitative research was used to make this thesis. The research sample consisted of 8 school cafeterias from the Vysocina Region which provide gluten-free meal to their pupils. Awareness about gluten-free diet principles of the managers of the cafeterias or of the cooks responsible for preparation of gluten-free meal was determined by means of semi-structured interviews. The calculation of the two-day menu of each cafeteria by means of the Nutriservis Profesional program was also part of this thesis. The results were compared with the recommended daily intake of energy, proteins, fat, and saccharides for pupils of elementary and secondary schools. The results of the quantitative research show that gluten-free diet is provided by only a small percentage of school cafeterias in the Vysocina Region. The qualitative research prove sufficient awareness of the cooks about gluten-free diet, with awareness of those cooks directly responsible for preparation of gluten free meals being at much higher level. It was also determined that the cooperation with parents of pupils with gluten-free diet is a usually one time occasion limited to an arrangement of nonperishable gluten free meal packages.
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