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Vliv tepelného stresu na kvalitu ejakulátu kanců
Přibilová, Magdalena
The aim of the study was to investigate the effect of high temperature on selected parameters of semen quality of duroc boars at the insemination station in Velké Mezirici (N 49°23.46667', E 15°52.70135') in season from May to September. For purpose of the experiment were chosen 20 boars of the Duroc breed, divided into two groups. Group A (the control group; n = 10) has average quality of semen and group B (the experimantal group; n = 10) showed below-average long-term quality of semen. Analysed parametres were volume of ejaculate (ml), concentration of sperm (thousands/ml), total account of sperm in ejaculate (mld. ks), motility (%) and rate of abnormal sperm (%). In the stable the temperature (°C) and relative humidity (%) were monitored at hourly intervals for whole period of this study. The results of the experiment shows that the volume of ejaculate from both monitored groups increased at the same rate (P > 0.05) and in group A from 198 ml to 252 ml; in group B from 203 ml to 241 ml. Concentration of sperm of group A decreased (from 499 000/ml to 436 000/ml), whereas concentration of sperm of group B was at the same level during the experiment. The motility of sperm of group A at the end of the experiment increased (from 71.4 % to 74.0 %) and motility of sperm of group B has intensively decreased (from 67.3 % to 62.2 %). The decreation of sperm motility was statisticaly significant (P < 0.05). The influence of ambient temperature in this case had no significant effect on boar semen with average values (group A), but has been reported statistical significance in deterioration of sperm motility (P <0.05) and number of morphologically abnormal sperm (P < 0.05) in group of boars, who showed below-average long-term semen quality (group B). In both groups there was lower sperm concentration, which could be due to the increased volume of ejaculate in the summer months.
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The role of stress granules and 4E-BP in heat-stressed cells of S. cerevisiae
Kolářová, Věra ; Hašek, Jiří (advisor) ; Zimmermannová, Olga (referee)
The cells are capable of very quick and specific reactions on stress conditions. Influence of translation, specifically initiation of translation by inhibition factors, is one of the main regulatory process. Two of eIF4E-binding proteins (4E-BP), Eap1p and Caf20p, are known as cap-dependent translation repressors in yeast Saccharomyces cerevisiae. We used in vivo fluorescent microscopy analysis to show different reaction of Caf20p and Eap1p to heat stress. Protein Caf20p does not react on heat shock and stays difused in cytoplasm. Contrary to Caf20p reaction, protein Eap1p accumulates in cytoplasm close to stress granules (SGs). This work shows that Eap1p is involved in stress granules assembly. In the absence of Eap1p, yeast cells react to the heat stress with small and less focused SGs. Dele- tion of CAF20 does not affect SG assembly. This points to specific function of SG in distribution of factors connected with stress reaction. Polysomal analysis shows that deletion of one of initiation translation repressors does not affect heat induced global repression of translation. In permisive condition deletion of EAP1 may cause defect in addition of 60S ribosomal subunits. Absence of protein Eap1p causes morphological defect. That point to a different reactions of Eap1p and Caf20p on heat stress and possible...
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Effects of temperature extremes on hospital admissions for cardiovascular diseases
Urban, Aleš ; Kyselý, Jan (advisor) ; Huth, Radan (referee)
Faculty of Sicence, Charles University Aleš Urban, Praha 2012 Effects of temperature extremes on hospital admissions for cardiovascular diseases The thesis compares differences in the impacts of warm and cold days on both excess mortality and hospitalizations for individual cardiovascular diseases (CVDs) in Prague and a selected rural region (southern Bohemia - JČ) consisting of the Jihočeský kraj and Vysočina districts in the period 1994- 2009. Population size and age structure are similar in the two regions. The differences are compared between selected population groups (men and women; < 65 and 65+ years). Value of the 90% (10%) percentile of daily mean air temperature in summer (winter) during the period were used for the definition of warm (cold) days for each region separately. The excess mortality and hospitalizations were determined as the difference from standardized daily counts of death and hospital admissions, adjusted for epidemics of influenza/acute respiratory infections, long-term changes, and for annual and weekly cycles of mortality and hospitalizations. Generally higher relative excess CVD mortality on warm days was identified in Prague, while for cold days we found higher excess mortality in south Bohemia. In contrast to mortality, weak excess CVD hospitalizations were observed for both...
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Effect of selected factors on reproductive characteristics of dairy cows
Šťásková, Michaela ; Toušová, Renata (advisor) ; Petr, Petr (referee)
The aim of the thesis was to evaluate the effect of selected factors on the reproductive characteristics of Montbeliard dairy cows. Hypothesis said that high milk production, poor health and high air temperatures have a negative effect on reproductive indicators of cows.
In the literature review, there were summarized knowledge about the factors affecting fertility, reproductive indicators and a description of the breed. Observation was carried out on the farm Osičky, which is one of the centers of the company Agrodružstvo Lhota pod Libčany. To assess the influence of milk yield and health were monitored all standard lactations of dairy cows, which were completed in the period from 1. 1. 2014 to 31. 12. 2015. This gave rise to a set of 632 lactations.
To evaluate the milk production was data set divided by the number of lactation, quarter of calving and the rate of milk production into three groups. As a disease with an expected negative impact on fertility, mastitis was selected. Besides air temperature, the relative humidity was assessed too. Indicators such as days open, days from calving to calving and services per conception were evaluated. In order to assess the impact of climate change on fertility data file was divided into 3 groups of air temperature, by quarter, according to the category of cows and by calendar year. Services per conception, pregnancy after the first insemination and pregnancy after all insemination, were assessed. Data could be obtained only from a whole herd of cows and heifers. For statistical evaluation has been used SAS 9.3 software (SAS / STAT 9.3, 2011).
Achieved an average length of days open was 98.07 days, days from calving to calving 380.62 days, services per conception was 1.94, pregnancy after the first insemination in heifers 54.28% and 48.43% in cows, yield per lactation was 8 407, 98 kg of milk with fat contents of 3.65 % and a protein contents of 3.53 %. Mastitis occurred only in 17.72 % of cases. The average monthly air temperature during the year 2014 ranged from 1.3 ° C to 21.2 ° C, in 2015 it was 1.5 ° C - 23.2 ° C.
From the results of the regression analysis, it was found that the milk production per lactation had a statistically significant effect on the length of the days open (r = 0.214; P <0.001), services per conception (r = 0.296; P <0.001) and days from calving to calving (r = 0.147; P < 0.01). Therefore we can talk about the significant influence of milk production per lactation. With the increasing amount of milk kg days open and days from calving to calving extended and services per conception also grew. Analysis of variance confirmed the effect of the amount of milk yield per lactation on days from calving to calving (P <0.05), days open (P <0.001) and services per conception (P <0.001). Furthermore, quarter of calving had a significant effect (P <0.05) on services per conception and days open and the effect of category on pregnancy after all insemination (P <0.01) and services per conception has been demonstrated (P <0.05). Heifers showed demonstrably better results of assessed reproductive characteristics compared to cows. There was no effect of the incidence of mastitis on days open, days from calving to calving and services per conception proven (P> 0.05). Effect of air temperature on services per conception, pregnancy after the first insemination and pregnancy after all insemination, was not statistically proven (P > 0.05). Furthermore it has been approved many correlations between different parameters at the levels of significance (P < 0.001, P < 0.05).
The hypothesis was confirmed only for the negative impact of high milk production, but the impact of poor health and high air temperatures on reproduction was not approved. The results indicate a healthy herd in terms of mastitis, good management of breeding, which minimizes heat stress and which is of relatively high milk yield and proven negative impact of high milk production to reproduction, achieved a good level of reproduction.
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Impacts of climate changes on milk production efficiency in dairy cattle during a calendar year
UHEROVÁ, Jaroslava
Negative effects of high temperatures on cattle milk production is a specific problem. Dairy-cows, who produce much more heat than cows that are not milked, are more susceptible to high temperatures of the surrounding environment than other cattle. Changes in temperatures and atmospheric pressure were monitored throughout a year and then its influence on the milk production of cattle has been evaluated. It has been discovered that low temperatures do not have any significant influence on dairy-cows. However, at high temperatures dairy-cows suffer from heat stress and it leads to lower volumes of the daily milk production. The Holstein breed showed a higher sensitivity to temperature fluctuations than the Czech spotted breed; however, the Holstein breed milk production is better balanced in a long run (a year period).
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