National Repository of Grey Literature 17,318 records found  beginprevious41 - 50nextend  jump to record: Search took 0.68 seconds. 

Iniciace pohybu byčíku, signalizace a regulace pohyblivosti spermií ryb: fyzikální a biochemické řízení
PROKOPCHUK, Galina
The current study attempted to shed light on the regulatory processes and response arrangements of fish spermatozoa during the course of maturation and motility initiation. The first intent of this study was to improve the understanding of the mechanism underlying the acquisition of potential for sperm motility in sturgeon. Up to present work, the physiological process underlying sperm maturation in this species has not been described at all. Our results showed that sperm maturation in sturgeon occurs outside the testes because of dilution of sperm by urine and involves the participation of high molecular weight substances as well as calcium ions present in seminal fluid and/or urine. The second aim of the present study was to investigate the coping mechanisms in fish spermatozoa with osmotic and ionic activating mode, as well as in spermatozoa of euryhaline fishes, to various environmental conditions. We showed that alteration of environmental osmolality might affect the fish sperm in different ways, depending on fish species and modes of spermatozoa motility activation either osmotic or ionic mode. In response to osmotic stress caused by hypotonicity, carp spermatozoa regulated the flow of water across their cell membrane and increased their cytoplasmic volume during their short motility period. In contrast, no indications of sperm volume changes were observed neither in sterlet nor in brook trout spermatozoa, both of which having an ionic mode of motility activation. We also examined the mechanism by which sperm motility triggering in euryhaline fishes can adapt to a broad range of environmental salinity. Our results demonstrated that spermatozoa of euryhaline tilapia, Sarotherodon melanotheron heudelotii, reared in fresh-, sea- or hypersaline water can be activated in hypotonic, isotonic or hypertonic conditions of swimming milieu, provided Ca2+ ions are present at various levels. It was established that the higher the fish rearing salinity or the more hypertonic ambient media at spermatozoa activation, the higher extracellular concentration of Ca2+ ions is required. The results obtained in the present study allow suggesting that osmolality is not the main factor inhibiting sperm motility inside the testis in the S. melanotheron heudelotii. A third aim of this study was investigation of the regulation of motility initiation process and description of flagellar beating initiation in chondrostean spermatozoa. We detected that K+ inhibition of sperm motility in sturgeon can be by-passed due to the pre-exposure of sperm cells to a high osmolality shock prior to its transfer to K+-rich swimming media. Thus, we hypothesized that sturgeon spermatozoa may be activated by use of an unexpected signaling pathway, independent from regular ionic stimulation. The successive activation steps in sturgeon spermatozoa were investigated by high-speed video microscopy, using specific experimental situation, where sperm motility initiation was delayed in time up to several seconds. At motility initiation, the first couple of bends formed at the basal region begins to propagate towards the flagellar tip, but gradually fades when reaching the mid-flagellum. This behavior repeats several times until a stage where the amplitudes of bends gradually reach similar value, what eventually leads to sperm progressive displacement. The total period needed for the flagellum to switch from immobility with rigid shape to full activity with regular propagating bends ranges from 0.4 to 1.2 seconds. In conclusion, the results of the current study bring valuable pieces of information into the general understanding of the processes of maturation of fish spermatozoa, their adaptability to different physical and biochemical circumstances, the extra- and intra-cellular signaling as well as the regulatory mechanisms of motility activation in fish spermatozoa.

Management of production populations of forest tree species utilizing methods of mathematical programing
Hořejší, Matouš ; Lstibůrek, Milan (advisor) ; Stejskal, Jan (referee)
Breeding of forest tree species is a great opportunity for the entire forestry sector to succeed in the present modern World. Genetically improved forest trees have much better growing quality and they can sustain higher stress and unfavorable climatic conditions. Efficient algorithms are necessary for optimizing and establishing seed orchards. These should optimally select clones as parents in future seed orchards. In the present thesis, we developed model, based on mathematical programming methods, which creates mix of clones with the maximum breeding value and constraints on genetic diversity.

Effect of dairy cows housing technology on mastitis occurrence
Brzáková, Lenka ; Stádník, Luděk (advisor) ; Jan, Jan (referee)
The objective of my bachelor thesis was evaluation of quality of housing, milking and making analysis of mastitis on chosen farm. First part of the thesis contains of literature summary about housing technologies, mastitis issues, their detection, originators, therapy and factors affects against their incidence. Thereafter is this part focused on tipes of milking parlours, corect milking procedures and mechanized milking. Materials and methodes of the thesis contains the characteristics of chosen farm where the quality and technology of housing, milking and nutrition of milk cows and other factors affecting presence of mastitis such as taking care of cloven hooves was watched in 2014. The incidence, detection and curation of mastitis was watched afterwards. Montamilk s.r.o. farm cradles 1,200 pieces of cattle and milk cows are about 419 out of it. In the part of thesis named results was watched and evaluated inspection of efficiency in inspecting year 2013 - 2014, which was stated on first lactated cows and on cows which are on second and further lactation. Milk yield was far better with cows on second or futher lactation according to data gathered during the study and expressed by diagram. Diagram of milk components (fat and proteins), which was divided by lactation, was expressed in this part too. Other examinated parameters was occurrence of mastitis - which milk cows, in which season is the occurrence more often, treatment and cost of treatment for one cow. At the end the number of somatic cells for 2014 was represented in diagram for particular lactations. In part of thesis called discusion the comparison was drowed between results from chosen farm and national average of efficiency checks. From results is obvious that milk cow in Mnotamilk has been better in first lactated cows by 427 kg and in second and more lactated cows by 602 kg than is the avarage in Czech republic. Far more the milk components in Montamilk was compared with rest of Czech republic and the results was quite similar. The volume of fat of Montamilk cows was lower in every lactation in comparison with milk cows from Czech. Value of fat in Czech republic avarage first lactated cows is 3,87 % in Montamilk 3,85 % and the value of fat on second and more lactation cows is 3,86 % in Czech average and 3,81 % in Montamilk.

Effect of sex on growth and formation of dorsal muscle of pigs
Fáberová, Gabriela ; Čítek, Jaroslav (advisor) ; Zadinová, Kateřina (referee)
Effect of sex on growth and formation of dorsal muscule of pigs Summary The aim of this thesis is to determine the influence of gender on the growth and formation of the pigs dorsal muscle. Growth is one of the basic phenomenon characterizing living organism. Is a creation of nonliving to living matter. The amount of body mass is not constant through the life, it is changing significantly. In the early postnatal period is skeleton growing faster compared to muscles and fat then leads to faster growth of muscle and in the last period called maturity to the fattening. Evaluating growth has a significant gender effect. In case of pigs, it is common to feed barrows and gilts. Nowadays it begins to think about feeding of boars or the imunocastrates. Due to different hormonal activities we can expect different muscle and fat deposition. The task of this study was to clarify the influence of gender on the formation and growth of pigs dorsal muscle. There were 72 pigs tested in total. Pigs were housed in pairs in cotes and divided by gender for pigs, boars, imunocastrates and sows. This subpopulation of genotype DanBred animals were divided to 1/4 (18ks) uncastrated male pigs (K) 1/4 (18ks) hormonally castrated male pigs (I), 1/4 (18ks) barrows (V) and 1/4 (18ks ) gilts (P). Average live weight of pigs at the start of the trial was 28.5 kg, while the test was conducted to average 107 kg bodyweight. Through all time pigs were fed ad-libitum KKS. During the test it was monitored at weekly intervals individual live weight, back fat thickness at A, B, muscle depth at A, B and the total percentage of muscle for all categories of pigs. The obtained results show that the growth and formation of a long dorsal muscle are influenced by gender. When comparing the weight in a given period, we conclude that during the time the difference between gilts and imunocastrates grow up. Best growth had imunocastrates gilts similarly, only was there an earlier stop of the growth. The highest increase in fat and muscle measured at the A and B, occurred in pigs, in sows we can see increasing gains in fat with respect to the period in which they are fattening. Boars had the lowest backfat thickness, imunocastrates. With imunocastrates we evaluate low fat increase compared to the beginning of the observation. The biggest muscle depth measured at A and B had the barrows with gilts and imunocastrates and especially boars did not reach the values as barrows and gilts, who had the highest muscle depth. Biggest % of muscle was measured in sows. A large proportion of muscle can be seen in male pigs. The proportion of muscle mass of imunocastrates was under the average and worst ratio of muscle had especially at the end of feeding barrows indicating that with increasing age there is a significant fattening, compared to the remaining groups of pigs Keywords: pig, growth rate, muscle fibers

The influence of time in feed enrichment with unsaturated fatty acids to selected parameters of pig carcass value with regard to the fatty acid composition of intramuscular fat
Pantoflíček, Jiří ; Čítek, Jaroslav (advisor) ; Miloslav, Miloslav (referee)
The thesis aims to evaluate the impact of aliment with higher contents of unsaturated fatty acids, consumed for a different period of time, to utilitarian attributes of pigs before a slaughter, with respect to the composition of fatty acids in the intramuscular fat of tested animals. The factors that influence the quality of meat are interior, exterior and technological. Among the qualitative markers of quality of meat we rank the share of meat and fat, acidification rate, color, viscosity, contents of intramuscular fat (marbling), smell, taste, juiciness and delicacy. Together with hygienic and nutritive attributes, consumers and processors consider these technological and sensory aspects to be the most important. The ultimate goal of this thesis is to compare the impact of different length of feeding soy oil on parameters of pork meat quality and growth. However, the interference of growth attributes was inconclusive and the test result came similar in different groups of tested pigs. What was influenced by adding the soy oil into the feed is the fatty acids profile. The contents of fatty acids remained unchanged in every test group. Over time the content of monounsaturated fatty acids decreased. The most significant change occurred in representation of polyunsaturated fatty acids, which increased in the test groups with longer period of feeding with enriched feed, mostly at the expense of monounsaturated fatty acids. The differences between the test groups of pigs were statistically inconclusive; therefore the soy oil enrichment did not worsen the technological parameters of meat and fat quality. The longer period of feeding the soy oil enriched feed led to significant increase in polyunsaturated fatty acids. According to the findings, adding the soy oil into the feed will have no effect at all if done short time before the slaughter.

The Economic Consequences of Organized Crime
Kunt, Lukáš ; Polišenský, Miroslav (advisor) ; Pavel, Pavel (referee)
Summary This thesis deals with the significance of the threat that organized crime poses to society. The aim is to provide an overview of its present forms and economic impact. In the theoretical part, there is an outline of basic terms associated with organized crime, its traditional and new forms, the most influential organized crime groups and their history regarding the Czech Republic and the EU and institutions that fight them. The empirical part focuses on the issue of illegal drugs. Drugs smuggling and illegal drug trade are defined from the perspective of criminology. Using addictology and police statistics, the features of illegal drug market are described. Comparing various facts, the crackdown on illegal drugs in the Czech Republic and the EU is analysed, and from statistical data - applying mathematical methods - the value of illegal drug market is estimated. Economic impact of chosen forms of organized crime is described by the assessment of their share in GDP and economy in general. In the conclusion of this thesis, some measures that could reduce the social and economic impact are drawn.

Clinical biochemical indicators used in diagnostics of equine diseases
Puldová, Doubravka ; Ptáčková, Zuzana (advisor) ; Krejčířová, Romana (referee)
The thesis aims to compile overview of main biochemical indicators that are important in for diagnostics of equine diseases. Clinical biochemistry is a medical discipline that uses biochemistry and pathobiochemistry for the determination of diagnosis based on activity changes of analytes observed. Laboratory evaluation of analytes has three phases: pre-analytical (preparation of patient to sampling, sampling and sample storage and transport), analytic (analysis) and post-analytical (evaluation of results, veterinarian also contributes in this part). Pre-analytial phase is the most time consuming and also the most error prone. The errors mostly occur during preparation of the patient, during sampling or sample transportation. The most analyzed materials for biochemical analysis are blood, urine and liquor. Biochemical indicators are compound that are often influenced by the disease, therefore it is possible to use them for the diagnosis. Nitrogen metabolism indicators include proteins, urea, creatinine and ammonia. Enzymes (aminotransferase, gama-glutamyltransferase, glutamatedehydrogenase, lactatedehydrogenase, alkaline phosphatase, creatinkinase and sorbitoldehydrogenase are the main indicators of liver function (they contribute on the metabolism of another compounds) or of the fitness of horse. Glucose and lactate values indicate energetic metabolism, cholesterol and triglycerides indicate lipid metabolism. Water and electrolyte metabolism indicators are sodium, potassium and chlorides. The mineral profile is shown by calcium, magnesium and phosphorus. The result of determination of analytes is compared with reference values that are not only species-specific but can be also influenced by age or sex. These values represent the range of the compound concentration in body fluid under physiological conditions. It is important to take the clinical symptoms into the account. Not all indicators that are usually indicated in human medicine or different animals are suitable for diagnosis of equine diseases. Majority of indicators diagnose equine-rare diseases (i.e. diabetes mellitus or hepatitis). Determinations of muscle enzymes and lactate are important for the fitness analysis.

The growth of Lodgepole Pine (Pinus contorta) in reclaimed spoil banks
Štrudl, Robin ; Bažant, Václav (advisor) ; Slávik, Martin (referee)
This diploma thesis deals with the detection of the dynamics of the growth and development of lodgepole pine, which is intended for the purposes of the forestry reclamation on anthropogenic soils spoil banks. In the first stage it is approached the issue of growth and development of woody plants on spoil banks. Are described recent formations, their cutting and editing, further forestry reclamation and associated issues, on which follows the description of the entitlements of tree species in different territories, further criteria necessary for the correct evaluation of the conditions on the habitats directive and appropriate ways of establishing the stands. Subsequently, we approached lodgepole pine, its description, extension, variability, etc. In the second part of the thesis is studied and evaluated growth of lodgepole pine. The first is characterized by the interest of the territory and its natural conditions. On the plots in the forestry arboretum on the spout Antonin samples were taken in the form of stem discs, which served as the basis for determining the necessary values. Values were obtained from tree rings.

Evaluation of pasive detectors in intrusion and hold-up alarm systems
Kalivoda, Petr ; Hart, Jan (advisor) ; Libich, Ladislav (referee)
Thesis deals with passive safety elements . The issue is dealt with in the theoretical part and a practical part . In the theoretical section provides information used for introduction and its current development . The practical part deals with the principles of magnetic -synaptic contacts , their reliability and proper functioning . It adds an option for simple - holding . Shown are the practical experiments from laboratory measurements to clarify the issue of magnetic contacts and compare actual values with the theoretical values indicated by the manufacturer . Finally, we evaluated the results of the work

Motivation as a leadership
Pluhař, Josef ; Fiedler, Jiří (advisor) ; Horáková, Jana (referee)
The topic of the bachelor's thesis is "motivation as a managing technique". In the first part it focuses on defining broad theoretical concepts and in the second it addresses the research itself. The first part puts the biggest emphasis on defining terms such as management and manager, which are the key organizational aspects of a company. Next, the thesis discusses basic managerial functions such as organizing, supervising and mainly managing people. An important topic is setting motivation, in which terms like motive, stimulus, value, need and other work motivators are discussed. The end of the theoretical part describes individual motivational theories by numerous authors. The ideas of Maslow, Herzberg, Vroom, McClleland, Adams and Skinner are analyzed in detail. In the practical part, all of the aforementioned theories confront with research. The research was conducted via structured interviews of five managers, three men and two women. The interviews analyze personal characteristics of the managers and the way they behave towards their employees. Furthermore, they discuss motivational stimuli, which the managers apply on their subordinates and which have the most profound influence on them. Benefits, which each company offers and their sufficiency. The managers react to managerial functions and their application in the field. In the last part, managers share what motivates them and what brings them joy from done work.