National Repository of Grey Literature 66 records found  beginprevious21 - 30nextend  jump to record: Search took 0.01 seconds. 
Methods of sperm selection for human and veterinary assisted reproduction
Pavlová, Hana ; Komrsková, Kateřina (advisor) ; Koubek, Pavel (referee)
Sperm selection is an important process influencing the progress of fertilization and the quality of resulting embryos. Competent sperm cells can be isolated from an ejaculate sample according to different criteria. Standard methods allow for sperm selection based on conventional parameters, particularly motility and density. Using advanced methods, sperm cells are selected according to molecular aspects including for instance membrane charge, presence of specific receptors, molecules indicating ongoing apoptosis, and others. The latter procedures are widely used particularly in human practice. Their use is uneconomical in veterinary practice and standard methods including the centrifugation step in the procedure are primarily used to select the sperm of livestock. Sperm cells of livestock are also often selected according to whether it carries the X or Y chromosome. Thus, the sex of the offspring can be effectively determined in order to increase the efficiency of the production of animal products. This thesis presents the most frequently used methods of sperm selection for the purpose of oocyte fertilization in human and veterinary sectors of assisted reproduction and discusses their impact on the parameters and fertilization potential of isolated cells.
Sperm centrioles and their role in reproduction
Vlčková, Monika ; Frolíková, Michaela (advisor) ; Liška, František (referee)
Centrioles are evolutionarily conserved protein structures composed of microtubules. In somatic cells, centrioles serve as the basal body of cilia and flagella and allow the assembly of pericentriolar material, thereby creating the centrosome. Without centrosome, animal cells are not capable of nuclear division. Centrioles do not arise de novo and their formation always requires the presence of a preexisting centriole. Since there are no centrioles in the egg at the time of fertilization, unlike spermatozoa, sperm is the carrier of centrioles and therefore all of the centrioles of the emerging organism are of paternal origin. There are two centrioles in the sperm - a cylindrical shape proximal and a distal one, which is perpendicular to the proximal. The sperm centrioles are the basis for the formation of the sperm flagellum and after fertilization form the mitotic spindle of the zygote, necessary for equal DNA and cell distribution. It follows from the above that the presence of centrioles in sperm is essential in mammals and defects in their structure may lead to male sterility or embryo development disorders. However, sperm centrioles differ from somatic centrioles in their structure and behavior and understanding these differences is one of the important tasks of reproductive biology.
Sperm cell penetration and membrane fusion with oocyte during fertilization in mammals
Klimková, Veronika ; Krylov, Vladimír (advisor) ; Frolíková, Michaela (referee)
Fertilization is a process involving multiple steps, which are in continuity and complement each other. Spermatozoa become competent to fertilize after capacitation, hyperactivation and acrosome reaction. Oocytes are surrounded by a layer of cumulus cells and give a signals for spermatozoa to activation and orientation. This study focuses on the latest knowledges about a roles of cumulus cells, production of chemoattractants and the possibility that cumulus cells induce the acrosome reaction after binding a novel sperm protein NYD-SP8 to the cumulus. It seems that progesterone induce the acrosome reaction and also is the best chemoattractant secreted by cumulus cells. Next I am focus on gamete fusion including the role of surface proteins such as Juno and IZUMO1. Key words: membrane fusion, cumulus cells, acrosome reaction, chemotaxis sperm, oocyte, fertilization
Immunological causes of female infertility
Bajerová, Kateřina ; Brynychová, Iva (advisor) ; Novák, Jan (referee)
Currently, up to 15 % of reproductive age couples struggle with infertility. Female infertility is the cause of conception issues in nearly 40 % of these cases. The origin of female infertility consists of wide range of causes and other factors. Immunological causes are certainly one of the most significant ones. In pathological conditions, defense mechanisms of female immune system can target alloantigens presented on sperm surface. Moreover, autoimmune response and antibody production can occur as well. Antibodies can target various parts of ovarian follicles and oocytes, phospholipids, nuclear antigens, enzymes etc. These antibodies can inhibit fertilization, maturation of oocytes and embryo, embryo implantation, and also recurrent miscarriages. The aim of this thesis is to summarize various causes of female infertility focusing on immunological pathologies. The thesis also describes functioning of immune mechanisms in the female reproductive tract and briefly touches on oogenesis and female hormonal cycle.
Vliv teploty na udržení schopnosti oplození a líhnivosti při přechovávání neoplozených jiker u lína obecného
ANDONIU, Andreas
This theses deals with the storage length of artificially spawn of hard roes of Tench (Tinca tinca) during different temperatures at the time before the semen discharging and activation to fertilization, hatching and consequent survival of fish hatchery throughout changeover from the embryonic to larval life period (beginning of active food intake). Homogeneous assortment of hard roes obtained from hormonally induced artificial hatching of 6 spawners has been used for this experiment. Samples of hard roes were put into plastic bowls and covered, immediately after artificial hatching. Subsequently, they were placed into tempered, thermo-isolating containers with temperatures of 5, 10, 15, 20, 25 and 30 °C. In time intervals of 0.5; 1; 1,5; 2; 3; 4; 6; 8 and 10 hours, a small amount of hard roes were taken away from each temperature (estimated 50 -100 pieces) and put into dry, glass beakers (in 3 repetitions in each temperature combination and length of storage). Subsequently, the semen discharging from 6 milters was carried out and activation by water was performed. Incubation took place in non-sticking environment. During the incubation, or more precisely during the consequent storage of embryos through temperatures between 19-20.5 °C, water was changed daily. Fertilization was evaluated 48 hours after fertilizing. Hatchery was determined 48 hours after beginning of hatching of first specimen. After changeover from embryonic to larval period of ontogenetic development, living food was offered to hatching fish (artemia sp.). Thereafter, the amount of hatched fish with filled intestines was counted. Ascertained values were depicted as a percentage from the total number of seeded hard roes as well as fertilized hard roes with the use of statistic methods (two factors Anovy with the repetition). The highest level (in statistic evaluation on the importance level alfa = 0.05) of hard roe hatchery was accomplished throughout the length of possession and temperature 1 hour/ 25 °C (68.0 +- 3.1 %). The high level of hatchery was maintained by hard roes stored for 2 hours, afterwards a gradual value decrease was registered. Similarly, that was achieved with hatching parameter, where the high level of hatching was achieved with hard roes possessed for the period of 3 hours (except temperature of 30 °C), afterwards the hatchery was decreased. Pursued survival and food intake parameters of hatched fish (from the practical point of view) confirmed above stated dispositions. The high hatchery from placed hard roes was maintained for 1.5 - 3 hours (except 30 °C), thereafter there was its gradual decrease. In the time of 8 hours (temperatures 5 - 20 °C), the survival of 1.2 +- 1.8 %, was found out, with the rest, the survival was nearly zero.
The yield formation of spring wheat in depending on preceding crop
ŽÁČEK, Josef
This diploma thesis deals with the comparison of the influence of three different pre-crops on the spring wheat growing in real conditions of a chosen agricultural business. In 2018, a pilot plant test was established on the property in KÚ Dolní Svince, č.p. 0802/23 with the total area of 13,19 ha. For the establishment of the pilot plant test, an area of 5 ha had been used, which, due to its position, occupied the area of all thre pre-crops (corn for silage, winter barley, winter triticale). During the vegetation period, the occurence of weeds had been monitored and the crop yield elements for all stages of all spring wheat had been evaluated. After the harvest, the real crop yield of the wheat had been evaluated and a final economical evaluation had been made. The average crop yield concerning the first option, (pre-crop corn for silage) reached the yield value of 5,65 t.ha-1 , which was a 0,42 t.ha-1 more than the second option (pre-crop winter barley), in which case the value of harvest was 5,23 t.ha-1. Concerning the third monitored option (pre-crop winter triticale), the harvest value was almost similar to the second option - 5,36 t.ha-1. The most suitable pre-crop for the highest harvest of spring wheat is corn for silage, which has reached the highest profit when compared to the other options. In spite of a less advantageous pre-crop, the third option reached the highest-quality of nitrogen and nitrogen compouns.
Typological classification and categorization og grasslands in selected area and recommendation of sutable grassland management
KADLECOVÁ, Jana
The aim of this thesis was to create the botanic snap of the chosen locations, which were meadows, grasslands, pastures and also fallow grass areas, to determine the area coverage of three main agrobotanic species i.e. grass, herbs and clover, to process it with the statistcal software and determine the method and intensity of use and fertilization of individual locations and suggest the suitable prato-technical methods. The cenological structure of the locations has been observed and described using botanic snaps. The prato-technic method used were documented for each of the locations and evaluated the influence on the cenological structure. The research was performed in locations Vřeskovice, Čeletice, Městiště in the region Pilsen, former district of Klatovy. In each location the botanic snaps were taken from 3 areas of about 5 x 6 meters each. There were determined the area coverage of grass, herbs and clovers and calculated the mean indication value of humidity. Mean indication value of humidity is the parameter usable for determination of permanent grassland management and utilization. The data from the research was elaborated in software MS Excel. I recommend to manage the analyzed permanent grasslands as follows: 1. The meadow Vřeskovice behind the sewage cleaning station - additional sow of perennial rye grass, meadow clover and white clover. 2. The meadow Mstice - total recovery alternatively conservative prato-technic measures - manure fertilization for about 20t/ha and additional sow of meadow and white clover and grass - red fescue, blue grass and perennial ryegrass. 3. The meadow above the transformer station Vřeskovice - keep on current management od additional clovers sow. 4. The pasture Čeletice grazed by horses - keep on current management or additional sow of red fescue, tall fescue and timothy grass. 5. The meadow Městiště with combined utilization by cattle pasture and mowing - keep on current way of use. 6. The pasture Vřeskovice grazed by cattle - keep on current utilization or additional sow meadow and white clover. 7. The pasture Vřeskovice grazed by sheep - keep on the current utilization, in future after the reduction of dangerous knapweed to decrease the amount of pastured animals. 8. The fallow meadow Vřeskovice behind Petrovický neither mowed nor pastured - proposed mulching twice a year for about 1 or 2 years, then pasture or pasture of extensive cattle breed (Galloway) or sheep or periodical mowing once or twice a year. 9. The fallow meadow Vřeskovice trench at the farmhouse - leave as a fallow meadow improves the biodivesity, optionally to mow once or twice a year from estetical reasons.
Species-specific structural differences of mammalian sperm and function of their key proteins during fertilization.
Dobrodinská, Anna ; Frolíková, Michaela (advisor) ; Kuntová, Barbora (referee)
The fertilization is a process during which a male and a female gamete merge so that a new organism may come into being. The sperm-egg fusion is preceded by several essential processes, such as the capacitation, acrosome reaction, the sperm binding to the zona pellucida and oolemma, and membrane fusion of the gametes. Numerous proteins, which are located in both sperm and eggs, are major actors in controlling the listed, essential processes. During the process of fertilization these proteins fulfil one or more functions. In mammalian sperm, significant species-specific differences may be found both in their morphology and at the protein level. A complex understanding of species-specific distinctions in sperm structure and functions of key sperm proteins would contribute to a better insight into the process of fertilization, thereby enabling us to better diagnose and subsequently treat the causes of infertility in humans. This bachelor's thesis summarizes the current knowledge of sperm structure and its key proteins that has been acquired through the studies of the following model mammal species: bull, boar, mouse, and human. Further, this thesis brings an interspecific comparison between the studied species. Keywords: sperm, fertilization, acrosome reaction, capacitation, sperm proteins, bull,...
Long-term field experiments and their contribution to environmentally balanced agriculture: Abstract proceedings of the international colloquium and of the workshop Unbalanced potassium plant nutrition: causes, consequences and threats
Madaras, Mikuláš ; Stehlíková, Iva ; Teplá, Daniela
Proceedings of the scientific conference on long-term field experiments and their contribution to environmentally balanced agriculture with focus on unbalanced potassium nutrition.
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Foliar fertilizers containing collagen hydrolyzate for nutrition of grapevine: applied methodology with certification
Horák, Jaroslav ; Raimanová, Ivana ; Kurešová, Gabriela ; Trčková, Marie
A comprehensive methodology describing the use of products made from collagen hydrolyzate for leaf nutrition of main field crops and vines grown in conditions of organic farming as well as within the conventional method of cultivation. Elaboration of the methodology was preceded by applied research to develop environmentally acceptable ingredient - collagen hydrolyzate, where undesirable sodium is replaced by biogenic, often scarce potassium. Another objective was to optimize content and a mutual ratio of trace elements from the perspective of requirements of particular crops or their groups. Within the methodology are stated all the information needed for qualified decision-making regarding to foliar application of newly developed products in organic and conventional mode of farming. Examples of practical use of both types of fertilizers are the result of their application in field trials and South Moravian vineyards with standard and biological growing system.
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