National Repository of Grey Literature 191 records found  previous11 - 20nextend  jump to record: Search took 0.00 seconds. 
Sex chromosomes of Nematocera
Ryšan, Tadeáš ; Volf, Petr (advisor) ; Šťáhlavský, František (referee)
The paraphyletic group Nematocera is highly diversified in both body morphology and life strategies. Based on sex chromosome morphology, it can be divided into four groups defined as early as the mid- 20th century. All these systems are based on the presence of the XY/XX sex chromosomes or the loss of the Y chromosome. The different groups are distinguished based on whether the chromosomes are differentiated, whether chiasmata are present and whether the Y chromosome is retained. However, later research has shown much higher sex chromosome diversity, mostly in groups with homomorphic gonosomes. Even though most representatives of this group do not have differentiated sex chromosomes, we find the recurrence of differentiated gonosomes and even the X1X2Y1Y2/ X1X1X2X2 and ZW/ZZ sex systems, which are less typical for Diptera. These findings suggest that the form of sex chromosomes in Diptera may not be as stable as previously thought. The recently discovered non- homology of gonosomes across the Diptera, including several representatives of Nematocera, supports this idea. Multiple independent gonosome formation could also explain the diversity of primary sex- determining factors in those groups where these factors are known. Key words: Nematocera, Phlebotomus, Lutzomyia, sex chromosomes, sex determination
Possibilities of cognitive development in preschool children
Černá, Klára ; Krykorková, Hana (advisor) ; Volf, Petr (referee)
This thesis aims to create an elementary task situation for preschool children, which would allow the development of cognitive functions and facilitate the child's understanding of relationships and connections between objects and phenomena. Task situation also reflects the wider social and cultural context where the process of learning and cognition takes place. Preschool age is a period when shaping the personality of the child and his cognitive apparatus necessary for preparation for school and future life.
Salivary glycoproteins of bloodsucking arthropods
Sumová, Petra ; Volf, Petr (advisor) ; Mikeš, Libor (referee)
During obtaining their blood meal, bloodsucking arthropods salivate into their host. Bloodsucking arthropods' saliva contains wide array of bioactive macromolecules. Host organism develops antibody response against many of these molecules. Due to interspecies variability in salivary protein composition, detection of antibody response may serve as a marker of the exposure to individual species of bloodsucking arthropods. Host antibody response is mostly elicited by proteins or glycoproteins. Glycoproteins contain one or more oligosaccharide chains attached to the protein. Glycoprotein's antigenicity could be caused by either both parts, or by only the protein, or the sugar part. This fact has to be taken into consideration for choice of the expression system for recombinant glycoprotein synthesis. This work summarizes current knowledge about structure, function and features of salivary glycoproteins in various species of bloodsucking arthropods.
Intraspecific variability of Phlebotomus sergenti, a major vector of Leishmania tropica
Dvořák, Vít ; Volf, Petr (advisor) ; DEPAQUIT, Jérôme (referee) ; Maroli, Michele (referee)
t ( Results l. We demonstratedthat crossing b possible betweenP. sergenti laboratory-reared specimens tom coloníes originating fiom Turkey and brael. Succesful mating and irseminationwas oberved and viable hybrid Fl and F2 offEpringswercobtaínedfromboth parentalcombinatiors.No satbtically significantdíftrencewas bund in theegg production oťthehybrideswtrcncomparcd!o theparents. 2. RAPD analysš was able to dštingušh clearly beween membes of Turkish and hneli colony.When Fl pÍogenyobtainedfromthecÍossflatingstudywere includedin the RAPD anallsb, thesesamples 6rmed a dbtinct groupwith positionintermediatebetween Turkish and lsraelisubgroup,not only sharinga portionof ban& with each of the parenal coloniesbutalsoexhibitingseveraluniqueloci. The rcsultsofRAPD analysbwerc in accord with geometricmorphometricanalysb of wing shapeof P. sergentifrom TuŘey and Israe| demomtratingtbatbothmolecutarbiologyandmorphologicalapproacbesarecomplementary. 3. RAPD provedto be a rseful methodfur identificationandcomparisonof P. sergenti specimem tom two foci of cutaneors leishmaniasbin northemIsraelwhich difrr in the vector. 4. No microsatsllitemarkes pÍeviouslyšolated for otherphlebotominespecieswerc found applicableon P. sergeni. A developmentof speciesspecific microsatellitemarker panel was sbÍtedand two suitable ma*es were...
Analysis of occurrence of extremal values in time and space
Starý, Ladislav ; Volf, Petr (advisor) ; Dvořák, Jiří (referee)
This thesis describes and compares methods for statistical modeling of spatio- temporal data. Methods are extended by examples and numerical studies on real world data. Basic point of interest is statistical analysis of spatial data with unknown correlation structure and known position in space. Further analysis is focused on spatial data with temporal component - spatio-temporal data. Fi- nally, extremal values and their occurrences are discussed. The main aspiration of my thesis is to provide statistical tools for spatio-temporal data and analysis of extremal values of prediction. 1
Methods of longitudinal data analysis
Jindrová, Linda ; Volf, Petr (advisor) ; Prášková, Zuzana (referee)
Práce se zabývá longitudinálními daty - měřeními, která jsou prová- děna opakovaně na stejných subjektech. Popisuje r·zné typy model·, které jsou vhodné pro jejich analýzu. Postupuje od nejjednodušších lineárních model· s pevnými nebo náhodnými efekty, přes lineární a nelineární modely se smíšenými efekty, až ke zobecněným lineárním model·m a generalized estimating equati- ons (GEE). Vždy je uveden tvar modelu a zp·sob odhadu parametr·. Jednotlivé modely jsou také porovnávány mezi sebou. Teoretické poznatky jsou doplněny aplikacemi na reálná data. Pomocí lineárních model· analyzujeme data o výrobě v USA, nelineární modely využijeme k vysvětlení závislosti koncentrace léčiva v krvi na čase a GEE aplikujeme na data týkající se dýchacích potíží u dětí. 1
Xenodiagnosis and its use in leishmaniases research
Vojtková, Barbora ; Volf, Petr (advisor) ; Svobodová, Milena (referee)
The aim of these theses was to summarize the knowledge about the use of xenodiagnostic methods in the past and their current potential for parasitological research. Xenodiagnosis it is a diagnostic method using bloodsucking arthropods (disease vectors) as a biologic medium suitable for detection of parasites in the blood of investigated individuals (vertebrates). It is expected that parasites grow within the midgut of the vector and then are easily detectable microscopically. The method was used for the first time in 1914 by French researcher Émile Bumpt for detection of Trypasoma cruzi, causative agent of Chargas' disease. During few decades and thanks to engagement of many scientific groups, it became one of the most efficient and effective diagnostic methods. For instance, the most suitable species of vectors, the experiment duration and the optimal numbers of vectors and/or experiments were assigned to get reliable results. Xenodiagnoses as a diagnostic method lost its importance after introduction of molecular methods, first of all after onset of polymerase chain reaction. At present, however, the xenodiagnosis is suitable for experiments studiing if the host is infectious for the vector. This method appears as a good tool for testing of new reservoir hosts and for the monitoring of the role...

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