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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Kryptická diverzita u sladkovodní řasy Synura sphagnicola (Chrysophyceae, Stramenopiles) / Cryptic diversity of freshwater alga Synura sphagnicola (Chrysophyceae, Stramenopiles)

Slámová, Pavla January 2014 (has links)
A common alga of oligotrophic slightly acidic fresh water habitats, Synura sphagnicola, has never been suspected for a presence of cryptic diversity. The publicly available SSU rDNA sequences showed very slight genetic differences between the S. sphagnicola isolates. However, I suspected that if any cryptic lineages exist, the sequencing of ITS region will show the differences between them. A total of 37 S. sphagnicola sequences (36 from Europe and 1 from Korea) were analyzed in this thesis. The ITS rDNA sequencing clearly recognized the presence of two distinct cryptic species, referred here as lineage SP1 and SP2. The morphological analysis of 14 cultivated strains (6 belonging to the lineage SP1 and 8 to the lineage SP2) validated the genetic distinction. The statistical analyses showed that 4 morphological aspects (length of a scale, width of a scale, length of a spine, length of a rim) were found to have significant differences in length of measured factors between species. The most visible difference is in the length of a spine that is connected to the scale. The analysis of published S. sphagnicola scales showed that the two lineages can be morphologically distinguished also in natural conditions. According to the morphological analyses, the lineage SP2 (species with a longer spine)...
2

Diverzita a taxonomie zástupců rodu Geastrum ve Střední Americe / Diversity and taxonomy of members of genus Geastrum in Central America

Zehnálek, Petr January 2017 (has links)
In temperate zone, especially Europe and North America, is the genus Geastrum very well inspected group of Gasteromycetes with long lasting and comprehensive history of research. Our knowledge of the diversity in other areas of distribution, especially in tropics, is more than limited. The aim of this diploma thesis is to contribute for cognition of diversity of this genus in Panama, Costa Rica and Colombia I have collected 86 samples belonging to genus Geastrum during three expeditions to Panama (Chiriqué province) in the years 2015, 2016, 2017. I have characterized those based on morphological and molecular data. I have also studied morphology of 40 borrowed herbarium specimens from Costa Rica, Colombia and Panama. I have successfully sequenced four locuses of DNA from my own samples (ITS, LSU, RPB1 and ATP6). This method had lover efficiency in herbarium specimens due to present contaminations, age of specimens or probably badly stored. Molecular phylogenetic analysis was carried out by Bayesian method and its results have in agreement with morphologic traits shown many lineages new for Panama and moreover at least four new species completely new to science. Variability in species complexes (e.g. G. lageniforme, G. saccatum, G. velutinum) is presented in more detail with emphasis to lineages...
3

Klonální vývoj leukemických buněk a jeho úloha při progresi leukémií a preleukémií / Clonal evolution of leukemic cells and its role in the progression of leukemia and preleukemia

Svobodová, Karla January 2020 (has links)
Clonal evolution is a multistep process characterized by progression of the disease, adverse prognosis and shortening of overall survival. The aim of the dissertation was a detailed characterization of identified changes in patients with myelodysplastic syndromes (MDS) and clonal evolution and evaluation of their prognostic impact. We performed detail cytogenomic analyses in 36/469 (8%) patients with confirmed linear clonal evolution. We described 57 primary abnormalities (32% MDS-specific) at the time of diagnosis, the most frequent was deletion of long arm of chromosome 5. We proved 156 secondary aberrations (21% MDS-specific) during the course of the clonal evolution, the most frequent were trisomies/tetrasomies of chromosome 8. We identified acquired uniparental disomies (aUPD) in 19% of patients. In MDS-specific aUPDs 4q, 11q and 17p, we proved homozygous mutations of TET2, c-CBL and TP53 genes. We found a statistically significant difference in overall survival between the groups of patients divided according to their diagnostic cytogenomic findings. In patients with clonal evolution before treatment 54% of aberrations were gains of whole chromosomes, by contrast 44% of abnormalities identified in patients with clonal evolution after treatment were monosomies or deletions. The study of clonal...
4

Odhalování skryté druhové diverzity u krásivek (Desmidiales, Viridiplantae) / Unveiling hidden species diversity in desmids (Desmidiales, Viridiplantae)

Šťastný, Jan January 2013 (has links)
The delineation of desmid species was traditionally based on purely morphological features. However, a frequent misinterpretation of morphological variability in desmids has led in the past to extensive taxonomical confusion within this important group of green algae which complicates the interpretation of their biodiversity in freshwater ecology, biogeography and biomonitoring. Consequently, I focused in this thesis predominantly on a previously neglected issue, the application of polyphasic approaches in the species-level taxonomy of desmids. In the most studies, a combination of both traditional morphological and modern molecular phylogenetic and geometric morphometric methods has been used to evaluate the taxonomy of selected desmid species, particularly representatives of the morphologically complex genera Micrasterias and Xanthidium. In two papers, I used the combination of traditional morphological and autecological data to clear up the taxonomy of several morphologically less prominent desmid taxa. Generally, the results of the thesis demonstrated that the way we recently see the diversity and distribution of desmids should be thoroughly changed. The real species diversity is mostly distinctly finer than that estimated by classical morphological taxonomy, often corresponds to varieties of...
5

Taxonomy of selected groups of the genus \kur{Caloplaca} / Taxonomy of selected groups of the genus \kur{Caloplaca}

ŠOUN, Jaroslav January 2011 (has links)
The thesis deals with phylogeny, taxonomy and nomenclature of selected groups of the lichen genus Caloplaca. Particularly, the C. cerina group was closely investigated using molecular methods (ITS sequences), morphology and chemistry, based on material from Europe, and to some extent also from North America and western Asia. This approach resulted in the description of three new species (C. sterilis, C. subalpina, C. thracopontica), and detected an unexpected richness of lineages. Nomenclature, taxonomy, morphology and ecology of C. aurantia and C. flavescens from the C. aurantia group were studied in detail, including selection of the neotype of the former species. Their distribution was reviewed for the territory of the Czech Republic. Poorly known taxon C. aurantiomurorum from Algeria was lectotypified and synonymized with C. aurantia. Apart from the two groups, C. phlogina and C. scythica, differing partly in thallus colour and distinctly in distribution, were examined using both molecular (ITS sequences) and phenotypic data and found to be conspecific.
6

Molekulárně genetická analýza u pacientů s podezřením na kryptické přestavby. / Molecular Genetic Analysis in Patients Suspected of Cryptic Rearrangements.

Šolc, Roman January 2010 (has links)
Such chromosomal rearrangements, which cannot be detected by using of cytogenetic banding of metaphase chromosomes, i.e. chromosomes smaller than 3 - 5 Mb, and therefore modern molecular genetic methods are used to detect them, are called "cryptic rearrangements". Their important role in human pathology is more and more significant. By using of the multiplex ligation-probe dependent amplification method (MLPA) we examined a group of 50 probands with idiopathic mental retardation. A cryptic rearrangement was found at 8 probands (16 %), at 6 of them it was demonstrably causal. Then we examined a group of 40 probands suspected of gene SHOX pathology. A cryptic rearrangement was found at 17 probands (42.5 %) and at 8 of them it was demonstrably causal. Presence of small deletion founded isolated at 7 probands was verified in a population set, but without a positive result. An analysis of mutations was made too.

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