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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.
51

Populační struktura a fenotypová diferenciace Campanula moravica / Population cytotype structure and phenotypic variation of Campanula moravica

Šemberová, Kristýna January 2013 (has links)
Polyploidisation plays a major role in plant evolution. It can also cause taxonomic complexities as morphological differences are often blurred in higher ploidy levels. One of the taxonomically-intrigued groups of Central Europe is C. rotundifolia agg. Three ploidy- heterogeneous species are traditionally recognized in the Czech Republic: C. gentilis (2x, 4x), C. rotundifolia (2x, 4x) and C. moravica (4x, 6x). The thesis examines karyological and phenotypic variation of C. moravica, in the centre of its distribution (the Czech Republic and Slovakia). With the aid of modern biosystematics tools (DNA flow cytometry, multivariate morphometrics), marked discrepancies were revealed between published data and actual cytotype distribution pattern and morphological variation. In contrast to literature records, cytotype distribution in C. moravica is largely parapatric, with hexaploids occurring in Pannonian basin and tetraploids in Central and Eastern Slovakia. The type population of presumed tetraploids turned out to be hexaploid. The coexistence of one majority (4x) and six minority cytotypes (2x, 3x, 5x, 6x, 8x, 9x) was found in one population in central Slovakia and represent the most salient case of ploidy coexistence ever reported. Multivariate morphometrics showed that species identification on the...
52

Genetická a morfologická variabilita skupiny \kur{Melampyrum nemorosum}

DRAHNÍK, Petr January 2016 (has links)
Melampyrum nemorosum agg. is very complicated group of hemiparasitic plants. According to the traditional concept, 15 species is distinguished. Recent molecular analyses show a need of critical taxonomic revision of group and a potential importance of ancient hybridization. Analysis of 3 regions of cpDNA (trnTUGU-trnLUAA, psbA-trnHGUG, rpl32-trnLUAG) and 2 regions of nuclear DNA (Agt1 and At103) reveals well supported lineage with limited geographical distribution. Morphology and genome size of genetically supported lineages were compared.
53

Genetická a morfologická variabilita skupiny \kur{Melampyrum nemorosum}

DRAHNÍK, Petr January 2016 (has links)
Melampyrum nemorosum agg. is very complicated group of hemiparasitic plants. According to the traditional concept, 15 species is distinguished. Recent molecular analyses show a need of critical taxonomic revision of group and a potential importance of ancient hybridization. Analysis of 3 regions of cpDNA (trnTUGU-trnLUAA, psbA-trnHGUG, rpl32-trnLUAG) and 2 regions of nuclear DNA (Agt1 and At103) reveals well supported lineage with limited geographical distribution. Morphology and genome size of genetically supported lineages were compared.
54

Četnost výskytu fertilních a sterilních populací hasivky orličí \kur{(Pteridium aquilinum)} s porovnáním jednotlivých cytotypů

PODROUŽEK, Jan January 2017 (has links)
The data from public herbal collections were used to determine the frequency of the occurence of fertile bracken populations. Samples of bracken were collected to assess the degree of fertility and also to reveal the frequency of both diploid and triploid cytotypes using flow cytometry. Collected samples were also used for SSR analysis to characterize the population structure of both cytotypes and the propagation of triploid plants of bracken.
55

Analyse de données de cytometrie de flux pour un grand nombre d'échantillons / Automated flow cytometric analysis across a large number of samples

Chen, Xiaoyi 06 October 2015 (has links)
Cette thèse a conduit à la mise au point de deux nouvelles approches statistiques pour l'identification automatique de populations cellulaires en cytometrie de flux multiparamétrique, et ceci pour le traitement d'un grand nombre d'échantillons, chaque échantillon étant prélevé sur un donneur particulier. Ces deux approches répondent à des besoins exprimés dans le cadre du projet Labex «Milieu Intérieur». Dix panels cytométriques de 8 marqueurs ont été sélectionnés pour la quantification des populations principales et secondaires présentes dans le sang périphérique. Sur la base de ces panels, les données ont été acquises et analysées sur une cohorte de 1000 donneurs sains.Tout d'abord, nous avons recherché une quantification robuste des principales composantes cellulaires du système immunitaire. Nous décrivons une procédure computationnelle, appelée FlowGM, qui minimise l'intervention de l'utilisateur. Le cœur statistique est fondé sur le modèle classique de mélange de lois gaussiennes. Ce modèle est tout d'abord utilisé pour obtenir une classification initiale, le nombre de classes étant déterminé par le critère d'information BIC. Après cela, une méta-classification, qui consiste en l'étiquetage des classes et la fusion de celles qui ont la même étiquette au regard de la référence, a permis l'identification automatique de 24 populations cellulaires sur quatre panels. Ces identifications ont ensuite été intégrées dans les fichiers de cytométrie de flux standard (FCS), permettant ainsi la comparaison avec l'analyse manuelle opérée par les experts. Nous montrons que la qualité est similaire entre FlowGM et l'analyse manuelle classique pour les lymphocytes, mais notamment que FlowGM montre une meilleure discrimination des sous-populations de monocytes et de cellules dendritiques (DC), qui sont difficiles à obtenir manuellement. FlowGM fournit ainsi une analyse rapide de phénotypes cellulaires et se prête à des études de cohortes.A des fins d'évaluation, de diagnostic et de recherche, une analyse tenant compte de l'influence de facteurs, comme par exemple les effets du protocole, l'effet de l'âge et du sexe, a été menée. Dans le contexte du projet MI, les 1000 donneurs sains ont été stratifiés selon le sexe et l'âge. Les résultats de l'analyse quantitative faite avec FlowGM ont été jugés concordants avec l'analyse manuelle qui est considérée comme l'état de l'art. On note surtout une augmentation de la précision pour les populations CD16+ et CDC1, où les sous-populations CD14loCD16hi et HLADRhi CDC1 ont été systématiquement identifiées. Nous démontrons que les effectifs de ces deux populations présentent une corrélation significative avec l'âge. En ce qui concerne les populations qui sont connues pour être associées à l'âge, un modèle de régression linéaire multiple a été considéré qui fournit un coefficient de régression renforcé. Ces résultats établissent une base efficace pour l'évaluation de notre procédure FlowGM.Lors de l'utilisation de FlowGM pour la caractérisation détaillée de certaines sous-populations présentant de fortes variations au travers des différents échantillons, par exemple les cellules T, nous avons constaté que FlowGM était en difficulté. En effet, dans ce cas, l'algorithme EM classique initialisé avec la classification de l'échantillon de référence est insuffisant pour garantir l'alignement et donc l'identification des différentes classes entre tous échantillons. Nous avons donc amélioré FlowGM en une nouvelle procédure FlowGMP. Pour ce faire, nous avens ajouté au modèle de mélange, une distribution a priori sur les paramètres de composantes, conduisant à un algorithme EM contraint. Enfin, l'évaluation de FlowGMP sur un panel difficile de cellules T a été réalisée, en effectuant une comparaison avec l'analyse manuelle. Cette comparaison montre que notre procédure Bayésienne fournit une identification fiable et efficace des onze sous-populations de cellules T à travers un grand nombre d'échantillons. / In the course of my Ph.D. work, I have developed and applied two new computational approaches for automatic identification of cell populations in multi-parameter flow cytometry across a large number of samples. Both approaches were motivated and taken by the LabEX "Milieu Intérieur" study (hereafter MI study). In this project, ten 8-color flow cytometry panels were standardized for assessment of the major and minor cell populations present in peripheral whole blood, and data were collected and analyzed from 1,000 cohorts of healthy donors.First, we aim at robust characterization of major cellular components of the immune system. We report a computational pipeline, called FlowGM, which minimizes operator input, is insensitive to compensation settings, and can be adapted to different analytic panels. A Gaussian Mixture Model (GMM) - based approach was utilized for initial clustering, with the number of clusters determined using Bayesian Information Criterion. Meta-clustering in a reference donor, by which we mean labeling clusters and merging those with the same label in a pre-selected representative donor, permitted automated identification of 24 cell populations across four panels. Cluster labels were then integrated into Flow Cytometry Standard (FCS) files, thus permitting comparisons to human expert manual analysis. We show that cell numbers and coefficient of variation (CV) are similar between FlowGM and conventional manual analysis of lymphocyte populations, but notably FlowGM provided improved discrimination of "hard-to-gate" monocyte and dendritic cell (DC) subsets. FlowGM thus provides rapid, high-dimensional analysis of cell phenotypes and is amenable to cohort studies.After having cell counts across a large number of cohort donors, some further analysis (for example, the agreement with other methods, the age and gender effect, etc.) are required naturally for the purpose of comprehensive evaluation, diagnosis and discovery. In the context of the MI project, the 1,000 healthy donors were stratified across gender (50% women and 50% men) and age (20-69 years of age). Analysis was streamlined using our established approach FlowGM, the results were highly concordant with the state-of-art gold standard manual gating. More important, further precision of the CD16+ monocytes and cDC1 population was achieved using FlowGM, CD14loCD16hi monocytes and HLADRhi cDC1 cells were consistently identified. We demonstrate that the counts of these two populations show a significant correlation with age. As for the cell populations that are well-known to be related to age, a multiple linear regression model was considered, and it is shown that our results provided higher regression coefficient. These findings establish a strong foundation for comprehensive evaluation of our previous work.When extending this FlowGM method for detailed characterization of certain subpopulations where more variations are revealed across a large number of samples, for example the T cells, we find that the conventional EM algorithm initiated with reference clustering is insufficient to guarantee the alignment of clusters between all samples due to the presence of technical and biological variations. We then improved FlowGM and presented FlowGMP pipeline to address this specific panel. We introduce a Bayesian mixture model by assuming a prior distribution of component parameters and derive a penalized EM algorithm. Finally the performance of FlowGMP on this difficult T cell panel with a comparison between automated and manual analysis shows that our method provides a reliable and efficient identification of eleven T cell subpopulations across a large number of samples.
56

Protinádorová imunoterapie založená na instalaci manózy na povrch nádorových buněk / Anticancer immunotherapy based on the installation of mannose on the surface of tumor cells

MAIEROVÁ, Veronika January 2012 (has links)
The aim of this thesis was to find optimal therapy based on combination of membrane-anchored phagocytic ligands (mannose-(G)5-(K)10-STE, mannan-BAM, mannan-SMCC) with LPS (ligand of signal receptor)for treatment of murine melanoma B16-F10. Mixture of mannan-BAM with LPS applied in pulse regime proved to be the most effective, resulting in heigh reduction of tumor growth and significant prolongation of survival.
57

Taxonomic study of the Eurasian taxa of Tortula muralis (Pottiaceae, Musci) complex / Taxonomic study of the Eurasian taxa of Tortula muralis (Pottiaceae, Musci) complex

KOŠNAR, Jiří January 2014 (has links)
The thesis aims at clarifying the taxonomic difficulties in the Tortula muralis complex. For the first time, the group was studied by means of morphometric analysis, ploidy level assessment by flow cytometry, and molecular analysis based on sequencing of ITS region of nuclear ribosomal DNA. Morphometric and cytometric studies found only two well distinguished groups within the complex. These groups corresponded to the markedly variable species T. muralis and to the rather uniform species T. lingulata. Variability in ITS sequences suggested extensive gene flow among some of traditional morphologically defined taxa of the complex. Multiple polytopic autopolyploid origin of polyploids was revealed in some taxa. Changes in taxonomic conception of T. muralis complex were proposed in order to reflect structure of morphological, karyological, and DNA variability in the group. Natural hybridization is probably an important evolutionary mechanism that generated morphological diversity and taxonomic complexity in the mosses of T. muralis complex.
58

Fenotypová plasticita a cytotypy \kur{Agrostis stolonifera} v České republice / Phenotypic plasticity and cytotypes of \kur{Agrostis stolonifera} in the Czech Republic

KUBEŠOVÁ, Magdalena January 2007 (has links)
Presence and range of phenotypic plasticity in the Agrostis stolonifera polyploid complex (Poaceae) was studied in the territory of the Czech Republic. Plants were cultivated under different experimental conditions. Stomatal size of different Agrostis stolonifera cytotypes was measured. Flow cytometry was applied for genome size estimation. Ploidy levels were determined for more than 150 samples of Agrostis stolonifera as well as several specimens of Agrostis canina, A. capillaris, A. gigantea, A. rupestris and A. vinealis. Absolute DNA content was estimated in all studied species. Isozyme analysis was used to test the possibility of the hybrid origin of pentaploid individuals of Agrostis stolonifera species.
59

Změny v distribuci subpopulací B lymfocytů u pacientů s Crohnovou chorobou před a po biologické léčbě / Changes in distribution of B lymphocyte subpopulations in patients with Crohn disease before and after biological therapy

Suchá, Renata January 2016 (has links)
B-lymphocytes are lymphoid cells, which are a part of the adaptive/innate immune system and generate antibodies. Recently, many studies have supported hypothesis that different rather minor B-lymphocyte subpopulations may play a direct and indirect role in immunopathogenesis in human pathologies such as Crohn's disease (CD). The aim of current study was therefore to investigate distribution of frequencies of B lymphocyte subpopulations (from transient to mature effector B cell stages) in peripheral blood of healthy subjects (CO), patients with Crohn's disease (CD) and ulcerative colitis (UC). Thus, using 11-colour flow cytometry we have analysed 30 blood samples of individuals, including 14 healthy controls, 11 patients with Crohn's disease and 5 with UC. In 6 patients with CD we have had an opportunity to analyze blood samples collected 2 hours after an administration of anti-TNF therapy. Higher frequencies of memory B-lymphocytes (CD19+ CD27+ , CD19+ CD20+ CD27+ and CD19+ CD20+ CD27+ IgM+) were found in patients with CD as compared to COs. (20.06±13.58%; 17.61±13.48%; 88.60±20.56% vs. 11.75±26.47%; 11.25±26.50%; and 66.82±22.60%), in case of CD19+CD20-CD27-IgM+ B-lymphocytes the difference was statistically significant (57.15±17.21% in CD vs. 19.59±31.79% in CO; p=0.0341), which is in accordance...
60

Zhodnocení cytotypové a morfologické variability spolu s mírou hybridizace u rodu stolístek (Myriophyllum) na území ČR a sousedních států / Evaluation of cytotype and morphological variability and hybridization rate in water-milfoils (Myriophyllum) in the Czech Republic and adjacent territories

Hrdinová, Magdalena January 2015 (has links)
Myriophyllum L. (watermilfoil) belongs to one of the most invasive genus of the Northern Hemisphere. The three most agressive species, one of which is native to Europe (M. spicatum), are widespread throughout the majority of United states and two of them (M. aquaticum and M. heterophyllum) are becoming invasive in several Europaean countries as well. Therefore, Europaean populations of both native and invasive species, represents ideal place where to study processes which account for watermilfoils' invasivness. In this study, flow cytometry, morphometric analyses and germination experiments were employed to evaluate cytotype and morphological variability of Myriophyllum along with its potential to hybridize and propagate generatively. Five ploidy levels were detected in Europe, however no ploidy variability has been found within any species except for M. sibiricum (hexaploids and nonaploids) and one population of M. aquaticum (hexaploids and oktoploids). Flow cytometry proved to be useful tool for purposes of distinguishing species of different ploidy level and their potential hybrids. Nevertheless, the key species - M. sibiricum and M. spicatum - among which probably even more aggressive hybrids were recently identified, have similar hexaploid level. Thus flow cytometry cannot facilitate...

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