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Hidden diversity and evolutionary trends in malacosporean parasites (Cnidaria: Myxozoa) identified using molecular phylogenetics
HRABCOVÁ, Martina
Malacosporeans represent only a minor part of the huge myxozoan diversity, accounting for more than 2000 species. In contrast to the remainder of the Myxozoa, malacosporeans cycle between vertebrate (fish) and invertebrate (bryozoans) hosts and are restricted to freshwater habitats. The present study applies light microscopy and molecular methods to scrutinize the morphology, prevalence, diversity, distribution as well as host and habitat preference of malacosporeans in fish hosts. Comprehensive phylogenetic analyses based on newly obtained malacosporean SSU rDNA sequences and those available in GenBank reveal important evolutionary trends in this group. The significant increase in malacosporean species richness unveiled in the present study points to a hidden biodiversity. Reasons for this cryptic species diversity, the potential existence of malacosporean life cycles in marine environment as well as the evolution of worm- and sac-like morphology in bryozoan host are discussed.
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Evolution of the tetrapyrrole synthesis in eukaryotes
KOŘENÝ, Luděk
This thesis focuses on the nature of heme metabolism in various eukaryotes. One of the aims was the elucidation of the origin of the unique heme biosynthesis pathway in apicomplexan parasites through a comparative study of their photosynthetic relative Chromera velia combining molecular biology, biochemistry and bioinformatics approach. Using similar strategy, I have also investigated the origin and spatial organization of tetrapyrrole biosynthesis in Euglena gracilis. Based on the phylogenetic data I described the complex evolution of heme metabolism in kinetoplastid flagellates including pathogenic trypanosomes. I revealed that one of them (Phytomonas) does not require heme for viability by the combination of various biochemical and molecular biology experiments and bioinformatic analyses.
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Dynamic karyotype evolution and unique sex determination systems in Leptidea wood white butterflies
VOLENÍKOVÁ, Anna
Chromosomal rearrangements such as fusions and fissions play an important role in promoting and maintaining speciation. To study these phenomena, genome architecture of three cryptic species of Leptidea wood white butterflies was investigated by means of standard and molecular cytogenetics. High variability in chromosome number and localization of cytogenetic markers was revealed, suggesting dynamic karyotype evolution in these species. Moreover, unique sex-determination system with 3-4 W chromosomes and 3-4 Z was found, possibly playing a role in the speciation process as well.
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Effect of surface of semiconductor nanocrystals on their properties: investigation by laser spectroscopy
Preclíková, Jana ; Malý, Petr (advisor) ; Franc, Jan (referee)
The topic of the diploma thesis is chemical treatment of the surfaces of semiconductor nanocrystals CdS and CdSe in the form of thin nanocrystalline films prepared by chemical bath deposition. The evolution of photoluminescence and absorption spectra was investigated under treatment by water, toluene, butylamine, pyridine and hydrogen peroxide. The strongest changes were observed by samples soaked in water, pyridine and aqueous solution of pyridine. The observed effects were explained by partly dissolving of nanocrystals by water and affecting behaviour of photoexcited holes in the presence of the strong hole acceptor pyridine. The second part of this diploma thesis deals with photochromic properties of silver nanoparticles in a titanium oxide matrix. The photochromic behaviour of the samples was examined in detail. A phenomenological model of photochromic changes was suggested in analogy with the hole burning spectroscopy. In order to better understand the microscopic processes in this composite material other experiments were realized - e.g. samples were UV irradiated, or laser illuminated under lowered air pressure, pump & probe experiment. Under laser irradiation optical extinction of some nanoparticles was decreased. Simultaneously, changes of plasmon resonances of the rest of nanoparticels were...
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Aplikační řešení nákupu v prostředí cloudu a trendy v jejich vývoji
Štangl, Rastislav ; Donát, Jiří (advisor) ; Žamberský, Martin (referee)
The goal of the presented thesis is to screen market and to assess the Procurement application solutions provided in cloud with focus on SMB companies. Understanding of Procurement process is base for identification of key functions and requirements on Procurement applications. Market research results in initial high level picture about the Procurement applications available with attention to cloud. Procurement applications assessment determines conclusions on market evolution and trends. The first part of the thesis introduces theoretical background of Procurement process and cloud computing. This part is completed by the list of key functions and requirements, of expected benefits, and of the steps that are important during assessment and selection of Procurement application in business. The second part investigates the Procurement application market and vendors. The screening is oriented on application features, client set, delivery models, and on other characteristics. Eight Procurement application solutions were selected for detailed assessment: Bellwether ePMX, Compleat Spend Control, Coupa, eBid eXchange, Ion Wave Technologies, PurchaseControl, Trade Interchange (ARCUS), and Xtenza. Assessment of the applications results in comparative data that are presented in predefined structure. The primary focus is on application features and Procurement functions supported. Other important evaluation categories are delivery models, security, underlying infrastructure, approval workflows, and commercials. Communication with application vendors contributed to the assessment. This part is finalized with evolution and trend conclusions focusing on cloud proliferation dynamics, and on forecast of new application functions and features that will result in new business benefits.
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GRAPHENE UNDER UNIAXIAL DEFORMATION: A RAMAN STUDY
Frank, Otakar ; Tsoukleri, G. ; Parthenios, J. ; Papagelis, K. ; Riaz, I. ; Jalil, R. ; Novoselov, K. S. ; Kalbáč, Martin ; Kavan, Ladislav ; Galiotis, C.
The presented work summarizes various aspects of uniaxial deformation in monolayer graphene studied by means of Raman spectroscopy. Graphene flakes were subjected to tension - compression uniaxial loading using the cantilever beam technique. The evolution of the Raman single-resonance (G) and double-resonance (2D) bands was monitored at strain levels < 1%. The position of all peaks redshifts under tension and blueshifts under compression. The G peak splitting into two sub-bands (G(-) and G(+)) which is caused by symmetry lowering, is observed in both strain directions. The sub-bands' intensities are used to calculate the crystal lattice orientation of the measured graphene flakes with respect to the strain axis. The nature and splitting of the 2D band even in the unstrained flakes, when excited by the 785 nm (1.58 eV) laser line, is interpreted as the interplay between two distinct double resonance scattering processes.
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Sol-gel synthesis of ternary ZnxTiyOz nanostructures for applications in solar cell technologies and photonics
Mrázek, Jan ; Nižňanský, Daniel (advisor) ; Pinkas, Jiří (referee) ; Pollert, Emil (referee)
The presented study deals with the sol-gel synthesis of nanocrystalline ternary phases of the general formula ZnxTiyOz, their characterization and potential application in photonics. Achieved results brings new fundamental knowledge about the processes leading to the formation of ZnxTiyOz nanocrystals from amorphous xerogels and gives novel information about structural and opto-electrical properties of prepared materials. Based on the presented results, most of all up-to-date reported ZnxTiyOz compounds with tailored nanocrystalline size and structure can be prepared as powders or thin films. Two sol-gel approaches based on the cluster process and direct heteronucleation were employed to prepare initial sol. Sols were optionally doped by Eu3+ ions to evaluate the effects of rare earth element to crystallization properties of formed compounds. In the first part of our study crystallization properties and structural evolution of thermally treated xerogels were analyzed. As a result a versatile method allowing the preparation of inverse spinel Zn2TiO4, cubic defect spinel ZnTiO3 and rhombohedral ZnTiO3 with tailored nanocrystal sizes was established. Initial composition and thermal annealing allow us to prepare selected ternary phase with tailored nanocrystal size ranging from tens of nanometers up to...
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Genome size variation and evolution of Hieracium L.
Zahradníček, Jaroslav ; Suda, Jan (referee) ; Chrtek, Jindřich (advisor)
In this study, 43 "main" species (Zahn) of the subgenus Hieracium and 3 species of the subgenus Chionoracium were studied karyologically and cytometrically. Triploid cyto- types predominate in the whole of Europe. Diploid cytotypes are mainly concentrated in specific areas of presumed glacial refugia in southern Europe. Chromosome counts of plants from the subgenus Chionoracium are congruent with all values published so far. The measured monoploid genome size in subgen. Hieracium correlated with the concurrently produced molecular phylogeny (ETS), which also separated two main lineages of species that correspond to their geographic distribution. Both these lineages differed significantly in genome size (Cx). On average, members of the "eastern" group had over 1 pg more DNA members of the "western" group. Some of the "main" species were marked as hybridogeneous/hybrid between the two lineages by ETS markers. The genome size of these hybridogeneous species was surprisingly higher than the average genome size of both main lineages. Intraspecies variability in genome size was found in seven species. It has been explained by the presence of populations of hybridogeneous origin, multiple polyploidization events and, in one species, turned out to be a methodical artifact. Both subgenera under study markedly...
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