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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.
11

Molekulární fylogeneze a evoluční trendy v rodě Hieracium (Asteraceae, Lactuceae) / Molecular phylogeny and evolutionary trends in Hieracium (Asteraceae, Lactuceae)

Krak, Karol January 2012 (has links)
The hawkweed subgenus Hieracium s. str. is notoriously known for its extreme morphological variability and variation in ploidy levels that is associated with differences in modes of reproduction. Extensive past hybridization is supposed for the subgenus, but recent hybridization was evidenced only in few cases. The subgenus attracts the attention of botanists already for more than a century. Therefore the species diversity is largely examined and the taxonomy of the subgenus is well elaborated, although several contradictory taxonomic concepts exist. However the relationships among the species are unknown and haven't been studied yet. The investigation of these relationships from a phylogenetic perspective using molecular approaches was the main aim of the presented thesis. Basic species (both diploid and polyploid), representing morphologically unique taxa, that are supposed to be the basic evolutionary units of the subgenus were studied. The sequences of two intergenic spacers of the cpDNA (trnT-trnL and trnV-ndhC) and the external transcribed spacer of the nuclear ribosomal DNA (nrDNA ETS) were analyzed. Moreover, three new low-copy nuclear markers with higher variability than nrDNA and cpDNA markers were developed and their suitability for phylogenetic studies in Hieracium s. str. was...
12

XML Query Adaptation / XML Query Adaptation

Polák, Marek January 2011 (has links)
In the presented work we study XML schema evolution, its types and impact on queries which are related on the particular schema. The thesis contains a review of existing approaches of this problem. The approach presented in this work shows a possible solution how to adapt related queries while schema evolves. The thesis contains a description of an algorithm which modies queries related to the evolved schema. Finally the work contains a number of exper- iments that verify proposal of the algorithms and show their advantages and disadvantages. 1
13

Adaptation of Relational Database Schema / Adaptation of Relational Database Schema

Chytil, Martin January 2012 (has links)
In the presented work we study evolution of a database schema and its impact on related issues. The work contains a review of important problems related to the change in a respective storage of the data. It describes existing approaches of these problems as well. In detail the work analyzes an impact of database schema changes on database queries, which relate to the particular database schema. The approach presented in this thesis shows a ability to model database queries together with a database schema model. The thesis describes a solution how to adapt database queries related to the evolved database schema. Finally the work contains a number of experiments that verify a proposal of the presented solution.
14

Evoluční a vývojové aspekty dentice šupinatých plazů / Evolutionary and developmental aspects of dentition of squamate reptiles

Zahradníček, Oldřich January 2011 (has links)
EVOLUTIONARY AND DEVELOPMENTAL ASPECTS OF DENTITION OF SQUAMATE REPTILES Summary of the PhD. thesis Dentition and its evolutionary modifications played important roles during the radiation of reptiles. It is generally accepted that a plesiomorphic state for reptiles is represented by homodont, polyphyodont dentition with conical or cylindroconical teeth. However, in contrast to mammalian dentition which is the object of intensive research, reptilian dentition is studied only rarely. I therefore focused on developmental and evolutionary aspects of squamate dentition and used histological, immunohistochemical and in situ hybridization methods, computerised tomography, rentgenography and scanning electron microskopy. The goals of this work were as following: (a) to choose the model taxa representing squamate lineages relevant from a phylogenetic position as well as possessing dissimilar types of dental adaptations; (b) to evaluate using of these taxa as model species; (c) in these taxa describe basic odontogenic features. As a species with generalized dentition gecko Paroedura picta was chosen, the up coming reptilian model species with features also present in a wide spectrum of other lizards. I focused mainly on the developmental differences between teeth of the null and functional generations, development...
15

Fylogeneze parazitických vosiček čeledi Torymidae (Hymenoptera: Chalcicoidea) a evoluce jejich parazitických životních strategií / Phylogeny of parasitic wasps of Torymidae (Hymenoptera: Chalcidoidea) and evolution of their life-strategies

Janšta, Petr January 2014 (has links)
The thesis is focused on phylogeny of the family Torymidae (Hymenoptera: Chalcidoidea) and evolution of their life-strategies. The study consists of general introduction to the phylogeny and classification of the family Torymidae chapter, four published papers in international journals and one manuscript prepared for submission. Firstly, our aim was to figure out the phylogenetic position of Torymidae as well as the position of other chalcidoid families inside superfamily Chalcidoidea (paper I and II). The supermatrix of sequencies of two ribosomal genes (18S rDNA and 28S rDNA) were developed for 649 species of chalcidoid taxa. However, family Torymidae was considered as polyphyletic group with the subfamily Megastigminae unrelated to the subfamily Toryminae (paper I). Monophyly of Torymidae was corroborated in another study (paper II) focused on molecular and morphological characters. We used a web-based, systematics workbench mx database for scoring 233 characters of 300 members of all chalcidoid families. Contrary to our previous only DNA-based study, we revealed also potential sister relationships of Torymidae with Ormyridae+Colotrechninae or Cerocephalinae+Diparinae respectively. Other paper (paper V) was focused on detailed study of Torymidae phylogeny. A total of 5 genes (18S rDNA, 28S rDNA,...
16

Fylogeografie a ekologie štěnic rodu Cimex (Heteroptera: Cimicidae) v Evropě; evoluce taxonů a hostitelské specializace / Phylogeography and ecology of the Cimex species (Heteroptera: Cimicidae) in Europe; the evolution of taxa and specialization of hosts

Balvín, Ondřej January 2013 (has links)
The life strategies of parasites and evolutionary mechanisms forming their diversity are particularly various and become frequent objects of study. The Ph.D. thesis deals with one of the obligate ectoparasitic haematophagous groups of insects, the species of the genus Cimex (Heteroptera: Cimicidae). Unlike in most other ectoparasites, the strategy of cimicids consists of remaining hidden in the shelter of their host. They use the host body only to feed and disperse. The advantage of the lower competition with other ectoparasites is counterbalanced by the need for particularly stable blood source, for which the cimicids choose social hosts living in colonies. The most frequent and the original hosts of cimicids are bats. The host range of particular species of Cimicidae is often rather broad. The morphological analysis of the Cimex pipistrelli species group showed, however, differentiation according to host bat species. This suggests a need for adaptation to particular host species within the usual range. The differentiation was not found reflected in the mitochondrial DNA. It is thus possible that cimicids can exhibit phenotype plasticity. The host associated morphological variability likely caused as many as three species of C. pipistrelli group to be described from Europe, from which two were...
17

Ekologické a evoluční důsledky edafické diferenciace v polyploidních komplexech rostlin / Ecological and evolutionary consequences of edaphic differentiation in plant polyploid systems

Kolář, Filip January 2014 (has links)
The thesis deals with evolutionary and ecological consequences of edaphic speciation (adaptation to different soil types) and genome duplication (polyploidization), acting in concert. Using a wide range of ecological, karyological and molecular approaches, several hypotheses of general importance have been examined in three model angiosperm systems (ploidy variable species or species aggregates occurring both on and off specific substrates, including serpentines and calcareous soils). In the Knautia arvensis group (Caprifoliaceae) a unique cryptic diploid lineage in central Europe was identified to be restricted to serpentine and limestone outcrops, which served as refugia during environmental changes (forest spread, human impact) in the Holocene. These refugial populations exhibited strong evolutionary potential because they were able to polyploidize and escape beyond the borders of their original edaphically-conditioned refugia owing to hybridization with surrounding widespread homoploid genotypes. Survival of both Knautia cytotypes on serpentine soils was facilitated by their high tolerance to chemical stress factors such as high Ni concentrations and low Ca/Mg ratios. In the Galium pusillum group (Rubiaceae), a striking cytological, ecological, and taxonomic, diversity was revealed in northern and...
18

Znalosti žáků ZŠ z oblasti evoluční biologie - tvorba didaktického testu. / Knowledge of elementary school pupils from the field of evolutionary biology - creation of a standardized test

ZAHRADNÍKOVÁ, Milena January 2018 (has links)
The main aim of my diploma thesis is to create a didactic test, which deals with the knowledge of pupils of the 9th year at elementary schools in the field of evolution. The literary overview is focused on the concept of evolution and its main principles, evolution within the scope of the educational program framework, publications dealing with this topic, especially with the emphasis on the current qualification work in this field, didactic tests, their types and aspects. In order to determine the level of knowledge in the field of evolution, a didactic test was then created. A total of 252 respondents participated in the test. All data was subsequently evaluated and discussed.
19

Znalosti žáků ZŠ z oblasti evoluční biologie - tvorba didaktického testu. / Knowledge of elementary school pupils from the field of evolutionary biology - creation of a standardized test

ZAHRADNÍKOVÁ, Milena January 2019 (has links)
The main objective of my diploma thesis was to create a didactic test dealing with the knowledge of grade 9 primary school pupils about the area of evolution. The literary review is focused on the term of evolution and its main principles. A part of the review is also formed by the framework education programme, mainly by the expected outputs in evolution biology. Subsequently, the theoretical part carries out an analysis of qualification works dealing with the issue of evolution biology. In the conclusion, information about didactic tests, their types and aspects is collected. To find out about the measure of knowlede from the area of evolution, a didactic test was constructed, and distributed among 252 respondents within the region of South Bohemia. All the data was subsequently evaluated and discussed.
20

Evoluce sociálního parasitismu rodu Phengaris (Maculinea) / The evolution of the social parasitism of Phengaris (Maculinea)

PECH, Pavel January 2009 (has links)
The presented thesis deals with the evolution of the social parasitism of Phengaris (Maculinea) butterflies. It consists of three related problems: I) The phylogeny of Glaucopsyche section (Lepidoptera: Lycaenidae: Polyommatinae) {--} the social parasitism occured only once in the Glaucopsyche section. II) The conditions in which the social parasitism of Phengaris evolved {--} the process was probably facilitated by unique species composition of the myrmecofauna of the biotopes inhabited by the ancestor of Phengaris. III) The host specificity of Phengaris {--} today{\crq}s view on the host specificity of Phengaris is poorly supported.

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