National Repository of Grey Literature 39 records found  beginprevious20 - 29next  jump to record: Search took 0.01 seconds. 
Changes of the facial skeleton in Central Europe during the last 1200 years
Bejdová, Šárka
The objective of the Dissertation was to describe, quantify and interpret to which degree the shape and size of the facial skeleton of people living in the territory of today's Czech Republic in the period from the Early Middle Ages to the present day, i.e. in the course of the approx. last 1200 years, have changed. In this time period, morphological differences between populations, changes in the sexual dimorphism, modularity and allometry of the facial skeleton were examined. The evaluation was based on CT-images of skulls from three historical populations, specifically from the Early Middle Ages, High Middle Ages and the early modern period. The current population was represented by CT-images of living people. We studied the facial skeletons of a total of 329 individuals, of which 183 were men and 146 women. The CT- images were used as a base for the creation of virtual 3D surface models. The facial skeleton was divided into three morphological units, which were further examined. These were the skeleton of the upper face, lower jaw and palate. The statistical processing was carried out applying methods of geometric morphometrics allowing the separate studying of the shape and size variability of the examined units. When comparing the size and shape differences between studied populations it is...
Shape variability of proximal and distal human tibia.
Brzobohatá, Hana ; Velemínská, Jana (advisor) ; Beňuš, Radoslav (referee) ; Macholán, Miloš (referee)
The aim of this study was to detect and describe the trends in shape variability of proximal and distal human tibia related to sex, age, social status and time period. The variability of its shape and form was analysed first in an early medieval sample, then in two modern populations, an early 20th century sample and the contemporary Czech population. Finally, data from the whole studied time span were analysed. The initial raw data were acquired by optical scanning and computed tomography (CT) scanning of the lower limbs; the three-dimensional bone surfaces of the contemporary tibias were segmented from the clinical CT scan sequences. Geometric morphometrics and multivariate statistical methods were applied to study the variations in shape and form quantitatively. Proximal and distal tibias were evaluated independently, and the potential influence of sex, age at death and time period were investigated. In the early medieval population, we also explored the relationship between tibial morphology and presumed social status derived from the respective grave location within the settlement. Because traditional morphometric analysis revealed statistically significant sex differences in the parameters of both tibial extremities (e.g., Steyn and Işcan, 1997; Šlaus et al., 2013), we thus assumed the...
Shape variability of proximal and distal human tibia.
Brzobohatá, Hana
The aim of this study was to detect and describe the trends in shape variability of proximal and distal human tibia related to sex, age, social status and time period. The variability of its shape and form was analysed first in an early medieval sample, then in two modern populations, an early 20th century sample and the contemporary Czech population. Finally, data from the whole studied time span were analysed. The initial raw data were acquired by optical scanning and computed tomography (CT) scanning of the lower limbs; the three-dimensional bone surfaces of the contemporary tibias were segmented from the clinical CT scan sequences. Geometric morphometrics and multivariate statistical methods were applied to study the variations in shape and form quantitatively. Proximal and distal tibias were evaluated independently, and the potential influence of sex, age at death and time period were investigated. In the early medieval population, we also explored the relationship between tibial morphology and presumed social status derived from the respective grave location within the settlement. Because traditional morphometric analysis revealed statistically significant sex differences in the parameters of both tibial extremities (e.g., Steyn and Işcan, 1997; Šlaus et al., 2013), we thus assumed the...
Changes of the facial skeleton in Central Europe during the last 1200 years
Bejdová, Šárka ; Velemínský, Petr (advisor) ; Bigoni, Lucie (referee) ; Galeta, Patrik (referee)
The objective of the Dissertation was to describe, quantify and interpret to which degree the shape and size of the facial skeleton of people living in the territory of today's Czech Republic in the period from the Early Middle Ages to the present day, i.e. in the course of the approx. last 1200 years, have changed. In this time period, morphological differences between populations, changes in the sexual dimorphism, modularity and allometry of the facial skeleton were examined. The evaluation was based on CT-images of skulls from three historical populations, specifically from the Early Middle Ages, High Middle Ages and the early modern period. The current population was represented by CT-images of living people. We studied the facial skeletons of a total of 329 individuals, of which 183 were men and 146 women. The CT- images were used as a base for the creation of virtual 3D surface models. The facial skeleton was divided into three morphological units, which were further examined. These were the skeleton of the upper face, lower jaw and palate. The statistical processing was carried out applying methods of geometric morphometrics allowing the separate studying of the shape and size variability of the examined units. When comparing the size and shape differences between studied populations it is...
Variation in dragonfly wing venation with application of geometric morphometrics (Insecta: Odonata)
Přibylová, Petra ; Prokop, Jakub (advisor) ; Růžička, Jan (referee)
The pattern of wing venation in dragonflies (Odonata) bears a set of characters commonly used in systematics. The aim of this thesis is to identify the wing venation variability of dragonflies by various methods of geometric morphometric. The wing venation variability was examined on the level of suborder, family, species and also in respect to dimorphism through the principal component analysis (PCA), redundancy analysis (RDA) and centroid size. Data set consisting of images of 46 dragonfly species, belonging to 43 genera and 24 families was obtained from institutional entomological collections. The research carried out that Zygoptera have a large variety of wing contours. The wing venation variability of Epiprocta is shown primarily in the costa and node area. Between sexes there is no noticeable difference in shape or structure of the wing. The ratio between wing length and width and the pterostigma shape is dependent on dragonfly body size. Key words: Odonatoptera, Odonata, Epiprocta, Zygoptera, wing venation, variability, geometric morphometrics
Origin and Biological Affinity of the Alleged Gravettian Mandible Předmostí 30.
Drahošová, Michala ; Brůžek, Jaroslav (advisor) ; Velemínský, Petr (referee)
Dissertation solves the problem of the origin of the mandible from collection of Moravian Museum in Brno. Publications of authors working in the location Předmostí u Přerova since the year 1884 have been used to achieve this goal. Simultaneously records in the incremental books of MZM in Brno have been researched, unfortunately without success. Therefore research of the biological affinity of the mandible P30 with others gravettiens discovery has been accepted as well as variability of recent humans. For study we used methods of geometric morphometrics, which allows us better clarify shape discrepancies in comparison with standard analytic methods. Comparison of shape variability of the mandible we used 91 cranial CT exposures of the recent Czech population. We placed 42 landmarks to segmented 3D models of the mandible and we made a PCA analysis. To extend the argument for justifiability to incorporate studied sample among discoveries from Předmostí u Přerova we created file of linear proportions of the tooth crown based on available publications and our own measuring. Morphological study, shape analysis of the mandible and dimension of the teeth leads us to results that the mandible P30 in our study can really belong to the Gravettien Age. Key words: Mandible, Molars, Předmostí u Přerova,...
Cryptic and pseudocryptic diversity of conjugating green algae (Zygnematophyceae)
Kupčíková, Eva ; Šťastný, Jan (advisor) ; Škaloud, Pavel (referee)
This bachelor thesis summarizes the most commonly used species concepts in the class Zygnematophyceae. This group of algae and the molecular markers used in the zygnematophytes' molecular phylogeny will be presented in this thesis. Zygnematophytes have unicellular or multicellular forms and they generally occur in freshwater habitats. Desmids are useful as indicators of water quality and they are also used for scoring of conservation value. Therefore it is important to have the species well defined. The confusion in defining of desmid species was caused by often very variable morphology. Some authors had different opinions on the classifying of desmid species and theirs subunits. The combination of molecular phylogeny, electron microscopy and geometric morphometrics was used in revealing of (pseudo)cryptic species in the genera Micrasterias or Xanthidium. The geometic morphometrics was helpful for finding of important details for distinguishing of particular pseudocryptic species. Key words: cryptic and pseudocryptic diversity, conjugation, desmids, Micrasterias, Euastrum, Xanthidium, molecular phylogeny, taxonomy, geometric morphometrics, biogeography, green algae
Shape variability of diatom frustules during the life cycle.
Woodard, Kateřina ; Kulichová, Jana (advisor) ; Kleisner, Karel (referee)
The determination of diatom species is mostly based on morphology of a silicified cell wall. It is complicated by the fact of cell diminution during the vegetative phase of the life cycle, which is conected with shape changes and loss of some taxonomically importat characters. Even though the diminution during the life cycle is generally known phenomeon, there is a lack of studies on this theme. In this masters thesis, four monoclonal populations of model pennate diatom strains were used in order to study shape dynamics during the life cycle. The strains were cultivated for almost three years and parts of the cultures with a different size stages were fixed in permanent preparations. The digital photographs of the cells were used as a material for the geometric morphometrics analyses. The study revealed high contribution of significant allometric changes to an overall shape variability. During the vegetative phase of the life cycle, disparity of the cells increases and complexity of the cells decreases. The contribution of symetric variability to an overall shape variability is more than eighty percent. Phenotypic plasticity in a monoclonal populations is an interesting finding from an evolutionary point of view. It may indicate constraints caused by the silica cell wall. During the size diminution...
Assessing the threat of hybridization between Prunus fruticosa and cultivated Prunus species
Musilová, Lenka ; Vít, Petr (advisor) ; Chrtek, Jindřich (referee)
Presented thesis evaluates the risk of ongoing hybridization (antropohybridization) in highly endangered Prunus fruticosa in the Czech Republic and selected adjacent countries. Absolute genome size analysis (estimated by flow cytometry) combined with both numeric and geometric morphometrics were used for evaluation of hybridization. Prunus fruticosa frequently hybridize with naturalized Prunus cerasus (emerging tetraploid hybrid Prunus ×eminens) and native Prunus avium (forming triploid hybrid Prunus ×mohacsyana). Discrimination between P. ×eminens and P. ×mohacsyana is difficult, when using leaf morphology characters only, so the occurrence of triploid hybrids was strongly underestimated in the Czech Republic (only tetraploid hybrids were reported). Both hybrids are surely differentiated using flow cytometry analysis (based on different ploidy level). The majority of analyzed populations is formed by either individuals of pure P. fruticosa or one of the mentioned hybrids. Only four populations were mixed. Continuous variability in absolute genome size was found in two of them, which may indicate hybrid swarm forming (incl. primary hybrids and backcrosses). Our findings can be considered only as indirect evidence for introgression, which needs to be confirmed by molecular markers (for example...
Unveiling hidden species diversity in desmids (Desmidiales, Viridiplantae)
Šťastný, Jan ; Neustupa, Jiří (advisor) ; F.M. Coesel, Peter (referee) ; Kaštovský, Jan (referee)
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...

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