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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.
71

Porovnání genetické variability geograficky vzdálených populací vybraných evropských mořských druhů hlaváčů / Comparison of the genetic variability of geographically distant populations of selected species of European marine gobies

Chalupecká, Katarína January 2018 (has links)
Gobies (Gobiidae, Actinopterygii) are small, predominantly cryptic, marine, brackish and freshwater fishes. They abundantly inhabit coastal waters, although their occurrence is far from being mapped due to their inconspicity, often hidden lifestyle and a lack of commercial use. Information about distribution of many species is therefore still rather poor. Many species are known only from a few locations scattered throughout the Mediterranean Sea and the Atlantic. This suggests that most species could actually have a relatively continuous distribution area. Comparing the genetic variability of geographically distant populations of the same species can help to detect whether there is some population subdivision and whether populations are genetically isolated from each other. The aim of my thesis was to compare genetic variability of the populations of eight goby species: Corcyrogobius liechtensteini, Gobius cruentatus, Gobius geniporus, Gobius incognitus, Chromogobius quadrivittatus, Chromogobius zebratus, Millerigobius macrocephalus and Zebrus zebrus within Mediterranean Sea and north-eastern Atlantic Ocean. Samples used in this work were collected from two Atlantic (Spain and Portugal) and seven Mediterranean localities (France, Sicily, Croatia, Montenegro, Greece, and Cyprus - northern and...
72

Taxonomické principy, reprodukční systémy,populační genetika a~vztahy mezi vybranými skupinami rodu Taraxacum (Asteraceae) / Taxonomic principles, reproductive systems, population genetics and relationships within selected groups of genus Taraxacum (Asteraceae)

Zeisek, Vojtěch January 2018 (has links)
Chapter 3 Summary - shrnutí English and Czech summaries (abstracts) of the thesis. 3.1 English abstract Genus Taraxacum (Asteraceae), having ∼60 sections and 2,800 species, is known for its complicated evolutionary relationships and taxonomy due to processes like frequent hy- bridization, polyploidization, asexual reproduction, clonality and low structural morpho- logical variability. Various taxonomical concepts and approaches are reviewed, evaluated and discussed from point of view of their ability to deal with such a complicated genera as is Taraxacum. Various processes responsible for the complicated situation within Taraxacum are discussed and reviewed. Section Dioszegia, comprising T. serotinum and its allies, are an exception because only sexuals are reported for all the members of this group. On the basis of the analysis of mi- crosatellite (SSRs) variation, distribution and morphology, we addressed problems related to their mode of reproduction, among-population relationships, taxonomy and within- population variation. As a rule, outcrossing was the dominant mode of reproduction, with one notable exception: T. serotinum subsp. tomentosum (≡ T. pyrrhopappum) was autogamous and not heterozygous. A taxonomic revision of sect. Dioszegia recognizes T. serotinum subsp. serotinum (including an aberrant...
73

Aktuální vědní poznatky a jejich didaktická transformace na příkladu tématu evoluce hominidů / Contemporary Scientific Knowledges and its Pedagogical Transformation by Way of Example of Human Evolution's Topic

Dvořáková, Radka January 2018 (has links)
This thesis is about the pedagogical transformation of modern scientific knowledge from the field of palaeoanthropology and evolution anthropology to the teaching about human at the first and high schools in the Czech Republic. The main objective of this thesis (realised through four constituent research studies) is to analyse and to describe this complex and multilevel process. The first step was the content analyse of 32 textbooks. We also analysed the framework of the whole process. We realise questionnaire survey among 217 teachers and also interview with 10 teachers. The last research study about student's attitude and knowledge was questionnaire survey among 660 students. We found that there are no serious obstacles in the teaching of (human) evolution from the field of believers in the Czech Republic like in some other countries. It takes usually few decades to get new findings and conceptions into the textbooks, despite it some exceptions exist. Teachers seem to be the key participants of the process of pedagogical transformation. It is not only about the information they teach in their lessons but also about the way how they teach and about the attitude the build-up towards the topic among their students.
74

Vliv prostředí na tvarovou variabilitu ultrafialových signálů u žluťáska rodu Gonepteryx (Lepidoptera, Pieridae) / Environmental influences on the shape of ultraviolet signals in genus Gonepteryx (Lepidoptera, Pieridae).

Pecháček, Pavel January 2019 (has links)
Like many other animals, butterflies are able to visually perceive the ultraviolet (UV) light; many species even have patterns on their wings which are visible in this part of the electromagnetic spectrum. Over the last forty years, it has been shown that these UV patterns play an important role in behaviour of many butterflies, especially in relation to sexual selection - they are involved in the process of recognising a suitable mate, and likely can signal some of the mate's qualities, such as its age, ability to handle stressful environmental factors, or efficiency in foraging. The patterns may also be used for taxonomical purposes. This dissertation thesis contains a comprehensive research into ultraviolet patterns of the Gonepteryx brimstones, with a primary focus on the issue of environmental influences in relation to the expression of these traits, on the patterns' potential role in sexual selection, or on their evolution. It has been successfully demonstrated that UV patterns of at least some Gonepteryx species are affected by the environment to a strong degree, significantly more than the traits not involved in sexual selection. On the whole, the conclusions made by submitted publications suggest that UV patterns play a role in the sexual selection of the chosen brimstones, though it is not clear...
75

Prostorová a časová variabilita UV reflektance ve vztahu s proměnnými prostředí u rodu Pieris a Colias / Spatial and temporal variation of UV reflectance in relation to environmental factors in genus Pieris and Colias.

Stella, David January 2020 (has links)
A bst r a ct Ultravi olet ( U V) mea ns' bey o n d vi olet' (fr o m t he Lati n - ultra - bey on d), w here by vi oletis t he c ol o ur wit h hig hestfre q ue nciesi n t he'visi ble'lig ht s pectr u m. By'visi ble' we refer t o h u ma n visi o n b utit m ust be ta ke n i nt o acc o u nt t hat h u ma n vis ual perce pti o n is i n c o m paris o n t o ma ny ot her orga nis ms rat her li mite di n ter ms of wavele ngt hsit ca n perceive. isis w hy c o m m u nicati o ni n t he U V s pectr u mis of- te n calle d hi d de n, alt h o ug hit m ostli kely plays a ver yi m p orta nt r olei n t he c o m m u nicati o n of vari o us ki n ds ofi nf or mati o n a m o ng a wi de variet y of orga nis ms. e ai m of t he prese nt t hesis is t o el uci date t he fu ncti o ns a n d relative i m p orta nce of U V pa er ns mai nl y i n L e pi d o ptera fr o m a h olistic ec ol o gical a n d ev ol uti o nar y pers pective. U V re fl ecta nce ca n- n ot be st u die d i n is olati o n: i m p orta nt i nteracti o ns a m o n g several ot her varia bles s uc h as li g ht c o n - dit i o ns, ge neral o ptic pr o perties of nat ural o bjects, t he vis ual s yste m, a n d si g nal pr ocessi n g are t h us disc usse d as well, b ut a n overall e m p hasis o n U V re flecta nce is mai ntai ne d t hr o u g h o ut. M ore over, t his w or k...
76

Friedrich August von Hayek a otázka evoluce liberárních pravidel / Friedrich August von Hayek a otázka evoluce liberárních pravidel

Doleček, Pavel January 2018 (has links)
The present dissertation deals with the topic of the relationship between political and moral philosophy and the epistemological and methodological arguments of Friedrich August von Hayek. The aim of the dissertation is to defend in general the assertion that Hayek's philosophy is the application of epistemological and methodological positions to moral and political philosophy and that this application is implemented through the continuous process of defining the basic theoretical positions towards philosophical tradition. This general statement is elaborated on in several perspectives. The first perspective puts the concept of knowledge in the forefront, both in the sense of a certain concept of rationality, i.e. the nature of reason and human thinking, and also in the sense of defining the nature and limits of scientific inquiry. The latter follows the development of Hayek's thinking, pointing out the aspects of his philosophy, which are the elaboration of the theories of his predecessors in thought within the Austrian economic school or classical sociology. This perspective also shows that, at a certain stage of his thinking, Hayek considerably moves away from these predecessors, particularly in the context of grasping individualism. The third perspective shows the deeper roots of some of...
77

Evoluce sociality a rodičovské péče u včel rodu Ceratina / Evolution of sociality and parental care in bees of the genus Ceratina

Mikát, Michael January 2020 (has links)
Small carpenter bees (genus Ceratina) are an excellent model taxon for the study of evolution of parental care and origin of eusociality. Prolonged offspring care is typical for this bee genus. Females usually guard their offspring until adulthood and later feed their adult offspring pollen and nectar. Moreover, most of studied species are facultatively eusocial, a trait probably inherited from the common ancestor of the genus. Although Ceratina bees have generally very interesting behavior, detailed studies were performed in only a few species, usually from North America, Japan and Australia. Only anecdotal observations of natural history existed for a few European species, and detailed research has not been performed before my thesis. The goal of my thesis is to explore the natural history of European species of Ceratina and to identify possible costs and benefits of this species' behavioral traits. I focused on following these behavioral traits: social nesting, guarding of offspring until adulthood, and feeding of mature offspring. Through my master project, I discovered biparental care in species C. nigrolabiata, therefore the most important goal of my Ph.D. project is the evaluation of costs and benefits of this behavior. Guarding of offspring by mother significantly influences their survival,...
78

Fylogeneze a evoluce čeledi Megastigmidae (Hymenoptera: Chalcidoidea) / Phylogeny and evolution of the family Megastigmidae (Hymenoptera: Chalcidoidea)

Böhmová, Julie January 2020 (has links)
The family Megastigmidae (Hymenoptera: Chalcidoidea), one of the hymenopteran parasitoid families, is unique in containing many species with phytophagous larval feeding strategy. A number of species of different genera are seed-feeders and the genus Bortesia is even capable of inducing galls. The family Megastigmidae is found mainly in the Australian region but a few genera/species groups are widespread throughout different areas, mainly in the Oriental and the Holarctic region. The main goal of this study was to map phylogenetic relationships among genera and clarify the following: the overall number of transitions between a parasitoid and a phytophagous way of life, the ancestral feeding strategy of the family, the evolution of feeding strategies in the genus Megastigmus, and the geographical area of origin of the family. The questions were tested based on a phylogeny reconstructed by a state-of-the-art method - sequencing of "Ultra-Conserved Elements (UCEs)" - using 100 specimens of Megastigmidae from 11 out of 12 currently valid genera selected taking into consideration their feeding strategy and biogeographical origin. The final dataset contains 1210 loci (570,000 base pairs in length) and most nodes are supported by bootstrap value 100. The results show that the family can be divided into 3...
79

Evoluční a teoreticko-biologické aspekty díla Bohumila Němce / Evolutionary and theoretical aspects of the biological work of Bohumil Němec

Loginov, Ivan January 2020 (has links)
Plant physiologist Bohumil Němec is one of the most important people in the history of Czech science. In this thesis, crucial concepts and theories that B. Němec developed in his scientific and popularizing publications are described and put in context. In addition, materials from the personal fond of B. Němec located in the Archive of the CAS were used. Particular questions tackled in this thesis are those of stimuli transmission in plants, the starch-statolith theory of gravitropism, morphaesthesia, organogenes, Němec's approach to evolutionary theory, and genetics, and the division of organisms in two groups. Moreover, Němec's role in the contemporary debates about vitalism, mechanism, and the effect of these two philosophies on the approach towards scientific research is indicated. By that, Němec's transition from the mechanism to the so-called physiology of stimuli (Rheizphysiologie) is illustrated. The outcome of the thesis is broadening the knowledge in the history of plant physiology, especially the history of the natural sciences in the Czech context.
80

Evoluce vnímání světla u strunatců / Evolution of light detection in chordates

Pergner, Jiří January 2018 (has links)
Light detection is one of the crucial abilities of all animals. The light cues are important e.g. for maintaining of circadian rhythms, regulation of spawning cycles, changes of pigmentation and arguably most importantly for vision. Most animals detect light by opsins, members of the G protein coupled receptors superfamily. Amphioxus belongs to earliest branching chordate clade, cephalochordates. Thanks to their phylogenetic position, physiology and morphology, cephalochordates became the most relevant model organism for understanding the evolutionary origins of vertebrate specific traits. Amphioxus evince various reactions to light throughout its development. In the presented thesis light detecting systems of amphioxus were studied thoroughly. More specifically characterization of the opsin gene repertoire of two amphioxus species Branchiostoma floridae and Branchiostoma lanceolatum and their comparison with opsins from other animals is presented. In addition, remarkable similarity on the gene expression level between one of amphioxus visual organs, so called frontal eye, and neurons and retinal pigmented epithelium in vertebrate retina was shown. These data confirm the long time ago proposed homology between amphioxus frontal eye and vertebrate lateral eyes. Taken together all the presented data...

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