National Repository of Grey Literature 510 records found  1 - 10nextend  jump to record: Search took 0.03 seconds. 
Interaction of the human pathogen Bordetella pertussis with blood serum
Štipl, Daniel ; Večerek, Branislav (advisor) ; Kamanová, Jana (referee)
Bordetella pertussis is a Gram-negative strictly human pathogen and the major causative agent of whooping cough or pertussis. The incidence of this highly contagious respiratory disease in developed countries has increased in the last decades. One of the less characterized virulence factors of B. pertussis is the type three secretion system (TTSS) which is responsible for the secretion of the effector proteins into host eukaryotic cells. This diploma thesis sheds light onto factors influencing TTSS in vitro activity. Although TTSS of laboratory strain Tohama I was induced by biologically active compounds present in blood (e. g. complement proteins), TTSS of recent clinical isolate B1917 seems to be induced permanently. Furthermore, BB0302 encoding a GntR family transcription regulator in B. bronchiseptica RB50 (homologous to BP0209 of Tohama I) was studied, however, the deletion of this gene did not affect the TTSS functionality. Serum resistance is a factor that plays a key role in the pathogenesis of B pertussis. We show that Czech recent isolates (2008-2015) are significantly more resistant to serum killing in vitro than the original vaccine strains (1954-1965). This phenomenon seems to result from the adaptation of global B. pertussis population to its human host. In addition, this diploma...
What factors underlie gene reuse in adaptation?
Poštulková, Alžběta ; Bohutínská, Magdalena (advisor) ; Vosolsobě, Stanislav (referee)
Is the fate of a mutation predictable? The repeatability of evolution may indicate its predictability. If some change has emerged multiple times in the past, it may also occur in the future. Convergent evolution provides a natural model of repeated evolution and suggests the presence of certain constraints. Examination of the genetic processes, that have led to convergent adaptive traits, can contribute to the knowledge of the predictability of evolution. The aim of my work is to summarize the available knowledge about factors affecting gene reuse in adaptation. My work shows that the repeatability of evolution is biased by the genome characteristics, the population characteristics and also the trait encoding complexity. The likelihood of genomic region reuse increases with the amount of emerging mutations affecting the phenotype. Regarding the pleiotropic constraints of gene reuse, the most suitable is a mutation in the cis-regulatory region of the gene on the periphery of the functional pathway. Of the population traits, the greater effective size of the population, the higher standing genetic variation and the lower divergence between populations raise the chance of gene reuse. Despite the dependence of evolution on random processes, there are many factors that direct it and make it more...
Comparative methods for studying adaptive traits of fungal symbionts
Veselská, Tereza ; Kolařík, Miroslav (advisor) ; Voigt, Kerstin (referee) ; Dvořák, Miloň (referee)
The kingdom Fungi encompasses an estimated 2.2 to 6.2 million species that occupy diverse environments, including aquatic, extremely dry, and hot or frosty habitats all over the world. To cope with adverse environmental conditions, fungi have developed numerous adaptations and life strategies, including symbiosis with other organisms, ranging from close, reciprocally beneficial (mutualistic) associations to severe pathogenic infestations. These interactions have an enormous impact on ecosystem functioning, with implications for agriculture and human health. For this reason, understanding the mechanisms enabling the successful development of fungal interactions is necessary for their efficient management. Recent advances in different 'omics' approaches have enabled us to compare species responses to the environment in a more complex way than before and to gain deeper insights into the adaptive mechanisms underlying specific life strategies. My thesis is divided into four main sections. In the first section, I sum up findings about adaptations of fungal symbionts of plants and animals. Then, I introduce two fungal genera, Geosmithia and Pseudogymnoascus, to which I applied comparative methods for tracking adaptive traits. The ecological diversity of the genus Geosmithia allows to trace adaptive...
Adaptations of orchid roots to epiphytism
Ungrová, Anna ; Ponert, Jan (advisor) ; Soukup, Aleš (referee)
The evolutionary success of orchids is to a large extent driven by the ability to colonize epiphytic habitats. This ability is based on a number of adaptations at different levels, and the adaptive features of aerial roots can play a key role because the roots are practically the only organ providing water and nutrient uptake. The main aim of this work is to review available information about roots of epiphytic orchids (Orchidaceae), especially their adaptations to the epiphytic way of life. The roots of epiphytes must deal with a periodic lack of water and nutrients, often in conjunction with high irradiation. The roots of epiphytic orchids adapt to these conditions on many levels. Rhizodermis forms a velamen capable to retain water and nutrients and protecting roots against environmental conditions including UV radiation. Root cortex contains chloroplasts, which can perform photosynthesis at least in some orchid species. Exodermis is well differentiated with thick secondary cell walls and acts as a selective barrier for the transport of substances with the use of passage and aeration cells. The function of some adaptive structures is still unclear, for example, tilosomes could regulate transpiration. Epiphytism evolved multiple times in orchids, and some root adaptations therefore originated...
Ethnic Identity and conflict (on the Example of Multiethnic Territory of Cruise Ships)
Medvecká, Zuzana ; Skupnik, Jaroslav (advisor) ; Uherek, Zdeněk (referee) ; Kobes, Tomáš (referee)
In my doctoral thesis, which I have elaborated on the basis of my diploma thesis Doubled Identity of Crew Members on Cruise Ships as the Instrument of Cultural Adaptation, supervised by Mgr. Helena Tužinská, PhD., I have analysed the way of life of crew members sharing the multiethnical territory of cruise ships. Crew members working there come from over 50 different countries. In spite of their different origins and cultures which have been forming their behaviour and way of thinking, they share small space without any conflicts. My goal is to sum up the basic conditions which should be met in any multiethnical society to ensure that there would not be any conflicts between its habitants. According to my hypothesis there is a need of other than ethnical identity which could unify them on other than ethnical basis. In the territory of cruise ships it is the socio-professional identity of 'crew member '. I found out that there are two main factors responsible for successful co-existence of people from different cultures here - communication and the system of values. That is why from all factors in which we can observe socio-professional identity of crew members I preferably analyse rules and norms established by crew members and lingua franca used on cruise ships called 'ship language'. The specific...
The importance of income on subjective well-being
Sedlář, Jan ; Baxa, Jaromír (advisor) ; Skuhrovec, Jiří (referee)
1 Abstract My Bachelor thesis deals in a comprehensive way with the discussion unleashed by the publication of the Easterlin's article which called attention to more complex relations between the absolute level of income and the subjective well-being than the economic theory would ever assume . There is the literature shown which finds the explanation why the relation - the absolute level of income and the subjective well-being - does not hold without exceptions. A special attention is devoted to the human behaviour: comparison of the individual's situation with the situation of his reference group, comparison of the individual's situation with the situation he was accustomed to in the past, the individual's adaptation to the new situation and change of his aspiration and on the overvaluation of the benefits from the achieved goal. The first characteristic is tested experimentally with use of the analogy: the income as the evaluation of the job performance, the mark as the evaluation of the student. The experiment did not prove that the comparison of the student with his reference group would have the influence on his own performance. The second part of my thesis is focused on the description of the relationship between the gross national income per capita and the satisfaction of the inhabitants from the...
Plant adaptation to climate change
Koláříková, Veronika ; Münzbergová, Zuzana (advisor) ; Sklenář, Petr (referee)
Climate change represents important selective force for plants. They have to deal with this change otherwise they are facing the risk of extinction. Understanding the mechanism which plants use to avoid the risk is essential for effective conservation of biodiversity. The climate change can exceed the tolerance of plants to abiotic factors. The plants can react to the changes by migration, phenotypic plasticity, evolutionary adaption or by a combination of these strategies. Phenotypic plasticity and evolutionary adaption are manifested by a change of physiology, morphology and/or phenology of plants. This work summarizes the findings of these ecological and evolutionary strategies and also presents methods used for studying species response to climate change. Powered by TCPDF (www.tcpdf.org)
Influence of external conditions on egg incubation in lapwings (genus Vanellus) in temperate and subtropical climate
Pešková, Lucie ; Šálek, Miroslav (advisor) ; Hořák, David (referee)
During incubation, most birds require the presence of at least one parent to ensure suitable incubation conditions for embryo development. The main factors that affect the development of the embryo are temperature, humidity and egg turning. In this work, incubation conditions were investigated in two biparental Lapwing species (genus Vanellus), the Northern Lapwing (Vanellus vanellus), which faces the risk of egg cooling in temperate areas, and the Red-wattled Lapwing (Vanellus indicus), which faces the risk of egg overheating in the subtropics. A laboratory experiment testing the thermal properties of the Red-wattled Lapwing nest lining showed that it selects lining material that slows down temperature growth during egg heating, thus ensuring suitable thermal conditions during parental absence at high ambient temperatures. Temperature and egg turning during incubation were recorded by an artificial egg with a built-in sensors placed in the nests of both target species; data collected by the sensors were stored by a base-station located nearby. The average egg temperature was 32.5 řC for the Northern Lapwing, and 35.0 řC for the Red-wattled Lapwing. Egg temperature in both species fluctuated significantly, affected by many factors. Egg temperature increased with increasing ambient temperature, it...

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