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Biogeography of the herpetofauna of the Aegean Islands
Sýkorová, Marta ; Šmíd, Jiří (advisor) ; Papežík, Petr (referee)
In the last thirty years, the biogeography of the herpetofauna of the Aegean Sea has been the subject of thorough research. In evolutionary biology, islands are considered to be model ecosystems. Morphological, physiological and behavioral changes in some species can be observed on them. These changes are described as so-called "island syndromes". The occurrence of these syndromes depends on the size of the island, its distance from the mainland and the age of the island as well as on population density, availability of resources and presence of predators. The specific manifestations of these syndromes in reptiles of the Aegean islands are: the occurrence of endemism, gigantism and dwarfism, color changes, more frequent tail autotomy, cannibalism and food specialization. Most of these changes are described in lizards of the Podarcis genus, especially on Podarcis erhardii, as it is the most widespread reptile in this area. The second very widespread and therefore often researched reptile is Mediodactylus kotschyi. Changes often take place on small islands, so individuals tend to be compared with members of the same species from a larger island or mainland. The number of endemic species is significantly higher on islands that are longer separated from the mainland. The existence of gigantism and...
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Local action groups in the inner periphery of Bohemia: perception of success and its analysis
Ambrozková, Marie ; Chromý, Pavel (advisor) ; Konečný, Ondřej (referee)
This master's thesis examines the success of Local Action Groups (LAGs) from the perspective of how success is defined by LAG representatives, which is compared with the approaches of state and European authorities and experts. It further analyzes the factors influencing LAG activities with an emphasis on the context of the inner periphery of Bohemia. The research methods employed were qualitative, involving semi-structured interviews with representatives of six active LAGs from the inner periphery of Bohemia. The results indicate that, according to LAG representatives, the success lies in networking within the territory, LAG awareness, knowledge of the territory's needs, and active targeting of these needs. Particularly in terms of LAG awareness and informed targeting of territory needs, LAG representatives' perspectives differ from other approaches. Respondents identify a good team as the foundation of successful LAGs, which utilizes positive factors and overcomes negative influences on LAG activities. Key findings from the research include a description of the successful LAG team and an overview of factors influencing their activities, including those typical of the inner periphery. Internal factors such as small municipalities with non-full-time mayors, sparse population, and missing services...
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Chromatin modifications and small regulatory RNA in plant intergenerational and transgenerational stress memory: experiments in plants subjected to drought
Macek, Jan ; Holá, Dana (advisor) ; Čermák, Vojtěch (referee)
Water is important for many vital processes, and a lack of water in plants causes drought stress. In case plants survive drought, they can be better adapted for subsequent drought periods. This is defined as stress memory, which will last for a certain period after the stress ended, and can even be transmitted to offspring to help it deal with stressful environment. In such case it is called an inter- or transgenerational stress memory and is probably mediated by chromatin modifications or non-coding RNAs. In this thesis, I collected and discussed original papers dealing with the molecular basis of this phenomenon in drought-stressed plants, focusing mostly on various methodical aspects. It is evident that the maintenance of chromatin modifications across generations is quite a complex process. Currently available information is still scarce, concerns mostly DNA methylation, is incomplete and conflicting. To better understand this topic in the future, the methods of analysis of these modifications need to be adjusted (and focus also on histone modifications), the general design of the experiments has to be improved (analysed generations subjected to stress/control conditions, drought verification, number of replicates) and some factors that can affect plant stress memory should be purposefully...
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Blackflies of the Czech Republic and their feeding preferences
Blechová, Karolína ; Brzoňová, Jana (advisor) ; Dvořák, Vít (referee)
Blackflies are globally distributed small flies belonging to the order Diptera, known as common nuisance for humans and vectors of certain parasites. The most commonly transmitted parasites include the genera Onchocerca, Leucocytozoon and Trypanosoma. For humans the most significant species is Onchocerca volvulus, which causes onchocerciasis (or "river blindness") in tropical areas. This thesis is about faunistics of blackflies in the Czech Republic, where was described 45 species of these flies to this date. First mentions of the family Simuliidae are from 19th century. More specific studies about these arthropods have been published since the 1950s and the main concern of these studies was to study blackflies at specific locations. More recent studies put focus primarly on blackflies as vectors. Host preferences are an important aspect in the characterization of blackflies and all vectors in general. Host preferences of blackflies are highly variable among species, ranging from ornitophilic blackflies tied strictly to a single host species (S. euryadminiculum with specifity on common loon) to opportunist species feeding on both mammals and birds (S. vernum). Host preferences have been adressed in only small number of studies. Classic method used for determination of host preference is...
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Effect of temperature on sand fly biology and Leishmania transmission
Charvátová, Lada ; Sádlová, Jovana (advisor) ; Dvořák, Vít (referee)
and keywords The current rise in air temperature causes a range of global changes, affecting many species of organisms and their interactions. Phlebotomine sand flies are small members of Dipteran insects of the family Psychodidae, subfamily Phlebotominae, transmitting Leishmania, parasitic flagellates (Kinetoplastida: Trypanosomatidae) that cause the important human disease leishmaniasis. Based on the literature review, the external temperature significantly affects the biology of sand flies. High temperature accelerates their metabolism and shortens the growth rate of immature stages, also influencing body size and body weight (faster development in higher temperatures makes them smaller). The time needed for blood digestion is also reduced, and female defecation and oviposition are accelerated. On the other hand, cold temperatures prolong growth, and cause lower emergence of adult sand flies, slower digestion of blood, or number of laid eggs. Very high or very low temperatures can cause diapause in the larval stage or eggs. In general, the optimal temperature to cover all of their physiological needs is 24-28 řC. Temperature impacts the development of Leishmania in sand flies as well, it is likely that Leishmania has a lower optimal temperature as opposed to sand flies, and therefore some...
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Factors affecting the occurrence of rare protist species
Herciková, Zuzana ; Škaloud, Pavel (advisor) ; Jadrná, Iva (referee)
This bachelor thesis aims to answer the question that even Darwin asked, and which is still relevant today: which factors influence the occurrence of rare species? In the first part of this thesis, this question is applied in general to species of all organisms. First, the term rare species is defined and other general information on the distribution, proportion of rare species in ecosystem and importance of rare species are mentioned. Then biotic and abiotic factors, that influence the occurrence and existence of rare species of all organisms are mentioned. These include, for example, the size of the organism, abiotic environmental conditions, in which the organism is found, etc. The second part of this thesis is focused on the rarity of protists. First, it is discussed whether rare protists actually exist. Due to their small size, large populations, short generation time and easy dispersal, they are often considered ubiquitous. Factors that could influence the occurrence of protists are discussed next. These factors are for exapmple habitat size, dispersal ability and changes in the environment in which they occur. It is not possible to clearly say why some protists are rare, or even to categorize in general terms what factors are key to the occurrence of rare protists. Key words: rare species,...
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Phosphoinositides in membranes associated with RAB1
Růžička, Václav ; Doubravská, Lenka (advisor) ; Bouřa, Evžen (referee)
Small GTPases of the RAB protein family are key regulators of numerous cellular pathways, including membrane trafficking and autophagy. With the control of membrane processes are also associated phosphorylated phosphatidylinositol derivatives, known as phosphatidylinositol phosphates (PIPs). Our focus lies on the RAB1A and RAB1B GTPases and the processes of early protein secretion they regulate. The enzymes that control specific phosphorylated forms of phosphatidylinositol seem to be functionally related to this pathway, indicating that these lipids also regulate at least some aspects of protein secretion. However, the mechanism by which they do so remains unclear. This bachelor thesis therefore summarises the current knowledge of phosphatidylinositol phosphates on RAB1A and RAB1B associated membranes, including their role on the endoplasmic reticulum (ER) and its export sites (ERES), on the intermediate compartment between the ER and the Golgi apparatus (ERGIC), and on the Golgi apparatus itself. This thesis also specifically examines direct interactions between RAB1 GTPases and phosphatidylinositol phosphates or their related enzymes. In summary, it can be concluded that phosphatidylinositol phosphates play a significant role in the early stages of protein secretion.
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Perception of the Czechs in proprietates gentium at the end of the Middle Ages
Wolf, Martin ; Svátek, Jaroslav (advisor) ; Žůrek, Václav (referee)
The aim of the thesis is to examine in detail a largely neglected and fragmented source on the verge of oral and written culture, the so-called proprietates gentium or medieval catalogues of nations. These small verse texts, originally written in Latin, provide a rare record of medieval oral culture thanks to their connection with folklore. Defining oneself in relation to the ''other'' through the generally negative heterostereotypes in the studied source leads to manifestations of ethnic consciousness. Proprietates gentium are therefore a valuable source for the study of medieval ethnic identity. The thesis focuses mainly on the stereotypical view of Bohemians from the "outside". Taking into account both older and modern historiography, the author analyses selected works dealing with Bohemians and Moravians, without neglecting the question of Slavic identity. He then compares them with similar rhymes about other nations, but above all he compares the images in the catalogues of nations with two selected literary works of the late Middle Ages, which are Historia Bohemica by Aenea Silvio Piccolomini and Hodoporicon by Johannes Butzbach. The main purpose of the analysis and comparison is to trace the emergence and reception of ethnic stereotypes that may have been spread in the Middle Ages about the...
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Spatio-temporal activity of African ungulates at water sources in Mogalakwena River Reserve, South Africa
Homoláč, David ; Hořák, David (advisor) ; Bennitt, Emily (referee)
The large mammals of African savannah are a well-studied group of animals, but few studies focus on the temporal, circadian activity of this group of mammals. Such studies either use problematic methods of data collection (webcams, direct observations) or have been conducted in national parks or large reserves, where movement of the animals is not limited with anthropogenic structures. In such sites, the community of large mammals is usually complete, including the guild of large carnivores. Thus, small, fenced off reserves without a complete community of large mammals are understudied. Therefore, this work focuses on the spatio-temporal activity of ungulates at water sources in the Mogalakwena River Reserve in South Africa, which is an example of a reserve without large predators except the leopard (Panthera pardus). I used camera traps to assess the activity of ungulates, which I placed alongside the Mogalakwena River and at the water holes. With the help of artificial intelligence, I classified the photos to the level of activity of each species. I then tested this activity over space (type of water source) and against biotic and abiotic factors. The activity of ungulates at water sources is influenced by the maximum daily temperature, as the activity shifts to the evening hours during higher...
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Paneth cells in the small intestinal immune response
Dostalíková, Stela ; Šťastná, Monika (advisor) ; Věcek, Jan (referee)
Paneth cells are one of the cell types of the intestinal epithelium that participate in immune responses and maintain homeostasis in the intestinal lumen. Due to their production of antimicrobial substances and signalling molecules, Paneth cells have been investigated in many studies. This thesis briefly summarizes the anatomy of the small intestine and describes the current knowledge of intestinal cell types related to immune responses, with a focus on Paneth cells. The thesis also introduces selected mouse models used to study the intestine and Paneth cells, describes the possibilities of studying the intestinal epithelium in vitro using organoid cultures, and finally discusses the relationship between Paneth cells and inflammatory bowel diseases such as Crohn's disease and ulcerative colitis, and discusses potential therapeutic strategies for these pathologies.
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