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An intensity of plumage bacterial load and resistence against bacteria-caused feather degradation in tropical birds of Afromontane areas of Cameroon
Kyptová, Markéta ; Javůrková, Veronika (advisor) ; Adamík, Peter (referee)
Microorganisms are considered to be a significant selective factor affecting bird's life strategies. The body cover, including feather, is occupied by a wide range of bacteria that are in their host in different interactions. Group of microorganisms degradate keratins of feather is still most studied and most species of birds have them in feather. This feather degrading bacteria can disrupt the wear and its function and thus cause great losses to its fitness. Therefore, it seems likely that these feathers degrading bacteria and microorganisms generally play a significant role in creating defence mechanisms against their negative effects. One of the most important defence mechanisms to protect feathers against the action of microorganisms is the deposition of melanin pigments. This diploma thesis deals with the analysis of the total bacterial load in feathers and its resistance against bacterial degradation in 47 species of birds trapped in afromontan areas of western Cameroon. The specific aim of the thesis was to determine differences in the total number of bacteria in plumage in species with different life strategies, especially feeding and reproductive strategies. At the same time, the phtilochronological analysis of the quality of the plumage was performed and in vitro experiments were tested...
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The role of partial incubation in birds
Březinová, Monika ; Javůrková, Veronika (advisor) ; Sedláček, Ondřej (referee)
It was documented that many species of birds incubate their clutch before the clutch completion. This behaviour called partial or intermittent incubation usually takes only few hours per day. Eggs in clutch are from the time of laying until the time of full incubation exposed to many negative environmental factors and disturbances. These factors may reduce the viability of the embryo and brood survival. It is therefore predicted that birds use partial incubation as a protection against these negative factors. Most probable functions of partial incubation are a protection against clutch predation, intraspecific and interspecific brood parasitism, and antimicrobial actions linked with reduction of potentially harmful microorganisms on the eggshells and/or activation of proteins with antimicrobial potential in egg's yolk and albumen. This bachelor thesis summarizes overall knowledge of partial incubation, with special emphasis on its incidence and functions in birds. Moreover, this thesis reviews the problematics of synchronous and asynchronous hatching of partially incubated clutches. Although, based on literature review, partial incubation has strong impact on overall reproduction success in birds, study of this incubation behaviour is still neglected and more attention should be paid on comparative...
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Factors affecting deposition of selected antimicrobial substances into the egg structures
Pokorná, Monika ; Javůrková, Veronika (advisor) ; Svobodová, Jana (referee)
Both during the ovogenesis and immediately after the laying is a bird egg exposed to strong pressure from the microorganisms which are able to penetrate the egg through eggshell pores and infect its inner structures. With regard to the proved negative effects on hatchability, viability and phenotype of offspring, a cascade of obstacles has evolved which are able to minimize the risk of bacterial infection. The deposition of antimicrobial components into the eggshell and the egg white is considered to be one of them. A whole group of egg white proteins belong to them, among which lysozyme and ovotransferrin, which are also partially deposited into the eggshell and cuticular layer of the eggshell, dominate with their antimicrobial effect. The implication of the newest studies is that the microbial protection of the egg can be also performed by the eggshell pigments - biliverdin and protoporphyrin, which protect the egg from being colonized by microorganisms with an increased UV light and regulation of conductivity and water vapour condensation on the egg surface. Even though the presence of these antimicrobial components in different structures of the egg has been proved, there is no known comparative study which addresses the relation between deposition of selected antimicrobial components into...
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Temperature-dependent activity of egg-white antimicrobial proteins in precocial and altricial birds
Novotná, Lucie ; Javůrková, Veronika (advisor) ; Krist, Miloš (referee)
Microorganisms are considered to be crucial selective factor affecting reproductive success of birds. It is hypothesized that egg-white antimicrobial proteins and incubation behavior are the most important defense mechanisms that eliminates the risk of microbial trans-shell infection. The latest studies supposed that incubation temperatures may significantly affect the antimicrobial activity of egg white proteins. The concentration of egg white antimicrobial proteins as well as incubation patterns differ among altricial and precocial species of birds. However, experimental study testing the effect of incubation temperature on the antimicrobial potential of antimicrobial egg white proteins in altricial and precocial birds is missing. In this study we tested in manipulative experiment the effect of partial and full incubation, the concentration of lysozyme and ovotransferrin and their interactions on the antimicrobial activity of egg whites of two model species - Japanese quail (Coturnix japonica) and home pigeon (Columba livia). Antimicrobial protein activity was determined by the agar well diffusion method against two Gram-positive bacteria - Bacillus subtilis and Micrococcus luteus that have been documented as pathogenic egg-white invaders of several birds. Moreover, we analyzed the effect of...
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Physiological aspects of the variability in eggshell pigmentation
Mengr, Jan ; Javůrková, Veronika (advisor) ; Krist, Miloš (referee)
The avian eggshell colouration is caused by specific pigments deposited into the eggshell. These pigments differ in colour, chemical structure and the eggshell deposition place. The function of the eggshell pigmentation is traditionally considered to have cryptic or thermoregulatory role. However, most recent hypotheses provide a new perspective on the function of eggshell pigmentation. As between species variability in the eggshell pigmentation is under strong genetic control, within species variability is considered to be a result of adaptation to environmental factors affecting physiology of female bird. This work focuses on the description and characteristics of particular eggshell pigments, their synthesis, deponation process and also the importance of variability in the avian eggshell pigmentation and its physiological aspects. Powered by TCPDF (www.tcpdf.org)
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Case study of physiotherapy treatment of a patient with the diagnosis of status after ankle fracture osteosynthesis.
Javurková, Veronika ; Sohrová, Jana (advisor) ; Šáchová, Dana (referee)
Title: Case study of physiotherapy treatment of a patient with the diagnosis of status after ankle fracture osteosynthesis. Aim: The aim of this bachelor' s thesis is to present basic information on ankle fractures and to elaborate a case report of a patient with this diagnoses. Methods: This research was based on the processing of literature on the topic. It is divided into two parts - a general part and a special part. The general part contains basic information about anatomy and function of the ankle joint, kinesiology. It contains also traumatology, physioterapeutic methods and procedures that can be used in a patient with mentioned diagnosis. The special part contains casuistic of a patient and includes anamnestic data, input kinesiological analysis. The therapies are processed individually according to the patient' s attendance and are finished with the output of kinesiological analysis with evaluation of the therapy effects. Keywords: ankle joint, fracture, osteosynthesis, physiotherapy, case study
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Factors affecting prey detectability for visual predators
Machalková, Kateřina ; Exnerová, Alice (advisor) ; Javůrková, Veronika (referee)
The cryptic coloration is one of the main ways to protect prey before the visually directing predators. Most animals use two basic strategies of crypsis, background-matching and disruptive coloration. The aim of this thesis was to summarize and evaluate knowledge about different strategies of cryptic coloration. The study was mainly focused on the confrontation between insect prey and predator bird. Experimental studies are comparing the effectiveness of cryptic coloration of prey by a combination of background-matching and disruptive coloration with prey characteristics (inner pattern contrast, background contrast, shape and pattern distribution, symmetry) or background parameters (background complexity, multiple backgrounds, the distance between the prey and the predator) that affect detectability. The results of the study conclude that disruptive coloration pattern in cryptic prey has better effects than the strategy of background-matching. Prey characteristics can affect detectability, but the results of individual studies are not conclusive. Even the background parameters results were unambiguous, the highest efficiency for prey detection time was a combination of disruptive coloration and the background complexity. The issue of camouflage is so complex that the majority of studies do not have...
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Mechanisms of relationship between melanin-based colouration and behavioural syndromes in birds
Nacházelová, Martina ; Javůrková, Veronika (advisor) ; Tomášek, Oldřich (referee)
Melanins are the most common pigments incorporated into birds' feathers. Since melanin-based coloration is variable in the extent and intensity, its function is considered to be particularly cryptic and mechanical, hardening the feather structure. However, recently it has been found that melanin- based coloration also has a signaling function, due to the observed correlation between this type of coloration and many physiological and behavioral traits. These relationships follow from the pleiotropic effects of genes regulating the melanocortin system and the physiological effects of testosterone and corticosterone, which are involved in melanogenesis. This work describes genetic and physiological mechanisms of the relationship between melanin-based coloration and behavioral traits in birds and, based on available studies, supports the signaling function of this type of coloration. Melanin-based coloration has been shown to be positively correlated with aggressiveness and dominance, sexual activity, coping with stress, a fast strategy of exploratory behavior, parental care, and anti-predator behavior in many bird species. However, despite intense research interest in this topic in last decade, it is worth noting that more experiments focused on species with a distinct sexual dichromatism or...
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Diversity and evolutionary significance of feather-degrading bacteria in birds
Kyptová, Markéta ; Javůrková, Veronika (advisor) ; Reif, Jiří (referee)
Although to date this fact has been widely neglected, avian plumage is inhabited by a wide range of bacteria able to utilize keratin, the basic structural unit of feathers. If these keratinophilic, so called feather-degrading bacteria (hereafter FDB) get out of control, it can lead to significant changes in the plumage structural properties, resulting in impaired thermoregulation, flight performance, and expression of plumage ornaments. These may have significant consequences on reproductive success and overall fitness of individual. Based on these facts, it is hypothesized that PDB pose strong selective pressure lying behind the evolution of defense mechanisms such as size and chemical composition of uropygial gland, deposition of pigments into the feathers, or molting strategies that have been observed to eliminate the negative effect of FDB. The aims of this bachelor thesis are, on the basis of available literature, to summarize findings related to overall diversity and characteristics of plumage bacteria, to evaluate their effect on quality of plumage and individual fitness, and also to assess a role of microorganism in the evolution of different life- strategies in birds. Finally, this bachelor thesis points out the shortcomings of recent studies and proposes the concept for future research...
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