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Aquatic insects versus fish: adaptations to fish predation
Chawner, Adam Mark ; Černý, Martin (advisor) ; Jor, Tomáš (referee)
in English In this thesis, I review how aquatic insects have adapted to fish predation in various habitats during all phases of their life cycles. Aquatic insects are a large group of heterogeneous species and this review introduces these orders and species, including the environments they inhabit. Fish are some of the most common and most impactful predators of aquatic insects and this thesis identifies a wide range of behavioural, morphological, chemical and life history defence mechanisms of various complexity and uniqueness aquatic insect orders have developed to counter fish predation. Most aquatic insects are subject to predation during their aquatic larval stage. A few orders also inhabit the water as adults, as is the case most notably for aquatic Coleoptera. More complex adaptations to fish predation are presented in this order. Oviposition is noted as a strategy used to negate fish predation even before individuals hatch. The use of fish predation as means to control mosquito larvae communities is presented and reviewed. Keywords: aquatic insects, fish predation, defence mechanisms, adaptation to predation
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A Volunteer with a Big "V" - Laid-back, or Self-sacrificing?
Vondrušová, Gabriela ; Pospíšilová, Tereza (advisor) ; Šťovíčková Jantulová, Magdaléna (referee)
Volunteering - one of the topics which are still present in the society, as it can be perceived as a unique instrument to solve social challenges or organizing society with its specific conditions. The topic of my diploma thesis, based on the grounded theory method, is the process of building and maintaining the relationship of the volunteer to their voluntary work from the volunteers' perspective. I was curious as to what circumstances or limits accompany the forming of such a relationship in the social context and if certain "prototypes" can be found, which would differ in negotiating their role to their surroundings. In my thesis, I focus exclusively on those volunteers who have been given the "Křesadlo" award for the volunteer of the year, which provides the framework of this relationship. I would like to use my results to enrich the knowledge of volunteering's image, which could be used both on the academic field and when working with volunteers. Keywords: civic sector, volunteering, self-perspective, role, identity, "looking-glass self", norm, defence mechanisms, information management, Křesadlo.
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Crisis Intervention in a School Environment
Matasová, Lenka ; Koťa, Jaroslav (advisor) ; Sedláčková, Daniela (referee)
The first chapter of the theoretical part of this master's thesis summarizes basic knowledge about crises. The second chapter deals with ways of protecting people from crises. It covers defence mechanisms, coping strategies and social support. Chapter 3 describes specialist help for people suffering crises, and provides a summary of basic information about crisis intervention. The next chapter deals with children in crisis situations, major types of stress situations for children, their manifestations and their consequences for the child's psyche and behaviour. The final chapter of the theoretical part of the master's thesis deals with ways of intervening in crises in the school environment. The practical part of the master's thesis is an empirical study in the form of semi-structured interviews with lower secondary stage teachers. The interviews investigate the experience and the preparedness of teachers for resolving crisis situations in the school environment. The research carried out in this project provides material for an analysis of the interviews. Keywords: crisis, crisis intervention, defence mechanisms, coping strategies, skills for crisis intervention.
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How do plants manage to survive on toxic spoil-mining sites? Physiological and structural properties of plants on substrates with high As and Hg contents
Kovářová, Monika ; Albrechtová, Jana (advisor) ; Soudek, Petr (referee)
The heavy metals contamination of environment represents a worldwide problem lately. Heavy metals cause harmful effects not only to plants, but also to other organisms. Throught their acumulation in plant biomass, heavy metals enter a food chain and could negatively influence the human health. The impact of heavy metals on plants and their defence mechanisms against toxicity of heavy metals have been in focus of plant physiology and ecology research for decades. Importance of this topic arises from plant role in environment, ecosystem services and in human nutrition. Investigation in proces and mechanisms of heavy metal hyperacumulation in plants offer progress in fytoremediation and genetic engineering. The experiments on agricultural crops show how heavy metals enter the food chain and how they affect the crop yield. The aim of this thesis is to summarize information about heavy metals' effects on plants. The thesis is focused on arsenic and mercury, because the Czech Republic have also problem with heavy metals contamination and these two metals occur in high concentration in the spoil banks and soils adjacent to the lignite mining areas of Sokolovsko. The spoil banks with heavy metal content have to be revegatated, thus, the topic of their effect on plants is of high importance. In the first part of the...
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Defence mechanisms of sugarbeet participating on resistance against pathogens and pests
Grigová, Vendula ; Burketová, Lenka
The plants dispose their own defence mechanisms against pathogen attack, which include both constitutive and induced structural changes, but mainly biochemical changes. SAR (Systemic Acquired Resistance) is an important defence mechanism. The objective was to compare defence reactions of sugar beet against the causal agent of rhizomania, i.e. BNYVV and its vector Polymyxa betae, with sugar beet reaction after soil nematode attack and with reaction to treatment with chemical and biological inductors of resistance. We have shown that the same spectrum of hydrolytic PR-proteins (basic -1,3-glucanase (Glu2), basic class IV chitinase (Ch4), acidic class III chitinase (SE2), basic class II chitinase (Ch2)) is induced both after pathogen/pest attack and after BTH inductor treatment; nevertheless, the intensity of induction is related to a particular agent. Increased accumulation of glucanase was detected immunohistologically in sugar beet tissues both after pathogen/pest attack and after BTH inductor treatment.
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