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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.
151

Komplexní charakteristika hlístice Phasmarhabditis hemaphrodita. / The complex characterisation of nematode Phasmarhabditis hermaphrodita

NERMUŤ, Jiří January 2012 (has links)
Ph.D. thesis "The complex chacterisation of the nematode Phasmarhabditis hermpahrodita" is focused on the study of ecology of slug parasitic nematode P. hermaphrodita, its general characterisation in the context of all nowadays knowledge. The thesis consists the general introduction, that introduces the whole nowadays research of P. hermaphrodita, and four original works, that follow the introductory chapter. The first work deals with the orientation of P. hermaphrodita in 2D and 3D space and reaction on the presence of different hosts or nutritive substrates. The other study deals with the reaction of P. hermaphrodita on various animal and plant nutritive substrates and in the first place the influence of these substrates on the development of nematodes and quality and quantity of progeny. The third scope of this thesis is the influence of intraspecific competition on development, quality and quantity of nematodes and the last part of this text comprises a short study of the persistence of P. hermaphrodita in different substrates, from mineral to organic.
152

Vliv postřiku insekticidy na diverzitu střevlíků (\kur{Carabidae}) na poli ozimé řepky / Impact of the application of the insecticides on the diversity of ground beetles (Carabidae) in a winter rape stand

KEPL, Lukáš January 2013 (has links)
This thesis deals with the determination of the direct impact of spraying on soil invertebrates by comparing the treated and untreated surfaces by spraying with plant protection products. The experiment took place in crop of winter oilseed rape in the western part of South Bohemia in spring 2012. As bio-indicators were used ground beetles beetles (Carabidae). Trapping was conducted using pitfall traps. In this work we compared the difference in the occurrence of ground beetles in treated and untreated crop of winter oilseed rape and subsequent tree alley. Only 15% of beetles was recorded sprayed areas, 69% in untreated areas and and 16% in the alley. This suggests the direct impact of spraying on non-target organisms. That's followed by a second experiment, which aim was to determine the long-term effects of intensive farming on ground beetle populations in habitats related to reporting rape field. The selected habitats were meadow, pasture, alley, ruderals and riparian vegetation. The results indicated the inportance of the biotops consequent to field as tthe refugium and the center of spreading of groujd beetles to the field where they provide ecosystem service of biological control.
153

Hunter-gatherer archaeobotany: Central European Mesolithic

PTÁKOVÁ, Michaela January 2014 (has links)
The present work attempts to provide understanding of the issue of Mesolithic archaeobotany, especially in terms of plant use, woodland clearance, and discussion concerning Mesolithic agriculture. Special attention is also paid to taxa occurring within archaeological context at European Mesolithic sites and some methodological implications. Also, specific patterns in food preparation and consumption are considered, particularly with emphasis on certain archaeological features. The thesis also brings new original data from the Czech Republic. In this regard, assemblage from Dvojitá Brána u Rohlin has provided hints towards the study of the Neolithisation process in the Czech Republic, whereas case study from the Schwarzenberg Lake has brought considerable focus on the issue of depositional/postdepositional processes, especially when dealing with shallow sandy sediments. The thesis also strongly reflects the growing need for interdisciplinary work to address issues related to Mesolithic hunter-gatherers.
154

Využití secích strojů pro přípravu půdy při pěstování obilnin / Use of seeding machinery for soil preparation in the cultivation of cereals

JÍRA, Václav January 2014 (has links)
The aim of the thesis is to extend knowledge in terms of the application of modern seeding machinery for soil preparation for sowing in the cultivation of cereals. In the literary section of the report a brief overview of the use of seed drills for minimum tillage. Load small-plot experiment on the selected station and simultaneously perform evaluation activities seeders work to prepare the ground in terms of quality seed, seed depth, coming in plants (growth phase), or the occurrence of weeds. The thesis will brief overview of the analysis of operating costs. The results evaluate and propose recommendations for possible use in agricultural practice.
155

Dynamika obsahu sekundárních metabolitů v rostlinách během vegetační sezóny (Artemisia sp.) / Seasonal variability of plant secondary metabolism (Artemisia sp.)

Koutská, Barbora January 2018 (has links)
Plant secondary metabolites (SM) are widely used by humans in many ways (pharmacy, biotechnology etc.). For making their use even more effective, it is important to know the seasonality of these chemicals in plants and what affect those changes. Three Artemisia species (Artemisia annua, A. absinthium, A. vulgaris) were cultivated during one vegetation season (from April to September 2016). Plant growth parameters and the beginning of their generative stages were observed, and leaf samples were collected regularly. Samples of some plants were collected repeatedly. A generalist herbivore (migratory locust), was used as a proxy for studying changes in plant secondary metabolism during the vegetation season. The results proved presence of defence secondary metabolites in plants except A. vulgaris species where the role of SM in defence was not shown. Levels of SM changed nonlinearly during the vegetational season and were time-dependent. Plant size did not influence the levels of SM in plants. Levels of SM were low at the beginning of the experiment followed by rapid increase and remaining on maximal levels. The plants which lost their biomass repetitively grew slowly and bloomed later than the plants which were clipped only once. A delay trend showing seasonality of the plant SM was not proved. In...
156

Fytotoxicita vybraných naftochinonů na vybraném rostlinném modelu / Phytotoxicity of selected naphthoquinones on a selected plant model

Rucký, Jakub January 2013 (has links)
The introductory part of this thesis is focused on the theoretical analysis of solved problems as examining the toxicity of naphthoquinones plumbagine and juglone, especially with regard to their allelopatic action. The next section is focuses on the plant stress, caused by the action of stress factors leading to their death. There is an experimental protocol and the possibilities of determination the effect of naphthoquinones on the plant model. Experimental section discusses changing growth parameters of the plant samples in different concentrations of the naphthoquinone. There is examined cell viability and changes in the synthesis of the secondary metabolites. Data obtained by using spectrophotometric and microscopic analysis are evaluated with STATISTICA software and statistical significance are plotted.
157

Spektrofotometrie přírodních látek – sekundárních metabolitů rostlin / Spectrophotometry of natural drugs - secondary metabolites of plants

Hořavová, Lenka January 2013 (has links)
Plants are an important source of secondary metabolites, such as substances that have a beneficial biological effect on the health of humans and they are irreplaceable in the modern medicine. They may operate in prevention and in the treatment of civilization diseases. In terms of content substances, the phenolic come to fore, especially polyphenols, which have been related to a number of overview studies due to their wide distribution and high concentration in plants. They also represent an important part of substances with redox effects present in the human diet and have an important role for the plant itself. Currently, many laboratories are dedicated to pharmaceutical and biological testing of plants. Individual polyphenols in plant matrices are determined primarily by chromatography, electrophoresis methods, mass spectrometry and nuclear magnetic resonance. Valuable information on the content of polyphenols in plant extract can be obtained also by using spectrophotometric methods. The subject of this thesis is to provide information, characterization and comparison of conventional and modern techniques for the determination of natural substances – phenolic compounds using spectral techniques.
158

GM plodiny v přípravě nových potravin, farmak a technických materiálů: inovace gymnaziálního učiva. / GM crops for new food, pharmacological and technical use: inovation of secondary school study

Koblihová, Kateřina January 2012 (has links)
The demand for plant and other production is increasing with the growth of human population when the territory where plants can be grown is continually decreasing. The present agricultural production of food, industrial materials and drugs of plant origin is not enough for people, as for the effort to achieve higher environmental comfort, especially in developed countries. We are trying to find a simpler, cleaner and cheaper ways of crop production. The genetic modification is one of the modern ways how to achieve this goal. Students get a lot of information about this topic from various sources, but mainly just from the internet and television. It is recommended that students should be able to compare information received from the media with school knowledge as for avoiding opinion pressure and manipulations.
159

Floristické asociace miocenních rašelinišť na základě studia fuzitových klastů / Floristic associations of Miocene mires based on fuzite clasts study

Fischlová, Kateřina January 2012 (has links)
The thesis presents systematical study and taphonomical evaluation of fusite wood specimens collected in the middle bench of the main lignite seam in the Bilina mine. In the introduction part, there are a general characteristic of the Most Basin and its geological setting with respect to the main lignite seam. Consequently, the charcoal is described in detail. Generally, the charcoaled wood, which was produced during wildfires in the Tertiary forests, shows well preserved anatomical details. The final part resumes systematics and taphonomy of the charcoal specimens collected by the author.
160

Evoluční procesy podmiňující diverzifikaci rostlin v tropických Andách / Evolutionary processes underlying plant diversification in the tropical Andean highlands

Aparicio Vásquez, Diana Libeth January 2018 (has links)
The highlands in the northern Andes, which are known as the páramo, are recognized worldwide for their unique and species-rich flora. Many páramo plant groups underwent radiations, which have been shown to be very recent and outstandingly fast. These radiations have usually been linked to (1) the uplift of the northern Andes, which provided new ecological opportunities in the highlands that originated in this process, (2) Quaternary climate change that produced range shifts of the páramo, resulting in periods of páramo contraction and isolation, during cold periods, and periods of páramo expansion and connection, during warm periods (3) the Andean physiographical and ecological heterogeneity, which provides extent oppornuties for isolation and for ecological divergence. In spite of increasing research efforts to understand the evolution of the páramo flora, the actual processes underlying species diversification remain unclear. The main aim of this thesis is to contribute to the understanding of these processes. We use three different approaches in two different study systems: (1) A population genetics approach, which remains rare among páramo plant studies, focuses on three páramo Lupinus species (Lupinus alopecuroides, L. nubigenus, L. microphyllus). These species belong to one of the best...

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