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Leptosporangiate ferns from the Carboniferous basins of Bohemia, selected taxa
Frojdová, Jana ; Opluštil, Stanislav (advisor) ; Kvaček, Jiří (referee)
The diploma thesis revises ten selected species of sphenopterid ferns of Carboniferous age deposited in the National Museum in Prague, the West-Bohemian Museum in Pilsen and the British Geological Survey in Keyworth, England. Sphenopterid ferns were studied based on reproductive organs aquired by maceration of coalified plant remains preserved as compressions. Sporangia and their annulus are important diagnostic features for individual genera and species of sphenopterid ferns and for selected species have not been described yet. Following species were studied: Boweria schatzlarensis, Myriotheca anglica, Renaultia crépini, Sturia amoena, Oligocarpia gutbiery, Zeilleria hymenophylloides, Zeilleria avoldensis, Discopteris sp. ("doubravensis"), Scolecopteris elegans a Waldenburgia corynepteroides. With the exception of Waldenburgia corynepteroides, Scolecopteris elegans, Zeilleria hymenophylloides and Zeilleria avoldensis species type material was studied. Maceration of sporangia of Boweria schatzlarensis showed presence of lateral annulus while in case of Myriotheca anglica the annulus is lateral or more likely of a special type, placed on both sides of the sporangia. Annulus type determination of Renaultia crépini also made possible to assign this species within the range of the genus Tenchovia and...
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Cigarette Demand and Cigarette Taxation in Czech Republic
Kvaček, Jan ; Gregor, Martin (advisor) ; Janský, Petr (referee)
5 Abstract: This thesis addresses to the cigarette demand and excise tax on cigarettes in the Czech Republic The aim is to describe behavior of smokers and especially their reaction to the changes in price of cigarettes. Data for household spending are used for this purpose. First part of this thesis is dedicated to description of the cigarette market and socio-demographic characteristics of smokers. Second part concerns with question whether smokers are rational or myopic and how price elastic is their behavior. Then the rest of the thesis describes excise tax payment mechanism and analyzes excise duty incomes. The thesis finds that cigarettes are more affordable these days than in the beginning of 90's. Czech smokers do not fully realize future impact of their behavior and they seem to be very inelastic witch respect to price. The price elasticity was estimated on value -0.2. Given low price elassticitty and increasing purchasing power, the current cigarette excise tax is considered to be too low. Keywords: Excise tax on tobacco, Smoking, Cigarettes, Tobacco, Rational addiction, tobacco consumption of households, Cigarette prices
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Gondwanian element of Latin American Flora
Potůčková, Anna ; Stančík, Daniel (advisor) ; Kvaček, Jiří (referee)
The concept of plate tectonics accepted during 20th century fundamentally changed general opinion on the origin of Latin American flora. It was found, that South America formed a part of the ancient continent Gondwana. This continent was covered by a unique flora until 100 million years ago. Actual disjunction of widely distributed tropical taxa present in South America originated after disruption of that original flora distribution. It was deduced that the separation of South America from Gondwana finished about 100 million years ago and led to the isolation of their flora until the formation of the Isthmus of Panama about 3 million years ago. However, recent studies based on molecular clock approaches shows that the exchange of biota between South America and rest of the World was possible several times in different ways before the closure of the Isthmus of Panama. The reevaluation of our opinion about the gondwanan origin of Latin American flora based on advanced molecular analysis is the aim of this work.
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Palaeoecology of selected localities of the Whetstone Horizon
Libertín, Milan ; Kvaček, Jiří (advisor) ; Teodoridis, Vasilis (referee) ; Cleal, Christopher J. (referee)
Palaeoecology of selected localities of the Whetstone Horizon In frames of the present thesis taphonomical and paleoecological processed were described in selected localities of whetstone horizon. Fossil plant assemblage known from the locality Štilec represents plant community buried in situ by volcanic ash after volcanic explosion (Pennsylvanian, Bolsov). Plant community exhibits relatively low diversity assemblage of herbaceous and subarborescent plants. This unique taphocoenose was interpreted as pioneer assemblage growing in partly drained lake. In the locality Ovčín the peat bog of Lower Radnice Seam was buried during the same volcanic eruption by volcanic ash. Up to now 5 excavations were recovered of the area of seats over 150 m 2 on two sites which are approximately 40 m distant from each other. In this area 27 morphotaxa of fossil plant was recorded. They represent 20 whole plants. Fossil plant remains represent fossil plant assemblage dominated by lycopod plants of planar (rheotrophic) swamp situated in narrow palaeovalley with active fluvial system. Second part of the thesis is focused on systematic descriptions of fossil plant taxa from localities of the Whetstone horizon. A monotypic genus Huttonia and species Huttonia spicata from Class Sphenopsids was emended. Further there were described...
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Metodika pro práci s přírodovědeckým typovým materiálem
Holec, Jan ; Kment, Petr ; Wagner, Jan ; Šmíd, Jiří ; Šída, Otakar ; Kvaček, Jiří ; Sejkora, Jiří ; Kuželka, Vítězslav
The book deals with basic, really existing elements of nomenclature in natural sciences - types, which represent pillars for scientific names of organisms and minerals. It describes especially the managing of types governed by zoological and botanical codes (ICZN, ICN), both for their living and extinct representatives. The text covers the following aspects of managing types: their distinguishing, terminology, preparation, preventive conservation, packaging, labelling, documentation, publishing, studying, and loaning.
Fulltext:  PDF
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