National Repository of Grey Literature 35 records found  beginprevious21 - 30next  jump to record: Search took 0.00 seconds. 
Stable isotopes and the study of insects ecology
Javůrková, Jaroslava ; Šípek, Petr (advisor) ; Harant, Karel (referee)
Animal foraging ecology is an important part in the puzzle ecosystem relationships. This bachelor thesis presents review in the field of food ecology, especially insects. It focuses on the method of analysis of stable isotopes, which is one of the current and in recent decades a modern approach for studying this issue. Stable isotope analysis is compared with other frequently used methods for animal food ecology. The aim of this work is to introduce this method and its possible use in the study of insect food ecology. The first part provides the necessary theoretical background, practical application in laboratory and then it deals with the problems typically adressed by this method. Key words: stable isotopes, stable isotopes analysis, food ecology, food preferences, insects
Atmospheric deposition of nitrogen - application of stable isotopes
Hanzlová, Barbora ; Hůnová, Iva (advisor) ; Hovorka, Jan (referee)
Human impact on particular parts of ecosystems has become a highly discussed topic. Due to different isotopic values of nitrogen, it is possible to evaluate the extent to which human influences the natural nitrogen cycle, using isotope measurements. Stable isotope measurement has been used in various scientific disciplines around the world. This thesis summarizes the findings about atmospheric deposition and the subsequent use of stable nitrogen isotopes. The objective of this work was to gather the information about the use of stable isotopes in the study of the atmospheric deposition and how to make better use of the information obtained from the measurements. Based on the literature review, it has been found that, unlike other countries, nitrate substances such as NH3 and HNO3 are not measured in the Czech Republic, which distorts the data on the nitrogen produced. The use of stable isotopes is a convenient method of measuring both not yet quantified substances as well as already measured substances contributing to atmospheric deposition. The stable isotope measurement method represents an improvement for the overall estimation of atmospheric deposition to provide more realistic values compared to the current approach. Key words: atmospheric deposition, nitrogen, stable isotopes
What is the water contribution of fog to atmospheric deposition? Use of stable isotopes.
Hanusková, Darina ; Hůnová, Iva (advisor) ; Šantrůček, Jiří (referee)
The objective of the Master thesis is to estimate the fog contribution on atmospheric deposition with the usage of stable isotopes. The crucial part of the thesis was to perform (first of its kind in the Czech Republic) the relative isotope composition 18 O a 2 H of fog. In the same time, the composition of rain and throughfall was performed. The collection of each type of precipitation took place in five sampling points of Academy of Science within three mountain regions including Krkonoše, Šumava and Jizerské Hory during October and November 2017. The sampling took 14 days in total and it was performed by using TC/EA ThermoBremen and mass spectrometer Delta ThermoBremen at South Bohemian University in České Budějovice. The results confirmed that fog is isotopically heavier in comparison to regular rain. As for the relative isotope composition 18 O and 2 H of each areas, no significant difference was observed. Results of the fog participation on atmospheric deposition in Krkonoše and Šumava can be seen after drafting a simple linear mixing model. The fog contribution on atmospheric deposition in Šumava for 18 O is 4,7 % and for 2 H is 6,4 18 O. For one area in Krkonoše, the average participation for 18 O is 3,6 %. Key words: stable isotopes, oxygen, hydrogen, fog
Pedogenic carbonates of loess-paleosol sequences
Máslo, Jaroslav ; Flašarová, Kristýna (advisor) ; Šefrna, Luděk (referee)
Loess is sediment composed predominantly os silt-size particles. Silt-size particles are transoported mainly by wind. Loess covers 10 % of earth surface. If the loess can be layed for a longer time when the glacials and interglacials alternate, the loess-paleosol sequences are created. Common part of loess and loess-paleosol sequences are pedogenic carbonates, which are particles of CaCO3. There are many types of carbonates, e.g. Calcified root cells. hypocoatings, needle-fiber calcite… Loess-paleosol sequences and carbonates in them are realy useful source of information about paleoenvirnonment. In practicle part of this work the isotopic composition of C and O in pedogenic carbonates from loess-paleosol sequence in Dejvice (Prague) was measured.
Childhood diet in relation to the determination of social roles and health status in Great Moravian population
Jílková, Michaela ; Brůžek, Jaroslav (advisor) ; Kovačiková, Lenka (referee)
This study is focused on dietary reconstruction according to stable isotope analysis of carbon and nitrogen in bone and tooth collagen. The material used for this study is represented by set of 46 skeletons of adult individuals from 6th church's burial site in Mikulčice, which belong to the Great Moravian era (9th -10th century). Isotopic values are discussed in relation to the formation of social roles and health status. The presence and eventually degree of severity of some non-specific stress indicators and pathologies (Cribra orbitalia, presence of tooth caries, caries intensity, linear enamel hypoplasias, dental wear and length od femur) was observed. The results of isotopic analysis suggest, that diet in this population sample was based on terrestrial sources, both animal and plant protein. Plants in Great Moravian diet belonged to C3 and C4 group. C4 group of plants in Mikulčice was represented by millet (Panicum miliaceum), which supports the hypothesis of "Millet - typical crop of old Slavs" (Reitsema and Kozlowski, 2013). Millet was consumed mainly in childhood. Significant differences between diets of high social class and rest of population was found with people of higher social rank consuming more animal protein. These differences were created in childhood and persisted to adulthood....
Multiproxy evidence of Late Pleistocene environmental changes in the loess/paleosol sequence of Bůhzdař
Flašarová, Kristýna ; Strouhalová, Barbora (advisor) ; Trubač, Jakub (referee)
Loess-paleosol sequences preserve information that can be used to reconstruct paleoenvironement, specifically the climatic conditions and the vegetation present at the time of their formation. A dense network of reliably analyzed sequences from different geographic locations is crucial for representation of ecological and climatic trends during the Pleistocene (Frechen, 2011). The aim of this thesis is to fill the gap in the geographical distribution of well described loess-paleosol sequences in Central Europe. Therefore, it focuses on a loess- paleosol sequence in Bůhzdař, situated 9 km NW of Prague, Czech Republic. This profile was last studied in 1952 by naturalist Vojen Ložek. This thesis uses a number of analyses in order to get a multi-proxy record of local paleoenvironmental changes archived in a sequence of alternating loess sediments and paleosols in Bůhzdař. Geochemical approaches are combined with grain size distribution to define climatic conditions at the time of formation of the strata. Key words: loess/paleosol sequences, Bůhzdař, Czech Republic, particle size distribution, total organic carbon, XRF, XRD, stable isotopes 13 C and 18 O
Diet and social stratification in Early Medieval France: Carbon and nitrogen stable isotope analysis of adult population from Merovingian burial site of Le-Norroy-le-Veneur (France, 5th-8th century)
Vytlačil, Zdeněk ; Brůžek, Jaroslav (advisor) ; Kovačiková, Lenka (referee)
The aim of this work was to characterize the diet of a Merovingian population sample and examine if apparent differences in grave good assemblages of Merovingian burials and transfromation of this funerary rite during 6th and 7th centuries were reflected in diet. Dietary composition was assessed using a carbon and nitrogen stable isotope analysis of 74 bone collagen samples from adults buried at an early medieval cemetery of le-Norroy-le-Veneur, France. Results showed diet based primarily on C3 plants, supplemented with animal protein in a range similar to other contemporary sites. No significant contribution of C4 plants (e.g. millet) or marine-derived protein has been detected and neither has δ15 N dependency on status, sex or datation been found. However, persons with rich grave good assemblages had significantly higher δ13 C than low-ranking individuals. Also, during the time of use of the cemetery there has been a population-wide decrease of 0,33 ‰ in mean value of δ13 C, independent of social status or sex. Results indicate that dietary differentiation steaming from social stratification was only in its early phase of formation, slowly following a progressive rise in power of the Merovingian nobility, and the general subsistence was affected by another independent change in society, most...
Carbon and Oxygen Stable Isotope Ratio from Foraminiferal Tests as a Key to the Paleoenvironmental Interpretations in the Middle Miocene of the Carpathian Foredeep (Central Paratethys)
Scheiner, Filip ; Holcová, Katarína (advisor) ; Soták, Ján (referee)
The (Lomnice) LOM-1 borehole records a nutrient-rich quiet environment of the outer shelf to upper bathyal in the Mid Badenian (sensu Hohenegger et al. (2014)) of the Carpathian Foredeep. The LOM-1 borehole is rich of a fossil content with a relatively good preservation. The studied section can be correlated with the interval from 14.6 Ma (the FO of Orbulina spp.) to 13.42 Ma (the LO of Sphenolithus heteromorphus) which agrees with the beginning of the "Middle Miocene Climate Transition". The foraminifera for the carbon and oxygen stable isotope analysis were picked from the fraction 0.063-2 mm. The suitability for the stable isotope analysis was carefully evaluated based on the inner wall preservation. The isotopic analysis was done for fifteen samples with total 373 tests analyzed. Each analysis was performed from exactly one test. The following foraminiferal genera from different paleobiotops were used for the isotope analysis: Globigerina bulloides; Orbulina universa, Praeorbulina glomerosa; Globigerinoides spp.; Uvigerina spp.; Heterolepa dutemplei; Cibicidoides spp.; Gyroidinoides spp. and Melonis pompilioides to document the isotopic signal for the superficial and bottom waters. The oxygen and carbon isotope analysis from foraminiferal tests were used for the verification of the...
Nutrition in medieval Europe and stable isotopes
Jílková, Michaela ; Brůžek, Jaroslav (advisor) ; Kaupová, Sylva (referee)
Stable isotope analyses of human bone collagen are the valuable tool of the diet reconstruction in bioarchaeology. These analyses help to understand the lifestyle of our ancestors. Values of carbon and nitrogen stable isotope ratios show if an analysed specimen used more terrestrial or aquatic food sources, plants with C3 or C4 pathway of photosyntesis or whether his primary protein source were plants or animals. The stable isotopes also provide information about diet differences between different sexes, people with different socioeconomical status or different ages. We can study long- distance trade and residental mobility by results of isotope analyses. A combination of isotope ratios and archaeological knowledge provides valuable information not only about the diet but also about the lifestyle of historical populations. For example in several medieval Europian populations were discovered geographical differences and partly chronological differences which can be explained by the different diet in different localities and diet changes in Middle ages.
Altitudinal migrations in animals and their study methods
Zenklová, Tereza ; Sedláček, Ondřej (advisor) ; Klvaňa, Petr (referee)
Migration as a response to the seasonality of the environment is common in many animal taxa. Strong fluctuation of the climate is usually connected to regions in the temperate zone, quite common is in the tropical regions as well. Typically, it is even more pronounced in high altitudes. In such environment, many animals could migrate altitudinaly as a response to changes in the climatic conditions or food abundance. But determinants of altitudinal and long-distance latitudinal migrations could be different. The objective of this work is to determine factors influencing altitudinal migrations in diverse taxa (particularly in birds and bats) and in different biogeographical regions. I am trying to find some common features of migrating species, such as diet or temperature and rain tolerance. Especially tropical species are partial migrants, which means that only some individuals of the population migrate. I will discuss common features of such migrating infividuals. Study methods of altitudinal migration will be a part of this research as well. The work will be primarily concentrated on tropical regions.

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