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Identification of microbial pigments in evaporites using Raman spectroscopy: implications for astrobiology
Vítek, Petr ; Jehlička, Jan (advisor) ; Marshall, Craig P. (referee) ; Vandenabeele, Peter (referee)
Raman spectroscopy is a powerful tool for identification both inorganic and organic compounds including microbial biomolecules. Together with the fact, that it is considered to be the important nondestructive instrument for use on Mars within future robotic missions, it is necessary to assess its capabilities in scenarios relevant for both Martian and terrestrial conditions. In this work, the potential of Raman spectrometry was tested - including both bench-top laboratory systems as well as portable counterparts - to detect traces of life within evaporitic matrices through biomolecular identification. Due to their chemical and physical nature resulting in optical properties, pigments are important organic compounds in Raman spectroscopic analysis using visible excitation. Hence in this work we have focused on the Raman spectroscopic identification of pigments as biomarkers with relevance for investigation of life in both extreme terrestrial and potentially extraterrestrial environments. Results of methodical work are presented in Appendices I to III, dealing particularly with β-carotene as a model carotenoid pigment. The concentration limits of this biomarker in three different evaporitic matrices (halite, gypsum and epsomite) have been determined for artificially prepared powdered mixtures alone...
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Detecting biomarkers of extremophiles in Martian analogues
Němečková, Kateřina ; Jehlička, Jan (advisor) ; Hauer, Tomáš (referee) ; Vandenabeele, Peter (referee)
The main focus of this thesis is on the examination of endolithic microorganisms within gypsum from Sicily. This region is of particular interest because gypsum outcrops are common and accessible there, but the environment is not considered to be extreme in terms of solar radiation or other factors. The research aims to detect endolithic biomarkers and analyse their distribution in their natural environment, to identify endoliths with a focus on phototrophs, and to assign the detected biomarkers to their producers. One of the key tools used in this study was a portable Raman spectrometer with a 532 nm laser, used for the detection of carotenoids under field conditions. Further, the Raman fingerprints of scytonemin and gloeocapsin can be used for the taxonomic identification of some cyanobacteria. With the use of a combination of different excitation wavelengths (445nm, 532 nm, 780 nm), it was possible to detect good quality spectra of various pigments in situ, conditions also in isolated cells and colonies. The results of the molecular analysis also suggest that gypsum habitats in non-extreme regions have a similar microbial composition as those found in extreme regions; i.e., Cyanobacteria being the most abundant group of these microorganisms. This has previously been described as the "hypothesis...
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Temporal sequence iconicity: An artificial language learning experiment
Burda, David ; Láznička, Michal (advisor) ; Jehlička, Jakub (referee)
This thesis is devoted to the concept of linguistic iconicity and especially to the iconicity of sequence, which suggests that the order of individual forms in language should correspond to the actual order of experience they describe. In particular, I focused on temporal iconicity in complex sentences describing two consecutive events. The most crucial part of this work consists of an experiment based on artificial language learning. During the experiment, participants were presented a language allowing both iconic and non-iconic clause order in complex sentences, and then, based on the knowledge they had gained, produced their own complex sentences describing events they were shown illustrations of. I then examined what the prevalent sentence order in the answers was, which were the most common errors and in which situations they occurred. The results show a slight tendency towards the use of sentence orders which are in accord with the iconicity of sequence hypothesis. Key words: artificial language learning, iconicity, temporal sequence
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Language trajectories of CODAs in the Czech Republic
Tylšová, Kateřina ; Hudáková, Andrea (advisor) ; Jehlička, Jakub (referee)
This bachelor thesis focuses on the language trajectories of CODA or hearing adults who have deaf parents (cf. e. g.: Preston, 1994; Bishop, Hicks, 2005; Moroe, 2019). The theoretical and methodological framework of this work is based on the research of Sherman and Homoláč (2014, 2021), who worked with the theory of language management and the method of language biographies. The focus of the work is a research survey with ten CODA adults (aged 20-60) living in the Czech Republic. The author conducted linguistic biographical interviews with all respondents, on the basis of which she compiled the language trajectories of each of the respondents and identified the so-called turning points in them. Subsequently, she tried to define turning points typical for Czech adult CODAs and to trace certain features that would allow the monitored CODAs to be divided into specific groups showing some common features in language biographies.
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Raman spectormetry in Art
Minaříková, Laura ; Jehlička, Jan (advisor) ; Osterrothová, Kateřina (referee)
This thesis deals with the use of Raman spectroscopy in the arts, specifically in the identification of precious stones and semi-precious stones in various art works. This work describes the basics of this method, options and practical use based on selected scientific publications. The existing results of research in recent years shows that this spectroscopic analytical method on the rise. It is thanks to the many advantages that this method offers skilled in the art. The main advantages of Raman spectroscopy include speed and affordability analysis, minimal or no sample preparation, and most importantly - non-destructive to sample and explore the possibility of sample on the spot, without having to often very difficult transport to the laboratory. Key words Raman spectrometry, art, characterization of artifacts
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Use of portable Raman spectrometers for detection of sulfates: potential application in exobiology
Košek, Filip ; Jehlička, Jan (advisor) ; Němec, Ivan (referee)
The detection of mineral phases under in situ conditions has become a primary but sometimes also challenging task in many fields of geoscience. Raman spectroscopy has been used as a powerful tool for the identification of various minerals and organic compounds. The advantages and the relative simplicity made this method a promising choice in the future planetary exploration missions to Mars. The deposits of aqueous minerals including sulfates have been found on the Martian surface. With the development of miniaturized handheld spectrometers there is a need for evaluation of Raman spectroscopy as a method of identification of sulfate phases in their natural conditions. In the first part of this work a handheld spectrometer equipped with 532 nm excitation laser was tested under laboratory conditions during which the ability to distinguish mineral samples representing sulfates of different chemical composition and different degree of hydration was investigated. In the second part, two handheld Raman spectrometers equipped with 532 and 785 nm excitation lasers were used for the characterization of sulfate phases on sites of their natural occurrence located in the Czech Republic. The quality of the Raman spectra acquired under outdoor conditions by both spectrometers was rather average but sufficient to...
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Extremophiles and their environments - possibilities of using Raman spectroscopy for key biomarkers detection
Kovács, Michal ; Jehlička, Jan (advisor) ; Osterrothová, Kateřina (referee)
The Earth has a huge variety of living environments. Most of them, in terms of human, are affected by factors with extreme values. Species diversity, especially in the world of microorganisms, have created adaptations that help manage these conditions. Organisms, which live in these conditions, are called extremophiles. Each of them leaves a trace of their existence, whether present or past. These traces are called biomarkers and if we use appropriate method, we are able to identify them. This bachelor thesis brings a brief overview of the basic extremophiles and the environment in which they live. Furthermore, briefly describes the use of Raman spectroscopy to identify significant biomarkers, such as for the needs of exobiology.
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Application of Raman spectroscopy for the identification of organic inclusions in minerals for the field of exobiology
Osterrothová, Kateřina ; Jehlička, Jan (advisor) ; Němec, Ivan (referee) ; Vandenabeele, Peter (referee)
The multidisciplinary field of astrobiology has grown rapidly in recent years. The major goals of research in the field have been the search for habitable environments both within and outside our solar system, the search for evidence of prebiotic chemistry and life on Mars and other bodies in our solar system, laboratory and field research into the origins and early evolution of life on Earth, and studies of the potential for life to adapt to challenges on Earth and in space. NASA and ESA are heavily focused on a number of upcoming exploratory missions (e.g., the Mars Science Laboratory, with its planned launch in the fall 2011; ExoMars 2018; and the follow-up Mars Sample Return missions beyond 2020). A Raman spectrometer is now being miniaturized for the ExoMars Rover Instrument Suite. This Raman instrument is expected to be used to identify organic compounds and mineral products that could be related to signatures of life, as well as provide a general mineralogical overview, especially those minerals produced by water- related processes. This thesis describes the results of laboratory investigation into the feasibility of Raman spectroscopy to detect different types of biomarkers (pigments, carboxylic acids, and aminoacids) first mixed in the mineral matrices and...
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