Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 22 for “"Biosignatures"”.
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Organic geochemical biosignatures in alkaline Hydrothermal ecosystems
The 13C content of microbial products are controlled by many factors, including the 13C content of the growth substrate, growth rate, the flux of carbon through various parts of the biochemical network, and the isotopic fractionation imposed by the enzymes of that network. We analyzed the 13C …
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Light hydrocarbon ratios as biosignatures of microbial activity
The River Colne, UK, is a temperate estuary with large expanses of anoxic mudflats, referred to as a “microbial observatory”. Methane and ethane emissions were characterised over three sites spanning from the head of the estuary (Hythe), mid-estuary (Alresford) and the mouth (Mersea) which were …
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Organic influences on hydrated magnesium carbonate mineral formation
… and may have the potential to preserve biosignatures from a habitable early martian environment. Microbial influences on calcium carbonate precipitation are well documented, but magnesium carbonates have received considerably less attention as a result of their relative scarcity in …
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Last Call for Life: Habitability of Terrestrial Planets Orbiting Red Giants and White Dwarfs
… atmospheric photochemistry along with detectable biosignatures. We use EXO-Prime, which consists of a 1D coupled climate/photochemistry and a line-by-line radiative transfer code, to model the atmospheres and spectra of habitable zone planets around red giants and white dwarfs, and assess the time …
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The Search For Volatile Biogenic Emissions In Geothermal Areas
… life outside of the earth’s ecosystem. Detecting biosignatures in outer space is one way this search is conducted. To understand the biosignatures to look for and study in space, it is useful to gain a better understanding of life in diverse environments on earth. This research tested the …
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The Search For Volatile Biogenic Emissions In Geothermal Areas
… life outside of the earth’s ecosystem. Detecting biosignatures in outer space is one way this search is conducted. To understand the biosignatures to look for and study in space, it is useful to gain a better understanding of life in diverse environments on earth. This research tested the …
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BIO/ORGANIC COMPOUND DETECTION USING SODIUM SULFATE MINERALS: IMPLICATIONS IN THE SEARCH FOR LIFE ON MARS AND EUROPA
… on their ability to assist in the detection of biosignatures. On Earth, biotic and biotic processes can assist in the formation and deposition of these minerals. A primary objective of these studies is the detection of bio/organic compounds that may be associated with the mineral. These …
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BIO/ORGANIC COMPOUND DETECTION USING SODIUM SULFATE MINERALS: IMPLICATIONS IN THE SEARCH FOR LIFE ON MARS AND EUROPA
… on their ability to assist in the detection of biosignatures. On Earth, biotic and biotic processes can assist in the formation and deposition of these minerals. A primary objective of these studies is the detection of bio/organic compounds that may be associated with the mineral. These …
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Technologies of perception : searches for life and intelligence beyond Earth
… sites beyond Earth might harbor microbes, "biosignatures," radio astronomers searched for extraterrestrial intelligence (SETI) in the form of "technosignatures." This dissertation explores how scientists since the Space Age have constructed experimental assemblages to imagine, relate to, and …
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Investigating Microbial Trace-fossils and Abiotic Alteration in Hydrovolcanic Tuffs of the Fort Rock Volcanic Field, Oregon
… microbes and potentially extraterrestrial biosignatures. Here, the textures, mineralogy, and geochemistry of two continental basaltic hydrovolcanic deposits - Reed Rocks and Black Hills - in the Fort Rock Volcanic Field (FRVF) are investigated. Methods include petrographic microscopy, micro …
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Microtextures of Cyanobacterial Mats in Siliciclastic Sedimentary Environments (Modern & Ancient): Applications to the Search for Life on Mars
… recommendations on the applicability of MISS as biosignatures. Predominantly, I employed instrumentation portable by future rovers. To search for life on other planets, we need to have information on how this life might look. Most astrobiological studies therefore focus on Earthly analogues of …
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CHARACTERIZATION OF HALOPHILIC MICROORGANISMS AND SULFATE SALTS FROM THE HYPERSALINE LAKES OF BRITISH COLUMBIA, CANADA; AN ASTROBIOLOGICAL PERSPECTIVE
… that reflectance IR is capable of detecting biosignatures within a sulfate matrix, the most sensitive of which are the 1550 ± 20 cm'1, C-N, N-H, -COOH absorptions and the 1040 ±10 cm'1C-OH, C-N, PO43' bond features. Due to its sensitivity and non-destructive nature reflectance IR can be …
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Methanogens from Siberian permafrost as models for life on Mars : response to simulated martian conditions and biosignature characterization
… Siberian permafrost, and to characterize their biosignatures by means of Raman spectroscopy, a powerful technology for microbial identification that will be used in the ExoMars mission. For this purpose, methanogens from Siberian permafrost and non-permafrost habitats were subjected to simulated …
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Biosignature storage in sulfate minerals- synthetic and natural investigations of the jarosite group minerals
… the possibility that jarosite can store biosignatures. Natural samples were analyzed by x-ray diffraction, elemental carbon analysis and laser-desorption Fourier transform mass spectrometry (LD-FTMS) and were found to contain the amino acid glycine. Synthetic experiments were conducted in …
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Biosignature storage in sulfate minerals- synthetic and natural investigations of the jarosite group minerals
… the possibility that jarosite can store biosignatures. Natural samples were analyzed by x-ray diffraction, elemental carbon analysis and laser-desorption Fourier transform mass spectrometry (LD-FTMS) and were found to contain the amino acid glycine. Synthetic experiments were conducted in …
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A multi-parameter approach to exoplanet habitability
… will be able to remotely detect potential biosignatures in exoplanet atmospheres and discover signs of life beyond our Solar System. To make the most of the limited observational resources available, target selection has focused on 'habitable worlds' defined as rocky bodies orbiting their …
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A multi-parameter approach to exoplanet habitability
… will be able to remotely detect potential biosignatures in exoplanet atmospheres and discover signs of life beyond our Solar System. To make the most of the limited observational resources available, target selection has focused on 'habitable worlds' defined as rocky bodies orbiting their …
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Anxiety and Anhedonia in Major Depressive Disorder: The Contributing Roles of Neuroticism, Cognitive Control, and Reward Learning
… MDD (N=296) in the Establishing Moderators and Biosignatures of Antidepressant Response in Clinical Care (EMBARC) study, we conducted a path analysis using structural equation modeling to model hypothesized relationships between the constructs of neuroticism, cognitive control, and reward …
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Radiative Transfer in the Martian Environment: In-Situ Results from the MSL Curiosity Rover and Laboratory Experimentation on Martian Regolith and Crystalline Rock Analogs
… materials are potential ecological niches for biosignatures, and this dissertation aims to guide the search for these environments on present day Mars. Studies into the habitability of martian surface analogs typically assess the amount of radiation transmitting perpendicular into a surface. …
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