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 9 of 9 for “"leaf wax"”.
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Environmental and biochemical controls on the molecular distribution and stable isotope composition of leaf wax biomarkers
Leaf wax n-alkyl lipids are increasingly used as proxies in palaeoclimate studies. Palaeovegetation assemblages are reconstructed from their molecular distribution patterns, while their δ13C and δ2H signals are thought to reflect plant-environment interactions and palaeohydrological shifts, …
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Holocene variations in the strength of the Indian Monsoon system
… mixed forest type produced a greater amount of leaf wax n-alkanes and a greater fraction of n-C31 and n-C33 alkanes relative to n-C27 and n-C29. Relatively high average chain length (ACL) values (29.6–32.8) for these plants seem common for vegetation from an arid and warm climate. Additionally I …
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Geochemical tools and paleoclimate clues : multi-molecular and isotopic investigations of tropical marine sediments and alpine ice
… records. Compounds derived from vascular plant leaf waxes and delivered to the marine sedimentary environment, including long-chain (C24-C32) nalkanoic acids, were used as proxies for terrestrial vegetation type, aridity, and atmospheric circulation. Marine biomarkers, such as sterols and …
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Geochemical tools and paleoclimate clues : multi-molecular and isotropic investigations of tropical marine sediments and alpine ice
… records. Compounds derived from vascular plant leaf waxes and delivered to the marine sedimentary environment, including long-chain (C24-C32) n-alkanoic acids, were used as proxies for terrestrial vegetation type, aridity, and atmospheric circulation. Marine biomarkers, such as sterols and …
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ADVANCING METHODS FOR APPORTIONING THE SOURCES OF SEDIMENT IN RIVERS: COMBINING SPECTROSCOPY AND STABLE ISOTOPES WITH BAYESIAN MIXING MODELS
… compound-specific isotope analysis (CSIA) of leaf wax n-alkane biomarkers is conducted to demonstrate the apportionment of plant-specific organic matter contributions to streambed sediments. Employing these developments in conjunction with automatic water samplers, high-temporal resolution SPM …
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Localization of monoterpenoid indole alkaloid (MIA) biosynthesis by in situ hybridization (ISH)
… topic of study. Previous work highlighting the leaf epidermis and leaf surface as a highly active area in MIA biosynthesis and MIA accumulation has made the epidermis a major focus of this thesis. This thesis provides an in-depth analysis of the valuable technique of RNA in situ hybridization …
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Towards a coupled δ18O sugar and δ2H n-alkane approach in paleoclimate research
… isotopic composition of (hemi)cellulose and leaf wax-derived lipids, respectively, are increasingly used in paleohydrological and -climate reconstructions. However, previous studies found it challenging to disentangle the effects of past changes in δ18O and δ2H of precipitation (δ18Oprec and …
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The role of wind and water in shaping earth's plateaus
The overarching goal of this dissertation is to provide a better understanding of the role of wind and water in shaping Earth’s Cenozoic orogenic plateaus - prominent high-elevation, low relief sectors in the interior of Cenozoic mountain belts. In particular, the feedbacks between surface uplift, …
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The Use of Biomarker and Stable Isotope Analyses in Palaeopedology / Reconstruction of Middle and Late Quaternary Environmental and Climate History, with examples from Mt. Kilimanjaro, NE Siberia and NE Argentina
… analyzes. Specifically, I focused on plant leaf wax-derived n-alkanes, amino acid enantiomers, stable carbon and nitrogen isotopes (d13C and d15N) in bulk soil organic matter (SOM) and on compound-specific isotope analysis (CSIA) of n-alkanes. The respective methods were partly optimized and …