Global ETD Search
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Showing 1 to 15 of 15 for “"Carbon Isotope Composition"”.
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Carbonatites as a record of the carbon isotope composition of large igneous province outgassing
… in some cases to major perturbations of Earth’s carbon cycle. However, few observations directly constrain the isotopic composition of carbon released by LIP magmas because carbon isotopes fractionate during degassing, which hampers understanding of the relative roles of mantle versus crustal …
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The Biogeochemistry of Carbon Isotopes in Local Lakes
… of organic matter all involve the transfer of carbon among the carbon-bearing species in the systems. These biogeochemical processes also fractionate the carbon isotope composition, which results in changes to the carbon isotope composition of the dissolved inorganic carbon (DIC) pool. This …
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Diamonds and their mineral inclusions from the Sloan diatremes of the Colorado-Wyoming State Line kimberlite district, North America
… characteristics, inclusion mineralogy and composition, and carbon isotope composition. The relationships between these features are described and interpreted with respect to diamond genesis. The physical characteristics investigated include crystal state, crystal regularity, primary …
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Using oxygen and carbon stable isotopes, 53Mn-53Cr isotope systematics, and petrology to constrain the history of carbonates and water in the CR and CM chondrite parent bodies
… out a petrologic and Mn-Cr isotopic study of carbonates in the paired CM1 chondrites, ALH 84049 and ALH 84051, in an effort to understand the origin and chronology of formation of carbonates in the most heavily altered CM chondrites. Dolomite is strongly compositionally zoned (Ca, Mg, Fe, Mn), …
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The Spatial Distribution of Terrestrial Stable Carbon Isotopes in North America, and the Impacts of Spatial and Temporal Resolution on Static Ecological Models
… resolution on the modeling of terrestrial stable carbon isotopic landscapes (isoscapes). I model the distribution of leaf stable carbon isotope composition (delta<sup>13</sup>C) for the continent of North America at multiple temporal and spatial resolutions. I generate each delta<sup>13</sup>C …
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A multifaceted approach to identifying targets for the improvement of water-use efficiency in Zea mays
… able to screen large quantities of lines. Stable carbon isotope composition (δ13C) has been successfully used to breed for higher WUE in C3 crops. This has not been the case in C4 species due to their more complex photosynthetic mechanism. We present data demonstrating that leaf δ13C variation …
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Physiology, genetics and genomics of drought adaptation in Populus
… showed differences in stomatal conductance and carbon isotope composition in both clones and the F2 progeny. It was also used to discover QTL related to water use efficiency highlighting interesting areas of the genome. Combining QTL discovery and microarray analysis of the two clones in …
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Engineering a Reverse C4 Photosynthetic Pathway in C3 species Arabidopsis thaliana
C4 photosynthesis is a specialised carbon concentrating mechanism that achieves higher rates of photosynthesis. Engineering C4 photosynthesis into C3 plants could improve agronomic features of staple C3 crops. Introducing the biochemistry of C4 photosynthesis is considered a key step in engineering …
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High throughput phenotyping and quantitative genetics of leaf functional traits in C4 grasses
… traits, especially those traits reflected in carbon isotope composition (δ13C) and leaf nitrogen content, as possible avenues for improving crop performance. Further work focusing on the role of leaf functional traits in crop performance and the physiological mechanisms involved in phenotypic …
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Neogene to quaternary foraminifera from the western margin of southern Africa
… to Pleistocene phosphatic sediments. Strontium isotope stratigraphy and planktic foraminifera biostratigraphy provide age control of the Namibian shelf sediments. The planktic indicator species Globoquadrina dehsicens and Globigerinoides bisphericus support strontium isotope stratigraphy results …
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Photosynthesis and transpiration in a dry-land Pinus radiata forest
… explain a seasonal pattern in stable carbon isotope composition (δ¹³C) measured within annual rings of P. radiata from two sites which differed markedly in annual water balance. Over two growing seasons there was good agreement between mean canopy-level cᵢ derived from the tree-ring …
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Investigating the circulation of Southern Ocean deep water masses over the last 1.5 million years by geochemical fingerprinting of marine sediments
… 1.5 million years are investigated using stable carbon isotope $δ^{13}C$ measurements made on the tests of the benthic foraminfer Cibicidoides ($δ^{13}C_{b}$), and the rare earth element concentrations and Neodymium isotope ($ɛ_{Nd}$) values of marine sediments and their authigenic ferromanganese …
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The composition of noble gas and co2 in the european subcontinental lithospheric mantle
… and mixing of volatiles modified the pristine composition of fluids stored in European SCLM and give clues on its geodynamic evolution. Mantle xenoliths from a few key regions where magmatism occurred in different temporal and geodynamic conditions were selected: Lower Silesia (Eger Rift) in SW …
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Investigations on rainfall variability during the late Quaternary based on geochemical analyses of lake sediments from tropical and subtropical southern Africa
… content and periods of low detrital input, carbonatic or evaporitic sedimentation and high autochthonous organic matter content. These alternations are interpreted as changes between relatively humid and arid conditions, respectively. Before c. 75 kyr BP, they seem to follow changes in local …
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Genetic diversity, developmental timing, and physiological efficiency for climate-resilient maize
Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2026-05-01