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Showing 1 to 20 of 183 for “"δ13C"”.
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Radiocarbon (Δ14C) and Stable Carbon (δ13C) Isotopic Composition of Dissolved Inorganic Carbon (DIC) in Baffin Bay
… change. Radiocarbon (D14C) and stable carbon (δ13C) measurements of DIC are powerful tools for parameterizing water mass sources, aging and residence times. However, very few DIC Δ14C and d13C data have been reported in the Arctic Ocean, comprising only a handful of stations in the Eurasian …
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Syn-sedimentary tectonostratigraphic influence and isotopic δ18O and δ13C characterization of the Kimmeridgian Akimpech Formation, Campeche-Chiapas Subbasin (Campeche Sound), offshore Mexico.
Carbonate reservoirs are notoriously heterogeneous, with variability driven by both depositional and diagenetic controls. In such reservoirs, conceptual models play an important role in generating understanding and predictive insights. Yet, predictions are only as good as the conceptual models. …
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The physiology, mapping, and prediction of stable carbon isotopes: a proxy trait for water-use efficiency in maize
… between stable carbon isotope ratios (δ13C) and WUE has been well characterized in C3 crops, but only recently gained attention in C4 plants. We observed high correlations between WUE and δ13C in greenhouse grown maize, which is important towards developing an effective method to …
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Genetics of Physiological Traits Associated with Drought Tolerance in Soybean (Glycine max)
… production. For example, carbon isotope ratio (δ13C) is positively correlated with water use efficiency (WUE), and nitrogen isotope ratio (δ15N) is negatively correlated with N2 fixation; canopy temperature (CT) is an indicator for genetic variation in transpiration and stomatal conductance. …
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Western South Atlantic holocene and glacial deepwater hydrography derived from benthic foraminiferal Cd/Ca and stable carbon isotope data
… production. Last glacial maximum (LGM) Cd/Ca and δ13C data indicate a nutrient-depleted intermediate-depth water mass. In the mid-depth western South Atlantic, a simple conversion of LGM δ13C data suggests significantly less nutrient enrichment than LGM Cd/Ca ratios, but Cd/Ca and δ13C data can be …
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A study of indigenous sorghum agriculture in Southern Africa: combining isotope and indigenous knowledge systems approaches
… the present study investigates the variation in δ13C and δ15N in three varieties of sorghum, mshalane, 236 and 308. These were cultivated at four localities in different regions of Eswatini and South Africa, either by small-scale traditional farmers or in accordance with their methods. In …
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A multifaceted approach to identifying targets for the improvement of water-use efficiency in Zea mays
… 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 exists across lines of Z. mays, …
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A comparative study on the effect of acid preparation methodologies on bulk organic materials, and a long-core geochemical palaeoenvironmental reconstruction from South China.
… of the effect of acid treatment on C/N, δ13C and δ15N of organic materials and; ii) the reconstruction of palaeoenvironmental change from a lake sediment sequence from south China, using geochemical proxies. To address these aims, a systematic comparative study was developed to examine …
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Dynamics of baseline stable isotopes within a temperate coastal ecosystem: Relationships and projections using physical and biogeochemical factors
Measurements of carbon (13C/12C; δ13C) and nitrogen (15N/14N; δ15N) stable isotope ratios have become important tools for: estimating energy flow and trophic positions in aquatic foodwebs; comparing food webs; and aiding in the tracking of wide-ranging consumers. However, each of these applications …
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What do paleo-geochemical tracers tell us about the deep ocean circulation during the last ice age?
… of the paleo-data. An end-member analysis of the δ13C data indicates a larger volume of AABW and a smaller volume of Lower NADW during the LGM. It is not yet possible, however, to quantify the extent of the volume differences between the modern and the glacial distributions, because the LGM δ13C …
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A study of the remineralization of organic carbon in nearshore sediments using carbon isotopes
… species were measured in the pore waters: ΣCO2, δ13C-ΣCO2, PO4, ΣH2S, Alk, DOC, and Ca. Measurements of pore water collected seasonally show large gradients with depth, which are larger in summer than in winter. The δ13C (PDB) of ΣCO2 varies from 1.3 o/oo in the bottom water to approximately -10 …
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High Throughput Phenotypic Evaluation of Drought-related Traits in Soybean
… image analysis, carbon isotope discrimination (Δ13C) and oxygen isotope composition (δ18O). Five fast-and five slow-wilting genotypes derived from a cross of Benning × PI416937 were evaluated under three water treatments that included a full and two deficit-irrigation treatments of increasing …
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Soil Stable Carbon Isoptope Analysis of Landscape Features at Aguateca, Guatemala
… analyzed on a mass spectrometer to determine δ13C values. Graphs of the isotopic values were examined and the bulk and humin δ13C enrichment values for the landscape feature categories were compared statistically using ANOVA methods. We determined that the bulk and humin δ13C values of the …
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Tracing mantle degassing along the East African Rift using He and C isotopes: a geospatial approach
Helium (R/Ra) and carbon (δ13C-CO2) isotopes in fluids and lavas were used as tracers to detect mantle-degassing across the East African Rift. From the literature, a database of R/Ra and δ13C-CO2 values was produced with accompanying isotopic and geochemical data. The data was filtered, removing …
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Investigating population structure and resource use diversity in Lake Huron Lake (Coregonus clupeaformis) and Round (Prosopium cylindraceum) Whitefish using compound specific stable isotopes analysis
… marker types. The stable isotopes of carbon (δ13C) and nitrogen (δ15N) are biochemical markers that reflect differences in prey, habitat, and trophic position within food webs making these isotopes valuable in differentiating ecological populations. Bulk stable isotope analysis (BSIA) has been …
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Stable isotope ecology of modern herbivores from Mmabolela, Limpopo
… aim is to investigate and interpret patterns in δ13C, δ15N and δ18O values of different species of herbivores and to compare these results with previous studies. As expected in this summer-rainfall region, δ 13Cbone collagen values fall into two distinct groups: predominant browsers with mean …
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An organic geochemical approach to problems of glacial-interglacial climatic variability
… concentration and carbon isotopic composition (δ13C) of sedimentary organic carbon (Corg), N/C ratios, and terrigenous and marine δ13C-Corg end-members form a basis from which to address problems of Late Quaternary glacial-interglacial climatic variability in a 208.7 m hydraulic piston core …
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Petrography and Diagenesis of Cambrian Dolomite in Tabei Uplift, Northern Tarim Basin, China
… value ranges from -5.7 to -10.0 (‰ vPDB) and δ13C value from 0.0 to -2.0 (‰ vPDB). Type 2 dolomite is very fine- to fine-crystalline replacement dolomite. It consists of non-planar to planar-s, anhedral to subhedral dolomite crystals with δ18O values from -5.7 to -10.0 (‰ vPDB) and δ13C value …
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Small scale hydrogeomorphic features influence macroinvertebrate food webs in two Great Plains rivers
… to reveal hydrogeomorphic relationships with δ13C in the food web, consumer resource use, trophic community metrics and size corrected standard ellipse area (SEAc) a measure of consumer niche breadth. I found river sinuosity and percent fine grain sediment to have a large influence on the food …
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Naturalization of Salt Marsh Restoration Sites in the Elizabeth River, Virginia, Assessed by Feeding Activity and Trophic Level of Mummichogs (<i>Fundulus Heteroclitus</i>)
… gut contents and stable isotopes values (δ13C and δ15N) from mummichogs (Fundulus heteroclitus), the functional equivalency of restored salt marshes compared to natural marshes was measured. In July 2013 I collected mummichogs from three restored and three reference salt marshes in the …
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