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Full-Text Articles in Earth Sciences
Accuracy And Practical Considerations For Doubly Labeled Water Analysis In Nutrition Studies Using A Laser-Based Isotope Instrument (Off-Axis Integrated Cavity Output Spectroscopy), Linda M. Reynard, William W. Wong, Noreen Tuross
Accuracy And Practical Considerations For Doubly Labeled Water Analysis In Nutrition Studies Using A Laser-Based Isotope Instrument (Off-Axis Integrated Cavity Output Spectroscopy), Linda M. Reynard, William W. Wong, Noreen Tuross
Geosciences Faculty Publications and Presentations
Background: Given the utility of the doubly labeled water (DLW) method for determination of energy expenditure, additional techniques for isotope analysis of the samples are welcome. Laser-based instruments are one such new analytical tool, but their accuracy and feasibility for DLW studies are grossly understudied.
Objectives: We assessed the accuracy of laser-based isotope ratio measurements as part of the DLW method for estimation of carbon dioxide production rate (rCO2) and total energy expenditure (TEE), in between-group comparison study designs.
Methods: Urine samples from a previous study were analyzed with a laser-based instrument [off-axis integrated cavity output spectroscopy (OA-ICOS)]. …
The Hera Orebody: A Complex Distal (Au–Zn–Pb–Ag–Cu) Skarn In The Cobar Basin Of Central New South Wales, Australia, Corey Wall
Geosciences Faculty Publications and Presentations
The Hera Au–Pb–Zn–Ag deposit in the southeastern Cobar Basin of central New South Wales preserves calc-silicate veins and remnant sandstone/carbonate-hosted skarn within a reduced anchizonal Siluro-Devonian turbidite sequence. The skarn orebody distribution is controlled by a long-lived, basin margin fault system, that has intersected a sedimentary horizon dominated by siliciclastic turbidite, with lesser gritstone and thick sandstone intervals, and rare carbonate-bearing stratigraphy. Foliation (S1) envelopes the orebody and is crosscut by a series of late-stage east–west and north–south trending faults. Skarn at Hera displays mineralogical zonation along strike, from southern spessartine–grossular–biotite–actinolite-rich associations, to central diopside-rich–zoisite–actinolite/tremolite–grossular-bearing associations, through to the northern …
Stable Isotopes Of Water Reveal Differences In Plant – Soil Water Relationships Across Northern Environments, Matthew J. Kohn, James P. Mcnamara
Stable Isotopes Of Water Reveal Differences In Plant – Soil Water Relationships Across Northern Environments, Matthew J. Kohn, James P. Mcnamara
Geosciences Faculty Publications and Presentations
We compared stable isotopes of water in plant stem (xylem) water and soil collected over a complete growing season from five well‐known long‐term study sites in northern/cold regions. These spanned a decreasing temperature gradient from Bruntland Burn (Scotland), Dorset (Canadian Shield), Dry Creek (USA), Krycklan (Sweden), to Wolf Creek (northern Canada). Xylem water was isotopically depleted compared to soil waters, most notably for deuterium. The degree to which potential soil water sources could explain the isotopic composition of xylem water was assessed quantitatively using overlapping polygons to enclose respective data sets when plotted in dual isotope space. At most sites …
A Preliminary Assessment Of Water Partitioning And Ecohydrological Coupling In Northern Headwaters Using Stable Isotopes And Conceptual Runoff Models, James P. Mcnamara
A Preliminary Assessment Of Water Partitioning And Ecohydrological Coupling In Northern Headwaters Using Stable Isotopes And Conceptual Runoff Models, James P. Mcnamara
Geosciences Faculty Publications and Presentations
We combined a conceptual rainfall-runoff model and input–output relationships of stable isotopes to understand ecohydrological influences on hydrological partitioning in snow-influenced northern catchments. Six sites in Sweden (Krycklan), Canada (Wolf Creek; Baker Creek; Dorset), Scotland (Girnock) and the USA (Dry Creek) span moisture and energy gradients found at high latitudes. A meta-analysis was carried out using the Hydrologiska Byråns Vattenbalansavdelning (HBV) model to estimate the main storage changes characterizing annual water balances. Annual snowpack storage importance was ranked as Wolf Creek > Krycklan > Dorset > Baker Creek > Dry Creek > Girnock. The subsequent rate and longevity of melt were reflected in calibrated parameters …
Stable Isotopes And Climate Change, Ray Bradley, Rob Snyder
Stable Isotopes And Climate Change, Ray Bradley, Rob Snyder
IPY STEM Polar Connections
The following description of the role of the study of stable isotopes in water and carbon dioxide molecules when constructing a record of Earth’s pattern of climate change is an excerpt from:
Climate Change and Society by Raymond S. Bradley & Norman E. Law (2001) Nelson Thornes, Cheltenham, UK (ISBN: 0 7487 5823 2)