Above-ground thermonuclear weapons testing from 1952 through 1962 nearly doubled the concentration of radiocarbon ((14)C) in the atmosphere. As a result, organic material formed during or after this period may be radiocarbon-dated using the abrupt rise and steady fall of the atmospheric (14)C concentration known as the bomb-curve. We test the accuracy of accelerator mass spectrometry radiocarbon dating of 29 herbivore and plant tissues collected on known dates between 1905 and 2008 in East Africa. Herbivore samples include teeth, tusks, soft tissue, hair, and horn. Tissues formed after 1955 are dated to within 0.3-1.3 y of formation, depending on the tissue type, whereas tissues older than ca. 1955 have high age uncertainties (>17 y) due to the Suess effect. (14)C dating of tissues has applications to stable isotope (paleo)ecology and wildlife forensics. We use data from 41 additional samples to determine growth rates of tusks, molars, and hair, which improve interpretations of serial stable isotope data for (paleo)ecological studies. (14)C dating can also be used to calculate the time interval represented in periodic histological structures in dental tissues (i.e., perikymata), which in turn may be used as chronometers in fossil teeth. Bomb-curve (14)C dating of confiscated animal tissues (e.g., ivory statues) can be used to determine whether trade of the item is legal, because many Convention of International Trade of Endangered Species restrictions are based on the age of the tissue, and thus can serve as a powerful forensic tool to combat illegal trade in animal parts.
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http://dx.doi.org/10.1073/pnas.1302226110 | DOI Listing |
Kidney360
November 2024
The Departments of Medicine, Veterans Affairs Palo Alto Healthcare System and Stanford University, Palo Alto, CA, USA 94304.
Background: Hemodialysis may excessively remove valuable solutes. Untargeted metabolomics data from a prior study suggested that ergothioneine was depleted in the plasma of hemodialysis subjects. Ergothioneine is a dietary-derived solute with antioxidant properties.
View Article and Find Full Text PDFAnal Chem
January 2025
Instrumental Analytical Chemistry, University of Duisburg-Essen, Universitätsstraße 5, 45141 Essen, Germany.
Compound-specific stable isotope analysis (CSIA) using liquid chromatography-isotope ratio mass spectrometry (LC-IRMS) is a powerful tool for determining the isotopic composition of carbon in analytes from complex mixtures. However, LC-IRMS methods are constrained to fully aqueous eluents. Previous efforts to overcome this limitation were unsuccessful, as the use of organic eluents in LC-IRMS was deemed impossible.
View Article and Find Full Text PDFGlob Chang Biol
January 2025
Department of Surface Waters-Research and Management, EAWAG, Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland.
The primary production of fjords across the Arctic and Subarctic is undergoing significant transformations due to the climatically driven retreat of glaciers and ice sheets. However, the implications of these changes for upper trophic levels remain largely unknown. In this study, we employ both bulk and compound-specific stable isotope analyses to investigate how shifts at the base of fjord food webs impact the carbon and energy sources of consumers.
View Article and Find Full Text PDFMater Today Bio
February 2025
Department of Nuclear Medicine, Gansu Provincial Cancer Hospital, Lanzhou, Gansu, 730050, China.
Liposomal nanocarriers are able to carry peptides for efficient and selective delivery of radioactive tracer and drugs into the tumors. Angiopoietin 2 (ANGPT2) is an excellent biomarker for precise diagnosis and therapy of glioma. The present study aimed to design ANGPT2-specific peptides to modify the surface of nanoliposomes containing doxorubicin (Dox) for integrative imaging and targeting therapy of glioma.
View Article and Find Full Text PDFFront Plant Sci
January 2025
Faculty of Agricultural, Environmental and Food Sciences, Free University of Bolzano, Bolzano, Italy.
The ecophysiological and ecohydrological impacts of climate change and progressively increasing atmospheric carbon dioxide (CO) concentration on agroecosystems are not well understood compared to the forest ecosystems. In this study, we utilized the presence of old apple and pear trees in the alpine valleys of Northern Italy (maintained for cultural heritage purposes) to investigate climate-scale physiological responses. We developed long-term tree-ring stable isotopic records (δC and δO) from apple (1976-2021) and pear trees (1943-2021).
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