A5014678224- Geological and Geochemical Analysis
- earthquake and tectonic studies
- Astro and Planetary Science
- Geochemistry and Geologic Mapping
- High-pressure geophysics and materials
- Geology and Paleoclimatology Research
- Paleontology and Stratigraphy of Fossils
- Planetary Science and Exploration
- Geochemistry and Elemental Analysis
- Ethics in Clinical Research
- Origins and Evolution of Life
- Cardiac, Anesthesia and Surgical Outcomes
- Geomagnetism and Paleomagnetism Studies
- Geological Studies and Exploration
- Marine and environmental studies
- Mineralogy and Gemology Studies
- Nuclear physics research studies
- Anesthesia and Pain Management
- Geological and Geophysical Studies
- Data Quality and Management
- Patient-Provider Communication in Healthcare
- Electronic Health Records Systems
- Wildlife Ecology and Conservation
- Nuclear materials and radiation effects
- Microbial Metabolic Engineering and Bioproduction
Planetary Science Institute
2016-2025
University of California, Los Angeles
2016-2025
The University of Texas at Austin
2024
Wildlife Management International
2015-2023
National Institute for Health and Care Excellence
2023
University of Nebraska Medical Center
2023
Clemson University
2023
Los Angeles City College
2020
University of California System
2020
California State University, San Marcos
2019
Significance Evidence for carbon cycling or biologic activity can be derived from isotopes, because a high 12 C/ 13 C ratio is characteristic of biogenic due to the large isotopic fractionation associated with enzymatic fixation. The earliest materials measured isotopes at 3.8 Ga are isotopically light, and thus potentially biogenic. Because Earth’s known rock record extends only ∼4 Ga, earlier periods history accessible through mineral grains deposited in later sediments. We report graphite...
The Great Unconformity, a profound gap in Earth’s stratigraphic record often evident below the base of Cambrian system, has remained among most enigmatic field observations Earth science for over century. While long associated directly or indirectly with occurrence earliest complex animal fossils, conclusive explanation formation and global extent Unconformity elusive. Here we show that is set large oxygen hafnium isotope excursions magmatic zircon suggest late Neoproterozoic crustal erosion...
The widespread presence of ribonucleic acid (RNA) catalysts and cofactors in Earth's biosphere today suggests that RNA was the first biopolymer to support Darwinian evolution. However, most "path-hypotheses" generate building blocks for require reduced nitrogen-containing compounds not made useful amounts CO2-N2-H2O atmospheres Hadean. We review models impact history invoke a single ~10^23 kg impactor (Moneta) account measured platinum, gold, other siderophilic ("iron-loving") elements on...
<h3>Importance</h3> Patients increasingly demand transparency in and control of how their medical records biospecimens are shared for research. How much they willing to share what factors influence sharing preferences remain understudied real settings. <h3>Objectives</h3> To examine whether various presentations consent forms associated with differences electronic health record biospecimen rates these vary according user interface design, data recipients, items, patient characteristics....
Research Article| August 01, 2017 Hadean Zircon Petrochronology T. Mark Harrison; Harrison Department of Earth, Planetary and Space Sciences, University California, Los Angeles, CA 90095, USA Search for other works by this author on: GSW Google Scholar Elizabeth A. Bell; Bell Patrick Boehnke Reviews in Mineralogy Geochemistry (2017) 83 (1): 329–363. https://doi.org/10.2138/rmg.2017.83.11 Article history first online: 10 Nov Cite View This Citation Add to Manager Share Icon Facebook Twitter...
Research Article| August 23, 2017 Zircon age-temperature-compositional spectra in plutonic rocks Kyle M. Samperton; Samperton * 1Department of Geosciences, Princeton University, Princeton, New Jersey 08544, USA *Current address: Nuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA; E-mail: samperton1@llnl.gov. Search for other works by this author on: GSW Google Scholar Elizabeth A. Bell; Bell 2Department Earth,...
Background: Implementation of patient preferences for use electronic health records research has been traditionally limited to identifiable data. Tiered e-consent de-identified data deemed unnecessary or impractical implementation in clinical settings. Methods: We developed a web-based tiered informed consent tool called and bio-sample (iCONCUR) that honors granular record research. piloted this 4 outpatient clinics an academic medical center. Results: Of patients offered access iCONCUR, 394...
Double-Wien filter-selection-aperture and hexapole-collision-cell technologies coupled to laser ablation multicollector inductively plasma mass spectrometry (LA-MC-ICP-MS/MS) enables in situ analysis of 87 Sr variations produced by Rb decay.
Lunar rock fragments, particularly those deemed pristine, have long been considered vital records of the Moon's formation and magmatic evolution. These fragments were thought to largely escaped intense impact history, offering a window into early lunar crust. However, concept "pristine" is increasingly debated, as traditional criteria for identifying pristine samples—based on texture, mineral content, siderophile element abundances—may overlook extensive effects reworking. In this study, we...
In paleogeographic reconstructions of the Columbia and Rodinia Supercontinents, position Greater India landmass is ambiguous. This, coupled with a limited understanding tectonic evolution mobile belts along which mosaic crustal domains in accreted, impedes precise correlation among dispersed fragments supercontinent reconstructions. Using structural, metamorphic phase equilibria, chronological geochemical investigations, this study aims to reconstruct Chottanagpur Gneiss Complex (CGC) as...
Significance To understand early Earth’s habitability, we need to know when the continental crust first formed. However, due combined actions of plate tectonics and erosion, most evidence has been destroyed. shed light on this debate, analyzed strontium isotopic composition apatite inclusions in zircons from Nuvvuagittuq, Canada, where independent suggests a crust-forming event prior 4.2 Ga, possibly as 4.4 Ga. Our results show that had high Rb/Sr ratio therefore silica content. This Earth...
Research Article| March 01, 2018 Secondary magnetic inclusions in detrital zircons from the Jack Hills, Western Australia, and implications for origin of geodynamo Benjamin P. Weiss; Weiss 1Department Earth, Atmospheric, Planetary Sciences, Massachusetts Institute Technology, Cambridge, 02139, USA Search other works by this author on: GSW Google Scholar Roger R. Fu; Fu 2Department Earth Harvard University, 02138, Joshua F. Einsle; Einsle 3Department University Cambridge CB2 3EQ,...
Zircon crystals from the Jack Hills, Western Australia, are one of few surviving mineralogical records Earth's first 500 million years and have been proposed to contain a paleomagnetic record Hadean geodynamo. A prerequisite for preservation magnetization is presence primary magnetic inclusions within pristine igneous zircon. To date no images recorders ancient zircon presented. Here we use high-resolution transmission electron microscopy demonstrate that all observed secondary features...