Sulfur_X: A Model of Sulfur Degassing During Magma Ascent Ding, Shuo; Plank, Terry; Wallace, Paul J. ...
Geochemistry, geophysics, geosystems : G3,
April 2023, 2023-04-00, 20230401, 2023-04-01, Volume:
24, Issue:
4
Journal Article
Peer reviewed
Open access
The degassing of CO2 and S from arc volcanoes is fundamentally important to global climate, eruption forecasting, ore deposits, and the cycling of volatiles through subduction zones. However, all ...existing thermodynamic/empirical models have difficulties reproducing CO2‐H2O‐S trends observed in melt inclusions and provide widely conflicting results regarding the relationships between pressure and CO2/SO2 in the vapor. In this study, we develop an open‐source degassing model, Sulfur_X, to track the evolution of S, CO2, H2O, and redox states in melt and vapor in ascending mafic‐intermediate magma. Sulfur_X describes sulfur degassing by parameterizing experimentally derived sulfur partition coefficients for two equilibria: RxnI. FeS (m) + H2O (v) → $\to $ H2S (v) + FeO (m), and RxnII. CaSO4(m) → $\to $ SO2 (v) + O2 (v) + CaO (m), based on the sulfur speciation in the melt (m) and co‐existing vapor (v). Sulfur_X is also the first to track the evolution of fO2 and sulfur and iron redox states accurately in the system using electron balance and equilibrium calculations. Our results show that a typical H2O‐rich (4.5 wt.%) arc magma with high initial S6+/ΣS ratio (>0.5) will degas much more (∼2/3) of its initial sulfur at high pressures (>200 MPa) than H2O‐poor ocean island basalts with low initial S6+/ΣS ratio (<0.1), which will degas very little sulfur until shallow pressures (<50 MPa). The pressure‐S relationship in the melt predicted by Sulfur_X provides new insights into interpreting the CO2/ST ratio measured in high‐T volcanic gases in the run‐up to the eruption.
Plain Language Summary
Understanding how CO2 and S are emitted from volcanoes, called degassing, is important in interpreting the CO2/ST gas precursors to volcanic eruptions and quantifying the total amount of gases released into the atmosphere that are climatically important. However, existing models show significant discrepancies in predicting the behavior of sulfur during degassing. In this study, we employ a new approach to describe sulfur behavior during magma degassing and develop a new model, Sulfur_X, that successfully reproduces the distinct S, CO2, and H2O degassing behavior recorded in melts from different volcanoes. Sulfur_X shows that sulfur can either degas early at high pressure or late at low pressure during magma ascent to the surface, depending on the initial sulfur speciation and H2O contents in the magma. In addition, sulfur is one of the most commonly measured volcanic gas components used for volcano monitoring. Therefore, the predicted compositional evolution of co‐existing vapor by Sulfur_X during magma ascent bears directly on the interpretation of CO2/ST ratio measured in high‐T volcanic gases and the development of eruption forecast models.
Key Points
Sulfur_X is a new open‐source magma degassing model that accurately predicts the volatile and redox evolution of ascending arc magmas
Sulfur_X shows that sulfur can start degassing in the lower crust or near‐surface, depending on the initial S6+/ΣS and H2O in the melt
The vapor compositions predicted by Sulfur_X can be used to interpret the CO2/ST ratios in high‐T volcanic gases, an eruption precursor
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Systemic lupus erythematosus (SLE) is an inflammatory, multisystem autoimmune disease of unknown cause that has protean clinical and laboratory manifestations along with a variable course and ...prognosis.
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Approximately 200,000 patients in the United States currently meet the diagnostic criteria for lupus, but up to 500,000 have features that fall on a spectrum that overlaps with that of lupus, such as both undifferentiated and mixed connective-tissue disease and antiphospholipid syndrome. Lupus is associated with multiple complications and is one of the leading causes of death in young women.
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In those between the ages of 15 and 24 years, it is the . . .
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5.
Edmund Lawrence Dubois (1923-1985) Wallace, Daniel J
Rheumatic diseases clinics of North America,
02/2024, Volume:
50, Issue:
1
Journal Article
Peer reviewed
In the year 1950, Edmund Dubois was asked to evaluate eight patients who had positive results from a new blood test known as the LE cell prep. This was the springboard for him to launch a career that ...elucidated new and unique insights into the pathogenesis, clinical presentation, laboratory testing, and treatment of systemic lupus erythematosus. Between 1950 and 1985, he treated more than 2000 patients with the disorder and wrote the principal textbook on the subject.
Sequencing the RNA in a biological sample can unlock a wealth of information, including the identity of bacteria and viruses, the nuances of alternative splicing or the transcriptional state of ...organisms. However, current methods have limitations due to short read lengths and reverse transcription or amplification biases. Here we demonstrate nanopore direct RNA-seq, a highly parallel, real-time, single-molecule method that circumvents reverse transcription or amplification steps. This method yields full-length, strand-specific RNA sequences and enables the direct detection of nucleotide analogs in RNA.
Drug discovery in systemic lupus erythematosus (SLE) has lagged behind other rheumatic diseases, in large part because of difficulty in measuring change or improvement in a disorder that involves ...multiple organ systems to varying degrees at different times. The metrics currently used as primary endpoints are composite indices that rely mainly on disease assessment measures derived before the era of clinical trials of targeted therapies. Only one agent has been approved for the treatment of SLE since 1957. This monograph reviews the evolution of drug development for SLE, problems and pitfalls that have been encountered, and outlines the domains used to evaluate SLE in the clinic. Finally, several initiatives underway to improve clinical trial design are outlined.
Abstract
JWST has revolutionized the field of extragalactic astronomy with its sensitive and high-resolution infrared view of the distant Universe. Adding to the new legacy of JWST observations, we ...present the first NIRCam imaging data release from the JWST Advanced Deep Extragalactic Survey (JADES), providing nine filters of infrared imaging of ∼25 arcmin
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covering the Hubble Ultra Deep Field and portions of Great Observatories Origins Deep Survey South. Utilizing 87 on-sky dual-filter hours of exposure time, these images reveal the deepest ever near-infrared view of this iconic field. We supply carefully constructed nine-band mosaics of the JADES bands, as well as matching reductions of five additional bands from the JWST Extragalactic Medium-band Survey. Combining with existing Hubble Space Telescope imaging, we provide 23-band space-based photometric catalogs and photometric redshifts for ≈47,500 sources. To promote broad engagement with JADES, we have created an interactive
FitsMap
website to provide an interface for professional researchers and the public to experience these JWST data sets. Combined with the first JADES NIRSpec data release, these public JADES imaging and spectroscopic data sets provide a new foundation for discoveries of the infrared Universe by the worldwide scientific community.
To revise the current juvenile idiopathic arthritis (JIA) International League of Associations for Rheumatology (ILAR) classification criteria with an evidence-based approach, using clinical and ...routine laboratory measures available worldwide, to identify homogeneous clinical groups and to distinguish those forms of chronic arthritis typically seen only in children from the childhood counterpart of adult diseases.
The overall project consists of 4 steps. This work represents Step 1, a Delphi Web-based consensus and Step 2, an international nominal group technique (NGT) consensus conference for the new provisional Pediatric Rheumatology International Trials Organization JIA classification criteria. A future large data collection of at least 1000 new-onset JIA patients (Step 3) followed by analysis and NGT consensus (Step 4) will provide data for the evidence-based validation of the JIA classification criteria.
In Step 1, three Delphi rounds of interactions were implemented to revise the 7 ILAR JIA categories. In Step 2, forty-seven questions with electronic voting were implemented to derive the new proposed criteria. Four disorders were proposed: (a) systemic JIA; (b) rheumatoid factor-positive JIA; (c) enthesitis/spondylitis-related JIA; and (d) early-onset antinuclear antibody-positive JIA. The other forms were gathered under the term "others." These will be analyzed during the prospective data collection using a list of descriptors to see whether the clustering of some of them could identify homogeneous entities.
An international consensus was reached to identify different proposed homogeneous chronic disorders that fall under the historical term
. These preliminary criteria will be formally validated with a dedicated project.
We evaluated the performance of the MinION DNA sequencer in-flight on the International Space Station (ISS), and benchmarked its performance off-Earth against the MinION, Illumina MiSeq, and PacBio ...RS II sequencing platforms in terrestrial laboratories. Samples contained equimolar mixtures of genomic DNA from lambda bacteriophage, Escherichia coli (strain K12, MG1655) and Mus musculus (female BALB/c mouse). Nine sequencing runs were performed aboard the ISS over a 6-month period, yielding a total of 276,882 reads with no apparent decrease in performance over time. From sequence data collected aboard the ISS, we constructed directed assemblies of the ~4.6 Mb E. coli genome, ~48.5 kb lambda genome, and a representative M. musculus sequence (the ~16.3 kb mitochondrial genome), at 100%, 100%, and 96.7% consensus pairwise identity, respectively; de novo assembly of the E. coli genome from raw reads yielded a single contig comprising 99.9% of the genome at 98.6% consensus pairwise identity. Simulated real-time analyses of in-flight sequence data using an automated bioinformatic pipeline and laptop-based genomic assembly demonstrated the feasibility of sequencing analysis and microbial identification aboard the ISS. These findings illustrate the potential for sequencing applications including disease diagnosis, environmental monitoring, and elucidating the molecular basis for how organisms respond to spaceflight.
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