113 research outputs found
Insights into the 9 December 2019 eruption of Whakaari/White Island from analysis of TROPOMI SO<sub>2</sub> imagery.
From Europe PMC via Jisc Publications RouterHistory: ppub 2021-06-01, epub 2021-06-18Publication status: PublishedSmall, phreatic explosions from volcanic hydrothermal systems pose a substantial proximal hazard on volcanoes, which can be popular tourist sites, creating casualty risks in case of eruption. Volcano monitoring of gas emissions provides insights into when explosions are likely to happen and unravel processes driving eruptions. Here, we report SO2 flux and plume height data retrieved from TROPOMI satellite imagery before, during, and after the 9 December 2019 eruption of Whakaari/White Island volcano, New Zealand, which resulted in 22 fatalities and numerous injuries. We show that SO2 was detected without explosive activity on separate days before and after the explosion, and that fluxes increased from 10 to 45 kg/s ~40 min before the explosion itself. High temporal resolution gas monitoring from space can provide key insights into magmatic degassing processes globally, aiding understanding of eruption precursors and complementing ground-based monitoring
A demographic decomposition of elderly living arrangements with a Mexican example
Population trends in developing countries raise concern about support for the elderly. The proportion of elderly living with extended kin is an indicator of support. This paper considers the analytic utility of a demographic decomposition of living arrangements of elderly Mexicans into population components which include weights for age and marital composition and corresponding rates or propensities. Separate decompositions for elderly males and females demonstrate the importance of population composition to the makeup of the elderly population who are living with extended kin. The utility of the decomposition for comparative analysis is demonstrated by decomposing gender differences in living arrangements. The higher proportion of women living with extended kin is primarily the result of gender differences in age-specific marital status and only secondarily the results of actual differences in propensities toward this type of living arrangement. The utility and limitations of this analytic tool for comparative research are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42990/1/10823_2004_Article_BF00116824.pd
CP violation in
We study CP violation in decay.
This decay provides a good place to look for CP violation. Some observables are
very sensitive to the electric dipole moment and
therefore can be used to improve the experimental upper bound on .
CP violations in the lepton pair decays of and are also
discussed.Comment: 8 pages, RevTex, UM-P-92/113, OZ-92/3
Order-disorder criticality, wetting, and morphological phase transitions in the irreversible growth of far-from-equilibrium magnetic films
An exhaustive numerical investigation of the growth of magnetic films in
confined -dimensional stripped geometries () is carried out by
means of extensive Monte Carlo simulations. Thin films in contact with a
thermal bath are grown by adding spins with two possible orientations and
considering ferromagnetic (nearest-neighbor) interactions. At low temperatures,
it is observed that the films exhibit ``spontaneous magnetization reversals''
during the growth process. Furthermore, it is found that for the system
is non-critical, while a continuous order-disorder phase transition at finite
temperature takes place in the case. Using standard finite-size scaling
procedures, the critical temperature and some relevant critical exponents are
determined. Finally, the growth of magnetic films in dimensions with
competing short-range magnetic fields acting along the confinement walls is
studied. Due to the antisymmetric condition considered, an interface between
domains with spins having opposite orientation develops along the growing
direction. Such an interface undergoes a localization-delocalization transition
that is the precursor of a wetting transition in the thermodynamic limit.
Furthermore, the growing interface also undergoes morphological transitions in
the growth mode. A comparison between the well-studied equilibrium Ising model
and the studied irreversible magnetic growth model is performed throughout.
Although valuable analogies are encountered, it is found that the
nonequilibrium nature of the latter introduces new and rich physical features
of interest.Comment: 23 pages, 10 figure
Non-dispersive UV Absorption Spectroscopy: A Promising New Approach for in-situ Detection of Sulfur Dioxide
A new type of instrument for in-situ detection of volcanic sulfur dioxide is presented on the basis of non-dispersive UV absorption spectroscopy. It is a promising alternative to presently used compact and low-cost SO2 monitoring techniques, over which it has a series of advantages, including an inherent calibration, fast response times (< 2 s to reach 90 % of the applied concentration), a measurement range spanning about 5 orders of magnitude and small, well-known cross sensitivities to other gases. Compactness, cost-efficiency and detection limit (< 1 ppm, few ppb under favorable conditions) are comparable to other presently used in-situ instruments. Our instrument prototype has been extensively tested in comparison studies with established methods. In autumn 2015, diverse volcanic applications were investigated such as fumarole sampling, proximal plume measurements and airborne measurements several kilometers downwind from the vent on Mt. Etna and White Island. General capabilities and limitations of the measurement principle are discussed, considering different instrument configurations and future applications
CP Violation in Fermion Pair Decays of Neutral Boson Particles
We study CP violation in fermion pair decays of neutral boson particles with
spin 0 or 1. We study a new asymmetry to measure CP violation in decays and discuss the possibility of measuring it
experimentally. For the spin-1 particles case, we study CP violation in the
decays of to octet baryon pairs. We show that these decays can
be used to put stringent constraints on the electric dipole moments of
, and .Comment: 14p, OZ-93/22, UM-93/89, OITS 51
Halogen (Cl, F) release during explosive, effusive, and intrusive phases of the 2011 rhyolitic eruption at Cordón Caulle volcano (Chile)
We investigate sulphur, chlorine and fluorine release during explosive, effusive and intrusive phases the 2011 Cordón Caulle eruption, with a focus on halogen devolatilization. Petrological analysis shows halogen release to have been promoted by isobaric crystallization in slowly-cooled magma that was emplaced in a lava flow and sub-vent intrusion. Fluorine in particular mobilized only after extensive groundmass crystallization and incipient devitrification. By 2017, the gas emitted from vent-proximal fumaroles had hydrothermal compositions, with HCl/HF ratios decreasing with decreasing temperature. We estimate that the eruption could eventually emit up to 0.84 Mt of SO2, 6.3 Mt of HCl, and 1.9 Mt of HF, but only ~7% and ~2% of total HCl and HF were emitted during explosive phases, and significant halogens are yet to be released from the intrusion. Halogen devolatilization and its associated hazards can persist long after the cessation of rhyolite eruptions with complex magma emplacement mechanisms
Venting of a separate CO2-rich gas phase from submarine arc volcanoes: Examples from the Mariana and Tonga-Kermadec arcs
Submersible dives on 22 active submarine volcanoes on the Mariana and Tonga-Kermadec arcs have discovered systems on six of these volcanoes that, in addition to discharging hot vent fluid, are also venting a separate CO2-rich phase either in the form of gas bubbles or liquid CO2 droplets. One of the most impressive is the Champagne vent site on NW Eifuku in the northern Mariana Arc, which is discharging cold droplets of liquid CO2 at an estimated rate of 23 mol CO2/s, about 0.1% of the global mid-ocean ridge (MOR) carbon flux. Three other Mariana Arc submarine volcanoes (NW Rota-1, Nikko, and Daikoku), and two volcanoes on the Tonga-Kermadec Arc (Giggenbach and Volcano-1) also have vent fields discharging CO2-rich gas bubbles. The vent fluids at these volcanoes have very high CO2 concentrations and elevated C/3He and δ 13C (CO2) ratios compared to MOR systems, indicating a contribution to the carbon flux from subducted marine carbonates and organic material. Analysis of the CO2 concentrations shows that most of the fluids are undersaturated with CO2. This deviation from equilibrium would not be expected for pressure release degassing of an ascending fluid saturated with CO2. Mechanisms to produce a separate CO2-rich gas phase at the seafloor require direct injection of magmatic CO2-rich gas. The ascending CO2-rich gas could then partially dissolve into seawater circulating within the volcano edifice without reaching equilibrium. Alternatively, an ascending high-temperature, CO2-rich aqueous fluid could boil to produce a CO2-rich gas phase and a CO2-depleted liquid. These findings indicate that carbon fluxes from submarine arcs may be higher than previously estimated, and that experiments to estimate carbon fluxes at submarine arc volcanoes are merited. Hydrothermal sites such as these with a separate gas phase are valuable natural laboratories for studying the effects of high CO2 concentrations on marine ecosystems
Genetic analyses identify GSDMB associated with asthma severity, exacerbations, and antiviral pathways
Background
The Chr17q12-21.2 region is the strongest and most consistently associated region with asthma susceptibility. The functional genes or single nucleotide polymorphisms (SNPs) are not obvious due to linkage disequilibrium.
Objectives
We sought to comprehensively investigate whole-genome sequence and RNA sequence from human bronchial epithelial cells to dissect functional genes/SNPs for asthma severity in the Severe Asthma Research Program.
Methods
Expression quantitative trait loci analysis (n = 114), correlation analysis (n = 156) of gene expression and asthma phenotypes, and pathway analysis were performed in bronchial epithelial cells and replicated. Genetic association for asthma severity (426 severe vs 531 nonsevere asthma) and longitudinal asthma exacerbations (n = 273) was performed.
Results
Multiple SNPs in gasdermin B (GSDMB) associated with asthma severity (odds ratio, >1.25) and longitudinal asthma exacerbations (P < .05). Expression quantitative trait loci analyses identified multiple SNPs associated with expression levels of post-GPI attachment to proteins 3, GSDMB, or gasdermin A (3.1 × 10−9 < P < 1.8 × 10−4). Higher expression levels of GSDMB correlated with asthma and greater number of exacerbations (P < .05). Expression levels of GSDMB correlated with genes involved in IFN signaling, MHC class I antigen presentation, and immune system pathways (false-discovery rate–adjusted P < .05). rs1031458 and rs3902920 in GSDMB colocalized with IFN regulatory factor binding sites and associated with GSDMB expression, asthma severity, and asthma exacerbations (P < .05).
Conclusions
By using a unique set of gene expression data from lung cells obtained using bronchoscopy from comprehensively characterized subjects with asthma, we show that SNPs in GSDMB associated with asthma severity, exacerbations, and GSDMB expression levels. Furthermore, its expression levels correlated with asthma exacerbations and antiviral pathways. Thus, GSDMB is a functional gene for both asthma susceptibility and severity
Comparison of serum, EDTA plasma and P100 plasma for luminex-based biomarker multiplex assays in patients with chronic obstructive pulmonary disease in the SPIROMICS study
Background:
As a part of the longitudinal Chronic Obstructive Pulmonary Disease (COPD) study, Subpopulations and Intermediate Outcome Measures in COPD study (SPIROMICS), blood samples are being collected from 3200 subjects with the goal of identifying blood biomarkers for sub-phenotyping patients and predicting disease progression. To determine the most reliable sample type for measuring specific blood analytes in the cohort, a pilot study was performed from a subset of 24 subjects comparing serum, Ethylenediaminetetraacetic acid (EDTA) plasma, and EDTA plasma with proteinase inhibitors (P100â„¢).
Methods:
105 analytes, chosen for potential relevance to COPD, arranged in 12 multiplex and one simplex platform (Myriad-RBM) were evaluated in duplicate from the three sample types from 24 subjects. The reliability coefficient and the coefficient of variation (CV) were calculated. The performance of each analyte and mean analyte levels were evaluated across sample types.
Results:
20% of analytes were not consistently detectable in any sample type. Higher reliability and/or smaller CV were determined for 12 analytes in EDTA plasma compared to serum, and for 11 analytes in serum compared to EDTA plasma. While reliability measures were similar for EDTA plasma and P100 plasma for a majority of analytes, CV was modestly increased in P100 plasma for eight analytes. Each analyte within a multiplex produced independent measurement characteristics, complicating selection of sample type for individual multiplexes.
Conclusions:
There were notable detectability and measurability differences between serum and plasma. Multiplexing may not be ideal if large reliability differences exist across analytes measured within the multiplex, especially if values differ based on sample type. For some analytes, the large CV should be considered during experimental design, and the use of duplicate and/or triplicate samples may be necessary. These results should prove useful for studies evaluating selection of samples for evaluation of potential blood biomarkers.
Keywords:
Chronic obstructive pulmonary disease COPD SPIROMICS Biomarkers Blood analytes Multiplex assays P100 plasma Serum EDTA plasma Pilot stud
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