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"Schultz, Adam"
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Superman : President Luthor
His fame bolstered after helping to rebuild Gotham City after an earthquake, billionaire Lex Luthor decides to run for the highest office in the land, the American presidency.
Global electromagnetic induction constraints on transition-zone water content variations
2009
Hydrating the mantle
Water plays a fundamental role in the Earth's interior, influencing the melting temperature of mantle minerals, the tendency of plumes of mantle melt to form, and the viscosity of the convecting mantle. The electrical conductivity of mantle minerals is influenced significantly by water content. Kelbert
et al
. have used long-period geomagnetic response functions to derive a global-scale three-dimensional model of electrical conductivity variations in the Earth's mantle. Their study reveals variations in the mantle transition zone (at depths of 410–660 km) of approximately one order of magnitude, with high conductivities associated with cold, seismically fast areas where slabs have subducted. This supports the view that at least some of the water in the transition zone has been carried into that region by cold subducting slabs.
Electrical conductivity is highly sensitive to the presence of hydrogen in mantle materials, an important measure as small amounts of water can significantly affect the physical properties of mantle materials, with profound implications for the dynamic and geochemical evolution of the Earth. Here, long-period geomagnetic response functions are used to derive a global-scale three-dimensional model of electrical conductivity variations in the Earth's mantle.
Small amounts of water can significantly affect the physical properties of mantle materials, including lowering of the solidus
1
, and reducing effective viscosity
2
and seismic velocity
3
. The amount and distribution of water within the mantle thus has profound implications for the dynamics and geochemical evolution of the Earth
4
,
5
. Electrical conductivity is also highly sensitive to the presence of hydrogen in mantle minerals
6
. The mantle transition zone minerals wadsleyite and ringwoodite in particular have high water solubility
4
, and recent high pressure experiments show that the electrical conductivity of these minerals is very sensitive to water content
7
,
8
,
9
. Thus estimates of the electrical conductivity of the mantle transition zone derived from electromagnetic induction studies have the potential to constrain the water content of this region. Here we invert long period geomagnetic response functions to derive a global-scale three-dimensional model of electrical conductivity variations in the Earth’s mantle, revealing variations in the electrical conductivity of the transition zone of approximately one order of magnitude. Conductivities are high in cold, seismically fast, areas where slabs have subducted into or through the transition zone. Significant variations in water content throughout the transition zone provide a plausible explanation for the observed patterns. Our results support the view
10
,
11
that at least some of the water in the transition zone has been carried into that region by cold subducting slabs.
Journal Article
Crustal inheritance and a top-down control on arc magmatism at Mount St Helens
by
Bowles-Martinez, Esteban
,
Bedrosian, Paul A
,
Hill, Graham J
in
Ascent
,
Batholiths
,
Crustal structure
2018
In a subduction zone, the volcanic arc marks the location where magma, generated via flux melting in the mantle wedge, migrates through the crust and erupts. While the location of deep magma broadly defines the arc position, here we argue that crustal structures, identified in geophysical data from the Washington Cascades magmatic arc, are equally important in controlling magma ascent and defining the spatial distribution and compositional variability of erupted material. As imaged by a three-dimensional resistivity model, a broad lower-crustal mush zone containing 3–10% interconnected melt underlies this segment of the arc, interpreted to episodically feed upper-crustal magmatic systems and drive eruptions. Mount St Helens is fed by melt channelled around a mid-Tertiary batholith also imaged in the resistivity model and supported by potential–field data. Regionally, volcanism and seismicity are almost exclusive of the batholith, while at Mount St Helens, along its margin, the ascent of viscous felsic melt is enabled by deep-seated metasedimentary rocks. Both the anomalous forearc location and composition of St Helens magmas are products of this zone of localized extension along the batholith margin. This work is a compelling example of inherited structural control on local stress state and magmatism.
Journal Article
Fluid transport and storage in the Cascadia forearc influenced by overriding plate lithology
2022
Subduction of hydrated oceanic lithosphere can carry water deep into the Earth, with consequences for a range of tectonic and magmatic processes. Most of the fluid is released in the forearc where it plays a critical role in controlling the mechanical properties and seismic behaviour of the subduction megathrust. Here we present results from three-dimensional inversions of data from nearly 400 long-period magnetotelluric sites, including 64 offshore, to provide insights into the distribution of fluids in the forearc of the Cascadia subduction zone. We constrain the geometry of the electrically resistive Siletz terrane, a thickened section of oceanic crust accreted to North America in the Eocene, and the conductive accretionary complex underthrust along the margin. We find that fluids accumulate over timescales exceeding 1 My above the plate in metasedimentary units, while the mafic rocks of Siletzia remain dry. Fluid concentrations tend to peak at slab depths of 17.5 and 30 km, suggesting control by metamorphic processes, but also concentrate around the edges of Siletzia, suggesting that this mafic block is impermeable, with dehydration fluids escaping up-dip along the megathrust. Our results demonstrate that the lithology of the overriding crust can play a critical role in controlling fluid transport in a subduction zone.
The lithology of the overriding plate plays a critical role in determining fluid transport in subduction zones, according to magnetotelluric imaging of the impact of the dry, mafic Siletzia terrane on fluids in the Cascadia subduction zone, North America.
Journal Article
A Unique Case of Concurrent, Multilocational Papillary Thyroid Cancer in Hyoid Bone: Case Report
by
Liu, Changxing
,
Schultz, Adam
,
Bhakta, Hanisha
in
Case Report
,
Case Reports
,
ectopic thyroid gland
2024
PTC has a great prognosis with a 5-year survival rate approaching 99% when regionalized. To our knowledge, involvement of the hyoid bone is extremely rare and has only been reported twice in English-language literature. During the following surveillance of post radioactive iodine treatment, with blood thyroglobulin level and TSH levels, the patient's thyroglobulin has been very low, less than 0.5 ng/mL, on every 3 month laboratory test results, and the level of antithyroglobulin antibodies has been less than 1 ng/mL.
Journal Article
Estimating Geomagnetically Induced Currents in Southern Brazil Using 3‐D Earth Resistivity Model
2023
Geomagnetically induced currents (GICs) result from the interaction of the time variation of ground magnetic field during a geomagnetic disturbance with the Earth's deep electrical resistivity structure. In this study, we simulate induced GICs in a hypothetical representation of a low‐latitude power transmission network located mainly over the large Paleozoic Paraná basin (PB) in southern Brazil. Two intense geomagnetic storms in June and December 2015 are chosen and geoelectric fields are calculated by convolving a three‐dimensional (3‐D) Earth resistivity model with recorded geomagnetic variations. The dB/dt proxy often used to characterize GIC activity fails during the June storm mainly due to the relationship of the instantaneous geoelectric field to previous magnetic field values. Precise resistances of network components are unknown, so assumptions are made for calculating GIC flows from the derived geoelectric field. The largest GICs are modeled in regions of low conductance in the 3‐D resistivity model, concentrated in an isolated substation at the northern edge of the network and in a cluster of substations in its central part where the east‐west (E‐W) oriented transmission lines coincide with the orientation of the instantaneous geoelectric field. The maximum magnitude of the modeled GIC was obtained during the main phase of the June storm, modeled at a northern substation, while the lowest magnitudes were found over prominent crustal anomalies along the PB axis and bordering the continental margin. The simulation results will be used to prospect the optimal substations for installation of GIC monitoring equipment.
Journal Article
Screening of urine identifies PLA2G16 as a field defect methylation biomarker for prostate cancer detection
2019
Prostate cancer (PC) is a multifocal disease. DNA methylation alterations are not restricted to the immediate peritumor environment, but spatially widespread in the adjacent and distant histologically normal prostate tissues. In the current study, we utilized high-throughput methylation arrays to identify epigenetic changes in the urine from men with and without cancer.
DNA urine samples were enriched for methylated fragments using MBD methyl-binding antibodies and applied to high density CytoScanHD arrays. Significant loci were validated using quantitative pyrosequencing and binary logistic regression modeling applied to urine sample analyses in a training (n = 83) and validation approach (n = 84). Methylation alterations in prostate tissues using pyrosequencing at the PLA2G16 locus were examined in 38 histologically normal specimens from men with (TA, n = 26) and without (NTA, n = 12) cancer and correlated to gene expression.
Methylation microarrays identified 3,986 loci showing significantly altered methylation in the urine samples from patients with PC compared to those without (TA vs NTA; p<0.01). These loci were then compared against subjects with their prostates removed to exclude non-prostate cell markers yielding 196 significant regions. Multiple CpGs adjacent to PLA2G16 CpG island showed increased methylation in TA compared to NTA (p<0.01) in a large validation study of urine samples. The predictive accuracy of PLA2G16 methylation at CG2 showed the highest predictive value at 0.8 (odds ratio, 1.37; 95% confidence interval, 1.16-1.62; p<0.001). Using a probability cutoff of 0.065, the sensitivity and specificity of the multivariate model was 92% and 35%. When histologically normal prostate tissues/biopsies from patients with PC (TA) were compared to subjects without cancer, significant hypermethylation of PLA2G16 was noted (odds ratio, 1.35; 95% confidence interval, 1.07-1.71; p = 0.01).
PLA2G16 methylation defines an extensive field defect in histologically normal prostate tissue associated with PC. PLA2G16 methylation in urine and prostate tissues can detect the presence of PC.
Journal Article
Osteopathic Manipulative Medicine: A Brief Review of the Hands-On Treatment Approaches and Their Therapeutic Uses
2022
Osteopathic manipulative medicine (OMM) is an emerging practice in the healthcare field with increasing popularity and evidence-based therapy. Osteopathic manipulative treatments (OMT) include hands-on manipulations of different body structures to increase systemic homeostasis and total patient well-being. Indeed, this new realm of the whole patient-based approach is being taught in osteopathic schools around the country, and the osteopathic principles of a mind-body-spirit-based treatment are being instilled in many new Doctor of Osteopathy (D.O.) students. However, despite their proven therapeutic value, there are still many individuals, both in and outside the medical profession, who are unaware (or misinformed) of the therapeutic uses and potential benefits of OMT. Here, we provide a brief introduction to this osteopathic therapeutic approach, focusing on the hands-on techniques that are regularly implemented in the clinical setting. It is becoming increasingly evident that different OMTs can be implemented to enhance patient recovery, both alone and in conjunction with the targeted therapies used in allopathic regimens. Therefore, it may be beneficial to inform the general medical community and educate the public and those associated with the healthcare field about the benefits of using OMT as a treatment modality. OMT is lower-cost, noninvasive, and highly effective in promoting full-body healing by targeting the nervous, lymphatic, immune, and vascular systems. There is a growing body of literature related to osteopathic research and the possible molecular pathways involved in the healing process, and this burgeoning field of medicine is expected to increase in value in the healthcare field. This brief review article explains the frequently utilized OMT modalities and their recognized therapeutic benefits, which underscore the need to understand the possible molecular mechanisms and circulating biomarkers linked to the systemic benefits of osteopathic medicine.
Journal Article
A thermodynamic explanation for black smoker temperatures
2000
There is a remarkable difference between the maximum temperature of black smoker effluent (350 °C–400 °C) and the temperature of the solidifying magma which heats it (∼1,200 °C)
1
,
2
,
3
. It has been suspected
4
for some time that the nonlinear thermodynamic properties of water
5
might be responsible for this discrepancy. Here, we translate this hypothesis into a physical model, by examining the internal temperature structure of convection cells in a porous medium. We demonstrate that, at pressures appropriate to seafloor crust, plumes of pure water form naturally at ∼400 °C for any heat source with temperature greater than ∼500 °C. Higher temperatures are confined to a boundary layer at the base of the convection cell, where the flow is horizontal. The phenomenon is explained analytically using the thermodynamic properties of water, and is illustrated by numerical simulations. Our model predicts the existence of the high-temperature ‘reaction zone’ found in ophiolites
6
and suggests that vent temperatures will remain steady as magma chambers solidify and cool
7
.
Journal Article
Controls on the physics and chemistry of seafloor hydrothermal circulation
1997
By combining direct measurements of the physical properties of diffusely flowing effluent within axial hydrothermal systems
with concurrent sampling of the chemical properties of that effluent, and by considering also the chemistry of unmixed black
smoker endmember fluids from the same hydrothermal systems, the processes of mineral deposition and dissolution can be studied
directly. By referring to the present–day lithology of such areas, it is possible to examine the balance between concurrent
mineral deposition and dissolution processes, and the retention rate of specific mineral assemblages integrated over the history
of the hydrothermal system. Thus details of the episodicity of hydrothermal venting within the system may be revealed. An
example of this method of combining a variety of direct measurements of diffuse and high temperature effluent properties is
given from the TAG hydrothermal field, Mid–Atlantic Ridge. Long time series observations of the physical properties of diffuse
and high temperature effluent reveal the importance both of tidal variability and also the response to changes in the permeability
structure of the system brought about by natural and anthropogenic processes. Several mechanisms are considered to explain
the relationship between ocean tidal loading, solid Earth tidal deformations, and the observed changes in flow within axial
hydrothermal systems.
Journal Article