Uplift and Seismicity driven by Magmatic Inflation at Sierra Negra Volcano, Galápagos Islands

Catalogue of detected earthquakes and cGPS uplift timeseries for Sierra Negra Volcano, Galapagos Island

Jahn-Teller stabilization of a "polar" metal oxide surface: Fe3O4(001)

Using ab initio thermodynamics we compile a phase diagram for the surface of Fe3O4(001) as a function of temperature and oxygen pressures. A hitherto ignored polar termination with octahedral iron and oxygen forming a wave-like structure along the [110]-direction is identified as the lowest energy configuration over a broad range of oxygen gas-phase conditions. This novel geometry is confirmed in a x-ray diffraction analysis. The stabilization of the Fe3O4(001)-surface goes together with dramatic changes in the electronic and magnetic properties, e.g., a halfmetal-to-metal transition.Comment: 4 pages, 4 figure

Surface structure, bonding, and dynamics: The universality of zincblende (110) potential energy surfaces

Using a tight-binding, total energy (TBTE) model we examine the hypothesis that the potential energy surfaces (PES) describing the (110) cleavage faces of the tetrahedrally coordinated, zincblende-structure compound semiconductors exhibit a common universal'' form if expressed in terms of suitably scaled parameters. TBTE calculations on both III-V and II-VI compounds reveal a linear scaling with bulk lattice constant of the geometric parameters of the reconstructed surfaces. This scaling is analogous to that found using low-energy, electron-diffraction surface-structure determination. The surface atomic force constants (found from a TBTE calculation) also scale monotonically with the lattice constant. Using TBTE models proposed previously for GaP, GaAs, GaSb, InP, and ZnSe, we find that the force constants scale as the inverse square of the bulk lattice constant. These results suggest that if distances are measured in units of the bulk lattice constant, the PES may be a universal function for the cleavage surface of zincblende-structure compound semiconductors, on average, with small fluctuations from this average occurring in individual materials. 22 refs., 5 figs., 1 tab

GPS constraints on deformation in northern Central America from 1999 to 2017, Part 1 – Time-dependent modelling of large regional earthquakes and their post-seismic effects

We use continuous and campaign measurements from 215 GPS sites in northern Central America and southern Mexico to estimate coseismic and afterslip solutions for the 2009 Mw = 7.3 Swan Islands fault strike-slip earthquake and the 2012 Mw = 7.3 El Salvador and Mw = 7.4 Guatemala thrust-faulting earthquakes on the Middle America trench. Our simultaneous, time-dependent inversion of more than 350 000 daily GPS site positions gives the first jointly consistent estimates of the coseismic slips for all three earthquakes, their combined time-dependent post-seismic effects and secular station velocities corrected for both the coseismic and post-seismic deformation. Our geodetic slip solutions for all three earthquakes agree with previous estimates that were derived via static coseismic-offset modelling. Our time-dependent model, which attributes all transient post-seismic deformation to earthquake afterslip, fits nearly all of the continuous GPS site position time-series within their severalmillimetre position noise. Afterslip moments for the three earthquakes range from 35 to 140 per cent of the geodetic coseismic moments, with the largest afterslip estimated for the 2012 El Salvador earthquake along the weakly coupled El Salvador trench segment. Forward modelling of viscoelastic deformation triggered by all three earthquakes for a range of assumed mantle and lower crustal viscosities suggests that it accounts for under 20 per cent of the observed post-seismic deformation and possibly under 10 per cent

Contemporary Analysis of Malignancies in Women of Child-Bearing Age: An NSQIP Analysis

Background: Recent evidence suggests that cancer incidence among pregnant women is increasing. The pattern of malignancies in pregnant women and how these compare to their nonpregnant counterparts has not been explored. Here we describe the differences in the proportion of resected malignancies in this population. Methods: The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was used to identify women aged 18-49 who underwent an operation for malignancy from 2007-2012. Age-adjusted distribution of specific surgical interventions for malignancy based on ICD-9 codes were compared among pregnant and non-pregnant women using logistic regression analysis. Results: 42,732 subjects with malignancies surgically treated during child-bearing age were identified. 0.33% (n=143) were pregnant. The most common tumors requiring resection were breast (51%), thyroid (17%), and colorectal (9%). The distribution for most cancers was similar between groups. The age-adjusted proportion was significantly increased in breast, major salivary gland and oropharyngeal malignancies (p\u3c0.05). The proportion of resected colorectal cancers was significantly lower in pregnant women (p\u3c0.05; Table 1). Conclusion: This study serves as the first comprehensive and contemporary overview of malignancies resected in women of childbearing age. This study demonstrates that the proportion of resections among pregnant women was significantly greater in breast, major salivary gland and oropharyngeal cancers and lower for colorectal cancers. While these data might represent true differences in cancer incidence, further work is necessary to demonstrate if these are true differences in incidence versus differences in detection and treatment of the pregnant patient

Improving patient notification of solid abdominal viscera incidental findings with a standardized protocol

BACKGROUND: The increasing use of computed tomography (CT) scans in the evaluation of trauma patients has led to increased detection of incidental radiologic findings. Incidental findings (IFs) of the abdominal viscera are among the most commonly discovered lesions and can carry a risk of malignancy. Despite this, patient notification regarding these findings is often inadequate. METHODS: We identified patients who underwent abdominopelvic CTs as part of their trauma evaluation during a recent 1-year period (9/2011-8/2012). Patients with IFs of the kidneys, liver, adrenal glands, pancreas and/or ovaries had their charts reviewed for documentation of the lesion in their discharge paperwork or follow-up. A quality improvement project was initiated where patients with abdominal IFs were verbally informed of the finding, it was noted on their discharge summary and/or were referred to specialists for evaluation. Nine months after the implementation of the IF protocol, a second chart review was performed to determine if the rate of patient notification improved. RESULTS: Of 1,117 trauma patients undergoing abdominopelvic CT scans during the 21 month study period, 239 patients (21.4%) had 292 incidental abdominal findings. Renal lesions were the most common (146 patients, 13% of all patients) followed by hepatic (95/8.4%) and adrenal (38/3.4%) lesions. Pancreatic (10/0.9%) and ovarian lesions (3/0.3%) were uncommon. Post-IF protocol implementation patient notification regarding IFs improved by over 80% (32.4% vs. 17.7% pre-protocol, p = 0.02). CONCLUSION: IFs of the solid abdominal organs are common in trauma patients undergoing abdominopelvic CT scan. Patient notification regarding these lesions is often inadequate. A systematic approach to the documentation and evaluation of incidental radiologic findings can significantly improve the rate of patient notification

Surface electronic structure of the Fe3O4(100): Evidence of a half-metal to metal transition

In situ prepared Fe3O4(100) thin films were studied by means of scanning tunneling microscopy (STM) and spin-polarized photoelectron spectroscopy (SP-PES). The atomically resolved (2×2)R45°wavelike surface atomic structure observed by STM is explained based on density functional theory (DFT) and ab initio atomistic thermodynamics calculations as a laterally distorted surface layer containing octahedral iron and oxygen, referred to as a modified B layer. The work-function value of the Fe3O4(100) surface extracted from the cutoff of the photoelectron spectra is in good agreement with that predicted from DFT. On the Fe3O4(100) surface both the SP-PES measurements and the DFT results show a strong reduction of the spin polarization at the Fermi level (EF) compared to the bulk density of states. The nature of the states in the majority band gap of the Fe3O4 surface layer is analyzed

Changes in arginase isoforms in a murine model of neonatal brain hypoxia-ischemia.

BackgroundArginases (ARG isoforms, ARG-1/ARG-2) are key regulatory enzymes of inflammation and tissue repair; however, their role after neonatal brain hypoxia (H) and hypoxia-ischemia (HI) remains unknown.MethodsC57BL/6 mice subjected to the Vannucci procedure on postnatal day (P9) were sacrificed at different timepoints. The degree of brain damage was assessed histologically. ARG spatiotemporal localization was determined via immunohistochemistry. ARG expression was measured by Western blot and activity spectrophotometrically.ResultsARG isoform expression increased during neurodevelopment (P9-P17) in the cortex and hippocampus. This was suppressed with H and HI only in the hippocampus. In the cortex, both isoforms increased with H alone and only ARG-2 increased with HI at 3 days. ARG activity during neurodevelopment remained unchanged, but increased at 1 day with H and not HI. ARG-1 localized with microglia at the injury site as early as 4 h after injury, while ARG-2 localized with neurons.ConclusionsARG isoform expression increases with age from P9 to P17, but is suppressed by injury specifically in the hippocampus and not in the cortex. Both levels and activity of ARG isoforms increase with H, while ARG-1 immunolabelling is upregulated in the HI cortex. Evidently, ARG isoforms in the brain differ in spatiotemporal localization, expression, and activity during neurodevelopment and after injury.ImpactArginase isoforms change during neurodevelopment and after neonatal brain HI. This is the first study investigating the key enzymes of inflammation and tissue repair called arginases following murine neonatal brain HI. The highly region- and cell-specific expression suggests the possibility of specific functions of arginases. ARG-1 in microglia at the injury site may regulate neuroinflammation, while ARG-2 in neurons of developmental structures may impact neurodevelopment. While further studies are needed to describe the exact role of ARGs after neonatal brain HI, our study adds valuable data on anatomical localization and expression of ARGs in brain during development and after stroke

Genetic identification of cytomegaloviruses in a rural population of Côte d'Ivoire.

BACKGROUND: Cytomegaloviruses (CMVs) are herpesviruses that infect many mammalian species, including humans. Infection generally passes undetected, but the virus can cause serious disease in individuals with impaired immune function. Human CMV (HCMV) is circulating with high seroprevalence (60-100 %) on all continents. However, little information is available on HCMV genoprevalence and genetic diversity in subsaharan Africa, especially in rural areas of West Africa that are at high risk of human-to-human HCMV transmission. In addition, there is a potential for zoonotic spillover of pathogens through bushmeat hunting and handling in these areas as shown for various retroviruses. Although HCMV and nonhuman CMVs are regarded as species-specific, potential human infection with CMVs of non-human primate (NHP) origin, shown to circulate in the local NHP population, has not been studied. FINDINGS: Analysis of 657 human oral swabs and fecal samples collected from 518 individuals living in 8 villages of Côte d'Ivoire with generic PCR for identification of human and NHP CMVs revealed shedding of HCMV in 2.5 % of the individuals. Determination of glycoprotein B sequences showed identity with strains Towne, AD169 and Toledo, respectively. NHP CMV sequences were not detected. CONCLUSIONS: HCMV is actively circulating in a proportion of the rural Côte d'Ivoire human population with circulating strains being closely related to those previously identified in non-African countries. The lack of NHP CMVs in human populations in an environment conducive to cross-species infection supports zoonotic transmission of CMVs to humans being at most a rare event