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The moment magnitude (M-w) similar to 7 earthquake that struck Charleston, South Carolina, on 31 August 1886 is the largest historical earthquake in the United States east of the Appalachian Mountains. The fault(s) that ruptured during this earthquake has never been conclusively identified, and conflicting fault models have been proposed. Here we interpret reprocessed seismic reflection profiles, reprocessed legacy aeromagnetic data, and newly collected ground penetrating radar (GPR) profiles to delineate faults deforming the Cretaceous and younger Atlantic Coastal Plain (ACP) strata in the epicentral area of the 1886 earthquake. The data show evidence for faults folding or vertically displacing ACP strata, including apparent displacements of near-surface strata (upper similar to 20 m). Aeromagnetic data show several northeast (NE)-trending lineaments, two of which correlate with faults and folds with vertical displacements as great as 55 m on the seismic reflection and radar profiles. ACP strata show only minor thickness changes across these structures, indicating that much of the displacement postdates the shallowest well-imaged ACP strata of Eocene age. Faults imaged on the seismic reflection profiles appear on GPR profiles to displace the erosional surface at the top of the upper Eocene to Oligocene Cooper Group, including where railroad tracks were bent during the 1886 earthquake. Some faults coincide with changes in river trends, bifurcations of river channels, and unusual river meanders that could be related to recent fault motion. In contrast to our interpreted NE fault trends, earthquake locations and some focal mechanisms in the modern seismic zone have been interpreted as defining a nearly north-striking, west-dipping zone of aftershocks from the 1886 earthquake. The relationship between the modern seismicity and the faults we image is therefore enigmatic. However, multiple faults in the area clearly have been active since the Eocene and deform strata in the upper 20 m, providing potential targets for field-based geologic investigations. Published version Public domain – authored by a U.S. government employee

Oilfield wastewater disposal causes fluid pressure transients that induce earthquakes. Here we show that, in addition to pressure transients related to pumping, there are pressure transients caused by density differences between the wastewater and host rock fluids. In northern Oklahoma, this effect caused earthquakes to migrate downward at ~0.5 km per year during a period of high-rate injections. Following substantial injection rate reductions, the downward earthquake migration rate slowed to ~0.1 km per year. Our model of this scenario shows that the density-driven pressure front migrates downward at comparable rates. This effect may locally increase fluid pressure below injection wells for 10+ years after substantial injection rate reductions. We also show that in north-central Oklahoma the relative proportion of high-magnitude earthquakes increases at 8+ km depth. Thus, our study implies that, following injection rate reductions, the frequency of high-magnitude earthquakes may decay more slowly than the overall earthquake rate., Oilfield wastewater is commonly discarded by pumping it into deep geologic formations, but this process is now known to cause earthquakes. Here, he authors show that high-density oilfield wastewater may sink deeper in the Earth’s crust than previously considered possible, thus increasing fluid pressure and inducing earthquakes for years after injection rates decline.

Background The aim of the BSP090 project is the establishment of European Pharmacopoeia Chemical Reference Substances (CRSs) in combination with corresponding standard ELISA methods for quantification of major allergens in allergen products. Here, we present data of a Phl p 5-specific sandwich ELISA that proved suitable for the quantification of Phl p 5, one of the major Timothy grass (Phleum pratense) pollen allergens. Methods A Phl p 5-specific ELISA system was assessed with respect to accuracy, precision, inter-assay (within laboratory) and inter-laboratory variations, in a ring trial including 14 laboratories in Europe and the USA. Model samples containing recombinant Phl p 5a CRS as well as native grass pollen extracts were analysed. Each participant was instructed to perform at least one preliminary assay to familiarise with the protocol, followed by three independent assays. Results The candidate standard ELISA proved suitable to quantify recombinant and native Phl p 5 with satisfactory precision (93% of results within ±30% acceptance range). Inter-assay variation (max. GCV 24%) and especially inter-laboratory variation (max. GCV 13%) showed conclusive results. When assessing accuracy by means of recovery of recombinant spikes from a grass pollen extract matrix, similarly satisfactory spike recovery results were observed for the two spikes with higher concentrations (all within ±30% acceptance range), whereas recovery of the lowest concentration spike was slightly poorer with mean results of six laboratories exceeding acceptance range. Conclusions Based on the collaborative study results, the assessed Phl p 5-specific immunoassay is appropriate to be proposed as European Pharmacopoeia standard method.

Rationale: Individuals with asthma may be at higher risk of becoming severely ill from COVID-19 which targets the respiratory tract and may cause asthma exacerbations. Serological testing can be useful to assess the true spread of COVID-19 and help protect vulnerable individuals. The SARS-CoV-2 spike and nucleocapsid proteins are the primary viral antigens against which antibodies are raised. We developed an efficient method for production of select SARS-CoV-2 proteins in E. coli to facilitate the development of diagnostics, research, and drug discovery. Methods: SARS-CoV-2 Spike-RBD, full-length Nucleocapsid, and Nucleocapsid RNA binding domain (BD), were expressed in E. coli under IPTG induction. The proteins were purified using multi-step chromatography techniques. The purity of the SARS-CoV-2 proteins was assessed by LC-MS/MS, and their IgG reactivity tested using COVID-19 positive patients’ sera by ELISA. Results: The Spike-RBD and Nucleocapsid proteins were expressed with high yields. The purified proteins had a relative abundance of >95% as assessed by LC-MS/MS with only trace contamination of host cell proteins. All three proteins showed high IgG reactivity (titers >1/10,000) against COVID-19 sera (n=50), with Spike-RBD and Nucleocapsid RNA-BD exhibiting the highest sensitivity. Conclusions: Production of high quality SARS-CoV-2 proteins is feasible in E.coli and the purified proteins will provide useful tools to study the immune responses involved in COVID-19 including antibody and T cell responses, epitope mapping, diagnostics and drug discovery.