Atomic force microscopy imaging reveals the formation of ASIC/ENaC cross-clade ion channels

ASIC and ENaC are co-expressed in various cell types, and there is evidence for a close association between them. Here, we used atomic force microscopy (AFM) to determine whether ASIC1a and ENaC subunits are able to form cross-clade hybrid ion channels. ASIC1a and ENaC could be co-isolated from detergent extracts of tsA 201 cells co-expressing the two subunits. Isolated proteins were incubated with antibodies against ENaC and Fab fragments against ASIC1a. AFM imaging revealed proteins that were decorated by both an antibody and a Fab fragment with an angle of ∼120° between them, indicating the formation of ASIC1a/ENaC heterotrimers.J.M.E. and P.J. are supported by Kidney Research U.K. A.P.S. was a member of the University of Cambridge MB/PhD Programme, and was supported by the Jean Shanks Foundation and the James Baird Fund. A research stay of S.H. at Cambridge was supported by a PhD fellowship from the Bayerische Forschungsstiftung

The effect of fluoride on the structure, function, and proteome of intestinal epithelia.

Fluoride exposure is widespread, with drinking water commonly containing natural and artificially added sources of the ion. Ingested fluoride undergoes absorption across the gastric and intestinal epithelia. Previous studies have reported adverse gastrointestinal effects with high levels of fluoride exposure. Here, we examined the effects of fluoride on the transepithelial ion transport and resistance of three intestinal epithelia. We used the Caco-2 cell line as a model of human intestinal epithelium, and rat and mouse colonic epithelia for purposes of comparison. Fluoride caused a concentration-dependent decline in forskolin-induced Cl- secretion and transepithelial resistance of Caco-2 cell monolayers, with an IC50 for fluoride of about 3 mM for both parameters. In the presence of 5 mM fluoride, transepithelial resistance fell exponentially with time, with a t1/2 of about 7 hours. Subsequent imaging by immunofluorescence and scanning electron microscopy showed structural abnormalities in Caco-2 cell monolayers exposed to fluoride. The Young's modulus of the epithelium was not affected by fluoride, although proteomic analysis revealed changes in expression of a number of proteins, particularly those involved in cell-cell adhesion. In line with its effects on Caco-2 cell monolayers, fluoride, at 5 mM, also had profound effects on Cl- secretion and transepithelial resistance of both rat and mouse colonic epithelia. Our results show that treatment with fluoride has major effects on the structure, function, and proteome of intestinal epithelia, but only at concentrations considerably higher than those likely to be encountered in vivo, when much lower fluoride doses are normally ingested on a chronic basis

ClimateBench v1.0: a benchmark for data-driven climate projections

Many different emission pathways exist that are compatible with the Paris climate agreement, and many more are possible that miss that target. While some of the most complex Earth System Models have simulated a small selection of Shared Socioeconomic Pathways, it is impractical to use these expensive models to fully explore the space of possibilities. Such explorations therefore mostly rely on one-dimensional impulse response models, or simple pattern scaling approaches to approximate the physical climate response to a given scenario. Here we present ClimateBench—the first benchmarking framework based on a suite of Coupled Model Intercomparison Project, AerChemMIP and Detection-Attribution Model Intercomparison Project simulations performed by a full complexity Earth System Model, and a set of baseline machine learning models that emulate its response to a variety of forcers. These emulators can predict annual mean global distributions of temperature, diurnal temperature range and precipitation (including extreme precipitation) given a wide range of emissions and concentrations of carbon dioxide, methane and aerosols, allowing them to efficiently probe previously unexplored scenarios. We discuss the accuracy and interpretability of these emulators and consider their robustness to physical constraints such as total energy conservation. Future opportunities incorporating such physical constraints directly in the machine learning models and using the emulators for detection and attribution studies are also discussed. This opens a wide range of opportunities to improve prediction, robustness and mathematical tractability. We hope that by laying out the principles of climate model emulation with clear examples and metrics we encourage engagement from statisticians and machine learning specialists keen to tackle this important and demanding challenge

Impact of integrating disaster risk reduction philosophies into infrastructure reconstruction projects in Sri Lanka

Major impacts on infrastructures due to natural and man-made hazards could result in secondary and additional impacts, compounding the problem for those communities already affected by the hazard. Integration of disaster risk reduction (DRR) philosophies into infrastructure projects has been an important solution to mitigate and prevent such disaster risks, as well as for a speedy recovery after disasters. “Vulnerability reduction” is defined by the research community as an enabler which facilitates the process of DRR. However, there is a research need to identify the most beneficial DRR strategies that would result in vulnerability reduction in an effective way. As part of this main aim, this paper seeks to explore the nature of various vulnerabilities within infrastructure reconstruction projects and their respective communities and to evaluate the DRR practises within these projects. Finally the paper attempts to map the effects of integration of DRR into infrastructure reconstruction on vulnerability reduction of infrastructure reconstruction projects and the communities which benefited from such projects. This study adopts the case study approach and the paper is entirely based on data collated from semi-structured interviews and a questionnaire survey conducted within one case study (a water supply and sanitation reconstruction project) in Sri Lanka and expert interviews conducted in Sri Lanka and the United Kingdom. Results reveal that emergency preparedness strategies are the most important group of DRR strategies, while physical/technical strategies are also very important. However, none of the emergency preparedness strategies are satisfactorily implemented, while most of the physical/technical strategies are adequately implemente