5,690 research outputs found

    Hard paternalism, fairness and clinical research: why not?

    Get PDF
    Jansen and Wall suggest a new way of defending hard paternalism in clinical research. They argue that non-therapeutic research exposing people to more than minimal risk should be banned on egalitarian grounds: in preventing poor decision-makers from making bad decisions, we will promote equality of welfare. We argue that their proposal is flawed for four reasons. First, the idea of poor decision-makers is much more problematic than Jansen and Wall allow. Second, pace Jansen and Wall, it may be practicable for regulators to uncover the values that a potential research participant holds when agreeing to enter a research project, so their claim that we must ban such research projects for all if we are to ban them for poor decision-makers looks to be unmotivated. Third, there seem to be cases where the liberty to enter the sort of research project Jansen and Wall discuss is morally weighty, and arguably should outweigh concerns of egalitarian distribution. Fourth, banning certain types of research, which seem on the face of it to offer an unfavourable risk-benefit ratio, would have unwelcome consequences for all clinical research, which Jansen and Wall do not recognize

    Multiple origins for mantle harzburgites: examples from the Lewis Hills, Bay of Islands ophiolite, Newfoundland

    Get PDF
    Study in the Bay of Islands ophiolite exposed in the Lewis Hills of Newfoundland has enabled the identification of four major types of harzburgite, which represent examples of a complete spectrum of this rock type. Enrichments and depletions of orthopyroxene by solution-precipitation reactions may result not only in the variety of harzburgite types, which on partial melting might produce a range of melt products, but also in fronts of harzburgite migrating through the mantle. -from Authorspublished_or_final_versio

    Determination of the urinary aglycone metabolites of vitamin K by HPLC with redox-mode electrochemical detection

    Get PDF
    We describe a method for the determination of the two major urinary metabolites of vitamin K as the methyl esters of their agyclone structures, 2-methyl-3-(3-3-carboxymethylpropyl)-1,4-naphthoquinone (5C-side-chain metabolite) and 2-methyl-3-(5-carboxy-3-methyl-2-pentenyl)-1,4-naphthoquinone (7C-side-chain metabolite), by HPLC with electrochemical detection (ECD) in the redox mode. Urinary salts were removed by reversed-phase (C18) solid phase extraction (SPE) and the predominately conjugated vitamin K metabolites hydrolysed with methanolic HCl. The resultant carboxylic acid aglycones were quantitatively methylated with diazomethane and fractionated by normal-phase (silica) SPE. Final analysis was by reversed-phase (C18) HPLC with a methanol-aqueous mobile phase. Metabolites were detected by amperometric, oxidative ECD of their quinol forms, which were generated by post-column coulometric reduction at an upstream electrode. The assay gave excellent linearity (r2 typically = 0.999) and high sensitivity with an on-column detection limit of <3.5 fmol (<1pg). The inter-assay precision was typically 10%. Metabolite recovery was compared to that of an internal standard (2-methyl-3-(7'-carboxy-heptyl)-1,4-naphthoquinone), added to urine samples just before analysis. Using this methodology we confirmed that the 5C- and 7C-metabolite were major catabolites of both phylloquinone (vitamin K1) and menaquinones (vitamin K2) in humans. We propose that the measurement of urinary vitamin K metabolite excretion is a candidate non-invasive marker of total vitamin K status

    PIN8 PATIENT FLOW PATHWAY FOR PATIENTS ADMITTED TO CRITICAL CARE UNITS WITH A SEVERE BACTERIAL INFECTION IN ENGLAND

    Get PDF

    Extrapolating Monte Carlo Simulations to Infinite Volume: Finite-Size Scaling at ξ/L ≫1

    Get PDF
    We present a simple and powerful method for extrapolating finite-volume Monte Carlo data to infinite volume, based on finite-size-scaling theory. We discuss carefully its systematic and statistical errors, and we illustrate it using three examples: the two-dimensional three-state Potts antiferromagnet on the square lattice, and the two-dimensional O(3)O(3) and O(∞)O(\infty) σ\sigma-models. In favorable cases it is possible to obtain reliable extrapolations (errors of a few percent) even when the correlation length is 1000 times larger than the lattice

    Community exposure and vulnerability to water quality and availability: a case study in the mining-affected Pazña Municipality, Lake Poopó Basin, Bolivian Altiplano

    Get PDF
    This is the final version of the article. Available from Springer Verlag via the DOI in this record.Assessing water sources for drinking and irrigation along with community vulnerability, especially in developing and rural regions, is important for reducing risk posed by poor water quality and limited water availability and accessibility. We present a case study of rural mining-agricultural communities in the Lake Poopó Basin, one of the poorest regions on the Bolivian Altiplano. Here, relatively low rainfall, high evaporation, salinization and unregulated mining activity have contributed to environmental degradation and water issues, which is a situation facing many Altiplano communities. Social data from 72 households and chemical water quality data from 27 surface water and groundwater sites obtained between August 2013 and July 2014 were used to develop locally relevant vulnerability assessment methodologies and ratings with respect to water availability and quality, and Chemical Water Quality Hazard Ratings to assess water quality status. Levels of natural and mining-related contamination in many waters (CWQHR ≥ 6; 78% of assessed sites) mean that effective remediation would be challenging and require substantial investment. Although waters of fair to good chemical quality (CWQHR ≤ 5; 22% of assessed sites) do exist, treatment may still be required depending on use, and access issues remain problematic. There is a need to comply with water quality legislation, improve and maintain basic water supply and storage infrastructure, build and operate water and wastewater treatment plants, and adequately and safely contain and treat mine waste. This study serves as a framework that could be used elsewhere for assessing and mitigating water contamination and availability affecting vulnerable populations.This project was funded by the University College London (UCL) Institute for Risk and Disaster Reduction and the Catholic Agency for Overseas Development (CAFOD) under the initiative of water risk and its management in Bolivia’s Altiplano development strategy, which was led by Stephen Edwards. The Natural Environment Research Council Probability, Uncertainty and Risk in the Environment grant PA13-010 (risk visualisation and quantification for enhanced disaster risk reduction) to Stephen Edwards informed the approach to and outputs from the project

    The 1831 eruption of Babuyan Claro that never happened: has the source of the one of the largest volcanic climate forcing events of the nineteenth century been misattributed?

    Get PDF
    The 1831 eruption of Babuyan Claro in the Philippines is regarded as one of the most significant volcanic climate forcing events of the nineteenth century. Modern databases have assigned the eruption a VEI of 4? and Magnitude of 4.7. Our analysis of historical sources, however, suggests that there was no such eruption in 1831 and that this date is the result of a misinterpretation of a traveller’s account which had been taken to be the primary source. We therefore suggest that the 1831 eruption is a false event. In this case, one or more eruptions elsewhere must have been responsible for producing the climate-impacting stratospheric sulphate aerosol in 1831. Our results reveal the need to re-evaluate the hazard assessment of Babuyan Claro volcano and also, potentially, the quantitative treatment of the 1831 stratospheric sulphate aerosol in climate models. The Babuyan Claro example discussed in this paper therefore reinforces a call for the careful analysis of primary historical sources in volcanology

    InGaN nano-ring structures for high-efficiency light emitting diodes

    Get PDF
    A technique based on the Fresnel diffraction effect for the fabrication of nano-scale site-controlled ring structures in InGaN/GaN multi-quantum well structures has been demonstrated. The ring structures have an internal diameter of 500 nm and a wall width of 300 nm. A 1 cm-1 Raman shift has been measured, signifying substantial strain relaxation from the fabricated structure. The 9 nm blueshift observed in the cathodoluminescence spectra can be attributed to band filling and/or screening of the piezoelectric field. A light emitting diode based on this geometry has been demonstrated. © 2005 American Institute of Physics.published_or_final_versio
    • …
    corecore