3 results
A comparison of seismic and radar methods to establish the thickness and density of glacier snow cover
- Adam D. Booth, Andrew Mercer, Roger Clark, Tavi Murray, Peter Jansson, Charlotte Axtell
-
- Journal:
- Annals of Glaciology / Volume 54 / Issue 64 / 2013
- Published online by Cambridge University Press:
- 26 July 2017, pp. 73-82
-
- Article
-
- You have access Access
- HTML
- Export citation
-
We show that geophysical methods offer an effective means of quantifying snow thickness and density. Opportunistic (efficient but non-optimized) seismic refraction and ground-penetrating radar (GPR) surveys were performed on Storglaciären, Sweden, co-located with a snow pit that shows the snowpack to be 1.73 m thick, with density increasing from ∼120 to ∼500 kg m–3 (with a +50 kg m–3 anomaly between 0.73 and 0.83 m depth). Depths estimated for two detectable GPR reflectors, 0.76 ±0.02 and 1.71 ± 0.03 m, correlate extremely well with ground-truth observations. Refraction seismic predicts an interface at 1.90 ± 0.31 m depth, with a refraction velocity (3730 ± 190 ms–1) indicative of underlying glacier ice. For density estimates, several standard velocity-density relationships are trialled. In the best case, GPR delivers an excellent density estimate for the upper snow layer (observed = 321 ± 74 kg m–3, estimated = 319 ± 10 kgm–3) but overestimates the density of the lower layer by 20%. Refraction seismic delivers a bulk density of 404 ±22 kgm–3 compared with a ground-truth average of 356 ± 22 kg m–3. We suggest that geophysical surveys are an effective complement to mass-balance measurements (particularly for controlling estimates of snow thickness between pits) but should always be validated against ground-truth observations.
two - Pedagogies of hope: the Gypsy Council and the National Gypsy Education Council
- Edited by Andrew Ryder, Budapesti Corvinus Egyetem, Sarah Cemlyn, University of Bristol, Thomas Acton
-
- Book:
- Hearing the Voices of Gypsy, Roma and Traveller Communities
- Published by:
- Bristol University Press
- Published online:
- 04 March 2022
- Print publication:
- 08 October 2014, pp 29-48
-
- Chapter
- Export citation
-
Summary
This chapter provides an account of the formation in the 1960s and development of the Gypsy Council and its successor organisations (Figure 2.1). Most accounts of the origins, trajectories and achievements of Romani organisations concentrate upon the story of how they interacted with state authorities and what result they had upon the overt policy and actions of the local and central state and, more recently, transnational organisations. Over the last 25 years narratives have been set within the banal discourse of the ‘NGO’. Although the phrase ‘non-governmental organisation’ appeared in the UN Charter of 1945 (in a rather different context), the acronym NGO was popularised only in the 1980s, through the abbreviation of the somewhat more euphonious acronym the ‘QUANGO’, or ‘quasi-autonomous non-governmental organisation’. That phrase, first used in 1967, was itself acronymised only in 1969 (Pifer, 1987), but was picked up by right-wing governments, such as the Heath government (1970–74) in the UK as the welfare state staggered under the twin shocks of the oil price rises and the rapid growth in the number of old-age pensioners and sought to outsource welfare provision to independent agencies that it nevertheless had to fund. Acknowledging that they were only quasi-autonomous, however, meant that the government was still held accountable for their performance. Neoliberal discourse swiftly dropped the ‘quasi’ bit, and reinvented government as the righteous, avenging popular regulator of the agencies that perpetually failed to manage the poor on the budgets they are given. The modern use of the term ‘NGO’ invites one to consider them only in relation to governments. How strange it is that at the very moment when the last major version of state utopian authoritarianism lost legitimacy in 1989, the neoliberal ascendancy was able thus to appropriate an inverted vision of the ubiquity of the state. Most of the Romani organisations bravely and ineffectually (according to some) taking grants across Europe to cover for the failings of the welfare state might better be termed ‘wholly non-autonomous fully funded non-governmental organisations’ (WONNAFFUNGOs).
The Gypsy Council, from its foundation in 1966 down to its local offshoots, and the two Gypsy Councils which dispute the title to be its legitimate successor today, have never been one of these WONAFFUNGOs.
8 - Levosimendan
-
- By Scott Mercer, Pharmacy St Thomas' Hospital Lambeth Palace Road London SEI 7EH UK, Andrew Rhodes, St George's Hospital Blackshaw Road London SW17 0QT UK
- Edited by Jeremy Cashman, Michael Grounds
-
- Book:
- Recent Advances in Anaesthesia and Intensive Care
- Published online:
- 15 December 2009
- Print publication:
- 18 October 2007, pp 131-142
-
- Chapter
- Export citation
-
Summary
Calcium sensitisers are a new class of positive inotropic drugs that are potentially useful in the treatment of acute decompensated heart failure. They have a unique mechanism of action that differs from other available intravenous agents such as dobutamine, a β-agonist, and milrinone, a phosphodiesterase inhibitor. Unlike dobutamine and milrinone, calcium sensitisers increase myocardial contractility without increasing cytosolic calcium release, reducing myocardial energy demand and the incidence of serious arrhythmias. Clinical trials have focused on demonstrating improved survival with levosimendan when compared to placebo and dobutamine. Levosimendan is the first intravenous calcium sensitiser to be approved in Europe for the treatment of acute decompensated heart failure.
Pharmacology
Chemical structure
Levosimendan is a pyridazinone-dinitrile derivative with the chemical name ((R) − (4-(1,4,5,6-tetrahydro-4-methyl-6-oxo-3-pyridazinyl)-phenyl)hydrazono)propanedinitrile. Levosimendan is the levo-isomer of the racemic compound simendan. It is moderately lipophilic with a small molecular weight (280.29) and is a weak acid (pKa 6.26).
Pharmacological action
β-adrenergic agonists and phosphodiesterase inhibitors produce positive inotropic effects by increasing intracellular concentrations of free calcium. This energy-dependent process involves increasing the intracellular concentration of cyclic adenosine monophosphate (cAMP). Levosimendan has a dual mechanism of action, acting as a positive inotrope and a vasodilator. The positive inotropic effect of levosimendan is achieved by calcium sensitisation rather than increasing intracellular free calcium concentration, therefore avoiding the energy-dependent process. Levosimendan binds to cardiac troponin C and stabilises the conformational changes of troponin C, facilitating actin-myosin cross-bridge formation. This binding occurs in a calcium concentration-dependent manner.