Calibration of pressure-dependent sensitivity and discrimination in Nier-type noble gas ion sources

The efficiency of many noble gas mass spectrometers to ionize gas species is known to be a function of the pressure of gas in the spectrometer. This work shows how the half plate voltage for maximum He or Ar signal depends on the spectrometer pressure and shows that the half plate voltage for maximum 4He sensitivity does not coincide with the half plate voltage for maximum 3He sensitivity. In addition, half plate voltage has a greater control on sensitivity at higher spectrometer pressures. Variations in He and Ar sensitivity and isotopic discrimination as a function of pressure are due, at least in part, to these variations in the position of maximum sensitivity with respect to half plate voltage. The maximum sensitivity settings shift to lower half plate voltage at high spectrometer pressures, irrespective of if the pressure increase is due to the gas being investigated or a different species. Therefore noble gas mass spectrometers should always be tuned at the maximum possible pressure; measurements at higher pressures should be avoided. Significant errors in the spectrometer sensitivity and discrimination can result from improper tuning and calibration of noble gas mass spectrometers

Developing creative learning through possibility thinking with children aged 3-7

Abstract not available

Quantifying brine assimilation by submarine magmas: Examples from the Galápagos Spreading Centre and Lau Basin

Volatiles are critically important in controlling the chemical and physical properties of the mantle. However, determining mantle volatile abundances via the preferred proxy of submarine volcanic glass can be hampered by seawater assimilation. This study shows how combined Cl, Br, I, K and H2O abundances can be used to unambiguously constrain the dominant mechanism by which melts assimilate seawater-derived components, and provide an improved method for determining mantle H2O and Cl abundances. We demonstrate that melts from the northwest part of the Lau Basin, the Galápagos Spreading Centre and melts from other locations previously shown to have anomalously high Cl contents, all assimilated excess Cl and H2O from ultra-saline brines with estimated salinities of 55±15wt.% salts. Assimilation probably occurs at depths of ~3-6km in the crust when seawater-derived fluids come into direct contact with deep magmas. In addition to their ultra-high salinity, the brines are characterised by K/Cl of <0.2, I/Cl of close to the seawater value (~3×10-6) and distinctive Br/Cl ratios of 3.7-3.9×10-3, that are higher than both the seawater value of 3.5×10-3 and the range of Br/Cl in 43 pristine E-MORB and OIB glasses that are considered representative of diverse mantle reservoirs [Br/Clmantle=(2.8±0.6)×10-3 and I/Clmantle=(60±30)×10-6 (2σ)]. The ultra-saline brines, with characteristically elevated Br/Cl ratios, are produced by a combination of fluid-rock reactions during crustal hydration and hydrothermal boiling. The relative importance of these processes is unknown; however, it is envisaged that a vapour phase will be boiled off when crustal fluids are heated to magmatic temperatures during assimilation. Furthermore, the ultra-high salinity of the residual brine that is assimilated may be partly determined by the relative solubilities of H2O and Cl in basaltic melts. The most contaminated glasses from the Galápagos Spreading Centre and Lau Basin have assimilated ~95% of their total Cl and up to 35-40% of their total H2O, equivalent to the melts assimilating 1000-2000ppm brine at an early stage of their evolution. Dacite glasses from Galapagos contain even higher concentrations of brine components (e.g. 12,000ppm), but the H2O and Cl in these melts was probably concentrated by fractional crystallisation after assimilation. The Cl, Br, I and K data presented here confirm the proportion of seawater-derived volatiles assimilated by submarine magmas can vary from zero to nearly 100%, and that assimilation is closely related to hydrothermal activity. Assimilation of seawater components has previously been recognised as a possible source of atmospheric noble gases in basalt glasses. However, hydrothermal brines have metal and helium concentrations up to hundreds of times greater than seawater, and brine assimilation could also influence the helium isotope systematics of some submarine glasse

Quality Assurance in Swiss University Hospitals: a Survey Among Clinical Department Heads

Objective: To obtain information to help design and implement quality improvement programmes. Design: Questionnaire survey. Setting: Swiss University Hospitals. Setting: Swiss University Hospitals. Study participants: Clinical Department heads. Main outcome measures: Attitudes towards quality assurance and percentage of departments with procedures for measurement and improvement of structure, process and outcome of medical care. Results: Among 138 departments responding, 69 indicated a designated person or group in charge of quality and 57 were involved in collaborative quality improvement programmes. Mortality data at the level of the department was unavailable to 33% of respondents, and data on adverse treatment effects to 67% of them. Most respondents (69%) favoured the use of outcome indicators for quality control; only 13% favoured indicators pertaining to process or structure of care. Among indicators of outcome, patient satisfaction was the preferred indicator (25% of respondents), followed by morbidity (16%) and mortality (12%) data. Conclusion: Although the quality of medical care in Switzerland enjoys an excellent reputation, this study highlights important gaps in the information system and the processes necessary to evaluate quality. Copyright © 1996 Eslevier Science Lt

A comparison of intramuscular diamorphine and intramuscular pethidine for labour analgesia: a two-centre randomised blinded controlled trial.

Intramuscular (i.m.) pethidine is used worldwide for labour analgesia and i.m. diamorphine usage has increased in the UK in the last 15 years. This trial aims to ascertain the relative efficacy and adverse effects of diamorphine and pethidine for labour pain

Young children’s experiences of music and soundings in museum spaces: lessons, trends and turns from the literature

This article considers the value and role of early years music and sound activities in museum spaces – in relation to children themselves, as well as to their families and wider communities. The article reviews literature around early years music and sound activities; early childhood and the museum; and the use of music and sound in museum spaces – reflecting on reconceptualisation’s of the child within museum spaces and in relation to music and sound. In particular, the article highlights gaps in the literature that present an opportunity to explore the role of music and sound with young children (and particularly with so-called ‘hard-to-reach’ communities or families) within museums

Collaborative creativity in instrumental group music learning as a site for enhancing pupil wellbeing

This study explores the nature of the elements that co-influence collaborative creativity in instrumental group music learning and the intrinsic potential for enhancing pupil wellbeing as evidenced in a particular secondary-school (extra-curricular) group instrumental programme Percussion 1. Wenger's Community of Practice (CoP) and Engestrom's Activity Theory (AT) provide an in-depth analytical framework for the analysis of 14 rehearsals, 13 semi-structured interviews and 41 teachers' and pupils' reflective diary entries. Findings support the intrinsic potential for enhancing pupil wellbeing by empowering them through supportive statements and decision-making, and engaging them through the embodiment of music learning

In Search of the Solar Wind Nitrogen Isotope Composition: Analysis of a Gold Plate from the Genesis Spacecraft Concentrator

We report N isotope analysis of a gold plate from the Genesis spacecraft concentrator. We did not find evidence for a light N component in the solar wind

The development of Sonic Pi and its use in educational partnerships: Co-creating pedagogies for learning computer programming

Sonic Pi is a new open source software tool and platform originally developed for the Raspberry Pi computer, designed to enable school children to learn programming by creating music. In this article we share insights from a scoping study on the development of Sonic Pi and its use in educational partnerships. Our findings draw attention to the importance of collaborative relationships between teacher and computer scientist and the value of creative pedagogies for learning computer programming as a live-coded participatory enterprise.We would like to thank Broadcom Foundation and Raspberry Pi Foundation for their funding of this scoping study