Radon measurement in karstic waters with Lucas cell technique

Based on Lucas cell technique, the portable device named “PRASSI” (SILENA mod. 5S) was used to realise discrete radon measurements in water samples. The calibration factor is (64.766.9) cpmQBq21 and, with the present set-up for measuring radon in water, the detection and the determination limits are, respectively, 0.007 and 0.020 Bq. Thus, the device is well adapted for determining low radon content in karstic waters. Several discrete radon samplings were performed nearly every week in the three main springs of the Bastareny karstic system (Catalonian Pyrenees, N-E Spain). Thus, it was possible to estimate the reproducibility of the methodology as well as to characterise every spring of the aquifer in relation to their hydrogeological features. With the portable radon monitor, some useful measurements were achieved to estimate radon loss due to degassing process over short distances, with important consequences for radon studies in karstic waters. Lastly, it was possible to perform intensive sampling during a flood and the results point out the great variability of radon levels, closely related to the flow rate trend. That permitted also an intercomparison with other radon probes installed previously in every spring, for continuous radon measurements

Organizational and Leadership Implications for Transformational Development

Transformational development is a concept of change that originated in the Christian context but has now become generally used in the work of both secular and faith-based organizations. The growing use of the concept by organizations that are fundamentally different has naturally led to some confusion about what the concept means and what it takes to effectively implement it. In this article, we describe the key features of the concept and how they are important in determining the organizational requirements for its effective implementation. Drawing on a few cases, the paper highlights the centrality of faith in transformational development work

The trans-ancestral genomic architecture of glycemic traits

Glycemic traits are used to diagnose and monitor type 2 diabetes and cardiometabolic health. To date, most genetic studies of glycemic traits have focused on individuals of European ancestry. Here we aggregated genome-wide association studies comprising up to 281,416 individuals without diabetes (30% non-European ancestry) for whom fasting glucose, 2-h glucose after an oral glucose challenge, glycated hemoglobin and fasting insulin data were available. Trans-ancestry and single-ancestry meta-analyses identified 242 loci (99 novel; P < 5 x 10(-8)), 80% of which had no significant evidence of between-ancestry heterogeneity. Analyses restricted to individuals of European ancestry with equivalent sample size would have led to 24 fewer new loci. Compared with single-ancestry analyses, equivalent-sized trans-ancestry fine-mapping reduced the number of estimated variants in 99% credible sets by a median of 37.5%. Genomic-feature, gene-expression and gene-set analyses revealed distinct biological signatures for each trait, highlighting different underlying biological pathways. Our results increase our understanding of diabetes pathophysiology by using trans-ancestry studies for improved power and resolution.A trans-ancestry meta-analysis of GWAS of glycemic traits in up to 281,416 individuals identifies 99 novel loci, of which one quarter was found due to the multi-ancestry approach, which also improves fine-mapping of credible variant sets.Diabetes mellitus: pathophysiological changes and therap

Fibre reinforcement in earthen construction materials

Earthen construction materials are generally brittle with low tensile strength. To deal with this in practice, it is often proposed that reinforcement be added in the form of fibres of various materials. Construction in earthquake-prone parts of the world is thought to benefit from this form of reinforcement, and indeed fibres (in the form of straw) are a key part of many adobe (unit-based) materials. To remain in harmony with the generally excellent environmental credentials of these materials, the reinforcement should be obtained from a natural material ideally obtained as a waste stream, so natural fibres are often chosen. While some studies have been published on the macroscopic mechanical behaviour of reinforced earthen materials, little is known of what is happening at the interface between the soil matrix and the fibres. In this paper, the authors present laboratory-based studies that attempt to fill this gap, covering pull-out behaviour of natural fibres embedded in earthen construction materials, both stabilised and unstabilised

Mass spectrometry of refractory black carbon particles from six sources: carbon-cluster and oxygenated ions

We discuss the major mass spectral features of different types of refractory carbonaceous particles, ionized after laser vaporization with an Aerodyne high-resolution soot-particle aerosol mass spectrometer (SP-AMS). The SP-AMS was operated with a switchable 1064 nm laser and a 600 °C thermal vaporizer, yielding respective measurements of the refractory and non-refractory particle components. Six samples were investigated, all of which were composed primarily of refractory material: fuel-rich and fuel-lean propane/air diffusion-flame combustion particles; graphite-spark-generated particles; a commercial fullerene-enriched soot; Regal Black, a commercial carbon black; and nascent aircraft-turbine combustion particles. All samples exhibited a spectrum of carbon-cluster ions Cxn+ in their refractory mass spectrum. Smaller clusters (x xn+ distribution. For fullerene soot, fuel-rich-flame particles and spark-generated particles, significant Cxn+ clusters at x &gg; 6 were present, with significant contributions from multiply charged ions (n > 1). In all six cases, the ions C1+ and C3+ contributed over 60% to the total C1+ intensity. Furthermore, the ratio of these major ions C1+ / C3+ could be used to predict whether significant Cxn+ signals with x > 5 were present. When such signals were present, C1+ / C3+ was close to 1. When absent, C1+ / C3+ was < 0.8. This ratio may therefore serve as a proxy to distinguish between the two types of spectra in atmospheric SP-AMS measurements. Significant refractory oxygenated ions such as CO+ and CO2+ were also observed for all samples. We discuss these signals in detail for Regal Black, and describe their formation via decomposition of oxygenated moieties incorporated into the refractory carbon structure. These species may be of importance in atmospheric processes such as water uptake and heterogeneous chemistry. If atmospherically stable, these oxidized species may be useful for distinguishing between different combustion sources. If unstable, they may provide a means to estimate the atmospheric age of an rBC sample. Future studies should attempt to establish which of these scenarios is more realistic