Recovering the lost gold of the developing world : bibliographic database

This report contains a library of 181 references, including abstracts, prepared for Project R 7120 "Recovering the lost gold of the developing world" funded by the UK' s Department for International Development (DFID) under the Knowledge and Research (KAR) programme. As part of an initial desk study, a literature review of gold processing methods used by small-scale miners was carried out using the following sources; the lSI Science Citation Index accessed via Bath Information and Data Services (BIDS), a licensed GEOREF CD-ROM database held at the BGS's Library in Keyworth and IMMage a CD-ROM database produced by the Institution of Mining and Metallurgy held by the Minerals group ofBGS. Information on the search terms used is available from the author

UV Spectroscopy of Metal-Poor Massive Stars in the Small Magellanic Cloud

The Hubble Space Telescope has provided the first clear evidence for weaker winds of metal-poor massive stars in the Small Magellanic Cloud, confirming theoretical predictions of the metallicity dependence of mass-loss rates and wind terminal velocities. For lower luminosity O-type stars however, derived mass-loss rates are orders of magnitude lower than predicted, and are at present unexplained.Comment: 4 pages, 3 figures. To appear in 'The Impact of HST on European Astronomy', Eds., G. De Marchi & F.D. Macchetto, Astrophysics & Space Science, Springe

The E-ELT Multi-Object Spectrograph: latest news from MOSAIC

There are 8000 galaxies, including 1600 at z larger than 1.6, which could be simultaneously observed in an E-ELT field of view of 40 sq. arcmin. A considerable fraction of astrophysical discoveries require large statistical samples, which can only be obtained with multi-object spectrographs (MOS). MOSAIC will provide a vast discovery space, enabled by a multiplex of 200 and spectral resolving powers of R=5000 and 20000. MOSAIC will also offer the unique capability of more than 10 "high-definition" (multi-object adaptive optics, MOAO) integral-field units, optimised to investigate the physics of the sources of reionization. The combination of these modes will make MOSAIC the world-leading MOS facility, contributing to all fields of contemporary astronomy, from extra-solar planets, to the study of the halo of the Milky Way and its satellites, and from resolved stellar populations in nearby galaxies out to observations of the earliest "first-light" structures in the Universe. It will also study the distribution of the dark and ordinary matter at all scales and epochs of the Universe. Recent studies of critical technical issues such as sky-background subtraction and MOAO have demonstrated that such a MOS is feasible with state-of-the-art technology and techniques. Current studies of the MOSAIC team include further trade-offs on the wavelength coverage, a solution for compensating for the non-telecentric new design of the telescope, and tests of the saturation of skylines especially in the near-IR bands. In the 2020s the E-ELT will become the world's largest optical/IR telescope, and we argue that it has to be equipped as soon as possible with a MOS to provide the most efficient, and likely the best way to follow-up on James Webb Space Telescope (JWST) observations.Comment: 10 pages, 3 Figures, in Ground-based and Airborne Instrumentation for Astronomy VI, 2016, Proc. SPI

Characterisation of Quaternary sediments from East Anglia

This report describes the mineralogical investigations of Quaternary sediments,mainly Cromer Till, collected from East Anglia. The main aim of the work was to characterise the mineralogical and physical properties of the till samples to facilitate correlation between tills from different localities. The clast composition of the samples was determined using a binocular microscope and the mineralogy of the matrix was determined using X-ray diffraction and thermogravimetry. Calibration charts were used to quantify the amount of quartz and calcite present. Cumulative frequency graphs were plotted from the particle-size data to determine the mean, median, standard deviation and skewness. Also ternary sand/silt/clay diagrams were plotted. The Cromer Till samples typically contained 2% gravel (mainly flint, sandstone, quartz and chalk), 45% sand, 31 % silt and 22% clay. The Starston Till contained 12% gravel (mainly flint), 46% sand, 16% silt and 26% clay. The 'Clay' from Sea Palling contained 1 % gravel (mainly flint), 10% sand, 78% silt and 11 % clay. The Lowestoft Till samples had different particle-size distributions and the gravel consisted mainly of chalk.The Crag Clay samples contained 1 % gravel (mainly sandstone), 11 % sand, 49% silt and 39% clay. The Blue Clay samples contained virtually no gravel, 4% sand, 59% silt and 37% silt. The Holocene sample contained 1 % gravel (mainly flint), 21% sand, 39% silt and 39% clay. The CaC03 contents and particle-size distributions of the Cromer Till samples were compared with published data (Lunkka, 1994). Based upon this comparison the samples were tentatively classified as either Walcott Diamicton, Happisburgh Diamicton or Norwich Brickearth. The 'Blue Clay' samples were also tentatively classified as Crag Clay. Recommendations for further work include detailed logging and sampling of coastal sections; collection of large samples for more accurate clast analysis ; and heavy mineral analysis

Hydrogeological and geotechnical rock property characterization from geophysics

Boreholes drilled at Sellafield penetrated a variety of rock units. Core samples and wireline logs indicate that rock mass properties and in situ fluid properties vary from one unit to another, but that properties are relatively uniform for each unit within a particular borehole. Variability is superimposed upon the bulk rock mass properties, however, where faults or zones of fractured rock intersect a borehole. Furthermore, lateral variability within a particular unit may be expected between boreholes and throughout the rock volume. The primary objectives of the work were: to establish a means of determining the spatial heterogeneity and distribution of rock mass and fluid properties using measurements made on core samples and derived from wireline logs; to determine the spatial heterogeneity and distribution of rock mass properties away from boreholes and in three-dimensions, by extrapolating the detailed understanding gained from boreholes into the seismic survey volume; and to develop a visualization model of rock mass properties in three-dimensions. It has been demonstrated that acoustic impedance is the principal property in common between surface seismic and borehole measurements, and that it provides a link between the various scales of measurement. Dynamic rock quality and hydrogeological indices have been developed which allow qualitative comparisons to be made between the boreholes. Empirical relationships have also been established between acoustic impedance and rock quality, and between acoustic impedance and hydrogeological properties. These relationships enable continuous profile quantitative estimations of Rock Mass Rating and hydraulic conductivity to be made from wireline logs, and have allowed these properties to be extrapolated into the seismic acoustic impedance volume, thereby providing three-dimensional visualizations of the spatial heterogeneity of rock mass properties

How auditory experience differentially influences the function of left and right superior temporal cortices

To investigate how hearing status, sign language experience and task demands influence functional responses in the human superior temporal cortices (STC) we collected fMRI data from deaf and hearing participants (male and female), who either acquired sign language early or late in life. Our stimuli in all tasks were pictures of objects. We varied the linguistic and visuospatial processing demands in three different tasks that involved decisions about (1) the sublexical (phonological) structure of the British Sign Language (BSL) signs for the objects; (2) the semantic category of the objects; and (3) the physical features of the objects. Neuroimaging data revealed that in participants who were deaf from birth, STC showed increased activation during visual processing tasks. Importantly, this differed across hemispheres. Right STC was consistently activated regardless of the task whereas left STC was sensitive to task demands. Significant activation was detected in the left STC only for the BSL phonological task. This task, we argue, placed greater demands on visuospatial processing than the other two tasks. In hearing signers, enhanced activation was absent in both left and right STC during all three tasks. Lateralisation analyses demonstrated that the effect of deafness was more task-dependent in the left than the right STC whereas it was more task-independent in the right than the left STC. These findings indicate how the absence of auditory input from birth leads to dissociable and altered functions of left and right STC in deaf participants

The comparison of core and geophysical log measurements obtained in the Nirex investigation of the Sellafield region

The Sellafield region, west Cumbria, is the focus of one of the most thorough geological investigations in the United Kingdom. The Sellafield Site is defined as an area immediately around the potential repository, extending 6.5 km north-south by 8 km eastwest. Twenty six deep boreholes were drilled within the area up to the end of 1995, with a total depth of approximately 28 km. Most of these boreholes have been continuously cored, a total of over 17 kilometres of core, with average core recovery well in excess of 90%. All boreholes were logged with a comprehensive suite of geophysical logs, including many state of the art tools. Laboratory physical property analysis of hundreds of sample cores has been carried out. Pilot studies were carried out to compare and contrast datasets and to investigate the relationships between the different data scales. Various techniques, including fractal analysis and Artificial Neural Networks, were tried in order to explore the relationships of these data at a variety of measurement scales. The pilot study was conducted in two stages: (1) evaluation of the primary controlling factors of the physical properties; (2) testing the validity of ‘Up-scaling’. The rocks of the Borrowdale Volcanic Group provided the most challenging problems due to the physical properties being dominated by fracturing and associated alteration zones. Relationships between data types at different scales were established suggesting that the extrapolation of properties derived from core and wireline logs across three-dimensional seismic grids would allow an understanding of the properties throughout a three-dimensional volum

Sign and speech share partially overlapping conceptual representations

Conceptual knowledge is fundamental to human cognition. Yet the extent to which it is influenced by language is unclear. Studies of semantic processing show that similar neural patterns are evoked by the same concepts presented in different modalities (e.g. spoken words and pictures or text) [1–3]. This suggests that conceptual representations are ‘modality independent’. However, an alternative possibility is that the similarity reflects retrieval of common spoken language representations. Indeed, in hearing spoken language users, text and spoken language are co-dependent [4,5] and pictures are encoded via visual and verbal routes [6]. A parallel approach investigating semantic cognition, shows that bilinguals activate similar patterns for the same words in their different languages [7,8]. This suggests that conceptual representations are ‘language independent’. However, this has only been tested in spoken language bilinguals. If different languages evoke different conceptual representations, this should be most apparent comparing languages that differ greatly in structure. Hearing people with signing deaf parents are bilingual in sign and speech: languages conveyed in different modalities. Here we test the influence of modality and bilingualism on conceptual representation by comparing semantic representations elicited by spoken British English and British Sign Language in hearing early, sign-speech bilinguals. We show that representations of semantic categories are shared for sign and speech, but not for individual spoken words and signs. This provides evidence for partially shared representations for sign and speech, and shows that language acts as a subtle filter through which we understand and interact with the world

Strategies towards robust interpretations of in situ zircon Lu–Hf isotope analyses

The combination of U–Pb and Lu–Hf compositions measured in zircon crystals is a remarkably powerful isotopic couplet that provides measures on both the timing of mineral growth and the radiogenic enrichment of the source from which the zircon grew. The U–Pb age documents the timing of zircon crystallization/recrystallization and Hf isotopes inform on the degree to which the host melt was derived from a radiogenic reservoir (e.g. depleted mantle) versus an unradiogenic reservoir (e.g. ancient continental crust), or some mixture of these sources. The ease of generating large quantities of zircon U–Pb and Lu–Hf data has been in large part facilitated by instrument advances. However, the dramatic increase in time constrained zircon Lu–Hf analyses in the Earth science community has brought to the fore the importance of careful data collection and reduction workflows, onto which robust geological interpretations may be based. In this work, we discuss the fundamentals of Lu–Hf isotopes in zircon, which then allows us to provide a robust, accessible, methodology for the assessment of data quality. Additionally, we discuss some novel techniques for: data visualization — that facilitates better transparency of data interpretation; integration of geographic information — that may reveal spatial trends where temporal trends were only apparent before; and some novel statistical evaluation tools — that may provide more rigorous inter- and intra-sample comparisons