Auditing Ranked Voting Elections with Dirichlet-Tree Models: First Steps

Ranked voting systems, such as instant-runo voting (IRV) and single transferable vote (STV), are used in many places around the world. They are more complex than plurality and scoring rules, pre- senting a challenge for auditing their outcomes: there is no known risk- limiting audit (RLA) method for STV other than a full hand count. We present a new approach to auditing ranked systems that uses a sta- tistical model, a Dirichlet-tree, that can cope with high-dimensional pa- rameters in a computationally e cient manner. We demonstrate this ap- proach with a ballot-polling Bayesian audit for IRV elections. Although the technique is not known to be risk-limiting, we suggest some strategies that might allow it to be calibrated to limit risk

BRITICE Glacial Map, version 2: a map and GIS database of glacial landforms of the last British-Irish Ice Sheet

During the last glaciation, most of the British Isles and the surrounding continental shelf were covered by the British–Irish Ice Sheet (BIIS). An earlier compilation from the existing literature (BRITICE version 1) assembled the relevant glacial geomorphological evidence into a freely available GIS geodatabase and map (Clark et al. 2004: Boreas 33, 359). New high-resolution digital elevation models, of the land and seabed, have become available casting the glacial landform record of the British Isles in a new light and highlighting the shortcomings of the V.1 BRITICE compilation. Here we present a wholesale revision of the evidence, onshore and offshore, to produce BRITICE version 2, which now also includes Ireland. All published geomorphological evidence pertinent to the behaviour of the ice sheet is included, up to the census date of December 2015. The revised GIS database contains over 170 000 geospatially referenced and attributed elements – an eightfold increase in information from the previous version. The compiled data include: drumlins, ribbed moraine, crag-and-tails, mega-scale glacial lineations, glacially streamlined bedrock (grooves, roches moutonnées, whalebacks), glacial erratics, eskers, meltwater channels (subglacial, lateral, proglacial and tunnel valleys), moraines, trimlines, cirques, trough-mouth fans and evidence defining ice-dammed lakes. The increased volume of features necessitates different map/database products with varying levels of data generalization, namely: (i) an unfiltered GIS database containing all mapping; (ii) a filtered GIS database, resolving data conflicts and with edits to improve geo-locational accuracy (available as GIS data and PDF maps); and (iii) a cartographically generalized map to provide an overview of the distribution and types of features at the ice-sheet scale that can be printed at A0 paper size at a 1:1 250 000 scale. All GIS data, the maps (as PDFs) and a bibliography of all published sources are available for download from: https://www.sheffield.ac.uk/geography/staff/clark_chris/britice

Regional geochemical patterns in SE Scotland: source lithology, inheritance and glacial overprinting

The Lower Palaeozoic Southern Uplands terrane shows a NE–SW, strike-parallel coincidence of regional geochemical lineaments defined from stream-sediment data, and major lithostratigraphically significant structures. West of Moffat, Silurian strata of the Gala and Hawick groups are divided by geochemical lineaments coincident with the Laurieston Fault. East of Moffat, the geochemical lineaments diverge towards the NE with Gala-type regional geochemistry (high Sr and Ba, low CaO) to the north of the Moffat Valley Fault, whilst Hawick-type regional geochemistry (low Sr and Ba, high CaO) continues to the south of the Laurieston Fault; between the faults lies the recently-defined Ettrick Group. Beyond the eastern end of the Lower Palaeozoic outcrop, its geochemical lineaments extend across the unconformable cover of Devonian ‘Old Red Sandstone’. This is partly a drainage catchment effect, but two other possible explanations are considered: a localized derivation of the Devonian clastic rocks, such that they inherit the compositional patterns of the underlying Lower Palaeozoic sandstones; or a geochemical signature imposed by glacial deposits derived from the Lower Palaeozoic outcrop. The local effect of glacial dispersion is confirmed by the distribution of TiO2; anomalously high levels associated with Carboniferous mafic lavas have been transported NE across the low-TiO2 Carboniferous sedimentary rocks of the Tweed Basin

Bedrock controls on subglacial landform distribution and geomorphological processes : evidence from the Late Devensian Irish Sea Ice Stream

Ice streams play an important role as regulators of the behaviour of modern ice sheets, taking the form of corridors of fast flowing ice. Similar zones of fast moving ice have also been recognised draining the margins of the Late Devensian British and Irish Ice Sheet. Although the geomorphological and sedimentary signatures of palaeo ice streams have received significant attention, allowing the identification of these former ice streams, the influence of bedrock geology on the processes occurring beneath these palaeo ice streams is less well understood, even though subglacial geology has been shown to control the location ice streams within the West Antarctic Ice Steam. This paper highlights the role played by bedrock geology on landform distribution beneath a much older ice stream, the Late Devensian Irish Sea Ice Stream. The spatial relationships displayed between subglacial landforms and bedrock geology are described from Anglesey, northwest Wales, and the Rhins of Galloway, southwest Scotland; both sites occur close to the eastern margin of this Irish Sea Ice Stream. A link has been established between landform morphology and distribution, and the disposition of the main tectonostratigraphical units within the bedrock. Changes in landform morphology are shown to have been locally controlled by large-scale faults and/or major lithological boundaries, with less durable bedrock lithologies controlling the location and lateral extent of relatively faster flowing portions of the ice stream

Investigation into the Pathology of Idiopathic Systemic Amyloidosis in Four Captive Badgers (Meles meles)

Systemic idiopathic amyloidosis was described in four captive badgers (Meles meles). Two animals (B1 and B2) were not enrolled in any trial, while animals B3 and B4 took part in a vaccine efficacy study and had been challenged with Mycobacterium bovis. A full set of tissues was collected and processed routinely for histopathological, immunohistochemical and ultrastructural studies. Splenomegaly was found in three out of four animals. Histopathological evaluation revealed congophilic, permanganate-resistant systemic amyloid deposits in the tissues of all badgers. Animals B2 and B4 displayed a marked granulomatous response to amyloid within the spleen. Animals B1 and B2 also displayed clinicopathological findings suggestive of chronic kidney disease. Ultrastructural examination identified peculiar star-shaped arrays of amyloid. Immunohistochemical studies were unrewarding. Systemic amyloidosis should be considered among the differentials of wasting in captive badgers

Cosmogenic 10Be insights into the extent and chronology of the last deglaciation in Wester Ross, northwest Scotland

Cosmogenic 10Be surface exposure ages for bedrock sites around Torridon and the Applecross Peninsula in Wester Ross, northwest Scotland, provide new insights into the Lateglacial transition. Accounting for postglacial weathering, six statistically comparable exposure ages give a late Younger Dryas (G-1) exposure age of 11.8 ` 1.1 ka. Two further outliers are tentative pre- Younger Dryas exposure ages of 13.4 ` 0.5 ka in Torridon, and 17.5 ` 1.2 ka in Applecross. The Younger Dryas exposure ages have compelling implications for the deglaciation of marginal Loch Lomond Stadial ice fields in Torridon and Applecross. Firstly, they conflict with predictions of restricted ice cover and rapid retreat based on modelling experiments and climate proxies, instead fitting a model of vertically extensive and prolonged ice coverage in Wester Ross. Secondly, they indicate that >2 m of erosion took place in the upper valleys of Torridon and Applecross during the Younger Dryas, implying a dominantly warm-based glacial regime. Finally, the exposure ages have clarified that corrie (cirque) glaciers did not readvance in Wester Ross, following final deglaciation