Following May’s speech, we now have a clear picture of what an EU-UK free trade agreement could look like

With Theresa May indicating that the UK will leave the single market following its exit from the EU, what kind of agreement is likely to be on the table during the Brexit negotiations? Mark Manger writes that the general parameters of an EU-UK free trade agreement can now be sketched out, but that the government is still demonstrating a lack of understanding when it comes to essential trade policy principles

David Davis has demonstrated a decidedly muddled understanding of trade policy

One of the arguments made by the Leave campaign during the UK’s referendum was that Brexit would allow Britain to negotiate trade deals with other countries around the world more quickly than would be possible via the EU. Mark Manger writes that the plans outlined so far by David Davis, the UK’s new ‘Brexit Secretary’, indicate this is likely to be a key priority for Theresa May’s government. However, he argues that the model put forward by Davis illustrates considerable confusion about how trade policy works in practice

The EU isn't protectionist - it's one of the most open economies in the world

US President Donald Trump recently criticised the EU for being protectionist, and several political figures in the UK have suggested that Brexit will allow the country to remove protectionist tariffs and regulations to boost trade. But how accurate is this claim in reality? Using data on various aspects of trade, Mark Manger and Atom Vayalinkal argue that the EU is ..

Age and Correlation of the Moorefield Shale (Upper Mississippian) in its Type Area, Northeastern Arkansas

The name Moorefield was proposed by Adams and Ulrich (1904) for exposures of gray to brown, phosphatic shale with a basal limestone, overlying the Lower Mississippian Boone Formation, and underlying the Upper Mississippian Batesville Sandstone, in the vicinity of Moorefield, Independence County, northeastern Arkansas. Gordon (1944) 1) restricted the name Moorefield to the lower limestone-bearing interval, 2) applied a new name, Ruddell, to the succeeding shale section that comprises the bulk of the interval, with a type area near Moorefield, and 3) interpreted the interval contacts as unconformities. The name Ruddell was used for the revised Geological Map of Arkansas (1993), but later publications by the Arkansas Geological Survey and other sources refer the entire interval to the Moorefield Shale, and report a maximum thickness of 91.44 m. (300 feet). Age assignments for the Moorefield Shale are based almost entirely on ammonoid cephalopods (e.g. Gordon 1965, Saunders et al. 1977, Korn and Titus 2011). Brachiopods (e.g. Girty 1911) have provided a supporting role, but never to the precision of the ammonoids. Initially, Gordon (1965) recognized two ammonoid zones and four subzones through all the Moorefield, except the base. Korn and Titus (2011) reexamined Gordon’s published ammonoid assemblages, and made additional collections from the type Moorefield. They recognized only two Moorefield ammonoid zones: the lower Goniatites eganensis - Girtyoceras welleri zone, succeeded by the upper Goniatites multiliratus zone concentrated near the middle of the interval. The best age assignment for these abundant, middle Moorefield ammonoid assemblages is to the lower Chesterian Series (Korn and Titus 2011). The unfossiliferous lower Moorefield Shale spans the Meramecian-Chesterian boundary. The upper section, above the ammonoid occurrences, but also barren of ammonoids, and other biostratigraphically useful fossils, likely extends to at least the middle Chesterian. Thus, the bulk of the Moorefield formation represents the Chesterian, not the Meramecian Series. This age assignment is complicated further by the reduction of the lithostratigraphic units comprising the type Meramecian Series (Lane and Brenckle 2005), and a lack of ammonoid assemblages in its type area, St. Louis County, Missouri

The application of proton computed tomography to reduce proton therapy range uncertainties

Proton therapy is a method of radiotherapy utilising protons to deliver a therapeutic dose of radiation to target cancer. Unlike x-rays, protons in the therapeutic energy range (< 250 MeV) have a finite range in the body. The physics of proton interactions mean that protons deposit most of their radiation dose at the end of their range. Hence, through careful selection of proton energy, protons have the potential to deliver dose to the target whilst sparing healthy surrounding tissue, as well as reducing the total dose given to the patient. This is particularly favourable for paediatric patients. However, the accuracy of proton therapy is currently limited by uncertainty in the delivered proton range. Because of this range uncertainty, a margin of typically 3.5 mm + 3% is added to the proton range. A major source of range uncertainty in proton therapy arises from the use of x-ray CT when imaging the patient for treatment planning. Here, an alternative imaging modality is tested in an effort to reduce range uncertainty. A proposed solution to remove this source of uncertainty is the use of proton CT. In proton CT, the stopping power relative to water (RSP) of the patient is measured directly, potentially increasing the accuracy of imaging for proton therapy treatment planning. The PRaVDA prototype proton CT system is a proton-tracking CT system designed using fully solid-state technology to resolve the paths of individual protons entering and exiting a phantom, and then measure the residual range of the phantom. With this information, an image is constructed of proton stopping power. In this thesis, the first results from the PRaVDA proton CT system are xiv shown. An image of a test phantom was acquired and the RSP accuracy of the image was shown to be better than 1.3% in materials replicating soft tissue and bone. The image contained artefacts arising from the raw data acquired and the source of these artefacts is investigated. Further study into the use of proton CT for proton range calculation was performed using a dosimetric phantom. The dosimetric phantom contains a section of EBT-3 radiochromic film capable of measuring a 2D dose distribution. The phantom was exposed to proton beams at two different energies, and images of the phantom were acquired using proton CT and x-ray CT. The proton CT and x-ray CT images were used to calculate the expected proton range using a validated Monte Carlo simulation, and the simulated results were compared against the experimental measurement

The bony labyrinth of late Permian Biarmosuchia: palaeobiology and diversity in non-mammalian Therapsida

Biarmosuchia, as the basalmost group of Therapsida (the stem group of mammals), are important for understanding mammalian origins and evolution. Unlike other therapsid groups, the bony labyrinth of biarmosuchians has not yet been studied, despite insightful clues that bony labyrinth morphology can provide to address palaeobiology and phylogeny of extinct animals. Here, using CT scanning, surface reconstruction and a 3D geometric-morphometric protocol of 60 semi-landmarks on the bony labyrinth of 30 therapsids (including three Mammaliaformes), it is demonstrated that bony labyrinth morphology of biarmosuchians is very distinctive compared to that of other therapsids. Despite the primitive nature of their cranial morphology, biarmosuchians display highly derived traits in the structure of the bony labyrinth. The most noticeable are the presence of a long and slender canal linking the vestibule to the fenestra vestibuli, an enlarged and dorsally expanded anterior canal, and the absence of a secondary common crus (except for one specimen), which sets them apart from other non-mammalian therapsids. These characters provide additional support for the monophyly of Biarmosuchia, the most recently recognized major therapsid subclade. Although implications of the derived morphology of the biarmosuchian bony labyrinth are discussed, definitive interpretations are dependent on the discovery of well-preserved postcranial material. It nevertheless sheds light on a previously overlooked diversity of bony labyrinth morphology in non-mammalian therapsids.The Palaeontological Scientific Trust (PAST) and its Scatterlings of Africa Programmes NRF South Africa DST-NRF Centre of Excellence in PalaeosciencesJN