A Case Study on Logical Relations using Contextual Types

Proofs by logical relations play a key role to establish rich properties such as normalization or contextual equivalence. They are also challenging to mechanize. In this paper, we describe the completeness proof of algorithmic equality for simply typed lambda-terms by Crary where we reason about logically equivalent terms in the proof environment Beluga. There are three key aspects we rely upon: 1) we encode lambda-terms together with their operational semantics and algorithmic equality using higher-order abstract syntax 2) we directly encode the corresponding logical equivalence of well-typed lambda-terms using recursive types and higher-order functions 3) we exploit Beluga's support for contexts and the equational theory of simultaneous substitutions. This leads to a direct and compact mechanization, demonstrating Beluga's strength at formalizing logical relations proofs.Comment: In Proceedings LFMTP 2015, arXiv:1507.0759

Language variety and communicative style as local and subcultural identity in a South Yorkshire coalmining community

The study has two broad objectives. The first is to describe the regional and sociooccupational language varieties and communicative styles used locally through the collection of empirical data. The second is to explore the extent to which the various components of such language function as markers of social identity for certain individuals. It is an ethnographic, synchronic study looking at the complex link between language and identity, and is cross-disciplinary, drawing on the knowledge already generated via research in sociolinguistics, anthropology and folklore. It is argued that such an eclectic approach will provide profitable insights and reveal new possibilities, both in the description of regional and occupational language varieties and in their role of local identity construction. The concept of someone having a particular social identity or 'self in this study refers not only to geographical, territorially-based group affiliations, but to locally-based, social categories. The study group comprised men and women from the village of Royston and neighbouring communities in South Yorkshire, who have, until recently, relied on coalmining as a way of life and as their major source of income. Undoubtedly, as with all people, each individual is affiliated to different, overlapping and sometimes conflicting social groups, which they can enter and leave easily. Subjective feelings of identification to a geographical region or a social group are not necessarily expressed via language behaviour. This study however, argues that, among many people still living in communities such as Royston, Grimethorpe and Darfield in South Yorkshire, the coalmining industry has been a significant factor in their lives, and continues to be an important retrospective resource, which in certain contexts, can be manipulated symbolically for the display of a distinctive local social identity. The study emphasises that language is not simply an emblem of membership to a preexisting group, but rather these affiliations and boundaries are constituted, maintained and negotiated through the process of interaction

Towards MRI microarrays

Superparamagnetic iron oxide nanometre scale particles have been utilised as contrast agents to image staked target binding oligonucleotide arrays using MRI to correlate the signal intensity and relaxation times in different NMR fluids

A new troglomorphic whip spider of the genus Charinus from the Sultanate of Oman (Amblypygi: Charinidae)

Charinus omanensis n. sp. is described from the Al Fallah - Al Hota cave system in the Jebel Akhdar in northern Oman. It is a troglomorphic species with reduced eyes and in most characters is very similar to Charinus stygochthobius from Socotra. However, the different tibia IV articulation, the possession of lateral eye vestiges, and the different genitalia, particularly in the male, suggest that both species evolved their nearly identical troglomorphic appearance by convergent evolution

The statistical physics of the 1-D to 2-D crossover using transfer function techniques

We develop a novel technique that allows us to directly probe the thermodynamics of the two dimensional limit of the nearest neighbour square lattice clock model. It is a process that uses exact diagonalisation techniques through the use of transfer functions. It is conceptually easy to understand as an extension of the transfer matrices used to solve the 1D Ising model and other similar Hamiltonians. This transfer function technique is applied to a set of 1D spiral geometries with increasing radius N. In the limit N → ∞ the spiral becomes the square lattice and our results are interpreted with respect to this limit. We present convincing evidence that the two transitions that are exhibited in the p > 4 clock model have singular behaviour and above a certain temperature between the transitions convergently behave like the plane rotator model

Computerized 3-dimensional Localization of a Video Capsule in the Abdominal Cavity: Validation by Digital Radiography

Background: Video capsule endoscopy has become the gold standard for examining the small bowel and defining pathological lesions, however, localization of a specific lesion remains largely guesswork. We report the validation of a new 3D localization software using radiological localization in volunteers. Methods: 30 volunteers with no known prior history of gastrointestinal disease swallowed the EC-10 video capsule. A sensor array with six radiopaque markers was placed on the anterior abdominal wall. Once the capsule was visualized to be in the small intestine using a real time viewer, five sets of low dose x-rays were taken every thirty minutes. Distances between sensor points and the capsule were measured on the x-rays to provide X, Y, and Z coordinates and compared with the distances calculated by the software from the same points. Results: Data from 27 of the 30 subjects were suitable for analysis. There were three technical failures. Our study evaluated the accuracy of the “Capsule 3D Track function” which calculated the capsule position based on the signal strength received at the sensor array. The accuracy of the position was compared to the actual position of the capsule as determined by radiographic images obtained during the capsule’s transit through the small bowel. The average error for the software measurement for each of the three coordinates was: X -2.00 cm (SD 1.64 cm), Y -- 2.64 cm (SD 2.39 cm), and Z --2.51 cm (1.83 cm). Conclusion: The localization error reported here is comparable to the existing system for localization, however, it provides localization across all three spatial dimensions which has never been achieved before. The potential utility of this technology is yet to be seen, however, as it needs to now be studied in a prospective clinical trial for patients with suspected small bowel pathology

Gyrodactylus orecchiae sp. n. (Monogenea: Gyrodactylidae) from farmed populations of gilthead seabream (Sparus aurata) in the Adriatic Sea

Gyrodactylus orecchiae sp. n. (Monogenea, Gyrodactylidae) is described from the skin, fins, eyes and gills of juvenile Sparus aurata L. (gilthead seabream) following two outbreaks of gyrodactylosis amongst stocks held in inshore floating cages on the Adriatic coast of Albania and Croatia. Fish were heavily infected (1000+ gyrodactylids/fish) with G. orecchiae which reportedly resulted in ~2–10% mortality amongst the infected stock. Morphologically, the haptoral hooks of G. orecchiae most closely resemble those of Gyrodactylus arcuatus Bychowsky, 1933 in the approximate shape of the ventral bar with its pronounced ventral bar processes and marginal hook sickles which possess a square line to the inner edge of the sickle blade and large rounded heels. The marginal hooks are also morphologically similar to those of Gyrodactylus quadratidigitus Longshaw, Pursglove et Shinn, 2003 and Gyrodactylus colemanensis Mizelle et Kritsky, 1967, but G. orecchiae can be readily discriminated from all three species by the characteristic infolding of the hamuli roots and the shape of the marginal hook sickle. Molecular sequencing of the ITS1, 5.8S, ITS2 regions (513+157+404 bp, respectively) of G. orecchiae and alignment with other gyrodactylids for which these same genomic regions have been determined, suggests that this is a new species. No similarities were found when the ITS1 region of G. orecchiae was compared with 84 species of Gyrodactylus available on GenBank

Dynamic Site Characterisation of the Waikato Basin using Passive and Active surface Wave Methods

Despite the relatively low seismicity, a large earthquake in the Waikato region is expected to have a high impact, when the fourth-largest regional population and economy and the high density critical infrastructure systems in this region are considered. Furthermore, Waikato has a deep soft sedimentary basin, which increases the regional seismic hazard due to trapping and amplification of seismic waves and generation of localized surface waves within the basin. This phenomenon is known as the “Basin Effect”, and has been attributed to the increased damage in several historic earthquakes, including the 2010-2011 Canterbury earthquakes. In order to quantitatively model the basin response and improve the understanding of regional seismic hazard, geophysical methods will be used to develop shear wave velocity profiles across the Waikato basin. Active surface wave methods involve the deployment of linear arrays of geophones to record the surface waves generated by a sledge hammer. Passive surface wave methods involve the deployment of two-dimensional seismometer arrays to record ambient vibrations. At each site, the planned testing includes one active test and two to four passive arrays. The obtained data are processed to develop dispersion curves, which describe surface wave propagation velocity as a function of frequency (or wavelength). Dispersion curves are then inverted using the Geopsy software package to develop a suite of shear wave velocity profiles. Currently, more than ten sites in Waikato are under consideration for this project. This poster presents the preliminary results from the two sites that have been tested. The shear wave velocity profiles from all sites will be used to produce a 3D velocity model for the Waikato basin, a part of QuakeCoRE flagship programme 1