Comprehensive parametric polymorphism : categorical models and type theory

This paper combines reflexive-graph-category structure for relational parametricity with fibrational models of impredicative polymorphism. To achieve this, we modify the definition of fibrational model of impredicative polymorphism by adding one further ingredient to the structure: comprehension in the sense of Lawvere. Our main result is that such comprehensive models, once further endowed with reflexive-graph-category structure, enjoy the expected consequences of parametricity. This is proved using a type-theoretic presentation of the category-theoretic structure, within which the desired consequences of parametricity are derived. The formalisation requires new techniques because equality relations are not available, and standard arguments that exploit equality need to be reworked

Phase 2 trial of montelukast for prevention of pain in sickle cell disease.

Cysteinyl leukotrienes (CysLTs) are lipid mediators of inflammation. In patients with sickle cell disease (SCD), levels of CysLTs are increased compared with controls and associated with a higher rate of hospitalization for pain. We tested the hypothesis that administration of the CysLT receptor antagonist montelukast would improve SCD-related comorbidities, including pain, in adolescents and adults with SCD. In a phase 2 randomized trial, we administered montelukast or placebo for 8 weeks. The primary outcome measure was a >30% reduction in soluble vascular cell adhesion molecule 1 (sVCAM), a marker of vascular injury. Secondary outcome measures were reduction in daily pain, improvement in pulmonary function, and improvement in microvascular blood flow, as measured by laser Doppler velocimetry. Forty-two participants with SCD were randomized to receive montelukast or placebo for 8 weeks. We found no difference between the montelukast and placebo groups with regard to the levels of sVCAM, reported pain, pulmonary function, or microvascular blood flow. Although montelukast is an effective treatment for asthma, we did not find benefit for SCD-related outcomes. This clinical trial was registered at www.clinicaltrials.gov as #NCT01960413

Access visits using video communication

An online video communication system is presented that enables Occupational Therapists (OTs) assess patient homes for assistive technology needs before acute care discharge to ensure appropriate independence and recovery conditions. Explorations under multiple conditions revealed perspectives from OTs and volunteer facilitators. Preliminary key findings and insights are reported

Variscan sourcing of Westphalian (Pennsylvanian) sandstones in the Canobie Coalfield, UK

The zircon age spectrum in a sample from the Canonbie Bridge Sandstone Formation (Asturian) of southern Scotland contains two main peaks. One is Early Carboniferous in age (348– 318 Ma), and corresponds to the age of igneous activity during the Variscan Orogeny. The other is of late Neoproterozoic to early Cambrian age (693–523 Ma), corresponding to the Cadomian. Together, these two groups comprise 70 % of the zircon population. The presence of these two peaks shows unequivocally that a significant proportion of the sediment was derived from the Variscides of western or central Europe. The zircon population also contains a range of older Proterozoic zircons and a small Devonian component. These could have been derived from the Variscides, but it is possible that some were locally derived through recycling of northerly derived sandstones of Devonian–Carboniferous age. The zircon age data confirm previous suggestions of Variscide sourcing to the Canonbie area, made on the basis of petrographical, heavy mineral and palaeocurrent evidence, and extend the known northward distribution of Variscan-derived Westphalian sediment in the UK

Peasants and politics in the western Transvaal, 1920-1940

This thesis examines the political and ideological struggles within Tswana chiefdoms in the Rustenburg district of the Western Transvaal in the period 1920 - 1940. This period was characterized by a spate of struggles against tribal chiefs which took on similar forms in most of the chiefdoms of the district. These challenges to chiefly political authority reflected a variety of underlying material interests which were rooted in the process of class formation resulting from the development of capitalist relations of production within the wider society. Despite the variations in material conditions in the different chiefdoms of the district, the forms of political and ideological resistance were very similar. The thesis examines the extent of the influences of Christian missions and national political organizations in these localized struggles, and also explores the relationship between chiefs, Native Affairs Department officials and the rural African population in the context of developing segregationist ideology during the inter-war period

Squirrelpox virus: assessing prevalence, transmission and environmental degradation

Red squirrels (Sciurus vulgaris) declined in Great Britain and Ireland during the last century, due to habitat loss and the introduction of grey squirrels (Sciurus carolinensis), which competitively exclude the red squirrel and act as a reservoir for squirrelpox virus (SQPV). The disease is generally fatal to red squirrels and their ecological replacement by grey squirrels is up to 25 times faster where the virus is present. We aimed to determine: (1) the seropositivity and prevalence of SQPV DNA in the invasive and native species at a regional scale; (2) possible SQPV transmission routes; and, (3) virus degradation rates under differing environmental conditions. Grey (n = 208) and red (n = 40) squirrel blood and tissues were sampled. Enzyme-linked immunosorbent assay (ELISA) and quantitative real-time polymerase chain reaction (qPCR) techniques established seropositivity and viral DNA presence, respectively. Overall 8% of squirrels sampled (both species combined) had evidence of SQPV DNA in their tissues and 22% were in possession of antibodies. SQPV prevalence in sampled red squirrels was 2.5%. Viral loads were typically low in grey squirrels by comparison to red squirrels. There was a trend for a greater number of positive samples in spring and summer than in winter. Possible transmission routes were identified through the presence of viral DNA in faeces (red squirrels only), urine and ectoparasites (both species). Virus degradation analyses suggested that, after 30 days of exposure to six combinations of environments, there were more intact virus particles in scabs kept in warm (25°C) and dry conditions than in cooler (5 and 15°C) or wet conditions. We conclude that SQPV is present at low prevalence in invasive grey squirrel populations with a lower prevalence in native red squirrels. Virus transmission could occur through urine especially during warm dry summer conditions but, more notably, via ectoparasites, which are shared by both species

The tax and price index

A feature of this year's Budget was the shift in emphasis from direct taxation to indirect taxation. The annual yield of income tax has been reduced by £4½ billion while that of direct taxes was increased by a similar amount. It must be acknowledged that the new tax and price index has a number of deficiencies. It is only applicable to a proportion of the population, namely those who pay tax and whose gross income is less than £10,000 per annum. It takes no account of the social wage, nor of changes in benefits, such as the recent restructuring of child allowance. It smoothes out tax payments over a full year even though, for administrative reasons, these may fluctuate widely from month to month. This brief paper explores some of these deficiencies in more detail and assess their impact on taxation

Review of the quarter's economic trends [April 1980]

This brief paper surveys recent world and UK economic data and reveals that there are some signs to suggest that the world economy will withstand the 1979 oil price shock better than it did in 1973/74. The main difference is that the 1979 price rise was not super-imposed on as severe an inflation as that which occurred on the previous occasion. The present rate of increase in the world prices should not reach the levels of the last cycle when the twelve month increase in manufacturing prices peaked at 23%. Advance warning by US economists that 1979 was going to be a year of difficulty did not go unnoticed by businessmen in that country who took steps in 1978 to avoid a repetition of the inventory boom and bust cycle which had proved so costly in the recession of 1973/74. Also, consumer expectations are adjusting towards a continuing rise in the price of oil. In the UK real GDP is expected to fall by 2½% from mid-year 1980. Thereafter, it is assumed to grow at an average annual rate of 1% for the next four years

The Scottish economy [October 1979]

The previous two issues of this Commentary have both indicated that the Scottish economy has been performing poorly since the mid 1970's. This is true in both an absolute and a relative sense. Manufacturing production only increased by 1.2% between 1976 and 1978 and, after dropping below 1975 levels in the first quarter of 1979, is unlikely to show any substantial improvement for the year as a whole. In an international context the 1975-1978 performance can best be described as appalling. Over the same period industrial production in Eire grew by 28%, in Japan and the US by 23% and in West Germany and France by 15%. Inertia in developing new markets and lack of competitiveness in existing markets both contributed substantially to the virtual stagnation of Scottish output. Because the problems are so diverse, so too must be the solutions