Processes of granite emplacement: NW Ireland and SE Brazil

This thesis is a study of some of the processes which operate at mid crustal levels (10- 20km) during the emplacement of granitoid magmas, with particular reference to the process of in-situ expansion and the association between magma emplacement and orogen evolution. A number of plutons were studied to assess this the Ardara pluton from Donegal, NW Ireland, together with the Atibaia, Morro Azul, Imbiricu and Itapeti plutons from the Rio Paraiba do Sul shear belt (RPSSB), Sao Paulo state, SE Brazil. The emplacement of the Ardara pluton has been the subject of studies by many authors since the 1950's. It has been interpreted as a diapir ascending along a thrust, a granite balloon which forcefully created more than 60% of its space and, most recently, as a set of nested diapirs which forcefully created only 30% of their own space. Field mapping together with the determination of finite strain within the pluton, shortening estimates, shear sense determinations, petrographic deformation fabrics and computer modelling indicates that: i) the pluton displays a concentrically increasing finite strain and it expanded in-situ from a central 'injection point', having possibly ascended along a shear zone-related conduit; ii) the country rocks partitioned intense strains into the 500m closest to the pluton, a deformation feature which is shown to be consistent with a power-law wallrock theology; Hi) earlier granite pulses and the country rock were 'shouldered aside' to the east and west, expansion of the pluton, which was preferentially in a northwards direction; iv) that the intrusion related shortening preserved within the wallrocks was approximately equivalent to the strain preserved within pluton and the space requirements for the pluton are essentially met by preserved forceful emplacement-related strains; and v) if the pluton magma is considered as having ascended through dyke-like conduits emplacement could occur in a minimum of ~4000yrs, whereas magma ascent as a Hot Stokes diapir would require hundreds of thousands to millions of years for complete emplacement. Finally, the Ardara pluton does not conform to any of the established criteria for diapir-like ascent of a magma body and the data demonstrate it to be a testable example of a pluton which expanded entirely in-situ. The Rio Paraiba do Sul shear belt (RPSSB) is a dextral transpressional segment of the Late Precambrian Brasiliano-Pan African orogenic belt. The studied plutons were emplaced in the latter stages of this orogen in close spatial association with one of the many northeast-southwest trending, sub-vertical, continental-scale shear zones. All the granites show a similar emplacement and deformation history despite their different petrographic features and isotopic ages. This history consists of an early shallowly dipping, low angle fabric, in the country rocks, associated with crustal thickening, the later development of dominantly dextral sub-vertical shear zones, followed by the emplacement of the studied plutons and finally overprinting by a pervasive dextral plane strain and late-stage discrete mylonitic shears. Field examination demonstrates that: i) each of the plutons preserves an internally homogeneous emplacement-related finite strain, weak magmatic fabric, magma sheets and weakly deformed wallrocks; ii) magmatic shear sense determinations and wallrock deformation fabrics indicate that, during emplacement, the RPSSB was extending (at least at the emplacement level) in an east-west direction creating sinistral dilatational pull-aparts along the major shear zones, into which granitic magma was preferentially emplaced; and Hi) within this generally extensional context there was a component of long axis perpendicular in-situ forceful expansion, this created no more than 20% of the width of any one granite. Applying a simple pull-apart extension model suggests that pluton emplacement was associated with approximately 40% regional extension sub-parallel to the former orogenic convergence direction. This emplacement, as a result of sheeting through dyke-like conduits, requires thousands of years, rather than the millions of years required for ascent and emplacement of a Hot Stokes diapir. Interpreting these results suggests that the intruded granitoids are associated with a mid-crustal component of orogen perpendicular extension I collapse during the latter stages of the Brasiliano orogeny. Such extension I collapse could have been initiated by: a cessation in continental convergence or; by the delamination of a thickened thermal boundary layer, a process which has been suggested to be the driving force behind orogenic collapse in younger orogenic belts. These examples demonstrate that: i) 'forceful' balloon-like emplacement of granitic magma can occur; ii) there are very close inter-relationships between granite emplacement and orogenic dynamics; and Hi) that 'space' for granitoid magma can be created by a combination of forceful and dilatational and fault-related mechanisms

A Potent Fuel?: Faith Identity And Development Impact In World Vision Community Programming

This paper explores the role of faith identity on impact in development by looking at the programming of a major international faith‐based development organisation (FBDO). It argues that faith identity rests not only in the internal projected identity of the FBDO but also on perceptions of that identity in the community, highlighting the role context plays in the formulation of faith identity and its impact. Secondly, the paper argues that FBDOs possess not only a faith identity but also a development one and that it is the interplay between both that allows for the creation of engagement and trust in interventions

Burkitt's lymphoma

Burkitt's lymphoma is a highly aggressive B-cell non-Hodgkin lymphoma and is the fastest growing human tumour. The disease is associated with Epstein-Barr virus and was one of the first tumours shown to have a chromosomal translocation that activates an oncogene (c-MYC). Burkitt's lymphoma is the most common childhood cancer in areas where malaria is holoendemic. The incidence is very high in immunosuppressed patients in non-endemic areas, especially when associated with HIV infection. Outcome with intensive chemotherapy has improved and is now excellent in children, but the prognosis is poor in elderly adults. The success of intensive treatment relies on good supportive care. The therapy offered in oncology units in low-income countries is not as aggressive as in centres in high-income countries and outcomes are less successful. Adjuvant monoclonal antibody therapy with rituximab shows promise for improved outcomes and reduced toxic effects in the future

Spatial distribution of podoconiosis in relation to environmental factors in Ethiopia: a historical review

BACKGROUND An up-to-date and reliable map of podoconiosis is needed to design geographically targeted and cost-effective intervention in Ethiopia. Identifying the ecological correlates of the distribution of podoconiosis is the first step for distribution and risk maps. The objective of this study was to investigate the spatial distribution and ecological correlates of podoconiosis using historical and contemporary survey data. METHODS Data on the observed prevalence of podoconiosis were abstracted from published and unpublished literature into a standardized database, according to strict inclusion and exclusion criteria. In total, 10 studies conducted between 1969 and 2012 were included, and data were available for 401,674 individuals older than 15 years of age from 229 locations. A range of high resolution environmental factors were investigated to determine their association with podoconiosis prevalence, using logistic regression. RESULTS The prevalence of podoconiosis in Ethiopia was estimated at 3.4% (95% CI 3.3%-3.4%) with marked regional variation. We identified significant associations between mean annual Land Surface Temperature (LST), mean annual precipitation, topography of the land and fine soil texture and high prevalence of podoconiosis. The derived maps indicate both widespread occurrence of podoconiosis and a marked variability in prevalence of podoconiosis, with prevalence typically highest at altitudes >1500 m above sea level (masl), with >1500 mm annual rainfall and mean annual LST of 19-21°C. No (or very little) podoconiosis occurred at altitudes 24°C. CONCLUSION Podoconiosis remains a public health problem in Ethiopia over considerable areas of the country, but exhibits marked geographical variation associated in part with key environmental factors. This is work in progress and the results presented here will be refined in future work

Epidemiology and individual, household and geographical risk factors of podoconiosis in ethiopia: results from the first nationwide mapping

Although podoconiosis is one of the major causes of tropical lymphoedema and is endemic in Ethiopia its epidemiology and risk factors are poorly understood. Individual-level data for 129,959 individuals from 1,315 communities in 659 woreda (districts) were collected for a nationwide integrated survey of lymphatic filariasis and podoconiosis. Blood samples were tested for circulating Wuchereria bancrofti antigen using immunochromatographic card tests. A clinical algorithm was used to reach a diagnosis of podoconiosis by excluding other potential causes of lymphoedema of the lower limb. Bayesian multilevel models were used to identify individual and environmental risk factors. Overall, 8,110 of 129,959 (6.2%, 95% confidence interval [CI] 6.1-6.4%) surveyed individuals were identified with lymphoedema of the lower limb, of whom 5,253 (4.0%, 95% CI 3.9-4.1%) were confirmed to be podoconiosis cases. In multivariable analysis, being female, older, unmarried, washing the feet less frequently than daily, and being semiskilled or unemployed were significantly associated with increased risk of podoconiosis. Attending formal education and living in a house with a covered floor were associated with decreased risk of podoconiosis. Podoconiosis exhibits marked geographical variation across Ethiopia, with variation in risk associated with variation in rainfall, enhanced vegetation index, and altitude

Representations of sport in the revolutionary socialist press in Britain, 1988–2012

This paper considers how sport presents a dualism to those on the far left of the political spectrum. A long-standing, passionate debate has existed on the contradictory role played by sport, polarised between those who reject it as a bourgeois capitalist plague and those who argue for its reclamation and reformation. A case study is offered of a political party that has consistently used revolutionary Marxism as the basis for its activity and how this party, the largest in Britain, addresses sport in its publications. The study draws on empirical data to illustrate this debate by reporting findings from three socialist publications. When sport did feature it was often in relation to high profile sporting events with a critical tone adopted and typically focused on issues of commodification, exploitation and alienation of athletes and supporters. However, readers’ letters, printed in the same publications, revealed how this interpretation was not universally accepted, thus illustrating the contradictory nature of sport for those on the far left

Abnormal IgD and IgA1 O-glycosylation in hyperimmunoglobulinaemia D and periodic fever syndrome

In order to determine the glycosylation pattern for IgD, and to examine whether there are changes in the pattern of IgD and IgA1 O-glycosylation in patients with hyperimmunoglobulinaemia D and periodic fever syndrome (HIDS) during acute febrile attacks and during periods of quiescence, serum was obtained from 20 patients with HIDS and 20 control subjects. In the HIDS group, serum was obtained either during an acute febrile episode (n = 9) or during a period of quiescence (n = 11). The O-glycosylation profiles of native and desialylated IgA1 and IgD were measured in an ELISA-type system using the lectins Helix aspersa and peanut agglutinin, which bind to alternative forms of O-glycan moieties. IgD is more heavily O-galactosylated and less O-sialylated than IgA1 in healthy subjects. HIDS is associated with more extensive O-galactosylation of IgD and a reduction in O-sialylation of both IgD and IgA1. These changes are present both during acute febrile attacks and periods of quiescence. The T cell IgD receptor is a lectin with binding affinity for the O-glycans of both IgD and IgA1. The observed changes in IgD and IgA1 O-glycosylation are likely to have a significant effect on IgD/IgA1–T cell IgD receptor interactions including basal immunoglobulin synthesis, and possibly myeloid IgD receptor-mediated cytokine release