Language in Education Policy and Practice in Post-Colonial Africa: An ethnographic case-study of The Gambia

This thesis examines the interaction between the language in education policy and classroom practices in The Gambia, West Africa. This examination takes place against a background of current and vigorous academic debate regarding policies for language in education and the learning and teaching of students, particularly in post-colonial countries. Using an ethnographic case study this thesis builds on the analysis of more than 38 hours of data collected during classroom observations of 10 teachers in three schools. Conversational interviews were held with 10 teachers and field notes from all observations were produced. Stimulated recall interviews were held with four teachers. The findings of this research suggest that the language in education policy currently in use in The Gambia is regularly subverted by the teachers and students in order to meet the pragmatic and pedagogic needs of the classroom. It was noted that the local languages were used differently in the urban sites, where evidence of a language amalgam was recorded, when compared with the rural sites, in which a phenomenon of serial monolingualism was observed. The impact of historical, political and cultural norms also affected the language in all the sites in the study. The thesis argues that there is an observable subversion of the language in education policy and different language practices are present as a result of heteroglossic conflict (Bakhtin 1981). The conflict is caused by the imposition of a monolingual language in education policy on a multilingual community. The findings reveal that the teachers and learners have developed a repertoire of pedagogic techniques, some of which are geographically specific, in order to present a demonstration of effective teaching and learning. In answering the research questions this thesis demonstrates that local languages do have a place in classroom interactions and that a reconsideration of the current English Only policy would be appropriate. There are few studies of language use in classrooms in The Gambia. This research therefore makes a significant contribution to this literature and to the ways in which language use is theorised

Ras/Raf-1/MAPK pathway mediates response to tamoxifen but not chemotherapy in breast cancer patients

<b>Purpose</b>: The expression and activation of the Ras/Raf-1/mitogen-activated protein kinase (MAPK) pathway plays an important role in the development and progression of cancer, and may influence response to treatments such as tamoxifen and chemotherapy. In this study we investigated whether the expression and activation of the key components of this pathway influenced clinical outcome, to test the hypothesis that activation of the MAPK pathway drives resistance to tamoxifen and chemotherapy in women with breast cancer. <b>Experimental Design</b>: Breast tumors from patients at the Glasgow Royal Infirmary and others treated within the BR9601 trial were analyzed for expression of the three Ras isoforms, total Raf-1, active and inactive forms of Raf-1 [pRaf(ser338) and pRaf(ser259), respectively], MAPK, and phospho-MAPK using an immunohistochemical approach. Analyses were done with respect to disease free-survival and overall survival. <b>Results</b>: Expression and activation of the Ras pathway was associated with loss of benefit from treatment with tamoxifen but not chemotherapy. Overexpression of pRaf(ser338) was associated with shortened disease-free and overall survival time in univariate analyses. Multivariate analysis suggested pRaf(ser338) was independent of known prognostic markers in predicting outcome following tamoxifen treatment (<i>P</i>=0.03). <b>Conclusion</b>: This study suggests that activation of the Ras pathway predicts for poor outcome on tamoxifen but not chemotherapy, and identifies pRaf(ser338) as a potential marker of resistance to estrogen receptor–targeted therapy. In addition, it suggests that expression of pRaf(ser338) could identify patients for whom tamoxifen alone is insufficient adjuvant systemic therapy, but for whom the addition of chemotherapy may be of benefit

Extremely narrow spectrum of GRB110920A: further evidence for localised, subphotospheric dissipation

Much evidence points towards that the photosphere in the relativistic outflow in GRBs plays an important role in shaping the observed MeV spectrum. However, it is unclear whether the spectrum is fully produced by the photosphere or whether a substantial part of the spectrum is added by processes far above the photosphere. Here we make a detailed study of the $\gamma-$ray emission from single pulse GRB110920A which has a spectrum that becomes extremely narrow towards the end of the burst. We show that the emission can be interpreted as Comptonisation of thermal photons by cold electrons in an unmagnetised outflow at an optical depth of $\tau \sim 20$. The electrons receive their energy by a local dissipation occurring close to the saturation radius. The main spectral component of GRB110920A and its evolution is thus, in this interpretation, fully explained by the emission from the photosphere including localised dissipation at high optical depths.Comment: 14 pages, 11 figures, accepted to MNRA

Comparison of fission and quasi-fission modes

Quantum shell effects are known to affect the formation of fragments in nuclear fission. Shell effects also affect quasi-fission reactions occurring in heavy-ion collisions. Systematic time-dependent Hartree-Fock simulations of 50Ca+176Yb collisions show that the mass equilibration between the fragments in quasi-fission is stopped when they reach similar properties to those in the asymmetric fission mode of the 226Th compound nucleus. Similar shell effects are then expected to determine the final repartition of nucleons between the nascent fragments in both mechanisms. Future experimental studies that could test these observations are discussed.Comment: 8 pages, 4 figures, 1 tabl

Solid-state transition metal dichalcogenide electrocatalysts for the hydrogen evolution reaction

This work seeks to understand the origins of catalytic behaviour in transition metal dichalcogenide electrocatalysts, which are currently convoluted by a variety of factors. To achieve this, a solid-state approach to molybdenum ditelluride (MoTe2) is investigated, which allows for the synthesis of both semiconducting 2H- and metallic 1T’-phases in the bulk form. In doing so, not only is the effect of surface area excluded as the route to advanced activity, but also the role that lithium may play in altering the elemental composition. Therefore, the only factor remaining that may affect the electrocatalytic activity of MoTe2 is the change in coordination geometry which governs the semiconducting / metallic character. As a result, one may confidently attribute the emergence of catalytic activity to the result of polymorphic transition. Continuing with the quest of understanding the origins of catalytic behaviour, the metallic 1T’-MoTe2 material is studied exclusively, with the effect of surface area now being considered. Again using a solid-state approach, thus removing external factors which may otherwise contaminate this study, a low temperature variant of 1T’-MoTe2 is synthesised in order to explore the result of introducing a degree of disorder to the crystalline material. This method will then highlight the importance of intrinsic activity measurements when comparing HER electrocatalysts. Upon fully characterising the 1T’-MoTe2 materials, the phenomenon of activation is explored. With the aim of understanding the origins of catalytic enhancement in mind, efforts are turned towards determining the primary reason of activation, and excluding changes in structure and composition as the root cause of the improvement. Following ex-situ characterisation, intrinsic activity measurements coupled with computational studies such as Density Functional Theory (DFT) explore the possibility of an electrochemical activation, which may be inherent to 1T’-MoTe2. In a final endeavour to understand the mechanism behind electrochemical activation, attempts were made to scale up the working electrode to comply with in operando electrochemical cells. Additionally, alternative activation mechanisms are considered and confirmation of the catalytic sites at which activation takes place is revealed. Thus, this thesis aims to provide a coherent explanation for the observed catalytic activity in MoTe2, which may also be applied to other members of the TMDC family