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The bacterial genus Bradyrhizobium is biologically important within soils, with different representatives found to perform a range of functions including nitrogen fixation through symbioses, photosynthesis and denitrification. The Highfield experiment at Rothamsted provides an opportunity to study the impact of plants on microbial communities as it has three long-term contrasting regimes; permanent grassland, arable and bare fallow (devoid of plants). The bare fallow plots have a significant reduction in soil carbon and microbial biomass. Bradyrhizobium has been shown by metagenomic studies on soil to be one of the most abundant and active groups including in bare fallow soil indicating that some phenotypes are adapted to survive in the absence of plants. A culture collection was created with isolates obtained from contrasting soil types from Highfield in addition to woodland soil, gorse (Ulex europeaus) and broom (Cytisus scoparius) root nodules. The collection’s phylogeny has been explored by sequencing housekeeping genes to determine whether soil treatment affects the core genome. One grassland and one bare fallow isolate had their genome sequenced and differences have been assessed to establish their potential for a range of functions and to direct future experiments. The functional diversity of the collection has been investigated using carbon metabolism assays to identify key substrates and determine whether the isolates group according to soil treatment. Symbiosis capacity and role in nitrogen cycling has been examined using nodulation tests, anaerobic growth on nitrate and nitrous oxide production and reduction through denitrification. A high level of diversity can be seen throughout the collection with differences being linked to niche adaptation. Understanding more about Bradyrhizobium could give clues on how above ground management impacts a key group within the soil community. Furthermore, the first assembled genomes of two non-symbiotic Bradyrhizobium strains isolated from soil provide an important resource for microbiology and soil ecology.

To the modern audience, the visual and aural qualities of the alphorn are quintessentially evocative of the Swiss Alps. While the alphorn has been used both literally and metaphorically by many Western art composers in works written for the concert hall, the theatre, the church and the salon to evoke this quality, this phenomenon has been neither investigated in critical musicology nor subjected to historical scrutiny. In this thesis, I seek to identify those appearances, discuss their significance and site them in their historical and cultural background. There will be an introductory examination of the use of the alphorn in both mountainous and non-mountainous landscapes in order to assess to what a composer might refer. This will then inform an exploration of how a composer may have become aware of the acoustic characteristics of the alphorn, why a composer might have chosen to incorporate an alphorn or alphorn-suggestive material in a composition and upon what grounds he may have believed that his audience should understand such a reference. Many examples of citations will then be discussed and their historical and cultural contexts examined in order to determine the relevance of this material to the anticipated audience. The music examined will span from the eighteenth century to the present day. It is primarily music written in central Europe; in addition there is discussion of the use of the alphorn in the UK and there will be references to alphorn-inspired material across the globe. The influence of modern experimental music, rock music and brass techniques on both formal composed repertoire for the alphorn and on alphorn playing in Switzerland will be investigated in brief. Finally some assessment is given as to the overall significance of the alphorn in composed repertoire and the cross-fertilisation of influences that have blurred the boundaries between art music and the traditional music of the instrument as it is found in Switzerland today.

Reciprocal Teaching (RT) is a metacognitive training programme that was found to improve reading comprehension during the 1980s (Palincsar and Brown, 1984). Four strategies: predicting, clarifying, questioning and summarising are taught, then students gradually assume control of teaching within a heterogeneous small group until they are actively involved in constructing meaning from text. A review of the literature revealed that there is “very little” research on RT in the UK (Brooks, 2013), little research worldwide in whole class settings, and little evidence that RT is effective for children under twelve (Cain, 2010). Three intervention studies presented here investigated the effectiveness of RT in whole class UK settings with young readers, and the effect of incorporating visualisation as an additional strategy (RTV). Study 1 was delivered by the researcher with three Year 5 classes (N=50). Results revealed a significant improvement in comprehension scores for the RT groups over a normal instruction group after ten hours of training, but no difference between the RT and RTV groups. A second mixed-methods study (Study 2) involved Year 3 children (N=12) with ten weeks of RT instruction, followed by ten weeks of RTV, delivered by the class teacher. Think-aloud protocols and interviews revealed an increase in strategy use. There was a significant improvement in reading comprehension scores immediately after the intervention, and a one year follow-up assessment showed improvement close to significance (p=.09). The third study (Study 3) in a different school with Year 3 children (N=28), replicated the results from Study 2, but with a significant increase in reading comprehension scores at the one-year follow-up assessment. Overall, the results revealed that RT was effective in three different whole class settings, with children as young as seven. Qualitative measures indicated that the instruction worked by increasing strategy use.

Aims: The cornea is a tough, transparent tissue providing the primary refractive element of the eye. The stroma consists of specially arranged collagen required for corneal transparency. Correct stromal hydration is important in the maintenance of transparency, a feature controlled by the endothelial cells on the posterior surface of the cornea. The aims of this research were firstly to investigate the morphology of corneal endothelial cells and their expression of the sodium bicarbonate cotransporter during avian embryonic development and secondly, to clarify the effect of disease, surgery and drugs on the posterior cornea including in particular the corneal endothelium. Methods: The corneal endothelial cell morphology and posterior stroma were examined using transmission electron microscopy to determine the ultrastructure of the cells and collagen fibril arrangement in the stroma in all results chapters. Immunohistochemistry and A-scan ultrasonography were employed to identify the presence of the Na+HCO3- cotransporter and to determine the thickness changes in embryonic chick cornea, respectively. Electron tomography was also used to determine the collagen arrangement in Descemet’s membrane. Results: The expression of the Na+HCO3- cotransporter was identified in the endothelial layer of the embryonic chicks at all stages imaged. Central corneal thickness increased in the initial stages of development before a plateau between the E12-E15 developmental period followed by a steady thickness decrease. The ultrastructure of Descemet’s membrane was determined using electron tomography of transverse and en face resin embedded sections from which a model was produced. Polygonal and elongated structures were observed with proteoglycans present at the intermodal regions of the collagenous structures. The polygonal lattice visualised in en face sections appeared to be composed of stacked globular domains which were integrated into the collagen type VIII model. Predominant changes in the Col8a2 knock-in mouse models were observed in the posterior cornea. Differences included increased proteoglycans at the Descemet’s endothelial interface, dilated rough endoplasmic reticulum and focal posterior oedema. This animal model exhibits features similar to those seen in the human form of early-onset Fuchs’ endothelial corneal dystrophy, unlike previous models reported. The final chapter is concerned with regeneration of the corneal endothelial cells. Tissue from posterior corneal surgery examined using electron microscopy revealed the presence of the host endothelial cells and fibrous tissue at the interface in non-Descemet’s membrane stripping automated endothelial keratoplasty and interface haze in Descemet’s membrane stripping automated endothelial keratoplasty. However, these features did not appear to interfere with the adhesion of the graft nor the clarity. Finally, ultrastructural analysis of Rho-kinase inhibited cells showed cells with typical morphology when compared with the untreated group Conclusions: 1) The Na+HCO3- cotransporter is present in the embryonic cornea. It is possible that the cotransporter is involved in the developmental stages and probably the thickness changes we observe during this period. 2) The ultrastructure of Descemet’s membrane appears to be composed of stacked globular domains arranged in a polygonal lattice alongside more elongated structures interspersed with proteoglycans within the internodal regions. 3) Our studies have helped validate Col4a2 mice as a promising Fuchs’ endothelial corneal dystrophy model. 4) Our investigation into posterior corneal surgery revealed ultrastructural changes that occur post-surgery at the graft interface.