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The retrosplenial cortex and hippocampus are brain regions which have been shown to be highly involved in contextual memory. In order to discover neurophysiological correlates of contextual memory in these regions, we used in vivo electrophysiology in awake, behaving mice while they explored a series of novel and familiar environments. Additionally, in order to better understand the specific neurophysiological effects of Alzheimer's disease-associated amyloid pathology on the retrosplenial cortex and hippocampus, we compared network activity between wild-type mice and J20 mice, a transgenic mouse model which develops widespread age-related amyloid pathology and memory impairments. We detected transient bursts of beta oscillations in both the retrosplenial cortex and hippocampus that were synchronous between these regions and upregulated during contextual novelty. Moreover, spiking of neurons in the retrosplenial cortex was significantly increased during beta bursts. In J20 mice, we noted numerous examples of altered network activity, including aberrant beta bursting which is not coupled to neuronal spiking. Through the use of EEG recordings in mice, we demonstrated that beta bursts can be detected across the cortex, and are highly synchronous between different brain regions. Finally, we demonstrated that it is possible to pharmacologically induce beta bursting in the retrosplenial cortex in vitro through the use of carbachol, a muscarinic acetylcholine receptor agonist, providing an assay for better understanding the mechanisms underlying beta bursting. These findings suggest that transient beta bursting across the brain provides brief windows of effective communication between brain regions, which may underlie the formation of cortical representation of contexts, and may be impaired in Alzheimer's disease.

For over 200 years, the formation of bubbles in the body as a result of ambient pres- sure changes has been linked to decompression sickness (DCS). The mechanisms by which bubbles may lead to DCS are poorly understood, despite this long history of re- search. Mathematical modelling has played a key role in DCS prevention through the development of dive computer algorithms. Algorithms which incorporate mechanistic bubble models must make assumptions about a selected bubble property being statisti- cally related to the incidence of DCS. This poses a problem for the validation of such algorithms. Given the uncertain relationship between the mechanistic model output and the symptoms of DCS, direct bubble observation is required to validate the mechanistic portion of the model; such measurements, however, are not currently possible in vivo. The use of biomimetic in vitro models provides a new research avenue to investigate the causal mechanism as well address the validation problem currently faced. In the work described in this thesis an in vitro matrix model (collagen type I gel) was used to validate and further develop a 3D computational model of extravascular bubble dynamics. The collagen gels together with a microscope compatible pressure chamber provided the means to directly measure bubble formation and dynamics within the gels during decompression profiles. The effect of material and dive parameter vari- ations on bubble growth was first investigated and validated. Bubble-bubble interaction and coalescence were then analysed. Both the computational and experimental results of these analyses indicated that a model of bubble nucleation would be essential to model bubble dynamics accurately. The possible nature and distribution of nucleation sites was investigated. Options for incorporation of the nucleation findings are anal- ysed. Finally the influence of live cells bubble dynamics through oxygen consumption and the effect bubble proximity has on cell viability were investigated.

This thesis offers and applies a new theoretical and methodological framework for understanding the diplomatic relationships between the ancient court societies in the Bronze Age Eastern Mediterranean (Egypt, Upper Nubia, Levant, Anatolia, and the Aegean) with particular focus on the Middle Bronze Age covering first half of the 2nd millennium BC. Previous scholarship on diplomacy has largely concentrated on the philological analyses of Late Bronze Age diplomatic texts and the artistic styles of luxury visual arts, attempting to identify the origins of specific artistic styles and correlate gift lists with actual material objects. This thesis departs from these prior studies by adopting a more firmly sociological and anthropological approach, focusing on the social and ceremonial contexts of diplomatic activity. In particular, the role of etiquette (ritualized and codified forms of behavior) in diplomacy is the primary focus. Via a holistic analysis incorporating material culture, texts, and art, the thesis discusses how forms of etiquette can be reconstructed from the archaeological record, if forms of etiquette transmission can be identified, and the extent to which these transmissions can be used to reconstruct diplomatic relationships.

Cormac McCarthy’s western novels have made him one of the most prominent authors in contemporary American fiction, and they have received a great deal of critical attention. Yet the western novels were preceded by four novels set in East Tennessee that set the mythic, historic and thematic template for McCarthy’s later work. Like East Tennessee itself, McCarthy’s early works have suffered from a lack of detailed critical and historical analysis. I contend in this study that McCarthy’s Southern work can only truly be understood when read within the context of East Tennessee exceptionalism, and I shall explore how the mythic and historic character of the region is played out in McCarthy’s Southern aesthetic. I will also show how this region and McCarthy’s work is unique within Southern letters, the most marginal, dispossessed area within the large South itself. This is captured with East Tennessee’s struggle to resist modernity following the birth of the Tennessee Valley Authority, and this struggle forms the central component of McCarthy’s Southern aesthetic. Two strands of comparative analysis help us in establishing the centrality of East Tennessee exceptionalism to McCarthy’s work. Each chapter will compare his work to that of other Southern authors in order to show that McCarthy is an author who maintains a mythic and very Southern interest in myth, albeit in terms very different to the Southern renaissance. Each chapter will also include a comparative analysis of his later work in order to highlight how the imaginative and mythic culture of East Tennessee informs Blood Meridian and the Border Trilogy.