An investigation into the role and impact of the volume of trade in UK futures markets

In this thesis a detailed examination is carried out into the role and impact of the volume of trade in UK futures markets. While the success of a market may be judged by the number of investors that it attracts, how does the behaviour of individuals influence such key variables as price volatility and the cost of trading? The empirical work carried out here allows a unique appreciation of issues that have important implications for policy makers, investors and the practitioner. Motivated by a desire to understand whether volatility is destabilising or a reflection of fundamental factors, as well as the nature of the distribution of price returns, the relationship between volume and price movements is investigated in detail. The preliminary analysis suggests an important role for the flow of information which is confirmed by the rigorous testing of Anderson's (1996) specification of the Mixture of Distributions Hypothesis. The exploitation of this model allows an in-depth analysis of the information process including the identification of the informed and uninformed components of volume. There is also an investigation into the possibility that the volume statistic itself has an informative value. Using the Blume et al. (1994) approach the results suggest that, for a variety of futures contracts, the markets show a high degree of information dispersion. The need to attract investors has never been more acute than in today's competitive financial environment. It is therefore important to obtain a good appreciation of the relationship between volume and the cost of trading. This thesis includes a comprehensive intra-day study of the relation within a simultaneous econometric framework that exploits state-space models to investigate how markets react to unexpected levels of trading. The results question the dominance of inventory cost models and suggest that patterns of trade have become more predictable since contract inception, despite increases in volume

"May, Juncker and Farage walk into a bar...": comedy is playing a vital role in enabling people to come to terms with Brexit

Comedy is inherently linked to identity. Joking enables us to present ourselves and our view of the world to others while simultaneously inviting them to form connections with us through laughter. If you are 'in' on the joke, you form a connection with the joke-teller; you are (however briefly) a community united by humour. So what does this have to do with Brexit? Quite a bit, argues Ellie Tomsett (Birmingham City University)

A novel simulation framework for modelling extracellular recordings in cortical tissue : implementation, validation and application to gamma oscillations in mammals

PhD ThesisThis thesis concerns the simulation of local field potentials (LFPs) from cortical network activity; network gamma oscillations in particular. Alterations in gamma oscillation measurements are observed in many brain disorders. Understanding these measurements in terms of the underlying neuronal activity is crucial for developing effective therapies. Modelling can help to unravel the details of this relationship. We first investigated a reduced compartmental neuron model for use in network simulations. We showed that reduced models containing <10 compartments could reproduce the LFP characteristics of the equivalent full-scale compartmental models to a reasonable degree of accuracy. Next, we created the Virtual Electrode Recording Tool for EXtracellular Potentials (VERTEX): a Matlab tool for simulating LFPs in large, spatially organised neuronal networks. We used VERTEX to implement a large-scale neocortical slice model exhibiting gamma frequency oscillations under bath kainate application, an experimental preparation frequently used to investigate properties of gamma oscillations. We built the model based on currently available data on neocortical anatomy. By positioning a virtual electrode grid to match Utah array placement in experiments in vitro, we could make a meaningful direct comparison between simulated and experimentally recorded LFPs. We next investigated the spatial properties of the LFP in more detail, using a smaller model of neocortical layer 2/3. We made several observations about the spatial features of the LFP that shed light on past experimental recordings: how gamma power and coherence decays away from an oscillating region, how layer thickness affects the LFP, which neurons contribute most to the LFP signal, and how the LFP power scales with frequency at different model locations. Finally, we discuss the relevance of our simulation results to experimental neuroscience. Our observations on the dominance of parvalbumin-expressing basket interneuron synapses on the LFP are of particular relevance to epilepsy and schizophrenia: changes in parvalbumin expression have been observed in both disorders. We suggest how our results could inform future experiments and aid in the interpretation of their results

Sanity Checks for Saliency Metrics

Saliency maps are a popular approach to creating post-hoc explanations of image classifier outputs. These methods produce estimates of the relevance of each pixel to the classification output score, which can be displayed as a saliency map that highlights important pixels. Despite a proliferation of such methods, little effort has been made to quantify how good these saliency maps are at capturing the true relevance of the pixels to the classifier output (i.e. their "fidelity"). We therefore investigate existing metrics for evaluating the fidelity of saliency methods (i.e. saliency metrics). We find that there is little consistency in the literature in how such metrics are calculated, and show that such inconsistencies can have a significant effect on the measured fidelity. Further, we apply measures of reliability developed in the psychometric testing literature to assess the consistency of saliency metrics when applied to individual saliency maps. Our results show that saliency metrics can be statistically unreliable and inconsistent, indicating that comparative rankings between saliency methods generated using such metrics can be untrustworthy.Comment: Accepted for publication at the Thirty Fourth AAAI conference on Artificial Intelligence (AAAI-20

Reflections on UK Comedy’s Glass Ceiling: Stand-Up Comedy and Contemporary Feminisms

This thesis considers the ways in which the current UK stand-up comedy industry both accommodates and simultaneously marginalises female voices. This research concerns itself with three key areas of enquiry: Firstly, I examine how the development of stand-up comedy, alongside gender stereotypes, has resulted in additional barriers to women’s participation in live comedy, and how these barriers are maintained in a digital era. Stand-up comedy as an art form has emerged from, and been developed within, male dominated spaces. This has impacted upon the style and content of the comedy produced in the live arena, as well as broadcast comedy. This research considers how the origins of stand-up comedy still impact on current live comedy production and how this is intrinsically linked to wider societal stereotypes about the capabilities of women. Secondly, I consider the work being undertaken in the current context to address the continuing gender inequality on the UK circuit, and what these initiatives mean to performers and audiences. My original contribution to knowledge is to synthesise the results of immersive research with the UK Women in Comedy Festival in Manchester, which investigated practical initiatives seeking to make the industry more inclusive to women, with the results of qualitative and mixed-methods research into the perspectives of performers, promoters and audiences on the importance of these initiatives. As a result I offer both an overview of the current scene and suggestions for the future. Lastly, I analyse examples of stand-up comedy performed by women in the current context and how these performances relate to conceptions of feminist and postfeminist humour, as well as notions of backlash against contemporary feminisms. This research focuses on live comedy that is explicitly feminist in its presentation and content to consider how social attitudes to women, the increasing visibility of female labour outside the home, and the emergence of multiple (occasionally contradictory) feminisms has influenced the comedy produced by female comedians in 21st century Britain