VictorJuiz/thesis huggingface dataset:
The role of spatial scale in binocular stereopsis
Keywords: human psychophysics
3D vision
spatial frequency
binocular stereopsis

A model of stereopsis is proposed in which information from each eye's image is organised as a scale-based hierarchy before binocular comparison. The algorithm incorporates coarse-to-fine matching (like Marr and Poggio, 1979) but differs from previous models in that the position, and hence disparity, of features is defined relatively rather than by their retinal coordinate. Thus, fine scale disparities are measured and recorded relative to coarse scale disparities. Local surface slant and curvature is represented explicitly at a range of spatial scales. The theory is based on a hierarchical model of encoding position (Watt, 1988).
The first experiment investigates the time course of shape discrimination in random dot stereograms. The results are compatible with a model in which the scale of analysis changes from coarse to fine over the first second of viewing. The second experiment measures the magnitude of a new "3-D" Mueller-Lyer illusion and compares it the that of the classical (2-D) illusion. Both these and the cyclopean Mueller-Lyer illusion are consistent with a model in which hierarchical encoding of position is used by the visual system for 2-D (length comparison) and 3-D (slant) judgements. The third experiment compares the detection of large disparities and large displacements. "Dmax" for the motion and stereo tasks is shown to be similar over a wide range of dot densities. The results are interpreted as evidence that similar spatial primitives are used in the correspondence process in both domains. The spacing of MIRAGE centroids (Watt and Morgan, 1985) fit the data well.
The proposed hierarchical model is similar to that put forward by Mitchison and McKee (1987), although their scheme was not based on spatial scale. The model bridges the gap between a primal and a 2.5-D sketch (Marr, 1982) and has important implications for many issues within stereopsis.
Becoming goth: geographies of an (un)popular culture
Keywords: subculture
affect
enchantment
Gothic
cultural studies
Non-representational theory
Goth
atmosphere
social anxiety

Within this thesis I explore what can be achieved when culture is critically assessed through a series of theories that mobilise a spatial imaginary. I place the concepts of atmosphere, connection, site and encounter, and theories of emergence via terms such as movement, practice and embodiment, into tension with a single case study: Goth. Goth is a music based grouping, emerging from Punk, New Romantic, Indie and Glam Rock style and music cultures in the late 1970s, with a significant near-global presence in the popular culture industries and links to several salient media controversies; including the Columbine High School massacre, the murder of Sophie Lancaster, and fears over self-harm and suicide. I specifically draw on the vocabularies from within non-representational geographies of performance, relational materiality, affect and social anxiety to re-work understandings of this collectivity. I question what is involved in the material practices of Goth, explore how the practice and experience of Goth is articulated through specific sites, examine how Goth participates in the production and circulation of cultures of anxiety or (un)popularity; and reconsider the concept of ‘subculture’. To do so, I employ a range of methodologies, from guided walks to photo-diaries, within multi-site field research throughout the UK, Tokyo and New York City. I conclude that Goth and culture more generally can be theorised in a number of ways: it emerges as a performed series of embodied acts; it is co-produced in complex relations with non-humans; it can be thought of as a series of modulating affective atmospheres; it coalesces as a collectivity and circulates through events; and it is co-produced through sites and media events. None of these dominates over or diminishes the other; rather they are co-constitutive and interdependent.
Numerical methods of resonant dynamics for the Galaxy
Keywords: galactic dynamics
dynamics
classical mechanics

Numerical methods of resonant dynamics with applications to the Galaxy are considered in this thesis. We derive generating functions for first-order perturbation theory and the associated orbital frequencies by matrix calculus. For two action-angle spaces (J,θ) and (i,φ) related by a canonical map I·φ+s, we show that J can be averaged over ergodic orbits φ to provide an estimator of I to within O(|s|2). We provide examples in one and two dimensions and compare the technique to calculations of actions by numerical line integration in Poincaré sections.
We then use spectral dynamics and the Laskar frequency map (Laskar, 1993) to identify the dynamically important resonances of the 'flattened' axisymmetric isochrone potential. We simulate resonant capture in a low-order resonance by populating representative tori of a spherical isochrone Hamiltonian and integrating the orbits while adiabatically introducing axisymmetry. We use the averaging technique described above to observe the fraction of orbits captured, and we compare the result to a theoretical prediction.
We return to first-order perturbation theory to analyse its strengths and weaknesses, in particular near orbital pericentre, and when one action is significantly smaller than another. We also reproduce the expected pendulum dynamics in the resonant action-angle plane for orbits in our capture simulation.
We develop the concept of adaptive dynamics: we vary the initial orbital energy of the particles in the capture simulations and show that resonant and non-resonant orbits can be identified as clusters in the perturbed action plane. For a given Hamiltonian, we use the perturbed frequencies and a linear regression fit in the action plane as diagnostics of a set of model Hamiltonians on a grid in a suitable parameter space. We find we are able to constrain the parameters of a model Hamiltonian by this method. Finally, we reject the null hypothesis that resonant structures in phase space can be found by traditional methods of density estimation.
The development of intra-train beam stabilisation system prototypes for a future linear collider
Keywords: Linear colliders
Particle accelerators

Any future linear collider requires a beam stabilisation system at the interaction point to the to maintain luminosities. This thesis details the development of prototypes of three such systems based at the Accelerator Test Facility 2 (ATF2) at KEK, Japan.
The upstream feedback system utilises two stripline beam position monitors (BPMs) and two stripline kickers located in the ATF2 extraction line to stabilise the position and angle of the beam; the correction is then measured downstream at the ATF2 beam waist by a cavity BPM. The feedforward system uses the two upstream stripline BPMs to measure the position of the beam and calculate a correction signal which is then implemented locally by a stripline kicker located near the beam waist; the correction is then measured at the beam waist by a cavity BPM. The IP feedback system uses the position measured at the ATF2 beam waist by a cavity BPM and implements a correction based on this position using the local stripline kicker; the correction is then measured at the beam waist by a cavity BPM. Tests of the upstream feedback system have demonstrated stabilisation of the ATF2 beam waist at approximately the 300 nm level; tests of the feedforward and IP feedback systems have demonstrated stabilisation of the ATF2 beam waist at approximately the 100 nm level.
Additional work undertaken to improve the processing electronics of the stripline BPMs is detailed. The cavity BPMs and their electronics are characterised and offline analysis techniques to improve the BPM resolutions set out. Results demonstrating resolutions of approximately 350 nm for the stripline BPMs and 80 nm for the cavity BPMs are presented.
The King is dead, long live the King: commemoration in skaldic verse of the Viking age
Keywords: Viking age literature
kings' sagas
Skaldic verse
Old Norse

This thesis examines the function of commemorative skaldic verse at the Viking-age court. The first chapter demonstrates that the commemoration of past kings could provide a prestigious genealogical record that was used to legitimize both pagan and early Christian rulers. In the ninth and early tenth centuries, poets crafted competing genealogies to assert the primacy of their patrons and of their patrons’ religions. The second chapter looks at the work of tenth-century poets who depict their rulers’ entrances into the afterlife. Such poets interrogate the role public speech and poetic discourse play in the commemoration of the king, especially during the political turmoil that follows his death. A discussion follows of the relationship between poets and their patrons in the tenth and eleventh centuries: although this relationship is often praised as one of mutual trust and reliance, the financial aspects of the relationship were often juxtaposed uneasily with expressions of emotional attachment. The death of the patron caused a crisis in these seemingly contradictory bonds between poet and patron. The final chapter demonstrates the dramatic development in the eleventh century of deeply emotional commemorative verse as poets become adopted into their patrons’ families through such Christian ceremonies as baptism and marriage. In these verses poets express their grief after the death of the king and record the performances of public mourning on the part of the kings’ followers. As the petty warlords of the Viking age adapted to medieval models of Christian kingship, the role of the skald changed too. Formerly serving as a propagandist and retainer in the king’s service, a skald documenting the lives of kings at the end of the Viking age could occupy an almost infinite number of roles, from kinsman and friend to advisor and hagiographer.
Rentier Islamism: Muslim Brotherhood affiliates in Kuwait, Qatar, and the United Arab Emirates
Keywords: Muslim Brotherhood
Gulf states
GCC
Islamism
Political Islam

This study, using contemporary history and empirical research, updates traditional rentier state theory, which largely fails to account for the existence of opposition movements, by demonstrating the political capital held by Muslim Brotherhood affiliates in Kuwait, Qatar, and the United Arab Emirates (UAE). This study thus also fills a critical gap in existing literature on political Islam by examining previously unstudied movements in the smaller Gulf states that do not require Brotherhood organisations to provide services, to form social networks, or to contest elections (aside from in Kuwait). Through a divergent case study, we demonstrate the degree to which and the means through which the Ikhwan shapes domestic politics in the some of the world’s wealthiest oil states, the super-rentiers.
This research helps to break the causal link established by rentier state theory between oil rents and lack of politically relevant Islamist organizations. As will be shown, Muslim Brotherhood organizations in the Gulf are politically influential entities. It is important to note, however, that these groups shape cultural and social ideas as readily as political notions. The division between these sectors is often blurred in the atmosphere of the socially conservative super-rentiers, as politics is often displaced to the social sphere in restricted political systems. We therefore elucidate a new model for understanding how Muslim Brotherhood movements influence government policies, in addition to cultural and social policies, in the wealthiest rentier states of the Gulf, which we call rentier Islamism.
Kant's theory of experience
Keywords: representation
Kant
sensibility
sensation
conceptual content
intuition
non-conceptual content
perception
imagination
experience
non-veridical
naive realism
intentionality

In this thesis I present and defend an interpretation of Kant’s theory of experience as it stands from the viewpoint of his empirical realism. My central contention is that Kant’s is a conception of everyday experience, a kind of immediate phenomenological awareness as of empirical objects, and although he takes this to be representational, it cannot itself amount to empirical knowledge because it can be non-veridical, because in such experience it is possible to misrepresent the world. I outline my view in an extended introduction. In Part I I offer a novel interpretation of Kant’s doctrine of sensibility and sensation. Utilizing a data-processor schematic as an explanatory framework, I give an account of how outer sense, as a collection of sensory capacities, is causally affected by empirical objects to produce bodily state sensations that naturally encode information about those objects. This information is then processed through inner sense to present to the understanding a manifold of mental state sensations that similarly encode information. I also give accounts of how the reproductive imagination operates in hallucination to produce sensible manifolds in lieu of current causal affection, and of the restricted role that consciousness plays at this low level of cognitive function. In Part II I turn to the role of the understanding in experience. I offer a two-stage model of conceptual synthesis and explain how Kant’s theory of experience is a unique blend of conceptualist and non-conceptualist elements. I show that it explains how our experience can provide us with reasons for belief while at the same time accounting for the fact that experience is what anchors us to the world. Finally, I return to non-veridical experience. I confront recent naïve realist readings of Kant and argue that, for Kant, the possibility of non-veridicality is built into the very nature of the human mind and the way it relates to the world.
An Investigation of isotropic and anisotropic magnetic field effects in fluorescent systems
Keywords: Dicyanobenzene
Anthracene
Fluorescent
Magnetic Field Effects
Pyrene
Anisotropic
Isotropic

Interest into the effects of weak static magnetic fields on chemical reactions involving spin correlated radical pairs has increased over the last few decades, particularly as scientists have become more curious about the mechanisms by which animals can sense and respond to small variations in the Earth's weak (50 µT) magnetic field. The magnetosensitivity of radical pairs, as dictated by the radical pair mechanism, lies at the heart of the most heavily supported hypothesis of this magnetoreception phenomenon.
This thesis is concerned with the spectroscopic investigations of isotropic and anisotropic magnetic field effects in fluorescent systems. First of all, an introduction to spin chemistry and magnetoreception is presented. In chapter 3, the effects of weak radiofrequency oscillating fields when applied in combination with weak static fields are explored in isotropic solutions. The validity of the high-field model, typically used to describe spin dynamics in magnetic resonance, is tested and the effects of orientation and field strength on magnetic field effects are discussed in detail.
In Chapter 4, a range of exciplex systems are studied by fluorescence methods and their energetics are explored. The factors which determine the formation of an exciplex, i.e. the complex equilibrium between the exciplex and the spin-correlated radical pair,are considered and used to assess the existence and magnitude of MFEs.
Radical pair systems investigated, using MARY spectroscopy, with respect to their potential to act as model chemical compasses are introduced in chapter 5. Solid-state media are used to align the exciplex systems to detect any magnetic field direction dependence. Finally, in chapter 6, AMELIA, an experiment which can directly measure the anisotropic magnetic field response of a system, is presented and applied successfully to systems to detect directly the anisotropic field response of a photoexcited anthracene crystal.
Molecular magnetic resonance imaging of vascular inflammation using microparticles of iron oxide
Keywords: MRI
molecular imaging
contrast agents
iron oxide
microparticles
vascular inflammation

One approach that has demonstrated success in the field of molecular imaging utilizes microparticles of iron oxide (MPIO) conjugated to specific antibodies and/or peptides to provide contrast effects on MRI in relation to the molecular expression of a specified target. The experimental aims of this thesis were 1) to investigate the ability of VCAM-1 and P-selectin targeted MPIO to detect the expression of VCAM-1 and P-selectin on the activated endothelium in-vitro and in-vivo in mouse models of renal and cerebral ischemia reperfusion injury, and 2) develop a novel contrast agent for imaging αvβ3-integrin expression in angiogenesis using RGD peptide conjugated MPIO (RGD-MPIO) in-vitro.
MPIO (1.0 µm) were conjugated to monoclonal antibodies against VCAM-1 (VCAM-MPIO) or P-selectin (PSEL-MPIO). In vitro, MPIO bound in a dose-dependent manner to tumor necrosis factor (TNF)-alpha stimulated sEND-1 endothelial cells when conjugated to VCAM-1 (R² = 0.88, P<0.01) and P-selectin antibodies (R² = 0.93, P<0.01), reflecting molecular VCAM-1 and P-selectin mRNA and protein expression. Mice subjected to unilateral, transient (30 minutes) renal ischemia and subsequent reperfusion received intravenous VCAM-MPIO and PSEL-MPIO (4.5 mg iron/kg body weight). In ischemic kidneys, MR related contrast effects of VCAM-MPIO were 4-fold higher than unclamped kidneys (P<0.01) and 1.5-fold higher than clamped kidneys of PSEL-MPIO injected mice (P<0.05). VCAM-MPIO binding was less evident in IRI kidneys pre-treated with VCAM-1 antibody (P<0.001). VCAM-1 mRNA expression and VCAM-MPIO contrast volume were highly correlated (R² = 0.901, P<0.01), indicating that quantification of contrast volume reflected renal VCAM-1 transcription. In mice subjected to cerebral ischemia, contrast volume was 11-fold greater in animals injected with VCAM-MPIO versus control IgG-MPIO (P<0.05). Finally, S-nitroso-N-acetylpenicillamine (SNAP) stimulated HUVEC-C cells, which express αvβ3-integrin, showed 44-fold greater RGD-MPIO binding than unstimulated cells (P<0.001) and 4-fold greater RGD-MPIO binding than SNAP stimulated cells blocked with soluble RGD peptide (P<0.001) in-vitro.
This thesis demonstrated that targeted MPIO exhibited contrast effects that defined and quantified the molecular expression of specific targets through the use of high-resolution MRI in in-vitro and in-vivo models of vascular inflammation.
Assessing the utility of wearable cameras in the measurement of walking and cycling
Keywords: wearable cameras
measurement
self-report
active travel
travel

Walking and cycling are considered very important behaviours in public health. This thesis is a study of the measurement of walking, cycling and overall travel behaviour.
In the first part I present a systematic review of studies comparing Global Positioning System (GPS) measured travel to self-report. I found 12 results from eight eligible studies. All studies showed self-reported journey times were greater than GPS measured times. The differences ranged from over-reporting of +2.2 to +13.5 minutes per journey.
In the second part of this thesis, I describe the development of a feasible, valid and reliable method for measuring travel with automated wearable cameras (SenseCam) through field testing and two pilot studies. I compared my new method to direct observation (considered a criterion measure) and found very good agreement and reliability (inter-rater, intra-rater and inter-measure). I also present an ethical framework for the measurement of health-related behaviours using automated wearable cameras.
In the third part of the thesis, I report findings from an experiment designed to assess a well known UK travel diary (The National Travel Survey). Across four locations (Oxford, UK; Romford, UK; San Diego, USA; and Auckland, New Zealand) I collected 3-4 days of SenseCam and travel diary data from n=84 participants (convenience sample). Compliance with the collection protocol was high and inspection of the crude results suggests relative agreement between measures. Analysis of matched pairs of measurements (n=1,127 journeys) suggests a significant positive bias on self-reported durations (2:08 minutes; 95% CI = 1:48 to 2:28; 95% limits-of-agreement = -9:10 to 13:26).
These results suggest self-reported journey exposure is valid at a population level, though corrections according to my reported bias could be considered. The large limits of agreement on duration estimates suggest self-report may be unsuitable for assessment of individual travel behaviour.
Genome engineering and gene drive in the mosquito aedes aegypti
Keywords: mosquito
genetic engineering
sterile insect technique
RNAi
Aedes
dengue fever
transposons
piggybac
gene drive
aegypti

Genetic control strategies are a novel method for reducing populations of pest insects such as the yellow fever mosquito Aedes aegypti, a major vector of several important arboviral diseases. This thesis describes efforts to develop new tools to engineer the Ae. aegypti genome and to better understand existing tools, and furthermore to use these to engineer a gene drive system in Ae. aegypti. The piggyBac transposon was found to be extremely stable in the germline of Ae. aegypti, and transposons engineered into the germline could not be remobilized with either an endogenous or exogenous source of piggyBac transposase. Conversely, somatic remobilization of piggyBac transposons was found to be readily detectable in the presence of a source of active transposase, the first report of such remobilization in Ae. aegypti. Toward new tools for genome engineering, the site-specific integrase from the phage φC31 was successfully used to promote exchange between a transgene cassette inserted into the genome of Ae. aegypti and a cassette in a plasmid vector, in the first demonstration of recombinase mediated cassette exchange technology in a pest insect species. The integrases from phages φRV1 and Bxb1 were not found to be active in the germline of the mosquito. Finally, development of a gene drive system in Ae. aegypti using an RNAi-mediated killer-rescue mechanism was attempted. Tissue-specific expression of tTAV-regulated-toxic effectors genes, using the promoter regions of the blood meal induced genes Carboxypeptidase A-1, 30Kb and Vitellogenin A, was possible, but sex-specificity was not achieved. A blood meal inducible lethal phenotype was not possible using the chosen promoters, with expression of the effectors either leading to death in early development or to a sublethal phenotype. RNAi against tTAV fused to the Mnp fragment of the dengue virus’ genome was tissue specific, but was found to be highly effective in the fat body suggesting that the Vitellogenin A was the best candidate for the engineering of killer-rescue systems in the mosquito.