VictorJuiz/thesis huggingface dataset:
Flexoelectric and dielectric phenomena in helicoidal liquid crystals
Keywords: cholesteric
chirality
LCs
optics
experimental
blue phase
birefringence
liquid crystals
device engineering
dielectric
display
LCD
physics
engineering science
switching
engineering
soft matter
flexoelectric
Kerr

The unique features of flexoelectric and dielectric effects are investigated, and exploited for a variety of functions, in a wide range of helicoidal liquid crystal systems, including non-chiral, cholesteric and blue phases.
Electrooptic techniques are developed to measure flexoelectric parameters in non-chiral and cholesteric liquid crystals using twisted nematic and Grandjean geometries respectively. A crystal rotation method, and using a lock-in amplifier, is used to enable the measurement of a very small e/K of 0.011 C/N-1m-1.
Enhancement in chiral-flexoelectric switching is demonstrated theoretically in liquid crystals with negative dielectric anisotropy and in systems in which the pitch is constrained to be other than the natural pitch.
A methodological framework for inducing stable Uniform Lying Helix alignment is developed based on weak homeotropic alignment conditions and a method to bias the helicoidal axis orientation; a series of approaches within this framework are demonstrated, including nano-grooved interfaces, periodic boundaries conditions, in-plane fields, and mould-templated micro-channels. The latter approach is potentially commercially viable for sub-millisecond electrooptic technology.
The contribution to a cholesteric material's effective dielectric permittivity of flexoelectric polarization is formulated, and an ability to switch a cholesteric between Grandjean and lying-helix configurations based on the dispersion in the flexoelectric polarization and resultant relaxation in dielectric properties is demonstrated. The flexoelectric contribution to dielectric permittivity is exploited to enable switching in bistable reflective displays and alignment of the Uniform Lying Helix.
The existence of a flexoelectric contribution to Kerr switching in blue phases is demonstrated, and a semi-empirical model for the effect is developed. The effect is the first known example of a non-polar flexoelectrooptic effect. Independent flexoelectric and dielectric contributions to Kerr switching in blue phases are measured experimentally by measuring the induced birefringence as a function of driving frequency in flexoelectric- and dielectric-dominated wide-temperature-range blue phase materials.
Eugenics and Christian mission. Charitable welfare in transition: London and New York, c. 1865–1940.
Keywords: the Salvation Army
Scientific Racism
Philanthropy
Christian Mission
New York City Mission
Eugenics
London City Mission

In this thesis it is argued that a full and complete understanding of the eugenics movement may only be gained by examining those who were implicated in its criticisms.
Using the example of three Christian missionary organisations that worked amongst largely poor and immigrant communities in London and New York, it is demonstrated that eugenics was a pervasive ideology outside its 'official' societies.
Moving away from an understanding grounded in ideas of conflict and concession, it will be demonstrated that those whose work was challenged by eugenic claims were able to interpret the ideology according to their existing reformist agendas. Hereditarian ideas did not sound the death knell for reformers, and these organisations demonstrated both the willingness and capacity to shape eugenic ideas within and outside their organisations.
From these examples it is argued there is a need to move beyond definitions of eugenics that limit the movement to a small subset of its methods. Far from being a peripheral aspect to the history of eugenics, it will be seen that these missionary agencies occupied a position at the centre of eugenicists' concerns. As prominent providers of charity, a work charged by eugenicists with unnaturally hindering the natural laws of selection, religious communities were, in part, one of the reasons that eugenics was deemed necessary in the first place.
This picture is confirmed by an examination of two eugenics societies, one on each side of the Atlantic, where the impact of religious sentiment and ideas exerted a dramatic effect upon policies and propaganda work.
There was no one-way flow of ideology from eugenicists towards reformers, but rather a two-way dialogue which created a marked impression on both groups.
Light scattering from ultracold atomic gases
Keywords: quantum optics
optical lattices
ultracold atoms
quantum imaging

Systems of ultracold atoms in optical potentials have taken a place at the forefront of research into many-body atomic systems because of the clean experimental environment they exist in and the tunability of the system parameters. In this thesis we study how light scattered from these ultracold atomic gases reveals information about the state of the atomic gas and also leads to changes in that state.
We begin by investigating the angular dependence of light scattered from atoms in optical lattices at finite temperature. We demonstrate how correlations in the superfluid and Mott insulator states affect the scattering pattern, and we show that temperature affects the number of photons scattered. This effect could be used to measure the temperature of the gas, however, we show that when the lattice band structure is taken into account the efficiency of this temperature measurement is reduced.
We then investigate light scattering from small optical lattices where the Bose-Hubbard Hamiltonian can be solved exactly. For small lattices, scattering a photon from the atomic system significantly perturbs the atomic system. We develop a model of the evolution of the many-body state that results from the consecutive scattering and detection of photons. This model shows that light scattering pushes the system towards eigenstates of the light scattering measurement process, in some cases leading to a superposition of atomic states.
In the second half of this thesis we study light scattering that depends on the internal hyperfine spin state of the atoms, in which case the scattered light can form images of the spatial atomic spin distribution. We demonstrate how scattering spatially correlated light from the atoms can result in spin state images with enhanced spatial resolution. We also show how using spatially correlated light can lead to direct measurement of the spatial correlations of the atomic spin distribution.
We then apply this theory of spin-dependent light scattering to the detection of different spin states of ultracold gases in synthetic magnetic fields. We show that it is possible to distinguish between ground states in the quantum Hall regime using light scattering. Moreover, we show how noise correlation analysis of the spin state images can be used to identify the correlations between atoms and how a variant on phase-contrast imaging can reveal the relationship between the atomic spins.
Musical thought and the early German Reformation
Keywords: Conrad Wimpina
Johannes Cochlaeus
Luther
Listenius
Georg Witzel
Musica poetica

German musicology has customarily situated a paradigm shift in musical aesthetics some time during the first half of the sixteenth century. This dissertation examines the suggestion that German Reformation theology inspired a modern musical aesthetic. In Part One, the existing narrative of relationship between theological and musical thought is tested and rejected. Chapter 1 analyses twentieth-century music historians' positive expectation of commensurability between Luther's theological ideas and the sixteenth-century concepts of the musical work and musical rhetoric, concluding that their positive expectation was dependent on a Germanocentric modernity narrative. Chapter 2 assesses Listenius' Musica (1537), the textbook in which the concepts of the musical work and musica poetica were expounded for the first time. I argue that, since Listenius' textbook was intended as a pedagogical tool, it is inappropriate to read his exposition of musica poetica and opus as if logical sentences on musical aesthetics. Part Two investigates the treatment of musica in the theology of early German Reformation disputants. Chapter 3 finds that Luther's early musical thought was borrowed from the late mediæval mystics, and resisted the influence of the Renaissance Platonists. Chapter 4 shows that, far from embracing humanist ideas of musical rhetoric, Luther's Reformed musical aesthetic became increasingly anti-rational and sceptical of music's relation to verbal meaning. Chapter 5 examines the discussions of music by the German Romanist polemicists. It finds that their music-aesthetic assertions were opportunistic attempts to situate the Lutherans outside the bounds of orthodoxy. The dissertation concludes that the discussions of music in early German Reformation texts ran counter to the general sixteenth-century trajectory towards a humanistic or modern aesthetic of music. It further argues that the aesthetic proposals of sixteenth-century German theologians should be taken seriously in the formation of our present-day picture of sixteenth-century musical thought.
Biak morphosyntax
Keywords: morphology
syntax
Biak language

This thesis is a general description of the morphology and syntax of the Biak language. The Biak language belongs to the West New Guinea subgroup of the Austronesian language family and is spoken by around 50,000 to 70,000 speakers in West Papua in the northern part of the Geelvink Bay. The thesis consists of 7 main chapters that cover demographic and ethnographic information of the language, morphology, grammatical categories, basic constituent order, noun compounding and denominalization, relative clauses, and predicate nominal constructions.
The main findings of the thesis are:
The Biak language is predominantly a head-initial language.
The Biak language has morphological variation from monomorphemic to polymorphemic with the polymorphemic being the dominant pattern in the language.
Inflectional patterns on verbal and prepositional predicates, demonstratives, and possessive pronouns are divided into two patterns: the consonantal pattern and the vocal pattern.,/li>
Biak has alienable and inalienable nouns. Alienability in Biak is a syntactic distinction, not exactly corresponding to the semantic distinction.
The basic constituent order is SVO or AVP. Variations occur with predicate nominal (OV) and internally headed relative clause which uses SOV pattern.
Three types of relative clauses were identified:
Post nominal relative clause;
Headless relative clause; and
Internally headed relative clause.
The Biak language allows stacked and nested relative clauses.
Two kinds of predicate nominal constructions were identified:
copular clitics (clitic –ri, -s-, and free pronoun clitics) and
copular verbs –iri and iso. The two kinds of predicate nominal constructions can be distinguished syntactically.
Investigating non-image forming photoreception in a mouse model of autosomal dominant optic atrophy
Keywords: neuroprotection
retinal ganglion cells
dominant optic atrophy
melanopsin

Autosomal Dominant Optic Atrophy (ADOA) is a progressive optic neuropathy affecting mainly the retinal ganglion cells (RGCs). It is associated with mutations in the Opa1 gene and is phenotypically characterized by decreased visual acuity, central field deficits and colour vision defects. Experimental work on Opa1 mutant mice (B6; C3-Opa1Q285STOP) has permitted further characterisation of the pathophysiology of the disease. A specific functional visual deficit in the photopic negative response of the electroretinogram has been described in these mice, possibly due to altered dendritic pruning of RGCs. However, non-image-forming (NIF) visual function, which is regulated by a subset of RGCs that express the photopigment melanopsin, has not yet been extensively investigated in Opa1 mutant mice. We were interested in whether RGC dysfunction in Opa1 mutants affects NIF behaviours. We evaluated circadian behaviour, sleep behaviour and melanopsin expression in Opa1 mutant mice (Opa1+/-) and littermate controls (Opa1+/+). Opa1 mutant mice were able to entrain their behaviour rhythm to a normal 12:12 hr light/dark cycle, confining their activity to the dark phase. The suppression of activity by acute light exposure at night (negative masking) was equivalent between genotypes. Circadian phase shift responses to 480 nm or 520 nm light pulses during the subjective night were preserved in Opa1+/- mice relative to wildtype controls. The acute induction of sleep by light exposure at night was also present in Opa1+/- mice and not significantly different to Opa1+/+ animals. Immunohistochemical characterisation of melanopsin cells in flatmount retinae revealed no significant differences in cell numbers betweeen genotypes. Melanopsin (Opn4) transcript levels were also equivalent between Opa1 wildtype and mutant mice. There was also no obvious difference in melanopsin cell stratification patterns. The data overwhelmingly support the preservation of the NIF visual system in Opa1 mutant mice. The findings are consistent with patient studies suggesting increased resistance of melanopsin-expressing RGCs in conditions of mitochondrial optic atrophy. Further work is needed to extend our understanding of the possible neuroprotective mechanism involved which could lead to exciting therapeutic strategies.
The role of ultraviolet light in the image and non-image forming visual systems of mice
Keywords: EYE
OPHTHALMOLOGY
MOUSE
SHORT-WAVELENGTH
S-CONES
CIRCADIAN
VISION
OPN1SW
ULTRAVIOLET
LIGHT
NON-IMAGE FORMING VISUAL SYSTEM
PHOTORECEPTORS
UVS CONES
CONE

Long thought to be absent from mammals, UV sensitivity has now been established in many species, including mice, where it has been found to provide visual sensitivity and drive circadian responses. Compared to closely related species, the murine UVS cone photopigment is both in relatively high abundance and is associated with a unique expression gradient across the retina, raising questions concerning the function of UV sensitivity that may be relevant to other mammals. Here we investigate the non-image and image forming roles of UV light in mice. Phase-shifting sensitivity changes in rod and cone photoreceptor mutants/ transgenics indicated a significant contribution by cone photoreceptors to this assay of photic-entrainment under UV light. Generation of an Opn1sw knockout lacking the UVS opsin gene confirmed a critical role of UVS cones in the non-image forming system of the mouse, differing from that established for the middle-wave sensitive (MWS) cone opsin, and confirmed that UV light could be used for visual tasks in a visual adaptation of the novel-object recognition assay. Finally, examination of retinal c-fos induction found evidence of an inhibitory influence of the cone pathway linked to short-wavelength sensitivity. That the contribution of UVS opsin was significantly greater than similar experiments have found for MWS cones, despite widespread cone opsin co-expression, may indicate a distinct role for the UVS-only s-cones in the non-image forming visual system. Overall these data suggest that the role of ultraviolet light in the circadian system of the mouse may be central to its unique cone opsin characteristics and provides new insight concerning this critical research model relevant to its use in the investigation of human biology.
Anomaly detection in vessel track data
Keywords: Maritime Traffic
Gaussian Process
Outlier Detection
Novelty Detection
Extreme Value

This thesis introduces novelty detection techniques that use a combination of Gaussian processes, extreme value theory and divergence measurement to identify anomalous behaviour in both streaming and batch marine data. The work is set in context by a review of current methodologies, identifying the limitations of current modelling processes within this domain.
Marine data modelling is first improved by endowing the Gaussian process with the capacity to model both first order and second order dynamics; enhancing maritime data modelling through exploration of appropriate Gaussian process kernels. Gaussian processes are then used to forecast probable future vessel positions. The concept of combining the predictive uncertainty from the Gaussian process with extreme value distributions is then introduced. This provides a means of detecting anomalous vessel dynamics given the previously learnt model. The process is made amenable to online operation through adaption of the Gaussian process to sequential updates. The latter allows the model to be updated in an efficient online manner, after confirming that received data lies within the probability bounds of the model forecast behaviour. Finally a means of measuring distance between functions is introduced, which is used to identify communities of similar vessel types based on the underlying vessel dynamics. This is used to address the issue of vessel class (i.e. fishing vessel, cargo vessel etc.) misrepresentation through detection of anomalies between the inferred vessel class and the class broadcast by the vessel.
Dimension reduction of streaming data via random projections
Keywords: maximum likelihood estimation
cardinality
MCMC convergence diagnostics
random projections
data streaming
L-estimation
entropy

A data stream is a transiently observed sequence of data elements that arrive unordered, with repetitions, and at very high rate of transmission. Examples include Internet traffic data, networks of banking and credit transactions, and radar derived meteorological data. Computer science and engineering communities have developed randomised, probabilistic algorithms to estimate statistics of interest over streaming data on the fly, with small computational complexity and storage requirements, by constructing low dimensional representations of the stream known as data sketches. This thesis combines techniques of statistical inference with algorithmic approaches, such as hashing and random projections, to derive efficient estimators for cardinality, l_{alpha} distance and quasi-distance, and entropy over streaming data. I demonstrate an unexpected connection between two approaches to cardinality estimation that involve indirect record keeping: the first using pseudo-random variates and storing selected order statistics, and the second using random projections. I show that l_{alpha} distances and quasi-distances between data streams, and entropy, can be recovered from random projections that exploit properties of alpha-stable distributions with full statistical efficiency. This is achieved by the method of L-estimation in a single-pass algorithm with modest computational requirements. The proposed estimators have good small sample performance, improved by the methods of trimming and winsorising; in other words, the value of these summary statistics can be approximated with high accuracy from data sketches of low dimension. Finally, I consider the problem of convergence assessment of Markov Chain Monte Carlo methods for simulating from complex, high dimensional, discrete distributions. I argue that online, fast, and efficient computation of summary statistics such as cardinality, entropy, and l_{alpha} distances may be a useful qualitative tool for detecting lack of convergence, and illustrate this with simulations of the posterior distribution of a decomposable Gaussian graphical model via the Metropolis-Hastings algorithm.
Structural and biophysical studies of HIV Rev and HBV e-antigen
Keywords: X-ray crystallography
cryo-electron microscopy
structural biology

Human immunodeficiency virus (HIV) Rev and Hepatitis B virus (HBV) e-antigen are both viral proteins that have key functions in their respective viral replication cycles. Both have evaded crystallization for decades due to their tendency to aggregate and/or form higher-order species. In this thesis the structure determination of HIV Rev and HBV e-antigen is presented—achieved via complexing with monoclonal antibody Fab fragments—and their structures are analysed.
HIV Rev is a small regulatory protein that mediates the nuclear export of viral mRNAs, an essential step in the HIV replication cycle. In this process, Rev cooperatively oligomerises onto a highly structured RNA motif, the Rev response element. The structure of Rev (complexed with Fab), determined to 2.3 Å resolution, reveals a molecular dimer where the ordered portion of each subunit (N-terminal domain; NTD; residues 9-65) contains two coplanar a-helices arranged in hairpin fashion. Rev subunits dimerise via interaction of identical hydrophobic patches that overlap to form a V-shaped assembly. Mating of hydrophobic patches on the outer surface of the dimer promotes higher order interactions. Cryo-electron microscopy and helical image reconstruction of in vitro assembled Rev filaments were performed to better understand higher-order Rev oligomerisation. Reconstructions of Rev filaments were determined to ~13 Å resolution, permitting docking of the Rev NTD structure. Conformational variability of the Rev dimer subunits and use of a third ligomerisation interface engender filaments that can expand and contract. Both characteristics were also observed in the crystal structures of Rev. Surface features of the Rev filaments are altered in different expansion states, which may have implications for the assembled forms that Rev adopts during nuclear export of RNA and subsequent re-import into the nucleus. Various models for Rev oligomerisation onto the viral RNA are proposed.
Chronic Hepatitis B virus (HBV) infection afflicts millions worldwide with cirrhosis and liver cancer. HBV e-antigen (HBeAg), a clinical marker for disease severity, is a soluble variant of the protein (core antigen, HBcAg) that forms the building-blocks of capsids. HBeAg is not required for virion production, but is implicated in establishing immune tolerance and chronic infection. The crystal structure of HBeAg clarifies how the short N-terminal propeptide of HBeAg induces a radically altered mode of dimerisation relative to HBcAg (~140 rotation), which is locked into place through formation of intramolecular disulfide bridges. This structural switch precludes capsid assembly and engenders a distinct antigenic repertoire, explaining why the two antigens are cross-reactive at the T-cell level (through sequence identity) but not at the B-cell level (through conformation). The structure offers insight into how HBeAg may establish immune tolerance for HBcAg while evading its robust immunogenicity.