VictorJuiz/thesis huggingface dataset:
Neutron reflection study on surfactant systems at different interfaces
Keywords: Surfactant mixtures
Neutron Reflection

The interfacial behaviour of several surfactant mixtures containing zwitterionic surfactants has been studied employing surface tension measurements and neutron reflection experiments. The mixing of surfactants at air–liquid interface could not be well understood using the pesudophase approximation and the regular solution model. By introducing the expansion of excess free energy to analysis the surface tension and neutron reflection data simultaneously, it is found that the mixing deviates strongly from ideal and the excess free energy is asymmetric.
It is observed that the presence of ionic surfactant at solid–liquid interface enhanced the adsorption of zwitterionic surfactants. The configuration of the surfactant molecule in the inner layer adjacent to the surface is invoked to explain the underlying mechanism. Maxima in the adsorption just above the CMC occurred at all three compositions studied for the mixed system SDS with dodecyl dimethylammonium propanesulfonate (DSB). The neutron reflection experiments suggest that the phenomenon may result in part from the mixture and in part from ion segregation in the micelles.
Structural studies on a series of dodecyl dimethylammonium acetate with different inter–charge spacer revealed that the configuration of the surfactants changes dramatically as the headgroup gets larger. Combined with the higher pKa value, it is highly possible that the carboxybetaine with longer spacer is adsorbed in its undissociated form, and the headgroup is oriented towards the air. This configuration might explain why the saturated monolayer structure is favoured over the micellization.
The utilisation of biomarkers of a reduced immune response to predict squamous cell carcinoma in long-term renal transplant recipients
Keywords: Immune senescence
Operational Tolerance
Squamous cell carcinoma
Renal Transplantation

Cutaneous squamous cell carcinoma (SCC) is the most common malignancy in renal transplant recipients (RTR) with an incidence up to 250 times that of the general population. SCC is frequently recurrent and more aggressive than in non-transplant cohorts. Immunological and clinical measures have been developed to stratify RTR by future SCC risk but their comparative performance in long-term RTR has not been assessed.
We hypothesised that biomarkers of two potential mechanisms underlying a reduced immune response may predict SCC development. These biomarkers comprised ‘signatures’ of immune regulation developed in RTR who have successfully ceased immunosuppression without development of graft dysfunction ('operational tolerance') and immunophenotypic changes associated with immunosenescence. Immunosenescence leads to a reduction of immune responses with increasing age.
A prospective cohort study was undertaken of 117 long-term RTR, half with a history of previous SCC. RTR were stratified by phenotype based on a majority ('CD57hi') or minority ('CD57lo') of peripheral blood CD8+ T cells expressing CD57. CD57hi RTR were 2.4 times more likely to develop SCC during follow-up, independent of age or history of previous SCC. This was more predictive than previously developed clinical and immunological measures. CD57hi RTR exhibited other functional and phenotypic changes associated with immunosenescence.
Signatures of operational tolerance did not predict SCC risk but were heavily influenced by the effect upon circulating B cells due to immunosuppressive regime, particularly azathioprine and calcineurin inhibition. Further evaluation indicated that azathioprine use was associated with the presence of donor-specific antibodies.
This study indicates that biomarkers of 'operational tolerance' are confounded by immunosuppression use and may not be suitable for clinical application in their current format. Biomarkers of immunosenescence, such as the CD57hi phenotype proposed in this study, may identify RTR at increased risk of subsequent SCC who may benefit from pre-emptive immunosuppression reduction.
Topics in the theory of Selmer varieties
Keywords: Diophantine Geometry
Arithmetic Fundamental Groups
Number Theory

The Selmer varieties of a hyperbolic curve X over &Qopf; are refinements of the Selmer group arising from replacing the Tate module of the Jacobian with higher quotients of the unipotent étale fundamental group. It is hoped that these refinements carry extra arithmetic information. In particular the nonabelian Chabauty method developed by Kim uses the Selmer variety to give a new method to find the set X(&Qopf;). This thesis studies certain local and global properties of the Selmer varieties associated to finite dimensional quotients of the unipotent fundamental group of a curve over &Qopf;. We develop new methods to prove finiteness of the intersection of the Selmer varieties with the set of local points (and hence of the set of rational points) and new methods to implement this explicitly, giving the first examples of explicit nonabelian Chabauty theory for rational points on projective curves.
Development and application of enantioselective H-bond donor organocatalysts
Keywords: H-bond donor
Phase transfer
Organocatalysis
Enantioselective

This thesis presents the application and development of H-bond donor organocatalysts. Chapter 2 presents an intramolecular Michael addition of β-dicarbonyls onto α,β-unsaturated esters catalyzed by tertiary amine/H-bond donor bifunctional catalysts, achieving up to 88% ee.
Chapter 3 outlines the design and synthesis of a new family of cinchona-derived H-bond donor/ammonium salt phase-transfer catalysts. The ability of these asymmetric phase-transfer catalysts to activate less reactive substrates than their tertiary amine analogues and to induce higher levels of enantiocontrol than commercially available phase-transfer catalysts was demonstrated in an intramolecular Michael addition.
Chapter 4 details the highly successful application of these new H-bond donor/ammonium salt phase-transfer catalysts to the enantio- and diastereoselective nitro-Mannich reaction of α-amido sulfones with nitroalkanes.
Preliminary investigations into a novel phase-transfer catalyzed asymmetric ketimine reduction demonstrate the ability of these catalysts to provide access to new methods.
Ab initio modelling of magnetoelectric materials
Keywords: magnetoelectrics
materials science
magnetism
chromia
DFT
cr2o3
ab initio
physics
density functional theory
first principles
multiferroics
doping

The search for magnetoelectric materials, i.e. materials that respond with a polarisation (magnetisation) when an external magnetic (electric) field is applied, has become more important in recent years---both for the standalone magnetoelectricity and as part of the cross-coupling in modern multiferroics. To date, applications of magnetoelectrics (MEs) in technology are hampered by either small coupling strengths or low operating temperatures.
In the present work, the linear magnetoelectric coupling is examined by means of density functional theory with the aim to understand the physics of the coupling, and in turn open up pathways in the search for improved coupling properties.
The spin part of the ME coupling tensor was shown to be the sum of the electronic and the lattice contribution. Recently developed first-principles frameworks allow us to gain insights into the microscopic mechanisms of the coupling and are applied to compute the response in modifications of the prototypical ME Cr2O3 and isostructural compounds. We find that strains at ambient pressures influence the lattice contribution significantly. At higher pressures, a magnetic phase transition is shown to destabilise magneto-active phonon modes and lead to a divergence of the longitudinal lattice response due to magnetic softness, with a coupling strength 650 times larger than its zero-pressure value. Equivalently, a divergence of the electronic response is measured at the transition from insulator to metal---previously suggested in literature, but to date not measured. The largest value of the electronic response is shown to be 31.4ps/m, which is larger than the ambient value by a factor of 70, and also large in terms of the absolute value. We exemplify both the magnetic softness and band-gap alterations by doping the Cr2O3 parent structure with Fe and Ti. We show that doping provides a powerful way to include magnetic frustration resulting in a ten-fold increase of magnetic contributions to the lattice response. When the dopants lower the Cr2O3 band gap, the electronic response is measured to be ten times larger than reported for pure Cr2O3. Finally, the high-symmetry configurations of the spin flop phase of Cr2O3 are modelled. A combined phenomenological and group-theoretical analysis reveals a novel ME coupling mechanism only present in the spin flop phases. Akin to the ferroaxial mechanism in multiferroics, a chiral in-plane transverse coupling term is observed, whose Landau invariant is of 5th order.
Optogenetic gene therapy for vision restoration
Keywords: Opsin
Microarray
Gene therapy
Retina
Retinal degeneration
Bipolar cell
Optogenetics

Inherited retinal dystrophies are a heterogeneous group of retinal diseases that often lead to blindness. The diverse range of causative gene mutations poses great challenges to developing therapies to improve the vision of affected people. One technique being investigated is optogenetics for vision restoration, a technique that aims to deliver light-sensitising molecules to the affected retina. This research project provides data on a range of variables that need to be optimised in order to successfully restore vision using an optogenetic gene therapy approach.
Fifteen wild type, chimeric and fusion constructs based on human opsins were compared by in vitro and in vivo tests to select the optimal light-sensitising construct. Of these, wild type rhodopsin, melanopsin and melanopsin–Gα subunit fusion constructs show the most promise for future studies.
For delivery of the light-sensitising construct, the adeno-associated virus (AAV) serotype AAV2/2(7m8) was shown to perform best compared to two other AAV serotypes when tested in degenerate mouse eyes and macaque and human retinal explants. The importance of the delivery route to the eye, the use of a targeted versus non-targeted approach and the AAV vector concentration were all tested in in vivo experiments.
In addition to testing such variables, the gene expression changes in target retinal bipolar cells in late-stage retinal degeneration were examined by microarray analysis of bipolar cell enriched samples isolated by fluorescence-activated cell sorting. Genes important for G protein signalling were generally expressed at a similar level in the degenerate state, while genes associated with oxidative stress and metabolism were differentially expressed.
Collectively, these data will inform the choice of construct, delivery method and target cell in future research into optogenetic strategies for vision restoration.
Ritual in development: Improving children’s ability to delay gratification
Keywords: cross-cultural psychology
ritual
future discounting
delay of gratification
experimental anthropology
executive function

To be accepted into social groups, individuals must internalise and reproduce appropriate group conventions, such as rituals. The high fidelity copying of such rigid and socially stipulated behavioural sequences places heavy demands on executive function abilities. Given previous research showing that challenging executive functioning also improves it, it was hypothesised that prolonged engagement in ritualistic behaviours would improve executive functioning in children, in turn improving their ability to delay gratification. A three month circle-time-games intervention with primary school children in two contrasting cultural environments (Slovakia and Vanuatu) was conducted. In both environments we found the intervention improved children's executive function and in turn their ability to delay gratification. Moreover, these effects were amplified when the intervention task was imbued with ritual, rather than instrumental, cues. The findings presented in this thesis have potentially far-reaching implications for child-rearing and educational practices, suggesting ritual participation may be necessary for the cultivation of future mindedness.
Desire and the ethics of advertising
Keywords: Platonism
Capitalism
Advertising
Art
Ethics
Plato
Christianity
Virtue
Education of desire
Desire
Religion
Advertisements
God
Augustine

The aim of this thesis is to examine advertising from the point of view of Christian ethics: how it works, what is wrong with it and how it might go right as a practice. It argues that much existing criticism of advertising is justified, but that its power to create desire might be turned towards serving the good of the education of desire, leading us towards, or strengthening, a love of God, and helping us relate to products and services based on this love. This is significant because learning to desire well is central to living a Christian life, and because advertising influences how many people desire today. In contrast to authors who simply criticise advertising, often as part of a general critique of consumer culture, this thesis offers a constructive and detailed examination of the practice itself, looking at how its techniques work and how they might be reformed into an ‘art of advertising’. In making this argument the thesis draws primarily on Augustine, in addition to Plato, and modern critics of advertising. First, it describes desire, before examining how advertisements create desire, followed by an assessment of existing criticisms of this process. It then develops an account of the education of desire, identifying what an art of advertising should aim to achieve, before examining the techniques by which an advertisement might achieve this. The argument is intended to contribute to a project within Christian ethics of critiquing advertising, and presenting a workable ethical vision for the future of the industry.
Schedule 21 and its impact on the sentencing of homicide
Keywords: Guidelines
Schedule 21
Criminal Justice Act 2003
Murder
Sentencing
Manslaughter

This thesis examines Schedule 21 to the Criminal Justice Act 2003 and its impact on the law for sentencing homicide. It seeks to establish the intention behind the statutory guidelines for murder, and critique the rules therein, using this analysis to inform an evaluation of the Court of Appeal (Criminal Division)'s interpretation and application of the schedule in appellate cases. It also, by virtue of the investigation into the schedule's motivations and the statutory framework accompanying it, considers if Schedule 21 has implications for the sentencing of other homicide offences, and concluding that it does, goes on to explore whether any such influence has been accorded to the schedule in the sentencing of manslaughter.
Synthesis and biological evaluation of rare monosaccharides and their mimics
Keywords: Rhamnose operon
Rare Sugar
Iminosugar
Rhamnose
Azetidine Carboxylic Acid

This thesis describes work in the synthesis and biological evaluation of different carbohydrates and their derivatives.
Azetidine carboxylic acid (Aze), as a pharmacophore in medicinal chemistry, is attracting more and more researchers in recent years. As a four membered ring analogue of proline, this nature occurring compound can be mis-incorporated into proteins and can cause changes in protein conformation and therefore induce toxic effects. It is therefore useful to study how Aze and its derivatives affect protein confirmation. Previous research has identified some azetidine iminosugars to be promising inhibitors of certain glycosidases. Chapter 2 describes the synthesis, from D-glucose, of various novel 3-fluoro-Aze, 3-azido-Aze analogues and a trans,trans-3,4-difluoro-proline as novel peptidomimetics. Short oligomers of these amino acids were synthesized. A number of 3-fluoro-azetidine iminosugars were obtained to test their inhibition of glycosidases and cancer cell growth. A 3-fluoro-azetidine diol showed significant growth inhibition of several different human cancer cell lines compared with anti-cancer drugs 5-fluorouracil and gemcitabine.
Most rare sugars are still difficult to produce in quantity by either chemical or biotechnological methods. Some of them have interesting activities and potential applications; however, research on these rare sugars is constrained by their high price and inaccessibility. In Chapter 3 an approach to economically and easily produce rare sugars, in high purity, is developed. A number of rare sugars, including L-glucose, D-gulose, D-idose and 6-deoxy-hexoses, were synthesized from cheap D-glucose or its derivatives on large scales and in high yields. Complicated purification methods were avoided. The development of this methodology can contribute not only to the accessibility of these expensive sugars but also to increase their availability for biological evaluation.
The L-rhamnose inducible promoter system (L-rhamnose operon) in E. coli. is a commercially available gene expression system which is widely used for various purposes. L-Rhamnose regulates the gene expression of L-rhamnose operon in E. coli. Moreover, L-rhamnose processing enzymes play crucial roles in different pathogenic bacteria while they have no role in mammalian metabolism, suggesting L-rhamnose processing enzymes could be potential therapeutic targets. Searching for L-rhamnose analogues, which have induction activity for the L-rhamnose operon, or specific inhibitory activity towards L-rhamnose processing enzymes, is of both commercial and academic interest. In Chapter 4 the synthesis of a large number of L-rhamnose analogues, including 6-deoxy-hexoses and 6-deoxy-iminosugars, from L-rhamnose, is described. Biological assays identified five hexoses as non-metabolizable inducers for the L-rhamnose operon and several inhibitors of L-rhamnosidases and rhamnose isomerases.
'A learned man and a patriot': the reception Of Cicero in the early imperial period
Keywords: Early Roman Empire
Roman Republic
Latin Historiography
Roman Republican Literature
Augustan Rome
Latin Poetry
Cicero
Roman Imperial Culture
Roman Oratory

This thesis is a literary study of how the life and works of Marcus Tullius Cicero were received in the century that followed his death. There are two ways of understanding the importance of such a study: the first is to think of it as a vital first step in assessing Cicero's impact on European thought and literature; the second is to see it as a study of how the people of early imperial Rome interacted with their Republican past. In order to provide a broad overview of this subject, I have chosen to focus on three separate areas of imperial literature which together provide a representative snapshot of Roman literary activity in this period. The period in question is essentially an extended Augustan age: beginning with Cicero's death ending in the reign of Tiberius.
The first area of imperial literature under consideration is historiography. This section begins with a consideration of Sallust's decision to downplay Cicero's role in defeating the Catilinarian Conspiracy, ultimately concluding that this is authorial posturing on Sallust's part, a reflection of Cicero's importance in the years immediately following his death. This is followed by a chapter on the presence of Ciceronian allusions in Livy, arguing that they were a key means by which he enriched his narrative of the Hannibalic war. It concludes with two chapters on historiographical descriptions of Cicero's death, noting that these treatments become markedly more hagiographic the further one progresses into Tiberius' Principate.
The second area under consideration is rhetoric, specifically focussing on the prominence of the declamation hall in this era. The three chapters in this section study the testimony of Valerius Maximus and Seneca the Elder, both of whom bear witness to Cicero's fundamental importance to this institution. The section concludes that the world of declamation was the prime motor for the hagiographic treatments of Cicero that was noted in the later historical accounts of his death.
The third and final section considers the poetry of the Augustan era, demonstrating that a process of declining sophistication is not the whole story in Cicero's reception. By looking at Virgil and Ovid's intertextual relationships with Cicero, this section demonstrates that he was a rich source of inspiration for some of the ancient world's most erudite authors.
The unnameable: limits of language in early analytic philosophy
Keywords: Frege
Early Analytic Philosophy
Inexpressibility
Unnameability
Metaphysics
Philosophy of Language

This thesis concerns the view, shared by Frege, Russell and the early Wittgenstein, that there are entities that cannot be named. Chapter 1 clarifies the particular form this commitment takes in the work of these three authors. The chapter also details a distinctive cluster of philosophical difficulties attending the view certain entities are unnameable, and explores the relation between unnameability and inexpressibility. The remaining chapters are devoted to investigating what grounds there are for countenancing the unnameable. The particular focus throughout is Frege's thesis that concepts cannot be named. Chapters 2 and 3 are devoted to giving a detailed hearing to two arguments for Frege's thesis distinguishable in the locus classicus, 'On Concept and Object'. The first argument concerns the relationship between co-reference and intersubstitutability; the second concerns the unity of thought. It is contended that these arguments fail to substantiate Frege's thesis. Chapters 4 and 5 examine two further arguments for Frege's rejection of singular reference to concepts. The first is based upon the alleged impossibility of expressing identities between objects and concepts; the second draws on upon considerations pertaining to diagonalization and Russell's paradox. It is contended that each of these arguments can be resisted in defence of singular reference to concepts.