VictorJuiz/thesis huggingface dataset:
Biocompatible carbon nanotube/β-titanium alloy composite materials

The thesis describes a study of the modifications of orthopaedic Ti-based substrates using nanomaterials, and the evaluation of their biocompatibility for further use as implant material, with the aim to develop new, biocompatible β-Ti/CNT composite materials. Traditionally, CNTs require the presence of a transition metal catalyst such as Fe, Ni, Co, for successful growth. Different aspects of a catalyst-assisted CVD MWCNTs growth on various Ti-based substrates including bulk, thin films and 3D porous scaffolds, have been investigated. Low concentrations of catalyst were deposited using spin coating on titanium substrates of various forms and shapes. A strong influence of the surface topography was observed. In contrast, no effect of the elemental composition of the substrate could be detected.
To evaluate the biocompatibility of the newly created materials, cell culture studies using fetal human osteoblasts (fHobs) were performed. It was shown that β-Ti/MWCNTs samples possess good initial osteoblast attachment, but no long-term osteoblast activity. Hence the biocompatibility of isolated (i.e. without a Ti substrate) MWCNTs was studied, using MWCNT carpets and various types of MWCNTs buckypapers. All the samples revealed very low cell activity. While β-Ti/MWCNTs samples did not exhibit good biocompatibility, alternative β-Ti/TiC samples were synthesized with a simple CVD method and revealed good osteoblast response with increased mineralization. Moreover, good corrosion resistance and mechanical properties of β-Ti/TiC samples have been reported.
Finally, successful method for non-catalytic CVD MWCNTs growth on Ti substrates was developed for the first time, thereby excluding potentially toxic catalysts from the implant material. CVD was performed with acetylene precursor on bulk titanium substrates etched with Piranha solution, which generated an appropriate surface to foster MWCNTs growth. A combination of the change in the surface roughness, improved hydrophilicity, and elemental composition of the surface as a result of the Piranha etching is likely to be responsible for the successful formation of MWCNTs.

Keywords: Carbon nanotubes, titanium, biocompatibility
Advisor: Grobert, N
British cohabitation and the household division of labour

The structure of the family unit in the United Kingdom has undergone monumental changes in recent decades. The legal definition of a family has evolved substantially to include a wider range of family forms, most recently same-sex marriage, which became legal in the United Kingdom (excluding Northern Ireland) in 2014. Legal changes in the family accompany a range of social changes – among the most common of these is an expansion in the number of different-sex non-marital co-residential unions (concisely called "cohabitation") (Ermisch and Francesconi, 2000; Beaujouan and Bhrolcháin, 2011).
Since the 1970s, these types of relationships have become widely accepted (Coast, 2009) and increasingly common (Office for National Statistics, 2012a). However, despite its prevalence, cohabitation in the United Kingdom is seldom studied independently of marriage. My dissertation strives to fill this gap in the literature.
Specifically, my dissertation adds to the understanding of the household division of labour during cohabitation. Instead of merely examining cohabitation as one homogenous relationship type, Chapter 2 profiles three groups of cohabitants: 1) pre-marital cohabitants; 2) non-marital short-term cohabitants; 3) long-term cohabitants who reside together for five years or longer. Subsequent chapters examine how each of these groups, in turn, addresses the household division of labour – pre-marital and early couple formation cohabitation in Chapter 3, couples transitioning from cohabitation to marriage in Chapter 4, and during long-term cohabitation in Chapter 5. This dissertation is a significant contribution to the field of economic sociology because the household division of labour has not yet been explored during cohabitation in this way.

Keywords: work
household division of labour
domestic work
housework
economic sociology
sociology
cohabitation
Advisor: Gershuny, J
Simulations of systems of cold Rydberg atoms

The past three decades have seen extraordinary progress in the manipulation of neutral atoms with laser light, to the point where it is now routine to trap and cool both individual atoms and entire atomic clouds to temperatures of only a few tens of nanoKelvin in a controlled and repeatable fashion. In this thesis we study several applications of Rydberg atoms – atoms with an electron in a highly excited state – within such ultracold atomic systems. Due to their highly-excited electron, Rydberg atoms have a number of exaggerated properties: in addition to being physically large, they have long radiative lifetimes, and interact strongly both with one another and with applied external fields. Rydberg atoms consequently find many interesting applications within ultracold atomic physics.
We begin this thesis by analysing the way in which a rubidium atom prepared in an excited Rydberg state decays to the ground state. Using quantum defect theory to model the wavefunction of the excited electron, we compute branching ratios for the various decay channels that lead out of the Rydberg states of rubidium. By using these results to carry out detailed simulations of the radiative cascade process, we show that the dynamics of spontaneous emission from Rydberg states cannot be adequately described by a truncated atomic level structure.
We then investigate the stability of ultra-large diatomic molecules formed by pairs of Rydberg atoms. Using quantum defect theory to model the electronic wavefunctions, we apply molecular integral techniques to calculate the equilibrium distance and binding energy of these molecular Rydberg states. Our results indicate that these Ryberg macro-dimers are predicted to show a potential minimum, with equilibrium distances of up to several hundred nanometres.
In the second half of this thesis, we present a new method of symbolically evaluating functions of matrices. This method, which we term the method of path-sums, has applications to the simulation of strongly-correlated many-body Rydberg systems, and is based on the combination of a mapping between matrix multiplications and walks on weighted directed graphs with a universal result on the structure of such walks. After presenting and proving this universal graph theoretic result, we develop the path-sum approach to matrix functions. We discuss the application of path-sums to the simulation of strongly-correlated many-body quantum systems, and indicate future directions for the method.

Keywords: Walks and paths on graphs
Cold atoms
Graph theory
Rydberg states
Advisor: Jaksch, D
Understanding violence in medieval London: an examination of the skeletal evidence

It is often presumed that the medieval period was an exceptionally violent one. But, previously, this idea has predominately been based on historical evidence of violence. As this data is subject to numerous biases based on past perception of what connoted criminally violent behaviour, this assumption of excessive medieval violence can be called into question. This study attempts to rectify this problem by adding evidence of violence from the skeletal record, helping to create a more well-rounded picture of medieval violence. In total, data from over 6,000 skeletons, representing six different sites from medieval London, were analysed for evidence of violence-related injuries. The skeletal evidence was then interpreted using an approach that integrates both the historical evidence and cultural patterns of violence. The overall findings suggest that violence was prominent and affected all aspects of medieval London society, but how that violence was characterised depended on an individual’s sex, age, social status, and century of life.

Advisor: Schulting, R
The road to prohibition: nuclear hierarchy and disarmament, 1968–2017

Year in year out, hundreds of diplomats and civil society representatives partake in a seemingly endless stream of meetings on nuclear disarmament. These meetings seldom produce materially significant agreements. In fact, no nuclear warhead has ever been dismantled as a direct result of multilateral negotiations. And yet the web of institutions that make up the ‘multilateral nuclear disarmament framework’ continues to expand. Why? In this thesis, I identify three waves of institutional expansion in the multilateral nuclear disarmament framework (1975–1978; 1991–1999; 2013–2017), linking them to crises of legitimacy in the nuclear order. Institutional expansion, I argue, has been driven by ‘struggles for recognition’ by non-nuclear powers loath to accept permanent legal subordination. Institutional contestation has allowed non-nuclear powers to exercise symbolic resistance to the frozen nuclear hierarchy enshrined by the Nuclear Non-Proliferation Treaty (NPT) and its distinction between nuclear ‘haves’ and ‘have-nots’. But the relegitimising function of institutional contestation reveals an irony: By solving recurrent crises of legitimacy in the nuclear order, the expansion of the disarmament framework has served to stabilise nuclear inequality in the long term. However, the 2017 adoption of the Treaty on the Prohibition of Nuclear Weapons (TPNW) may signal an end to this cyclical pattern of de- and relegitimisation. After half a century of contestation within the hierarchical NPT framework, the TPNW represents a legal negation of nuclear hierarchy as such.

Keywords: hierarchy
punctuated equilibrium
institutions
recognition
Advisor: Nicolaidis, K
Study of the structure and function of the influenza virus RNA-dependent RNA polymerase

Influenza viruses are segmented, negative-sense RNA viruses responsible for influenza disease. Unlike other negative-sense RNA viruses, influenza virus genome replication occurs in the nucleus of infected cells. The virus encodes a heterotrimeric RNA-dependent RNA polymerase (FluPol) that is responsible for transcribing and replicating the viral genome. In order to transcribe, the FluPol generates capped RNA primers by a process termed “cap-snatching”. In it, the polymerase binds host capped RNAs and cleaves them 10-13 nucleotides downstream of the cap structure. The catalytic core of FluPol is found in the PB1 (Polymerase Basic protein 1) subunit, which associates with PB2 (Polymerase Basic protein 2) and PA (Polymerase Acidic protein). PB2 and PA contain a cap binding domain and an endonuclease domain respectively, which enable cap-snatching to take place. Viral transcription and replication occur in the context of a ribonucleoprotein (RNP) complex, where an RNA segment is coated by nucleoprotein and bound by a single copy of FluPol. Regulation of transcription and replication during infection is dependent on multiple viral and host factors, including nucleoprotein, cellular DNA-dependent RNA polymerase II (Pol II) and nuclear import factors. While high-resolution structures of the FluPol heterotrimer and low-resolution structures of RNPs are available, multiple aspects of the mechanisms involved in polymerase activity and its modulation remain poorly understood.
In this DPhil project, I have employed a combination of functional and structural approaches towards exploring FluPol activity. Here I present the work carried out towards optimising the methods for FluPol structural analysis, more specifically, the use of cryo-electron microscopy to explore both the structure of the heterotrimer in complex with modulators of polymerase activity as well as RNPs. I also describe the work carried out on characterisation of the requirements for transcription and replication by FluPol. This includes the role of Pol II in transcription regulation as well as those of FluPol, nucleoprotein and host factor ANP32 in controlling viral replication. Furthermore, I also present the characterisation of a panel of 24 camelid single-chain antibodies, known as nanobodies, as tools to explore polymerase activity. Within these, nanobodies which exhibited robust inhibition of all polymerase activity were found, which opens the possibility of employing these to identify sites on the polymerase that would be suitable targets for small molecule inhibitor design.

Advisor: Fodor, E
Grimes, J
Roll-to-roll deposition of highly flexible organic-inorganic barrier layers for printed electronics and photovoltaics

This thesis investigates how to improve transparent flexible water vapour barriers by understanding how water permeates through them. The barriers consisted of a reactively sputtered aluminium oxide coating on an industrial-grade polypropylene substrate. Some also incorporated a di-acrylate smoothing layer.
Key deposition conditions were studied and optimised for permeation and visible-light transparency: sputtering power, thickness & sequential deposition rate. One of the main deposition conditions corresponded to increasing coating nitrogen content in order to induce barrier-water interaction. The final investigation consisted of including acrylate layers in different barrier stacking combinations.
It was found that thin, high sputter power coatings formed the best barriers to permeation. This was due to denser packing of the oxide and the inclusion of fewer macro-defects (large defects allowing unhindered permeation) and nano-defects (defects small enough to cause the permeant to interact with the coating).
No clear benefit to permeation was found from the inclusion of nitrogen, but refractive index was seen to increase and the oxynitride coatings mechanically failed at a greater force than the oxides. This case illustrated the importance of considering the role of permeation through nano-defects: although a high activation energy was achieved for the nitrogen containing films, possibly suggesting greater interaction between the water vapour and the barrier, the amount of permeation was not reduced as the nitrogen gave rise to increased permeation due to nano-defects, thus changing the processing and chemistry can affect both the macro-defect and nano-defect permeation.
Smoothing layers were found to reduce the permeation rate by covering large substrate features, thus allowing rough substrates to be used even for high barriers. Although a coating of acrylate on top of a barrier oxide showed no improvement, a 1-2-1-2 stack of smoothing layer (1) and oxide (2) was found to exhibit a large delay in the onset of permeation.

Keywords: Gas Barrier
Water permeation
Advisor: Assender, H
Justice in Health

Within and across all societies, some people live longer and healthier lives than others. Although many of us intuitively think of health as a very important good, general theories of justice have hitherto paid little attention to its distribution. This is a thesis about what we owe to one another, as a matter of justice, in view of our unequal levels of health.
The first part of the thesis addresses the problem of social justice in health. I argue that the basic institutional framework of society must be arranged so as to ensure an egalitarian distribution of the ‘social bases of health,’ that is, the socioeconomic conditions that shape our opportunities for a healthy life. Inequalities in health, including those caused by differences in individual lifestyles, are only fair when people have been given fair opportunities. This egalitarian approach to the social bases of health must be complemented by a sufficientarian concern for meeting all basic health needs, regardless of whether these originate in unfair social arrangements.
The second part of the thesis takes up the problem of global justice in health. Although I argue against the idea that domestic principles of justice can be simply replicated on a global scale, I emphasise the fact that there are a number of international institutions and practices that shape people’s opportunities for health. One of these is the state system—the division of the world into sovereign states—which I argue grounds the idea of the human right to health. I also examine two more specific examples of global practices that contribute to global inequalities in health, namely global trade in tobacco and the global labour market for healthcare workers. Both of these, I suggest, must be restricted in light of their impact on health levels worldwide.

Keywords: global justice
social justice
health inequalities
social determinants of health
Advisor: Miller, D
Fabre, C
Development of AAV-mediated gene therapy for autosomal recessive bestrophinopathy

The bestrophinopathies are a set of inherited retinal degenerations caused by mutations in BEST1, and include Best vitelliform macular dystrophy (BVMD), autosomal dominant vitreoretinochoroidopathy (ADVIRC) and autosomal recessive bestrophinopathy (ARB). The corresponding protein, bestrophin-1, is localised to the basolateral membrane of the retinal pigment epithelium (RPE), where it is thought to function as a Ca2+-activated Cl- channel. Currently, there are no treatments for these conditions. In recent years, gene therapy has emerged as an exciting treatment option for inherited retinal disorders (IRDs). Gene delivery to retinal cells using a recombinant adeno-associated virus (rAAV) has produced positive results in several IRDs. Given the recessive nature of ARB, this thesis proposes that the rAAV-mediated delivery of bestrophin-1 to the RPE could represent a potential therapy. The aims of this thesis were to produce and compare rAAV vectors in vitro and in vivo for protein expression, localisation following transduction, restoration of chloride conductance in vitro and safety following sub-retinal injection in vivo. Following the production of two rAAV vectors expressing bestrophin-1, western blots confirmed bestrophin-1 protein expression following transduction of HEK293 cells in vitro. Immunocytochemistry (ICC) revealed bestrophin-1 expression that was localised to the cytosol. Whole-cell patch-clamping revealed a significant increase in chloride conductance in HEK293 cells transduced with AAV-BEST1 vectors which was then ablated upon the removal of chloride from the buffers. Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS) indicated that the bestrophin-1 protein was successfully transcribed and translated from the BEST1 coding sequence (CDS). Sub-retinal injections of AAV-BEST1 produced bestrophin-1 expression in the RPE of wild-type C57BL/6 mice however significant retinal thinning was seen at higher doses of vector. In conclusion, rAAV-mediated transfer of bestrophin-1 to the RPE has potential to be a future therapy for ARB, however safety issues need to be addressed and an RPE-specific promoter could be more suitable.

Keywords: Bestrophin
Retina
AAV
RPE
Advisor: Maclaren, R
The stories of quantum physics

This thesis investigates quantum physics narratives for non-physicists, covering four interlocking modes of writing for adults and children, fictional and nonfictional, from 1900 to the present. It brings together three separate scholarly fields: literature and science, science fiction, and science communication. The thesis has revealed parallels between the approaches to quantum physics in these disparate narratives that have not been addressed before, shedding new light on the mutual influences between science and narrative form.
The thesis argues that similar narrative tropes have been employed in popular science writing and in fiction across all age groups, changing non-physicists’ ideas of quantum physics. This understanding differs significantly from the professional understanding of quantum physics, as I establish by means of a series of case studies, including popular science books for adults by Alastair I.M. Rae, George Gamow and Robert Gilmore; popularizations for children by Lucy and Stephen Hawking, Russell Stannard, and Otto Fong; children’s fiction by Philip Pullman and Madeleine L’Engle; and fiction for adults by Greg Egan, David Walton, Blake Crouch, and Iain Pears. An analysis of authors who wrote for various audiences or in multiple genres, such as Fred Hoyle, Stephen Hawking, and Ian Stewart, shows how the same concerns and conflicts surface in a wide range of stories.
Quantum physics is not yet fully understood; the Copenhagen, conscious collapse, many-worlds and other interpretations compete for both scientific and public acceptance. Influential physics communicators such as John Gribbin and Brian Cox have written popularizations in which they express a personal preference for one interpretation, arguing against others. Scientific conflict, which tends to be omitted from university teaching, is thus explicitly present in popularizations, making it clear to the reader that quantum physics is in a constant state of flux. I investigate the conflicts between Fred Hoyle and George Gamow, and Stephen Hawking and Leonard Susskind, to see how they undermine the alleged objectivity of science. The interplay between the different stories of quantum physics shows how the science not only shapes the stories: the stories shape the science, too.

Keywords: history of science
English literature
quantum physics
fantasy
Philip Pullman
science for children
Stephen Hawking
popular science
conflict in science
Advisor: Shuttleworth, S
Whitworth, MH
Essays on risk management

This thesis consists of three parts. The first part studies the optimal portfolio selection of expected utility maximizing investors who must also manage their market-risk exposures. The risk is measured by a so-called weighted Value-at-Risk (WVaR) risk measure, which is a generalization of both Value-at-Risk (VaR) and Expected Shortfall (ES). The feasibility, well-posedness, and existence of the optimal solution are examined. We obtain the optimal solution (when it exists) and show how risk measures change asset allocation patterns.
The second part analyses the impact of ES-based market-risk regulation on portfolio choice and asset prices. We study the optimal, dynamic portfolio and wealth/consumption policies of expected utility maximizing investors who must also manage market-risk exposure which is measured by Expected Shortfall (ES). We find that ES managers can incur larger losses when losses occur, compared to both VaR and benchmark managers. A general-equilibrium analysis reveals that the presence of ES managers increases the market volatility during periods of significant financial market stress, in both pure-exchange and production economies.
The third part studies the optimal dynamic reinsurance policy for an insurance company whose surplus is modeled by the diffusion approximation of the classical Cram\'{e}r-Lundberg model. We assume the reinsurance premium is calculated according to the Mean-CVaR premium principle which generalizes Denneberg's absolute deviation principle and expected value principle. Moreover, we require that both the ceded loss and retention functions are non-decreasing to rule out the moral hazard. Under the objective of minimizing the ruin probability, we obtain the optimal reinsurance policy explicitly, which is more complicated than the contracts widely studied in the dynamic reinsurance literature.

Advisor: Zhou, X
Jin, H