VictorJuiz/thesis huggingface dataset:
Africans in Britain, 1500-1640
Keywords: Tudor England
Caribbean
Africans
Renaissance England
Tudor
early modern
early modern Scotland
slavery
Stuart
black British history
Africa
West Africa
black history
black presence
maroons

This study of Africans in Britain 1500-1640 employs evidence from a wide range of primary sources including parish registers, tax returns, household accounts, wills and court records to challenge the dominant account, which has been overly influenced by the language of Shakespeare’s Othello and other contemporary literature. I explain the international context of growing trade and increased diplomatic relations with Africa and a concomitant increased level of contact with Africans in the Atlantic world. I then explore the ways in which Africans might come to Britain. Some travelled via Europe in the entourages of royals, gentlemen or foreign merchants; some came from Africa to train as trade factors and interpreters for English merchants; large numbers arrived as a result of privateering activity in which they were captured from Spanish and Portuguese ships. Once in Britain, they were to be found in every kind of household from those of kings to seamstresses. Some were entirely independent, some poor, though few resorted to crime. They performed a wide range of skilled roles and were remunerated in the same mix of wage, reward and gifts in kind as others. They were accepted into society, into which they were baptized, married and buried. They inter-married with the local population and had children. Africans accused of fornication and men who fathered illegitimate children with African women were punished in the same way as others. The legacy of villeinage coupled with the strong rhetoric of freedom in legal and popular discourse ensured that Africans in Britain were not viewed as slaves in the eyes of the law. Neither were they treated as such. They were paid wages, married, and allowed to testify in court. Those scholars who have sought to place the origins of racial slavery in Elizabethan and early Stuart England must now look elsewhere.
Fluid injection and migration in layered aquifers
Keywords: gravity currents
geophysical fluid dynamics
carbon capture and storage

Large-scale fluid injection into the subsurface is important for a number of industrial applications, including the injection and storage of CO2 for the mitigation of anthropogenic climate change. A vast amount of seismic data suggests that vertical heterogeneity dominates the distribution of fluids in layered aquifers. However, most studies of fluid injection typically neglect layering. This thesis aims to characterise the fundamental dynamics of subsurface fluid injection and migration in a layered aquifer system. This goal is achieved via the derivation of a novel theoretical model that is both accurate and computationally efficient. This vertically integrated sharp-interface model utilises a weakly compressible gravity current formulation that accounts for vertical flow of water and gas across a stratified system consisting of relatively thick higher permeability aquifers, alternating with thinner and much lower permeability seals. The coupling with vertical water leakage, and the corresponding vertical dissipation of pressure out of the injection aquifer, is found to have a leading-order role on lateral gas migration. Results demonstrate that vertical pressure dissipation acts to significantly reduce the lateral extent of the plume. Furthermore, vertical pressure dissipation has a significant impact on gas leakage which occurs when a capillary entry threshold is exceeded by controlling the magnitude, and style, of capillary pressure buildup. Results further indicate that distributed CO2 leakage during CO2 injection into layered aquifers such as at Sleipner is more likely than previously considered. As the model developed here retains the plume shape and pressure field at the end of injection, the model can be used to provide unique insights into post-injection migration. Results suggest that due to the strongly tongued shape present at the end of CO2 injection, a period of stagnant lateral migration occurs after an initial phase of depressurisation, and before the transition towards late-time self-similar spreading.
The effects of antibiotic exposure on selection of antimicrobial resistance in the human gut microbiome 
Keywords: gut microbiome
metagenomic DNA sequencing
antimicrobial resistance

The gut is a major reservoir of human pathogens, and increasing antimicrobial resistance (AMR) in these organisms is an important problem. Selection of AMR by antimicrobials occurs against a background of disruption in a rich bacterial ecosystem, the gut microbiome. Our understanding of this has recently been transformed by new techniques, such as metagenomic sequencing, that can describe the whole community and directly detect AMR genes. Efforts to control AMR would be greatly helped by reliable measures of the impacts of different antimicrobials on the gut microbiome, but these are generally not available. The aim of this thesis is to address this problem.

A significant limitation of using metagenomic sequencing to study AMR is its inability to detect important resistance genes present at low abundance, and in initial work I explore methods to improve the detection of these using plasmid DNA extraction and selective culture-enrichment. These approaches improve the limit of detection of specific resistance mechanisms, but prove unsuitable for use in a quantitative assay.

I then analyse data from an observational study that I conducted, which recorded antimicrobial exposures and collected stool samples from hospital patients and healthy volunteers. Using multiple regression models with data from metagenomic sequencing, I estimate the effects of specific antimicrobial exposures on global microbiome diversity, the abundance of specific taxa, and the abundance of specific classes of AMR genes. The study utilised both cross-sectional and longitudinal sampling frames, which I analyse separately, providing independent estimates that are supportive of one another. These data allow the direct, quantitative, comparison of many different antimicrobials used in the study. The work also develops approaches to the analysis of these types of observational data that could be used in future studies.
Perovskite nanocrystals for optoelectronics and photovoltaics
Keywords: optoelectronics
perovskite
nanocrystal
halide
lead
colloidal
synthesis

Lead halide perovskite nanocrystals, APbX3, are an astounding candidate for optoelectronic and photovoltaic applications. Their tunable band gap, through both composition and quantum size effects, allows for a wide colour gamut spanning the visible to infra-red region. The colour purity achievable through narrow full width at half maximum (FWHM) in their emission spectra, and bright emission with reports of near unity photoluminescence quantum yield (PLQY), place lead halide perovskite nanocrystals at the forefront of research into display technologies. Despite a vast research effort into these materials over the past five years, questions remain regarding their surface chemistry, optimal synthesis for compositional breadth, and their stability.
In this thesis, a mixed cation mixed anion lead halide perovskite nanocrystal synthesis is investigated. Although fine tuning of the band gap is achieved, the miscibility of the inorganic cation, cesium (Cs), and organic cation, formamidinium (FA), is unclear due to concurrent changes in size and shape of the nanocrystals across the compositional range. To resolve this, a new synthesis to perovskite nanocrystals is investigated utilising a phosphine oxide, with the aim to simplify the ligand shell. This is motivated to decouple size and shape control from composition in a mixed cation perovskite nanocrystal synthesis. All inorganic CsPbX3 nanocrystals are synthesised through this phosphine oxide assisted synthesis, and achieve up to 70 % PLQY whilst maintaining monodispersity at high reaction yields close to the theoretical limit. A simple oleate-only ligand shell is achieved, and confirmed through nuclear magnetic resonance spectroscopy (NMR) and X-ray photoelectron spectroscopy (XPS). The synthesis is translated across to form FAPbBr3 nanocrystals. Although similar PLQYs are achieved, the size and shape control is lost. This lack of control is attributed to the interaction of the labile ammonium protons on FA with the ligands used in the synthesis, which is determined via NMR.
Towards HANK: Investigating interactions between labour and credit-market frictions in a new Keynesian economy
Keywords: Search &amp; matching
New Keynesian models
Two-agent model
Household heterogeneity

How can the presence of unemployment affect the properties of economic fluctuations and the effectiveness of monetary policy when a fraction of households are also credit-constrained? This paper presents a New Keynesian model with limited asset market participation combined with a search & matching model of the labour market. The resulting framework uncovers a novel mechanism whereby aggregate shocks affect the hiring incentives of firms and the prevailing wage through fluctuations in the total expected surplus from an employment relationship. In the presence of credit-constraints, this will have implications for the distribution of consumption across households. Quantitative evidence suggests that these effects are indeed significant, leading to a greater volatility in labour market tightness and aggregate labour income. In response to a contraction in monetary policy, the fall in output is found to be much greater due to the interaction between credit and labour frictions, whilst the response of inflation remains quantitatively close to the baseline New Keynesian model.
International coordination of macroprudential policy
Keywords: Loan-to-value ratio
Macroeconomics
Collateralised borrowing constraint
Optimal policy
International cooperation
Macroprudential policy

Given cross-border spillovers from macroprudential policy, international policy coordination may improve global welfare. This paper's contribution is to investigate the benefits of policy coordination in a setting where some countries are "foreign-banked", meaning their bank sector assets are mostly held by foreign credit institutions. I use a two-country model where one of the countries is foreign-banked, and where each country has a borrower subject to a collateralised borrowing constraint. The constraint depends on the value of the borrower's housing and the country's loan-to-value ratio limit, which is the instrument of macroprudential policy. The main finding is that policy coordination is beneficial for welfare. Specifically, in the uncoordinated steady state, the foreign-banked country exerts direct control over net foreign assets through its loan-to-value ratio, which it uses to its advantage. In effect, in a foreign-banked country, borrower-targeting macroprudential policy doubles as a capital control. In reality, the effect is not limited to strongly foreign-banked countries. Rather, it may apply to any country whose bank sector assets are not purely domestically owned. Given that coordination is beneficial, I use the model to characterise the coordinated optimal policy response to a housing demand shock. Such policy consists of moving each country's loan-to-value ratio inversely proportionally to its house price, which nullifies the shock's effect on debt. Coordinated policy thereby maintains household consumption and welfare at their steady state levels, preventing any adverse effects of the shock.
Asymptotic analysis of outliers dectection algorithms using a new empirical process result
Keywords: weighted and marked empirical processes
The iterated 1-step Huber-skip M-estimator
Poisson approximation to gauge
Outliers robustness

The Robustified Least Squares and the Impulse Indicator Saturation are iterative algorithms concerned with detecting outliers and other unsuspected structures in data. These two algorithms are constructed when the full or split sample least squares are chosen as the initial estimators for the iterated 1-step Huber-skip M-estimator. These methods classify observations as outliers or not. This paper establishes an asymptotic theory considering the role of the varying cut-off in such algorithms. In particular, we demonstrate the tightness property for estimates in each iterated step with the varying cut-off. Moreover, a Poisson exceedence theory to the gauge is built for all iterations. The argument involves a theory for a new class of the weighted and marked empirical process.
Machine learning applications and observation of Higgs boson decays into a pair of bottom quarks with the ATLAS detector
Keywords: bottom quarks
Fast Simulation
Standard Model
ATLAS
Similarity Search
Higgs boson
LHC
Effective Field Theory
Machine Learning

The discovery in 2012 of the Higgs boson at the Large Hadron Collider (LHC) represents a milestone for the Standard Model (SM) of particle physics. Most of the SM Higgs production and decay rates have been measured at the LHC with increased precision.
This thesis presents the analysis that led to the observation of the SM Higgs boson decay into pairs of bottom quarks. The analysis exploits the production of a Higgs boson associated with a vector boson whose signatures enable efficient triggering and powerful background reduction. The main strategy to maximise the signal sensitivity is based on a multivariate approach. The analysis is performed on a dataset corresponding to a luminosity of 79.8 fb-1; collected by the ATLAS experiment during Run-2 at a centre-of-mass energy of 13 TeV. An excess of events over the expected background is found with an observed (expected) significance of 4.9 (4.3) standard deviation. A combination with results from other H → bb searches provides an observed (expected) significance of 5.4 (5.5). The corresponding ratio between the signal yield and the SM expectation is 1.01 ± 0.12 (stat.) + 0.16 - 0.15 (syst.).
The measurement of cross sections in exclusive regions of phase space of the VH production times the H → bb branching ratio is reported as well. These measurements are used to search for possible deviations from the SM with an effective field theory approach, based on anomalous couplings of the Higgs boson.
This thesis also describes a novel technique for the fast simulation of the forward calorimeter response, based on similarity search methods. The new simulation approach outperforms the default technique used by ATLAS.
The regulation of international commercial arbitrators
Keywords: dispute resolution
international commercial arbitrators
regulation
arbitration
arbitration market

International commercial arbitration has established itself as the main dispute resolution mechanism for international commercial disputes. This increased visibility has drawn attention to arbitrators’ public role, leading to a well-established general perception that arbitrators are bound to special obligations, such as the duty to be independent and impartial or the obligation to assure that arbitral proceedings are not abused to achieve nefarious goals. Despite this general acknowledgement, little attention has been paid to the mechanisms that ensure that arbitrators adhere to these obligations. In particular, there has been limited analysis of the underlying mechanisms that incentivise the production and enforcement of professional norms in this field.
This thesis argues that the particulars of the arbitration market largely explains why the evolution of the regulation of international arbitrators has not matched those of other professions. At the same time, it will argue that those same particularities create incentives for several actors, most notably the arbitral community itself, to step in and occupy this regulatory vacuum. In particular, it explores the notion that the market strategies employed by arbitrators, arbitral institutions and other members of the arbitral community have the production of professional norms as a by-product. It further explores how the arbitral market tends to create an environment where compliance with professional norms is rewarded, leading, at the same time, the arbitral community to work as a network that promotes adherence to professional norms through mostly informal sanctions.
Ab initio theory of polarons
Keywords: Electronic structure
Electron-phonon coupling
First-principles calculations
Polarons

The polaron is a quasiparticle formed by collectively dressing an electron with a phonon cloud. It emerges in a crystal lattice when an extra electron is trapped at the lattice distortion induced by itself. Due to its unique role and technological implications, this subject has consistently received attention for many years. To date, first-principle studies of polarons in materials are still based on direct calculations with large simulation cells. In this thesis we develop a theoretical and computational framework that allows for the modelling of lattice polarons in different materials of interest, but using unit-cell calculations of electronic, vibrational properties and electron-phonon couplings. We explain the architecture of the implementation in detail, and propose a self-interaction corrected DFT scheme for the validation of our methodology and implementation. We present extensive tests and benchmark for the code. We apply this new approach to investigate polaron properties in LiF and Li2O2 as prototypical bulk materials that host large and small polarons. We demonstrate that our method can describe both large and small polarons on the same footing, and capture both Fr ̈ohlich-type polar electron-phonon coupling and non-Fr ̈ohlich couplings to acoustic and optical phonons. Furthermore, we report cal- culations of formation energy, excitation energy, and wavefunction of polarons. To establish a quantitative understanding of which KS states and phonon modes con- tribute to the formation of polarons, we analysis the polaron spectral decomposition in a spirit similar to the Eliashberg spectral function. The last part of the thesis is devoted to explore the dimensionality effect on the polaron properties in h-BN. In this case, we compare the polaron energies for a localised hole between the h-BN in bulk and in monolayer, and show that the two-dimensional hole polaron trapped in the h-BN monolayer exhibits a layer formation energy in comparison to the bulk one. This work will open the door to predictive calculations of polarons in more complicated systems, such as van der Waals heterostructure and interfacial systems, and constitutes as a first step toward complete ab initio many-body calculations of polarons in real materials.
Labour market effects of social programmes: evidence from Ethiopia’s productive safety net
Keywords: Provision and Effects of Welfare Programs
Productive Safety Net Programme
Labour Markets
Ethiopia

This thesis assesses how a large safety-net programme in rural Ethiopia affects local labour markets. Combining repeated cross-sections of the National Labour Force Survey with information on the geographical targeting of the programme, a differencein- differences approach is used to estimate whether employment outcomes have changed differently over time in targeted districts relative to those that did not receive the programme.
The results suggest that a combination of public works employment and unconditional transfers to food-insecure households does not affect the local labour supply in this rural economy. I explore whether differential trends and population composition could explain these results, which are more likely due to programme design. Albeit scantily observed, the wages of private sector labourers also seem unaffected, in contrast to findings from similar studies focusing on labour markets from other developing countries outside Africa.
Synthetic post- translational protein modification as a switch for activity
Keywords: Histone
H3K36me3
H3K36me2
Dehydroalanine
cAbLys3
Chromodomain
MRG15
Post-translational modification

The ‘post-translational mutagenesis’ chemistry, utilising a bio-orthogonal radical reaction with Dha on proteins, has opened up a vast range of novel possibilities in generating post- translational modification (PTM) mimics. Two case studies are described in this thesis, around the theme of PTMs as switches for protein-protein interactions. The first case study recapitulates the natural PTMs H3K36me2 and -me3. Functional evidence from in vivo observations suggests that the chromodomain reader protein MRG15 should preferentially bind H3K36me3 over its dimethyl counterpart. However, in vitro studies using peptides or isolated H3 as a substrate have failed to recapitulate this observation. Here, using synthetic, ‘post-translational mutagenesis’, fully-intact model nucleosomes containing both H3K36me2 and H3K36me3 were generated. Binding of MRG15 to these intact nucleosomes revealed a marked preference for H3K36me3 containing nucleosomes over those containing H3K36me2, recapitulating physiologically relevant observations. A model was suggested in which the H3K36 side chain is normally sequestered in intact nucleosomes in a hydrogen bonding interaction with the phosphate of the DNA backbone, and the interaction entirely abrogated only when the third methyl group is added to form H3K36me3, providing a ‘methyl- switch’ mechanism for context-dependent reader selectivity. The second case study was centred around installing a natural PTM in an unnatural location to produce a novel sensor. Dha chemistry was once again employed to install O- and N-linked GlcNAc mimics in the complement determining region (CDR) of a nanobody cAbLys3, with the aim of reversibly blocking its antigen binding capacity. Enzymatic extension of cAbLys3- O-GlcNAc to produce an Fc decasaccharide was also investigated as an alternative means of tuning a nanobody’s effects for potential therapeutic applications. Overall, the aim of this thesis was to demonstrate the use of the post-translational mutagenesis method to install mimics of labile PTMs; both to study their function in a natural setting, and to create novel biosensors.