VictorJuiz/thesis huggingface dataset:
Colour and cloud structure in the atmospheres of the giant planets
Keywords: Outer Planets
Giant Planets
Jupiter
Cloud
Radiative Transfer
Saturn
Chromophore
Atmospheres

For decades, the origin of colour-carrying compounds ('chromophores') in Jupiter and Saturn's atmospheres has remained elusive. Changes in colour are often associated with cyclical meteorological events ('upheavals') on Jupiter. Multiple datasets were obtained from the VLT/MUSE instrument between 2014 and 2018, each containing spatially-resolved spectra of Jupiter and Saturn between 0.48um and 0.93um. We describe the analysis of these datasets to characterise Jovian and Saturnian chromophores and to retrieve abundance profiles of aerosol and gaseous ammonia. Through limb-darkening analysis of Jupiter's NEB, we retrieved chromophore optical constants similar to the laboratory chromophore of (Carlson et al. [2016] Icarus 274, 106-115). These also provided a good fit to spectra of the Great Red Spot, but not to spectra of Jupiter's zones. We applied these chromophore optical constants to other regions of Jupiter, and found that red haze in the NTBs was initially associated with elevated aerosol abundances, but remained in the atmosphere long after upwelling had subsided. We verified previous findings of colour and haze structure changes relating to the shrinkage of the Great Red Spot, where we retrieved the altitude of the chromophore layer at the tropopause. We found no evidence of changes to the cloud structure of Oval BA to explain its fade in colour in 2018. An equivalent retrieval of chromophore optical constants from Saturn's NEB resulted in an absorption spectrum similar to the laboratory chromophore of (Noy et al. [1981] JGR:Oceans 86, 11985-11988), which we located just above Saturn's tropospheric haze. However, we found considerable variability in Saturn spectra that was not entirely consistent with a single chromophore compound. We believe that this work provides a significant contribution to our understanding of both colour and tropospheric aerosol structure on Jupiter and Saturn, and sheds light on the origin of spatial and temporal changes in the visible appearance of the two planets.
Developing treatments for rhodopsin-related dominant retinitis pigmentosa
Keywords: Retina
Gene therapy
AAV
Rhodopsin
Inherited retinal disease
Mirtron
Retinitis pigmentosa

Mutations in the rhodopsin gene are one of the most common causes of autosomal dominant retinitis pigmentosa (ADRP) and there is at present no treatment available. In this thesis, three potential treatments were developed and tested in a RhoP23H/+ knock-in mouse model.
In the first, animals were housed in red cages which acted as long-pass light filters. This resulted in a significant slowing in the rate of both rod and cone photoreceptor degeneration as determined anatomically using non-invasive in vivo imaging and immunohistochemistry, and functionally by dark- and light-adapted electroretinography.
In the second, efficient adeno-associated viral (AAV) vectors expressing wild type human rhodopsin were manufactured and injected subretinally in RhoP23H/+ mice to test the hypothesis that overexpression of the normal protein might overcome the effect of the P23H mutant. No structural or functional rescue effect was however observed.
The final treatment strategy involved development of artificial mirtrons to suppress expression of endogenous rhodopsin. Mirtrons are novel RNA interference effectors that are spliced from mRNA transcripts. Both efficient mirtrons and a codon modified mirtron-resistant version of the human rhodopsin coding sequence were designed and validated in vitro. These elements were then combined under the control of a single rhodopsin promoter within AAVs as knockdown/replacement gene therapy vectors for ADRP. Subretinal injection in the RhoP23H/+ mouse resulted in mouse-to-human rhodopsin mRNA replacement, and this was associated with a modest rescue effect when injected at a dose of 2x108 gc. This represents the first use of an artificial mirtron to induce gene knockdown in vivo.
Agricultural development, mechanization, and rental markets: theory and empirics from Ghana
Keywords: technology adoption
mechanization
social institutions
Africa
agricultural development
Ghana
farming systems

The subject of this thesis is the process of agricultural mechanization in the tropical farming systems of Ghana. Three original research papers are presented which explore separate research questions with different methodological approaches. All three papers draw upon detailed empirical analysis of the decisions by farm households over the use of tractor plowing in cereal-producing farming systems of Ghana. This empirical analysis informs our theoretical understandings of mechanization, its use, and its impacts.
The questions considered are: (i) to what extent can the patterns of agricultural mechanization be explained by changes in population, urbanization, and agro-ecological conditions? (ii) Given the heterogeneity of conditions and farming systems, is it right to assume that mechanization will reduce the labour requirements for production? What is the impact of mechanization on other farming decisions and productivity? And (iii) what role do informal institutions and social capital play in facilitating access to more productive technologies by farmers of all scales?
By revisiting the theories of mechanization developed in the1960s through to the 1980s, the first paper argues that farmers’ technology adoption decisions continue to be linked to system-wide drivers such as population change and urbanization. The second paper argues that farmers are taking up tractor plowing in this production system in large part because of the advantage it confers in shortening the required time for land preparation, even as mechanization has little impact on post-planting farm practices, which remain highly labour intensive. The final paper examines the market for tractor plowing services, which is the primary mode of access to mechanized technology for farmers in Ghana. I argue that the social embeddedness of farmers in rural Ghana is key to the functioning of the market for tractor services, allowing communities to manage spatial externalities and time constraints.
Studying galaxy evolution with modern radio surveys
Keywords: Radio Astronomy
Large Scale Structure

Modern radio surveys are transforming our view of the extragalactic sky, observing both Star Forming Galaxies (SFGs) and Active Galactic Nuclei (AGN) over large fractions of the history of the Universe. This allows us to investigate their evolution. In Chapter 2, I investigate how the relationship between galaxies and their dark matter environments evolves, through studying their angular clustering. Using the VLA 3 GHz COSMOS Survey (Smolcic et al., 2017a,b), I find that AGN reside in more massive haloes than SFGs and that radiatively inefficient AGN tend to reside in more massive haloes than their efficient counterparts. I investigate this further, in Chapter 3, by parameterising the Conditional Luminosity Function (CLF), which links environment to the luminosity distribution of these sources. This is novel at radio frequencies. From this, I study how the typical properties of galaxies vary with environment (or luminosity), again concluding that inefficient AGN reside in the most massive haloes, but that the halo mass supporting AGN and SFGs is smaller at higher redshifts. In Chapter 4, I investigate whether the multi-wavelength source extraction software ProFound (Robotham et al., 2018) can accurately quantify the flux densities of radio sources, irrespective of morphology. This is especially important for modern telescopes with a combination of long and short baselines. I find that Pro- Found is able to outperform commonly used software (PyBDSF and AEGEAN) when complex morphologies are considered and perform competitively when modelling sources with smooth morphologies. Finally, in Chapter 5, I present the deepest low frequency (144 MHz) observations of the XMM-LSS field, using LOFAR. This provides a low frequency catalogue which can be used in conjunction with higher frequency radio surveys. Combining the work of this Thesis will enable greater understanding of the relationship between galaxies and their environments, using future deep extragalactic radio surveys and this is discussed in Chapter 6.
‘Brotherly strangers’: historicising and disaggregating Kenya and Zambia’s relations with China (1961-2000)
Keywords: China-Africa
African history
Cold War

This thesis examines post-colonial Kenya and Zambia’s relations with the People’s Republic of China from ideological, political, economic and social perspectives, encompassing encounters between Kenyans, Zambians and Chinese as well as between their states. China’s growing significance in Africa is a popular subject in the press and academia but hitherto has been little analysed from a historical dimension. Through the triangulation of the global Cold War, African history, and Chinese history, the thesis examines the encounters, conflicts, and dynamics of China-Kenya/Zambia relations from 1961 until 2000, as well as the basis on which historical narratives regarding Chinese encounters with Kenyans/Zambians have been constructed. In doing so, it explains the on-going development of these relationships and sheds light on the historical underpinnings – or lack thereof – on contemporary China-Africa relations.
The thesis title, ‘brotherly strangers’, identifies two key ostensibly contradictory aspects of China-Africa relations: ‘strangers’ in the sense of their diverse historical trajectories, but ‘brotherly’ in terms of an asserted shared historical lineage of western domination. The dynamics of their changing relations across a wide span of time are examined by the comparative studies of Kenya and Zambia’s respective relations with China. From a Chinese state perspective, Zambia has been primarily of political/strategic importance, whereas Kenya, although politically estranged and even hostile, has been of greater economic significance. Their distinctive historical legacies, and the variation in China’s relations with specific African states, challenges both the ‘taken for granted’ role of the China-Africa historical lineage in contemporary analyses, as well as its tendency to assume uniformity in these relationships.
Rural, remote, raiya: Social differentiation on the pastoralist periphery in Turkana, Kenya
Keywords: Stratification
Turkana
Pastoralists
Kenya
Pastoralism
Nomadism
Urbanisation

In places formerly characterised by the economic and political predominance of mobile pastoralists, the rise of urban centres can dramatically alter the social landscape, with both positive and negative consequences for herders. While many studies describe the processes (e.g. sedentarisation and commercialisation) affecting pastoralism as a livelihood system, there are fewer accounts of the divisions that emerge when these effects are unequally experienced by different people within that system. Through an ethnography of development- induced social differentiation in Turkana, Kenya, this study examines the ways that herders perceive, make sense of, and respond to their changing circumstances.
Many herders in contemporary Turkana refer to themselves as raiya, a word derived from the Swahili term for ‘civilian’ or ‘subject’ but reworked through historical encounters between rural Turkana-speaking communities and various agents of “development”, including missionaries, international agencies, and the state. This term takes on different connotations for differently-positioned speakers: Formally educated urbanites describe the raiya as rural people who “lack” education, development, and global awareness, while rural herders use the term with pride to describe their toughness, pastoral knowledge, and adherence to customary practices (ng’italio). To explore the meaning of raiya – as both an exonym applied by urban dwellers and an endonym adopted by the rural periphery – and its implications for social stratification, I conducted 18 months of fieldwork between 2015 and 2016 along a rural-to- urban transect.
Using the concept of the cultural archive (James 1988), I discuss how herders draw on notions from an idealised nomadic past to distinguish themselves as raiya. This is manifested in explicit descriptions of “tradition” (etal), but also in everyday performances of style, skilled livelihood practices, and attunement to the remote landscapes in the borderlands where they live. However, while the notion of raiya makes explicit reference to conventional binaries – distinguishing rural/traditional/non-literate herders from their urban/modern/educated counterparts – I argue that the flexibility of its more implicit meanings has made it useful in negotiating relationships across these dichotomies. This is especially important as herders manage kinship obligations and political relations with educated elites. The future prospects for herders in Turkana are not a matter of their persistence as pastoralists or their adherence to conservative tradition, but the particular ways that they re-articulate kinship and political relations with elites, who are increasingly untethered from the pastoralist moral economy as urban opportunities reduce their reliance on the family herd.
Senior military officers, politics, and the country estate in Britain, c. 1700-1750
Keywords: Early Georgian Britain
Military officers
Country estates
Late Stuart Britain

This thesis investigates how senior military officers (generals and admirals) in the army and navy interacted with and integrated into elite society in late Stuart and early Georgian Britain both during their years of active service and afterwards. A valuable tool with which to analyse these officers is the country estate, the basis of the landed elite’s political, economic, social, and cultural power. This thesis therefore explores the acquisition and development of country estates, and officers’ political participation in Parliament, at court, and in the political and social life of their localities. This raises and helps to answer important questions about how senior military officers in the first half of the eighteenth century used their country estates, and what social, cultural, and political activities they engaged in. Examining these issues is crucial to understanding the place of senior military officers in Britain during this period, and consequently aspects of elite society more generally.
This thesis brings together multiple historiographical traditions, with architectural and garden history playing important roles alongside social and political approaches. It is therefore a highly interdisciplinary piece of research which draws on many different strands of scholarship. The purpose in this study of the country estate (and other houses and properties where relevant) is therefore to act as a medium through which to discuss wider issues such as estate acquisition and development, material culture, patronage and personal relationships, and senior officers’ wider interaction with politics. The latter could take many forms, be that jostling for a peerage, a place at court, membership of the House of Commons or Lords, or cultivating a family interest in a local parliamentary seat.
Grain boundary engineering in Ni-based alloys: processing, mechanisms and effect on mechanical properties
Keywords: Carbide
HR-EBSD
Creep
Ni-based superalloy
Cavitation
Grain boundary engineering
TKD

The property of polycrstalline nickel alloys are crucially dependent upon grain boundaries, as they are the strength limiting sites at high temperatures. Engineering of grain boundary structure and phases can be effective means of pursuing optimum properties of a component. Grain boundary morphologies are known to have critical impact on time dependent deformation, such as creep and fatigue. However, the reason for such an improvement is only understood qualitatively, the mechanisms of its formation or strengthening are not well understood. Roles of second phase particles on mechanical properties, such as carbides and borides, are still in an open debate. The present research tackled the questions from a fundamental perspective. The results accomplished have gained a deep understanding on the underlying science and satisfied industrial interests. This is achieved by carefully controlled experimentation and advanced characterisation. First, grain boundary morphologies are shown to be sensitive to the heat treatment that is given, and intergranular phases are proven to be responsible for obtaining serrated boundaries. Next, mechanical response between different grain boundary structures are distinctive, which is further elucidated by strain and tomography analysis. Last, minor element additions showed drastic improvement of creep life by redecoration of grain boundary phases. Overall, the thesis presents the mechanistic study of grain boundary structures, which is thoroughly investigated through the processing parameters on alteration of second phase particles and its influence on mechanical properties.
Revelation and the intuition of dualism
Keywords: dualism
qualia
consciousness
revelation
physicalism

There is a broad consensus among philosophers that when we think about the nature of consciousness, there is a persistent and plausibly widespread intuition of dualism – a belief or a disposition to believe that consciousness is nonphysical. This dissertation addresses the intuition of dualism and what explains it. The main body of the dissertation focuses on expounding a rational explanation of our dualistic intuition by drawing on what is known as the ‘thesis of revelation’ in the philosophy of mind, the claim that the essences of phenomenal properties are revealed in phenomenal experiences. The thesis of revelation, as I clarify, is incompatible with physicalism. Furthermore, as I argue, it is part of our ordinary conception of experience and its intuitiveness is what underlies our intuition of dualism. In my dissertation, I also defend the thesis of revelation from existing and potential objections.
The dissertation is divided into three main parts. Part I introduces the theme of the dissertation (chapter 1), elucidates the intuition of dualism (chapter 2), and critically assesses a number of candidate explanations of the intuition (chapter 3). Part II is dedicated to sharpening our understanding of revelation (chapter 4), clarifying its alleged incompatibility with standard versions of physicalism (chapter 5), and putting forward a linguistic argument for its intuitiveness (chapter 6). Discussion of these issues helps to bring forth a rational explanation for the intuition of dualism in terms of the intuitiveness of revelation (chapter 7). The issues of whether similar intuitions of distinctness can arise in other areas and of what explains the intuitiveness of revelation are also addressed (chapter 7). Parts I and II complete the main narrative of the dissertation. Part III deals with some further issues regarding revelation. It addresses objections against the revelation argument against physicalism and the thesis of revelation itself (chapter 8). It also provides a preliminary defence of property dualism, a position compatible with revelation, from the exclusion problem (chapter 9).
Studies in magnon spintronics
Keywords: Magnon
Magnonics
Spin Battery
Spintronics

This thesis is a thesis of two halves. The first investigates the Spintronic idea of generating charge-decoupled spin currents in metallic systems, whereas the second contains discussions on the topic of Magnon Computing.
Chapters 2 and 3 investigate the relevance of the ‘old knowledge’ of Magnetic Resonance to the modern-day research field of Spintronics. A model based on the Overhauser Effect is presented that explains microscopically how a pure spin current can be generated in a metallic bilayer system, and an experiment is proposed to explore this model, which is dubbed the ‘Overhauser Spin Battery’.
Chapter 3 contains details of all three aspects of the Spin Battery experimental process - that of sample fabrication, sample experimentation, and a presentation of the results. The results support the model presented in Chapter 2, and suggest that the Overhauser Spin Battery can indeed be used to generate pure spin currents.
Chapter 4 looks at the problem of how information is encoded into magnonic streams. A simple device for converting between amplitude modulated (AM) and phase modulated (PM) signals is demonstrated. Potential novel applications of this device are also considered.
Chapter 5 investigates methods of separating magnonic signals of differing frequencies that have been transmitted down a single waveguide simultaneously, which is known as multiplexing. It was determined that heterodyning is a viable method for extracting signals from a multiplexed data stream, and that it is applicable to both AM and PM signals. Quadrature phase-shift keying is shown to be a valid method for doubling the information transmitted down a magnonic waveguide, and a discussion is presented about how the principles of phase-shift keying could be applied to wider questions in Magnon Computing.
Chapter 6 summarises the key ideas and results of the thesis, and considers some further experiments that may be of interest.
Neural networks for inference, inference for neural networks
Keywords: variational autoencoders
variational inference
deep generative models
probabilistic programming

Bayesian statistics is a powerful framework for modeling the world and reasoning over uncertainty. It provides a principled method for representing our prior knowledge, and updating that knowledge in the light of new information. Traditional Bayesian statistics, however, has been limited to simple models. Two of the main limiting factors for this are the expressiveness and flexibility of the probability distributions used, and the computational restrictions in performing inference and model learning. In this thesis, we consider how neural networks (NNs) can be used to assist with both of these problems. In particular, we will look at how NNs can assist in the inference process and how we can perform inference over flexible NN models.
NNs are helpful for Bayesian inference in generative models. They are useful for producing the flexible variational families required for successful variational inference (VI), as well as learning distributed representations of model variables for guiding the distributional relationships of the model. Inference, on the other hand, is useful for quantifying uncertainty in NN discriminative models. For instance, with "Bayesian NNs" one can use inference to learn a distribution over the NNs parameters and hence quantify our uncertainty over the model's predictions. However, this increased flexibility in modeling and inference comes with challenges in inference and representation.
We present three pieces of original work in this thesis towards solving these challenges. We produce an algorithm for constructing the factorization of variational approximations in an optimal way to improve the fidelity and scalability of VI. We develop a framework for distributed Bayesian learning that is particularly useful for large Bayesian NNs and is less prone to the stale gradient of non-Bayesian approaches. We finish by considering an example of how Bayesian inference can be applied to NNs in a non-standard context by reinterpreting the problem of estimating NN robustness as an inference problem.