VictorJuiz/thesis huggingface dataset:
Essays in development economics

This thesis comprises three stand-alone chapters:
The first chapter is on the effect of natural disasters on labor markets. Using data from the Indonesia Family Life Survey, the Desinventar database, the US Geological Survey and district level employment indicators, we explore how a large earthquake in Indonesia affected local labor markets, in particular the evolution of wages and employment across sectors. We find that wage growth in the agriculture sector is significantly higher in earthquake affected areas. We propose two mechanisms for this result and show evidence for both mechanisms.
vThe second chapter investigates the intra-household allocation of leisure and consumption among siblings. Children are often treated as passive members in the household and their preferences over consumption and leisure are rarely modeled. This chapter considers children as agents with their own preferences over leisure and consumption and builds a theoretical and empirical model for children's time and consumption allocations in a household. We test the predictions of the model with data from Ethiopia, India, Peru and Vietnam. The results suggest that differences in siblings' relative time and consumption allocations are driven by their relative preferences over leisure and consumption rather than differences in parents' relative altruism.
The third chapter examines the cost of transport infrastructure in developing countries. To our knowledge, this is the first study that analyzes drivers of unit costs of construction of transport infrastructure using a large data set of 3,322 unit costs of road work activities in low and middle income countries. We find a large dispersion in unit costs for comparable work activities. Unit costs are significantly higher in conflict and corrupt countries, and these effects are robust to controlling for a country's public investment capacity and business environment. Finally, higher unit costs are significantly negatively correlated with infrastructure provision.

Keywords: economics
natural disasters
infrastructure
intra-household allocation
local labour markets
children
transport
construction
Advisor: Dercon, S
Moving the Maasai

This dissertation examines the two major forced moves of the Maasai in British East Africa in the 1900s, through which the 'northern' sections lost the greater part of their land, and non-violent resistance to these events which culminated in a landmark court case in 1913. The Maasai lost this action, the so-called Maasai Case, on a technicality. The dissertation amis to compare the parallel and contested narratives of the British and the Maasai about these events and related issues, drawing on original oral testimony and archival sources in Kenya and Britain. It attempts to address major omissions in the historiography which include a failure to examine these events from a Maasai perspective and include Maasai voices, to fully analyse their significance and effects, and to place Maasai responses to the moves within the context of contemporary African resistance. It focuses as much on people's perspectives as it does on events, and on a metaphysical as well as material realm. The immediate frame of reference is 1904 to 1918, with the broader frame c. 1896 to the 1930s.
The two leading characters around whom the story revolves are Dr Norman Leys, a colonial dissident who orchestrated support for the Maasai in Britain, and Parsaloi Ole Gilisho, an important age-set spokesman of the Purko section who launched the legal action against the British. New evidence reveals the full extent of their actions, motivation and influence, and casts light upon the activities of other European colonial critics inside British East Africa.
Secondary themes include the legal implications of the Maasai Case and Agreements; the relative powers of Maasai leaders and a critique of 'anthrohistorical' models; the complex relationship between Maasai leaders and prominent settlers; labour relations on highland farms; the post-war return of Maasai to their former northern territories; the role of East Coast fever in relation to the second move; disease as a social metaphor; and a reinterpretation of the causes of rebellions in 1918, 1922 and 1935 which may be connected to the earlier land alienation.

Advisor: Professor W. Beinart, D
Neural degeneration and plasticity following damage to the post-chiasmal visual pathway

Hemianopia is a disorder where a patient loses vision in one half of their visual field, following damage to the post-chiasmal visual pathway. If the hemianopia does not spontaneously resolve within the first few months, the prognosis for recovery is poor, with very few patients recovering vision in the affected area of the visual field. The reasons for this are unclear, although it is likely that both degeneration and plasticity in the visual system have an impact on patient outcome. The goal of this research is to investigate the changes that occur in hemianopia, and how these differ for lesions at different locations in the visual pathway and with differing underlying pathologies.
Patients with hemianopia arising from different causes were recruited, including 17 with a hemianopia acquired in adulthood, 9 with congenital hemianopia, and 6 patients with hemianopia due to posterior cortical atrophy (PCA). Structural, functional, and diffusion-weighted MRI data were acquired for each patient, in order to examine changes in the structural and function of the visual pathways. Analyses focused on either atrophy, or plasticity and residual function. Atrophy was assessed in acquired and congenital hemianopia by quantifying transneuronal degeneration in the optic tract, which was present in all patients with long-term lesions. Degeneration was also assessed more generally in PCA, who have substantial loss of white and grey matter in posterior brain regions. Investigation of plasticity and residual function focused on the motion processing area (MT), quantifying the level of functional activity in MT, and assessing whether subcortical pathways from the pulvinar to MT exist in hemianopia. A wide degree of variation existed between patients in the extent to which motion processing was preserved, which had no clear link to lesion location, however was related to the size of the lesion.

Keywords: stroke
hemianopia
magnetic resonance imaging
vision
Advisor: Kennard, C
Bridge, H
Synthesis and use of new chiral DABCO derivatives for asymmetric fluorination

In this thesis, the synthesis, reactivity and enantioselectivity of novel chiral Selectfluor Analogues were investigated.
Chapter 1: Discussed is a general introduction to Selectfluor as an achiral electrophilic fluorinating reagent and its role as an oxidant in a wide variety of transformations and summarises the aims and objectives of the project.
Chapter 2: The synthesis of chiral 2-monosubstituted, 2,3-disusbstituted and 2,5-disubstituted DABCO derivatives is described. We selected two strategies to prepare these chiral analogues of DABCO. Strategy A takes advantage of a large range of commercially available natural and unnatural amino acids. 2,3-Disubstituted DABCO motifs were prepared via a protocol of Sharpless in strategy B. Eleven chiral DABCO systems have been synthesized, six of which are novel compounds.
Chapter 3 describes the synthesis of novel chiral non-racemic Selectfluor analogues using F₂. Mono-fluorinated chiral DABCOs were found to be unstable at low temperature, however, quaternized derivatives of these chiral reagents induced stability1. The fluorination proved challenging with chiral DABCO derivatives having sterically demanding substituents.
Moreover, we have developed a practical and general process for the synthesis of novel chiral non-racemic Selectfluor using N-fluoropentachloropyridinium triflate 221. This methodology alleviates the need to handle F₂ gas.
In Chapter 4: An investigation into how chiral Selectfluor analogues compare to N-F derived cinchona alkaloids in term of reactivity and enantioselectivity. The reactivity of the chiral Selectfluor analogues was challenged with both activated and less activated substrates. The novel chiral Selectfluor analogues showed superior reactivity than the cinchona alkaloids. Moderate to excellent yields of the desired products were obtained for all of the substrates studied.

Keywords: Synthetic organic chemistry
Advisor: Gouverneur, V
Computational studies of cell-penetrating peptides interactions with complex membranes models

Membrane active peptides with the ability to cross the plasma membrane represent a promising class of therapeutic compounds. However, translocation efficacy and membrane toxicity of these peptides appear correlated and a better understanding of their mechanisms of action is needed to achieve the desired effect. Here, a range of coarse grain molecular dynamics simulations have been performed to systematically investigate the interactions of such cell-penetrating peptides (CPPs) with biologically relevant membranes. Challenges associated to the development of a suitable asymmetric mammalian membrane model demonstrated the importance of lipid species distribution on the bilayer mechanical properties, as well as the effect of coarse graining on its electrostatic properties. However, simulations successfully discriminated between two CPPs, penetratin and transportan, and were consistent with the experimental data available for these. The results obtained suggest that the ability of transportan peptides to aggregate into flexible, dynamic, transmembrane bundles is responsible for their relative membrane toxicity. The stability and structure of these aggregates, as well as the extent of the bilayer perturbations they induced, were shown to depend on the membrane composition and asymmetry, thus providing a molecular basis to explain how the toxicity of CPPs is modulated by membranes. In particular, bilayer destabilisation was enhanced by the presence of anionic lipids and hampered by that of cholesterol. Transportan aggregates were also observed to trigger lipid flip-flops above a certain size and a new pathway for such events, not relying on the formation of water defects, was characterised.

Keywords: bilayer
MD
CPP
molecular dynamics
membrane
cell-penetrating peptides
CG
coarse grain
Advisor: Sansom, M
Deane, C
Milletti, F
Marine geophysical studies of the southern margins of the Iberian Peninsula

A wide variety of tectonic settings are juxtaposed at the southern margins of the Iberian Peninsula. The regional geology comprises an Atlantic passive margin in western Iberia, the convergent eastern part of the Azores-Gibraltar plate boundary zone between Africa and Eurasia, and an orogenic arc (the Betic-Rif mountains) surrounding an extensional basin (the Alboran Sea). The complex tectonic history of the southern Iberian margins is recorded in its sediments and structure, and these were investigated in this study using multichannel seismic reflection techniques in conjunction with other marine geophysical data.
Multichannel seismic reflection and well data from the Gulf of Cadiz have shown that the earliest sediments are Triassic evaporites, followed by Jurassic carbonates, which form rotated fault blocks in the Gulf of Cadiz. Backstripping and thermal modelling has indicated that a rifting event took place in the Late Jurassic, which stretched the crust by ~20-50%. Gravity modelling, and mapping of stretching factors, has suggested that two zones of thinning underlie the Gulf of Cadiz, which are related to the original rifting event. Backstripped subsidence curves indicate passive margin thermal subsidence until the Miocene, when westward-directed thrusting and loading from the Betic-Rif mountain belt is reflected in a typical foreland basin tectonic subsidence signature of accelerated subsidence with time.
A giant, chaotic body of allochthonous sediment was emplaced into the central Gulf of Cadiz as westward migration of the Gibraltar Arc led to oversteepening of the margin west of the Gibraltar Straits, while the Alboran Sea was simultaneously undergoing active extension. These allochthonous deposits are composed mainly of Triassic evaporites and Palaeogene shales. In the Gulf of Cadiz and Seine Abyssal Plains this body has the appearance of an accretionary wedge, but a 300 km long northern lobe of the body extends into the Horseshoe Abyssal Plain. This lobe is interpreted as being a cumulative mass wasting feature, formed by the gravity-driven downslope transport of large allochthonous masses as debris flows and slides and slumps, encouraged by a regional gradient and a pre-existing trough in the Horseshoe Abyssal Plain. The total volume of sediments involved was of the order of 72 000 km 3 , and the time of emplacement has been estimated as being Tortonian on the basis of seismic correlation with core data at DSDP site 135. This chaotic unit has formed a series of longitudinal diapiric ridges in the northern Gulf of Cadiz, which have been interpreted to act as a transport system for gas generated in the lower slope area to migrate to the upper slope where gas-related features are seen. Gas hydrates are present beneath the lower continental slope, as inferred from a bottom-simulating reflection on seismic reflection profiles.
Charge transfer processes of atomic hydrogen Rydberg states near surfaces

When approaching a metal surface, the electronic structure of Rydberg atoms or molecules is perturbed by the surface potential and at close enough distances resonant ionisation of the Rydberg electron into the conduction band of the surface can occur. It is possible to interfere in this process and steer the ionisation distance by making use of the polarisability of the Rydberg orbital in the presence of electric fields. The resulting ions from the surface can extracted via electric fields and subsequently detected via well established ion detection schemes. The question of how this charge-transfer process is affected by different properties of the surface (both electronic and structural) represents the main aspect of the work presented in this thesis.
At first, the charge transfer of atomic hydrogen Rydberg atoms with a flat gold metal surface is investigated. While such a surface might appear homogeneous, stray fields are present in its vicinity due to local variations in the surface work function. The surface ionisation process as a function of applied electric field is therefore measured experimentally and the results are compared with classical Monte-Carlo simulations (which include stray field effects). This way the possibility to utilize Rydberg states as a probe of the magnitude of such stray fields is demonstrated. To investigate the effect the surface structure can have on the ionisation process, the interaction of Rydberg atoms with surfaces covered by nanoparticles is investigated. Surface ionisation is measured at a 5 nm nanoparticle monolayer surface and it is shown that population transfer between surface- and vacuum-oriented Rydberg states occurs. In addition, results are presented, which suggest a dependence of the ionisation process on the relative size of Rydberg orbital and nanoparticle. Furthermore, charge transfer between a Rydberg state and discrete electronic states at the surface vacuum interface are investigated by performing experiments with a Cu(100) band-gap semiconductor surface. By analysing surface ionisation as a function of collisional velocity ionisation rates can be determined and are subsequently compared with theoretical predictions. The potential of identifying resonant ionisation is thereby demonstrated. Last, a new method to produce 2s atomic hydrogen via mixing of the 2s and 2p state in an electric field is proposed and first experimental results are presented, thus demonstrating viability of the idea.
The experiments presented in this thesis represent the most in depth analysis of the charge-transfer process between atomic hydrogen Rydberg states and a range of different surfaces to date. As such, they demonstrate the potential of utilizing the unique properties of Rydberg states and their applicability as surface probes. In addition, these results pave the way for further experiments involving thin films or the phenomenon of quantum reflectivity.

Keywords: nanoparticles
molecular beam
charge-transfer
Rydberg
surface interaction
atomic hydrogen
Advisor: Softley, T
Delineating the Gawain-poet: myth, desire, and visuality

This thesis adopts an interdisciplinary approach, drawing on literary, art historical and textual sources to examine how the act of looking, images, and artistic and textual creation are both dramatized and problematized in the works of the Gawain-poet: Pearl, Cleanness, Patience, and Sir Gawain and the Green Knight (with some discussion of St Erkenwald, a work often attributed to the same author). Analyzing in detail the texts and illustrations in the Gawain-manuscript (British Library, Cotton MS Nero A.x), the thesis argues that the poet weaves together classical and biblical narratives, along with exegetical and iconographic traditions, in shaping his distinctive reflections on the use and making of images, body and performance, in response to late fourteenth-century religious controversies.
The thesis starts by tracing a network of ideas about gaze, sin, body and text through late-medieval biblical and mythographical texts and images. Working text-by-text through the poet’s oeuvre, it then discusses the use of Ovidian materials and the motif of metamorphosis in his complex meditation on ethical and specifically gendered practices of reading, writing and looking. It concludes by assessing the poet’s idea of poetic creation and his own role as a creative artist. In doing so, it suggests that the poet’s self-conscious artistry works together with a consistent emphasis on humility in human’s relations with the divine. The thesis contributes to a growing scholarly interest in the Gawain-illustrations, and a developing focus on visuality in studies of late-medieval devotional and literary works. By linking the analysis of classical/biblical intertexts, visual traditions and the manuscript’s own illustrated texts, it suggests a fresh area of study for the Gawain-poet and his milieux.

Keywords: medieval manuscripts
visual art
the Gawain-poet
Advisor: Perkins, N
Identification of novel genes involved in brain abnormality syndromes using next generation sequencing

Since the 1980s there has been a steady increase in the number of genes identified which play a role in human disease. The Human Genome Project and arrival of Next Generation Sequencing (NGS) have helped accelerate the rate of discovery such that the recent update of the Human Gene Mutation Database (HGMD) lists over 140 thousand genetic variants linked to human disease. However, causative genes have only been identified in half of the 7000 rare monogenic disorders. It is predicted that within 10 years the majority of disease-causing genes will be identified. In many ways the era of next-generation sequencing has become the “gold rush” of disease gene discovery.
The aim of this thesis was to demonstrate the validity of an NGS approach to identify novel disease genes associated with brain abnormality phenotypes. In a cohort of 23 families with a range of brain abnormality phenotypes, novel disease genes were found in 2 families and there was an overall clinical diagnosis rate of 38%. The results from this thesis have already expanded the spectrum of brain abnormality mechanisms to include the gene PGAP3. The strategy outlined will become part of the clinical framework for the diagnosis and identification of brain abnormality syndromes with NGS.

Keywords: genetics
exome sequencing
medical genetics
next generation sequencing
brain abnormalities
brain malformations
NGS
Advisor: Taylor, J
Bell, J
Control of the unidirectional motor in Rhodobacter sphaeroides

The control of the flagellar motor in Rhodobacter sphaeroides was investigated. Unlike most flagellar motors which are controlled by reversing the direction of rotation, the R. sphaeroides motor is controlled via a stop-start mechanism. Advanced optical microscopy was employed alongside genetic, biochemical, and behavioural techniques.
High-resolution measurements of rotating beads on flagellar stubs revealed that the R. sphaeroides motor is similar to its E. coli counterpart, rotating counterclockwise at comparable torques/speeds (1,300 pNnm/rad at stall torque), and exhibiting transient step changes in speed. The mean stop duration, mean stop frequency (number of stops per s), and run bias (fraction of time spent rotating) of wild-type at steady-state were 0.66 ± 1.01 s, 0.31 ± 0.19 s-1, and 0.80 ± 0.20, respectively.
Manipulating signal inputs to the motor genetically, or by exposing cells to chemotactic stimuli revealed that (i) without chemotactic stimulation the motor rotates continuously, (ii) phosphorylated CheYs are required to stop the motor, and (iii) the chemotaxis system cannot control the speed of rotation of the motor (termed chemokinesis) as previously reported. Complementation studies revealed that CheY3, CheY4, and CheY5 are functionally equivalent. The copy numbers per cell of important CheYs were found to vary greatly under the conditions tested (<1,000, ~3,000, ~60,000 for CheY3, CheY4, and CheY6 respectively).
To determine how CheY-P binding causes the motor to stop, external force (viscous flow or optical tweezers) was applied to chemotactically stopped motors. CheY-P binding might either cause the torque-generating units to disengage from the rotor, analogous to a clutch, or trigger the rotor to jam, analogous to a brake. The rotor resisted re-orientation during a chemotactic stop implying that the motor was held in a locked state. The value of torque resisting forward motion (keeping it locked) was estimated to be 2-3 x stall torque (2,500-4,000 pNnm/rad).
Furthermore beads attached to flagellar stubs stop at fixed angles for several seconds, showing no large-scale Brownian motion. Step analysis revealed that these stop events occur at 27-28 discrete angles around the motor, which most likely reflect the periodicity of the rotor (i.e. copies of FliG). This represents the first experimental resolution of steps in the rotation of a wild-type bacterial flagellar motor with a full complement of torque-generating units.

Keywords: clutch
flagellum
flagellar motor
chemotaxis
rhodobacter
brake
Advisor: Armitage, J