VictorJuiz/thesis huggingface dataset:
Computationally bounded rationality from three perspectives: precomputation, regret tradeoffs, and lifelong learning

What does it mean for a computer program to be optimal? Many fields in optimal decision making, from game theory to Bayesian decision theory, define optimal solutions which can be computationally intractable to implement or find. This is problematic, because it means that sometimes these solutions are not physically realizable. To address this problem, bounded rationality studies what it means to behave optimally subject to constraints on processing time, memory and knowledge. This thesis contributes three new models for studying bounded rationality in different contexts. The first model considers games like chess. We suppose each player can spend some time before the game precomputing (memorizing) strong moves from an oracle, but has limited memory to remember these moves. We show how to analytically quantify how randomly optimal strategies play in equilibrium, and give polynomial- time algorithms for computing a best response and an ε-Nash equilibrium. We use the best response algorithm to empirically evaluate the chess playing program Stockfish. The second model takes place in the setting of adversarial online learning. Here, we imagine an algorithm receives new problems online, and is given a computational budget to run B problem solvers for each problem. We show how to trade off the budget B for a strengthening of the algorithm’s regret guarantee in both the full and semi-bandit feedback settings. We then show how this tradeoff implies new results for Online Submodular Function Maximization (OSFM) (Streeter and Golovin, 2008) and Linear Programming. We use these observations to derive and benchmark a new algorithm for OSFM. The third model approaches bounded rationality from the perspective of lifelong learning (Chen and Liu, 2018). Instead of modelling the final solution, lifelong learning models how a computationally bounded agent can accumulate knowledge over time and attempt to solve tractable subproblems it encounters. We develop models for incrementally accumulating and learning knowledge in a domain agnostic setting, and use these models to give an abstract framework for a lifelong reinforcement learner. The framework attempts to make a step towards making the best of analytical performance guarantees, while still being able to make use of black box techniques such as neural networks which may perform well in practice.

Keywords: computationally bounded rationality
lifelong learning
Advisor: Santhanam, R
Zivny, S
Kanade, V
A probabilistic approach to fractional reaction-diffusion equations

This thesis consists of two projects. In the first project, we prove a new result relating the solution interface of the scaled fractional Allen–Cahn equation to motion by mean curvature flow. More precisely, we show that, for α ∈ (1, 2) and d ≥ 2, if u is a solution to the scaled fractional Allen–Cahn equation
∂tu=− I(ε)^(α-2)(−∆)^(α/2) u+ε^(-2)u(1−u)(2u-1) t>0, x∈R^d
with a suitably chosen initial condition and scaling then as ε → 0, u converges to the indicator function of a set whose boundary evolves according to motion by mean curvature flow. Here, I(ε) can be chosen from a family of possible ‘scaling functions’, distinguishing our result from known convergence results such as [IS09]. Our proof is purely probabilistic (taking inspiration from [EFP17]) and describes solutions of the fractional Allen–Cahn equation in terms of ternary branching α-stable motions. Finally, we prove that this mean curvature flow behaviour is preserved for a stochastic analogue of the fractional Allen–Cahn equation. We do so via the Spatial Λ-Fleming-Viot process. In our second project, we prove a new result on the spreading speed of solutions to one-dimensional fractional Fisher– KPP type equations with appropriately chosen initial condition, such as the equation
∂tu=−(−∆)^(alpha/2) u+u(1−u) t>0, x∈R.
Taking inspiration from [Pen18], we use the Feynman–Kac formula to prove probabilistically that the front position of solutions to these equations grow exponentially in time, and state the precise order of this spread- ing speed, improving known results such as those from [CR13].

Keywords: mean curvature flow
long range process
fractional reaction-diffusion equation
Allen-Cahn equation
stable process
Advisor: Etheridge, A
What does it mean to decolonise the curriculum?

The events of the summer of 2020, with the murder of George Floyd and the toppling of the statue of Edward Colston, reignited calls for curriculum change in the UK. Activists voiced the need for a more racially diverse, decolonised curriculum, particularly in school history. With the ambiguity surrounding the contested term, decolonisation, this paper explores what it may mean in practice. It considers why decolonisation is important and relevant in education before scrutinising the history curriculum more specifically. The centrality of engaged pedagogy in service of decolonisation is also emphasised. Borne out of collaboration with local history organisation, Uncomfortable Oxford, this paper examines the impact of a series of nine lessons jointly planned on local history, taught to one year seven class. These lessons aimed to provide answers to three research questions: what might be the impact of local history in decolonising the curriculum?; how does a focus on construction of history impact on students historical thinking?; and lastly, how does a pedagogy built around praxis, voice and usefulness support decolonisation? A mixed methods approach, consisting of an initial iterative questionnaire, field notes, and second questionnaire, was employed to collect both qualitative and quantitative data. The findings suggest that pupils may not initially realise the range of places history can be located, their own ability to participate in the discipline, or the importance of the topic taught (in this case, local history). But, when taught with a focus on decolonisation, revealing the processes that have constructed historical narratives, considering alternative histories, emphasising praxis and student voice, the importance, meaning and power of the discipline can be unlocked.

Keywords: pedagogy
qualitative
history
racism
quantitative
curriculum
school
MLT2021
mixed methods
MLT
education
questionnaire
decolonisation
Advisor: Todd, J
Non-compensatory damages and public interests

According to received wisdom, non-compensatory damages (NCDs) have nothing significant in common with each other save that they are not compensatory. Indeed, the awards of punitive, nominal, contemptuous, vindicatory, restitutionary and disgorgement damages are typically seen as a group of disparate remedies.

This thesis is the first attempt to analyse NCDs as a category. It focuses on damages in English tort and contract law. The thesis argues that most awards traditionally referred to as NCDs can be collectively defined as awards justified by damage to public interests. The contrast between such ‘public interest damages’ and compensatory awards, as the thesis shows, can be traced back to a fundamental distinction between measures of damages justified by considerations giving effect to individual rights and measures justified by non-rights-based considerations, namely violations of public interests. The law should acknowledge these two fundamental justifications because the distinction between them has doctrinal implications. For example, the thesis contends that unlike compensatory awards, public interest damages should not be available as of right.

The thesis shows that the similarities and overlaps amongst individual types of public interest damages and the distinctions between compensatory and non-compensatory damages (qua public interest damages) are too important to be ignored. Thus, it is recommended that we understand and develop public interest damages collectively as a distinct class of awards. Dealing with potential counter arguments, the thesis shows how such a collective approach could be implemented in practice and that this approach would not compromise the core tenets of the doctrines governing the award of NCDs. It also reveals the benefits of approaching public interest damages collectively.

Overall, by way of advancing a new interpretation of the law of NCDs, the thesis also contributes to our understanding of the English law of damages more generally and of the typically overlooked, yet significant role of public interests in the law of damages.

Keywords: liability
disgorgement damages
private law
non-compensatory damages
public interest
discretion
nominal damages
damages
English law
as of right
waiver
compensation
contemptuous damages
vindicatory damages
public interest damages
restitutionary damages
judicial remedies
punitive damages
Advisor: Goudkamp, J
Emotional and behavioural responses to GCSE: a case study in England

The General Certificate of Secondary Education (GCSE) is widely viewed as a pivotal milestone for young people in England, with its outcomes shaping future educational and professional opportunities. Despite its high-stakes nature, the perspectives and experiences of the students – those directly navigating this landscape – often remain underrepresented in educational research and policy discussions. This study seeks to amplify student voices and extend beyond the predominant narratives centred on test anxiety and student well-being to capture a more holistic view of their GCSE journey. Through semi-structured interviews, this study centred on students' emotional and behavioural responses towards GCSEs. Data analysis primarily drew from 22 Year 11 and 12 students from a comprehensive suburban London school, complemented by insights from five educators, field notes, and a reflexive journal. A specially designed timeline was used for Year 12 participants to aid memory recall during interviews. Reflexive Thematic Analysis was employed as the analytical strategy, yielding three salient themes: the omnipresence of stress in students’ GCSE experience, the positive value of exam preparation, and the tension between curriculum depth and breadth. This study also reveals factors that could enhance students’ GCSE experience and capture their aspirations and hopes for the future GCSE system. In conclusion, this study underscores the importance of direct student engagement, valuing their articulate and invaluable feedback. While debates around the utility of GCSE persist, this research advocates for their reform rather than elimination. Drawing from the rich tapestry of student experiences can guide future policy and practice, fostering a GCSE experience that is both rewarding and sensitive to student well-being.

Keywords: educational assessment
exam stress
student voice
exam preparation
narrowed curriculum
washback
GCSE
test anxiety
test preparation
Engineering cell free protein synthesis and synthetic cells

Mimicking the structure and function of natural cells, synthetic cells hold significant potential in various applications. These synthetic cells, which come in numerous forms, are developed from different materials, including lipids and proteins, as well as synthetic materials such as polymers. The method of producing synthetic cells depends largely on their intended use and the materials used in their formation. Expression of genes within a synthetic cell can allow its usage in many fields to either study minimal cellular behaviour and function or use them as cargo holding vehicles for controlled delivery to target sites.
This thesis focuses on the production of lipid-based synthetic cells using a cell-free protein expression system and a DNA template. The primary objective of this study was to generate synthetic cells capable of producing a target protein, which can be released in a controlled manner upon the application of heat. Heat is a promising stimulus for future applications in SCs due to its thermal control to allow precise manipulation, biocompatibility, non-invasiveness, versatility, scalability, and integration with existing technologies.
To produce the SCs, we initially optimized the inverted-emulsion method to create giant unilamellar vesicles. These vesicles successfully encapsulated the cell-free protein expression system, enabling the production of a fluorescent protein or a reporter enzyme. However, incorporating heat-sensitive lipids into the synthetic cells using this approach proved unsuccessful. Consequently, we pursued an alternative strategy to produce SCs known as the freeze-dried empty liposomes (FDEL) method. Through optimization, this method enabled us to incorporate thermosensitive materials such as DPPC, lysolipids, and PEG into the SCs at specific compositions, facilitating controlled release upon heating.
Furthermore, we investigate a genetic engineering method to enhance the protein yield in the E. coli cell-free protein expression system, PURExpress, by introducing a short sequence referred to as a "booster." We identify specific cell penetrating peptide nucleotide sequences and their derivatives which allow higher expression of the fluorescent protein, mVenus.

Keywords: Increasing protein yield in IVTT
Thermoresponsive vesicles
IVTT
Thermosensitive vesicles
Synthetic cells
Liposome
Lipid vesicles
Advisor: Booth, M
A multidisciplinary investigation of magmatic overpressure and its implications for volcanic eruption triggering

Magmatic overpressure – pressure in excess of lithostatic – can be generated by processes such as thermal expansion, crystallisation or magma injection. We cannot observe these processes directly, yet the magnitude and timescale of overpressure build-up are both critical for understanding failure limits and forecasting volcanic eruptions. This thesis explores variations in the magnitude and rate of overpressure build-up with varying magmatic and crustal properties. It also assesses the use of electron backscatter diffraction as a new tool for probing reservoir overpressurisation and storage conditions.
Chapter 2 demonstrates that there are variations in the intrinsic overpressure-generating capacity of magmas according to their initial fluid content. Overpressure due to second boiling increases in magnitude with increasing XH2O, and is at a peak in magmas with initial H2O contents which are at the solubility limit. The implications of this variability in overpressure are discussed in the context of eruption style, and results are coupled with a thermal model to determine the associated timescales of overpressurisation. Chapter 3 continues with this novel coupling of thermodynamic and thermal models by quantifying the effect of changes in magma reservoir volume, geometry and crustal properties on timescales of overpressurisation. These timescales are discussed in the context of other overpressurisation mechanisms, including magma buoyancy and bubble rise. The importance of overpressurisation rate, as well as the absolute value, is highlighted in the context of eruption triggering. Chapter 4 explores overpressurisation from a different angle, by analysing deformation in natural and experimentally deformed volcanic samples to investigate physical signals of overpressurisation. Crystal plastic deformation is quantified using electron backscatter diffraction, and demonstrates potential for determining long-term magma storage conditions. Further experimentation to assess the effect of crystallinity, and analysis of samples from a range of explosive eruptions are the most useful next steps to achieve this goal.

Keywords: electron backscatter diffraction (EBSD)
overpressure
relaxation timescales
crustal properties
thermal modelling
experimental petrology
magma
volcanic systems
Advisor: Cassidy, M
Hanssen, L
Identifying the mechanisms driving pancreatic ductal adenocarcinoma stem cell characteristics using single-cell RNA-sequencing

Pancreatic ductal adenocarcinoma (PDAC) is among the deadliest human malignancies. Surgery, the only curative treatment, is precluded by the late stage at diagnosis in 80% of cases. Recurrence after surgery is common, and the disease does not respond well to chemotherapy and radiotherapy. Resistance to therapy and recurrence are thought to be driven by pancreatic cancer stem cells (PCSCs), a subset of cells with self-renewal and differentiation capacities. Annihilating these cells is therefore of paramount importance for treating PDAC. Identifying these cells, however, has proven challenging. Currently, there is no gene signature able to identify PCSCs. In this thesis, I employed single-cell RNA-sequencing to integrate multiple approaches towards the identification of PCSCs (experimentally-derived markers, bioinformatics-based gene sets, and computational tools to infer developmental potential from expression data), to uncover the genes and processes characterizing PCSCs, and to assess the effects of I-BRD9, an inhibitor of BRD9, a bromodomain-containing protein involved in chromatin remodelling upon the PCSCs, using two single-cell RNA-sequencing PDAC datasets. The results evidenced cell cycle abnormalities as crucial to cancer stemness in PDAC, with multiple lines of evidence converging towards the identification of clusters whose markers significantly overlapped with cell cycle-related stemness-associated gene sets as PCSCs. Traditionally-derived PCSC markers were found to be largely of low reliability. A transitional cell population distinct from both PCSCs and the bulk of the cells, and one with an advanced stage of differentiation which however regained partial stemness-like characteristics, were identified as highly drug-resistant, suggesting that greater than previously believed PDAC cell heterogeneity, not merely PCSCs, is involved in chemoresistance. I-BRD9 achieves a ~6-fold reduction of PCSCs in one dataset, likely mediated by the demonstrated downregulation of key G2/M DNA replication checkpoint-linked genes such as TOP2A and CDK1, but the effects are partially reversed by the addition of PDAC drug gemcitabine.

Keywords: Bioinformatics
Single-cell RNA-sequencing
Pancreatic cancer
Advisor: Oppermann, U
Pauklin, S
Cribbs, A
Re-presenting dislocation: the poetics of exile and diaspora in ancient Jewish texts

This thesis considers examples of ancient Jewish literature that present open-ended poetics concerning exile and diaspora. Part I of the thesis focuses on the book of Lamentations, Second Isaiah, and 1QS to demonstrate that these examples present the resolve of exile as deferred, and do not focus solely on physical homecoming. Part II considers how the diaspora narratives of Esther and Joseph also reflect an open-ended poetics towards exile and diaspora by the way in which they characterise the diaspora heroes/heroines. Moreover, the interpretations of Esther in antiquity present an open-ended poetics by portraying the exile and diaspora as part of a larger history of displacement that is neither inherently negative nor absent of divine providence.
The language of “opened-endedness” is inspired from the work of Sidra DeKoven Ezrahi, who discusses how some Jewish texts offer “closure” to the “narrative of exile,” whereas others are more “open-ended.”1 In terms of biblical scholarship, and scholarship on Second Temple, Hellenistic literature and beyond, ancient Jewish literature is often regarded as containing closed poetic expressions concerning exile and diaspora. In the case of texts such as Second Isaiah, this literature is largely portrayed as a body of work that failed as prophecy because its idealized imagery of homecoming did not historically come to pass. Moreover, the diaspora narratives of Esther and Joseph, and the interpretations of Esther in antiquity, are often regarded as apologising for aspects of diaspora life, or as viewing the state of exile and diaspora as a burden. However, this thesis argues that these examples belong to a larger history of ancient Jewish texts that reflect upon displacement, suffering, and its impact on the divine’s relationship with the people in poetically nuanced ways.

Keywords: diaspora
exile
Hebrew Bible
poetics
Advisor: Najman, H
Administrative jurisdiction

Jurisdiction is the extent of a power. This gives rise to an important distinction. Jurisdictional errors take an authority outside the scope of its power. Nonjurisdictional errors do not, even if they render the ensuing exercise of power unlawful. Unwelcome baggage has made the task of arriving at a coherent account of jurisdiction needlessly difficult. That baggage is the common assumption that lack of jurisdiction is the sole basis for judicial review. This is wrong. Abandoning it makes space for an attractive account of when an error is jurisdictional. An error is jurisdictional if (i) it is an instance of a kind of error, in the sense of ground of review, which could arise at the outset of proceedings, but (ii) it does not pertain to a collateral matter, the purpose of which is tangential to the purpose of the inquiry. I shall call this the revised temporal view of jurisdiction. It accepts the possibility of judicial review on both jurisdictional and nonjurisdictional grounds. But the distinction has practical significance for at least three reasons. First, only acts with a jurisdictional flaw are nullities. Second, jurisdictional questions take analytical priority over nonjurisdictional ones. Third, post hoc explanations are only acceptable for jurisdictional issues.

Keywords: judicial review
administrative law
jurisdiction
Advisor: Endicott, T
High-fidelity, near-field microwave gates in a cryogenic surface trap

We present a novel dynamical decoupling strategy for near field microwave gradient driven, Mølmer-Sørensen style, two-ion quantum logic gates, which suppresses errors from both fluctuations in the qubit frequency and imperfection in the decoupling drive itself. Using a microwave-integrated surface-trap which is operated cryogenically at 25 K and a magnetically insensitive 43-Ca+ qubit at 288 G, we demonstrate a 331 us two-ion quantum logic gates, with 4.9(11)e-3 logic error probability. This is below the 1% error threshold required for quantum error correction and represents a ~10x gate time reduction when compared to previously demonstrated near field gradient driven microwave gates below the 1% error probability threshold. Additionally, two faster gates were demonstrated without the use of dynamical decoupling. Respectively, these two gates had gate operation durations of 216.8 us & 153.8 us and measured gate error probabilities of 8.5(20)e-3 & 9.8(21)e-3. Further, we develop a method for rapid calculation of ion transport operations. We successfully demonstrate ion transport as well as crystal splitting and merging operations within two different ion traps using the waveforms calculated by this ion transport toolbox.

Keywords: laser free gates
microwave gates
two-qubit gates
quantum computing
calcium 43
ion transport
surface trap
dynamical decoupling
trapped ions
Advisor: Lucas, D