VictorJuiz/thesis huggingface dataset:
Action potential alterations induced by single neuron mechanical loading

Since the 1940s, an extensive body of empirical evidence has been gathered about non-electrical alterations accompanying the voltage depolarisation of a neuron during the generation and propagation of an action potential (AP). The prevailing traditional electrochemical models do not account for these changes, and are as a result incomplete. At the same time, multiple research programmes have demonstrated how ultrasound (US) -a mechanical wave- can non-invasively and reversibly mechanically perturb neuronal functions. Strikingly, the mechanisms of action remain largely unknown.
In this framework, this thesis takes the approach to focus on single cell studies to better understand and exploit the multiphysics of the neuronal action potential and aims at studying the effects of direct mechanical loadings on the shape and dynamics of the neuronal signal. First, a multiphysics platform combining nanoindentation and patch clamp systems, assembled in an inverted microscope, is designed to simultaneously measure mechanical and electrophysiological properties of single neurons while imaging the cell morphology. The functionality of the setup is first used to provide a full characterisation of the neuronal cell line chosen here, i.e., dorsal root ganglion-derived cells, and then to quantify the alterations in the magnitude and dynamics of single neuron spontaneous APs before, during and after quasi-static and dynamic mechanical loadings over a wide range of frequencies (up to 1 MHz).
Quasi-static indentation tests show transiently smaller, wider and slower depolarising APs during compressions within the cell's linear viscoelastic regime, which translates in slower AP dynamics, as well as sustained hyperpolarised cells with longer repolarisation rates after the indentation. Dynamic loading results, instead, show narrower APs with shorter depolarisation and repolarisation phases, i.e., faster induced AP dynamics, at increasing frequencies, particularly for stimulations at around 1 MHz. In addition, results at this frequency are more evident after indentation, hinting at a cumulative or lagged effect of mechanical stimulation at US frequencies. These observations are attributed to the stiffening of the membrane and membrane cortex as a result of the mechanical oscillations, as well as potentially related phase state alterations. Taken together, these findings highlight the importance of mechanical cues in shaping the neuronal AP, and the often overlooked role of the membrane and its mechanical properties in determining cell functionality. In particular, the promoted faster AP dynamics that emerge after high frequency mechanical oscillations suggest a potential mechanism of US neuromodulation and support the assumption that direct mechanical cellular agitations induced by US stimulation protocols assist the observed neuromodulatory effects.

Keywords: patch-clamp
neuronal membrane mechanics
mechanoelectrical coupling
ultrasound neuromodulation
nanoindentation
neuronal action potential
neuron multiphysics
Advisor: Jerusalem, A
Ye, H
What are the brain specializations underlying human vocal control?

One uniquely human experience is our ability to communicate via speech and language. Specialized laryngeal motor control has been suggested to be a critical adaptation in the human brain that enabled speech. The aim of this thesis was to study the human brain specializations underlying laryngeal motor control and to study evolutionary principles of brain organization within the primate lineage. I investigated these questions using magnetic resonance imaging and comparative primate neuroanatomy.
To characterize the representations of the larynx in the human brain, I used anatomical and functional studies. First, I mapped the motor representations of the larynx and other effectors using fMRI. I designed a novel functional paradigm to isolate brain activity related to laryngeal activity during vocalization whilst controlling for breathing. Then, I characterized the cortical microstructure underlying the activated regions using structural and quantitative neuroimaging. The results revealed the existence of a dorsal larynx representation in primary motor cortex and a ventral larynx representation presumed to be in premotor cortex as indexed by lower cortical thickness and lower myelin content.
Next, I examined whether variability in cortical folding explains inter-individual variability in the location of the larynx representations. I provided a systematic description of the sulcal patterns in the central and subcentral region. I showed that the anterior subcentral sulcus typically consists of two distinct segments, as opposed to being one continuous sulcus as previously described in a brain atlas. I demonstrated a tight link between morphological landmarks in the central and subcentral region and functional activation maxima for several movement types. This result indicates that inter-individual variability in brain morphology might have contributed to controversies and inconsistent reports in the case of the ventral larynx representation.
Furthermore, I set out to dissociate different scenarios of cortical brain reorganization during primate evolution. Using a surface-based cross-species registration, I studied if changes to the relative location of brain areas and cortical expansions went hand in hand with changes to connectivity profiles. The registration was based on homologous maps of cortical myelin in humans, chimpanzees and macaques to model local cortical expansions and relocations of brain areas. Then we applied this registration to surface tract maps of a set of homologous white matter tracts. Our results demonstrated that several tracts can be predicted well by cortical expansion and relocation, but that the arcuate fasciculus underwent additional evolutionary modifications affecting the temporal lobe connectivity pattern.

Keywords: white matter
quantitative neuroimaging
evolution
larynx
neuroanatomy
fMRI
sulcal morphology
speech
Advisor: Mars, R
Watkins, KE
Burnout market feminism: urban Chinese businesswomen in the internet age

Based on a one-year multi-sited ethnography with businesswomen in Shenzhen and Hefei and three-years' working experiences in an online educational platform economy, this thesis makes two main contributions. Theoretically, by using my concept of burnout market feminism, it unravels the puzzle of why women in China thrive in business in the Internet age during a state crackdown on feminism. Burnout market feminism is a critical theoretical combination of Chinese feminist Li Xiaojiang’s market feminism and Korean-German cultural theorist Han Byung-Chul’s Burnout Society. While Li's market feminism contributes the Chinese local perspective with empowerment and contexts at its centre to allow gendered subjectivities and solidarity to burgeon from the market, Han warns us that the Internet age has made us voluntarily self-exploit and burn out. In short, women burn out for market feminism. Empirically, it demonstrates the multiplicities and nuances of businesswomen's lived experiences and negotiations with patriarchy in different social-culture locations. Businesswomen’s negotiation with patriarchy in the Internet age is shaped by the intersectionality of place, gender, age, class and migration trajectory. I compare business ideas, business practices and especially in terms of the well-researched male-centred guanxi practices, and intimacy as well as family practices in three different groups of women. In doing so, I avoid a yes or no monolithic answer to questions such as “are women empowered by the Internet?” and show instead nuanced diversified presences of my interlocutors empowered by their materialistic advancements.

Keywords: Burnout
China
Xiaojiang Li
Businesswomen
Burnout Market Feminism
Feminism
Internet
E-commerce
Byung-Chul Han
Market Feminism
Chinese Feminism
Female Entrepreneur
Advisor: Jaschok, M
Murphy, R
Are audio-files a more useful methods for providing feedback?

The aim of this research project was to see if audio-files are a more useful way of providing feedback to students in a secondary school setting compared with the researcher’s standard form of written feedback. Feedback is a crucial part of the learning process and should always aim to be as useful as possible. Clarity and precision are the two key parameters used in this research to ensure feedback is useful and easily understandable. The literature emphasises there is a lack of knowledge with understanding student perspectives when receiving feedback, especially with regards to receiving audio-files. This research hopes to provide more evidence towards the usefulness of audio-file feedback at secondary school level. A class of Year 9 Geography students completed three GCSE style 8 mark questions and subsequently received both written and audio-file feedback. Student views on audio-files were gathered through group interviews; teacher views were collected through an online questionnaire. The data collected from these qualitative methods were analysed through a coding process which led to particular themes being identified. The principle finding that 78% of students valued the audio-files and believed them to be more useful compared with the written feedback. The recordings provided more detail and the verbal nuances added greater clarity. The remaining students preferred written feedback because they could see the comments written down. Teachers found audio-files to be useful and highlighted how recordings sped up the feedback process together with providing a personalised piece of feedback.

Keywords: MLT2020
MLT
The electrochemical leaf: driving and observing nanoconfined enzyme cascades

The co-localisation of cooperating enzymes within nanozones is crucial in biological catalytic processes to ensure fast and efficient catalysis. The Electrochemical Leaf is a novel electrode which mimics that principle. Entrapping two cooperating enzymes, Ferredoxin NADP+ reductase (FNR) and a NADPH-dependent dehydrogenase, within the nanopores of an Indium-Tin-Oxide (ITO) electrode produces a massive catalytic enhancement. Upon application of a small potential FNR catalyses the interconversion of NADP+/NADPH, while the NADP(H)-dependent dehydrogenase uses the produced cofactor to catalyse the oxidation or reduction of a substrate. By nanoconfining the two catalysts the effective concentration of the enzymes is greatly increased, and diffusion distances of the cofactor minimized. The system makes it possible to drive and monitor complex biotransformations. This Thesis shows that by incorporating the NADPH-dependent Malic Enzyme (ME), the resulting electrode, (FNR+ME)@ITO/Support, is able to drive reductive CO2 incorporation into pyruvate (C3) forming malate (C4). The favourable catalysis within the electrode pores allows for the design of a system which mimics biological oxygenic photosynthesis by incorporating a PEC-PV system with a photoanode in conjunction with a 0.5 V Silicon solar cell. For the first time the Electrochemical Leaf was exploited to drive multi-enzyme cascade reactions where the overall rate is measured directly as an electric current through the FNR-NADPH-dependent dehydrogenase couple. As a proof of concept, the reversible amination of pyruvate (C3) to L-aspartate (C4) was investigated by entrapping FNR, ME, carbonic anhydrase, fumarase and L-aspartate ammonia lyase. The Electrochemical Leaf can be coupled to any natural or artificial multienzyme cascade provided one enzyme is NAD(P)(H) dependent. The implications are numerous for synthesis, biosensing and fundamental investigation of systems catalysis.

Keywords: NADP(H) recycling
Biosensor
Nanoconfinement
Enzyme cascades
Biocatalysis
Artificial Photosynthesis
Electrochemistry
Advisor: Armstrong, F
Development of a post-16 feedback policy: Staff and student perceptions

Feedback can be considered one of the key strategies for improving student achievement. While much focus has been given to effective feedback strategies, an area of increasing focus is students’ perceptions of the feedback they receive, as it is suggested that without positive perceptions, feedback will not be fully utilised. This study aimed to introduce a post-16 feedback policy. The policy was developed collaboratively within the school, incorporating staff and student perceptions of feedback, as well as building on good practice, as outlined by the literature. As a mixed methods investigation, staff and student perceptions were gathered by quantitative questionnaires, with the intention of developing more detailed views through the use of interviews. The study found that students’ perceptions of feedback were largely positive, and that the introduction of the policy resulted in an increase in these positive views, although the majority of these changes were not statistically significant. One area in which a significant difference was found, was between male and female students’ perceptions of feedback, particularly relating to its usefulness and its perceived importance. This is an area that has not been identified by other studies and may warrant further investigation. In contrast to existing literature, alignment was found between staff and student perceptions regarding the provision of the feedback, and the extent to which students utilise it. Staff perceptions of feedback can be considered important, as increased workload, relating to feedback, can be a barrier to implementation. This study found that workload was minimally impacted by the introduction of the feedback policy. However, low staff perceptions of the benefits of this policy, and the changes to feedback practices, may have resulted in limited engagement with the policy.

Keywords: MLT
MLT2020
Polanyi, China and the environmental impasse: unconscious retrogression and conscious advance

This thesis re-examines core concepts of Polanyian thought in order to evaluate the contemporary value of Polanyian theory. Since the 2008 financial crisis there has been an increased focus on Polanyi’s double movement and countermovement concepts to help explain the fallout of 2008. However this thesis argues a significant proportion of the contemporary Polanyian literature has mis-interpreted these core concepts leading to interpretations that undercut the explanatory potential of Polanyi’s main arguments. Through an interrogation of the countermovement and double movement concepts this thesis puts forward a new vocabulary of consciousness, which I argue can help better understand general Polanyian thought. To demonstrate the potential importance of the new vocabulary, as well as Polanyi’s contemporary value, I use this re-examination to interrogate two Chinese case-studies. The first examines what I argue is an unconscious countermovement occurring in wet markets in China as people look to the rural as a sphere of food safety from the negative effects of China’s rapid market transformation and agroindustrialization. The second case study examines what I term conscious Polanyian movements; urban residents ‘returning’ to the rural to gain refuge from the market. These movements are ‘conscious’ as they explicitly attack market ideals and call for a new political synthesis in similar ways to Polanyi. The environmental crisis is at the core of these communities’ ideology and they connect that crisis to market norms. Both these case studies illuminate the importance of the consciousness vocabulary within Polanyi’s work as well as bring out specific issues within Chinese political economy. The final chapter puts forward a contemporary interpretation of the unconsciousness/consciousness dichotomy by examining the current environmental crisis impasse. It argues that only conscious Polanyian movements, which bear responsibility for our part in mutual human relationships, are able to solve our collective climate emergency. Consciousness of this responsibility would necessitate dramatic changes in the social and economic structures of the global north. The interpretation of Polanyi’s theory in this thesis is important for scholars to use to demonstrate the explanatory potential of Polanyi’s thought in future analysis.

Keywords: China
Wet market
Environment
Karl Polanyi
Ecovillage
Advisor: Thornton, P
Understanding small molecule conformations using statistical machine learning

The generation of conformations for small molecules is one of the cornerstones of computational chemistry. Identifying diverse low energy conformers and, in particular, the lowest energy conformer are essential for applications, such as molecular docking and molecular property predictions. The large conformational space of flexible molecules and the high computational cost of accurate energy evaluation with methods such as quantum mechanics are two key challenges.
This thesis explores the use of statistical techniques to (i) understand the factors governing the conformational preferences of small molecules and their population, and (ii) improve the efficiency in finding the lowest energy conformer of a molecule. I first provide an overview of conformer sampling and Bayesian optimisation, followed by an introduction to circular data analysis for analyzing torsional distribution in small molecule conformations.
I demonstrate the effectiveness of Bayesian optimisation algorithm in finding the lowest energy conformation of molecules, which requires orders of magnitude fewer energy evaluation to find the lowest energy conformation. I also show how sampling efficiency can be further improved by biasing the search towards low energy regions through a knowledge-based acquisition function. To extend the sampling framework, I explore the use of Cremer Pople puckering parameters to characterise complex ring geometries, and study the resulting ring puckering preferences extensively.
Finally, I investigate the factors contributing to the conformational entropies of small molecules, and develop linear models that predict the conformational entropies of small molecules accurately and rapidly.
In summary, this thesis contributes an improved understanding of small molecule conformational preferences, and introduces new methods to improve the efficiency of sampling conformers and entropy calculations.

Keywords: Conformers
Conformational sampling
Advisor: Morris, GM
The promises of “Going digital” for all: where technology meets social policy? A Statistical Analysis of European Union’s Digital Skills Inclusion Policies and Digital Skills Inequality

Digital skills have never been more relevant to social policy. The European Union’s policy agenda has been increasingly linking digital skills to social matters such as employment, poverty, income or education. However, wide disparities in national levels of digital skills are observed across member states. This study investigates the associations between digital inclusion policies and national levels of digital skills across the European Union using Eurostat data from 2010 to 2019. Digital skills inequalities are also explored by gender and educational levels. Results suggest that public digital skills policies are associated with higher levels of digital skills, and lower levels of digital skills inequality. Conversely, private digital skills policies increase digital skills inequality. This paper explicitly links digital skills with social welfare, bridging human capital and labour market perspectives with nuanced understandings of digital skills and their reflection of preexisting socio-economic inequalities. The main theoretical contributions lie in thinking of digital skills policies within a social investment framework, inciting a broader reflection on the role of digitalisation for the future of social policy and the welfare state.

Keywords: Digital Agenda for Europe
Digital skills
Digital Welfare State
Digital inclusion
Skill inequality
Digital skills policies
Digitalisation
Advisor: Weisstanner, D
The myth of the benevolent autocrat? Internal constraints, external constraints, and economic development in autocracies

Why do some autocracies produce high economic development while others falter? Despite the large literature comparing democracies and autocracies we know little about differences amongst autocratic regimes. I focus on the rule of one autocrat over time instead of comparing across regimes, and argue that an autocrat can be constrained by both a strong ruling elite (internal constraints) and an organized civil society (external constraints). I depart from the literature focusing on institutional constraints and use Arendt’s concept of isolation to conceptualize constraints. The two types of constraints generate political accountability. This will result in a pluralistic and thoughtful decision-making process and a better environment for investment. I theorize that both types of constraints are associated with better economic outcomes, but that only external constraints promote better human development. To test this, I rely on three analyses. First, I conduct a cross-national analysis using a novel dataset, WhoGov, which provides information on the ruling elites. I show that only constrained autocrats are punished for governing over a severe recession. Furthermore, the same dictator governs over better economic outcomes when his rule is constrained. That said, only external constraints are related to improvements in human development. Second, I use a synthetic control design to investigate the effect of the Tulip Revolution in Kyrgyzstan, and show that the regime, despite not democratizing, increased public spending on health care and education. Third, I show that there is a cost to the ruling elite if they unsuccessfully try to coup the autocrat. In addition, I find that a successful coup is associated with better growth when there is an orderly transfer of power to a new, constrained autocrat, but not if the coup causes political instability. Overall, I show that the belief in the developmental benefits of having a strong autocrat is not supported empirically. Instead, autocrats govern over worse economic development when they become more powerful.

Keywords: Elites
Autocracies
Economic development
Civil society
Accountability
Advisor: Ansell, B
Spin systems and boundary conditions on random planar graphs

In this thesis we discuss the multi-matrix integral formulation of spin systems on random planar graphs, as a discretised model of 2D Euclidean quantum gravity coupled to matter.
We begin by extending a recent analysis of the q-states Potts model with p < q allowed, equally weighted spins on a random lattice with a connected boundary. We explore the(q < 4, p < q) parameter space of the model, classify solutions in (q, p) that yield finite-sheeted resolvents, and derive the associated critical exponents. For the particular case of q = 3 we find a new solution with p = 3/2, which we conjecture to be the random lattice analogue of the New boundary condition.
Following this we study the Kramers-Wannier dual of the 3-state Potts model on the random lattice. We explicitly construct the known boundary conditions and show that the mixed boundary condition is dual to the New boundary condition, in accordance with the fixed lattice identification. However, we find that the mixed boundary condition of the dual theory, and the corresponding New boundary condition are not described by conventional resolvents.
Finally, we formalise a combinatorial method for calculating the partition function of the 3-states Potts model on a random planar lattice with various boundary conditions imposed. We determine the p = 1, 2 and 3 boundary conditions via this technique, and discuss other types of boundary condition that may be calculated, before turning our attention to the dilute Ising and dilute Potts models, where we compute the p = 1 boundary condition.

Keywords: Matrix model
Spin systems
Dynamical triangulations
2D quantum gravity
Liouville quantum gravity
Random planar graphs
Random matrices
Advisor: Wheater, J