VictorJuiz/thesis huggingface dataset:
Three-dimensional geometric image analysis for interventional electrophysiology
Keywords: random forest
cardiac ct
image analysis
cardiac mri
image segmentation
machine learning
cardiac electrophysiology

Improving imaging hardware, computational power, and algorithmic design are driving advances in interventional medical imaging. We lay the groundwork here for more effective use of machine learning and image registration in clinical electrophysiology.
To achieve identification of atrial fibrosis using image data, we registered the electroanatomic map (EAM) data of atrial fibrillation (AF) patients undergoing pulmonary vein isolation (PVI) with MR (n = 16) or CT (n = 18) images. The relationship between image features and bipolar voltage was evaluated using single-parameter regression and random forest models. Random forest performed significantly better than regression, identifying fibrosis with area under the receiver operating characteristic curve (AUC) 0.746 (MR) and 0.977 (CT). This is the first evaluation of voltage prediction using image data.
Next, we compared the character of native atrial fibrosis with ablation scar in MR images. Fourteen AF patients undergoing repeat PVI were recruited. EAM data from their first PVI was registered to the MR images acquired before the first PVI (‘pre-operative’) and before the second PVI ('post-operative' with respect to the first PVI). Non-ablation map points had similar characteristics in the two images, while ablation points exhibited higher intensity and more heterogeneity in post-operative images. Ablation scar is more strongly enhancing and more heterogeneous than native fibrosis.
Finally, we addressed myocardial measurement in 3-D echocardiograms. The circular Hough transform was modified with a feature asymmetry filter, epicardial edges, and a search constraint. Manual and Hough measurements were compared in 5641 slices from 3-D images. The enhanced Hough algorithm was more accurate than the unmodified version (Dice coefficient 0.77 vs. 0.58). This method promises utility in segmentation-assisted cross-modality registration.
By improving the information that can be extracted from medical images and the ease with which that information can be accessed, this progress will contribute to the advancing integration of imaging in electrophysiology.
Strategies in robust and stochastic model predictive control
Keywords: optimization-based control
model predictive control
stochastic control
robust control
control policies

The presence of uncertainty in model predictive control (MPC) has been accounted for using two types of approaches: robust MPC (RMPC) and stochastic MPC (SMPC). Ideal RMPC and SMPC formulations consider closed-loop optimal control problems whose exact solution, via dynamic programming, is intractable for most systems. Much effort then has been devoted to find good compromises between the degree of optimality and computational tractability. This thesis expands on this effort and presents robust and stochastic MPC strategies with reduced online computational requirements where the conservativeness incurred is made as small as conveniently possible.
Two RMPC strategies are proposed for linear systems under additive uncertainty. They are based on a recently proposed approach which uses a triangular prediction structure and a non-linear control policy. One strategy considers a transference of part of the computation of the control policy to an offline stage. The other strategy considers a modification of the prediction structure so that it has a striped structure and the disturbance compensation extends throughout an infinite horizon. An RMPC strategy for linear systems with additive and multiplicative uncertainty is also presented. It considers polytopic dynamics that are designed so as to maximize the volume of an invariant ellipsoid, and are used in a dual-mode prediction scheme where constraint satisfaction is ensured by an approach based on a variation of Farkas' Lemma.
Finally, two SMPC strategies for linear systems with additive uncertainty are presented, which use an affine-in-the-disturbances control policy with a striped structure. One strategy considers an offline sequential design of the gains of the control policy, while these are variables in the online optimization in the other.
Control theoretic properties, such as recursive feasibility and stability, are studied for all the proposed strategies. Numerical comparisons show that the proposed algorithms can provide a convenient compromise in terms of computational demands and control authority.
Five modes of scepticism: an analysis of the Agrippan modes in Sextus Empiricus' outlines of Pyrrhonism
Keywords: epistemology
Sextus Empiricus

This thesis has as its focus five argumentative modes that lie at the heart of Sextus Empiricus’ Outlines of Pyrrhonism. They are the modes of disagreement, hypothesis, infinite regression, reciprocity and relativity. They are analysed, individually, in the first five chapters of the thesis (one mode per chapter) and, collectively, in the sixth. The first four chapters deal, respectively, with the modes of disagreement, hypothesis, infinite regression and reciprocity. They distinguish between two versions of these modes: “dogmatic versions”, on the basis of which a dogmatic philosopher, who holds some theoretical beliefs, might reach a sceptical conclusion; and “sceptical versions”, on the basis of which a sceptical philosopher, who lacks all theoretical beliefs, might do so. It is argued that scholars such as Jonathan Barnes have offered reconstructions of these modes which are dogmatic in the sense just described, and alternative sceptical versions of the modes are presented. A stand-alone fifth chapter offers an analysis of a stand-alone mode - the mode of relativity. It argues that there are in fact three different modes of relativity at play in the Outlines, that only one of them is non-trivial, and that the non-trivial version is incompatible with the mode of disagreement. The sixth and final chapter offers an analysis of how the modes (excluding relativity) are meant to work in combination with one another. Four different combinations are presented and it is argued that all of them are underscored by a variety of theoretical assumptions, which a sceptic, who lacks all theoretical beliefs, cannot make. The ultimate conclusion of the thesis is that, though the sceptic can deploy the various modes individually (by means of exercising his particular sceptical ability), he is not able to systematise them into a net by means of which he might trap his dogmatic opponent. Unless specified otherwise, translations are based on Annas, J., and Barnes, J., Sextus Empiricus: Outlines of Scepticism (Cambridge: Cambridge University Press, 2000).
The linguistics of orality: a psycholinguistic approach to private and public performance of classical Attic prose
Keywords: oral performance
psycholinguistics
Greek rhetoric
Attic oratory

The thesis tests the hypothesis that certain aspects of linguistic variation in Attic prose are related to the type of oral performance, private or public, which the author envisaged for his text. This hypothesis rests on the assumption that authors more or less consciously optimized their texts for their intended communicative situation. A crucial feature of texts optimized for public delivery was clarity, which figures as an essential component of the 'virtue of speech' in the Greek rhetorical thought. In private situations the audience itself could alter the pace of reading or recitation. Clarifications could be sought, and pauses and repetitions would be possible. The case was different with public situations, where the text itself coincided with its performance and it was entirely up to the speaker to determine the way in which the audience would access it. Especially in political and judicial contexts, where important decisions were to be made, public speakers could not afford being unclear.
In order to test whether public texts were clearer than private texts, 'clarity' must be defined in a linguistically thorough way. Modern psycholinguistics studies human language comprehension, and experimental research has revealed language-independent mechanisms which can be confidently applied to dead languages. In the thesis, clarity is measured by the number of syntactic, semantic, and referential reanalyses which linguistics structures induce in a given amount of text.
This methodology is tested on a corpus of Attic speeches, which includes both texts that were devised exclusively for written circulation and private delivery, and texts that were at least conceived for public delivery, although we do not know to what extent they correspond to the versions which were actually delivered. The difference between the average score of 'public texts' and that of 'private texts' is statistically significant and supports the hypothesis that 'public texts' were generally clearer than 'private texts' for audiences of native speakers.
Compatible domain structures in ferroelectric single crystals
Keywords: compatibility
ferroelectric
microstructure

The aim of the current study is to develop an efficient model which can predict low-energy compatible microstructures in ferroelectric bulks and film devices and their dynamic behaviour. The results are expected to assist in the interpretation of microstructure observations and provide a knowledge of the possible domain arrangements that can be used to design future materials with optimum performance.
Several recent models of ferroelectric crystals assume low energy domain configurations. They are mainly based on the idea of fine phase mixtures and average compatibility, and can require intensive computation resulting in complex domain configurations which rarely occur in nature. In this research, criteria for the exact compatibility of domain structure in the form of a periodic multi-rank laminate are developed. Exactly compatible structure is expected to be energetically favourable and does not require the concept of a fine mixture to eliminate incompatibilities. The resulting method is a rapid and systematic procedure for finding exactly compatible microstructures. This is then used to explore minimum rank compatible microstructure in various crystal systems and devices. The results reveal routes in polarization and strain spaces along which microstructure can continuously evolve, including poling paths for ferro- electric single crystals. Also, the method is capable to generate all possible exactly compatible laminate configurations for given boundary conditions. It is found that simple configurations are often energetically favourable in conditions where previous approaches would predict more complex domain patterns. Laminate domain patterns in ferroelectrics are classified and corre- lated with observations of domains in single crystals, showing good agreement.
The evolution of microstructures under applied mechanical and electrical loads is studied. A variational method, which minimises the overall energy of the crystal is developed. A new concept of transitional “pivot states” is introduced which allows the model to capture the feature that the microstructure in ferroelectric crystal switches between possible domain patterns that are energetically favourable, rather than assuming one particular domain pattern throughout. This model is applied to study the hysteresis responses of barium titanate (BaTiO3) single crystals subjected to a variety of loads. The results have good agreement with experimental data in the literature. The relationship between domain patterns and ferroelectric hysteresis responses is discussed.
Application of magnetic torque on the bacterial flagellar motor
Keywords: bacterial flagellar motor
Single-molecule biophysics
electromagnetic tweezers

There is a strong need to develop a mechanical method to apply external torque to the bacterial flagellar motor. Such a method will allow us to probe the behaviour of the motor at a range of different speeds under different external conditions.
In this thesis, I explored various methods to deliver torque at the single-molecule level, in particular the use of angular optical trapping and magnetic tweezers. I have identified rutile particles as suitable handles for use in angular optical trapping due to their high birefringence. Further progress was not achieved using angular optical trapping due to the lack of a suitable method to attach birefringent particles to the bacterial flagellar motor. On the other hand, I was able to make further progress using magnetic tweezers. A highly-reproducible and high-yielding magnetic bead assay was developed along with electromagnets capable of generating fast-rotating magnetic fields at magnitudes on the order of tens of mT.
Using the system of delivering magnetic torque developed, I was able to stall and rotate the motor forward at speeds up to 220 Hz and in the reverse direction. Stalling experiments carried out on the motor revealed the stator mechanosensing depends on torque and not rotation. Signatures of stators dropping out at low load experiments further confirm the load dependence of stators.
Soviet policy in West Africa, 1957-64
Keywords: Soviet Union
Cold War
Africa

Between 1957 and 1964 the Soviet Union sought to export to West Africa a model of economic and social development. Moscow’s policy was driven by the conviction that socialism was a superior economic system, and could be replicated in Ghana, Guinea, and Mali. However, Soviet confidence in the project was undermined by the unreliability of local leaders, and then by the Congo crisis. The setback in West Africa taught the Soviet leadership crucial lessons, including the importance of supporting ideologically reliable leaders, and the necessity of building military strength to bolster intervention. Combining Soviet and Ghanaian sources with those more readily available in the UK and the US, this thesis shows the importance of modernisation of the Third World for Moscow’s foreign policy during the Khrushchev era, and contributes to the new sets of literature on the cold war in the third world, and on the Soviet Union’s foreign policy.
Psychiatry’s 'golden age': making sense of mental health care in Uganda, 1894-1972 
Keywords: missionaries
mental health
Uganda
Africa
psychiatry
education

This thesis investigates the emergence of an internationally renowned psychiatric community in Uganda. Starting at the beginning of colonial rule in 1894, it traces the changing nature of mental health care both within and beyond the state, examining the conditions that allowed psychiatry to develop as a significant intellectual tradition in the years following Independence in 1962. This ‘golden age’ of psychiatry saw Uganda establish itself as a leader of mental health care in Africa, an aspect of history that is all the more marked for its contrast with the almost complete collapse of mental health care after the expulsion of the Asian population by Idi Amin in 1972. Using a wide range of new source material, including interviews with psychiatrists, traditional healers, and community elders, this thesis pushes the history of psychiatry in Africa beyond the examination of government policy and colonial hegemony. It brings together the history of psychiatry with the histories of missionary medicine, medical education, and international health by asking what types of people, institutions, and organisations were involved in the provision of mental health care; how important the growth of Makerere Medical School was for intellectual and institutional psychiatry; and how African mental health care had become by the end of the period. It presents a history of mental health care in a country that has tended to be overshadowed by Kenya in the historiography, yet whose engagement with medical missionaries and efforts to advance medical training meant that the trajectory of psychiatry came to be quite different. Focusing in particular on the significance of western-trained Ugandan medical practitioners for mental health care, the thesis not only analyses African psychiatrists as historical actors in their own right, but represents the first attempt to examine the development of psychiatric education in Africa.
The practical accomplishment of novelty in the UK patent system
Keywords: sociology of knowledge
intellectual property
patents
science &amp; technology studies

Novelty is a widespread notion that has not been given commensurate critical attention. This research is an ethnographically-inclined exploration of practices surrounding the accomplishment of novelty in an institution for which novelty is a central notion: the patent system of the United Kingdom. The research is based on interviews with patent examiners at the UK patent office, interviews with patent attorneys at various legal firms, and documentary analysis of legislation and numerous legal judgments. The thesis brings to bear themes from Science and Technology Studies and ethnomethodology to assess the extent to which they can account for the practices surrounding novelty in the UK patent system. As a fundamental legal requirement for the patentability of inventions, novelty is a central part of the practices of patent composition, assessment and contestation. Rather than being a straightforward technical criterion, however, novelty is shown to be a complex and heterogeneous phenomenon emerging from interwoven legal, bureaucratic and individual practices. The local resolution of whether or not a given invention is new, and the cross-institutional coherence of novelty as a practicable notion, raise questions concerning ontology, accountability, scale and inconcludability, and provide an opportunity for empirically grounded engagement with these longstanding analytical concerns.
Evidence based hypothermic preservation of the kidney and liver for transplantation
Keywords: systematic review
organ preservation
transplantation
surgery

Improving the techniques used for the preservation of livers and kidneys for transplantation has the potential to enhance the outcomes of transplant procedures. With an ever increasing demand for suitable organs, we now turn to the use of organs that may once have been considered to have lower success rates. The importance of preventing further damage to these organs during preservation is even greater than for standard organs. National and international guidelines for the use of such techniques in health service provision should be based upon the best level of evidence available; this is a particular challenge in a specialty with relatively few numbers of procedures each year.
This thesis describes a cohesive group of complementary studies which analyse the comparative effectiveness of preservation fluids for the cold storage of kidney and liver allografts from deceased donors. It also describes the comparison of hypothermic machine perfusion with static cold storage of kidneys. The systematic reviews carried out have a wider scope than any previously conducted. A novel approach was also taken towards the analysis of survival outcomes after transplantation as described in multiple studies. This work includes an analysis of national registry data that is the only large-scale comparison between Marshall’s Solution and University of Wisconsin Solution for kidney preservation.
There is limited trial evidence that suggests similarity between the effectiveness of current preservation fluids for kidney preservation, and good evidence that Celsior and University of Wisconsin Solutions are equivalent for liver preservation. Good randomised trial evidence suggests that hypothermic machine perfusion reduces delayed graft function of kidneys. Hypothermic machine perfusion may also result in improved graft survival, but robust evidence is not available for this. The continued use of Marshall’s Solution for kidney preservation in the UK results in equivalent adjusted outcomes compared to University of Wisconsin Solution.
Natural language variables: variable-based semantic theories of pronouns and proper names
Keywords: pronouns
variables
anaphora

Semanticists, philosophers and logicians have standardly analyzed a range of natural language expressions on the model of the variables of formal languages. This dissertation explores variable- based semantic theories of pronounsand proper names.
The first two chapters argue that a variable-based, presuppositional semantics for pronouns proposed by Cooper (1979, 1983) resolves an apparent trilemma arising from the conjunction of three plausible commitments concerning the semantics of pronouns: that some anaphoric pronouns with quantifier antecedents are bound variables, that referential pronouns have context-independent meanings, and that the relation between bound and referential pronouns is not ambiguity or homonymy.
The first chapter argues that Cooper’s semantics is descriptively and empirically superior to alternative theories, including Kaplan’s account, which does not resolve the trilemma. The second addresses an important objection to the view that bound and referential pronouns make the same semantic contribution, involving cases where bound pronouns do not appear to trigger semantic presuppositions. I argue that this appearance is misleading: bound pronouns do trigger semantic presuppositions and have the same (Cooper-style) denotations as referential pronouns.
The third chapter addresses the phenomenon of non c-command or ‘donkey’ anaphora. These anaphors appear to require a departure from Cooper’s semantics and, more generally, from the view that anaphoric pronouns correspond to (classical) bound variables. I consider D-type accounts of donkey anaphora and argue that these accounts must be revised in ways that bring the denotations of donkey anaphors closer to those of ordinary bound and referential pronouns.
The last chapter asks whether proper names require a variable-based semantics. I consider a pair of recent anaphoric theories of proper names, according to which proper names have anaphoric uses and are thus better modeled as variables. I argue that there are important reasons to reject a variable-based model for proper names, in contrast with pronouns.
The evolution of cooperation, especially in humans
Keywords: Evolutionary biology
Human Evolution
Sociobiology
Inclusive Fitness
Cultural Evolution
Kin Selection

I develop social evolution theory to study the evolution of cooperation as follows: (1) Many organisms undergo a dispersal phase prior to breeding; I demonstrate that knowing ones dispersal status aids the evolution of helping (by non-dispersers) and harming (by dispersers). (2) Policing driven by group-benefits may be selected to enforce cooperation in human and animal societies. I extend existing theory to show that policing may be harder to evolve that previously thought, but that it is maintained more readily than it evolves. (3) Archeological and anthropological evidence suggests that warfare was prevalent during our evolution. I show that, contrary to previous suggestions, between-group competition can favour any social behaviour (pro-social or anti-social) so long as it helps the group compete, and that such traits can be altruistic or mutually beneficial. (4) Reproductive leveling is analogous to policing; in the human literature there is doubt as to whether it can evolve. I extend my previous work to consider the coevolution of culturally and genetically inherited traits for reproductive leveling and selfishness. I find that cooperation can evolve between non-kin if they share the same culture. (5) Monogamy is thought to favour the evolution of cooperative breeding. I show that in the simplest case, because of the cost of competition between non-dispersing siblings, the level of promiscuity has little or no effect on the evolution of cooperation. (6) Spatial structure (limited dispersal) is thought to favour the evolution of inter-specific mutualisms as it aligns the partners’ interests. I consider the case of plant-fungi mutualisms and show that spatial structure can disfavour cooperation if it limits the potential fungal partners available to the plant.