VictorJuiz/thesis huggingface dataset:
Mobile phone-based rheumatic heart disease detection

Rheumatic heart disease (RHD), the permanent damage of the heart valves caused by an untreated “strep throat” infection, is the leading cause of cardiovascular mortality and morbidity in children and young adults worldwide. Simple penicillin treatment after the early diagnosis of RHD can stop recurring bouts of the condition, which lead to the most severe valvulopathy, and ultimately, heart failure. However, RHD is an under-diagnosed condition in the developing world, as such a diagnosis requires, at a minimum, a trained clinician to perform auscultation to detect pathological heart sounds. Trained medical personnel are scarce in the countries where RHD is most prevalent. A low-cost, mobile phone-based automatic diagnostic tool offers a potential solution, allowing a non-medically trained individual to screen for RHD in those countries.
An essential feature of such a device is feedback on the signal quality of heart sound recordings. The first major contribution of this thesis is the investigation of features and algorithms for the automatic signal quality assessment of heart sound recordings. These algorithms are able to differentiate between good- and poor-quality recordings in over 80% of cases when using both a low-cost mobile phone-based stethoscope and an electronic stethoscope.
Once the quality of recordings is ensured, the positions of the first and second heart sounds need to be located in a process called segmentation. This thesis extends the state-of-the art hidden semi-Markov models by: investigating additional features; extending the Viterbi algorithm; incorporating logistic regression into the model to form a hybrid generative-discriminative model; and investigating a discriminative duration-dependent probabilistic model – a conditional random field. These extensions are found to outperform the state-of-the-art method.
Lastly, the period between the first and second heart sounds can be analysed for the presence of a pathological murmur. This thesis presents automated systolic murmur classification algorithms based on wavelet and mel-frequency cepstral coefficient-based features along with denoising via cycle averaging. These algorithms outperform three methods from the literature when detecting valvulopathy, while also outperforming a cardiologist and commercial software when detecting RHD in mobile phone-based heart sound recordings.

Keywords: Hidden Markov Models
Mobile Health
Conditional Random Fields
Rheumatic Heart Disease
Advisor: Tarassenko, L
Clifford, G
Computational neuroscience of speech recognition

Physical variability of speech combined with its perceptual constancy make speech recognition a challenging task. The human auditory brain, however, is able to perform speech recognition effortlessly. This thesis aims to understand the precise computational mechanisms that allow the auditory brain to do so. In particular, we look for the minimal subset of sub-cortical auditory brain areas that allow the primary auditory cortex to learn 'good representations' of speech-like auditory objects through spike-timing dependent plasticity (STDP) learning mechanisms as described by Bi & Poo (1998). A 'good representation' is defined as that which is informative of the stimulus class regardless of the variability in the raw input, while being less redundant and more compressed than the representations within the auditory nerve, which provides the firing inputs to the rest of the auditory brain hierarchy (Barlow 1961).
Neurophysiological studies have provided insights into the architecture and response properties of different areas within the auditory brain hierarchy. We use these insights to guide the development of an unsupervised spiking neural network grounded in the neurophysiology of the auditory brain and equipped with spike-time dependent plasticity (STDP) learning (Bi & Poo 1998). The model was exposed to simple controlled speech- like stimuli (artificially synthesised phonemes and naturally spoken words) to investigate how stable representations that are invariant to the within- and between-speaker differences can emerge in the output area of the model. The output of the model is roughly equivalent to the primary auditory cortex.
The aim of the first part of the thesis was to investigate what was the minimal taxonomy necessary for such representations to emerge through the interactions of spiking dynamics of the network neurons, their ability to learn through STDP learning and the statistics of the auditory input stimuli. It was found that sub-cortical pre-processing within the ventral cochlear nucleus and inferior colliculus was necessary to remove jitter inherent to the auditory nerve spike rasters, which would disrupt STDP learning in the primary auditory cortex otherwise.
The second half of the thesis investigated the nature of neural encoding used within the primary auditory cortex stage of the model to represent the learnt auditory object categories. It was found that single cell binary encoding (DeWeese & Zador 2003) was sufficient to represent two synthesised vowel classes, however more complex population encoding using precisely timed spikes within polychronous chains (Izhikevich 2006) represented more complex naturally spoken words in speaker-invariant manner.

Advisor: Stringer, S
Schnupp, J
Phonon magnonics

This thesis reports on some recent results in the field of acoustics and magnonics.
Chapter 1 reviews the literature on magnonics and GHz frequency transducers, and highlights the lack of understanding of the growth mechanism of magnetron sputtered ZnO thin films. A novel configuration for exciting magnetostatic spinwaves using ZnO transducers is proposed.
Chapter 2 is an introduction to piezoelectricity and how it can be used to generate GHz acoustic waves. A detailed formulation of the Mason model is presented in chapter 3 for predicting the performance of ZnO transducers.
In chapter 4, the fabrication protocol of ZnO transducers in the custom-built sputtering plant is discussed and the transducer characterisation techniques including X-ray and pulse echo measurement are described.
In chapter 5, the characterised properties of the film are compared with modelling prediction. It is found that the piezoelectric and structural properties of the fabricated ZnO films are strongly correlated and are critically dependent on the sputtering conditions and thicknesses.
Chapter 6 is dedicated to plasma characterisation of the sputtering conditions using Langmuir probe diagnostics. The making of the Langmuir probe system and its development are discussed.
Chapter 7 examines the various possible growth mechanisms of the ZnO films with a view to understanding how the c-axis texture forms during sputtering. The results from the Langmuir probe diagnostics and X-ray characterization indicate the detrimental in uence of ion bombardment on the film qualities. It is deduced that the c-axis self texturing of ZnO films is driven dominantly by the 'survival of the fastest' mechanism.
Chapter 8 describes the theoretical formulation of magnetostatic spin-wave modes and the mechanism for which the laterally propagating magnetostatic modes are coupled to local elastic standing waves. The experimental evidence (using time resolved spectroscopy) of the acoustic excitation of magnetostatic spin-waves in a YIG film waveguide is then presented in chapter 9; the excitation efficiencies at various magnetic field configurations and carrier frequencies are investigated.
Finally, chapter 10 ends the thesis with the summary of results and outlooks.

Advisor: Gregg, J
Between the diaspora and the nation-state: transnational continuity and fragmentation among Hmong in Laos and the United States

Based on fourteen-months of multi-sited, ethnographic fieldwork that compares two Hmong communities in Vang Vieng, Laos, and Sacramento, California in the United States, my doctoral thesis examines how the Hmong diaspora is constituted in the absence of a territorial ethnic homeland. Although scholars claim that the Hmong originated in the southwestern part of China, many Hmong are uncertain about their origins and have lost their connections to the ancestral homeland. This thesis suggests we examine diasporas as a dialectical process involving both transnational continuity and national differentiation. Despite their further migratory dispersal after the Vietnam War, Hmong in Laos and the United States have actively created a transnational diasporic community by maintaining their cultural practices across national borders, particularly in the domains of kinship practices and spiritual rituals.
At the same time, diasporic Hmong have also created partial 'homes' in the nation-states where they reside. Therefore, their ethnic traditions and perceptions are transformed according to different national contexts, such as local socioeconomic conditions, state policies, and access to economic capital. This results in cultural differences within the diaspora. In addition, Hmong in different countries disagree about their relative position in the diaspora in relation to each other, leading to discursive fragmentation. As a result, diasporas are refracted through different national affiliations.
Nonetheless, the sense of national belonging among diasporic Hmong remains partial because they continue to experience social, economic, and ethnic marginalization as an ethnic minority group in both Laos and the United States, which causes them to maintain a diasporic affiliation to Hmong scattered in other countries as an alternative source of ethnic belonging. In this sense, the Hmong are constantly positioned 'in-between' the diaspora and the nation-state.

Advisor: Xiang, B
The sustainable seafood movement: bringing together supply, demand, and governance of capture fisheries in the U.S. and U.K. to achieve sustainability

The Sustainable Seafood Movement's "theory of change" is predicated on using markets to improve the supply of, demand for and governance of sustainable fisheries. Over four articles, this thesis will examine the implications of this approach. Article I evaluates the cultural model of seafood eco-labelling and demonstrates that while the theory of using market demand to motivate fishery improvements has been a powerful incentive, consumers have had a minimal role in incentivising that change. This is validated through semi-structured consumer interviews and structured surveys (n=196), which indicate consumers’ general understanding of sustainability issues.
Article II examines the roles of actors in the Sustainable Seafood Movement in facilitating the growth of sustainable seafood products in the supply chain, thus explaining how in the absence of large consumer demand, certified sustainable seafood product offerings have continued to grow. Article III examines the private governance mechanisms that the Sustainable Seafood Movement has established in the supply chain and how these are rivalling, complementing and substituting those of state-led fisheries governance mechanisms. At the same time both private and public governance mechanisms continue to monopolise certain spaces, such as flag state authority. Greater coordination between these two governance systems is needed to facilitate additional sustainability gains and strengthen the resilience of these governance systems. When public and private governance efforts to improve the supply, demand and governance of sustainable seafood are looked as whole, as in Article IV, it is evident that consumers/citizens are minimally engaged. Lack of consumer/citizen engagement could lead to an undervaluing of these governance systems by society. Civic engagement organizations are needed to bridge these systems and facilitate citizen/consumer/steward engagement. Public accountability mechanisms are one means to better engage the public in both governance systems, so that sustainable fisheries are realised by collective engagement of all actors.

Keywords: coordination
non-state market driven governance
governance
Advisor: Thornton, T
The early military thought of Winston S. Churchill

Winston S. Churchill was a war leader during two world wars, and yet there are few substantive studies of his younger years when he was a practising soldier. This thesis aims to study the early intellectual development of Churchill in those areas which have direct impact on the art of war. The chapters are arranged narratively (Chapters 2-3) and thematically (Chapters 4-8). The introduction covers the scope and methodology of the work. Chapters 2-3 give an account of Churchill’s early years, and trace the development of several prominent features of his character that helped form and inform the presuppositions of his later military intellectual development. Chapter 4 addresses Churchill's interactions with late Victorian cavalry doctrine and debate. Chapters 5-7 each address themes of an expanding scope of influence and conceptualization: first, the tactics of war; second, the policy and strategy of war; and finally, Churchill’s conceptions of war. The conclusion summarizes the hallmarks and syntheses of Churchill's early military intellectual development, and identifies judgments which can be drawn about his perspicacity as soldier and commander.

Advisor: Gregory, A
Does mental imagery act as an emotional amplifier in bipolar disorders?

Bipolar disorder is characterized by episodes of mania and depression and serious suicidal risks. Recent studies reported high mental imagery susceptibility (general use of imagery in daily life and emotional impact of prospective imagery) in euthymic bipolar patients. This thesis aims to: a) replicate these findings in patients at different phases of bipolar disorder and with varying degrees of bipolarity, and b) explore how mental imagery susceptibility, ruminative processing, and behavioural approach system (BAS) sensitivity interact to amplify mood symptoms.
Chapter 1 provides an overview of current theories of mood amplification and recurrence in bipolar disorders. Chapter 2 details the local validation of scales used in the thesis. Chapter 3 (Study 1) investigated whether mental imagery susceptibility, positive rumination and BAS sensitivity were elevated in remitted bipolar I disorder compared with major depressive disorder and non-psychiatric controls. Results suggested that these cognitive variables were elevated in remitted bipolar I disorder. Positive rumination also interacted with positive prospective images to predict bipolarity. Chapter 4 (Study 2) found that these cognitive variables were elevated in bipolar I disorder during manic and euthymic phases, compared to major depression. Further, the number of positive prospective images predicted recovery status and manic symptom severity. Chapters 5, 6 and 7 report that, compared with people without bipolar spectrum conditions, these cognitive characteristics were elevated in sub-threshold bipolar disorder (Study 3), individuals with high bipolar risks based on a behavioural paradigm (Study 4), and individuals with high familial risk (Study 5). Studies 3-5 confirmed that positive and negative prospective images interacted with rumination to amplify hypomanic and depressive symptoms respectively. Chapter 8 (Study 6) showed that suicidal flash-forwards function as a psychological escape from perceived entrapment and defeat in suicidality. Based on these findings, Chapter 9 proposes novel imagery-based techniques for targeting problematic imagery in bipolar disorders.

Keywords: cognitive behavioural therapy
mental imagery
bipolar disorders
Advisor: McManus, F
Student environmentalism in Beijing, China

This dissertation explores student environmentalism in Beijing, China. It traces students' political norms and values, explains their activism and experience of pollution, and investigates the role of environmental non-governmental organisation (ENGOs) in forming youth environmentalism. To serve these objectives, the work takes forward theories on youth activism and agency and recent debates on environmental health, environmentalism and ENGOs. This study was designed as a qualitative research project based primarily on interviews and complemented by ethnographic methods, content analysis, pictorial evidence and survey results provided by the Jane Goodall Institute China. Research findings and methodology are presented in four papers and a framing document. My work challenges labels of agency and activism as either protest and resistance or ‘quiescence’ and questions the influence of globalisation on activists' norms and values. I put forward 'fragmented activism' as a new concept to capture the nature of youth environmental activism in Beijing.
I contribute to environmental health literature by tracing how young people develop discursive mechanisms to mitigate the fear of air pollution and argue that their response offers invaluable insights into the interplay between space and the body in polluted environments. This thesis further shows that the repertoire of student environmental associations in Beijing represents a type of 'place based environmentalism' (Smith, 2001) but argues that, whilst this may be a contradictory response to contemporary environmental issues, it is not usefully assessed against abstract and normative notions of what environmentalism should be. I also challenge scholarly assessments of ENGO action. By exploring ENGO strategies in China that rely on extant societal and governmental narratives about good citizenship and moral values – instead of radical alternatives to mainstream development models or political processes – I argue for new research paradigms guiding the study of environmental movements.

Advisor: Jeffrey, C
Lora-Wainwright, A
Capable subjects: power and politics in India

The principal aim of this thesis is to elaborate a politicized reading of Amartya Sen’s Capability Approach. It explores how capabilities are augmented through the forging of contentious political subjectivities. In it, I build on the criticism that Sen's framework can be more sensitive to questions of power and politics. Against some of his critics, however, I argue that its 'politicization' must focus analytical attention on politics as the struggle to produce subjects rather than limiting its understanding to negotiations over authority, resources and allocations. I draw on quantitative and qualitative analysis of ethnographic data from rural eastern India to substantiate my argument.
The first two chapters outline the contours of the debates and introduce the social, economic and political life of the study localities. Each of the four subsequent chapters elucidates the manner in which the contentious processes through which political subjectivity are forged augments capabilities. In Chapter 3 I advance the case that any discussion on capabilities needs to analyze how subjects interrogate the relations of domination and subordination which they have hitherto been compelled to inhabit. Based on an analysis of the contentions spawned by the Indian Government's National Rural Employment Guarantee Scheme, I point to how the notion of cooperative conflict is helpful in understanding these processes. In Chapter 4, I draw attention to the analytic importance that needs to be accorded to 'voice' in order to understand how subjects contest and reconstitute these relationships: I base my analysis on the claims made on elected representatives by different groups of people in respect to 'poverty cards'. This emphasis leads in Chapter 5 to an investigation of the ways in which agonistic exchanges in public spaces augments capabilities: this I do through an examination of two specific disputes involving a variety of local actors. I develop these insights further in Chapter 6 to show how our understanding of the processes through which capabilities may be enhanced gains analytically from an analysis of the manner in which subjects construct their identities. Chapter 7 concludes.

Keywords: democracy
negotiations
capabilities
poverty
caste
Advisor: Gooptu, N
Alkire, S
Tracing visual knowledge: the presence and value of images for Bedouin history and society in the Negev

Based on eighteen months fieldwork with Bedouin of the Negev, this thesis explores the varied presence of images as photographs and digital copies for local historicity in order to achieve a greater understanding of representational politics in southern Israel. It emphasizes pictures' ability to transmute, circulate, and acquire value in various social settings in contrast to popular academic treatments, which primarily focus on photographs' iconography and visual history in the Middle East. To do so, the thesis details the biographies of a series of 'significant images' (c. 1906-2010) circulating in this society. It describes their photographic and digital graphic contents as floating referents with the capacity to be coded and recoded by people but also their presence as historical evidence that acquire value in different contexts. The thesis builds on the concept of visual economy as opposed to visual culture in order to landscape images' meanings, material and digital transformations, and their influence for the making of Bedouin history over the last century amid Orientalist, national, and local imaginings.
It argues that Bedouin in the Negev possess diverse representational repertoires and utilise a variety of techniques to pursue historical capital. In particular, local representations of the past are selective and instrumental but increasingly reliant on archival mediums such as photographs. Although it may be obvious, anthropologists of the Middle East have yet to adequately account for these occurrences among peripheral peoples and not merely urbanites in the region. Research found that Bedouin spokespersons treat photographs and digital images as evidentiary documentation during self-presentations of historical knowledge in the Negev. As they travel between visual economies, however, images become malleable proof for local history projects alternating between the tribal past, Islamic heritage, and ethnohistory. In conclusion, the thesis develops two theoretical themes in anthropology and visual culture studies of the Middle East: the material and visual efficacy of images for local historicity, and complicating self-representations among Bedouin in the Negev.

Advisor: Banks, M
Parizot, C