VictorJuiz/thesis huggingface dataset:
SPARCLE: an instrument for aerosol size and refractive index measurement

In the last few decades, there is an increasing need to improve in situ aerosol measurements. The improved measurements can provide a better understanding of the role of atmospheric aerosol on the Earth climate change. The improved measurement can also help to indicate the quality of ambient air to prevent health problems caused by aerosol exposure. Most in situ optically based aerosol photometer assume the refractive in- dex of measured particles to give size-estimate. This type of instrument can have a bias when measuring a particle whose refractive index is differ- ent from the assumed value. SPARCLE was designed with two measure- ment goals. First, SPARCLE measures both the size and refractive index of a particle provided that the particle is a homogeneous sphere. Second, SPARCLE is able to measure particles whose sizes range from 500 nm to 2,500 nm. This size range is within the range of the accumulation mode of tropospheric size distribution.
The purpose of this work is to investigate the feasibility of SPARCLE. A threshold level to detect particles was applied to differentiate between background and scattering signals and it was found that applying the threshold level can limit SPARCLE to detect particles smaller than 640 nm. SPARCLE was calibrated using four monodisperse aerosols containing Polystyrene latex (PSL) beads. The mean size of the aerosols are 1,100 nm, 1,800 nm, 2,000 nm and 3,000 nm. The refractive index of PSL is 1.59. The results indicate that SPARCLE can measure the aerosols with the deviation of the measured size and refractive index less than 2.2% and 1.05%, respectively, of the size and refractive index specified by the aerosol manufacturers.
SPARCLE was used to measure a test aerosol. The test aerosol was a mixture of water and liquid soap. The refractive index of the liquid soap is 1.37. One of the main ingredient of the liquid soap is sodium dodecyl sulphate whose the refractive index is 1.44. The refractive index of the test aerosol measured by SPARCLE is 1.47. This value is close to the refractive index of the sulphate suggesting that the test aerosol was quickly dried and, then, a solid aerosol was formed which mainly composed of the sulphate.

Keywords: aerosol
refractive index
Optical Particle Counter
particle size
Advisor: Grainger, R
Peters, D
Proud, S
Processing collocations in the L2: semantic transparency & congruency

Mastering collocations is one of the most challenging aspects of vocabulary acquisition, especially for adult learners of a second language (L2). Research shows that frequency, congruency, and semantic transparency are important factors that affect L2 collocational processing. Frequency is known to interact with both congruency and semantic transparency. However, congruency and semantic transparency have not been explored simultaneously. This study aims to investigate L2 collocational processing in proficient L2 English speakers (L1 Portuguese) by exploring the role of semantic transparency in conjunction with congruency. Specifically, it investigates whether free combinations, congruent collocations, and incongruent collocations differ in terms of processing by incorporating congruency into Howarth’s Continuum Model.
A semantic acceptability judgement task was completed by 329 adults (122 Brazilian Portuguese, 108 European Portuguese, and 99 L1 English speakers). The reaction times and error rates were analysed using Generalized Linear Mixed-effects Models. The results showed that the Brazilian Portuguese speakers processed free combinations faster and more accurately than congruent and incongruent collocations. The European Portuguese speakers processed free combinations faster and more accurately than incongruent collocations. Both groups processed congruent collocations faster and more accurately than incongruent collocations. The L1 English group showed no processing advantages for any of the three conditions. Moreover, the L1 group outperformed the L2 groups only on the incongruent condition.
Although there seems to be an effect of semantic transparency in the results of the L2 groups, it could not be isolated from the effects of frequency and congruency. Future research should consider testing incongruent free combinations along with incongruent collocations to properly isolate these effects. With respect to congruency, this study lends support to the growing body of evidence that L2 speakers incur processing costs for incongruent collocations. This highlights the critical role of the L1 in L2 collocational processing. Based on these findings, recommendations are made for incongruent collocations to be explicitly taught in the L2 classroom.

Keywords: ALSLA2021
quantitative
L2 English
ALSLA
applied psycholinguistics
vocabulary acquisition
lextale
generalised linear mixed-effects models
semantic acceptability judgement task
multi-word units
L1 Portuguese
MScEducation
phraseological framework
applied linguistics
collocations
SLA
second language learning
Advisor: Chalmers, H
Trusting judges: a socio-legal inquiry about access to health care via litigation in Brazil

In 1988, the Brazilian Constitution enshrined in its text the right to universal health care, which formed the basis of the public health system, SUS. However, since the 90s the country observed an increasing trend of citizens starting legal action against the State to get access to drugs, treatments and medical devices not offered by SUS. The stark increase in successful health care cases is today a source of major concern. Against this backdrop, this thesis aims to understand what are the main socio-legal factors that influence the rise of successful litigation for access to health care in Brazil.
To answer this question, the thesis provides an in-depth analysis of qualitative empirical data about health care litigation in Brazil, based on semi-structured interviews with 55 actors – with a particular focus on judges and litigants.
The main outcome of the research is a middle-range theory about the links between internal and external socio-legal factors that influence the rise of successful health care litigation in Brazil. The thesis argues that there is a complex socio-legal web which combines various types of factors. A central factor which influences judges to grant health care claims is a deep-sited distrust in the quality of the health care public policy and the policy maker, aligned with an individual self-empowerment and tendency to altruism. The result is an attenuated form of judicial activism which uses the substantive constitutional law as a hindsight justification for granting claims. In parallel, a utilitarian trust in the positive outcome of legal action and low costs of litigating incentivises litigants to start legal action against the state. These various factors are analysed in the context of a post-colonial society, where citizens’ individualist approach to the state, and the commodification of health incentivise the multiplication of individual litigation for access to health care.

Keywords: trust
empowerment
socio-legal
social-economic rights
pharmaceutical
litigation
brazil
health care
judicial activism
separation of powers
third-party funding
constitutionalism
health
Advisor: Lange, B
The authenticity game: order, recognition, and customary rule for empire to the international system

This thesis attempts to diversify International Relations’ understanding of the patterns of ordering that governed European empire in the 19th and early 20th–centuries, and in doing so to identify an overlooked but crucial precursor to the contemporary international order. IR research has overwhelmingly focused on liberal universalism and civilizing missions in Empire’s politics of recognition, its ideas of difference, and its strategies of rule. This thesis argues that our focus has been too narrow, and draws from work in colonial history, political thought and anthropology, as well as original archival research, to illustrate the ideas and practices of customary rule that predominated in the British Empire after the 1857 Indian Rebellion. I argue that this form of rule was not simply a set of ideas, or a top–down imposed regime, but a ‘game’ of jurisdictional jockeying. In this game, life in colonized societies was increasingly bifurcated into ‘traditional’ and ‘modern’ spheres as local elites and colonial officials worked to define increasing swaths of governance as belonging to one or another, while avoiding violent responses to overreach on either side. From 1857 through the scramble for Africa and the League of Nations mandates system, I use records of official knowledge work to study the ways that colonized and colonizer alike vied to craft new language of legitimacy: language through which new subjects in international politics could be recognized and heard. Studying knowledge work as strategic interaction, I find that non–European intermediaries exercised crucial agency in crafting these new customary forms of governance, leveraging revolts and violence to narrate crisis to power in ways that shaped colonial and eventually international rule. Beyond its historical value, this work has implications for the ways IR understands the emergence of order from interaction, and for present debates on the questionably liberal nature of international order.

Keywords: international order
colonial violence
liberal international order
self-determination
imperial law
India
game theory
nationalism
historical international relations
agency
Africa
empire
politics of recognition
indirect rule
Advisor: Keene, E
Cryogenic phonon-scintillation detectors with PMT readout for rare event search experiments and characterisation of a PMT at milli-Kelvin temperatures

Reliable, robust, efficient, and scalable light detectors operated at milli-Kelvin temperature that can resolve individual photons in a scintillation event are required by the cryogenic phonon-scintillation detectors (CPSD) for next generation rare-event search experiments. This thesis demonstrates a cryogenic detector with a scintillating crystal as the absorber, equipped with a Neutron Transmutation Doped Germanium (NTD-Ge) phonon sensor and a Hamamatsu R8520-06 photomultiplier tube (PMT) with platinum underlay as the light detector. The PMT is powered by a Cockcroft-Walton generator. In this experiment, two CPSD modules are successfully tested, one with CaWO4 and the other with CaMoO4 as the scintillating absorber. The detector modules were cooled down to ~ 18 milli- Kelvin inside a dilution refrigerator. The CPSD modules are demonstrated to be able to measure signals from the phonon channel and light channel simultaneously, which is critical for particle identification. The full-width-at-half-maximum (FWHM) energy resolutions at 122.1 keV for the phonon channel are 2.17 keV (1.8%) for CaWO4 and 0.97 keV (0.79%) for CaMoO4. The FWHM resolutions at 122.1 keV γ excitation for the scintillation/photon channel are 19.9% for CaWO4 and 29.7% for CaMoO4. At milli-Kelvin temperatures, the dark count rate of the PMT is determined to be less than 5 Hz while the gain of the PMT is found to be 3.3 × 10E6. These characteristics of the CPSD in this work compare favourably to conventional CPSDs with cryogenic calorimeter-based light detectors currently deployed in cryogenic rare-event search experiments, especially in the energy region of interest for dark matter direct detection. The PMT is demonstrated to have low dark count rate and high gain at milli-Kelvin temperatures, thus it remains an effective single photon detector. From the radioactivity of a similar model of PMT as input to a Geant4 simulation, the radioactivity introduced by the PMT contributes only minorly (<10%) to the overall radioactive background of a hypothetical CPSD module for WIMP searches. The CPSD module with PMT readout benefits a reliable, well-tested and commercially available apparatus, while the PMT as a photon detector at milli-Kelvin temperatures offers a much better time resolution than cryogenic light detectors, allowing to resolve individual photons. The technology in this study can potentially revolutionise the science reach of rare event search experiments using CPSD (e.g. the CRESST experiment), by offering an alternative light detector solution which is much more scalable and more consistent in performance than conventional CPSDs with cryogenic calorimeter-based light detectors, addressing two major issues that the present techniques face.

Keywords: CaWO4
Dark matter
PMT
CPSD
Rare event searches
photomultiplier
neutrinoless double-beta decay
Low-temperature
photomultiplier tube
cryogenic
CaMoO4
Calorimeter
Advisor: Kraus, H
On the existence of representer theorems in Banach spaces

We consider general regularisation and regularised interpolation problems for learning parameter vectors from data. In particular in Hilbert spaces regularisation methods have been applied very successfully, largely due to the well known representer theorem. Classical formulations of the theorem state that under certain conditions on the regulariser there exists a solution of the optimisation problem which is contained in a linear subspace spanned by the data points. This is at the core of kernel methods in machine learning as it significantly reduces the dimensionality and thus makes the problem computationally tractable. Most of the literature only deals with sufficient conditions on the regulariser for a representer theorem to hold, mostly in Hilbert spaces with some generalisations to certain classes of Banach spaces. In this work we give an essentially complete answer to the question of existence of representer theorems in general Banach spaces. This question had previously been answered for Hilbert spaces with an intuitive characterisation for differentiable regularisers. We show how the necessary and sufficient conditions extend to arbitrary Banach spaces and give the more intuitive geometric characterisation for a variety of classes of Banach spaces, which contain all spaces we know of which are commonly used in applications. We conjecture that the same characterisation can also be given for any other Banach space not currently covered by those classes. We further show that, if the learning relies on the linear representer theorem, in most cases the solution is actually independent of the regulariser and determined by the function space alone. This is interesting for two reasons. Firstly it means one is free to choose whichever regulariser is most suitable for the application at hand, whether this is computational efficiency or ease of calculations. Moreover it shows the importance of extending classical elements of learning theory such as kernel methods from Hilbert spaces to Banach spaces.

Keywords: regularisation
regularised interpolation
representer theorem
Banach space learning
Advisor: Kristensen, J
Research waste and inefficiency in cardiovascular prediction rule development: exploration of causes and implications

Background: Research waste and inefficiency occur when research studies do not contribute to the decisions of patients, clinicians, and policymakers. In this thesis, I examine research waste and inefficiency throughout the stages of cardiovascular clinical prediction rule (CPRs) development and explore their causes and implications.
Methods: This thesis includes six research projects. A mixed-methods study, which consists of a review of derivation studies, thematic content analysis, and author survey, assesses justifications for deriving a new cardiovascular CPR. Using survival analysis, I evaluate the probability for a CPR for cardiovascular disease risk to have an independent external validation study after its derivation. I assess whether external validation studies update the Framingham Wilson coronary heart disease (CHD) risk rule when it performs poorly, and external validation studies contribute to understanding the performance in meta- analyses. A systematic review evaluates the design, methods, and reporting of studies assessing the impact of cardiovascular CPRs. I conduct an online survey to understand which cardiovascular CPRs are recognised and used by GPs in the UK. Lastly, an exploratory qualitative interview study with thematic analysis explores how perceptions of and experiences with cardiovascular CPR research influence primary care providers’ (PCPs) decisions about using cardiovascular CPRs.
Results: I found that the authors of derivation studies do not cite existing evidence when justifying a new cardiovascular CPR even though they believe it is important to do so. Most of cardiovascular CPRs do not have a timely conducted independent external validation study. External validation studies of Framingham Wilson CHD risk rule fail to generate the evidence of generalizability to their full potential because they do not update the CPR when it performs poorly, or do not contribute to understanding the CPR’s overall performance. The vast majority of impact studies had flaws in study design, methods or reporting. GPs’ use of cardiovascular CPRs in the UK has evolved and is focused on a few CPRs, such as the QRISK scores. PCPs’ decisions about using cardiovascular CPRs seem to be influenced by their familiarity, trust, and confidence in using research evidence.
Conclusions: To reduce research waste and inefficiency in cardiovascular CPR development, it is necessary to shift the paradigm from deriving new CPRs to externally validating, assessing the impact of, and promoting the adoption of high-quality existing cardiovascular CPRs. Also, systematic efforts are needed to reduce the flaws in design, methods, and reporting of CPR studies, and strengthen evidence-base to support the use of cardiovascular CPRs.

Keywords: clinical prediction rule
research waste
external validation
impact analysis
evidence-based medicine
Advisor: Perera-Salazar, R
Stevens, R
Exploring the Lower Xiajiadian in Northeast China (ca. 2000-1300 BC)

This thesis investigates the Lower Xiajiadian culture (ca. 2000-1300 BC) in northeast China, with a focus on two major questions: first, what were the principal cultural features of the Lower Xiajiadian culture; second, how did it emerge in China’s northern borderland. Three groups of archaeological materials are analyzed and presented: the settlement data from excavated Lower Xiajiadian sites and regional surveys in northeast China, the burial evidence from the Dadianzi cemetery, and the material remain in the Chinese Central Plains of the same period. It argues that the Lower Xiajiadian’s cultural distinctiveness reveals strong local characteristics as well as many features that can be attributed to the Yellow River area in the south and the Eurasian steppe to the north and west. These include the introduction of mudbrick constructions, lime-floor plastering, stone buildings, bronze metallurgy, animal husbandry, and tripod vessel types of the 3rd millennium BC. It is also revealed from the mortuary data at Dadianzi that the status manifestations of the Lower Xiajiadian society were structured to emphasize a higher value on foreign artifacts than local grave goods in northeast China. Overall, a wide range of new materials, technologies, and activities were brought into the Lower Xiajiadian area after 2000 BC and were employed in a local fashion that was different from other contemporary borderland communities. With benefits from contacts with a variety of regions, what we see from the Lower Xiajiadian archaeological records is a society that was deeply engaged with its southern predecessor—Longshan, as well as in contact with cultural entities in the north and west.

Advisor: Rawson, J
Pollard, AM
Interplay between retinal light responses and the circadian clock, and their implications for retinal degenerative diseases

Multiple aspects of mammalian physiology display circadian rhythms, which allow the organism to better adapt to the external environment. Several circadian rhythms, such as the sleep-wake cycle and the retinal function, are primarily regulated by light detection in the retina. The molecular properties of melanopsin, a blue light sensitive photopigment expressed in a subset of retinal ganglion cells, make it ideal for encoding environmental light levels. Indeed, melanopsin has been shown to regulate several aspects of the retinal circadian function. However, the molecular mechanisms underpinning melanopsin’s role in retinal circadian rhythms remain unknown. By analysing the circadian transcriptome of wild-type and melanopsin-null retinas, I discovered that the absence of melanopsin leads to dampened rhythmicity in the expression of core clock genes. Furthermore, while the melanopsin-null retinas retained the rhythmic expression of dopamine- related and gap junction genes, the circadian rhythmicity of sphingolipid and phototransduction pathways were aberrant.
Alongside its role in the retinal circadian clock, melanopsin is also modulat- ing functional aspects of retinal light adaption, and it has been suggested that melanopsin may mediate retinoprotection in response to bright light exposure. However, using a mouse model of light-induced retinal damage, I did not detect an increased susceptibility to light damage in animals lacking melanopsin. I further studied how well the mouse model of retinal light damage mirrors the human retinal degenerations. I conducted a meta-analysis of all available datasets probing retinal transcriptome changes in this model and discovered that the genes affected by light damage were enriched for genes implicated in human retinal degenerations, indicating that the model indeed mimics the molecular aspects of human diseases.
Finally, melanopsin signalling also regulates the central light responses in the suprachiasmatic nucleus (SCN), but several reports on its role in retinal light sensitivity are conflicting. Therefore, I further researched how retinal and SCN responses to light are regulated. I found that the retinal light responses of animals lacking melanopsin were slightly attenuated, similarly to what is known about their SCN light responses. However, in a mouse model showing increased SCN light sensitivity, the retinal responses were not enhanced, suggesting differential regulation of the retinal and SCN light sensitivity.
These results provide valuable insights into the molecular and functional aspects of retinal light responses in both local and central circadian rhythms, and dissect their implications for retinal degenerative diseases, together providing a wealth of avenues for future research.

Keywords: retina
melanopsin
circadian rhythms
retinal light damage
Advisor: Jagannath, A
Foster, R