VictorJuiz/thesis huggingface dataset:
An exploration of the mechanisms of action of transcranial direct current stimulation (tDCS) in mood and anxiety disorder research

The difficulty in treating mood and anxiety disorders has brought about renewed clinical interest in alternative treatments, such as transcranial direct current stimulation (tDCS) of the dorsolateral prefrontal cortex (DLPFC). However, the optimal parameters for stimulation and underlying mechanisms of action are unclear. Psychiatric treatments have acute effects on emotional processing which predict later therapeutic action. Such effects have been proposed as cognitive biomarkers for screening novel treatments for depression and anxiety disorders. In this thesis the proposed cognitive, behavioural and neural underpinnings of mood and anxiety disorders are explored using tDCS of the DLPFC in humans.
This is investigated with a series of studies which measure the acute effects of tDCS on emotional processing relevant to depression and trait anxiety or anxiety disorders. An initial investigation in healthy volunteers revealed an anxiolytic like effect (reduced threat vigilance) of a single session of tDCS on a behavioural test of proven clinical relevance. In addition, stimulation parameters were refined for future studies. The subsequent two behavioural investigations combined tDCS with an attentional bias modification (ABM) training paradigm. However, no bias modification was achieved in these studies and predictably, no subsequent effects on attentional bias, mood/ trait anxiety or worry were observed. The first of the ABM investigations included a measure of cortisol awakening response (CAR) and it was found that a single session of tDCS (regardless of ABM condition) reduced subsequent CAR in healthy volunteers, also suggesting an anxiolytic effect. The final study, in a sample of trait anxious females, used functional imaging to reveal that tDCS of the DLPFC increased frontal activation and reduced amygdala response to fearful face distractors during low cognitive effort. This provides the first causal evidence that modulating activity directly in the DLPFC inhibits amygdala response to threat in humans, and provides a potential neural mechanism for the previous reduction in vigilance to threat, and also for the efficacy of tDCS in the treatment of depression and anxiety disorders.
The evidence from this thesis puts forward an anxiolytic-like effect of frontal tDCS on cognitive, neural and adrenal biomarkers relevant to clinical anxiety disorders, and indicates a potential cognitive mechanism (reduced fear vigilance) and an underlying neural mechanism (increased top-down control of amygdala response) that may partially mediate the reported clinical efficacy of prefrontal tDCS in the literature.
Microscope-mode imaging mass spectrometry with the PImMS camera

Until recently, the use of microscope-mode imaging mass spectrometry (MSI) was restricted by the available technology. Fast cameras were limited to acquiring a single image relating to a set m/z range which had to be predeﬁned before the experiment was started. Now, new developments in camera technology have produced time-stamping cameras that can record the arrival time of ions at a detector, without the need to deﬁne an exposure time. This allows the images relating to diﬀerent species with a range of m/z to be acquired simultaneously. One of these cameras is the Pixel Imaging Mass Spectrometry (PImMS) camera, which has the added advantage that each pixel within the sensor has four memory registers. This means that up to four events can be observed, by each pixel, within a single time-of-ﬂight cycle. Here, the application of the PImMS camera to microscope-mode MSI is presented. Initial experiments are conducted using a converted conventional velocity-map imaging instrument. Simulations are presented in order to predict the performance of the ion optics when used for spatial imaging, and the result of these simulations is then compared to those obtained experimentally, using a commercially available charge-coupled device (CCD) camera and a photomultiplier tube (PMT). These spatial resolutions along with simultaneously obtained mass resolutions are then compared to those obtained using a PImMS1 camera. Further experiments are presented in which the PImMS1 camera is used in conjunction with a modiﬁed commercially available mass spectrometer, the LT2 Plus (produced by Scientiﬁc Analysis Instruments Ltd — SAI). This instrument is designed to obtain isotopic resolution for m/z &LT; 1000, whilst also maintaining a spatial resolution better than 50µm. These speciﬁcations are obtained using the PImMS1 camera, and it is shown that images of multiple chemical species can be obtained simultaneously. A new data analysis method is developed, which attempts to model the shape of PImMS data event clusters. Although the application of this method cannot be fully realised with data obtained with a PImMS1 camera, a modiﬁed version is successfully applied to PImMS1 data and produces both an improvement in the time precision of the camera, as well as a more eﬃcient use of the available data. Finally, various designs for a primary ion beam are presented that could be used in place of the standard laser desorption system. The ion beam is designed for use with an MSI instrument, ablating sample from a large area of sample, and with a short pulse length for time-of-ﬂight analysis. A ﬁnal design is presented that can produce beam pulse that can be focussed down to form a pulse length of 5ns, across a target of 2.5mm. As a collection, the works detailed in this thesis present the development of a stigmatic ion microscope that uses the PImMS camera, from a proof-of-concept to a viable analytical instrument.

Advisor: Brouard, M
Poetik und Politik der Lesbarkeit in der deutschen Literatur

In 1990, German literary critics agreed that the end of the Cold War should mark the end of politically committed post-war literature. The political caesura prompted a debate about the future of German literature during which the concept of 'readability' evolved as a contested issue. It was championed in particular by the author Matthias Politycki and the publishers Uwe Wittstock and Martin Hielscher. Ever since, 'readability' has remained a benchmark for authors and critics alike in the battle for value and success.
The thesis will establish a theoretical basis for ‘readability’ that draws on narratology, the Aristotelian concept of ‘mimesis’, classical rhetoric, and the poetics of contemporary authors who explicitly engage with 'readability'. Discussion will centre on the novel since this genre has been the focus of debate ever since the novel gained prominence with the rise of the reading middle classes in the eighteenth century. An analysis of the historical role of 'readability' will demonstrate that the debate as it manifested itself around 1990 developed out of a specifically German tradition, in which authors and critics alike viewed it as potentially in conflict with true art.
The thesis will demonstrate that 'readability' is key to understanding the debates about German literature in an era of globalisation when readers are more attracted to works by foreign authors than to works by German ones. It will examine how writers such as Helmut Krausser, Daniel Kehlmann, and Thomas Glavinic have exploited the opportunities of the changed parameters by writing and promoting 'readable' books. It will further explore to what extent 'readability' has opened up new avenues even for authors like Felicitas Hoppe and Ulrike Draesner, who distrust the quest for 'readability'. The thesis will conclude with a reflection on the prospects for 'readability' in the current literary landscape in Germany.

Advisor: Kohl, K
Greek myths abroad: a regional comparative study of their funerary uses in fourth-century BC Apulia and Etruria

This dissertation presents a regional comparative study of the uses of Greek heroic stories as illustrated on funerary monuments of Apulia and Etruria in the fourth century BC. Founded on the grounds of contextual archaeology and reception theory, it approaches a group of Apulian red-figure vases, Etruscan sarcophagi and tomb-paintings from both regions as a means of investigating the cultural significance of the myths presented in the grave by different peoples in Italy. Moreover, this study emphasises the possible ways in which viewers engaged with the images depicted on these monuments by defining a cultural frame ('horizon of expectations') for their interpretation of the images. Further contributions include the development of a model for the interpretation of the myths depicted on Apulian red-figure vases and the prominence of the corpus of Etruscan mythological sarcophagi, a type of monument often neglected in Etruscan studies. At the end of the dissertation, it will become clear – it is expected – that there were regional preferences for particular myths and differences in both the media and the ways in which Greek myths were used and displayed during the funeral.

Keywords: Etruria
Greek myths
Funerary art
Apulia
Advisor: Smith, R
Repetition and internal allusion in Lucretius' De Rerum Natura

This thesis aims to solve the apparent problem of the frequent repetitions in Lucretius' De Rerum Natura (DRN). Verbal repetitions of many different lengths pervade DRN, and are noted in the scholarship. Yet a consensus has not been reached as to their purpose and function, or even if they rightly belong in the text. Multi-linear repetitions are viewed as a temporary stop-gap which Lucretius would have removed or adjusted had he lived long enough to effect it; or as later interpolations; while shorter repetitions are underplayed or even ignored altogether. But repetitions and internal allusions in DRN are part of a purposeful, meaningful didactic and rhetorical strategy, and they form much of the intellectual structure of the poem. These internal connections combine in DRN to form a remarkably complex intratextual network. The thesis argues that repetition is a crucial way in which Lucretius conveys his arguments and persuades the reader to pursue a rational life.
Chapter 1 analyses the ways in which Lucretius’ epic predecessors used repetition and how Lucretius may have applied these models. Chapter 2 looks at the internal evidence for the alleged unfinished state of the poem and examines the function of long repetitions in DRN. Chapter 3 investigates the rhetorical background to and functions of different kinds of repetition in DRN. Chapter 4 explores the didactic and psychological effects of repetitions and internal allusions. Chapter 5 shows how repetition creates an image of the world Lucretius describes: just as Lucretius tells us that atoms and compounds make up different substances depending on their arrangement in combination, so repetitions perform different functions and produce different outcomes depending on their placement in the text. Throughout the poem, repetition serves again and again to reinforce Lucretius’ message, creating argumentative unity, and bringing order from chaos.

Keywords: Intratextuality
De Rerum Natura
Repetition
Self-Allusion
Internal Allusion
Lucretius
Advisor: Harrison, S
Reinhardt, T
Structure, function and FliM interaction studies of CheY6 in Rhodobacter sphaeroides

Bacteria control their swimming direction by signalling from chemoreceptors via a small protein, CheY, to the rotary flagellar motor. Rhodobacter sphaeroides has a complex chemosensory network with two pathways, including three different CheYs controlling a stop-start motor. Deletions of these cheYs result in a non-chemotactic phenotype. CheY6 is essential for chemotaxis, whereas CheY3 and CheY4 have some functional redundancies. Although CheY6 alone can stop the motor, the presence of either CheY3 or CheY4 is required for a chemotactic phenotype. To date, little is known about how these three CheY proteins interact with the flagellar motor, or the switch mechanism used between the inactive and active states.
Structural studies of CheY6 using NMR experiments, highlighted a flexible loop region (residues S109-K118) that is not present in CheY3, CheY4 or CheYs in other bacterial species. This elongated loop region was deleted (CheY6-ΔLoop), and in vivo studies were used to investigate its function. CheY6 ΔLoop is folded, retains the ability to be phosphorylated by CheA3, localises at the cytoplasmic chemoreceptor cluster, but appears unable to stop the flagellar motor. Circular dichroism and NMR data suggest that CheY6-ΔLoop is a folded protein that shows similar peak shifts to wild type CheY6 upon activation. In wild type CheY6, residues in this loop show chemical shift changes upon addition of the phosphoryl mimic BeF3-, suggesting that the loop is involved in the activation mechanism.
The switch mechanism of CheY6 was probed using multidimensional NMR studies. The active state was mimicked using BeF3- . Wild type CheY6 was shown to undergo structural changes upon addition of BeF3-. In particular, the β4 α4-loop and residues located near the phosphorylatable D56 show large changes in chemical shift. Superposition of this loop region revealed possible steric clashes with the N-terminus of FliM. S83 shows evidence of involvement in the switch mechanism. Residual dipolar coupling experiments suggest that the published crystal of CheY6 in complex with CheA3, is more like the inactive conformation in solution. CheY has been shown to interact with the motor switch protein FliM in other bacterial species. CheY6-FliM interactions were probed using a combination of in vitro and in vivo studies. Bacterial two hybrid assays and NMR studies suggest that CheY6 cannot interact with monomeric FliM. Single molecule total internal reflection microscopy revealed CheY6 does interact with the motor in vivo.
The data in combination suggests a model in which CheY6-P only interacts with FliM when it is part of the switch ring, and structural changes involved in stopping the motor depend on the large conformational changes in the β4-α4-loop.

Advisor: Redfield, C
Armitage, J
Development and application of computational tools to analyse selectivity in organic chemistry

The work described in this thesis illustrates how a range of computational methods may be applied to explain, both experimentally observed and computationally predicted, selectivity, in the field of Organic Chemistry. We begin with a discussion of the theory behind Computational Chemistry and also background to the ever growing field of organocatalysis, followed by a synopsis on the importance of asymmetry in synthesis.
The second chapter focusses on an asymmetric organocatalysed reaction for the diastereoselective and enantioselective synthesis of the morphan motif. We look at a range of primary amine organocatalysts in this section, and are able to account for the observed asymmetry that is imparted, both qualitatively and quantitatively. Furthermore, through the course of our investigation, we were able to propose synthetic modifications to an existing organocatalyst used in this reaction, resulting in improvement to the enantioselectivity and atom economy of the reaction.
In chapter three, we examine the various factors influencing ring closing reactions for a range of systems and investigate the origin of the underlying preference for cyclisations to follow Baldwin’s rules for selectivity. In order to do this, we use a range of computational techniques, including nucleus independent chemical shift (NICS) analysis to gain a better understanding of the magnetic properties of ring closing transitions structures (TS).
Chapter four contains an in depth look into the stereoelectronic effects altering enantioselectivity in alkylation reactions with bicyclic enamine chiral auxiliaries. In this study, we were able to develop, improve, and implement a new methodology for explaining stereoselective alkylations of tropane-type enamine systems. Our computationally derived predictions of selectivity made for a number of systems have been subsequently verified with experimental results which were within 5 kJ/mol of our values.
In chapter five, we use computational analysis to provide insight into the regiodi-vergent α- and α’-lithiation-electrophile trapping of N-thiopivaloyl- and N-(tert- butoxythiocarbonyl)-α-alkylazetidines. We calculated the magnitudes of rotational barriers for a range of protected azetidine systems and showed that rotamer interconversion could not occur for the aforementioned species at the temperature and on the time scale of the lithiations.
In the final chapter, we describe the development of computational tools that have been essential in the other investigations discussed in this thesis. We also look at potential future applications of these programs in the field of Organic Chemistry.

Advisor: Paton, R
An appeal to principle: a theory of appeals and review of migration status decision-making in the United Kingdom

The question asked by this thesis is when and why, as a matter of principle, should there be judicial scrutiny on the merits of administrative decisions on migration status (‘migration status decisions’) in the United Kingdom? It argues that this is a moral question, engaging concerns of fair treatment. The first two chapters examine the question theoretically. It is argued that access to justice is not a gift of citizenship and that migration status decision-making should be reviewable on the merits to avoid the appearance and/or occurrence of injustice in the light of the effects of migration control on individual migrants and the nature of migration status decision-making as ‘very imperfect procedural justice’ (save where a decision is not based on the judgment discretion of an administrator). The latter five chapters apply the normative claims to the United Kingdom constitutional context, including the relevant European regimes (European Convention on Fundamental Rights and European Union). First, as background to the argument, a history of recourse from migration status decision-making in the UK from the initial establishment of a review system in 1905 is sketched out. The history demonstrates the absence of a coherent or principled account of migration status appeals. The history is followed by a three-part critique of the current system of recourse in the UK. First rights of appeal in three case studies (deportation, offshore visitors and students) are examined. Secondly, the three standards of review available under judicial review (rationality, anxious scrutiny and proportionality) are critiqued, and thirdly, the contribution of European and international norms is considered. In general terms the thesis concludes that the current UK system of recourse is deficient in certain respects and suggests reform to the current appeals system.

Advisor: Costello, C
Novel developments in time-of-flight particle imaging

In the field of physical chemistry, the relatively recently developed technique of velocity-map imaging has allowed chemical dynamics to be explored with a greater depth than could be previously achieved using other methods. Capturing the scattering image associated with the products resulting from fragmentation of a molecule allows the dissociative pathways and energy landscape to be investigated.
In the study of particle physics, the neutron has become an irreplaceable spectroscopic tool due to the unique nature of the interaction with certain materials. Neutron spectroscopy is a non-destructive imaging technique that allows a number of properties to be discerned, including chemical identification, strain tensor measurements and the identification of beneath the sample surface using radiography and tomography.
In both of these areas, as well as a multitude of other disciplines, a flight tube is used to separate particles, distinguishing them based upon their mass in the former case and their energy in the latter. The experiments can be vastly enhanced by the ability to record both the position and arrival time of the particle of interest. This thesis describes several new developments made in instrumentation for experiments involving time-of-flight particle imaging.
The first development described is the construction of a new velocity-map imaging instrument that utilises electron ionisation to perform both steps of molecular fragmentation and ionisation. Data from CO2 is presented as an example of the ability of the instrument, and a preliminary analysis of the images is performed.
The second presented project is the design of a time-resolved and position-resolved detector developed for ion imaging experiments. The hardware, software and firmware are described and presented alongside data from a variety of the experiments showcasing the breadth of investigations that are possible using the sensor.
Finally, the modifications made to the detector to allow time-resolved neutron imaging are detailed, with an in-depth description of the various proof-of-concept experiments carried out as part of the development process.

Keywords: velocity-map imaging
chemistry
time-of-flight
electron impact
physics
time-resolved
particle imaging
dynamics
CMOS sensors
PImMS
neutron imaging
Advisor: Vallance, C
Long-term diasporic return migration in post-Soviet Armenia: Balancing mobility and sedentarism

This thesis examines the immigration to and long-term settlement in post-Soviet Armenia of Armenians from well-established diasporic communities — mostly from Iran, Syria, Lebanon, Iraq, Canada, and the United States. It argues that diverse levels and combinations of anchoring and floating co-exist in the diasporan returnees’ return motivations, post-return integration experiences, and identity and belonging (re)conceptualization processes. They are manifested in the returnees’ habitual dispositions, imaginative aspirations, and practical considerations, which develop within a particular sociohistorical environment. The study also considers the changes that occur over time in the structural context and in the ways returnees engage with it. It demonstrates that the inclination of returnees toward more rooted or more mobile directions depends, to a large extent, on their diasporic community background, the generation they belong to, and more immediate factors related to their life-cycle stages. Throughout the analysis, the important role of emotions in the return visions and experiences is highlighted.
The thesis makes an empirical contribution by studying the largely uncharted case of Armenian diasporic return in the post-Soviet era. At a more theoretical level, it promotes a balanced approach that goes beyond the overemphasis on mobility and the relative neglect of sedentarism that have characterized many works in the fields of diaspora and migration studies over the past few decades. Underlying this balanced path is the goal of recognizing the equal importance of and complex inter-relationship between human agency and objective structures. To this end, the thesis relies on a theoretical framework based primarily on some of Pierre Bourdieu’s key conceptual tools, with certain modifications. Thus, the study frames the topic of long-term diasporic return migration within broader social theory. This way, not only does it link diasporic return to paradigms in migration and diaspora studies, but it also views it from a wider angle of social action.

Keywords: repatriation
Armenian diaspora-homeland relations
Pierre Bourdieu and migration studies
diaspora
returnees
diasporic return
Armenian diaspora
ethnicity and nationalism
return migration
application of social theory to diasporic return
Armenian identity
Advisor: Chatty, D
Bakewell, O