VictorJuiz/thesis huggingface dataset:
Exploring the use of Tetris as a post-trauma ‘cognitive vaccine’: from memory consolidation to reconsolidation
Keywords: emotion
experimental psychopathology
Tetris
cognitive science
posttraumatic stress disorder
PTDS

Re-experiencing trauma in the form of intrusive, image-based memories (here referred to as flashbacks) is a hallmark symptom of Post-Traumatic Stress Disorder (PTSD). There are successful treatments available for full-blown PTSD; however, these can only be administered one month post trauma. There are limited interventions that can be administered to reduce flashbacks in the early aftermath of trauma. The overarching aim of this thesis was to use an experimental psychopathology approach, the trauma film paradigm, to investigate the reduction of flashbacks post-trauma using the cognitive task, Tetris.
Chapter 1 provides a literature review of experimental research that has used the trauma film paradigm. Chapter 2 reviews experimental work on disrupting memory reconsolidation in humans. Chapter 3 details pilot work on the development of an experimental protocol based upon these literature reviews.
Experiment 1 (Chapter 4) investigated disrupting reconsolidation for a 24 hour old analogue trauma (aversive film material) using the cognitive task, Tetris. A procedure designed to disrupt flashback reconsolidation (a memory reactivation task for the film followed by playing the computer game Tetris) was compared with a no-task Control. Compared to Control, those in the Tetris condition reported fewer flashbacks to the film in an intrusion diary across the subsequent week and on convergent measures of flashback frequency. Experiment 2 (Chapter 5) provided a test of replication for findings from Experiment 1, in addition to extending findings by dismantling the procedure’s component parts. Participants who underwent Tetris only (without memory reactivation) or memory reactivation (without Tetris) did not demonstrate a reduction in flashbacks and were comparable to the no-task control condition. Both a memory reactivation task plus Tetris in combination were critical for reducing subsequent flashbacks for a consolidated memory for a trauma film.
Experiment 3 (Chapter 6) tested whether playing Tetris could help disrupt flashback memories for an analogue trauma (film) if administered prior to film viewing, relative to a no-task control condition. Results showed that playing Tetris before a trauma film did not reduce flashbacks, as demonstrated via an intrusion diary and convergent flashback measures.
Chapters 7 reviews email feedback relating to playing Tetris after experiencing real-life adversity from members of the public. Chapter 8 explores a form of treatment for trauma in a NHS, complex patient setting. Chapter 9 discusses the findings from all chapters with reference to their implications and limitations, and new directions for future research. Overall, findings using analogue trauma suggest that memory reactivation followed by playing Tetris may be promising for development as a post-trauma ‘cognitive vaccine’ to disrupt the both the consolidation and potential reconsolidation of flashback memories.
Functional characterization of the teleost multiple tissue (tmt) opsin family and their role in light detection.
Keywords: Photopigment
Photosensory
Transduction
Multiple Tissue expression
Opsin
G protein-coupled receptor
Biological rhythms

In addition to a central circadian clock in the suprachiasmatic nucleus (SCN), zebrafish (Danio rerio) have local clock systems in their peripheral tissues. These peripheral tissues express a complement of clock genes that can be synchronized with the 24 h light/dark cycle and thus may be entrained by light. To date, teleost multiple tissue (tmt) opsin identified from Fugu rubripes and Danio rerio is the only opsin that has been proposed as a candidate to mediate this cellular photoentrainment (Moutsaki et al., 2003). Here we report the discovery of a multigene family of tmt opsins found not only in the teleost fishes, but in vertebrates,including amphibians, birds, reptiles, and some mammals.
Phylogenetic analysis demonstrated that this gene family consists of three main classes, tmtI, tmtII and tmtIII, with each duplicating further to give two paralogues in the zebrafish genome. Their predicted amino acid sequences contain most of the characteristic features for the function of a photopigment opsin, as well as seven transmembrane segments indicative of a G protein coupled receptor (GPCR) superfamily. Significantly, reverse transcription polymerase chain reaction (RT-PCR) reveals that the tmt opsin genes in zebrafish are both temporally and spatially regulated. To investigate if these tmt photopigments mediate light-activated currents in cells, each opsin was expressed in vitro and the responses characterised by calcium imaging, whole-cell patch clamp electrophysiology, UV-Vis spectrophotometric analysis, and bioluminescence reporter assay. Collectively, these data suggest that some of the opsin photoproteins signal via Gi-type G protein pathway. Interestingly, the spectral analysis obtained shows that most tmt opsins tested are UV-sensitive when reconstituted in vitro with 11-cis and all-trans retinal, indicating an intrinsic bistable dynamics. Using site directed mutagenesis on one of the tmt opsins, tmt10, the potential spectral tuning sites involved in UV detection were tested.
As part of this study, tmt opsin cDNAs were isolated from three populations of Mexican tetra (Astyanax mexicanus): surface, Pachon and Steinhardt. This allowed for a direct comparison between the tmt opsins present in the dark adapted species (cavefish) versus those of the light adapted species (zebrafish). It is hoped that the findings from this project will contribute to our understanding of non-visual light detection in fish and the evolution of their non-image forming photoreception.
Geodetic observation and modelling of continental deformation in Iran and Turkey
Keywords: active tectonics
interseismic
earthquakes
geodesy
geophysics
Middle East
InSAR

In this thesis I use Interferometric Synthetic Aperture Radar (InSAR) and GPS geodetic observations, along with numerical models, to examine the distribution of strain, assess seismic hazard, and study the dynamics of deformation across Turkey and Iran.
I measure interseismic strain accumulation across the Ashkabad fault using InSAR, and find that atmospheric corrections using MERIS (Medium Resolution Imaging Spectrometer) data are necessary in order to retrieve the tectonic signal in the presence of large atmospheric delays. I estimate a slip rate of 5-12 mm/yr for the Ashkabad fault which is faster than previous geodetic estimates. I also attempt to validate atmospheric corrections derived from the ERA-Interim numerical weather model and find that they do not work satisfactorily for this region.
I produce InSAR-derived velocity maps for five overlapping tracks in Eastern Turkey, covering both the North Anatolian Fault (NAF) and East Anatolian Fault (EAF), and measure slip rates for the NAF and EAF of 20+/-3 mm/yr and 10+/-2 mm/yr respectively. I calculate a velocity field for Eastern Turkey from these InSAR data and a compilation of GPS data, and find that strain is mainly localised across the NAF and EAF and that there is negligible differential vertical motion across the Anatolian Plateau.
I construct a thin viscous sheet model for Iran and find that the GPS velocity field is well described by deformation of a ductile lithosphere. Contrary to previous suggestions, a rigid central Iran is not required to match the kinematics of Iranian deformation, but buoyancy forces acting in the lithosphere are found to play an important role. I develop a new method to assess slip rates and therefore seismic hazard on major faults in Iran from this continuum model.
In this thesis I have measured slip rates across three major strike-slip faults using InSAR; the first time this has been achieved for the Ashkabad fault and the EAF. I have demonstrated the importance of atmospheric correction for these results, and have shown that Iran deforms as a continuous medium.
A study of soil nailing in sand
Keywords: sand
soil nailing

This dissertation is concerned with a study of soil nailing, in particular the interaction mechanism between the soil and a nail and the failure mechanism and suitable design procedure for nailed slopes in sand. The interaction mechanism of a nail was studied by carrying out a number of pull-out tests, direct shear tests of nailed sand and interface tests using two uniform sands. Major parameters of the tests were flexibility, surface roughness and diameter of a nail. From the tests, it was found that: (1) flexibility of a nail significantly influences the interaction mechanism. Both the interaction parameter and apparent friction coefficient differ between a flexible and a stiff nail. Theoretical consideration indicates that the mobilization of nail forces is dominated by the relative stiffness between soil and nail. (2) a smooth-surface nail produces smaller bond friction than the critical state friction angle and mineral-to-mineral angle of the soil. This is due to the very thin rupture surface developed around the nail. On the other hand, a rough-surface nail was observed to produce two to four times larger bond friction than the direct shear friction angle of sand, due to the thick rupture surface developed and the dilatancy of the soil. (3) increasing the diameter of a nail produces a smaller apparent friction coefficient. Restrained dilatancy was found to play an important role. (4) the pull-out test, direct shear test of nailed sand and interface test produce different values of apparent friction coefficient , due to the different amount of restrained dilatancy effect around the nail (or reinforcement). The overall behaviour of nailed slopes was studied by carrying out a comprehensive series of centrifuge tests. Excavation of soil was simulated by draining water from two rubber bags in front of the facing wall. The centrifuge tests have provided much useful information on the mechanics of soil nailing. From the tests, it was found that: (1) draining of the water significantly influences both the earth pressure on the facing wall and the displacements of the nailed slope. Horizontal displacements of the facing wall were decreased by increasing the length and/or friction (bond) of the nail. (2) earth pressures on the facing wall do not exhibit a simple hydrostatic distribution. The deviations of the earth pressure are not negligible especially near the top and bottom of the facing wall. (3) roughness and bending stiffness of the facing wall considerably influence the stability and displacement of the nailed slope, respectively. (4) the observed failure surfaces were well described by a logarithmic spiral passing through the toe of the facing wall. (5) fairly good predictions for the failure acceleration were made using stability analysis of the nailed slopes based on the limit equilibrium method, provided an accurate friction angle for the sand and pull-out resistance of each nail could be determined. The factor of safety F5 of the nailed slopes was estimated by comparing the total available force and the total required force based on the observed failure surfaces.
The foreign policy of Anwar Sadat: continuity and change, 1970-1981
Keywords: Cold War
International Relations
Arab-Israeli conflict
Middle East
Egypt

This thesis aims to examine both continuity and change in Egyptian foreign policy between 1970 and 1981. The overarching question of this work is: Why and how did President Sadat affect changes in foreign policy? More specifically, the thesis examines the evolution of Egyptian foreign policy in three concentric circles: the Superpowers, the Arab world, and Israel. The broader aim of the thesis is to provide a detailed study of Egyptian foreign policy in this period, which witnessed a multitude of watershed events. The topic is important because Egypt is a leading state in the Arab world, a core actor in the Arab-Israeli conflict, and a strategic ally of the superpowers during the Cold War.
The thesis offers a detailed chronological account of Egyptian foreign policy during the 1970s. It advances a revisionist interpretation of the early Sadat years, arguing that there was much greater continuity with the foreign policy of Gamal Abdel-Nasser than is commonly believed. The account ends in 1981, with the assassination of Anwar Sadat and the succession of Hosni Mubarak. It is argued that Sadat not only managed to reverse Nasser’s radical path in foreign policy, but that he also succeeded in institutionalising his most significant policy changes: peace with Israel and the removal of Egypt from the Arab-Israeli conflict.
The methodology of the thesis is principally empirical and qualitative in nature. The thesis is based on extensive archival research, recently declassified official documents, memoirs of policymakers in English and Arabic, and oral histories in the form of interviews and transcripts of discussions with former Egyptian policymakers.
Development of coherent detector technologies for sub-millimetre wave astronomy observations
Keywords: superconducting detectors
heterodyne receiver
Superconductor-insulator-superconductor
sub-millimetre astronomy

Superconductor-Insulator-Superconductor (SIS) mixers are now used regularly in sub- millimetre astronomical receivers. They have already achieved sensitivity approaching the quantum limit at frequencies below the superconducting gap of niobium (~680 GHz). Above that, the mixer performance is compromised by losses, unless materials with higher superconducting gap are employed in conjunction with the niobium tunnel junction. In this thesis, we present the development of 700 GHz niobium SIS mixers, employing a unilateral finline taper on a thin Silicon-On-Insulator (SOI) substrate. These mixers are broadband with full on-chip planar circuit integration, and require only a very simple mixer block. They were designed using rigorous 3-D electromagnetic simulator (HFSS), in conjunction with a quantum mixing software package (SuperMix), and have demonstrated good performance with the best noise temperature measured at 143 K. Our mixer devices were fed by multiple flare angle smooth-walled horns, which are easy to fabricated, yet retain the high performance of corrugated horns. The radiation patterns measured from 600–740 GHz have shown good beam circularity, low sidelobe and cross-polarization levels.
In this thesis, we also present SIS mixer designs with balanced and sideband separ- ating capability. These mixers employ back-to-back finline tapers, so that the RF and local oscillator (LO) signals can be injected separately without a beam splitter. We have fabricated and tested the performance of the balanced mixers, and analysed their performance thoroughly. We have also investigated a new method of generating LO signals by beating the tones of two infrared lasers.
Using the current 16-pixel 350 GHz SIS receiver, HARP-B, we have observed the 12CO J=3→2 emission lines from two nearby galaxies. An important result we found is that the 12CO J=3→2 correlates strongly with the 8 μm Polycyclic Aromatic Hydrocarbon emission.
Becoming a non-immigration country with immigrants: the institutional regime of Japanese immigration policy towards economic migrants
Keywords: immigration policy
Japan
historical institutionalism

How can one detect and understand change in the face of apparent continuity? This is the question which has been asked by some scholars of institutionalism. One way of answering this is to make analytical room for incremental change as an endogenous source of institutional transformation. Put bluntly, one does not always need spectacular exogenous events, such as wars and revolutions, to explain institutional change.
The present thesis is a qualitative case study of Japan’s immigration policy towards economic migrants since the 1980s. Its aim is to uncover a causal mechanism behind the policy development by drawing on a model of institutional change put forward by James Mahoney, Wolfgang Streeck and Kathleen Thelen. At first, the inquiry may seem ill-founded for Japan is neither an immigration country nor an immigrant-receiving country. Indeed, the country still lacks an immigration policy to speak of, and immigrants continue to be called gaikokujin (foreigners) as opposed to imin (immigrants).
A closer examination of the recent policy development, however, shows that the content and practice of Japanese immigration policy simply belie its self-description. Since 2012 the Japanese government has admitted highly-skilled migrants as potential permanent residents using a points-based system and has incorporated foreigners into the resident register system for Japanese citizens in order to facilitate their integration into Japanese society. The central claim of the present research is that Japanese immigration policy has become increasingly settlement-oriented as an unexpected consequence of earlier policy decisions and that the change has been endogenously effected without dismantling the pre-existing institution of immigration management. In making this claim, I particularly draw attention to the way in which a cumulative effect of minor changes eventually transformed the basic nature of the policy institution.
Obesity monitoring in schools
Keywords: measurement
weight status
monitoring and surveillance
public health
Childhood obesity

BACKGROUND Population level child measurement is an established international practice. However, there is limited clarity around the protocol and roles of school-based child measurement programmes (CMPs). Furthermore, questions remain about the positive and adverse outcomes associated with CMPs, as well as their longer-term sustainability. This research contributes new information by addressing these key unanswered questions.
METHODS This thesis describes a three-part, mixed methods research project incorporating: a systematic literature review of existing CMPs; an in-depth case study of England’s National Child Measurement Programme; and the development, pilot implementation and evaluation of a CMP in Guernsey. This research was conducted sequentially; individual components informed and guided subsequent work.
RESULTS Routine child measurement is a popular, complex and adaptive practice and offers significant epidemiological value. The principal roles of CMPs are delivery of local prevalence data and assessment of longitudinal trends. However, CMPs are often tasked with additional, diverse and changing roles that do not translate to acknowledged outcomes. Specifically, feedback of individual results represents an unproven programme element. Programme roles can evolve according to political, logistical, or other influences, without consideration of available evidence or wider-reaching implications. There is no evidence of short-term harm from CMPs. Evaluation of the pilot CMP in Guernsey demonstrated that these programmes are perceived to be feasible, acceptable and sustainable.
CONCLUSIONS To maximise the broader utility of CMPs, there should be clarity and consistency around their aims, roles and outcomes. Overall, surveillance reflects the preferred programme type. All CMPs should incorporate a standardised, rigorously applied protocol and routine evaluation. These features are essential to ensure the accuracy and comparability of resultant data, as well as programme credibility. Population level CMPs should not function in isolation; instead, they should be integrated into comprehensive strategies for obesity management. This research has important implications for CMP stakeholders and the wider public health arena.
Microstructural properties of semiconductor nanostructures
Keywords: nanostructures
semiconductors
transmission electron microscopy

Semiconductor nanostructures have attracted great interest owing to their unique physical properties and potential applications in nanoscale functional devices. The enhancement of the physical properties of semiconductor nanostructures and their performance in devices requires a deeper understanding of their fundamental microstructural properties. Thus this thesis is focused on the experimental and theoretical studies of the microstructural properties of two important semiconductor nanostructures: axial heterostructured silicon nanowires with varying doping and indium nitride colloidal nanoparticles.
In this thesis, axial heterostructured silicon nanowires with varying doping were synthesized on an oxide-removed Si{111} substrate using a vapour-liquid-solid approach. Their fundamental microstructural properties, including the crystalline structure, wire growth direction and morphologies, were studied using various characterization techniques. It is found that a very small fraction of the silicon nanowires crystallize in a hexagonal (wurtzite) phase, which is thermodynamically unstable in bulk silicon under ambient conditions, while a large majority of the synthesized silicon nanowires exhibit the expected diamond cubic crystalline structure. About 75% of the diamond cubic silicon nanowires synthesized grow in a single <111> direction, while the rest contain growth-related kinks, where the nanowire switches to another direction during the growth. The ~109° silicon nanowire kinks are the most commonly observed, and the growth direction before and after such ~109° kink are both <111>. The sidewalls of silicon nanowires do not change abruptly at the ~109° kink, but exhibit an elbow-shaped structure. It is also found that the nanowire sidewalls exhibit periodic nanofaceting, which is strongly doping-dependent. The nanofaceting is found to occur during the enhanced sidewall growth that arises when the diborane dopant gas is introduced. A thermodynamic model predicting the dependence of nanofacet period on the wire diameter is developed.
Another semiconductor nanostructure studied in this thesis is indium nitride colloidal nanoparticles, which were grown using a solution-phase chemical method. The formation of such indium nitride colloidal nanoparticles is confirmed by studying their compositions, crystalline structures and shape using various electron microscopy techniques. The size of the indium nitride colloidal nanoparticles was controlled by varying the time of solution-phase reactions. The most probable size of the colloidal nanoparticles increases and the size distribution broadens with the increase of reaction time. The crystalline structures of the indium nitride colloidal nanoparticles are found to be particle size dependent. The observed dependence of the band gap blueshift of the indium nitride colloidal nanoparticles on the reaction time (hence the particle size) is explained by the quantum-size effect.