VictorJuiz/thesis huggingface dataset:
Essays in macroeconomic modelling with frictions and rigidities
Keywords: DSGE modelling

This thesis presents three dynamic stochastic general equilibrium models to answer three macroeconomic questions. In each model, I impose one or more frictions or constraints and analyse how these frictions affect macroeconomic dynamics.
Chapter 2 studies the coordination of fiscal and monetary policies under optimal commitment and discretion policies under a New Keynesian framework. The chapter shows that when there is indexation in price setting which depends on the lagged output gap as in Steinsson (2003), under the optimal commitment policy, both fiscal and monetary policies have active roles in inflation stabilisation, even although debt follows a unit-root process. Under the optimal discretion policy, both fiscal and monetary policies have active roles in inflation stabilisation to drive debt back to the pre-shock level, consistent with Leith and Wren-Lewis (2008). Extending the model to include capital accumulation does not alter these results.
Chapter 3 presents a microfounded two-country model of global imbalances and debt deleveraging. During global imbalances a sustained rise in saving in one country can lead to a worldwide fall in the interest rates and an accumulation of debt in the other country. When an ensuing deleveraging shock occurs as a result of the global financial crisis, the interest rates are forced further down. I show that in the presence of a liquidity trap the deleveraging country may face a combination of a large fall in output, deflation and real exchange rate appreciation, as a result of debt deflation.
Chapter 4 adds a highly-leveraged financial sector to the Ramsey model and shows that this augments the macroeconomic effects of aggregate productivity shocks. My model is built on the financial-accelerator approach of Bernanke, Gertler and Gilchrist (BGG), in which leveraged goods-producers borrow from a competitive financial sector. In this chapter, by contrast, financial institutions are leveraged and subject to idiosyncratic productivity shocks. They obtain funds by paying an interest rate above the risk free rate, and this risk premium is anti-cyclical, and so amplifies the shocks. My parameterisation, based on US data, is one in which the leverage of the financial sector is two and a half times that of the goods-producers in the BGG model. This causes a much more significant augmentation of aggregate productivity shocks than that found in the BGG model.
The adult neural stem cell niche in ischaemic stroke
Keywords: svz
neuroblast migration
ependymal cells
stroke
galectin-3
MCAO
gal-3
cerebral ischaemia
stem cells
subventricular zone
CSF

Ischaemic stroke is a major cause of mortality and chronic disability for which there is no effective treatment. The subventricular zone (SVZ) is an adult neurogenic niche which mediates limited endogenous repair following stroke. To harness this phenomenon for therapy, it is important to understand how the SVZ niche is altered in stroke, and the processes that recruit neural precursors to the site of injury, which becomes a de facto neurogenic niche. Galectin-3 (Gal-3) is a β-galactoside binding protein involved in cellular adhesion, inflammation and tumour metastasis. Gal-3 is specifically expressed in the SVZ and maintains neuroblast migration to the olfactory bulb, although its role in post-stroke neurogenesis is not well-understood. Therefore, this project aimed to (1) characterise the cytoarchitecture of the SVZ in response to stroke, and (2) examine the role of Gal-3 in stroke outcome and tissue remodelling, and test the hypothesis that Gal-3 is required for neuroblast ectopic migration into the ischaemic striatum.
Using the intraluminal filament model of middle cerebral artery occlusion (MCAO) in mice, and whole mounts of the lateral ventricular wall, significant SVZ reactive astrocytosis and increased vascular branching were observed, thereby disrupting the neuroblast migratory scaffold. Stroke increased SVZ cell proliferation without increase in cell death. Post-stroke ependymal cells were enlarged and non-proliferative, and assumed a reactive astroglial phenotype, expressing de novo high levels of glial fibrillary acidic protein. This was associated with focal planar cell polarity misalignment, and turbulent and decreased rate of cerebrospinal fluid flow. These findings demonstrate significant changes in multiple SVZ cell types which are positioned to influence post-stroke neurogenesis and regulation of the neural stem cell niche
Gal-3 was up-regulated in the ischaemic brain and ipsilateral SVZ. To elucidate the role of Gal-3 after stroke, MCAO was performed in wildtype and Gal-3 null (Gal-3-/-) mice, and parameters of stroke outcome and post-stroke neurogenesis compared. The deletion of Gal-3 did not affect infarct volumes or neurological outcomes, although neuroblast migration into the ischaemic striatum was increased in Gal-3-/- brains. Gal-3-/- mice failed to mount an angiogenic response in the ischaemic striatum, and this was associated with lower levels of vascular endothelial growth factor (VEGF) and increased anti-angiogenic protein levels. Loss of Gal-3 further disrupted the pro-proliferative neural-vascular interaction at the basement membrane. The current data indicate that Gal-3 is a pleiotropic molecule which has distinct roles in both the SVZ and the post-stroke striatum as niches of adult neurogenesis.
The role of IL-18 in intestinal immune regulation
Keywords: intestine
Foxp3
IL-18
Th17
immunity

Elevated levels of the cytokine interleukin-18 (IL-18) are found in many chronic inflammatory disorders, including inflammatory bowel disease (IBD). However, the role of IL-18 in mucosal immunity and inflammation is not well understood. At mucosal and environmental interfaces, Th17 cells have been shown to contribute to protection from pathogenic infection. In contrast, regulatory T (Treg) cells maintain intestinal homeostasis by preventing aberrant inflammatory responses to the resident microbiota. We demonstrate that under homeostatic conditions, colonic Th17 cells highly express IL-18 receptor (IL-18R1) and that intestinal epithelial cell production of IL-18 acts directly on CD4+ T cells to limit colonic Th17 differentiation. Furthermore, whilst IL-18R1-signalling is dispensable for induction of colitis, we observed a critical role for IL-18R1-signalling in Foxp3+ Treg mediated control of colitis. Together, these studies demonstrate that the intestinal epithelium regulates colonic CD4+ T cell responses through production of the cytokine IL-18.
Graphical representation of independence structures 
Keywords: MC graph
bidirected graph
composition property
graphoid
independence model
summary graph
global and pairwise Markov property
chain graph
ancestral graph
directed acyclic graph
separation criterion
undirected graph
maximality
marginalisation and conditioning

In this thesis we describe subclasses of a class of graphs with three types of edges, called loopless mixed graphs (LMGs). The class of LMGs contains almost all known classes of graphs used in the literature of graphical Markov models. We focus in particular on the subclass of ribbonless graphs (RGs), which as special cases include undirected graphs, bidirected graphs, and directed acyclic graphs, as well as ancestral graphs and summary graphs. We define a unifying interpretation of independence structure for LMGs and pairwise and global Markov properties for RGs, discuss their maximality, and, in particular, prove the equivalence of pairwise and global Markov properties for graphoids defined over the nodes of RGs. Three subclasses of LMGs (MC, summary, and ancestral graphs) capture the modified independence model after marginalisation over unobserved variables and conditioning on selection variables of variables satisfying independence restrictions represented by a directed acyclic graph (DAG). We derive algorithms to generate these graphs from a given DAG or from a graph of a specific subclass, and we study the relationships between these classes of graphs. Finally, a manual and codes are provided that explain methods and functions in R for implementing and generating various graphs studied in this thesis.
Studies in the demonstrative pronouns of early Greek
Keywords: Aeolic
Cretan
Homer
Greek inscriptions
Mycenaean
Theran
Thessalian
pronouns
Greek grammar
Indo-European
Pamphylian
Laconian
Greek dialects
Elean
deixis
Boeotian
Lesbian
Greek particles
Cyrenaean
demonstratives
Cyprian
Arcadian
anaphora

This study identifies and describes constituents, patterns and distribution of the system –or systems- of demonstratives of a representative selection of early Greek dialects, namely the “Arcado-Cyprian” group: Arcadian and Cyprian, including a short analysis of Pamphylian as well as a discussion of the particle νι/νυ and a brief note on Mycenaean; the “Aeolic” group: Lesbian, Boeotian and Thessalian; and a selection of West Greek dialects, including both “Doric” and “Northwest Greek” dialects: Elean, Cretan, Laconian, Cyrenaean and Theran. It also examines, describes and compares the syntactic functions and, where possible, pragmatic uses of the series of demonstratives in operation in the selected dialects, providing a classification capable of accounting for all uses cross-dialectically, as well as a succinct account of the evolution of the system of demonstratives from Indo-European to “Ancient Greek”. Additionally, it offers a glimpse of the way in which deixis and anaphora seem to have worked in early Greek dialectal inscriptions, addressing the issue of defining demonstrative pronouns, as well as deixis and anaphora in general terms. Finally, this thesis provides the basis for a cross-dialectal comparison of the structure and operation of the different systems of demonstratives, and corrects some general misconceptions about the scope, usage and inter-dialectal connections of some series of demonstratives, particularly with regard to Arcadian and Cyprian. The results of such a study might contribute towards the discussion of the classification and history of the evolution of early Greek dialects.
Film cooling of turbine blade trailing edges
Keywords: Film Cooling
Mixed out loss
Heat Transfer
CFD
Trailing Edge

In modern gas turbine engines, film cooling is extensively used to cool the components exposed to the hot mainstream gas path. In implementing film cooling on modern gas turbine engines, the trailing edge film poses a particularly challenging design problem. From an aerodynamic point of view, the trailing edge of a blade is designed to be as thin as possible. However, this conflicts with the implementation of the cooling design. The most common method of film cooling the trailing edge is via late pressure surface discrete film cooling holes. Another method of cooling the trailing edge is by using discrete pressure surface slots. This thesis documents a comparative aerodynamic and heat transfer study of three trailing edge cooling configurations. The study was carried out using a large scale, low speed wind tunnel situated at the Southwell Laboratory. The three trailing edge cooling configurations considered were as follows. First is the common late pressure film cooling of the trailing edge via discrete film cooling holes. This configuration is designated as datum configuration. Second is the pressure surface slot coolant ejection. This configuration was designated as cast cutback configuration. The third is the pressure surface ejection via discrete film cooling holes within a step cutback. This configuration was designated the machined cutback configuration. The above configurations were incorporated into three flat plates manufactured using stereolithography. In the aerodynamic study, the static pressure distribution and discharge coefficient for the three configurations were compared. Furthermore, two dimensional total pressure measurements were carried out using a traverse mechanism downstream of the test plates. The total pressure measurements were used to compute the mixed out losses for the three configurations. It was found that the datum and machined cutback configurations have similar discharge coefficients and mixed out losses whilst the cast cutback configuration produces greater mixed out loss. The film effectiveness and heat transfer coefficient on the pressure surface downstream of the coolant ejection was obtained using a steady state heat transfer technique. The effectiveness measurements were compared with those from the literature and correlated against the two dimensional slot model. The heat transfer measurements show that the cast cutback configuration has the potential to give higher effectiveness at the trailing edge.
Iterative Local Model Selection for tracking and mapping
Keywords: data association
slds
inference
computer vision
robotics
mapping
slam
tracking

The past decade has seen great progress in research on large scale mapping and perception in static environments. Real world perception requires handling uncertain situations with multiple possible interpretations: e.g. changing appearances, dynamic objects, and varying motion models. These aspects of perception have been largely avoided through the use of heuristics and preprocessing. This thesis is motivated by the challenge of including discrete reasoning directly into the estimation process.
We approach the problem by using Conditional Linear Gaussian Networks (CLGNs) as a generalization of least-squares estimation which allows the inclusion of discrete model selection variables. CLGNs are a powerful framework for modeling sparse multi-modal inference problems, but are difficult to solve efficiently. We propose the Iterative Local Model Selection (ILMS) algorithm as a general approximation strategy specifically geared towards the large scale problems encountered in tracking and mapping.
Chapter 4 introduces the ILMS algorithm and compares its performance to traditional approximate inference techniques for Switching Linear Dynamical Systems (SLDSs). These evaluations validate the characteristics of the algorithm which make it particularly attractive for applications in robot perception. Chief among these is reliability of convergence, consistent performance, and a reasonable trade off between accuracy and efficiency.
In Chapter 5, we show how the data association problem in multi-target tracking can be formulated as an SLDS and effectively solved using ILMS. The SLDS formulation allows the addition of additional discrete variables which model outliers and clutter in the scene. Evaluations on standard pedestrian tracking sequences demonstrates performance competitive with the state of the art.
Chapter 6 applies the ILMS algorithm to robust pose graph estimation. A non-linear CLGN is constructed by introducing outlier indicator variables for all loop closures. The standard Gauss-Newton optimization algorithm is modified to use ILMS as an inference algorithm in between linearizations. Experiments demonstrate a large improvement over state-of-the-art robust techniques.
The ILMS strategy presented in this thesis is simple and general, but still works surprisingly well. We argue that these properties are encouraging for wider applicability to problems in robot perception.
Anthracene-fused porphyrins
Keywords: anthracene
dye sensitised solar cells
porphyrin

This thesis describes the synthesis of a novel family of porphyrins fused to anthracenes, together with investigations into their optical and electrochemical properties, as well as exploring their potential for application in dye-sensitised solar cells.
Chapter 1 gives an overview of the structure-property relationships of large planar pi- systems for organic electronic applications. Porphyrins are introduced as suitable building blocks for such systems, and approaches for extending the pi-conjugation of these macrocycles are presented.
A literature review of porphyrins fused to aromatic units is presented in Chapter 2, with a focus on the influence of structure on the optoelectronic properties of such systems. The chapter concludes with a summary of my previous work on the synthesis of anthracene-fused porphyrins, and the aims of this project are stated.
Chapter 3 describes the syntheses of fully and partially fused bis-anthracene porphyrin monomers and dimers. By varying peripheral substituents, it was possible to solve problems of aggregation encountered for these systems. Fusion of anthracene units to a porphyrin core was found to result in systems displaying strong absorption in the near-IR, small HOMO-LUMO gaps, and low oxidation potentials.
Chapter 4 explores the synthesis, crystal structure and optoelectronic properties of a porphyrin fused to four anthracenes, revealing this system to exhibit the longest wavelength absorption of any porphyrin monomer. The synthesis of a liquid crystalline tetra-anthracene-fused porphyrin was proposed, and attempts to synthesise the necessary anthracene precursors were undertaken.
Chapter 5 describes the molecular design and synthetic pathway to a mono-anthracene fused porphyrin, and its unfused analogue, for use in liquid electrolyte dye-sensitised solar cells. By varying the metal oxide layer or lithium ion concentration of the device, it was possible to achieve incident photon to current conversion efficiency (IPCE) responses at wavelengths beyond 1050 nm.
Chapter 6 details the experimental synthetic procedures and characterisation data for all the compounds synthesised during this project.
Negotiating and constructing religious identities in English secondary schools: a study of the reported experiences of adolescent Christians, Jews, and Muslims
Keywords: negotiation
England
religious identity
formation
Jews
development
identity
faith
Christians
Muslims
construction
adolescents
religion
secondary school

The increasing diversity of societies is one of the most important educational issues of the globalised era. However, while some attention has been paid to the schooling experiences of racial, ethnic and immigrant minorities in Western societies, little research has been conducted with religious adolescents.
This thesis explores the complexities of religious adolescents’ experiences of English secondary schools. As an exploratory study, I employed an emergent research design carrying out loosely-structured, group and single interviews at eleven places of worship to investigate the schooling experiences of 99 adolescent Christians, Jews and Muslims. In order to interpret their reported experiences, I applied a theoretical model based on the Students’ Multiple World Framework in conjunction with concepts of religious identity negotiation and construction.
The interview data show how Christians, Jews and Muslims negotiate their religious identities in the context of the numerous challenges presented by secondary schools in a religiously plural and largely secular society. In classroom worlds participants perceived their religious traditions to be distorted, inaccurately or unfairly represented. In peer worlds participants reported that they could experience prejudice, and criticism of their beliefs. Christians, Jews and Muslims reported two principal management strategies in the face of these challenges, either: declaring their religious identity openly, or by masking it in public.
The findings of this study are highly relevant to debates about the role of religion in education, including those concerning faith and Church schools and the nature and purpose of the curriculum subject Religious Education.
Holographic quantum liquids
Keywords: AdS/CFT
holography

In this thesis, applications of Holography in the context of Condensed Matter Physics and in particular hydrodynamics, will be studied. Holog- raphy or gauge/gravity duality has been an enormously useful tool in studying strongly-coupled Field Theories with particular success in their low-frequency and large-wavelength fluctuation regime, i.e the hydrody- namical regime. Here, following a phenomenological approach, gravita- tional systems, simple enough to be properly examined, will be studied in order to derive as much information as possible about their dual theories, given that their exact form is not accessible in this way. After a review of the most important elements of standard Condensed Matter Theory, the gauge/gravity duality itself will be presented, along with some of its most important achievements. Having established the framework of this work, the main results of this thesis will be presented. Initially the sound channel of the theory dual to the anti-de Sitter Reissner–Nordstro ̈m black hole space-time will be studied, at finite temperature and finite chemical potential. Hydrodynamical properties of the boundary theory will be of major interest. Following that, focus will be shifted towards another grav- itational system, namely the Electron Star. There, the shear channel of the dual theory will be mainly examined. The goal will be, as before, to extract information about the hydrodynamical properties of the boundary theory.
Advances in the surgical management of early-onset spinal deformities (EOSD) 
Keywords: Scoliosis

Early-onset spinal deformity (EOSD) is characterised by detection of spinal deformity (scoliosis, kyphosis or multi-planar) in children at aged less than five years. The common causes could be classified under congenital, neuromuscular, syndromic and idiopathic etiologies. Early treatment is paramount in preventing rigid, severe and progressive deformities that can cause pulmonary compromise. The inability of lungs and thoracic cage to support normal ventilation at rest constitutes the pathophysiology in manifestation of thoracic insufficiency syndrome (TIS).
The treatment options have evolved from observation, serial casting, bracing to surgery. Early definitive spinal fusion is now obsolete and contra-indicated for EOSD. Growing rods (submuscular or subfascial) continues to be the standard of care in treating these challenging deformities. Vertebral expandable prosthetic titanium rib (VEPTR) continues to be an attractive option for TIS but is fraught with high complication rate.
I hereby present a theme on EOSD with a set of thirty three peer reviewed indexed publications and one surgical patent in treating such challenging conditions highlighting my original contribution as Consultant spinal surgeon spanning over two decades. My pioneering and ground-breaking research that has shaped the surgical management of EOSD and helped define 'standard of care' is presented. My novel and innovative concept of treating EOSD using magnet driven growing rod (MdGR) along with its preliminary results is discussed. MdGRs are an attractive alternative in eliminating need for repetitive anaesthesia facilitating normal cognitive development in comparison to growing rods (CGRs). They also improve pulmonary function in neuromuscular scoliosis. A brief one page summary of all my indexed publications with comments on originality and how they contributed to spinal surgery is enclosed at the end of each chapter. My current research update on MdGR project at Royal National Orthopaedic Hospital (Stanmore), my surgical patent National institute of clinical excellence (NICE) position statement on MdGRs and clinical guidance documents are attached appendices I - III.