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UCL University College London Eprints (354,303 recursos)
UCL Eprints collects the work of UCL researchers and makes it freely available over the web, helping the worldwide scholarly community to discover UCL research. Institutional repositories like UCL Eprints complement the traditional academic publishing and scholarly communications processes. They raise the visibility of research and help to maximise its impact. UCL researchers are encouraged to deposit a copy of each journal article, conference paper, working paper, and any other research output, in the UCL Eprints at the earliest opportunity, ensuring that their research reaches as wide an audience as possible.

Mostrando recursos 61 - 80 de 353,915

61. A Network Model of Financial Markets - Rice, O
This thesis introduces a network representation of equity markets.The model is based on the premise that assets share dependencies on abstract ‘factors’ resulting in exploitable patterns among asset price levels.The network model is a collection of long-run market trends estimated by a 3 layer machine learning framework.The network model’s comprehensive validity is established with 2 simulations in the fields of algorithmic trading, and systemic risk.The algorithmic trading validation applies expectations derived from the network model to estimating expected future returns. It further utilizes the network’s expectations to actively manage a theoretically market neutral portfolio.The validation demonstrates that the network model’s...

62. Freedom to park: post-socialist automobility in Tallinn, Estonia - Tuvikene, T
This dissertation examines a significant—yet seemingly banal and largely unstudied question of urban living: car parking. While car parking has emerged as a problem in various parts of the world throughout the twentieth century, the rapid motorisation since 1991 has made it a particularly intense topic in the former Soviet Union. By investigating the problematic of parking governing in the city of Tallinn (Estonia) the dissertation has two aims. Firstly, it draws attention to the role of materialities in urban research. It is argued that to govern means to govern in relation to materialities. Thus, the research develops the notion...

63. Revisiting the Turkevich Synthesis and Established New Routes to Colloidal Gold & Gold-Silver Nanoparticles - Uppal, MA
The use of gold and silver nanoparticles has experienced a renaissance over the last 10 years and their number of uses in a variety of commercial products has dramatically increased. The first chapter of this thesis addresses the current and future uses of gold and silver nanoparticles, the methods employed in synthesising them and the theory behind their fascinating surface plasmon resonance properties. For the remainder of this thesis we will revisit one of the most common methods for growing gold nanoparticles, the Turkevich method, and then experimentally modify this method as our basis for growing gold nanoparticles in various...

64. Scoping out of adjuncts: Evidence for the parallelism between QR and WH-movement - Tanaka, M
What gives rise to reversal of quantifier scope has been a long-standing question in the study of linguistics. In the framework of Generative Grammar, it has been standard since May (1977) to analyse scope-shift as a form of covert movement, Quantifier Raising (QR). Evidence for this analysis comes from the fact that QR is sensitive to the very same island constraints that restrict overt movement (e.g. wh-movement). However, the widely assumed parallelism between scope-shift and wh-movement, which the theory of QR rests on, has not been experimentally examined in any depth. This thesis reports an experimental study that examined the...

65. Understanding the Genetic Basis of Diabetes Mellitus and Sensorineural Deafness - Sherif, MMA
Diabetes mellitus (DM) is a common chronic disorder in children. Type1 DM is the most common form of DM and is due to the loss of insulin secretion by autoimmune destruction of pancreatic β-cells. Type2 DM is due to insulin resistance. Maturity Onset Diabetes of the Young is a heterogeneous group of monogenic disorders due to single gene defects. DM and sensorineural deafness (SND) are associated with rare syndromes such as Wolfram syndrome (WS), Rogers syndromes and Mitochondrial DM. WS is an autosomal recessive disorder characterised by diabetes insipidus, DM, optical atrophy and SND, caused by mutations in the WFS1...

66. Virus-host interactions in early HIV-1 infection - Rowley, JC
After entry into a target cell, HIV-1 must traverse the cytoplasm and enter the nucleus in order to integrate into host chromatin. Until recently, the viral CA core was thought to play a passive role in infection, simply delivering its contents to the cytoplasm soon after entry. However, CA has recently been found to interact with and/or determine interaction with several nuclear entry cofactors. In this study, we investigate the consequences of CA interacting with the host mRNA-processing factor CPSF6. We provide evidence that the interaction between CA and cytoplasmic CPSF6 during early infection dictates the downstream nuclear entry pathway...

67. Political ideology and housing supply: rethinking New Towns and the building of new communities in England - Rivera, H
Throughout the twentieth century, England experienced a chronic problem of housing supply that persists to this day. In an attempt to manage it, philanthropists, policymakers and politicians have directed planning policies and legislation to build new planned communities: Howard’s town/country magnet; New Labour’s sustainable communities; and, the recent Coalition government’s initiatives in delivering locally-led garden cities. Problematically, this results in planning being trapped between political ideology and problems of housing supply. To examine this tension, the New Towns programme provides an important example of how goal-driven planning policy was used during the period 1946-1976 to address housing supply. This research...

68. Involvement of short RNAs in polycomb-mediated gene repression - Araújo, CC
Polycomb group proteins maintain cell identity by repressing developmental regulator genes specific for other cell types. There are two main complexes: Polycomb repressive complex 1 (PRC1) and 2 (PRC2). PRC2 methylates histone H3 lysine 27 (H3K27me3), creating a binding site for PRC1 that ubiquitinates H2AK119. Polycomb target genes are associated with stalled RNA polymerase II (RNAPII), and the initiation marker H3K4me3, known as bivalent chromatin. Our laboratory has demonstrated that short RNAs are transcribed from the promoter region of these genes in human T-cells, while the work carried out as part of the present thesis demonstrates that short RNAs are...

69. Moral Equality and Rights: A Specificationist Account of Rights in Conflict - Smith, RH
This thesis explores the philosophical nature of the relationship between equality, individual rights, and human dignity, and seeks a normative framework for resolving seemingly incommensurable conflicts of fundamental rights. Part I explores theories of individual partiality, and the potential for consonance between contemporary egalitarian rights theory and a specificationist methodology for the resolution of incommensurable value conflicts. Chapters 2, 3, and 4 put forward an interpretation of human dignity based upon particular conceptions of individual moral equality and partiality; while chapter 5 moves on to explore the relationship between egalitarian rights theory and specification theory, with a view to providing...

70. Essays on Firm Performance and Multinationals - Szemeredi, K
The first chapter uses the entry of large corporations into U.S. counties during the 1980s and 1990s to analyse the effect these firms had on local firms’ innovation. We use a difference-in-differences identification strategy based on counties competing for the entry of a large multinational where we take losing bidders as a counterfactual for winning bidders. We find that inventors located in winning counties start citing the patents of these large corporations three times more than inventors located in losing counties. We also find a positive effect on patent production by winning counties, however this seems to be limited to...

71. T.S. Eliot and Renaissance Drama - Toda, K
The crucial importance of non-Shakespearian Renaissance dramatists to T.S. Eliot is evident in both his poetry and his prose. Eliot himself drew attention to this: he credited his own ‘poetic formation’ to the ‘minor Elizabethan dramatists’, and when reviewing his ‘critical output for the last thirty-odd years’ in 1951, he confessed himself ‘surprised to find how constantly I have returned to the drama, whether by examining the work of the contemporaries of Shakespeare, or by reflecting on the possibilities of the future.’ As C.S. Lewis disapprovingly wrote, Eliot’s ‘sympathy with depraved poets (Marlowe, Jonson, Webster) is apparent’. This thesis will...

72. Remote Sensing of Phytoplankton Characteristics in The Baltic Sea - Zhang, D
In this thesis, optical properties of phytoplankton assemblages are investigated to identify the relationship between Chlorophyll-a spectral signatures and the assemblage abundance. A new algorithm is developed to determine Chlorophyll-a concentrations from three types of waters, including eukaryote dominant waters, cyanobacteria dominant waters and waters that have a mixture of eukaryotes and cyanobacteria; with a flag being proposed for mapping of spatial distributions of surface scums. The result of the algorithm calibration indicates that 79% of the variance within the near concurrent in situ data is explained by the new algorithm, with the MAPE of 16.9%. The validation result shows...

73. Constructing concepts and word meanings: the role of context and memory traces - Urquiza Arribas, C
The main aim of this thesis is to develop a new account of concepts and word meaning which provides a fully adequate basis for inferential accounts of linguistic communication, while both respecting philosophical insights into the nature of concepts and cohering with empirical findings in psychology on memory processes. In accord with the ‘action’ tradition in linguistic theorising, I maintain that utterance/speaker meaning is more basic than sentence meaning and that the approach to word meaning that naturally follows from this is ‘contextualism’. Contextualism challenges two assumptions of the traditional ‘minimalist’ approach to semantics: (i) that semantics (rather than pragmatics)...

74. The CBF3 complex structure and function during point centromere establishment - Perriches, TRA
This thesis investigates the structure and function of the kinetochore centromere binding factor 3 (CBF3) complex. The kinetochore is a multi-protein complex, which controls the chromosome attachment to the mitotic or meiotic spindle and nucleates on the centromere. The latter is a specific chromosomal loci divided in two groups highly divergent in length and composition: regional and point centromeres. Regional centromeres are composed of long arrays of repetitive DNA supporting multiple microtubule nucleations. On the contrary, point centromeres are characterised by a short and conserved sequence supporting a single microtubule attachment. Despite this discrepancy, both point and regional centromere establishment...

75. In vivo quantification of metabolic activity in aortic aneurysms using PET - Kotze, CW
Objective: To investigate the role of hybrid 18F-FDG PET/CT as a potential risk-stratification tool of aneurysm expansion by measuring metabolic activity on PET and textural analysis on CT in abdominal aortic aneurysm (AAA). Histological markers of AAA wall inflammatory cell infiltrate and enzymatic degradation have been associated with increased 18F-Fluorodeoxyglucose (18F-FDG)-Positron Emission Tomography /Computed Tomography (PET/CT) uptake. Methods: Fifty patients with asymptomatic infrarenal AAA enrolled under surveillance at one of our institutions underwent 18F-FDG-PET/CT. Seventeen subjects were investigated for increased glucolysis in the AAA wall and optimal circulation imaging time for 18F-FDG. In 25 subjects the relationship between aneurysm metabolic...

76. Phosphorylation of Rab7 at serine 72 and its role in the regulation of the late endocytic pathway - Wallace, M
The small GTPase Rab7 is a key component of the endocytic pathway that controls endosomal maturation and fusion of late endosomes with lysosomes. Rab7 also regulates growth factor signaling by modulating receptor levels at the plasma membrane. While it is known how Rab7 is regulated through the GTPase cycle and interaction with its GEF and GAP, little is known about its regulation by post-translational modifications. In this study, I identified two kinases, TBK1 and IKKε, which phosphorylate Rab7 at S72 in in vitro kinase assays. Both kinases are highly homologous and are activated in the innate immune response to bacterial...

77. Drivers, associations and consequences of the diel variability in high-resolution lake surface water temperature measurements - Woolway, RI
The primary objective of this dissertation is to examine the drivers, consequences and associations of the diel variability in high-resolution lake surface water temperature. This dissertation consists of the high temporal resolution monitoring of up to 100 lakes, the creation of a predictive method to estimate the diel temperature range, and the development of an open source numerical program called Lake Heat Flux Analyzer, designed to calculate accurately the surface energy fluxes in lakes and reservoirs. A method for estimating the onset of thermal stratification from surface temperature measurements is also provided, where the association between the diel temperature range...

78. Graphene-Diamond Heterostructures - Zhao, F
Graphene obtained by mechanical exfoliation of graphite displays unique electronic properties with high mobility and saturation velocity. However, this is not a scalable technique, the film being limited to small area. Large area synthesis of good quality graphene has been achieved by CVD. The choice of substrate apparently influences the electronic properties of graphene. Most of reports have used SiO2-Si due to the widespread availability, but it is a poor choice of the material to degrade the graphene performace. In this thesis, more ideal platforms are introduced, including single crystal diamond (SCD), nanodiamond (ND), and diamond-like-carbon (DLC). It was found...

79. Accent intelligibility across native and non-native accent pairings:investigating links with electrophysiological measures of word recognition - Stringer, LM
The intelligibility of accented speech in noise depends on the interaction of the accents of the talker and the listener. However, it is not yet clear how this influence arises. Accent familiarity is commonly proposed to be a major contributor to accent intelligibility, but recent evidence suggests that the similarity between talker and listener accents may also be able to account for accent intelligibility across talker-listener pairings. In addition, differences in accent intelligibility are also often only found in the presence of other adverse conditions, so it is not clear if the talker-listener pairing also influences speech processing in quiet...

80. Investigation of Shadow Matching for GNSS Positioning in Urban Canyons - Wang, L
All travel behavior of people in urban areas relies on knowing their position. Obtaining position has become increasingly easier thanks to the vast popularity of ‘smart’ mobile devices. The main and most accurate positioning technique used in these devices is global navigation satellite systems (GNSS). However, the poor performance of GNSS user equipment in urban canyons is a well-known problem and it is particularly inaccurate in the cross-street direction. The accuracy in this direction greatly affects many applications, including vehicle lane identification and high-accuracy pedestrian navigation. Shadow matching is a new technique that helps solve this problem by integrating GNSS...

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