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UCL University College London Eprints (354,258 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 1 - 20 de 353,870

1. Equilibrium Shapes with Stress Localisation for Inextensible Elastic Mobius and Other Strips - Starostin, EL; van der Heijden, GHM
We formulate the problem of finding equilibrium shapes of a thin inextensible elastic strip, developing further our previous work on the Möbius strip. By using the isometric nature of the deformation we reduce the variational problem to a second-order one-dimensional problem posed on the centreline of the strip. We derive Euler–Lagrange equations for this problem in Euler–Poincaré form and formulate boundary-value problems for closed symmetric one- and two-sided strips. Numerical solutions for the Möbius strip show a singular point of stress localisation on the edge of the strip, a generic response of inextensible elastic sheets under torsional strain. By cutting...

2. The suburban question: grassroots politics and place making in Spanish suburbs - Phelps, NA; Vento, AT; Roitman, S
Manuel Castells spoke of the urban as a unit of collective consumption, yet much of the politics of collective consumption he documented was evident in the suburbs. The tendency for suburbs of most complexions to lack services and amenities has been and continues to be a focus of politics in Europe. In Spain, as elsewhere in Europe, a grassroots politics surrounding the making good of these deficits in basic services and amenities has broadened and formalised somewhat to become part of a competitive local representative politics concerned with shaping a sense of place. Here we consider this legacy of grassroots...

3. Dynamic Effect of Young’s Modulus on Attachment and Differentiation of Mouse Embryonic Stem Cells - Ali, S
Embryonic stem cells have generated much interest due to their ability to differentiate into any cell type within the body. This ability could potentially allow for scientists and engineers to develop a number of therapies for diseases, which currently have no cure such as Parkinson’s disease, Alzheimer’s disease and diabetes. However, the differentiation process itself is one of the major bottlenecks in developing potential therapies. Currently protocols involve the use of mixtures of growth factors in order to create a suitable soluble microenvironment for differentiation. These growth factors are often expensive, thereby limiting the potential for scale-up of cell bioprocesses....

4. Non-signalling energy use in the brain. - Engl, E; Attwell, D
Energy use limits the information processing power of the brain. However, apart from the ATP used to power electrical signalling, a significant fraction of the brain's energy consumption is not directly related to information processing. The brain spends just under half of its energy on non-signalling processes, but it remains poorly understood which tasks are so energetically costly for the brain. We review existing experimental data on subcellular processes that may contribute to this non-signalling energy use, and provide modelling estimates, to try to assess the magnitude of their ATP consumption and consider how their changes in pathology may compromise...

5. Speech production and perception in adult Arabic learners of English: A comparative study of the role of production and perception training in the acquisition of British English vowels - Alshangiti, WMM
This thesis presents the results of four studies that investigated the perception and production of English by Saudi Arabic learners. Additionally, the thesis sought to investigate the role of different types of training, production- or perception-based, in learning, with the aim of understanding how training in different domains contributes to second language acquisition. A preliminary study (Study 1) investigated problematic phonemic contrasts for Arabic speakers, confirming that accuracy in perception and production depends on the similarity between L1 and L2 phonemes. Study 2 investigated the specificity of second language phonetic training by comparing the effect of three training programmes on...

6. The effects of inflammation on the regeneration and degeneration of axons in the CNS - Acosta-Saltos, FC
Microglia have neurotoxic and neuroprotective effects. The aim of the current project was to investigate the effects of perineuronal microglial activation on axonal regeneration in adult rats and the effects of prolonged neuroinflammation on foetal mouse brain. In contrast to the PNS, the CNS only displays limited axonal regeneration after injury and little perineuronal inflammation. Inflammation around the cell bodies of axotomised neurons has been demonstrated to promote CNS regeneration. Polyinosinic:polycytidylic acid (Poly I:C) is an inflammatory agent. Following delivery of Poly I:C into the motor cortex and a concomitant C4 dorsal corticospinal tract (CST) injury, rats exhibited more CST...

7. Quality of life among people with epilepsy in Saudi Arabia, and their beliefs about the causes and treatment of epilepsy - Alkhamees, HAA
Aims: The current survey investigated the religious and cultural beliefs about the causes and treatment of epilepsy for people with epilepsy (PWEs) in Saudi Arabia, and also various aspects of their quality of life (QoL). Participants: A total of 360 participants – 110 people with epilepsy (PWEs), 114 people with multiple sclerosis (PWMSs) and 136 healthy controls (HCs) – were recruited from the Prince Sultan Military Medical City in Riyadh, Saudi Arabia. Methods: The study proceeded with: (1) a focus group for instrument development; (2) a pilot study for validation and assessment of logistic and statistical aspects; and (3) the main survey....

8. Lentiviral vectors for gene therapy of Gaucher disease - Aitchison, KL
Gaucher disease (GD), a recessive disorder characterised by hepatosplenomegaly, pancytopenia and skeletal complications, is caused by deficiency of the enzyme glucocerebrosidase (GC). GD leads to the accumulation of glucocerebrosides within macrophages, particularly in the liver and spleen. Current treatment is limited to enzyme replacement therapy (ERT) which is effective for most symptoms however skeletal problems are slow to respond. Treatment also has significant cost and impact on quality of life as infusions must be administered every two weeks. GD is a candidate for gene therapy as bone marrow transplantation has been shown to be curative which serves as a proof-of-concept...

9. Implicit attitudes towards food and the self in sub-clinical eating disorder pathology - Anokhina, A
This thesis focuses on the assessment of implicit cognition in disordered eating behaviour, and specifically on the role of implicit attitudes towards the self and food in sub-clinical levels of eating disorder (ED) pathology. Chapter I reviews key theoretical approaches to implicit cognition and an assessment of the properties of implicit attitudes. Chapter II discusses methodological approaches to implicit attitude assessment, with a focus on the Implicit Attitude Test (IAT) which was used in the empirical studies. Chapter III (Study 1) outlines research in implicit cognition in ED pathology and assesses differences in implicit self-esteem (i.e., implicit attitude towards the...

10. Motor learning during reaching movements: model acquisition and recalibration - Telgen, SJ
This thesis marks a departure from the traditional task-based distinction between sensorimotor adaptation and skill learning by focusing on the mechanisms that underlie adaptation and skill learning. I argue that adaptation is a recalibration of an existing control policy, whereas skill learning is the acquisition and subsequent automatization of a new control policy. A behavioral criterion to distinguish the two mechanisms is offered. The first empirical chapter contrasts learning in visuomotor rotations of 40° with learning left-right reversals during reaching movements. During left-right reversals, speed-accuracy trade-offs increased and offline gains emerged, whereas during visual rotations, speed-accuracy trade-offs remained constant and...

11. Application of Optical Fibre Raman Spectroscopy for Characterising Carbonation and Chloride Attack of Cementitious Materials - Yue, Y
Carbonation and chloride attack are the main causes of the corrosion of rebars in concrete. In the past, attempts have been made to develop various sensors to monitor these deterioration mechanisms. However, amongst the most popular sensors, the Electrical Resistance Sensor cannot differentiate each individual deterioration mechanism, whilst the long term stability and the need for recalibration are the two main limitations of the Fibre Optical Sensor. The optical fibre Raman system, combining the fingerprint characterisation capacity of Raman spectroscopy and the light transmission capacity of optical fibres, offers the potential for monitoring the deterioration mechanisms in concrete. This thesis...

12. Interaction in architectural review meetings: seeking models of collective concept creation - Pinheiro Cavalcante Maciel Jnr, A
This research examines in detail the concept stage of architectural design, giving emphasis on the strategic behaviour in collaborative concept design activity, exploring how this can inform digital tools and workflows in the architectural digital prototyping process. To attain this, this research has been developed in four complementary stages: a survey investigating some aspects of common knowledge in design practice, an ethnography of design review meetings; experiments measuring specific aspects found in this ethnography; and finally an investigation of the findings as game theoretical model, proposing variations of strategic behaviour within this workflow. To start with, the survey was conducted...

13. Development of Novel Metabolically Stable Analogues of PAR-1 Antagonist RWJ-58259 - Robinson, E
This thesis describes the investigation into the development of novel antagonists of the major thrombin receptor, protease-activated receptor-1, in the aim of generating analogues of the project lead compound with improved metabolic stability. Chapter 1 provides an introduction to the research project and the biological rationale for targeting protease-activated receptor-1 for inhibition. Chapter 2 describes modifications made to the synthetic route to produce RWJ-58259, the project lead, and subsequent biological evaluation carried out in order to confirm the compound’s identity and verify batch quality. Chapter 3 describes the investigation into the metabolic profile of RWJ 58259 to identify major sites...

14. Biomarker Development in Endometrial Cancer: Circulating Tumour Cells, Tissue Methylation and Genotyping Studies - Lemech, CR
Endometrial cancer (EC) is the most common gynaecological malignancy in the developed world and 4th most common women’s cancer in the UK. Although approximately 75% of women present with surgically resectable disease, 20% of these will relapse and 25% of initial diagnoses occur with metastatic disease. There are currently no validated biomarkers to assess treatment response or target molecular therapies, despite evidence for targetable aberrations in the literature. The PI3K pathway in particular is commonly mutated in EC and stathmin is a recently identified phosphoprotein associated with PI3K pathway activation and with prognostic significance in EC. I investigated biomarker development...

15. Implementation, evaluation and application of multiple imputation for missing data in longitudinal electronic health record research - Welch, CA
Longitudinal electronic health records are a valuable resource for research because they contain information on many patients over long follow-up periods. Missing data commonly occur in these data because it was collected for clinical and not research purposes. Analysing data with missing values can potentially bias estimates and standard errors resulting in invalid inferences. Multiple imputation, commonly used in research to impute missing values, is increasingly regarded as the standard method for handling missing data in medical research because of its practicality and flexibility under the assumption the data is missing at random (MAR). Until now, few imputation approaches are...

16. 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...

17. 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...

18. 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...

19. 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...

20. 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...

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