6,640 Works

Mechanisms Underlying Immunomodulation of HIV-1-Specific T-cell Responses

Anna Aracely Herasimtschuk
Highly active antiretroviral therapy (HAART) improves morbidity and mortality in HIV-1-infected patients yet reversal of immune dysfunction remains incomplete. The study objective was to determine the impact of immunomodulatory agents on T-cell function and phenotype in treated, chronic HIV-1 infection. Recombinant human growth hormone (rhGH) was administered daily to patients at a pharmacological dose for 12 weeks. Proliferative CD4 and IFN-γ-producing CD8 HIV- 1-specific T-cell responses were induced, however these responses declined with less frequent...

Improving End-to-End Internet Performance by Detouring

Sing Wang Ho
The Internet provides a best-effort service, which gives a robust fault-tolerant network. However, the performance of the paths found in regular Internet routing is suboptimal. As a result, applications rarely achieve all the benefits that the Internet can provide. The problem is made more difficult because the Internet is formed of competing ISPs which have little incentives to reveal information about the performance of Internet paths. As a result, the Internet is sometimes referred as...

Data Integration for Regulatory Module Discovery

Alok Mishra
Genomic data relating to the functioning of individual genes and their products are rapidly being produced using many different and diverse experimental techniques. Each piece of data provides information on a specific aspect of the cell regulation process. Integration of these diverse types of data is essential in order to identify biologically relevant regulatory modules. In this thesis, we address this challenge by analyzing the nature of these datasets and propose new techniques of data...

The mechanical behaviour of nano-particle modified thermoplastics

Koucheng Zuo
Hybrids made up of polymers and nano-particles have received great interest both in academia and industry. The uniformly dispersed nano-sized particles create a large interfacial area per unit volume and could result in a remarkable improvement in thermal and mechanical properties when compared with virgin polymer or conventional micron-sized particle modified composites. This thesis presents and discusses the effects of adding rigid nano-sized ZnO particles into four thermoplastic systems at 23 °C and 80 °C....

Multiscale Wavelet and Upscaling-Downscaling for Reservoir Simulation

Masoud Babaei
The unfortunate case of hydrocarbon reservoirs being often too large and filled with uncertain details in a large range of scales has been the main reason for developments of upscaling methods to overcome computational expenses. In this field lots of approaches have been suggested, amongst which the wavelets application has come to our attention. The wavelets have a mathematically multiscalar nature which is a desirable property for the reservoir upscaling purposes. While such a property...

Investigating energy homeostasis using in vivo imaging techniques

Mohammed Khair Hankir
Obesity is a major growing cause of death with no effective long-term treatment apart from surgical procedures such as Roux-en-Y gastric bypass (RYGB). The sustained weight loss following surgery is thought to be due in part to the increased levels of circulating anorexigenic gut hormones such as peptide YY3-36 (PYY3-36). Peripheral administration of PYY3-36 suppresses appetite in rodents and man and represents a potential therapy for obesity however its effects on feeding are transient. Here...

Synthetic, structural and electrochemical studies of superstructured rare-earth niobates

Ryan David Bayliss
Materials with inherent oxygen excess are of great interest for high-temperature electrochemical applications, such as solid oxide fuel cells (SOFCs) and oxygen permeation membranes due to their rapid ion conductivity. Cerium niobate has received a lot of attention recently due to its rapid oxide ion conductivity in the intermediate temperature range (500-650 °C). Cerium niobate has several interesting characteristics, such as the range of excess oxygen structures that stabilise in the monoclinic crystal system and...

Investigating Acute Gastrointestinal Inflammation Associated with Feeding a Fat-Enriched Diet in Zebrafish Larvae

Navjyot Singh Sangha
Diseases of the metabolic syndrome such as obesity, type II diabetes and atherosclerosis are caused by an excess accumulation of dietary lipid and are currently a major burden on healthcare. The NLRP3 inflammasome is a molecular platform that leads to activation of caspase-1 and has received considerable attention recently regarding its role in promoting the inflammation associated with these diseases. The chronic inflammation associated with these states is well understood but the acute inflammation has...

Information and Dynamics in Urban Traffic Networks

Giovanni Petri
The study of complex systems has intensified in recent years. Researchers from many different disciplines have realised that the study of systems possessing a large number of degrees of freedom interacting in a non-linear way can offer insights into problems in engineering, biology, economics and many other fields besides. Among the themes in complexity, we focus here the issues of congestion and congestion emergence in the context of urban networks, with particular reference to the...

Resolving spin physics in self-assembled InAs/GaAs quantum dots

Matthew William Taylor
Semiconductor nanostructures and, in particular, quantum dots (QDs) have been at the forefront of solid-state research for several decades and represent attractive candidates for applications in quantum information and spintronics. QDs are characterised by their quasi-three-dimensional quantum confinement of electrons and holes which results in an ‘artificial-atom’ like structure with discrete but accessible energy levels. In addition, the spin of carriers in QDs are relatively isolated from typical spin relaxation mechanisms. This thesis investigates the...

Behaviour Profiling using Wearable Sensors for Pervasive Healthcare

Syed Muhammad Raza Ali
In recent years, sensor technology has advanced in terms of hardware sophistication and miniaturisation. This has led to the incorporation of unobtrusive, low-power sensors into networks centred on human participants, called Body Sensor Networks. Amongst the most important applications of these networks is their use in healthcare and healthy living. The technology has the possibility of decreasing burden on the healthcare systems by providing care at home, enabling early detection of symptoms, monitoring recovery remotely,...

Environmental Quality Management for Soil Protection: The Role of Citizen Science in the Process

James Bone
Soil is a vital and non-renewable resource, which performs many important functions. Soil quality management is faced with a number of challenges including overcoming objections to policies for soil protection, and the resource requirements implementation will entail. Further to this, soil is often neglected, as it is not high on the public or regulatory agenda. This work has focused on collecting large and cost effective data sets and raising awareness of soil, through the use...

Chiral theory of DNA supercoiling

Ruggero Cortini
DNA supercoiling is a fundamental biological process occurring in all cells. We developed a theory of braiding (supercoiling) of a pair of DNA molecules that takes into account the contribution of the bending and the electrostatic energy. The electrostatic interaction was calculated within the framework of the Kornyshev-Leikin theory of DNA interactions, which takes into account realistic helical patterns of charge. Because of the chirality of the charge patterns, we predict that left-handed braiding of...

Lock Inference for Java

Khilan Gudka
Atomicity is an important property for concurrent software, as it provides a stronger guarantee against errors caused by unanticipated thread interactions than race-freedom does. However, concurrency control in general is tricky to get right because current techniques are too low-level and error-prone. With the introduction of multicore processors, the problems are compounded. Consequently, a new software abstraction is gaining popularity to take care of concurrency control and the enforcing of atomicity properties, called atomic sections....

Reconfigurable Architectures for Cryptographic Systems

Adrien Le Masle
Field Programmable Gate Arrays (FPGAs) are suitable platforms for implementing cryptographic algorithms in hardware due to their flexibility, good performance and low power consumption. Computer security is becoming increasingly important and security requirements such as key sizes are quickly evolving. This creates the need for customisable hardware designs for cryptographic operations capable of covering a large design space. In this thesis we explore the four design dimensions relevant to cryptography - speed, area, power consumption...

Medium-Term Planning in Deregulated Energy Markets with Decision Rules

Paula Cristina Martins Da Silva Rocha
The ongoing deregulation of energy markets has greatly impacted the power industry. In this new environment, firms shift their focus from cost-efficient energy supply to more profit-oriented goals, trading energy at the price set by the market. Consequently, traditional management approaches based on cost minimisation disregarding market uncertainties and financial risk are no longer applicable. In this thesis, we investigate medium-term planning problems in deregulated energy markets. These problems typically involve taking decisions over many...

Exploring inhibition of the bacterial enhancer binding protein PspF and transcription factor sigma 54 using peptide-based chemical genetic approaches

Lucy Jane Rayner
AAA+ proteins (ATPases Associated with various cellular Activities) are a sub-family of P-loop NTPases which convert chemical energy into physical motion to carry out a multitude of functions. The AAA+ protein phage shock protein F (PspF) is a bacterial enhancer binding protein (bEBP) for the major variant transcription factor sigma 54 (σ54) in E. coli. PspF binds to and remodels the promoter DNA bound σ54-RNA polymerase holoenzyme (Eσ54), inducing isomerisation from a transcriptionally silent closed...

High efficiency recuperated ceramic gas turbine engines for small unmanned air vehicle propulsion

Michael J. Vick
To perform long missions, small unmanned air vehicles (UAVs) need efficient, lightweight propulsion systems that can operate on energy dense fuels. Gas turbines offer better reliability, life, fuel flexibility, noise, and vibration than internal combustion (IC) engines, but they are uncompetitive due to fuel efficiencies around 6%. At this scale, conventional efficiency improvement approaches such as high pressure ratios and cooled metal turbines are impractical. Ceramic turbines could withstand high temperatures without cooling, but their...

Wenchuan Earthquake Deformation 3D Modelling based on ALOS/PALSAR Data

Meng-Che Wu
A devastating earthquake of magnitude Mw 7.9 occurred in Wenchuan area of Sichuan Province, China on 12th May 2008 and caused great casualties and economic damage. This study is aiming to investigate the faulting geometry and motion of the major seismic faults in Longmenshan fault thrust belt that caused this earthquake, based on the surface rupture displacement data measured using differential interferometric synthetic aperture radar (DInSAR) and SAR amplitude pixel-offset techniques. The cross-event Japanese ALOS...

Locating binding sites of the general anaesthetic propofol using photoaffinity labelling

Gracce Mei Shan Yip
3-(5’-isopropyl-6’-hydroxyphenyl)-3-trifluoromethyl-diazirine (photofol), a new drug developed in our laboratory, is structurally homologus to the general anaesthetic propofol with one of its isopropyl groups being substituted for a trifluoromethyl-diazirine group. Photofol was shown to act in a similar manner to propofol, albeit with a three-fold reduction in potency on inducing a loss of righting reflex in rats and with reduced modulation of GABA-evoked currents on α1 β2 γ2s GABAA receptors for the concentration tested. The soluble...

Sensitivities to Component Characterizations of Heavy Oil Viscosity in Numerical Reservoir Simulation of Steam-Injection Processes

Jacoba De La Porte
This work examines heavy oil viscosity modelling during simulation of steam injection processes, such as steam-line-drive and SAGD, and the sensitivity of oil recovery predictions to the uncertainty in the oil viscosity. Analytical models to predict the sensitivity have been developed, confirmed by numerical simulation. Heavy oil compositional component viscosities are modelled with the Free Volume model. The model is extended in this thesis to estimate the viscosities of long-chain n-alkanes from C6H14 to C45H92...

Measurements of CO2 trapping in carbonate and sandstone rocks

Rehab Motasiem Nasr Ali El-Maghraby
CO2 storage in saline aquifers (sandstone/carbonate types) has been proposed as a promising solution to help reduce CO2 emissions to the atmosphere. CO2 will likely be stored as a dense, supercritical (sc.) phase. There are different mechanisms by which CO2 could be stored safely underground; structural and stratigraphic trapping, dissolution trapping, capillary trapping, and mineral trapping. I study capillary trapping. We assume that in the middle of a CO2 plume, many kilometres in extent, the...

Characterisation of bone marrow progenitor cells in disease

Kate Hayley Christine Gowers
The bone marrow serves as a reservoir for leukocytes and stem cells, from where cells can be mobilised into the circulation and can be recruited to sites of inflammation. Mobilisation of cells out of the bone marrow is dependent on their migration across the bone marrow sinusoidal endothelium, which is thought to be structurally and functionally different to endothelial cells from other vascular beds. In order to characterise the bone marrow endothelium and to study...

Mechanisms of NOD1-induced inflammation in vascular tissue

Timothy Gatheral
Blood vessels play a vital role in human disease including pathogen driven conditions such as septic shock and acute lung injury. In the innate immune system, host pattern recognition receptors (PRRs) recognise preserved pathogen associated molecular patterns (PAMPs) leading to cell activation. Previous work has shown that blood vessels respond to Gram negative bacteria via the PRRs Toll like receptor 4 (TLR4) and nucleotide oligomerisation domain 1 (NOD1). Indeed stimulation with a specific NOD1 agonist...

Microbial and Metabolic Interactions in the Zucker Rat

Hannah Lees
The metabolic syndrome is known to have a direct and indirect impact on endogenous metabolism. Additionally, there is emerging evidence of an obesity-­‐associated microbiome with the potential to influence caloric extraction from the diet and host energy metabolism. However, the nature of the shift in relative contributions of bacterial phyla in obesity, and the question of whether the observed shift in microbiome is more associated with a high-­‐fat diet than genetically induced obesity per se,...

Registration Year

  • 2019

Resource Types

  • Text


  • Imperial College London