Thursday, January 29, 2015

 

 



Soy un nuevo usuario

Olvidé mi contraseña

Entrada usuarios

Lógica Matemáticas Astronomía y Astrofísica Física Química Ciencias de la Vida
Ciencias de la Tierra y Espacio Ciencias Agrarias Ciencias Médicas Ciencias Tecnológicas Antropología Demografía
Ciencias Económicas Geografía Historia Ciencias Jurídicas y Derecho Lingüística Pedagogía
Ciencia Política Psicología Artes y Letras Sociología Ética Filosofía
 

rss_1.0 Recursos de colección

UCL University College London Eprints (347,674 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 161 - 180 de 347,364

161. Origins of multicellular evolvability in snowflake yeast - Greig, D; Fankhauser, JD; Rogers, DW; Ratcliff, WC; Travisano, M
Complex life has arisen through a series of ‘major transitions’ in which collectives of formerly autonomous individuals evolve into a single, integrated organism. A key step in this process is the origin of higher-level evolvability, but little is known about how higher-level entities originate and gain the capacity to evolve as an individual. Here we report a single mutation that not only creates a new level of biological organization, but also potentiates higher-level evolvability. Disrupting the transcription factor ACE2 in Saccharomyces cerevisiae prevents mother-daughter cell separation, generating multicellular ‘snowflake’ yeast. Snowflake yeast develop through deterministic rules which produce geometrically-defined clusters...

162. Novel CMOS Integrated Current Driver Circuits for Bioimpedance Measurements - Constantinou, L
Bioimpedance spectroscopy is a study of the variation of tissue’s electrical properties, both conductive and dielectric, through a frequency spectrum (100Hz to 1MHz). It involves the application of AC signals to the surface of the tissue via electrode pairs, which can either be a current signal or a voltage signal, and the resulting surface signals are recorded via a separate or the same pair. The recorded signals are converted to impedance measurements via a demodulation procedure. The study of tissue’s electrical properties can provide with useful information regarding both its physiology and pathology. The main aim of the work described...

163. Examining the extent to which hotspot analysis can support spatial predictions of crime - Chainey, S
The premise that where crime has occurred previously, informs where crime is likely to occur in the future has long been used for geographically targeting police and public safety services. Hotspot analysis is the most applied technique that is based on this premise – using crime data to identify areas of crime concentration, and in turn predict where crime is likely to occur. However, the extent to which hotspot analysis can accurately predict spatial patterns of crime has not been comprehensively examined. The current research involves an examination of hotspot analysis techniques, measuring the extent to which these techniques accurately...

164. Insights from an individual-level model of HIV programmes in southern Africa: HIV testing, ART and resistance - Cambiano, V
Antiretroviral therapy (ART) has transformed HIV infection from a death sentence into a chronic condition. In sub-Saharan Africa, the area most affected by this disease, availability of ART has increased dramatically over the last few years. Nevertheless, many people are still not receiving ART either because they are not aware of being HIV-positive or because they struggle to access ART or to engage in HIV care. It is fundamental to take decisions which maximise the health benefits with the limited resources available. When I was writing this thesis, there were countless discussions regarding whether the recommendation on when to start...

165. Quality end of life care for people with dementia: The views and experiences of family carers - Davies, N
Background Many have reported the difficulty of defining ‘quality’ with several concepts emerging to characterise quality end of life care. People with dementia have been described as the ‘disadvantaged dying’ with poor end of life care. Towards the end of life people with dementia cannot report on the care they receive. It is therefore important to talk to carers; however, few have explored the views about end of life care from the carers’ perspective. Aim To explore the features of ‘good’ and ‘bad’ quality end of life care for people with dementia from the perspective of family carers. Method 1)...

166. The roles and regulation of the Drosophila Lgl tumour suppressor in cell division - Bell, GP
Cell polarity is a fundamental feature of most cells, and is required for a diverse range of cell functions. A conserved set of proteins is involved in the establishment and maintenance of cell polarity. Several of these polarity proteins in Drosophila are recognized as neoplastic tumour suppressors, and loss of cell polarity in general has been linked to cancer malignancy. Although much is known about the general role of the polarity proteins, many questions still remain about the details and extent of their functions. I have focused on the Lgl protein in Drosophila epithelia: a basolaterally-localized tumour suppressor. In mitosis,...

167. Anglo-Italian Radical Literary Culture, 1815–1824 - Bowers, WJ
The thesis has two objectives. The first is to examine the Italian aspects of Second Generation Romantic verse. Through close readings of works by Byron, Shelley, and Hunt the thesis shows the importance of Italy and its traditions to these poets. The second objective is to reveal the ambassadorial role of Italians in London for their literature and homeland. Exiles such as Augustus Bozzi and Ugo Foscolo used a growing cosmopolitan press to educate Britons about Italy. I pay particular attention to the public reception of these writers and their works, across a range of forms such as pamphlets, songs,...

168. Use of gaze and gait analysis to assess the effect of footway environmental factors on older pedestrians' accessibility - Cheng, T
Walking in the footway environment is an essential activity of daily living and the physical activity associated can also improve an individual’s quality of life. The possibility and ability for the individual to reach opportunities and participate in activities on foot indicate the accessibility of the footway environment. One of the major hazards in the footway environment that impedes the accessibility is falling. While it may happen to anyone, falling is more common in older people and the consequence of falling could seriously deteriorate their quality of life. Falls among older people is one of the major public health problems....

169. Furthering our understanding of heterogeneous ice nucleation with molecular simulation - Cox, SJ
Ice formation is arguably the most common phase transition on the planet and almost always occurs heterogeneously. Despite the importance of ice formation to the climate, medical and geological sciences, as well as the food and transport industries, a clear understanding of how the properties of a material affect its ability to nucleate ice has remained elusive. This has prevented the rational design of new materials to either inhibit or promote ice nucleation. In this thesis, a wide variety of computational techniques are used to try and further our understanding of heterogeneous ice nucleation. This includes: testing long established theories;...

170. Using a Functional Tagged Calcium Channel to Investigate Trafficking - Cassidy, JS
3 Abstract N - type calcium channels belong to the family of voltage gated calcium channels , which open in response to membrane depolarisation. These channels are responsible for the calcium influx that triggers neurotransmitter release at presynaptic terminals. N - type channels are particularly important in mediating neurotransmitter release at the presynaptic terminals of peripheral sensory neurons and have been implicated i n neuropathic pain. Understanding the regulation of N - type channels is critical to the development of treatments that target these channels. Until now it has been difficult to directly investigate the regulation of their expression at...

171. Exploring the potential for recombinant protein production in microalgae - Braun Galleani, SC
Microalgae are considered as attractive platforms for the synthesis of high-value heterologous proteins due to their many beneficial attributes including ease of cultivation, lack of pathogenic agents, and low-cost downstream processing. However, recombinant protein levels are low compared to microbial platforms and commercial production is not a reality yet. Promising research using the model microalga Chlamydomonas reinhardtii has highlighted this potential, particularly for transgene expression in the chloroplast. The objective of this research was to study different strategies for expression in the C. reinhardtii chloroplast aimed at increasing growth rate and recombinant protein production, by means of cell engineering and...

172. Identification and Characterization of Cancer promoting genes in Breast Stromal fibroblasts - Alrakan, MAA
It is well known now that changes in the cellular microenvironment contribute to tumour genesis through paracrine effects. Fibroblasts, the predominant cells of the stromal breast carcinomas, play an important role in the development and spread of cancer cells. However, the nature, molecular mediators and pathways of the crosstalk between cancer cells and their stromal fibroblasts are still not well defined. There is evidence that normal breast stromal fibroblasts (NBFs) suppress tumor growth while cancer-associated fibroblasts (CAFs) promote tumorogenesis through functional interactions with cancer cells. Little is known about the biology and the carcinogenic potential of stromal fibroblasts present in...

173. Applied synthesis and characterisation of nanoparticles - Bear, JC
This thesis covers three areas of development of nanomaterials synthesis; namely the synthesis of superhydrophobic polymer-nanoparticle composites (chapter 3), the synthesis of doped quantum dots for catalysis and photoluminescence enhancement (chapter 4) and the synthesis of magnetic iron oxide nanoparticles from inexpensive, readily available reagents (chapter 5). Details of characterisation and analytical techniques and synthetic methods used are given in chapter 2, and the thesis summarised in chapter 6. Superhydrophobic polymer-nanoparticle composites represent a class of material which combine the superhydrophobicity of the polymer with the functionality of incorporated nanoparticles. Reactive oxygen species generated by photocatalytic nanoparticles degrade organic matter,...

174. The fission yeast non-coding transcriptome - Atkinson, SR
Long non-coding RNAs (lncRNAs) are emerging as important regulators of gene expression, although it remains unclear to what extent they contribute overall to the information flow from genotype to phenotype. Using strand-specific RNAsequencing, I identify thousands of novel unstable, or cryptic, lncRNAs in Schizosaccharomyces pombe. The nuclear exosome, the RNAi pathway and the cytoplasmic exonuclease Exo2 represent three key pathways regulating lncRNAs in S. pombe, defining the overlapping classes of CUTs, RUTs and XUTs, respectively. The nuclear exosome and the RNAi pathway act cooperatively to control nuclear lncRNA expression, while the cytoplasmic Exo2 pathway is more distinct. Impairing both the...

175. $rec.titulo - Uzoh, OG

176. The Immunomodulatory Effects of Vitamin D on Mononuclear Phagocytes - Evans, R
Expression of the vitamin D receptor on mononuclear phagocytes renders them susceptible to modulation by 1,25(OH)2D3, which is metabolised from its precursor 25(OH)D3 by the enzyme CYP27B1. Modulation of dendritic cells (DC) with 1,25(OH)2D3 has been shown in vitro to suppress their ability to prime proinflammatory T cells responses, suggesting extra renal synthesis of 1,25(OH)2D3 from the precursor 25(OH)D3 may promote tolerance in vivo. I sought to gain a greater mechanistic understanding of these phenomena at molecular, cellular and intercellular levels in the human system. I found that 1,25(OH)2D3 stimulation of DC results in a selective preservation of NFκB-mediated transcriptional...

177. Dopamine and oculomotor impulsivity in health and disease. - Adam, RJ
The role of subcortical pathology in altered cognition is increasingly recognised. However, measurement and monitoring of impairments in motivation and behaviour due to subcortical disease is challenging. Basal ganglia – cortico-thalamo-cortical loops and the neurotransmitter, dopamine, are recognised to be important in modulating both reward learning and oculomotor performance. This thesis considers the use of novel and adapted oculomotor (saccadic) tasks as a means of interrogating these dynamic circuits as measures of rewarded decision-making under risk and time pressure. I first describe a novel rewarded oculomotor task, the Traffic Light Task, which provokes two distributions of saccades – one anticipatory,...

178. Impact of basin tectonics and climate change on the timing of sediment flux to the Ainsa Basin, Middle Eocene, Spanish Pyrenees - Cantalejo Lopez, B
This thesis integrates sedimentological, geochemical, magnetostratigraphic and spectral work from field and core data from the Middle Eocene, deep-marine siliciclastic sediments in the Ainsa Basin, Spanish Pyrenees. The deep-marine sediments of the Ainsa Basin comprise an alternation of coarse-grained sandbodies (submarine fans) and fine-grained packages of fan lateral-margin and interfan deposits. Time-series analysis performed on spectral gamma-ray and sandstone turbidite intensity data from 10 fine-grained interfan stratigraphic sections covering ~ 1.5 km of stratigraphy, and using multiple geochemical proxies (including high-resolution elemental XRF scanning, total organic carbon and carbon stable isotopes), all show that the interfan sediments contain a strong...

179. Separation of VOCl3 from TiCl4 using soya oil - Crane, JH
This thesis investigated the reactivity of the metal chlorides TiCl4, VOCl3 and VCl4 with different organic ligands. The chosen ligands were based around the chemical structure of soya oil due to its relevance to the industrial chlorine process used to manufacture TiO2. This thesis primarily used nuclear magnetic resonance (NMR)spectroscopy to characterise the reactions of the metal chlorides with soya oil and component parts, namely the glycerol and the alkene. This thesis goes on to investigate the coordination chemistry of the metal chlorides with ligands including diester groups. The chemical properties of the metal chlorides are known to be similar...

180. PAC'nPost: A Peer-to-Peer Micro-blogging Social Network - Asthana, H
In this thesis we provide a framework for a micro-blogging social network in an unstructured peer-to-peer network. At a user level, a micro-blogging service provides (i) a means for publishing a micro-blog, (ii) a means to follow a micro-blogger, and (iii) a means to search for micro-blogs containing keywords. Since unstructured peer-to-peer networks do not bind either the data or the location of data to the nodes in the network, search in an unstructured network is necessarily probabilistic. Using the probably approximately correct (PAC) search architecture, the search of an unstructured network is based on a probabilistic search that queries...

 

Busque un recurso