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Exploration Of Relevance Effects In Reasoning, Simon Francis Venn Jan 2003

Exploration Of Relevance Effects In Reasoning, Simon Francis Venn

School of Psychology Theses

The study examines possible underlying mechanisms that may be responsible for generally observed biased response patterns in two conditional reasoning tasks: the Wason selection task and the conditional inference evaluation task. It is proposed that memory processes that may account for priming phenomenon, may also account for the phenomena of matching bias and double-negation effects in reasoning. A new mental activation model is proposed, based on distributed theories of memory, which models relevance effects of the problem materials by way of a simple algorithm. The model is seen to parsimoniously predict previous general response patterns found using the two reasoning …

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Influence Of Natural And Anthropogenic Disturbance On The Soft Bottom Macrobenthic Community Of The Campeche Bank, Mexico, Hector Abuid Hernandez-Arana Jan 2003

Influence Of Natural And Anthropogenic Disturbance On The Soft Bottom Macrobenthic Community Of The Campeche Bank, Mexico, Hector Abuid Hernandez-Arana

School of Biological and Marine Sciences Theses

The structure of macrobenthic communities was investigated in carbonate and transitional carbonate-terrigenous sediments of the Southern Gulf of Mexico (Campeche Bank). The aim was to assess the influence of natural disturbance represented by winter storms and river runoff and the putative influence of oil-related activities using a regional approach. At a scale of > 100 km community composition of benthic macroinfauna was characterised as distinct assemblages within the carbonate and transitional sedimentary provinces controlled by natural disturbance. The carbonate assemblage was numerous and diverse influenced by a heterogeneous substratum. Winter storms had a severe impact with mortality probably resulting from abrasion …

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Development And Modelling Of A Point Source Integrating Cavity Absorption Meter (Psicam), Christophe Jean-Yves Joel Lerebourg Jan 2003

Development And Modelling Of A Point Source Integrating Cavity Absorption Meter (Psicam), Christophe Jean-Yves Joel Lerebourg

School of Biological and Marine Sciences Theses

The absorption coefficient is a fundamental parameter in understanding the underwater light field, for solving the Radiative Tranfer Equation and understanding/interpreting remotely sensed data from the ocean. Measuring the absorption coefficient is particularly complicated in coastal areas where the optical properties of the water body are the result of a complex mixture of dissolved and particulate components, but mainly because of the interfering effect that scattering has upon the measurements. A great variety of in situ instruments and laboratory techniques have been developed to measure total absorption or the absorption by the various fractions that constitute the total absorption. They …

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The Cardiotoxicity Of Carbon Monoxide, Ashvin P. Patel Jan 2003

The Cardiotoxicity Of Carbon Monoxide, Ashvin P. Patel

Peninsula Medical School Theses

The mechanism(s) responsible for the cardiotoxicity of CO are not clear and do not appear to arise solely from tissue hypoxia. Tissue hypoxia is produced by CO binding to haemoglobin and reducing the amount of oxygen carried by the blood in vivo. CO-induced hypoxia in vivo may be responsible for producing conditions such as those found during ischaemia/reperfusion (l/R) injury. Reactive oxygen species (ROS) produced during l/R injury is established and responsible for cellular/tissue damage from the oxidative damage. We postulate that oxidative stress is responsible for the CO-associated cardiac morbidities found in some cases following severe acute exposure to …

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Risk Factors Associated With The Mucociliary Apparatus In Intensive Care Patients, Ross James Kay Jan 2003

Risk Factors Associated With The Mucociliary Apparatus In Intensive Care Patients, Ross James Kay

Peninsula Medical School Theses

Initially, there were two principal aims of this investigation. A laboratory based project studying the effect of elevated fraction of inspired oxygen on the ciliary coverage of rat trachea in culture and a clinically based investigation of the ciliary coverage and frequency of ciliary ultrastructural abnormalities in the bronchus of intensive care unit patients. The mucociliary apparatus is the main airway defence mechanism protecting the lungs from respiratory infections. It is vital in intubated patients, as they lack the back up clearance mechanism normally provided by the cough reflex. Ciliary coverage and ultrastructural integrity are two key components of effective …

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The International Telecommunications Sector : A Financial Investigation Of Post Privatisation Performance, Nasser Mubarak Shafi Al-Shafi Jan 2003

The International Telecommunications Sector : A Financial Investigation Of Post Privatisation Performance, Nasser Mubarak Shafi Al-Shafi

Plymouth Business School Theses

The focus of this thesis is an investigation of the post-privatisation performance of the international telecoms sector. Firstly, the general hypothesis (1) of this thesis has been pursued, which states that the privatised telecoms companies perform differently from their non-privatised (private) counterparts. Several tests were applied; namely, ANOVA, and multiple regression analysis. The principal finding was that there was no significant difference in performance. Secondly, the next hypothesis (2) states that the financial performance of each company is positively related to that of the other two selected companies. For this purpose, multiple regression tests were performed to investigate any inter-relationships …

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An Empirical Study Of Malaysian Firms' Capital Structure, Sharifah Raihan Syed Mohd Zain Jan 2003

An Empirical Study Of Malaysian Firms' Capital Structure, Sharifah Raihan Syed Mohd Zain

Plymouth Business School Theses

It is sometimes purported that one of the factors affecting a firm's value is its capital structure. The event of the 1997 Asian financial crisis was expected to affect the firms' gearing level as the firms' earnings deteriorated and the capital market collapsed. The main objective of this research is to examine empirically the determinants of the capital structure of Malaysian firms. The main additional aim is to study the capital structure pattern following the 1997 financial crisis. Empirical tests were conducted on two different data sets: the first data set is the published data extracted from Datastream and consists …

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Environmental Impacts Of Modern Agricultural Technology Diffusion In Bangladesh: An Analysis Of Farmers' Perceptions And Their Determinants, S Rahman Jan 2003

Environmental Impacts Of Modern Agricultural Technology Diffusion In Bangladesh: An Analysis Of Farmers' Perceptions And Their Determinants, S Rahman

School of Geography, Earth and Environmental Sciences

Farmers' perception of the environmental impacts of modern agricultural technology diffusion and factors determining such awareness were examined using survey data from 21 villages in three agro-ecological regions of Bangladesh. Results reveal that farmers are well aware of the adverse environmental impacts of modern agricultural technology, although their awareness remains confined within visible impacts such as soil fertility, fish catches, and health effects. Their perception of intangible impacts such as, toxicity in water and soils is weak. Level and duration of modern agricultural technology adoption directly influence awareness of its adverse effects. Education and extension contacts also play an important …

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An Interactive Visualisation System For Engineering Design Using Evolutionary Computing, Ian Stephen James Packham Jan 2003

An Interactive Visualisation System For Engineering Design Using Evolutionary Computing, Ian Stephen James Packham

School of Engineering, Computing and Mathematics Theses

This thesis describes a system designed to promote collaboration between the human and computer during engineering design tasks. Evolutionary algorithms (in particular the genetic algorithm) can find good solutions to engineering design problems in a small number of iterations, but a review of the interactive evolutionary computing literature reveals that users would benefit from understanding the design space and having the freedom to direct the search. The main objective of this research is to fulfil a dual requirement: the computer should generate data and analyse the design space to identify high performing regions in terms of the quality and robustness …

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Retrieval, Action And The Representation Of Distance In Cognitive Maps, Davi Vann Bugmann Jan 2003

Retrieval, Action And The Representation Of Distance In Cognitive Maps, Davi Vann Bugmann

School of Psychology Theses

This thesis examines the context effects on retrieval, and the influence of action on the representation of distance in cognitive maps. It is proposed that bias in distance estimation is a function of the contexts of retrieval that trigger the representation of action in memory during evaluation tasks. The proposal is consistent with embodied cognition evidence that suggests that actions are implicitly a part of the representation, and will be naturally extracted as part of the retrieval process. The experimental work presented examines two different contextual cues; the frequency of visitation to landmarks, and the importance of activity performed at …

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Infra-Red Divergences In 2+1 Dimensional Gauge Theories, Zakaria Mazumder Jan 2003

Infra-Red Divergences In 2+1 Dimensional Gauge Theories, Zakaria Mazumder

School of Engineering, Computing and Mathematics Theses

Quantum field theories generally exhibit divergences. Ultra-violet divergences are treated through the renormalisation programme. Infra-red divergences, which accompany massless particles, are a characteristic of unbroken gauge theories and make it difficult to extract physical predictions. In this thesis we analyse various approaches to the infra-red problem and apply them to 2+1 dimensional gauge theories. These are useful as toy models, are related to the high temperature limit and are important in condensed matter physics. After briefly reviewing various responses to the infra-red problem in 3H-1 dimensions, we begin our study of gauge theories in 2+1 dimensions by performing a one …

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Analytical Investigations In Magnetic Recording, Stephen J. C. Brown Jan 2003

Analytical Investigations In Magnetic Recording, Stephen J. C. Brown

School of Engineering, Computing and Mathematics Theses

The Fourier method is used to provide new analytic solutions for idealized mathematical models of double-element shielded magnetoresistive (MR) recording heads. The general two-dimensional model allows analysis of various recording head configurations; a single pole head, a ring head, a dual stripe head and a differential head. The analysis accommodates both longitudinal recording (with no soft magnetic underlayer present) and perpendicular recording (in the presence of a soft underlayer). Typical field, spectral response function and output voltage pulse plots for double-element MR heads are given and compared to published, approximate solutions. The integrals arising in the determination of the Fourier …

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An Investigation Into Reinforced Brickwork Beams Using Quetta Bond, Colln Southcombe Jan 2003

An Investigation Into Reinforced Brickwork Beams Using Quetta Bond, Colln Southcombe

School of Engineering, Computing and Mathematics Theses

This study considered the design, development and testing of a new type of reinforced grouted cavity clay brickwork beam, the University of Plymouth Quetta Style Beam (the "Beam"). Under experimental load, the beam format results in asymmetric, non-linear, elastic bending and shear stress contours. This is contrary to beam behaviour acknowledged, in the codes, for reinforced brickwork and other structural materials. A suggested hypothesis is "evidence has been produced of excessive tensile stress beyond the steel yield stress, which may or may not be due to brick tensile strength". This hypothesis is based on a relatively small sample and upon …

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Formal Concept Matching And Reinforcement Learning In Adaptive Information Retrieval, Rohana Kithsiri Rajapakse Jan 2003

Formal Concept Matching And Reinforcement Learning In Adaptive Information Retrieval, Rohana Kithsiri Rajapakse

School of Engineering, Computing and Mathematics Theses

The superiority of the human brain in information retrieval (IR) tasks seems to come firstly from its ability to read and understand the concepts, ideas or meanings central to documents, in order to reason out the usefulness of documents to information needs, and secondly from its ability to learn from experience and be adaptive to the environment. In this work we attempt to incorporate these properties into the development of an IR model to improve document retrieval. We investigate the applicability of concept lattices, which are based on the theory of Formal Concept Analysis (FCA), to the representation of documents. …

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A Correlation Framework For Continuous User Authentication Using Data Mining, Harjit Singh Jan 2003

A Correlation Framework For Continuous User Authentication Using Data Mining, Harjit Singh

School of Engineering, Computing and Mathematics Theses

The increasing security breaches revealed in recent surveys and security threats reported in the media reaffirms the lack of current security measures in IT systems. While most reported work in this area has focussed on enhancing the initial login stage in order to counteract against unauthorised access, there is still a problem detecting when an intruder has compromised the front line controls. This could pose a senous threat since any subsequent indicator of an intrusion in progress could be quite subtle and may remain hidden to the casual observer. Having passed the frontline controls and having the appropriate access privileges, …

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Intelligent Vision-Based Navigation System, Kheng Lee Koay Jan 2003

Intelligent Vision-Based Navigation System, Kheng Lee Koay

School of Engineering, Computing and Mathematics Theses

This thesis presents a complete vision-based navigation system that can plan and follow an obstacle-avoiding path to a desired destination on the basis of an internal map updated with information gathered from its visual sensor. For vision-based self-localization, the system uses new floor-edges-specific filters for detecting floor edges and their pose, a new algorithm for determining the orientation of the robot, and a new procedure for selecting the initial positions in the self-localization procedure. Self-localization is based on matching visually detected features with those stored in a prior map. For planning, the system demonstrates for the first time a real-world …

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Wavelet-Based Multi-Carrier Code Division Multiple Access Systems, Ali Muayyadi Jan 2003

Wavelet-Based Multi-Carrier Code Division Multiple Access Systems, Ali Muayyadi

School of Engineering, Computing and Mathematics Theses

This thesis proposes a wavelet-based multicarrier CDMA system that uses wavelet basis instead of DFT basis to deal with the problem of inter-channel interference (ICI) and spectral bandwidth efficiency. The theoretical analysis shows that the proposed system has lower side lobe components and higher bandwidth efficiency. The simulation further shows that the wavelet-based multi-carrier CDMA system gives lower ICI and better BER performance than that using DFT basis under multipath fading channel. Moreover the proposed system is more robust against narrow band interference signal. This thesis exploits the wavelet correlation properties to perform timing synchronisation in multicarrier CDMA systems. This …

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A Procedural Model For Integrating Physical And Cyberspaces In Architecture, Peter Anders Jan 2003

A Procedural Model For Integrating Physical And Cyberspaces In Architecture, Peter Anders

School of Engineering, Computing and Mathematics Theses

This dissertation articiilates opportunities offered by architectural computation, in particular the digital simulation of space known as virtual reality (VR) and its networked, social variant cyberspace. The thesis will argue that VR/cyberspace has exacerbated differences between architecture's materialist and idealist practices, widening the gap that separates them. In an effort to bridge this gap it presents a procedural model for how VR and cyberspace may be integrated within the practice and product of architecture. The dissertation presents important developments in architectural computation that disclose concepts and values that contrast with orthodox practice. Virtual reality and cyberspace, the foci of this …

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Principles Of Metadesign : Processes And Levels Of Co-Creation In The New Design Space, Elisa Giaccardi Jan 2003

Principles Of Metadesign : Processes And Levels Of Co-Creation In The New Design Space, Elisa Giaccardi

School of Engineering, Computing and Mathematics Theses

In the tight of the material and cultural conditions of the present world and within the context of current design theories, this research aims to provide an understanding of Metadesign as emerging design cutture, and to integrate and advance its conceptual framework and principles through a tra nsdisci pli nary dialogue with the aesthetics and practice of Net Art. By rejecting the notion of Metadesign as an established design approach and practice, the creation of an etymological hypothesis based on the meanings of the prefix "-meta" (behind, together, between) becomes possible. Following this historical and cultural path, the research describes …

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Fatigue Properties Of Metal Inert Gas And Friction Stir Welded Aluminium Alloy 5383-H321, Gareth Richard Bradley Jan 2003

Fatigue Properties Of Metal Inert Gas And Friction Stir Welded Aluminium Alloy 5383-H321, Gareth Richard Bradley

School of Engineering, Computing and Mathematics Theses

The following dissertation details the development of a simple defect-tolerant based model for determining the fatigue properties of a 5383-H321 aluminium alloy and metal inert gas and friction stir welded butt joints in the same alloy. The model considers the fatigue life to consist of three regimes, crack initiation and short and long crack growth, in contrast to the typical defect-tolerant approaches which only consider the long crack growth period. Crack initiation was considered to consist of an initial short crack, present prior to fatigue loading, identical in length to the crack initiator. The short crack growth rate was considered …

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Closed-Loop Controlled Total Intra Venous Anaesthesia, Chao Dong Jan 2003

Closed-Loop Controlled Total Intra Venous Anaesthesia, Chao Dong

School of Engineering, Computing and Mathematics Theses

Anaesthesia is important for both surgery and intensive care and intravenous anaesthetics are widely used to provide rapid onset, stable maintenance, and rapid recovery compared with inhaled anaesthetics. The aim of the project on which this thesis is based was to investigate a reliable and safe methodology for delivering total intravenous anaesthesia using closed-loop control technology and bispectral analysis of human electroencephalogram (EEG) waveform. In comparison with Target Controlled Infusion (TCI), drug effect is measured during drug infusion in closed loop anaesthesia (CLAN). This may provide superior safety, better patient care, and better quality of anaesthesia whilst relieving the clinician …

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Retrieval, Action And The Representation Of Distance In Cognitive Maps, Davi Vann Bugmann Jan 2003

Retrieval, Action And The Representation Of Distance In Cognitive Maps, Davi Vann Bugmann

School of Psychology Theses

This thesis examines the context effects on retrieval, and the influence of action on the representation of distance in cognitive maps. It is proposed that bias in distance estimation is a function of the contexts of retrieval that trigger the representation of action in memory during evaluation tasks. The proposal is consistent with embodied cognition evidence that suggests that actions are implicitly a part of the representation, and will be naturally extracted as part of the retrieval process. The experimental work presented examines two different contextual cues; the frequency of visitation to landmarks, and the importance of activity performed at …

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Tgf-Beta-Induced Socs3 Expression Augments Tnf-Alpha-Induced Osteoclast Formation, Ac Lovibond, Sj Haque, Tj Chambers, Sw Fox Jan 2003

Tgf-Beta-Induced Socs3 Expression Augments Tnf-Alpha-Induced Osteoclast Formation, Ac Lovibond, Sj Haque, Tj Chambers, Sw Fox

School of Biomedical Sciences

No abstract provided.

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Supporting Biosciences In The Nursing Curriculum: Development And Evaluation Of An Online Resource, Ka Gresty, Dre Cotton Jan 2003

Supporting Biosciences In The Nursing Curriculum: Development And Evaluation Of An Online Resource, Ka Gresty, Dre Cotton

School of Biomedical Sciences

Aims. The aim of this project was to develop and evaluate an online resource designed to improve the biosciences knowledge of preregistration nursing students. Background. A number of studies have identified lack of biological subject knowledge and anxiety about studying biosciences as serious problems for nursing students. The availability of a contextualized biological information resource prior to and early in their studies might help to reduce this fear and anxiety. Methods. The project used an action research approach, involving an initial analysis of the extent of the problems with biosciences encountered by our nursing students, followed by the development and …

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Farm-Level Pesticide Use In Bangladesh: Determinants And Awareness, S Rahman Jan 2003

Farm-Level Pesticide Use In Bangladesh: Determinants And Awareness, S Rahman

School of Geography, Earth and Environmental Sciences

Farmers' awareness of beneficial and harmful effects of pesticides and factors determining use of pesticides were analyzed using survey data from 21 villages in three agro-ecological regions of Bangladesh. Pesticide cost accounts for about 7.7% of the gross value of output in cotton, 3.6% in vegetables, 2.5% in potato, 1.8% in modern rice, 1.6% in spices and less than 1% in other cereal and non-cereal crops. About 77% of farmers (highest 94% in Comilla) used pesticides at least once (37% applied once and 31% applied twice, and the rest applied for 3-5 times) in a crop season. Cultivation of traditional …

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Increased Brain Histamine H3 Receptor Expression During Hibernation In Golden-Mantled Ground Squirrels, T Sallmen, Af Lozada, Ov Anichtchik, Al Beckman, P Panula Jan 2003

Increased Brain Histamine H3 Receptor Expression During Hibernation In Golden-Mantled Ground Squirrels, T Sallmen, Af Lozada, Ov Anichtchik, Al Beckman, P Panula

School of Biological and Marine Sciences

BACKGROUND: Hibernation is a state of extremely reduced physiological functions and a deep depression of CNS activity. We have previously shown that the histamine levels increase in the brain during hibernation, as does the ratio between histamine and its first metabolite, suggesting increased histamine turnover during this state. The inhibitory histamine H3 receptor has both auto- and heteroreceptor function, rendering it the most likely histamine receptor to be involved in regulating the activity of histamine as well as other neurotransmitters during hibernation. In view of accumulating evidence that there is a global depression of transcription and translation during hibernation, of …

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Value Conflicts In Intergroup Perception: A Social Cognitive Perspective, N Wyer Jan 2003

Value Conflicts In Intergroup Perception: A Social Cognitive Perspective, N Wyer

School of Psychology

No abstract provided.

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A New Hplc‐Elsd Method To Quantify Indican In Polygonum Tinctorium L. And To Evaluate Β‐Glucosidase Hydrolysis Of Indican For Indigo Production, Lg Angelini, E Campeol, S Tozzi, Et Al Jan 2003

A New Hplc‐Elsd Method To Quantify Indican In Polygonum Tinctorium L. And To Evaluate Β‐Glucosidase Hydrolysis Of Indican For Indigo Production, Lg Angelini, E Campeol, S Tozzi, Et Al

Peninsula Medical School

A method to quantify the indigo precursor indican (indoxyl-β-d-glucoside) in Polygonum tinctoriumL. has been developed. Plant material was extracted in deionized water, and indican was identified and quantified using high performance liquid chromatography (HPLC) coupled to an evaporative light scattering detector (ELSD). Results confirmed that with this method it is possible to measure indican content in a short time, obtaining reliable and reproducible data. Using this method, leaf indican content was quantified every 15 days during the growing season (from May to October) in P. tinctorium crops grown in a field experiment in Central Italy. Results showed that indican increased …

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A Stochastic Frontier Approach To Total Factor Productivity Measurement In Bangladesh Crop Agriculture, 1961–1992, T Coelli, S Rahman, C Thirtle Jan 2003

A Stochastic Frontier Approach To Total Factor Productivity Measurement In Bangladesh Crop Agriculture, 1961–1992, T Coelli, S Rahman, C Thirtle

School of Geography, Earth and Environmental Sciences

This paper applies a stochastic production frontier model to measure total factor productivity growth, technical efficiency change and technological change in Bangladesh crop agriculture for the 31 observations from 1960/61 to 1991/92, using data for 16 regions. The results reveal that technical change followed a U‐shaped pattern, rising from the early 1970s, when the green revolution varieties were adopted, giving an overall rate of technical progress at 0.27 per cent per year. However, technical efficiency declined throughout, at an estimated annual rate of 0.47 per cent. The combined effect of slow technical progress, dominated by the fall in technical efficiency …

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Genetic And Molecular Factors In The Aetio-Pathogenesis Of Pancreatitis In Humans, Mark Timothy Cartmell Jan 2003

Genetic And Molecular Factors In The Aetio-Pathogenesis Of Pancreatitis In Humans, Mark Timothy Cartmell

Other Faculty of Health Theses

Both acute (AP) and chronic (CP) pancreatitis are complex diseases, with a number of aetiologies and complex pathogeneses. A number of contributing factors are assessed here. Genetic studies were performed looking at a high activity polymorphism of the alcohol metabolising enzyme cytochrome P450 2E l. Assessing a role in alcohol abuse and end organ disease; alcohol abusers (n= 239) and controls (n= 208) were studied. A significantly lower number of alcohol consumers (2.1 %) had the polymorphism than controls (5.8%); p= 0.049, Fisher's exact test. Any association with end organ disease could not be further elucidated due to the rarity …

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