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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

African trypanosomes : a model for the improvement of molecular diagnosis of blood borne parasites

Abd-Alla, Heba Ahmed January 2009 (has links)
Historically, diagnosis has relied on clinical signs of disease, microscopy and serological testing. However, these approaches have a number of drawbacks for example, differential diagnosis, low sensitivity (microscopy) and the inability to differentiate past from current infections (serology). In the past decade the use of molecular techniques, such as the polymerase chain reactions (PCR) have gained favour. Many research groups have used these techniques to study the molecular epidemiology of diseases in sub-Saharan Africa. Such methodologies rely on the detection of genetic materials and as such are reliant on the specificity of their components and the quality of the starting materials. It is the aim of this thesis is to demonstrate improvements that can be made to sample collection that will help to enhance the reliability of these tests and highlight the importance of the diagnostic parameters. The model that I will use to demonstrate these improvements are African trypanosomes, these are the causative agents of sleeping sickness in humans and nagana in animals, and are wide spread across much of sub-Saharan Africa. My work will be presented as three main sections: Firstly, a comparison of the suitability of various different approaches to cattle blood sample collection – including the genetic materials prepared directly in the field and the use of Whatman FTA®cards – in terms of the provision of appropriate materials for molecular screening will be presented. It was found that uneven distribution of genetic materials occurs across the surface of the FTA®cards due to the matrix chemistry. Therefore suggestions for improvements for the preparation of materials to be stored on these cards and their downstream application are made. Secondly, a comparison between the specificity of the pan-Trypanosoma ITS-PCR reaction and the species-specific reactions is made. The ITS-PCR has gained favour in recent years as it is reported to be capable of identifying a wide range of trypanosomes, as this is a single nested PCR reaction the reduction in time and cost has been very appealing to researchers in this field. My work suggests that this test is not reliable in terms of the accurate detection of trypanosomes species, and in fact on a direct comparison of 969 samples, 37 parasitic events where identified by this approach compared to 197 when species-specific tests were applied. Thirdly, based on my findings from the previous two chapters I present two case studies, the first of which looks to evaluate the impact on the prevalence of trypanosome species in cattle after drug treatment during the Ugandan, Stamp Out Sleeping sickness (www.sleepingsickness.com) campaign. The results of this case study highlight the importance of understanding the relationship that occurs between trypanosome species in mixed infections, my second case study therefore looks to quantifying the infection load of Trypanosoma brucei and T. congolense within the midgut of their insect vector (Glossina morsitans morsitans) using qPCR.
212

An investigation into the data collection process for the development of cost models

Delgado-Arvelo, Ysolina January 2012 (has links)
This thesis is the result of many years of research in the field of manufacturing cost modelling. It particularly focuses on the Data Collection Process for the development of manufacturing cost models in the UK Aerospace Industry with no less important contributions from other areas such as construction, process and software development. The importance of adopting an effective model development process is discussed and a new CMD Methodology is proposed. In this respect, little research has considered the development of the cost model from the point of view of a standard and systematic Methodology, which is essential if an optimum process is to be achieved. A Model Scoping 3 Framework, a functional Data Source and Data Collection Library and a referential Data Type Library are the core elements of the proposed Cost Model Development Methodology. The research identified a number of individual data collection methods, along with a comprehensive list of data sources and data types, from which essential data for developing cost models could be collected. A Taxonomy based upon sets of generic characteristics for describing the individual data collection, data sources and data types was developed. The methods, tools and techniques were identified and categorised according to these generic characteristics. This provides information for selecting between alternative methods, tools and techniques. The need to perform frequent iterations of data collection, data identification, data analysis and decision making tasks until an acceptable cost model has been developed has become an inherent feature of the CMDP. It is expected that the proposed model scoping framework will assist cost engineering and estimating practitioners in: defining the features, activities of the process and the attributes of the product for which a cost model is required, and also in identifying the cost model characteristics before the tasks of data identification and collection start. It offers a structured way of looking at the relationship between data sources, cost model characteristics and data collection tools and procedures. The aim was to make the planning process for developing cost models more effective and efficient and consequently reduce the time to generate cost models.
213

International Clostridium difficile animal strain collection and large diversity of animal associated strains

Janezic, Sandra, Zidaric, Valerija, Pardon, Bart, Indra, Alexander, Kokotovic, Branko, Blanco, Jose, Seyboldt, Christian, Diaz, Cristina, Poxton, Ian, Perreten, Vincent, Drigo, Ilenia, Jiraskova, Alena, Ocepek, Matjaz, Weese, J., Songer, J., Wilcox, Mark, Rupnik, Maja January 2014 (has links)
BACKGROUND:Clostridium difficile is an important cause of intestinal infections in some animal species and animals might be a reservoir for community associated human infections. Here we describe a collection of animal associated C. difficile strains from 12 countries based on inclusion criteria of one strain (PCR ribotype) per animal species per laboratory.RESULTS:Altogether 112 isolates were collected and distributed into 38 PCR ribotypes with agarose based approach and 50 PCR ribotypes with sequencer based approach. Four PCR ribotypes were most prevalent in terms of number of isolates as well as in terms of number of different host species: 078 (14.3% of isolates / 4 hosts), 014/020 (11.6% / 8 hosts) / 002 (5.4% / 4 hosts) and 012 (5.4% / 5 hosts). Two animal hosts were best represented / cattle with 31 isolates (20 PCR ribotypes / 7 countries) and pigs with 31 isolates (16 PCR ribotypes / 10 countries).CONCLUSIONS:This results show that although PCR ribotype 078 is often reported as the major animal C. difficile type, especially in pigs, the variability of strains in pigs and other animal hosts is substantial. Most common human PCR ribotypes (014/020 and 002) are also among most prevalent animal associated C. difficile strains worldwide. The widespread dissemination of toxigenic C. difficile and the considerable overlap in strain distribution between species furthers concerns about interspecies, including zoonotic, transmission of this critically important pathogen.
214

Les amusements de l'esprit : réseaux sociaux, curiosité, plaisir et construction des savoirs à Paris au XVIIIe siècle

Lemonnier, Marie January 2013 (has links)
Le XVIIIe siècle français est un terrain fertile pour s'intéresser à la dimension historique du plaisir puisqu'il valorise la quête des plaisirs matériels et intellectuels parmi les élites. Il est à la fois paradoxal et logique que la satisfaction intellectuelle s'exprime dans le luxe et par l'accumulation d'objets, qu'illustre ici le collectionnisme. Les deux types de quêtes, intellectuelle et matérielle, se croisent, coexistent et se rejoignent sans jamais se poser véritablement comme des antithèses. Pourtant, si on jette un coup d'oeil à l'historiographie, force est de constater que la révolution intellectuelle du XVIIIe siècle français et la recherche de plaisir des Parisiens aisés ont été jusqu'à maintenant étudiées de façon séparée, sinon dichotomique. La présente analyse se base sur un questionnement principal : comment se manifeste le plaisir dans l'acquisition des connaissances et comment les notions de plaisir et de culture savante s'intègrent-elles dans les pratiques sociales du savoir au XVIIIe siècle à Paris? Cela soulève des questionnements plus spécifiques. Par exemple, quelle part peut-on accorder au plaisir dans la révolution scientifique du XVIIIe siècle; les lieux habituellement associés au plaisir personnel comme les cabinets de curiosités y ont-ils un rôle à jouer? La collection remplit trois fonctions principales pour le collectionneur et dans la société parisienne et française du XVIIIe siècle : une fonction sociale, une fonction éducative, mais également, une fonction sensible ou émotionnelle. Il nous apparaît que le rejet du plaisir et de l'aspect émotif de la quête du savoir dans une science véritablement institutionnalisée et professionnalisée se concrétise davantage au XIXe qu'au XVIIIe siècle. La "curiosité" comme moteur de la science est une idée encore bien vivante dans les discours du XVIIIe siècle.
215

POST-FLIGHT DATA DISTRIBUTION SYSTEM

Lloyd, Joseph W. Jr 10 1900 (has links)
International Telemetering Conference Proceedings / October 25-28, 1993 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Desktop Processors (IBM PC, PC-compatible, and Macintosh) have made a major impact on how the Naval Air Warfare Center Aircraft Division (NAWCAD}, Patuxent River engineering community performs their work in aircraft weapons tests. The personal processors are utilized by the flight-test engineers not only for report preparation, but also for post-flight Engineering Unit (EU) data reduction and analysis. Present day requirements direct a need for improved post-flight data handling than those of the past. These requirements are driven by the need to analyze all the vehicle's parameters prior to the succeeding test flight, and to generate test reports in a more cost effective and timely manner. This paper defines the post-flight data distribution system at NAWCAD, Patuxent River, explains how these tasks were handled in the past, and the development of a real-time data storage designed approach for post-flight data handling. This engineering design is then described explaining how it sets the precedence for NAWCAD, Patuxent River's future plans; and how it provides the flight-test engineer with the test vehicle's EU data immediately available post-flight at his desktop processor.
216

Applications of Lie methods to computations with polycyclic groups

Assmann, Björn January 2007 (has links)
In this thesis we demonstrate the algorithmic usefulness of the so-called Mal'cev correspondence for computations with infinite polycyclic groups. This correspondence between Q-powered nilpotent groups and rational nilpotent Lie algebras was discovered by Anatoly Mal'cev in 1951. We show how the Mal'cev correspondence can be realized on a computer. We explore two possibilities for this purpose and compare them: the first one uses matrix embeddings and the second the Baker-Campbell-Hausdorff formula. Then, we describe a new collection algorithm for polycyclically presented groups, which we call Mal'cev collection. Algorithms for collection lie at the heart of most methods dealing with polycyclically presented groups. The current state of the art is "collection from the left" as recently studied by Gebhardt, Leedham-Green/Soicher and Vaughan-Lee. Mal'cev collection is in some cases dramatically faster than collection from the left, while using less memory. Further, we explore how the Mal'cev correspondence can be used to describe symbolically the collection process in polycyclically presented groups. In particular, we describe an algorithm that computes the collection functions for splittable polycyclic groups. This algorithm is based on work by du Sautoy. We apply it to the computation of pro-p-completions of polycyclic groups. Finally we describe a practical algorithm for testing polycyclicity of finitely generated rational matrix groups. Previously, not only did no such method exist but it was not clear whether this question was decidable at all. Most of the methods described in this thesis are implemented in the computer algebra system GAP and publicly available as part of the GAP packages Guarana and Polenta. Reports on the implementation including runtimes for some examples are given at the appropriate places.
217

Design of grid service-based power system control centers for future electricity systems

Zhou, Huafeng., 周華鋒. January 2008 (has links)
published_or_final_version / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy
218

Spolia and Spectacle: Art Collecting Culture in Late Republican Rome

Penman, Jill Diana 01 January 2015 (has links)
This thesis looks at the evolution of art collection in the middle to late Roman Republic. Through the examination of military triumphs, manubial structures, and the sculpture collection of the Villa of the Papyri in Herculaneum, this paper investigates the social motivations for art collection. Art’s role in Roman society as both spolia and luxuria is discussed through use of ancient literary sources and archaeological evidence. The evolving role of collection is considered as an expression of national and social identity in a politically changing Rome.
219

Resource management in open tuple space systems

Menezes, Ronaldo Parente de January 1999 (has links)
No description available.
220

Wireless Transmission Method of Emergency Response---An Implementation for Multiple Sinks Data Collection in Wireless Sensor Networks

Nan Chen, Nan January 2013 (has links)
In wireless sensor networks, source nodes usually send their data packets to a single sink following a specific routing protocol. In this way, unicast delivery becomes a dominant means of data transmission through the network. However, if one of links in the route is out of order, a dynamic routing protocol will rule the search by the routers for a new transmission route and thus, more time will be taken with regards to searching for the route. In this paper, a condition in which an emergency occurs is envisioned. Source nodes must send the emergency information packets to the possible sink as soon as possible. Then the multicast delivery should be taken instead of the unicast delivery so as to save more time.

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