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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.
1

Lactate utilisation in the rumen bacterium Selenomonas ruminantium

Gilmour, Martin January 1994 (has links)
No description available.
2

Three Essays on International Agricultural Trade

Costa, Rafael 2012 May 1900 (has links)
There are many factors that affect international agricultural trade. One of them is international transportation costs. Another important factor is non-tariff barriers such as sanitary and phytosanitary regulations caused by animal disease outbreaks. The main purpose of this dissertation was to analyze how these factors interfere in the international agricultural trade by examining three cases. In Chapter II, a spatial price equilibrium model of the international cotton sector was utilized to evaluate the effects of the Panama Canal expansion (PCE) on the world cotton industry. Three scenarios were evaluated by reducing ocean freight rates from U.S. Gulf and Atlantic ports to Asian destinations. All scenarios suggested that cotton exports from U.S. Gulf and Atlantic ports would considerably increase. On the other hand, the West Coast ports decreased its participation in total U.S. cotton exports. Overall, total U.S. cotton exports were expected to increase due to the PCE. By using the same model which was used in Chapter II, the third chapter analyzes port improvements in Brazil. By March of 2012, the port of Salvador is expected to have undergone relevant improvements. As a result, the port of Salvador is expected to attract ocean shipping companies which are willing to export directly to Asian importing markets. Scenarios with different reductions in cotton export cost for this port were examined. In general, results indicated a shift in Brazil cotton export flows from the port of Santos to the port of Salvador as well as an increase in exports and producer revenues for the country. Finally, in Chapter IV, the impacts of the 2005 FMD outbreak on the Brazilian meat market was examined. The imposition of an import ban by Russia on Brazilian meat exports was also investigated. By using time series methods, it was found that the outbreak along with the import ban caused a temporary negative price shock to the Brazilian meat market. Export pork and export chicken prices were found to not fully recover after the removal of the import ban by Russia. On the other hand, the export beef price was indicated to undergo a complete recovery.
3

Transboundary animal disease preparedness and response efforts: disconnects between federal and state levels of government

Crnic, Tarrie A. January 1900 (has links)
Master of Public Health / Department of Diagnostic Medicine/Pathobiology / Katherine Stenske / Over the past few decades, animal and public health professionals have become increasingly concerned about the global animal population’s vulnerability to Transboundary Animal Diseases (TADs). Through analysis of the lessons learned by the United Kingdom (UK), Taiwan, and Egypt in responding to FMD outbreaks in their countries, it becomes apparent that even with response plans in place at the time of an outbreak, problems still arose as the outbreaks progressed. To better understand why these deviations from the planned course occur, the concept of “disconnects” in the various “domains” of TAD emergency preparedness and response were explored for the United States (U.S.). Particular emphasis was placed on issues related to the collaboration and cooperation between the federal and state levels of government. The domains of communication, knowledge, and resourcing were selected to be analyzed due to their importance in TAD emergency outbreak preparedness and response. The research questions this thesis explores concern three domains of TAD emergency preparedness and response that experience disconnects between federal and state levels of government. They also explore how these disconnects affect Food and Agriculture Security in the U.S. Three different methods were used to research these topics. Literature reviews of lessons learned and after action reports from TAD outbreak exercises and real events were conducted. Direct observations of the author’s experiences at conferences, seminars, and training events were also included. Finally, personal interviews were conducted with Food and Agriculture Security experts. Through this analysis, numerous disconnects emerged in each of the domains. Several disconnects traverse all three domains. These disconnects related to laboratory collaboration with the federal government, the process of declaring a federal emergency, and the roles and responsibilities of individuals and groups involved in TAD outbreak preparedness and response. Overall, the disconnects affect the ability of state and federal governments to rapidly respond to and coordinate response efforts. This affects Food and Agriculture Security by compromising the safety, security, and ongoing operation of the food and agriculture sector. Further study will be needed to alleviate these disconnects so that better cooperation and collaboration can occur between federal and state levels of government.
4

Animal disease investigations : Comparison of methods for information collection and identification of attributes for information management systems

2015 September 1900 (has links)
In an infectious animal disease outbreak, effective management of the event requires timely and accurate information collection, processing, storage and distribution. This thesis focuses on the tools to assist information collection and management. The first study describes the comparison of questionnaire methodology for the information collection in the initial epidemiologic investigation of a Canadian federally reportable disease. The second study defines attributes of an animal disease outbreak information management system (IMS). The studies were performed within a one-year period (July 2013-July 2014). The first study performed two comparisons to determine differences in the information quality (completeness and accuracy) between differing questionnaire methodology and modes of completion (hard copy and electronic). The study was conducted with 24 Canadian Food Inspection Agency (CFIA) inspectors and veterinarians using a fictitious Canadian reportable disease scenario. The first comparison used a hard copy of a Canadian Food Inspection Agency (CFIA) questionnaire designed to be applicable (or generic) for all highly infectious reportable disease investigations with a supplementary disease specific section compared to an electronic disease specific reportable disease questionnaire. There was no significant difference in the information quality (N = 22; P = 0.09). The mean difference in completeness and accuracy scores was 3.5% (95% CI -0.6, 7.6). The second comparison focused on the hard copy disease questionnaire and assessed differences in information quality between using only the generic sections of the questionnaire compared to the supplementation of a disease specific section. A difference in information quality was determined (N = 24; P < 0.0001). The mean completeness and accuracy score for the generic only sections was 50.2% (95% CI 43.6, 57.2) compared to 80.2% (95% CI 76.2, 84.5) with the inclusion of the disease-specific section. The greatest difference in information quality occurred in the tracing specific information categories (P < 0.0001) with a mean difference of completeness and accuracy scores of 67.7% (95% CI 52.0, 83.4) for the trace-in (exposure history) category and 38.3% (95% CI 28.3, 48.3) for the trace-out (potential spread of disease) category. The absence of disease-specific questions were determined to be the primary factor in the difference in information quality. The second study determined a comprehensive list of user-defined attributes of an animal disease outbreak IMS and further identified the most important (key) attributes. A list of 34 attributes and associated definitions were determined through a series of focus group sessions and two surveys of Canadian animal health stakeholders. The animal health stakeholders included federal and provincial governments, veterinary academia and animal production industry representatives. The key attributes of an animal disease outbreak IMS identified were: ‘user friendly’, ‘effectiveness’, ‘accessibility’, ‘data accuracy’, ‘reliability’ and ‘timeliness’. ‘User friendly’ received the highest frequency of ranking as the most important attribute, followed by ‘effectiveness’. Information management was identified as the main purpose of an animal disease outbreak IMS with a median rating of 10 (rating scale of 0-10 with 10 = strongly agree). The occurrence of a federally reportable disease or a large-scale animal disease outbreak can have a great impact on the animal agriculture sector, regulatory government agencies and the economy. Information collection and management are essential to assist with the epidemiologic investigation and disease control measures. The study provided a novel opportunity to study information management for an animal disease outbreak from a Canadian perspective. The knowledge obtained will add value to the future development of tools and systems designed for information collection and management involving an animal disease outbreak.
5

Using simulated annealing to improve the information dissemination network structure of a foreign animal disease outbreak response

Pleuss, James D. January 1900 (has links)
Master of Science / Department of Industrial & Manufacturing Systems Engineering / Jessica L. Heier Stamm / Communication is an integral part of emergency response, and improving the information dissemination network for crisis communication can save time, resources, and lives. This thesis focuses specifically on emergency response to a foreign animal disease (FAD) outbreak, an incident in which an animal disease that is not active domestically is introduced and being spreading in the U.S. In a FAD outbreak, timeliness of detection and response are critical. An outbreak of foot-and-mouth disease, a particularly significant FAD, could cripple the agriculture economy and every hour of poor communication could result in the loss of thousands of animals. Improving this and other such crisis communication networks is of high importance. There is a comparatively large amount of prior research that critiques past catastrophic events but very little that aims to quantitatively improve such networks. This research uses communication data from a FAD response exercise in Kansas to develop a reliable network model, contributing a general method for creating an information dissemination network from empirical communication data. The thesis then introduces a simulated annealing heuristic to alter the network structure, reducing the overall information transmission time by almost 90%. Both the application of simulated annealing in network design and the use of discrete event simulation to calculate the heuristic objective function are new contributions to the field of crisis communication and emergency response. This work begins by extracting data from communication logs, grouping the large numbers of stakeholders into more manageable clusters, and developing a simulation model framework that accurately depicts the flow of information in the actual network. Then a simulated annealing heuristic is used to alter the network structure. The goal is to identify an alternative network structure in which the time for information to reach all response participants is minimized. The resultant network structures are analyzed to reveal observations and recommendations for FAD response communication. This research finds that not only can such a network be improved significantly, but the quantitative results support the qualitative observations from early in the data extraction process. This paper adds original methods to the literature and opens the door for future quantitative work in the area of crisis communication and emergency response.
6

Modeling management of foot and mouth disease in the central United States

McReynolds, Sara W. January 1900 (has links)
Doctor of Philosophy / Department of Diagnostic Medicine and Pathobiology / Michael W. Sanderson / The last outbreak for Foot and Mouth Disease (FMD) in the United States (U.S.) was in 1929. Since that time the U.S. has not had any exposure to the disease or vaccination, creating a very susceptible livestock population. The central U.S. has a large susceptible livestock population including cattle, swine, sheep, and goats. The impact of FMD in the U.S. would be devastating. Simulation modeling is the only avenue available to study the potential impacts of an introduction in the U.S. Simulation models are dependent on accurate estimates of the frequency and distance distribution of contacts between livestock operations to provide valid model results for planning and decision making including the relative importance of different control strategies. Due to limited data on livestock movement rates and distance distribution for contacts a survey was conducted of livestock producers in Colorado and Kansas. These data fill a need for region specific contact rates to provide parameters for modeling a foreign animal disease. FMD outbreaks often require quarantine, depopulation and disposal of whole herds in order to prevent the continued spread of the disease. Experts were included in a Delphi survey and round table discussion to critically evaluate the feasibility of depopulating a large feedlot. No clearly acceptable method of rapidly depopulating a large feedlot was identified. Participants agreed that regardless of the method used for depopulation of cattle in a large feedlot, it would be very difficult to complete the task quickly, humanely, and be able to dispose of the carcasses in a timely fashion. Simulation models were developed to assess the impact of livestock herd types and vaccination on FMD outbreaks in the central U.S. using the North American Animal Disease Spread Model (NAADSM), a spatially explicit, stochastic state-transition simulation model. Simulation scenarios with large vaccination zones had decreased outbreak length and number of herds destroyed. Vaccination did not provide additional benefit to control compared to depopulation alone when biosecurity and movement controls were high, however the ability to achieve high levels of biosecurity and movement control may be limited by labor and animal welfare concerns.
7

Visualisations pour la veille en épidémiologie animale / Visualizations for animal epidemiology surveillance

Fadloun, Samiha 15 November 2018 (has links)
De nombreux documents concernant l'émergence, la propagation ou le suivi de maladies humaines et animales sont quotidiennement publiés sur le Web. Afin de prévenir l'expansion des maladies, les épidémiologistes doivent constamment rechercher ces documents et les étudier afin de détecter les foyers de propagation le plus tôt possible. Dans cette thèse, nous nous intéressons aux deux activités liées à ce travail de veille afin de proposer des outils visuels permettant de faciliter/accélérer l'accès aux informations pertinentes. Nous nous focalisons sur les maladies animales, qui ont été moins étudiées et qui pourtant peuvent avoir de lourdes conséquences sur les activités humaines (maladies transmises d'animaux à humains, épidémies dans les élevages, ...).La première activité du veilleur consiste à collecter les documents issus du Web. Pour cela, nous proposons EpidVis, un outil visuel permettant aux épidémiologistes de regrouper et structurer les mots-clés nécessaires à leurs recherches, construire visuellement des requêtes complexes, les lancer sur différents moteurs de recherche et visualiser les résultats retournés. La seconde activité du veilleur consiste à explorer un grand nombre de documents concernant les maladies. Ces documents contiennent non seulement des informations telles que les noms des maladies, les symptômes associés, les espèces infectées, mais aussi des informations de type spatio-temporelles. Nous proposons EpidNews, un outil de visualisation analytique permettant d'explorer ces données en vue d'en extraire des informations. Les deux outils ont été réalisés dans le cadre d'une étroite collaboration avec des experts en épidémiologie. Ces derniers ont réalisé des études de cas pour montrer que les fonctionnalités des propositions étaient complètement adaptées et permettaient de pouvoir facilement extraire de la connaissance. / Many documents concerning emergence, spread or follow-up of human and animal diseases are published daily on the Web. In order to prevent the spread of disease, epidemiologists must frequently search for these documents and analyze them to detect outbreaks as early as possible. In this thesis, we are interested in the two activities related to this monitoring work in order to produce visual tools facilitating the access to relevant information. We focus on animal diseases, which have been less studied but can have serious consequences for human activities (diseases transmitted from animals to humans, epidemics in livestock ...).The first activity is to collect documents from the Web. For this, we propose EpidVis, a visual tool that allows epidemiologists to group and organize the keywords used for their research, visually build complex queries, launch them on different search engines and view the results returned. The second activity is to explore a large number of documents concerning diseases. These documents contain not only information such as disease names, associated symptoms, infected species, but also spatio-temporal information. We propose EpidNews, a visual analytics tool to explore this data for information extraction. Both tools were developed in close collaboration with experts in epidemiology. The latter carried out case studies to show that the functionalities of the proposals were completely adapted and made it possible to easily extract knowledge.
8

Efeito do fotossensibilizador butyl azul de toluidina na terapia fotodinâmica antimicrobiana para o tratamento da periodontite experimental em ratos /

Nuernberg, Marta Aparecida Alberton. January 2019 (has links)
Orientador: Leticia Helena Theodoro / Coorientador: Valdir Gouveia Garcia / Banca: Leonardo Perez Faverani / Banca: Edilson Ervolino / Banca: Cassius Carvalho Torres Pereira / Banca: Mark Wainwright / Resumo: O presente estudo avaliou pela primeira vez "in vivo" os efeitos de três concentrações do butyl azul de toluidina (BuTB) como agente fotossensibilizador na terapia fotodinâmica antimicrobiana (aPDT), como terapia coadjuvante a raspagem e alisamento radicular (RAR), para o tratamento de periodontite experimental (PE) em ratos. A PE foi induzida por meio da instalação de um fio de algodão ao redor do primeiro molar inferior esquerdo. Posteriormente os animais foram aleatoriamente distribuídos em 7 grupos com 15 animais cada, através de uma tabela gerada por computador, de acordo com os seguintes tratamentos: RAR (n=15) - RAR seguido de irrigação local de solução salina fisiológica; BuTB-0,1 (n=15) - RAR seguido de aplicação local de BuTB na concentração de 0,1 mg/mL; aPDT-0,1 (n=15) - RAR seguido da aplicação local de BuTB na concentração de 0,1 mg/mL e irradiação com laser de diodo (LD) de InGaAlP (660 nm, 40 mW, 60 s, 2,4 J); BuTB-0,5 (n=15) - RAR seguido de aplicação local de BuTB na concentração de 0,5 mg/mL; aPDT-0,5 (n=15) - RAR seguido da aplicação local de BuTB na concentração de 0,5 mg/mL e irradiação com LD; BuTB-2,0 (n=15) - RAR seguido de aplicação local de BuTB na concentração de 2 mg/mL; aPDT-2,0 (n=15) - RAR seguido da aplicação local de BuTB na concentração de 2 mg/mL e irradiação com LD. Decorridos 7, 15 e 30 dias pós-tratamento, 5 animais de cada grupo foram submetidos à eutanásia. A área de furca dos molares foi submetida às análises histológica, histométrica... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The present study evaluated for the first time the effects of three concentrations of butyl toluidine blue (BuTB) as a photosensitizing agent on antimicrobial photodynamic therapy (aPDT), as adjuvant therapy to scaling and root planing (SRP), for the treatment of experimental periodontitis (EP) in rats. EP was induced by placing a cotton thread around the lower left first molar. Subsequently, the animals were randomly distributed into seven groups with 15 animals each, through a computer generated table, according to the following treatments: SRP (n = 15), SRP followed by local irrigation of physiological saline solution; BuTB-0.1 (n = 15), SRP followed by local application of 0.1 mg/mL BuTB; aPDT-0.1 (n = 15), SRP followed by local application of BuTB at 0.1 mg/mL concentration and irradiation with InGaAlP diode laser (DL) (660 nm, 40 mW, 60 s, 4 J); BuTB-0.5 (n = 15), SRP followed by local application of BuTB at 0.5 mg/mL concentration; aPDT-0.5 (n = 15), SRP followed by local application of BuTB at 0.5 mg/mL concentration and DL irradiation; BuTB-2.0 (n = 15), SRP followed by local application of BuTB at 2 mg/mL concentration; aPDT-2.0 (n = 15), SRP followed by local application of BuTB at 2 mg/mL concentration and DL irradiation. The animals (n=5) from each group were submitted to euthanasia at 7, 15 and 30 days post-treatment. The furcation area of the first lower molar was submitted to histological, histometric and immunohistochemical analyses to identify TGF-ß1, OCN an... (Complete abstract click electronic access below) / Doutor
9

In vivo infection biology of contagious bovine pleuropneumonia

Gull, Tamara Brownsey 15 May 2009 (has links)
Contagious Bovine Pleuropneumonia (CBPP), caused by Mycoplasma mycoides mycoides small colony (MmmSC), is a devastating respiratory disease of cattle in Africa, Asia and the Middle East. Little investigation has been done on molecular disease pathogenesis and host response beyond soluble cytokine detection. This study developed and characterized models for three strains of MmmSC of varying severity. Strains used were Gladysdale, Ondangwa and Shawawa. Samples of bronchoalveolar lavage fluid, bronchial biopsy, nasal epithelial cells and blood were obtained prior to and at weekly time points post-infection. Microarray analysis of RNA extracted from samples revealed host cellular pathways and genes important in the pathogenesis of CBPP, including multiple immune system and inflammatory response pathways. A number of pathways whose influence on disease pathogenesis was not immediately clear were also activated, including pathways involved in amino acid synthesis, fat metabolism, and endocrine hormone responses. Microarray results were confirmed with real-time polymerase chain reaction (RT-PCR) of selected genes. Comparative RT-PCR analysis of selected genes between the three strains of MmmSC revealed genes possibly responsible for differential strain virulence, including interleukins 1B, 6, 8, and 18 and the gene nuclear factor of kappa light polypeptide gene enhancer in B cells inhibitor, alpha (NFKBIA). A similar analysis of selected genes between survivors and nonsurvivors of the virulent Gladysdale strain of MmmSC suggested genes involved in survival, including interleukin 8, calmodulin 2 (CALM2), and NFKBIA. Avenues of additional study were identified.
10

An Analysis on Agricultural Market Behavior

Choi, Chul 2010 August 1900 (has links)
This dissertation is concerned with (i) how to model an agricultural market, (ii) how to analyze the impacts of a certain event (i.e. animal disease outbreak) on the market, and (iii) what are the relationships between different markets. The research on the first two issues will focus on the US beef market, and the impact of the bovine spongiform encephalopathy (BSE) outbreak (Dec. 2003) on the US beef market will be analyzed. For the third issue, a multinational meat market will be considered, which includes three countries (Korea, US, and UK) and three meat products (beef, pork, and poultry). Their market movements will be compared, considering the impacts of the major animal disease outbreaks: BSE, foot and mouth disease (FMD), and avian influenza (AI). Based on the properties of an agricultural product (longer cycle of production and perishability) and the extensive empirical results, it is concluded that a recursive model is appropriate for modeling an agricultural market. A variety of structural change tests are applied to reveal that the change due to the BSE event still lies in an allowable range of the prediction error. For the comparisons between market movements, some multivariate statistical methods such as canonical correlation analysis (CCA) and principal component analysis (PCA) are used, and the main finding is that the knowledge about the threat of BSE to human health played an important role in changing people's attitude towards an animal disease event.

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