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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.
11

Intoxicação em búfalos (Bubalus bubalis) por Baccharis megapotamica var. weirii / Poisoning in water buffalo (Bubalus bubalis) by Baccharis megapotamica var. weirii

Oliveira Filho, Jose Carlos de 09 March 2012 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In the first part of the thesis, the spontaneous occurrence of an outbreak of Baccharis megapotamica var. weirii poisoning in buffalo in the Central region of the State of Rio Grande do Sul is reported. Ten out of 50 buffalo died 24 48 hr after being introduced into a pasture containing abundant amounts of the plant. Factors influencing the ingestion of the plant and consequent toxicosis included hunger, stress caused by shipment, and unfamiliarity with the plant. Clinical signs included serous ocular discharge, incoordination, mild bloat, and muscle trembling. One buffalo was necropsied. Gross findings included dehydration, abundant liquid in the rumen, reddening of the mucosa of forestomachs, abomasum, and intestine, and edema of the wall of the rumen. The main histologic lesions were superficial to full thickness degeneration and necrosis of the stratified epithelium lining the forestomachs, necrosis of the intestinal mucosa, and widespread lymphoid necrosis. A calf (Bos taurus) was fed a single dose of 5 g/kg/body weight of B. megapotamica var. weirii harvested from the same site where the buffalo died. Twenty hours after the administration of the plant this calf died with clinical signs and lesions similar to those observed in the naturally poisoned buffalo.sido consumida pelos búfalos. In the second part of the thesis, Five male 6-8 month-old Murrah buffalo calves were orally dosed with the fresh aerial parts of Baccharis megapotamica var. weirii at doses of 1, 3, 4, 5 and 10 g/kg body weight (bw) (~1-10 mg macrocyclic trichothecenes/kg/bw). The B. megapotamica used for the experiment was harvested on a farm where a recent spontaneous outbreak of poisoning caused by such plant had occurred. Clinical signs appeared 4-20 hours and 4 buffalo died 18-49 hours after the ingestion of the plant. Clinical signs were apathy, anorexia, and watery diarrhea, fever, colic, drooling, muscle tremors, restlessness, laborious breathing and ruminal atony, and dehydration. The most consistent gross findings were restricted to the gastrointestinal (GI) tract consisted of varying degrees of edema and reddening of the mucosa of the fore-stomachs. Histopathological findings consisted of varying degrees of necrosis of the epithelial lining of the fore-stomachs and of lymphocytes within lymphoid organs and aggregates. Fibrin thrombi were consistently found in sub-mucosal vessels of the fore stomachs and in the lumen of hepatic sinusoids. It is suggested that dehydration, septicemia and disseminated intravascular coagulation participate in the pathogenesis of the intoxication and play a role as a cause of death. A subsample of the B. megapotamica var. weirii was frozen-dried and ground and analyzed using UHPLC (Ultra High Performance Liquid Chromatography) with high resolution Time of Flight mass spectrometry and tandem mass spectrometry, it was shown that the plant material contained at least 51 different macrocyclic trichothecenes at a total level of 1.1-1.2 mg/g. About 15-20% of the total trichothecenes contents was found to be monosaccharide conjugates, with two thirds of these being glucose conjugates and one third constituted by six aldopentose conjugates (probably xylose), which has never been reported in the literature. / Na primeira parte dessa tese, relatamos a ocorrência natural de um surto de intoxicação por Baccharis megapotamica var. weirii em búfalos na Região Central do Rio Grande do Sul. Os animais haviam sido transportados de uma propriedade onde a planta não ocorria para uma propriedade infestada pela planta. Durante o transporte, os animais foram submetidos a um longo período de jejum e estresse. Como resultado, após o desembarque dos 50 búfalos transportados, dez morreram com doença de evolução aguda (24-48 horas). A maioria dos búfalos foi encontrada morta, mas os sinais clínicos observados em um búfalo incluíam lacrimejamento, incoordenação e fraqueza dos membros posteriores, desorientação, decúbito esternal, lateral e morte. Na necropsia de um animal foi observado acentuada desidratação, avermelhamento e edema da mucosa dos pré-estômagos e intestino. Na microscopia, as áreas vermelhas dos pré-estômagos e intestino correspondiam à necrose acentuada do epitélio. Em visita à propriedade foi observada grande quantidade de B. megapotamica (identificada posteriormente como B. megapotamica var. weirii) com sinais de ter sido consumida pelos búfalos. Na segunda parte da tese, reproduzimos experimentalmente a intoxicação por B. megapotamica var. weirii em búfalos para melhor caracterizar o quadro clínico-patológico da intoxicação na espécie, assim como determinar a dose tóxica e avançar no estudo da patogênese da intoxicação. Para tal, utilizamos cinco búfalos da raça Murrah com 6 a 8 meses de idade e peso variando entre 122 e 143 kg. Esses animais receberam em uma única administração por via oral, 1, 3, 4, 5 e 10 g/Kg das partes aéreas de Baccharis megapotamica var. weirii. A planta usada no experimento foi colhida na fazenda onde ocorreu o surto de intoxicação espontânea descrito acima. Os sinais clínicos apareceram 4-20 horas e quatro búfalos morreram 18-49 horas após a ingestão da planta. Os sinais clínicos consistiram de apatia, anorexia, diarreia aquosa, febre, cólica, salivação, tremores musculares, inquietação, respiração laboriosa, atonia ruminal e desidratação. Os achados macroscópicos mais consistentes estavam restritos ao trato gastrointestinal (GI) e consistiram de graus variados de edema e avermelhamento da mucosa dos pré-estômagos. Os achados histopatológicos consistiam de vários graus de necrose do epitélio de revestimento dos pré-estômagos e de linfócitos em agregados e órgãos linfoides. Trombos de fibrina foram consistentemente encontrados nos vasos da submucosa dos pré-estômagos e na luz dos sinusoides hepáticos. Uma subamostra de B. megapotamica var. weirii foi congelada a seco, moída e analisada usando UHPLC (Cromatografia Líquida de Ultra Alta Performance) com espectrometria de tempo-de-vôo de alta resolução e espectrometria de massa em tandem. Foi demonstrado que o material de planta analisado continha pelo menos 51 tricotecenos macrocíclicos diferentes num nível total de 1,1-1,2 mg/g. Cerca de 15-20% do conteúdo total de tricotecenos eram conjugados de monossacarídeos, sendo dois terços desses, conjugados de glicose e um terço constituídos por seis conjugados de aldopentose (provavelmente xilose). Em conclusão, o presente estudo descreveu pela primeira vez a intoxicação em búfalos por plantas do gênero Baccharis. A reprodução experimental demostrou que búfalos são um pouco mais resistentes a intoxicação por B. megapotamica var. weirii do que bovinos. Quanto à patogênese, foi sugerido que desidratação, septicemia e coagulação intravascular disseminada sejam fatores responsáveis pela morte dos animais afetados. Adicionalmente, foi descrito presença de tricotecenos constituídos por seis conjugados de aldopentose (provavelmente xilose) no B. megapotamica var. weirii, o que nunca tinha sido antes relatado na literatura.
12

Gribshunden (1495) : En jämförande studie av samtida skeppsavbildningar

Ingers, Ellen January 2017 (has links)
The aim of the MA thesis is to discuss and analyse different illustrations, paintings, carvings in wood and stone and woodcuts of ships of the new kind (Carrack, carvels), from the 15th century to the middle of the 16th century, and compare them to the Griffon-hound ship, and to understand how they have evolved. The ships of the time had large stern and end castles, three to four masts, and where built for the war tactic of boarding. The oldest ship of the new kind that have been found, is the Griffon-hound, a ship that belonged to the Danish king Hans, and sunk due to a fire 1495 outside of Ronneby in southern Sweden. Besides being the oldest of its kind, the ship also has a very specific figurehead that resembles a monster with a screaming human head in its gap. By discussing and analysing the artworks it is possible to learn more about the ships. After analysing them, the result is that the artworks do show how the ships have evolved. Some of the different attributes that the artworks display have also been found when investigating the wreck of the Griffon-hound. More attributes might still be on the wreck site, hidden under the sediment. An example is the remains of the anti-boarding nets that a lot of the artworks show, and that have been found on the wreck of the Mary Rose, the English ship that belonged to king Henry VIII. The Mary Rose is younger than the Griffon-hound, but artworks of older ships also show the anti-boarding nets, or the beams on top of the castles. The purpose behind having a large variety of different artwork is to increase the knowledge about the ships of the time, and to make sure that the attributes that is being analysed doesn’t only occur in one or two artworks.
13

Assessing foresight to advance management of complex global problems

Berze, Ottilia E. 15 April 2019 (has links)
Many people do not like thinking about the future. If they do, over 50% of Canadians think “our way of life” (p. 7) will end within 100 years and over 80% of Canadians think “we need to change our worldview and way of life if we are to create a better future for the world” (Randle & Eckersley, 2015, p. 9). There is a good reason for this. Alarms have sounded over global urgent complex problems with potential for catastrophic consequences such as the development of artificial intelligence, climate change, mass extinction, nuclear war and pandemics (Marien & Halal, 2011). Society is also increasingly fragmenting as imminent crises build on lack of understanding, the sense of incapacity to act, fear, distrust, blame and a lack of hope. This struggle for humanity’s survival is complicated by the turbulent global environment in which institutions continue to follow path-dependent trajectories set forth in a different time and context. Governments at various levels face a problem of “fit” between current structures and processes, that have not progressed sufficiently to meet changing needs of a global society mired in complexity and governance challenges. However, hope exists. Incremental progress on many fronts and a massive amount of efforts and resources are being engaged worldwide. There are emerging fields, lenses and tools that can potentially alleviate complex problems and address this emergency. The purpose of this dissertation is to understand and assess dialogue-based foresight practices being applied towards complex problems in Canada to provide insights into how these practices can assist society to alleviate global urgent complex problems and their impacts, within this backdrop of looming crises. Foresight, alternatively known as future studies or scenario-building, is a forward-looking practice recognized and used globally with over 100 research organizations focused on foresight, widespread usage by firms and over 18 countries involved in foresight activities (Berze, 2014b). Overall literature findings suggest foresight is widely and at least incrementally effective with a number of impacts in various areas (Calof, Miller, & Jackson, 2012; March, Therond, & Leenhardt, 2012; Meissner, Gokhberg, & Sokolov, 2013) but the extent of this effectiveness, the mechanisms involved, and the specific foresight benefits per type of project needs further research and evidence. For instance, limited literature exists on whether foresight can transform complex situations and if so, under what conditions. Thus, opportunities exist for assessing and increasing foresight’s impact. This dissertation is a contextualized, systematic empirical study that taps into transdisciplinary literature and practice, case studies of how foresight has been used to address specific types of complex problems in Canada, as well as surveys and interviews with foresight experts and participants. This dissertation uses a foresight community scan and a comparative case study approach to provide practical and theoretical benefits to foresight and complex problem area stakeholders. The research focuses on studying the broad interactions of foresight and identifying the impacts of dialogue-based foresight projects on people and the outcomes of complex problems. The dissertation concludes that dialogue-based foresight is a valuable and unique practice for ameliorating complex problems and their consequences. Insights are offered towards dialogue-based foresight’s potential contributions within the context of other efforts directed at humanity’s struggle for survival and global complex problems. These insights can then foster the further development and application of dialogue-based foresight on a global scale to alleviate complex problems and their effects. The dissertation outlines recommendations on key next steps to realize these potential contributions. / Graduate

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