Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2014-10-03T20:19:52Z No. of bitstreams: 2 Tese - Maria_Auxiliadora Andrade - 2005.pdf: 1009311 bytes, checksum: fc89542ce0a0fb7c6a73727f348fc5a1 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Jaqueline Silva (jtas29@gmail.com) on 2014-10-03T20:41:47Z (GMT) No. of bitstreams: 2 Tese - Maria_Auxiliadora Andrade - 2005.pdf: 1009311 bytes, checksum: fc89542ce0a0fb7c6a73727f348fc5a1 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-10-03T20:41:47Z (GMT). No. of bitstreams: 2 Tese - Maria_Auxiliadora Andrade - 2005.pdf: 1009311 bytes, checksum: fc89542ce0a0fb7c6a73727f348fc5a1 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2005-09-16 / Two experiments were carried out to evaluate the use of quaternary ammonia on Salmonella Enteritidis inoculated in eggshell and its penetration capacities, verify the ability to infect the egg inoculated in eggshell, determine embryo mortality, infect hatched chicks and affect incubation parameters of two broiler lines. A total of 302 and 290 fertile eggs of Ross and ISA Label, respectively, were distributed in six treatments: eggs sanitized with placebo (Treatment 1- PC) quaternary ammonia inoculated with Salmonella Enteritidis (Treatment 2-PI); eggs non-sanitized and inoculated placebo (Treatment 3- NPC) with Salmonella Enteritidis (Treatment 4- NPI); eggs inoculated in allantoidal cavity with placebo (Treatment 5-CAC) or Salmonella Enteritidis (Treatment 6- CAI). Immediately after inoculation, the eggs were hatched and embryo mortality was evaluated after 96, 432 and 528 hours. The qualitative results were analyzed by non-parametric tests of chi-square and Kruskall-Wallis. The incubation parameters were not affected when the pathogen was inoculated in eggshell. It was observed that Salmonella Enteritidis inoculated in allantoidal cavity determined late embryo mortality in fast 17,02% and slow growing 13,04% lines, and eggs inoculated in allantoidal cavity originated chicks with high frequency of intestinal colonization by Salmonella Enteritidis of 76,67% and 26,67% Ross and ISA Label, respective. / Foram conduzidos dois experimentos para avaliar os efeitos de quaternários de amônia sobre Salmonella Enteritidis inoculados na casca e a capacidade de penetração deste patógeno na casca e para verificar sua habilidade em infectar os ovos inoculados pela casca e cavidade alantóide, determinar mortalidade embrionária, infectar os pintos eclodidos e afetar os parâmetros de incubação em duas linhagens de frango de corte. Utilizaram-se, respectivamente, 302 e 290 ovos férteis das linhagens Ross e ISA Label, distribuídos em seis tratamentos: ovos sanitizados e inoculados com o placebo (tratamento 1- PC) ou com quaternários de amônio inoculados na casca com Salmonella Enteritidis fagotipo 4 (tratamento 2-PI); ovos não sanitizados e inoculados na casca com placebo (tratamento 3-NPC) ou com Salmonella Enteritidis (tratamento 4-NPI); ovos inoculados na cavidade alantóide com placebo (tratamento 5-CAC) ou com Salmonella Enteritidis (tratamento 6-CAI). Imediatamente após a inoculação, os ovos foram incubados e a mortalidade embrionária avaliada após 96, 432 e 528 horas. As respostas qualitativas foram analisadas pelos testes não paramétricos de qui-quadrado e de Kruskal-Wallis. Constatou-se que a sanitização dos ovos não eliminou a Salmonella Enteritidis inoculada na casca sendo que o agente manteve-se viável na casca durante todo o período de incubação e migrou para o interior dos ovos em três das 20 amostras analisadas. Os parâmetros de incubação não foram afetados quando o patógeno foi inoculado na casca. Constatou-se também que a Salmonella Enteritidis inoculada na cavidade alantóide determinou mortalidade embrionária tardia nas linhagens Ross de 17,02% e ISA Label de 13,04%, assim como os ovos inoculados nesta cavidade originaram pintos com maior freqüência de colonização intestinal pela Salmonella Enteritidis de 76,67% e 26,67% para Ross e ISA Label, respectivamente.

Submitted by Cláudia Bueno (claudiamoura18@gmail.com) on 2016-04-05T17:29:19Z No. of bitstreams: 2 Tese - Maria Auxiliadora Andrade - 2005.pdf: 1009311 bytes, checksum: fc89542ce0a0fb7c6a73727f348fc5a1 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-04-06T11:11:10Z (GMT) No. of bitstreams: 2 Tese - Maria Auxiliadora Andrade - 2005.pdf: 1009311 bytes, checksum: fc89542ce0a0fb7c6a73727f348fc5a1 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-04-06T11:11:10Z (GMT). No. of bitstreams: 2 Tese - Maria Auxiliadora Andrade - 2005.pdf: 1009311 bytes, checksum: fc89542ce0a0fb7c6a73727f348fc5a1 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2006-09-16 / Two experiments were carried out to evaluate the use of quaternary ammonia on Salmonella Enteritidis inoculated in eggshell and its penetration capacities, verify the ability to infect the egg inoculated in eggshell, determine embryo mortality, infect hatched chicks and affect incubation parameters of two broiler lines. A total of 302 and 290 fertile eggs of Ross and ISA Label, respectively, were distributed in six treatments: eggs sanitized with placebo (Treatment 1- PC) quaternary ammonia inoculated with Salmonella Enteritidis (Treatment 2-PI); eggs non-sanitized and inoculated placebo (Treatment 3- NPC) with Salmonella Enteritidis (Treatment 4- NPI); eggs inoculated in allantoidal cavity with placebo (Treatment 5-CAC) or Salmonella Enteritidis (Treatment 6- CAI). Immediately after inoculation, the eggs were hatched and embryo mortality was evaluated after 96, 432 and 528 hours. The qualitative results were analyzed by non-parametric tests of chi-square and Kruskall-Wallis. The incubation parameters were not affected when the pathogen was inoculated in eggshell. It was observed that Salmonella Enteritidis inoculated in allantoidal cavity determined late embryo mortality in fast 17,02% and slow growing 13,04% lines, and eggs inoculated in allantoidal cavity originated chicks with high frequency of intestinal colonization by Salmonella Enteritidis of 76,67% and 26,67% Ross and ISA Label, respective. / Foram conduzidos dois experimentos para avaliar os efeitos de quaternários de amônia sobre Salmonella Enteritidis inoculados na casca e a capacidade de penetração deste patógeno na casca e para verificar sua habilidade em infectar os ovos inoculados pela casca e cavidade alantóide, determinar mortalidade embrionária, infectar os pintos eclodidos e afetar os parâmetros de incubação em duas linhagens de frango de corte. Utilizaram-se, respectivamente, 302 e 290 ovos férteis das linhagens Ross e ISA Label, distribuídos em seis tratamentos: ovos sanitizados e inoculados com o placebo (tratamento 1- PC) ou com quaternários de amônio inoculados na casca com Salmonella Enteritidis fagotipo 4 (tratamento 2-PI); ovos não sanitizados e inoculados na casca com placebo (tratamento 3-NPC) ou com Salmonella Enteritidis (tratamento 4-NPI); ovos inoculados na cavidade alantóide com placebo (tratamento 5-CAC) ou com Salmonella Enteritidis (tratamento 6-CAI). Imediatamente após a inoculação, os ovos foram incubados e a mortalidade embrionária avaliada após 96, 432 e 528 horas. As respostas qualitativas foram analisadas pelos testes não paramétricos de qui-quadrado e de Kruskal-Wallis. Constatou-se que a sanitização dos ovos não eliminou a Salmonella Enteritidis inoculada na casca sendo que o agente manteve-se viável na casca durante todo o período de incubação e migrou para o interior dos ovos em três das 20 amostras analisadas. Os parâmetros de incubação não foram afetados quando o patógeno foi inoculado na casca. Constatou-se também que a Salmonella Enteritidis inoculada na cavidade alantóide determinou mortalidade embrionária tardia nas linhagens Ross de 17,02% e ISA Label de 13,04%, assim como os ovos inoculados nesta cavidade originaram pintos com maior freqüência de colonização intestinal pela Salmonella Enteritidis de 76,67% e 26,67% para Ross e ISA Label, respectivamente.

Einleitung: Das Ziel dieser Arbeit war die Darstellung der Ergebnisse der Ross- Operation in der Kinderherzchirurgie der Universitätsmedizin Göttingen als Verfahren des AKE durch die eigene Pulmonalklappe (Autograft) bei Kindern und Jugendlichen unter besonderer Berücksichtigung der Haltbarkeit und Funktion des pulmonalen Autografts und der postoperativen Entwicklung des hypertrophierten linken Ventrikels. Zu diesem Zwecke wurden retrospektiv klinische Daten bezüglich der linksventrikulären Funktion und Haltbarkeit des pulmonalen Autografts und der klinischen Belastbarkeit ausgewertet. Patienten und Methoden: Untersucht wurden die Entwicklung der Neo-Aortenklappe (Autograftklappe) und des linken Ventrikels nach Ross-Operation bei 31 Patienten unter 21 Jahren, die zwischen 1994 und 2008 in Göttingen operiert wurden. Das Alter der untersuchten Patienten betrug zum Operationszeitpunkt zwischen 6 Monaten und 20 Jahren (Mittelwert: 133 Monate b= 11,1 Jahre). Der Nachbeobachtungszeitraum variierte zwischen 10 Monaten und 14 Jahren (Mittelwert: 67 Monate b= 5,6 Jahre). Retrospektiv wurden 2 verfügbare postoperative Echokardiographien bezüglich der Durchmesser des Aortenklappenrings, der Aortenwurzel, des sino-tubulären Übergangs, des LVESD, des LVEDD, des IVS und der linksventrikulären HW ausgewertet. Zur Vergleichbarkeit des untersuchten Kollektivs mit gesunden Kindern und Jugendlichen wurden mit Hilfe von Regressionskurven nach Daubeney et al. (1999) und Pettersen et al. (2008) Z-Werte für die gemessenen Durchmesser bestimmt und ihre Entwicklung durch statistische Methoden ausgewertet. Ergebnisse: Im untersuchten Patientenkollektiv konnte kein signifikanter Anstieg der Z-Werte der Durchmesser der Neo-Aortenklappe und des linken Ventrikels beobachtet werden. Die Z-Werte des Neo-Aortenwurzel-Durchmessers und des LVEDD näherten sich im Verlauf signifikant den Normkurven an. Bei keinem Patienten wurde ein Ersatz des Autografts notwendig. 1 Patient benötigte eine operative Revision der Neo-Aortenklappe in Form einer supravalvul¨aren Kürzung und Ummantelung der Autograft-Wurzel bzw. des sino-tubulären Übergangs. Bei 15 Patienten kam es im Verlauf zu einer Autograftinsuffizienz ersten Grades. Diese beobachteten Einschränkungen der Neo-Aortenklappenfunktion im Sinne einer geringen oder trivialen Insuffizienz waren ohne klinische Relevanz. 1 Patientin verstarb unmittelbar postoperativ an einer intrazerebralen Blutung. Zu weiteren schwerwiegenden Komplikationen kam es nicht. Die Haltbarkeit des Pulmonalis-Ersatzes durch einen Homograft oder einen Xenograft war bereits innerhalb der ersten postoperativen Dekade limitiert. Im postoperativen Nachbeobachtungszeitraum benötigten 5 Patienten einen Austausch des Implantats. Bei den ausgetauschten Homografts handelte es sich in 3 Fällen um Pulmonalis-Homografts und in 2 Fällen um Aortenhomografts. Fazit: Die Ross-Operation ist ein Verfahren des AKE, das besonders für Kinder und Jugendliche auf Grund des Wachstumspotentials, der exzellenten Hämodynamik, der Regenerationsfähigkeit, der Infektresistenz, der uneingeschränkten natürlichen Funktion und der Athrombogenität besonders geeignet ist. Auch für Frauen mit Kinderwunsch und junge Männer mit Risikoprofil (durch Sport oder verletzungsträchtige Berufstätigkeit) oder Patienten mit Kontraindikation für eine Phenprocoumon-Therapie ist die Ross- Operation wegen der nicht notwendigen Marcumarisierung eine attraktive Behandlungsoption. Die befürchtete Dilatation des Autografts im Langzeitverlauf konnte nicht beobachtet werden.

La procédure de Ross: Propriétés biomécaniques de l'artère pulmonaire en fonction du phénotype valvulaire aortique Pierre Olivier Dionne, Evan Wener, Alexander Emmott, Raymond Cartier, Rosaire Mongrain, Richard Leask et Ismail El-Hamamsy OBJECTIFS: Le but de cette étude est de déterminer si les propriétés des artères pulmonaires des patients bénéficiant d'une procédure de Ross ayant une valve aortique bicuspide sont différentes que celles des patients ayant une valve aortique tricuspide. MÉTHODOLOGIE: Trente-deux artères pulmonaires et 20 aortes ont été prélevées chez des patients subissant une procédure de Ross au moment de la chirurgie, dans une cohorte de 32 patients. L'analyse histologique et l'étude tensile equi-biaxiale ex-vivo complétées dans les 8 heures suivant le prélèvement furent utilisées afin d'évaluer les différences entre les groupes de patients et entre les artères pulmonaires et les aortes ascendantes. RÉSULTATS: Il n'y avait aucune différence d'épaisseur au niveau des artères pulmonaires lorsque comparées en fonction du phénotype valvulaire aortique (P = 0.94). Il n'y avait aucune différence au niveau des propriétés tensiles parmi les aortes et les artères pulmonaires lorsque comparées en fonction du phénotype valvulaire. Lorsque comparées en fonction de leur indication chirurgicale, les artères pulmonaires de patients ayant une régurgitation aortique pure étaient moins rigides que leur contre-partie (P = 0.002). Il n'y avait aucune différence au niveau du nombre de lamelles élastiques entre les spécimens d'artère pulmonaire en fonction du phénotype valvulaire aortique (Tricuspide, bicuspide ou unicuspide), ni entre les spécimens aortiques. CONCLUSION: Aucune différence significative ne fut observée au niveau des propriétés biomécaniques des artères pulmonaires lorsque comparées selon leur phénotype valvulaire aortique associé. / The Ross procedure: biomechanical properties of the pulmonary artery according to aortic valve phenotype Pierre Olivier Dionne, Evan Wener, Alexander Emmott, Raymond Cartier, Rosaire Mongrain, Richard Leask and Ismail El-Hamamsy OBJECTIVES: The aim of this study is to determine whether patients undergoing the Ross procedure with bicuspid aortic valves have different pulmonary artery biomechanical properties from those with tricuspid valves. METHODS: Thirty-two pulmonary arteries and 20 aortas were obtained from patients undergoing the Ross procedure at the time of surgery, from a cohort of 32 patients. Histological analysis and ex vivo equi-biaxial tensile testing completed within 8 hours of surgery were used to evaluate differences in patient groups and between the pulmonary artery and the ascending aorta. RESULTS: There was no difference in thickness among pulmonary arteries when compared according to aortic valve phenotype (P = 0.94). There was no difference in the tensile tissue properties among aortas and pulmonary arteries when compared according to aortic valve phenotype, in either the circumferential or longitudinal axis. When compared according to the main surgical indication, pulmonary artery walls from patients with pure aortic regurgitation were less stiff than their counterparts (P = 0.002). There was no difference in the number of elastic lamellae in pulmonary artery specimens from the three different aortic valve phenotypes (Tricuspid, bicuspid or unicuspid), as well as in the aortic specimens. CONCLUSION: No significant differences were observed in the biomechanical properties of pulmonary arteries when compared according to aortic valve phenotype.

Indiana University-Purdue University Indianapolis (IUPUI) / Petrography of the sand fraction, particle size analysis, and detrital zircon U/Pb isotope data, and pebble count data were collected from Byrd Glacier moraines and central/western Ross Sea till in order to study the glacially-driven sedimentological dynamics of the Byrd Glacier and to trace material transported from the Byrd Glacier into the Ross embayment. Most of the petrographic data show evidence of local derivation with the exception of the sites from the Lonewolf Nunataks as indicated by exotic rock types within the sand and pebble fractions. This, in conjunction with particle-size data of the samples from the Lonewolf Nunataks indicate that material from underneath the East Antarctic Ice Sheet (EAIS) is being transported to the surface and deposited in this area. The U/Pb ages of zircons from the Byrd Glacier show dominant populations of Ross to Pan-African ages (~533 - 610 Ma) with varying populations of older (Grenville to Archean) zircons. Late Precambrian (~588 – 610 Ma) aged detrital zircons in samples from the head of the Byrd Glacier are older than other dated grains found in the vicinity and may be evidence of early development of the Ross belt or represent evidence of sub-glacial extension of the Mozambique structure found in Dronning Maud Land. The west central Ross Sea till samples have a variety of mineral and lithic fragments that include a dominant population of polymict at certain depth intervals. Detrital zircon data suggests the potential provenance of two of these intervals may be derived from Marie Byrd Land and possibly the Byrd Glacier. Using sand petrography and U/Pb detrital zircon age dating, positive correlation was found between specific samples from the head of the Byrd Glacier and the western Ross Sea. The ice-sheet flow models of Stuiver et al. (1981), Licht and Fastook (1998), and Licht et al. (2005) each show potential support from aspects of this study. It is possible that dynamic ice-flow regime changes of the West and East Antarctic Ice Sheets into the Ross Sea may have occurred some time during the LGM as suggested by geochemical and petrographical evidence found within intervals of central and western Ross Sea cores.

Diatoms (Bacillariophyta) are one of the most diverse algal groups in the Antarctic Region and play a dominant role in almost all freshwater and terrestrial ecosystems. Despite this overall occurrence, little is known about the diversity, ecology and biogeography of this group in the Maritime Antarctic Region. The main objective of this thesis is therefore to define the taxonomical, ecological and biogeographical characterisation of aquatic, semi- aquatic and moss-inhabiting diatom communities from two islands in the Maritime Antarctic Region: James Ross Island and Livingston Island, located on opposite sides of the Antarctic Peninsula. In this study, a total of 250 samples from three different habitat types (lakes, streams & seepage areas and mosses) from Byers Peninsula (Livingston Island) and Ulu Peninsula (James Ross Island) have been analysed. Using light and scanning electron microscopy, a rather diverse diatom flora composed of 178 taxa, belonging to 43 genera has been identified. Although even until recently, it was generally accepted that the Antarctic diatom flora was mostly composed of cosmopolitan taxa, several new species could be described as a new for science during this PhD study (a reflection of this work is presented in chapters 2 & 3 and in Appendices). Habitat type and...

A complexa interação que ocorre entre os processos oceânicos e atmosféricos no Oceano Austral afeta a circulação oceânica global em diferentes camadas. O Mar de Weddell e o Mar de Ross possuem reconhecida importância na formação da Água de Fundo Antártica (AABW). O objetivo principal deste trabalho é caracterizar as massas de água dos Mares de Weddell e Ross, através dos dados mais recentes de reanálise oceânica SODA (Simple Ocean Data Assimilation). Através da técnica de separação de massas de água Análise Multiparamétrica Ótima (AMO) foi possível a identificação de 3 principais massas de água no Mar de Ross: Água Profunda Circumpolar Superior (UCDW), Água Profunda Circumpolar Inferior (LCDW) e Água de Plataforma de Baixa Salinidade (LSSW). A UCDW foi a que apresentou a maior variabilidade, não atingindo a Plataforma de gelo do MR durante os anos de 1950-1974. No Mar de Weddell foi possível a identificação das seguintes massas de água: Água Profunda Cálida (WDW), Água Profunda do Mar de Weddell (WSDW) e Água de Fundo do Mar de Weddell (WSBW). A WDW atingiu valores >70% à 800m. A WSDW possui em seu núcleo valores > 90% entre 2000 e 3500m. A WSBW, apresenta ~100% em profundidades > 4000m. / The complex interaction that occurs between the oceanic and atmospheric processes in the Southern Ocean affects global ocean circulation in different layers. The Weddell and Ross Seas have recognized importance in the formation of Antarctic Bottom Water (AABW). This work aims to characterize the water masses of the Weddell and Ross Seas, using the latest ocean data reanalysis SODA (Simple Ocean Data Assimilation). Through the water masses separation technique, Optimum Multiparameter Analysis (OMP), it was possible to identify three main water masses in Ross Sea: Upper Circumpolar Deep Water (UCDW), Lower Circumpolar Deep Water (LCDW) and Low Salinity Shelf Water (LSSW). UCDW showed the greatest variability, not reaching the Ross Sea Ice Shelf during the years 1950-1974. It was possible to identify the following water masses in Weddell Sea: Warm Deep Water (WDW), Weddell Sea Deep Water (WSDW) and Weddell Sea Bottom Water (WSBW). WDW reached values up to 70% in 800m. WSDW has in its core values > 90% between 2000 and 3500m. WSBW presents a contribution up to 100% at depths > 4000m.

O oceano desempenha papel fundamental na configuração e manutenção do clima da Terra, sendo considerado um dos componentes principais do sistema climático.Diversos estudo foram conduzidos para avaliar as mudanças nos processos climáticos e como o clima, em contrapartida, é afetado por tais mudanças. O presente trabalho visa investigar o impacto das mudanças climáticas na formação de massas de água do oceano austral. Foram analisados resultados de simulação numérica para os séculos XX e XXI pelo modelo CCSM3 para os cenários 20c3m e SRESA1B do IPCC. Através da técnica de separação de mássas de água Análise Otimizada de Parâmetros Múltiplos (OMP) foram identificadas 3 massas de água no Mar de Ross: Água Profunda Circumpolar (CDW); Água da Plataforma de Gelo (ISW); Água de Plataforma de Baixa Salinidade (LSSW). A ISW, precursora da Água de Fundo Antártica (AABW), apresenta maior variação espacial tornando-se mais rasa no século XX e assumindo camadas mais profundas no século XXI. A variação da ISW está relacionada à variação do Modo Anular Sul (SAM) e à variação do gelo marinho. / It has been known for a long time that the ocean plays the most important role on Earth\'s heat budget, what turns it into a major component of the global climate system. Therefore, many studies have been made to assess whether features of climate processes are changing and how may climate itself be affected by these changes. This work aims to look at the impact of climate changes on water masses formation in the Southern Ocean. Results from the 20th century and SRESA1b CCSM3/NCAR simulation (1870 to 2100) were analyzed using the Optimum Multiparameter Analysis (OMP) to separate water masses. Three water masses were identified in the Ross Sea: Circumpolar Deep Water (CDW); Ice Shelf Water (ISW); Low Salinity Shelf Water (LSSW). Simulation results have shown that the ISW gets shallower during the 20th century and then, during the 21stcentury, it gets deeper and occupies the deepest layer by 2100 while it flows towards higher latitudes as AABW. Much closely to what has been shown by observational studies, water masses formation in the Southern Ocean is intrinsically linked to atmospheric vaiability modes, such as the southern annular mode--SAM, and to sea ice variation.

Esta dissertação propõe analisar os diálogos da peça Glengarry Glen Ross, de David Mamet, um dos principais dramaturgos do teatro norte-americano contemporâneo. A hipótese sugerida é que esses diálogos substituem a ação dramática e representam o substrato social que serviu de ponto de referência para a criação do enredo. São neles que as \"relações venais\" e o jogo de poder entre os personagens se concretizam, numa linguagem ilusória e ambígua, na qual valores individuais e comunitários, como a confiança, a amizade, a afeição, a lealdade e a verdade se subverteram, diante da necessidade de sobrevivência ou do sucesso a qualquer preço, ditados pelas práticas comerciais, pelas relações de poder, por uma mentalidade de negócios predatória e se transformaram em mercadoria, lucro e roubo. Glengarry Glen Ross (1983) faz parte da chamada \"trilogia do poder\", que abarca ainda American Buffalo (1975) e Speed-the-Plow (1985). As personagens dessas peças ou vivem à margem da sociedade capitalista norteamericana, como o triângulo masculino em American Buffalo, ou são representantes da baixa classe média, como os corretores de imóveis de Glengary Glen Ross, submetidos a uma competição feroz imposta pela direção da firma, onde os vencedores são promovidos e os perdedores, demitidos. Nessas circunstâncias, o contato humano entre eles foi corrompido pela ganância, pelo dinheiro, pela necessidade de sobrevivência. Essas peças são um exercício de crítica ao darwinismo social. / This dissertation aims to analyze the speeches in Glengarry Glen Ross, a play by David Mamet, one of the leading playwrights of the contemporary American theatre. The hypotheses suggested are that these speeches replace the dramatic action and that they represent the social stratum which has served as reference point for the creation of the plot. They also make the \'venal relations\' and the power game between the characters concrete, but they do so through the use of a deceptive and ambiguous language, in which individual and communal values, such as trust, friendship, affection, loyalty and truth, are subverted, in face of the need for survival or success at any cost, determined by commercial practices, power relations, predatory business mindset, and are turned into commodities, profit and theft. Glengarry Glen Ross (1983) is part of the \"power trilogy\", which also comprises American Buffalo (1975) and Speed-the-Plow (1985). The characters in these plays either live on the margins of the American capitalist society, as the ones in the masculine triangle in American Buffalo, or are representatives of the lowermiddle- class, such as the realtors in Glengarry Glen Ross, subjected to a cutthroat competition by the corporation owners, in which the winners are promoted and the losers are fired. In these circumstances, genuine human contact among them is corrupted by greed, money, and the need for survival. These plays are an exercise of criticism of social Darwinism.

Nesta dissertação de mestrado nós trabalhamos com o processo de Cox-Ingersoll- Ross, que foi originalmente proposto por John C. Cox, Jonathan E. Ingersoll Jr. e Stephen A. Ross em 1985. Este processo é amplamente utilizado em modelagem financeira, por exemplo, para descrever a evolução de taxas de juros ou como o processo de volatilidade no modelo de Heston. A equação diferencial estocástica que define este processo não possui solução fechada, logo faz-se necessária a aproximação do processo via algum método numérico. Na literatura diversos trabalhos propõem aproximações baseadas em esquemas de discretização intervalar. Nós aproximamos o processo de Cox-Ingersoll-Ross através de um método numérico do tipo Euler- Maruyama baseado na discretização aleatória proposta por Leão e Ohashi (2013) sob a condição de Feller. Neste contexto, mostramos que esta aproximação possui uma ordem de convergência exponencial e utilizamos técnicas de simulação Monte Carlo para comparar resultados numéricos com valores teóricos. / In this master\'s thesis we work with Cox-Ingersoll-Ross (CIR) process. This process was originally proposed by John C. Cox, Jonathan E. Ingersoll Jr. and Stephen A. Ross in 1985. Nowadays, this process is widely used in financial modeling, e.g. as a model for short-time interest rates or as volatility process in the Heston model. The stochastic differential equation (SDE) which defines this model does not have closed form solution, so we need to approximate the process by some numerical method. In the literature, several numerical approximations has been proposed based in interval discretization. We approximate the CIR process by Euler-Maruyama-type method based in random discretization proposed by Leão e Ohashi (2013) under Feller condition. In this context, we obtain an exponential convergence order for this approximation and we use Monte Carlo techniques to compare the numerical results with theoretical values.