La technique d’empreinte génétique par rep-PCR, qui utilise des séquences d’ADN répétitives, a été utilisée pour mettre en évidence la présence de groupes d’Escherichia coli signatures pour divers poulaillers et d’évaluer leur évolution suite au détassement. L’amorce (GTG)5 a été utilisée pour générer des empreintes d’ADN de 522 isolats provenant de 7 poulaillers échantillonnés deux fois : juste avant et 5 jours après le détassement. Les empreintes d’ADN ont été analysées selon l’algorithme de correspondance de bandes de Jaccard. Les analyses de Jackknife des coefficients de similitude ont révélé qu’entre 73% et 93% des isolats ont pu être correctement regroupés selon leur poulailler d’origine. Un dendrogramme construit à partir des coefficients de similitude de Jaccard a groupé les isolats dans 42 grappes avec près de la moitié dans une seule grappe. Environ 80% des isolats ont été groupés dans les 6 plus grosses grappes. Quatre de ces grappes été constituées majoritairement d’isolats provenant d’un seul site. Ces grappes pourraient être des grappes signatures qui permettraient d’identifier des poulaillers en particulier. La comparaison des nombres de grappes présentes avant et après le détassement a révélé une variabilité de l’impact du détassement sur les populations fécales d’E. coli. Pour certains sites, il y avait peu d’agrégats présents tant avant qu’après le détassement alors que pour d’autres sites c’était le contraire. Quoique plus de recherches soient nécessaires afin de valider les conclusions, nos résultats suggèrent la présence de sous-populations signatures d’E. coli pour certains poulaillers et une réponse variable à l’effet du détassement. / Rep-PCR genomic fingerprinting, which uses repetitive intergenic DNA sequences, was investigated as a mean to identify signature pattern of chicken fecal Escherichia coli populations and evaluate their changes over time. The (GTG)5 primer was used to generate DNA fingerprints from 522 isolates originating from 7 chicken houses just prior to, and five days after, thinning. The DNA fingerprints were analysed by using the Jaccard band-matching algorithm. Jackknife analysis of the resulting similarity coefficients revealed that between 73% and 93% of the isolates could correctly be grouped in their house of origin. A dendrogram constructed by using Jaccard similarity coefficients grouped the isolates in 42 clusters with approximately half of them in the same cluster. Out of the 6 largest clusters, containing 80% of all isolates, 4 consisted mostly of isolates coming from only 1 house. These clusters could represent signature clusters identifying specific houses. A comparison of the number of clusters present before and after thinning for each house revealed a substantial difference in the behaviour of the fecal E. coli. For some houses, there were few clusters represented both before and after thinning, with a high number of new clusters appearing after thinning whereas in other houses, the contrary was observed. Our results suggest the presence of a signature subpopulation in some chicken houses and a variable response of the E. coli population to the effect of thinning.

Dans le cadre de ce travail, nous nous sommes intéressés à un concept innovant d’empoisonnement homogène des neutrons par insertion de terres rare (erbium et gadolinium) dans les gaines en alliage de zirconium pour les réacteurs à eau pressurisée. L’étude des équilibres entre phases des alliages erbium–zirconium et gadolinium–zirconium est indispensable comme préalable à la mise en oeuvre industrielle de ce procédé prometteur d’empoisonnement. Ce travail a consisté à déterminer expérimentalement le diagramme de phases du système erbium–zirconium. Nous avons, par le biais de différentes caractérisations, obtenu des données diagrammatiques. Avec celles-ci, nous proposons un nouveau tracé du diagramme de phases. Celui-ci est radicalement différent de celui disponible dans la littérature. Nous avons modélisé le système par l’approche CALPHAD. Nous avons également déterminé les limites de solubilité des solutions solides terminales du système gadolinium–zirconium. Les données obtenues expérimentalement sont en accord avec le tracé expérimental de la littérature et avec le modèle thermodynamique disponible. Afin de prendre en compte l’oxydation des gaines en service, nous nous sommes également intéressés aux systèmes erbium–oxygène–zirconium et gadolinium–oxygène–zirconium. Le premier système a fait l’objet d’une étude expérimentale. Nous avons mis en place un procédé de synthèse par métallurgie des poudres, incluant la synthèse de celles-ci à partir de métaux massifs. La caractérisation des échantillons ternaires nous a permis de proposer deux coupes isothermes (800°C et 1100°C). Pour le système gadolinium–oxygène–zirconium, nous avons prédit les équilibres entre phases à différentes températures à l’aide de calculs effectués à partir d’une base de données que nous avons construite avec les modèles thermodynamiques de la littérature des systèmes oxygène–zirconium, gadolinium–zirconium et sesquioxyde de gadolinium–zircone. Enfin, nous avons travaillé avec des alliages erbium–zirconium fabriqués en milieu industriel. Nous nous sommes intéressés à leurs propriétés mécaniques en traction, en lien avec leur microstructure. Nous avons mis en évidence l’effet durcissant de l’erbium, notamment à 325‰°C / This work is a contribution to the development of innovating concepts for fuel cladding in pressurized water nuclear reactors. This concept implies the insertion of rare earth (erbium and gadolinium) in the zirconium fuel cladding. The determination of the phase equilibrium in the systems is essential prior to the realisation of such a promising solution. This study consisted in the experimental determination of the erbium–zirconium phase diagram. For this, we used many different techniques to get diagram data like solubility limits and solidus, liquidus or invariant temperatures. With these data, we were able to give a new diagram, very different from the literature one. With the experimental data we collected, we also assessed the diagram, using the CALPHAD approach. In this work, we also determined the solubility limits of the gadolinium–zirconium system. Those limits had never been determined before, and the values we obtained are in excellent agreement with the experimental and with the assessed diagrams. Because these alloys are subjected to oxygen diffusion throughout their life, we focused our attention on the erbium–oxygen–zirconium and gadolinium–oxygen–zirconium system. The first system has been investigated experimentally.We used many different synthesis techniques, and we finally have opted for a powder metallurgy one. As raw material, we fabricated powder from erbium and zirconium bulk metals using hydrogen absorption/desorption. With the formed ternary pellets, we investigated the phase equilibria at 800°C and 1100°C. With the obtained data, we propose two isotherms at those two temperatures. For the gadolinium–oxygen–zirconium system, we calculated the phase equilibria at temperatures ranging from 800°C to 1100‰°C, using a homemade database compiled from literature assessments of the oxygen–zirconium, gadolinium–zirconium et gadolia-zirconia systems. We also determined the mechanical properties, in connexion with the microstructure, of industrial quality alloys in order to identify the influence of erbium content. We highlighted the hardening influence of erbium at 325‰°C

Made available in DSpace on 2015-04-14T13:47:12Z (GMT). No. of bitstreams: 1 425809.pdf: 1019133 bytes, checksum: 9dfcb1e38d729c66b3d9922fdee85331 (MD5) Previous issue date: 2010-08-20 / Este trabalho que traz por t?tulo Cotidiano, Escritas de si e o Coronelismo: a correspond?ncia de Manoel de Freitas Valle Filho a Borges de Medeiros (1903 a 1916), visa analisar um Corpus documental ainda n?o usado, formado por 58 correspond?ncias de Manoel de Freitas Valle Filho a Borges de Medeiros, no per?odo entre 1903 a 1916. Justifica-se por tratar de uma conjuntura da hist?ria do Rio Grande do Sul de extrema import?ncia, pois ? o momento de cria??o de uma forma de poder pol?tico o coronelismo de historiografia lacunosa; tamb?m por analisar correspond?ncias reservadas trocadas entre coron?is ga?chos; h? poucas informa??es na historiografia ga?cha sobre o coronel Manoel de Freitas Valle Filho, que foi Vice-Presidente do Estado do Rio Grande do Sul junto ao Presidente Carlos Barbosa Gon?alves, no per?odo que vai de 1908 a 1912. Essa fase foi um momento de descontinuidade no longo per?odo em que Borges de Medeiros exerceu um poder autorit?rio neste Estado (1898 1928). O trabalho tem como objetivo: Investigar as rela??es entre o chefe pol?tico estadual Borges de Medeiros e o chefe pol?tico local Manoel de Freitas Valle Filho, no per?odo de 1903 a 1916, protagonistas do coronelismo ga?cho. Tendo em vista as rela??es pessoais de Manoel de Freitas Valle Filho com o partido de oposi??o ao PRR, questiona-se at? que ponto a presen?a do mesmo, como Vice-Governador do Estado do Rio Grande do Sul, pode ter sido tramada para acalmar os ?nimos da oposi??o? Constata-se nas correspond?ncias, que Freitas Valle era um autor que escrevia discursos com objetivos de quem deseja apaziguar ?nimos, na busca de resolver disc?rdias, sem, entretanto, lograr agradar a todos, como evidenciam suas cartas.

Made available in DSpace on 2015-04-14T13:47:54Z (GMT). No. of bitstreams: 1 447097.pdf: 1751018 bytes, checksum: 0d8871a4cd97aaa54cce2a2f5129a716 (MD5) Previous issue date: 2013-03-25 / This paper analyzes the period of republican propaganda in Brazil (between 1880 and 1889) through the agency of a main character: Joaquim Francisco de Assis Brasil. The analysis of the trajectory of this young propagandist and his investments in the world of literacy and politics helps to reflect on two phenomena discussed throughout the text: the circulation of ideas in Brazil in the late nineteenth century and the strength of the republican movement in the countryside and missions in the state Rio Grande do Sul, Southern Brazil. Our focus is on the range of social relations in which Assis Brasil was involved. Therefore, he was always taken in interaction with other individuals such as their family, friends and political associates. The use of prosopography and the concepts of social networking, family and mediation strategy are some of the methodological theoretical contributions that allowed us to perform this research, based on the study of the social context in that period. Thus, it is possible to identify that young propagandists were not used to acting alone but they were part of a project shared by other family members which sought the access to power. Similarly, the existence of some bonds of friendship and kinship as well as the subsequent formulation of the relationship networks among propagandists from the most diverse Brazilian provinces collaborated to spread the republican ideal. On the other hand, by trying to identify the profile of the republicans from the third constituency, who also contributed to the election of Assis Brasil to the position of provincial deputy, we conclude that this group was formed from social rural roots - most of them involved with the raising of cattle, and with strongly hierarchical ideas while the analysis of the profile of the leaders from Rio-Grandense Republican Party demonstrated strong professional feature in this group, even though they belonged to families of rural society elites, who were traditionally involved in conservative politics of the province. At last, our focus is on the performance of Assis Brasil as provincial deputy and about his trial seeking grants and support to the industry of cattle production from the parliament so that it could benefit not only his family but also relatives, friends and his political base in the border region of southern Brazil. / O presente trabalho analisa o per?odo da propaganda republicana (entre os anos de 1880 e 1889) atrav?s da atua??o de um personagem principal: Joaquim Francisco de Assis Brasil. A an?lise da trajet?ria do jovem propagandista e de seus investimentos no mundo das letras e da pol?tica colabora para pensarmos a respeito de dois fen?menos trabalhados ao longo do texto: a circula??o de ideias no Brasil de fins do s?culo XIX e a for?a do movimento republicano nas regi?es da campanha e missioneira, no Rio Grande do Sul. Nosso enfoque recai sobre o leque de rela??es sociais nas quais Assis Brasil estava envolto. Logo, ele ? tomado sempre em intera??o com outros indiv?duos, sejam eles seus familiares, amigos e correligion?rios pol?ticos. A utiliza??o da prosopografia e o uso das no??es de rede social, estrat?gia familiar e mediador s?o alguns dos aportes te?ricos metodol?gicos que nos permitiram realizar esta investiga??o, partindo de uma leitura do social. Nesse sentido, ? poss?vel identificar que os jovens propagandistas n?o atuavam isoladamente, mas, pelo contr?rio, faziam parte de um projeto compartilhado pelos demais membros da fam?lia e que visava acessar o poder. Do mesmo modo, a exist?ncia de alguns la?os de amizade e parentesco e a consequente formula??o de redes de relacionamento entre os propagandistas das mais variadas prov?ncias brasileiras colaboravam na divulga??o do ideal republicano. Por outro lado, tentando identificar o perfil dos republicanos do terceiro c?rculo eleitoral, e que colaboraram para a elei??o de Assis Brasil ao cargo de deputado provincial, conclu?mos que se tratava de um grupo com bases sociais rurais, envolvido em sua maioria com a cria??o de gado, e fortemente hierarquizado, enquanto que a an?lise do perfil das lideran?as do Partido Republicano Rio-Grandense demonstrou o forte car?ter profissional deste grupo, muito embora os mesmos pertencessem ?s fam?lias de elites estancieiras, tradicionalmente envolvidas com a pol?tica conservadora da prov?ncia. Por fim, nosso foco recai sobre a atua??o de Assis Brasil como deputado provincial e sobre a tentativa deste em buscar subs?dios e apoio ? ind?stria pecuarista no parlamento, beneficiando, assim, n?o s? a sua fam?lia, como tamb?m parentes, amigos e sua base pol?tica na fronteira.

Made available in DSpace on 2015-04-14T13:47:57Z (GMT). No. of bitstreams: 1 448009.pdf: 5718766 bytes, checksum: fcdc0ed165f9b223c0eded95c8f2eb8d (MD5) Previous issue date: 2013-03-26 / In "An international problem of serious proportions": The cooperation between the Rockefeller Foundation and the Government of the State of Rio Grande do Sul to fight ancylostomiasis and its consequences (1919-1929)", our proposal is to analyze the cooperation between the International Health Board of the Rockefeller Foundation and the government of the state of Rio Grande do Sul to fight a rural endemic disease, ancylostomiasis, in the 1920s, and the developments and consequences of this cooperation on public health in the state, both as regards the fight against ancylostomiasis and the organization of health in the state, taking aspects of the international, national and local context into account. Based on the discussion in the literature concerning the topic and the analysis of the documents produced, especially by the Rockefeller Foundation (reports, letters and publications), and by the government of the state of Rio Grande do Sul (Reports of the Department of the State for Internal and Foreign Affairs), we shall focus on activities to fight the disease performed in Rio Grande do Sul municipalities as a result of the cooperation between the Foundation and the state government, guided by the North American institution and performed through the state Directorate of Hygiene between 1920 and 1923. / Em An international problem of serious proportions : A coopera??o entre a Funda??o Rockefeller e o governo do estado do Rio Grande do Sul no combate ? ancilostom?ase e seus desdobramentos (1919-1929), nossa proposta ? analisar, levando em considera??o aspectos do contexto internacional, nacional e local, a coopera??o entre a divis?o internacional de sa?de International Health Board da Funda??o Rockefeller e o governo estadual do Rio Grande do Sul no combate a uma endemia rural, a ancilostom?ase, na d?cada de 1920, e os desdobramentos, as consequ?ncias desta coopera??o na sa?de p?blica estadual, tanto no que se refere ao combate ? ancilostom?ase em si quanto ? organiza??o da sa?de no estado. A partir da discuss?o de bibliografia pertinente ao tema e da an?lise de documenta??o produzida, principalmente, pela Funda??o Rockefeller (relat?rios, correspond?ncia e publica??es) e pelo governo do estado do Rio Grande do Sul (Relat?rios da Secretaria de Estado dos Neg?cios do Interior e Exterior), enfocaremos as atividades de combate ? doen?a realizadas em munic?pios ga?chos a partir da coopera??o entre a Funda??o e o governo estadual, orientadas pela institui??o norte-americana e realizadas atrav?s da Diretoria de Higiene estadual entre 1920 e 1923. Al?m disso, discutiremos tamb?m o trabalho de combate ? ancilostom?ase mantido pelo governo estadual ap?s o t?rmino da coopera??o com a Funda??o, com a organiza??o do Servi?o de Postos de Profilaxia Rural estadual em funcionamento entre 1924 e 1929. Por fim, abordaremos a atua??o da Funda??o na forma??o de profissionais de sa?de p?blica, pois, durante a coopera??o entre a institui??o e o governo estadual, um m?dico da Diretoria de Higiene, Fernando de Freitas e Castro, recebeu uma bolsa para realizar estudos em sa?de p?blica nos Estados Unidos entre 1922 e 1923. Em 1929, Freitas e Castro, ent?o ? frente da pasta da sa?de no Rio Grande do Sul, p?s fim ?s atividades do Servi?o de Postos de Profilaxia Rural a partir da proposta de uma Reforma Sanit?ria que introduzia, no estado, os health centers ou centros de sa?de, um modelo de organiza??o em sa?de p?blica difundido pela Funda??o.

Made available in DSpace on 2015-04-14T13:55:02Z (GMT). No. of bitstreams: 1 419772.pdf: 577605 bytes, checksum: 2e838d9686c1eb2d03dec4db04d1e570 (MD5) Previous issue date: 2009-11-30 / Com o surgimento da comunica??o em n?vel global, os seres humanos encontramse ligados como nunca antes na hist?ria da humanidade. Em meio ao que convencionamos denominar de Globaliza??o, a racionalidade humana recebe novos desafios que se perfilaram com o desenrolar hist?rico. Frente a estes novos desafios, os antigos paradigmas da racionalidade ocidental, bem como nossa organiza??o social tentam configurar-se com sa?das que respeitem as conquistas anteriores tais como a condena??o da escravid?o e os direitos humanos e, ao mesmo tempo, criem solu??es para graves problemas como os de cunho ambiental e da satisfa??o das necessidades sejam elas econ?micas ou morais da comunidade globalizada. Para tanto, baseado no ideal Kantiano de uma Paz Perp?tua onde os povos, al?m de adotarem um modelo republicano, ainda viveriam em harmonia com as demais republicas, Otrified H?ffe, prop?em a forma??o de uma Republica Mundial ?nica. Respeitando a diversidade e os Estados nacionais j? existentes, garanta o cumprimento de normas ambientais e dos direitos humanos. Tal rep?blica remonta sua legitima??o frente a uma nova forma de teoriza??o sobre o estado, que n?o busca mais suas especifica??es apenas no conflito ou apenas na coopera??o, mas em uma nova forma de fundamenta??o: a troca. H?ffe n?o mais embasa a legitima??o sob pontos de vistas que se polarizam entre um altru?smo ou um ego?smo, mas em trocas rec?procas que garantam determinados objetivos. Tal mudan?a ? acompanhada pela proposta de uma mudan?a no paradigma racional, que agora visa uma comunica??o ?tica. Onde um sistema ou a burocracia estatal deve manter-se afastada de um mundo da vida, de cada sujeito, proporcionando de forma ?tica a conviv?ncia de todos os seres humanos. Em sua teoria de agir comunicativo, Habermas apresenta tal prot?tipo, relegando uma importante contribui??o para filosofia. No presente trabalho, ap?s uma apresenta??o detalhada de ambas as propostas, ser? proposta um debate entre as id?ias de ambos os autores, a fim de proporcionar uma nova vis?o sobre a possibilidade da cria??o de uma Rep?blica Mundial Subsidi?ria, de tal forma que a import?ncia de tal discuss?o se apresenta no mesmo grau da inova??o para uma Rep?blica Mundial Subsidi?ria, que, por sua vez, se efetivada, tocar? na vida cotidiana de cada um dos sujeitos do mundo.

Made available in DSpace on 2015-04-14T14:23:14Z (GMT). No. of bitstreams: 1 431032.pdf: 8474817 bytes, checksum: dbf6a31dce88df573c082ad5cd2b3c67 (MD5) Previous issue date: 2011-03-01 / O estudo analisa o espa?o e a arquitetura escolar do Col?gio Elementar Fernando Gomes, constru?do em Porto Alegre em 1913, com o projeto do engenheiro Affonso H?bert. Examina quest?es referentes ? inadequa??o dos espa?os adaptados para a escola prim?ria e a necessidade de constru??o de pr?dios escolares, estabelecendo uma rela??o com o planejamento e constru??o visual das cidades, no in?cio da Primeira Rep?blica no Brasil. O objetivo principal consiste em acompanhar o per?odo de constru??o do Col?gio Elementar Fernando Gomes (1913-1922) relacionando-o com os projetos de reformas da cidade de Porto Alegre. Foi realizada uma busca sobre outras aquisi??es, constru??es e reformas de pr?dios escolares por parte do Governo do Estado, a fim de inventariar o conjunto dos espa?os escolares em Porto Alegre, assim como do interior do Estado. A pesquisa documental analisa os Relat?rios de Obras P?blicas e Relat?rios da Instru??o P?blica. Utiliza como corpus emp?rico fontes iconogr?ficas e peri?dicos de ?poca. Podemos constatar que a constru??o do pr?dio do Col?gio Elementar Fernando Gomes inaugura no Rio Grande do Sul uma nova concep??o de espa?o e arquitetura escolar para a escola prim?ria, que al?m de seu aspecto funcional, ou seja, para receber um n?mero elevado de alunos, incorpora uma s?rie de significados simb?licos, alinhados ao ideal republicano. A melhora visual da Capital do Estado era de grande import?ncia e a constru??o de pr?dios escolares uma das principais propagandas do regime instaurado com o advento da Rep?blica

Submitted by (lucia.rodrigues@ufrpe.br) on 2017-03-17T14:39:22Z No. of bitstreams: 1 Janaina Cortez de Oliveira.pdf: 616667 bytes, checksum: 9d56953508b1cd4518224b8966b15c92 (MD5) / Made available in DSpace on 2017-03-17T14:39:22Z (GMT). No. of bitstreams: 1 Janaina Cortez de Oliveira.pdf: 616667 bytes, checksum: 9d56953508b1cd4518224b8966b15c92 (MD5) Previous issue date: 2010-10-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The bacterial blight caused by Xanthomonas citri subsp. malvacearum (Xcm) is the most important bacterial disease of cotton in the Middle-West and Northeast Regions of Brazil. The variability of a population formed by 100 Xcm strains obtained from commercial fields in the states of Goiás, Mato Grosso, Mato Grosso do Sul and Bahia, Brazil, was analyzed based upon genetic and phenotypic characteristics. The enzymes amylase, lipase, cellulase and the polysaccharide levan were produced by all Xcm isolates while the caseinase was only produced by 20 strains. All strains induced hipersensitivity reaction in tomato leaves. The 100 strains were sensitive to copper oxychloride (1500 mg L-1), copper hidroxide (1614 mg L-1), oxytetracicline (600 mg L-1), oxytetracicline (90 mg L-1) + tribasic copper sulfate (1500 mg L-1) and oxytetracicline (76.6 mg L-1) + streptomycin sulfate (367.2 mg L-1), but resistant to kasugamycin (60 mg L-1). Among the eighteen tested antibiotics the strains presented variable reaction in relation to: nalidixic acid, amoxicillin, azithromycin, bacitracin, eritromicin, kanamycin, pefloxacin, tobramycin e vancomycin. Rep-PCR (REP, ERIC and BOX) showed the formation of five groups at 70% similarity level. Group I contained 98 strains, including the reference strain Xcm IBSBF1733, group II contained only two strains from Bahia and the other three groups included strains of Xanthomonas citri pv. anacardii, X. citri pv. mangiferaeindicae e X. axonopodis pv. spondiae used for comparison. This work also evaluated the effect of silicon (Si) on the bacterial blight of cotton control and the putative mechanisms involved in the resistance potentialized by this element were evaluated. Calcium silicate (CaSiO3) was incorporated into the soil at concentrations of 0.00, 0.25, 0.50, 1.50 and 3.00 g of SiO2 kg-1 soil 25 days before planting. Leaves of 33-day-old-plants were inoculated by infiltration with 0.5 mL suspension of Xcm (108 CFU ml-1). Components of resistance were evaluated every two days until 10 days after inoculation, at which point plant development and the accumulation of Si and Calcium (Ca) were also determined. H2O2 production and the activity of enzymes related to plant defenses were analyzed at 6, 12 and 24 hours after inoculation in plants +/-Si. In vitro inhibition of pathogen growth due to Si was also assessed. No significant difference was seen among the treatments regarding incubation period, disease incidence or inhibition of bacterial growth. However, with the application of 1.50 g of SiO2 kg-1 of soil, a reduction in severity (54.9%) was observed along with a reduction in the area under the disease progression curve (35.76%) and an increase in plant height (7.04%). There was no observable accumulation of Si in the cotton leaves. Levels of soluble proteins and H2O2 and activity of the enzymes SOD, APX, guaiacol peroxidase, PAL and b Glu were altered in the presence of Si (1.80 g SiO2 kg-1). Thus based on the genetic and phenotypic characteristics studied we conclude that the population of 100 Xcm strains presents low variability, and that the reduction of cotton bacterial blight severity mediated by Si is probably associated to the characteristic events of induced resistance observed. / A mancha-angular, causada por Xanthomonas citri subsp. malvacearum (Xcm), é a principal doença bacteriana do algodoeiro no Centro-Oeste e Nordeste do Brasil. A variabilidade de uma população de 100 isolados de Xcm, oriundos de plantas com sintomas típicos de mancha-angular em áreas produtoras de algodoeiro dos estados de Goiás, Mato Grosso, Mato Grosso do Sul e Bahia, Brasil, foi analisada com base em características fenotípicas e genéticas. As enzimas amilase, lipase e celulase e o polissacarídeo levana foram produzidos por todos os isolados de Xcm, enquanto a caseinase foi produzida apenas por 20 isolados. Todos os isolados induziram reação de hipersensibilidade em folhas de tomateiro. Os 100 isolados foram sensíveis a oxicloreto de cobre (1500 mg l-1), hidróxido de cobre (1614 mg l-1), oxitetraciclina (600 mg l-1), oxitetraciclina (90 mg l-1) + sulfato tribásico de cobre (1500 mg l-1) e oxitetraciclina (76,6 mg l-1) + sulfato de estreptomicina (367,2 mg l-1), e resistentes a casugamicina (60 mg l-1). Dentre os 18 antibióticos testados, os isolados bacterianos apresentaram reação variável a nove: ácido nalidíxico, amoxicilina, azitromicina, bacitracina, eritromicina, kanamicina, pefloxacina, tobramicina e vancomicina. Rep-PCR (REP, ERIC e BOX) revelou a formação de cinco grupos ao nível de 70% de similaridade, sendo o grupo I constituído de 98 isolados, incluindo o isolado referência de Xcm IBSBF1733, o grupo II, formado apenas por dois isolados oriundos da Bahia e os três outros grupos por isolados de X. citri pv. anacardii, X. citri pv. mangiferaeindicae e X. axonopodis pv. spondiae utilizados para comparação. Neste trabalho também foi avaliado o efeito do silício (Si) no controle da mancha-angular do algodoeiro, e os possíveis mecanismos envolvidos na resistência potencializada por este elemento. O silicato de cálcio (CaSiO3) foi incorporado ao solo nas doses de 0,00; 0,25; 0,50; 1,50 e 3,00 g de SiO2 kg-1 de solo 25 dias antes do plantio. Plantas com 33 dias tiveram as folhas inoculadas por infiltração com 0,5 mL de suspensão de Xcm (108 UFC ml-1). Os componentes da resistência foram avaliados a cada dois dias até 10 dias após a inoculação, quando o desenvolvimento da planta e o acúmulo de Si e Ca foram também determinados. Foram ainda analisadas a atividade de enzimas relacionadas à defesa vegetal e a produção de H2O2 às 6, 12 e 24 h após a inoculação em plantas +/-Si e a inibição in vitro do crescimento do patógeno. Não foi verificada diferença significativa entre os tratamentos quanto ao período de incubação, incidência da mancha-angular e inibição do crescimento da bactéria. Com a aplicação da dose 1,50 g SiO2 kg-1 de solo, observou-se redução da severidade (54,9%), da área abaixo da curva de progresso da doença (35,76%) e aumento na altura das plantas (7,04%). Não foi verificado acúmulo de Si nas folhas de algodoeiro. Níveis de proteínas solúveis e H2O2 e atividade das enzimas SOD, APX, POX, PAL e GLU foram alterados na presença do Si (1,80 g SiO2 kg-1). Com base nas características fenotípicas e genéticas analisadas, conclui-se que a população de 100 isolados de Xcm estudada apresenta baixa variabilidade e que a redução da severidade da mancha-angular do algodoeiro mediada por Si está provavelmente associada aos eventos característicos de indução de resistência observados.

L'objectif du travail présenté est d'acquérir expérimentalement de nouvelles données thermodynamiques sur les espèces qui constituent les produits de corrosion présents dans le circuit primaire des REP. Le volet expérimental de cette étude se focalise sur deux phases solides du nickel : l'oxyde de nickel NiO (ou bunsenite) et le ferrite de nickel NiFe2O4. La vitesse de dissolution de l'oxyde de nickel a été mesurée jusqu'à 130°C en milieu acide (pH 3 à 5). Un modèle cinétique a été utilisé afin de décrire les vitesses de dissolution mesurées expérimentalement. Ce modèle a permis de déterminer l'énergie d'activation réelle de la réaction de dissolution de l'oxyde de nickel. La solubilité d'un ferrite de nickel stœchiométrique synthétisé expérimentalement a été mesurée entre 100 et 200°C dans une cellule potentiométrique à électrodes à hydrogène. La spéciation du fer et du nickel dans la solution expérimentale a été discutée au regard des données thermodynamiques disponibles à haute température et des constantes d'équilibre calculées par le code MULTEQ. L'un des aspects de cette étude a consisté en la conception et la mise en route d'une cellule de mesure de solubilité à haute température : la boucle SOLO. Les spécifications techniques et le fonctionnement de cette installation seront présentés en détail.

Blend recognition and suppression from a tessellated model is important in applications such as model simplification in analysis and collaborative design where tessellated models are being used. This could also be used to pre-process the model before attempting to recognize form features in it. A procedure is described for recognizing and subsequently suppressing blends (fillets/rounds) in a tessellated model of a part. Earlier efforts on recognizing secondary features such as blends have used the boundary representation (B-Rep) of the part as input. Blend recognition and suppression from a tessellated model has not been addressed to the best of our knowledge. There has been work reported on the related problem of segmentation of tessellated surfaces. Segmentation refers to the decomposition of the object into regions where the underlying surfaces having similar characteristics. The segmented surface may be of any of surface like plane surface. There are two broad approaches to segmentation - vertex-based and edge-based. The vertex-based method clusters triangles consisting of connected vertices having the same attribute. One drawback of this method is that the boundaries of the clustered regions are not clearly defined due to difference in the labels of contiguous vertices. The edge-based method is based upon the dihedral angle at each edge in the tessellated model. The main drawback of this method is that edges in the boundary of the segmented patches are disconnected. This will result in an incomplete bounding loop when used for recognizing features. Smooth transitions at the boundary of features cannot be trapped with this approach. These techniques cannot be therefore used for recognizing blends. There have been efforts to recognize and suppress blends in a B-Rep model. Suppressing blend features in a B-Rep model is easier (compared to suppression from tessellated model) because smooth edges provide a clue to presence of blends. In the case of a tessellated model, the bounding loop of blends will not consist of smooth edges and no explicit signature is available for blends. In B-Rep model, information about the radius of blend is also available while this is not directly available in a tessellated model. Constant radius blends meet the requirements of most blending features encountered in mechanical part design. The surfaces forming a constant radius blend may be classified as cylindrical, spherical and toroidal surfaces. Spherical blend is formed by a blending operation at a vertex at which either three concave linear edges or three convex linear edges are incident. Blending operation on a linear edge forms cylindrical blend. Toroidal blend is formed by a blending operation on a circular edge. This circular edge may be closed (end vertices are identical) or open. Toroidal blend is also formed at a vertex at which at least one convex and one concave edge is incident. So toroidal blend can be classified into closed toroidal blend, open toroidal blend and vertex toroidal blend. In recognition process, for every triangle, cylindrical, spherical and toroidal surface parameters are calculated. In the second step, triangles having same surface parameters are clustered. The cluster of triangles are then classified as a blend or a form feature. Finally, toroidal blends are classified as one of the three types of toroidal blend. Procedures for the suppression of edge cylindrical blend and edge toroidal blend are described. At the present time, vertex blends are not suppressed individually. Rather in the process of suppressing edge blends, vertex blends are also suppressed. The parent surfaces that were blended are identified using the bounding loops of the blends. Triangles in the blend are then deleted and the parent surfaces are extended to suppress the feature. The key issues in suppression are - identification of all the surfaces at the blend, identification of the entities that were blended (edges and vertices) and updating the tessellated model. Results of constant radius blend recognition and suppression, on benchmark parts from NIST design repository are presented. This is followed by a discussion on the correctness of the recognition procedures. The thesis concludes by summarizing the contributions and identifies the following are as recognition of variable radius blends, blends on non-linear surfaces, suppression of all small volumetric feature as areas for further research.