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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.
421

Os efeitos da estrutura moraica do latim em tr?s l?nguas rom?nicas : italiano, portugu?s e espanhol

Costa, Evellyne Patr?cia Figueiredo de Sousa 20 January 2011 (has links)
Made available in DSpace on 2015-04-14T13:38:22Z (GMT). No. of bitstreams: 1 430139.pdf: 875048 bytes, checksum: ad3eb84f134a91797f19ffbdb77403f3 (MD5) Previous issue date: 2011-01-20 / Este estudo tem como objetivo investigar a evolu??o da estrutura moraica do latim ?s l?nguas neorrom?nicas, mais precisamente, ao italiano, portugu?s e espanhol. A l?ngua latina, que possui distin??o quantitativa voc?lica e consonantal, apresenta os seguintes padr?es: (i) s?labas leves, portadoras de uma mora (e.le.men.tum); (ii) s?labas pesadas, portadoras de duas moras (bul.ga); (iii) s?labas superpesadas, portadoras de tr?s moras segundo a nossa proposta (paul.lum). Na evolu??o ao romance, h? a perda da distintividade quantitativa dentre as vogais e, na passagem ?s l?nguas neorrom?nicas, a estrutura moraica tem seus efeitos. Diante desse cen?rio e a partir dos pressupostos da Teoria Moraica de Hayes (1989), buscamos investigar os efeitos dessa mudan?a nas referidas l?nguas atrav?s de processos fonol?gicos envolvidos, tais como gemina??o, ditonga??o, monotonga??o, palataliza??o. A Teoria Moraica busca caracterizar de que modo as l?nguas atribuem estrutura moraica e que princ?pios atuam nessas l?nguas. Hayes (1989) define mora como uma unidade de peso do tier pros?dico e representa o contraste entre s?labas longas e s?labas breves, al?m de contar como uma posi??o fonol?gica (segmento longo ? representado como duplamente ligado). Propomos que as escolhas feitas pelo italiano, portugu?s e espanhol para lidar com a estrutura moraica do latim j? est?o dispon?veis em latim vulgar e que, de acordo com a op??o feita, princ?pios como Stray Erasure e Parasitic Delinking, relacionados com Licenciamento Pros?dico, t?m maior ou menor atua??o.
422

Modalidade e modaliza??o : uma interface sint?tico-sem?ntica em portugu?s brasileiro, ingl?s e romeno

Monawar, M?nica Deitos Stedile 20 January 2011 (has links)
Made available in DSpace on 2015-04-14T13:38:22Z (GMT). No. of bitstreams: 1 430154.pdf: 1062562 bytes, checksum: d53893f44028d0ebb89de1da6597e303 (MD5) Previous issue date: 2011-01-20 / O presente trabalho tem por objetivo, por meio de um recorte te?rico da Sintaxe Gerativa e da Sem?ntica Formal em interface, promover a compara??o entre tr?s l?nguas: o portugu?s brasileiro, o ingl?s e o romeno, no que concerne a no??o de modalidade. Este trabalho ? divido em tr?s partes principais: a primeira elabora fundamentos da Sintaxe Gerativa relevantes para o estudo da modalidade, tais como o papel do IP (inflectional phrase) na senten?a; o segundo, relacionado ? no??o cl?ssica de modalidade vinda de Arist?teles, a sem?ntica de mundos poss?veis de Kripke e a teoria da L?gica Modal de Kratzer, onde proposi??es n?o s?o apenas verdadeiras ou falsas em um determinado mundo poss?vel, elas s?o conjuntos de mundos poss?veis que tamb?m podem ser gradu?veis. A terceira e ?ltima parte constr?i um objeto de estudo do ponto de vista comparativo da aplica??o dos fundamentos abordados nas duas partes anteriores ? an?lise da modalidade nas tr?s l?nguas. Conclui-se que a pesquisa em modalidade tem ainda um longo percurso ? frente, mas as abordagens mais atuais que levam em considera??o interfaces como a da Sem?ntica com a Sintaxe t?m tido melhores e mais elucidativos resultados.
423

O valor argumentativo da ora??o relativa no discurso : uma proposta para o ensino de l?ngua materna

Wittke, Cleide In?s 28 November 2006 (has links)
Made available in DSpace on 2015-04-14T13:39:00Z (GMT). No. of bitstreams: 1 388577.pdf: 1515958 bytes, checksum: a600c7c5aad180d4cd0686304fb2966b (MD5) Previous issue date: 2006-11-28 / Considerando a insatisfa??o que o efeito do ensino de l?ngua materna, principalmente nas quest?es referentes aos aspectos gramaticais (em fun??o da forte influ?ncia da Gram?tica Tradicional), vem ocasionando ? pr?tica escolar e acad?mica, bem como a nova concep??o de l?ngua, linguagem e gram?tica, preconizada pelos Par?metros Curriculares Nacionais (PCNs,1998, 1999), o presente trabalho constr?i uma reflex?o sobre esse ensino, enfocando-o n?o como um exerc?cio de metalinguagem mas como um processo interativo, levando em conta tanto a forma quanto o sentido veiculado pela l?ngua em uso. Acreditando ser poss?vel p?r em pr?tica a abordagem dial?gico-discursiva proposta pelos PCNs e tendo como hip?tese geral a id?ia de que o funcionamento ling??stico, enquanto forma (sistema), ? importante ? compreens?o do sentido constru?do no discurso, investiga-se o papel sem?nticoargumentativo que a ora??o relativa (adjetiva) exerce no enunciado em que opera, auxiliando na constitui??o do sentido. Concebendo a pr?tica escolar de L?ngua Portuguesa no Ensino Fundamental (EF) e M?dio (EM) sob um enfoque tanto ling??stico como did?tico-pedag?gico, busca-se aparato te?rico nessas duas perspectivas. No que tange ? concep??o de l?ngua e ? descri??o sem?ntica de linguagem, a presente pesquisa ap?ia-se no quadro te?rico geral da Teoria da Argumenta??o na L?ngua (ANL), na sua vers?o atual, a Teoria dos Blocos Sem?nticos (TBS). Essa teoria define o enunciado como uma unidade sem?ntica (DUCROT, 2002; CAREL, 2002), encadeada argumentativamente por um conector, podendo o locutor manifestar seu ponto de vista ora de modo normativo (em portanto DC), ora de maneira transgressiva (em no entanto PT), com base em um mesmo princ?pio argumentativo (lugar comum social). No que diz respeito ?s quest?es did?tico-pedag?gicas que constituem o ensino de l?ngua, busca-se apoio te?rico (e pr?tico) na Transposi??o Did?tica (TD) (BRONCKART e GIGER, 1998; PETITJEAN, 1998ab), teoria voltada a quest?es que envolvem a constru??o do saber no meio escolar, englobando tr?s elementos fundamentais: professor, aluno e saber. Embora esse processo seja constitu?do por tr?s etapas cont?nuas mas distintas, este trabalho aborda somente a primeira fase, ou seja, a rela??o que o professor estabelece com o saber, no eixo do ensino: a passagem do saber cient?fico ou t?cnico a saber a ser ensinado (didatizado), implicando sua forma??o inicial e continuada e o material did?tico que orienta sua pr?tica cotidiana, em especial o livro did?tico, uma das principais fontes do seu saber. Nesse contexto, analisa-se a maneira como o livro de portugu?s descreve o saber ora??o relativa, tanto na oitava s?rie do EF quanto no terceiro ano do EM, diferentes momentos em que esse conte?do ? abordado na escola, comparando-o com nossa abordagem sem?ntica das relativas, atuando em diferentes situa??es enunciativas, em cr?nicas veiculadas pela m?dia. Espera-se que o presente estudo funcione como um dos tantos meios poss?veis que capacitem o aluno a desenvolver seu potencial comunicativo, tanto na pr?tica oral como na escrita, e tamb?m inspire novas reflex?es sobre a import?ncia do funcionamento sem?ntico no ensino de l?ngua materna.
424

As vozes verbais sob a perspectiva da teoria da reg?ncia e liga??o : uma an?lise de manuais de ensino da l?ngua portuguesa

Silva, Ana M?rcia Martins da 15 December 2006 (has links)
Made available in DSpace on 2015-04-14T13:39:16Z (GMT). No. of bitstreams: 1 389262.pdf: 544405 bytes, checksum: 6280c4cfa7ca4ad45d31bf6c76a1c124 (MD5) Previous issue date: 2006-12-15 / Esta disserta??o versa sobre as vozes verbais, utilizando a Teoria da Reg?ncia e Liga??o, proposta por Chomsky (1981), que fornecer? subs?dios para a an?lise de conceitos e exemplos trazidos por quatro gram?ticas do Portugu?s Brasileiro amplamente adotadas pelos falantes brasileiros, especialmente por alunos e professores de escolas de Ensino Fundamental e M?dio. Discute-se a inadequa??o de alguns conceitos e exemplos e sugere-se que tal problema ? gerado pela exist?ncia de outro tipo de voz verbal a Voz M?dia no PB, que ? desconsiderada pelos autores das obras do corpus.
425

Bacteriophage SPP1 entry into the host cell / Entrée de bactériophage SPP1 dans la cellule hôte

Jakutyte, Lina 15 December 2011 (has links)
Les quatre étapes principales d'infection des bactéries par leurs virus sont (i) la reconnaissance spécifique de la cellule hôte et l'entrée du génome dans le cytoplasme,(ii) la réplication du génome viral, (iii) l'assemblage des particules virales, et (iv) leur relâchement, menant dans la plupart des cas à la lyse de la cellule. Bien que la description des étapes individuelles du cycle viral a été relativement bien établie, les détails de comment d'ADN viral chemine du virion jusqu’au cytoplasme de la bactérie hôte et de comment l'environnement cellulaire participe au processus restent mal compris.La première étape de l’infection est la reconnaissance d’un récepteur à la surface de la bactérie hôte par la machinerie d’adsorption du phage. Les barrières que l’agent infectieux doit franchir par la suite sont la membrane externe de la bactérie Gram-negative, la paroi cellulaire et la membrane cytoplasmique. Ceci implique une dégradation localisée de la paroi et le cheminement de l’ADN à travers un pore dans la membrane. L‘ADN linéaire se circularise normalement dans le cytoplasme et il est répliqué par la suite. On a utilisé le bactériophage SPP1 qui infecte la bactérie Gram-positive Bacillus subtilis comme modèle d’étude pour disséquer ces différentes étapes clés pour le démarrage de l’infection virale. Dans ce travail de thèse les conditions d’infection et d’acquisition de données pour suivre en temps réel la dépolarisation de la membrane cellulaire de B. subtilis lors de l’infection par SPP1 ont été mis au point. Il est montré que le démarrage de l’infection déclenche une dépolarisation très rapide de la membrane cytoplasmique.Le potentiel de membrane n’est plus rétablit pendant toute la durée du cycle d'infection. Ce changement du potentiel de membrane au début de l’infection dépend de la présence du récepteur YueB. L’amplitude de la dépolarisation dépend du nombre de particules virales infectieuses présentes et de la concentration du récepteur YueB à la surface de la bactérie hôte. L’interaction du phage avec le récepteur YueB conduit à l’interaction irréversible et à l'éjection de l’ADN de SPP1. Pour établir si c’est l’interaction avec YueB ou le début de l’entrée de l’ADN qui conduit à la dépolarisation de la membrane on a utilisé des phages SPP1 éclates par EDTA qui adsorbent normalement à B. subtilis mais qui n’avaient plus leur ADN. Les résultats obtenus ont montré que la dépolarisation requiert l’interaction du virus intacte avec le récepteur YueB. Des concentrations sous-millimolaire de Ca2+ sont nécessaires et suffisantes pour SPP1 liaison réversible à l'enveloppe d'hôte et donc de déclencher la dépolarisation.La cinétique d’entrée de l’ADN du bactériophage SPP1 dans la bactérie Bacillus subtilis a été suivie en temps réel par microscopie de fluorescence. On a mis au point une méthode de microscopie pour visualiser des particules virales marquées avec des «quantum dots» ce qui permit de démontrer que ces particules se fixent préférentiellement aux pôles des bacilli. L’immuno-marquage du récepteur de SPP1,la protéine YueB, a montré que celle-ci a une organisation ponctuée à la surface de B.subtilis et se concentre particulièrement aux extrémités de la bactérie. Cette localisation particulière du phage sur la surface de la cellule hôte corrèle avec l’observation que l’ADN viral rentre dans le cytoplasme (<2 min) et se réplique dans des foci situés dans la plupart des cas à proximité des pôles de B. subtilis. L’étude spatio-temporelle de l’interaction de SPP1 avec son hôte Gram-positive montre que le virus cible des régions spécifiques de la bactérie pour son entrée et pour sa réplication. Transfert d'ADN dans le cytoplasme dépend des concentrations millimolaires de Ca2+. Un modèle décrivant les événements précoces de l'infection bactériophage SPP1 est présenté. / The four main steps of bacterial viruses (bacteriophages) lytic infection are (i) specific recognition and genome entry into the host bacterium, (ii) replication of the viral genome, (iii) assembly of viral particles, and (iv) their release, leading in most cases to cell lysis. Although the course of individual steps of the viral infection cycle has been relatively well established, the details of how viral DNA transits from the virion to the host cytoplasm and of how the cellular environment catalyzes and possibly organizes the entire process remain poorly understood.Tailed bacteriophages are by far the most abundant viruses that infect Eubacteria. The first event in their infection is recognition of a receptor on the surface of host bacterium by the phage adsorption machinery. The barriers that the infectious particle overcomes subsequently are the cell wall and the cytoplasmic membrane of bacteria. This implies a localized degradation of the wall and the flow of its double stranded DNA (dsDNA) through a hydrophilic pore in the membrane. The lineards DNA molecule is most frequently circularized in the cytoplasm followed by its replication. In this study we used bacteriophage SPP1 that infects the Gram-positive bacterium Bacillus subtilis as a model system to dissect the different steps leading to transfer of the phage genome from the viral capsid to the host cell cytoplasm.normally to B. subtilis but do not trigger depolarization of the CM. Attachment of intact SPP1 particles is thus required for phage-induced depolarization.The beginning of B. subtilis infection by bacteriophage SPP1 was followed inspace and time. The position of SPP1 binding at the cell surface was imaged by fluorescence microscopy using virus particles labeled with "quantum dots". We found that SPP1 reversible adsorption occurs preferentially at the cell poles. This initial binding facilitates irreversible adsorption to the SPP1 phage receptor protein YueB,which is encoded by a putative type VII secretion system gene cluster.Immunostaining and YueB – GFP fusion showed that the phage receptor protein YueB is found over the entire cell surface. It concentrates at the bacterial poles too,and displays a punctate distribution over the sidewalls. The dynamics of SPP1 DNA entry and replication was visualised in real time by assaying specific binding of a fluorescent protein to tandem sequences present in the SPP1 genome. During infection, most of the infecting phages DNA entered and replicated near the bacterial poles in a defined focus. Therefore, SPP1 assembles a replication factory at a specific location in the host cell cytoplasm. DNA delivery to the cytoplasm depends on millimolar concentrations of Ca2+ allowing uncoupling it from the precedent steps of SPP1 adsorption to the cell envelope and CM depolarization that require only micromolar amounts of this divalent cation. A model describing the early events of bacteriophage SPP1 infection is presented.
426

Efeito de doses de nitrog?nio, intervalos de corte e irriga??o sobre a produ??o, composi??o qu?mica e digestibilidade do capim-estrela (Cynodon nlemfuensis) / Effect of nitrogen levels, harvest intervals and irrigation on yield, chemical composition and digestibility of the stargrass (Cynodon nlemfuensis)

AGUIAR, Fl?vio dos Santos de 13 March 2007 (has links)
Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This work was carried out in the county of Valen?a - RJ, with the objective to evaluate production and quality of the stargrass, in function of: two irrigation levels (with and without); four cut intervals (21, 28, 35 and 42 at the rainy season and 28, 35, 42 and 49 days at the dry season of the year); as well as four levels of nitrogen (0, 150, 300 e 600 kg/ha/year). The dry matter production (DMP) and the efficiency of the nitrogen utilization (ENU) in plots of 6,25 m2, were estimated from October 2004 to October 2005. In the months of January, June/July and September/October samples were collected to determine chemical composition and digestibility such as: crude protein (CP), neutral-detergent fiber (NDF) and in vitro dry matter digestibility (IVDMD). The Irrigation when increased DMP and ENU, reduced the forrage quality and only had significative effect (P<0,05) during the rainy season. The harvest intervals does not affected (P>0,05) on DMP. However, there was tendency to increase. Harvest intervals should be 42/49 days to obtain good forage quality and yield. The chemical composition and digestibility of the dry matter decreased with the spacing of the cuts and the effect of the interval of cuts on ENU was dependent of the irrigation. At that time it dries the irrigated treatments had her ENU increased with the decrease of the frequency of the cut. The nitrogen fertilization was the only factor that increased (P<0,05) DMP and the quality of the stargrass. However, the answer of DMP to the nitrogen fertilization was reduced and ENU was not affected in function of the nitrogen levels. In the conditions of experiment was realized, it is approved as the most appropriate handling of the studied factors: The interval of cuts of 42/49 days, that formed an alliance high yield with a satisfactory quality and the irrigation, only accomplished in favorable climatic conditions. / Este trabalho foi conduzido no munic?pio de Valen?a - RJ, com o objetivo de avaliar a produ??o e a qualidade do capim-estrela, em fun??o de: dois regimes h?dricos (irrigado e n?o-irrigado); quatro intervalos de cortes (21, 28, 35 e 42 na ?poca chuvosa e 28, 35, 42 e 49 dias na ?poca seca do ano); e quatro doses de nitrog?nio (0, 150, 300 e 600 kg/ha/ano). Durante o per?odo de outubro de 2004 a outubro de 2005, foram estimadas a produ??o de mat?ria seca (PMS) e a efici?ncia da aduba??o nitrogenada (EAN) em parcelas de 6,25 m2. Nos meses de janeiro, junho/julho e setembro/outubro coletaram-se amostras para a estimativa do valor nutritivo e digestibilidade, determinando a prote?na bruta (PB), a fibra em detergente neutro (FDN) e a digestibilidade in vitro da mat?ria seca (DIVMS). Os resultados mostraram que a irriga??o aumentou a PMS e a EAN, reduziu o valor nutritivo e DIV da mat?ria seca. Entretanto somente houve resposta (P<0,05) ao regime h?drico apenas quando as condi??es clim?ticas n?o foram limitantes ao crescimento da forrageira. O intervalo de cortes n?o alterou (P>0,05) a PMS, embora tenha sido observada a tend?ncia de incremento da mesma em fun??o da diminui??o da freq??ncia de cortes, sendo a maior produ??o obtida nos tratamentos 42/49 dias. A qualidade da forrageira diminuiu com o espa?amento dos cortes e o efeito do intervalo de cortes sobre a EAN foi dependente da irriga??o. Na ?poca seca do ano os tratamentos irrigados tiveram sua EAN aumentada com a diminui??o da freq??ncia do corte. A aduba??o nitrogenada foi o ?nico fator que aumentou (P<0,05), simultaneamente, a PMS e a qualidade do capim-estrela. No entanto, a resposta da PMS ? aduba??o nitrogenada foi pequena e a EAN n?o foi alterada (P>0,05) em fun??o das doses de nitrog?nio. Nas condi??es experimentais, preconiza-se como o manejo mais adequado: o intervalo de cortes de 42/49 dias, que aliou rendimentos elevados a uma qualidade satisfat?ria; e a irriga??o deve ser usada apenas quando as condi??es clim?ticas s?o favor?veis.
427

Contribui??o das bact?rias diazotr?ficas no crescimento de Brachiaria brizhanta cv. Marandu / Contribution of diazotrophic bacteria in the growth of Brachiaria brizhanta cv. Marandu

SHOCKNESS, Leonardo dos Santos Fran?a 29 February 2016 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-10-13T20:11:22Z No. of bitstreams: 1 2016 - Leonardo dos Santos Fran?a Shockness.pdf: 1003791 bytes, checksum: efd5f4204bec8c095ea24c37002fd302 (MD5) / Made available in DSpace on 2017-10-13T20:11:22Z (GMT). No. of bitstreams: 1 2016 - Leonardo dos Santos Fran?a Shockness.pdf: 1003791 bytes, checksum: efd5f4204bec8c095ea24c37002fd302 (MD5) Previous issue date: 2016-02-29 / CAPES / One of the main factors that affect growth and persistence of grasses in the tropics, thus increasing the degradation of pastures, is a nitrogen deficiency in the soil. However, nitrogen fertilizers much burden the production costs, and the demand for food increasing year by year, has emphasized the need for sustainable alternatives, such as biological nitrogen fixation. It is necessary to do more research on Biological Nitrogen Fixation (BNF) in forage grasses, especially about diversity among nitrogen-fixing bacteria associated with these plants, so that new bacteria can be discovered, as well as its potential to FBN. This study aimed to isolate diazotrophic bacteria of the genus Azospirillum spp. or Herbaspirillum spp., from two cultivars of B. brizhanta (Marandu and Xara?s) and one of B. decumbens (IPEAN), to test them, and to assess their contribution to the growth of Brachiaria brizhanta cv. Marandu identifying the three most promising. This study was conducted at Embrapa Agrobiology in Serop?dica - RJ, in two stages. The first was to isolate possible diazotrophic bacteria from Brachiaria brizantha and B. decumbens plants, using the cultivars Marandu and Xara?s B. brizantha, and the cultivar IPEAN of B. decumbens. The isolation was performed using three semi-solid media, NFB, LGI and JNFb, where the first two selected bacteria of the genus Azospirillum, and the third one Herbaspirillum bacteria. There were selected 46 isolates and, after purification, it was obtained 15 isolates pure, and made the phenotypic characterization thereof. Further biochemical tests were the phosphate solubilization, acetylene reduction analysis (ARA), and production of acid-3-indole acetic (IAA). All tested isolates produced ARA ethylene, even in small quantities, with prominence for isolates L2, L4, J3, J6, J7 and J8. In the phosphate solubilization the isolates N1, L1, J2, J3, J4, J5, J6, J7, J8, and T14 were able to solubilize phosphate. In the EIA production the isolates N1, J1, J2, J3, J4, J5, J6, J7, J8 and J9 excelled. In the second phase it was conducted an experiment to study plant - bacteria interaction. It consisted of the inoculation of 15 isolates from the first phase plus three isolates known as references (SP245, Z94, CBAMC) in B. brizhanta cultivar Marandu, plus the control without inoculation and without N. In this experiment the isolates L2, L4 and J6 outstand when compared to the other seven parameters evaluated. On the basis of this study we can conclude that there are nitrogen fixing bacteria, phosphate solubilizing, and that produce 3-indoleacetic acid, associated to Brachiaria brizhanta and Brachiaria decumbens. The isolated bacteria of the two B. brizhanta cultivars (Marandu and Xara?s), and the Brachiaria decumbens (IPEAN) cultivar were more efficient in the growth of B. brizhanta cultivar Marandu than the bacteria standards obtained from other plant species. Also, among the 15 isolates from Brachiaria plants, the J6, L2 and L4 were statistically different from the others, and are considered the three most promising. / Um dos principais fatores que afeta o crescimento e a persist?ncia de gram?neas nos tr?picos, aumentando assim a degrada??o das pastagens, ? a defici?ncia de nitrog?nio no solo. Entretanto, fertilizantes nitrogenados oneram muito os custos de produ??o, e com a demanda por alimentos crescendo ano a ano, tem-se enfatizado a necessidade de alternativas sustent?veis, tal como a fixa??o biol?gica de nitrog?nio. Faz-se necess?rio pesquisas com Fixa??o Biol?gica de Nitrog?nio (FBN) em gram?neas forrageiras, principalmente sobre diversidade de bact?rias diazotr?ficas associadas a essas plantas, para que novas bact?rias possam ser descobertas, assim como seu potencial de FBN. Este trabalho teve como objetivo isolar bact?rias diazotr?ficas do g?nero Azospirillum Spp. ou Herbaspirillum Spp., provenientes de duas cultivares de B. brizhanta (Marandu e Xar?es) e de uma cultivar de B. decumbens (Ipean), testar as mesmas, e avaliar sua contribui??o no crescimento de Brachiaria brizhanta cv. Marandu identificando as tr?s mais promissoras. O trabalho foi realizado na Embrapa Agrobiologia em Serop?dica ? RJ, em duas etapas. Na primeira foi feito o isolamento de poss?veis bact?rias dizotr?ficas provenientes de plantas de Brachiaria brizantha e Brachiaria decumbens, sendo utilizadas as cultivares Marandu e Xara?s de B. brizantha e a cultivar IPEAN de B. decumbens. O isolamento foi realizado utilizando tr?s meios semiss?lidos, NFB, LGI e JNFB, onde os dois primeiros selecionaram bact?rias do g?nero Azospirillum, e o terceiro bact?rias do g?nero Herbaspirillum. Foram selecionados 46 isolados, e ap?s a purifica??o obteve-se 15 isolados puros, sendo feita a caracteriza??o fenot?pica dos mesmos, e posteriormente os testes bioqu?micos de solubiliza??o de fosfato, an?lise da redu??o de acetileno (ARA) e produ??o de ?cido-3-indolac?tico (AIA). Na ARA todos isolados avaliados produziram etileno, mesmo em pequenas quantidades, tendo destaque os isolados L2, L4, J3, J6, J7, e J8. Na solubiliza??o de fosfato os isolados N1, L1, J2, J3, J4, J5, J6, J7, J8 e T14 foram capazes de solubilizar fosfato. Na produ??o de AIA se sobressa?ram os isolados N1, J1, J2, J3, J4, J5, J6, J7, J8 e J9. Na segunda etapa foi realizado o experimento de intera??o planta - bact?ria; que consistiu da inocula??o dos 15 isolados da primeira etapa, acrescidos de tr?s isolados conhecidos como padr?es (SP245, Z94, CBAMC) em B. brizhanta cv. Marandu, mais a testemunha n?o inoculada e sem N. Neste experimento os isolados L2, L4 e J6 se destacaram em rela??o aos outros nos sete par?metros avaliados. Com base neste trabalho podemos concluir que existem bact?rias fixadoras de nitrog?nio, solubilizadoras de fosfato e que produzem ?cido-3-indolac?tico associadas a Brachiaria brizhanta e Brachiaria decumbens. As bact?rias isoladas de duas cultivares de B. brizhanta (Marandu e Xar?es) e de uma cultivar de B. decumbens (Ipean) se mostraram mais eficientes no crescimento de B. brizhanta cv. Marandu do que as bact?rias padr?es provenientes de outras esp?cies de plantas. Ainda, dentre os 15 isolados de plantas do g?nero Brachiaria, os isolados J6, L2 e L4 diferiram estatisticamente dos demais, sendo considerados os tr?s mais promissores.
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Suscetibilidade de Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae) à proteína inseticida Cry1F de Bacillus thuringiensis Berliner no Brasil / Susceptibility of Diatraeasaccharalis(Fabricius) (Lepidoptera: Crambidae) to Cry1F insecticidal protein from Bacillus thuringiensis Berliner in Brazil

Souza, Dariane Sagaseta de Oliveira 26 April 2013 (has links)
A broca-da-cana Diatraeasaccharalis(Fabricius) é uma das pragas-alvo do milho geneticamente modificado que expressagene(s) que codifica(m) proteína(s) de BacillusthuringiensisBerliner(milho Bt) no Brasil. Para estabelecer estratégias proativas de manejo de resistência, os objetivos do presente trabalho foram (1)estabelecer linhas-básicas de suscetibilidade à proteína Cry1F de B. thuringiensisem populações de D. saccharalis coletadas nas principais regiões produtoras de milho no Brasil na safra de 2010/2011, (2) realizar monitoramentoda suscetibilidade de populações de D. saccharalis na safra 2011/2012 e (3) avaliar a atividade biológica do milho Bt (evento TC1507) em diferentes estádios fenológicos no controle de D. saccharalis em condições laboratoriais. Para a caracterização das linhas-básicas de suscetibilidade foram realizados bioensaios com a proteína purificada Cry1F aplicada superficialmente em dieta artificial.As CL50 de Cry1F estimadas variaram de 0,47 a 7,02 ng de Cry1F/ cm2 dieta artificial para as populações avaliadas (variação de ?15 vezes). Foi definida e validada a concentração diagnóstica de 112 ng de Cry1F/cm²,baseada na estimativa da CL99 das populações testadas para o monitoramento da suscetibilidade. A avaliação da atividade biológica de milho Bt (evento TC1507) foi realizada com dois híbridos (Pioneer 30F35 e Dow 2B688) nos estádios fenológicos V3, V6 e V9 e em duas épocas de plantio. Alta atividade de controle de D. saccharalis foi obtida para os dois híbridos de milho Bt nos diferentes estádios fenológicos e épocas de plantio. Portanto, verificou-se que a espécie D. saccharalis é altamente suscetível à proteína Cry1F. Contudo, a implementação de estratégias de manejo da resistência é de fundamental importância para preservar a vida útil da tecnologia de milho Bt como importante ferramenta em programas de MIP. / The sugarcane borer Diatraeasaccharalis (Fabricius) is one of the target pests of genetically modified maizeexpressinggenes that code for insecticidal proteins from Bacillus thuringiensis Berliner (Bt maize) in Brazil. To implement proactive resistance management strategies, we leaded studies (1) to establish baseline susceptibility to Cry1F protein from B. thuringiensis in populations of D. saccharalis collected from major maize production regions in Brazil during 2010/2011 growing season, (2) to leadsusceptibility monitoring in populations of D. saccharalis collected in 2011/2012 growing season, and (3) to assess the biological activity of Bt maize (event TC1507) at different growth stages forD. saccharaliscontrol under laboratory conditions. The baseline susceptibility wascharacterizedwith purified protein Cry1F applied superficially on artificial diet. The estimatesof LC50 of Cry1F ranged from 0.47 to 7.02 ng Cry1F/cm2of artificial diet for the populations evaluated (? 15-fold variation).A diagnostic concentration of 112 ng Cry1F/cm ² was defined and validated for monitoring the susceptibility based on estimation of CL99 of all tested populations. The biological activity of Bt maize (event TC1507) was assessed by using two hybrids (Pioneer 30F35 and Dow 2B688) at growth stages V3, V6 and V9 and two planting seasons. High level of D. saccharaliscontrol was obtained for the twoBt maize hybrids at different growth stages and planting seasons. Therefore, we conclude that D. saccharalis is highly susceptible to Cry1F protein. However, implementation of insect resistance management strategies is essentialin order to preserve the lifetime of Bttechnology as an important tool in IPM programs.
429

EXTRACTION AND PREDICTION OF SYSTEM PROPERTIES USING VARIABLE-N-GRAM MODELING AND COMPRESSIVE HASHING

Muthukumarasamy, Muthulakshmi 01 January 2010 (has links)
In modern computer systems, memory accesses and power management are the two major performance limiting factors. Accesses to main memory are very slow when compared to operations within a processor chip. Hardware write buffers, caches, out-of-order execution, and prefetch logic, are commonly used to reduce the time spent waiting for main memory accesses. Compiler loop interchange and data layout transformations also can help. Unfortunately, large data structures often have access patterns for which none of the standard approaches are useful. Using smaller data structures can significantly improve performance by allowing the data to reside in higher levels of the memory hierarchy. This dissertation proposes using lossy data compression technology called ’Compressive Hashing’ to create “surrogates”, that can augment original large data structures to yield faster typical data access. One way to optimize system performance for power consumption is to provide a predictive control of system-level energy use. This dissertation creates a novel instruction-level cost model called the variable-n-gram model, which is closely related to N-Gram analysis commonly used in computational linguistics. This model does not require direct knowledge of complex architectural details, and is capable of determining performance relationships between instructions from an execution trace. Experimental measurements are used to derive a context-sensitive model for performance of each type of instruction in the context of an N-instruction sequence. Dynamic runtime power prediction mechanisms often suffer from high overhead costs. To reduce the overhead, this dissertation encodes the static instruction-level predictions into a data structure and uses compressive hashing to provide on-demand runtime access to those predictions. Genetic programming is used to evolve compressive hash functions and performance analysis of applications shows that, runtime access overhead can be reduced by a factor of ~3x-9x.
430

Pharmacokinetic and Pharmacodynamic Modeling of Antibiotics and Bacterial Drug Resistance

Syed Mohamed, Ami Fazlin January 2013 (has links)
Exposure to antibiotics is an important factor influencing the development of bacterial resistance.  In an era where very few new antibiotics are being developed, a strategy for the development of optimal dosing regimen and combination treatment that reduces the rate of resistance development and overcome existing resistance is of utmost importance. In addition, the optimal dosing in subpopulations is often not fully elucidated. The aim of this thesis was to develop pharmacokinetic (PK) and pharmacokinetic-pharmacodynamic (PKPD) models that characterize the interaction of antibiotics with bacterial growth, killing and resistance over time, and can be applied to guide optimization of dosing regimens that enhance the efficacy of mono- and combination antibiotic therapy. A mechanism-based PKPD model that incorporates the growth, killing kinetics and adaptive resistance development in Escherichia coli against gentamicin was developed based on  in vitro time-kill curve data. After some adaptations, the model was successfully applied for similar data on colistin and meropenem alone, and in combination, on one wild type and one meropenem-resistant strain of Pseudomonas aeruginosa. The developed population PK model for colistin and its prodrug colistin methanesulfonate (CMS) in combination with the PKPD model showed the benefits for applying a loading dose for this drug. Simulations predicted the variability in bacteria kill to be larger between dosing occasions than between patients. A flat-fixed loading dose followed by an 8 or 12 hourly maintenance dose with infusion duration of up to 2 hours was shown to result in satisfactory bacterial kill under these conditions. Pharmacometric models that characterize the time-course of drug concentrations, bacterial growth, antibacterial killing and resistance development were successfully developed. Predictions illustrated how PKPD models based on in vitro data can be utilized to guide development of antibiotic dosing, with examples advocating regimens that (i) promote bacterial killing and reduce risk for toxicity in preterm and term newborn infants receiving gentamicin, (ii) achieve a fast initial bacterial killing and reduced resistance development of colistin in critically ill patients by application of a loading dose, and (iii) overcome existing meropenem resistance by combining colistin and meropenem

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