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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Caracteriza??o gen?tica de arroz (Oryza Sativa L.) atrav?s de marcadores moleculares RAPD e efici?ncia na aquisi??o de N. / Genetic Characterization of Rice (Oryza sativa l.) Using the RAPD Molecular Markers and Nitrogen Uptake Efficiency.

Baptista, Jane de Ara?jo 27 March 2002 (has links)
Submitted by Leticia Schettini (leticia@ufrrj.br) on 2016-08-05T14:09:04Z No. of bitstreams: 1 2002 Jane Ara?jo Baptista.pdf: 1264077 bytes, checksum: 40b93a67e37e2aad7edfc01cc029f2c4 (MD5) / Made available in DSpace on 2016-08-05T14:09:04Z (GMT). No. of bitstreams: 1 2002 Jane Ara?jo Baptista.pdf: 1264077 bytes, checksum: 40b93a67e37e2aad7edfc01cc029f2c4 (MD5) Previous issue date: 2002-03-27 / We have studied the influence of using 6 different coefficients of similarity when grouping 16 varieties of rice analyzed by the RAPD technique. DNA samples of these varieties were amplified using 20 primers, only 15 (75%) of which produced amplified fragments, compresing 90 of these were polimorphic fragments. The analysis of the band, profile produced a ?fingerprint?. For the calculation of the similarity index several coefficients were tested: Nei & Li, Jaccard, Ochiai, Russel & Rao, Simple Matching and Rogers & Tanimoto. Comparison among them was carried out through the evaluation of the dendrograms generated by the UPGMA algorithm and by the correlations between the genetic pitches. The coefficients of Nei & Li, Jaccard, and Ochiai discriminated the varieties in three main groups according to their genetic similarities. Our results show that the coefficients of Nei & Li, Jaccard and Ochiai adjusted better the groups with hight genetic similarities. While the coefficients Simple Matching and Rogers & Tanimoto were not as efficient, banding together varieties that are genetically different. In experiments, with the objective to studies the effect of levels (20 or 60 mg N/L) e forms of N (NH4 + and NO3 -) under the kinetics parameters, proton extrusion, the activity of the N-assimilation enzymes and the N-partition in the plant, were conducted in greenhouse, using 5 upland rice varieties (Lageado, IAC 47, Dobradinho, Agulha e Bico Ganga), in nutrient solution. It was observed an ample variation of the kinetics parameters and biochemists, and a distinguishing behavior among varieties in the uptake and use of N. The varieties Agulha and IAC-47 had presented the best combination of KM, Vm?x, GS/GOGAT in conditions of hight avaibility of N- NO3 -, and Bico Ganga, in conditions of low avaibility of N- NO3 - in nutrient solution. In another experiment, with the objective to study the assimilation and remobiliza??o of N in season nitrate conditions, used varieties Sagrim?o, Goiano, Zebu, Agulha, IAC 1278, IR08, Comum Branco, IAC 47 e Ligeiro had been cultivated in nutritional solution. The N-assimilation enzymes were estudied in the leaf blades and root of 62 and 69 days old rice plants, under 20 and 200 mg mgN-NO3 -/L. Under higher nitrate supply had increase the activity of the NR, GS and GOGAT in rice plants. The GS activities had been low in roots, in comparison with the activities observed in leaf. The GOGAT activity was bigger in roots, in both the treatments. The GDH-A activity occurred mainly in tessues foliar. The GDH-D activity occurred in leaf as in roots. The GDH-D activity not occurred in tissues foliar. The activity of the enzymes of N-assimilation was higher in tissues foliar. These results seem indicate the leaves as the main site of NH4 +-N assimilation in rice plants under higher NO3 --supply. / Neste trabalho avaliaram-se as altera??es provocadas por 6 diferentes coeficientes de similaridade no agrupamento de 16 variedades de arroz analisadas pela t?cnica de RAPD. Amostras de DNA das variedades foram amplificadas com 20 iniciadores, sendo 15 (75%) produziram fragmentos amplificados, resultando em 90 fragmentos polim?rficos. A an?lise dos resultados se constituiu na descri??o do padr?o de bandas. Para o c?lculo do coeficiente de similaridade foram testados os coeficientes Nei & Li, Jaccard, Ochiai, Russel & Rao, Simple Matching e Rogers & Tanimoto, sendo as compara??es entre eles realizadas pela avalia??o dos dendrogramas gerados pelo algoritmo UPGMA e pelas correla??es entre as dist?ncias gen?ticas. Os resultados obtidos indicam que os melhores coeficientes para determina??o da similaridade foram os de Nei & Li, de Jaccard e de Ochiai que foram capazes de agrupar as variedades com alta similaridade, enquanto os coeficientes Simple Matching e de Rogers & Tanimoto foram ligeiramente inferiores colocando variedades distantes no mesmo grupo. Em experimentos objetivando analisar o efeito de n?veis (20 e 60 mg N/L) e formas de N (NH4 + e NO3 -) sob os par?metros cin?ticos de absor??o, a extrus?o de pr?tons, a atividade das enzimas de assimila??o de N, e a parti??o de N na planta, usou-se 5 variedades de arroz-de-sequeiro (Lageado, IAC 47, Dobradinho, Agulha e Bico Ganga), cultivadas em solu??o nutritiva. Houve um comportamento diferencial entre as variedades quanta ? capacidade de absor??o e uso de N. As variedades Agulha e IAC 47 apresentaram a melhor combina??o de KM, Vm?x, GS/GOGAT em condi??es de alta disponibilidade de N-NO3 -, e a variedade Bico Ganga, sob condi??es de baixa disponibilidade de N. Noutro experimento, objetivando estudar a assimila??o e remobiliza??o de N em condi??es sazonais de N, utilizou-se as variedades Sagrim?o, Goiano, Zebu, Agulha, IAC 1278, IR 08, Comum Branco, IAC 25 e Ligeiro, com 62 e 69 dias de idade, cultivadas em solu??o nutritiva, com 20 e 200 mg N-NO3 -/L. O aumento no suprimento de N aumentou a atividade da NR, da GS e GOGAT. A atividade de NR ocorreu em ra?zes e na parte a?rea. A atividade da GS foi baixa em ra?zes. A atividade da GOGAT foi maior nas ra?zes, em ambos os tratamentos. A atividade de GDH-A ocorreu principalmente em tecidos foliares. A atividade de GDHD ocorreu tanto em folhas como em ra?zes. A atividade das enzimas de assimila??o de N foi superior nas folhas, indicando serem estas os principais s?tios de incorpora??o de am?nio em amino?cidos, quando plantas de arroz s?o submetidas a altos n?veis de NO3 -.
2

S?crates m?dico / Medical Socrates

SERRA, Luciano Torcione 04 March 2016 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-02-15T17:19:23Z No. of bitstreams: 1 2016 - Luciano Torcione Serra.pdf: 1627999 bytes, checksum: ef4988a80c87ad0118dca214851fb2f1 (MD5) / Made available in DSpace on 2017-02-15T17:19:23Z (GMT). No. of bitstreams: 1 2016 - Luciano Torcione Serra.pdf: 1627999 bytes, checksum: ef4988a80c87ad0118dca214851fb2f1 (MD5) Previous issue date: 2016-03-04 / This study went on the medical aspects in socratic action, by following part of the platonic opera combined with twentieth century specialists that have explored the field of science in Plato, remarkably showing his attention towards medical arts of his contemporanity. Moving forward to Epictetus, Galen and Sextus, and back to Empedocles and Zeno from Eleia, the search for medicine in the platonic Socrates concerns altogether with that one on minimum Socrates, spread among these authors, that reveals as most significant characteristics either a fisicality that remains although the supposed abdication in favor of the concepts, and related do pratical ativities, as well as a special kind of visuality attained to discourse, that together seems to make singularly plausible that method of him. In connection to this, Epictetus and Empedocles let us know a negative skeptical conception related to natural sepsis and to peptical assimilation, exposing thus the words of the eps theme, in parallel to their respective prevalent aspects of negative skepticism, induced sepsis and noetical assimilation. This connection, seeming now surprisingly, ensures that one between the logical-discursive medium usually associated to philosophy and the experimental one equally usually associated to medicine. Plato operates on technical words from crafts doing operatory terms with properly philosophical character, enabled and activated to use in notions such as homoi?sis, analogy assimilation and others, upon a variety of themes, beyond a political-clinical attitude compromised with man-city unity in such a clinical enterprise, that debates with and encloses resources from the peste, war, and theatrological drama, worlds for whose transitions into the third century shows himself as a major catalizer through Socratic attitude. Methodical insistance on visuality provides the the following and reellaboration of Zeno arguments, of skema generalized notion, of a convenient proximity of c?tharsis to refutation and anamnesis, of empedoclitian conception of negative skepticism connected to natural sepsis that make summing to skopic distinction, as rethorical and skeptic, the positive skeptical division of unexamined humours and gases, now diagnostical. / Investigamos as caracter?sticas m?dicas na a??o socr?tica, seguindo parte da obra plat?nica e recorrendo a especialistas que ao longo do s?culo XX exploraram o campo novo da ci?ncia em Plat?o, notadamente seu acompanhamento atento ? arte m?dica de sua contemporaneidade. Com avan?os a Epiteto, Galeno e Sexto Emp?rico, e retornos a Emp?docles e Zen?o de El?ia, a pesquisa pela medicina no S?crates plat?nico coincide em parte com a pesquisa pelo S?crates m?nimo, espalhado no seu m?todo por estes autores que revelam como caracter?sticas principais uma fisicalidade permanente ? suposta abdica??o em favor do estudo do conceito e relacionada ?s pr?ticas dos of?cios, bem como uma visualidade especial ligada ao discurso, que numa composi??o singular parecem tornar seu m?todo cl?nico fact?vel. Em conex?o, Epiteto e Emp?docles fazem perceber uma concep??o de ceticismo positivo que se relaciona ? sepse natural e ? assimila??o p?ptica, expondo as palavras deste mesmo tema ?ps, em paralelo a seus respectivos aspectos prevalentes de ceticismo negativo, sepse induzida e assimila??o no?tica. Esse v?nculo, agora surpreendente, garante a conex?o entre o meio l?gico-discursivo usualmente associado ? filosofia e o meio experimental usualmente associados ? medicina. Plat?o opera sobre os jarg?es t?cnicos dos of?cios fazendo termos operat?rios de car?ter propriamente filos?fico, aptos e ativados para aplica??o de no??es como homoi?sis, assimila??o por analogia, e outras, sobre uma diversidade de temas, dentro de atitude pol?tico-diagn?stica comprometida com o par homem-cidade numa empreita cl?nica, que debate e incorpora recursos da guerra, da peste e da trag?dia, ?mbitos para cujas transi??es ao quarto s?culo ele se mostra um principal catalizador atrav?s da a??o socr?tica. O investimento met?dico na visualidade enseja o acompanhamento e reelabora??o dos argumentos de Zen?o, da no??o generalizada de esquema, de uma conveni?ncia da c?tharsis concomitante ? refuta??o e anamnese, da concep??o empedocl?tica de ceticismo negativo ligado ? sepse natural que faz somar ? distin??o esc?pica, antes ret?rica e c?tica, a divis?o s?ptica positiva dos humores e ventos inexaminados, agora diagn?stica.
3

Absor??o, assimila??o e remobiliza??o de nitrog?nio em arroz, sob nutri??o n?trica. Avalia??o da express?o g?nica diferencial. / Nitrogen uptake, assimilation and remobilization in rice under supply of nitrate. Evaluation of differential genic expression

Santos, Andr? Marques dos 27 February 2007 (has links)
Made available in DSpace on 2016-04-26T19:39:29Z (GMT). No. of bitstreams: 1 2007-Andre Marques dos Santos.pdf: 1289315 bytes, checksum: 28a3126a64acf0f1d9ab8338c8a0ac19 (MD5) Previous issue date: 2007-02-27 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Rice is one of the most important cereals for the humanity, because it is primary source of nutrition for more than half of the world s population. Nitrogen is the most important element for plants and is predominantly present in aerated soils in the nitrate form. As a result of the poor quality of the cultivated areas, the usage of nitrogen fertilizers intensified, contributing to the increase of pollution, since this nutrient has high mobility in the soil. With the objective of evaluating physiologic, biochemical and molecular mechanisms responsible for the efficiency of the application of nitrogen in rice, experiments were conducted at the Soils Department of Federal Rural University of Rio de Janeiro. Two rice varieties were used, Piaui (traditional rice) and IAC-47 (improved rice). In the beginning, both varieties were cultivated in nutrition solutions and submitted to treatments simulating the seasonal fluctuation of nitrate, characteristic of the tropical region. Under this condition an evaluation was done in order to define the soluble sugar levels, nitrogen fractions, and the Nitrate Reductase Activity (NRA) as well as Glutamine Synthetase Activity. Piaui rice was more efficient in the acquisition and usage of nitrogen compared to IAC-47, accumulating nitrate in its tissue during the initial phase of growth for future consumption. Later, these same rice varieties were cultivated in a growth chamber with the objective of studying the effect of increased nitrate concentrations over nitrogen fraction levels, NRA, relative expression of genes for nitrate transporters (NRT1 and NRT2) as well as a nitrate reductase (Nia2). From the results obtained it was observed that the traditional rice variety contained less NRA, higher levels of nitrogen and free amino-N. Further, traditional variety presented higher relative expression of the genes which codify nitrate transporters of low affinity (NRT1) and those of high affinity (NRT2). These plants seemed to adopt a differentiated control of NRA, because even having a higher relative expression of the genes, the NRA maintained practically without influence from the different concentrations of nitrate in the solution. In the last experiment, genes in the tips of rice roots were identified, induced by different concentrations of nitrate (0.1 and 10 mM). Several genes were sequenced, were the most important data was the subunit E1 of the dehydrogenase pyruvate complex, and phosphofructokinase, suggesting the need for a better understanding of the complexity of the interaction between carbon and nitrogen metabolism. There were also found sequences homologous to the alpha actin, myosin, tropomyosin 1, creatin kinase, and glyoxalase I genes. / O arroz ? um dos mais importantes cereais para o homem, porque ? fonte prim?ria na alimenta??o de mais da metade da popula??o do mundo. As plantas necessitam de nitrog?nio para seu desenvolvimento, sendo este presente em solos aerados, na forma de nitrato. Em fun??o do desgaste das ?reas cultivadas, tem sido intensificada a utiliza??o de fertilizantes nitrogenados, o que contribui para o aumento da polui??o, visto que, esse composto possui grande mobilidade no solo. Objetivando-se avaliar os mecanismos fisiol?gicos, bioqu?micos e moleculares respons?veis pela efici?ncia no uso de nitrog?nio em arroz foram conduzidos tr?s experimentos no Departamento de Solos da Universidade Federal Rural do Rio de Janeiro, com duas variedades de arroz, uma tradicional (Piau?) e outra melhorada (IAC-47). Primeiramente, ambas as variedades foram cultivadas em solu??o nutritiva e submetidas a tratamentos simulando o fluxo sazonal de nitrato, caracter?stico das regi?es tropicais. Nessa condi??o, foram avaliados os teores de a??cares sol?veis, fra??es nitrogenadas e a atividade das enzimas Nitrato Redutase (ANR) e Glutamina Sintetase. A variedade Piau? foi mais eficiente na aquisi??o e uso do N quando comparada a IAC-47, acumulando nitrato em seus tecidos durante as fases iniciais de crescimento. Depois, essas mesmas variedades foram cultivadas em c?mara de crescimento para estudar o efeito de concentra??es crescentes de nitrato sobre os teores das fra??es nitrogenadas, ANR e sobre o perfil de express?o relativa dos genes dos transportadores de nitrato (NRT1 e NRT2) e da Nitrato Redutase (Nia2). Dos resultados obtidos, foi observado que a variedade tradicional possui menor ANR, maiores teores de nitrato e N-amino livre. Al?m disso, esta apresentou maior express?o relativa dos genes que codificam os transportadores de nitrato de baixa (NRT1) e os de alta (NRT2) afinidade, sendo esse na parte a?rea. Estas plantas pareceram adotar um controle diferenciado da ANR, pois mesmo tendo maior express?o relativa desse gene, a atividade desta enzima se mant?m praticamente sem sofrer influ?ncia das concentra??es de nitrato na solu??o. No ?ltimo experimento, foram identificados os genes induzidos por duas concentra??es de nitrato (0,1 e 10 mM) em ?pices radiculares de arroz. Diversos genes foram seq?enciados, dentre eles, destacou-se a subunidade E1 do complexo piruvato desidrogenase e fosfofrutoquinase, indicando a necessidade de se melhor entender a complexidade da intera??o entre o metabolismo de carbono e nitrog?nio. Foram encontradas tamb?m seq??ncias hom?logas aos genes da alfa actina, miosina, tropomiosina 1, creatina cinase e glioxalase I.

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