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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

STUDY OF SHORT CHAIN DEHYDROGENASE / REDUCTASES (SDRs) IN SINORHIZOBIUM MELILOTI

Jacob, Asha Ivy January 2007 (has links)
Sinorhizobium meliloti maintains a complex lifestyle, including saprotrophy, rhizophere colonization and root hair infection leading to the formation of root nodules in which the plant provides sustenance in return for nitrogen fixation. S. meliloti cells use a variety of carbon substrates for growth; this omnivory probably contributes to competitive ability in the soil. Several candidates for contribution to the catabolic capacity are found within the family of short chain dehydrogenases /reductases (SDR), which catalyze NAD(P)(H) dependent oxidation / reduction reactions. The 6.7 Mb genome of S. meliloti contains 78 SDR-encoding genes distributed on all three replicons. In this work each of these genes were disrupted by single crossover mutagenesis. These mutants were screened for growth on 93 different compounds as carbon source, and phenotypes were found for 17 of the mutants, providing suggestions for potential substrates of the corresponding enzymes. Carbon sources for which phenotype was observed include sugar alcohols, leucine, lysine, ornithine, galactitol, rhamnose, arabinose, mono-methyl succinate and ribono-γ-lactone. In addition, one of the mutants was found to be a proline auxotroph. In several cases, the phenotypes were consistent with the phenotypes of deletion mutants in which large sections of pSymB were absent. Eight of the mutants exhibited symbiotic deficiency after inoculation of alfalfa, while viable cells of three of the mutants could not be isolated from the nodules even though nitrogen fixation occurred. The results suggest that the corresponding SDR enzymes are involved in a pathway that is required for maintenance of viability by cells throughout infection and nodule development. This work demonstrates that members of the SDR family contribute to both the catabolic capacity and the symbiotic interactions of S. meliloti. Further experiments will address the details of the biochemical pathways involved. Knowledge of the substrate specificities of these enzymes should also prove informative in the description and annotation of orthologs that are identified in other genome sequences.
2

STUDY OF SHORT CHAIN DEHYDROGENASE / REDUCTASES (SDRs) IN SINORHIZOBIUM MELILOTI

Jacob, Asha Ivy January 2007 (has links)
Sinorhizobium meliloti maintains a complex lifestyle, including saprotrophy, rhizophere colonization and root hair infection leading to the formation of root nodules in which the plant provides sustenance in return for nitrogen fixation. S. meliloti cells use a variety of carbon substrates for growth; this omnivory probably contributes to competitive ability in the soil. Several candidates for contribution to the catabolic capacity are found within the family of short chain dehydrogenases /reductases (SDR), which catalyze NAD(P)(H) dependent oxidation / reduction reactions. The 6.7 Mb genome of S. meliloti contains 78 SDR-encoding genes distributed on all three replicons. In this work each of these genes were disrupted by single crossover mutagenesis. These mutants were screened for growth on 93 different compounds as carbon source, and phenotypes were found for 17 of the mutants, providing suggestions for potential substrates of the corresponding enzymes. Carbon sources for which phenotype was observed include sugar alcohols, leucine, lysine, ornithine, galactitol, rhamnose, arabinose, mono-methyl succinate and ribono-γ-lactone. In addition, one of the mutants was found to be a proline auxotroph. In several cases, the phenotypes were consistent with the phenotypes of deletion mutants in which large sections of pSymB were absent. Eight of the mutants exhibited symbiotic deficiency after inoculation of alfalfa, while viable cells of three of the mutants could not be isolated from the nodules even though nitrogen fixation occurred. The results suggest that the corresponding SDR enzymes are involved in a pathway that is required for maintenance of viability by cells throughout infection and nodule development. This work demonstrates that members of the SDR family contribute to both the catabolic capacity and the symbiotic interactions of S. meliloti. Further experiments will address the details of the biochemical pathways involved. Knowledge of the substrate specificities of these enzymes should also prove informative in the description and annotation of orthologs that are identified in other genome sequences.
3

Les marges passives volcaniques : origine, structure et développement / Volcanic passive margins : origin, structure and development

Guan, Huixin 12 July 2018 (has links)
Une marge passive est une zone de transition non-active entre lithosphère continentale et lithosphère océanique. De nombreuses marges passives présentent un fort développement magmatique (>50%). Ces marges passives volcaniques (MPVs) marquent la rupture lithosphérique au-dessus d’un manteau en fusion (partielle) et sont typiquement caractérisées par l’intrusion et l’extrusion d’un volume significatif de produits magmatiques dans la croûte lors des périodes ante-rift, syn-rift et post-rift. A partir d’une compilation bibliographique, de données sismiques (profils de sismique réflexion ION-GXT, sismique 3D) et d’observations réalisées sur le terrain à l’Est et à l’Ouest du Groenland, les objectifs de cette thèse étaient : (1) de mieux caractériser les modes tectoniques d’accommodation des flexures de la croûte supérieure sous les SDRs (seaward dipping reflectors) et l’interprétation des SDRs externes et, (2), de placer la rupture magmatique à l’échelle de la fragmentation d’un supercontinent. Les principaux résultats obtenus sont: 1) La rupture d’un supercontinent est toujours synmagmatique. Cette rupture se propage ensuite de manière non-magmatique (article en préparation); 2) Les SDRs externes sont découplés tectoniquement d’une croûte inférieure d’origine continentale exhumée. Du matériel d’origine continental pourrait exister en profondeur de manière continue au niveau de rides asismiques transverses (comme GIFR) (article soumis); 3) La flexure crustale est aussi accommodée par du magma qui circule dans les failles de détachement sous SDRs. Un découplage existe à l’extrados des flexures accommodé par des injections de magma syn-tectoniques sous forme de laccolithes à la base des SDRs internes. / A passive margin is a non-active transition zone between the continental lithosphere and the oceanic lithosphere. Most of passive margins (>50%) show a strong magmatic development. These volcanic passive margins (VPMs) mark the lithospheric breakup over a melted mantle and they are typically characterized by a huge volume of intrusive and extrusive magmatism into the crust during ante-rift, syn-rift, and post-rift periods.Based on bibliographies, seismic data (IONGXT seismic reflection profiles, 3D seismic) and observations and results gained from fieldtrips on East and West Greenland coast, the objectives of this thesis were: (1) to better characterize the tectonic accommodation of the flexure of the upper crust which beneath inner SDRs and the signification of outer SDRs, and (3) to place the magmatic breakup on the scale of the fragmentation of a supercontinent.The main results obtained are: 1) the breakup of a supercontinent is always syn-magmatic. This breakup then propagates in a non-magmatic way (paper in preparation); 2) the outer SDRs are tectonically decoupled from an exhumed continental lower crust.The material of continental origin could exist deeply continuously across a transverse aseismic ridge such as the GIFR (paper submitted); 3) The crustal flexure is also accommodated by the magma that circulate in detachment faults beneath the inner SDRs. There is a decoupling at the extrados zone of the flexure which is accommodated by syn-tectonic magma injections in the form of laccoliths between inner SDRs and upper crust.
4

Santa Catarina : desenvolvimento, desigualdades regionais e ação do Estado no início do século XXI

Rodolfo, Fabiano January 2016 (has links)
O aumento das desigualdades entre as regiões catarinenses foi tema de grande interesse no estado nos anos 2000. No início do período, o governo de Santa Catarina levou a cabo uma política que pretendia ser pró-ativa no combate às desigualdades regionais, que implicou na instalação de 36 (trinta e seis) secretarias de desenvolvimento regional (SDRs) em todas as regiões do estado. Em que pese o ineditismo e as intenções declaradas da política, seus efeitos sobre as desigualdades regionais não puderam ser notados. A análise dos dados para o período de operação da política denotam que as desigualdades acentuaram-se, com as regiões mais próximas do litoral concentrando as melhores condições de crescimento econômico. Considerando as contribuições hoje majoritárias no campo da economia regional, este trabalho propôs que fossem considerados fatores locais para auxiliar na compreensão dessas desigualdades. Nesse sentido, verificou-se que as regiões mais dinâmicas economicamente são também aquelas que reúnem as melhores condições de aprendizagem. Na parte final do trabalho, observou-se que o âmbito municipal é o prevalecente, não sendo possível verificar a existência de relações capazes de impactar na aprendizagem ou na construção territorial no plano regional. No que tange às políticas, notou-se que há uma homogeneidade muito grande na forma de atuar do estado, em que pese o fato das estruturas das secretarias nas regiões mais ricas serem melhores. / The increase in inequality between the regions of Santa Catarina state, in Brazil, was the subject of great interest in the 2000s. Early in the period, the government of Santa Catarina has carried out a policy that was intended to be proactive in the fight against regional inequalities, which involved the installation of 36 regional development offices (SDRs) in all regions of the state. Despite the novelty and the declared intentions of the policy, its effects on regional inequalities could not be noticed. Data analysis for the policy period of operation denote that inequalities grow up, with the nearest coastal regions concentrating the best conditions for economic growth. Considering the main actual contributions in regional economy, this work proposed to be considered local factors to assist in the understanding of these inequalities. In this sense, it was found that the most economically dynamic regions are also those that bring together the best learning conditions. In the final part of the work, it was observed that the municipal level is prevalent, it is not possible to verify the existence of relationships able to impact the learning or territorial building at the regional level. With respect to policy, it noted that stands out a very great homogeneity in the way of acting, despite the fact that the structures of the secretariats in the wealthier regions are best.
5

Santa Catarina : desenvolvimento, desigualdades regionais e ação do Estado no início do século XXI

Rodolfo, Fabiano January 2016 (has links)
O aumento das desigualdades entre as regiões catarinenses foi tema de grande interesse no estado nos anos 2000. No início do período, o governo de Santa Catarina levou a cabo uma política que pretendia ser pró-ativa no combate às desigualdades regionais, que implicou na instalação de 36 (trinta e seis) secretarias de desenvolvimento regional (SDRs) em todas as regiões do estado. Em que pese o ineditismo e as intenções declaradas da política, seus efeitos sobre as desigualdades regionais não puderam ser notados. A análise dos dados para o período de operação da política denotam que as desigualdades acentuaram-se, com as regiões mais próximas do litoral concentrando as melhores condições de crescimento econômico. Considerando as contribuições hoje majoritárias no campo da economia regional, este trabalho propôs que fossem considerados fatores locais para auxiliar na compreensão dessas desigualdades. Nesse sentido, verificou-se que as regiões mais dinâmicas economicamente são também aquelas que reúnem as melhores condições de aprendizagem. Na parte final do trabalho, observou-se que o âmbito municipal é o prevalecente, não sendo possível verificar a existência de relações capazes de impactar na aprendizagem ou na construção territorial no plano regional. No que tange às políticas, notou-se que há uma homogeneidade muito grande na forma de atuar do estado, em que pese o fato das estruturas das secretarias nas regiões mais ricas serem melhores. / The increase in inequality between the regions of Santa Catarina state, in Brazil, was the subject of great interest in the 2000s. Early in the period, the government of Santa Catarina has carried out a policy that was intended to be proactive in the fight against regional inequalities, which involved the installation of 36 regional development offices (SDRs) in all regions of the state. Despite the novelty and the declared intentions of the policy, its effects on regional inequalities could not be noticed. Data analysis for the policy period of operation denote that inequalities grow up, with the nearest coastal regions concentrating the best conditions for economic growth. Considering the main actual contributions in regional economy, this work proposed to be considered local factors to assist in the understanding of these inequalities. In this sense, it was found that the most economically dynamic regions are also those that bring together the best learning conditions. In the final part of the work, it was observed that the municipal level is prevalent, it is not possible to verify the existence of relationships able to impact the learning or territorial building at the regional level. With respect to policy, it noted that stands out a very great homogeneity in the way of acting, despite the fact that the structures of the secretariats in the wealthier regions are best.
6

Santa Catarina : desenvolvimento, desigualdades regionais e ação do Estado no início do século XXI

Rodolfo, Fabiano January 2016 (has links)
O aumento das desigualdades entre as regiões catarinenses foi tema de grande interesse no estado nos anos 2000. No início do período, o governo de Santa Catarina levou a cabo uma política que pretendia ser pró-ativa no combate às desigualdades regionais, que implicou na instalação de 36 (trinta e seis) secretarias de desenvolvimento regional (SDRs) em todas as regiões do estado. Em que pese o ineditismo e as intenções declaradas da política, seus efeitos sobre as desigualdades regionais não puderam ser notados. A análise dos dados para o período de operação da política denotam que as desigualdades acentuaram-se, com as regiões mais próximas do litoral concentrando as melhores condições de crescimento econômico. Considerando as contribuições hoje majoritárias no campo da economia regional, este trabalho propôs que fossem considerados fatores locais para auxiliar na compreensão dessas desigualdades. Nesse sentido, verificou-se que as regiões mais dinâmicas economicamente são também aquelas que reúnem as melhores condições de aprendizagem. Na parte final do trabalho, observou-se que o âmbito municipal é o prevalecente, não sendo possível verificar a existência de relações capazes de impactar na aprendizagem ou na construção territorial no plano regional. No que tange às políticas, notou-se que há uma homogeneidade muito grande na forma de atuar do estado, em que pese o fato das estruturas das secretarias nas regiões mais ricas serem melhores. / The increase in inequality between the regions of Santa Catarina state, in Brazil, was the subject of great interest in the 2000s. Early in the period, the government of Santa Catarina has carried out a policy that was intended to be proactive in the fight against regional inequalities, which involved the installation of 36 regional development offices (SDRs) in all regions of the state. Despite the novelty and the declared intentions of the policy, its effects on regional inequalities could not be noticed. Data analysis for the policy period of operation denote that inequalities grow up, with the nearest coastal regions concentrating the best conditions for economic growth. Considering the main actual contributions in regional economy, this work proposed to be considered local factors to assist in the understanding of these inequalities. In this sense, it was found that the most economically dynamic regions are also those that bring together the best learning conditions. In the final part of the work, it was observed that the municipal level is prevalent, it is not possible to verify the existence of relationships able to impact the learning or territorial building at the regional level. With respect to policy, it noted that stands out a very great homogeneity in the way of acting, despite the fact that the structures of the secretariats in the wealthier regions are best.
7

A NOVEL MULTI-FUNCTIONAL SOFTWARE-DEFINED RADAR: THEORY & EXPERIMENTS

Jameson, Brian Douglas 14 August 2013 (has links)
No description available.
8

Design and Implementation of Physical Layer Network Coding Protocols

Maduike, Dumezie K. 2009 August 1900 (has links)
There has recently been growing interest in using physical layer network coding techniques to facilitate information transfer in wireless relay networks. The physical layer network coding technique takes advantage of the additive nature of wireless signals by allowing two terminals to transmit simultaneously to the relay node. This technique has several performance benefits, such as improving utilization and throughput of wireless channels and reducing delay. In this thesis, we present an algorithm for joint decoding of two unsynchronized transmitters to a modulo-2 sum of their transmitted messages. We address the problems that arise when the boundaries of the signals do not align with each other and when their phases are not identical. Our approach uses a state-based Viterbi decoding scheme that takes into account the timing offsets between the interfering signals. As a future research plan, we plan to utilize software-defined radios (SDRs) as a testbed to show the practicality of our approach and to verify its performance. Our simulation studies show that the decoder performs well with the only degrading factor being the noise level in the channel.

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